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linux/fs/btrfs/inode.c
Josef Bacik f4b1363cae btrfs: do not do delalloc reservation under page lock 
We ran into a deadlock in production with the fixup worker.  The stack
traces were as follows:

Thread responsible for the writeout, waiting on the page lock

  [<0>] io_schedule+0x12/0x40
  [<0>] __lock_page+0x109/0x1e0
  [<0>] extent_write_cache_pages+0x206/0x360
  [<0>] extent_writepages+0x40/0x60
  [<0>] do_writepages+0x31/0xb0
  [<0>] __writeback_single_inode+0x3d/0x350
  [<0>] writeback_sb_inodes+0x19d/0x3c0
  [<0>] __writeback_inodes_wb+0x5d/0xb0
  [<0>] wb_writeback+0x231/0x2c0
  [<0>] wb_workfn+0x308/0x3c0
  [<0>] process_one_work+0x1e0/0x390
  [<0>] worker_thread+0x2b/0x3c0
  [<0>] kthread+0x113/0x130
  [<0>] ret_from_fork+0x35/0x40
  [<0>] 0xffffffffffffffff

Thread of the fixup worker who is holding the page lock

  [<0>] start_delalloc_inodes+0x241/0x2d0
  [<0>] btrfs_start_delalloc_roots+0x179/0x230
  [<0>] btrfs_alloc_data_chunk_ondemand+0x11b/0x2e0
  [<0>] btrfs_check_data_free_space+0x53/0xa0
  [<0>] btrfs_delalloc_reserve_space+0x20/0x70
  [<0>] btrfs_writepage_fixup_worker+0x1fc/0x2a0
  [<0>] normal_work_helper+0x11c/0x360
  [<0>] process_one_work+0x1e0/0x390
  [<0>] worker_thread+0x2b/0x3c0
  [<0>] kthread+0x113/0x130
  [<0>] ret_from_fork+0x35/0x40
  [<0>] 0xffffffffffffffff

Thankfully the stars have to align just right to hit this.  First you
have to end up in the fixup worker, which is tricky by itself (my
reproducer does DIO reads into a MMAP'ed region, so not a common
operation).  Then you have to have less than a page size of free data
space and 0 unallocated space so you go down the "commit the transaction
to free up pinned space" path.  This was accomplished by a random
balance that was running on the host.  Then you get this deadlock.

I'm still in the process of trying to force the deadlock to happen on
demand, but I've hit other issues.  I can still trigger the fixup worker
path itself so this patch has been tested in that regard, so the normal
case is fine.

Fixes: 87826df0ec ("btrfs: delalloc for page dirtied out-of-band in fixup worker")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-31 14:02:15 +01:00

10492 lines
287 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2007 Oracle. All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/writeback.h>
#include <linux/compat.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/falloc.h>
#include <linux/slab.h>
#include <linux/ratelimit.h>
#include <linux/btrfs.h>
#include <linux/blkdev.h>
#include <linux/posix_acl_xattr.h>
#include <linux/uio.h>
#include <linux/magic.h>
#include <linux/iversion.h>
#include <linux/swap.h>
#include <linux/sched/mm.h>
#include <asm/unaligned.h>
#include "misc.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "print-tree.h"
#include "ordered-data.h"
#include "xattr.h"
#include "tree-log.h"
#include "volumes.h"
#include "compression.h"
#include "locking.h"
#include "free-space-cache.h"
#include "inode-map.h"
#include "props.h"
#include "qgroup.h"
#include "delalloc-space.h"
#include "block-group.h"
struct btrfs_iget_args {
struct btrfs_key *location;
struct btrfs_root *root;
};
struct btrfs_dio_data {
u64 reserve;
u64 unsubmitted_oe_range_start;
u64 unsubmitted_oe_range_end;
int overwrite;
};
static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_inode_operations;
static const struct inode_operations btrfs_special_inode_operations;
static const struct inode_operations btrfs_file_inode_operations;
static const struct address_space_operations btrfs_aops;
static const struct file_operations btrfs_dir_file_operations;
static const struct extent_io_ops btrfs_extent_io_ops;
static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_path_cachep;
struct kmem_cache *btrfs_free_space_cachep;
struct kmem_cache *btrfs_free_space_bitmap_cachep;
static int btrfs_setsize(struct inode *inode, struct iattr *attr);
static int btrfs_truncate(struct inode *inode, bool skip_writeback);
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent);
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock);
static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
u64 orig_start, u64 block_start,
u64 block_len, u64 orig_block_len,
u64 ram_bytes, int compress_type,
int type);
static void __endio_write_update_ordered(struct inode *inode,
const u64 offset, const u64 bytes,
const bool uptodate);
/*
* Cleanup all submitted ordered extents in specified range to handle errors
* from the btrfs_run_delalloc_range() callback.
*
* NOTE: caller must ensure that when an error happens, it can not call
* extent_clear_unlock_delalloc() to clear both the bits EXTENT_DO_ACCOUNTING
* and EXTENT_DELALLOC simultaneously, because that causes the reserved metadata
* to be released, which we want to happen only when finishing the ordered
* extent (btrfs_finish_ordered_io()).
*/
static inline void btrfs_cleanup_ordered_extents(struct inode *inode,
struct page *locked_page,
u64 offset, u64 bytes)
{
unsigned long index = offset >> PAGE_SHIFT;
unsigned long end_index = (offset + bytes - 1) >> PAGE_SHIFT;
u64 page_start = page_offset(locked_page);
u64 page_end = page_start + PAGE_SIZE - 1;
struct page *page;
while (index <= end_index) {
page = find_get_page(inode->i_mapping, index);
index++;
if (!page)
continue;
ClearPagePrivate2(page);
put_page(page);
}
/*
* In case this page belongs to the delalloc range being instantiated
* then skip it, since the first page of a range is going to be
* properly cleaned up by the caller of run_delalloc_range
*/
if (page_start >= offset && page_end <= (offset + bytes - 1)) {
offset += PAGE_SIZE;
bytes -= PAGE_SIZE;
}
return __endio_write_update_ordered(inode, offset, bytes, false);
}
static int btrfs_dirty_inode(struct inode *inode);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_inode_set_ops(struct inode *inode)
{
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
}
#endif
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
struct inode *inode, struct inode *dir,
const struct qstr *qstr)
{
int err;
err = btrfs_init_acl(trans, inode, dir);
if (!err)
err = btrfs_xattr_security_init(trans, inode, dir, qstr);
return err;
}
/*
* this does all the hard work for inserting an inline extent into
* the btree. The caller should have done a btrfs_drop_extents so that
* no overlapping inline items exist in the btree
*/
static int insert_inline_extent(struct btrfs_trans_handle *trans,
struct btrfs_path *path, int extent_inserted,
struct btrfs_root *root, struct inode *inode,
u64 start, size_t size, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct extent_buffer *leaf;
struct page *page = NULL;
char *kaddr;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
int ret;
size_t cur_size = size;
unsigned long offset;
ASSERT((compressed_size > 0 && compressed_pages) ||
(compressed_size == 0 && !compressed_pages));
if (compressed_size && compressed_pages)
cur_size = compressed_size;
inode_add_bytes(inode, size);
if (!extent_inserted) {
struct btrfs_key key;
size_t datasize;
key.objectid = btrfs_ino(BTRFS_I(inode));
key.offset = start;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(cur_size);
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (ret)
goto fail;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, size);
ptr = btrfs_file_extent_inline_start(ei);
if (compress_type != BTRFS_COMPRESS_NONE) {
struct page *cpage;
int i = 0;
while (compressed_size > 0) {
cpage = compressed_pages[i];
cur_size = min_t(unsigned long, compressed_size,
PAGE_SIZE);
kaddr = kmap_atomic(cpage);
write_extent_buffer(leaf, kaddr, ptr, cur_size);
kunmap_atomic(kaddr);
i++;
ptr += cur_size;
compressed_size -= cur_size;
}
btrfs_set_file_extent_compression(leaf, ei,
compress_type);
} else {
page = find_get_page(inode->i_mapping,
start >> PAGE_SHIFT);
btrfs_set_file_extent_compression(leaf, ei, 0);
kaddr = kmap_atomic(page);
offset = offset_in_page(start);
write_extent_buffer(leaf, kaddr + offset, ptr, size);
kunmap_atomic(kaddr);
put_page(page);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
/*
* we're an inline extent, so nobody can
* extend the file past i_size without locking
* a page we already have locked.
*
* We must do any isize and inode updates
* before we unlock the pages. Otherwise we
* could end up racing with unlink.
*/
BTRFS_I(inode)->disk_i_size = inode->i_size;
ret = btrfs_update_inode(trans, root, inode);
fail:
return ret;
}
/*
* conditionally insert an inline extent into the file. This
* does the checks required to make sure the data is small enough
* to fit as an inline extent.
*/
static noinline int cow_file_range_inline(struct inode *inode, u64 start,
u64 end, size_t compressed_size,
int compress_type,
struct page **compressed_pages)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_trans_handle *trans;
u64 isize = i_size_read(inode);
u64 actual_end = min(end + 1, isize);
u64 inline_len = actual_end - start;
u64 aligned_end = ALIGN(end, fs_info->sectorsize);
u64 data_len = inline_len;
int ret;
struct btrfs_path *path;
int extent_inserted = 0;
u32 extent_item_size;
if (compressed_size)
data_len = compressed_size;
if (start > 0 ||
actual_end > fs_info->sectorsize ||
data_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info) ||
(!compressed_size &&
(actual_end & (fs_info->sectorsize - 1)) == 0) ||
end + 1 < isize ||
data_len > fs_info->max_inline) {
return 1;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
btrfs_free_path(path);
return PTR_ERR(trans);
}
trans->block_rsv = &BTRFS_I(inode)->block_rsv;
if (compressed_size && compressed_pages)
extent_item_size = btrfs_file_extent_calc_inline_size(
compressed_size);
else
extent_item_size = btrfs_file_extent_calc_inline_size(
inline_len);
ret = __btrfs_drop_extents(trans, root, inode, path,
start, aligned_end, NULL,
1, 1, extent_item_size, &extent_inserted);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
if (isize > actual_end)
inline_len = min_t(u64, isize, actual_end);
ret = insert_inline_extent(trans, path, extent_inserted,
root, inode, start,
inline_len, compressed_size,
compress_type, compressed_pages);
if (ret && ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
goto out;
} else if (ret == -ENOSPC) {
ret = 1;
goto out;
}
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
btrfs_drop_extent_cache(BTRFS_I(inode), start, aligned_end - 1, 0);
out:
/*
* Don't forget to free the reserved space, as for inlined extent
* it won't count as data extent, free them directly here.
* And at reserve time, it's always aligned to page size, so
* just free one page here.
*/
btrfs_qgroup_free_data(inode, NULL, 0, PAGE_SIZE);
btrfs_free_path(path);
btrfs_end_transaction(trans);
return ret;
}
struct async_extent {
u64 start;
u64 ram_size;
u64 compressed_size;
struct page **pages;
unsigned long nr_pages;
int compress_type;
struct list_head list;
};
struct async_chunk {
struct inode *inode;
struct page *locked_page;
u64 start;
u64 end;
unsigned int write_flags;
struct list_head extents;
struct cgroup_subsys_state *blkcg_css;
struct btrfs_work work;
atomic_t *pending;
};
struct async_cow {
/* Number of chunks in flight; must be first in the structure */
atomic_t num_chunks;
struct async_chunk chunks[];
};
static noinline int add_async_extent(struct async_chunk *cow,
u64 start, u64 ram_size,
u64 compressed_size,
struct page **pages,
unsigned long nr_pages,
int compress_type)
{
struct async_extent *async_extent;
async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
BUG_ON(!async_extent); /* -ENOMEM */
async_extent->start = start;
async_extent->ram_size = ram_size;
async_extent->compressed_size = compressed_size;
async_extent->pages = pages;
async_extent->nr_pages = nr_pages;
async_extent->compress_type = compress_type;
list_add_tail(&async_extent->list, &cow->extents);
return 0;
}
/*
* Check if the inode has flags compatible with compression
*/
static inline bool inode_can_compress(struct inode *inode)
{
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW ||
BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
return false;
return true;
}
/*
* Check if the inode needs to be submitted to compression, based on mount
* options, defragmentation, properties or heuristics.
*/
static inline int inode_need_compress(struct inode *inode, u64 start, u64 end)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if (!inode_can_compress(inode)) {
WARN(IS_ENABLED(CONFIG_BTRFS_DEBUG),
KERN_ERR "BTRFS: unexpected compression for ino %llu\n",
btrfs_ino(BTRFS_I(inode)));
return 0;
}
/* force compress */
if (btrfs_test_opt(fs_info, FORCE_COMPRESS))
return 1;
/* defrag ioctl */
if (BTRFS_I(inode)->defrag_compress)
return 1;
/* bad compression ratios */
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
return 0;
if (btrfs_test_opt(fs_info, COMPRESS) ||
BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS ||
BTRFS_I(inode)->prop_compress)
return btrfs_compress_heuristic(inode, start, end);
return 0;
}
static inline void inode_should_defrag(struct btrfs_inode *inode,
u64 start, u64 end, u64 num_bytes, u64 small_write)
{
/* If this is a small write inside eof, kick off a defrag */
if (num_bytes < small_write &&
(start > 0 || end + 1 < inode->disk_i_size))
btrfs_add_inode_defrag(NULL, inode);
}
/*
* we create compressed extents in two phases. The first
* phase compresses a range of pages that have already been
* locked (both pages and state bits are locked).
*
* This is done inside an ordered work queue, and the compression
* is spread across many cpus. The actual IO submission is step
* two, and the ordered work queue takes care of making sure that
* happens in the same order things were put onto the queue by
* writepages and friends.
*
* If this code finds it can't get good compression, it puts an
* entry onto the work queue to write the uncompressed bytes. This
* makes sure that both compressed inodes and uncompressed inodes
* are written in the same order that the flusher thread sent them
* down.
*/
static noinline int compress_file_range(struct async_chunk *async_chunk)
{
struct inode *inode = async_chunk->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 blocksize = fs_info->sectorsize;
u64 start = async_chunk->start;
u64 end = async_chunk->end;
u64 actual_end;
u64 i_size;
int ret = 0;
struct page **pages = NULL;
unsigned long nr_pages;
unsigned long total_compressed = 0;
unsigned long total_in = 0;
int i;
int will_compress;
int compress_type = fs_info->compress_type;
int compressed_extents = 0;
int redirty = 0;
inode_should_defrag(BTRFS_I(inode), start, end, end - start + 1,
SZ_16K);
/*
* We need to save i_size before now because it could change in between
* us evaluating the size and assigning it. This is because we lock and
* unlock the page in truncate and fallocate, and then modify the i_size
* later on.
*
* The barriers are to emulate READ_ONCE, remove that once i_size_read
* does that for us.
*/
barrier();
i_size = i_size_read(inode);
barrier();
actual_end = min_t(u64, i_size, end + 1);
again:
will_compress = 0;
nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0);
nr_pages = min_t(unsigned long, nr_pages,
BTRFS_MAX_COMPRESSED / PAGE_SIZE);
/*
* we don't want to send crud past the end of i_size through
* compression, that's just a waste of CPU time. So, if the
* end of the file is before the start of our current
* requested range of bytes, we bail out to the uncompressed
* cleanup code that can deal with all of this.
*
* It isn't really the fastest way to fix things, but this is a
* very uncommon corner.
*/
if (actual_end <= start)
goto cleanup_and_bail_uncompressed;
total_compressed = actual_end - start;
/*
* skip compression for a small file range(<=blocksize) that
* isn't an inline extent, since it doesn't save disk space at all.
*/
if (total_compressed <= blocksize &&
(start > 0 || end + 1 < BTRFS_I(inode)->disk_i_size))
goto cleanup_and_bail_uncompressed;
total_compressed = min_t(unsigned long, total_compressed,
BTRFS_MAX_UNCOMPRESSED);
total_in = 0;
ret = 0;
/*
* we do compression for mount -o compress and when the
* inode has not been flagged as nocompress. This flag can
* change at any time if we discover bad compression ratios.
*/
if (inode_need_compress(inode, start, end)) {
WARN_ON(pages);
pages = kcalloc(nr_pages, sizeof(struct page *), GFP_NOFS);
if (!pages) {
/* just bail out to the uncompressed code */
nr_pages = 0;
goto cont;
}
if (BTRFS_I(inode)->defrag_compress)
compress_type = BTRFS_I(inode)->defrag_compress;
else if (BTRFS_I(inode)->prop_compress)
compress_type = BTRFS_I(inode)->prop_compress;
/*
* we need to call clear_page_dirty_for_io on each
* page in the range. Otherwise applications with the file
* mmap'd can wander in and change the page contents while
* we are compressing them.
*
* If the compression fails for any reason, we set the pages
* dirty again later on.
*
* Note that the remaining part is redirtied, the start pointer
* has moved, the end is the original one.
*/
if (!redirty) {
extent_range_clear_dirty_for_io(inode, start, end);
redirty = 1;
}
/* Compression level is applied here and only here */
ret = btrfs_compress_pages(
compress_type | (fs_info->compress_level << 4),
inode->i_mapping, start,
pages,
&nr_pages,
&total_in,
&total_compressed);
if (!ret) {
unsigned long offset = offset_in_page(total_compressed);
struct page *page = pages[nr_pages - 1];
char *kaddr;
/* zero the tail end of the last page, we might be
* sending it down to disk
*/
if (offset) {
kaddr = kmap_atomic(page);
memset(kaddr + offset, 0,
PAGE_SIZE - offset);
kunmap_atomic(kaddr);
}
will_compress = 1;
}
}
cont:
if (start == 0) {
/* lets try to make an inline extent */
if (ret || total_in < actual_end) {
/* we didn't compress the entire range, try
* to make an uncompressed inline extent.
*/
ret = cow_file_range_inline(inode, start, end, 0,
BTRFS_COMPRESS_NONE, NULL);
} else {
/* try making a compressed inline extent */
ret = cow_file_range_inline(inode, start, end,
total_compressed,
compress_type, pages);
}
if (ret <= 0) {
unsigned long clear_flags = EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_error_op;
page_error_op = ret < 0 ? PAGE_SET_ERROR : 0;
/*
* inline extent creation worked or returned error,
* we don't need to create any more async work items.
* Unlock and free up our temp pages.
*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be done _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(inode, start, end, NULL,
clear_flags,
PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
page_error_op |
PAGE_END_WRITEBACK);
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
return 0;
}
}
if (will_compress) {
/*
* we aren't doing an inline extent round the compressed size
* up to a block size boundary so the allocator does sane
* things
*/
total_compressed = ALIGN(total_compressed, blocksize);
/*
* one last check to make sure the compression is really a
* win, compare the page count read with the blocks on disk,
* compression must free at least one sector size
*/
total_in = ALIGN(total_in, PAGE_SIZE);
if (total_compressed + blocksize <= total_in) {
compressed_extents++;
/*
* The async work queues will take care of doing actual
* allocation on disk for these compressed pages, and
* will submit them to the elevator.
*/
add_async_extent(async_chunk, start, total_in,
total_compressed, pages, nr_pages,
compress_type);
if (start + total_in < end) {
start += total_in;
pages = NULL;
cond_resched();
goto again;
}
return compressed_extents;
}
}
if (pages) {
/*
* the compression code ran but failed to make things smaller,
* free any pages it allocated and our page pointer array
*/
for (i = 0; i < nr_pages; i++) {
WARN_ON(pages[i]->mapping);
put_page(pages[i]);
}
kfree(pages);
pages = NULL;
total_compressed = 0;
nr_pages = 0;
/* flag the file so we don't compress in the future */
if (!btrfs_test_opt(fs_info, FORCE_COMPRESS) &&
!(BTRFS_I(inode)->prop_compress)) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
}
}
cleanup_and_bail_uncompressed:
/*
* No compression, but we still need to write the pages in the file
* we've been given so far. redirty the locked page if it corresponds
* to our extent and set things up for the async work queue to run
* cow_file_range to do the normal delalloc dance.
*/
if (async_chunk->locked_page &&
(page_offset(async_chunk->locked_page) >= start &&
page_offset(async_chunk->locked_page)) <= end) {
__set_page_dirty_nobuffers(async_chunk->locked_page);
/* unlocked later on in the async handlers */
}
if (redirty)
extent_range_redirty_for_io(inode, start, end);
add_async_extent(async_chunk, start, end - start + 1, 0, NULL, 0,
BTRFS_COMPRESS_NONE);
compressed_extents++;
return compressed_extents;
}
static void free_async_extent_pages(struct async_extent *async_extent)
{
int i;
if (!async_extent->pages)
return;
for (i = 0; i < async_extent->nr_pages; i++) {
WARN_ON(async_extent->pages[i]->mapping);
put_page(async_extent->pages[i]);
}
kfree(async_extent->pages);
async_extent->nr_pages = 0;
async_extent->pages = NULL;
}
/*
* phase two of compressed writeback. This is the ordered portion
* of the code, which only gets called in the order the work was
* queued. We walk all the async extents created by compress_file_range
* and send them down to the disk.
*/
static noinline void submit_compressed_extents(struct async_chunk *async_chunk)
{
struct inode *inode = async_chunk->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct async_extent *async_extent;
u64 alloc_hint = 0;
struct btrfs_key ins;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
int ret = 0;
again:
while (!list_empty(&async_chunk->extents)) {
async_extent = list_entry(async_chunk->extents.next,
struct async_extent, list);
list_del(&async_extent->list);
retry:
lock_extent(io_tree, async_extent->start,
async_extent->start + async_extent->ram_size - 1);
/* did the compression code fall back to uncompressed IO? */
if (!async_extent->pages) {
int page_started = 0;
unsigned long nr_written = 0;
/* allocate blocks */
ret = cow_file_range(inode, async_chunk->locked_page,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
&page_started, &nr_written, 0);
/* JDM XXX */
/*
* if page_started, cow_file_range inserted an
* inline extent and took care of all the unlocking
* and IO for us. Otherwise, we need to submit
* all those pages down to the drive.
*/
if (!page_started && !ret)
extent_write_locked_range(inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
WB_SYNC_ALL);
else if (ret && async_chunk->locked_page)
unlock_page(async_chunk->locked_page);
kfree(async_extent);
cond_resched();
continue;
}
ret = btrfs_reserve_extent(root, async_extent->ram_size,
async_extent->compressed_size,
async_extent->compressed_size,
0, alloc_hint, &ins, 1, 1);
if (ret) {
free_async_extent_pages(async_extent);
if (ret == -ENOSPC) {
unlock_extent(io_tree, async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
/*
* we need to redirty the pages if we decide to
* fallback to uncompressed IO, otherwise we
* will not submit these pages down to lower
* layers.
*/
extent_range_redirty_for_io(inode,
async_extent->start,
async_extent->start +
async_extent->ram_size - 1);
goto retry;
}
goto out_free;
}
/*
* here we're doing allocation and writeback of the
* compressed pages
*/
em = create_io_em(inode, async_extent->start,
async_extent->ram_size, /* len */
async_extent->start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
async_extent->ram_size, /* ram_bytes */
async_extent->compress_type,
BTRFS_ORDERED_COMPRESSED);
if (IS_ERR(em))
/* ret value is not necessary due to void function */
goto out_free_reserve;
free_extent_map(em);
ret = btrfs_add_ordered_extent_compress(inode,
async_extent->start,
ins.objectid,
async_extent->ram_size,
ins.offset,
BTRFS_ORDERED_COMPRESSED,
async_extent->compress_type);
if (ret) {
btrfs_drop_extent_cache(BTRFS_I(inode),
async_extent->start,
async_extent->start +
async_extent->ram_size - 1, 0);
goto out_free_reserve;
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/*
* clear dirty, set writeback and unlock the pages.
*/
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK);
if (btrfs_submit_compressed_write(inode,
async_extent->start,
async_extent->ram_size,
ins.objectid,
ins.offset, async_extent->pages,
async_extent->nr_pages,
async_chunk->write_flags,
async_chunk->blkcg_css)) {
struct page *p = async_extent->pages[0];
const u64 start = async_extent->start;
const u64 end = start + async_extent->ram_size - 1;
p->mapping = inode->i_mapping;
btrfs_writepage_endio_finish_ordered(p, start, end, 0);
p->mapping = NULL;
extent_clear_unlock_delalloc(inode, start, end,
NULL, 0,
PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
}
alloc_hint = ins.objectid + ins.offset;
kfree(async_extent);
cond_resched();
}
return;
out_free_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_free:
extent_clear_unlock_delalloc(inode, async_extent->start,
async_extent->start +
async_extent->ram_size - 1,
NULL, EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_DO_ACCOUNTING,
PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
PAGE_SET_ERROR);
free_async_extent_pages(async_extent);
kfree(async_extent);
goto again;
}
static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
u64 num_bytes)
{
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
u64 alloc_hint = 0;
read_lock(&em_tree->lock);
em = search_extent_mapping(em_tree, start, num_bytes);
if (em) {
/*
* if block start isn't an actual block number then find the
* first block in this inode and use that as a hint. If that
* block is also bogus then just don't worry about it.
*/
if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
free_extent_map(em);
em = search_extent_mapping(em_tree, 0, 0);
if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
alloc_hint = em->block_start;
if (em)
free_extent_map(em);
} else {
alloc_hint = em->block_start;
free_extent_map(em);
}
}
read_unlock(&em_tree->lock);
return alloc_hint;
}
/*
* when extent_io.c finds a delayed allocation range in the file,
* the call backs end up in this code. The basic idea is to
* allocate extents on disk for the range, and create ordered data structs
* in ram to track those extents.
*
* locked_page is the page that writepage had locked already. We use
* it to make sure we don't do extra locks or unlocks.
*
* *page_started is set to one if we unlock locked_page and do everything
* required to start IO on it. It may be clean and already done with
* IO when we return.
*/
static noinline int cow_file_range(struct inode *inode,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written, int unlock)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 alloc_hint = 0;
u64 num_bytes;
unsigned long ram_size;
u64 cur_alloc_size = 0;
u64 blocksize = fs_info->sectorsize;
struct btrfs_key ins;
struct extent_map *em;
unsigned clear_bits;
unsigned long page_ops;
bool extent_reserved = false;
int ret = 0;
if (btrfs_is_free_space_inode(BTRFS_I(inode))) {
WARN_ON_ONCE(1);
ret = -EINVAL;
goto out_unlock;
}
num_bytes = ALIGN(end - start + 1, blocksize);
num_bytes = max(blocksize, num_bytes);
ASSERT(num_bytes <= btrfs_super_total_bytes(fs_info->super_copy));
inode_should_defrag(BTRFS_I(inode), start, end, num_bytes, SZ_64K);
if (start == 0) {
/* lets try to make an inline extent */
ret = cow_file_range_inline(inode, start, end, 0,
BTRFS_COMPRESS_NONE, NULL);
if (ret == 0) {
/*
* We use DO_ACCOUNTING here because we need the
* delalloc_release_metadata to be run _after_ we drop
* our outstanding extent for clearing delalloc for this
* range.
*/
extent_clear_unlock_delalloc(inode, start, end, NULL,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
*nr_written = *nr_written +
(end - start + PAGE_SIZE) / PAGE_SIZE;
*page_started = 1;
goto out;
} else if (ret < 0) {
goto out_unlock;
}
}
alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
btrfs_drop_extent_cache(BTRFS_I(inode), start,
start + num_bytes - 1, 0);
while (num_bytes > 0) {
cur_alloc_size = num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
fs_info->sectorsize, 0, alloc_hint,
&ins, 1, 1);
if (ret < 0)
goto out_unlock;
cur_alloc_size = ins.offset;
extent_reserved = true;
ram_size = ins.offset;
em = create_io_em(inode, start, ins.offset, /* len */
start, /* orig_start */
ins.objectid, /* block_start */
ins.offset, /* block_len */
ins.offset, /* orig_block_len */
ram_size, /* ram_bytes */
BTRFS_COMPRESS_NONE, /* compress_type */
BTRFS_ORDERED_REGULAR /* type */);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_reserve;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
ram_size, cur_alloc_size, 0);
if (ret)
goto out_drop_extent_cache;
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID) {
ret = btrfs_reloc_clone_csums(inode, start,
cur_alloc_size);
/*
* Only drop cache here, and process as normal.
*
* We must not allow extent_clear_unlock_delalloc()
* at out_unlock label to free meta of this ordered
* extent, as its meta should be freed by
* btrfs_finish_ordered_io().
*
* So we must continue until @start is increased to
* skip current ordered extent.
*/
if (ret)
btrfs_drop_extent_cache(BTRFS_I(inode), start,
start + ram_size - 1, 0);
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
/* we're not doing compressed IO, don't unlock the first
* page (which the caller expects to stay locked), don't
* clear any dirty bits and don't set any writeback bits
*
* Do set the Private2 bit so we know this page was properly
* setup for writepage
*/
page_ops = unlock ? PAGE_UNLOCK : 0;
page_ops |= PAGE_SET_PRIVATE2;
extent_clear_unlock_delalloc(inode, start,
start + ram_size - 1,
locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC,
page_ops);
if (num_bytes < cur_alloc_size)
num_bytes = 0;
else
num_bytes -= cur_alloc_size;
alloc_hint = ins.objectid + ins.offset;
start += cur_alloc_size;
extent_reserved = false;
/*
* btrfs_reloc_clone_csums() error, since start is increased
* extent_clear_unlock_delalloc() at out_unlock label won't
* free metadata of current ordered extent, we're OK to exit.
*/
if (ret)
goto out_unlock;
}
out:
return ret;
out_drop_extent_cache:
btrfs_drop_extent_cache(BTRFS_I(inode), start, start + ram_size - 1, 0);
out_reserve:
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 1);
out_unlock:
clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
EXTENT_DEFRAG | EXTENT_CLEAR_META_RESV;
page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY | PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK;
/*
* If we reserved an extent for our delalloc range (or a subrange) and
* failed to create the respective ordered extent, then it means that
* when we reserved the extent we decremented the extent's size from
* the data space_info's bytes_may_use counter and incremented the
* space_info's bytes_reserved counter by the same amount. We must make
* sure extent_clear_unlock_delalloc() does not try to decrement again
* the data space_info's bytes_may_use counter, therefore we do not pass
* it the flag EXTENT_CLEAR_DATA_RESV.
*/
if (extent_reserved) {
extent_clear_unlock_delalloc(inode, start,
start + cur_alloc_size,
locked_page,
clear_bits,
page_ops);
start += cur_alloc_size;
if (start >= end)
goto out;
}
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits | EXTENT_CLEAR_DATA_RESV,
page_ops);
goto out;
}
/*
* work queue call back to started compression on a file and pages
*/
static noinline void async_cow_start(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
int compressed_extents;
async_chunk = container_of(work, struct async_chunk, work);
compressed_extents = compress_file_range(async_chunk);
if (compressed_extents == 0) {
btrfs_add_delayed_iput(async_chunk->inode);
async_chunk->inode = NULL;
}
}
/*
* work queue call back to submit previously compressed pages
*/
static noinline void async_cow_submit(struct btrfs_work *work)
{
struct async_chunk *async_chunk = container_of(work, struct async_chunk,
work);
struct btrfs_fs_info *fs_info = btrfs_work_owner(work);
unsigned long nr_pages;
nr_pages = (async_chunk->end - async_chunk->start + PAGE_SIZE) >>
PAGE_SHIFT;
/* atomic_sub_return implies a barrier */
if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) <
5 * SZ_1M)
cond_wake_up_nomb(&fs_info->async_submit_wait);
/*
* ->inode could be NULL if async_chunk_start has failed to compress,
* in which case we don't have anything to submit, yet we need to
* always adjust ->async_delalloc_pages as its paired with the init
* happening in cow_file_range_async
*/
if (async_chunk->inode)
submit_compressed_extents(async_chunk);
}
static noinline void async_cow_free(struct btrfs_work *work)
{
struct async_chunk *async_chunk;
async_chunk = container_of(work, struct async_chunk, work);
if (async_chunk->inode)
btrfs_add_delayed_iput(async_chunk->inode);
if (async_chunk->blkcg_css)
css_put(async_chunk->blkcg_css);
/*
* Since the pointer to 'pending' is at the beginning of the array of
* async_chunk's, freeing it ensures the whole array has been freed.
*/
if (atomic_dec_and_test(async_chunk->pending))
kvfree(async_chunk->pending);
}
static int cow_file_range_async(struct inode *inode,
struct writeback_control *wbc,
struct page *locked_page,
u64 start, u64 end, int *page_started,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct cgroup_subsys_state *blkcg_css = wbc_blkcg_css(wbc);
struct async_cow *ctx;
struct async_chunk *async_chunk;
unsigned long nr_pages;
u64 cur_end;
u64 num_chunks = DIV_ROUND_UP(end - start, SZ_512K);
int i;
bool should_compress;
unsigned nofs_flag;
const unsigned int write_flags = wbc_to_write_flags(wbc);
unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS &&
!btrfs_test_opt(fs_info, FORCE_COMPRESS)) {
num_chunks = 1;
should_compress = false;
} else {
should_compress = true;
}
nofs_flag = memalloc_nofs_save();
ctx = kvmalloc(struct_size(ctx, chunks, num_chunks), GFP_KERNEL);
memalloc_nofs_restore(nofs_flag);
if (!ctx) {
unsigned clear_bits = EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DELALLOC_NEW | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING;
unsigned long page_ops = PAGE_UNLOCK | PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK | PAGE_END_WRITEBACK |
PAGE_SET_ERROR;
extent_clear_unlock_delalloc(inode, start, end, locked_page,
clear_bits, page_ops);
return -ENOMEM;
}
async_chunk = ctx->chunks;
atomic_set(&ctx->num_chunks, num_chunks);
for (i = 0; i < num_chunks; i++) {
if (should_compress)
cur_end = min(end, start + SZ_512K - 1);
else
cur_end = end;
/*
* igrab is called higher up in the call chain, take only the
* lightweight reference for the callback lifetime
*/
ihold(inode);
async_chunk[i].pending = &ctx->num_chunks;
async_chunk[i].inode = inode;
async_chunk[i].start = start;
async_chunk[i].end = cur_end;
async_chunk[i].write_flags = write_flags;
INIT_LIST_HEAD(&async_chunk[i].extents);
/*
* The locked_page comes all the way from writepage and its
* the original page we were actually given. As we spread
* this large delalloc region across multiple async_chunk
* structs, only the first struct needs a pointer to locked_page
*
* This way we don't need racey decisions about who is supposed
* to unlock it.
*/
if (locked_page) {
/*
* Depending on the compressibility, the pages might or
* might not go through async. We want all of them to
* be accounted against wbc once. Let's do it here
* before the paths diverge. wbc accounting is used
* only for foreign writeback detection and doesn't
* need full accuracy. Just account the whole thing
* against the first page.
*/
wbc_account_cgroup_owner(wbc, locked_page,
cur_end - start);
async_chunk[i].locked_page = locked_page;
locked_page = NULL;
} else {
async_chunk[i].locked_page = NULL;
}
if (blkcg_css != blkcg_root_css) {
css_get(blkcg_css);
async_chunk[i].blkcg_css = blkcg_css;
} else {
async_chunk[i].blkcg_css = NULL;
}
btrfs_init_work(&async_chunk[i].work, async_cow_start,
async_cow_submit, async_cow_free);
nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE);
atomic_add(nr_pages, &fs_info->async_delalloc_pages);
btrfs_queue_work(fs_info->delalloc_workers, &async_chunk[i].work);
*nr_written += nr_pages;
start = cur_end + 1;
}
*page_started = 1;
return 0;
}
static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info,
u64 bytenr, u64 num_bytes)
{
int ret;
struct btrfs_ordered_sum *sums;
LIST_HEAD(list);
ret = btrfs_lookup_csums_range(fs_info->csum_root, bytenr,
bytenr + num_bytes - 1, &list, 0);
if (ret == 0 && list_empty(&list))
return 0;
while (!list_empty(&list)) {
sums = list_entry(list.next, struct btrfs_ordered_sum, list);
list_del(&sums->list);
kfree(sums);
}
if (ret < 0)
return ret;
return 1;
}
/*
* when nowcow writeback call back. This checks for snapshots or COW copies
* of the extents that exist in the file, and COWs the file as required.
*
* If no cow copies or snapshots exist, we write directly to the existing
* blocks on disk
*/
static noinline int run_delalloc_nocow(struct inode *inode,
struct page *locked_page,
const u64 start, const u64 end,
int *page_started, int force,
unsigned long *nr_written)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_path *path;
u64 cow_start = (u64)-1;
u64 cur_offset = start;
int ret;
bool check_prev = true;
const bool freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode));
u64 ino = btrfs_ino(BTRFS_I(inode));
bool nocow = false;
u64 disk_bytenr = 0;
path = btrfs_alloc_path();
if (!path) {
extent_clear_unlock_delalloc(inode, start, end, locked_page,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
return -ENOMEM;
}
while (1) {
struct btrfs_key found_key;
struct btrfs_file_extent_item *fi;
struct extent_buffer *leaf;
u64 extent_end;
u64 extent_offset;
u64 num_bytes = 0;
u64 disk_num_bytes;
u64 ram_bytes;
int extent_type;
nocow = false;
ret = btrfs_lookup_file_extent(NULL, root, path, ino,
cur_offset, 0);
if (ret < 0)
goto error;
/*
* If there is no extent for our range when doing the initial
* search, then go back to the previous slot as it will be the
* one containing the search offset
*/
if (ret > 0 && path->slots[0] > 0 && check_prev) {
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key,
path->slots[0] - 1);
if (found_key.objectid == ino &&
found_key.type == BTRFS_EXTENT_DATA_KEY)
path->slots[0]--;
}
check_prev = false;
next_slot:
/* Go to next leaf if we have exhausted the current one */
leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
if (ret > 0)
break;
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* Didn't find anything for our INO */
if (found_key.objectid > ino)
break;
/*
* Keep searching until we find an EXTENT_ITEM or there are no
* more extents for this inode
*/
if (WARN_ON_ONCE(found_key.objectid < ino) ||
found_key.type < BTRFS_EXTENT_DATA_KEY) {
path->slots[0]++;
goto next_slot;
}
/* Found key is not EXTENT_DATA_KEY or starts after req range */
if (found_key.type > BTRFS_EXTENT_DATA_KEY ||
found_key.offset > end)
break;
/*
* If the found extent starts after requested offset, then
* adjust extent_end to be right before this extent begins
*/
if (found_key.offset > cur_offset) {
extent_end = found_key.offset;
extent_type = 0;
goto out_check;
}
/*
* Found extent which begins before our range and potentially
* intersect it
*/
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
extent_offset = btrfs_file_extent_offset(leaf, fi);
extent_end = found_key.offset +
btrfs_file_extent_num_bytes(leaf, fi);
disk_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf, fi);
/*
* If the extent we got ends before our current offset,
* skip to the next extent.
*/
if (extent_end <= cur_offset) {
path->slots[0]++;
goto next_slot;
}
/* Skip holes */
if (disk_bytenr == 0)
goto out_check;
/* Skip compressed/encrypted/encoded extents */
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out_check;
/*
* If extent is created before the last volume's snapshot
* this implies the extent is shared, hence we can't do
* nocow. This is the same check as in
* btrfs_cross_ref_exist but without calling
* btrfs_search_slot.
*/
if (!freespace_inode &&
btrfs_file_extent_generation(leaf, fi) <=
btrfs_root_last_snapshot(&root->root_item))
goto out_check;
if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
goto out_check;
/* If extent is RO, we must COW it */
if (btrfs_extent_readonly(fs_info, disk_bytenr))
goto out_check;
ret = btrfs_cross_ref_exist(root, ino,
found_key.offset -
extent_offset, disk_bytenr);
if (ret) {
/*
* ret could be -EIO if the above fails to read
* metadata.
*/
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
WARN_ON_ONCE(freespace_inode);
goto out_check;
}
disk_bytenr += extent_offset;
disk_bytenr += cur_offset - found_key.offset;
num_bytes = min(end + 1, extent_end) - cur_offset;
/*
* If there are pending snapshots for this root, we
* fall into common COW way
*/
if (!freespace_inode && atomic_read(&root->snapshot_force_cow))
goto out_check;
/*
* force cow if csum exists in the range.
* this ensure that csum for a given extent are
* either valid or do not exist.
*/
ret = csum_exist_in_range(fs_info, disk_bytenr,
num_bytes);
if (ret) {
/*
* ret could be -EIO if the above fails to read
* metadata.
*/
if (ret < 0) {
if (cow_start != (u64)-1)
cur_offset = cow_start;
goto error;
}
WARN_ON_ONCE(freespace_inode);
goto out_check;
}
if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr))
goto out_check;
nocow = true;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = found_key.offset + ram_bytes;
extent_end = ALIGN(extent_end, fs_info->sectorsize);
/* Skip extents outside of our requested range */
if (extent_end <= start) {
path->slots[0]++;
goto next_slot;
}
} else {
/* If this triggers then we have a memory corruption */
BUG();
}
out_check:
/*
* If nocow is false then record the beginning of the range
* that needs to be COWed
*/
if (!nocow) {
if (cow_start == (u64)-1)
cow_start = cur_offset;
cur_offset = extent_end;
if (cur_offset > end)
break;
path->slots[0]++;
goto next_slot;
}
btrfs_release_path(path);
/*
* COW range from cow_start to found_key.offset - 1. As the key
* will contain the beginning of the first extent that can be
* NOCOW, following one which needs to be COW'ed
*/
if (cow_start != (u64)-1) {
ret = cow_file_range(inode, locked_page,
cow_start, found_key.offset - 1,
page_started, nr_written, 1);
if (ret) {
if (nocow)
btrfs_dec_nocow_writers(fs_info,
disk_bytenr);
goto error;
}
cow_start = (u64)-1;
}
if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 orig_start = found_key.offset - extent_offset;
struct extent_map *em;
em = create_io_em(inode, cur_offset, num_bytes,
orig_start,
disk_bytenr, /* block_start */
num_bytes, /* block_len */
disk_num_bytes, /* orig_block_len */
ram_bytes, BTRFS_COMPRESS_NONE,
BTRFS_ORDERED_PREALLOC);
if (IS_ERR(em)) {
if (nocow)
btrfs_dec_nocow_writers(fs_info,
disk_bytenr);
ret = PTR_ERR(em);
goto error;
}
free_extent_map(em);
ret = btrfs_add_ordered_extent(inode, cur_offset,
disk_bytenr, num_bytes,
num_bytes,
BTRFS_ORDERED_PREALLOC);
if (ret) {
btrfs_drop_extent_cache(BTRFS_I(inode),
cur_offset,
cur_offset + num_bytes - 1,
0);
goto error;
}
} else {
ret = btrfs_add_ordered_extent(inode, cur_offset,
disk_bytenr, num_bytes,
num_bytes,
BTRFS_ORDERED_NOCOW);
if (ret)
goto error;
}
if (nocow)
btrfs_dec_nocow_writers(fs_info, disk_bytenr);
nocow = false;
if (root->root_key.objectid ==
BTRFS_DATA_RELOC_TREE_OBJECTID)
/*
* Error handled later, as we must prevent
* extent_clear_unlock_delalloc() in error handler
* from freeing metadata of created ordered extent.
*/
ret = btrfs_reloc_clone_csums(inode, cur_offset,
num_bytes);
extent_clear_unlock_delalloc(inode, cur_offset,
cur_offset + num_bytes - 1,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC |
EXTENT_CLEAR_DATA_RESV,
PAGE_UNLOCK | PAGE_SET_PRIVATE2);
cur_offset = extent_end;
/*
* btrfs_reloc_clone_csums() error, now we're OK to call error
* handler, as metadata for created ordered extent will only
* be freed by btrfs_finish_ordered_io().
*/
if (ret)
goto error;
if (cur_offset > end)
break;
}
btrfs_release_path(path);
if (cur_offset <= end && cow_start == (u64)-1)
cow_start = cur_offset;
if (cow_start != (u64)-1) {
cur_offset = end;
ret = cow_file_range(inode, locked_page, cow_start, end,
page_started, nr_written, 1);
if (ret)
goto error;
}
error:
if (nocow)
btrfs_dec_nocow_writers(fs_info, disk_bytenr);
if (ret && cur_offset < end)
extent_clear_unlock_delalloc(inode, cur_offset, end,
locked_page, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DEFRAG |
EXTENT_DO_ACCOUNTING, PAGE_UNLOCK |
PAGE_CLEAR_DIRTY |
PAGE_SET_WRITEBACK |
PAGE_END_WRITEBACK);
btrfs_free_path(path);
return ret;
}
static inline int need_force_cow(struct inode *inode, u64 start, u64 end)
{
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
!(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC))
return 0;
/*
* @defrag_bytes is a hint value, no spinlock held here,
* if is not zero, it means the file is defragging.
* Force cow if given extent needs to be defragged.
*/
if (BTRFS_I(inode)->defrag_bytes &&
test_range_bit(&BTRFS_I(inode)->io_tree, start, end,
EXTENT_DEFRAG, 0, NULL))
return 1;
return 0;
}
/*
* Function to process delayed allocation (create CoW) for ranges which are
* being touched for the first time.
*/
int btrfs_run_delalloc_range(struct inode *inode, struct page *locked_page,
u64 start, u64 end, int *page_started, unsigned long *nr_written,
struct writeback_control *wbc)
{
int ret;
int force_cow = need_force_cow(inode, start, end);
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 1, nr_written);
} else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC && !force_cow) {
ret = run_delalloc_nocow(inode, locked_page, start, end,
page_started, 0, nr_written);
} else if (!inode_can_compress(inode) ||
!inode_need_compress(inode, start, end)) {
ret = cow_file_range(inode, locked_page, start, end,
page_started, nr_written, 1);
} else {
set_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags);
ret = cow_file_range_async(inode, wbc, locked_page, start, end,
page_started, nr_written);
}
if (ret)
btrfs_cleanup_ordered_extents(inode, locked_page, start,
end - start + 1);
return ret;
}
void btrfs_split_delalloc_extent(struct inode *inode,
struct extent_state *orig, u64 split)
{
u64 size;
/* not delalloc, ignore it */
if (!(orig->state & EXTENT_DELALLOC))
return;
size = orig->end - orig->start + 1;
if (size > BTRFS_MAX_EXTENT_SIZE) {
u32 num_extents;
u64 new_size;
/*
* See the explanation in btrfs_merge_delalloc_extent, the same
* applies here, just in reverse.
*/
new_size = orig->end - split + 1;
num_extents = count_max_extents(new_size);
new_size = split - orig->start;
num_extents += count_max_extents(new_size);
if (count_max_extents(size) >= num_extents)
return;
}
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
spin_unlock(&BTRFS_I(inode)->lock);
}
/*
* Handle merged delayed allocation extents so we can keep track of new extents
* that are just merged onto old extents, such as when we are doing sequential
* writes, so we can properly account for the metadata space we'll need.
*/
void btrfs_merge_delalloc_extent(struct inode *inode, struct extent_state *new,
struct extent_state *other)
{
u64 new_size, old_size;
u32 num_extents;
/* not delalloc, ignore it */
if (!(other->state & EXTENT_DELALLOC))
return;
if (new->start > other->start)
new_size = new->end - other->start + 1;
else
new_size = other->end - new->start + 1;
/* we're not bigger than the max, unreserve the space and go */
if (new_size <= BTRFS_MAX_EXTENT_SIZE) {
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
spin_unlock(&BTRFS_I(inode)->lock);
return;
}
/*
* We have to add up either side to figure out how many extents were
* accounted for before we merged into one big extent. If the number of
* extents we accounted for is <= the amount we need for the new range
* then we can return, otherwise drop. Think of it like this
*
* [ 4k][MAX_SIZE]
*
* So we've grown the extent by a MAX_SIZE extent, this would mean we
* need 2 outstanding extents, on one side we have 1 and the other side
* we have 1 so they are == and we can return. But in this case
*
* [MAX_SIZE+4k][MAX_SIZE+4k]
*
* Each range on their own accounts for 2 extents, but merged together
* they are only 3 extents worth of accounting, so we need to drop in
* this case.
*/
old_size = other->end - other->start + 1;
num_extents = count_max_extents(old_size);
old_size = new->end - new->start + 1;
num_extents += count_max_extents(old_size);
if (count_max_extents(new_size) >= num_extents)
return;
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), -1);
spin_unlock(&BTRFS_I(inode)->lock);
}
static void btrfs_add_delalloc_inodes(struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
spin_lock(&root->delalloc_lock);
if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
&root->delalloc_inodes);
set_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags);
root->nr_delalloc_inodes++;
if (root->nr_delalloc_inodes == 1) {
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(!list_empty(&root->delalloc_root));
list_add_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
spin_unlock(&root->delalloc_lock);
}
void __btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
if (!list_empty(&inode->delalloc_inodes)) {
list_del_init(&inode->delalloc_inodes);
clear_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags);
root->nr_delalloc_inodes--;
if (!root->nr_delalloc_inodes) {
ASSERT(list_empty(&root->delalloc_inodes));
spin_lock(&fs_info->delalloc_root_lock);
BUG_ON(list_empty(&root->delalloc_root));
list_del_init(&root->delalloc_root);
spin_unlock(&fs_info->delalloc_root_lock);
}
}
}
static void btrfs_del_delalloc_inode(struct btrfs_root *root,
struct btrfs_inode *inode)
{
spin_lock(&root->delalloc_lock);
__btrfs_del_delalloc_inode(root, inode);
spin_unlock(&root->delalloc_lock);
}
/*
* Properly track delayed allocation bytes in the inode and to maintain the
* list of inodes that have pending delalloc work to be done.
*/
void btrfs_set_delalloc_extent(struct inode *inode, struct extent_state *state,
unsigned *bits)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if ((*bits & EXTENT_DEFRAG) && !(*bits & EXTENT_DELALLOC))
WARN_ON(1);
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 len = state->end + 1 - state->start;
u32 num_extents = count_max_extents(len);
bool do_list = !btrfs_is_free_space_inode(BTRFS_I(inode));
spin_lock(&BTRFS_I(inode)->lock);
btrfs_mod_outstanding_extents(BTRFS_I(inode), num_extents);
spin_unlock(&BTRFS_I(inode)->lock);
/* For sanity tests */
if (btrfs_is_testing(fs_info))
return;
percpu_counter_add_batch(&fs_info->delalloc_bytes, len,
fs_info->delalloc_batch);
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->delalloc_bytes += len;
if (*bits & EXTENT_DEFRAG)
BTRFS_I(inode)->defrag_bytes += len;
if (do_list && !test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&BTRFS_I(inode)->runtime_flags))
btrfs_add_delalloc_inodes(root, inode);
spin_unlock(&BTRFS_I(inode)->lock);
}
if (!(state->state & EXTENT_DELALLOC_NEW) &&
(*bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&BTRFS_I(inode)->lock);
BTRFS_I(inode)->new_delalloc_bytes += state->end + 1 -
state->start;
spin_unlock(&BTRFS_I(inode)->lock);
}
}
/*
* Once a range is no longer delalloc this function ensures that proper
* accounting happens.
*/
void btrfs_clear_delalloc_extent(struct inode *vfs_inode,
struct extent_state *state, unsigned *bits)
{
struct btrfs_inode *inode = BTRFS_I(vfs_inode);
struct btrfs_fs_info *fs_info = btrfs_sb(vfs_inode->i_sb);
u64 len = state->end + 1 - state->start;
u32 num_extents = count_max_extents(len);
if ((state->state & EXTENT_DEFRAG) && (*bits & EXTENT_DEFRAG)) {
spin_lock(&inode->lock);
inode->defrag_bytes -= len;
spin_unlock(&inode->lock);
}
/*
* set_bit and clear bit hooks normally require _irqsave/restore
* but in this case, we are only testing for the DELALLOC
* bit, which is only set or cleared with irqs on
*/
if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
struct btrfs_root *root = inode->root;
bool do_list = !btrfs_is_free_space_inode(inode);
spin_lock(&inode->lock);
btrfs_mod_outstanding_extents(inode, -num_extents);
spin_unlock(&inode->lock);
/*
* We don't reserve metadata space for space cache inodes so we
* don't need to call delalloc_release_metadata if there is an
* error.
*/
if (*bits & EXTENT_CLEAR_META_RESV &&
root != fs_info->tree_root)
btrfs_delalloc_release_metadata(inode, len, false);
/* For sanity tests. */
if (btrfs_is_testing(fs_info))
return;
if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID &&
do_list && !(state->state & EXTENT_NORESERVE) &&
(*bits & EXTENT_CLEAR_DATA_RESV))
btrfs_free_reserved_data_space_noquota(
&inode->vfs_inode,
state->start, len);
percpu_counter_add_batch(&fs_info->delalloc_bytes, -len,
fs_info->delalloc_batch);
spin_lock(&inode->lock);
inode->delalloc_bytes -= len;
if (do_list && inode->delalloc_bytes == 0 &&
test_bit(BTRFS_INODE_IN_DELALLOC_LIST,
&inode->runtime_flags))
btrfs_del_delalloc_inode(root, inode);
spin_unlock(&inode->lock);
}
if ((state->state & EXTENT_DELALLOC_NEW) &&
(*bits & EXTENT_DELALLOC_NEW)) {
spin_lock(&inode->lock);
ASSERT(inode->new_delalloc_bytes >= len);
inode->new_delalloc_bytes -= len;
spin_unlock(&inode->lock);
}
}
/*
* btrfs_bio_fits_in_stripe - Checks whether the size of the given bio will fit
* in a chunk's stripe. This function ensures that bios do not span a
* stripe/chunk
*
* @page - The page we are about to add to the bio
* @size - size we want to add to the bio
* @bio - bio we want to ensure is smaller than a stripe
* @bio_flags - flags of the bio
*
* return 1 if page cannot be added to the bio
* return 0 if page can be added to the bio
* return error otherwise
*/
int btrfs_bio_fits_in_stripe(struct page *page, size_t size, struct bio *bio,
unsigned long bio_flags)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 logical = (u64)bio->bi_iter.bi_sector << 9;
u64 length = 0;
u64 map_length;
int ret;
struct btrfs_io_geometry geom;
if (bio_flags & EXTENT_BIO_COMPRESSED)
return 0;
length = bio->bi_iter.bi_size;
map_length = length;
ret = btrfs_get_io_geometry(fs_info, btrfs_op(bio), logical, map_length,
&geom);
if (ret < 0)
return ret;
if (geom.len < length + size)
return 1;
return 0;
}
/*
* in order to insert checksums into the metadata in large chunks,
* we wait until bio submission time. All the pages in the bio are
* checksummed and sums are attached onto the ordered extent record.
*
* At IO completion time the cums attached on the ordered extent record
* are inserted into the btree
*/
static blk_status_t btrfs_submit_bio_start(void *private_data, struct bio *bio,
u64 bio_offset)
{
struct inode *inode = private_data;
blk_status_t ret = 0;
ret = btrfs_csum_one_bio(inode, bio, 0, 0);
BUG_ON(ret); /* -ENOMEM */
return 0;
}
/*
* extent_io.c submission hook. This does the right thing for csum calculation
* on write, or reading the csums from the tree before a read.
*
* Rules about async/sync submit,
* a) read: sync submit
*
* b) write without checksum: sync submit
*
* c) write with checksum:
* c-1) if bio is issued by fsync: sync submit
* (sync_writers != 0)
*
* c-2) if root is reloc root: sync submit
* (only in case of buffered IO)
*
* c-3) otherwise: async submit
*/
static blk_status_t btrfs_submit_bio_hook(struct inode *inode, struct bio *bio,
int mirror_num,
unsigned long bio_flags)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
enum btrfs_wq_endio_type metadata = BTRFS_WQ_ENDIO_DATA;
blk_status_t ret = 0;
int skip_sum;
int async = !atomic_read(&BTRFS_I(inode)->sync_writers);
skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (btrfs_is_free_space_inode(BTRFS_I(inode)))
metadata = BTRFS_WQ_ENDIO_FREE_SPACE;
if (bio_op(bio) != REQ_OP_WRITE) {
ret = btrfs_bio_wq_end_io(fs_info, bio, metadata);
if (ret)
goto out;
if (bio_flags & EXTENT_BIO_COMPRESSED) {
ret = btrfs_submit_compressed_read(inode, bio,
mirror_num,
bio_flags);
goto out;
} else if (!skip_sum) {
ret = btrfs_lookup_bio_sums(inode, bio, (u64)-1, NULL);
if (ret)
goto out;
}
goto mapit;
} else if (async && !skip_sum) {
/* csum items have already been cloned */
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
goto mapit;
/* we're doing a write, do the async checksumming */
ret = btrfs_wq_submit_bio(fs_info, bio, mirror_num, bio_flags,
0, inode, btrfs_submit_bio_start);
goto out;
} else if (!skip_sum) {
ret = btrfs_csum_one_bio(inode, bio, 0, 0);
if (ret)
goto out;
}
mapit:
ret = btrfs_map_bio(fs_info, bio, mirror_num);
out:
if (ret) {
bio->bi_status = ret;
bio_endio(bio);
}
return ret;
}
/*
* given a list of ordered sums record them in the inode. This happens
* at IO completion time based on sums calculated at bio submission time.
*/
static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
struct inode *inode, struct list_head *list)
{
struct btrfs_ordered_sum *sum;
int ret;
list_for_each_entry(sum, list, list) {
trans->adding_csums = true;
ret = btrfs_csum_file_blocks(trans,
BTRFS_I(inode)->root->fs_info->csum_root, sum);
trans->adding_csums = false;
if (ret)
return ret;
}
return 0;
}
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
unsigned int extra_bits,
struct extent_state **cached_state)
{
WARN_ON(PAGE_ALIGNED(end));
return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
extra_bits, cached_state);
}
/* see btrfs_writepage_start_hook for details on why this is required */
struct btrfs_writepage_fixup {
struct page *page;
struct inode *inode;
struct btrfs_work work;
};
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
{
struct btrfs_writepage_fixup *fixup;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
struct page *page;
struct inode *inode;
u64 page_start;
u64 page_end;
int ret = 0;
bool free_delalloc_space = true;
fixup = container_of(work, struct btrfs_writepage_fixup, work);
page = fixup->page;
inode = fixup->inode;
page_start = page_offset(page);
page_end = page_offset(page) + PAGE_SIZE - 1;
/*
* This is similar to page_mkwrite, we need to reserve the space before
* we take the page lock.
*/
ret = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
PAGE_SIZE);
again:
lock_page(page);
/*
* Before we queued this fixup, we took a reference on the page.
* page->mapping may go NULL, but it shouldn't be moved to a different
* address space.
*/
if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
/*
* Unfortunately this is a little tricky, either
*
* 1) We got here and our page had already been dealt with and
* we reserved our space, thus ret == 0, so we need to just
* drop our space reservation and bail. This can happen the
* first time we come into the fixup worker, or could happen
* while waiting for the ordered extent.
* 2) Our page was already dealt with, but we happened to get an
* ENOSPC above from the btrfs_delalloc_reserve_space. In
* this case we obviously don't have anything to release, but
* because the page was already dealt with we don't want to
* mark the page with an error, so make sure we're resetting
* ret to 0. This is why we have this check _before_ the ret
* check, because we do not want to have a surprise ENOSPC
* when the page was already properly dealt with.
*/
if (!ret) {
btrfs_delalloc_release_extents(BTRFS_I(inode),
PAGE_SIZE);
btrfs_delalloc_release_space(inode, data_reserved,
page_start, PAGE_SIZE,
true);
}
ret = 0;
goto out_page;
}
/*
* We can't mess with the page state unless it is locked, so now that
* it is locked bail if we failed to make our space reservation.
*/
if (ret)
goto out_page;
lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state);
/* already ordered? We're done */
if (PagePrivate2(page))
goto out_reserved;
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
PAGE_SIZE);
if (ordered) {
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
page_end, &cached_state);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
&cached_state);
if (ret)
goto out_reserved;
/*
* Everything went as planned, we're now the owner of a dirty page with
* delayed allocation bits set and space reserved for our COW
* destination.
*
* The page was dirty when we started, nothing should have cleaned it.
*/
BUG_ON(!PageDirty(page));
free_delalloc_space = false;
out_reserved:
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
if (free_delalloc_space)
btrfs_delalloc_release_space(inode, data_reserved, page_start,
PAGE_SIZE, true);
unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
&cached_state);
out_page:
if (ret) {
/*
* We hit ENOSPC or other errors. Update the mapping and page
* to reflect the errors and clean the page.
*/
mapping_set_error(page->mapping, ret);
end_extent_writepage(page, ret, page_start, page_end);
clear_page_dirty_for_io(page);
SetPageError(page);
}
ClearPageChecked(page);
unlock_page(page);
put_page(page);
kfree(fixup);
extent_changeset_free(data_reserved);
/*
* As a precaution, do a delayed iput in case it would be the last iput
* that could need flushing space. Recursing back to fixup worker would
* deadlock.
*/
btrfs_add_delayed_iput(inode);
}
/*
* There are a few paths in the higher layers of the kernel that directly
* set the page dirty bit without asking the filesystem if it is a
* good idea. This causes problems because we want to make sure COW
* properly happens and the data=ordered rules are followed.
*
* In our case any range that doesn't have the ORDERED bit set
* hasn't been properly setup for IO. We kick off an async process
* to fix it up. The async helper will wait for ordered extents, set
* the delalloc bit and make it safe to write the page.
*/
int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_writepage_fixup *fixup;
/* this page is properly in the ordered list */
if (TestClearPagePrivate2(page))
return 0;
/*
* PageChecked is set below when we create a fixup worker for this page,
* don't try to create another one if we're already PageChecked()
*
* The extent_io writepage code will redirty the page if we send back
* EAGAIN.
*/
if (PageChecked(page))
return -EAGAIN;
fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
if (!fixup)
return -EAGAIN;
/*
* We are already holding a reference to this inode from
* write_cache_pages. We need to hold it because the space reservation
* takes place outside of the page lock, and we can't trust
* page->mapping outside of the page lock.
*/
ihold(inode);
SetPageChecked(page);
get_page(page);
btrfs_init_work(&fixup->work, btrfs_writepage_fixup_worker, NULL, NULL);
fixup->page = page;
fixup->inode = inode;
btrfs_queue_work(fs_info->fixup_workers, &fixup->work);
return -EAGAIN;
}
static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
struct inode *inode, u64 file_pos,
u64 disk_bytenr, u64 disk_num_bytes,
u64 num_bytes, u64 ram_bytes,
u8 compression, u8 encryption,
u16 other_encoding, int extent_type)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_extent_item *fi;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key ins;
u64 qg_released;
int extent_inserted = 0;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/*
* we may be replacing one extent in the tree with another.
* The new extent is pinned in the extent map, and we don't want
* to drop it from the cache until it is completely in the btree.
*
* So, tell btrfs_drop_extents to leave this extent in the cache.
* the caller is expected to unpin it and allow it to be merged
* with the others.
*/
ret = __btrfs_drop_extents(trans, root, inode, path, file_pos,
file_pos + num_bytes, NULL, 0,
1, sizeof(*fi), &extent_inserted);
if (ret)
goto out;
if (!extent_inserted) {
ins.objectid = btrfs_ino(BTRFS_I(inode));
ins.offset = file_pos;
ins.type = BTRFS_EXTENT_DATA_KEY;
path->leave_spinning = 1;
ret = btrfs_insert_empty_item(trans, root, path, &ins,
sizeof(*fi));
if (ret)
goto out;
}
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi, trans->transid);
btrfs_set_file_extent_type(leaf, fi, extent_type);
btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
btrfs_set_file_extent_offset(leaf, fi, 0);
btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
btrfs_set_file_extent_compression(leaf, fi, compression);
btrfs_set_file_extent_encryption(leaf, fi, encryption);
btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
inode_add_bytes(inode, num_bytes);
ins.objectid = disk_bytenr;
ins.offset = disk_num_bytes;
ins.type = BTRFS_EXTENT_ITEM_KEY;
/*
* Release the reserved range from inode dirty range map, as it is
* already moved into delayed_ref_head
*/
ret = btrfs_qgroup_release_data(inode, file_pos, ram_bytes);
if (ret < 0)
goto out;
qg_released = ret;
ret = btrfs_alloc_reserved_file_extent(trans, root,
btrfs_ino(BTRFS_I(inode)),
file_pos, qg_released, &ins);
out:
btrfs_free_path(path);
return ret;
}
static void btrfs_release_delalloc_bytes(struct btrfs_fs_info *fs_info,
u64 start, u64 len)
{
struct btrfs_block_group *cache;
cache = btrfs_lookup_block_group(fs_info, start);
ASSERT(cache);
spin_lock(&cache->lock);
cache->delalloc_bytes -= len;
spin_unlock(&cache->lock);
btrfs_put_block_group(cache);
}
/* as ordered data IO finishes, this gets called so we can finish
* an ordered extent if the range of bytes in the file it covers are
* fully written.
*/
static int btrfs_finish_ordered_io(struct btrfs_ordered_extent *ordered_extent)
{
struct inode *inode = ordered_extent->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans = NULL;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
u64 start, end;
int compress_type = 0;
int ret = 0;
u64 logical_len = ordered_extent->num_bytes;
bool freespace_inode;
bool truncated = false;
bool range_locked = false;
bool clear_new_delalloc_bytes = false;
bool clear_reserved_extent = true;
unsigned int clear_bits;
start = ordered_extent->file_offset;
end = start + ordered_extent->num_bytes - 1;
if (!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_DIRECT, &ordered_extent->flags))
clear_new_delalloc_bytes = true;
freespace_inode = btrfs_is_free_space_inode(BTRFS_I(inode));
if (test_bit(BTRFS_ORDERED_IOERR, &ordered_extent->flags)) {
ret = -EIO;
goto out;
}
btrfs_free_io_failure_record(BTRFS_I(inode), start, end);
if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered_extent->flags)) {
truncated = true;
logical_len = ordered_extent->truncated_len;
/* Truncated the entire extent, don't bother adding */
if (!logical_len)
goto out;
}
if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
BUG_ON(!list_empty(&ordered_extent->list)); /* Logic error */
/*
* For mwrite(mmap + memset to write) case, we still reserve
* space for NOCOW range.
* As NOCOW won't cause a new delayed ref, just free the space
*/
btrfs_qgroup_free_data(inode, NULL, start,
ordered_extent->num_bytes);
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &BTRFS_I(inode)->block_rsv;
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
range_locked = true;
lock_extent_bits(io_tree, start, end, &cached_state);
if (freespace_inode)
trans = btrfs_join_transaction_spacecache(root);
else
trans = btrfs_join_transaction(root);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
trans->block_rsv = &BTRFS_I(inode)->block_rsv;
if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
compress_type = ordered_extent->compress_type;
if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
BUG_ON(compress_type);
btrfs_qgroup_free_data(inode, NULL, start,
ordered_extent->num_bytes);
ret = btrfs_mark_extent_written(trans, BTRFS_I(inode),
ordered_extent->file_offset,
ordered_extent->file_offset +
logical_len);
} else {
BUG_ON(root == fs_info->tree_root);
ret = insert_reserved_file_extent(trans, inode, start,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes,
logical_len, logical_len,
compress_type, 0, 0,
BTRFS_FILE_EXTENT_REG);
if (!ret) {
clear_reserved_extent = false;
btrfs_release_delalloc_bytes(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes);
}
}
unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
ordered_extent->file_offset,
ordered_extent->num_bytes, trans->transid);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = add_pending_csums(trans, inode, &ordered_extent->list);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_ordered_update_i_size(inode, 0, ordered_extent);
ret = btrfs_update_inode_fallback(trans, root, inode);
if (ret) { /* -ENOMEM or corruption */
btrfs_abort_transaction(trans, ret);
goto out;
}
ret = 0;
out:
clear_bits = EXTENT_DEFRAG;
if (range_locked)
clear_bits |= EXTENT_LOCKED;
if (clear_new_delalloc_bytes)
clear_bits |= EXTENT_DELALLOC_NEW;
clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, clear_bits,
(clear_bits & EXTENT_LOCKED) ? 1 : 0, 0,
&cached_state);
if (trans)
btrfs_end_transaction(trans);
if (ret || truncated) {
u64 unwritten_start = start;
if (truncated)
unwritten_start += logical_len;
clear_extent_uptodate(io_tree, unwritten_start, end, NULL);
/* Drop the cache for the part of the extent we didn't write. */
btrfs_drop_extent_cache(BTRFS_I(inode), unwritten_start, end, 0);
/*
* If the ordered extent had an IOERR or something else went
* wrong we need to return the space for this ordered extent
* back to the allocator. We only free the extent in the
* truncated case if we didn't write out the extent at all.
*
* If we made it past insert_reserved_file_extent before we
* errored out then we don't need to do this as the accounting
* has already been done.
*/
if ((ret || !logical_len) &&
clear_reserved_extent &&
!test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags) &&
!test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
/*
* Discard the range before returning it back to the
* free space pool
*/
if (ret && btrfs_test_opt(fs_info, DISCARD_SYNC))
btrfs_discard_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes,
NULL);
btrfs_free_reserved_extent(fs_info,
ordered_extent->disk_bytenr,
ordered_extent->disk_num_bytes, 1);
}
}
/*
* This needs to be done to make sure anybody waiting knows we are done
* updating everything for this ordered extent.
*/
btrfs_remove_ordered_extent(inode, ordered_extent);
/* once for us */
btrfs_put_ordered_extent(ordered_extent);
/* once for the tree */
btrfs_put_ordered_extent(ordered_extent);
return ret;
}
static void finish_ordered_fn(struct btrfs_work *work)
{
struct btrfs_ordered_extent *ordered_extent;
ordered_extent = container_of(work, struct btrfs_ordered_extent, work);
btrfs_finish_ordered_io(ordered_extent);
}
void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
u64 end, int uptodate)
{
struct inode *inode = page->mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_ordered_extent *ordered_extent = NULL;
struct btrfs_workqueue *wq;
trace_btrfs_writepage_end_io_hook(page, start, end, uptodate);
ClearPagePrivate2(page);
if (!btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
end - start + 1, uptodate))
return;
if (btrfs_is_free_space_inode(BTRFS_I(inode)))
wq = fs_info->endio_freespace_worker;
else
wq = fs_info->endio_write_workers;
btrfs_init_work(&ordered_extent->work, finish_ordered_fn, NULL, NULL);
btrfs_queue_work(wq, &ordered_extent->work);
}
static int __readpage_endio_check(struct inode *inode,
struct btrfs_io_bio *io_bio,
int icsum, struct page *page,
int pgoff, u64 start, size_t len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
SHASH_DESC_ON_STACK(shash, fs_info->csum_shash);
char *kaddr;
u16 csum_size = btrfs_super_csum_size(fs_info->super_copy);
u8 *csum_expected;
u8 csum[BTRFS_CSUM_SIZE];
csum_expected = ((u8 *)io_bio->csum) + icsum * csum_size;
kaddr = kmap_atomic(page);
shash->tfm = fs_info->csum_shash;
crypto_shash_init(shash);
crypto_shash_update(shash, kaddr + pgoff, len);
crypto_shash_final(shash, csum);
if (memcmp(csum, csum_expected, csum_size))
goto zeroit;
kunmap_atomic(kaddr);
return 0;
zeroit:
btrfs_print_data_csum_error(BTRFS_I(inode), start, csum, csum_expected,
io_bio->mirror_num);
memset(kaddr + pgoff, 1, len);
flush_dcache_page(page);
kunmap_atomic(kaddr);
return -EIO;
}
/*
* when reads are done, we need to check csums to verify the data is correct
* if there's a match, we allow the bio to finish. If not, the code in
* extent_io.c will try to find good copies for us.
*/
static int btrfs_readpage_end_io_hook(struct btrfs_io_bio *io_bio,
u64 phy_offset, struct page *page,
u64 start, u64 end, int mirror)
{
size_t offset = start - page_offset(page);
struct inode *inode = page->mapping->host;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_root *root = BTRFS_I(inode)->root;
if (PageChecked(page)) {
ClearPageChecked(page);
return 0;
}
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
return 0;
if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM);
return 0;
}
phy_offset >>= inode->i_sb->s_blocksize_bits;
return __readpage_endio_check(inode, io_bio, phy_offset, page, offset,
start, (size_t)(end - start + 1));
}
/*
* btrfs_add_delayed_iput - perform a delayed iput on @inode
*
* @inode: The inode we want to perform iput on
*
* This function uses the generic vfs_inode::i_count to track whether we should
* just decrement it (in case it's > 1) or if this is the last iput then link
* the inode to the delayed iput machinery. Delayed iputs are processed at
* transaction commit time/superblock commit/cleaner kthread.
*/
void btrfs_add_delayed_iput(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_inode *binode = BTRFS_I(inode);
if (atomic_add_unless(&inode->i_count, -1, 1))
return;
atomic_inc(&fs_info->nr_delayed_iputs);
spin_lock(&fs_info->delayed_iput_lock);
ASSERT(list_empty(&binode->delayed_iput));
list_add_tail(&binode->delayed_iput, &fs_info->delayed_iputs);
spin_unlock(&fs_info->delayed_iput_lock);
if (!test_bit(BTRFS_FS_CLEANER_RUNNING, &fs_info->flags))
wake_up_process(fs_info->cleaner_kthread);
}
static void run_delayed_iput_locked(struct btrfs_fs_info *fs_info,
struct btrfs_inode *inode)
{
list_del_init(&inode->delayed_iput);
spin_unlock(&fs_info->delayed_iput_lock);
iput(&inode->vfs_inode);
if (atomic_dec_and_test(&fs_info->nr_delayed_iputs))
wake_up(&fs_info->delayed_iputs_wait);
spin_lock(&fs_info->delayed_iput_lock);
}
static void btrfs_run_delayed_iput(struct btrfs_fs_info *fs_info,
struct btrfs_inode *inode)
{
if (!list_empty(&inode->delayed_iput)) {
spin_lock(&fs_info->delayed_iput_lock);
if (!list_empty(&inode->delayed_iput))
run_delayed_iput_locked(fs_info, inode);
spin_unlock(&fs_info->delayed_iput_lock);
}
}
void btrfs_run_delayed_iputs(struct btrfs_fs_info *fs_info)
{
spin_lock(&fs_info->delayed_iput_lock);
while (!list_empty(&fs_info->delayed_iputs)) {
struct btrfs_inode *inode;
inode = list_first_entry(&fs_info->delayed_iputs,
struct btrfs_inode, delayed_iput);
run_delayed_iput_locked(fs_info, inode);
}
spin_unlock(&fs_info->delayed_iput_lock);
}
/**
* btrfs_wait_on_delayed_iputs - wait on the delayed iputs to be done running
* @fs_info - the fs_info for this fs
* @return - EINTR if we were killed, 0 if nothing's pending
*
* This will wait on any delayed iputs that are currently running with KILLABLE
* set. Once they are all done running we will return, unless we are killed in
* which case we return EINTR. This helps in user operations like fallocate etc
* that might get blocked on the iputs.
*/
int btrfs_wait_on_delayed_iputs(struct btrfs_fs_info *fs_info)
{
int ret = wait_event_killable(fs_info->delayed_iputs_wait,
atomic_read(&fs_info->nr_delayed_iputs) == 0);
if (ret)
return -EINTR;
return 0;
}
/*
* This creates an orphan entry for the given inode in case something goes wrong
* in the middle of an unlink.
*/
int btrfs_orphan_add(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
int ret;
ret = btrfs_insert_orphan_item(trans, inode->root, btrfs_ino(inode));
if (ret && ret != -EEXIST) {
btrfs_abort_transaction(trans, ret);
return ret;
}
return 0;
}
/*
* We have done the delete so we can go ahead and remove the orphan item for
* this particular inode.
*/
static int btrfs_orphan_del(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode)
{
return btrfs_del_orphan_item(trans, inode->root, btrfs_ino(inode));
}
/*
* this cleans up any orphans that may be left on the list from the last use
* of this root.
*/
int btrfs_orphan_cleanup(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_key key, found_key;
struct btrfs_trans_handle *trans;
struct inode *inode;
u64 last_objectid = 0;
int ret = 0, nr_unlink = 0;
if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
return 0;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->reada = READA_BACK;
key.objectid = BTRFS_ORPHAN_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/*
* if ret == 0 means we found what we were searching for, which
* is weird, but possible, so only screw with path if we didn't
* find the key and see if we have stuff that matches
*/
if (ret > 0) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
/* pull out the item */
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
/* make sure the item matches what we want */
if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
break;
if (found_key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
/* release the path since we're done with it */
btrfs_release_path(path);
/*
* this is where we are basically btrfs_lookup, without the
* crossing root thing. we store the inode number in the
* offset of the orphan item.
*/
if (found_key.offset == last_objectid) {
btrfs_err(fs_info,
"Error removing orphan entry, stopping orphan cleanup");
ret = -EINVAL;
goto out;
}
last_objectid = found_key.offset;
found_key.objectid = found_key.offset;
found_key.type = BTRFS_INODE_ITEM_KEY;
found_key.offset = 0;
inode = btrfs_iget(fs_info->sb, &found_key, root);
ret = PTR_ERR_OR_ZERO(inode);
if (ret && ret != -ENOENT)
goto out;
if (ret == -ENOENT && root == fs_info->tree_root) {
struct btrfs_root *dead_root;
struct btrfs_fs_info *fs_info = root->fs_info;
int is_dead_root = 0;
/*
* this is an orphan in the tree root. Currently these
* could come from 2 sources:
* a) a snapshot deletion in progress
* b) a free space cache inode
* We need to distinguish those two, as the snapshot
* orphan must not get deleted.
* find_dead_roots already ran before us, so if this
* is a snapshot deletion, we should find the root
* in the dead_roots list
*/
spin_lock(&fs_info->trans_lock);
list_for_each_entry(dead_root, &fs_info->dead_roots,
root_list) {
if (dead_root->root_key.objectid ==
found_key.objectid) {
is_dead_root = 1;
break;
}
}
spin_unlock(&fs_info->trans_lock);
if (is_dead_root) {
/* prevent this orphan from being found again */
key.offset = found_key.objectid - 1;
continue;
}
}
/*
* If we have an inode with links, there are a couple of
* possibilities. Old kernels (before v3.12) used to create an
* orphan item for truncate indicating that there were possibly
* extent items past i_size that needed to be deleted. In v3.12,
* truncate was changed to update i_size in sync with the extent
* items, but the (useless) orphan item was still created. Since
* v4.18, we don't create the orphan item for truncate at all.
*
* So, this item could mean that we need to do a truncate, but
* only if this filesystem was last used on a pre-v3.12 kernel
* and was not cleanly unmounted. The odds of that are quite
* slim, and it's a pain to do the truncate now, so just delete
* the orphan item.
*
* It's also possible that this orphan item was supposed to be
* deleted but wasn't. The inode number may have been reused,
* but either way, we can delete the orphan item.
*/
if (ret == -ENOENT || inode->i_nlink) {
if (!ret)
iput(inode);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
btrfs_debug(fs_info, "auto deleting %Lu",
found_key.objectid);
ret = btrfs_del_orphan_item(trans, root,
found_key.objectid);
btrfs_end_transaction(trans);
if (ret)
goto out;
continue;
}
nr_unlink++;
/* this will do delete_inode and everything for us */
iput(inode);
}
/* release the path since we're done with it */
btrfs_release_path(path);
root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;
if (test_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &root->state)) {
trans = btrfs_join_transaction(root);
if (!IS_ERR(trans))
btrfs_end_transaction(trans);
}
if (nr_unlink)
btrfs_debug(fs_info, "unlinked %d orphans", nr_unlink);
out:
if (ret)
btrfs_err(fs_info, "could not do orphan cleanup %d", ret);
btrfs_free_path(path);
return ret;
}
/*
* very simple check to peek ahead in the leaf looking for xattrs. If we
* don't find any xattrs, we know there can't be any acls.
*
* slot is the slot the inode is in, objectid is the objectid of the inode
*/
static noinline int acls_after_inode_item(struct extent_buffer *leaf,
int slot, u64 objectid,
int *first_xattr_slot)
{
u32 nritems = btrfs_header_nritems(leaf);
struct btrfs_key found_key;
static u64 xattr_access = 0;
static u64 xattr_default = 0;
int scanned = 0;
if (!xattr_access) {
xattr_access = btrfs_name_hash(XATTR_NAME_POSIX_ACL_ACCESS,
strlen(XATTR_NAME_POSIX_ACL_ACCESS));
xattr_default = btrfs_name_hash(XATTR_NAME_POSIX_ACL_DEFAULT,
strlen(XATTR_NAME_POSIX_ACL_DEFAULT));
}
slot++;
*first_xattr_slot = -1;
while (slot < nritems) {
btrfs_item_key_to_cpu(leaf, &found_key, slot);
/* we found a different objectid, there must not be acls */
if (found_key.objectid != objectid)
return 0;
/* we found an xattr, assume we've got an acl */
if (found_key.type == BTRFS_XATTR_ITEM_KEY) {
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
if (found_key.offset == xattr_access ||
found_key.offset == xattr_default)
return 1;
}
/*
* we found a key greater than an xattr key, there can't
* be any acls later on
*/
if (found_key.type > BTRFS_XATTR_ITEM_KEY)
return 0;
slot++;
scanned++;
/*
* it goes inode, inode backrefs, xattrs, extents,
* so if there are a ton of hard links to an inode there can
* be a lot of backrefs. Don't waste time searching too hard,
* this is just an optimization
*/
if (scanned >= 8)
break;
}
/* we hit the end of the leaf before we found an xattr or
* something larger than an xattr. We have to assume the inode
* has acls
*/
if (*first_xattr_slot == -1)
*first_xattr_slot = slot;
return 1;
}
/*
* read an inode from the btree into the in-memory inode
*/
static int btrfs_read_locked_inode(struct inode *inode,
struct btrfs_path *in_path)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_path *path = in_path;
struct extent_buffer *leaf;
struct btrfs_inode_item *inode_item;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key location;
unsigned long ptr;
int maybe_acls;
u32 rdev;
int ret;
bool filled = false;
int first_xattr_slot;
ret = btrfs_fill_inode(inode, &rdev);
if (!ret)
filled = true;
if (!path) {
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
}
memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
if (ret) {
if (path != in_path)
btrfs_free_path(path);
return ret;
}
leaf = path->nodes[0];
if (filled)
goto cache_index;
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
inode->i_mode = btrfs_inode_mode(leaf, inode_item);
set_nlink(inode, btrfs_inode_nlink(leaf, inode_item));
i_uid_write(inode, btrfs_inode_uid(leaf, inode_item));
i_gid_write(inode, btrfs_inode_gid(leaf, inode_item));
btrfs_i_size_write(BTRFS_I(inode), btrfs_inode_size(leaf, inode_item));
inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->atime);
inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->atime);
inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->mtime);
inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->mtime);
inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, &inode_item->ctime);
inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, &inode_item->ctime);
BTRFS_I(inode)->i_otime.tv_sec =
btrfs_timespec_sec(leaf, &inode_item->otime);
BTRFS_I(inode)->i_otime.tv_nsec =
btrfs_timespec_nsec(leaf, &inode_item->otime);
inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
BTRFS_I(inode)->last_trans = btrfs_inode_transid(leaf, inode_item);
inode_set_iversion_queried(inode,
btrfs_inode_sequence(leaf, inode_item));
inode->i_generation = BTRFS_I(inode)->generation;
inode->i_rdev = 0;
rdev = btrfs_inode_rdev(leaf, inode_item);
BTRFS_I(inode)->index_cnt = (u64)-1;
BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
cache_index:
/*
* If we were modified in the current generation and evicted from memory
* and then re-read we need to do a full sync since we don't have any
* idea about which extents were modified before we were evicted from
* cache.
*
* This is required for both inode re-read from disk and delayed inode
* in delayed_nodes_tree.
*/
if (BTRFS_I(inode)->last_trans == fs_info->generation)
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
/*
* We don't persist the id of the transaction where an unlink operation
* against the inode was last made. So here we assume the inode might
* have been evicted, and therefore the exact value of last_unlink_trans
* lost, and set it to last_trans to avoid metadata inconsistencies
* between the inode and its parent if the inode is fsync'ed and the log
* replayed. For example, in the scenario:
*
* touch mydir/foo
* ln mydir/foo mydir/bar
* sync
* unlink mydir/bar
* echo 2 > /proc/sys/vm/drop_caches # evicts inode
* xfs_io -c fsync mydir/foo
* <power failure>
* mount fs, triggers fsync log replay
*
* We must make sure that when we fsync our inode foo we also log its
* parent inode, otherwise after log replay the parent still has the
* dentry with the "bar" name but our inode foo has a link count of 1
* and doesn't have an inode ref with the name "bar" anymore.
*
* Setting last_unlink_trans to last_trans is a pessimistic approach,
* but it guarantees correctness at the expense of occasional full
* transaction commits on fsync if our inode is a directory, or if our
* inode is not a directory, logging its parent unnecessarily.
*/
BTRFS_I(inode)->last_unlink_trans = BTRFS_I(inode)->last_trans;
path->slots[0]++;
if (inode->i_nlink != 1 ||
path->slots[0] >= btrfs_header_nritems(leaf))
goto cache_acl;
btrfs_item_key_to_cpu(leaf, &location, path->slots[0]);
if (location.objectid != btrfs_ino(BTRFS_I(inode)))
goto cache_acl;
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
if (location.type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_ref_index(leaf, ref);
} else if (location.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ptr;
BTRFS_I(inode)->dir_index = btrfs_inode_extref_index(leaf,
extref);
}
cache_acl:
/*
* try to precache a NULL acl entry for files that don't have
* any xattrs or acls
*/
maybe_acls = acls_after_inode_item(leaf, path->slots[0],
btrfs_ino(BTRFS_I(inode)), &first_xattr_slot);
if (first_xattr_slot != -1) {
path->slots[0] = first_xattr_slot;
ret = btrfs_load_inode_props(inode, path);
if (ret)
btrfs_err(fs_info,
"error loading props for ino %llu (root %llu): %d",
btrfs_ino(BTRFS_I(inode)),
root->root_key.objectid, ret);
}
if (path != in_path)
btrfs_free_path(path);
if (!maybe_acls)
cache_no_acl(inode);
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
break;
case S_IFDIR:
inode->i_fop = &btrfs_dir_file_operations;
inode->i_op = &btrfs_dir_inode_operations;
break;
case S_IFLNK:
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode->i_mapping->a_ops = &btrfs_aops;
break;
default:
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
break;
}
btrfs_sync_inode_flags_to_i_flags(inode);
return 0;
}
/*
* given a leaf and an inode, copy the inode fields into the leaf
*/
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode)
{
struct btrfs_map_token token;
btrfs_init_map_token(&token, leaf);
btrfs_set_token_inode_uid(leaf, item, i_uid_read(inode), &token);
btrfs_set_token_inode_gid(leaf, item, i_gid_read(inode), &token);
btrfs_set_token_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size,
&token);
btrfs_set_token_inode_mode(leaf, item, inode->i_mode, &token);
btrfs_set_token_inode_nlink(leaf, item, inode->i_nlink, &token);
btrfs_set_token_timespec_sec(leaf, &item->atime,
inode->i_atime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->atime,
inode->i_atime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->mtime,
inode->i_mtime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->mtime,
inode->i_mtime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->ctime,
inode->i_ctime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->ctime,
inode->i_ctime.tv_nsec, &token);
btrfs_set_token_timespec_sec(leaf, &item->otime,
BTRFS_I(inode)->i_otime.tv_sec, &token);
btrfs_set_token_timespec_nsec(leaf, &item->otime,
BTRFS_I(inode)->i_otime.tv_nsec, &token);
btrfs_set_token_inode_nbytes(leaf, item, inode_get_bytes(inode),
&token);
btrfs_set_token_inode_generation(leaf, item, BTRFS_I(inode)->generation,
&token);
btrfs_set_token_inode_sequence(leaf, item, inode_peek_iversion(inode),
&token);
btrfs_set_token_inode_transid(leaf, item, trans->transid, &token);
btrfs_set_token_inode_rdev(leaf, item, inode->i_rdev, &token);
btrfs_set_token_inode_flags(leaf, item, BTRFS_I(inode)->flags, &token);
btrfs_set_token_inode_block_group(leaf, item, 0, &token);
}
/*
* copy everything in the in-memory inode into the btree.
*/
static noinline int btrfs_update_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
struct btrfs_inode_item *inode_item;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
ret = btrfs_lookup_inode(trans, root, path, &BTRFS_I(inode)->location,
1);
if (ret) {
if (ret > 0)
ret = -ENOENT;
goto failed;
}
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, leaf, inode_item, inode);
btrfs_mark_buffer_dirty(leaf);
btrfs_set_inode_last_trans(trans, inode);
ret = 0;
failed:
btrfs_free_path(path);
return ret;
}
/*
* copy everything in the in-memory inode into the btree.
*/
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
/*
* If the inode is a free space inode, we can deadlock during commit
* if we put it into the delayed code.
*
* The data relocation inode should also be directly updated
* without delay
*/
if (!btrfs_is_free_space_inode(BTRFS_I(inode))
&& root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
&& !test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
btrfs_update_root_times(trans, root);
ret = btrfs_delayed_update_inode(trans, root, inode);
if (!ret)
btrfs_set_inode_last_trans(trans, inode);
return ret;
}
return btrfs_update_inode_item(trans, root, inode);
}
noinline int btrfs_update_inode_fallback(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
int ret;
ret = btrfs_update_inode(trans, root, inode);
if (ret == -ENOSPC)
return btrfs_update_inode_item(trans, root, inode);
return ret;
}
/*
* unlink helper that gets used here in inode.c and in the tree logging
* recovery code. It remove a link in a directory with a given name, and
* also drops the back refs in the inode to the directory
*/
static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
const char *name, int name_len)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
int ret = 0;
struct btrfs_dir_item *di;
u64 index;
u64 ino = btrfs_ino(inode);
u64 dir_ino = btrfs_ino(dir);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
path->leave_spinning = 1;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto err;
}
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret)
goto err;
btrfs_release_path(path);
/*
* If we don't have dir index, we have to get it by looking up
* the inode ref, since we get the inode ref, remove it directly,
* it is unnecessary to do delayed deletion.
*
* But if we have dir index, needn't search inode ref to get it.
* Since the inode ref is close to the inode item, it is better
* that we delay to delete it, and just do this deletion when
* we update the inode item.
*/
if (inode->dir_index) {
ret = btrfs_delayed_delete_inode_ref(inode);
if (!ret) {
index = inode->dir_index;
goto skip_backref;
}
}
ret = btrfs_del_inode_ref(trans, root, name, name_len, ino,
dir_ino, &index);
if (ret) {
btrfs_info(fs_info,
"failed to delete reference to %.*s, inode %llu parent %llu",
name_len, name, ino, dir_ino);
btrfs_abort_transaction(trans, ret);
goto err;
}
skip_backref:
ret = btrfs_delete_delayed_dir_index(trans, dir, index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto err;
}
ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len, inode,
dir_ino);
if (ret != 0 && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
goto err;
}
ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len, dir,
index);
if (ret == -ENOENT)
ret = 0;
else if (ret)
btrfs_abort_transaction(trans, ret);
/*
* If we have a pending delayed iput we could end up with the final iput
* being run in btrfs-cleaner context. If we have enough of these built
* up we can end up burning a lot of time in btrfs-cleaner without any
* way to throttle the unlinks. Since we're currently holding a ref on
* the inode we can run the delayed iput here without any issues as the
* final iput won't be done until after we drop the ref we're currently
* holding.
*/
btrfs_run_delayed_iput(fs_info, inode);
err:
btrfs_free_path(path);
if (ret)
goto out;
btrfs_i_size_write(dir, dir->vfs_inode.i_size - name_len * 2);
inode_inc_iversion(&inode->vfs_inode);
inode_inc_iversion(&dir->vfs_inode);
inode->vfs_inode.i_ctime = dir->vfs_inode.i_mtime =
dir->vfs_inode.i_ctime = current_time(&inode->vfs_inode);
ret = btrfs_update_inode(trans, root, &dir->vfs_inode);
out:
return ret;
}
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_inode *dir, struct btrfs_inode *inode,
const char *name, int name_len)
{
int ret;
ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
if (!ret) {
drop_nlink(&inode->vfs_inode);
ret = btrfs_update_inode(trans, root, &inode->vfs_inode);
}
return ret;
}
/*
* helper to start transaction for unlink and rmdir.
*
* unlink and rmdir are special in btrfs, they do not always free space, so
* if we cannot make our reservations the normal way try and see if there is
* plenty of slack room in the global reserve to migrate, otherwise we cannot
* allow the unlink to occur.
*/
static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
/*
* 1 for the possible orphan item
* 1 for the dir item
* 1 for the dir index
* 1 for the inode ref
* 1 for the inode
*/
return btrfs_start_transaction_fallback_global_rsv(root, 5, 5);
}
static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
struct inode *inode = d_inode(dentry);
int ret;
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
btrfs_record_unlink_dir(trans, BTRFS_I(dir), BTRFS_I(d_inode(dentry)),
0);
ret = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
BTRFS_I(d_inode(dentry)), dentry->d_name.name,
dentry->d_name.len);
if (ret)
goto out;
if (inode->i_nlink == 0) {
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret)
goto out;
}
out:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(root->fs_info);
return ret;
}
static int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
struct inode *dir, struct dentry *dentry)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_inode *inode = BTRFS_I(d_inode(dentry));
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key key;
const char *name = dentry->d_name.name;
int name_len = dentry->d_name.len;
u64 index;
int ret;
u64 objectid;
u64 dir_ino = btrfs_ino(BTRFS_I(dir));
if (btrfs_ino(inode) == BTRFS_FIRST_FREE_OBJECTID) {
objectid = inode->root->root_key.objectid;
} else if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
objectid = inode->location.objectid;
} else {
WARN_ON(1);
return -EINVAL;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(trans, root, path, dir_ino,
name, name_len, -1);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto out;
}
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &key);
WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
ret = btrfs_delete_one_dir_name(trans, root, path, di);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_release_path(path);
/*
* This is a placeholder inode for a subvolume we didn't have a
* reference to at the time of the snapshot creation. In the meantime
* we could have renamed the real subvol link into our snapshot, so
* depending on btrfs_del_root_ref to return -ENOENT here is incorret.
* Instead simply lookup the dir_index_item for this entry so we can
* remove it. Otherwise we know we have a ref to the root and we can
* call btrfs_del_root_ref, and it _shouldn't_ fail.
*/
if (btrfs_ino(inode) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
di = btrfs_search_dir_index_item(root, path, dir_ino,
name, name_len);
if (IS_ERR_OR_NULL(di)) {
if (!di)
ret = -ENOENT;
else
ret = PTR_ERR(di);
btrfs_abort_transaction(trans, ret);
goto out;
}
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
index = key.offset;
btrfs_release_path(path);
} else {
ret = btrfs_del_root_ref(trans, objectid,
root->root_key.objectid, dir_ino,
&index, name, name_len);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
}
ret = btrfs_delete_delayed_dir_index(trans, BTRFS_I(dir), index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out;
}
btrfs_i_size_write(BTRFS_I(dir), dir->i_size - name_len * 2);
inode_inc_iversion(dir);
dir->i_mtime = dir->i_ctime = current_time(dir);
ret = btrfs_update_inode_fallback(trans, root, dir);
if (ret)
btrfs_abort_transaction(trans, ret);
out:
btrfs_free_path(path);
return ret;
}
/*
* Helper to check if the subvolume references other subvolumes or if it's
* default.
*/
static noinline int may_destroy_subvol(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct btrfs_dir_item *di;
struct btrfs_key key;
u64 dir_id;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* Make sure this root isn't set as the default subvol */
dir_id = btrfs_super_root_dir(fs_info->super_copy);
di = btrfs_lookup_dir_item(NULL, fs_info->tree_root, path,
dir_id, "default", 7, 0);
if (di && !IS_ERR(di)) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &key);
if (key.objectid == root->root_key.objectid) {
ret = -EPERM;
btrfs_err(fs_info,
"deleting default subvolume %llu is not allowed",
key.objectid);
goto out;
}
btrfs_release_path(path);
}
key.objectid = root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret < 0)
goto out;
BUG_ON(ret == 0);
ret = 0;
if (path->slots[0] > 0) {
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid == root->root_key.objectid &&
key.type == BTRFS_ROOT_REF_KEY)
ret = -ENOTEMPTY;
}
out:
btrfs_free_path(path);
return ret;
}
/* Delete all dentries for inodes belonging to the root */
static void btrfs_prune_dentries(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct rb_node *node;
struct rb_node *prev;
struct btrfs_inode *entry;
struct inode *inode;
u64 objectid = 0;
if (!test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
WARN_ON(btrfs_root_refs(&root->root_item) != 0);
spin_lock(&root->inode_lock);
again:
node = root->inode_tree.rb_node;
prev = NULL;
while (node) {
prev = node;
entry = rb_entry(node, struct btrfs_inode, rb_node);
if (objectid < btrfs_ino(entry))
node = node->rb_left;
else if (objectid > btrfs_ino(entry))
node = node->rb_right;
else
break;
}
if (!node) {
while (prev) {
entry = rb_entry(prev, struct btrfs_inode, rb_node);
if (objectid <= btrfs_ino(entry)) {
node = prev;
break;
}
prev = rb_next(prev);
}
}
while (node) {
entry = rb_entry(node, struct btrfs_inode, rb_node);
objectid = btrfs_ino(entry) + 1;
inode = igrab(&entry->vfs_inode);
if (inode) {
spin_unlock(&root->inode_lock);
if (atomic_read(&inode->i_count) > 1)
d_prune_aliases(inode);
/*
* btrfs_drop_inode will have it removed from the inode
* cache when its usage count hits zero.
*/
iput(inode);
cond_resched();
spin_lock(&root->inode_lock);
goto again;
}
if (cond_resched_lock(&root->inode_lock))
goto again;
node = rb_next(node);
}
spin_unlock(&root->inode_lock);
}
int btrfs_delete_subvolume(struct inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dentry->d_sb);
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = d_inode(dentry);
struct btrfs_root *dest = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
struct btrfs_block_rsv block_rsv;
u64 root_flags;
int ret;
int err;
/*
* Don't allow to delete a subvolume with send in progress. This is
* inside the inode lock so the error handling that has to drop the bit
* again is not run concurrently.
*/
spin_lock(&dest->root_item_lock);
if (dest->send_in_progress) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu during send",
dest->root_key.objectid);
return -EPERM;
}
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
down_write(&fs_info->subvol_sem);
err = may_destroy_subvol(dest);
if (err)
goto out_up_write;
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
* One for dir inode,
* two for dir entries,
* two for root ref/backref.
*/
err = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
if (err)
goto out_up_write;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_release;
}
trans->block_rsv = &block_rsv;
trans->bytes_reserved = block_rsv.size;
btrfs_record_snapshot_destroy(trans, BTRFS_I(dir));
ret = btrfs_unlink_subvol(trans, dir, dentry);
if (ret) {
err = ret;
btrfs_abort_transaction(trans, ret);
goto out_end_trans;
}
btrfs_record_root_in_trans(trans, dest);
memset(&dest->root_item.drop_progress, 0,
sizeof(dest->root_item.drop_progress));
dest->root_item.drop_level = 0;
btrfs_set_root_refs(&dest->root_item, 0);
if (!test_and_set_bit(BTRFS_ROOT_ORPHAN_ITEM_INSERTED, &dest->state)) {
ret = btrfs_insert_orphan_item(trans,
fs_info->tree_root,
dest->root_key.objectid);
if (ret) {
btrfs_abort_transaction(trans, ret);
err = ret;
goto out_end_trans;
}
}
ret = btrfs_uuid_tree_remove(trans, dest->root_item.uuid,
BTRFS_UUID_KEY_SUBVOL,
dest->root_key.objectid);
if (ret && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
err = ret;
goto out_end_trans;
}
if (!btrfs_is_empty_uuid(dest->root_item.received_uuid)) {
ret = btrfs_uuid_tree_remove(trans,
dest->root_item.received_uuid,
BTRFS_UUID_KEY_RECEIVED_SUBVOL,
dest->root_key.objectid);
if (ret && ret != -ENOENT) {
btrfs_abort_transaction(trans, ret);
err = ret;
goto out_end_trans;
}
}
out_end_trans:
trans->block_rsv = NULL;
trans->bytes_reserved = 0;
ret = btrfs_end_transaction(trans);
if (ret && !err)
err = ret;
inode->i_flags |= S_DEAD;
out_release:
btrfs_subvolume_release_metadata(fs_info, &block_rsv);
out_up_write:
up_write(&fs_info->subvol_sem);
if (err) {
spin_lock(&dest->root_item_lock);
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
} else {
d_invalidate(dentry);
btrfs_prune_dentries(dest);
ASSERT(dest->send_in_progress == 0);
/* the last ref */
if (dest->ino_cache_inode) {
iput(dest->ino_cache_inode);
dest->ino_cache_inode = NULL;
}
}
return err;
}
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = d_inode(dentry);
int err = 0;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_trans_handle *trans;
u64 last_unlink_trans;
if (inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
if (btrfs_ino(BTRFS_I(inode)) == BTRFS_FIRST_FREE_OBJECTID)
return btrfs_delete_subvolume(dir, dentry);
trans = __unlink_start_trans(dir);
if (IS_ERR(trans))
return PTR_ERR(trans);
if (unlikely(btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
err = btrfs_unlink_subvol(trans, dir, dentry);
goto out;
}
err = btrfs_orphan_add(trans, BTRFS_I(inode));
if (err)
goto out;
last_unlink_trans = BTRFS_I(inode)->last_unlink_trans;
/* now the directory is empty */
err = btrfs_unlink_inode(trans, root, BTRFS_I(dir),
BTRFS_I(d_inode(dentry)), dentry->d_name.name,
dentry->d_name.len);
if (!err) {
btrfs_i_size_write(BTRFS_I(inode), 0);
/*
* Propagate the last_unlink_trans value of the deleted dir to
* its parent directory. This is to prevent an unrecoverable
* log tree in the case we do something like this:
* 1) create dir foo
* 2) create snapshot under dir foo
* 3) delete the snapshot
* 4) rmdir foo
* 5) mkdir foo
* 6) fsync foo or some file inside foo
*/
if (last_unlink_trans >= trans->transid)
BTRFS_I(dir)->last_unlink_trans = last_unlink_trans;
}
out:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(root->fs_info);
return err;
}
/*
* Return this if we need to call truncate_block for the last bit of the
* truncate.
*/
#define NEED_TRUNCATE_BLOCK 1
/*
* this can truncate away extent items, csum items and directory items.
* It starts at a high offset and removes keys until it can't find
* any higher than new_size
*
* csum items that cross the new i_size are truncated to the new size
* as well.
*
* min_type is the minimum key type to truncate down to. If set to 0, this
* will kill all the items on this inode, including the INODE_ITEM_KEY.
*/
int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode,
u64 new_size, u32 min_type)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
struct btrfs_key found_key;
u64 extent_start = 0;
u64 extent_num_bytes = 0;
u64 extent_offset = 0;
u64 item_end = 0;
u64 last_size = new_size;
u32 found_type = (u8)-1;
int found_extent;
int del_item;
int pending_del_nr = 0;
int pending_del_slot = 0;
int extent_type = -1;
int ret;
u64 ino = btrfs_ino(BTRFS_I(inode));
u64 bytes_deleted = 0;
bool be_nice = false;
bool should_throttle = false;
BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
/*
* for non-free space inodes and ref cows, we want to back off from
* time to time
*/
if (!btrfs_is_free_space_inode(BTRFS_I(inode)) &&
test_bit(BTRFS_ROOT_REF_COWS, &root->state))
be_nice = true;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->reada = READA_BACK;
/*
* We want to drop from the next block forward in case this new size is
* not block aligned since we will be keeping the last block of the
* extent just the way it is.
*/
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
root == fs_info->tree_root)
btrfs_drop_extent_cache(BTRFS_I(inode), ALIGN(new_size,
fs_info->sectorsize),
(u64)-1, 0);
/*
* This function is also used to drop the items in the log tree before
* we relog the inode, so if root != BTRFS_I(inode)->root, it means
* it is used to drop the logged items. So we shouldn't kill the delayed
* items.
*/
if (min_type == 0 && root == BTRFS_I(inode)->root)
btrfs_kill_delayed_inode_items(BTRFS_I(inode));
key.objectid = ino;
key.offset = (u64)-1;
key.type = (u8)-1;
search_again:
/*
* with a 16K leaf size and 128MB extents, you can actually queue
* up a huge file in a single leaf. Most of the time that
* bytes_deleted is > 0, it will be huge by the time we get here
*/
if (be_nice && bytes_deleted > SZ_32M &&
btrfs_should_end_transaction(trans)) {
ret = -EAGAIN;
goto out;
}
path->leave_spinning = 1;
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
/* there are no items in the tree for us to truncate, we're
* done
*/
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
while (1) {
fi = NULL;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
found_type = found_key.type;
if (found_key.objectid != ino)
break;
if (found_type < min_type)
break;
item_end = found_key.offset;
if (found_type == BTRFS_EXTENT_DATA_KEY) {
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
extent_type = btrfs_file_extent_type(leaf, fi);
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
item_end +=
btrfs_file_extent_num_bytes(leaf, fi);
trace_btrfs_truncate_show_fi_regular(
BTRFS_I(inode), leaf, fi,
found_key.offset);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
item_end += btrfs_file_extent_ram_bytes(leaf,
fi);
trace_btrfs_truncate_show_fi_inline(
BTRFS_I(inode), leaf, fi, path->slots[0],
found_key.offset);
}
item_end--;
}
if (found_type > min_type) {
del_item = 1;
} else {
if (item_end < new_size)
break;
if (found_key.offset >= new_size)
del_item = 1;
else
del_item = 0;
}
found_extent = 0;
/* FIXME, shrink the extent if the ref count is only 1 */
if (found_type != BTRFS_EXTENT_DATA_KEY)
goto delete;
if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
u64 num_dec;
extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
if (!del_item) {
u64 orig_num_bytes =
btrfs_file_extent_num_bytes(leaf, fi);
extent_num_bytes = ALIGN(new_size -
found_key.offset,
fs_info->sectorsize);
btrfs_set_file_extent_num_bytes(leaf, fi,
extent_num_bytes);
num_dec = (orig_num_bytes -
extent_num_bytes);
if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state) &&
extent_start != 0)
inode_sub_bytes(inode, num_dec);
btrfs_mark_buffer_dirty(leaf);
} else {
extent_num_bytes =
btrfs_file_extent_disk_num_bytes(leaf,
fi);
extent_offset = found_key.offset -
btrfs_file_extent_offset(leaf, fi);
/* FIXME blocksize != 4096 */
num_dec = btrfs_file_extent_num_bytes(leaf, fi);
if (extent_start != 0) {
found_extent = 1;
if (test_bit(BTRFS_ROOT_REF_COWS,
&root->state))
inode_sub_bytes(inode, num_dec);
}
}
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
/*
* we can't truncate inline items that have had
* special encodings
*/
if (!del_item &&
btrfs_file_extent_encryption(leaf, fi) == 0 &&
btrfs_file_extent_other_encoding(leaf, fi) == 0 &&
btrfs_file_extent_compression(leaf, fi) == 0) {
u32 size = (u32)(new_size - found_key.offset);
btrfs_set_file_extent_ram_bytes(leaf, fi, size);
size = btrfs_file_extent_calc_inline_size(size);
btrfs_truncate_item(path, size, 1);
} else if (!del_item) {
/*
* We have to bail so the last_size is set to
* just before this extent.
*/
ret = NEED_TRUNCATE_BLOCK;
break;
}
if (test_bit(BTRFS_ROOT_REF_COWS, &root->state))
inode_sub_bytes(inode, item_end + 1 - new_size);
}
delete:
if (del_item)
last_size = found_key.offset;
else
last_size = new_size;
if (del_item) {
if (!pending_del_nr) {
/* no pending yet, add ourselves */
pending_del_slot = path->slots[0];
pending_del_nr = 1;
} else if (pending_del_nr &&
path->slots[0] + 1 == pending_del_slot) {
/* hop on the pending chunk */
pending_del_nr++;
pending_del_slot = path->slots[0];
} else {
BUG();
}
} else {
break;
}
should_throttle = false;
if (found_extent &&
(test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
root == fs_info->tree_root)) {
struct btrfs_ref ref = { 0 };
btrfs_set_path_blocking(path);
bytes_deleted += extent_num_bytes;
btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF,
extent_start, extent_num_bytes, 0);
ref.real_root = root->root_key.objectid;
btrfs_init_data_ref(&ref, btrfs_header_owner(leaf),
ino, extent_offset);
ret = btrfs_free_extent(trans, &ref);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
if (be_nice) {
if (btrfs_should_throttle_delayed_refs(trans))
should_throttle = true;
}
}
if (found_type == BTRFS_INODE_ITEM_KEY)
break;
if (path->slots[0] == 0 ||
path->slots[0] != pending_del_slot ||
should_throttle) {
if (pending_del_nr) {
ret = btrfs_del_items(trans, root, path,
pending_del_slot,
pending_del_nr);
if (ret) {
btrfs_abort_transaction(trans, ret);
break;
}
pending_del_nr = 0;
}
btrfs_release_path(path);
/*
* We can generate a lot of delayed refs, so we need to
* throttle every once and a while and make sure we're
* adding enough space to keep up with the work we are
* generating. Since we hold a transaction here we
* can't flush, and we don't want to FLUSH_LIMIT because
* we could have generated too many delayed refs to
* actually allocate, so just bail if we're short and
* let the normal reservation dance happen higher up.
*/
if (should_throttle) {
ret = btrfs_delayed_refs_rsv_refill(fs_info,
BTRFS_RESERVE_NO_FLUSH);
if (ret) {
ret = -EAGAIN;
break;
}
}
goto search_again;
} else {
path->slots[0]--;
}
}
out:
if (ret >= 0 && pending_del_nr) {
int err;
err = btrfs_del_items(trans, root, path, pending_del_slot,
pending_del_nr);
if (err) {
btrfs_abort_transaction(trans, err);
ret = err;
}
}
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) {
ASSERT(last_size >= new_size);
if (!ret && last_size > new_size)
last_size = new_size;
btrfs_ordered_update_i_size(inode, last_size, NULL);
}
btrfs_free_path(path);
return ret;
}
/*
* btrfs_truncate_block - read, zero a chunk and write a block
* @inode - inode that we're zeroing
* @from - the offset to start zeroing
* @len - the length to zero, 0 to zero the entire range respective to the
* offset
* @front - zero up to the offset instead of from the offset on
*
* This will find the block for the "from" offset and cow the block and zero the
* part we want to zero. This is used with truncate and hole punching.
*/
int btrfs_truncate_block(struct inode *inode, loff_t from, loff_t len,
int front)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct address_space *mapping = inode->i_mapping;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
char *kaddr;
u32 blocksize = fs_info->sectorsize;
pgoff_t index = from >> PAGE_SHIFT;
unsigned offset = from & (blocksize - 1);
struct page *page;
gfp_t mask = btrfs_alloc_write_mask(mapping);
int ret = 0;
u64 block_start;
u64 block_end;
if (IS_ALIGNED(offset, blocksize) &&
(!len || IS_ALIGNED(len, blocksize)))
goto out;
block_start = round_down(from, blocksize);
block_end = block_start + blocksize - 1;
ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
block_start, blocksize);
if (ret)
goto out;
again:
page = find_or_create_page(mapping, index, mask);
if (!page) {
btrfs_delalloc_release_space(inode, data_reserved,
block_start, blocksize, true);
btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
ret = -ENOMEM;
goto out;
}
if (!PageUptodate(page)) {
ret = btrfs_readpage(NULL, page);
lock_page(page);
if (page->mapping != mapping) {
unlock_page(page);
put_page(page);
goto again;
}
if (!PageUptodate(page)) {
ret = -EIO;
goto out_unlock;
}
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, block_start, block_end, &cached_state);
set_page_extent_mapped(page);
ordered = btrfs_lookup_ordered_extent(inode, block_start);
if (ordered) {
unlock_extent_cached(io_tree, block_start, block_end,
&cached_state);
unlock_page(page);
put_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
clear_extent_bit(&BTRFS_I(inode)->io_tree, block_start, block_end,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, &cached_state);
ret = btrfs_set_extent_delalloc(inode, block_start, block_end, 0,
&cached_state);
if (ret) {
unlock_extent_cached(io_tree, block_start, block_end,
&cached_state);
goto out_unlock;
}
if (offset != blocksize) {
if (!len)
len = blocksize - offset;
kaddr = kmap(page);
if (front)
memset(kaddr + (block_start - page_offset(page)),
0, offset);
else
memset(kaddr + (block_start - page_offset(page)) + offset,
0, len);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
unlock_extent_cached(io_tree, block_start, block_end, &cached_state);
out_unlock:
if (ret)
btrfs_delalloc_release_space(inode, data_reserved, block_start,
blocksize, true);
btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize);
unlock_page(page);
put_page(page);
out:
extent_changeset_free(data_reserved);
return ret;
}
static int maybe_insert_hole(struct btrfs_root *root, struct inode *inode,
u64 offset, u64 len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_trans_handle *trans;
int ret;
/*
* Still need to make sure the inode looks like it's been updated so
* that any holes get logged if we fsync.
*/
if (btrfs_fs_incompat(fs_info, NO_HOLES)) {
BTRFS_I(inode)->last_trans = fs_info->generation;
BTRFS_I(inode)->last_sub_trans = root->log_transid;
BTRFS_I(inode)->last_log_commit = root->last_log_commit;
return 0;
}
/*
* 1 - for the one we're dropping
* 1 - for the one we're adding
* 1 - for updating the inode.
*/
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_drop_extents(trans, root, inode, offset, offset + len, 1);
if (ret) {
btrfs_abort_transaction(trans, ret);
btrfs_end_transaction(trans);
return ret;
}
ret = btrfs_insert_file_extent(trans, root, btrfs_ino(BTRFS_I(inode)),
offset, 0, 0, len, 0, len, 0, 0, 0);
if (ret)
btrfs_abort_transaction(trans, ret);
else
btrfs_update_inode(trans, root, inode);
btrfs_end_transaction(trans);
return ret;
}
/*
* This function puts in dummy file extents for the area we're creating a hole
* for. So if we are truncating this file to a larger size we need to insert
* these file extents so that btrfs_get_extent will return a EXTENT_MAP_HOLE for
* the range between oldsize and size
*/
int btrfs_cont_expand(struct inode *inode, loff_t oldsize, loff_t size)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map *em = NULL;
struct extent_state *cached_state = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
u64 hole_start = ALIGN(oldsize, fs_info->sectorsize);
u64 block_end = ALIGN(size, fs_info->sectorsize);
u64 last_byte;
u64 cur_offset;
u64 hole_size;
int err = 0;
/*
* If our size started in the middle of a block we need to zero out the
* rest of the block before we expand the i_size, otherwise we could
* expose stale data.
*/
err = btrfs_truncate_block(inode, oldsize, 0, 0);
if (err)
return err;
if (size <= hole_start)
return 0;
btrfs_lock_and_flush_ordered_range(io_tree, BTRFS_I(inode), hole_start,
block_end - 1, &cached_state);
cur_offset = hole_start;
while (1) {
em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
block_end - cur_offset);
if (IS_ERR(em)) {
err = PTR_ERR(em);
em = NULL;
break;
}
last_byte = min(extent_map_end(em), block_end);
last_byte = ALIGN(last_byte, fs_info->sectorsize);
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
struct extent_map *hole_em;
hole_size = last_byte - cur_offset;
err = maybe_insert_hole(root, inode, cur_offset,
hole_size);
if (err)
break;
btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
cur_offset + hole_size - 1, 0);
hole_em = alloc_extent_map();
if (!hole_em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
goto next;
}
hole_em->start = cur_offset;
hole_em->len = hole_size;
hole_em->orig_start = cur_offset;
hole_em->block_start = EXTENT_MAP_HOLE;
hole_em->block_len = 0;
hole_em->orig_block_len = 0;
hole_em->ram_bytes = hole_size;
hole_em->compress_type = BTRFS_COMPRESS_NONE;
hole_em->generation = fs_info->generation;
while (1) {
write_lock(&em_tree->lock);
err = add_extent_mapping(em_tree, hole_em, 1);
write_unlock(&em_tree->lock);
if (err != -EEXIST)
break;
btrfs_drop_extent_cache(BTRFS_I(inode),
cur_offset,
cur_offset +
hole_size - 1, 0);
}
free_extent_map(hole_em);
}
next:
free_extent_map(em);
em = NULL;
cur_offset = last_byte;
if (cur_offset >= block_end)
break;
}
free_extent_map(em);
unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state);
return err;
}
static int btrfs_setsize(struct inode *inode, struct iattr *attr)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
loff_t oldsize = i_size_read(inode);
loff_t newsize = attr->ia_size;
int mask = attr->ia_valid;
int ret;
/*
* The regular truncate() case without ATTR_CTIME and ATTR_MTIME is a
* special case where we need to update the times despite not having
* these flags set. For all other operations the VFS set these flags
* explicitly if it wants a timestamp update.
*/
if (newsize != oldsize) {
inode_inc_iversion(inode);
if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
inode->i_ctime = inode->i_mtime =
current_time(inode);
}
if (newsize > oldsize) {
/*
* Don't do an expanding truncate while snapshotting is ongoing.
* This is to ensure the snapshot captures a fully consistent
* state of this file - if the snapshot captures this expanding
* truncation, it must capture all writes that happened before
* this truncation.
*/
btrfs_wait_for_snapshot_creation(root);
ret = btrfs_cont_expand(inode, oldsize, newsize);
if (ret) {
btrfs_end_write_no_snapshotting(root);
return ret;
}
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
btrfs_end_write_no_snapshotting(root);
return PTR_ERR(trans);
}
i_size_write(inode, newsize);
btrfs_ordered_update_i_size(inode, i_size_read(inode), NULL);
pagecache_isize_extended(inode, oldsize, newsize);
ret = btrfs_update_inode(trans, root, inode);
btrfs_end_write_no_snapshotting(root);
btrfs_end_transaction(trans);
} else {
/*
* We're truncating a file that used to have good data down to
* zero. Make sure it gets into the ordered flush list so that
* any new writes get down to disk quickly.
*/
if (newsize == 0)
set_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
&BTRFS_I(inode)->runtime_flags);
truncate_setsize(inode, newsize);
/* Disable nonlocked read DIO to avoid the endless truncate */
btrfs_inode_block_unlocked_dio(BTRFS_I(inode));
inode_dio_wait(inode);
btrfs_inode_resume_unlocked_dio(BTRFS_I(inode));
ret = btrfs_truncate(inode, newsize == oldsize);
if (ret && inode->i_nlink) {
int err;
/*
* Truncate failed, so fix up the in-memory size. We
* adjusted disk_i_size down as we removed extents, so
* wait for disk_i_size to be stable and then update the
* in-memory size to match.
*/
err = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (err)
return err;
i_size_write(inode, BTRFS_I(inode)->disk_i_size);
}
}
return ret;
}
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = d_inode(dentry);
struct btrfs_root *root = BTRFS_I(inode)->root;
int err;
if (btrfs_root_readonly(root))
return -EROFS;
err = setattr_prepare(dentry, attr);
if (err)
return err;
if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
err = btrfs_setsize(inode, attr);
if (err)
return err;
}
if (attr->ia_valid) {
setattr_copy(inode, attr);
inode_inc_iversion(inode);
err = btrfs_dirty_inode(inode);
if (!err && attr->ia_valid & ATTR_MODE)
err = posix_acl_chmod(inode, inode->i_mode);
}
return err;
}
/*
* While truncating the inode pages during eviction, we get the VFS calling
* btrfs_invalidatepage() against each page of the inode. This is slow because
* the calls to btrfs_invalidatepage() result in a huge amount of calls to
* lock_extent_bits() and clear_extent_bit(), which keep merging and splitting
* extent_state structures over and over, wasting lots of time.
*
* Therefore if the inode is being evicted, let btrfs_invalidatepage() skip all
* those expensive operations on a per page basis and do only the ordered io
* finishing, while we release here the extent_map and extent_state structures,
* without the excessive merging and splitting.
*/
static void evict_inode_truncate_pages(struct inode *inode)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map_tree *map_tree = &BTRFS_I(inode)->extent_tree;
struct rb_node *node;
ASSERT(inode->i_state & I_FREEING);
truncate_inode_pages_final(&inode->i_data);
write_lock(&map_tree->lock);
while (!RB_EMPTY_ROOT(&map_tree->map.rb_root)) {
struct extent_map *em;
node = rb_first_cached(&map_tree->map);
em = rb_entry(node, struct extent_map, rb_node);
clear_bit(EXTENT_FLAG_PINNED, &em->flags);
clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
remove_extent_mapping(map_tree, em);
free_extent_map(em);
if (need_resched()) {
write_unlock(&map_tree->lock);
cond_resched();
write_lock(&map_tree->lock);
}
}
write_unlock(&map_tree->lock);
/*
* Keep looping until we have no more ranges in the io tree.
* We can have ongoing bios started by readpages (called from readahead)
* that have their endio callback (extent_io.c:end_bio_extent_readpage)
* still in progress (unlocked the pages in the bio but did not yet
* unlocked the ranges in the io tree). Therefore this means some
* ranges can still be locked and eviction started because before
* submitting those bios, which are executed by a separate task (work
* queue kthread), inode references (inode->i_count) were not taken
* (which would be dropped in the end io callback of each bio).
* Therefore here we effectively end up waiting for those bios and
* anyone else holding locked ranges without having bumped the inode's
* reference count - if we don't do it, when they access the inode's
* io_tree to unlock a range it may be too late, leading to an
* use-after-free issue.
*/
spin_lock(&io_tree->lock);
while (!RB_EMPTY_ROOT(&io_tree->state)) {
struct extent_state *state;
struct extent_state *cached_state = NULL;
u64 start;
u64 end;
unsigned state_flags;
node = rb_first(&io_tree->state);
state = rb_entry(node, struct extent_state, rb_node);
start = state->start;
end = state->end;
state_flags = state->state;
spin_unlock(&io_tree->lock);
lock_extent_bits(io_tree, start, end, &cached_state);
/*
* If still has DELALLOC flag, the extent didn't reach disk,
* and its reserved space won't be freed by delayed_ref.
* So we need to free its reserved space here.
* (Refer to comment in btrfs_invalidatepage, case 2)
*
* Note, end is the bytenr of last byte, so we need + 1 here.
*/
if (state_flags & EXTENT_DELALLOC)
btrfs_qgroup_free_data(inode, NULL, start, end - start + 1);
clear_extent_bit(io_tree, start, end,
EXTENT_LOCKED | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
&cached_state);
cond_resched();
spin_lock(&io_tree->lock);
}
spin_unlock(&io_tree->lock);
}
static struct btrfs_trans_handle *evict_refill_and_join(struct btrfs_root *root,
struct btrfs_block_rsv *rsv)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv;
struct btrfs_trans_handle *trans;
u64 delayed_refs_extra = btrfs_calc_insert_metadata_size(fs_info, 1);
int ret;
/*
* Eviction should be taking place at some place safe because of our
* delayed iputs. However the normal flushing code will run delayed
* iputs, so we cannot use FLUSH_ALL otherwise we'll deadlock.
*
* We reserve the delayed_refs_extra here again because we can't use
* btrfs_start_transaction(root, 0) for the same deadlocky reason as
* above. We reserve our extra bit here because we generate a ton of
* delayed refs activity by truncating.
*
* If we cannot make our reservation we'll attempt to steal from the
* global reserve, because we really want to be able to free up space.
*/
ret = btrfs_block_rsv_refill(root, rsv, rsv->size + delayed_refs_extra,
BTRFS_RESERVE_FLUSH_EVICT);
if (ret) {
/*
* Try to steal from the global reserve if there is space for
* it.
*/
if (btrfs_check_space_for_delayed_refs(fs_info) ||
btrfs_block_rsv_migrate(global_rsv, rsv, rsv->size, 0)) {
btrfs_warn(fs_info,
"could not allocate space for delete; will truncate on mount");
return ERR_PTR(-ENOSPC);
}
delayed_refs_extra = 0;
}
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return trans;
if (delayed_refs_extra) {
trans->block_rsv = &fs_info->trans_block_rsv;
trans->bytes_reserved = delayed_refs_extra;
btrfs_block_rsv_migrate(rsv, trans->block_rsv,
delayed_refs_extra, 1);
}
return trans;
}
void btrfs_evict_inode(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv;
int ret;
trace_btrfs_inode_evict(inode);
if (!root) {
clear_inode(inode);
return;
}
evict_inode_truncate_pages(inode);
if (inode->i_nlink &&
((btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID) ||
btrfs_is_free_space_inode(BTRFS_I(inode))))
goto no_delete;
if (is_bad_inode(inode))
goto no_delete;
btrfs_free_io_failure_record(BTRFS_I(inode), 0, (u64)-1);
if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
goto no_delete;
if (inode->i_nlink > 0) {
BUG_ON(btrfs_root_refs(&root->root_item) != 0 &&
root->root_key.objectid != BTRFS_ROOT_TREE_OBJECTID);
goto no_delete;
}
ret = btrfs_commit_inode_delayed_inode(BTRFS_I(inode));
if (ret)
goto no_delete;
rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
goto no_delete;
rsv->size = btrfs_calc_metadata_size(fs_info, 1);
rsv->failfast = 1;
btrfs_i_size_write(BTRFS_I(inode), 0);
while (1) {
trans = evict_refill_and_join(root, rsv);
if (IS_ERR(trans))
goto free_rsv;
trans->block_rsv = rsv;
ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
trans->block_rsv = &fs_info->trans_block_rsv;
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
if (ret && ret != -ENOSPC && ret != -EAGAIN)
goto free_rsv;
else if (!ret)
break;
}
/*
* Errors here aren't a big deal, it just means we leave orphan items in
* the tree. They will be cleaned up on the next mount. If the inode
* number gets reused, cleanup deletes the orphan item without doing
* anything, and unlink reuses the existing orphan item.
*
* If it turns out that we are dropping too many of these, we might want
* to add a mechanism for retrying these after a commit.
*/
trans = evict_refill_and_join(root, rsv);
if (!IS_ERR(trans)) {
trans->block_rsv = rsv;
btrfs_orphan_del(trans, BTRFS_I(inode));
trans->block_rsv = &fs_info->trans_block_rsv;
btrfs_end_transaction(trans);
}
if (!(root == fs_info->tree_root ||
root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID))
btrfs_return_ino(root, btrfs_ino(BTRFS_I(inode)));
free_rsv:
btrfs_free_block_rsv(fs_info, rsv);
no_delete:
/*
* If we didn't successfully delete, the orphan item will still be in
* the tree and we'll retry on the next mount. Again, we might also want
* to retry these periodically in the future.
*/
btrfs_remove_delayed_node(BTRFS_I(inode));
clear_inode(inode);
}
/*
* Return the key found in the dir entry in the location pointer, fill @type
* with BTRFS_FT_*, and return 0.
*
* If no dir entries were found, returns -ENOENT.
* If found a corrupted location in dir entry, returns -EUCLEAN.
*/
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
struct btrfs_key *location, u8 *type)
{
const char *name = dentry->d_name.name;
int namelen = dentry->d_name.len;
struct btrfs_dir_item *di;
struct btrfs_path *path;
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
di = btrfs_lookup_dir_item(NULL, root, path, btrfs_ino(BTRFS_I(dir)),
name, namelen, 0);
if (IS_ERR_OR_NULL(di)) {
ret = di ? PTR_ERR(di) : -ENOENT;
goto out;
}
btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
if (location->type != BTRFS_INODE_ITEM_KEY &&
location->type != BTRFS_ROOT_ITEM_KEY) {
ret = -EUCLEAN;
btrfs_warn(root->fs_info,
"%s gets something invalid in DIR_ITEM (name %s, directory ino %llu, location(%llu %u %llu))",
__func__, name, btrfs_ino(BTRFS_I(dir)),
location->objectid, location->type, location->offset);
}
if (!ret)
*type = btrfs_dir_type(path->nodes[0], di);
out:
btrfs_free_path(path);
return ret;
}
/*
* when we hit a tree root in a directory, the btrfs part of the inode
* needs to be changed to reflect the root directory of the tree root. This
* is kind of like crossing a mount point.
*/
static int fixup_tree_root_location(struct btrfs_fs_info *fs_info,
struct inode *dir,
struct dentry *dentry,
struct btrfs_key *location,
struct btrfs_root **sub_root)
{
struct btrfs_path *path;
struct btrfs_root *new_root;
struct btrfs_root_ref *ref;
struct extent_buffer *leaf;
struct btrfs_key key;
int ret;
int err = 0;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
err = -ENOENT;
key.objectid = BTRFS_I(dir)->root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = location->objectid;
ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0);
if (ret) {
if (ret < 0)
err = ret;
goto out;
}
leaf = path->nodes[0];
ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
if (btrfs_root_ref_dirid(leaf, ref) != btrfs_ino(BTRFS_I(dir)) ||
btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
goto out;
ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
(unsigned long)(ref + 1),
dentry->d_name.len);
if (ret)
goto out;
btrfs_release_path(path);
new_root = btrfs_read_fs_root_no_name(fs_info, location);
if (IS_ERR(new_root)) {
err = PTR_ERR(new_root);
goto out;
}
*sub_root = new_root;
location->objectid = btrfs_root_dirid(&new_root->root_item);
location->type = BTRFS_INODE_ITEM_KEY;
location->offset = 0;
err = 0;
out:
btrfs_free_path(path);
return err;
}
static void inode_tree_add(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_inode *entry;
struct rb_node **p;
struct rb_node *parent;
struct rb_node *new = &BTRFS_I(inode)->rb_node;
u64 ino = btrfs_ino(BTRFS_I(inode));
if (inode_unhashed(inode))
return;
parent = NULL;
spin_lock(&root->inode_lock);
p = &root->inode_tree.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_inode, rb_node);
if (ino < btrfs_ino(entry))
p = &parent->rb_left;
else if (ino > btrfs_ino(entry))
p = &parent->rb_right;
else {
WARN_ON(!(entry->vfs_inode.i_state &
(I_WILL_FREE | I_FREEING)));
rb_replace_node(parent, new, &root->inode_tree);
RB_CLEAR_NODE(parent);
spin_unlock(&root->inode_lock);
return;
}
}
rb_link_node(new, parent, p);
rb_insert_color(new, &root->inode_tree);
spin_unlock(&root->inode_lock);
}
static void inode_tree_del(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int empty = 0;
spin_lock(&root->inode_lock);
if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
empty = RB_EMPTY_ROOT(&root->inode_tree);
}
spin_unlock(&root->inode_lock);
if (empty && btrfs_root_refs(&root->root_item) == 0) {
spin_lock(&root->inode_lock);
empty = RB_EMPTY_ROOT(&root->inode_tree);
spin_unlock(&root->inode_lock);
if (empty)
btrfs_add_dead_root(root);
}
}
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
struct btrfs_iget_args *args = p;
inode->i_ino = args->location->objectid;
memcpy(&BTRFS_I(inode)->location, args->location,
sizeof(*args->location));
BTRFS_I(inode)->root = args->root;
return 0;
}
static int btrfs_find_actor(struct inode *inode, void *opaque)
{
struct btrfs_iget_args *args = opaque;
return args->location->objectid == BTRFS_I(inode)->location.objectid &&
args->root == BTRFS_I(inode)->root;
}
static struct inode *btrfs_iget_locked(struct super_block *s,
struct btrfs_key *location,
struct btrfs_root *root)
{
struct inode *inode;
struct btrfs_iget_args args;
unsigned long hashval = btrfs_inode_hash(location->objectid, root);
args.location = location;
args.root = root;
inode = iget5_locked(s, hashval, btrfs_find_actor,
btrfs_init_locked_inode,
(void *)&args);
return inode;
}
/*
* Get an inode object given its location and corresponding root.
* Path can be preallocated to prevent recursing back to iget through
* allocator. NULL is also valid but may require an additional allocation
* later.
*/
struct inode *btrfs_iget_path(struct super_block *s, struct btrfs_key *location,
struct btrfs_root *root, struct btrfs_path *path)
{
struct inode *inode;
inode = btrfs_iget_locked(s, location, root);
if (!inode)
return ERR_PTR(-ENOMEM);
if (inode->i_state & I_NEW) {
int ret;
ret = btrfs_read_locked_inode(inode, path);
if (!ret) {
inode_tree_add(inode);
unlock_new_inode(inode);
} else {
iget_failed(inode);
/*
* ret > 0 can come from btrfs_search_slot called by
* btrfs_read_locked_inode, this means the inode item
* was not found.
*/
if (ret > 0)
ret = -ENOENT;
inode = ERR_PTR(ret);
}
}
return inode;
}
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
struct btrfs_root *root)
{
return btrfs_iget_path(s, location, root, NULL);
}
static struct inode *new_simple_dir(struct super_block *s,
struct btrfs_key *key,
struct btrfs_root *root)
{
struct inode *inode = new_inode(s);
if (!inode)
return ERR_PTR(-ENOMEM);
BTRFS_I(inode)->root = root;
memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
set_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags);
inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
/*
* We only need lookup, the rest is read-only and there's no inode
* associated with the dentry
*/
inode->i_op = &simple_dir_inode_operations;
inode->i_opflags &= ~IOP_XATTR;
inode->i_fop = &simple_dir_operations;
inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
inode->i_mtime = current_time(inode);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
return inode;
}
static inline u8 btrfs_inode_type(struct inode *inode)
{
/*
* Compile-time asserts that generic FT_* types still match
* BTRFS_FT_* types
*/
BUILD_BUG_ON(BTRFS_FT_UNKNOWN != FT_UNKNOWN);
BUILD_BUG_ON(BTRFS_FT_REG_FILE != FT_REG_FILE);
BUILD_BUG_ON(BTRFS_FT_DIR != FT_DIR);
BUILD_BUG_ON(BTRFS_FT_CHRDEV != FT_CHRDEV);
BUILD_BUG_ON(BTRFS_FT_BLKDEV != FT_BLKDEV);
BUILD_BUG_ON(BTRFS_FT_FIFO != FT_FIFO);
BUILD_BUG_ON(BTRFS_FT_SOCK != FT_SOCK);
BUILD_BUG_ON(BTRFS_FT_SYMLINK != FT_SYMLINK);
return fs_umode_to_ftype(inode->i_mode);
}
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *sub_root = root;
struct btrfs_key location;
u8 di_type = 0;
int index;
int ret = 0;
if (dentry->d_name.len > BTRFS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);
ret = btrfs_inode_by_name(dir, dentry, &location, &di_type);
if (ret < 0)
return ERR_PTR(ret);
if (location.type == BTRFS_INODE_ITEM_KEY) {
inode = btrfs_iget(dir->i_sb, &location, root);
if (IS_ERR(inode))
return inode;
/* Do extra check against inode mode with di_type */
if (btrfs_inode_type(inode) != di_type) {
btrfs_crit(fs_info,
"inode mode mismatch with dir: inode mode=0%o btrfs type=%u dir type=%u",
inode->i_mode, btrfs_inode_type(inode),
di_type);
iput(inode);
return ERR_PTR(-EUCLEAN);
}
return inode;
}
index = srcu_read_lock(&fs_info->subvol_srcu);
ret = fixup_tree_root_location(fs_info, dir, dentry,
&location, &sub_root);
if (ret < 0) {
if (ret != -ENOENT)
inode = ERR_PTR(ret);
else
inode = new_simple_dir(dir->i_sb, &location, sub_root);
} else {
inode = btrfs_iget(dir->i_sb, &location, sub_root);
}
srcu_read_unlock(&fs_info->subvol_srcu, index);
if (!IS_ERR(inode) && root != sub_root) {
down_read(&fs_info->cleanup_work_sem);
if (!sb_rdonly(inode->i_sb))
ret = btrfs_orphan_cleanup(sub_root);
up_read(&fs_info->cleanup_work_sem);
if (ret) {
iput(inode);
inode = ERR_PTR(ret);
}
}
return inode;
}
static int btrfs_dentry_delete(const struct dentry *dentry)
{
struct btrfs_root *root;
struct inode *inode = d_inode(dentry);
if (!inode && !IS_ROOT(dentry))
inode = d_inode(dentry->d_parent);
if (inode) {
root = BTRFS_I(inode)->root;
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
if (btrfs_ino(BTRFS_I(inode)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return 1;
}
return 0;
}
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct inode *inode = btrfs_lookup_dentry(dir, dentry);
if (inode == ERR_PTR(-ENOENT))
inode = NULL;
return d_splice_alias(inode, dentry);
}
/*
* All this infrastructure exists because dir_emit can fault, and we are holding
* the tree lock when doing readdir. For now just allocate a buffer and copy
* our information into that, and then dir_emit from the buffer. This is
* similar to what NFS does, only we don't keep the buffer around in pagecache
* because I'm afraid I'll mess that up. Long term we need to make filldir do
* copy_to_user_inatomic so we don't have to worry about page faulting under the
* tree lock.
*/
static int btrfs_opendir(struct inode *inode, struct file *file)
{
struct btrfs_file_private *private;
private = kzalloc(sizeof(struct btrfs_file_private), GFP_KERNEL);
if (!private)
return -ENOMEM;
private->filldir_buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!private->filldir_buf) {
kfree(private);
return -ENOMEM;
}
file->private_data = private;
return 0;
}
struct dir_entry {
u64 ino;
u64 offset;
unsigned type;
int name_len;
};
static int btrfs_filldir(void *addr, int entries, struct dir_context *ctx)
{
while (entries--) {
struct dir_entry *entry = addr;
char *name = (char *)(entry + 1);
ctx->pos = get_unaligned(&entry->offset);
if (!dir_emit(ctx, name, get_unaligned(&entry->name_len),
get_unaligned(&entry->ino),
get_unaligned(&entry->type)))
return 1;
addr += sizeof(struct dir_entry) +
get_unaligned(&entry->name_len);
ctx->pos++;
}
return 0;
}
static int btrfs_real_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_file_private *private = file->private_data;
struct btrfs_dir_item *di;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_path *path;
void *addr;
struct list_head ins_list;
struct list_head del_list;
int ret;
struct extent_buffer *leaf;
int slot;
char *name_ptr;
int name_len;
int entries = 0;
int total_len = 0;
bool put = false;
struct btrfs_key location;
if (!dir_emit_dots(file, ctx))
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
addr = private->filldir_buf;
path->reada = READA_FORWARD;
INIT_LIST_HEAD(&ins_list);
INIT_LIST_HEAD(&del_list);
put = btrfs_readdir_get_delayed_items(inode, &ins_list, &del_list);
again:
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = ctx->pos;
key.objectid = btrfs_ino(BTRFS_I(inode));
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto err;
while (1) {
struct dir_entry *entry;
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto err;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != key.objectid)
break;
if (found_key.type != BTRFS_DIR_INDEX_KEY)
break;
if (found_key.offset < ctx->pos)
goto next;
if (btrfs_should_delete_dir_index(&del_list, found_key.offset))
goto next;
di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
name_len = btrfs_dir_name_len(leaf, di);
if ((total_len + sizeof(struct dir_entry) + name_len) >=
PAGE_SIZE) {
btrfs_release_path(path);
ret = btrfs_filldir(private->filldir_buf, entries, ctx);
if (ret)
goto nopos;
addr = private->filldir_buf;
entries = 0;
total_len = 0;
goto again;
}
entry = addr;
put_unaligned(name_len, &entry->name_len);
name_ptr = (char *)(entry + 1);
read_extent_buffer(leaf, name_ptr, (unsigned long)(di + 1),
name_len);
put_unaligned(fs_ftype_to_dtype(btrfs_dir_type(leaf, di)),
&entry->type);
btrfs_dir_item_key_to_cpu(leaf, di, &location);
put_unaligned(location.objectid, &entry->ino);
put_unaligned(found_key.offset, &entry->offset);
entries++;
addr += sizeof(struct dir_entry) + name_len;
total_len += sizeof(struct dir_entry) + name_len;
next:
path->slots[0]++;
}
btrfs_release_path(path);
ret = btrfs_filldir(private->filldir_buf, entries, ctx);
if (ret)
goto nopos;
ret = btrfs_readdir_delayed_dir_index(ctx, &ins_list);
if (ret)
goto nopos;
/*
* Stop new entries from being returned after we return the last
* entry.
*
* New directory entries are assigned a strictly increasing
* offset. This means that new entries created during readdir
* are *guaranteed* to be seen in the future by that readdir.
* This has broken buggy programs which operate on names as
* they're returned by readdir. Until we re-use freed offsets
* we have this hack to stop new entries from being returned
* under the assumption that they'll never reach this huge
* offset.
*
* This is being careful not to overflow 32bit loff_t unless the
* last entry requires it because doing so has broken 32bit apps
* in the past.
*/
if (ctx->pos >= INT_MAX)
ctx->pos = LLONG_MAX;
else
ctx->pos = INT_MAX;
nopos:
ret = 0;
err:
if (put)
btrfs_readdir_put_delayed_items(inode, &ins_list, &del_list);
btrfs_free_path(path);
return ret;
}
/*
* This is somewhat expensive, updating the tree every time the
* inode changes. But, it is most likely to find the inode in cache.
* FIXME, needs more benchmarking...there are no reasons other than performance
* to keep or drop this code.
*/
static int btrfs_dirty_inode(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret;
if (test_bit(BTRFS_INODE_DUMMY, &BTRFS_I(inode)->runtime_flags))
return 0;
trans = btrfs_join_transaction(root);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
if (ret && ret == -ENOSPC) {
/* whoops, lets try again with the full transaction */
btrfs_end_transaction(trans);
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_update_inode(trans, root, inode);
}
btrfs_end_transaction(trans);
if (BTRFS_I(inode)->delayed_node)
btrfs_balance_delayed_items(fs_info);
return ret;
}
/*
* This is a copy of file_update_time. We need this so we can return error on
* ENOSPC for updating the inode in the case of file write and mmap writes.
*/
static int btrfs_update_time(struct inode *inode, struct timespec64 *now,
int flags)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
bool dirty = flags & ~S_VERSION;
if (btrfs_root_readonly(root))
return -EROFS;
if (flags & S_VERSION)
dirty |= inode_maybe_inc_iversion(inode, dirty);
if (flags & S_CTIME)
inode->i_ctime = *now;
if (flags & S_MTIME)
inode->i_mtime = *now;
if (flags & S_ATIME)
inode->i_atime = *now;
return dirty ? btrfs_dirty_inode(inode) : 0;
}
/*
* find the highest existing sequence number in a directory
* and then set the in-memory index_cnt variable to reflect
* free sequence numbers
*/
static int btrfs_set_inode_index_count(struct btrfs_inode *inode)
{
struct btrfs_root *root = inode->root;
struct btrfs_key key, found_key;
struct btrfs_path *path;
struct extent_buffer *leaf;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = (u64)-1;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/* FIXME: we should be able to handle this */
if (ret == 0)
goto out;
ret = 0;
/*
* MAGIC NUMBER EXPLANATION:
* since we search a directory based on f_pos we have to start at 2
* since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
* else has to start at 2
*/
if (path->slots[0] == 0) {
inode->index_cnt = 2;
goto out;
}
path->slots[0]--;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != btrfs_ino(inode) ||
found_key.type != BTRFS_DIR_INDEX_KEY) {
inode->index_cnt = 2;
goto out;
}
inode->index_cnt = found_key.offset + 1;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper to find a free sequence number in a given directory. This current
* code is very simple, later versions will do smarter things in the btree
*/
int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index)
{
int ret = 0;
if (dir->index_cnt == (u64)-1) {
ret = btrfs_inode_delayed_dir_index_count(dir);
if (ret) {
ret = btrfs_set_inode_index_count(dir);
if (ret)
return ret;
}
}
*index = dir->index_cnt;
dir->index_cnt++;
return ret;
}
static int btrfs_insert_inode_locked(struct inode *inode)
{
struct btrfs_iget_args args;
args.location = &BTRFS_I(inode)->location;
args.root = BTRFS_I(inode)->root;
return insert_inode_locked4(inode,
btrfs_inode_hash(inode->i_ino, BTRFS_I(inode)->root),
btrfs_find_actor, &args);
}
/*
* Inherit flags from the parent inode.
*
* Currently only the compression flags and the cow flags are inherited.
*/
static void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
{
unsigned int flags;
if (!dir)
return;
flags = BTRFS_I(dir)->flags;
if (flags & BTRFS_INODE_NOCOMPRESS) {
BTRFS_I(inode)->flags &= ~BTRFS_INODE_COMPRESS;
BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
} else if (flags & BTRFS_INODE_COMPRESS) {
BTRFS_I(inode)->flags &= ~BTRFS_INODE_NOCOMPRESS;
BTRFS_I(inode)->flags |= BTRFS_INODE_COMPRESS;
}
if (flags & BTRFS_INODE_NODATACOW) {
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
if (S_ISREG(inode->i_mode))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
}
btrfs_sync_inode_flags_to_i_flags(inode);
}
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir,
const char *name, int name_len,
u64 ref_objectid, u64 objectid,
umode_t mode, u64 *index)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct inode *inode;
struct btrfs_inode_item *inode_item;
struct btrfs_key *location;
struct btrfs_path *path;
struct btrfs_inode_ref *ref;
struct btrfs_key key[2];
u32 sizes[2];
int nitems = name ? 2 : 1;
unsigned long ptr;
unsigned int nofs_flag;
int ret;
path = btrfs_alloc_path();
if (!path)
return ERR_PTR(-ENOMEM);
nofs_flag = memalloc_nofs_save();
inode = new_inode(fs_info->sb);
memalloc_nofs_restore(nofs_flag);
if (!inode) {
btrfs_free_path(path);
return ERR_PTR(-ENOMEM);
}
/*
* O_TMPFILE, set link count to 0, so that after this point,
* we fill in an inode item with the correct link count.
*/
if (!name)
set_nlink(inode, 0);
/*
* we have to initialize this early, so we can reclaim the inode
* number if we fail afterwards in this function.
*/
inode->i_ino = objectid;
if (dir && name) {
trace_btrfs_inode_request(dir);
ret = btrfs_set_inode_index(BTRFS_I(dir), index);
if (ret) {
btrfs_free_path(path);
iput(inode);
return ERR_PTR(ret);
}
} else if (dir) {
*index = 0;
}
/*
* index_cnt is ignored for everything but a dir,
* btrfs_set_inode_index_count has an explanation for the magic
* number
*/
BTRFS_I(inode)->index_cnt = 2;
BTRFS_I(inode)->dir_index = *index;
BTRFS_I(inode)->root = root;
BTRFS_I(inode)->generation = trans->transid;
inode->i_generation = BTRFS_I(inode)->generation;
/*
* We could have gotten an inode number from somebody who was fsynced
* and then removed in this same transaction, so let's just set full
* sync since it will be a full sync anyway and this will blow away the
* old info in the log.
*/
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
key[0].objectid = objectid;
key[0].type = BTRFS_INODE_ITEM_KEY;
key[0].offset = 0;
sizes[0] = sizeof(struct btrfs_inode_item);
if (name) {
/*
* Start new inodes with an inode_ref. This is slightly more
* efficient for small numbers of hard links since they will
* be packed into one item. Extended refs will kick in if we
* add more hard links than can fit in the ref item.
*/
key[1].objectid = objectid;
key[1].type = BTRFS_INODE_REF_KEY;
key[1].offset = ref_objectid;
sizes[1] = name_len + sizeof(*ref);
}
location = &BTRFS_I(inode)->location;
location->objectid = objectid;
location->offset = 0;
location->type = BTRFS_INODE_ITEM_KEY;
ret = btrfs_insert_inode_locked(inode);
if (ret < 0) {
iput(inode);
goto fail;
}
path->leave_spinning = 1;
ret = btrfs_insert_empty_items(trans, root, path, key, sizes, nitems);
if (ret != 0)
goto fail_unlock;
inode_init_owner(inode, dir, mode);
inode_set_bytes(inode, 0);
inode->i_mtime = current_time(inode);
inode->i_atime = inode->i_mtime;
inode->i_ctime = inode->i_mtime;
BTRFS_I(inode)->i_otime = inode->i_mtime;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
memzero_extent_buffer(path->nodes[0], (unsigned long)inode_item,
sizeof(*inode_item));
fill_inode_item(trans, path->nodes[0], inode_item, inode);
if (name) {
ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
struct btrfs_inode_ref);
btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
ptr = (unsigned long)(ref + 1);
write_extent_buffer(path->nodes[0], name, ptr, name_len);
}
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
btrfs_inherit_iflags(inode, dir);
if (S_ISREG(mode)) {
if (btrfs_test_opt(fs_info, NODATASUM))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
if (btrfs_test_opt(fs_info, NODATACOW))
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW |
BTRFS_INODE_NODATASUM;
}
inode_tree_add(inode);
trace_btrfs_inode_new(inode);
btrfs_set_inode_last_trans(trans, inode);
btrfs_update_root_times(trans, root);
ret = btrfs_inode_inherit_props(trans, inode, dir);
if (ret)
btrfs_err(fs_info,
"error inheriting props for ino %llu (root %llu): %d",
btrfs_ino(BTRFS_I(inode)), root->root_key.objectid, ret);
return inode;
fail_unlock:
discard_new_inode(inode);
fail:
if (dir && name)
BTRFS_I(dir)->index_cnt--;
btrfs_free_path(path);
return ERR_PTR(ret);
}
/*
* utility function to add 'inode' into 'parent_inode' with
* a give name and a given sequence number.
* if 'add_backref' is true, also insert a backref from the
* inode to the parent directory.
*/
int btrfs_add_link(struct btrfs_trans_handle *trans,
struct btrfs_inode *parent_inode, struct btrfs_inode *inode,
const char *name, int name_len, int add_backref, u64 index)
{
int ret = 0;
struct btrfs_key key;
struct btrfs_root *root = parent_inode->root;
u64 ino = btrfs_ino(inode);
u64 parent_ino = btrfs_ino(parent_inode);
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
memcpy(&key, &inode->root->root_key, sizeof(key));
} else {
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
}
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_add_root_ref(trans, key.objectid,
root->root_key.objectid, parent_ino,
index, name, name_len);
} else if (add_backref) {
ret = btrfs_insert_inode_ref(trans, root, name, name_len, ino,
parent_ino, index);
}
/* Nothing to clean up yet */
if (ret)
return ret;
ret = btrfs_insert_dir_item(trans, name, name_len, parent_inode, &key,
btrfs_inode_type(&inode->vfs_inode), index);
if (ret == -EEXIST || ret == -EOVERFLOW)
goto fail_dir_item;
else if (ret) {
btrfs_abort_transaction(trans, ret);
return ret;
}
btrfs_i_size_write(parent_inode, parent_inode->vfs_inode.i_size +
name_len * 2);
inode_inc_iversion(&parent_inode->vfs_inode);
/*
* If we are replaying a log tree, we do not want to update the mtime
* and ctime of the parent directory with the current time, since the
* log replay procedure is responsible for setting them to their correct
* values (the ones it had when the fsync was done).
*/
if (!test_bit(BTRFS_FS_LOG_RECOVERING, &root->fs_info->flags)) {
struct timespec64 now = current_time(&parent_inode->vfs_inode);
parent_inode->vfs_inode.i_mtime = now;
parent_inode->vfs_inode.i_ctime = now;
}
ret = btrfs_update_inode(trans, root, &parent_inode->vfs_inode);
if (ret)
btrfs_abort_transaction(trans, ret);
return ret;
fail_dir_item:
if (unlikely(ino == BTRFS_FIRST_FREE_OBJECTID)) {
u64 local_index;
int err;
err = btrfs_del_root_ref(trans, key.objectid,
root->root_key.objectid, parent_ino,
&local_index, name, name_len);
if (err)
btrfs_abort_transaction(trans, err);
} else if (add_backref) {
u64 local_index;
int err;
err = btrfs_del_inode_ref(trans, root, name, name_len,
ino, parent_ino, &local_index);
if (err)
btrfs_abort_transaction(trans, err);
}
/* Return the original error code */
return ret;
}
static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct dentry *dentry,
struct btrfs_inode *inode, int backref, u64 index)
{
int err = btrfs_add_link(trans, dir, inode,
dentry->d_name.name, dentry->d_name.len,
backref, index);
if (err > 0)
err = -EEXIST;
return err;
}
static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode, rdev);
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock;
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
0, index);
if (err)
goto out_unlock;
btrfs_update_inode(trans, root, inode);
d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
return err;
}
static int btrfs_create(struct inode *dir, struct dentry *dentry,
umode_t mode, bool excl)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
int err;
u64 objectid;
u64 index = 0;
/*
* 2 for inode item and ref
* 2 for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_unlock;
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
0, index);
if (err)
goto out_unlock;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct btrfs_trans_handle *trans = NULL;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = d_inode(old_dentry);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
u64 index;
int err;
int drop_inode = 0;
/* do not allow sys_link's with other subvols of the same device */
if (root->root_key.objectid != BTRFS_I(inode)->root->root_key.objectid)
return -EXDEV;
if (inode->i_nlink >= BTRFS_LINK_MAX)
return -EMLINK;
err = btrfs_set_inode_index(BTRFS_I(dir), &index);
if (err)
goto fail;
/*
* 2 items for inode and inode ref
* 2 items for dir items
* 1 item for parent inode
* 1 item for orphan item deletion if O_TMPFILE
*/
trans = btrfs_start_transaction(root, inode->i_nlink ? 5 : 6);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
trans = NULL;
goto fail;
}
/* There are several dir indexes for this inode, clear the cache. */
BTRFS_I(inode)->dir_index = 0ULL;
inc_nlink(inode);
inode_inc_iversion(inode);
inode->i_ctime = current_time(inode);
ihold(inode);
set_bit(BTRFS_INODE_COPY_EVERYTHING, &BTRFS_I(inode)->runtime_flags);
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry, BTRFS_I(inode),
1, index);
if (err) {
drop_inode = 1;
} else {
struct dentry *parent = dentry->d_parent;
int ret;
err = btrfs_update_inode(trans, root, inode);
if (err)
goto fail;
if (inode->i_nlink == 1) {
/*
* If new hard link count is 1, it's a file created
* with open(2) O_TMPFILE flag.
*/
err = btrfs_orphan_del(trans, BTRFS_I(inode));
if (err)
goto fail;
}
d_instantiate(dentry, inode);
ret = btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent,
true, NULL);
if (ret == BTRFS_NEED_TRANS_COMMIT) {
err = btrfs_commit_transaction(trans);
trans = NULL;
}
}
fail:
if (trans)
btrfs_end_transaction(trans);
if (drop_inode) {
inode_dec_link_count(inode);
iput(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct inode *inode = NULL;
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
int err = 0;
u64 objectid = 0;
u64 index = 0;
/*
* 2 items for inode and ref
* 2 items for dir items
* 1 for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_fail;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(BTRFS_I(dir)), objectid,
S_IFDIR | mode, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_fail;
}
/* these must be set before we unlock the inode */
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_fail;
btrfs_i_size_write(BTRFS_I(inode), 0);
err = btrfs_update_inode(trans, root, inode);
if (err)
goto out_fail;
err = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
dentry->d_name.name,
dentry->d_name.len, 0, index);
if (err)
goto out_fail;
d_instantiate_new(dentry, inode);
out_fail:
btrfs_end_transaction(trans);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static noinline int uncompress_inline(struct btrfs_path *path,
struct page *page,
size_t pg_offset, u64 extent_offset,
struct btrfs_file_extent_item *item)
{
int ret;
struct extent_buffer *leaf = path->nodes[0];
char *tmp;
size_t max_size;
unsigned long inline_size;
unsigned long ptr;
int compress_type;
WARN_ON(pg_offset != 0);
compress_type = btrfs_file_extent_compression(leaf, item);
max_size = btrfs_file_extent_ram_bytes(leaf, item);
inline_size = btrfs_file_extent_inline_item_len(leaf,
btrfs_item_nr(path->slots[0]));
tmp = kmalloc(inline_size, GFP_NOFS);
if (!tmp)
return -ENOMEM;
ptr = btrfs_file_extent_inline_start(item);
read_extent_buffer(leaf, tmp, ptr, inline_size);
max_size = min_t(unsigned long, PAGE_SIZE, max_size);
ret = btrfs_decompress(compress_type, tmp, page,
extent_offset, inline_size, max_size);
/*
* decompression code contains a memset to fill in any space between the end
* of the uncompressed data and the end of max_size in case the decompressed
* data ends up shorter than ram_bytes. That doesn't cover the hole between
* the end of an inline extent and the beginning of the next block, so we
* cover that region here.
*/
if (max_size + pg_offset < PAGE_SIZE) {
char *map = kmap(page);
memset(map + pg_offset + max_size, 0, PAGE_SIZE - max_size - pg_offset);
kunmap(page);
}
kfree(tmp);
return ret;
}
/**
* btrfs_get_extent - Lookup the first extent overlapping a range in a file.
* @inode: file to search in
* @page: page to read extent data into if the extent is inline
* @pg_offset: offset into @page to copy to
* @start: file offset
* @len: length of range starting at @start
*
* This returns the first &struct extent_map which overlaps with the given
* range, reading it from the B-tree and caching it if necessary. Note that
* there may be more extents which overlap the given range after the returned
* extent_map.
*
* If @page is not NULL and the extent is inline, this also reads the extent
* data directly into the page and marks the extent up to date in the io_tree.
*
* Return: ERR_PTR on error, non-NULL extent_map on success.
*/
struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
struct page *page, size_t pg_offset,
u64 start, u64 len)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
int ret;
int err = 0;
u64 extent_start = 0;
u64 extent_end = 0;
u64 objectid = btrfs_ino(inode);
int extent_type = -1;
struct btrfs_path *path = NULL;
struct btrfs_root *root = inode->root;
struct btrfs_file_extent_item *item;
struct extent_buffer *leaf;
struct btrfs_key found_key;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &inode->extent_tree;
struct extent_io_tree *io_tree = &inode->io_tree;
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
read_unlock(&em_tree->lock);
if (em) {
if (em->start > start || em->start + em->len <= start)
free_extent_map(em);
else if (em->block_start == EXTENT_MAP_INLINE && page)
free_extent_map(em);
else
goto out;
}
em = alloc_extent_map();
if (!em) {
err = -ENOMEM;
goto out;
}
em->start = EXTENT_MAP_HOLE;
em->orig_start = EXTENT_MAP_HOLE;
em->len = (u64)-1;
em->block_len = (u64)-1;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out;
}
/* Chances are we'll be called again, so go ahead and do readahead */
path->reada = READA_FORWARD;
/*
* Unless we're going to uncompress the inline extent, no sleep would
* happen.
*/
path->leave_spinning = 1;
ret = btrfs_lookup_file_extent(NULL, root, path, objectid, start, 0);
if (ret < 0) {
err = ret;
goto out;
} else if (ret > 0) {
if (path->slots[0] == 0)
goto not_found;
path->slots[0]--;
}
leaf = path->nodes[0];
item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY) {
/*
* If we backup past the first extent we want to move forward
* and see if there is an extent in front of us, otherwise we'll
* say there is a hole for our whole search range which can
* cause problems.
*/
extent_end = start;
goto next;
}
extent_type = btrfs_file_extent_type(leaf, item);
extent_start = found_key.offset;
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
/* Only regular file could have regular/prealloc extent */
if (!S_ISREG(inode->vfs_inode.i_mode)) {
ret = -EUCLEAN;
btrfs_crit(fs_info,
"regular/prealloc extent found for non-regular inode %llu",
btrfs_ino(inode));
goto out;
}
extent_end = extent_start +
btrfs_file_extent_num_bytes(leaf, item);
trace_btrfs_get_extent_show_fi_regular(inode, leaf, item,
extent_start);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
size_t size;
size = btrfs_file_extent_ram_bytes(leaf, item);
extent_end = ALIGN(extent_start + size,
fs_info->sectorsize);
trace_btrfs_get_extent_show_fi_inline(inode, leaf, item,
path->slots[0],
extent_start);
}
next:
if (start >= extent_end) {
path->slots[0]++;
if (path->slots[0] >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0) {
err = ret;
goto out;
} else if (ret > 0) {
goto not_found;
}
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != objectid ||
found_key.type != BTRFS_EXTENT_DATA_KEY)
goto not_found;
if (start + len <= found_key.offset)
goto not_found;
if (start > found_key.offset)
goto next;
/* New extent overlaps with existing one */
em->start = start;
em->orig_start = start;
em->len = found_key.offset - start;
em->block_start = EXTENT_MAP_HOLE;
goto insert;
}
btrfs_extent_item_to_extent_map(inode, path, item, !page, em);
if (extent_type == BTRFS_FILE_EXTENT_REG ||
extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
goto insert;
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
unsigned long ptr;
char *map;
size_t size;
size_t extent_offset;
size_t copy_size;
if (!page)
goto out;
size = btrfs_file_extent_ram_bytes(leaf, item);
extent_offset = page_offset(page) + pg_offset - extent_start;
copy_size = min_t(u64, PAGE_SIZE - pg_offset,
size - extent_offset);
em->start = extent_start + extent_offset;
em->len = ALIGN(copy_size, fs_info->sectorsize);
em->orig_block_len = em->len;
em->orig_start = em->start;
ptr = btrfs_file_extent_inline_start(item) + extent_offset;
btrfs_set_path_blocking(path);
if (!PageUptodate(page)) {
if (btrfs_file_extent_compression(leaf, item) !=
BTRFS_COMPRESS_NONE) {
ret = uncompress_inline(path, page, pg_offset,
extent_offset, item);
if (ret) {
err = ret;
goto out;
}
} else {
map = kmap(page);
read_extent_buffer(leaf, map + pg_offset, ptr,
copy_size);
if (pg_offset + copy_size < PAGE_SIZE) {
memset(map + pg_offset + copy_size, 0,
PAGE_SIZE - pg_offset -
copy_size);
}
kunmap(page);
}
flush_dcache_page(page);
}
set_extent_uptodate(io_tree, em->start,
extent_map_end(em) - 1, NULL, GFP_NOFS);
goto insert;
}
not_found:
em->start = start;
em->orig_start = start;
em->len = len;
em->block_start = EXTENT_MAP_HOLE;
insert:
btrfs_release_path(path);
if (em->start > start || extent_map_end(em) <= start) {
btrfs_err(fs_info,
"bad extent! em: [%llu %llu] passed [%llu %llu]",
em->start, em->len, start, len);
err = -EIO;
goto out;
}
err = 0;
write_lock(&em_tree->lock);
err = btrfs_add_extent_mapping(fs_info, em_tree, &em, start, len);
write_unlock(&em_tree->lock);
out:
btrfs_free_path(path);
trace_btrfs_get_extent(root, inode, em);
if (err) {
free_extent_map(em);
return ERR_PTR(err);
}
BUG_ON(!em); /* Error is always set */
return em;
}
struct extent_map *btrfs_get_extent_fiemap(struct btrfs_inode *inode,
u64 start, u64 len)
{
struct extent_map *em;
struct extent_map *hole_em = NULL;
u64 delalloc_start = start;
u64 end;
u64 delalloc_len;
u64 delalloc_end;
int err = 0;
em = btrfs_get_extent(inode, NULL, 0, start, len);
if (IS_ERR(em))
return em;
/*
* If our em maps to:
* - a hole or
* - a pre-alloc extent,
* there might actually be delalloc bytes behind it.
*/
if (em->block_start != EXTENT_MAP_HOLE &&
!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
return em;
else
hole_em = em;
/* check to see if we've wrapped (len == -1 or similar) */
end = start + len;
if (end < start)
end = (u64)-1;
else
end -= 1;
em = NULL;
/* ok, we didn't find anything, lets look for delalloc */
delalloc_len = count_range_bits(&inode->io_tree, &delalloc_start,
end, len, EXTENT_DELALLOC, 1);
delalloc_end = delalloc_start + delalloc_len;
if (delalloc_end < delalloc_start)
delalloc_end = (u64)-1;
/*
* We didn't find anything useful, return the original results from
* get_extent()
*/
if (delalloc_start > end || delalloc_end <= start) {
em = hole_em;
hole_em = NULL;
goto out;
}
/*
* Adjust the delalloc_start to make sure it doesn't go backwards from
* the start they passed in
*/
delalloc_start = max(start, delalloc_start);
delalloc_len = delalloc_end - delalloc_start;
if (delalloc_len > 0) {
u64 hole_start;
u64 hole_len;
const u64 hole_end = extent_map_end(hole_em);
em = alloc_extent_map();
if (!em) {
err = -ENOMEM;
goto out;
}
ASSERT(hole_em);
/*
* When btrfs_get_extent can't find anything it returns one
* huge hole
*
* Make sure what it found really fits our range, and adjust to
* make sure it is based on the start from the caller
*/
if (hole_end <= start || hole_em->start > end) {
free_extent_map(hole_em);
hole_em = NULL;
} else {
hole_start = max(hole_em->start, start);
hole_len = hole_end - hole_start;
}
if (hole_em && delalloc_start > hole_start) {
/*
* Our hole starts before our delalloc, so we have to
* return just the parts of the hole that go until the
* delalloc starts
*/
em->len = min(hole_len, delalloc_start - hole_start);
em->start = hole_start;
em->orig_start = hole_start;
/*
* Don't adjust block start at all, it is fixed at
* EXTENT_MAP_HOLE
*/
em->block_start = hole_em->block_start;
em->block_len = hole_len;
if (test_bit(EXTENT_FLAG_PREALLOC, &hole_em->flags))
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
} else {
/*
* Hole is out of passed range or it starts after
* delalloc range
*/
em->start = delalloc_start;
em->len = delalloc_len;
em->orig_start = delalloc_start;
em->block_start = EXTENT_MAP_DELALLOC;
em->block_len = delalloc_len;
}
} else {
return hole_em;
}
out:
free_extent_map(hole_em);
if (err) {
free_extent_map(em);
return ERR_PTR(err);
}
return em;
}
static struct extent_map *btrfs_create_dio_extent(struct inode *inode,
const u64 start,
const u64 len,
const u64 orig_start,
const u64 block_start,
const u64 block_len,
const u64 orig_block_len,
const u64 ram_bytes,
const int type)
{
struct extent_map *em = NULL;
int ret;
if (type != BTRFS_ORDERED_NOCOW) {
em = create_io_em(inode, start, len, orig_start,
block_start, block_len, orig_block_len,
ram_bytes,
BTRFS_COMPRESS_NONE, /* compress_type */
type);
if (IS_ERR(em))
goto out;
}
ret = btrfs_add_ordered_extent_dio(inode, start, block_start,
len, block_len, type);
if (ret) {
if (em) {
free_extent_map(em);
btrfs_drop_extent_cache(BTRFS_I(inode), start,
start + len - 1, 0);
}
em = ERR_PTR(ret);
}
out:
return em;
}
static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
u64 start, u64 len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_map *em;
struct btrfs_key ins;
u64 alloc_hint;
int ret;
alloc_hint = get_extent_allocation_hint(inode, start, len);
ret = btrfs_reserve_extent(root, len, len, fs_info->sectorsize,
0, alloc_hint, &ins, 1, 1);
if (ret)
return ERR_PTR(ret);
em = btrfs_create_dio_extent(inode, start, ins.offset, start,
ins.objectid, ins.offset, ins.offset,
ins.offset, BTRFS_ORDERED_REGULAR);
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (IS_ERR(em))
btrfs_free_reserved_extent(fs_info, ins.objectid,
ins.offset, 1);
return em;
}
/*
* returns 1 when the nocow is safe, < 1 on error, 0 if the
* block must be cow'd
*/
noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
u64 *orig_start, u64 *orig_block_len,
u64 *ram_bytes)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_path *path;
int ret;
struct extent_buffer *leaf;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_file_extent_item *fi;
struct btrfs_key key;
u64 disk_bytenr;
u64 backref_offset;
u64 extent_end;
u64 num_bytes;
int slot;
int found_type;
bool nocow = (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_lookup_file_extent(NULL, root, path,
btrfs_ino(BTRFS_I(inode)), offset, 0);
if (ret < 0)
goto out;
slot = path->slots[0];
if (ret == 1) {
if (slot == 0) {
/* can't find the item, must cow */
ret = 0;
goto out;
}
slot--;
}
ret = 0;
leaf = path->nodes[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != btrfs_ino(BTRFS_I(inode)) ||
key.type != BTRFS_EXTENT_DATA_KEY) {
/* not our file or wrong item type, must cow */
goto out;
}
if (key.offset > offset) {
/* Wrong offset, must cow */
goto out;
}
fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(leaf, fi);
if (found_type != BTRFS_FILE_EXTENT_REG &&
found_type != BTRFS_FILE_EXTENT_PREALLOC) {
/* not a regular extent, must cow */
goto out;
}
if (!nocow && found_type == BTRFS_FILE_EXTENT_REG)
goto out;
extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
if (extent_end <= offset)
goto out;
disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
if (disk_bytenr == 0)
goto out;
if (btrfs_file_extent_compression(leaf, fi) ||
btrfs_file_extent_encryption(leaf, fi) ||
btrfs_file_extent_other_encoding(leaf, fi))
goto out;
/*
* Do the same check as in btrfs_cross_ref_exist but without the
* unnecessary search.
*/
if (btrfs_file_extent_generation(leaf, fi) <=
btrfs_root_last_snapshot(&root->root_item))
goto out;
backref_offset = btrfs_file_extent_offset(leaf, fi);
if (orig_start) {
*orig_start = key.offset - backref_offset;
*orig_block_len = btrfs_file_extent_disk_num_bytes(leaf, fi);
*ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi);
}
if (btrfs_extent_readonly(fs_info, disk_bytenr))
goto out;
num_bytes = min(offset + *len, extent_end) - offset;
if (!nocow && found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 range_end;
range_end = round_up(offset + num_bytes,
root->fs_info->sectorsize) - 1;
ret = test_range_bit(io_tree, offset, range_end,
EXTENT_DELALLOC, 0, NULL);
if (ret) {
ret = -EAGAIN;
goto out;
}
}
btrfs_release_path(path);
/*
* look for other files referencing this extent, if we
* find any we must cow
*/
ret = btrfs_cross_ref_exist(root, btrfs_ino(BTRFS_I(inode)),
key.offset - backref_offset, disk_bytenr);
if (ret) {
ret = 0;
goto out;
}
/*
* adjust disk_bytenr and num_bytes to cover just the bytes
* in this extent we are about to write. If there
* are any csums in that range we have to cow in order
* to keep the csums correct
*/
disk_bytenr += backref_offset;
disk_bytenr += offset - key.offset;
if (csum_exist_in_range(fs_info, disk_bytenr, num_bytes))
goto out;
/*
* all of the above have passed, it is safe to overwrite this extent
* without cow
*/
*len = num_bytes;
ret = 1;
out:
btrfs_free_path(path);
return ret;
}
static int lock_extent_direct(struct inode *inode, u64 lockstart, u64 lockend,
struct extent_state **cached_state, int writing)
{
struct btrfs_ordered_extent *ordered;
int ret = 0;
while (1) {
lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state);
/*
* We're concerned with the entire range that we're going to be
* doing DIO to, so we need to make sure there's no ordered
* extents in this range.
*/
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), lockstart,
lockend - lockstart + 1);
/*
* We need to make sure there are no buffered pages in this
* range either, we could have raced between the invalidate in
* generic_file_direct_write and locking the extent. The
* invalidate needs to happen so that reads after a write do not
* get stale data.
*/
if (!ordered &&
(!writing || !filemap_range_has_page(inode->i_mapping,
lockstart, lockend)))
break;
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
cached_state);
if (ordered) {
/*
* If we are doing a DIO read and the ordered extent we
* found is for a buffered write, we can not wait for it
* to complete and retry, because if we do so we can
* deadlock with concurrent buffered writes on page
* locks. This happens only if our DIO read covers more
* than one extent map, if at this point has already
* created an ordered extent for a previous extent map
* and locked its range in the inode's io tree, and a
* concurrent write against that previous extent map's
* range and this range started (we unlock the ranges
* in the io tree only when the bios complete and
* buffered writes always lock pages before attempting
* to lock range in the io tree).
*/
if (writing ||
test_bit(BTRFS_ORDERED_DIRECT, &ordered->flags))
btrfs_start_ordered_extent(inode, ordered, 1);
else
ret = -ENOTBLK;
btrfs_put_ordered_extent(ordered);
} else {
/*
* We could trigger writeback for this range (and wait
* for it to complete) and then invalidate the pages for
* this range (through invalidate_inode_pages2_range()),
* but that can lead us to a deadlock with a concurrent
* call to readpages() (a buffered read or a defrag call
* triggered a readahead) on a page lock due to an
* ordered dio extent we created before but did not have
* yet a corresponding bio submitted (whence it can not
* complete), which makes readpages() wait for that
* ordered extent to complete while holding a lock on
* that page.
*/
ret = -ENOTBLK;
}
if (ret)
break;
cond_resched();
}
return ret;
}
/* The callers of this must take lock_extent() */
static struct extent_map *create_io_em(struct inode *inode, u64 start, u64 len,
u64 orig_start, u64 block_start,
u64 block_len, u64 orig_block_len,
u64 ram_bytes, int compress_type,
int type)
{
struct extent_map_tree *em_tree;
struct extent_map *em;
int ret;
ASSERT(type == BTRFS_ORDERED_PREALLOC ||
type == BTRFS_ORDERED_COMPRESSED ||
type == BTRFS_ORDERED_NOCOW ||
type == BTRFS_ORDERED_REGULAR);
em_tree = &BTRFS_I(inode)->extent_tree;
em = alloc_extent_map();
if (!em)
return ERR_PTR(-ENOMEM);
em->start = start;
em->orig_start = orig_start;
em->len = len;
em->block_len = block_len;
em->block_start = block_start;
em->orig_block_len = orig_block_len;
em->ram_bytes = ram_bytes;
em->generation = -1;
set_bit(EXTENT_FLAG_PINNED, &em->flags);
if (type == BTRFS_ORDERED_PREALLOC) {
set_bit(EXTENT_FLAG_FILLING, &em->flags);
} else if (type == BTRFS_ORDERED_COMPRESSED) {
set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
em->compress_type = compress_type;
}
do {
btrfs_drop_extent_cache(BTRFS_I(inode), em->start,
em->start + em->len - 1, 0);
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
/*
* The caller has taken lock_extent(), who could race with us
* to add em?
*/
} while (ret == -EEXIST);
if (ret) {
free_extent_map(em);
return ERR_PTR(ret);
}
/* em got 2 refs now, callers needs to do free_extent_map once. */
return em;
}
static int btrfs_get_blocks_direct_read(struct extent_map *em,
struct buffer_head *bh_result,
struct inode *inode,
u64 start, u64 len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
if (em->block_start == EXTENT_MAP_HOLE ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
return -ENOENT;
len = min(len, em->len - (start - em->start));
bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
inode->i_blkbits;
bh_result->b_size = len;
bh_result->b_bdev = fs_info->fs_devices->latest_bdev;
set_buffer_mapped(bh_result);
return 0;
}
static int btrfs_get_blocks_direct_write(struct extent_map **map,
struct buffer_head *bh_result,
struct inode *inode,
struct btrfs_dio_data *dio_data,
u64 start, u64 len)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em = *map;
int ret = 0;
/*
* We don't allocate a new extent in the following cases
*
* 1) The inode is marked as NODATACOW. In this case we'll just use the
* existing extent.
* 2) The extent is marked as PREALLOC. We're good to go here and can
* just use the extent.
*
*/
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
em->block_start != EXTENT_MAP_HOLE)) {
int type;
u64 block_start, orig_start, orig_block_len, ram_bytes;
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
type = BTRFS_ORDERED_PREALLOC;
else
type = BTRFS_ORDERED_NOCOW;
len = min(len, em->len - (start - em->start));
block_start = em->block_start + (start - em->start);
if (can_nocow_extent(inode, start, &len, &orig_start,
&orig_block_len, &ram_bytes) == 1 &&
btrfs_inc_nocow_writers(fs_info, block_start)) {
struct extent_map *em2;
em2 = btrfs_create_dio_extent(inode, start, len,
orig_start, block_start,
len, orig_block_len,
ram_bytes, type);
btrfs_dec_nocow_writers(fs_info, block_start);
if (type == BTRFS_ORDERED_PREALLOC) {
free_extent_map(em);
*map = em = em2;
}
if (em2 && IS_ERR(em2)) {
ret = PTR_ERR(em2);
goto out;
}
/*
* For inode marked NODATACOW or extent marked PREALLOC,
* use the existing or preallocated extent, so does not
* need to adjust btrfs_space_info's bytes_may_use.
*/
btrfs_free_reserved_data_space_noquota(inode, start,
len);
goto skip_cow;
}
}
/* this will cow the extent */
len = bh_result->b_size;
free_extent_map(em);
*map = em = btrfs_new_extent_direct(inode, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
len = min(len, em->len - (start - em->start));
skip_cow:
bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
inode->i_blkbits;
bh_result->b_size = len;
bh_result->b_bdev = fs_info->fs_devices->latest_bdev;
set_buffer_mapped(bh_result);
if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
set_buffer_new(bh_result);
/*
* Need to update the i_size under the extent lock so buffered
* readers will get the updated i_size when we unlock.
*/
if (!dio_data->overwrite && start + len > i_size_read(inode))
i_size_write(inode, start + len);
WARN_ON(dio_data->reserve < len);
dio_data->reserve -= len;
dio_data->unsubmitted_oe_range_end = start + len;
current->journal_info = dio_data;
out:
return ret;
}
static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map *em;
struct extent_state *cached_state = NULL;
struct btrfs_dio_data *dio_data = NULL;
u64 start = iblock << inode->i_blkbits;
u64 lockstart, lockend;
u64 len = bh_result->b_size;
int ret = 0;
if (!create)
len = min_t(u64, len, fs_info->sectorsize);
lockstart = start;
lockend = start + len - 1;
if (current->journal_info) {
/*
* Need to pull our outstanding extents and set journal_info to NULL so
* that anything that needs to check if there's a transaction doesn't get
* confused.
*/
dio_data = current->journal_info;
current->journal_info = NULL;
}
/*
* If this errors out it's because we couldn't invalidate pagecache for
* this range and we need to fallback to buffered.
*/
if (lock_extent_direct(inode, lockstart, lockend, &cached_state,
create)) {
ret = -ENOTBLK;
goto err;
}
em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto unlock_err;
}
/*
* Ok for INLINE and COMPRESSED extents we need to fallback on buffered
* io. INLINE is special, and we could probably kludge it in here, but
* it's still buffered so for safety lets just fall back to the generic
* buffered path.
*
* For COMPRESSED we _have_ to read the entire extent in so we can
* decompress it, so there will be buffering required no matter what we
* do, so go ahead and fallback to buffered.
*
* We return -ENOTBLK because that's what makes DIO go ahead and go back
* to buffered IO. Don't blame me, this is the price we pay for using
* the generic code.
*/
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
em->block_start == EXTENT_MAP_INLINE) {
free_extent_map(em);
ret = -ENOTBLK;
goto unlock_err;
}
if (create) {
ret = btrfs_get_blocks_direct_write(&em, bh_result, inode,
dio_data, start, len);
if (ret < 0)
goto unlock_err;
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
lockend, &cached_state);
} else {
ret = btrfs_get_blocks_direct_read(em, bh_result, inode,
start, len);
/* Can be negative only if we read from a hole */
if (ret < 0) {
ret = 0;
free_extent_map(em);
goto unlock_err;
}
/*
* We need to unlock only the end area that we aren't using.
* The rest is going to be unlocked by the endio routine.
*/
lockstart = start + bh_result->b_size;
if (lockstart < lockend) {
unlock_extent_cached(&BTRFS_I(inode)->io_tree,
lockstart, lockend, &cached_state);
} else {
free_extent_state(cached_state);
}
}
free_extent_map(em);
return 0;
unlock_err:
unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
&cached_state);
err:
if (dio_data)
current->journal_info = dio_data;
return ret;
}
static inline blk_status_t submit_dio_repair_bio(struct inode *inode,
struct bio *bio,
int mirror_num)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
blk_status_t ret;
BUG_ON(bio_op(bio) == REQ_OP_WRITE);
ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DIO_REPAIR);
if (ret)
return ret;
ret = btrfs_map_bio(fs_info, bio, mirror_num);
return ret;
}
static int btrfs_check_dio_repairable(struct inode *inode,
struct bio *failed_bio,
struct io_failure_record *failrec,
int failed_mirror)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
int num_copies;
num_copies = btrfs_num_copies(fs_info, failrec->logical, failrec->len);
if (num_copies == 1) {
/*
* we only have a single copy of the data, so don't bother with
* all the retry and error correction code that follows. no
* matter what the error is, it is very likely to persist.
*/
btrfs_debug(fs_info,
"Check DIO Repairable: cannot repair, num_copies=%d, next_mirror %d, failed_mirror %d",
num_copies, failrec->this_mirror, failed_mirror);
return 0;
}
failrec->failed_mirror = failed_mirror;
failrec->this_mirror++;
if (failrec->this_mirror == failed_mirror)
failrec->this_mirror++;
if (failrec->this_mirror > num_copies) {
btrfs_debug(fs_info,
"Check DIO Repairable: (fail) num_copies=%d, next_mirror %d, failed_mirror %d",
num_copies, failrec->this_mirror, failed_mirror);
return 0;
}
return 1;
}
static blk_status_t dio_read_error(struct inode *inode, struct bio *failed_bio,
struct page *page, unsigned int pgoff,
u64 start, u64 end, int failed_mirror,
bio_end_io_t *repair_endio, void *repair_arg)
{
struct io_failure_record *failrec;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
struct bio *bio;
int isector;
unsigned int read_mode = 0;
int segs;
int ret;
blk_status_t status;
struct bio_vec bvec;
BUG_ON(bio_op(failed_bio) == REQ_OP_WRITE);
ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
if (ret)
return errno_to_blk_status(ret);
ret = btrfs_check_dio_repairable(inode, failed_bio, failrec,
failed_mirror);
if (!ret) {
free_io_failure(failure_tree, io_tree, failrec);
return BLK_STS_IOERR;
}
segs = bio_segments(failed_bio);
bio_get_first_bvec(failed_bio, &bvec);
if (segs > 1 ||
(bvec.bv_len > btrfs_inode_sectorsize(inode)))
read_mode |= REQ_FAILFAST_DEV;
isector = start - btrfs_io_bio(failed_bio)->logical;
isector >>= inode->i_sb->s_blocksize_bits;
bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
pgoff, isector, repair_endio, repair_arg);
bio->bi_opf = REQ_OP_READ | read_mode;
btrfs_debug(BTRFS_I(inode)->root->fs_info,
"repair DIO read error: submitting new dio read[%#x] to this_mirror=%d, in_validation=%d",
read_mode, failrec->this_mirror, failrec->in_validation);
status = submit_dio_repair_bio(inode, bio, failrec->this_mirror);
if (status) {
free_io_failure(failure_tree, io_tree, failrec);
bio_put(bio);
}
return status;
}
struct btrfs_retry_complete {
struct completion done;
struct inode *inode;
u64 start;
int uptodate;
};
static void btrfs_retry_endio_nocsum(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct inode *inode = done->inode;
struct bio_vec *bvec;
struct extent_io_tree *io_tree, *failure_tree;
struct bvec_iter_all iter_all;
if (bio->bi_status)
goto end;
ASSERT(bio->bi_vcnt == 1);
io_tree = &BTRFS_I(inode)->io_tree;
failure_tree = &BTRFS_I(inode)->io_failure_tree;
ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(inode));
done->uptodate = 1;
ASSERT(!bio_flagged(bio, BIO_CLONED));
bio_for_each_segment_all(bvec, bio, iter_all)
clean_io_failure(BTRFS_I(inode)->root->fs_info, failure_tree,
io_tree, done->start, bvec->bv_page,
btrfs_ino(BTRFS_I(inode)), 0);
end:
complete(&done->done);
bio_put(bio);
}
static blk_status_t __btrfs_correct_data_nocsum(struct inode *inode,
struct btrfs_io_bio *io_bio)
{
struct btrfs_fs_info *fs_info;
struct bio_vec bvec;
struct bvec_iter iter;
struct btrfs_retry_complete done;
u64 start;
unsigned int pgoff;
u32 sectorsize;
int nr_sectors;
blk_status_t ret;
blk_status_t err = BLK_STS_OK;
fs_info = BTRFS_I(inode)->root->fs_info;
sectorsize = fs_info->sectorsize;
start = io_bio->logical;
done.inode = inode;
io_bio->bio.bi_iter = io_bio->iter;
bio_for_each_segment(bvec, &io_bio->bio, iter) {
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
pgoff = bvec.bv_offset;
next_block_or_try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
ret = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
pgoff, start, start + sectorsize - 1,
io_bio->mirror_num,
btrfs_retry_endio_nocsum, &done);
if (ret) {
err = ret;
goto next;
}
wait_for_completion_io(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto next_block_or_try_again;
}
next:
start += sectorsize;
nr_sectors--;
if (nr_sectors) {
pgoff += sectorsize;
ASSERT(pgoff < PAGE_SIZE);
goto next_block_or_try_again;
}
}
return err;
}
static void btrfs_retry_endio(struct bio *bio)
{
struct btrfs_retry_complete *done = bio->bi_private;
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
struct extent_io_tree *io_tree, *failure_tree;
struct inode *inode = done->inode;
struct bio_vec *bvec;
int uptodate;
int ret;
int i = 0;
struct bvec_iter_all iter_all;
if (bio->bi_status)
goto end;
uptodate = 1;
ASSERT(bio->bi_vcnt == 1);
ASSERT(bio_first_bvec_all(bio)->bv_len == btrfs_inode_sectorsize(done->inode));
io_tree = &BTRFS_I(inode)->io_tree;
failure_tree = &BTRFS_I(inode)->io_failure_tree;
ASSERT(!bio_flagged(bio, BIO_CLONED));
bio_for_each_segment_all(bvec, bio, iter_all) {
ret = __readpage_endio_check(inode, io_bio, i, bvec->bv_page,
bvec->bv_offset, done->start,
bvec->bv_len);
if (!ret)
clean_io_failure(BTRFS_I(inode)->root->fs_info,
failure_tree, io_tree, done->start,
bvec->bv_page,
btrfs_ino(BTRFS_I(inode)),
bvec->bv_offset);
else
uptodate = 0;
i++;
}
done->uptodate = uptodate;
end:
complete(&done->done);
bio_put(bio);
}
static blk_status_t __btrfs_subio_endio_read(struct inode *inode,
struct btrfs_io_bio *io_bio, blk_status_t err)
{
struct btrfs_fs_info *fs_info;
struct bio_vec bvec;
struct bvec_iter iter;
struct btrfs_retry_complete done;
u64 start;
u64 offset = 0;
u32 sectorsize;
int nr_sectors;
unsigned int pgoff;
int csum_pos;
bool uptodate = (err == 0);
int ret;
blk_status_t status;
fs_info = BTRFS_I(inode)->root->fs_info;
sectorsize = fs_info->sectorsize;
err = BLK_STS_OK;
start = io_bio->logical;
done.inode = inode;
io_bio->bio.bi_iter = io_bio->iter;
bio_for_each_segment(bvec, &io_bio->bio, iter) {
nr_sectors = BTRFS_BYTES_TO_BLKS(fs_info, bvec.bv_len);
pgoff = bvec.bv_offset;
next_block:
if (uptodate) {
csum_pos = BTRFS_BYTES_TO_BLKS(fs_info, offset);
ret = __readpage_endio_check(inode, io_bio, csum_pos,
bvec.bv_page, pgoff, start, sectorsize);
if (likely(!ret))
goto next;
}
try_again:
done.uptodate = 0;
done.start = start;
init_completion(&done.done);
status = dio_read_error(inode, &io_bio->bio, bvec.bv_page,
pgoff, start, start + sectorsize - 1,
io_bio->mirror_num, btrfs_retry_endio,
&done);
if (status) {
err = status;
goto next;
}
wait_for_completion_io(&done.done);
if (!done.uptodate) {
/* We might have another mirror, so try again */
goto try_again;
}
next:
offset += sectorsize;
start += sectorsize;
ASSERT(nr_sectors);
nr_sectors--;
if (nr_sectors) {
pgoff += sectorsize;
ASSERT(pgoff < PAGE_SIZE);
goto next_block;
}
}
return err;
}
static blk_status_t btrfs_subio_endio_read(struct inode *inode,
struct btrfs_io_bio *io_bio, blk_status_t err)
{
bool skip_csum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
if (skip_csum) {
if (unlikely(err))
return __btrfs_correct_data_nocsum(inode, io_bio);
else
return BLK_STS_OK;
} else {
return __btrfs_subio_endio_read(inode, io_bio, err);
}
}
static void btrfs_endio_direct_read(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
struct inode *inode = dip->inode;
struct bio *dio_bio;
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
blk_status_t err = bio->bi_status;
if (dip->flags & BTRFS_DIO_ORIG_BIO_SUBMITTED)
err = btrfs_subio_endio_read(inode, io_bio, err);
unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
dip->logical_offset + dip->bytes - 1);
dio_bio = dip->dio_bio;
kfree(dip);
dio_bio->bi_status = err;
dio_end_io(dio_bio);
btrfs_io_bio_free_csum(io_bio);
bio_put(bio);
}
static void __endio_write_update_ordered(struct inode *inode,
const u64 offset, const u64 bytes,
const bool uptodate)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_ordered_extent *ordered = NULL;
struct btrfs_workqueue *wq;
u64 ordered_offset = offset;
u64 ordered_bytes = bytes;
u64 last_offset;
if (btrfs_is_free_space_inode(BTRFS_I(inode)))
wq = fs_info->endio_freespace_worker;
else
wq = fs_info->endio_write_workers;
while (ordered_offset < offset + bytes) {
last_offset = ordered_offset;
if (btrfs_dec_test_first_ordered_pending(inode, &ordered,
&ordered_offset,
ordered_bytes,
uptodate)) {
btrfs_init_work(&ordered->work, finish_ordered_fn, NULL,
NULL);
btrfs_queue_work(wq, &ordered->work);
}
/*
* If btrfs_dec_test_ordered_pending does not find any ordered
* extent in the range, we can exit.
*/
if (ordered_offset == last_offset)
return;
/*
* Our bio might span multiple ordered extents. In this case
* we keep going until we have accounted the whole dio.
*/
if (ordered_offset < offset + bytes) {
ordered_bytes = offset + bytes - ordered_offset;
ordered = NULL;
}
}
}
static void btrfs_endio_direct_write(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
struct bio *dio_bio = dip->dio_bio;
__endio_write_update_ordered(dip->inode, dip->logical_offset,
dip->bytes, !bio->bi_status);
kfree(dip);
dio_bio->bi_status = bio->bi_status;
dio_end_io(dio_bio);
bio_put(bio);
}
static blk_status_t btrfs_submit_bio_start_direct_io(void *private_data,
struct bio *bio, u64 offset)
{
struct inode *inode = private_data;
blk_status_t ret;
ret = btrfs_csum_one_bio(inode, bio, offset, 1);
BUG_ON(ret); /* -ENOMEM */
return 0;
}
static void btrfs_end_dio_bio(struct bio *bio)
{
struct btrfs_dio_private *dip = bio->bi_private;
blk_status_t err = bio->bi_status;
if (err)
btrfs_warn(BTRFS_I(dip->inode)->root->fs_info,
"direct IO failed ino %llu rw %d,%u sector %#Lx len %u err no %d",
btrfs_ino(BTRFS_I(dip->inode)), bio_op(bio),
bio->bi_opf,
(unsigned long long)bio->bi_iter.bi_sector,
bio->bi_iter.bi_size, err);
if (dip->subio_endio)
err = dip->subio_endio(dip->inode, btrfs_io_bio(bio), err);
if (err) {
/*
* We want to perceive the errors flag being set before
* decrementing the reference count. We don't need a barrier
* since atomic operations with a return value are fully
* ordered as per atomic_t.txt
*/
dip->errors = 1;
}
/* if there are more bios still pending for this dio, just exit */
if (!atomic_dec_and_test(&dip->pending_bios))
goto out;
if (dip->errors) {
bio_io_error(dip->orig_bio);
} else {
dip->dio_bio->bi_status = BLK_STS_OK;
bio_endio(dip->orig_bio);
}
out:
bio_put(bio);
}
static inline blk_status_t btrfs_lookup_and_bind_dio_csum(struct inode *inode,
struct btrfs_dio_private *dip,
struct bio *bio,
u64 file_offset)
{
struct btrfs_io_bio *io_bio = btrfs_io_bio(bio);
struct btrfs_io_bio *orig_io_bio = btrfs_io_bio(dip->orig_bio);
blk_status_t ret;
/*
* We load all the csum data we need when we submit
* the first bio to reduce the csum tree search and
* contention.
*/
if (dip->logical_offset == file_offset) {
ret = btrfs_lookup_bio_sums(inode, dip->orig_bio, file_offset,
NULL);
if (ret)
return ret;
}
if (bio == dip->orig_bio)
return 0;
file_offset -= dip->logical_offset;
file_offset >>= inode->i_sb->s_blocksize_bits;
io_bio->csum = (u8 *)(((u32 *)orig_io_bio->csum) + file_offset);
return 0;
}
static inline blk_status_t btrfs_submit_dio_bio(struct bio *bio,
struct inode *inode, u64 file_offset, int async_submit)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_dio_private *dip = bio->bi_private;
bool write = bio_op(bio) == REQ_OP_WRITE;
blk_status_t ret;
/* Check btrfs_submit_bio_hook() for rules about async submit. */
if (async_submit)
async_submit = !atomic_read(&BTRFS_I(inode)->sync_writers);
if (!write) {
ret = btrfs_bio_wq_end_io(fs_info, bio, BTRFS_WQ_ENDIO_DATA);
if (ret)
goto err;
}
if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
goto map;
if (write && async_submit) {
ret = btrfs_wq_submit_bio(fs_info, bio, 0, 0,
file_offset, inode,
btrfs_submit_bio_start_direct_io);
goto err;
} else if (write) {
/*
* If we aren't doing async submit, calculate the csum of the
* bio now.
*/
ret = btrfs_csum_one_bio(inode, bio, file_offset, 1);
if (ret)
goto err;
} else {
ret = btrfs_lookup_and_bind_dio_csum(inode, dip, bio,
file_offset);
if (ret)
goto err;
}
map:
ret = btrfs_map_bio(fs_info, bio, 0);
err:
return ret;
}
static int btrfs_submit_direct_hook(struct btrfs_dio_private *dip)
{
struct inode *inode = dip->inode;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct bio *bio;
struct bio *orig_bio = dip->orig_bio;
u64 start_sector = orig_bio->bi_iter.bi_sector;
u64 file_offset = dip->logical_offset;
int async_submit = 0;
u64 submit_len;
int clone_offset = 0;
int clone_len;
int ret;
blk_status_t status;
struct btrfs_io_geometry geom;
submit_len = orig_bio->bi_iter.bi_size;
ret = btrfs_get_io_geometry(fs_info, btrfs_op(orig_bio),
start_sector << 9, submit_len, &geom);
if (ret)
return -EIO;
if (geom.len >= submit_len) {
bio = orig_bio;
dip->flags |= BTRFS_DIO_ORIG_BIO_SUBMITTED;
goto submit;
}
/* async crcs make it difficult to collect full stripe writes. */
if (btrfs_data_alloc_profile(fs_info) & BTRFS_BLOCK_GROUP_RAID56_MASK)
async_submit = 0;
else
async_submit = 1;
/* bio split */
ASSERT(geom.len <= INT_MAX);
atomic_inc(&dip->pending_bios);
do {
clone_len = min_t(int, submit_len, geom.len);
/*
* This will never fail as it's passing GPF_NOFS and
* the allocation is backed by btrfs_bioset.
*/
bio = btrfs_bio_clone_partial(orig_bio, clone_offset,
clone_len);
bio->bi_private = dip;
bio->bi_end_io = btrfs_end_dio_bio;
btrfs_io_bio(bio)->logical = file_offset;
ASSERT(submit_len >= clone_len);
submit_len -= clone_len;
if (submit_len == 0)
break;
/*
* Increase the count before we submit the bio so we know
* the end IO handler won't happen before we increase the
* count. Otherwise, the dip might get freed before we're
* done setting it up.
*/
atomic_inc(&dip->pending_bios);
status = btrfs_submit_dio_bio(bio, inode, file_offset,
async_submit);
if (status) {
bio_put(bio);
atomic_dec(&dip->pending_bios);
goto out_err;
}
clone_offset += clone_len;
start_sector += clone_len >> 9;
file_offset += clone_len;
ret = btrfs_get_io_geometry(fs_info, btrfs_op(orig_bio),
start_sector << 9, submit_len, &geom);
if (ret)
goto out_err;
} while (submit_len > 0);
submit:
status = btrfs_submit_dio_bio(bio, inode, file_offset, async_submit);
if (!status)
return 0;
bio_put(bio);
out_err:
dip->errors = 1;
/*
* Before atomic variable goto zero, we must make sure dip->errors is
* perceived to be set. This ordering is ensured by the fact that an
* atomic operations with a return value are fully ordered as per
* atomic_t.txt
*/
if (atomic_dec_and_test(&dip->pending_bios))
bio_io_error(dip->orig_bio);
/* bio_end_io() will handle error, so we needn't return it */
return 0;
}
static void btrfs_submit_direct(struct bio *dio_bio, struct inode *inode,
loff_t file_offset)
{
struct btrfs_dio_private *dip = NULL;
struct bio *bio = NULL;
struct btrfs_io_bio *io_bio;
bool write = (bio_op(dio_bio) == REQ_OP_WRITE);
int ret = 0;
bio = btrfs_bio_clone(dio_bio);
dip = kzalloc(sizeof(*dip), GFP_NOFS);
if (!dip) {
ret = -ENOMEM;
goto free_ordered;
}
dip->private = dio_bio->bi_private;
dip->inode = inode;
dip->logical_offset = file_offset;
dip->bytes = dio_bio->bi_iter.bi_size;
dip->disk_bytenr = (u64)dio_bio->bi_iter.bi_sector << 9;
bio->bi_private = dip;
dip->orig_bio = bio;
dip->dio_bio = dio_bio;
atomic_set(&dip->pending_bios, 0);
io_bio = btrfs_io_bio(bio);
io_bio->logical = file_offset;
if (write) {
bio->bi_end_io = btrfs_endio_direct_write;
} else {
bio->bi_end_io = btrfs_endio_direct_read;
dip->subio_endio = btrfs_subio_endio_read;
}
/*
* Reset the range for unsubmitted ordered extents (to a 0 length range)
* even if we fail to submit a bio, because in such case we do the
* corresponding error handling below and it must not be done a second
* time by btrfs_direct_IO().
*/
if (write) {
struct btrfs_dio_data *dio_data = current->journal_info;
dio_data->unsubmitted_oe_range_end = dip->logical_offset +
dip->bytes;
dio_data->unsubmitted_oe_range_start =
dio_data->unsubmitted_oe_range_end;
}
ret = btrfs_submit_direct_hook(dip);
if (!ret)
return;
btrfs_io_bio_free_csum(io_bio);
free_ordered:
/*
* If we arrived here it means either we failed to submit the dip
* or we either failed to clone the dio_bio or failed to allocate the
* dip. If we cloned the dio_bio and allocated the dip, we can just
* call bio_endio against our io_bio so that we get proper resource
* cleanup if we fail to submit the dip, otherwise, we must do the
* same as btrfs_endio_direct_[write|read] because we can't call these
* callbacks - they require an allocated dip and a clone of dio_bio.
*/
if (bio && dip) {
bio_io_error(bio);
/*
* The end io callbacks free our dip, do the final put on bio
* and all the cleanup and final put for dio_bio (through
* dio_end_io()).
*/
dip = NULL;
bio = NULL;
} else {
if (write)
__endio_write_update_ordered(inode,
file_offset,
dio_bio->bi_iter.bi_size,
false);
else
unlock_extent(&BTRFS_I(inode)->io_tree, file_offset,
file_offset + dio_bio->bi_iter.bi_size - 1);
dio_bio->bi_status = BLK_STS_IOERR;
/*
* Releases and cleans up our dio_bio, no need to bio_put()
* nor bio_endio()/bio_io_error() against dio_bio.
*/
dio_end_io(dio_bio);
}
if (bio)
bio_put(bio);
kfree(dip);
}
static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
const struct iov_iter *iter, loff_t offset)
{
int seg;
int i;
unsigned int blocksize_mask = fs_info->sectorsize - 1;
ssize_t retval = -EINVAL;
if (offset & blocksize_mask)
goto out;
if (iov_iter_alignment(iter) & blocksize_mask)
goto out;
/* If this is a write we don't need to check anymore */
if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
return 0;
/*
* Check to make sure we don't have duplicate iov_base's in this
* iovec, if so return EINVAL, otherwise we'll get csum errors
* when reading back.
*/
for (seg = 0; seg < iter->nr_segs; seg++) {
for (i = seg + 1; i < iter->nr_segs; i++) {
if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
goto out;
}
}
retval = 0;
out:
return retval;
}
static ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_dio_data dio_data = { 0 };
struct extent_changeset *data_reserved = NULL;
loff_t offset = iocb->ki_pos;
size_t count = 0;
int flags = 0;
bool wakeup = true;
bool relock = false;
ssize_t ret;
if (check_direct_IO(fs_info, iter, offset))
return 0;
inode_dio_begin(inode);
/*
* The generic stuff only does filemap_write_and_wait_range, which
* isn't enough if we've written compressed pages to this area, so
* we need to flush the dirty pages again to make absolutely sure
* that any outstanding dirty pages are on disk.
*/
count = iov_iter_count(iter);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_fdatawrite_range(inode->i_mapping, offset,
offset + count - 1);
if (iov_iter_rw(iter) == WRITE) {
/*
* If the write DIO is beyond the EOF, we need update
* the isize, but it is protected by i_mutex. So we can
* not unlock the i_mutex at this case.
*/
if (offset + count <= inode->i_size) {
dio_data.overwrite = 1;
inode_unlock(inode);
relock = true;
} else if (iocb->ki_flags & IOCB_NOWAIT) {
ret = -EAGAIN;
goto out;
}
ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
offset, count);
if (ret)
goto out;
/*
* We need to know how many extents we reserved so that we can
* do the accounting properly if we go over the number we
* originally calculated. Abuse current->journal_info for this.
*/
dio_data.reserve = round_up(count,
fs_info->sectorsize);
dio_data.unsubmitted_oe_range_start = (u64)offset;
dio_data.unsubmitted_oe_range_end = (u64)offset;
current->journal_info = &dio_data;
down_read(&BTRFS_I(inode)->dio_sem);
} else if (test_bit(BTRFS_INODE_READDIO_NEED_LOCK,
&BTRFS_I(inode)->runtime_flags)) {
inode_dio_end(inode);
flags = DIO_LOCKING | DIO_SKIP_HOLES;
wakeup = false;
}
ret = __blockdev_direct_IO(iocb, inode,
fs_info->fs_devices->latest_bdev,
iter, btrfs_get_blocks_direct, NULL,
btrfs_submit_direct, flags);
if (iov_iter_rw(iter) == WRITE) {
up_read(&BTRFS_I(inode)->dio_sem);
current->journal_info = NULL;
if (ret < 0 && ret != -EIOCBQUEUED) {
if (dio_data.reserve)
btrfs_delalloc_release_space(inode, data_reserved,
offset, dio_data.reserve, true);
/*
* On error we might have left some ordered extents
* without submitting corresponding bios for them, so
* cleanup them up to avoid other tasks getting them
* and waiting for them to complete forever.
*/
if (dio_data.unsubmitted_oe_range_start <
dio_data.unsubmitted_oe_range_end)
__endio_write_update_ordered(inode,
dio_data.unsubmitted_oe_range_start,
dio_data.unsubmitted_oe_range_end -
dio_data.unsubmitted_oe_range_start,
false);
} else if (ret >= 0 && (size_t)ret < count)
btrfs_delalloc_release_space(inode, data_reserved,
offset, count - (size_t)ret, true);
btrfs_delalloc_release_extents(BTRFS_I(inode), count);
}
out:
if (wakeup)
inode_dio_end(inode);
if (relock)
inode_lock(inode);
extent_changeset_free(data_reserved);
return ret;
}
#define BTRFS_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC)
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len)
{
int ret;
ret = fiemap_check_flags(fieinfo, BTRFS_FIEMAP_FLAGS);
if (ret)
return ret;
return extent_fiemap(inode, fieinfo, start, len);
}
int btrfs_readpage(struct file *file, struct page *page)
{
struct extent_io_tree *tree;
tree = &BTRFS_I(page->mapping->host)->io_tree;
return extent_read_full_page(tree, page, btrfs_get_extent, 0);
}
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
int ret;
if (current->flags & PF_MEMALLOC) {
redirty_page_for_writepage(wbc, page);
unlock_page(page);
return 0;
}
/*
* If we are under memory pressure we will call this directly from the
* VM, we need to make sure we have the inode referenced for the ordered
* extent. If not just return like we didn't do anything.
*/
if (!igrab(inode)) {
redirty_page_for_writepage(wbc, page);
return AOP_WRITEPAGE_ACTIVATE;
}
ret = extent_write_full_page(page, wbc);
btrfs_add_delayed_iput(inode);
return ret;
}
static int btrfs_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return extent_writepages(mapping, wbc);
}
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
return extent_readpages(mapping, pages, nr_pages);
}
static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
int ret = try_release_extent_mapping(page, gfp_flags);
if (ret == 1) {
ClearPagePrivate(page);
set_page_private(page, 0);
put_page(page);
}
return ret;
}
static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
if (PageWriteback(page) || PageDirty(page))
return 0;
return __btrfs_releasepage(page, gfp_flags);
}
static void btrfs_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
struct inode *inode = page->mapping->host;
struct extent_io_tree *tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
u64 page_start = page_offset(page);
u64 page_end = page_start + PAGE_SIZE - 1;
u64 start;
u64 end;
int inode_evicting = inode->i_state & I_FREEING;
/*
* we have the page locked, so new writeback can't start,
* and the dirty bit won't be cleared while we are here.
*
* Wait for IO on this page so that we can safely clear
* the PagePrivate2 bit and do ordered accounting
*/
wait_on_page_writeback(page);
tree = &BTRFS_I(inode)->io_tree;
if (offset) {
btrfs_releasepage(page, GFP_NOFS);
return;
}
if (!inode_evicting)
lock_extent_bits(tree, page_start, page_end, &cached_state);
again:
start = page_start;
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), start,
page_end - start + 1);
if (ordered) {
end = min(page_end,
ordered->file_offset + ordered->num_bytes - 1);
/*
* IO on this page will never be started, so we need
* to account for any ordered extents now
*/
if (!inode_evicting)
clear_extent_bit(tree, start, end,
EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
EXTENT_LOCKED | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 1, 0, &cached_state);
/*
* whoever cleared the private bit is responsible
* for the finish_ordered_io
*/
if (TestClearPagePrivate2(page)) {
struct btrfs_ordered_inode_tree *tree;
u64 new_len;
tree = &BTRFS_I(inode)->ordered_tree;
spin_lock_irq(&tree->lock);
set_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags);
new_len = start - ordered->file_offset;
if (new_len < ordered->truncated_len)
ordered->truncated_len = new_len;
spin_unlock_irq(&tree->lock);
if (btrfs_dec_test_ordered_pending(inode, &ordered,
start,
end - start + 1, 1))
btrfs_finish_ordered_io(ordered);
}
btrfs_put_ordered_extent(ordered);
if (!inode_evicting) {
cached_state = NULL;
lock_extent_bits(tree, start, end,
&cached_state);
}
start = end + 1;
if (start < page_end)
goto again;
}
/*
* Qgroup reserved space handler
* Page here will be either
* 1) Already written to disk
* In this case, its reserved space is released from data rsv map
* and will be freed by delayed_ref handler finally.
* So even we call qgroup_free_data(), it won't decrease reserved
* space.
* 2) Not written to disk
* This means the reserved space should be freed here. However,
* if a truncate invalidates the page (by clearing PageDirty)
* and the page is accounted for while allocating extent
* in btrfs_check_data_free_space() we let delayed_ref to
* free the entire extent.
*/
if (PageDirty(page))
btrfs_qgroup_free_data(inode, NULL, page_start, PAGE_SIZE);
if (!inode_evicting) {
clear_extent_bit(tree, page_start, page_end, EXTENT_LOCKED |
EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 1, 1,
&cached_state);
__btrfs_releasepage(page, GFP_NOFS);
}
ClearPageChecked(page);
if (PagePrivate(page)) {
ClearPagePrivate(page);
set_page_private(page, 0);
put_page(page);
}
}
/*
* btrfs_page_mkwrite() is not allowed to change the file size as it gets
* called from a page fault handler when a page is first dirtied. Hence we must
* be careful to check for EOF conditions here. We set the page up correctly
* for a written page which means we get ENOSPC checking when writing into
* holes and correct delalloc and unwritten extent mapping on filesystems that
* support these features.
*
* We are not allowed to take the i_mutex here so we have to play games to
* protect against truncate races as the page could now be beyond EOF. Because
* truncate_setsize() writes the inode size before removing pages, once we have
* the page lock we can determine safely if the page is beyond EOF. If it is not
* beyond EOF, then the page is guaranteed safe against truncation until we
* unlock the page.
*/
vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = file_inode(vmf->vma->vm_file);
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
char *kaddr;
unsigned long zero_start;
loff_t size;
vm_fault_t ret;
int ret2;
int reserved = 0;
u64 reserved_space;
u64 page_start;
u64 page_end;
u64 end;
reserved_space = PAGE_SIZE;
sb_start_pagefault(inode->i_sb);
page_start = page_offset(page);
page_end = page_start + PAGE_SIZE - 1;
end = page_end;
/*
* Reserving delalloc space after obtaining the page lock can lead to
* deadlock. For example, if a dirty page is locked by this function
* and the call to btrfs_delalloc_reserve_space() ends up triggering
* dirty page write out, then the btrfs_writepage() function could
* end up waiting indefinitely to get a lock on the page currently
* being processed by btrfs_page_mkwrite() function.
*/
ret2 = btrfs_delalloc_reserve_space(inode, &data_reserved, page_start,
reserved_space);
if (!ret2) {
ret2 = file_update_time(vmf->vma->vm_file);
reserved = 1;
}
if (ret2) {
ret = vmf_error(ret2);
if (reserved)
goto out;
goto out_noreserve;
}
ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
again:
lock_page(page);
size = i_size_read(inode);
if ((page->mapping != inode->i_mapping) ||
(page_start >= size)) {
/* page got truncated out from underneath us */
goto out_unlock;
}
wait_on_page_writeback(page);
lock_extent_bits(io_tree, page_start, page_end, &cached_state);
set_page_extent_mapped(page);
/*
* we can't set the delalloc bits if there are pending ordered
* extents. Drop our locks and wait for them to finish
*/
ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start,
PAGE_SIZE);
if (ordered) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state);
unlock_page(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
if (page->index == ((size - 1) >> PAGE_SHIFT)) {
reserved_space = round_up(size - page_start,
fs_info->sectorsize);
if (reserved_space < PAGE_SIZE) {
end = page_start + reserved_space - 1;
btrfs_delalloc_release_space(inode, data_reserved,
page_start, PAGE_SIZE - reserved_space,
true);
}
}
/*
* page_mkwrite gets called when the page is firstly dirtied after it's
* faulted in, but write(2) could also dirty a page and set delalloc
* bits, thus in this case for space account reason, we still need to
* clear any delalloc bits within this page range since we have to
* reserve data&meta space before lock_page() (see above comments).
*/
clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING |
EXTENT_DEFRAG, 0, 0, &cached_state);
ret2 = btrfs_set_extent_delalloc(inode, page_start, end, 0,
&cached_state);
if (ret2) {
unlock_extent_cached(io_tree, page_start, page_end,
&cached_state);
ret = VM_FAULT_SIGBUS;
goto out_unlock;
}
/* page is wholly or partially inside EOF */
if (page_start + PAGE_SIZE > size)
zero_start = offset_in_page(size);
else
zero_start = PAGE_SIZE;
if (zero_start != PAGE_SIZE) {
kaddr = kmap(page);
memset(kaddr + zero_start, 0, PAGE_SIZE - zero_start);
flush_dcache_page(page);
kunmap(page);
}
ClearPageChecked(page);
set_page_dirty(page);
SetPageUptodate(page);
BTRFS_I(inode)->last_trans = fs_info->generation;
BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;
BTRFS_I(inode)->last_log_commit = BTRFS_I(inode)->root->last_log_commit;
unlock_extent_cached(io_tree, page_start, page_end, &cached_state);
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
sb_end_pagefault(inode->i_sb);
extent_changeset_free(data_reserved);
return VM_FAULT_LOCKED;
out_unlock:
unlock_page(page);
out:
btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE);
btrfs_delalloc_release_space(inode, data_reserved, page_start,
reserved_space, (ret != 0));
out_noreserve:
sb_end_pagefault(inode->i_sb);
extent_changeset_free(data_reserved);
return ret;
}
static int btrfs_truncate(struct inode *inode, bool skip_writeback)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_block_rsv *rsv;
int ret;
struct btrfs_trans_handle *trans;
u64 mask = fs_info->sectorsize - 1;
u64 min_size = btrfs_calc_metadata_size(fs_info, 1);
if (!skip_writeback) {
ret = btrfs_wait_ordered_range(inode, inode->i_size & (~mask),
(u64)-1);
if (ret)
return ret;
}
/*
* Yes ladies and gentlemen, this is indeed ugly. We have a couple of
* things going on here:
*
* 1) We need to reserve space to update our inode.
*
* 2) We need to have something to cache all the space that is going to
* be free'd up by the truncate operation, but also have some slack
* space reserved in case it uses space during the truncate (thank you
* very much snapshotting).
*
* And we need these to be separate. The fact is we can use a lot of
* space doing the truncate, and we have no earthly idea how much space
* we will use, so we need the truncate reservation to be separate so it
* doesn't end up using space reserved for updating the inode. We also
* need to be able to stop the transaction and start a new one, which
* means we need to be able to update the inode several times, and we
* have no idea of knowing how many times that will be, so we can't just
* reserve 1 item for the entirety of the operation, so that has to be
* done separately as well.
*
* So that leaves us with
*
* 1) rsv - for the truncate reservation, which we will steal from the
* transaction reservation.
* 2) fs_info->trans_block_rsv - this will have 1 items worth left for
* updating the inode.
*/
rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
if (!rsv)
return -ENOMEM;
rsv->size = min_size;
rsv->failfast = 1;
/*
* 1 for the truncate slack space
* 1 for updating the inode.
*/
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
/* Migrate the slack space for the truncate to our reserve */
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
min_size, false);
BUG_ON(ret);
/*
* So if we truncate and then write and fsync we normally would just
* write the extents that changed, which is a problem if we need to
* first truncate that entire inode. So set this flag so we write out
* all of the extents in the inode to the sync log so we're completely
* safe.
*/
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &BTRFS_I(inode)->runtime_flags);
trans->block_rsv = rsv;
while (1) {
ret = btrfs_truncate_inode_items(trans, root, inode,
inode->i_size,
BTRFS_EXTENT_DATA_KEY);
trans->block_rsv = &fs_info->trans_block_rsv;
if (ret != -ENOSPC && ret != -EAGAIN)
break;
ret = btrfs_update_inode(trans, root, inode);
if (ret)
break;
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
trans = btrfs_start_transaction(root, 2);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
break;
}
btrfs_block_rsv_release(fs_info, rsv, -1);
ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
rsv, min_size, false);
BUG_ON(ret); /* shouldn't happen */
trans->block_rsv = rsv;
}
/*
* We can't call btrfs_truncate_block inside a trans handle as we could
* deadlock with freeze, if we got NEED_TRUNCATE_BLOCK then we know
* we've truncated everything except the last little bit, and can do
* btrfs_truncate_block and then update the disk_i_size.
*/
if (ret == NEED_TRUNCATE_BLOCK) {
btrfs_end_transaction(trans);
btrfs_btree_balance_dirty(fs_info);
ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
if (ret)
goto out;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
}
if (trans) {
int ret2;
trans->block_rsv = &fs_info->trans_block_rsv;
ret2 = btrfs_update_inode(trans, root, inode);
if (ret2 && !ret)
ret = ret2;
ret2 = btrfs_end_transaction(trans);
if (ret2 && !ret)
ret = ret2;
btrfs_btree_balance_dirty(fs_info);
}
out:
btrfs_free_block_rsv(fs_info, rsv);
return ret;
}
/*
* create a new subvolume directory/inode (helper for the ioctl).
*/
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
struct btrfs_root *new_root,
struct btrfs_root *parent_root,
u64 new_dirid)
{
struct inode *inode;
int err;
u64 index = 0;
inode = btrfs_new_inode(trans, new_root, NULL, "..", 2,
new_dirid, new_dirid,
S_IFDIR | (~current_umask() & S_IRWXUGO),
&index);
if (IS_ERR(inode))
return PTR_ERR(inode);
inode->i_op = &btrfs_dir_inode_operations;
inode->i_fop = &btrfs_dir_file_operations;
set_nlink(inode, 1);
btrfs_i_size_write(BTRFS_I(inode), 0);
unlock_new_inode(inode);
err = btrfs_subvol_inherit_props(trans, new_root, parent_root);
if (err)
btrfs_err(new_root->fs_info,
"error inheriting subvolume %llu properties: %d",
new_root->root_key.objectid, err);
err = btrfs_update_inode(trans, new_root, inode);
iput(inode);
return err;
}
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
struct btrfs_inode *ei;
struct inode *inode;
ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
ei->root = NULL;
ei->generation = 0;
ei->last_trans = 0;
ei->last_sub_trans = 0;
ei->logged_trans = 0;
ei->delalloc_bytes = 0;
ei->new_delalloc_bytes = 0;
ei->defrag_bytes = 0;
ei->disk_i_size = 0;
ei->flags = 0;
ei->csum_bytes = 0;
ei->index_cnt = (u64)-1;
ei->dir_index = 0;
ei->last_unlink_trans = 0;
ei->last_log_commit = 0;
spin_lock_init(&ei->lock);
ei->outstanding_extents = 0;
if (sb->s_magic != BTRFS_TEST_MAGIC)
btrfs_init_metadata_block_rsv(fs_info, &ei->block_rsv,
BTRFS_BLOCK_RSV_DELALLOC);
ei->runtime_flags = 0;
ei->prop_compress = BTRFS_COMPRESS_NONE;
ei->defrag_compress = BTRFS_COMPRESS_NONE;
ei->delayed_node = NULL;
ei->i_otime.tv_sec = 0;
ei->i_otime.tv_nsec = 0;
inode = &ei->vfs_inode;
extent_map_tree_init(&ei->extent_tree);
extent_io_tree_init(fs_info, &ei->io_tree, IO_TREE_INODE_IO, inode);
extent_io_tree_init(fs_info, &ei->io_failure_tree,
IO_TREE_INODE_IO_FAILURE, inode);
ei->io_tree.track_uptodate = true;
ei->io_failure_tree.track_uptodate = true;
atomic_set(&ei->sync_writers, 0);
mutex_init(&ei->log_mutex);
btrfs_ordered_inode_tree_init(&ei->ordered_tree);
INIT_LIST_HEAD(&ei->delalloc_inodes);
INIT_LIST_HEAD(&ei->delayed_iput);
RB_CLEAR_NODE(&ei->rb_node);
init_rwsem(&ei->dio_sem);
return inode;
}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
void btrfs_test_destroy_inode(struct inode *inode)
{
btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
#endif
void btrfs_free_inode(struct inode *inode)
{
kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}
void btrfs_destroy_inode(struct inode *inode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_ordered_extent *ordered;
struct btrfs_root *root = BTRFS_I(inode)->root;
WARN_ON(!hlist_empty(&inode->i_dentry));
WARN_ON(inode->i_data.nrpages);
WARN_ON(BTRFS_I(inode)->block_rsv.reserved);
WARN_ON(BTRFS_I(inode)->block_rsv.size);
WARN_ON(BTRFS_I(inode)->outstanding_extents);
WARN_ON(BTRFS_I(inode)->delalloc_bytes);
WARN_ON(BTRFS_I(inode)->new_delalloc_bytes);
WARN_ON(BTRFS_I(inode)->csum_bytes);
WARN_ON(BTRFS_I(inode)->defrag_bytes);
/*
* This can happen where we create an inode, but somebody else also
* created the same inode and we need to destroy the one we already
* created.
*/
if (!root)
return;
while (1) {
ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
if (!ordered)
break;
else {
btrfs_err(fs_info,
"found ordered extent %llu %llu on inode cleanup",
ordered->file_offset, ordered->num_bytes);
btrfs_remove_ordered_extent(inode, ordered);
btrfs_put_ordered_extent(ordered);
btrfs_put_ordered_extent(ordered);
}
}
btrfs_qgroup_check_reserved_leak(inode);
inode_tree_del(inode);
btrfs_drop_extent_cache(BTRFS_I(inode), 0, (u64)-1, 0);
}
int btrfs_drop_inode(struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
if (root == NULL)
return 1;
/* the snap/subvol tree is on deleting */
if (btrfs_root_refs(&root->root_item) == 0)
return 1;
else
return generic_drop_inode(inode);
}
static void init_once(void *foo)
{
struct btrfs_inode *ei = (struct btrfs_inode *) foo;
inode_init_once(&ei->vfs_inode);
}
void __cold btrfs_destroy_cachep(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(btrfs_inode_cachep);
kmem_cache_destroy(btrfs_trans_handle_cachep);
kmem_cache_destroy(btrfs_path_cachep);
kmem_cache_destroy(btrfs_free_space_cachep);
kmem_cache_destroy(btrfs_free_space_bitmap_cachep);
}
int __init btrfs_init_cachep(void)
{
btrfs_inode_cachep = kmem_cache_create("btrfs_inode",
sizeof(struct btrfs_inode), 0,
SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD | SLAB_ACCOUNT,
init_once);
if (!btrfs_inode_cachep)
goto fail;
btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle",
sizeof(struct btrfs_trans_handle), 0,
SLAB_TEMPORARY | SLAB_MEM_SPREAD, NULL);
if (!btrfs_trans_handle_cachep)
goto fail;
btrfs_path_cachep = kmem_cache_create("btrfs_path",
sizeof(struct btrfs_path), 0,
SLAB_MEM_SPREAD, NULL);
if (!btrfs_path_cachep)
goto fail;
btrfs_free_space_cachep = kmem_cache_create("btrfs_free_space",
sizeof(struct btrfs_free_space), 0,
SLAB_MEM_SPREAD, NULL);
if (!btrfs_free_space_cachep)
goto fail;
btrfs_free_space_bitmap_cachep = kmem_cache_create("btrfs_free_space_bitmap",
PAGE_SIZE, PAGE_SIZE,
SLAB_RED_ZONE, NULL);
if (!btrfs_free_space_bitmap_cachep)
goto fail;
return 0;
fail:
btrfs_destroy_cachep();
return -ENOMEM;
}
static int btrfs_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags)
{
u64 delalloc_bytes;
struct inode *inode = d_inode(path->dentry);
u32 blocksize = inode->i_sb->s_blocksize;
u32 bi_flags = BTRFS_I(inode)->flags;
stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = BTRFS_I(inode)->i_otime.tv_sec;
stat->btime.tv_nsec = BTRFS_I(inode)->i_otime.tv_nsec;
if (bi_flags & BTRFS_INODE_APPEND)
stat->attributes |= STATX_ATTR_APPEND;
if (bi_flags & BTRFS_INODE_COMPRESS)
stat->attributes |= STATX_ATTR_COMPRESSED;
if (bi_flags & BTRFS_INODE_IMMUTABLE)
stat->attributes |= STATX_ATTR_IMMUTABLE;
if (bi_flags & BTRFS_INODE_NODUMP)
stat->attributes |= STATX_ATTR_NODUMP;
stat->attributes_mask |= (STATX_ATTR_APPEND |
STATX_ATTR_COMPRESSED |
STATX_ATTR_IMMUTABLE |
STATX_ATTR_NODUMP);
generic_fillattr(inode, stat);
stat->dev = BTRFS_I(inode)->root->anon_dev;
spin_lock(&BTRFS_I(inode)->lock);
delalloc_bytes = BTRFS_I(inode)->new_delalloc_bytes;
spin_unlock(&BTRFS_I(inode)->lock);
stat->blocks = (ALIGN(inode_get_bytes(inode), blocksize) +
ALIGN(delalloc_bytes, blocksize)) >> 9;
return 0;
}
static int btrfs_rename_exchange(struct inode *old_dir,
struct dentry *old_dentry,
struct inode *new_dir,
struct dentry *new_dentry)
{
struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = new_dentry->d_inode;
struct inode *old_inode = old_dentry->d_inode;
struct timespec64 ctime = current_time(old_inode);
struct dentry *parent;
u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
u64 new_ino = btrfs_ino(BTRFS_I(new_inode));
u64 old_idx = 0;
u64 new_idx = 0;
int ret;
bool root_log_pinned = false;
bool dest_log_pinned = false;
struct btrfs_log_ctx ctx_root;
struct btrfs_log_ctx ctx_dest;
bool sync_log_root = false;
bool sync_log_dest = false;
bool commit_transaction = false;
/* we only allow rename subvolume link between subvolumes */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
return -EXDEV;
btrfs_init_log_ctx(&ctx_root, old_inode);
btrfs_init_log_ctx(&ctx_dest, new_inode);
/* close the race window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID ||
new_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&fs_info->subvol_sem);
/*
* We want to reserve the absolute worst case amount of items. So if
* both inodes are subvols and we need to unlink them then that would
* require 4 item modifications, but if they are both normal inodes it
* would require 5 item modifications, so we'll assume their normal
* inodes. So 5 * 2 is 10, plus 2 for the new links, so 12 total items
* should cover the worst case number of items we'll modify.
*/
trans = btrfs_start_transaction(root, 12);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root)
btrfs_record_root_in_trans(trans, dest);
/*
* We need to find a free sequence number both in the source and
* in the destination directory for the exchange.
*/
ret = btrfs_set_inode_index(BTRFS_I(new_dir), &old_idx);
if (ret)
goto out_fail;
ret = btrfs_set_inode_index(BTRFS_I(old_dir), &new_idx);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
BTRFS_I(new_inode)->dir_index = 0ULL;
/* Reference for the source. */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
btrfs_pin_log_trans(root);
root_log_pinned = true;
ret = btrfs_insert_inode_ref(trans, dest,
new_dentry->d_name.name,
new_dentry->d_name.len,
old_ino,
btrfs_ino(BTRFS_I(new_dir)),
old_idx);
if (ret)
goto out_fail;
}
/* And now for the dest. */
if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
btrfs_pin_log_trans(dest);
dest_log_pinned = true;
ret = btrfs_insert_inode_ref(trans, root,
old_dentry->d_name.name,
old_dentry->d_name.len,
new_ino,
btrfs_ino(BTRFS_I(old_dir)),
new_idx);
if (ret)
goto out_fail;
}
/* Update inode version and ctime/mtime. */
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
inode_inc_iversion(new_inode);
old_dir->i_ctime = old_dir->i_mtime = ctime;
new_dir->i_ctime = new_dir->i_mtime = ctime;
old_inode->i_ctime = ctime;
new_inode->i_ctime = ctime;
if (old_dentry->d_parent != new_dentry->d_parent) {
btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
BTRFS_I(old_inode), 1);
btrfs_record_unlink_dir(trans, BTRFS_I(new_dir),
BTRFS_I(new_inode), 1);
}
/* src is a subvolume */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
} else { /* src is an inode */
ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
BTRFS_I(old_dentry->d_inode),
old_dentry->d_name.name,
old_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, root, old_inode);
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
/* dest is a subvolume */
if (new_ino == BTRFS_FIRST_FREE_OBJECTID) {
ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
} else { /* dest is an inode */
ret = __btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
BTRFS_I(new_dentry->d_inode),
new_dentry->d_name.name,
new_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, dest, new_inode);
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
new_dentry->d_name.name,
new_dentry->d_name.len, 0, old_idx);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
ret = btrfs_add_link(trans, BTRFS_I(old_dir), BTRFS_I(new_inode),
old_dentry->d_name.name,
old_dentry->d_name.len, 0, new_idx);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = old_idx;
if (new_inode->i_nlink == 1)
BTRFS_I(new_inode)->dir_index = new_idx;
if (root_log_pinned) {
parent = new_dentry->d_parent;
ret = btrfs_log_new_name(trans, BTRFS_I(old_inode),
BTRFS_I(old_dir), parent,
false, &ctx_root);
if (ret == BTRFS_NEED_LOG_SYNC)
sync_log_root = true;
else if (ret == BTRFS_NEED_TRANS_COMMIT)
commit_transaction = true;
ret = 0;
btrfs_end_log_trans(root);
root_log_pinned = false;
}
if (dest_log_pinned) {
if (!commit_transaction) {
parent = old_dentry->d_parent;
ret = btrfs_log_new_name(trans, BTRFS_I(new_inode),
BTRFS_I(new_dir), parent,
false, &ctx_dest);
if (ret == BTRFS_NEED_LOG_SYNC)
sync_log_dest = true;
else if (ret == BTRFS_NEED_TRANS_COMMIT)
commit_transaction = true;
ret = 0;
}
btrfs_end_log_trans(dest);
dest_log_pinned = false;
}
out_fail:
/*
* If we have pinned a log and an error happened, we unpin tasks
* trying to sync the log and force them to fallback to a transaction
* commit if the log currently contains any of the inodes involved in
* this rename operation (to ensure we do not persist a log with an
* inconsistent state for any of these inodes or leading to any
* inconsistencies when replayed). If the transaction was aborted, the
* abortion reason is propagated to userspace when attempting to commit
* the transaction. If the log does not contain any of these inodes, we
* allow the tasks to sync it.
*/
if (ret && (root_log_pinned || dest_log_pinned)) {
if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
(new_inode &&
btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
btrfs_set_log_full_commit(trans);
if (root_log_pinned) {
btrfs_end_log_trans(root);
root_log_pinned = false;
}
if (dest_log_pinned) {
btrfs_end_log_trans(dest);
dest_log_pinned = false;
}
}
if (!ret && sync_log_root && !commit_transaction) {
ret = btrfs_sync_log(trans, BTRFS_I(old_inode)->root,
&ctx_root);
if (ret)
commit_transaction = true;
}
if (!ret && sync_log_dest && !commit_transaction) {
ret = btrfs_sync_log(trans, BTRFS_I(new_inode)->root,
&ctx_dest);
if (ret)
commit_transaction = true;
}
if (commit_transaction) {
/*
* We may have set commit_transaction when logging the new name
* in the destination root, in which case we left the source
* root context in the list of log contextes. So make sure we
* remove it to avoid invalid memory accesses, since the context
* was allocated in our stack frame.
*/
if (sync_log_root) {
mutex_lock(&root->log_mutex);
list_del_init(&ctx_root.list);
mutex_unlock(&root->log_mutex);
}
ret = btrfs_commit_transaction(trans);
} else {
int ret2;
ret2 = btrfs_end_transaction(trans);
ret = ret ? ret : ret2;
}
out_notrans:
if (new_ino == BTRFS_FIRST_FREE_OBJECTID ||
old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
ASSERT(list_empty(&ctx_root.list));
ASSERT(list_empty(&ctx_dest.list));
return ret;
}
static int btrfs_whiteout_for_rename(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir,
struct dentry *dentry)
{
int ret;
struct inode *inode;
u64 objectid;
u64 index;
ret = btrfs_find_free_ino(root, &objectid);
if (ret)
return ret;
inode = btrfs_new_inode(trans, root, dir,
dentry->d_name.name,
dentry->d_name.len,
btrfs_ino(BTRFS_I(dir)),
objectid,
S_IFCHR | WHITEOUT_MODE,
&index);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
return ret;
}
inode->i_op = &btrfs_special_inode_operations;
init_special_inode(inode, inode->i_mode,
WHITEOUT_DEV);
ret = btrfs_init_inode_security(trans, inode, dir,
&dentry->d_name);
if (ret)
goto out;
ret = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
BTRFS_I(inode), 0, index);
if (ret)
goto out;
ret = btrfs_update_inode(trans, root, inode);
out:
unlock_new_inode(inode);
if (ret)
inode_dec_link_count(inode);
iput(inode);
return ret;
}
static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
struct btrfs_fs_info *fs_info = btrfs_sb(old_dir->i_sb);
struct btrfs_trans_handle *trans;
unsigned int trans_num_items;
struct btrfs_root *root = BTRFS_I(old_dir)->root;
struct btrfs_root *dest = BTRFS_I(new_dir)->root;
struct inode *new_inode = d_inode(new_dentry);
struct inode *old_inode = d_inode(old_dentry);
u64 index = 0;
int ret;
u64 old_ino = btrfs_ino(BTRFS_I(old_inode));
bool log_pinned = false;
struct btrfs_log_ctx ctx;
bool sync_log = false;
bool commit_transaction = false;
if (btrfs_ino(BTRFS_I(new_dir)) == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
return -EPERM;
/* we only allow rename subvolume link between subvolumes */
if (old_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
return -EXDEV;
if (old_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
(new_inode && btrfs_ino(BTRFS_I(new_inode)) == BTRFS_FIRST_FREE_OBJECTID))
return -ENOTEMPTY;
if (S_ISDIR(old_inode->i_mode) && new_inode &&
new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
return -ENOTEMPTY;
/* check for collisions, even if the name isn't there */
ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
new_dentry->d_name.name,
new_dentry->d_name.len);
if (ret) {
if (ret == -EEXIST) {
/* we shouldn't get
* eexist without a new_inode */
if (WARN_ON(!new_inode)) {
return ret;
}
} else {
/* maybe -EOVERFLOW */
return ret;
}
}
ret = 0;
/*
* we're using rename to replace one file with another. Start IO on it
* now so we don't add too much work to the end of the transaction
*/
if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size)
filemap_flush(old_inode->i_mapping);
/* close the racy window with snapshot create/destroy ioctl */
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
down_read(&fs_info->subvol_sem);
/*
* We want to reserve the absolute worst case amount of items. So if
* both inodes are subvols and we need to unlink them then that would
* require 4 item modifications, but if they are both normal inodes it
* would require 5 item modifications, so we'll assume they are normal
* inodes. So 5 * 2 is 10, plus 1 for the new link, so 11 total items
* should cover the worst case number of items we'll modify.
* If our rename has the whiteout flag, we need more 5 units for the
* new inode (1 inode item, 1 inode ref, 2 dir items and 1 xattr item
* when selinux is enabled).
*/
trans_num_items = 11;
if (flags & RENAME_WHITEOUT)
trans_num_items += 5;
trans = btrfs_start_transaction(root, trans_num_items);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out_notrans;
}
if (dest != root)
btrfs_record_root_in_trans(trans, dest);
ret = btrfs_set_inode_index(BTRFS_I(new_dir), &index);
if (ret)
goto out_fail;
BTRFS_I(old_inode)->dir_index = 0ULL;
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
/* force full log commit if subvolume involved. */
btrfs_set_log_full_commit(trans);
} else {
btrfs_pin_log_trans(root);
log_pinned = true;
ret = btrfs_insert_inode_ref(trans, dest,
new_dentry->d_name.name,
new_dentry->d_name.len,
old_ino,
btrfs_ino(BTRFS_I(new_dir)), index);
if (ret)
goto out_fail;
}
inode_inc_iversion(old_dir);
inode_inc_iversion(new_dir);
inode_inc_iversion(old_inode);
old_dir->i_ctime = old_dir->i_mtime =
new_dir->i_ctime = new_dir->i_mtime =
old_inode->i_ctime = current_time(old_dir);
if (old_dentry->d_parent != new_dentry->d_parent)
btrfs_record_unlink_dir(trans, BTRFS_I(old_dir),
BTRFS_I(old_inode), 1);
if (unlikely(old_ino == BTRFS_FIRST_FREE_OBJECTID)) {
ret = btrfs_unlink_subvol(trans, old_dir, old_dentry);
} else {
ret = __btrfs_unlink_inode(trans, root, BTRFS_I(old_dir),
BTRFS_I(d_inode(old_dentry)),
old_dentry->d_name.name,
old_dentry->d_name.len);
if (!ret)
ret = btrfs_update_inode(trans, root, old_inode);
}
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (new_inode) {
inode_inc_iversion(new_inode);
new_inode->i_ctime = current_time(new_inode);
if (unlikely(btrfs_ino(BTRFS_I(new_inode)) ==
BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
ret = btrfs_unlink_subvol(trans, new_dir, new_dentry);
BUG_ON(new_inode->i_nlink == 0);
} else {
ret = btrfs_unlink_inode(trans, dest, BTRFS_I(new_dir),
BTRFS_I(d_inode(new_dentry)),
new_dentry->d_name.name,
new_dentry->d_name.len);
}
if (!ret && new_inode->i_nlink == 0)
ret = btrfs_orphan_add(trans,
BTRFS_I(d_inode(new_dentry)));
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
}
ret = btrfs_add_link(trans, BTRFS_I(new_dir), BTRFS_I(old_inode),
new_dentry->d_name.name,
new_dentry->d_name.len, 0, index);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
if (old_inode->i_nlink == 1)
BTRFS_I(old_inode)->dir_index = index;
if (log_pinned) {
struct dentry *parent = new_dentry->d_parent;
btrfs_init_log_ctx(&ctx, old_inode);
ret = btrfs_log_new_name(trans, BTRFS_I(old_inode),
BTRFS_I(old_dir), parent,
false, &ctx);
if (ret == BTRFS_NEED_LOG_SYNC)
sync_log = true;
else if (ret == BTRFS_NEED_TRANS_COMMIT)
commit_transaction = true;
ret = 0;
btrfs_end_log_trans(root);
log_pinned = false;
}
if (flags & RENAME_WHITEOUT) {
ret = btrfs_whiteout_for_rename(trans, root, old_dir,
old_dentry);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto out_fail;
}
}
out_fail:
/*
* If we have pinned the log and an error happened, we unpin tasks
* trying to sync the log and force them to fallback to a transaction
* commit if the log currently contains any of the inodes involved in
* this rename operation (to ensure we do not persist a log with an
* inconsistent state for any of these inodes or leading to any
* inconsistencies when replayed). If the transaction was aborted, the
* abortion reason is propagated to userspace when attempting to commit
* the transaction. If the log does not contain any of these inodes, we
* allow the tasks to sync it.
*/
if (ret && log_pinned) {
if (btrfs_inode_in_log(BTRFS_I(old_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(new_dir), fs_info->generation) ||
btrfs_inode_in_log(BTRFS_I(old_inode), fs_info->generation) ||
(new_inode &&
btrfs_inode_in_log(BTRFS_I(new_inode), fs_info->generation)))
btrfs_set_log_full_commit(trans);
btrfs_end_log_trans(root);
log_pinned = false;
}
if (!ret && sync_log) {
ret = btrfs_sync_log(trans, BTRFS_I(old_inode)->root, &ctx);
if (ret)
commit_transaction = true;
}
if (commit_transaction) {
ret = btrfs_commit_transaction(trans);
} else {
int ret2;
ret2 = btrfs_end_transaction(trans);
ret = ret ? ret : ret2;
}
out_notrans:
if (old_ino == BTRFS_FIRST_FREE_OBJECTID)
up_read(&fs_info->subvol_sem);
return ret;
}
static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE | RENAME_WHITEOUT))
return -EINVAL;
if (flags & RENAME_EXCHANGE)
return btrfs_rename_exchange(old_dir, old_dentry, new_dir,
new_dentry);
return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
}
struct btrfs_delalloc_work {
struct inode *inode;
struct completion completion;
struct list_head list;
struct btrfs_work work;
};
static void btrfs_run_delalloc_work(struct btrfs_work *work)
{
struct btrfs_delalloc_work *delalloc_work;
struct inode *inode;
delalloc_work = container_of(work, struct btrfs_delalloc_work,
work);
inode = delalloc_work->inode;
filemap_flush(inode->i_mapping);
if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
&BTRFS_I(inode)->runtime_flags))
filemap_flush(inode->i_mapping);
iput(inode);
complete(&delalloc_work->completion);
}
static struct btrfs_delalloc_work *btrfs_alloc_delalloc_work(struct inode *inode)
{
struct btrfs_delalloc_work *work;
work = kmalloc(sizeof(*work), GFP_NOFS);
if (!work)
return NULL;
init_completion(&work->completion);
INIT_LIST_HEAD(&work->list);
work->inode = inode;
btrfs_init_work(&work->work, btrfs_run_delalloc_work, NULL, NULL);
return work;
}
/*
* some fairly slow code that needs optimization. This walks the list
* of all the inodes with pending delalloc and forces them to disk.
*/
static int start_delalloc_inodes(struct btrfs_root *root, int nr, bool snapshot)
{
struct btrfs_inode *binode;
struct inode *inode;
struct btrfs_delalloc_work *work, *next;
struct list_head works;
struct list_head splice;
int ret = 0;
INIT_LIST_HEAD(&works);
INIT_LIST_HEAD(&splice);
mutex_lock(&root->delalloc_mutex);
spin_lock(&root->delalloc_lock);
list_splice_init(&root->delalloc_inodes, &splice);
while (!list_empty(&splice)) {
binode = list_entry(splice.next, struct btrfs_inode,
delalloc_inodes);
list_move_tail(&binode->delalloc_inodes,
&root->delalloc_inodes);
inode = igrab(&binode->vfs_inode);
if (!inode) {
cond_resched_lock(&root->delalloc_lock);
continue;
}
spin_unlock(&root->delalloc_lock);
if (snapshot)
set_bit(BTRFS_INODE_SNAPSHOT_FLUSH,
&binode->runtime_flags);
work = btrfs_alloc_delalloc_work(inode);
if (!work) {
iput(inode);
ret = -ENOMEM;
goto out;
}
list_add_tail(&work->list, &works);
btrfs_queue_work(root->fs_info->flush_workers,
&work->work);
ret++;
if (nr != -1 && ret >= nr)
goto out;
cond_resched();
spin_lock(&root->delalloc_lock);
}
spin_unlock(&root->delalloc_lock);
out:
list_for_each_entry_safe(work, next, &works, list) {
list_del_init(&work->list);
wait_for_completion(&work->completion);
kfree(work);
}
if (!list_empty(&splice)) {
spin_lock(&root->delalloc_lock);
list_splice_tail(&splice, &root->delalloc_inodes);
spin_unlock(&root->delalloc_lock);
}
mutex_unlock(&root->delalloc_mutex);
return ret;
}
int btrfs_start_delalloc_snapshot(struct btrfs_root *root)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret;
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
ret = start_delalloc_inodes(root, -1, true);
if (ret > 0)
ret = 0;
return ret;
}
int btrfs_start_delalloc_roots(struct btrfs_fs_info *fs_info, int nr)
{
struct btrfs_root *root;
struct list_head splice;
int ret;
if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state))
return -EROFS;
INIT_LIST_HEAD(&splice);
mutex_lock(&fs_info->delalloc_root_mutex);
spin_lock(&fs_info->delalloc_root_lock);
list_splice_init(&fs_info->delalloc_roots, &splice);
while (!list_empty(&splice) && nr) {
root = list_first_entry(&splice, struct btrfs_root,
delalloc_root);
root = btrfs_grab_fs_root(root);
BUG_ON(!root);
list_move_tail(&root->delalloc_root,
&fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
ret = start_delalloc_inodes(root, nr, false);
btrfs_put_fs_root(root);
if (ret < 0)
goto out;
if (nr != -1) {
nr -= ret;
WARN_ON(nr < 0);
}
spin_lock(&fs_info->delalloc_root_lock);
}
spin_unlock(&fs_info->delalloc_root_lock);
ret = 0;
out:
if (!list_empty(&splice)) {
spin_lock(&fs_info->delalloc_root_lock);
list_splice_tail(&splice, &fs_info->delalloc_roots);
spin_unlock(&fs_info->delalloc_root_lock);
}
mutex_unlock(&fs_info->delalloc_root_mutex);
return ret;
}
static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_path *path;
struct btrfs_key key;
struct inode *inode = NULL;
int err;
u64 objectid;
u64 index = 0;
int name_len;
int datasize;
unsigned long ptr;
struct btrfs_file_extent_item *ei;
struct extent_buffer *leaf;
name_len = strlen(symname);
if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(fs_info))
return -ENAMETOOLONG;
/*
* 2 items for inode item and ref
* 2 items for dir items
* 1 item for updating parent inode item
* 1 item for the inline extent item
* 1 item for xattr if selinux is on
*/
trans = btrfs_start_transaction(root, 7);
if (IS_ERR(trans))
return PTR_ERR(trans);
err = btrfs_find_free_ino(root, &objectid);
if (err)
goto out_unlock;
inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
dentry->d_name.len, btrfs_ino(BTRFS_I(dir)),
objectid, S_IFLNK|S_IRWXUGO, &index);
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
inode = NULL;
goto out_unlock;
}
/*
* If the active LSM wants to access the inode during
* d_instantiate it needs these. Smack checks to see
* if the filesystem supports xattrs by looking at the
* ops vector.
*/
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
err = btrfs_init_inode_security(trans, inode, dir, &dentry->d_name);
if (err)
goto out_unlock;
path = btrfs_alloc_path();
if (!path) {
err = -ENOMEM;
goto out_unlock;
}
key.objectid = btrfs_ino(BTRFS_I(inode));
key.offset = 0;
key.type = BTRFS_EXTENT_DATA_KEY;
datasize = btrfs_file_extent_calc_inline_size(name_len);
err = btrfs_insert_empty_item(trans, root, path, &key,
datasize);
if (err) {
btrfs_free_path(path);
goto out_unlock;
}
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, ei, trans->transid);
btrfs_set_file_extent_type(leaf, ei,
BTRFS_FILE_EXTENT_INLINE);
btrfs_set_file_extent_encryption(leaf, ei, 0);
btrfs_set_file_extent_compression(leaf, ei, 0);
btrfs_set_file_extent_other_encoding(leaf, ei, 0);
btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);
ptr = btrfs_file_extent_inline_start(ei);
write_extent_buffer(leaf, symname, ptr, name_len);
btrfs_mark_buffer_dirty(leaf);
btrfs_free_path(path);
inode->i_op = &btrfs_symlink_inode_operations;
inode_nohighmem(inode);
inode_set_bytes(inode, name_len);
btrfs_i_size_write(BTRFS_I(inode), name_len);
err = btrfs_update_inode(trans, root, inode);
/*
* Last step, add directory indexes for our symlink inode. This is the
* last step to avoid extra cleanup of these indexes if an error happens
* elsewhere above.
*/
if (!err)
err = btrfs_add_nondir(trans, BTRFS_I(dir), dentry,
BTRFS_I(inode), 0, index);
if (err)
goto out_unlock;
d_instantiate_new(dentry, inode);
out_unlock:
btrfs_end_transaction(trans);
if (err && inode) {
inode_dec_link_count(inode);
discard_new_inode(inode);
}
btrfs_btree_balance_dirty(fs_info);
return err;
}
static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint,
struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
struct extent_map *em;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_key ins;
u64 cur_offset = start;
u64 i_size;
u64 cur_bytes;
u64 last_alloc = (u64)-1;
int ret = 0;
bool own_trans = true;
u64 end = start + num_bytes - 1;
if (trans)
own_trans = false;
while (num_bytes > 0) {
if (own_trans) {
trans = btrfs_start_transaction(root, 3);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
break;
}
}
cur_bytes = min_t(u64, num_bytes, SZ_256M);
cur_bytes = max(cur_bytes, min_size);
/*
* If we are severely fragmented we could end up with really
* small allocations, so if the allocator is returning small
* chunks lets make its job easier by only searching for those
* sized chunks.
*/
cur_bytes = min(cur_bytes, last_alloc);
ret = btrfs_reserve_extent(root, cur_bytes, cur_bytes,
min_size, 0, *alloc_hint, &ins, 1, 0);
if (ret) {
if (own_trans)
btrfs_end_transaction(trans);
break;
}
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
last_alloc = ins.offset;
ret = insert_reserved_file_extent(trans, inode,
cur_offset, ins.objectid,
ins.offset, ins.offset,
ins.offset, 0, 0, 0,
BTRFS_FILE_EXTENT_PREALLOC);
if (ret) {
btrfs_free_reserved_extent(fs_info, ins.objectid,
ins.offset, 0);
btrfs_abort_transaction(trans, ret);
if (own_trans)
btrfs_end_transaction(trans);
break;
}
btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
cur_offset + ins.offset -1, 0);
em = alloc_extent_map();
if (!em) {
set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
goto next;
}
em->start = cur_offset;
em->orig_start = cur_offset;
em->len = ins.offset;
em->block_start = ins.objectid;
em->block_len = ins.offset;
em->orig_block_len = ins.offset;
em->ram_bytes = ins.offset;
set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
em->generation = trans->transid;
while (1) {
write_lock(&em_tree->lock);
ret = add_extent_mapping(em_tree, em, 1);
write_unlock(&em_tree->lock);
if (ret != -EEXIST)
break;
btrfs_drop_extent_cache(BTRFS_I(inode), cur_offset,
cur_offset + ins.offset - 1,
0);
}
free_extent_map(em);
next:
num_bytes -= ins.offset;
cur_offset += ins.offset;
*alloc_hint = ins.objectid + ins.offset;
inode_inc_iversion(inode);
inode->i_ctime = current_time(inode);
BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
if (!(mode & FALLOC_FL_KEEP_SIZE) &&
(actual_len > inode->i_size) &&
(cur_offset > inode->i_size)) {
if (cur_offset > actual_len)
i_size = actual_len;
else
i_size = cur_offset;
i_size_write(inode, i_size);
btrfs_ordered_update_i_size(inode, i_size, NULL);
}
ret = btrfs_update_inode(trans, root, inode);
if (ret) {
btrfs_abort_transaction(trans, ret);
if (own_trans)
btrfs_end_transaction(trans);
break;
}
if (own_trans)
btrfs_end_transaction(trans);
}
if (cur_offset < end)
btrfs_free_reserved_data_space(inode, NULL, cur_offset,
end - cur_offset + 1);
return ret;
}
int btrfs_prealloc_file_range(struct inode *inode, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint,
NULL);
}
int btrfs_prealloc_file_range_trans(struct inode *inode,
struct btrfs_trans_handle *trans, int mode,
u64 start, u64 num_bytes, u64 min_size,
loff_t actual_len, u64 *alloc_hint)
{
return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
min_size, actual_len, alloc_hint, trans);
}
static int btrfs_set_page_dirty(struct page *page)
{
return __set_page_dirty_nobuffers(page);
}
static int btrfs_permission(struct inode *inode, int mask)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
umode_t mode = inode->i_mode;
if (mask & MAY_WRITE &&
(S_ISREG(mode) || S_ISDIR(mode) || S_ISLNK(mode))) {
if (btrfs_root_readonly(root))
return -EROFS;
if (BTRFS_I(inode)->flags & BTRFS_INODE_READONLY)
return -EACCES;
}
return generic_permission(inode, mask);
}
static int btrfs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
struct btrfs_trans_handle *trans;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct inode *inode = NULL;
u64 objectid;
u64 index;
int ret = 0;
/*
* 5 units required for adding orphan entry
*/
trans = btrfs_start_transaction(root, 5);
if (IS_ERR(trans))
return PTR_ERR(trans);
ret = btrfs_find_free_ino(root, &objectid);
if (ret)
goto out;
inode = btrfs_new_inode(trans, root, dir, NULL, 0,
btrfs_ino(BTRFS_I(dir)), objectid, mode, &index);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
inode = NULL;
goto out;
}
inode->i_fop = &btrfs_file_operations;
inode->i_op = &btrfs_file_inode_operations;
inode->i_mapping->a_ops = &btrfs_aops;
BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
ret = btrfs_init_inode_security(trans, inode, dir, NULL);
if (ret)
goto out;
ret = btrfs_update_inode(trans, root, inode);
if (ret)
goto out;
ret = btrfs_orphan_add(trans, BTRFS_I(inode));
if (ret)
goto out;
/*
* We set number of links to 0 in btrfs_new_inode(), and here we set
* it to 1 because d_tmpfile() will issue a warning if the count is 0,
* through:
*
* d_tmpfile() -> inode_dec_link_count() -> drop_nlink()
*/
set_nlink(inode, 1);
d_tmpfile(dentry, inode);
unlock_new_inode(inode);
mark_inode_dirty(inode);
out:
btrfs_end_transaction(trans);
if (ret && inode)
discard_new_inode(inode);
btrfs_btree_balance_dirty(fs_info);
return ret;
}
void btrfs_set_range_writeback(struct extent_io_tree *tree, u64 start, u64 end)
{
struct inode *inode = tree->private_data;
unsigned long index = start >> PAGE_SHIFT;
unsigned long end_index = end >> PAGE_SHIFT;
struct page *page;
while (index <= end_index) {
page = find_get_page(inode->i_mapping, index);
ASSERT(page); /* Pages should be in the extent_io_tree */
set_page_writeback(page);
put_page(page);
index++;
}
}
#ifdef CONFIG_SWAP
/*
* Add an entry indicating a block group or device which is pinned by a
* swapfile. Returns 0 on success, 1 if there is already an entry for it, or a
* negative errno on failure.
*/
static int btrfs_add_swapfile_pin(struct inode *inode, void *ptr,
bool is_block_group)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_swapfile_pin *sp, *entry;
struct rb_node **p;
struct rb_node *parent = NULL;
sp = kmalloc(sizeof(*sp), GFP_NOFS);
if (!sp)
return -ENOMEM;
sp->ptr = ptr;
sp->inode = inode;
sp->is_block_group = is_block_group;
spin_lock(&fs_info->swapfile_pins_lock);
p = &fs_info->swapfile_pins.rb_node;
while (*p) {
parent = *p;
entry = rb_entry(parent, struct btrfs_swapfile_pin, node);
if (sp->ptr < entry->ptr ||
(sp->ptr == entry->ptr && sp->inode < entry->inode)) {
p = &(*p)->rb_left;
} else if (sp->ptr > entry->ptr ||
(sp->ptr == entry->ptr && sp->inode > entry->inode)) {
p = &(*p)->rb_right;
} else {
spin_unlock(&fs_info->swapfile_pins_lock);
kfree(sp);
return 1;
}
}
rb_link_node(&sp->node, parent, p);
rb_insert_color(&sp->node, &fs_info->swapfile_pins);
spin_unlock(&fs_info->swapfile_pins_lock);
return 0;
}
/* Free all of the entries pinned by this swapfile. */
static void btrfs_free_swapfile_pins(struct inode *inode)
{
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct btrfs_swapfile_pin *sp;
struct rb_node *node, *next;
spin_lock(&fs_info->swapfile_pins_lock);
node = rb_first(&fs_info->swapfile_pins);
while (node) {
next = rb_next(node);
sp = rb_entry(node, struct btrfs_swapfile_pin, node);
if (sp->inode == inode) {
rb_erase(&sp->node, &fs_info->swapfile_pins);
if (sp->is_block_group)
btrfs_put_block_group(sp->ptr);
kfree(sp);
}
node = next;
}
spin_unlock(&fs_info->swapfile_pins_lock);
}
struct btrfs_swap_info {
u64 start;
u64 block_start;
u64 block_len;
u64 lowest_ppage;
u64 highest_ppage;
unsigned long nr_pages;
int nr_extents;
};
static int btrfs_add_swap_extent(struct swap_info_struct *sis,
struct btrfs_swap_info *bsi)
{
unsigned long nr_pages;
u64 first_ppage, first_ppage_reported, next_ppage;
int ret;
first_ppage = ALIGN(bsi->block_start, PAGE_SIZE) >> PAGE_SHIFT;
next_ppage = ALIGN_DOWN(bsi->block_start + bsi->block_len,
PAGE_SIZE) >> PAGE_SHIFT;
if (first_ppage >= next_ppage)
return 0;
nr_pages = next_ppage - first_ppage;
first_ppage_reported = first_ppage;
if (bsi->start == 0)
first_ppage_reported++;
if (bsi->lowest_ppage > first_ppage_reported)
bsi->lowest_ppage = first_ppage_reported;
if (bsi->highest_ppage < (next_ppage - 1))
bsi->highest_ppage = next_ppage - 1;
ret = add_swap_extent(sis, bsi->nr_pages, nr_pages, first_ppage);
if (ret < 0)
return ret;
bsi->nr_extents += ret;
bsi->nr_pages += nr_pages;
return 0;
}
static void btrfs_swap_deactivate(struct file *file)
{
struct inode *inode = file_inode(file);
btrfs_free_swapfile_pins(inode);
atomic_dec(&BTRFS_I(inode)->root->nr_swapfiles);
}
static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
struct inode *inode = file_inode(file);
struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_state *cached_state = NULL;
struct extent_map *em = NULL;
struct btrfs_device *device = NULL;
struct btrfs_swap_info bsi = {
.lowest_ppage = (sector_t)-1ULL,
};
int ret = 0;
u64 isize;
u64 start;
/*
* If the swap file was just created, make sure delalloc is done. If the
* file changes again after this, the user is doing something stupid and
* we don't really care.
*/
ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (ret)
return ret;
/*
* The inode is locked, so these flags won't change after we check them.
*/
if (BTRFS_I(inode)->flags & BTRFS_INODE_COMPRESS) {
btrfs_warn(fs_info, "swapfile must not be compressed");
return -EINVAL;
}
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)) {
btrfs_warn(fs_info, "swapfile must not be copy-on-write");
return -EINVAL;
}
if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
btrfs_warn(fs_info, "swapfile must not be checksummed");
return -EINVAL;
}
/*
* Balance or device remove/replace/resize can move stuff around from
* under us. The EXCL_OP flag makes sure they aren't running/won't run
* concurrently while we are mapping the swap extents, and
* fs_info->swapfile_pins prevents them from running while the swap file
* is active and moving the extents. Note that this also prevents a
* concurrent device add which isn't actually necessary, but it's not
* really worth the trouble to allow it.
*/
if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
btrfs_warn(fs_info,
"cannot activate swapfile while exclusive operation is running");
return -EBUSY;
}
/*
* Snapshots can create extents which require COW even if NODATACOW is
* set. We use this counter to prevent snapshots. We must increment it
* before walking the extents because we don't want a concurrent
* snapshot to run after we've already checked the extents.
*/
atomic_inc(&BTRFS_I(inode)->root->nr_swapfiles);
isize = ALIGN_DOWN(inode->i_size, fs_info->sectorsize);
lock_extent_bits(io_tree, 0, isize - 1, &cached_state);
start = 0;
while (start < isize) {
u64 logical_block_start, physical_block_start;
struct btrfs_block_group *bg;
u64 len = isize - start;
em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
if (em->block_start == EXTENT_MAP_HOLE) {
btrfs_warn(fs_info, "swapfile must not have holes");
ret = -EINVAL;
goto out;
}
if (em->block_start == EXTENT_MAP_INLINE) {
/*
* It's unlikely we'll ever actually find ourselves
* here, as a file small enough to fit inline won't be
* big enough to store more than the swap header, but in
* case something changes in the future, let's catch it
* here rather than later.
*/
btrfs_warn(fs_info, "swapfile must not be inline");
ret = -EINVAL;
goto out;
}
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
btrfs_warn(fs_info, "swapfile must not be compressed");
ret = -EINVAL;
goto out;
}
logical_block_start = em->block_start + (start - em->start);
len = min(len, em->len - (start - em->start));
free_extent_map(em);
em = NULL;
ret = can_nocow_extent(inode, start, &len, NULL, NULL, NULL);
if (ret < 0) {
goto out;
} else if (ret) {
ret = 0;
} else {
btrfs_warn(fs_info,
"swapfile must not be copy-on-write");
ret = -EINVAL;
goto out;
}
em = btrfs_get_chunk_map(fs_info, logical_block_start, len);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out;
}
if (em->map_lookup->type & BTRFS_BLOCK_GROUP_PROFILE_MASK) {
btrfs_warn(fs_info,
"swapfile must have single data profile");
ret = -EINVAL;
goto out;
}
if (device == NULL) {
device = em->map_lookup->stripes[0].dev;
ret = btrfs_add_swapfile_pin(inode, device, false);
if (ret == 1)
ret = 0;
else if (ret)
goto out;
} else if (device != em->map_lookup->stripes[0].dev) {
btrfs_warn(fs_info, "swapfile must be on one device");
ret = -EINVAL;
goto out;
}
physical_block_start = (em->map_lookup->stripes[0].physical +
(logical_block_start - em->start));
len = min(len, em->len - (logical_block_start - em->start));
free_extent_map(em);
em = NULL;
bg = btrfs_lookup_block_group(fs_info, logical_block_start);
if (!bg) {
btrfs_warn(fs_info,
"could not find block group containing swapfile");
ret = -EINVAL;
goto out;
}
ret = btrfs_add_swapfile_pin(inode, bg, true);
if (ret) {
btrfs_put_block_group(bg);
if (ret == 1)
ret = 0;
else
goto out;
}
if (bsi.block_len &&
bsi.block_start + bsi.block_len == physical_block_start) {
bsi.block_len += len;
} else {
if (bsi.block_len) {
ret = btrfs_add_swap_extent(sis, &bsi);
if (ret)
goto out;
}
bsi.start = start;
bsi.block_start = physical_block_start;
bsi.block_len = len;
}
start += len;
}
if (bsi.block_len)
ret = btrfs_add_swap_extent(sis, &bsi);
out:
if (!IS_ERR_OR_NULL(em))
free_extent_map(em);
unlock_extent_cached(io_tree, 0, isize - 1, &cached_state);
if (ret)
btrfs_swap_deactivate(file);
clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
if (ret)
return ret;
if (device)
sis->bdev = device->bdev;
*span = bsi.highest_ppage - bsi.lowest_ppage + 1;
sis->max = bsi.nr_pages;
sis->pages = bsi.nr_pages - 1;
sis->highest_bit = bsi.nr_pages - 1;
return bsi.nr_extents;
}
#else
static void btrfs_swap_deactivate(struct file *file)
{
}
static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file,
sector_t *span)
{
return -EOPNOTSUPP;
}
#endif
static const struct inode_operations btrfs_dir_inode_operations = {
.getattr = btrfs_getattr,
.lookup = btrfs_lookup,
.create = btrfs_create,
.unlink = btrfs_unlink,
.link = btrfs_link,
.mkdir = btrfs_mkdir,
.rmdir = btrfs_rmdir,
.rename = btrfs_rename2,
.symlink = btrfs_symlink,
.setattr = btrfs_setattr,
.mknod = btrfs_mknod,
.listxattr = btrfs_listxattr,
.permission = btrfs_permission,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
.tmpfile = btrfs_tmpfile,
};
static const struct file_operations btrfs_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
.iterate_shared = btrfs_real_readdir,
.open = btrfs_opendir,
.unlocked_ioctl = btrfs_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = btrfs_compat_ioctl,
#endif
.release = btrfs_release_file,
.fsync = btrfs_sync_file,
};
static const struct extent_io_ops btrfs_extent_io_ops = {
/* mandatory callbacks */
.submit_bio_hook = btrfs_submit_bio_hook,
.readpage_end_io_hook = btrfs_readpage_end_io_hook,
};
/*
* btrfs doesn't support the bmap operation because swapfiles
* use bmap to make a mapping of extents in the file. They assume
* these extents won't change over the life of the file and they
* use the bmap result to do IO directly to the drive.
*
* the btrfs bmap call would return logical addresses that aren't
* suitable for IO and they also will change frequently as COW
* operations happen. So, swapfile + btrfs == corruption.
*
* For now we're avoiding this by dropping bmap.
*/
static const struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
.writepage = btrfs_writepage,
.writepages = btrfs_writepages,
.readpages = btrfs_readpages,
.direct_IO = btrfs_direct_IO,
.invalidatepage = btrfs_invalidatepage,
.releasepage = btrfs_releasepage,
.set_page_dirty = btrfs_set_page_dirty,
.error_remove_page = generic_error_remove_page,
.swap_activate = btrfs_swap_activate,
.swap_deactivate = btrfs_swap_deactivate,
};
static const struct inode_operations btrfs_file_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.listxattr = btrfs_listxattr,
.permission = btrfs_permission,
.fiemap = btrfs_fiemap,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_special_inode_operations = {
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.listxattr = btrfs_listxattr,
.get_acl = btrfs_get_acl,
.set_acl = btrfs_set_acl,
.update_time = btrfs_update_time,
};
static const struct inode_operations btrfs_symlink_inode_operations = {
.get_link = page_get_link,
.getattr = btrfs_getattr,
.setattr = btrfs_setattr,
.permission = btrfs_permission,
.listxattr = btrfs_listxattr,
.update_time = btrfs_update_time,
};
const struct dentry_operations btrfs_dentry_operations = {
.d_delete = btrfs_dentry_delete,
};
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