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linux/fs/btrfs/ioctl.c
Li Zefan fdfb1e4f6c Btrfs: Make async snapshot ioctl more generic 
If we had reserved some bytes in struct btrfs_ioctl_vol_args, we
wouldn't have to create a new structure for async snapshot creation.

Here we convert async snapshot ioctl to use a more generic ABI, as
we'll add more ioctls for snapshots/subvolumes in the future, readonly
snapshots for example.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-12-10 16:29:11 -05:00

2306 lines
56 KiB
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/*
* Copyright (C) 2007 Oracle. 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/kernel.h>
#include <linux/bio.h>
#include <linux/buffer_head.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/fsnotify.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/mount.h>
#include <linux/mpage.h>
#include <linux/namei.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
#include <linux/bit_spinlock.h>
#include <linux/security.h>
#include <linux/xattr.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include "compat.h"
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
#include "volumes.h"
#include "locking.h"
/* Mask out flags that are inappropriate for the given type of inode. */
static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
{
if (S_ISDIR(mode))
return flags;
else if (S_ISREG(mode))
return flags & ~FS_DIRSYNC_FL;
else
return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
}
/*
* Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
*/
static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
{
unsigned int iflags = 0;
if (flags & BTRFS_INODE_SYNC)
iflags |= FS_SYNC_FL;
if (flags & BTRFS_INODE_IMMUTABLE)
iflags |= FS_IMMUTABLE_FL;
if (flags & BTRFS_INODE_APPEND)
iflags |= FS_APPEND_FL;
if (flags & BTRFS_INODE_NODUMP)
iflags |= FS_NODUMP_FL;
if (flags & BTRFS_INODE_NOATIME)
iflags |= FS_NOATIME_FL;
if (flags & BTRFS_INODE_DIRSYNC)
iflags |= FS_DIRSYNC_FL;
return iflags;
}
/*
* Update inode->i_flags based on the btrfs internal flags.
*/
void btrfs_update_iflags(struct inode *inode)
{
struct btrfs_inode *ip = BTRFS_I(inode);
inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
if (ip->flags & BTRFS_INODE_SYNC)
inode->i_flags |= S_SYNC;
if (ip->flags & BTRFS_INODE_IMMUTABLE)
inode->i_flags |= S_IMMUTABLE;
if (ip->flags & BTRFS_INODE_APPEND)
inode->i_flags |= S_APPEND;
if (ip->flags & BTRFS_INODE_NOATIME)
inode->i_flags |= S_NOATIME;
if (ip->flags & BTRFS_INODE_DIRSYNC)
inode->i_flags |= S_DIRSYNC;
}
/*
* Inherit flags from the parent inode.
*
* Unlike extN we don't have any flags we don't want to inherit currently.
*/
void btrfs_inherit_iflags(struct inode *inode, struct inode *dir)
{
unsigned int flags;
if (!dir)
return;
flags = BTRFS_I(dir)->flags;
if (S_ISREG(inode->i_mode))
flags &= ~BTRFS_INODE_DIRSYNC;
else if (!S_ISDIR(inode->i_mode))
flags &= (BTRFS_INODE_NODUMP | BTRFS_INODE_NOATIME);
BTRFS_I(inode)->flags = flags;
btrfs_update_iflags(inode);
}
static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
{
struct btrfs_inode *ip = BTRFS_I(file->f_path.dentry->d_inode);
unsigned int flags = btrfs_flags_to_ioctl(ip->flags);
if (copy_to_user(arg, &flags, sizeof(flags)))
return -EFAULT;
return 0;
}
static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct btrfs_inode *ip = BTRFS_I(inode);
struct btrfs_root *root = ip->root;
struct btrfs_trans_handle *trans;
unsigned int flags, oldflags;
int ret;
if (copy_from_user(&flags, arg, sizeof(flags)))
return -EFAULT;
if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
FS_NOATIME_FL | FS_NODUMP_FL | \
FS_SYNC_FL | FS_DIRSYNC_FL))
return -EOPNOTSUPP;
if (!is_owner_or_cap(inode))
return -EACCES;
mutex_lock(&inode->i_mutex);
flags = btrfs_mask_flags(inode->i_mode, flags);
oldflags = btrfs_flags_to_ioctl(ip->flags);
if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
if (!capable(CAP_LINUX_IMMUTABLE)) {
ret = -EPERM;
goto out_unlock;
}
}
ret = mnt_want_write(file->f_path.mnt);
if (ret)
goto out_unlock;
if (flags & FS_SYNC_FL)
ip->flags |= BTRFS_INODE_SYNC;
else
ip->flags &= ~BTRFS_INODE_SYNC;
if (flags & FS_IMMUTABLE_FL)
ip->flags |= BTRFS_INODE_IMMUTABLE;
else
ip->flags &= ~BTRFS_INODE_IMMUTABLE;
if (flags & FS_APPEND_FL)
ip->flags |= BTRFS_INODE_APPEND;
else
ip->flags &= ~BTRFS_INODE_APPEND;
if (flags & FS_NODUMP_FL)
ip->flags |= BTRFS_INODE_NODUMP;
else
ip->flags &= ~BTRFS_INODE_NODUMP;
if (flags & FS_NOATIME_FL)
ip->flags |= BTRFS_INODE_NOATIME;
else
ip->flags &= ~BTRFS_INODE_NOATIME;
if (flags & FS_DIRSYNC_FL)
ip->flags |= BTRFS_INODE_DIRSYNC;
else
ip->flags &= ~BTRFS_INODE_DIRSYNC;
trans = btrfs_join_transaction(root, 1);
BUG_ON(!trans);
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
btrfs_update_iflags(inode);
inode->i_ctime = CURRENT_TIME;
btrfs_end_transaction(trans, root);
mnt_drop_write(file->f_path.mnt);
out_unlock:
mutex_unlock(&inode->i_mutex);
return 0;
}
static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
{
struct inode *inode = file->f_path.dentry->d_inode;
return put_user(inode->i_generation, arg);
}
static noinline int create_subvol(struct btrfs_root *root,
struct dentry *dentry,
char *name, int namelen,
u64 *async_transid)
{
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_root_item root_item;
struct btrfs_inode_item *inode_item;
struct extent_buffer *leaf;
struct btrfs_root *new_root;
struct dentry *parent = dget_parent(dentry);
struct inode *dir;
int ret;
int err;
u64 objectid;
u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
u64 index = 0;
ret = btrfs_find_free_objectid(NULL, root->fs_info->tree_root,
0, &objectid);
if (ret) {
dput(parent);
return ret;
}
dir = parent->d_inode;
/*
* 1 - inode item
* 2 - refs
* 1 - root item
* 2 - dir items
*/
trans = btrfs_start_transaction(root, 6);
if (IS_ERR(trans)) {
dput(parent);
return PTR_ERR(trans);
}
leaf = btrfs_alloc_free_block(trans, root, root->leafsize,
0, objectid, NULL, 0, 0, 0);
if (IS_ERR(leaf)) {
ret = PTR_ERR(leaf);
goto fail;
}
memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
btrfs_set_header_bytenr(leaf, leaf->start);
btrfs_set_header_generation(leaf, trans->transid);
btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
btrfs_set_header_owner(leaf, objectid);
write_extent_buffer(leaf, root->fs_info->fsid,
(unsigned long)btrfs_header_fsid(leaf),
BTRFS_FSID_SIZE);
write_extent_buffer(leaf, root->fs_info->chunk_tree_uuid,
(unsigned long)btrfs_header_chunk_tree_uuid(leaf),
BTRFS_UUID_SIZE);
btrfs_mark_buffer_dirty(leaf);
inode_item = &root_item.inode;
memset(inode_item, 0, sizeof(*inode_item));
inode_item->generation = cpu_to_le64(1);
inode_item->size = cpu_to_le64(3);
inode_item->nlink = cpu_to_le32(1);
inode_item->nbytes = cpu_to_le64(root->leafsize);
inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
btrfs_set_root_bytenr(&root_item, leaf->start);
btrfs_set_root_generation(&root_item, trans->transid);
btrfs_set_root_level(&root_item, 0);
btrfs_set_root_refs(&root_item, 1);
btrfs_set_root_used(&root_item, leaf->len);
btrfs_set_root_last_snapshot(&root_item, 0);
memset(&root_item.drop_progress, 0, sizeof(root_item.drop_progress));
root_item.drop_level = 0;
btrfs_tree_unlock(leaf);
free_extent_buffer(leaf);
leaf = NULL;
btrfs_set_root_dirid(&root_item, new_dirid);
key.objectid = objectid;
key.offset = 0;
btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
ret = btrfs_insert_root(trans, root->fs_info->tree_root, &key,
&root_item);
if (ret)
goto fail;
key.offset = (u64)-1;
new_root = btrfs_read_fs_root_no_name(root->fs_info, &key);
BUG_ON(IS_ERR(new_root));
btrfs_record_root_in_trans(trans, new_root);
ret = btrfs_create_subvol_root(trans, new_root, new_dirid,
BTRFS_I(dir)->block_group);
/*
* insert the directory item
*/
ret = btrfs_set_inode_index(dir, &index);
BUG_ON(ret);
ret = btrfs_insert_dir_item(trans, root,
name, namelen, dir->i_ino, &key,
BTRFS_FT_DIR, index);
if (ret)
goto fail;
btrfs_i_size_write(dir, dir->i_size + namelen * 2);
ret = btrfs_update_inode(trans, root, dir);
BUG_ON(ret);
ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
objectid, root->root_key.objectid,
dir->i_ino, index, name, namelen);
BUG_ON(ret);
d_instantiate(dentry, btrfs_lookup_dentry(dir, dentry));
fail:
dput(parent);
if (async_transid) {
*async_transid = trans->transid;
err = btrfs_commit_transaction_async(trans, root, 1);
} else {
err = btrfs_commit_transaction(trans, root);
}
if (err && !ret)
ret = err;
return ret;
}
static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
char *name, int namelen, u64 *async_transid)
{
struct inode *inode;
struct dentry *parent;
struct btrfs_pending_snapshot *pending_snapshot;
struct btrfs_trans_handle *trans;
int ret;
if (!root->ref_cows)
return -EINVAL;
pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_NOFS);
if (!pending_snapshot)
return -ENOMEM;
btrfs_init_block_rsv(&pending_snapshot->block_rsv);
pending_snapshot->dentry = dentry;
pending_snapshot->root = root;
trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto fail;
}
ret = btrfs_snap_reserve_metadata(trans, pending_snapshot);
BUG_ON(ret);
list_add(&pending_snapshot->list,
&trans->transaction->pending_snapshots);
if (async_transid) {
*async_transid = trans->transid;
ret = btrfs_commit_transaction_async(trans,
root->fs_info->extent_root, 1);
} else {
ret = btrfs_commit_transaction(trans,
root->fs_info->extent_root);
}
BUG_ON(ret);
ret = pending_snapshot->error;
if (ret)
goto fail;
btrfs_orphan_cleanup(pending_snapshot->snap);
parent = dget_parent(dentry);
inode = btrfs_lookup_dentry(parent->d_inode, dentry);
dput(parent);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto fail;
}
BUG_ON(!inode);
d_instantiate(dentry, inode);
ret = 0;
fail:
kfree(pending_snapshot);
return ret;
}
/* copy of check_sticky in fs/namei.c()
* It's inline, so penalty for filesystems that don't use sticky bit is
* minimal.
*/
static inline int btrfs_check_sticky(struct inode *dir, struct inode *inode)
{
uid_t fsuid = current_fsuid();
if (!(dir->i_mode & S_ISVTX))
return 0;
if (inode->i_uid == fsuid)
return 0;
if (dir->i_uid == fsuid)
return 0;
return !capable(CAP_FOWNER);
}
/* copy of may_delete in fs/namei.c()
* Check whether we can remove a link victim from directory dir, check
* whether the type of victim is right.
* 1. We can't do it if dir is read-only (done in permission())
* 2. We should have write and exec permissions on dir
* 3. We can't remove anything from append-only dir
* 4. We can't do anything with immutable dir (done in permission())
* 5. If the sticky bit on dir is set we should either
* a. be owner of dir, or
* b. be owner of victim, or
* c. have CAP_FOWNER capability
* 6. If the victim is append-only or immutable we can't do antyhing with
* links pointing to it.
* 7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
* 8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
* 9. We can't remove a root or mountpoint.
* 10. We don't allow removal of NFS sillyrenamed files; it's handled by
* nfs_async_unlink().
*/
static int btrfs_may_delete(struct inode *dir,struct dentry *victim,int isdir)
{
int error;
if (!victim->d_inode)
return -ENOENT;
BUG_ON(victim->d_parent->d_inode != dir);
audit_inode_child(victim, dir);
error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
if (error)
return error;
if (IS_APPEND(dir))
return -EPERM;
if (btrfs_check_sticky(dir, victim->d_inode)||
IS_APPEND(victim->d_inode)||
IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode))
return -EPERM;
if (isdir) {
if (!S_ISDIR(victim->d_inode->i_mode))
return -ENOTDIR;
if (IS_ROOT(victim))
return -EBUSY;
} else if (S_ISDIR(victim->d_inode->i_mode))
return -EISDIR;
if (IS_DEADDIR(dir))
return -ENOENT;
if (victim->d_flags & DCACHE_NFSFS_RENAMED)
return -EBUSY;
return 0;
}
/* copy of may_create in fs/namei.c() */
static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
{
if (child->d_inode)
return -EEXIST;
if (IS_DEADDIR(dir))
return -ENOENT;
return inode_permission(dir, MAY_WRITE | MAY_EXEC);
}
/*
* Create a new subvolume below @parent. This is largely modeled after
* sys_mkdirat and vfs_mkdir, but we only do a single component lookup
* inside this filesystem so it's quite a bit simpler.
*/
static noinline int btrfs_mksubvol(struct path *parent,
char *name, int namelen,
struct btrfs_root *snap_src,
u64 *async_transid)
{
struct inode *dir = parent->dentry->d_inode;
struct dentry *dentry;
int error;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(name, parent->dentry, namelen);
error = PTR_ERR(dentry);
if (IS_ERR(dentry))
goto out_unlock;
error = -EEXIST;
if (dentry->d_inode)
goto out_dput;
error = mnt_want_write(parent->mnt);
if (error)
goto out_dput;
error = btrfs_may_create(dir, dentry);
if (error)
goto out_drop_write;
down_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
goto out_up_read;
if (snap_src) {
error = create_snapshot(snap_src, dentry,
name, namelen, async_transid);
} else {
error = create_subvol(BTRFS_I(dir)->root, dentry,
name, namelen, async_transid);
}
if (!error)
fsnotify_mkdir(dir, dentry);
out_up_read:
up_read(&BTRFS_I(dir)->root->fs_info->subvol_sem);
out_drop_write:
mnt_drop_write(parent->mnt);
out_dput:
dput(dentry);
out_unlock:
mutex_unlock(&dir->i_mutex);
return error;
}
static int should_defrag_range(struct inode *inode, u64 start, u64 len,
int thresh, u64 *last_len, u64 *skip,
u64 *defrag_end)
{
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct extent_map *em = NULL;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
int ret = 1;
if (thresh == 0)
thresh = 256 * 1024;
/*
* make sure that once we start defragging and extent, we keep on
* defragging it
*/
if (start < *defrag_end)
return 1;
*skip = 0;
/*
* hopefully we have this extent in the tree already, try without
* the full extent lock
*/
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, len);
read_unlock(&em_tree->lock);
if (!em) {
/* get the big lock and read metadata off disk */
lock_extent(io_tree, start, start + len - 1, GFP_NOFS);
em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
unlock_extent(io_tree, start, start + len - 1, GFP_NOFS);
if (IS_ERR(em))
return 0;
}
/* this will cover holes, and inline extents */
if (em->block_start >= EXTENT_MAP_LAST_BYTE)
ret = 0;
/*
* we hit a real extent, if it is big don't bother defragging it again
*/
if ((*last_len == 0 || *last_len >= thresh) && em->len >= thresh)
ret = 0;
/*
* last_len ends up being a counter of how many bytes we've defragged.
* every time we choose not to defrag an extent, we reset *last_len
* so that the next tiny extent will force a defrag.
*
* The end result of this is that tiny extents before a single big
* extent will force at least part of that big extent to be defragged.
*/
if (ret) {
*last_len += len;
*defrag_end = extent_map_end(em);
} else {
*last_len = 0;
*skip = extent_map_end(em);
*defrag_end = 0;
}
free_extent_map(em);
return ret;
}
static int btrfs_defrag_file(struct file *file,
struct btrfs_ioctl_defrag_range_args *range)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
struct btrfs_ordered_extent *ordered;
struct page *page;
unsigned long last_index;
unsigned long ra_pages = root->fs_info->bdi.ra_pages;
unsigned long total_read = 0;
u64 page_start;
u64 page_end;
u64 last_len = 0;
u64 skip = 0;
u64 defrag_end = 0;
unsigned long i;
int ret;
if (inode->i_size == 0)
return 0;
if (range->start + range->len > range->start) {
last_index = min_t(u64, inode->i_size - 1,
range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
} else {
last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
}
i = range->start >> PAGE_CACHE_SHIFT;
while (i <= last_index) {
if (!should_defrag_range(inode, (u64)i << PAGE_CACHE_SHIFT,
PAGE_CACHE_SIZE,
range->extent_thresh,
&last_len, &skip,
&defrag_end)) {
unsigned long next;
/*
* the should_defrag function tells us how much to skip
* bump our counter by the suggested amount
*/
next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
i = max(i + 1, next);
continue;
}
if (total_read % ra_pages == 0) {
btrfs_force_ra(inode->i_mapping, &file->f_ra, file, i,
min(last_index, i + ra_pages - 1));
}
total_read++;
mutex_lock(&inode->i_mutex);
if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
BTRFS_I(inode)->force_compress = 1;
ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
if (ret)
goto err_unlock;
again:
if (inode->i_size == 0 ||
i > ((inode->i_size - 1) >> PAGE_CACHE_SHIFT)) {
ret = 0;
goto err_reservations;
}
page = grab_cache_page(inode->i_mapping, i);
if (!page) {
ret = -ENOMEM;
goto err_reservations;
}
if (!PageUptodate(page)) {
btrfs_readpage(NULL, page);
lock_page(page);
if (!PageUptodate(page)) {
unlock_page(page);
page_cache_release(page);
ret = -EIO;
goto err_reservations;
}
}
if (page->mapping != inode->i_mapping) {
unlock_page(page);
page_cache_release(page);
goto again;
}
wait_on_page_writeback(page);
if (PageDirty(page)) {
btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
goto loop_unlock;
}
page_start = (u64)page->index << PAGE_CACHE_SHIFT;
page_end = page_start + PAGE_CACHE_SIZE - 1;
lock_extent(io_tree, page_start, page_end, GFP_NOFS);
ordered = btrfs_lookup_ordered_extent(inode, page_start);
if (ordered) {
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
unlock_page(page);
page_cache_release(page);
btrfs_start_ordered_extent(inode, ordered, 1);
btrfs_put_ordered_extent(ordered);
goto again;
}
set_page_extent_mapped(page);
/*
* this makes sure page_mkwrite is called on the
* page if it is dirtied again later
*/
clear_page_dirty_for_io(page);
clear_extent_bits(&BTRFS_I(inode)->io_tree, page_start,
page_end, EXTENT_DIRTY | EXTENT_DELALLOC |
EXTENT_DO_ACCOUNTING, GFP_NOFS);
btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
ClearPageChecked(page);
set_page_dirty(page);
unlock_extent(io_tree, page_start, page_end, GFP_NOFS);
loop_unlock:
unlock_page(page);
page_cache_release(page);
mutex_unlock(&inode->i_mutex);
balance_dirty_pages_ratelimited_nr(inode->i_mapping, 1);
i++;
}
if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO))
filemap_flush(inode->i_mapping);
if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
/* the filemap_flush will queue IO into the worker threads, but
* we have to make sure the IO is actually started and that
* ordered extents get created before we return
*/
atomic_inc(&root->fs_info->async_submit_draining);
while (atomic_read(&root->fs_info->nr_async_submits) ||
atomic_read(&root->fs_info->async_delalloc_pages)) {
wait_event(root->fs_info->async_submit_wait,
(atomic_read(&root->fs_info->nr_async_submits) == 0 &&
atomic_read(&root->fs_info->async_delalloc_pages) == 0));
}
atomic_dec(&root->fs_info->async_submit_draining);
mutex_lock(&inode->i_mutex);
BTRFS_I(inode)->force_compress = 0;
mutex_unlock(&inode->i_mutex);
}
return 0;
err_reservations:
btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
err_unlock:
mutex_unlock(&inode->i_mutex);
return ret;
}
static noinline int btrfs_ioctl_resize(struct btrfs_root *root,
void __user *arg)
{
u64 new_size;
u64 old_size;
u64 devid = 1;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_trans_handle *trans;
struct btrfs_device *device = NULL;
char *sizestr;
char *devstr = NULL;
int ret = 0;
int mod = 0;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
mutex_lock(&root->fs_info->volume_mutex);
sizestr = vol_args->name;
devstr = strchr(sizestr, ':');
if (devstr) {
char *end;
sizestr = devstr + 1;
*devstr = '\0';
devstr = vol_args->name;
devid = simple_strtoull(devstr, &end, 10);
printk(KERN_INFO "resizing devid %llu\n",
(unsigned long long)devid);
}
device = btrfs_find_device(root, devid, NULL, NULL);
if (!device) {
printk(KERN_INFO "resizer unable to find device %llu\n",
(unsigned long long)devid);
ret = -EINVAL;
goto out_unlock;
}
if (!strcmp(sizestr, "max"))
new_size = device->bdev->bd_inode->i_size;
else {
if (sizestr[0] == '-') {
mod = -1;
sizestr++;
} else if (sizestr[0] == '+') {
mod = 1;
sizestr++;
}
new_size = memparse(sizestr, NULL);
if (new_size == 0) {
ret = -EINVAL;
goto out_unlock;
}
}
old_size = device->total_bytes;
if (mod < 0) {
if (new_size > old_size) {
ret = -EINVAL;
goto out_unlock;
}
new_size = old_size - new_size;
} else if (mod > 0) {
new_size = old_size + new_size;
}
if (new_size < 256 * 1024 * 1024) {
ret = -EINVAL;
goto out_unlock;
}
if (new_size > device->bdev->bd_inode->i_size) {
ret = -EFBIG;
goto out_unlock;
}
do_div(new_size, root->sectorsize);
new_size *= root->sectorsize;
printk(KERN_INFO "new size for %s is %llu\n",
device->name, (unsigned long long)new_size);
if (new_size > old_size) {
trans = btrfs_start_transaction(root, 0);
ret = btrfs_grow_device(trans, device, new_size);
btrfs_commit_transaction(trans, root);
} else {
ret = btrfs_shrink_device(device, new_size);
}
out_unlock:
mutex_unlock(&root->fs_info->volume_mutex);
kfree(vol_args);
return ret;
}
static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
char *name,
unsigned long fd,
int subvol,
u64 *transid)
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
struct file *src_file;
int namelen;
int ret = 0;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
namelen = strlen(name);
if (strchr(name, '/')) {
ret = -EINVAL;
goto out;
}
if (subvol) {
ret = btrfs_mksubvol(&file->f_path, name, namelen,
NULL, transid);
} else {
struct inode *src_inode;
src_file = fget(fd);
if (!src_file) {
ret = -EINVAL;
goto out;
}
src_inode = src_file->f_path.dentry->d_inode;
if (src_inode->i_sb != file->f_path.dentry->d_inode->i_sb) {
printk(KERN_INFO "btrfs: Snapshot src from "
"another FS\n");
ret = -EINVAL;
fput(src_file);
goto out;
}
ret = btrfs_mksubvol(&file->f_path, name, namelen,
BTRFS_I(src_inode)->root,
transid);
fput(src_file);
}
out:
return ret;
}
static noinline int btrfs_ioctl_snap_create(struct file *file,
void __user *arg, int subvol,
int v2)
{
struct btrfs_ioctl_vol_args *vol_args = NULL;
struct btrfs_ioctl_vol_args_v2 *vol_args_v2 = NULL;
char *name;
u64 fd;
int ret;
if (v2) {
u64 transid = 0;
u64 *ptr = NULL;
vol_args_v2 = memdup_user(arg, sizeof(*vol_args_v2));
if (IS_ERR(vol_args_v2))
return PTR_ERR(vol_args_v2);
if (vol_args_v2->flags & ~BTRFS_SUBVOL_CREATE_ASYNC) {
ret = -EINVAL;
goto out;
}
name = vol_args_v2->name;
fd = vol_args_v2->fd;
vol_args_v2->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
if (vol_args_v2->flags & BTRFS_SUBVOL_CREATE_ASYNC)
ptr = &transid;
ret = btrfs_ioctl_snap_create_transid(file, name, fd,
subvol, ptr);
if (ret == 0 && ptr &&
copy_to_user(arg +
offsetof(struct btrfs_ioctl_vol_args_v2,
transid), ptr, sizeof(*ptr)))
ret = -EFAULT;
} else {
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
name = vol_args->name;
fd = vol_args->fd;
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_ioctl_snap_create_transid(file, name, fd,
subvol, NULL);
}
out:
kfree(vol_args);
kfree(vol_args_v2);
return ret;
}
/*
* helper to check if the subvolume references other subvolumes
*/
static noinline int may_destroy_subvol(struct btrfs_root *root)
{
struct btrfs_path *path;
struct btrfs_key key;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
key.objectid = root->root_key.objectid;
key.type = BTRFS_ROOT_REF_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, root->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;
}
static noinline int key_in_sk(struct btrfs_key *key,
struct btrfs_ioctl_search_key *sk)
{
struct btrfs_key test;
int ret;
test.objectid = sk->min_objectid;
test.type = sk->min_type;
test.offset = sk->min_offset;
ret = btrfs_comp_cpu_keys(key, &test);
if (ret < 0)
return 0;
test.objectid = sk->max_objectid;
test.type = sk->max_type;
test.offset = sk->max_offset;
ret = btrfs_comp_cpu_keys(key, &test);
if (ret > 0)
return 0;
return 1;
}
static noinline int copy_to_sk(struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_key *key,
struct btrfs_ioctl_search_key *sk,
char *buf,
unsigned long *sk_offset,
int *num_found)
{
u64 found_transid;
struct extent_buffer *leaf;
struct btrfs_ioctl_search_header sh;
unsigned long item_off;
unsigned long item_len;
int nritems;
int i;
int slot;
int found = 0;
int ret = 0;
leaf = path->nodes[0];
slot = path->slots[0];
nritems = btrfs_header_nritems(leaf);
if (btrfs_header_generation(leaf) > sk->max_transid) {
i = nritems;
goto advance_key;
}
found_transid = btrfs_header_generation(leaf);
for (i = slot; i < nritems; i++) {
item_off = btrfs_item_ptr_offset(leaf, i);
item_len = btrfs_item_size_nr(leaf, i);
if (item_len > BTRFS_SEARCH_ARGS_BUFSIZE)
item_len = 0;
if (sizeof(sh) + item_len + *sk_offset >
BTRFS_SEARCH_ARGS_BUFSIZE) {
ret = 1;
goto overflow;
}
btrfs_item_key_to_cpu(leaf, key, i);
if (!key_in_sk(key, sk))
continue;
sh.objectid = key->objectid;
sh.offset = key->offset;
sh.type = key->type;
sh.len = item_len;
sh.transid = found_transid;
/* copy search result header */
memcpy(buf + *sk_offset, &sh, sizeof(sh));
*sk_offset += sizeof(sh);
if (item_len) {
char *p = buf + *sk_offset;
/* copy the item */
read_extent_buffer(leaf, p,
item_off, item_len);
*sk_offset += item_len;
}
found++;
if (*num_found >= sk->nr_items)
break;
}
advance_key:
ret = 0;
if (key->offset < (u64)-1 && key->offset < sk->max_offset)
key->offset++;
else if (key->type < (u8)-1 && key->type < sk->max_type) {
key->offset = 0;
key->type++;
} else if (key->objectid < (u64)-1 && key->objectid < sk->max_objectid) {
key->offset = 0;
key->type = 0;
key->objectid++;
} else
ret = 1;
overflow:
*num_found += found;
return ret;
}
static noinline int search_ioctl(struct inode *inode,
struct btrfs_ioctl_search_args *args)
{
struct btrfs_root *root;
struct btrfs_key key;
struct btrfs_key max_key;
struct btrfs_path *path;
struct btrfs_ioctl_search_key *sk = &args->key;
struct btrfs_fs_info *info = BTRFS_I(inode)->root->fs_info;
int ret;
int num_found = 0;
unsigned long sk_offset = 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
if (sk->tree_id == 0) {
/* search the root of the inode that was passed */
root = BTRFS_I(inode)->root;
} else {
key.objectid = sk->tree_id;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
root = btrfs_read_fs_root_no_name(info, &key);
if (IS_ERR(root)) {
printk(KERN_ERR "could not find root %llu\n",
sk->tree_id);
btrfs_free_path(path);
return -ENOENT;
}
}
key.objectid = sk->min_objectid;
key.type = sk->min_type;
key.offset = sk->min_offset;
max_key.objectid = sk->max_objectid;
max_key.type = sk->max_type;
max_key.offset = sk->max_offset;
path->keep_locks = 1;
while(1) {
ret = btrfs_search_forward(root, &key, &max_key, path, 0,
sk->min_transid);
if (ret != 0) {
if (ret > 0)
ret = 0;
goto err;
}
ret = copy_to_sk(root, path, &key, sk, args->buf,
&sk_offset, &num_found);
btrfs_release_path(root, path);
if (ret || num_found >= sk->nr_items)
break;
}
ret = 0;
err:
sk->nr_items = num_found;
btrfs_free_path(path);
return ret;
}
static noinline int btrfs_ioctl_tree_search(struct file *file,
void __user *argp)
{
struct btrfs_ioctl_search_args *args;
struct inode *inode;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
args = memdup_user(argp, sizeof(*args));
if (IS_ERR(args))
return PTR_ERR(args);
inode = fdentry(file)->d_inode;
ret = search_ioctl(inode, args);
if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
ret = -EFAULT;
kfree(args);
return ret;
}
/*
* Search INODE_REFs to identify path name of 'dirid' directory
* in a 'tree_id' tree. and sets path name to 'name'.
*/
static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
u64 tree_id, u64 dirid, char *name)
{
struct btrfs_root *root;
struct btrfs_key key;
char *ptr;
int ret = -1;
int slot;
int len;
int total_len = 0;
struct btrfs_inode_ref *iref;
struct extent_buffer *l;
struct btrfs_path *path;
if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
name[0]='\0';
return 0;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX];
key.objectid = tree_id;
key.type = BTRFS_ROOT_ITEM_KEY;
key.offset = (u64)-1;
root = btrfs_read_fs_root_no_name(info, &key);
if (IS_ERR(root)) {
printk(KERN_ERR "could not find root %llu\n", tree_id);
ret = -ENOENT;
goto out;
}
key.objectid = dirid;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
while(1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
l = path->nodes[0];
slot = path->slots[0];
if (ret > 0 && slot > 0)
slot--;
btrfs_item_key_to_cpu(l, &key, slot);
if (ret > 0 && (key.objectid != dirid ||
key.type != BTRFS_INODE_REF_KEY)) {
ret = -ENOENT;
goto out;
}
iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
len = btrfs_inode_ref_name_len(l, iref);
ptr -= len + 1;
total_len += len + 1;
if (ptr < name)
goto out;
*(ptr + len) = '/';
read_extent_buffer(l, ptr,(unsigned long)(iref + 1), len);
if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
break;
btrfs_release_path(root, path);
key.objectid = key.offset;
key.offset = (u64)-1;
dirid = key.objectid;
}
if (ptr < name)
goto out;
memcpy(name, ptr, total_len);
name[total_len]='\0';
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
static noinline int btrfs_ioctl_ino_lookup(struct file *file,
void __user *argp)
{
struct btrfs_ioctl_ino_lookup_args *args;
struct inode *inode;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
args = memdup_user(argp, sizeof(*args));
if (IS_ERR(args))
return PTR_ERR(args);
inode = fdentry(file)->d_inode;
if (args->treeid == 0)
args->treeid = BTRFS_I(inode)->root->root_key.objectid;
ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
args->treeid, args->objectid,
args->name);
if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
ret = -EFAULT;
kfree(args);
return ret;
}
static noinline int btrfs_ioctl_snap_destroy(struct file *file,
void __user *arg)
{
struct dentry *parent = fdentry(file);
struct dentry *dentry;
struct inode *dir = parent->d_inode;
struct inode *inode;
struct btrfs_root *root = BTRFS_I(dir)->root;
struct btrfs_root *dest = NULL;
struct btrfs_ioctl_vol_args *vol_args;
struct btrfs_trans_handle *trans;
int namelen;
int ret;
int err = 0;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
namelen = strlen(vol_args->name);
if (strchr(vol_args->name, '/') ||
strncmp(vol_args->name, "..", namelen) == 0) {
err = -EINVAL;
goto out;
}
err = mnt_want_write(file->f_path.mnt);
if (err)
goto out;
mutex_lock_nested(&dir->i_mutex, I_MUTEX_PARENT);
dentry = lookup_one_len(vol_args->name, parent, namelen);
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out_unlock_dir;
}
if (!dentry->d_inode) {
err = -ENOENT;
goto out_dput;
}
inode = dentry->d_inode;
dest = BTRFS_I(inode)->root;
if (!capable(CAP_SYS_ADMIN)){
/*
* Regular user. Only allow this with a special mount
* option, when the user has write+exec access to the
* subvol root, and when rmdir(2) would have been
* allowed.
*
* Note that this is _not_ check that the subvol is
* empty or doesn't contain data that we wouldn't
* otherwise be able to delete.
*
* Users who want to delete empty subvols should try
* rmdir(2).
*/
err = -EPERM;
if (!btrfs_test_opt(root, USER_SUBVOL_RM_ALLOWED))
goto out_dput;
/*
* Do not allow deletion if the parent dir is the same
* as the dir to be deleted. That means the ioctl
* must be called on the dentry referencing the root
* of the subvol, not a random directory contained
* within it.
*/
err = -EINVAL;
if (root == dest)
goto out_dput;
err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
if (err)
goto out_dput;
/* check if subvolume may be deleted by a non-root user */
err = btrfs_may_delete(dir, dentry, 1);
if (err)
goto out_dput;
}
if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
err = -EINVAL;
goto out_dput;
}
mutex_lock(&inode->i_mutex);
err = d_invalidate(dentry);
if (err)
goto out_unlock;
down_write(&root->fs_info->subvol_sem);
err = may_destroy_subvol(dest);
if (err)
goto out_up_write;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
goto out_up_write;
}
trans->block_rsv = &root->fs_info->global_block_rsv;
ret = btrfs_unlink_subvol(trans, root, dir,
dest->root_key.objectid,
dentry->d_name.name,
dentry->d_name.len);
BUG_ON(ret);
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 (!xchg(&dest->orphan_item_inserted, 1)) {
ret = btrfs_insert_orphan_item(trans,
root->fs_info->tree_root,
dest->root_key.objectid);
BUG_ON(ret);
}
ret = btrfs_end_transaction(trans, root);
BUG_ON(ret);
inode->i_flags |= S_DEAD;
out_up_write:
up_write(&root->fs_info->subvol_sem);
out_unlock:
mutex_unlock(&inode->i_mutex);
if (!err) {
shrink_dcache_sb(root->fs_info->sb);
btrfs_invalidate_inodes(dest);
d_delete(dentry);
}
out_dput:
dput(dentry);
out_unlock_dir:
mutex_unlock(&dir->i_mutex);
mnt_drop_write(file->f_path.mnt);
out:
kfree(vol_args);
return err;
}
static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_ioctl_defrag_range_args *range;
int ret;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
switch (inode->i_mode & S_IFMT) {
case S_IFDIR:
if (!capable(CAP_SYS_ADMIN)) {
ret = -EPERM;
goto out;
}
ret = btrfs_defrag_root(root, 0);
if (ret)
goto out;
ret = btrfs_defrag_root(root->fs_info->extent_root, 0);
break;
case S_IFREG:
if (!(file->f_mode & FMODE_WRITE)) {
ret = -EINVAL;
goto out;
}
range = kzalloc(sizeof(*range), GFP_KERNEL);
if (!range) {
ret = -ENOMEM;
goto out;
}
if (argp) {
if (copy_from_user(range, argp,
sizeof(*range))) {
ret = -EFAULT;
kfree(range);
goto out;
}
/* compression requires us to start the IO */
if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
range->extent_thresh = (u32)-1;
}
} else {
/* the rest are all set to zero by kzalloc */
range->len = (u64)-1;
}
ret = btrfs_defrag_file(file, range);
kfree(range);
break;
default:
ret = -EINVAL;
}
out:
mnt_drop_write(file->f_path.mnt);
return ret;
}
static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_init_new_device(root, vol_args->name);
kfree(vol_args);
return ret;
}
static long btrfs_ioctl_rm_dev(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_vol_args *vol_args;
int ret;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args))
return PTR_ERR(vol_args);
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
ret = btrfs_rm_device(root, vol_args->name);
kfree(vol_args);
return ret;
}
static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
u64 off, u64 olen, u64 destoff)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct file *src_file;
struct inode *src;
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct extent_buffer *leaf;
char *buf;
struct btrfs_key key;
u32 nritems;
int slot;
int ret;
u64 len = olen;
u64 bs = root->fs_info->sb->s_blocksize;
u64 hint_byte;
/*
* TODO:
* - split compressed inline extents. annoying: we need to
* decompress into destination's address_space (the file offset
* may change, so source mapping won't do), then recompress (or
* otherwise reinsert) a subrange.
* - allow ranges within the same file to be cloned (provided
* they don't overlap)?
*/
/* the destination must be opened for writing */
if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
return -EINVAL;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
src_file = fget(srcfd);
if (!src_file) {
ret = -EBADF;
goto out_drop_write;
}
src = src_file->f_dentry->d_inode;
ret = -EINVAL;
if (src == inode)
goto out_fput;
/* the src must be open for reading */
if (!(src_file->f_mode & FMODE_READ))
goto out_fput;
ret = -EISDIR;
if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
goto out_fput;
ret = -EXDEV;
if (src->i_sb != inode->i_sb || BTRFS_I(src)->root != root)
goto out_fput;
ret = -ENOMEM;
buf = vmalloc(btrfs_level_size(root, 0));
if (!buf)
goto out_fput;
path = btrfs_alloc_path();
if (!path) {
vfree(buf);
goto out_fput;
}
path->reada = 2;
if (inode < src) {
mutex_lock_nested(&inode->i_mutex, I_MUTEX_PARENT);
mutex_lock_nested(&src->i_mutex, I_MUTEX_CHILD);
} else {
mutex_lock_nested(&src->i_mutex, I_MUTEX_PARENT);
mutex_lock_nested(&inode->i_mutex, I_MUTEX_CHILD);
}
/* determine range to clone */
ret = -EINVAL;
if (off + len > src->i_size || off + len < off)
goto out_unlock;
if (len == 0)
olen = len = src->i_size - off;
/* if we extend to eof, continue to block boundary */
if (off + len == src->i_size)
len = ALIGN(src->i_size, bs) - off;
/* verify the end result is block aligned */
if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
!IS_ALIGNED(destoff, bs))
goto out_unlock;
/* do any pending delalloc/csum calc on src, one way or
another, and lock file content */
while (1) {
struct btrfs_ordered_extent *ordered;
lock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
ordered = btrfs_lookup_first_ordered_extent(src, off+len);
if (!ordered &&
!test_range_bit(&BTRFS_I(src)->io_tree, off, off+len,
EXTENT_DELALLOC, 0, NULL))
break;
unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
if (ordered)
btrfs_put_ordered_extent(ordered);
btrfs_wait_ordered_range(src, off, len);
}
/* clone data */
key.objectid = src->i_ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
while (1) {
/*
* note the key will change type as we walk through the
* tree.
*/
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0)
break;
nritems = btrfs_header_nritems(path->nodes[0]);
}
leaf = path->nodes[0];
slot = path->slots[0];
btrfs_item_key_to_cpu(leaf, &key, slot);
if (btrfs_key_type(&key) > BTRFS_EXTENT_DATA_KEY ||
key.objectid != src->i_ino)
break;
if (btrfs_key_type(&key) == BTRFS_EXTENT_DATA_KEY) {
struct btrfs_file_extent_item *extent;
int type;
u32 size;
struct btrfs_key new_key;
u64 disko = 0, diskl = 0;
u64 datao = 0, datal = 0;
u8 comp;
u64 endoff;
size = btrfs_item_size_nr(leaf, slot);
read_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
comp = btrfs_file_extent_compression(leaf, extent);
type = btrfs_file_extent_type(leaf, extent);
if (type == BTRFS_FILE_EXTENT_REG ||
type == BTRFS_FILE_EXTENT_PREALLOC) {
disko = btrfs_file_extent_disk_bytenr(leaf,
extent);
diskl = btrfs_file_extent_disk_num_bytes(leaf,
extent);
datao = btrfs_file_extent_offset(leaf, extent);
datal = btrfs_file_extent_num_bytes(leaf,
extent);
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
/* take upper bound, may be compressed */
datal = btrfs_file_extent_ram_bytes(leaf,
extent);
}
btrfs_release_path(root, path);
if (key.offset + datal <= off ||
key.offset >= off+len)
goto next;
memcpy(&new_key, &key, sizeof(new_key));
new_key.objectid = inode->i_ino;
new_key.offset = key.offset + destoff - off;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto out;
}
if (type == BTRFS_FILE_EXTENT_REG ||
type == BTRFS_FILE_EXTENT_PREALLOC) {
if (off > key.offset) {
datao += off - key.offset;
datal -= off - key.offset;
}
if (key.offset + datal > off + len)
datal = off + len - key.offset;
ret = btrfs_drop_extents(trans, inode,
new_key.offset,
new_key.offset + datal,
&hint_byte, 1);
BUG_ON(ret);
ret = btrfs_insert_empty_item(trans, root, path,
&new_key, size);
BUG_ON(ret);
leaf = path->nodes[0];
slot = path->slots[0];
write_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
extent = btrfs_item_ptr(leaf, slot,
struct btrfs_file_extent_item);
/* disko == 0 means it's a hole */
if (!disko)
datao = 0;
btrfs_set_file_extent_offset(leaf, extent,
datao);
btrfs_set_file_extent_num_bytes(leaf, extent,
datal);
if (disko) {
inode_add_bytes(inode, datal);
ret = btrfs_inc_extent_ref(trans, root,
disko, diskl, 0,
root->root_key.objectid,
inode->i_ino,
new_key.offset - datao);
BUG_ON(ret);
}
} else if (type == BTRFS_FILE_EXTENT_INLINE) {
u64 skip = 0;
u64 trim = 0;
if (off > key.offset) {
skip = off - key.offset;
new_key.offset += skip;
}
if (key.offset + datal > off+len)
trim = key.offset + datal - (off+len);
if (comp && (skip || trim)) {
ret = -EINVAL;
btrfs_end_transaction(trans, root);
goto out;
}
size -= skip + trim;
datal -= skip + trim;
ret = btrfs_drop_extents(trans, inode,
new_key.offset,
new_key.offset + datal,
&hint_byte, 1);
BUG_ON(ret);
ret = btrfs_insert_empty_item(trans, root, path,
&new_key, size);
BUG_ON(ret);
if (skip) {
u32 start =
btrfs_file_extent_calc_inline_size(0);
memmove(buf+start, buf+start+skip,
datal);
}
leaf = path->nodes[0];
slot = path->slots[0];
write_extent_buffer(leaf, buf,
btrfs_item_ptr_offset(leaf, slot),
size);
inode_add_bytes(inode, datal);
}
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(root, path);
inode->i_mtime = inode->i_ctime = CURRENT_TIME;
/*
* we round up to the block size at eof when
* determining which extents to clone above,
* but shouldn't round up the file size
*/
endoff = new_key.offset + datal;
if (endoff > destoff+olen)
endoff = destoff+olen;
if (endoff > inode->i_size)
btrfs_i_size_write(inode, endoff);
BTRFS_I(inode)->flags = BTRFS_I(src)->flags;
ret = btrfs_update_inode(trans, root, inode);
BUG_ON(ret);
btrfs_end_transaction(trans, root);
}
next:
btrfs_release_path(root, path);
key.offset++;
}
ret = 0;
out:
btrfs_release_path(root, path);
unlock_extent(&BTRFS_I(src)->io_tree, off, off+len, GFP_NOFS);
out_unlock:
mutex_unlock(&src->i_mutex);
mutex_unlock(&inode->i_mutex);
vfree(buf);
btrfs_free_path(path);
out_fput:
fput(src_file);
out_drop_write:
mnt_drop_write(file->f_path.mnt);
return ret;
}
static long btrfs_ioctl_clone_range(struct file *file, void __user *argp)
{
struct btrfs_ioctl_clone_range_args args;
if (copy_from_user(&args, argp, sizeof(args)))
return -EFAULT;
return btrfs_ioctl_clone(file, args.src_fd, args.src_offset,
args.src_length, args.dest_offset);
}
/*
* there are many ways the trans_start and trans_end ioctls can lead
* to deadlocks. They should only be used by applications that
* basically own the machine, and have a very in depth understanding
* of all the possible deadlocks and enospc problems.
*/
static long btrfs_ioctl_trans_start(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
int ret;
ret = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto out;
ret = -EINPROGRESS;
if (file->private_data)
goto out;
ret = mnt_want_write(file->f_path.mnt);
if (ret)
goto out;
mutex_lock(&root->fs_info->trans_mutex);
root->fs_info->open_ioctl_trans++;
mutex_unlock(&root->fs_info->trans_mutex);
ret = -ENOMEM;
trans = btrfs_start_ioctl_transaction(root, 0);
if (!trans)
goto out_drop;
file->private_data = trans;
return 0;
out_drop:
mutex_lock(&root->fs_info->trans_mutex);
root->fs_info->open_ioctl_trans--;
mutex_unlock(&root->fs_info->trans_mutex);
mnt_drop_write(file->f_path.mnt);
out:
return ret;
}
static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_root *new_root;
struct btrfs_dir_item *di;
struct btrfs_trans_handle *trans;
struct btrfs_path *path;
struct btrfs_key location;
struct btrfs_disk_key disk_key;
struct btrfs_super_block *disk_super;
u64 features;
u64 objectid = 0;
u64 dir_id;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (copy_from_user(&objectid, argp, sizeof(objectid)))
return -EFAULT;
if (!objectid)
objectid = root->root_key.objectid;
location.objectid = objectid;
location.type = BTRFS_ROOT_ITEM_KEY;
location.offset = (u64)-1;
new_root = btrfs_read_fs_root_no_name(root->fs_info, &location);
if (IS_ERR(new_root))
return PTR_ERR(new_root);
if (btrfs_root_refs(&new_root->root_item) == 0)
return -ENOENT;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->leave_spinning = 1;
trans = btrfs_start_transaction(root, 1);
if (!trans) {
btrfs_free_path(path);
return -ENOMEM;
}
dir_id = btrfs_super_root_dir(&root->fs_info->super_copy);
di = btrfs_lookup_dir_item(trans, root->fs_info->tree_root, path,
dir_id, "default", 7, 1);
if (IS_ERR_OR_NULL(di)) {
btrfs_free_path(path);
btrfs_end_transaction(trans, root);
printk(KERN_ERR "Umm, you don't have the default dir item, "
"this isn't going to work\n");
return -ENOENT;
}
btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_free_path(path);
disk_super = &root->fs_info->super_copy;
features = btrfs_super_incompat_flags(disk_super);
if (!(features & BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL)) {
features |= BTRFS_FEATURE_INCOMPAT_DEFAULT_SUBVOL;
btrfs_set_super_incompat_flags(disk_super, features);
}
btrfs_end_transaction(trans, root);
return 0;
}
static void get_block_group_info(struct list_head *groups_list,
struct btrfs_ioctl_space_info *space)
{
struct btrfs_block_group_cache *block_group;
space->total_bytes = 0;
space->used_bytes = 0;
space->flags = 0;
list_for_each_entry(block_group, groups_list, list) {
space->flags = block_group->flags;
space->total_bytes += block_group->key.offset;
space->used_bytes +=
btrfs_block_group_used(&block_group->item);
}
}
long btrfs_ioctl_space_info(struct btrfs_root *root, void __user *arg)
{
struct btrfs_ioctl_space_args space_args;
struct btrfs_ioctl_space_info space;
struct btrfs_ioctl_space_info *dest;
struct btrfs_ioctl_space_info *dest_orig;
struct btrfs_ioctl_space_info *user_dest;
struct btrfs_space_info *info;
u64 types[] = {BTRFS_BLOCK_GROUP_DATA,
BTRFS_BLOCK_GROUP_SYSTEM,
BTRFS_BLOCK_GROUP_METADATA,
BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA};
int num_types = 4;
int alloc_size;
int ret = 0;
int slot_count = 0;
int i, c;
if (copy_from_user(&space_args,
(struct btrfs_ioctl_space_args __user *)arg,
sizeof(space_args)))
return -EFAULT;
for (i = 0; i < num_types; i++) {
struct btrfs_space_info *tmp;
info = NULL;
rcu_read_lock();
list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
list) {
if (tmp->flags == types[i]) {
info = tmp;
break;
}
}
rcu_read_unlock();
if (!info)
continue;
down_read(&info->groups_sem);
for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
if (!list_empty(&info->block_groups[c]))
slot_count++;
}
up_read(&info->groups_sem);
}
/* space_slots == 0 means they are asking for a count */
if (space_args.space_slots == 0) {
space_args.total_spaces = slot_count;
goto out;
}
slot_count = min_t(int, space_args.space_slots, slot_count);
alloc_size = sizeof(*dest) * slot_count;
/* we generally have at most 6 or so space infos, one for each raid
* level. So, a whole page should be more than enough for everyone
*/
if (alloc_size > PAGE_CACHE_SIZE)
return -ENOMEM;
space_args.total_spaces = 0;
dest = kmalloc(alloc_size, GFP_NOFS);
if (!dest)
return -ENOMEM;
dest_orig = dest;
/* now we have a buffer to copy into */
for (i = 0; i < num_types; i++) {
struct btrfs_space_info *tmp;
info = NULL;
rcu_read_lock();
list_for_each_entry_rcu(tmp, &root->fs_info->space_info,
list) {
if (tmp->flags == types[i]) {
info = tmp;
break;
}
}
rcu_read_unlock();
if (!info)
continue;
down_read(&info->groups_sem);
for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
if (!list_empty(&info->block_groups[c])) {
get_block_group_info(&info->block_groups[c],
&space);
memcpy(dest, &space, sizeof(space));
dest++;
space_args.total_spaces++;
}
}
up_read(&info->groups_sem);
}
user_dest = (struct btrfs_ioctl_space_info *)
(arg + sizeof(struct btrfs_ioctl_space_args));
if (copy_to_user(user_dest, dest_orig, alloc_size))
ret = -EFAULT;
kfree(dest_orig);
out:
if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
ret = -EFAULT;
return ret;
}
/*
* there are many ways the trans_start and trans_end ioctls can lead
* to deadlocks. They should only be used by applications that
* basically own the machine, and have a very in depth understanding
* of all the possible deadlocks and enospc problems.
*/
long btrfs_ioctl_trans_end(struct file *file)
{
struct inode *inode = fdentry(file)->d_inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
struct btrfs_trans_handle *trans;
trans = file->private_data;
if (!trans)
return -EINVAL;
file->private_data = NULL;
btrfs_end_transaction(trans, root);
mutex_lock(&root->fs_info->trans_mutex);
root->fs_info->open_ioctl_trans--;
mutex_unlock(&root->fs_info->trans_mutex);
mnt_drop_write(file->f_path.mnt);
return 0;
}
static noinline long btrfs_ioctl_start_sync(struct file *file, void __user *argp)
{
struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
struct btrfs_trans_handle *trans;
u64 transid;
trans = btrfs_start_transaction(root, 0);
transid = trans->transid;
btrfs_commit_transaction_async(trans, root, 0);
if (argp)
if (copy_to_user(argp, &transid, sizeof(transid)))
return -EFAULT;
return 0;
}
static noinline long btrfs_ioctl_wait_sync(struct file *file, void __user *argp)
{
struct btrfs_root *root = BTRFS_I(file->f_dentry->d_inode)->root;
u64 transid;
if (argp) {
if (copy_from_user(&transid, argp, sizeof(transid)))
return -EFAULT;
} else {
transid = 0; /* current trans */
}
return btrfs_wait_for_commit(root, transid);
}
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
void __user *argp = (void __user *)arg;
switch (cmd) {
case FS_IOC_GETFLAGS:
return btrfs_ioctl_getflags(file, argp);
case FS_IOC_SETFLAGS:
return btrfs_ioctl_setflags(file, argp);
case FS_IOC_GETVERSION:
return btrfs_ioctl_getversion(file, argp);
case BTRFS_IOC_SNAP_CREATE:
return btrfs_ioctl_snap_create(file, argp, 0, 0);
case BTRFS_IOC_SNAP_CREATE_V2:
return btrfs_ioctl_snap_create(file, argp, 0, 1);
case BTRFS_IOC_SUBVOL_CREATE:
return btrfs_ioctl_snap_create(file, argp, 1, 0);
case BTRFS_IOC_SNAP_DESTROY:
return btrfs_ioctl_snap_destroy(file, argp);
case BTRFS_IOC_DEFAULT_SUBVOL:
return btrfs_ioctl_default_subvol(file, argp);
case BTRFS_IOC_DEFRAG:
return btrfs_ioctl_defrag(file, NULL);
case BTRFS_IOC_DEFRAG_RANGE:
return btrfs_ioctl_defrag(file, argp);
case BTRFS_IOC_RESIZE:
return btrfs_ioctl_resize(root, argp);
case BTRFS_IOC_ADD_DEV:
return btrfs_ioctl_add_dev(root, argp);
case BTRFS_IOC_RM_DEV:
return btrfs_ioctl_rm_dev(root, argp);
case BTRFS_IOC_BALANCE:
return btrfs_balance(root->fs_info->dev_root);
case BTRFS_IOC_CLONE:
return btrfs_ioctl_clone(file, arg, 0, 0, 0);
case BTRFS_IOC_CLONE_RANGE:
return btrfs_ioctl_clone_range(file, argp);
case BTRFS_IOC_TRANS_START:
return btrfs_ioctl_trans_start(file);
case BTRFS_IOC_TRANS_END:
return btrfs_ioctl_trans_end(file);
case BTRFS_IOC_TREE_SEARCH:
return btrfs_ioctl_tree_search(file, argp);
case BTRFS_IOC_INO_LOOKUP:
return btrfs_ioctl_ino_lookup(file, argp);
case BTRFS_IOC_SPACE_INFO:
return btrfs_ioctl_space_info(root, argp);
case BTRFS_IOC_SYNC:
btrfs_sync_fs(file->f_dentry->d_sb, 1);
return 0;
case BTRFS_IOC_START_SYNC:
return btrfs_ioctl_start_sync(file, argp);
case BTRFS_IOC_WAIT_SYNC:
return btrfs_ioctl_wait_sync(file, argp);
}
return -ENOTTY;
}
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