Re: linux-next: manual merge of the userns tree

From: Eric W. Biederman
Date: Sat Oct 19 2013 - 19:47:23 EST


Mark Brown <broonie@xxxxxxxxxx> writes:

> Today's linux-next merge of the userns tree got a conflict in
> fs/fuse/dir.c between 3c70b8eed (fuse: don't check_submounts_and_drop()
> in RCU walk) in the fuse tree and 40216baa0 (vfs: Lazily remove mounts
> on unlinked files and directories. v2) in the userns tree.
>
> I fixed it up as below and can carry as required:

The fix looks right.

However I think this conflict highlights a larger issue, as there are
several other filesystems that call check_submounts_and_drop from the
devalidate and possibly from rcu_walk today.

Miklos what problem did you run into?

Sigh. It looks like it probably makes sense to merge
shrink_submounts_and_drop with d_invalidate, so filesystems don't even
need to think about this issue.

Eric

> diff --cc fs/fuse/dir.c
> index 0747f6e,b1cd7b7..0000000
> --- a/fs/fuse/dir.c
> +++ b/fs/fuse/dir.c
> @@@ -263,9 -259,7 +263,10 @@@ out
>
> invalid:
> ret = 0;
> - shrink_submounts_and_drop(entry);
> +
> - if (!(flags & LOOKUP_RCU) && check_submounts_and_drop(entry) != 0)
> - ret = 1;
> ++ if (!(flags & LOOKUP_RCU))
> ++ shrink_submounts_and_drop(entry);
> ++
> goto out;
> }
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/