Merge branch 'for-linus' of git://neil.brown.name/md

* 'for-linus' of git://neil.brown.name/md: (24 commits)
  md: clean up do_md_stop
  md: fix another deadlock with removing sysfs attributes.
  md: move revalidate_disk() back outside open_mutex
  md/raid10: fix deadlock with unaligned read during resync
  md/bitmap:  separate out loading a bitmap from initialising the structures.
  md/bitmap: prepare for storing write-intent-bitmap via dm-dirty-log.
  md/bitmap: optimise scanning of empty bitmaps.
  md/bitmap: clean up plugging calls.
  md/bitmap: reduce dependence on sysfs.
  md/bitmap: white space clean up and similar.
  md/raid5: export raid5 unplugging interface.
  md/plug: optionally use plugger to unplug an array during resync/recovery.
  md/raid5: add simple plugging infrastructure.
  md/raid5: export is_congested test
  raid5: Don't set read-ahead when there is no queue
  md: add support for raising dm events.
  md: export various start/stop interfaces
  md: split out md_rdev_init
  md: be more careful setting MD_CHANGE_CLEAN
  md/raid5: ensure we create a unique name for kmem_cache when mddev has no gendisk
  ...

crypto/async_tx/Kconfig

@@ -22,6 +22,20 @@ config ASYNC_RAID6_RECOV
 	tristate
 	select ASYNC_CORE
 	select ASYNC_PQ
+	select ASYNC_XOR
+
+config ASYNC_RAID6_TEST
+	tristate "Self test for hardware accelerated raid6 recovery"
+	depends on ASYNC_RAID6_RECOV
+	select ASYNC_MEMCPY
+	---help---
+	  This is a one-shot self test that permutes through the
+	  recovery of all the possible two disk failure scenarios for a
+	  N-disk array.  Recovery is performed with the asynchronous
+	  raid6 recovery routines, and will optionally use an offload
+	  engine if one is available.
+
+	  If unsure, say N.
 
 config ASYNC_TX_DISABLE_PQ_VAL_DMA
 	bool

drivers/md/Kconfig

@@ -121,7 +121,7 @@ config MD_RAID10
 config MD_RAID456
 	tristate "RAID-4/RAID-5/RAID-6 mode"
 	depends on BLK_DEV_MD
-	select MD_RAID6_PQ
+	select RAID6_PQ
 	select ASYNC_MEMCPY
 	select ASYNC_XOR
 	select ASYNC_PQ
@@ -165,22 +165,6 @@ config MULTICORE_RAID456
 
 	  If unsure, say N.
 
-config MD_RAID6_PQ
-	tristate
-
-config ASYNC_RAID6_TEST
-	tristate "Self test for hardware accelerated raid6 recovery"
-	depends on MD_RAID6_PQ
-	select ASYNC_RAID6_RECOV
-	---help---
-	  This is a one-shot self test that permutes through the
-	  recovery of all the possible two disk failure scenarios for a
-	  N-disk array.  Recovery is performed with the asynchronous
-	  raid6 recovery routines, and will optionally use an offload
-	  engine if one is available.
-
-	  If unsure, say N.
-
 config MD_MULTIPATH
 	tristate "Multipath I/O support"
 	depends on BLK_DEV_MD

drivers/md/Makefile

@@ -12,13 +12,6 @@ dm-log-userspace-y \
 		+= dm-log-userspace-base.o dm-log-userspace-transfer.o
 md-mod-y	+= md.o bitmap.o
 raid456-y	+= raid5.o
-raid6_pq-y	+= raid6algos.o raid6recov.o raid6tables.o \
-		   raid6int1.o raid6int2.o raid6int4.o \
-		   raid6int8.o raid6int16.o raid6int32.o \
-		   raid6altivec1.o raid6altivec2.o raid6altivec4.o \
-		   raid6altivec8.o \
-		   raid6mmx.o raid6sse1.o raid6sse2.o
-hostprogs-y	+= mktables
 
 # Note: link order is important.  All raid personalities
 # and must come before md.o, as they each initialise 
@@ -29,7 +22,6 @@ obj-$(CONFIG_MD_LINEAR)		+= linear.o
 obj-$(CONFIG_MD_RAID0)		+= raid0.o
 obj-$(CONFIG_MD_RAID1)		+= raid1.o
 obj-$(CONFIG_MD_RAID10)		+= raid10.o
-obj-$(CONFIG_MD_RAID6_PQ)	+= raid6_pq.o
 obj-$(CONFIG_MD_RAID456)	+= raid456.o
 obj-$(CONFIG_MD_MULTIPATH)	+= multipath.o
 obj-$(CONFIG_MD_FAULTY)		+= faulty.o
@@ -45,75 +37,6 @@ obj-$(CONFIG_DM_MIRROR)		+= dm-mirror.o dm-log.o dm-region-hash.o
 obj-$(CONFIG_DM_LOG_USERSPACE)	+= dm-log-userspace.o
 obj-$(CONFIG_DM_ZERO)		+= dm-zero.o
 
-quiet_cmd_unroll = UNROLL  $@
-      cmd_unroll = $(AWK) -f$(srctree)/$(src)/unroll.awk -vN=$(UNROLL) \
-                   < $< > $@ || ( rm -f $@ && exit 1 )
-
-ifeq ($(CONFIG_ALTIVEC),y)
-altivec_flags := -maltivec -mabi=altivec
-endif
-
 ifeq ($(CONFIG_DM_UEVENT),y)
 dm-mod-objs			+= dm-uevent.o
 endif
-
-targets += raid6int1.c
-$(obj)/raid6int1.c:   UNROLL := 1
-$(obj)/raid6int1.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-targets += raid6int2.c
-$(obj)/raid6int2.c:   UNROLL := 2
-$(obj)/raid6int2.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-targets += raid6int4.c
-$(obj)/raid6int4.c:   UNROLL := 4
-$(obj)/raid6int4.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-targets += raid6int8.c
-$(obj)/raid6int8.c:   UNROLL := 8
-$(obj)/raid6int8.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-targets += raid6int16.c
-$(obj)/raid6int16.c:  UNROLL := 16
-$(obj)/raid6int16.c:  $(src)/raid6int.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-targets += raid6int32.c
-$(obj)/raid6int32.c:  UNROLL := 32
-$(obj)/raid6int32.c:  $(src)/raid6int.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-CFLAGS_raid6altivec1.o += $(altivec_flags)
-targets += raid6altivec1.c
-$(obj)/raid6altivec1.c:   UNROLL := 1
-$(obj)/raid6altivec1.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-CFLAGS_raid6altivec2.o += $(altivec_flags)
-targets += raid6altivec2.c
-$(obj)/raid6altivec2.c:   UNROLL := 2
-$(obj)/raid6altivec2.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-CFLAGS_raid6altivec4.o += $(altivec_flags)
-targets += raid6altivec4.c
-$(obj)/raid6altivec4.c:   UNROLL := 4
-$(obj)/raid6altivec4.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-CFLAGS_raid6altivec8.o += $(altivec_flags)
-targets += raid6altivec8.c
-$(obj)/raid6altivec8.c:   UNROLL := 8
-$(obj)/raid6altivec8.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
-	$(call if_changed,unroll)
-
-quiet_cmd_mktable = TABLE   $@
-      cmd_mktable = $(obj)/mktables > $@ || ( rm -f $@ && exit 1 )
-
-targets += raid6tables.c
-$(obj)/raid6tables.c: $(obj)/mktables FORCE
-	$(call if_changed,mktable)

drivers/md/bitmap.h

@@ -222,6 +222,10 @@ struct bitmap {
 	unsigned long file_pages; /* number of pages in the file */
 	int last_page_size; /* bytes in the last page */
 
+	unsigned long logattrs; /* used when filemap_attr doesn't exist
+				 * because we are working with a dirty_log
+				 */
+
 	unsigned long flags;
 
 	int allclean;
@@ -243,12 +247,14 @@ struct bitmap {
 	wait_queue_head_t behind_wait;
 
 	struct sysfs_dirent *sysfs_can_clear;
+
 };
 
 /* the bitmap API */
 
 /* these are used only by md/bitmap */
 int  bitmap_create(mddev_t *mddev);
+int bitmap_load(mddev_t *mddev);
 void bitmap_flush(mddev_t *mddev);
 void bitmap_destroy(mddev_t *mddev);
 

drivers/md/md.h

@@ -29,6 +29,26 @@
 typedef struct mddev_s mddev_t;
 typedef struct mdk_rdev_s mdk_rdev_t;
 
+/* generic plugging support - like that provided with request_queue,
+ * but does not require a request_queue
+ */
+struct plug_handle {
+	void			(*unplug_fn)(struct plug_handle *);
+	struct timer_list	unplug_timer;
+	struct work_struct	unplug_work;
+	unsigned long		unplug_flag;
+};
+#define	PLUGGED_FLAG 1
+void plugger_init(struct plug_handle *plug,
+		  void (*unplug_fn)(struct plug_handle *));
+void plugger_set_plug(struct plug_handle *plug);
+int plugger_remove_plug(struct plug_handle *plug);
+static inline void plugger_flush(struct plug_handle *plug)
+{
+	del_timer_sync(&plug->unplug_timer);
+	cancel_work_sync(&plug->unplug_work);
+}
+
 /*
  * MD's 'extended' device
  */
@@ -125,6 +145,10 @@ struct mddev_s
 	int				suspended;
 	atomic_t			active_io;
 	int				ro;
+	int				sysfs_active; /* set when sysfs deletes
+						       * are happening, so run/
+						       * takeover/stop are not safe
+						       */
 
 	struct gendisk			*gendisk;
 
@@ -297,9 +321,14 @@ struct mddev_s
 							 * hot-adding a bitmap.  It should
 							 * eventually be settable by sysfs.
 							 */
+		/* When md is serving under dm, it might use a
+		 * dirty_log to store the bits.
+		 */
+		struct dm_dirty_log *log;
+
 		struct mutex		mutex;
 		unsigned long		chunksize;
-		unsigned long		daemon_sleep; /* how many seconds between updates? */
+		unsigned long		daemon_sleep; /* how many jiffies between updates? */
 		unsigned long		max_write_behind; /* write-behind mode */
 		int			external;
 	} bitmap_info;
@@ -308,6 +337,8 @@ struct mddev_s
 	struct list_head		all_mddevs;
 
 	struct attribute_group		*to_remove;
+	struct plug_handle		*plug; /* if used by personality */
+
 	/* Generic barrier handling.
 	 * If there is a pending barrier request, all other
 	 * writes are blocked while the devices are flushed.
@@ -318,6 +349,7 @@ struct mddev_s
 	struct bio *barrier;
 	atomic_t flush_pending;
 	struct work_struct barrier_work;
+	struct work_struct event_work;	/* used by dm to report failure event */
 };
 
 
@@ -382,6 +414,18 @@ struct md_sysfs_entry {
 };
 extern struct attribute_group md_bitmap_group;
 
+static inline struct sysfs_dirent *sysfs_get_dirent_safe(struct sysfs_dirent *sd, char *name)
+{
+	if (sd)
+		return sysfs_get_dirent(sd, NULL, name);
+	return sd;
+}
+static inline void sysfs_notify_dirent_safe(struct sysfs_dirent *sd)
+{
+	if (sd)
+		sysfs_notify_dirent(sd);
+}
+
 static inline char * mdname (mddev_t * mddev)
 {
 	return mddev->gendisk ? mddev->gendisk->disk_name : "mdX";
@@ -474,5 +518,14 @@ extern int md_integrity_register(mddev_t *mddev);
 extern void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
 extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
 extern void restore_bitmap_write_access(struct file *file);
+extern void md_unplug(mddev_t *mddev);
+
+extern void mddev_init(mddev_t *mddev);
+extern int md_run(mddev_t *mddev);
+extern void md_stop(mddev_t *mddev);
+extern void md_stop_writes(mddev_t *mddev);
+extern void md_rdev_init(mdk_rdev_t *rdev);
 
+extern void mddev_suspend(mddev_t *mddev);
+extern void mddev_resume(mddev_t *mddev);
 #endif /* _MD_MD_H */

drivers/md/raid10.c

@@ -825,11 +825,29 @@ static int make_request(mddev_t *mddev, struct bio * bio)
 		 */
 		bp = bio_split(bio,
 			       chunk_sects - (bio->bi_sector & (chunk_sects - 1)) );
+
+		/* Each of these 'make_request' calls will call 'wait_barrier'.
+		 * If the first succeeds but the second blocks due to the resync
+		 * thread raising the barrier, we will deadlock because the
+		 * IO to the underlying device will be queued in generic_make_request
+		 * and will never complete, so will never reduce nr_pending.
+		 * So increment nr_waiting here so no new raise_barriers will
+		 * succeed, and so the second wait_barrier cannot block.
+		 */
+		spin_lock_irq(&conf->resync_lock);
+		conf->nr_waiting++;
+		spin_unlock_irq(&conf->resync_lock);
+
 		if (make_request(mddev, &bp->bio1))
 			generic_make_request(&bp->bio1);
 		if (make_request(mddev, &bp->bio2))
 			generic_make_request(&bp->bio2);
 
+		spin_lock_irq(&conf->resync_lock);
+		conf->nr_waiting--;
+		wake_up(&conf->wait_barrier);
+		spin_unlock_irq(&conf->resync_lock);
+
 		bio_pair_release(bp);
 		return 0;
 	bad_map:

drivers/md/raid5.c

@@ -201,11 +201,11 @@ static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
 		if (test_bit(STRIPE_HANDLE, &sh->state)) {
 			if (test_bit(STRIPE_DELAYED, &sh->state)) {
 				list_add_tail(&sh->lru, &conf->delayed_list);
-				blk_plug_device(conf->mddev->queue);
+				plugger_set_plug(&conf->plug);
 			} else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
 				   sh->bm_seq - conf->seq_write > 0) {
 				list_add_tail(&sh->lru, &conf->bitmap_list);
-				blk_plug_device(conf->mddev->queue);
+				plugger_set_plug(&conf->plug);
 			} else {
 				clear_bit(STRIPE_BIT_DELAY, &sh->state);
 				list_add_tail(&sh->lru, &conf->handle_list);
@@ -434,7 +434,6 @@ static int has_failed(raid5_conf_t *conf)
 }
 
 static void unplug_slaves(mddev_t *mddev);
-static void raid5_unplug_device(struct request_queue *q);
 
 static struct stripe_head *
 get_active_stripe(raid5_conf_t *conf, sector_t sector,
@@ -464,7 +463,7 @@ get_active_stripe(raid5_conf_t *conf, sector_t sector,
 						     < (conf->max_nr_stripes *3/4)
 						     || !conf->inactive_blocked),
 						    conf->device_lock,
-						    raid5_unplug_device(conf->mddev->queue)
+						    md_raid5_unplug_device(conf)
 					);
 				conf->inactive_blocked = 0;
 			} else
@@ -1337,10 +1336,14 @@ static int grow_stripes(raid5_conf_t *conf, int num)
 	struct kmem_cache *sc;
 	int devs = max(conf->raid_disks, conf->previous_raid_disks);
 
+	if (conf->mddev->gendisk)
 		sprintf(conf->cache_name[0],
 			"raid%d-%s", conf->level, mdname(conf->mddev));
-	sprintf(conf->cache_name[1],
-		"raid%d-%s-alt", conf->level, mdname(conf->mddev));
+	else
+		sprintf(conf->cache_name[0],
+			"raid%d-%p", conf->level, conf->mddev);
+	sprintf(conf->cache_name[1], "%s-alt", conf->cache_name[0]);
+
 	conf->active_name = 0;
 	sc = kmem_cache_create(conf->cache_name[conf->active_name],
 			       sizeof(struct stripe_head)+(devs-1)*sizeof(struct r5dev),
@@ -3614,7 +3617,7 @@ static void raid5_activate_delayed(raid5_conf_t *conf)
 			list_add_tail(&sh->lru, &conf->hold_list);
 		}
 	} else
-		blk_plug_device(conf->mddev->queue);
+		plugger_set_plug(&conf->plug);
 }
 
 static void activate_bit_delay(raid5_conf_t *conf)
@@ -3655,36 +3658,44 @@ static void unplug_slaves(mddev_t *mddev)
 	rcu_read_unlock();
 }
 
-static void raid5_unplug_device(struct request_queue *q)
+void md_raid5_unplug_device(raid5_conf_t *conf)
 {
-	mddev_t *mddev = q->queuedata;
-	raid5_conf_t *conf = mddev->private;
 	unsigned long flags;
 
 	spin_lock_irqsave(&conf->device_lock, flags);
 
-	if (blk_remove_plug(q)) {
+	if (plugger_remove_plug(&conf->plug)) {
 		conf->seq_flush++;
 		raid5_activate_delayed(conf);
 	}
-	md_wakeup_thread(mddev->thread);
+	md_wakeup_thread(conf->mddev->thread);
 
 	spin_unlock_irqrestore(&conf->device_lock, flags);
 
-	unplug_slaves(mddev);
+	unplug_slaves(conf->mddev);
 }
+EXPORT_SYMBOL_GPL(md_raid5_unplug_device);
 
-static int raid5_congested(void *data, int bits)
+static void raid5_unplug(struct plug_handle *plug)
+{
+	raid5_conf_t *conf = container_of(plug, raid5_conf_t, plug);
+	md_raid5_unplug_device(conf);
+}
+
+static void raid5_unplug_queue(struct request_queue *q)
+{
+	mddev_t *mddev = q->queuedata;
+	md_raid5_unplug_device(mddev->private);
+}
+
+int md_raid5_congested(mddev_t *mddev, int bits)
 {
-	mddev_t *mddev = data;
 	raid5_conf_t *conf = mddev->private;
 
 	/* No difference between reads and writes.  Just check
 	 * how busy the stripe_cache is
 	 */
 
-	if (mddev_congested(mddev, bits))
-		return 1;
 	if (conf->inactive_blocked)
 		return 1;
 	if (conf->quiesce)
@@ -3694,6 +3705,15 @@ static int raid5_congested(void *data, int bits)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(md_raid5_congested);
+
+static int raid5_congested(void *data, int bits)
+{
+	mddev_t *mddev = data;
+
+	return mddev_congested(mddev, bits) ||
+		md_raid5_congested(mddev, bits);
+}
 
 /* We want read requests to align with chunks where possible,
  * but write requests don't need to.
@@ -4075,7 +4095,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
 				 * add failed due to overlap.  Flush everything
 				 * and wait a while
 				 */
-				raid5_unplug_device(mddev->queue);
+				md_raid5_unplug_device(conf);
 				release_stripe(sh);
 				schedule();
 				goto retry;
@@ -4566,23 +4586,15 @@ raid5_show_stripe_cache_size(mddev_t *mddev, char *page)
 		return 0;
 }
 
-static ssize_t
-raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
+int
+raid5_set_cache_size(mddev_t *mddev, int size)
 {
 	raid5_conf_t *conf = mddev->private;
-	unsigned long new;
 	int err;
 
-	if (len >= PAGE_SIZE)
+	if (size <= 16 || size > 32768)
 		return -EINVAL;
-	if (!conf)
-		return -ENODEV;
-
-	if (strict_strtoul(page, 10, &new))
-		return -EINVAL;
-	if (new <= 16 || new > 32768)
-		return -EINVAL;
-	while (new < conf->max_nr_stripes) {
+	while (size < conf->max_nr_stripes) {
 		if (drop_one_stripe(conf))
 			conf->max_nr_stripes--;
 		else
@@ -4591,11 +4603,32 @@ raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
 	err = md_allow_write(mddev);
 	if (err)
 		return err;
-	while (new > conf->max_nr_stripes) {
+	while (size > conf->max_nr_stripes) {
 		if (grow_one_stripe(conf))
 			conf->max_nr_stripes++;
 		else break;
 	}
+	return 0;
+}
+EXPORT_SYMBOL(raid5_set_cache_size);
+
+static ssize_t
+raid5_store_stripe_cache_size(mddev_t *mddev, const char *page, size_t len)
+{
+	raid5_conf_t *conf = mddev->private;
+	unsigned long new;
+	int err;
+
+	if (len >= PAGE_SIZE)
+		return -EINVAL;
+	if (!conf)
+		return -ENODEV;
+
+	if (strict_strtoul(page, 10, &new))
+		return -EINVAL;
+	err = raid5_set_cache_size(mddev, new);
+	if (err)
+		return err;
 	return len;
 }
 
@@ -4958,7 +4991,7 @@ static int only_parity(int raid_disk, int algo, int raid_disks, int max_degraded
 static int run(mddev_t *mddev)
 {
 	raid5_conf_t *conf;
-	int working_disks = 0, chunk_size;
+	int working_disks = 0;
 	int dirty_parity_disks = 0;
 	mdk_rdev_t *rdev;
 	sector_t reshape_offset = 0;
@@ -5144,34 +5177,38 @@ static int run(mddev_t *mddev)
 							"reshape");
 	}
 
-	/* read-ahead size must cover two whole stripes, which is
-	 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
-	 */
-	{
-		int data_disks = conf->previous_raid_disks - conf->max_degraded;
-		int stripe = data_disks *
-			((mddev->chunk_sectors << 9) / PAGE_SIZE);
-		if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
-			mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
-	}
 
 	/* Ok, everything is just fine now */
 	if (mddev->to_remove == &raid5_attrs_group)
 		mddev->to_remove = NULL;
-	else if (sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
+	else if (mddev->kobj.sd &&
+	    sysfs_create_group(&mddev->kobj, &raid5_attrs_group))
 		printk(KERN_WARNING
-		       "md/raid:%s: failed to create sysfs attributes.\n",
+		       "raid5: failed to create sysfs attributes for %s\n",
 		       mdname(mddev));
+	md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
 
-	mddev->queue->queue_lock = &conf->device_lock;
+	plugger_init(&conf->plug, raid5_unplug);
+	mddev->plug = &conf->plug;
+	if (mddev->queue) {
+		int chunk_size;
+		/* read-ahead size must cover two whole stripes, which
+		 * is 2 * (datadisks) * chunksize where 'n' is the
+		 * number of raid devices
+		 */
+		int data_disks = conf->previous_raid_disks - conf->max_degraded;
+		int stripe = data_disks *
+			((mddev->chunk_sectors << 9) / PAGE_SIZE);
+		if (mddev->queue->backing_dev_info.ra_pages < 2 * stripe)
+			mddev->queue->backing_dev_info.ra_pages = 2 * stripe;
+
+		blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
 
-	mddev->queue->unplug_fn = raid5_unplug_device;
 		mddev->queue->backing_dev_info.congested_data = mddev;
 		mddev->queue->backing_dev_info.congested_fn = raid5_congested;
+		mddev->queue->queue_lock = &conf->device_lock;
+		mddev->queue->unplug_fn = raid5_unplug_queue;
 
-	md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
-
-	blk_queue_merge_bvec(mddev->queue, raid5_mergeable_bvec);
 		chunk_size = mddev->chunk_sectors << 9;
 		blk_queue_io_min(mddev->queue, chunk_size);
 		blk_queue_io_opt(mddev->queue, chunk_size *
@@ -5180,6 +5217,7 @@ static int run(mddev_t *mddev)
 		list_for_each_entry(rdev, &mddev->disks, same_set)
 			disk_stack_limits(mddev->gendisk, rdev->bdev,
 					  rdev->data_offset << 9);
+	}
 
 	return 0;
 abort:
@@ -5200,8 +5238,9 @@ static int stop(mddev_t *mddev)
 
 	md_unregister_thread(mddev->thread);
 	mddev->thread = NULL;
+	if (mddev->queue)
 		mddev->queue->backing_dev_info.congested_fn = NULL;
-	blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+	plugger_flush(&conf->plug); /* the unplug fn references 'conf'*/
 	free_conf(conf);
 	mddev->private = NULL;
 	mddev->to_remove = &raid5_attrs_group;
@@ -5545,10 +5584,7 @@ static int raid5_start_reshape(mddev_t *mddev)
 				sprintf(nm, "rd%d", rdev->raid_disk);
 				if (sysfs_create_link(&mddev->kobj,
 						      &rdev->kobj, nm))
-					printk(KERN_WARNING
-					       "md/raid:%s: failed to create "
-					       " link %s\n",
-					       mdname(mddev), nm);
+					/* Failure here is OK */;
 			} else
 				break;
 		}
@@ -5603,7 +5639,7 @@ static void end_reshape(raid5_conf_t *conf)
 		/* read-ahead size must cover two whole stripes, which is
 		 * 2 * (datadisks) * chunksize where 'n' is the number of raid devices
 		 */
-		{
+		if (conf->mddev->queue) {
 			int data_disks = conf->raid_disks - conf->max_degraded;
 			int stripe = data_disks * ((conf->chunk_sectors << 9)
 						   / PAGE_SIZE);

drivers/md/raid5.h

@@ -388,7 +388,7 @@ struct raid5_private_data {
 	 * two caches.
 	 */
 	int			active_name;
-	char			cache_name[2][20];
+	char			cache_name[2][32];
 	struct kmem_cache		*slab_cache; /* for allocating stripes */
 
 	int			seq_flush, seq_write;
@@ -398,6 +398,9 @@ struct raid5_private_data {
 					    * (fresh device added).
 					    * Cleared when a sync completes.
 					    */
+
+	struct plug_handle	plug;
+
 	/* per cpu variables */
 	struct raid5_percpu {
 		struct page	*spare_page; /* Used when checking P/Q in raid6 */
@@ -497,4 +500,8 @@ static inline int algorithm_is_DDF(int layout)
 {
 	return layout >= 8 && layout <= 10;
 }
+
+extern int md_raid5_congested(mddev_t *mddev, int bits);
+extern void md_raid5_unplug_device(raid5_conf_t *conf);
+extern int raid5_set_cache_size(mddev_t *mddev, int size);
 #endif

lib/Kconfig

@@ -7,6 +7,9 @@ config BINARY_PRINTF
 
 menu "Library routines"
 
+config RAID6_PQ
+	tristate
+
 config BITREVERSE
 	tristate
 

lib/Makefile

@@ -69,6 +69,7 @@ obj-$(CONFIG_ZLIB_DEFLATE) += zlib_deflate/
 obj-$(CONFIG_REED_SOLOMON) += reed_solomon/
 obj-$(CONFIG_LZO_COMPRESS) += lzo/
 obj-$(CONFIG_LZO_DECOMPRESS) += lzo/
+obj-$(CONFIG_RAID6_PQ) += raid6/
 
 lib-$(CONFIG_DECOMPRESS_GZIP) += decompress_inflate.o
 lib-$(CONFIG_DECOMPRESS_BZIP2) += decompress_bunzip2.o

lib/raid6/Makefile

+obj-$(CONFIG_RAID6_PQ)	+= raid6_pq.o
+
+raid6_pq-y	+= raid6algos.o raid6recov.o raid6tables.o \
+		   raid6int1.o raid6int2.o raid6int4.o \
+		   raid6int8.o raid6int16.o raid6int32.o \
+		   raid6altivec1.o raid6altivec2.o raid6altivec4.o \
+		   raid6altivec8.o \
+		   raid6mmx.o raid6sse1.o raid6sse2.o
+hostprogs-y	+= mktables
+
+quiet_cmd_unroll = UNROLL  $@
+      cmd_unroll = $(AWK) -f$(srctree)/$(src)/unroll.awk -vN=$(UNROLL) \
+                   < $< > $@ || ( rm -f $@ && exit 1 )
+
+ifeq ($(CONFIG_ALTIVEC),y)
+altivec_flags := -maltivec -mabi=altivec
+endif
+
+targets += raid6int1.c
+$(obj)/raid6int1.c:   UNROLL := 1
+$(obj)/raid6int1.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int2.c
+$(obj)/raid6int2.c:   UNROLL := 2
+$(obj)/raid6int2.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int4.c
+$(obj)/raid6int4.c:   UNROLL := 4
+$(obj)/raid6int4.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int8.c
+$(obj)/raid6int8.c:   UNROLL := 8
+$(obj)/raid6int8.c:   $(src)/raid6int.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int16.c
+$(obj)/raid6int16.c:  UNROLL := 16
+$(obj)/raid6int16.c:  $(src)/raid6int.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+targets += raid6int32.c
+$(obj)/raid6int32.c:  UNROLL := 32
+$(obj)/raid6int32.c:  $(src)/raid6int.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec1.o += $(altivec_flags)
+targets += raid6altivec1.c
+$(obj)/raid6altivec1.c:   UNROLL := 1
+$(obj)/raid6altivec1.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec2.o += $(altivec_flags)
+targets += raid6altivec2.c
+$(obj)/raid6altivec2.c:   UNROLL := 2
+$(obj)/raid6altivec2.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec4.o += $(altivec_flags)
+targets += raid6altivec4.c
+$(obj)/raid6altivec4.c:   UNROLL := 4
+$(obj)/raid6altivec4.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+CFLAGS_raid6altivec8.o += $(altivec_flags)
+targets += raid6altivec8.c
+$(obj)/raid6altivec8.c:   UNROLL := 8
+$(obj)/raid6altivec8.c:   $(src)/raid6altivec.uc $(src)/unroll.awk FORCE
+	$(call if_changed,unroll)
+
+quiet_cmd_mktable = TABLE   $@
+      cmd_mktable = $(obj)/mktables > $@ || ( rm -f $@ && exit 1 )
+
+targets += raid6tables.c
+$(obj)/raid6tables.c: $(obj)/mktables FORCE
+	$(call if_changed,mktable)