md: fix prexor vs sync_request race

[linux-2.6-omap-h63xx.git] / drivers / md / raid5.c

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 425958a76b84afc9d7608509f6c06954db342745..f0f0585c107ef4d79315b09efd171946c0201b70 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -2645,6 +2645,7 @@ static void handle_stripe5(struct stripe_head *sh)
        struct r5dev *dev;
        unsigned long pending = 0;
        mdk_rdev_t *blocked_rdev = NULL;
+       int prexor;
 
        memset(&s, 0, sizeof(s));
        pr_debug("handling stripe %llu, state=%#lx cnt=%d, pd_idx=%d "
@@ -2774,9 +2775,11 @@ static void handle_stripe5(struct stripe_head *sh)
        /* leave prexor set until postxor is done, allows us to distinguish
         * a rmw from a rcw during biodrain
         */
+       prexor = 0;
        if (test_bit(STRIPE_OP_PREXOR, &sh->ops.complete) &&
                test_bit(STRIPE_OP_POSTXOR, &sh->ops.complete)) {
 
+               prexor = 1;
                clear_bit(STRIPE_OP_PREXOR, &sh->ops.complete);
                clear_bit(STRIPE_OP_PREXOR, &sh->ops.ack);
                clear_bit(STRIPE_OP_PREXOR, &sh->ops.pending);
@@ -2810,6 +2813,8 @@ static void handle_stripe5(struct stripe_head *sh)
                                if (!test_and_set_bit(
                                    STRIPE_OP_IO, &sh->ops.pending))
                                        sh->ops.count++;
+                               if (prexor)
+                                       continue;
                                if (!test_bit(R5_Insync, &dev->flags) ||
                                    (i == sh->pd_idx && s.failed == 0))
                                        set_bit(STRIPE_INSYNC, &sh->state);