diff mbox series

[3/3] btrfs: skip transaction commit after failure to create subvolume

Message ID ce18f34525b95ad07579d8da6f6d854d301e1e59.1639384875.git.fdmanana@suse.com (mailing list archive)
State New, archived
Headers show
Series btrfs: fixes for an error path when creating a subvolume | expand

Commit Message

Filipe Manana Dec. 13, 2021, 8:45 a.m. UTC 
From: Filipe Manana <fdmanana@suse.com>

At ioctl.c:create_subvol(), when we fail to create a subvolume we always
commit the transaction. In most cases this is a no-op, since all the error
paths, except for one, abort the transaction - the only exception is when
we fail to insert the new root item into the root tree, in that case we
don't abort the transaction because we didn't do anything that is
irreversible - however we end up committing the transaction which although
is not a functional problem, it adds unnecessary rotation of the backup
roots in the superblock and unnecessary work.

So change that to commit a transaction only when no error happened,
otherwise just call btrfs_end_transaction() to release our reference on
the transaction.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
---
 fs/btrfs/ioctl.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7565b667f4fc..a5bd6926f7ff 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -544,7 +544,6 @@  static noinline int create_subvol(struct user_namespace *mnt_userns,
 	struct timespec64 cur_time = current_time(dir);
 	struct inode *inode;
 	int ret;
-	int err;
 	dev_t anon_dev = 0;
 	u64 objectid;
 	u64 index = 0;
@@ -724,9 +723,10 @@  static noinline int create_subvol(struct user_namespace *mnt_userns,
 	trans->bytes_reserved = 0;
 	btrfs_subvolume_release_metadata(root, &block_rsv);
 
-	err = btrfs_commit_transaction(trans);
-	if (err && !ret)
-		ret = err;
+	if (ret)
+		btrfs_end_transaction(trans);
+	else
+		ret = btrfs_commit_transaction(trans);
 
 	if (!ret) {
 		inode = btrfs_lookup_dentry(dir, dentry);