linux/fs/btrfs/free-space-cache.c
David Sterba 913e153572 btrfs: drop newlines from strings when using btrfs_* helpers
The helpers append "\n" so we can keep the actual strings shorter. The
extra newline will print an empty line.  Some messages have been
slightly modified to be more consistent with the rest (lowercase first
letter).

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:02 +02:00

3716 lines
92 KiB
C

/*
* Copyright (C) 2008 Red Hat. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public
* License v2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 021110-1307, USA.
*/
#include <linux/pagemap.h>
#include <linux/sched.h>
#include <linux/sched/signal.h>
#include <linux/slab.h>
#include <linux/math64.h>
#include <linux/ratelimit.h>
#include "ctree.h"
#include "free-space-cache.h"
#include "transaction.h"
#include "disk-io.h"
#include "extent_io.h"
#include "inode-map.h"
#include "volumes.h"
#define BITS_PER_BITMAP (PAGE_SIZE * 8UL)
#define MAX_CACHE_BYTES_PER_GIG SZ_32K
struct btrfs_trim_range {
u64 start;
u64 bytes;
struct list_head list;
};
static int link_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info);
static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info);
static int btrfs_wait_cache_io_root(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_io_ctl *io_ctl,
struct btrfs_path *path);
static struct inode *__lookup_free_space_inode(struct btrfs_root *root,
struct btrfs_path *path,
u64 offset)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key key;
struct btrfs_key location;
struct btrfs_disk_key disk_key;
struct btrfs_free_space_header *header;
struct extent_buffer *leaf;
struct inode *inode = NULL;
int ret;
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = offset;
key.type = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ERR_PTR(ret);
if (ret > 0) {
btrfs_release_path(path);
return ERR_PTR(-ENOENT);
}
leaf = path->nodes[0];
header = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_free_space_header);
btrfs_free_space_key(leaf, header, &disk_key);
btrfs_disk_key_to_cpu(&location, &disk_key);
btrfs_release_path(path);
inode = btrfs_iget(fs_info->sb, &location, root, NULL);
if (IS_ERR(inode))
return inode;
if (is_bad_inode(inode)) {
iput(inode);
return ERR_PTR(-ENOENT);
}
mapping_set_gfp_mask(inode->i_mapping,
mapping_gfp_constraint(inode->i_mapping,
~(__GFP_FS | __GFP_HIGHMEM)));
return inode;
}
struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache
*block_group, struct btrfs_path *path)
{
struct inode *inode = NULL;
u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
spin_lock(&block_group->lock);
if (block_group->inode)
inode = igrab(block_group->inode);
spin_unlock(&block_group->lock);
if (inode)
return inode;
inode = __lookup_free_space_inode(fs_info->tree_root, path,
block_group->key.objectid);
if (IS_ERR(inode))
return inode;
spin_lock(&block_group->lock);
if (!((BTRFS_I(inode)->flags & flags) == flags)) {
btrfs_info(fs_info, "Old style space inode found, converting.");
BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM |
BTRFS_INODE_NODATACOW;
block_group->disk_cache_state = BTRFS_DC_CLEAR;
}
if (!block_group->iref) {
block_group->inode = igrab(inode);
block_group->iref = 1;
}
spin_unlock(&block_group->lock);
return inode;
}
static int __create_free_space_inode(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_path *path,
u64 ino, u64 offset)
{
struct btrfs_key key;
struct btrfs_disk_key disk_key;
struct btrfs_free_space_header *header;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
u64 flags = BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC;
int ret;
ret = btrfs_insert_empty_inode(trans, root, path, ino);
if (ret)
return ret;
/* We inline crc's for the free disk space cache */
if (ino != BTRFS_FREE_INO_OBJECTID)
flags |= BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
leaf = path->nodes[0];
inode_item = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_inode_item);
btrfs_item_key(leaf, &disk_key, path->slots[0]);
memzero_extent_buffer(leaf, (unsigned long)inode_item,
sizeof(*inode_item));
btrfs_set_inode_generation(leaf, inode_item, trans->transid);
btrfs_set_inode_size(leaf, inode_item, 0);
btrfs_set_inode_nbytes(leaf, inode_item, 0);
btrfs_set_inode_uid(leaf, inode_item, 0);
btrfs_set_inode_gid(leaf, inode_item, 0);
btrfs_set_inode_mode(leaf, inode_item, S_IFREG | 0600);
btrfs_set_inode_flags(leaf, inode_item, flags);
btrfs_set_inode_nlink(leaf, inode_item, 1);
btrfs_set_inode_transid(leaf, inode_item, trans->transid);
btrfs_set_inode_block_group(leaf, inode_item, offset);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = offset;
key.type = 0;
ret = btrfs_insert_empty_item(trans, root, path, &key,
sizeof(struct btrfs_free_space_header));
if (ret < 0) {
btrfs_release_path(path);
return ret;
}
leaf = path->nodes[0];
header = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_free_space_header);
memzero_extent_buffer(leaf, (unsigned long)header, sizeof(*header));
btrfs_set_free_space_key(leaf, header, &disk_key);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
return 0;
}
int create_free_space_inode(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
int ret;
u64 ino;
ret = btrfs_find_free_objectid(fs_info->tree_root, &ino);
if (ret < 0)
return ret;
return __create_free_space_inode(fs_info->tree_root, trans, path, ino,
block_group->key.objectid);
}
int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
struct btrfs_block_rsv *rsv)
{
u64 needed_bytes;
int ret;
/* 1 for slack space, 1 for updating the inode */
needed_bytes = btrfs_calc_trunc_metadata_size(fs_info, 1) +
btrfs_calc_trans_metadata_size(fs_info, 1);
spin_lock(&rsv->lock);
if (rsv->reserved < needed_bytes)
ret = -ENOSPC;
else
ret = 0;
spin_unlock(&rsv->lock);
return ret;
}
int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct inode *inode)
{
struct btrfs_root *root = BTRFS_I(inode)->root;
int ret = 0;
bool locked = false;
if (block_group) {
struct btrfs_path *path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto fail;
}
locked = true;
mutex_lock(&trans->transaction->cache_write_mutex);
if (!list_empty(&block_group->io_list)) {
list_del_init(&block_group->io_list);
btrfs_wait_cache_io(trans, block_group, path);
btrfs_put_block_group(block_group);
}
/*
* now that we've truncated the cache away, its no longer
* setup or written
*/
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_CLEAR;
spin_unlock(&block_group->lock);
btrfs_free_path(path);
}
btrfs_i_size_write(BTRFS_I(inode), 0);
truncate_pagecache(inode, 0);
/*
* We don't need an orphan item because truncating the free space cache
* will never be split across transactions.
* We don't need to check for -EAGAIN because we're a free space
* cache inode
*/
ret = btrfs_truncate_inode_items(trans, root, inode,
0, BTRFS_EXTENT_DATA_KEY);
if (ret)
goto fail;
ret = btrfs_update_inode(trans, root, inode);
fail:
if (locked)
mutex_unlock(&trans->transaction->cache_write_mutex);
if (ret)
btrfs_abort_transaction(trans, ret);
return ret;
}
static void readahead_cache(struct inode *inode)
{
struct file_ra_state *ra;
unsigned long last_index;
ra = kzalloc(sizeof(*ra), GFP_NOFS);
if (!ra)
return;
file_ra_state_init(ra, inode->i_mapping);
last_index = (i_size_read(inode) - 1) >> PAGE_SHIFT;
page_cache_sync_readahead(inode->i_mapping, ra, NULL, 0, last_index);
kfree(ra);
}
static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
int write)
{
int num_pages;
int check_crcs = 0;
num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);
if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FREE_INO_OBJECTID)
check_crcs = 1;
/* Make sure we can fit our crcs into the first page */
if (write && check_crcs &&
(num_pages * sizeof(u32)) >= PAGE_SIZE)
return -ENOSPC;
memset(io_ctl, 0, sizeof(struct btrfs_io_ctl));
io_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);
if (!io_ctl->pages)
return -ENOMEM;
io_ctl->num_pages = num_pages;
io_ctl->fs_info = btrfs_sb(inode->i_sb);
io_ctl->check_crcs = check_crcs;
io_ctl->inode = inode;
return 0;
}
static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
{
kfree(io_ctl->pages);
io_ctl->pages = NULL;
}
static void io_ctl_unmap_page(struct btrfs_io_ctl *io_ctl)
{
if (io_ctl->cur) {
io_ctl->cur = NULL;
io_ctl->orig = NULL;
}
}
static void io_ctl_map_page(struct btrfs_io_ctl *io_ctl, int clear)
{
ASSERT(io_ctl->index < io_ctl->num_pages);
io_ctl->page = io_ctl->pages[io_ctl->index++];
io_ctl->cur = page_address(io_ctl->page);
io_ctl->orig = io_ctl->cur;
io_ctl->size = PAGE_SIZE;
if (clear)
clear_page(io_ctl->cur);
}
static void io_ctl_drop_pages(struct btrfs_io_ctl *io_ctl)
{
int i;
io_ctl_unmap_page(io_ctl);
for (i = 0; i < io_ctl->num_pages; i++) {
if (io_ctl->pages[i]) {
ClearPageChecked(io_ctl->pages[i]);
unlock_page(io_ctl->pages[i]);
put_page(io_ctl->pages[i]);
}
}
}
static int io_ctl_prepare_pages(struct btrfs_io_ctl *io_ctl, struct inode *inode,
int uptodate)
{
struct page *page;
gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
int i;
for (i = 0; i < io_ctl->num_pages; i++) {
page = find_or_create_page(inode->i_mapping, i, mask);
if (!page) {
io_ctl_drop_pages(io_ctl);
return -ENOMEM;
}
io_ctl->pages[i] = page;
if (uptodate && !PageUptodate(page)) {
btrfs_readpage(NULL, page);
lock_page(page);
if (!PageUptodate(page)) {
btrfs_err(BTRFS_I(inode)->root->fs_info,
"error reading free space cache");
io_ctl_drop_pages(io_ctl);
return -EIO;
}
}
}
for (i = 0; i < io_ctl->num_pages; i++) {
clear_page_dirty_for_io(io_ctl->pages[i]);
set_page_extent_mapped(io_ctl->pages[i]);
}
return 0;
}
static void io_ctl_set_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
{
__le64 *val;
io_ctl_map_page(io_ctl, 1);
/*
* Skip the csum areas. If we don't check crcs then we just have a
* 64bit chunk at the front of the first page.
*/
if (io_ctl->check_crcs) {
io_ctl->cur += (sizeof(u32) * io_ctl->num_pages);
io_ctl->size -= sizeof(u64) + (sizeof(u32) * io_ctl->num_pages);
} else {
io_ctl->cur += sizeof(u64);
io_ctl->size -= sizeof(u64) * 2;
}
val = io_ctl->cur;
*val = cpu_to_le64(generation);
io_ctl->cur += sizeof(u64);
}
static int io_ctl_check_generation(struct btrfs_io_ctl *io_ctl, u64 generation)
{
__le64 *gen;
/*
* Skip the crc area. If we don't check crcs then we just have a 64bit
* chunk at the front of the first page.
*/
if (io_ctl->check_crcs) {
io_ctl->cur += sizeof(u32) * io_ctl->num_pages;
io_ctl->size -= sizeof(u64) +
(sizeof(u32) * io_ctl->num_pages);
} else {
io_ctl->cur += sizeof(u64);
io_ctl->size -= sizeof(u64) * 2;
}
gen = io_ctl->cur;
if (le64_to_cpu(*gen) != generation) {
btrfs_err_rl(io_ctl->fs_info,
"space cache generation (%llu) does not match inode (%llu)",
*gen, generation);
io_ctl_unmap_page(io_ctl);
return -EIO;
}
io_ctl->cur += sizeof(u64);
return 0;
}
static void io_ctl_set_crc(struct btrfs_io_ctl *io_ctl, int index)
{
u32 *tmp;
u32 crc = ~(u32)0;
unsigned offset = 0;
if (!io_ctl->check_crcs) {
io_ctl_unmap_page(io_ctl);
return;
}
if (index == 0)
offset = sizeof(u32) * io_ctl->num_pages;
crc = btrfs_csum_data(io_ctl->orig + offset, crc,
PAGE_SIZE - offset);
btrfs_csum_final(crc, (u8 *)&crc);
io_ctl_unmap_page(io_ctl);
tmp = page_address(io_ctl->pages[0]);
tmp += index;
*tmp = crc;
}
static int io_ctl_check_crc(struct btrfs_io_ctl *io_ctl, int index)
{
u32 *tmp, val;
u32 crc = ~(u32)0;
unsigned offset = 0;
if (!io_ctl->check_crcs) {
io_ctl_map_page(io_ctl, 0);
return 0;
}
if (index == 0)
offset = sizeof(u32) * io_ctl->num_pages;
tmp = page_address(io_ctl->pages[0]);
tmp += index;
val = *tmp;
io_ctl_map_page(io_ctl, 0);
crc = btrfs_csum_data(io_ctl->orig + offset, crc,
PAGE_SIZE - offset);
btrfs_csum_final(crc, (u8 *)&crc);
if (val != crc) {
btrfs_err_rl(io_ctl->fs_info,
"csum mismatch on free space cache");
io_ctl_unmap_page(io_ctl);
return -EIO;
}
return 0;
}
static int io_ctl_add_entry(struct btrfs_io_ctl *io_ctl, u64 offset, u64 bytes,
void *bitmap)
{
struct btrfs_free_space_entry *entry;
if (!io_ctl->cur)
return -ENOSPC;
entry = io_ctl->cur;
entry->offset = cpu_to_le64(offset);
entry->bytes = cpu_to_le64(bytes);
entry->type = (bitmap) ? BTRFS_FREE_SPACE_BITMAP :
BTRFS_FREE_SPACE_EXTENT;
io_ctl->cur += sizeof(struct btrfs_free_space_entry);
io_ctl->size -= sizeof(struct btrfs_free_space_entry);
if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
return 0;
io_ctl_set_crc(io_ctl, io_ctl->index - 1);
/* No more pages to map */
if (io_ctl->index >= io_ctl->num_pages)
return 0;
/* map the next page */
io_ctl_map_page(io_ctl, 1);
return 0;
}
static int io_ctl_add_bitmap(struct btrfs_io_ctl *io_ctl, void *bitmap)
{
if (!io_ctl->cur)
return -ENOSPC;
/*
* If we aren't at the start of the current page, unmap this one and
* map the next one if there is any left.
*/
if (io_ctl->cur != io_ctl->orig) {
io_ctl_set_crc(io_ctl, io_ctl->index - 1);
if (io_ctl->index >= io_ctl->num_pages)
return -ENOSPC;
io_ctl_map_page(io_ctl, 0);
}
memcpy(io_ctl->cur, bitmap, PAGE_SIZE);
io_ctl_set_crc(io_ctl, io_ctl->index - 1);
if (io_ctl->index < io_ctl->num_pages)
io_ctl_map_page(io_ctl, 0);
return 0;
}
static void io_ctl_zero_remaining_pages(struct btrfs_io_ctl *io_ctl)
{
/*
* If we're not on the boundary we know we've modified the page and we
* need to crc the page.
*/
if (io_ctl->cur != io_ctl->orig)
io_ctl_set_crc(io_ctl, io_ctl->index - 1);
else
io_ctl_unmap_page(io_ctl);
while (io_ctl->index < io_ctl->num_pages) {
io_ctl_map_page(io_ctl, 1);
io_ctl_set_crc(io_ctl, io_ctl->index - 1);
}
}
static int io_ctl_read_entry(struct btrfs_io_ctl *io_ctl,
struct btrfs_free_space *entry, u8 *type)
{
struct btrfs_free_space_entry *e;
int ret;
if (!io_ctl->cur) {
ret = io_ctl_check_crc(io_ctl, io_ctl->index);
if (ret)
return ret;
}
e = io_ctl->cur;
entry->offset = le64_to_cpu(e->offset);
entry->bytes = le64_to_cpu(e->bytes);
*type = e->type;
io_ctl->cur += sizeof(struct btrfs_free_space_entry);
io_ctl->size -= sizeof(struct btrfs_free_space_entry);
if (io_ctl->size >= sizeof(struct btrfs_free_space_entry))
return 0;
io_ctl_unmap_page(io_ctl);
return 0;
}
static int io_ctl_read_bitmap(struct btrfs_io_ctl *io_ctl,
struct btrfs_free_space *entry)
{
int ret;
ret = io_ctl_check_crc(io_ctl, io_ctl->index);
if (ret)
return ret;
memcpy(entry->bitmap, io_ctl->cur, PAGE_SIZE);
io_ctl_unmap_page(io_ctl);
return 0;
}
/*
* Since we attach pinned extents after the fact we can have contiguous sections
* of free space that are split up in entries. This poses a problem with the
* tree logging stuff since it could have allocated across what appears to be 2
* entries since we would have merged the entries when adding the pinned extents
* back to the free space cache. So run through the space cache that we just
* loaded and merge contiguous entries. This will make the log replay stuff not
* blow up and it will make for nicer allocator behavior.
*/
static void merge_space_tree(struct btrfs_free_space_ctl *ctl)
{
struct btrfs_free_space *e, *prev = NULL;
struct rb_node *n;
again:
spin_lock(&ctl->tree_lock);
for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
e = rb_entry(n, struct btrfs_free_space, offset_index);
if (!prev)
goto next;
if (e->bitmap || prev->bitmap)
goto next;
if (prev->offset + prev->bytes == e->offset) {
unlink_free_space(ctl, prev);
unlink_free_space(ctl, e);
prev->bytes += e->bytes;
kmem_cache_free(btrfs_free_space_cachep, e);
link_free_space(ctl, prev);
prev = NULL;
spin_unlock(&ctl->tree_lock);
goto again;
}
next:
prev = e;
}
spin_unlock(&ctl->tree_lock);
}
static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode,
struct btrfs_free_space_ctl *ctl,
struct btrfs_path *path, u64 offset)
{
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_free_space_header *header;
struct extent_buffer *leaf;
struct btrfs_io_ctl io_ctl;
struct btrfs_key key;
struct btrfs_free_space *e, *n;
LIST_HEAD(bitmaps);
u64 num_entries;
u64 num_bitmaps;
u64 generation;
u8 type;
int ret = 0;
/* Nothing in the space cache, goodbye */
if (!i_size_read(inode))
return 0;
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = offset;
key.type = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return 0;
else if (ret > 0) {
btrfs_release_path(path);
return 0;
}
ret = -1;
leaf = path->nodes[0];
header = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_free_space_header);
num_entries = btrfs_free_space_entries(leaf, header);
num_bitmaps = btrfs_free_space_bitmaps(leaf, header);
generation = btrfs_free_space_generation(leaf, header);
btrfs_release_path(path);
if (!BTRFS_I(inode)->generation) {
btrfs_info(fs_info,
"the free space cache file (%llu) is invalid, skip it",
offset);
return 0;
}
if (BTRFS_I(inode)->generation != generation) {
btrfs_err(fs_info,
"free space inode generation (%llu) did not match free space cache generation (%llu)",
BTRFS_I(inode)->generation, generation);
return 0;
}
if (!num_entries)
return 0;
ret = io_ctl_init(&io_ctl, inode, 0);
if (ret)
return ret;
readahead_cache(inode);
ret = io_ctl_prepare_pages(&io_ctl, inode, 1);
if (ret)
goto out;
ret = io_ctl_check_crc(&io_ctl, 0);
if (ret)
goto free_cache;
ret = io_ctl_check_generation(&io_ctl, generation);
if (ret)
goto free_cache;
while (num_entries) {
e = kmem_cache_zalloc(btrfs_free_space_cachep,
GFP_NOFS);
if (!e)
goto free_cache;
ret = io_ctl_read_entry(&io_ctl, e, &type);
if (ret) {
kmem_cache_free(btrfs_free_space_cachep, e);
goto free_cache;
}
if (!e->bytes) {
kmem_cache_free(btrfs_free_space_cachep, e);
goto free_cache;
}
if (type == BTRFS_FREE_SPACE_EXTENT) {
spin_lock(&ctl->tree_lock);
ret = link_free_space(ctl, e);
spin_unlock(&ctl->tree_lock);
if (ret) {
btrfs_err(fs_info,
"Duplicate entries in free space cache, dumping");
kmem_cache_free(btrfs_free_space_cachep, e);
goto free_cache;
}
} else {
ASSERT(num_bitmaps);
num_bitmaps--;
e->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
if (!e->bitmap) {
kmem_cache_free(
btrfs_free_space_cachep, e);
goto free_cache;
}
spin_lock(&ctl->tree_lock);
ret = link_free_space(ctl, e);
ctl->total_bitmaps++;
ctl->op->recalc_thresholds(ctl);
spin_unlock(&ctl->tree_lock);
if (ret) {
btrfs_err(fs_info,
"Duplicate entries in free space cache, dumping");
kmem_cache_free(btrfs_free_space_cachep, e);
goto free_cache;
}
list_add_tail(&e->list, &bitmaps);
}
num_entries--;
}
io_ctl_unmap_page(&io_ctl);
/*
* We add the bitmaps at the end of the entries in order that
* the bitmap entries are added to the cache.
*/
list_for_each_entry_safe(e, n, &bitmaps, list) {
list_del_init(&e->list);
ret = io_ctl_read_bitmap(&io_ctl, e);
if (ret)
goto free_cache;
}
io_ctl_drop_pages(&io_ctl);
merge_space_tree(ctl);
ret = 1;
out:
io_ctl_free(&io_ctl);
return ret;
free_cache:
io_ctl_drop_pages(&io_ctl);
__btrfs_remove_free_space_cache(ctl);
goto out;
}
int load_free_space_cache(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct inode *inode;
struct btrfs_path *path;
int ret = 0;
bool matched;
u64 used = btrfs_block_group_used(&block_group->item);
/*
* If this block group has been marked to be cleared for one reason or
* another then we can't trust the on disk cache, so just return.
*/
spin_lock(&block_group->lock);
if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
spin_unlock(&block_group->lock);
return 0;
}
spin_unlock(&block_group->lock);
path = btrfs_alloc_path();
if (!path)
return 0;
path->search_commit_root = 1;
path->skip_locking = 1;
inode = lookup_free_space_inode(fs_info, block_group, path);
if (IS_ERR(inode)) {
btrfs_free_path(path);
return 0;
}
/* We may have converted the inode and made the cache invalid. */
spin_lock(&block_group->lock);
if (block_group->disk_cache_state != BTRFS_DC_WRITTEN) {
spin_unlock(&block_group->lock);
btrfs_free_path(path);
goto out;
}
spin_unlock(&block_group->lock);
ret = __load_free_space_cache(fs_info->tree_root, inode, ctl,
path, block_group->key.objectid);
btrfs_free_path(path);
if (ret <= 0)
goto out;
spin_lock(&ctl->tree_lock);
matched = (ctl->free_space == (block_group->key.offset - used -
block_group->bytes_super));
spin_unlock(&ctl->tree_lock);
if (!matched) {
__btrfs_remove_free_space_cache(ctl);
btrfs_warn(fs_info,
"block group %llu has wrong amount of free space",
block_group->key.objectid);
ret = -1;
}
out:
if (ret < 0) {
/* This cache is bogus, make sure it gets cleared */
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_CLEAR;
spin_unlock(&block_group->lock);
ret = 0;
btrfs_warn(fs_info,
"failed to load free space cache for block group %llu, rebuilding it now",
block_group->key.objectid);
}
iput(inode);
return ret;
}
static noinline_for_stack
int write_cache_extent_entries(struct btrfs_io_ctl *io_ctl,
struct btrfs_free_space_ctl *ctl,
struct btrfs_block_group_cache *block_group,
int *entries, int *bitmaps,
struct list_head *bitmap_list)
{
int ret;
struct btrfs_free_cluster *cluster = NULL;
struct btrfs_free_cluster *cluster_locked = NULL;
struct rb_node *node = rb_first(&ctl->free_space_offset);
struct btrfs_trim_range *trim_entry;
/* Get the cluster for this block_group if it exists */
if (block_group && !list_empty(&block_group->cluster_list)) {
cluster = list_entry(block_group->cluster_list.next,
struct btrfs_free_cluster,
block_group_list);
}
if (!node && cluster) {
cluster_locked = cluster;
spin_lock(&cluster_locked->lock);
node = rb_first(&cluster->root);
cluster = NULL;
}
/* Write out the extent entries */
while (node) {
struct btrfs_free_space *e;
e = rb_entry(node, struct btrfs_free_space, offset_index);
*entries += 1;
ret = io_ctl_add_entry(io_ctl, e->offset, e->bytes,
e->bitmap);
if (ret)
goto fail;
if (e->bitmap) {
list_add_tail(&e->list, bitmap_list);
*bitmaps += 1;
}
node = rb_next(node);
if (!node && cluster) {
node = rb_first(&cluster->root);
cluster_locked = cluster;
spin_lock(&cluster_locked->lock);
cluster = NULL;
}
}
if (cluster_locked) {
spin_unlock(&cluster_locked->lock);
cluster_locked = NULL;
}
/*
* Make sure we don't miss any range that was removed from our rbtree
* because trimming is running. Otherwise after a umount+mount (or crash
* after committing the transaction) we would leak free space and get
* an inconsistent free space cache report from fsck.
*/
list_for_each_entry(trim_entry, &ctl->trimming_ranges, list) {
ret = io_ctl_add_entry(io_ctl, trim_entry->start,
trim_entry->bytes, NULL);
if (ret)
goto fail;
*entries += 1;
}
return 0;
fail:
if (cluster_locked)
spin_unlock(&cluster_locked->lock);
return -ENOSPC;
}
static noinline_for_stack int
update_cache_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode,
struct btrfs_path *path, u64 offset,
int entries, int bitmaps)
{
struct btrfs_key key;
struct btrfs_free_space_header *header;
struct extent_buffer *leaf;
int ret;
key.objectid = BTRFS_FREE_SPACE_OBJECTID;
key.offset = offset;
key.type = 0;
ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
if (ret < 0) {
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
GFP_NOFS);
goto fail;
}
leaf = path->nodes[0];
if (ret > 0) {
struct btrfs_key found_key;
ASSERT(path->slots[0]);
path->slots[0]--;
btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
if (found_key.objectid != BTRFS_FREE_SPACE_OBJECTID ||
found_key.offset != offset) {
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0,
inode->i_size - 1,
EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0,
NULL, GFP_NOFS);
btrfs_release_path(path);
goto fail;
}
}
BTRFS_I(inode)->generation = trans->transid;
header = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_free_space_header);
btrfs_set_free_space_entries(leaf, header, entries);
btrfs_set_free_space_bitmaps(leaf, header, bitmaps);
btrfs_set_free_space_generation(leaf, header, trans->transid);
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
return 0;
fail:
return -1;
}
static noinline_for_stack int
write_pinned_extent_entries(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group,
struct btrfs_io_ctl *io_ctl,
int *entries)
{
u64 start, extent_start, extent_end, len;
struct extent_io_tree *unpin = NULL;
int ret;
if (!block_group)
return 0;
/*
* We want to add any pinned extents to our free space cache
* so we don't leak the space
*
* We shouldn't have switched the pinned extents yet so this is the
* right one
*/
unpin = fs_info->pinned_extents;
start = block_group->key.objectid;
while (start < block_group->key.objectid + block_group->key.offset) {
ret = find_first_extent_bit(unpin, start,
&extent_start, &extent_end,
EXTENT_DIRTY, NULL);
if (ret)
return 0;
/* This pinned extent is out of our range */
if (extent_start >= block_group->key.objectid +
block_group->key.offset)
return 0;
extent_start = max(extent_start, start);
extent_end = min(block_group->key.objectid +
block_group->key.offset, extent_end + 1);
len = extent_end - extent_start;
*entries += 1;
ret = io_ctl_add_entry(io_ctl, extent_start, len, NULL);
if (ret)
return -ENOSPC;
start = extent_end;
}
return 0;
}
static noinline_for_stack int
write_bitmap_entries(struct btrfs_io_ctl *io_ctl, struct list_head *bitmap_list)
{
struct btrfs_free_space *entry, *next;
int ret;
/* Write out the bitmaps */
list_for_each_entry_safe(entry, next, bitmap_list, list) {
ret = io_ctl_add_bitmap(io_ctl, entry->bitmap);
if (ret)
return -ENOSPC;
list_del_init(&entry->list);
}
return 0;
}
static int flush_dirty_cache(struct inode *inode)
{
int ret;
ret = btrfs_wait_ordered_range(inode, 0, (u64)-1);
if (ret)
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, inode->i_size - 1,
EXTENT_DIRTY | EXTENT_DELALLOC, 0, 0, NULL,
GFP_NOFS);
return ret;
}
static void noinline_for_stack
cleanup_bitmap_list(struct list_head *bitmap_list)
{
struct btrfs_free_space *entry, *next;
list_for_each_entry_safe(entry, next, bitmap_list, list)
list_del_init(&entry->list);
}
static void noinline_for_stack
cleanup_write_cache_enospc(struct inode *inode,
struct btrfs_io_ctl *io_ctl,
struct extent_state **cached_state)
{
io_ctl_drop_pages(io_ctl);
unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
i_size_read(inode) - 1, cached_state,
GFP_NOFS);
}
static int __btrfs_wait_cache_io(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_io_ctl *io_ctl,
struct btrfs_path *path, u64 offset)
{
int ret;
struct inode *inode = io_ctl->inode;
struct btrfs_fs_info *fs_info;
if (!inode)
return 0;
fs_info = btrfs_sb(inode->i_sb);
/* Flush the dirty pages in the cache file. */
ret = flush_dirty_cache(inode);
if (ret)
goto out;
/* Update the cache item to tell everyone this cache file is valid. */
ret = update_cache_item(trans, root, inode, path, offset,
io_ctl->entries, io_ctl->bitmaps);
out:
io_ctl_free(io_ctl);
if (ret) {
invalidate_inode_pages2(inode->i_mapping);
BTRFS_I(inode)->generation = 0;
if (block_group) {
#ifdef DEBUG
btrfs_err(fs_info,
"failed to write free space cache for block group %llu",
block_group->key.objectid);
#endif
}
}
btrfs_update_inode(trans, root, inode);
if (block_group) {
/* the dirty list is protected by the dirty_bgs_lock */
spin_lock(&trans->transaction->dirty_bgs_lock);
/* the disk_cache_state is protected by the block group lock */
spin_lock(&block_group->lock);
/*
* only mark this as written if we didn't get put back on
* the dirty list while waiting for IO. Otherwise our
* cache state won't be right, and we won't get written again
*/
if (!ret && list_empty(&block_group->dirty_list))
block_group->disk_cache_state = BTRFS_DC_WRITTEN;
else if (ret)
block_group->disk_cache_state = BTRFS_DC_ERROR;
spin_unlock(&block_group->lock);
spin_unlock(&trans->transaction->dirty_bgs_lock);
io_ctl->inode = NULL;
iput(inode);
}
return ret;
}
static int btrfs_wait_cache_io_root(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_io_ctl *io_ctl,
struct btrfs_path *path)
{
return __btrfs_wait_cache_io(root, trans, NULL, io_ctl, path, 0);
}
int btrfs_wait_cache_io(struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
return __btrfs_wait_cache_io(block_group->fs_info->tree_root, trans,
block_group, &block_group->io_ctl,
path, block_group->key.objectid);
}
/**
* __btrfs_write_out_cache - write out cached info to an inode
* @root - the root the inode belongs to
* @ctl - the free space cache we are going to write out
* @block_group - the block_group for this cache if it belongs to a block_group
* @trans - the trans handle
*
* This function writes out a free space cache struct to disk for quick recovery
* on mount. This will return 0 if it was successful in writing the cache out,
* or an errno if it was not.
*/
static int __btrfs_write_out_cache(struct btrfs_root *root, struct inode *inode,
struct btrfs_free_space_ctl *ctl,
struct btrfs_block_group_cache *block_group,
struct btrfs_io_ctl *io_ctl,
struct btrfs_trans_handle *trans)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_state *cached_state = NULL;
LIST_HEAD(bitmap_list);
int entries = 0;
int bitmaps = 0;
int ret;
int must_iput = 0;
if (!i_size_read(inode))
return -EIO;
WARN_ON(io_ctl->pages);
ret = io_ctl_init(io_ctl, inode, 1);
if (ret)
return ret;
if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA)) {
down_write(&block_group->data_rwsem);
spin_lock(&block_group->lock);
if (block_group->delalloc_bytes) {
block_group->disk_cache_state = BTRFS_DC_WRITTEN;
spin_unlock(&block_group->lock);
up_write(&block_group->data_rwsem);
BTRFS_I(inode)->generation = 0;
ret = 0;
must_iput = 1;
goto out;
}
spin_unlock(&block_group->lock);
}
/* Lock all pages first so we can lock the extent safely. */
ret = io_ctl_prepare_pages(io_ctl, inode, 0);
if (ret)
goto out;
lock_extent_bits(&BTRFS_I(inode)->io_tree, 0, i_size_read(inode) - 1,
&cached_state);
io_ctl_set_generation(io_ctl, trans->transid);
mutex_lock(&ctl->cache_writeout_mutex);
/* Write out the extent entries in the free space cache */
spin_lock(&ctl->tree_lock);
ret = write_cache_extent_entries(io_ctl, ctl,
block_group, &entries, &bitmaps,
&bitmap_list);
if (ret)
goto out_nospc_locked;
/*
* Some spaces that are freed in the current transaction are pinned,
* they will be added into free space cache after the transaction is
* committed, we shouldn't lose them.
*
* If this changes while we are working we'll get added back to
* the dirty list and redo it. No locking needed
*/
ret = write_pinned_extent_entries(fs_info, block_group,
io_ctl, &entries);
if (ret)
goto out_nospc_locked;
/*
* At last, we write out all the bitmaps and keep cache_writeout_mutex
* locked while doing it because a concurrent trim can be manipulating
* or freeing the bitmap.
*/
ret = write_bitmap_entries(io_ctl, &bitmap_list);
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
if (ret)
goto out_nospc;
/* Zero out the rest of the pages just to make sure */
io_ctl_zero_remaining_pages(io_ctl);
/* Everything is written out, now we dirty the pages in the file. */
ret = btrfs_dirty_pages(inode, io_ctl->pages, io_ctl->num_pages, 0,
i_size_read(inode), &cached_state);
if (ret)
goto out_nospc;
if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
up_write(&block_group->data_rwsem);
/*
* Release the pages and unlock the extent, we will flush
* them out later
*/
io_ctl_drop_pages(io_ctl);
unlock_extent_cached(&BTRFS_I(inode)->io_tree, 0,
i_size_read(inode) - 1, &cached_state, GFP_NOFS);
/*
* at this point the pages are under IO and we're happy,
* The caller is responsible for waiting on them and updating the
* the cache and the inode
*/
io_ctl->entries = entries;
io_ctl->bitmaps = bitmaps;
ret = btrfs_fdatawrite_range(inode, 0, (u64)-1);
if (ret)
goto out;
return 0;
out:
io_ctl->inode = NULL;
io_ctl_free(io_ctl);
if (ret) {
invalidate_inode_pages2(inode->i_mapping);
BTRFS_I(inode)->generation = 0;
}
btrfs_update_inode(trans, root, inode);
if (must_iput)
iput(inode);
return ret;
out_nospc_locked:
cleanup_bitmap_list(&bitmap_list);
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
out_nospc:
cleanup_write_cache_enospc(inode, io_ctl, &cached_state);
if (block_group && (block_group->flags & BTRFS_BLOCK_GROUP_DATA))
up_write(&block_group->data_rwsem);
goto out;
}
int btrfs_write_out_cache(struct btrfs_fs_info *fs_info,
struct btrfs_trans_handle *trans,
struct btrfs_block_group_cache *block_group,
struct btrfs_path *path)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct inode *inode;
int ret = 0;
spin_lock(&block_group->lock);
if (block_group->disk_cache_state < BTRFS_DC_SETUP) {
spin_unlock(&block_group->lock);
return 0;
}
spin_unlock(&block_group->lock);
inode = lookup_free_space_inode(fs_info, block_group, path);
if (IS_ERR(inode))
return 0;
ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
block_group, &block_group->io_ctl, trans);
if (ret) {
#ifdef DEBUG
btrfs_err(fs_info,
"failed to write free space cache for block group %llu",
block_group->key.objectid);
#endif
spin_lock(&block_group->lock);
block_group->disk_cache_state = BTRFS_DC_ERROR;
spin_unlock(&block_group->lock);
block_group->io_ctl.inode = NULL;
iput(inode);
}
/*
* if ret == 0 the caller is expected to call btrfs_wait_cache_io
* to wait for IO and put the inode
*/
return ret;
}
static inline unsigned long offset_to_bit(u64 bitmap_start, u32 unit,
u64 offset)
{
ASSERT(offset >= bitmap_start);
offset -= bitmap_start;
return (unsigned long)(div_u64(offset, unit));
}
static inline unsigned long bytes_to_bits(u64 bytes, u32 unit)
{
return (unsigned long)(div_u64(bytes, unit));
}
static inline u64 offset_to_bitmap(struct btrfs_free_space_ctl *ctl,
u64 offset)
{
u64 bitmap_start;
u64 bytes_per_bitmap;
bytes_per_bitmap = BITS_PER_BITMAP * ctl->unit;
bitmap_start = offset - ctl->start;
bitmap_start = div64_u64(bitmap_start, bytes_per_bitmap);
bitmap_start *= bytes_per_bitmap;
bitmap_start += ctl->start;
return bitmap_start;
}
static int tree_insert_offset(struct rb_root *root, u64 offset,
struct rb_node *node, int bitmap)
{
struct rb_node **p = &root->rb_node;
struct rb_node *parent = NULL;
struct btrfs_free_space *info;
while (*p) {
parent = *p;
info = rb_entry(parent, struct btrfs_free_space, offset_index);
if (offset < info->offset) {
p = &(*p)->rb_left;
} else if (offset > info->offset) {
p = &(*p)->rb_right;
} else {
/*
* we could have a bitmap entry and an extent entry
* share the same offset. If this is the case, we want
* the extent entry to always be found first if we do a
* linear search through the tree, since we want to have
* the quickest allocation time, and allocating from an
* extent is faster than allocating from a bitmap. So
* if we're inserting a bitmap and we find an entry at
* this offset, we want to go right, or after this entry
* logically. If we are inserting an extent and we've
* found a bitmap, we want to go left, or before
* logically.
*/
if (bitmap) {
if (info->bitmap) {
WARN_ON_ONCE(1);
return -EEXIST;
}
p = &(*p)->rb_right;
} else {
if (!info->bitmap) {
WARN_ON_ONCE(1);
return -EEXIST;
}
p = &(*p)->rb_left;
}
}
}
rb_link_node(node, parent, p);
rb_insert_color(node, root);
return 0;
}
/*
* searches the tree for the given offset.
*
* fuzzy - If this is set, then we are trying to make an allocation, and we just
* want a section that has at least bytes size and comes at or after the given
* offset.
*/
static struct btrfs_free_space *
tree_search_offset(struct btrfs_free_space_ctl *ctl,
u64 offset, int bitmap_only, int fuzzy)
{
struct rb_node *n = ctl->free_space_offset.rb_node;
struct btrfs_free_space *entry, *prev = NULL;
/* find entry that is closest to the 'offset' */
while (1) {
if (!n) {
entry = NULL;
break;
}
entry = rb_entry(n, struct btrfs_free_space, offset_index);
prev = entry;
if (offset < entry->offset)
n = n->rb_left;
else if (offset > entry->offset)
n = n->rb_right;
else
break;
}
if (bitmap_only) {
if (!entry)
return NULL;
if (entry->bitmap)
return entry;
/*
* bitmap entry and extent entry may share same offset,
* in that case, bitmap entry comes after extent entry.
*/
n = rb_next(n);
if (!n)
return NULL;
entry = rb_entry(n, struct btrfs_free_space, offset_index);
if (entry->offset != offset)
return NULL;
WARN_ON(!entry->bitmap);
return entry;
} else if (entry) {
if (entry->bitmap) {
/*
* if previous extent entry covers the offset,
* we should return it instead of the bitmap entry
*/
n = rb_prev(&entry->offset_index);
if (n) {
prev = rb_entry(n, struct btrfs_free_space,
offset_index);
if (!prev->bitmap &&
prev->offset + prev->bytes > offset)
entry = prev;
}
}
return entry;
}
if (!prev)
return NULL;
/* find last entry before the 'offset' */
entry = prev;
if (entry->offset > offset) {
n = rb_prev(&entry->offset_index);
if (n) {
entry = rb_entry(n, struct btrfs_free_space,
offset_index);
ASSERT(entry->offset <= offset);
} else {
if (fuzzy)
return entry;
else
return NULL;
}
}
if (entry->bitmap) {
n = rb_prev(&entry->offset_index);
if (n) {
prev = rb_entry(n, struct btrfs_free_space,
offset_index);
if (!prev->bitmap &&
prev->offset + prev->bytes > offset)
return prev;
}
if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset)
return entry;
} else if (entry->offset + entry->bytes > offset)
return entry;
if (!fuzzy)
return NULL;
while (1) {
if (entry->bitmap) {
if (entry->offset + BITS_PER_BITMAP *
ctl->unit > offset)
break;
} else {
if (entry->offset + entry->bytes > offset)
break;
}
n = rb_next(&entry->offset_index);
if (!n)
return NULL;
entry = rb_entry(n, struct btrfs_free_space, offset_index);
}
return entry;
}
static inline void
__unlink_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info)
{
rb_erase(&info->offset_index, &ctl->free_space_offset);
ctl->free_extents--;
}
static void unlink_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info)
{
__unlink_free_space(ctl, info);
ctl->free_space -= info->bytes;
}
static int link_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info)
{
int ret = 0;
ASSERT(info->bytes || info->bitmap);
ret = tree_insert_offset(&ctl->free_space_offset, info->offset,
&info->offset_index, (info->bitmap != NULL));
if (ret)
return ret;
ctl->free_space += info->bytes;
ctl->free_extents++;
return ret;
}
static void recalculate_thresholds(struct btrfs_free_space_ctl *ctl)
{
struct btrfs_block_group_cache *block_group = ctl->private;
u64 max_bytes;
u64 bitmap_bytes;
u64 extent_bytes;
u64 size = block_group->key.offset;
u64 bytes_per_bg = BITS_PER_BITMAP * ctl->unit;
u64 max_bitmaps = div64_u64(size + bytes_per_bg - 1, bytes_per_bg);
max_bitmaps = max_t(u64, max_bitmaps, 1);
ASSERT(ctl->total_bitmaps <= max_bitmaps);
/*
* The goal is to keep the total amount of memory used per 1gb of space
* at or below 32k, so we need to adjust how much memory we allow to be
* used by extent based free space tracking
*/
if (size < SZ_1G)
max_bytes = MAX_CACHE_BYTES_PER_GIG;
else
max_bytes = MAX_CACHE_BYTES_PER_GIG * div_u64(size, SZ_1G);
/*
* we want to account for 1 more bitmap than what we have so we can make
* sure we don't go over our overall goal of MAX_CACHE_BYTES_PER_GIG as
* we add more bitmaps.
*/
bitmap_bytes = (ctl->total_bitmaps + 1) * ctl->unit;
if (bitmap_bytes >= max_bytes) {
ctl->extents_thresh = 0;
return;
}
/*
* we want the extent entry threshold to always be at most 1/2 the max
* bytes we can have, or whatever is less than that.
*/
extent_bytes = max_bytes - bitmap_bytes;
extent_bytes = min_t(u64, extent_bytes, max_bytes >> 1);
ctl->extents_thresh =
div_u64(extent_bytes, sizeof(struct btrfs_free_space));
}
static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info,
u64 offset, u64 bytes)
{
unsigned long start, count;
start = offset_to_bit(info->offset, ctl->unit, offset);
count = bytes_to_bits(bytes, ctl->unit);
ASSERT(start + count <= BITS_PER_BITMAP);
bitmap_clear(info->bitmap, start, count);
info->bytes -= bytes;
}
static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info, u64 offset,
u64 bytes)
{
__bitmap_clear_bits(ctl, info, offset, bytes);
ctl->free_space -= bytes;
}
static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info, u64 offset,
u64 bytes)
{
unsigned long start, count;
start = offset_to_bit(info->offset, ctl->unit, offset);
count = bytes_to_bits(bytes, ctl->unit);
ASSERT(start + count <= BITS_PER_BITMAP);
bitmap_set(info->bitmap, start, count);
info->bytes += bytes;
ctl->free_space += bytes;
}
/*
* If we can not find suitable extent, we will use bytes to record
* the size of the max extent.
*/
static int search_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *bitmap_info, u64 *offset,
u64 *bytes, bool for_alloc)
{
unsigned long found_bits = 0;
unsigned long max_bits = 0;
unsigned long bits, i;
unsigned long next_zero;
unsigned long extent_bits;
/*
* Skip searching the bitmap if we don't have a contiguous section that
* is large enough for this allocation.
*/
if (for_alloc &&
bitmap_info->max_extent_size &&
bitmap_info->max_extent_size < *bytes) {
*bytes = bitmap_info->max_extent_size;
return -1;
}
i = offset_to_bit(bitmap_info->offset, ctl->unit,
max_t(u64, *offset, bitmap_info->offset));
bits = bytes_to_bits(*bytes, ctl->unit);
for_each_set_bit_from(i, bitmap_info->bitmap, BITS_PER_BITMAP) {
if (for_alloc && bits == 1) {
found_bits = 1;
break;
}
next_zero = find_next_zero_bit(bitmap_info->bitmap,
BITS_PER_BITMAP, i);
extent_bits = next_zero - i;
if (extent_bits >= bits) {
found_bits = extent_bits;
break;
} else if (extent_bits > max_bits) {
max_bits = extent_bits;
}
i = next_zero;
}
if (found_bits) {
*offset = (u64)(i * ctl->unit) + bitmap_info->offset;
*bytes = (u64)(found_bits) * ctl->unit;
return 0;
}
*bytes = (u64)(max_bits) * ctl->unit;
bitmap_info->max_extent_size = *bytes;
return -1;
}
/* Cache the size of the max extent in bytes */
static struct btrfs_free_space *
find_free_space(struct btrfs_free_space_ctl *ctl, u64 *offset, u64 *bytes,
unsigned long align, u64 *max_extent_size)
{
struct btrfs_free_space *entry;
struct rb_node *node;
u64 tmp;
u64 align_off;
int ret;
if (!ctl->free_space_offset.rb_node)
goto out;
entry = tree_search_offset(ctl, offset_to_bitmap(ctl, *offset), 0, 1);
if (!entry)
goto out;
for (node = &entry->offset_index; node; node = rb_next(node)) {
entry = rb_entry(node, struct btrfs_free_space, offset_index);
if (entry->bytes < *bytes) {
if (entry->bytes > *max_extent_size)
*max_extent_size = entry->bytes;
continue;
}
/* make sure the space returned is big enough
* to match our requested alignment
*/
if (*bytes >= align) {
tmp = entry->offset - ctl->start + align - 1;
tmp = div64_u64(tmp, align);
tmp = tmp * align + ctl->start;
align_off = tmp - entry->offset;
} else {
align_off = 0;
tmp = entry->offset;
}
if (entry->bytes < *bytes + align_off) {
if (entry->bytes > *max_extent_size)
*max_extent_size = entry->bytes;
continue;
}
if (entry->bitmap) {
u64 size = *bytes;
ret = search_bitmap(ctl, entry, &tmp, &size, true);
if (!ret) {
*offset = tmp;
*bytes = size;
return entry;
} else if (size > *max_extent_size) {
*max_extent_size = size;
}
continue;
}
*offset = tmp;
*bytes = entry->bytes - align_off;
return entry;
}
out:
return NULL;
}
static void add_new_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info, u64 offset)
{
info->offset = offset_to_bitmap(ctl, offset);
info->bytes = 0;
INIT_LIST_HEAD(&info->list);
link_free_space(ctl, info);
ctl->total_bitmaps++;
ctl->op->recalc_thresholds(ctl);
}
static void free_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *bitmap_info)
{
unlink_free_space(ctl, bitmap_info);
kfree(bitmap_info->bitmap);
kmem_cache_free(btrfs_free_space_cachep, bitmap_info);
ctl->total_bitmaps--;
ctl->op->recalc_thresholds(ctl);
}
static noinline int remove_from_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *bitmap_info,
u64 *offset, u64 *bytes)
{
u64 end;
u64 search_start, search_bytes;
int ret;
again:
end = bitmap_info->offset + (u64)(BITS_PER_BITMAP * ctl->unit) - 1;
/*
* We need to search for bits in this bitmap. We could only cover some
* of the extent in this bitmap thanks to how we add space, so we need
* to search for as much as it as we can and clear that amount, and then
* go searching for the next bit.
*/
search_start = *offset;
search_bytes = ctl->unit;
search_bytes = min(search_bytes, end - search_start + 1);
ret = search_bitmap(ctl, bitmap_info, &search_start, &search_bytes,
false);
if (ret < 0 || search_start != *offset)
return -EINVAL;
/* We may have found more bits than what we need */
search_bytes = min(search_bytes, *bytes);
/* Cannot clear past the end of the bitmap */
search_bytes = min(search_bytes, end - search_start + 1);
bitmap_clear_bits(ctl, bitmap_info, search_start, search_bytes);
*offset += search_bytes;
*bytes -= search_bytes;
if (*bytes) {
struct rb_node *next = rb_next(&bitmap_info->offset_index);
if (!bitmap_info->bytes)
free_bitmap(ctl, bitmap_info);
/*
* no entry after this bitmap, but we still have bytes to
* remove, so something has gone wrong.
*/
if (!next)
return -EINVAL;
bitmap_info = rb_entry(next, struct btrfs_free_space,
offset_index);
/*
* if the next entry isn't a bitmap we need to return to let the
* extent stuff do its work.
*/
if (!bitmap_info->bitmap)
return -EAGAIN;
/*
* Ok the next item is a bitmap, but it may not actually hold
* the information for the rest of this free space stuff, so
* look for it, and if we don't find it return so we can try
* everything over again.
*/
search_start = *offset;
search_bytes = ctl->unit;
ret = search_bitmap(ctl, bitmap_info, &search_start,
&search_bytes, false);
if (ret < 0 || search_start != *offset)
return -EAGAIN;
goto again;
} else if (!bitmap_info->bytes)
free_bitmap(ctl, bitmap_info);
return 0;
}
static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info, u64 offset,
u64 bytes)
{
u64 bytes_to_set = 0;
u64 end;
end = info->offset + (u64)(BITS_PER_BITMAP * ctl->unit);
bytes_to_set = min(end - offset, bytes);
bitmap_set_bits(ctl, info, offset, bytes_to_set);
/*
* We set some bytes, we have no idea what the max extent size is
* anymore.
*/
info->max_extent_size = 0;
return bytes_to_set;
}
static bool use_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info)
{
struct btrfs_block_group_cache *block_group = ctl->private;
struct btrfs_fs_info *fs_info = block_group->fs_info;
bool forced = false;
#ifdef CONFIG_BTRFS_DEBUG
if (btrfs_should_fragment_free_space(block_group))
forced = true;
#endif
/*
* If we are below the extents threshold then we can add this as an
* extent, and don't have to deal with the bitmap
*/
if (!forced && ctl->free_extents < ctl->extents_thresh) {
/*
* If this block group has some small extents we don't want to
* use up all of our free slots in the cache with them, we want
* to reserve them to larger extents, however if we have plenty
* of cache left then go ahead an dadd them, no sense in adding
* the overhead of a bitmap if we don't have to.
*/
if (info->bytes <= fs_info->sectorsize * 4) {
if (ctl->free_extents * 2 <= ctl->extents_thresh)
return false;
} else {
return false;
}
}
/*
* The original block groups from mkfs can be really small, like 8
* megabytes, so don't bother with a bitmap for those entries. However
* some block groups can be smaller than what a bitmap would cover but
* are still large enough that they could overflow the 32k memory limit,
* so allow those block groups to still be allowed to have a bitmap
* entry.
*/
if (((BITS_PER_BITMAP * ctl->unit) >> 1) > block_group->key.offset)
return false;
return true;
}
static const struct btrfs_free_space_op free_space_op = {
.recalc_thresholds = recalculate_thresholds,
.use_bitmap = use_bitmap,
};
static int insert_into_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info)
{
struct btrfs_free_space *bitmap_info;
struct btrfs_block_group_cache *block_group = NULL;
int added = 0;
u64 bytes, offset, bytes_added;
int ret;
bytes = info->bytes;
offset = info->offset;
if (!ctl->op->use_bitmap(ctl, info))
return 0;
if (ctl->op == &free_space_op)
block_group = ctl->private;
again:
/*
* Since we link bitmaps right into the cluster we need to see if we
* have a cluster here, and if so and it has our bitmap we need to add
* the free space to that bitmap.
*/
if (block_group && !list_empty(&block_group->cluster_list)) {
struct btrfs_free_cluster *cluster;
struct rb_node *node;
struct btrfs_free_space *entry;
cluster = list_entry(block_group->cluster_list.next,
struct btrfs_free_cluster,
block_group_list);
spin_lock(&cluster->lock);
node = rb_first(&cluster->root);
if (!node) {
spin_unlock(&cluster->lock);
goto no_cluster_bitmap;
}
entry = rb_entry(node, struct btrfs_free_space, offset_index);
if (!entry->bitmap) {
spin_unlock(&cluster->lock);
goto no_cluster_bitmap;
}
if (entry->offset == offset_to_bitmap(ctl, offset)) {
bytes_added = add_bytes_to_bitmap(ctl, entry,
offset, bytes);
bytes -= bytes_added;
offset += bytes_added;
}
spin_unlock(&cluster->lock);
if (!bytes) {
ret = 1;
goto out;
}
}
no_cluster_bitmap:
bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1, 0);
if (!bitmap_info) {
ASSERT(added == 0);
goto new_bitmap;
}
bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
bytes -= bytes_added;
offset += bytes_added;
added = 0;
if (!bytes) {
ret = 1;
goto out;
} else
goto again;
new_bitmap:
if (info && info->bitmap) {
add_new_bitmap(ctl, info, offset);
added = 1;
info = NULL;
goto again;
} else {
spin_unlock(&ctl->tree_lock);
/* no pre-allocated info, allocate a new one */
if (!info) {
info = kmem_cache_zalloc(btrfs_free_space_cachep,
GFP_NOFS);
if (!info) {
spin_lock(&ctl->tree_lock);
ret = -ENOMEM;
goto out;
}
}
/* allocate the bitmap */
info->bitmap = kzalloc(PAGE_SIZE, GFP_NOFS);
spin_lock(&ctl->tree_lock);
if (!info->bitmap) {
ret = -ENOMEM;
goto out;
}
goto again;
}
out:
if (info) {
if (info->bitmap)
kfree(info->bitmap);
kmem_cache_free(btrfs_free_space_cachep, info);
}
return ret;
}
static bool try_merge_free_space(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info, bool update_stat)
{
struct btrfs_free_space *left_info;
struct btrfs_free_space *right_info;
bool merged = false;
u64 offset = info->offset;
u64 bytes = info->bytes;
/*
* first we want to see if there is free space adjacent to the range we
* are adding, if there is remove that struct and add a new one to
* cover the entire range
*/
right_info = tree_search_offset(ctl, offset + bytes, 0, 0);
if (right_info && rb_prev(&right_info->offset_index))
left_info = rb_entry(rb_prev(&right_info->offset_index),
struct btrfs_free_space, offset_index);
else
left_info = tree_search_offset(ctl, offset - 1, 0, 0);
if (right_info && !right_info->bitmap) {
if (update_stat)
unlink_free_space(ctl, right_info);
else
__unlink_free_space(ctl, right_info);
info->bytes += right_info->bytes;
kmem_cache_free(btrfs_free_space_cachep, right_info);
merged = true;
}
if (left_info && !left_info->bitmap &&
left_info->offset + left_info->bytes == offset) {
if (update_stat)
unlink_free_space(ctl, left_info);
else
__unlink_free_space(ctl, left_info);
info->offset = left_info->offset;
info->bytes += left_info->bytes;
kmem_cache_free(btrfs_free_space_cachep, left_info);
merged = true;
}
return merged;
}
static bool steal_from_bitmap_to_end(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info,
bool update_stat)
{
struct btrfs_free_space *bitmap;
unsigned long i;
unsigned long j;
const u64 end = info->offset + info->bytes;
const u64 bitmap_offset = offset_to_bitmap(ctl, end);
u64 bytes;
bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
if (!bitmap)
return false;
i = offset_to_bit(bitmap->offset, ctl->unit, end);
j = find_next_zero_bit(bitmap->bitmap, BITS_PER_BITMAP, i);
if (j == i)
return false;
bytes = (j - i) * ctl->unit;
info->bytes += bytes;
if (update_stat)
bitmap_clear_bits(ctl, bitmap, end, bytes);
else
__bitmap_clear_bits(ctl, bitmap, end, bytes);
if (!bitmap->bytes)
free_bitmap(ctl, bitmap);
return true;
}
static bool steal_from_bitmap_to_front(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info,
bool update_stat)
{
struct btrfs_free_space *bitmap;
u64 bitmap_offset;
unsigned long i;
unsigned long j;
unsigned long prev_j;
u64 bytes;
bitmap_offset = offset_to_bitmap(ctl, info->offset);
/* If we're on a boundary, try the previous logical bitmap. */
if (bitmap_offset == info->offset) {
if (info->offset == 0)
return false;
bitmap_offset = offset_to_bitmap(ctl, info->offset - 1);
}
bitmap = tree_search_offset(ctl, bitmap_offset, 1, 0);
if (!bitmap)
return false;
i = offset_to_bit(bitmap->offset, ctl->unit, info->offset) - 1;
j = 0;
prev_j = (unsigned long)-1;
for_each_clear_bit_from(j, bitmap->bitmap, BITS_PER_BITMAP) {
if (j > i)
break;
prev_j = j;
}
if (prev_j == i)
return false;
if (prev_j == (unsigned long)-1)
bytes = (i + 1) * ctl->unit;
else
bytes = (i - prev_j) * ctl->unit;
info->offset -= bytes;
info->bytes += bytes;
if (update_stat)
bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
else
__bitmap_clear_bits(ctl, bitmap, info->offset, bytes);
if (!bitmap->bytes)
free_bitmap(ctl, bitmap);
return true;
}
/*
* We prefer always to allocate from extent entries, both for clustered and
* non-clustered allocation requests. So when attempting to add a new extent
* entry, try to see if there's adjacent free space in bitmap entries, and if
* there is, migrate that space from the bitmaps to the extent.
* Like this we get better chances of satisfying space allocation requests
* because we attempt to satisfy them based on a single cache entry, and never
* on 2 or more entries - even if the entries represent a contiguous free space
* region (e.g. 1 extent entry + 1 bitmap entry starting where the extent entry
* ends).
*/
static void steal_from_bitmap(struct btrfs_free_space_ctl *ctl,
struct btrfs_free_space *info,
bool update_stat)
{
/*
* Only work with disconnected entries, as we can change their offset,
* and must be extent entries.
*/
ASSERT(!info->bitmap);
ASSERT(RB_EMPTY_NODE(&info->offset_index));
if (ctl->total_bitmaps > 0) {
bool stole_end;
bool stole_front = false;
stole_end = steal_from_bitmap_to_end(ctl, info, update_stat);
if (ctl->total_bitmaps > 0)
stole_front = steal_from_bitmap_to_front(ctl, info,
update_stat);
if (stole_end || stole_front)
try_merge_free_space(ctl, info, update_stat);
}
}
int __btrfs_add_free_space(struct btrfs_fs_info *fs_info,
struct btrfs_free_space_ctl *ctl,
u64 offset, u64 bytes)
{
struct btrfs_free_space *info;
int ret = 0;
info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
if (!info)
return -ENOMEM;
info->offset = offset;
info->bytes = bytes;
RB_CLEAR_NODE(&info->offset_index);
spin_lock(&ctl->tree_lock);
if (try_merge_free_space(ctl, info, true))
goto link;
/*
* There was no extent directly to the left or right of this new
* extent then we know we're going to have to allocate a new extent, so
* before we do that see if we need to drop this into a bitmap
*/
ret = insert_into_bitmap(ctl, info);
if (ret < 0) {
goto out;
} else if (ret) {
ret = 0;
goto out;
}
link:
/*
* Only steal free space from adjacent bitmaps if we're sure we're not
* going to add the new free space to existing bitmap entries - because
* that would mean unnecessary work that would be reverted. Therefore
* attempt to steal space from bitmaps if we're adding an extent entry.
*/
steal_from_bitmap(ctl, info, true);
ret = link_free_space(ctl, info);
if (ret)
kmem_cache_free(btrfs_free_space_cachep, info);
out:
spin_unlock(&ctl->tree_lock);
if (ret) {
btrfs_crit(fs_info, "unable to add free space :%d", ret);
ASSERT(ret != -EEXIST);
}
return ret;
}
int btrfs_remove_free_space(struct btrfs_block_group_cache *block_group,
u64 offset, u64 bytes)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *info;
int ret;
bool re_search = false;
spin_lock(&ctl->tree_lock);
again:
ret = 0;
if (!bytes)
goto out_lock;
info = tree_search_offset(ctl, offset, 0, 0);
if (!info) {
/*
* oops didn't find an extent that matched the space we wanted
* to remove, look for a bitmap instead
*/
info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1, 0);
if (!info) {
/*
* If we found a partial bit of our free space in a
* bitmap but then couldn't find the other part this may
* be a problem, so WARN about it.
*/
WARN_ON(re_search);
goto out_lock;
}
}
re_search = false;
if (!info->bitmap) {
unlink_free_space(ctl, info);
if (offset == info->offset) {
u64 to_free = min(bytes, info->bytes);
info->bytes -= to_free;
info->offset += to_free;
if (info->bytes) {
ret = link_free_space(ctl, info);
WARN_ON(ret);
} else {
kmem_cache_free(btrfs_free_space_cachep, info);
}
offset += to_free;
bytes -= to_free;
goto again;
} else {
u64 old_end = info->bytes + info->offset;
info->bytes = offset - info->offset;
ret = link_free_space(ctl, info);
WARN_ON(ret);
if (ret)
goto out_lock;
/* Not enough bytes in this entry to satisfy us */
if (old_end < offset + bytes) {
bytes -= old_end - offset;
offset = old_end;
goto again;
} else if (old_end == offset + bytes) {
/* all done */
goto out_lock;
}
spin_unlock(&ctl->tree_lock);
ret = btrfs_add_free_space(block_group, offset + bytes,
old_end - (offset + bytes));
WARN_ON(ret);
goto out;
}
}
ret = remove_from_bitmap(ctl, info, &offset, &bytes);
if (ret == -EAGAIN) {
re_search = true;
goto again;
}
out_lock:
spin_unlock(&ctl->tree_lock);
out:
return ret;
}
void btrfs_dump_free_space(struct btrfs_block_group_cache *block_group,
u64 bytes)
{
struct btrfs_fs_info *fs_info = block_group->fs_info;
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *info;
struct rb_node *n;
int count = 0;
for (n = rb_first(&ctl->free_space_offset); n; n = rb_next(n)) {
info = rb_entry(n, struct btrfs_free_space, offset_index);
if (info->bytes >= bytes && !block_group->ro)
count++;
btrfs_crit(fs_info, "entry offset %llu, bytes %llu, bitmap %s",
info->offset, info->bytes,
(info->bitmap) ? "yes" : "no");
}
btrfs_info(fs_info, "block group has cluster?: %s",
list_empty(&block_group->cluster_list) ? "no" : "yes");
btrfs_info(fs_info,
"%d blocks of free space at or bigger than bytes is", count);
}
void btrfs_init_free_space_ctl(struct btrfs_block_group_cache *block_group)
{
struct btrfs_fs_info *fs_info = block_group->fs_info;
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
spin_lock_init(&ctl->tree_lock);
ctl->unit = fs_info->sectorsize;
ctl->start = block_group->key.objectid;
ctl->private = block_group;
ctl->op = &free_space_op;
INIT_LIST_HEAD(&ctl->trimming_ranges);
mutex_init(&ctl->cache_writeout_mutex);
/*
* we only want to have 32k of ram per block group for keeping
* track of free space, and if we pass 1/2 of that we want to
* start converting things over to using bitmaps
*/
ctl->extents_thresh = (SZ_32K / 2) / sizeof(struct btrfs_free_space);
}
/*
* for a given cluster, put all of its extents back into the free
* space cache. If the block group passed doesn't match the block group
* pointed to by the cluster, someone else raced in and freed the
* cluster already. In that case, we just return without changing anything
*/
static int
__btrfs_return_cluster_to_free_space(
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry;
struct rb_node *node;
spin_lock(&cluster->lock);
if (cluster->block_group != block_group)
goto out;
cluster->block_group = NULL;
cluster->window_start = 0;
list_del_init(&cluster->block_group_list);
node = rb_first(&cluster->root);
while (node) {
bool bitmap;
entry = rb_entry(node, struct btrfs_free_space, offset_index);
node = rb_next(&entry->offset_index);
rb_erase(&entry->offset_index, &cluster->root);
RB_CLEAR_NODE(&entry->offset_index);
bitmap = (entry->bitmap != NULL);
if (!bitmap) {
try_merge_free_space(ctl, entry, false);
steal_from_bitmap(ctl, entry, false);
}
tree_insert_offset(&ctl->free_space_offset,
entry->offset, &entry->offset_index, bitmap);
}
cluster->root = RB_ROOT;
out:
spin_unlock(&cluster->lock);
btrfs_put_block_group(block_group);
return 0;
}
static void __btrfs_remove_free_space_cache_locked(
struct btrfs_free_space_ctl *ctl)
{
struct btrfs_free_space *info;
struct rb_node *node;
while ((node = rb_last(&ctl->free_space_offset)) != NULL) {
info = rb_entry(node, struct btrfs_free_space, offset_index);
if (!info->bitmap) {
unlink_free_space(ctl, info);
kmem_cache_free(btrfs_free_space_cachep, info);
} else {
free_bitmap(ctl, info);
}
cond_resched_lock(&ctl->tree_lock);
}
}
void __btrfs_remove_free_space_cache(struct btrfs_free_space_ctl *ctl)
{
spin_lock(&ctl->tree_lock);
__btrfs_remove_free_space_cache_locked(ctl);
spin_unlock(&ctl->tree_lock);
}
void btrfs_remove_free_space_cache(struct btrfs_block_group_cache *block_group)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_cluster *cluster;
struct list_head *head;
spin_lock(&ctl->tree_lock);
while ((head = block_group->cluster_list.next) !=
&block_group->cluster_list) {
cluster = list_entry(head, struct btrfs_free_cluster,
block_group_list);
WARN_ON(cluster->block_group != block_group);
__btrfs_return_cluster_to_free_space(block_group, cluster);
cond_resched_lock(&ctl->tree_lock);
}
__btrfs_remove_free_space_cache_locked(ctl);
spin_unlock(&ctl->tree_lock);
}
u64 btrfs_find_space_for_alloc(struct btrfs_block_group_cache *block_group,
u64 offset, u64 bytes, u64 empty_size,
u64 *max_extent_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry = NULL;
u64 bytes_search = bytes + empty_size;
u64 ret = 0;
u64 align_gap = 0;
u64 align_gap_len = 0;
spin_lock(&ctl->tree_lock);
entry = find_free_space(ctl, &offset, &bytes_search,
block_group->full_stripe_len, max_extent_size);
if (!entry)
goto out;
ret = offset;
if (entry->bitmap) {
bitmap_clear_bits(ctl, entry, offset, bytes);
if (!entry->bytes)
free_bitmap(ctl, entry);
} else {
unlink_free_space(ctl, entry);
align_gap_len = offset - entry->offset;
align_gap = entry->offset;
entry->offset = offset + bytes;
WARN_ON(entry->bytes < bytes + align_gap_len);
entry->bytes -= bytes + align_gap_len;
if (!entry->bytes)
kmem_cache_free(btrfs_free_space_cachep, entry);
else
link_free_space(ctl, entry);
}
out:
spin_unlock(&ctl->tree_lock);
if (align_gap_len)
__btrfs_add_free_space(block_group->fs_info, ctl,
align_gap, align_gap_len);
return ret;
}
/*
* given a cluster, put all of its extents back into the free space
* cache. If a block group is passed, this function will only free
* a cluster that belongs to the passed block group.
*
* Otherwise, it'll get a reference on the block group pointed to by the
* cluster and remove the cluster from it.
*/
int btrfs_return_cluster_to_free_space(
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster)
{
struct btrfs_free_space_ctl *ctl;
int ret;
/* first, get a safe pointer to the block group */
spin_lock(&cluster->lock);
if (!block_group) {
block_group = cluster->block_group;
if (!block_group) {
spin_unlock(&cluster->lock);
return 0;
}
} else if (cluster->block_group != block_group) {
/* someone else has already freed it don't redo their work */
spin_unlock(&cluster->lock);
return 0;
}
atomic_inc(&block_group->count);
spin_unlock(&cluster->lock);
ctl = block_group->free_space_ctl;
/* now return any extents the cluster had on it */
spin_lock(&ctl->tree_lock);
ret = __btrfs_return_cluster_to_free_space(block_group, cluster);
spin_unlock(&ctl->tree_lock);
/* finally drop our ref */
btrfs_put_block_group(block_group);
return ret;
}
static u64 btrfs_alloc_from_bitmap(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
struct btrfs_free_space *entry,
u64 bytes, u64 min_start,
u64 *max_extent_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
int err;
u64 search_start = cluster->window_start;
u64 search_bytes = bytes;
u64 ret = 0;
search_start = min_start;
search_bytes = bytes;
err = search_bitmap(ctl, entry, &search_start, &search_bytes, true);
if (err) {
if (search_bytes > *max_extent_size)
*max_extent_size = search_bytes;
return 0;
}
ret = search_start;
__bitmap_clear_bits(ctl, entry, ret, bytes);
return ret;
}
/*
* given a cluster, try to allocate 'bytes' from it, returns 0
* if it couldn't find anything suitably large, or a logical disk offset
* if things worked out
*/
u64 btrfs_alloc_from_cluster(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster, u64 bytes,
u64 min_start, u64 *max_extent_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry = NULL;
struct rb_node *node;
u64 ret = 0;
spin_lock(&cluster->lock);
if (bytes > cluster->max_size)
goto out;
if (cluster->block_group != block_group)
goto out;
node = rb_first(&cluster->root);
if (!node)
goto out;
entry = rb_entry(node, struct btrfs_free_space, offset_index);
while (1) {
if (entry->bytes < bytes && entry->bytes > *max_extent_size)
*max_extent_size = entry->bytes;
if (entry->bytes < bytes ||
(!entry->bitmap && entry->offset < min_start)) {
node = rb_next(&entry->offset_index);
if (!node)
break;
entry = rb_entry(node, struct btrfs_free_space,
offset_index);
continue;
}
if (entry->bitmap) {
ret = btrfs_alloc_from_bitmap(block_group,
cluster, entry, bytes,
cluster->window_start,
max_extent_size);
if (ret == 0) {
node = rb_next(&entry->offset_index);
if (!node)
break;
entry = rb_entry(node, struct btrfs_free_space,
offset_index);
continue;
}
cluster->window_start += bytes;
} else {
ret = entry->offset;
entry->offset += bytes;
entry->bytes -= bytes;
}
if (entry->bytes == 0)
rb_erase(&entry->offset_index, &cluster->root);
break;
}
out:
spin_unlock(&cluster->lock);
if (!ret)
return 0;
spin_lock(&ctl->tree_lock);
ctl->free_space -= bytes;
if (entry->bytes == 0) {
ctl->free_extents--;
if (entry->bitmap) {
kfree(entry->bitmap);
ctl->total_bitmaps--;
ctl->op->recalc_thresholds(ctl);
}
kmem_cache_free(btrfs_free_space_cachep, entry);
}
spin_unlock(&ctl->tree_lock);
return ret;
}
static int btrfs_bitmap_cluster(struct btrfs_block_group_cache *block_group,
struct btrfs_free_space *entry,
struct btrfs_free_cluster *cluster,
u64 offset, u64 bytes,
u64 cont1_bytes, u64 min_bytes)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
unsigned long next_zero;
unsigned long i;
unsigned long want_bits;
unsigned long min_bits;
unsigned long found_bits;
unsigned long max_bits = 0;
unsigned long start = 0;
unsigned long total_found = 0;
int ret;
i = offset_to_bit(entry->offset, ctl->unit,
max_t(u64, offset, entry->offset));
want_bits = bytes_to_bits(bytes, ctl->unit);
min_bits = bytes_to_bits(min_bytes, ctl->unit);
/*
* Don't bother looking for a cluster in this bitmap if it's heavily
* fragmented.
*/
if (entry->max_extent_size &&
entry->max_extent_size < cont1_bytes)
return -ENOSPC;
again:
found_bits = 0;
for_each_set_bit_from(i, entry->bitmap, BITS_PER_BITMAP) {
next_zero = find_next_zero_bit(entry->bitmap,
BITS_PER_BITMAP, i);
if (next_zero - i >= min_bits) {
found_bits = next_zero - i;
if (found_bits > max_bits)
max_bits = found_bits;
break;
}
if (next_zero - i > max_bits)
max_bits = next_zero - i;
i = next_zero;
}
if (!found_bits) {
entry->max_extent_size = (u64)max_bits * ctl->unit;
return -ENOSPC;
}
if (!total_found) {
start = i;
cluster->max_size = 0;
}
total_found += found_bits;
if (cluster->max_size < found_bits * ctl->unit)
cluster->max_size = found_bits * ctl->unit;
if (total_found < want_bits || cluster->max_size < cont1_bytes) {
i = next_zero + 1;
goto again;
}
cluster->window_start = start * ctl->unit + entry->offset;
rb_erase(&entry->offset_index, &ctl->free_space_offset);
ret = tree_insert_offset(&cluster->root, entry->offset,
&entry->offset_index, 1);
ASSERT(!ret); /* -EEXIST; Logic error */
trace_btrfs_setup_cluster(block_group, cluster,
total_found * ctl->unit, 1);
return 0;
}
/*
* This searches the block group for just extents to fill the cluster with.
* Try to find a cluster with at least bytes total bytes, at least one
* extent of cont1_bytes, and other clusters of at least min_bytes.
*/
static noinline int
setup_cluster_no_bitmap(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
struct list_head *bitmaps, u64 offset, u64 bytes,
u64 cont1_bytes, u64 min_bytes)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *first = NULL;
struct btrfs_free_space *entry = NULL;
struct btrfs_free_space *last;
struct rb_node *node;
u64 window_free;
u64 max_extent;
u64 total_size = 0;
entry = tree_search_offset(ctl, offset, 0, 1);
if (!entry)
return -ENOSPC;
/*
* We don't want bitmaps, so just move along until we find a normal
* extent entry.
*/
while (entry->bitmap || entry->bytes < min_bytes) {
if (entry->bitmap && list_empty(&entry->list))
list_add_tail(&entry->list, bitmaps);
node = rb_next(&entry->offset_index);
if (!node)
return -ENOSPC;
entry = rb_entry(node, struct btrfs_free_space, offset_index);
}
window_free = entry->bytes;
max_extent = entry->bytes;
first = entry;
last = entry;
for (node = rb_next(&entry->offset_index); node;
node = rb_next(&entry->offset_index)) {
entry = rb_entry(node, struct btrfs_free_space, offset_index);
if (entry->bitmap) {
if (list_empty(&entry->list))
list_add_tail(&entry->list, bitmaps);
continue;
}
if (entry->bytes < min_bytes)
continue;
last = entry;
window_free += entry->bytes;
if (entry->bytes > max_extent)
max_extent = entry->bytes;
}
if (window_free < bytes || max_extent < cont1_bytes)
return -ENOSPC;
cluster->window_start = first->offset;
node = &first->offset_index;
/*
* now we've found our entries, pull them out of the free space
* cache and put them into the cluster rbtree
*/
do {
int ret;
entry = rb_entry(node, struct btrfs_free_space, offset_index);
node = rb_next(&entry->offset_index);
if (entry->bitmap || entry->bytes < min_bytes)
continue;
rb_erase(&entry->offset_index, &ctl->free_space_offset);
ret = tree_insert_offset(&cluster->root, entry->offset,
&entry->offset_index, 0);
total_size += entry->bytes;
ASSERT(!ret); /* -EEXIST; Logic error */
} while (node && entry != last);
cluster->max_size = max_extent;
trace_btrfs_setup_cluster(block_group, cluster, total_size, 0);
return 0;
}
/*
* This specifically looks for bitmaps that may work in the cluster, we assume
* that we have already failed to find extents that will work.
*/
static noinline int
setup_cluster_bitmap(struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
struct list_head *bitmaps, u64 offset, u64 bytes,
u64 cont1_bytes, u64 min_bytes)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry = NULL;
int ret = -ENOSPC;
u64 bitmap_offset = offset_to_bitmap(ctl, offset);
if (ctl->total_bitmaps == 0)
return -ENOSPC;
/*
* The bitmap that covers offset won't be in the list unless offset
* is just its start offset.
*/
if (!list_empty(bitmaps))
entry = list_first_entry(bitmaps, struct btrfs_free_space, list);
if (!entry || entry->offset != bitmap_offset) {
entry = tree_search_offset(ctl, bitmap_offset, 1, 0);
if (entry && list_empty(&entry->list))
list_add(&entry->list, bitmaps);
}
list_for_each_entry(entry, bitmaps, list) {
if (entry->bytes < bytes)
continue;
ret = btrfs_bitmap_cluster(block_group, entry, cluster, offset,
bytes, cont1_bytes, min_bytes);
if (!ret)
return 0;
}
/*
* The bitmaps list has all the bitmaps that record free space
* starting after offset, so no more search is required.
*/
return -ENOSPC;
}
/*
* here we try to find a cluster of blocks in a block group. The goal
* is to find at least bytes+empty_size.
* We might not find them all in one contiguous area.
*
* returns zero and sets up cluster if things worked out, otherwise
* it returns -enospc
*/
int btrfs_find_space_cluster(struct btrfs_fs_info *fs_info,
struct btrfs_block_group_cache *block_group,
struct btrfs_free_cluster *cluster,
u64 offset, u64 bytes, u64 empty_size)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry, *tmp;
LIST_HEAD(bitmaps);
u64 min_bytes;
u64 cont1_bytes;
int ret;
/*
* Choose the minimum extent size we'll require for this
* cluster. For SSD_SPREAD, don't allow any fragmentation.
* For metadata, allow allocates with smaller extents. For
* data, keep it dense.
*/
if (btrfs_test_opt(fs_info, SSD_SPREAD)) {
cont1_bytes = min_bytes = bytes + empty_size;
} else if (block_group->flags & BTRFS_BLOCK_GROUP_METADATA) {
cont1_bytes = bytes;
min_bytes = fs_info->sectorsize;
} else {
cont1_bytes = max(bytes, (bytes + empty_size) >> 2);
min_bytes = fs_info->sectorsize;
}
spin_lock(&ctl->tree_lock);
/*
* If we know we don't have enough space to make a cluster don't even
* bother doing all the work to try and find one.
*/
if (ctl->free_space < bytes) {
spin_unlock(&ctl->tree_lock);
return -ENOSPC;
}
spin_lock(&cluster->lock);
/* someone already found a cluster, hooray */
if (cluster->block_group) {
ret = 0;
goto out;
}
trace_btrfs_find_cluster(block_group, offset, bytes, empty_size,
min_bytes);
ret = setup_cluster_no_bitmap(block_group, cluster, &bitmaps, offset,
bytes + empty_size,
cont1_bytes, min_bytes);
if (ret)
ret = setup_cluster_bitmap(block_group, cluster, &bitmaps,
offset, bytes + empty_size,
cont1_bytes, min_bytes);
/* Clear our temporary list */
list_for_each_entry_safe(entry, tmp, &bitmaps, list)
list_del_init(&entry->list);
if (!ret) {
atomic_inc(&block_group->count);
list_add_tail(&cluster->block_group_list,
&block_group->cluster_list);
cluster->block_group = block_group;
} else {
trace_btrfs_failed_cluster_setup(block_group);
}
out:
spin_unlock(&cluster->lock);
spin_unlock(&ctl->tree_lock);
return ret;
}
/*
* simple code to zero out a cluster
*/
void btrfs_init_free_cluster(struct btrfs_free_cluster *cluster)
{
spin_lock_init(&cluster->lock);
spin_lock_init(&cluster->refill_lock);
cluster->root = RB_ROOT;
cluster->max_size = 0;
cluster->fragmented = false;
INIT_LIST_HEAD(&cluster->block_group_list);
cluster->block_group = NULL;
}
static int do_trimming(struct btrfs_block_group_cache *block_group,
u64 *total_trimmed, u64 start, u64 bytes,
u64 reserved_start, u64 reserved_bytes,
struct btrfs_trim_range *trim_entry)
{
struct btrfs_space_info *space_info = block_group->space_info;
struct btrfs_fs_info *fs_info = block_group->fs_info;
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
int ret;
int update = 0;
u64 trimmed = 0;
spin_lock(&space_info->lock);
spin_lock(&block_group->lock);
if (!block_group->ro) {
block_group->reserved += reserved_bytes;
space_info->bytes_reserved += reserved_bytes;
update = 1;
}
spin_unlock(&block_group->lock);
spin_unlock(&space_info->lock);
ret = btrfs_discard_extent(fs_info, start, bytes, &trimmed);
if (!ret)
*total_trimmed += trimmed;
mutex_lock(&ctl->cache_writeout_mutex);
btrfs_add_free_space(block_group, reserved_start, reserved_bytes);
list_del(&trim_entry->list);
mutex_unlock(&ctl->cache_writeout_mutex);
if (update) {
spin_lock(&space_info->lock);
spin_lock(&block_group->lock);
if (block_group->ro)
space_info->bytes_readonly += reserved_bytes;
block_group->reserved -= reserved_bytes;
space_info->bytes_reserved -= reserved_bytes;
spin_unlock(&space_info->lock);
spin_unlock(&block_group->lock);
}
return ret;
}
static int trim_no_bitmap(struct btrfs_block_group_cache *block_group,
u64 *total_trimmed, u64 start, u64 end, u64 minlen)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry;
struct rb_node *node;
int ret = 0;
u64 extent_start;
u64 extent_bytes;
u64 bytes;
while (start < end) {
struct btrfs_trim_range trim_entry;
mutex_lock(&ctl->cache_writeout_mutex);
spin_lock(&ctl->tree_lock);
if (ctl->free_space < minlen) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
break;
}
entry = tree_search_offset(ctl, start, 0, 1);
if (!entry) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
break;
}
/* skip bitmaps */
while (entry->bitmap) {
node = rb_next(&entry->offset_index);
if (!node) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
goto out;
}
entry = rb_entry(node, struct btrfs_free_space,
offset_index);
}
if (entry->offset >= end) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
break;
}
extent_start = entry->offset;
extent_bytes = entry->bytes;
start = max(start, extent_start);
bytes = min(extent_start + extent_bytes, end) - start;
if (bytes < minlen) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
goto next;
}
unlink_free_space(ctl, entry);
kmem_cache_free(btrfs_free_space_cachep, entry);
spin_unlock(&ctl->tree_lock);
trim_entry.start = extent_start;
trim_entry.bytes = extent_bytes;
list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
mutex_unlock(&ctl->cache_writeout_mutex);
ret = do_trimming(block_group, total_trimmed, start, bytes,
extent_start, extent_bytes, &trim_entry);
if (ret)
break;
next:
start += bytes;
if (fatal_signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
cond_resched();
}
out:
return ret;
}
static int trim_bitmaps(struct btrfs_block_group_cache *block_group,
u64 *total_trimmed, u64 start, u64 end, u64 minlen)
{
struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
struct btrfs_free_space *entry;
int ret = 0;
int ret2;
u64 bytes;
u64 offset = offset_to_bitmap(ctl, start);
while (offset < end) {
bool next_bitmap = false;
struct btrfs_trim_range trim_entry;
mutex_lock(&ctl->cache_writeout_mutex);
spin_lock(&ctl->tree_lock);
if (ctl->free_space < minlen) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
break;
}
entry = tree_search_offset(ctl, offset, 1, 0);
if (!entry) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
next_bitmap = true;
goto next;
}
bytes = minlen;
ret2 = search_bitmap(ctl, entry, &start, &bytes, false);
if (ret2 || start >= end) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
next_bitmap = true;
goto next;
}
bytes = min(bytes, end - start);
if (bytes < minlen) {
spin_unlock(&ctl->tree_lock);
mutex_unlock(&ctl->cache_writeout_mutex);
goto next;
}
bitmap_clear_bits(ctl, entry, start, bytes);
if (entry->bytes == 0)
free_bitmap(ctl, entry);
spin_unlock(&ctl->tree_lock);
trim_entry.start = start;
trim_entry.bytes = bytes;
list_add_tail(&trim_entry.list, &ctl->trimming_ranges);
mutex_unlock(&ctl->cache_writeout_mutex);
ret = do_trimming(block_group, total_trimmed, start, bytes,
start, bytes, &trim_entry);
if (ret)
break;
next:
if (next_bitmap) {
offset += BITS_PER_BITMAP * ctl->unit;
} else {
start += bytes;
if (start >= offset + BITS_PER_BITMAP * ctl->unit)
offset += BITS_PER_BITMAP * ctl->unit;
}
if (fatal_signal_pending(current)) {
ret = -ERESTARTSYS;
break;
}
cond_resched();
}
return ret;
}
void btrfs_get_block_group_trimming(struct btrfs_block_group_cache *cache)
{
atomic_inc(&cache->trimming);
}
void btrfs_put_block_group_trimming(struct btrfs_block_group_cache *block_group)
{
struct btrfs_fs_info *fs_info = block_group->fs_info;
struct extent_map_tree *em_tree;
struct extent_map *em;
bool cleanup;
spin_lock(&block_group->lock);
cleanup = (atomic_dec_and_test(&block_group->trimming) &&
block_group->removed);
spin_unlock(&block_group->lock);
if (cleanup) {
mutex_lock(&fs_info->chunk_mutex);
em_tree = &fs_info->mapping_tree.map_tree;
write_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, block_group->key.objectid,
1);
BUG_ON(!em); /* logic error, can't happen */
/*
* remove_extent_mapping() will delete us from the pinned_chunks
* list, which is protected by the chunk mutex.
*/
remove_extent_mapping(em_tree, em);
write_unlock(&em_tree->lock);
mutex_unlock(&fs_info->chunk_mutex);
/* once for us and once for the tree */
free_extent_map(em);
free_extent_map(em);
/*
* We've left one free space entry and other tasks trimming
* this block group have left 1 entry each one. Free them.
*/
__btrfs_remove_free_space_cache(block_group->free_space_ctl);
}
}
int btrfs_trim_block_group(struct btrfs_block_group_cache *block_group,
u64 *trimmed, u64 start, u64 end, u64 minlen)
{
int ret;
*trimmed = 0;
spin_lock(&block_group->lock);
if (block_group->removed) {
spin_unlock(&block_group->lock);
return 0;
}
btrfs_get_block_group_trimming(block_group);
spin_unlock(&block_group->lock);
ret = trim_no_bitmap(block_group, trimmed, start, end, minlen);
if (ret)
goto out;
ret = trim_bitmaps(block_group, trimmed, start, end, minlen);
out:
btrfs_put_block_group_trimming(block_group);
return ret;
}
/*
* Find the left-most item in the cache tree, and then return the
* smallest inode number in the item.
*
* Note: the returned inode number may not be the smallest one in
* the tree, if the left-most item is a bitmap.
*/
u64 btrfs_find_ino_for_alloc(struct btrfs_root *fs_root)
{
struct btrfs_free_space_ctl *ctl = fs_root->free_ino_ctl;
struct btrfs_free_space *entry = NULL;
u64 ino = 0;
spin_lock(&ctl->tree_lock);
if (RB_EMPTY_ROOT(&ctl->free_space_offset))
goto out;
entry = rb_entry(rb_first(&ctl->free_space_offset),
struct btrfs_free_space, offset_index);
if (!entry->bitmap) {
ino = entry->offset;
unlink_free_space(ctl, entry);
entry->offset++;
entry->bytes--;
if (!entry->bytes)
kmem_cache_free(btrfs_free_space_cachep, entry);
else
link_free_space(ctl, entry);
} else {
u64 offset = 0;
u64 count = 1;
int ret;
ret = search_bitmap(ctl, entry, &offset, &count, true);
/* Logic error; Should be empty if it can't find anything */
ASSERT(!ret);
ino = offset;
bitmap_clear_bits(ctl, entry, offset, 1);
if (entry->bytes == 0)
free_bitmap(ctl, entry);
}
out:
spin_unlock(&ctl->tree_lock);
return ino;
}
struct inode *lookup_free_ino_inode(struct btrfs_root *root,
struct btrfs_path *path)
{
struct inode *inode = NULL;
spin_lock(&root->ino_cache_lock);
if (root->ino_cache_inode)
inode = igrab(root->ino_cache_inode);
spin_unlock(&root->ino_cache_lock);
if (inode)
return inode;
inode = __lookup_free_space_inode(root, path, 0);
if (IS_ERR(inode))
return inode;
spin_lock(&root->ino_cache_lock);
if (!btrfs_fs_closing(root->fs_info))
root->ino_cache_inode = igrab(inode);
spin_unlock(&root->ino_cache_lock);
return inode;
}
int create_free_ino_inode(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_path *path)
{
return __create_free_space_inode(root, trans, path,
BTRFS_FREE_INO_OBJECTID, 0);
}
int load_free_ino_cache(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
{
struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
struct btrfs_path *path;
struct inode *inode;
int ret = 0;
u64 root_gen = btrfs_root_generation(&root->root_item);
if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
return 0;
/*
* If we're unmounting then just return, since this does a search on the
* normal root and not the commit root and we could deadlock.
*/
if (btrfs_fs_closing(fs_info))
return 0;
path = btrfs_alloc_path();
if (!path)
return 0;
inode = lookup_free_ino_inode(root, path);
if (IS_ERR(inode))
goto out;
if (root_gen != BTRFS_I(inode)->generation)
goto out_put;
ret = __load_free_space_cache(root, inode, ctl, path, 0);
if (ret < 0)
btrfs_err(fs_info,
"failed to load free ino cache for root %llu",
root->root_key.objectid);
out_put:
iput(inode);
out:
btrfs_free_path(path);
return ret;
}
int btrfs_write_out_ino_cache(struct btrfs_root *root,
struct btrfs_trans_handle *trans,
struct btrfs_path *path,
struct inode *inode)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_free_space_ctl *ctl = root->free_ino_ctl;
int ret;
struct btrfs_io_ctl io_ctl;
bool release_metadata = true;
if (!btrfs_test_opt(fs_info, INODE_MAP_CACHE))
return 0;
memset(&io_ctl, 0, sizeof(io_ctl));
ret = __btrfs_write_out_cache(root, inode, ctl, NULL, &io_ctl, trans);
if (!ret) {
/*
* At this point writepages() didn't error out, so our metadata
* reservation is released when the writeback finishes, at
* inode.c:btrfs_finish_ordered_io(), regardless of it finishing
* with or without an error.
*/
release_metadata = false;
ret = btrfs_wait_cache_io_root(root, trans, &io_ctl, path);
}
if (ret) {
if (release_metadata)
btrfs_delalloc_release_metadata(BTRFS_I(inode),
inode->i_size);
#ifdef DEBUG
btrfs_err(fs_info,
"failed to write free ino cache for root %llu",
root->root_key.objectid);
#endif
}
return ret;
}
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
/*
* Use this if you need to make a bitmap or extent entry specifically, it
* doesn't do any of the merging that add_free_space does, this acts a lot like
* how the free space cache loading stuff works, so you can get really weird
* configurations.
*/
int test_add_free_space_entry(struct btrfs_block_group_cache *cache,
u64 offset, u64 bytes, bool bitmap)
{
struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
struct btrfs_free_space *info = NULL, *bitmap_info;
void *map = NULL;
u64 bytes_added;
int ret;
again:
if (!info) {
info = kmem_cache_zalloc(btrfs_free_space_cachep, GFP_NOFS);
if (!info)
return -ENOMEM;
}
if (!bitmap) {
spin_lock(&ctl->tree_lock);
info->offset = offset;
info->bytes = bytes;
info->max_extent_size = 0;
ret = link_free_space(ctl, info);
spin_unlock(&ctl->tree_lock);
if (ret)
kmem_cache_free(btrfs_free_space_cachep, info);
return ret;
}
if (!map) {
map = kzalloc(PAGE_SIZE, GFP_NOFS);
if (!map) {
kmem_cache_free(btrfs_free_space_cachep, info);
return -ENOMEM;
}
}
spin_lock(&ctl->tree_lock);
bitmap_info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1, 0);
if (!bitmap_info) {
info->bitmap = map;
map = NULL;
add_new_bitmap(ctl, info, offset);
bitmap_info = info;
info = NULL;
}
bytes_added = add_bytes_to_bitmap(ctl, bitmap_info, offset, bytes);
bytes -= bytes_added;
offset += bytes_added;
spin_unlock(&ctl->tree_lock);
if (bytes)
goto again;
if (info)
kmem_cache_free(btrfs_free_space_cachep, info);
if (map)
kfree(map);
return 0;
}
/*
* Checks to see if the given range is in the free space cache. This is really
* just used to check the absence of space, so if there is free space in the
* range at all we will return 1.
*/
int test_check_exists(struct btrfs_block_group_cache *cache,
u64 offset, u64 bytes)
{
struct btrfs_free_space_ctl *ctl = cache->free_space_ctl;
struct btrfs_free_space *info;
int ret = 0;
spin_lock(&ctl->tree_lock);
info = tree_search_offset(ctl, offset, 0, 0);
if (!info) {
info = tree_search_offset(ctl, offset_to_bitmap(ctl, offset),
1, 0);
if (!info)
goto out;
}
have_info:
if (info->bitmap) {
u64 bit_off, bit_bytes;
struct rb_node *n;
struct btrfs_free_space *tmp;
bit_off = offset;
bit_bytes = ctl->unit;
ret = search_bitmap(ctl, info, &bit_off, &bit_bytes, false);
if (!ret) {
if (bit_off == offset) {
ret = 1;
goto out;
} else if (bit_off > offset &&
offset + bytes > bit_off) {
ret = 1;
goto out;
}
}
n = rb_prev(&info->offset_index);
while (n) {
tmp = rb_entry(n, struct btrfs_free_space,
offset_index);
if (tmp->offset + tmp->bytes < offset)
break;
if (offset + bytes < tmp->offset) {
n = rb_prev(&tmp->offset_index);
continue;
}
info = tmp;
goto have_info;
}
n = rb_next(&info->offset_index);
while (n) {
tmp = rb_entry(n, struct btrfs_free_space,
offset_index);
if (offset + bytes < tmp->offset)
break;
if (tmp->offset + tmp->bytes < offset) {
n = rb_next(&tmp->offset_index);
continue;
}
info = tmp;
goto have_info;
}
ret = 0;
goto out;
}
if (info->offset == offset) {
ret = 1;
goto out;
}
if (offset > info->offset && offset < info->offset + info->bytes)
ret = 1;
out:
spin_unlock(&ctl->tree_lock);
return ret;
}
#endif /* CONFIG_BTRFS_FS_RUN_SANITY_TESTS */