Merge branch 'next' into for-linus

1 files changed, 85 insertions, 31 deletions

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a368db2431a5..15dd59b84e94 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -523,6 +523,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 		rdev = rcu_dereference(conf->mirrors[disk].rdev);
 		if (r1_bio->bios[disk] == IO_BLOCKED
 		    || rdev == NULL
+		    || test_bit(Unmerged, &rdev->flags)
 		    || test_bit(Faulty, &rdev->flags))
 			continue;
 		if (!test_bit(In_sync, &rdev->flags) &&
@@ -614,6 +615,39 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 	return best_disk;
 }
 
+static int raid1_mergeable_bvec(struct request_queue *q,
+				struct bvec_merge_data *bvm,
+				struct bio_vec *biovec)
+{
+	struct mddev *mddev = q->queuedata;
+	struct r1conf *conf = mddev->private;
+	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);
+	int max = biovec->bv_len;
+
+	if (mddev->merge_check_needed) {
+		int disk;
+		rcu_read_lock();
+		for (disk = 0; disk < conf->raid_disks * 2; disk++) {
+			struct md_rdev *rdev = rcu_dereference(
+				conf->mirrors[disk].rdev);
+			if (rdev && !test_bit(Faulty, &rdev->flags)) {
+				struct request_queue *q =
+					bdev_get_queue(rdev->bdev);
+				if (q->merge_bvec_fn) {
+					bvm->bi_sector = sector +
+						rdev->data_offset;
+					bvm->bi_bdev = rdev->bdev;
+					max = min(max, q->merge_bvec_fn(
+							  q, bvm, biovec));
+				}
+			}
+		}
+		rcu_read_unlock();
+	}
+	return max;
+
+}
+
 int md_raid1_congested(struct mddev *mddev, int bits)
 {
 	struct r1conf *conf = mddev->private;
@@ -624,7 +658,7 @@ int md_raid1_congested(struct mddev *mddev, int bits)
 		return 1;
 
 	rcu_read_lock();
-	for (i = 0; i < conf->raid_disks; i++) {
+	for (i = 0; i < conf->raid_disks * 2; i++) {
 		struct md_rdev *rdev = rcu_dereference(conf->mirrors[i].rdev);
 		if (rdev && !test_bit(Faulty, &rdev->flags)) {
 			struct request_queue *q = bdev_get_queue(rdev->bdev);
@@ -737,9 +771,22 @@ static void wait_barrier(struct r1conf *conf)
 	spin_lock_irq(&conf->resync_lock);
 	if (conf->barrier) {
 		conf->nr_waiting++;
-		wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
+		/* Wait for the barrier to drop.
+		 * However if there are already pending
+		 * requests (preventing the barrier from
+		 * rising completely), and the
+		 * pre-process bio queue isn't empty,
+		 * then don't wait, as we need to empty
+		 * that queue to get the nr_pending
+		 * count down.
+		 */
+		wait_event_lock_irq(conf->wait_barrier,
+				    !conf->barrier ||
+				    (conf->nr_pending &&
+				     current->bio_list &&
+				     !bio_list_empty(current->bio_list)),
 				    conf->resync_lock,
-				    );
+			);
 		conf->nr_waiting--;
 	}
 	conf->nr_pending++;
@@ -1002,7 +1049,8 @@ read_again:
 			break;
 		}
 		r1_bio->bios[i] = NULL;
-		if (!rdev || test_bit(Faulty, &rdev->flags)) {
+		if (!rdev || test_bit(Faulty, &rdev->flags)
+		    || test_bit(Unmerged, &rdev->flags)) {
 			if (i < conf->raid_disks)
 				set_bit(R1BIO_Degraded, &r1_bio->state);
 			continue;
@@ -1322,6 +1370,7 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 	struct mirror_info *p;
 	int first = 0;
 	int last = conf->raid_disks - 1;
+	struct request_queue *q = bdev_get_queue(rdev->bdev);
 
 	if (mddev->recovery_disabled == conf->recovery_disabled)
 		return -EBUSY;
@@ -1329,23 +1378,17 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 	if (rdev->raid_disk >= 0)
 		first = last = rdev->raid_disk;
 
+	if (q->merge_bvec_fn) {
+		set_bit(Unmerged, &rdev->flags);
+		mddev->merge_check_needed = 1;
+	}
+
 	for (mirror = first; mirror <= last; mirror++) {
 		p = conf->mirrors+mirror;
 		if (!p->rdev) {
 
 			disk_stack_limits(mddev->gendisk, rdev->bdev,
 					  rdev->data_offset << 9);
-			/* as we don't honour merge_bvec_fn, we must
-			 * never risk violating it, so limit
-			 * ->max_segments to one lying with a single
-			 * page, as a one page request is never in
-			 * violation.
-			 */
-			if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
-				blk_queue_max_segments(mddev->queue, 1);
-				blk_queue_segment_boundary(mddev->queue,
-							   PAGE_CACHE_SIZE - 1);
-			}
 
 			p->head_position = 0;
 			rdev->raid_disk = mirror;
@@ -1370,6 +1413,19 @@ static int raid1_add_disk(struct mddev *mddev, struct md_rdev *rdev)
 			break;
 		}
 	}
+	if (err == 0 && test_bit(Unmerged, &rdev->flags)) {
+		/* Some requests might not have seen this new
+		 * merge_bvec_fn.  We must wait for them to complete
+		 * before merging the device fully.
+		 * First we make sure any code which has tested
+		 * our function has submitted the request, then
+		 * we wait for all outstanding requests to complete.
+		 */
+		synchronize_sched();
+		raise_barrier(conf);
+		lower_barrier(conf);
+		clear_bit(Unmerged, &rdev->flags);
+	}
 	md_integrity_add_rdev(rdev, mddev);
 	print_conf(conf);
 	return err;
@@ -1656,6 +1712,7 @@ static int process_checks(struct r1bio *r1_bio)
 	struct r1conf *conf = mddev->private;
 	int primary;
 	int i;
+	int vcnt;
 
 	for (primary = 0; primary < conf->raid_disks * 2; primary++)
 		if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
@@ -1665,9 +1722,9 @@ static int process_checks(struct r1bio *r1_bio)
 			break;
 		}
 	r1_bio->read_disk = primary;
+	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
 	for (i = 0; i < conf->raid_disks * 2; i++) {
 		int j;
-		int vcnt = r1_bio->sectors >> (PAGE_SHIFT- 9);
 		struct bio *pbio = r1_bio->bios[primary];
 		struct bio *sbio = r1_bio->bios[i];
 		int size;
@@ -1682,7 +1739,7 @@ static int process_checks(struct r1bio *r1_bio)
 				s = sbio->bi_io_vec[j].bv_page;
 				if (memcmp(page_address(p),
 					   page_address(s),
-					   PAGE_SIZE))
+					   sbio->bi_io_vec[j].bv_len))
 					break;
 			}
 		} else
@@ -2330,8 +2387,7 @@ static sector_t sync_request(struct mddev *mddev, sector_t sector_nr, int *skipp
 		int ok = 1;
 		for (i = 0 ; i < conf->raid_disks * 2 ; i++)
 			if (r1_bio->bios[i]->bi_end_io == end_sync_write) {
-				struct md_rdev *rdev =
-					rcu_dereference(conf->mirrors[i].rdev);
+				struct md_rdev *rdev = conf->mirrors[i].rdev;
 				ok = rdev_set_badblocks(rdev, sector_nr,
 							min_bad, 0
 					) && ok;
@@ -2491,7 +2547,7 @@ static struct r1conf *setup_conf(struct mddev *mddev)
 
 	err = -EINVAL;
 	spin_lock_init(&conf->device_lock);
-	list_for_each_entry(rdev, &mddev->disks, same_set) {
+	rdev_for_each(rdev, mddev) {
 		int disk_idx = rdev->raid_disk;
 		if (disk_idx >= mddev->raid_disks
 		    || disk_idx < 0)
@@ -2580,11 +2636,13 @@ static struct r1conf *setup_conf(struct mddev *mddev)
 	return ERR_PTR(err);
 }
 
+static int stop(struct mddev *mddev);
 static int run(struct mddev *mddev)
 {
 	struct r1conf *conf;
 	int i;
 	struct md_rdev *rdev;
+	int ret;
 
 	if (mddev->level != 1) {
 		printk(KERN_ERR "md/raid1:%s: raid level not set to mirroring (%d)\n",
@@ -2609,20 +2667,11 @@ static int run(struct mddev *mddev)
 	if (IS_ERR(conf))
 		return PTR_ERR(conf);
 
-	list_for_each_entry(rdev, &mddev->disks, same_set) {
+	rdev_for_each(rdev, mddev) {
 		if (!mddev->gendisk)
 			continue;
 		disk_stack_limits(mddev->gendisk, rdev->bdev,
 				  rdev->data_offset << 9);
-		/* as we don't honour merge_bvec_fn, we must never risk
-		 * violating it, so limit ->max_segments to 1 lying within
-		 * a single page, as a one page request is never in violation.
-		 */
-		if (rdev->bdev->bd_disk->queue->merge_bvec_fn) {
-			blk_queue_max_segments(mddev->queue, 1);
-			blk_queue_segment_boundary(mddev->queue,
-						   PAGE_CACHE_SIZE - 1);
-		}
 	}
 
 	mddev->degraded = 0;
@@ -2656,8 +2705,13 @@ static int run(struct mddev *mddev)
 	if (mddev->queue) {
 		mddev->queue->backing_dev_info.congested_fn = raid1_congested;
 		mddev->queue->backing_dev_info.congested_data = mddev;
+		blk_queue_merge_bvec(mddev->queue, raid1_mergeable_bvec);
 	}
-	return md_integrity_register(mddev);
+
+	ret =  md_integrity_register(mddev);
+	if (ret)
+		stop(mddev);
+	return ret;
 }
 
 static int stop(struct mddev *mddev)