Re: dm-raid1: keep writing after leg failure

[Mike Snitzer <snitzer@redhat.com>]

On Wed, May 13 2015 at  2:04am -0400,
Lidong Zhong <lzhong@suse.com> wrote:

> Currently if there is a leg failure, the bio will be put into the hold
> list until userspace replace/remove the leg. Here we are trying to make
> dm-raid1 ignore the failure and keep the following bios going on.
> This is because there maybe a temporary path failure in clvmd
> which leads to cluster raid1 remove/replace the fake device failure. And
> it takes a long time to do the full sync if we readd the device back.
> 
> This patch merges the former five small patches to implement this
> feature. The userspace should pass "keep_log" into kernel to make this feature to
> take effect when creating dm-raid1, same as "handle_errors".
> 
> Signed-off-by: Lidong Zhong <lzhong@suse.com>
> Tested-by: Liuhua Wang <lwang@suse.com>

I've staged a revised patch for 4.2 here:
https://git.kernel.org/cgit/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=for-next&id=164a064dd85801986f3190e6edd119b6fc9a05c5

The big things I clarified/cleaned are:
1) keep_log depends on handle_errors feature
2) feature reporting via 'dmsetup table' needed to be decoupled
   otherwise any future feature would've forced this same cleanup.
3) Cleaned up header and in-code comments.
4) bumped the target version

Please let me know if you see nay issues with this version.

Thanks,
Mike