Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/core

Conflicts:
	block/blk-core.c
	block/blk-flush.c
	drivers/md/raid1.c
	drivers/md/raid10.c
	drivers/md/raid5.c
	fs/nilfs2/btnode.c
	fs/nilfs2/mdt.c

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

1 files changed, 19 insertions, 71 deletions

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 747d061d8e05..c0d0f5f7e407 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;
@@ -649,23 +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);
-                /* Spinlock only taken to quiet a warning */
-                spin_lock(conf->mddev->queue->queue_lock);
-                blk_remove_plug(conf->mddev->queue);
-                spin_unlock(conf->mddev->queue->queue_lock);
                 spin_unlock_irq(&conf->device_lock);
                 /* flush any pending bitmap writes to disk
                  * before proceeding w/ I/O */
@@ -677,11 +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.
@@ -711,8 +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++;
@@ -720,8 +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);
 }
@@ -742,7 +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++;
@@ -779,7 +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);
 }
 
@@ -974,7 +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_unlocked(mddev->queue);
                 spin_unlock_irqrestore(&conf->device_lock, flags);
         }
 
@@ -991,7 +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;
@@ -1684,7 +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);
@@ -1692,7 +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)) {
@@ -1706,13 +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.
@@ -1759,14 +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);
 }
 
 
@@ -2377,7 +2326,6 @@ 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;