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

Pull MD updates from Shaohua Li:
 "A few fixes of MD for this merge window. Mostly bug fixes:

   - raid5 stripe batch fix from Amy

   - Read error handling for raid1 FailFast device from Gioh

   - raid10 recovery NULL pointer dereference fix from Guoqing

   - Support write hint for raid5 stripe cache from Mariusz

   - Fixes for device hot add/remove from Neil and Yufen

   - Improve flush bio scalability from Xiao"

* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  MD: fix lock contention for flush bios
  md/raid5: Assigning NULL to sh->batch_head before testing bit R5_Overlap of a stripe
  md/raid1: add error handling of read error from FailFast device
  md: fix NULL dereference of mddev->pers in remove_and_add_spares()
  raid5: copy write hint from origin bio to stripe
  md: fix two problems with setting the "re-add" device state.
  raid10: check bio in r10buf_pool_free to void NULL pointer dereference
  md: fix an error code format and remove unsed bio_sector

1 files changed, 15 insertions, 7 deletions

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 3507cab22cb6..2d148bdaba74 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -252,6 +252,19 @@ enum mddev_sb_flags {
 	MD_SB_NEED_REWRITE,	/* metadata write needs to be repeated */
 };
 
+#define NR_FLUSH_INFOS 8
+#define NR_FLUSH_BIOS 64
+struct flush_info {
+	struct bio			*bio;
+	struct mddev			*mddev;
+	struct work_struct		flush_work;
+	atomic_t			flush_pending;
+};
+struct flush_bio {
+	struct flush_info *fi;
+	struct md_rdev *rdev;
+};
+
 struct mddev {
 	void				*private;
 	struct md_personality		*pers;
@@ -457,13 +470,8 @@ struct mddev {
 						   * metadata and bitmap writes
 						   */
 
-	/* Generic flush handling.
-	 * The last to finish preflush schedules a worker to submit
-	 * the rest of the request (without the REQ_PREFLUSH flag).
-	 */
-	struct bio *flush_bio;
-	atomic_t flush_pending;
-	struct work_struct flush_work;
+	mempool_t			*flush_pool;
+	mempool_t			*flush_bio_pool;
 	struct work_struct event_work;	/* used by dm to report failure event */
 	void (*sync_super)(struct mddev *mddev, struct md_rdev *rdev);
 	struct md_cluster_info		*cluster_info;