Merge tag 'md/4.6-rc2-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md

Pull MD fixes from Shaohua Li:
 "This update mainly fixes bugs:

   - fix error handling (Guoqing)
   - fix a crash when a disk is hotremoved (me)
   - fix a dead loop (Wei Fang)"

* tag 'md/4.6-rc2-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/bitmap: clear bitmap if bitmap_create failed
  MD: add rdev reference for super write
  md: fix a trivial typo in comments
  md:raid1: fix a dead loop when read from a WriteMostly disk

Author: torvalds

drivers/md/bitmap.c

@@ -1673,6 +1673,9 @@ static void bitmap_free(struct bitmap *bitmap)
 	if (!bitmap) /* there was no bitmap */
 		return;
 
+	if (bitmap->sysfs_can_clear)
+		sysfs_put(bitmap->sysfs_can_clear);
+
 	if (mddev_is_clustered(bitmap->mddev) && bitmap->mddev->cluster_info &&
 		bitmap->cluster_slot == md_cluster_ops->slot_number(bitmap->mddev))
 		md_cluster_stop(bitmap->mddev);
@@ -1712,15 +1715,13 @@ void bitmap_destroy(struct mddev *mddev)
 	if (mddev->thread)
 		mddev->thread->timeout = MAX_SCHEDULE_TIMEOUT;
 
-	if (bitmap->sysfs_can_clear)
-		sysfs_put(bitmap->sysfs_can_clear);
-
 	bitmap_free(bitmap);
 }
 
 /*
  * initialize the bitmap structure
  * if this returns an error, bitmap_destroy must be called to do clean up
+ * once mddev->bitmap is set
  */
 struct bitmap *bitmap_create(struct mddev *mddev, int slot)
 {
@@ -1865,8 +1866,10 @@ int bitmap_copy_from_slot(struct mddev *mddev, int slot,
 	struct bitmap_counts *counts;
 	struct bitmap *bitmap = bitmap_create(mddev, slot);
 
-	if (IS_ERR(bitmap))
+	if (IS_ERR(bitmap)) {
+		bitmap_free(bitmap);
 		return PTR_ERR(bitmap);
+	}
 
 	rv = bitmap_init_from_disk(bitmap, 0);
 	if (rv)
@@ -2170,14 +2173,14 @@ location_store(struct mddev *mddev, const char *buf, size_t len)
 				else {
 					mddev->bitmap = bitmap;
 					rv = bitmap_load(mddev);
-					if (rv) {
-						bitmap_destroy(mddev);
+					if (rv)
 						mddev->bitmap_info.offset = 0;
-					}
 				}
 				mddev->pers->quiesce(mddev, 0);
-				if (rv)
+				if (rv) {
+					bitmap_destroy(mddev);
 					return rv;
+				}
 			}
 		}
 	}

drivers/md/md.c

@@ -718,6 +718,7 @@ static void super_written(struct bio *bio)
 
 	if (atomic_dec_and_test(&mddev->pending_writes))
 		wake_up(&mddev->sb_wait);
+	rdev_dec_pending(rdev, mddev);
 	bio_put(bio);
 }
 
@@ -732,6 +733,8 @@ void md_super_write(struct mddev *mddev, struct md_rdev *rdev,
 	 */
 	struct bio *bio = bio_alloc_mddev(GFP_NOIO, 1, mddev);
 
+	atomic_inc(&rdev->nr_pending);
+
 	bio->bi_bdev = rdev->meta_bdev ? rdev->meta_bdev : rdev->bdev;
 	bio->bi_iter.bi_sector = sector;
 	bio_add_page(bio, page, size, 0);
@@ -6883,7 +6886,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
 
 	case ADD_NEW_DISK:
 		/* We can support ADD_NEW_DISK on read-only arrays
-		 * on if we are re-adding a preexisting device.
+		 * only if we are re-adding a preexisting device.
 		 * So require mddev->pers and MD_DISK_SYNC.
 		 */
 		if (mddev->pers) {

drivers/md/raid1.c

@@ -570,7 +570,7 @@ static int read_balance(struct r1conf *conf, struct r1bio *r1_bio, int *max_sect
 			if (best_dist_disk < 0) {
 				if (is_badblock(rdev, this_sector, sectors,
 						&first_bad, &bad_sectors)) {
-					if (first_bad < this_sector)
+					if (first_bad <= this_sector)
 						/* Cannot use this */
 						continue;
 					best_good_sectors = first_bad - this_sector;