This is a note to let you know that I've just added the patch titled
btrfs: Explicitly handle btrfs_update_root failure
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: btrfs-explicitly-handle-btrfs_update_root-failure.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Mon Dec 18 13:28:59 CET 2017
From: Nikolay Borisov nborisov@suse.com Date: Thu, 28 Sep 2017 10:53:17 +0300 Subject: btrfs: Explicitly handle btrfs_update_root failure
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);
Patches currently in stable-queue which might be from nborisov@suse.com are
queue-4.14/btrfs-explicitly-handle-btrfs_update_root-failure.patch queue-4.14/btrfs-undo-writable-superblocke-when-sprouting-fails.patch