Commit 92986796 authored by Al Viro's avatar Al Viro Committed by root
Browse files

btrfs: don't mess with i_nlink of unlocked inode in rename() 



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: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarChris Mason <chris.mason@oracle.com>
parent c2db1073

fs/btrfs/inode.c

+25 −11
Original line number Diff line number Diff line
@@ -2664,7 +2664,7 @@ failed: 
 * 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

 */

int btrfs_unlink_inode(struct btrfs_trans_handle *trans,

static 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)
@@ -2739,12 +2739,25 @@ err: 
	btrfs_i_size_write(dir, dir->i_size - name_len * 2);

	inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;

	btrfs_update_inode(trans, root, dir);

out:

	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);

out:

	}

	return ret;

}

		



/* helper to check if there is any shared block in the path */

static int check_path_shared(struct btrfs_root *root,

			     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.len);

	} 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_name.name,

					old_dentry->d_name.len);

		if (!ret)

			ret = btrfs_update_inode(trans, root, old_inode);

	}

	BUG_ON(ret);

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