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>

14 files changed, 7 insertions, 143 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 9279272b3732..35658f445fca 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 946dad4caef3..b2fceb53e809 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 ba95cba192be..aca302492ff2 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 fd42832f785b..0645ca829a94 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 3803a0348937..b0bd27dfc1e8 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 29cd0dc9fe4f..8a43ce0edeed 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 24487d4fb202..8e68be939deb 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 11a75d32a2e2..ad3fc6228f27 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 34f224b018b3..e027446590d3 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 defdb5013ea3..53586fa5ae1b 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 3851dbc03e05..301d7a9a41a6 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3838,7 +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);
 
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 79c3079a6203..a076a14ca72d 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);
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index a077db27b7c9..07a382eaf0a8 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");
diff --git a/drivers/block/umem.c b/drivers/block/umem.c
index 9b102abe209c..031ca720d926 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;
@@ -897,7 +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);