block: remove per-queue plugging

Code has been converted over to the new explicit on-stack plugging,
and delay users have been converted to use the new API for that.
So lets kill off the old plugging along with aops->sync_page().

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

15 files changed, 58 insertions, 372 deletions

diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 9a35320fb59f..54bfc274b39a 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1339,8 +1339,7 @@ int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, unsigned long sect
                         prepare_to_wait(&bitmap->overflow_wait, &__wait,
                                         TASK_UNINTERRUPTIBLE);
                         spin_unlock_irq(&bitmap->lock);
-                        md_unplug(bitmap->mddev);
-                        schedule();
+                        io_schedule();
                         finish_wait(&bitmap->overflow_wait, &__wait);
                         continue;
                 }
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 4e054bd91664..2c62c1169f78 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -991,11 +991,6 @@ static void clone_init(struct dm_crypt_io *io, struct bio *clone)
         clone->bi_destructor = dm_crypt_bio_destructor;
 }
 
-static void kcryptd_unplug(struct crypt_config *cc)
-{
-        blk_unplug(bdev_get_queue(cc->dev->bdev));
-}
-
 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
 {
         struct crypt_config *cc = io->target->private;
@@ -1008,10 +1003,8 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
          * one in order to decrypt the whole bio data *afterwards*.
          */
         clone = bio_alloc_bioset(gfp, bio_segments(base_bio), cc->bs);
-        if (!clone) {
-                kcryptd_unplug(cc);
+        if (!clone)
                 return 1;
-        }
 
         crypt_inc_pending(io);
 
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index 924f5f0084c2..400cf35094a4 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -37,13 +37,6 @@ struct dm_kcopyd_client {
         unsigned int nr_pages;
         unsigned int nr_free_pages;
 
-        /*
-         * Block devices to unplug.
-         * Non-NULL pointer means that a block device has some pending requests
-         * and needs to be unplugged.
-         */
-        struct block_device *unplug[2];
-
         struct dm_io_client *io_client;
 
         wait_queue_head_t destroyq;
@@ -315,31 +308,6 @@ static int run_complete_job(struct kcopyd_job *job)
         return 0;
 }
 
-/*
- * Unplug the block device at the specified index.
- */
-static void unplug(struct dm_kcopyd_client *kc, int rw)
-{
-        if (kc->unplug[rw] != NULL) {
-                blk_unplug(bdev_get_queue(kc->unplug[rw]));
-                kc->unplug[rw] = NULL;
-        }
-}
-
-/*
- * Prepare block device unplug. If there's another device
- * to be unplugged at the same array index, we unplug that
- * device first.
- */
-static void prepare_unplug(struct dm_kcopyd_client *kc, int rw,
-                           struct block_device *bdev)
-{
-        if (likely(kc->unplug[rw] == bdev))
-                return;
-        unplug(kc, rw);
-        kc->unplug[rw] = bdev;
-}
-
 static void complete_io(unsigned long error, void *context)
 {
         struct kcopyd_job *job = (struct kcopyd_job *) context;
@@ -386,15 +354,12 @@ static int run_io_job(struct kcopyd_job *job)
                 .client = job->kc->io_client,
         };
 
-        if (job->rw == READ) {
+        if (job->rw == READ)
                 r = dm_io(&io_req, 1, &job->source, NULL);
-                prepare_unplug(job->kc, READ, job->source.bdev);
-        } else {
+        else {
                 if (job->num_dests > 1)
                         io_req.bi_rw |= REQ_UNPLUG;
                 r = dm_io(&io_req, job->num_dests, job->dests, NULL);
-                if (!(io_req.bi_rw & REQ_UNPLUG))
-                        prepare_unplug(job->kc, WRITE, job->dests[0].bdev);
         }
 
         return r;
@@ -466,6 +431,7 @@ static void do_work(struct work_struct *work)
 {
         struct dm_kcopyd_client *kc = container_of(work,
                                         struct dm_kcopyd_client, kcopyd_work);
+        struct blk_plug plug;
 
         /*
          * The order that these are called is *very* important.
@@ -473,18 +439,12 @@ static void do_work(struct work_struct *work)
          * Pages jobs when successful will jump onto the io jobs
          * list.  io jobs call wake when they complete and it all
          * starts again.
-         *
-         * Note that io_jobs add block devices to the unplug array,
-         * this array is cleared with "unplug" calls. It is thus
-         * forbidden to run complete_jobs after io_jobs and before
-         * unplug because the block device could be destroyed in
-         * job completion callback.
          */
+        blk_start_plug(&plug);
         process_jobs(&kc->complete_jobs, kc, run_complete_job);
         process_jobs(&kc->pages_jobs, kc, run_pages_job);
         process_jobs(&kc->io_jobs, kc, run_io_job);
-        unplug(kc, READ);
-        unplug(kc, WRITE);
+        blk_finish_plug(&plug);
 }
 
 /*
@@ -665,8 +625,6 @@ int dm_kcopyd_client_create(unsigned int nr_pages,
         INIT_LIST_HEAD(&kc->io_jobs);
         INIT_LIST_HEAD(&kc->pages_jobs);
 
-        memset(kc->unplug, 0, sizeof(kc->unplug));
-
         kc->job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache);
         if (!kc->job_pool)
                 goto bad_slab;
diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c
index b9e1e15ef11c..5ef136cdba91 100644
--- a/drivers/md/dm-raid.c
+++ b/drivers/md/dm-raid.c
@@ -394,7 +394,7 @@ static void raid_unplug(struct dm_target_callbacks *cb)
 {
         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 
-        md_raid5_unplug_device(rs->md.private);
+        md_raid5_kick_device(rs->md.private);
 }
 
 /*
diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index dee326775c60..976ad4688afc 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -842,8 +842,6 @@ static void do_mirror(struct work_struct *work)
         do_reads(ms, &reads);
         do_writes(ms, &writes);
         do_failures(ms, &failures);
-
-        dm_table_unplug_all(ms->ti->table);
 }
 
 /*-----------------------------------------------------------------
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 38e4eb1bb965..f50a7b952257 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1275,29 +1275,6 @@ int dm_table_any_busy_target(struct dm_table *t)
         return 0;
 }
 
-void dm_table_unplug_all(struct dm_table *t)
-{
-        struct dm_dev_internal *dd;
-        struct list_head *devices = dm_table_get_devices(t);
-        struct dm_target_callbacks *cb;
-
-        list_for_each_entry(dd, devices, list) {
-                struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
-                char b[BDEVNAME_SIZE];
-
-                if (likely(q))
-                        blk_unplug(q);
-                else
-                        DMWARN_LIMIT("%s: Cannot unplug nonexistent device %s",
-                                     dm_device_name(t->md),
-                                     bdevname(dd->dm_dev.bdev, b));
-        }
-
-        list_for_each_entry(cb, &t->target_callbacks, list)
-                if (cb->unplug_fn)
-                        cb->unplug_fn(cb);
-}
-
 struct mapped_device *dm_table_get_md(struct dm_table *t)
 {
         return t->md;
@@ -1345,4 +1322,3 @@ EXPORT_SYMBOL(dm_table_get_mode);
 EXPORT_SYMBOL(dm_table_get_md);
 EXPORT_SYMBOL(dm_table_put);
 EXPORT_SYMBOL(dm_table_get);
-EXPORT_SYMBOL(dm_table_unplug_all);
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index eaa3af0e0632..d22b9905c168 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -807,8 +807,6 @@ void dm_requeue_unmapped_request(struct request *clone)
         dm_unprep_request(rq);
 
         spin_lock_irqsave(q->queue_lock, flags);
-        if (elv_queue_empty(q))
-                blk_plug_device(q);
         blk_requeue_request(q, rq);
         spin_unlock_irqrestore(q->queue_lock, flags);
 
@@ -1613,10 +1611,10 @@ static void dm_request_fn(struct request_queue *q)
          * number of in-flight I/Os after the queue is stopped in
          * dm_suspend().
          */
-        while (!blk_queue_plugged(q) && !blk_queue_stopped(q)) {
+        while (!blk_queue_stopped(q)) {
                 rq = blk_peek_request(q);
                 if (!rq)
-                        goto plug_and_out;
+                        goto delay_and_out;
 
                 /* always use block 0 to find the target for flushes for now */
                 pos = 0;
@@ -1627,7 +1625,7 @@ static void dm_request_fn(struct request_queue *q)
                 BUG_ON(!dm_target_is_valid(ti));
 
                 if (ti->type->busy && ti->type->busy(ti))
-                        goto plug_and_out;
+                        goto delay_and_out;
 
                 blk_start_request(rq);
                 clone = rq->special;
@@ -1647,11 +1645,8 @@ requeued:
         BUG_ON(!irqs_disabled());
         spin_lock(q->queue_lock);
 
-plug_and_out:
-        if (!elv_queue_empty(q))
-                /* Some requests still remain, retry later */
-                blk_plug_device(q);
-
+delay_and_out:
+        blk_delay_queue(q, HZ / 10);
 out:
         dm_table_put(map);
 
@@ -1680,20 +1675,6 @@ static int dm_lld_busy(struct request_queue *q)
         return r;
 }
 
-static void dm_unplug_all(struct request_queue *q)
-{
-        struct mapped_device *md = q->queuedata;
-        struct dm_table *map = dm_get_live_table(md);
-
-        if (map) {
-                if (dm_request_based(md))
-                        generic_unplug_device(q);
-
-                dm_table_unplug_all(map);
-                dm_table_put(map);
-        }
-}
-
 static int dm_any_congested(void *congested_data, int bdi_bits)
 {
         int r = bdi_bits;
@@ -1817,7 +1798,6 @@ static void dm_init_md_queue(struct mapped_device *md)
         md->queue->backing_dev_info.congested_data = md;
         blk_queue_make_request(md->queue, dm_request);
         blk_queue_bounce_limit(md->queue, BLK_BOUNCE_ANY);
-        md->queue->unplug_fn = dm_unplug_all;
         blk_queue_merge_bvec(md->queue, dm_merge_bvec);
         blk_queue_flush(md->queue, REQ_FLUSH | REQ_FUA);
 }
@@ -2263,8 +2243,6 @@ static int dm_wait_for_completion(struct mapped_device *md, int interruptible)
         int r = 0;
         DECLARE_WAITQUEUE(wait, current);
 
-        dm_unplug_all(md->queue);
-
         add_wait_queue(&md->wait, &wait);
 
         while (1) {
@@ -2539,7 +2517,6 @@ int dm_resume(struct mapped_device *md)
 
         clear_bit(DMF_SUSPENDED, &md->flags);
 
-        dm_table_unplug_all(map);
         r = 0;
 out:
         dm_table_put(map);
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index 8a2f767f26d8..38861b5b9d90 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -87,22 +87,6 @@ static int linear_mergeable_bvec(struct request_queue *q,
         return maxsectors << 9;
 }
 
-static void linear_unplug(struct request_queue *q)
-{
-        mddev_t *mddev = q->queuedata;
-        linear_conf_t *conf;
-        int i;
-
-        rcu_read_lock();
-        conf = rcu_dereference(mddev->private);
-
-        for (i=0; i < mddev->raid_disks; i++) {
-                struct request_queue *r_queue = bdev_get_queue(conf->disks[i].rdev->bdev);
-                blk_unplug(r_queue);
-        }
-        rcu_read_unlock();
-}
-
 static int linear_congested(void *data, int bits)
 {
         mddev_t *mddev = data;
@@ -225,7 +209,6 @@ static int linear_run (mddev_t *mddev)
         md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
 
         blk_queue_merge_bvec(mddev->queue, linear_mergeable_bvec);
-        mddev->queue->unplug_fn = linear_unplug;
         mddev->queue->backing_dev_info.congested_fn = linear_congested;
         mddev->queue->backing_dev_info.congested_data = mddev;
         md_integrity_register(mddev);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 0cc30ecda4c1..ca0d79c264b9 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4812,7 +4812,6 @@ static int do_md_stop(mddev_t * mddev, int mode, int is_open)
                 __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' */
@@ -6669,8 +6668,6 @@ 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);
 }
@@ -6853,7 +6850,6 @@ void md_do_sync(mddev_t *mddev)
                      >= mddev->resync_max - mddev->curr_resync_completed
                             )) {
                         /* time to update curr_resync_completed */
-                        md_unplug(mddev);
                         wait_event(mddev->recovery_wait,
                                    atomic_read(&mddev->recovery_active) == 0);
                         mddev->curr_resync_completed = j;
@@ -6929,7 +6925,6 @@ 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)
                  */
-                md_unplug(mddev);
                 cond_resched();
 
                 currspeed = ((unsigned long)(io_sectors-mddev->resync_mark_cnt))/2
@@ -6948,8 +6943,6 @@ void md_do_sync(mddev_t *mddev)
          * this also signals 'finished resyncing' to md_stop
          */
  out:
-        md_unplug(mddev);
-
         wait_event(mddev->recovery_wait, !atomic_read(&mddev->recovery_active));
 
         /* tell personality that we are finished */
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index 6d7ddf32ef2e..1cc8ed44e4ad 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -106,36 +106,6 @@ static void multipath_end_request(struct bio *bio, int error)
         rdev_dec_pending(rdev, conf->mddev);
 }
 
-static void unplug_slaves(mddev_t *mddev)
-{
-        multipath_conf_t *conf = mddev->private;
-        int i;
-
-        rcu_read_lock();
-        for (i=0; i<mddev->raid_disks; i++) {
-                mdk_rdev_t *rdev = rcu_dereference(conf->multipaths[i].rdev);
-                if (rdev && !test_bit(Faulty, &rdev->flags)
-                    && atomic_read(&rdev->nr_pending)) {
-                        struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
-
-                        atomic_inc(&rdev->nr_pending);
-                        rcu_read_unlock();
-
-                        blk_unplug(r_queue);
-
-                        rdev_dec_pending(rdev, mddev);
-                        rcu_read_lock();
-                }
-        }
-        rcu_read_unlock();
-}
-
-static void multipath_unplug(struct request_queue *q)
-{
-        unplug_slaves(q->queuedata);
-}
-
-
 static int multipath_make_request(mddev_t *mddev, struct bio * bio)
 {
         multipath_conf_t *conf = mddev->private;
@@ -518,7 +488,6 @@ static int multipath_run (mddev_t *mddev)
          */
         md_set_array_sectors(mddev, multipath_size(mddev, 0, 0));
 
-        mddev->queue->unplug_fn = multipath_unplug;
         mddev->queue->backing_dev_info.congested_fn = multipath_congested;
         mddev->queue->backing_dev_info.congested_data = mddev;
         md_integrity_register(mddev);
diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 637a96855edb..6338c0fe6208 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -25,21 +25,6 @@
 #include "raid0.h"
 #include "raid5.h"
 
-static void raid0_unplug(struct request_queue *q)
-{
-        mddev_t *mddev = q->queuedata;
-        raid0_conf_t *conf = mddev->private;
-        mdk_rdev_t **devlist = conf->devlist;
-        int raid_disks = conf->strip_zone[0].nb_dev;
-        int i;
-
-        for (i=0; i < raid_disks; i++) {
-                struct request_queue *r_queue = bdev_get_queue(devlist[i]->bdev);
-
-                blk_unplug(r_queue);
-        }
-}
-
 static int raid0_congested(void *data, int bits)
 {
         mddev_t *mddev = data;
@@ -272,7 +257,6 @@ static int create_strip_zones(mddev_t *mddev, raid0_conf_t **private_conf)
                        mdname(mddev),
                        (unsigned long long)smallest->sectors);
         }
-        mddev->queue->unplug_fn = raid0_unplug;
         mddev->queue->backing_dev_info.congested_fn = raid0_congested;
         mddev->queue->backing_dev_info.congested_data = mddev;
 
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index a23ffa397ba9..b67d822d57ae 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -52,23 +52,16 @@
 #define NR_RAID1_BIOS 256
 
 
-static void unplug_slaves(mddev_t *mddev);
-
 static void allow_barrier(conf_t *conf);
 static void lower_barrier(conf_t *conf);
 
 static void * r1bio_pool_alloc(gfp_t gfp_flags, void *data)
 {
         struct pool_info *pi = data;
-        r1bio_t *r1_bio;
         int size = offsetof(r1bio_t, bios[pi->raid_disks]);
 
         /* allocate a r1bio with room for raid_disks entries in the bios array */
-        r1_bio = kzalloc(size, gfp_flags);
-        if (!r1_bio && pi->mddev)
-                unplug_slaves(pi->mddev);
-
-        return r1_bio;
+        return kzalloc(size, gfp_flags);
 }
 
 static void r1bio_pool_free(void *r1_bio, void *data)
@@ -91,10 +84,8 @@ static void * r1buf_pool_alloc(gfp_t gfp_flags, void *data)
         int i, j;
 
         r1_bio = r1bio_pool_alloc(gfp_flags, pi);
-        if (!r1_bio) {
-                unplug_slaves(pi->mddev);
+        if (!r1_bio)
                 return NULL;
-        }
 
         /*
          * Allocate bios : 1 for reading, n-1 for writing
@@ -520,37 +511,6 @@ static int read_balance(conf_t *conf, r1bio_t *r1_bio)
         return new_disk;
 }
 
-static void unplug_slaves(mddev_t *mddev)
-{
-        conf_t *conf = mddev->private;
-        int i;
-
-        rcu_read_lock();
-        for (i=0; i<mddev->raid_disks; i++) {
-                mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
-                if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
-                        struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
-
-                        atomic_inc(&rdev->nr_pending);
-                        rcu_read_unlock();
-
-                        blk_unplug(r_queue);
-
-                        rdev_dec_pending(rdev, mddev);
-                        rcu_read_lock();
-                }
-        }
-        rcu_read_unlock();
-}
-
-static void raid1_unplug(struct request_queue *q)
-{
-        mddev_t *mddev = q->queuedata;
-
-        unplug_slaves(mddev);
-        md_wakeup_thread(mddev->thread);
-}
-
 static int raid1_congested(void *data, int bits)
 {
         mddev_t *mddev = data;
@@ -580,20 +540,16 @@ static int raid1_congested(void *data, int bits)
 }
 
 
-static int flush_pending_writes(conf_t *conf)
+static void flush_pending_writes(conf_t *conf)
 {
         /* Any writes that have been queued but are awaiting
          * bitmap updates get flushed here.
-         * We return 1 if any requests were actually submitted.
          */
-        int rv = 0;
-
         spin_lock_irq(&conf->device_lock);
 
         if (conf->pending_bio_list.head) {
                 struct bio *bio;
                 bio = bio_list_get(&conf->pending_bio_list);
-                blk_remove_plug(conf->mddev->queue);
                 spin_unlock_irq(&conf->device_lock);
                 /* flush any pending bitmap writes to
                  * disk before proceeding w/ I/O */
@@ -605,10 +561,14 @@ static int flush_pending_writes(conf_t *conf)
                         generic_make_request(bio);
                         bio = next;
                 }
-                rv = 1;
         } else
                 spin_unlock_irq(&conf->device_lock);
-        return rv;
+}
+
+static void md_kick_device(mddev_t *mddev)
+{
+        blk_flush_plug(current);
+        md_wakeup_thread(mddev->thread);
 }
 
 /* Barriers....
@@ -640,8 +600,7 @@ static void raise_barrier(conf_t *conf)
 
         /* Wait until no block IO is waiting */
         wait_event_lock_irq(conf->wait_barrier, !conf->nr_waiting,
-                            conf->resync_lock,
-                            raid1_unplug(conf->mddev->queue));
+                            conf->resync_lock, md_kick_device(conf->mddev));
 
         /* block any new IO from starting */
         conf->barrier++;
@@ -649,8 +608,7 @@ static void raise_barrier(conf_t *conf)
         /* Now wait for all pending IO to complete */
         wait_event_lock_irq(conf->wait_barrier,
                             !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
-                            conf->resync_lock,
-                            raid1_unplug(conf->mddev->queue));
+                            conf->resync_lock, md_kick_device(conf->mddev));
 
         spin_unlock_irq(&conf->resync_lock);
 }
@@ -672,7 +630,7 @@ static void wait_barrier(conf_t *conf)
                 conf->nr_waiting++;
                 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
                                     conf->resync_lock,
-                                    raid1_unplug(conf->mddev->queue));
+                                    md_kick_device(conf->mddev));
                 conf->nr_waiting--;
         }
         conf->nr_pending++;
@@ -709,7 +667,7 @@ static void freeze_array(conf_t *conf)
                             conf->nr_pending == conf->nr_queued+1,
                             conf->resync_lock,
                             ({ flush_pending_writes(conf);
-                               raid1_unplug(conf->mddev->queue); }));
+                               md_kick_device(conf->mddev); }));
         spin_unlock_irq(&conf->resync_lock);
 }
 static void unfreeze_array(conf_t *conf)
@@ -959,7 +917,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
                 atomic_inc(&r1_bio->remaining);
                 spin_lock_irqsave(&conf->device_lock, flags);
                 bio_list_add(&conf->pending_bio_list, mbio);
-                blk_plug_device(mddev->queue);
                 spin_unlock_irqrestore(&conf->device_lock, flags);
         }
         r1_bio_write_done(r1_bio, bio->bi_vcnt, behind_pages, behind_pages != NULL);
@@ -968,7 +925,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
         /* In case raid1d snuck in to freeze_array */
         wake_up(&conf->wait_barrier);
 
-        if (do_sync)
+        if (do_sync || !bitmap)
                 md_wakeup_thread(mddev->thread);
 
         return 0;
@@ -1558,7 +1515,6 @@ static void raid1d(mddev_t *mddev)
         unsigned long flags;
         conf_t *conf = mddev->private;
         struct list_head *head = &conf->retry_list;
-        int unplug=0;
         mdk_rdev_t *rdev;
 
         md_check_recovery(mddev);
@@ -1566,7 +1522,7 @@ static void raid1d(mddev_t *mddev)
         for (;;) {
                 char b[BDEVNAME_SIZE];
 
-                unplug += flush_pending_writes(conf);
+                flush_pending_writes(conf);
 
                 spin_lock_irqsave(&conf->device_lock, flags);
                 if (list_empty(head)) {
@@ -1580,10 +1536,9 @@ static void raid1d(mddev_t *mddev)
 
                 mddev = r1_bio->mddev;
                 conf = mddev->private;
-                if (test_bit(R1BIO_IsSync, &r1_bio->state)) {
+                if (test_bit(R1BIO_IsSync, &r1_bio->state))
                         sync_request_write(mddev, r1_bio);
-                        unplug = 1;
-                } else {
+                else {
                         int disk;
 
                         /* we got a read error. Maybe the drive is bad.  Maybe just
@@ -1633,14 +1588,11 @@ static void raid1d(mddev_t *mddev)
                                 bio->bi_end_io = raid1_end_read_request;
                                 bio->bi_rw = READ | do_sync;
                                 bio->bi_private = r1_bio;
-                                unplug = 1;
                                 generic_make_request(bio);
                         }
                 }
                 cond_resched();
         }
-        if (unplug)
-                unplug_slaves(mddev);
 }
 
 
@@ -2064,7 +2016,6 @@ static int run(mddev_t *mddev)
 
         md_set_array_sectors(mddev, raid1_size(mddev, 0, 0));
 
-        mddev->queue->unplug_fn = raid1_unplug;
         mddev->queue->backing_dev_info.congested_fn = raid1_congested;
         mddev->queue->backing_dev_info.congested_data = mddev;
         md_integrity_register(mddev);
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3b607b28741b..e79f1c5bf71b 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -57,23 +57,16 @@
  */
 #define NR_RAID10_BIOS 256
 
-static void unplug_slaves(mddev_t *mddev);
-
 static void allow_barrier(conf_t *conf);
 static void lower_barrier(conf_t *conf);
 
 static void * r10bio_pool_alloc(gfp_t gfp_flags, void *data)
 {
         conf_t *conf = data;
-        r10bio_t *r10_bio;
         int size = offsetof(struct r10bio_s, devs[conf->copies]);
 
         /* allocate a r10bio with room for raid_disks entries in the bios array */
-        r10_bio = kzalloc(size, gfp_flags);
-        if (!r10_bio && conf->mddev)
-                unplug_slaves(conf->mddev);
-
-        return r10_bio;
+        return kzalloc(size, gfp_flags);
 }
 
 static void r10bio_pool_free(void *r10_bio, void *data)
@@ -106,10 +99,8 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data)
         int nalloc;
 
         r10_bio = r10bio_pool_alloc(gfp_flags, conf);
-        if (!r10_bio) {
-                unplug_slaves(conf->mddev);
+        if (!r10_bio)
                 return NULL;
-        }
 
         if (test_bit(MD_RECOVERY_SYNC, &conf->mddev->recovery))
                 nalloc = conf->copies; /* resync */
@@ -597,37 +588,6 @@ rb_out:
         return disk;
 }
 
-static void unplug_slaves(mddev_t *mddev)
-{
-        conf_t *conf = mddev->private;
-        int i;
-
-        rcu_read_lock();
-        for (i=0; i < conf->raid_disks; i++) {
-                mdk_rdev_t *rdev = rcu_dereference(conf->mirrors[i].rdev);
-                if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
-                        struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
-
-                        atomic_inc(&rdev->nr_pending);
-                        rcu_read_unlock();
-
-                        blk_unplug(r_queue);
-
-                        rdev_dec_pending(rdev, mddev);
-                        rcu_read_lock();
-                }
-        }
-        rcu_read_unlock();
-}
-
-static void raid10_unplug(struct request_queue *q)
-{
-        mddev_t *mddev = q->queuedata;
-
-        unplug_slaves(q->queuedata);
-        md_wakeup_thread(mddev->thread);
-}
-
 static int raid10_congested(void *data, int bits)
 {
         mddev_t *mddev = data;
@@ -649,20 +609,16 @@ static int raid10_congested(void *data, int bits)
         return ret;
 }
 
-static int flush_pending_writes(conf_t *conf)
+static void flush_pending_writes(conf_t *conf)
 {
         /* Any writes that have been queued but are awaiting
          * bitmap updates get flushed here.
-         * We return 1 if any requests were actually submitted.
          */
-        int rv = 0;
-
         spin_lock_irq(&conf->device_lock);
 
         if (conf->pending_bio_list.head) {
                 struct bio *bio;
                 bio = bio_list_get(&conf->pending_bio_list);
-                blk_remove_plug(conf->mddev->queue);
                 spin_unlock_irq(&conf->device_lock);
                 /* flush any pending bitmap writes to disk
                  * before proceeding w/ I/O */
@@ -674,11 +630,16 @@ static int flush_pending_writes(conf_t *conf)
                         generic_make_request(bio);
                         bio = next;
                 }
-                rv = 1;
         } else
                 spin_unlock_irq(&conf->device_lock);
-        return rv;
 }
+
+static void md_kick_device(mddev_t *mddev)
+{
+        blk_flush_plug(current);
+        md_wakeup_thread(mddev->thread);
+}
+
 /* Barriers....
  * Sometimes we need to suspend IO while we do something else,
  * either some resync/recovery, or reconfigure the array.
@@ -708,8 +669,7 @@ static void raise_barrier(conf_t *conf, int force)
 
         /* Wait until no block IO is waiting (unless 'force') */
         wait_event_lock_irq(conf->wait_barrier, force || !conf->nr_waiting,
-                            conf->resync_lock,
-                            raid10_unplug(conf->mddev->queue));
+                            conf->resync_lock, md_kick_device(conf->mddev));
 
         /* block any new IO from starting */
         conf->barrier++;
@@ -717,8 +677,7 @@ static void raise_barrier(conf_t *conf, int force)
         /* No wait for all pending IO to complete */
         wait_event_lock_irq(conf->wait_barrier,
                             !conf->nr_pending && conf->barrier < RESYNC_DEPTH,
-                            conf->resync_lock,
-                            raid10_unplug(conf->mddev->queue));
+                            conf->resync_lock, md_kick_device(conf->mddev));
 
         spin_unlock_irq(&conf->resync_lock);
 }
@@ -739,7 +698,7 @@ static void wait_barrier(conf_t *conf)
                 conf->nr_waiting++;
                 wait_event_lock_irq(conf->wait_barrier, !conf->barrier,
                                     conf->resync_lock,
-                                    raid10_unplug(conf->mddev->queue));
+                                    md_kick_device(conf->mddev));
                 conf->nr_waiting--;
         }
         conf->nr_pending++;
@@ -776,7 +735,7 @@ static void freeze_array(conf_t *conf)
                             conf->nr_pending == conf->nr_queued+1,
                             conf->resync_lock,
                             ({ flush_pending_writes(conf);
-                               raid10_unplug(conf->mddev->queue); }));
+                               md_kick_device(conf->mddev); }));
         spin_unlock_irq(&conf->resync_lock);
 }
 
@@ -971,7 +930,6 @@ static int make_request(mddev_t *mddev, struct bio * bio)
                 atomic_inc(&r10_bio->remaining);
                 spin_lock_irqsave(&conf->device_lock, flags);
                 bio_list_add(&conf->pending_bio_list, mbio);
-                blk_plug_device(mddev->queue);
                 spin_unlock_irqrestore(&conf->device_lock, flags);
         }
 
@@ -988,7 +946,7 @@ static int make_request(mddev_t *mddev, struct bio * bio)
         /* In case raid10d snuck in to freeze_array */
         wake_up(&conf->wait_barrier);
 
-        if (do_sync)
+        if (do_sync || !mddev->bitmap)
                 md_wakeup_thread(mddev->thread);
 
         return 0;
@@ -1681,7 +1639,6 @@ static void raid10d(mddev_t *mddev)
         unsigned long flags;
         conf_t *conf = mddev->private;
         struct list_head *head = &conf->retry_list;
-        int unplug=0;
         mdk_rdev_t *rdev;
 
         md_check_recovery(mddev);
@@ -1689,7 +1646,7 @@ static void raid10d(mddev_t *mddev)
         for (;;) {
                 char b[BDEVNAME_SIZE];
 
-                unplug += flush_pending_writes(conf);
+                flush_pending_writes(conf);
 
                 spin_lock_irqsave(&conf->device_lock, flags);
                 if (list_empty(head)) {
@@ -1703,13 +1660,11 @@ static void raid10d(mddev_t *mddev)
 
                 mddev = r10_bio->mddev;
                 conf = mddev->private;
-                if (test_bit(R10BIO_IsSync, &r10_bio->state)) {
+                if (test_bit(R10BIO_IsSync, &r10_bio->state))
                         sync_request_write(mddev, r10_bio);
-                        unplug = 1;
-                } else  if (test_bit(R10BIO_IsRecover, &r10_bio->state)) {
+                else if (test_bit(R10BIO_IsRecover, &r10_bio->state))
                         recovery_request_write(mddev, r10_bio);
-                        unplug = 1;
-                } else {
+                else {
                         int mirror;
                         /* we got a read error. Maybe the drive is bad.  Maybe just
                          * the block and we can fix it.
@@ -1756,14 +1711,11 @@ static void raid10d(mddev_t *mddev)
                                 bio->bi_rw = READ | do_sync;
                                 bio->bi_private = r10_bio;
                                 bio->bi_end_io = raid10_end_read_request;
-                                unplug = 1;
                                 generic_make_request(bio);
                         }
                 }
                 cond_resched();
         }
-        if (unplug)
-                unplug_slaves(mddev);
 }
 
 
@@ -2376,7 +2328,6 @@ static int run(mddev_t *mddev)
         md_set_array_sectors(mddev, size);
         mddev->resync_max_sectors = size;
 
-        mddev->queue->unplug_fn = raid10_unplug;
         mddev->queue->backing_dev_info.congested_fn = raid10_congested;
         mddev->queue->backing_dev_info.congested_data = mddev;
 
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 702812824195..e867ee42b152 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -433,8 +433,6 @@ static int has_failed(raid5_conf_t *conf)
         return 0;
 }
 
-static void unplug_slaves(mddev_t *mddev);
-
 static struct stripe_head *
 get_active_stripe(raid5_conf_t *conf, sector_t sector,
                   int previous, int noblock, int noquiesce)
@@ -463,8 +461,7 @@ get_active_stripe(raid5_conf_t *conf, sector_t sector,
                                                      < (conf->max_nr_stripes *3/4)
                                                      || !conf->inactive_blocked),
                                                     conf->device_lock,
-                                                    md_raid5_unplug_device(conf)
-                                        );
+                                                    md_raid5_kick_device(conf));
                                 conf->inactive_blocked = 0;
                         } else
                                 init_stripe(sh, sector, previous);
@@ -1473,8 +1470,7 @@ static int resize_stripes(raid5_conf_t *conf, int newsize)
                 wait_event_lock_irq(conf->wait_for_stripe,
                                     !list_empty(&conf->inactive_list),
                                     conf->device_lock,
-                                    unplug_slaves(conf->mddev)
-                        );
+                                    blk_flush_plug(current));
                 osh = get_free_stripe(conf);
                 spin_unlock_irq(&conf->device_lock);
                 atomic_set(&nsh->count, 1);
@@ -3645,58 +3641,19 @@ static void activate_bit_delay(raid5_conf_t *conf)
         }
 }
 
-static void unplug_slaves(mddev_t *mddev)
+void md_raid5_kick_device(raid5_conf_t *conf)
 {
-        raid5_conf_t *conf = mddev->private;
-        int i;
-        int devs = max(conf->raid_disks, conf->previous_raid_disks);
-
-        rcu_read_lock();
-        for (i = 0; i < devs; i++) {
-                mdk_rdev_t *rdev = rcu_dereference(conf->disks[i].rdev);
-                if (rdev && !test_bit(Faulty, &rdev->flags) && atomic_read(&rdev->nr_pending)) {
-                        struct request_queue *r_queue = bdev_get_queue(rdev->bdev);
-
-                        atomic_inc(&rdev->nr_pending);
-                        rcu_read_unlock();
-
-                        blk_unplug(r_queue);
-
-                        rdev_dec_pending(rdev, mddev);
-                        rcu_read_lock();
-                }
-        }
-        rcu_read_unlock();
-}
-
-void md_raid5_unplug_device(raid5_conf_t *conf)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(&conf->device_lock, flags);
-
-        if (plugger_remove_plug(&conf->plug)) {
-                conf->seq_flush++;
-                raid5_activate_delayed(conf);
-        }
+        blk_flush_plug(current);
+        raid5_activate_delayed(conf);
         md_wakeup_thread(conf->mddev->thread);
-
-        spin_unlock_irqrestore(&conf->device_lock, flags);
-
-        unplug_slaves(conf->mddev);
 }
-EXPORT_SYMBOL_GPL(md_raid5_unplug_device);
+EXPORT_SYMBOL_GPL(md_raid5_kick_device);
 
 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);
+        md_raid5_kick_device(conf);
 }
 
 int md_raid5_congested(mddev_t *mddev, int bits)
@@ -4100,7 +4057,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
                                  * add failed due to overlap.  Flush everything
                                  * and wait a while
                                  */
-                                md_raid5_unplug_device(conf);
+                                md_raid5_kick_device(conf);
                                 release_stripe(sh);
                                 schedule();
                                 goto retry;
@@ -4365,7 +4322,6 @@ static inline sector_t sync_request(mddev_t *mddev, sector_t sector_nr, int *ski
 
         if (sector_nr >= max_sector) {
                 /* just being told to finish up .. nothing much to do */
-                unplug_slaves(mddev);
 
                 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery)) {
                         end_reshape(conf);
@@ -4569,7 +4525,6 @@ static void raid5d(mddev_t *mddev)
         spin_unlock_irq(&conf->device_lock);
 
         async_tx_issue_pending_all();
-        unplug_slaves(mddev);
 
         pr_debug("--- raid5d inactive\n");
 }
@@ -5205,7 +5160,6 @@ static int run(mddev_t *mddev)
                 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;
 
                 chunk_size = mddev->chunk_sectors << 9;
                 blk_queue_io_min(mddev->queue, chunk_size);
diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 2ace0582b409..8d563a4f022a 100644
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -503,6 +503,6 @@ static inline int algorithm_is_DDF(int layout)
 }
 
 extern int md_raid5_congested(mddev_t *mddev, int bits);
-extern void md_raid5_unplug_device(raid5_conf_t *conf);
+extern void md_raid5_kick_device(raid5_conf_t *conf);
 extern int raid5_set_cache_size(mddev_t *mddev, int size);
 #endif