Merge branch 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.39/core' of git://git.kernel.dk/linux-2.6-block: (65 commits)
  Documentation/iostats.txt: bit-size reference etc.
  cfq-iosched: removing unnecessary think time checking
  cfq-iosched: Don't clear queue stats when preempt.
  blk-throttle: Reset group slice when limits are changed
  blk-cgroup: Only give unaccounted_time under debug
  cfq-iosched: Don't set active queue in preempt
  block: fix non-atomic access to genhd inflight structures
  block: attempt to merge with existing requests on plug flush
  block: NULL dereference on error path in __blkdev_get()
  cfq-iosched: Don't update group weights when on service tree
  fs: assign sb->s_bdi to default_backing_dev_info if the bdi is going away
  block: Require subsystems to explicitly allocate bio_set integrity mempool
  jbd2: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  jbd: finish conversion from WRITE_SYNC_PLUG to WRITE_SYNC and explicit plugging
  fs: make fsync_buffers_list() plug
  mm: make generic_writepages() use plugging
  blk-cgroup: Add unaccounted time to timeslice_used.
  block: fixup plugging stubs for !CONFIG_BLOCK
  block: remove obsolete comments for blkdev_issue_zeroout.
  blktrace: Use rq->cmd_flags directly in blk_add_trace_rq.
  ...

Fix up conflicts in fs/{aio.c,super.c}

24 files changed, 84 insertions, 206 deletions

diff --git a/drivers/block/DAC960.c b/drivers/block/DAC960.c
index 1f286ab461d..79882104e43 100644
--- a/drivers/block/DAC960.c
+++ b/drivers/block/DAC960.c
@@ -140,13 +140,14 @@ static int DAC960_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return 0;
 }
 
-static int DAC960_media_changed(struct gendisk *disk)
+static unsigned int DAC960_check_events(struct gendisk *disk,
+					unsigned int clearing)
 {
 	DAC960_Controller_T *p = disk->queue->queuedata;
 	int drive_nr = (long)disk->private_data;
 
 	if (!p->LogicalDriveInitiallyAccessible[drive_nr])
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 	return 0;
 }
 
@@ -163,7 +164,7 @@ static const struct block_device_operations DAC960_BlockDeviceOperations = {
 	.owner			= THIS_MODULE,
 	.open			= DAC960_open,
 	.getgeo			= DAC960_getgeo,
-	.media_changed		= DAC960_media_changed,
+	.check_events		= DAC960_check_events,
 	.revalidate_disk	= DAC960_revalidate_disk,
 };
 
@@ -2546,6 +2547,7 @@ static bool DAC960_RegisterBlockDevice(DAC960_Controller_T *Controller)
 	disk->major = MajorNumber;
 	disk->first_minor = n << DAC960_MaxPartitionsBits;
 	disk->fops = &DAC960_BlockDeviceOperations;
+	disk->events = DISK_EVENT_MEDIA_CHANGE;
    }
   /*
     Indicate the Block Device Registration completed successfully,
diff --git a/drivers/block/amiflop.c b/drivers/block/amiflop.c
index 363855ca376..456c0cc90dc 100644
--- a/drivers/block/amiflop.c
+++ b/drivers/block/amiflop.c
@@ -1658,12 +1658,12 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
 }
 
 /*
- * floppy-change is never called from an interrupt, so we can relax a bit
+ * check_events is never called from an interrupt, so we can relax a bit
  * here, sleep etc. Note that floppy-on tries to set current_DOR to point
  * to the desired drive, but it will probably not survive the sleep if
  * several floppies are used at the same time: thus the loop.
  */
-static int amiga_floppy_change(struct gendisk *disk)
+static unsigned amiga_check_events(struct gendisk *disk, unsigned int clearing)
 {
 	struct amiga_floppy_struct *p = disk->private_data;
 	int drive = p - unit;
@@ -1686,7 +1686,7 @@ static int amiga_floppy_change(struct gendisk *disk)
 		p->dirty = 0;
 		writepending = 0; /* if this was true before, too bad! */
 		writefromint = 0;
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 	}
 	return 0;
 }
@@ -1697,7 +1697,7 @@ static const struct block_device_operations floppy_fops = {
 	.release	= floppy_release,
 	.ioctl		= fd_ioctl,
 	.getgeo		= fd_getgeo,
-	.media_changed	= amiga_floppy_change,
+	.check_events	= amiga_check_events,
 };
 
 static int __init fd_probe_drives(void)
@@ -1736,6 +1736,7 @@ static int __init fd_probe_drives(void)
 		disk->major = FLOPPY_MAJOR;
 		disk->first_minor = drive;
 		disk->fops = &floppy_fops;
+		disk->events = DISK_EVENT_MEDIA_CHANGE;
 		sprintf(disk->disk_name, "fd%d", drive);
 		disk->private_data = &unit[drive];
 		set_capacity(disk, 880*2);
diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 605a67e40bb..c871eae1412 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -1324,23 +1324,24 @@ static void finish_fdc_done( int dummy )
  * due to unrecognised disk changes.
  */
 
-static int check_floppy_change(struct gendisk *disk)
+static unsigned int floppy_check_events(struct gendisk *disk,
+					unsigned int clearing)
 {
 	struct atari_floppy_struct *p = disk->private_data;
 	unsigned int drive = p - unit;
 	if (test_bit (drive, &fake_change)) {
 		/* simulated change (e.g. after formatting) */
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 	}
 	if (test_bit (drive, &changed_floppies)) {
 		/* surely changed (the WP signal changed at least once) */
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 	}
 	if (UD.wpstat) {
 		/* WP is on -> could be changed: to be sure, buffers should be
 		 * invalidated...
 		 */
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 	}
 
 	return 0;
@@ -1570,7 +1571,7 @@ static int fd_locked_ioctl(struct block_device *bdev, fmode_t mode,
 		 * or the next access will revalidate - and clear UDT :-(
 		 */
 
-		if (check_floppy_change(disk))
+		if (floppy_check_events(disk, 0))
 		        floppy_revalidate(disk);
 
 		if (UD.flags & FTD_MSG)
@@ -1904,7 +1905,7 @@ static const struct block_device_operations floppy_fops = {
 	.open		= floppy_unlocked_open,
 	.release	= floppy_release,
 	.ioctl		= fd_ioctl,
-	.media_changed	= check_floppy_change,
+	.check_events	= floppy_check_events,
 	.revalidate_disk= floppy_revalidate,
 };
 
@@ -1963,6 +1964,7 @@ static int __init atari_floppy_init (void)
 		unit[i].disk->first_minor = i;
 		sprintf(unit[i].disk->disk_name, "fd%d", i);
 		unit[i].disk->fops = &floppy_fops;
+		unit[i].disk->events = DISK_EVENT_MEDIA_CHANGE;
 		unit[i].disk->private_data = &unit[i];
 		unit[i].disk->queue = blk_init_queue(do_fd_request,
 					&ataflop_lock);
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 9279272b373..35658f445fc 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3170,12 +3170,6 @@ static void do_cciss_request(struct request_queue *q)
 	int sg_index = 0;
 	int chained = 0;
 
-	/* We call start_io here in case there is a command waiting on the
-	 * queue that has not been sent.
-	 */
-	if (blk_queue_plugged(q))
-		goto startio;
-
       queue:
 	creq = blk_peek_request(q);
 	if (!creq)
diff --git a/drivers/block/cpqarray.c b/drivers/block/cpqarray.c
index 946dad4caef..b2fceb53e80 100644
--- a/drivers/block/cpqarray.c
+++ b/drivers/block/cpqarray.c
@@ -911,9 +911,6 @@ static void do_ida_request(struct request_queue *q)
 	struct scatterlist tmp_sg[SG_MAX];
 	int i, dir, seg;
 
-	if (blk_queue_plugged(q))
-		goto startio;
-
 queue_next:
 	creq = blk_peek_request(q);
 	if (!creq)
diff --git a/drivers/block/drbd/drbd_actlog.c b/drivers/block/drbd/drbd_actlog.c
index ba95cba192b..aca302492ff 100644
--- a/drivers/block/drbd/drbd_actlog.c
+++ b/drivers/block/drbd/drbd_actlog.c
@@ -80,7 +80,7 @@ static int _drbd_md_sync_page_io(struct drbd_conf *mdev,
 
 	if ((rw & WRITE) && !test_bit(MD_NO_FUA, &mdev->flags))
 		rw |= REQ_FUA;
-	rw |= REQ_UNPLUG | REQ_SYNC;
+	rw |= REQ_SYNC;
 
 	bio = bio_alloc(GFP_NOIO, 1);
 	bio->bi_bdev = bdev->md_bdev;
@@ -689,8 +689,6 @@ void drbd_al_to_on_disk_bm(struct drbd_conf *mdev)
 		}
 	}
 
-	drbd_blk_run_queue(bdev_get_queue(mdev->ldev->md_bdev));
-
 	/* always (try to) flush bitmap to stable storage */
 	drbd_md_flush(mdev);
 
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c
index fd42832f785..0645ca829a9 100644
--- a/drivers/block/drbd/drbd_bitmap.c
+++ b/drivers/block/drbd/drbd_bitmap.c
@@ -840,7 +840,6 @@ static int bm_rw(struct drbd_conf *mdev, int rw) __must_hold(local)
 	for (i = 0; i < num_pages; i++)
 		bm_page_io_async(mdev, b, i, rw);
 
-	drbd_blk_run_queue(bdev_get_queue(mdev->ldev->md_bdev));
 	wait_event(b->bm_io_wait, atomic_read(&b->bm_async_io) == 0);
 
 	if (test_bit(BM_MD_IO_ERROR, &b->bm_flags)) {
diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 3803a034893..b0bd27dfc1e 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -377,7 +377,7 @@ union p_header {
 #define DP_HARDBARRIER	      1 /* depricated */
 #define DP_RW_SYNC	      2 /* equals REQ_SYNC    */
 #define DP_MAY_SET_IN_SYNC    4
-#define DP_UNPLUG             8 /* equals REQ_UNPLUG  */
+#define DP_UNPLUG             8 /* not used anymore   */
 #define DP_FUA               16 /* equals REQ_FUA     */
 #define DP_FLUSH             32 /* equals REQ_FLUSH   */
 #define DP_DISCARD           64 /* equals REQ_DISCARD */
@@ -2382,20 +2382,6 @@ static inline int drbd_queue_order_type(struct drbd_conf *mdev)
 	return QUEUE_ORDERED_NONE;
 }
 
-static inline void drbd_blk_run_queue(struct request_queue *q)
-{
-	if (q && q->unplug_fn)
-		q->unplug_fn(q);
-}
-
-static inline void drbd_kick_lo(struct drbd_conf *mdev)
-{
-	if (get_ldev(mdev)) {
-		drbd_blk_run_queue(bdev_get_queue(mdev->ldev->backing_bdev));
-		put_ldev(mdev);
-	}
-}
-
 static inline void drbd_md_flush(struct drbd_conf *mdev)
 {
 	int r;
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 29cd0dc9fe4..8a43ce0edee 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2477,12 +2477,11 @@ static u32 bio_flags_to_wire(struct drbd_conf *mdev, unsigned long bi_rw)
 {
 	if (mdev->agreed_pro_version >= 95)
 		return  (bi_rw & REQ_SYNC ? DP_RW_SYNC : 0) |
-			(bi_rw & REQ_UNPLUG ? DP_UNPLUG : 0) |
 			(bi_rw & REQ_FUA ? DP_FUA : 0) |
 			(bi_rw & REQ_FLUSH ? DP_FLUSH : 0) |
 			(bi_rw & REQ_DISCARD ? DP_DISCARD : 0);
 	else
-		return bi_rw & (REQ_SYNC | REQ_UNPLUG) ? DP_RW_SYNC : 0;
+		return bi_rw & REQ_SYNC ? DP_RW_SYNC : 0;
 }
 
 /* Used to send write requests
@@ -2719,35 +2718,6 @@ static int drbd_release(struct gendisk *gd, fmode_t mode)
 	return 0;
 }
 
-static void drbd_unplug_fn(struct request_queue *q)
-{
-	struct drbd_conf *mdev = q->queuedata;
-
-	/* unplug FIRST */
-	spin_lock_irq(q->queue_lock);
-	blk_remove_plug(q);
-	spin_unlock_irq(q->queue_lock);
-
-	/* only if connected */
-	spin_lock_irq(&mdev->req_lock);
-	if (mdev->state.pdsk >= D_INCONSISTENT && mdev->state.conn >= C_CONNECTED) {
-		D_ASSERT(mdev->state.role == R_PRIMARY);
-		if (test_and_clear_bit(UNPLUG_REMOTE, &mdev->flags)) {
-			/* add to the data.work queue,
-			 * unless already queued.
-			 * XXX this might be a good addition to drbd_queue_work
-			 * anyways, to detect "double queuing" ... */
-			if (list_empty(&mdev->unplug_work.list))
-				drbd_queue_work(&mdev->data.work,
-						&mdev->unplug_work);
-		}
-	}
-	spin_unlock_irq(&mdev->req_lock);
-
-	if (mdev->state.disk >= D_INCONSISTENT)
-		drbd_kick_lo(mdev);
-}
-
 static void drbd_set_defaults(struct drbd_conf *mdev)
 {
 	/* This way we get a compile error when sync_conf grows,
@@ -3222,9 +3192,7 @@ struct drbd_conf *drbd_new_device(unsigned int minor)
 	blk_queue_max_segment_size(q, DRBD_MAX_SEGMENT_SIZE);
 	blk_queue_bounce_limit(q, BLK_BOUNCE_ANY);
 	blk_queue_merge_bvec(q, drbd_merge_bvec);
-	q->queue_lock = &mdev->req_lock; /* needed since we use */
-		/* plugging on a queue, that actually has no requests! */
-	q->unplug_fn = drbd_unplug_fn;
+	q->queue_lock = &mdev->req_lock;
 
 	mdev->md_io_page = alloc_page(GFP_KERNEL);
 	if (!mdev->md_io_page)
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index 24487d4fb20..8e68be939de 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -187,15 +187,6 @@ static struct page *drbd_pp_first_pages_or_try_alloc(struct drbd_conf *mdev, int
 	return NULL;
 }
 
-/* kick lower level device, if we have more than (arbitrary number)
- * reference counts on it, which typically are locally submitted io
- * requests.  don't use unacked_cnt, so we speed up proto A and B, too. */
-static void maybe_kick_lo(struct drbd_conf *mdev)
-{
-	if (atomic_read(&mdev->local_cnt) >= mdev->net_conf->unplug_watermark)
-		drbd_kick_lo(mdev);
-}
-
 static void reclaim_net_ee(struct drbd_conf *mdev, struct list_head *to_be_freed)
 {
 	struct drbd_epoch_entry *e;
@@ -219,7 +210,6 @@ static void drbd_kick_lo_and_reclaim_net(struct drbd_conf *mdev)
 	LIST_HEAD(reclaimed);
 	struct drbd_epoch_entry *e, *t;
 
-	maybe_kick_lo(mdev);
 	spin_lock_irq(&mdev->req_lock);
 	reclaim_net_ee(mdev, &reclaimed);
 	spin_unlock_irq(&mdev->req_lock);
@@ -436,8 +426,7 @@ void _drbd_wait_ee_list_empty(struct drbd_conf *mdev, struct list_head *head)
 	while (!list_empty(head)) {
 		prepare_to_wait(&mdev->ee_wait, &wait, TASK_UNINTERRUPTIBLE);
 		spin_unlock_irq(&mdev->req_lock);
-		drbd_kick_lo(mdev);
-		schedule();
+		io_schedule();
 		finish_wait(&mdev->ee_wait, &wait);
 		spin_lock_irq(&mdev->req_lock);
 	}
@@ -1111,8 +1100,6 @@ next_bio:
 	/* > e->sector, unless this is the first bio */
 	bio->bi_sector = sector;
 	bio->bi_bdev = mdev->ldev->backing_bdev;
-	/* we special case some flags in the multi-bio case, see below
-	 * (REQ_UNPLUG) */
 	bio->bi_rw = rw;
 	bio->bi_private = e;
 	bio->bi_end_io = drbd_endio_sec;
@@ -1141,13 +1128,8 @@ next_bio:
 		bios = bios->bi_next;
 		bio->bi_next = NULL;
 
-		/* strip off REQ_UNPLUG unless it is the last bio */
-		if (bios)
-			bio->bi_rw &= ~REQ_UNPLUG;
-
 		drbd_generic_make_request(mdev, fault_type, bio);
 	} while (bios);
-	maybe_kick_lo(mdev);
 	return 0;
 
 fail:
@@ -1167,9 +1149,6 @@ static int receive_Barrier(struct drbd_conf *mdev, enum drbd_packets cmd, unsign
 
 	inc_unacked(mdev);
 
-	if (mdev->net_conf->wire_protocol != DRBD_PROT_C)
-		drbd_kick_lo(mdev);
-
 	mdev->current_epoch->barrier_nr = p->barrier;
 	rv = drbd_may_finish_epoch(mdev, mdev->current_epoch, EV_GOT_BARRIER_NR);
 
@@ -1636,12 +1615,11 @@ static unsigned long write_flags_to_bio(struct drbd_conf *mdev, u32 dpf)
 {
 	if (mdev->agreed_pro_version >= 95)
 		return  (dpf & DP_RW_SYNC ? REQ_SYNC : 0) |
-			(dpf & DP_UNPLUG ? REQ_UNPLUG : 0) |
 			(dpf & DP_FUA ? REQ_FUA : 0) |
 			(dpf & DP_FLUSH ? REQ_FUA : 0) |
 			(dpf & DP_DISCARD ? REQ_DISCARD : 0);
 	else
-		return dpf & DP_RW_SYNC ? (REQ_SYNC | REQ_UNPLUG) : 0;
+		return dpf & DP_RW_SYNC ? REQ_SYNC : 0;
 }
 
 /* mirrored write */
@@ -3556,9 +3534,6 @@ static int receive_skip(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned
 
 static int receive_UnplugRemote(struct drbd_conf *mdev, enum drbd_packets cmd, unsigned int data_size)
 {
-	if (mdev->state.disk >= D_INCONSISTENT)
-		drbd_kick_lo(mdev);
-
 	/* Make sure we've acked all the TCP data associated
 	 * with the data requests being unplugged */
 	drbd_tcp_quickack(mdev->data.socket);
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 11a75d32a2e..ad3fc6228f2 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -960,10 +960,6 @@ allocate_barrier:
 			bio_endio(req->private_bio, -EIO);
 	}
 
-	/* we need to plug ALWAYS since we possibly need to kick lo_dev.
-	 * we plug after submit, so we won't miss an unplug event */
-	drbd_plug_device(mdev);
-
 	return 0;
 
 fail_conflicting:
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index 34f224b018b..e027446590d 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -792,7 +792,6 @@ int drbd_resync_finished(struct drbd_conf *mdev)
 		 * queue (or even the read operations for those packets
 		 * is not finished by now).   Retry in 100ms. */
 
-		drbd_kick_lo(mdev);
 		__set_current_state(TASK_INTERRUPTIBLE);
 		schedule_timeout(HZ / 10);
 		w = kmalloc(sizeof(struct drbd_work), GFP_ATOMIC);
diff --git a/drivers/block/drbd/drbd_wrappers.h b/drivers/block/drbd/drbd_wrappers.h
index defdb5013ea..53586fa5ae1 100644
--- a/drivers/block/drbd/drbd_wrappers.h
+++ b/drivers/block/drbd/drbd_wrappers.h
@@ -45,24 +45,6 @@ static inline void drbd_generic_make_request(struct drbd_conf *mdev,
 		generic_make_request(bio);
 }
 
-static inline void drbd_plug_device(struct drbd_conf *mdev)
-{
-	struct request_queue *q;
-	q = bdev_get_queue(mdev->this_bdev);
-
-	spin_lock_irq(q->queue_lock);
-
-/* XXX the check on !blk_queue_plugged is redundant,
- * implicitly checked in blk_plug_device */
-
-	if (!blk_queue_plugged(q)) {
-		blk_plug_device(q);
-		del_timer(&q->unplug_timer);
-		/* unplugging should not happen automatically... */
-	}
-	spin_unlock_irq(q->queue_lock);
-}
-
 static inline int drbd_crypto_is_hash(struct crypto_tfm *tfm)
 {
         return (crypto_tfm_alg_type(tfm) & CRYPTO_ALG_TYPE_HASH_MASK)
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 77fc76f8aea..301d7a9a41a 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3770,13 +3770,14 @@ out2:
 /*
  * Check if the disk has been changed or if a change has been faked.
  */
-static int check_floppy_change(struct gendisk *disk)
+static unsigned int floppy_check_events(struct gendisk *disk,
+					unsigned int clearing)
 {
 	int drive = (long)disk->private_data;
 
 	if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags) ||
 	    test_bit(FD_VERIFY_BIT, &UDRS->flags))
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 
 	if (time_after(jiffies, UDRS->last_checked + UDP->checkfreq)) {
 		lock_fdc(drive, false);
@@ -3788,7 +3789,7 @@ static int check_floppy_change(struct gendisk *disk)
 	    test_bit(FD_VERIFY_BIT, &UDRS->flags) ||
 	    test_bit(drive, &fake_change) ||
 	    drive_no_geom(drive))
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 	return 0;
 }
 
@@ -3837,7 +3838,6 @@ static int __floppy_read_block_0(struct block_device *bdev)
 	bio.bi_end_io = floppy_rb0_complete;
 
 	submit_bio(READ, &bio);
-	generic_unplug_device(bdev_get_queue(bdev));
 	process_fd_request();
 	wait_for_completion(&complete);
 
@@ -3898,7 +3898,7 @@ static const struct block_device_operations floppy_fops = {
 	.release		= floppy_release,
 	.ioctl			= fd_ioctl,
 	.getgeo			= fd_getgeo,
-	.media_changed		= check_floppy_change,
+	.check_events		= floppy_check_events,
 	.revalidate_disk	= floppy_revalidate,
 };
 
@@ -4205,6 +4205,7 @@ static int __init floppy_init(void)
 		disks[dr]->major = FLOPPY_MAJOR;
 		disks[dr]->first_minor = TOMINOR(dr);
 		disks[dr]->fops = &floppy_fops;
+		disks[dr]->events = DISK_EVENT_MEDIA_CHANGE;
 		sprintf(disks[dr]->disk_name, "fd%d", dr);
 
 		init_timer(&motor_off_timer[dr]);
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index dbf31ec9114..a076a14ca72 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -540,17 +540,6 @@ out:
 	return 0;
 }
 
-/*
- * kick off io on the underlying address space
- */
-static void loop_unplug(struct request_queue *q)
-{
-	struct loop_device *lo = q->queuedata;
-
-	queue_flag_clear_unlocked(QUEUE_FLAG_PLUGGED, q);
-	blk_run_address_space(lo->lo_backing_file->f_mapping);
-}
-
 struct switch_request {
 	struct file *file;
 	struct completion wait;
@@ -917,7 +906,6 @@ static int loop_set_fd(struct loop_device *lo, fmode_t mode,
 	 */
 	blk_queue_make_request(lo->lo_queue, loop_make_request);
 	lo->lo_queue->queuedata = lo;
-	lo->lo_queue->unplug_fn = loop_unplug;
 
 	if (!(lo_flags & LO_FLAGS_READ_ONLY) && file->f_op->fsync)
 		blk_queue_flush(lo->lo_queue, REQ_FLUSH);
@@ -1019,7 +1007,6 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
 
 	kthread_stop(lo->lo_thread);
 
-	lo->lo_queue->unplug_fn = NULL;
 	lo->lo_backing_file = NULL;
 
 	loop_release_xfer(lo);
@@ -1636,9 +1623,6 @@ out:
 
 static void loop_free(struct loop_device *lo)
 {
-	if (!lo->lo_queue->queue_lock)
-		lo->lo_queue->queue_lock = &lo->lo_queue->__queue_lock;
-
 	blk_cleanup_queue(lo->lo_queue);
 	put_disk(lo->lo_disk);
 	list_del(&lo->lo_list);
diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index 62cec6afd7a..2f2ccf68625 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -172,7 +172,8 @@ module_param_array(drive3, int, NULL, 0);
 static int pcd_open(struct cdrom_device_info *cdi, int purpose);
 static void pcd_release(struct cdrom_device_info *cdi);
 static int pcd_drive_status(struct cdrom_device_info *cdi, int slot_nr);
-static int pcd_media_changed(struct cdrom_device_info *cdi, int slot_nr);
+static unsigned int pcd_check_events(struct cdrom_device_info *cdi,
+				     unsigned int clearing, int slot_nr);
 static int pcd_tray_move(struct cdrom_device_info *cdi, int position);
 static int pcd_lock_door(struct cdrom_device_info *cdi, int lock);
 static int pcd_drive_reset(struct cdrom_device_info *cdi);
@@ -257,10 +258,11 @@ static int pcd_block_ioctl(struct block_device *bdev, fmode_t mode,
 	return ret;
 }
 
-static int pcd_block_media_changed(struct gendisk *disk)
+static unsigned int pcd_block_check_events(struct gendisk *disk,
+					   unsigned int clearing)
 {
 	struct pcd_unit *cd = disk->private_data;
-	return cdrom_media_changed(&cd->info);
+	return cdrom_check_events(&cd->info, clearing);
 }
 
 static const struct block_device_operations pcd_bdops = {
@@ -268,14 +270,14 @@ static const struct block_device_operations pcd_bdops = {
 	.open		= pcd_block_open,
 	.release	= pcd_block_release,
 	.ioctl		= pcd_block_ioctl,
-	.media_changed	= pcd_block_media_changed,
+	.check_events	= pcd_block_check_events,
 };
 
 static struct cdrom_device_ops pcd_dops = {
 	.open		= pcd_open,
 	.release	= pcd_release,
 	.drive_status	= pcd_drive_status,
-	.media_changed	= pcd_media_changed,
+	.check_events	= pcd_check_events,
 	.tray_move	= pcd_tray_move,
 	.lock_door	= pcd_lock_door,
 	.get_mcn	= pcd_get_mcn,
@@ -318,6 +320,7 @@ static void pcd_init_units(void)
 		disk->first_minor = unit;
 		strcpy(disk->disk_name, cd->name);	/* umm... */
 		disk->fops = &pcd_bdops;
+		disk->events = DISK_EVENT_MEDIA_CHANGE;
 	}
 }
 
@@ -502,13 +505,14 @@ static int pcd_packet(struct cdrom_device_info *cdi, struct packet_command *cgc)
 
 #define DBMSG(msg)	((verbose>1)?(msg):NULL)
 
-static int pcd_media_changed(struct cdrom_device_info *cdi, int slot_nr)
+static unsigned int pcd_check_events(struct cdrom_device_info *cdi,
+				     unsigned int clearing, int slot_nr)
 {
 	struct pcd_unit *cd = cdi->handle;
 	int res = cd->changed;
 	if (res)
 		cd->changed = 0;
-	return res;
+	return res ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
 static int pcd_lock_door(struct cdrom_device_info *cdi, int lock)
diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index c0ee1558b9b..21dfdb77686 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -794,7 +794,7 @@ static int pd_release(struct gendisk *p, fmode_t mode)
 	return 0;
 }
 
-static int pd_check_media(struct gendisk *p)
+static unsigned int pd_check_events(struct gendisk *p, unsigned int clearing)
 {
 	struct pd_unit *disk = p->private_data;
 	int r;
@@ -803,7 +803,7 @@ static int pd_check_media(struct gendisk *p)
 	pd_special_command(disk, pd_media_check);
 	r = disk->changed;
 	disk->changed = 0;
-	return r;
+	return r ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
 static int pd_revalidate(struct gendisk *p)
@@ -822,7 +822,7 @@ static const struct block_device_operations pd_fops = {
 	.release	= pd_release,
 	.ioctl		= pd_ioctl,
 	.getgeo		= pd_getgeo,
-	.media_changed	= pd_check_media,
+	.check_events	= pd_check_events,
 	.revalidate_disk= pd_revalidate
 };
 
@@ -837,6 +837,7 @@ static void pd_probe_drive(struct pd_unit *disk)
 	p->fops = &pd_fops;
 	p->major = major;
 	p->first_minor = (disk - pd) << PD_BITS;
+	p->events = DISK_EVENT_MEDIA_CHANGE;
 	disk->gd = p;
 	p->private_data = disk;
 	p->queue = pd_queue;
diff --git a/drivers/block/paride/pf.c b/drivers/block/paride/pf.c
index 635f25dd9e1..7adeb1edbf4 100644
--- a/drivers/block/paride/pf.c
+++ b/drivers/block/paride/pf.c
@@ -243,7 +243,8 @@ static struct pf_unit units[PF_UNITS];
 static int pf_identify(struct pf_unit *pf);
 static void pf_lock(struct pf_unit *pf, int func);
 static void pf_eject(struct pf_unit *pf);
-static int pf_check_media(struct gendisk *disk);
+static unsigned int pf_check_events(struct gendisk *disk,
+				    unsigned int clearing);
 
 static char pf_scratch[512];	/* scratch block buffer */
 
@@ -270,7 +271,7 @@ static const struct block_device_operations pf_fops = {
 	.release	= pf_release,
 	.ioctl		= pf_ioctl,
 	.getgeo		= pf_getgeo,
-	.media_changed	= pf_check_media,
+	.check_events	= pf_check_events,
 };
 
 static void __init pf_init_units(void)
@@ -293,6 +294,7 @@ static void __init pf_init_units(void)
 		disk->first_minor = unit;
 		strcpy(disk->disk_name, pf->name);
 		disk->fops = &pf_fops;
+		disk->events = DISK_EVENT_MEDIA_CHANGE;
 		if (!(*drives[unit])[D_PRT])
 			pf_drive_count++;
 	}
@@ -377,9 +379,9 @@ static int pf_release(struct gendisk *disk, fmode_t mode)
 
 }
 
-static int pf_check_media(struct gendisk *disk)
+static unsigned int pf_check_events(struct gendisk *disk, unsigned int clearing)
 {
-	return 1;
+	return DISK_EVENT_MEDIA_CHANGE;
 }
 
 static inline int status_reg(struct pf_unit *pf)
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 77d70eebb6b..07a382eaf0a 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -1606,8 +1606,6 @@ static int kcdrwd(void *foobar)
 					min_sleep_time = pkt->sleep_time;
 			}
 
-			generic_unplug_device(bdev_get_queue(pd->bdev));
-
 			VPRINTK("kcdrwd: sleeping\n");
 			residue = schedule_timeout(min_sleep_time);
 			VPRINTK("kcdrwd: wake up\n");
@@ -2796,7 +2794,8 @@ static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd,
 	return ret;
 }
 
-static int pkt_media_changed(struct gendisk *disk)
+static unsigned int pkt_check_events(struct gendisk *disk,
+				     unsigned int clearing)
 {
 	struct pktcdvd_device *pd = disk->private_data;
 	struct gendisk *attached_disk;
@@ -2806,9 +2805,9 @@ static int pkt_media_changed(struct gendisk *disk)
 	if (!pd->bdev)
 		return 0;
 	attached_disk = pd->bdev->bd_disk;
-	if (!attached_disk)
+	if (!attached_disk || !attached_disk->fops->check_events)
 		return 0;
-	return attached_disk->fops->media_changed(attached_disk);
+	return attached_disk->fops->check_events(attached_disk, clearing);
 }
 
 static const struct block_device_operations pktcdvd_ops = {
@@ -2816,7 +2815,7 @@ static const struct block_device_operations pktcdvd_ops = {
 	.open =			pkt_open,
 	.release =		pkt_close,
 	.ioctl =		pkt_ioctl,
-	.media_changed =	pkt_media_changed,
+	.check_events =		pkt_check_events,
 };
 
 static char *pktcdvd_devnode(struct gendisk *gd, mode_t *mode)
@@ -2889,6 +2888,10 @@ static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
 	if (ret)
 		goto out_new_dev;
 
+	/* inherit events of the host device */
+	disk->events = pd->bdev->bd_disk->events;
+	disk->async_events = pd->bdev->bd_disk->async_events;
+
 	add_disk(disk);
 
 	pkt_sysfs_dev_new(pd);
diff --git a/drivers/block/swim.c b/drivers/block/swim.c
index 75333d0a332..24a482f2fbd 100644
--- a/drivers/block/swim.c
+++ b/drivers/block/swim.c
@@ -741,11 +741,12 @@ static int floppy_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return 0;
 }
 
-static int floppy_check_change(struct gendisk *disk)
+static unsigned int floppy_check_events(struct gendisk *disk,
+					unsigned int clearing)
 {
 	struct floppy_state *fs = disk->private_data;
 
-	return fs->ejected;
+	return fs->ejected ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
 static int floppy_revalidate(struct gendisk *disk)
@@ -772,7 +773,7 @@ static const struct block_device_operations floppy_fops = {
 	.release	 = floppy_release,
 	.ioctl		 = floppy_ioctl,
 	.getgeo		 = floppy_getgeo,
-	.media_changed	 = floppy_check_change,
+	.check_events	 = floppy_check_events,
 	.revalidate_disk = floppy_revalidate,
 };
 
@@ -857,6 +858,7 @@ static int __devinit swim_floppy_init(struct swim_priv *swd)
 		swd->unit[drive].disk->first_minor = drive;
 		sprintf(swd->unit[drive].disk->disk_name, "fd%d", drive);
 		swd->unit[drive].disk->fops = &floppy_fops;
+		swd->unit[drive].disk->events = DISK_EVENT_MEDIA_CHANGE;
 		swd->unit[drive].disk->private_data = &swd->unit[drive];
 		swd->unit[drive].disk->queue = swd->queue;
 		set_capacity(swd->unit[drive].disk, 2880);
diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index bf3a5b85929..4c10f56facb 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -250,7 +250,8 @@ static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
 			unsigned int cmd, unsigned long param);
 static int floppy_open(struct block_device *bdev, fmode_t mode);
 static int floppy_release(struct gendisk *disk, fmode_t mode);
-static int floppy_check_change(struct gendisk *disk);
+static unsigned int floppy_check_events(struct gendisk *disk,
+					unsigned int clearing);
 static int floppy_revalidate(struct gendisk *disk);
 
 static bool swim3_end_request(int err, unsigned int nr_bytes)
@@ -975,10 +976,11 @@ static int floppy_release(struct gendisk *disk, fmode_t mode)
 	return 0;
 }
 
-static int floppy_check_change(struct gendisk *disk)
+static unsigned int floppy_check_events(struct gendisk *disk,
+					unsigned int clearing)
 {
 	struct floppy_state *fs = disk->private_data;
-	return fs->ejected;
+	return fs->ejected ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
 static int floppy_revalidate(struct gendisk *disk)
@@ -1025,7 +1027,7 @@ static const struct block_device_operations floppy_fops = {
 	.open		= floppy_unlocked_open,
 	.release	= floppy_release,
 	.ioctl		= floppy_ioctl,
-	.media_changed	= floppy_check_change,
+	.check_events	= floppy_check_events,
 	.revalidate_disk= floppy_revalidate,
 };
 
@@ -1161,6 +1163,7 @@ static int __devinit swim3_attach(struct macio_dev *mdev, const struct of_device
 	disk->major = FLOPPY_MAJOR;
 	disk->first_minor = i;
 	disk->fops = &floppy_fops;
+	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	disk->private_data = &floppy_states[i];
 	disk->queue = swim3_queue;
 	disk->flags |= GENHD_FL_REMOVABLE;
diff --git a/drivers/block/ub.c b/drivers/block/ub.c
index 9ae3bb71328..68b9430c7cf 100644
--- a/drivers/block/ub.c
+++ b/drivers/block/ub.c
@@ -1788,7 +1788,8 @@ static int ub_bd_revalidate(struct gendisk *disk)
  *
  * The return code is bool!
  */
-static int ub_bd_media_changed(struct gendisk *disk)
+static unsigned int ub_bd_check_events(struct gendisk *disk,
+				       unsigned int clearing)
 {
 	struct ub_lun *lun = disk->private_data;
 
@@ -1806,10 +1807,10 @@ static int ub_bd_media_changed(struct gendisk *disk)
 	 */
 	if (ub_sync_tur(lun->udev, lun) != 0) {
 		lun->changed = 1;
-		return 1;
+		return DISK_EVENT_MEDIA_CHANGE;
 	}
 
-	return lun->changed;
+	return lun->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
 static const struct block_device_operations ub_bd_fops = {
@@ -1817,7 +1818,7 @@ static const struct block_device_operations ub_bd_fops = {
 	.open		= ub_bd_unlocked_open,
 	.release	= ub_bd_release,
 	.ioctl		= ub_bd_ioctl,
-	.media_changed	= ub_bd_media_changed,
+	.check_events	= ub_bd_check_events,
 	.revalidate_disk = ub_bd_revalidate,
 };
 
@@ -2333,6 +2334,7 @@ static int ub_probe_lun(struct ub_dev *sc, int lnum)
 	disk->major = UB_MAJOR;
 	disk->first_minor = lun->id * UB_PARTS_PER_LUN;
 	disk->fops = &ub_bd_fops;
+	disk->events = DISK_EVENT_MEDIA_CHANGE;
 	disk->private_data = lun;
 	disk->driverfs_dev = &sc->intf->dev;
 
diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 8be57151f5d..031ca720d92 100644
--- a/drivers/block/umem.c
+++ b/drivers/block/umem.c
@@ -241,8 +241,7 @@ static void dump_dmastat(struct cardinfo *card, unsigned int dmastat)
  *
  * Whenever IO on the active page completes, the Ready page is activated
  * and the ex-Active page is clean out and made Ready.
- * Otherwise the Ready page is only activated when it becomes full, or
- * when mm_unplug_device is called via the unplug_io_fn.
+ * Otherwise the Ready page is only activated when it becomes full.
  *
  * If a request arrives while both pages a full, it is queued, and b_rdev is
  * overloaded to record whether it was a read or a write.
@@ -333,17 +332,6 @@ static inline void reset_page(struct mm_page *page)
 	page->biotail = &page->bio;
 }
 
-static void mm_unplug_device(struct request_queue *q)
-{
-	struct cardinfo *card = q->queuedata;
-	unsigned long flags;
-
-	spin_lock_irqsave(&card->lock, flags);
-	if (blk_remove_plug(q))
-		activate(card);
-	spin_unlock_irqrestore(&card->lock, flags);
-}
-
 /*
  * If there is room on Ready page, take
  * one bh off list and add it.
@@ -535,7 +523,6 @@ static int mm_make_request(struct request_queue *q, struct bio *bio)
 	*card->biotail = bio;
 	bio->bi_next = NULL;
 	card->biotail = &bio->bi_next;
-	blk_plug_device(q);
 	spin_unlock_irq(&card->lock);
 
 	return 0;
@@ -779,20 +766,10 @@ static int mm_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return 0;
 }
 
-/*
- * Future support for removable devices
- */
-static int mm_check_change(struct gendisk *disk)
-{
-/*  struct cardinfo *dev = disk->private_data; */
-	return 0;
-}
-
 static const struct block_device_operations mm_fops = {
 	.owner		= THIS_MODULE,
 	.getgeo		= mm_getgeo,
 	.revalidate_disk = mm_revalidate,
-	.media_changed	= mm_check_change,
 };
 
 static int __devinit mm_pci_probe(struct pci_dev *dev,
@@ -907,7 +884,6 @@ static int __devinit mm_pci_probe(struct pci_dev *dev,
 	blk_queue_make_request(card->queue, mm_make_request);
 	card->queue->queue_lock = &card->lock;
 	card->queue->queuedata = card;
-	card->queue->unplug_fn = mm_unplug_device;
 
 	tasklet_init(&card->tasklet, process_page, (unsigned long)card);
 
diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c
index 2c590a796aa..73354b081ed 100644
--- a/drivers/block/xsysace.c
+++ b/drivers/block/xsysace.c
@@ -867,12 +867,12 @@ static void ace_request(struct request_queue * q)
 	}
 }
 
-static int ace_media_changed(struct gendisk *gd)
+static unsigned int ace_check_events(struct gendisk *gd, unsigned int clearing)
 {
 	struct ace_device *ace = gd->private_data;
-	dev_dbg(ace->dev, "ace_media_changed(): %i\n", ace->media_change);
+	dev_dbg(ace->dev, "ace_check_events(): %i\n", ace->media_change);
 
-	return ace->media_change;
+	return ace->media_change ? DISK_EVENT_MEDIA_CHANGE : 0;
 }
 
 static int ace_revalidate_disk(struct gendisk *gd)
@@ -953,7 +953,7 @@ static const struct block_device_operations ace_fops = {
 	.owner = THIS_MODULE,
 	.open = ace_open,
 	.release = ace_release,
-	.media_changed = ace_media_changed,
+	.check_events = ace_check_events,
 	.revalidate_disk = ace_revalidate_disk,
 	.getgeo = ace_getgeo,
 };
@@ -1005,6 +1005,7 @@ static int __devinit ace_setup(struct ace_device *ace)
 	ace->gd->major = ace_major;
 	ace->gd->first_minor = ace->id * ACE_NUM_MINORS;
 	ace->gd->fops = &ace_fops;
+	ace->gd->events = DISK_EVENT_MEDIA_CHANGE;
 	ace->gd->queue = ace->queue;
 	ace->gd->private_data = ace;
 	snprintf(ace->gd->disk_name, 32, "xs%c", ace->id + 'a');