btrfs: Explicitly handle btrfs_update_root failure
btrfs_udpate_root can fail and it aborts the transaction, the correct
way to handle an aborted transaction is to explicitly end with
btrfs_end_transaction. Even now the code is correct since
btrfs_commit_transaction would handle an aborted transaction but this is
more of an implementation detail. So let's be explicit in handling
failure in btrfs_update_root.
Furthermore btrfs_commit_transaction can also fail and by ignoring it's
return value we could have left the in-memory copy of the root item in
an inconsistent state. So capture the error value which allows us to
correctly revert the RO/RW flags in case of commit failure.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index feab6f6..86728e0 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1827,8 +1827,13 @@
ret = btrfs_update_root(trans, fs_info->tree_root,
&root->root_key, &root->root_item);
+ if (ret < 0) {
+ btrfs_end_transaction(trans);
+ goto out_reset;
+ }
- btrfs_commit_transaction(trans);
+ ret = btrfs_commit_transaction(trans);
+
out_reset:
if (ret)
btrfs_set_root_flags(&root->root_item, root_flags);