Commit 9417ebc8 authored Sep 28, 2017 by Nikolay Borisov Committed by David Sterba Oct 30, 2017

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>

parent 7132a262

fs/btrfs/ioctl.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1827,8 +1827,13 @@ static noinline int btrfs_ioctl_subvol_setflags(struct file *file,

		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);

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