md: make sure read errors are auto-corrected during a 'check' resync in raid1

Whenever a read error is found, we should attempt to overwrite with correct
data to 'fix' it.

However when do a 'check' pass (which compares data blocks that are
successfully read, but doesn't normally overwrite) we don't do that.  We
should.

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

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 0bcefad82413..16775a0df7f6 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1214,7 +1214,8 @@ static void sync_request_write(mddev_t *mddev, r1bio_t *r1_bio)
                                         j = 0;
                                 if (j >= 0)
                                         mddev->resync_mismatches += r1_bio->sectors;
-                                if (j < 0 || test_bit(MD_RECOVERY_CHECK, &mddev->recovery)) {
+                                if (j < 0 || (test_bit(MD_RECOVERY_CHECK, &mddev->recovery)
+                                              && test_bit(BIO_UPTODATE, &sbio->bi_flags))) {
                                         sbio->bi_end_io = NULL;
                                         rdev_dec_pending(conf->mirrors[i].rdev, mddev);
                                 } else {