[PATCH] md: allow checkpoint of recovery with version-1 superblock

For a while we have had checkpointing of resync.  The version-1 superblock
allows recovery to be checkpointed as well, and this patch implements that.

Due to early carelessness we need to add a feature flag to signal that the
recovery_offset field is in use, otherwise older kernels would assume that a
partially recovered array is in fact fully recovered.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index affeaefd4033..2ca18770575f 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -2015,7 +2015,8 @@ static int run(mddev_t *mddev)
 
                 disk = conf->mirrors + i;
 
-                if (!disk->rdev) {
+                if (!disk->rdev ||
+                    !test_bit(In_sync, &rdev->flags)) {
                         disk->head_position = 0;
                         mddev->degraded++;
                 }