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

Pull md updates from Shaohua Li:
 "Mainly fixes bugs and improves performance:

   - Improve scalability for raid1 from Coly

   - Improve raid5-cache read performance, disk efficiency and IO
     pattern from Song and me

   - Fix a race condition of disk hotplug for linear from Coly

   - A few cleanup patches from Ming and Byungchul

   - Fix a memory leak from Neil

   - Fix WRITE SAME IO failure from me

   - Add doc for raid5-cache from me"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: (23 commits)
  md/raid1: fix write behind issues introduced by bio_clone_bioset_partial
  md/raid1: handle flush request correctly
  md/linear: shutup lockdep warnning
  md/raid1: fix a use-after-free bug
  RAID1: avoid unnecessary spin locks in I/O barrier code
  RAID1: a new I/O barrier implementation to remove resync window
  md/raid5: Don't reinvent the wheel but use existing llist API
  md: fast clone bio in bio_clone_mddev()
  md: remove unnecessary check on mddev
  md/raid1: use bio_clone_bioset_partial() in case of write behind
  md: fail if mddev->bio_set can't be created
  block: introduce bio_clone_bioset_partial()
  md: disable WRITE SAME if it fails in underlayer disks
  md/raid5-cache: exclude reclaiming stripes in reclaim check
  md/raid5-cache: stripe reclaim only counts valid stripes
  MD: add doc for raid5-cache
  Documentation: move MD related doc into a separate dir
  md: ensure md devices are freed before module is unloaded.
  md/r5cache: improve journal device efficiency
  md/r5cache: enable chunk_aligned_read with write back cache
  ...

1 files changed, 11 insertions, 11 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index ba485dcf1064..985374f20e2e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -190,16 +190,6 @@ struct bio *bio_alloc_mddev(gfp_t gfp_mask, int nr_iovecs,
 }
 EXPORT_SYMBOL_GPL(bio_alloc_mddev);
 
-struct bio *bio_clone_mddev(struct bio *bio, gfp_t gfp_mask,
-			    struct mddev *mddev)
-{
-	if (!mddev || !mddev->bio_set)
-		return bio_clone(bio, gfp_mask);
-
-	return bio_clone_bioset(bio, gfp_mask, mddev->bio_set);
-}
-EXPORT_SYMBOL_GPL(bio_clone_mddev);
-
 /*
  * We have a system wide 'event count' that is incremented
  * on any 'interesting' event, and readers of /proc/mdstat
@@ -5228,8 +5218,11 @@ int md_run(struct mddev *mddev)
 		sysfs_notify_dirent_safe(rdev->sysfs_state);
 	}
 
-	if (mddev->bio_set == NULL)
+	if (mddev->bio_set == NULL) {
 		mddev->bio_set = bioset_create(BIO_POOL_SIZE, 0);
+		if (!mddev->bio_set)
+			return -ENOMEM;
+	}
 
 	spin_lock(&pers_lock);
 	pers = find_pers(mddev->level, mddev->clevel);
@@ -8980,7 +8973,14 @@ static __exit void md_exit(void)
 
 	for_each_mddev(mddev, tmp) {
 		export_array(mddev);
+		mddev->ctime = 0;
 		mddev->hold_active = 0;
+		/*
+		 * for_each_mddev() will call mddev_put() at the end of each
+		 * iteration.  As the mddev is now fully clear, this will
+		 * schedule the mddev for destruction by a workqueue, and the
+		 * destroy_workqueue() below will wait for that to complete.
+		 */
 	}
 	destroy_workqueue(md_misc_wq);
 	destroy_workqueue(md_wq);