a7y18lte-ubports/android_kernel_samsung_universal7885
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btrfs: don't mess with i_nlink of unlocked inode in rename()

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old_inode is not locked; it's not safe to play with its link
count.  Instead of bumping it and calling btrfs_unlink_inode(),
add a variant of the latter that does not do btrfs_drop_nlink()/
btrfs_update_inode(), call it instead of btrfs_inc_nlink()/
btrfs_unlink_inode() and do btrfs_update_inode() ourselves.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Al Viro 2011-03-04 17:14:37 +00:00 committed by root
parent c2db1073fd
commit 92986796d8
1 changed files with 25 additions and 11 deletions
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36
fs/btrfs/inode.c
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@ -2664,10 +2664,10 @@ failed:
* recovery code. It remove a link in a directory with a given name, and * recovery code. It remove a link in a directory with a given name, and
* also drops the back refs in the inode to the directory * also drops the back refs in the inode to the directory
*/ */
int btrfs_unlink_inode(struct btrfs_trans_handle *trans, static int __btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_root *root,
struct inode *dir, struct inode *inode, struct inode *dir, struct inode *inode,
const char *name, int name_len) const char *name, int name_len)
{ {
struct btrfs_path *path; struct btrfs_path *path;
int ret = 0; int ret = 0;
@ -2739,12 +2739,25 @@ err:
btrfs_i_size_write(dir, dir->i_size - name_len * 2); btrfs_i_size_write(dir, dir->i_size - name_len * 2);
inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME; inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
btrfs_update_inode(trans, root, dir); btrfs_update_inode(trans, root, dir);
btrfs_drop_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
out: out:
return ret; return ret;
} }
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *dir, struct inode *inode,
const char *name, int name_len)
{
int ret;
ret = __btrfs_unlink_inode(trans, root, dir, inode, name, name_len);
if (!ret) {
btrfs_drop_nlink(inode);
ret = btrfs_update_inode(trans, root, inode);
}
return ret;
}
/* helper to check if there is any shared block in the path */ /* helper to check if there is any shared block in the path */
static int check_path_shared(struct btrfs_root *root, static int check_path_shared(struct btrfs_root *root,
struct btrfs_path *path) struct btrfs_path *path)
@ -6999,11 +7012,12 @@ static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
old_dentry->d_name.name, old_dentry->d_name.name,
old_dentry->d_name.len); old_dentry->d_name.len);
} else { } else {
btrfs_inc_nlink(old_dentry->d_inode); ret = __btrfs_unlink_inode(trans, root, old_dir,
ret = btrfs_unlink_inode(trans, root, old_dir, old_dentry->d_inode,
old_dentry->d_inode, old_dentry->d_name.name,
old_dentry->d_name.name, old_dentry->d_name.len);
old_dentry->d_name.len); if (!ret)
ret = btrfs_update_inode(trans, root, old_inode);
} }
BUG_ON(ret); BUG_ON(ret);