1 files changed, 30 insertions, 5 deletions

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 05e4a105b9c..4bed5454b8d 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -668,6 +668,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			bi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			bi->bi_io_vec[0].bv_offset = 0;
 			bi->bi_size = STRIPE_SIZE;
+			/*
+			 * If this is discard request, set bi_vcnt 0. We don't
+			 * want to confuse SCSI because SCSI will replace payload
+			 */
+			if (rw & REQ_DISCARD)
+				bi->bi_vcnt = 0;
 			if (rrdev)
 				set_bit(R5_DOUBLE_LOCKED, &sh->dev[i].flags);
 
@@ -706,6 +712,12 @@ static void ops_run_io(struct stripe_head *sh, struct stripe_head_state *s)
 			rbi->bi_io_vec[0].bv_len = STRIPE_SIZE;
 			rbi->bi_io_vec[0].bv_offset = 0;
 			rbi->bi_size = STRIPE_SIZE;
+			/*
+			 * If this is discard request, set bi_vcnt 0. We don't
+			 * want to confuse SCSI because SCSI will replace payload
+			 */
+			if (rw & REQ_DISCARD)
+				rbi->bi_vcnt = 0;
 			if (conf->mddev->gendisk)
 				trace_block_bio_remap(bdev_get_queue(rbi->bi_bdev),
 						      rbi, disk_devt(conf->mddev->gendisk),
@@ -2800,6 +2812,14 @@ static void handle_stripe_clean_event(struct r5conf *conf,
 		}
 		/* now that discard is done we can proceed with any sync */
 		clear_bit(STRIPE_DISCARD, &sh->state);
+		/*
+		 * SCSI discard will change some bio fields and the stripe has
+		 * no updated data, so remove it from hash list and the stripe
+		 * will be reinitialized
+		 */
+		spin_lock_irq(&conf->device_lock);
+		remove_hash(sh);
+		spin_unlock_irq(&conf->device_lock);
 		if (test_bit(STRIPE_SYNC_REQUESTED, &sh->state))
 			set_bit(STRIPE_HANDLE, &sh->state);
 
@@ -3462,6 +3482,7 @@ static void handle_stripe(struct stripe_head *sh)
 		    test_and_clear_bit(STRIPE_SYNC_REQUESTED, &sh->state)) {
 			set_bit(STRIPE_SYNCING, &sh->state);
 			clear_bit(STRIPE_INSYNC, &sh->state);
+			clear_bit(STRIPE_REPLACED, &sh->state);
 		}
 		spin_unlock(&sh->stripe_lock);
 	}
@@ -3607,19 +3628,23 @@ static void handle_stripe(struct stripe_head *sh)
 			handle_parity_checks5(conf, sh, &s, disks);
 	}
 
-	if (s.replacing && s.locked == 0
-	    && !test_bit(STRIPE_INSYNC, &sh->state)) {
+	if ((s.replacing || s.syncing) && s.locked == 0
+	    && !test_bit(STRIPE_COMPUTE_RUN, &sh->state)
+	    && !test_bit(STRIPE_REPLACED, &sh->state)) {
 		/* Write out to replacement devices where possible */
 		for (i = 0; i < conf->raid_disks; i++)
-			if (test_bit(R5_UPTODATE, &sh->dev[i].flags) &&
-			    test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
+			if (test_bit(R5_NeedReplace, &sh->dev[i].flags)) {
+				WARN_ON(!test_bit(R5_UPTODATE, &sh->dev[i].flags));
 				set_bit(R5_WantReplace, &sh->dev[i].flags);
 				set_bit(R5_LOCKED, &sh->dev[i].flags);
 				s.locked++;
 			}
-		set_bit(STRIPE_INSYNC, &sh->state);
+		if (s.replacing)
+			set_bit(STRIPE_INSYNC, &sh->state);
+		set_bit(STRIPE_REPLACED, &sh->state);
 	}
 	if ((s.syncing || s.replacing) && s.locked == 0 &&
+	    !test_bit(STRIPE_COMPUTE_RUN, &sh->state) &&
 	    test_bit(STRIPE_INSYNC, &sh->state)) {
 		md_done_sync(conf->mddev, STRIPE_SECTORS, 1);
 		clear_bit(STRIPE_SYNCING, &sh->state);