Subject: [PATCH] md:change resync_mismatches to atomic64_t to avoid races

Now that multiple threads can handle stripes, it is safer to
use an atomic64_t for resync_mismatches, to avoid update races.

Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ab613efbbead..4cc6b0e398bc 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2973,7 +2973,7 @@ static void handle_parity_checks5(struct r5conf *conf, struct stripe_head *sh,
                          */
                         set_bit(STRIPE_INSYNC, &sh->state);
                 else {
-                        conf->mddev->resync_mismatches += STRIPE_SECTORS;
+                        atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
                         if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
                                 /* don't try to repair!! */
                                 set_bit(STRIPE_INSYNC, &sh->state);
@@ -3125,7 +3125,7 @@ static void handle_parity_checks6(struct r5conf *conf, struct stripe_head *sh,
                                  */
                         }
                 } else {
-                        conf->mddev->resync_mismatches += STRIPE_SECTORS;
+                        atomic64_add(STRIPE_SECTORS, &conf->mddev->resync_mismatches);
                         if (test_bit(MD_RECOVERY_CHECK, &conf->mddev->recovery))
                                 /* don't try to repair!! */
                                 set_bit(STRIPE_INSYNC, &sh->state);