Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md

Pull MD fixes from Shaohua Li:

 - fix a parity calculation bug of raid5 cache by Song

 - fix a potential deadlock issue by me

 - fix two endian issues by Jason

 - fix a disk limitation issue by Neil

 - other small fixes and cleanup

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/raid1: fix a trivial typo in comments
  md/r5cache: fix set_syndrome_sources() for data in cache
  md: fix incorrect use of lexx_to_cpu in does_sb_need_changing
  md: fix super_offset endianness in super_1_rdev_size_change
  md/raid1/10: fix potential deadlock
  md: don't impose the MD_SB_DISKS limit on arrays without metadata.
  md: move funcs from pers->resize to update_size
  md-cluster: remove useless memset from gather_all_resync_info
  md-cluster: free md_cluster_info if node leave cluster
  md: delete dead code
  md/raid10: submit bio directly to replacement disk

drivers/md/md-cluster.c

@@ -777,7 +777,6 @@ static int gather_all_resync_info(struct mddev *mddev, int total_slots)
 		bm_lockres->flags |= DLM_LKF_NOQUEUE;
 		ret = dlm_lock_sync(bm_lockres, DLM_LOCK_PW);
 		if (ret == -EAGAIN) {
-			memset(bm_lockres->lksb.sb_lvbptr, '\0', LVB_SIZE);
 			s = read_resync_info(mddev, bm_lockres);
 			if (s) {
 				pr_info("%s:%d Resync[%llu..%llu] in progress on %d\n",
@@ -974,6 +973,7 @@ static int leave(struct mddev *mddev)
 	lockres_free(cinfo->bitmap_lockres);
 	unlock_all_bitmaps(mddev);
 	dlm_release_lockspace(cinfo->lockspace, 2);
+	kfree(cinfo);
 	return 0;
 }
 

drivers/md/md.c

@@ -440,14 +440,6 @@ void md_flush_request(struct mddev *mddev, struct bio *bio)
 }
 EXPORT_SYMBOL(md_flush_request);
 
-void md_unplug(struct blk_plug_cb *cb, bool from_schedule)
-{
-	struct mddev *mddev = cb->data;
-	md_wakeup_thread(mddev->thread);
-	kfree(cb);
-}
-EXPORT_SYMBOL(md_unplug);
-
 static inline struct mddev *mddev_get(struct mddev *mddev)
 {
 	atomic_inc(&mddev->active);
@@ -1887,7 +1879,7 @@ super_1_rdev_size_change(struct md_rdev *rdev, sector_t num_sectors)
 	}
 	sb = page_address(rdev->sb_page);
 	sb->data_size = cpu_to_le64(num_sectors);
-	sb->super_offset = rdev->sb_start;
+	sb->super_offset = cpu_to_le64(rdev->sb_start);
 	sb->sb_csum = calc_sb_1_csum(sb);
 	do {
 		md_super_write(rdev->mddev, rdev, rdev->sb_start, rdev->sb_size,
@@ -2295,7 +2287,7 @@ static bool does_sb_need_changing(struct mddev *mddev)
 	/* Check if any mddev parameters have changed */
 	if ((mddev->dev_sectors != le64_to_cpu(sb->size)) ||
 	    (mddev->reshape_position != le64_to_cpu(sb->reshape_position)) ||
-	    (mddev->layout != le64_to_cpu(sb->layout)) ||
+	    (mddev->layout != le32_to_cpu(sb->layout)) ||
 	    (mddev->raid_disks != le32_to_cpu(sb->raid_disks)) ||
 	    (mddev->chunk_sectors != le32_to_cpu(sb->chunksize)))
 		return true;
@@ -6458,9 +6450,8 @@ static int set_array_info(struct mddev *mddev, mdu_array_info_t *info)
 	mddev->layout        = info->layout;
 	mddev->chunk_sectors = info->chunk_size >> 9;
 
-	mddev->max_disks     = MD_SB_DISKS;
-
 	if (mddev->persistent) {
+		mddev->max_disks = MD_SB_DISKS;
 		mddev->flags = 0;
 		mddev->sb_flags = 0;
 	}
@@ -6533,8 +6524,12 @@ static int update_size(struct mddev *mddev, sector_t num_sectors)
 			return -ENOSPC;
 	}
 	rv = mddev->pers->resize(mddev, num_sectors);
-	if (!rv)
+	if (!rv) {
+		if (mddev->queue) {
+			set_capacity(mddev->gendisk, mddev->array_sectors);
 			revalidate_disk(mddev->gendisk);
+		}
+	}
 	return rv;
 }
 

drivers/md/md.h

@@ -676,16 +676,10 @@ extern void mddev_resume(struct mddev *mddev);
 extern struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
 				   struct mddev *mddev);
 
-extern void md_unplug(struct blk_plug_cb *cb, bool from_schedule);
 extern void md_reload_sb(struct mddev *mddev, int raid_disk);
 extern void md_update_sb(struct mddev *mddev, int force);
 extern void md_kick_rdev_from_array(struct md_rdev * rdev);
 struct md_rdev *md_find_rdev_nr_rcu(struct mddev *mddev, int nr);
-static inline int mddev_check_plugged(struct mddev *mddev)
-{
-	return !!blk_check_plugged(md_unplug, mddev,
-				   sizeof(struct blk_plug_cb));
-}
 
 static inline void rdev_dec_pending(struct md_rdev *rdev, struct mddev *mddev)
 {

drivers/md/raid1.c

@@ -1027,7 +1027,7 @@ static int get_unqueued_pending(struct r1conf *conf)
 static void freeze_array(struct r1conf *conf, int extra)
 {
 	/* Stop sync I/O and normal I/O and wait for everything to
-	 * go quite.
+	 * go quiet.
 	 * This is called in two situations:
 	 * 1) management command handlers (reshape, remove disk, quiesce).
 	 * 2) one normal I/O request failed.
@@ -1587,9 +1587,30 @@ static void raid1_make_request(struct mddev *mddev, struct bio *bio)
 			split = bio;
 		}
 
-		if (bio_data_dir(split) == READ)
+		if (bio_data_dir(split) == READ) {
 			raid1_read_request(mddev, split);
-		else
+
+			/*
+			 * If a bio is splitted, the first part of bio will
+			 * pass barrier but the bio is queued in
+			 * current->bio_list (see generic_make_request). If
+			 * there is a raise_barrier() called here, the second
+			 * part of bio can't pass barrier. But since the first
+			 * part bio isn't dispatched to underlaying disks yet,
+			 * the barrier is never released, hence raise_barrier
+			 * will alays wait. We have a deadlock.
+			 * Note, this only happens in read path. For write
+			 * path, the first part of bio is dispatched in a
+			 * schedule() call (because of blk plug) or offloaded
+			 * to raid10d.
+			 * Quitting from the function immediately can change
+			 * the bio order queued in bio_list and avoid the deadlock.
+			 */
+			if (split != bio) {
+				generic_make_request(bio);
+				break;
+			}
+		} else
 			raid1_write_request(mddev, split);
 	} while (split != bio);
 }
@@ -3246,8 +3267,6 @@ static int raid1_resize(struct mddev *mddev, sector_t sectors)
 			return ret;
 	}
 	md_set_array_sectors(mddev, newsize);
-	set_capacity(mddev->gendisk, mddev->array_sectors);
-	revalidate_disk(mddev->gendisk);
 	if (sectors > mddev->dev_sectors &&
 	    mddev->recovery_cp > mddev->dev_sectors) {
 		mddev->recovery_cp = mddev->dev_sectors;

drivers/md/raid10.c

@@ -1478,11 +1478,24 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
 			mbio->bi_bdev = (void*)rdev;
 
 			atomic_inc(&r10_bio->remaining);
+
+			cb = blk_check_plugged(raid10_unplug, mddev,
+					       sizeof(*plug));
+			if (cb)
+				plug = container_of(cb, struct raid10_plug_cb,
+						    cb);
+			else
+				plug = NULL;
 			spin_lock_irqsave(&conf->device_lock, flags);
+			if (plug) {
+				bio_list_add(&plug->pending, mbio);
+				plug->pending_cnt++;
+			} else {
 				bio_list_add(&conf->pending_bio_list, mbio);
 				conf->pending_count++;
+			}
 			spin_unlock_irqrestore(&conf->device_lock, flags);
-			if (!mddev_check_plugged(mddev))
+			if (!plug)
 				md_wakeup_thread(mddev->thread);
 		}
 	}
@@ -1572,7 +1585,25 @@ static void raid10_make_request(struct mddev *mddev, struct bio *bio)
 			split = bio;
 		}
 
+		/*
+		 * If a bio is splitted, the first part of bio will pass
+		 * barrier but the bio is queued in current->bio_list (see
+		 * generic_make_request). If there is a raise_barrier() called
+		 * here, the second part of bio can't pass barrier. But since
+		 * the first part bio isn't dispatched to underlaying disks
+		 * yet, the barrier is never released, hence raise_barrier will
+		 * alays wait. We have a deadlock.
+		 * Note, this only happens in read path. For write path, the
+		 * first part of bio is dispatched in a schedule() call
+		 * (because of blk plug) or offloaded to raid10d.
+		 * Quitting from the function immediately can change the bio
+		 * order queued in bio_list and avoid the deadlock.
+		 */
 		__make_request(mddev, split);
+		if (split != bio && bio_data_dir(bio) == READ) {
+			generic_make_request(bio);
+			break;
+		}
 	} while (split != bio);
 
 	/* In case raid10d snuck in to freeze_array */
@@ -3944,10 +3975,6 @@ static int raid10_resize(struct mddev *mddev, sector_t sectors)
 			return ret;
 	}
 	md_set_array_sectors(mddev, size);
-	if (mddev->queue) {
-		set_capacity(mddev->gendisk, mddev->array_sectors);
-		revalidate_disk(mddev->gendisk);
-	}
 	if (sectors > mddev->dev_sectors &&
 	    mddev->recovery_cp > oldsize) {
 		mddev->recovery_cp = oldsize;

drivers/md/raid5.c

@@ -1401,7 +1401,8 @@ static int set_syndrome_sources(struct page **srcs,
 		     (test_bit(R5_Wantdrain, &dev->flags) ||
 		      test_bit(R5_InJournal, &dev->flags))) ||
 		    (srctype == SYNDROME_SRC_WRITTEN &&
-		     dev->written)) {
+		     (dev->written ||
+		      test_bit(R5_InJournal, &dev->flags)))) {
 			if (test_bit(R5_InJournal, &dev->flags))
 				srcs[slot] = sh->dev[i].orig_page;
 			else
@@ -7605,8 +7606,6 @@ static int raid5_resize(struct mddev *mddev, sector_t sectors)
 			return ret;
 	}
 	md_set_array_sectors(mddev, newsize);
-	set_capacity(mddev->gendisk, mddev->array_sectors);
-	revalidate_disk(mddev->gendisk);
 	if (sectors > mddev->dev_sectors &&
 	    mddev->recovery_cp > mddev->dev_sectors) {
 		mddev->recovery_cp = mddev->dev_sectors;