4.14-stable review patch. If anyone has any objections, please let me know.
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From: Nikolay Borisov nborisov@suse.com
[ Upstream commit 9417ebc8a676487c6ec8825f92fb28f7dbeb5f4b ]
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 Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/btrfs/ioctl.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1842,8 +1842,13 @@ static noinline int btrfs_ioctl_subvol_s
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; + } + + ret = btrfs_commit_transaction(trans);
- btrfs_commit_transaction(trans); out_reset: if (ret) btrfs_set_root_flags(&root->root_item, root_flags);