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
  ...

1 files changed, 176 insertions, 110 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 700c96edf9b2..11567c7999a2 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -262,7 +262,7 @@ static int md_make_request(struct request_queue *q, struct bio *bio)
  * Once ->stop is called and completes, the module will be completely
  * unused.
  */
-static void mddev_suspend(mddev_t *mddev)
+void mddev_suspend(mddev_t *mddev)
 {
         BUG_ON(mddev->suspended);
         mddev->suspended = 1;
@@ -270,13 +270,15 @@ static void mddev_suspend(mddev_t *mddev)
         wait_event(mddev->sb_wait, atomic_read(&mddev->active_io) == 0);
         mddev->pers->quiesce(mddev, 1);
 }
+EXPORT_SYMBOL_GPL(mddev_suspend);
 
-static void mddev_resume(mddev_t *mddev)
+void mddev_resume(mddev_t *mddev)
 {
         mddev->suspended = 0;
         wake_up(&mddev->sb_wait);
         mddev->pers->quiesce(mddev, 0);
 }
+EXPORT_SYMBOL_GPL(mddev_resume);
 
 int mddev_congested(mddev_t *mddev, int bits)
 {
@@ -385,6 +387,51 @@ void md_barrier_request(mddev_t *mddev, struct bio *bio)
 }
 EXPORT_SYMBOL(md_barrier_request);
 
+/* Support for plugging.
+ * This mirrors the plugging support in request_queue, but does not
+ * require having a whole queue
+ */
+static void plugger_work(struct work_struct *work)
+{
+        struct plug_handle *plug =
+                container_of(work, struct plug_handle, unplug_work);
+        plug->unplug_fn(plug);
+}
+static void plugger_timeout(unsigned long data)
+{
+        struct plug_handle *plug = (void *)data;
+        kblockd_schedule_work(NULL, &plug->unplug_work);
+}
+void plugger_init(struct plug_handle *plug,
+                  void (*unplug_fn)(struct plug_handle *))
+{
+        plug->unplug_flag = 0;
+        plug->unplug_fn = unplug_fn;
+        init_timer(&plug->unplug_timer);
+        plug->unplug_timer.function = plugger_timeout;
+        plug->unplug_timer.data = (unsigned long)plug;
+        INIT_WORK(&plug->unplug_work, plugger_work);
+}
+EXPORT_SYMBOL_GPL(plugger_init);
+
+void plugger_set_plug(struct plug_handle *plug)
+{
+        if (!test_and_set_bit(PLUGGED_FLAG, &plug->unplug_flag))
+                mod_timer(&plug->unplug_timer, jiffies + msecs_to_jiffies(3)+1);
+}
+EXPORT_SYMBOL_GPL(plugger_set_plug);
+
+int plugger_remove_plug(struct plug_handle *plug)
+{
+        if (test_and_clear_bit(PLUGGED_FLAG, &plug->unplug_flag)) {
+                del_timer(&plug->unplug_timer);
+                return 1;
+        } else
+                return 0;
+}
+EXPORT_SYMBOL_GPL(plugger_remove_plug);
+
+
 static inline mddev_t *mddev_get(mddev_t *mddev)
 {
         atomic_inc(&mddev->active);
@@ -417,7 +464,7 @@ static void mddev_put(mddev_t *mddev)
         spin_unlock(&all_mddevs_lock);
 }
 
-static void mddev_init(mddev_t *mddev)
+void mddev_init(mddev_t *mddev)
 {
         mutex_init(&mddev->open_mutex);
         mutex_init(&mddev->reconfig_mutex);
@@ -437,6 +484,7 @@ static void mddev_init(mddev_t *mddev)
         mddev->resync_max = MaxSector;
         mddev->level = LEVEL_NONE;
 }
+EXPORT_SYMBOL_GPL(mddev_init);
 
 static mddev_t * mddev_find(dev_t unit)
 {
@@ -533,25 +581,31 @@ static void mddev_unlock(mddev_t * mddev)
                  * an access to the files will try to take reconfig_mutex
                  * while holding the file unremovable, which leads to
                  * a deadlock.
-                 * So hold open_mutex instead - we are allowed to take
-                 * it while holding reconfig_mutex, and md_run can
-                 * use it to wait for the remove to complete.
+                 * So hold set sysfs_active while the remove in happeing,
+                 * and anything else which might set ->to_remove or my
+                 * otherwise change the sysfs namespace will fail with
+                 * -EBUSY if sysfs_active is still set.
+                 * We set sysfs_active under reconfig_mutex and elsewhere
+                 * test it under the same mutex to ensure its correct value
+                 * is seen.
                  */
                 struct attribute_group *to_remove = mddev->to_remove;
                 mddev->to_remove = NULL;
-                mutex_lock(&mddev->open_mutex);
+                mddev->sysfs_active = 1;
                 mutex_unlock(&mddev->reconfig_mutex);
 
-                if (to_remove != &md_redundancy_group)
-                        sysfs_remove_group(&mddev->kobj, to_remove);
-                if (mddev->pers == NULL ||
-                    mddev->pers->sync_request == NULL) {
-                        sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
-                        if (mddev->sysfs_action)
-                                sysfs_put(mddev->sysfs_action);
-                        mddev->sysfs_action = NULL;
+                if (mddev->kobj.sd) {
+                        if (to_remove != &md_redundancy_group)
+                                sysfs_remove_group(&mddev->kobj, to_remove);
+                        if (mddev->pers == NULL ||
+                            mddev->pers->sync_request == NULL) {
+                                sysfs_remove_group(&mddev->kobj, &md_redundancy_group);
+                                if (mddev->sysfs_action)
+                                        sysfs_put(mddev->sysfs_action);
+                                mddev->sysfs_action = NULL;
+                        }
                 }
-                mutex_unlock(&mddev->open_mutex);
+                mddev->sysfs_active = 0;
         } else
                 mutex_unlock(&mddev->reconfig_mutex);
 
@@ -1812,11 +1866,9 @@ static int bind_rdev_to_array(mdk_rdev_t * rdev, mddev_t * mddev)
                 goto fail;
 
         ko = &part_to_dev(rdev->bdev->bd_part)->kobj;
-        if ((err = sysfs_create_link(&rdev->kobj, ko, "block"))) {
-                kobject_del(&rdev->kobj);
-                goto fail;
-        }
-        rdev->sysfs_state = sysfs_get_dirent(rdev->kobj.sd, NULL, "state");
+        if (sysfs_create_link(&rdev->kobj, ko, "block"))
+                /* failure here is OK */;
+        rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
 
         list_add_rcu(&rdev->same_set, &mddev->disks);
         bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
@@ -2335,8 +2387,8 @@ state_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 set_bit(In_sync, &rdev->flags);
                 err = 0;
         }
-        if (!err && rdev->sysfs_state)
-                sysfs_notify_dirent(rdev->sysfs_state);
+        if (!err)
+                sysfs_notify_dirent_safe(rdev->sysfs_state);
         return err ? err : len;
 }
 static struct rdev_sysfs_entry rdev_state =
@@ -2431,14 +2483,10 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                         rdev->raid_disk = -1;
                         return err;
                 } else
-                        sysfs_notify_dirent(rdev->sysfs_state);
+                        sysfs_notify_dirent_safe(rdev->sysfs_state);
                 sprintf(nm, "rd%d", rdev->raid_disk);
                 if (sysfs_create_link(&rdev->mddev->kobj, &rdev->kobj, nm))
-                        printk(KERN_WARNING
-                               "md: cannot register "
-                               "%s for %s\n",
-                               nm, mdname(rdev->mddev));
-
+                        /* failure here is OK */;
                 /* don't wakeup anyone, leave that to userspace. */
         } else {
                 if (slot >= rdev->mddev->raid_disks)
@@ -2448,7 +2496,7 @@ slot_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 clear_bit(Faulty, &rdev->flags);
                 clear_bit(WriteMostly, &rdev->flags);
                 set_bit(In_sync, &rdev->flags);
-                sysfs_notify_dirent(rdev->sysfs_state);
+                sysfs_notify_dirent_safe(rdev->sysfs_state);
         }
         return len;
 }
@@ -2696,6 +2744,24 @@ static struct kobj_type rdev_ktype = {
         .default_attrs  = rdev_default_attrs,
 };
 
+void md_rdev_init(mdk_rdev_t *rdev)
+{
+        rdev->desc_nr = -1;
+        rdev->saved_raid_disk = -1;
+        rdev->raid_disk = -1;
+        rdev->flags = 0;
+        rdev->data_offset = 0;
+        rdev->sb_events = 0;
+        rdev->last_read_error.tv_sec  = 0;
+        rdev->last_read_error.tv_nsec = 0;
+        atomic_set(&rdev->nr_pending, 0);
+        atomic_set(&rdev->read_errors, 0);
+        atomic_set(&rdev->corrected_errors, 0);
+
+        INIT_LIST_HEAD(&rdev->same_set);
+        init_waitqueue_head(&rdev->blocked_wait);
+}
+EXPORT_SYMBOL_GPL(md_rdev_init);
 /*
  * Import a device. If 'super_format' >= 0, then sanity check the superblock
  *
@@ -2719,6 +2785,7 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
                 return ERR_PTR(-ENOMEM);
         }
 
+        md_rdev_init(rdev);
         if ((err = alloc_disk_sb(rdev)))
                 goto abort_free;
 
@@ -2728,18 +2795,6 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
 
         kobject_init(&rdev->kobj, &rdev_ktype);
 
-        rdev->desc_nr = -1;
-        rdev->saved_raid_disk = -1;
-        rdev->raid_disk = -1;
-        rdev->flags = 0;
-        rdev->data_offset = 0;
-        rdev->sb_events = 0;
-        rdev->last_read_error.tv_sec  = 0;
-        rdev->last_read_error.tv_nsec = 0;
-        atomic_set(&rdev->nr_pending, 0);
-        atomic_set(&rdev->read_errors, 0);
-        atomic_set(&rdev->corrected_errors, 0);
-
         size = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
         if (!size) {
                 printk(KERN_WARNING 
@@ -2768,9 +2823,6 @@ static mdk_rdev_t *md_import_device(dev_t newdev, int super_format, int super_mi
                 }
         }
 
-        INIT_LIST_HEAD(&rdev->same_set);
-        init_waitqueue_head(&rdev->blocked_wait);
-
         return rdev;
 
 abort_free:
@@ -2961,7 +3013,9 @@ level_store(mddev_t *mddev, const char *buf, size_t len)
          *  - new personality will access other array.
          */
 
-        if (mddev->sync_thread || mddev->reshape_position != MaxSector)
+        if (mddev->sync_thread ||
+            mddev->reshape_position != MaxSector ||
+            mddev->sysfs_active)
                 return -EBUSY;
 
         if (!mddev->pers->quiesce) {
@@ -3438,7 +3492,7 @@ array_state_store(mddev_t *mddev, const char *buf, size_t len)
         if (err)
                 return err;
         else {
-                sysfs_notify_dirent(mddev->sysfs_state);
+                sysfs_notify_dirent_safe(mddev->sysfs_state);
                 return len;
         }
 }
@@ -3736,7 +3790,7 @@ action_store(mddev_t *mddev, const char *page, size_t len)
         }
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
         md_wakeup_thread(mddev->thread);
-        sysfs_notify_dirent(mddev->sysfs_action);
+        sysfs_notify_dirent_safe(mddev->sysfs_action);
         return len;
 }
 
@@ -4282,13 +4336,14 @@ static int md_alloc(dev_t dev, char *name)
                        disk->disk_name);
                 error = 0;
         }
-        if (sysfs_create_group(&mddev->kobj, &md_bitmap_group))
+        if (mddev->kobj.sd &&
+            sysfs_create_group(&mddev->kobj, &md_bitmap_group))
                 printk(KERN_DEBUG "pointless warning\n");
  abort:
         mutex_unlock(&disks_mutex);
-        if (!error) {
+        if (!error && mddev->kobj.sd) {
                 kobject_uevent(&mddev->kobj, KOBJ_ADD);
-                mddev->sysfs_state = sysfs_get_dirent(mddev->kobj.sd, NULL, "array_state");
+                mddev->sysfs_state = sysfs_get_dirent_safe(mddev->kobj.sd, "array_state");
         }
         mddev_put(mddev);
         return error;
@@ -4326,14 +4381,14 @@ static void md_safemode_timeout(unsigned long data)
         if (!atomic_read(&mddev->writes_pending)) {
                 mddev->safemode = 1;
                 if (mddev->external)
-                        sysfs_notify_dirent(mddev->sysfs_state);
+                        sysfs_notify_dirent_safe(mddev->sysfs_state);
         }
         md_wakeup_thread(mddev->thread);
 }
 
 static int start_dirty_degraded;
 
-static int md_run(mddev_t *mddev)
+int md_run(mddev_t *mddev)
 {
         int err;
         mdk_rdev_t *rdev;
@@ -4345,13 +4400,9 @@ static int md_run(mddev_t *mddev)
 
         if (mddev->pers)
                 return -EBUSY;
-
-        /* These two calls synchronise us with the
-         * sysfs_remove_group calls in mddev_unlock,
-         * so they must have completed.
-         */
-        mutex_lock(&mddev->open_mutex);
-        mutex_unlock(&mddev->open_mutex);
+        /* Cannot run until previous stop completes properly */
+        if (mddev->sysfs_active)
+                return -EBUSY;
 
         /*
          * Analyze all RAID superblock(s)
@@ -4398,7 +4449,7 @@ static int md_run(mddev_t *mddev)
                                 return -EINVAL;
                         }
                 }
-                sysfs_notify_dirent(rdev->sysfs_state);
+                sysfs_notify_dirent_safe(rdev->sysfs_state);
         }
 
         spin_lock(&pers_lock);
@@ -4497,11 +4548,12 @@ static int md_run(mddev_t *mddev)
                 return err;
         }
         if (mddev->pers->sync_request) {
-                if (sysfs_create_group(&mddev->kobj, &md_redundancy_group))
+                if (mddev->kobj.sd &&
+                    sysfs_create_group(&mddev->kobj, &md_redundancy_group))
                         printk(KERN_WARNING
                                "md: cannot register extra attributes for %s\n",
                                mdname(mddev));
-                mddev->sysfs_action = sysfs_get_dirent(mddev->kobj.sd, NULL, "sync_action");
+                mddev->sysfs_action = sysfs_get_dirent_safe(mddev->kobj.sd, "sync_action");
         } else if (mddev->ro == 2) /* auto-readonly not meaningful */
                 mddev->ro = 0;
 
@@ -4519,8 +4571,7 @@ static int md_run(mddev_t *mddev)
                         char nm[20];
                         sprintf(nm, "rd%d", rdev->raid_disk);
                         if (sysfs_create_link(&mddev->kobj, &rdev->kobj, nm))
-                                printk("md: cannot register %s for %s\n",
-                                       nm, mdname(mddev));
+                                /* failure here is OK */;
                 }
         
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
@@ -4532,12 +4583,12 @@ static int md_run(mddev_t *mddev)
         md_wakeup_thread(mddev->sync_thread); /* possibly kick off a reshape */
 
         md_new_event(mddev);
-        sysfs_notify_dirent(mddev->sysfs_state);
-        if (mddev->sysfs_action)
-                sysfs_notify_dirent(mddev->sysfs_action);
+        sysfs_notify_dirent_safe(mddev->sysfs_state);
+        sysfs_notify_dirent_safe(mddev->sysfs_action);
         sysfs_notify(&mddev->kobj, NULL, "degraded");
         return 0;
 }
+EXPORT_SYMBOL_GPL(md_run);
 
 static int do_md_run(mddev_t *mddev)
 {
@@ -4546,7 +4597,11 @@ static int do_md_run(mddev_t *mddev)
         err = md_run(mddev);
         if (err)
                 goto out;
-
+        err = bitmap_load(mddev);
+        if (err) {
+                bitmap_destroy(mddev);
+                goto out;
+        }
         set_capacity(mddev->gendisk, mddev->array_sectors);
         revalidate_disk(mddev->gendisk);
         kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
@@ -4574,7 +4629,7 @@ static int restart_array(mddev_t *mddev)
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
         md_wakeup_thread(mddev->thread);
         md_wakeup_thread(mddev->sync_thread);
-        sysfs_notify_dirent(mddev->sysfs_state);
+        sysfs_notify_dirent_safe(mddev->sysfs_state);
         return 0;
 }
 
@@ -4645,9 +4700,10 @@ static void md_clean(mddev_t *mddev)
         mddev->bitmap_info.chunksize = 0;
         mddev->bitmap_info.daemon_sleep = 0;
         mddev->bitmap_info.max_write_behind = 0;
+        mddev->plug = NULL;
 }
 
-static void md_stop_writes(mddev_t *mddev)
+void md_stop_writes(mddev_t *mddev)
 {
         if (mddev->sync_thread) {
                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
@@ -4667,11 +4723,10 @@ static void md_stop_writes(mddev_t *mddev)
                 md_update_sb(mddev, 1);
         }
 }
+EXPORT_SYMBOL_GPL(md_stop_writes);
 
-static void md_stop(mddev_t *mddev)
+void md_stop(mddev_t *mddev)
 {
-        md_stop_writes(mddev);
-
         mddev->pers->stop(mddev);
         if (mddev->pers->sync_request && mddev->to_remove == NULL)
                 mddev->to_remove = &md_redundancy_group;
@@ -4679,6 +4734,7 @@ static void md_stop(mddev_t *mddev)
         mddev->pers = NULL;
         clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
 }
+EXPORT_SYMBOL_GPL(md_stop);
 
 static int md_set_readonly(mddev_t *mddev, int is_open)
 {
@@ -4698,7 +4754,7 @@ static int md_set_readonly(mddev_t *mddev, int is_open)
                 mddev->ro = 1;
                 set_disk_ro(mddev->gendisk, 1);
                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
-                sysfs_notify_dirent(mddev->sysfs_state);
+                sysfs_notify_dirent_safe(mddev->sysfs_state);
                 err = 0;        
         }
 out:
@@ -4712,26 +4768,29 @@ out:
  */
 static int do_md_stop(mddev_t * mddev, int mode, int is_open)
 {
-        int err = 0;
         struct gendisk *disk = mddev->gendisk;
         mdk_rdev_t *rdev;
 
         mutex_lock(&mddev->open_mutex);
-        if (atomic_read(&mddev->openers) > is_open) {
+        if (atomic_read(&mddev->openers) > is_open ||
+            mddev->sysfs_active) {
                 printk("md: %s still in use.\n",mdname(mddev));
-                err = -EBUSY;
-        } else if (mddev->pers) {
+                mutex_unlock(&mddev->open_mutex);
+                return -EBUSY;
+        }
 
+        if (mddev->pers) {
                 if (mddev->ro)
                         set_disk_ro(disk, 0);
 
+                md_stop_writes(mddev);
                 md_stop(mddev);
                 mddev->queue->merge_bvec_fn = NULL;
                 mddev->queue->unplug_fn = NULL;
                 mddev->queue->backing_dev_info.congested_fn = NULL;
 
                 /* tell userspace to handle 'inactive' */
-                sysfs_notify_dirent(mddev->sysfs_state);
+                sysfs_notify_dirent_safe(mddev->sysfs_state);
 
                 list_for_each_entry(rdev, &mddev->disks, same_set)
                         if (rdev->raid_disk >= 0) {
@@ -4741,21 +4800,17 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                         }
 
                 set_capacity(disk, 0);
+                mutex_unlock(&mddev->open_mutex);
                 revalidate_disk(disk);
 
                 if (mddev->ro)
                         mddev->ro = 0;
-                
-                err = 0;
-        }
-        mutex_unlock(&mddev->open_mutex);
-        if (err)
-                return err;
+        } else
+                mutex_unlock(&mddev->open_mutex);
         /*
          * Free resources if final stop
          */
         if (mode == 0) {
-
                 printk(KERN_INFO "md: %s stopped.\n", mdname(mddev));
 
                 bitmap_destroy(mddev);
@@ -4772,13 +4827,11 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                 kobject_uevent(&disk_to_dev(mddev->gendisk)->kobj, KOBJ_CHANGE);
                 if (mddev->hold_active == UNTIL_STOP)
                         mddev->hold_active = 0;
-
         }
-        err = 0;
         blk_integrity_unregister(disk);
         md_new_event(mddev);
-        sysfs_notify_dirent(mddev->sysfs_state);
-        return err;
+        sysfs_notify_dirent_safe(mddev->sysfs_state);
+        return 0;
 }
 
 #ifndef MODULE
@@ -5139,7 +5192,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
                 if (err)
                         export_rdev(rdev);
                 else
-                        sysfs_notify_dirent(rdev->sysfs_state);
+                        sysfs_notify_dirent_safe(rdev->sysfs_state);
 
                 md_update_sb(mddev, 1);
                 if (mddev->degraded)
@@ -5332,8 +5385,11 @@ static int set_bitmap_file(mddev_t *mddev, int fd)
         err = 0;
         if (mddev->pers) {
                 mddev->pers->quiesce(mddev, 1);
-                if (fd >= 0)
+                if (fd >= 0) {
                         err = bitmap_create(mddev);
+                        if (!err)
+                                err = bitmap_load(mddev);
+                }
                 if (fd < 0 || err) {
                         bitmap_destroy(mddev);
                         fd = -1; /* make sure to put the file */
@@ -5582,6 +5638,8 @@ static int update_array_info(mddev_t *mddev, mdu_array_info_t *info)
                                 mddev->bitmap_info.default_offset;
                         mddev->pers->quiesce(mddev, 1);
                         rv = bitmap_create(mddev);
+                        if (!rv)
+                                rv = bitmap_load(mddev);
                         if (rv)
                                 bitmap_destroy(mddev);
                         mddev->pers->quiesce(mddev, 0);
@@ -5814,7 +5872,7 @@ static int md_ioctl(struct block_device *bdev, fmode_t mode,
         if (_IOC_TYPE(cmd) == MD_MAJOR && mddev->ro && mddev->pers) {
                 if (mddev->ro == 2) {
                         mddev->ro = 0;
-                        sysfs_notify_dirent(mddev->sysfs_state);
+                        sysfs_notify_dirent_safe(mddev->sysfs_state);
                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
                         md_wakeup_thread(mddev->thread);
                 } else {
@@ -6065,10 +6123,12 @@ void md_error(mddev_t *mddev, mdk_rdev_t *rdev)
         mddev->pers->error_handler(mddev,rdev);
         if (mddev->degraded)
                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
-        sysfs_notify_dirent(rdev->sysfs_state);
+        sysfs_notify_dirent_safe(rdev->sysfs_state);
         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
         md_wakeup_thread(mddev->thread);
+        if (mddev->event_work.func)
+                schedule_work(&mddev->event_work);
         md_new_event_inintr(mddev);
 }
 
@@ -6526,7 +6586,7 @@ void md_write_start(mddev_t *mddev, struct bio *bi)
                 spin_unlock_irq(&mddev->write_lock);
         }
         if (did_change)
-                sysfs_notify_dirent(mddev->sysfs_state);
+                sysfs_notify_dirent_safe(mddev->sysfs_state);
         wait_event(mddev->sb_wait,
                    !test_bit(MD_CHANGE_CLEAN, &mddev->flags) &&
                    !test_bit(MD_CHANGE_PENDING, &mddev->flags));
@@ -6569,7 +6629,7 @@ int md_allow_write(mddev_t *mddev)
                         mddev->safemode = 1;
                 spin_unlock_irq(&mddev->write_lock);
                 md_update_sb(mddev, 0);
-                sysfs_notify_dirent(mddev->sysfs_state);
+                sysfs_notify_dirent_safe(mddev->sysfs_state);
         } else
                 spin_unlock_irq(&mddev->write_lock);
 
@@ -6580,6 +6640,14 @@ int md_allow_write(mddev_t *mddev)
 }
 EXPORT_SYMBOL_GPL(md_allow_write);
 
+void md_unplug(mddev_t *mddev)
+{
+        if (mddev->queue)
+                blk_unplug(mddev->queue);
+        if (mddev->plug)
+                mddev->plug->unplug_fn(mddev->plug);
+}
+
 #define SYNC_MARKS      10
 #define SYNC_MARK_STEP  (3*HZ)
 void md_do_sync(mddev_t *mddev)
@@ -6758,12 +6826,13 @@ void md_do_sync(mddev_t *mddev)
                      >= mddev->resync_max - mddev->curr_resync_completed
                             )) {
                         /* time to update curr_resync_completed */
-                        blk_unplug(mddev->queue);
+                        md_unplug(mddev);
                         wait_event(mddev->recovery_wait,
                                    atomic_read(&mddev->recovery_active) == 0);
                         mddev->curr_resync_completed =
                                 mddev->curr_resync;
-                        set_bit(MD_CHANGE_CLEAN, &mddev->flags);
+                        if (mddev->persistent)
+                                set_bit(MD_CHANGE_CLEAN, &mddev->flags);
                         sysfs_notify(&mddev->kobj, NULL, "sync_completed");
                 }
 
@@ -6835,7 +6904,7 @@ void md_do_sync(mddev_t *mddev)
                  * about not overloading the IO subsystem. (things like an
                  * e2fsck being done on the RAID array should execute fast)
                  */
-                blk_unplug(mddev->queue);
+                md_unplug(mddev);
                 cond_resched();
 
                 currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
@@ -6854,7 +6923,7 @@ void md_do_sync(mddev_t *mddev)
          * this also signals 'finished resyncing' to md_stop
          */
  out:
-        blk_unplug(mddev->queue);
+        md_unplug(mddev);
 
         wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
 
@@ -6956,10 +7025,7 @@ static int remove_and_add_spares(mddev_t *mddev)
                                         sprintf(nm, "rd%d", rdev->raid_disk);
                                         if (sysfs_create_link(&mddev->kobj,
                                                               &rdev->kobj, nm))
-                                                printk(KERN_WARNING
-                                                       "md: cannot register "
-                                                       "%s for %s\n",
-                                                       nm, mdname(mddev));
+                                                /* failure here is OK */;
                                         spares++;
                                         md_new_event(mddev);
                                         set_bit(MD_CHANGE_DEVS, &mddev->flags);
@@ -7052,7 +7118,7 @@ void md_check_recovery(mddev_t *mddev)
                                 mddev->safemode = 0;
                         spin_unlock_irq(&mddev->write_lock);
                         if (did_change)
-                                sysfs_notify_dirent(mddev->sysfs_state);
+                                sysfs_notify_dirent_safe(mddev->sysfs_state);
                 }
 
                 if (mddev->flags)
@@ -7091,7 +7157,7 @@ void md_check_recovery(mddev_t *mddev)
                         mddev->recovery = 0;
                         /* flag recovery needed just to double check */
                         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
-                        sysfs_notify_dirent(mddev->sysfs_action);
+                        sysfs_notify_dirent_safe(mddev->sysfs_action);
                         md_new_event(mddev);
                         goto unlock;
                 }
@@ -7153,7 +7219,7 @@ void md_check_recovery(mddev_t *mddev)
                                 mddev->recovery = 0;
                         } else
                                 md_wakeup_thread(mddev->sync_thread);
-                        sysfs_notify_dirent(mddev->sysfs_action);
+                        sysfs_notify_dirent_safe(mddev->sysfs_action);
                         md_new_event(mddev);
                 }
         unlock:
@@ -7162,7 +7228,7 @@ void md_check_recovery(mddev_t *mddev)
                         if (test_and_clear_bit(MD_RECOVERY_RECOVER,
                                                &mddev->recovery))
                                 if (mddev->sysfs_action)
-                                        sysfs_notify_dirent(mddev->sysfs_action);
+                                        sysfs_notify_dirent_safe(mddev->sysfs_action);
                 }
                 mddev_unlock(mddev);
         }
@@ -7170,7 +7236,7 @@ void md_check_recovery(mddev_t *mddev)
 
 void md_wait_for_blocked_rdev(mdk_rdev_t *rdev, mddev_t *mddev)
 {
-        sysfs_notify_dirent(rdev->sysfs_state);
+        sysfs_notify_dirent_safe(rdev->sysfs_state);
         wait_event_timeout(rdev->blocked_wait,
                            !test_bit(Blocked, &rdev->flags),
                            msecs_to_jiffies(5000));