md - remove old plugging code.

md has some plugging infrastructure for RAID5 to use because the
normal plugging infrastructure required a 'request_queue', and when
called from dm, RAID5 doesn't have one of those available.

This relied on the ->unplug_fn callback which doesn't exist any more.

So remove all of that code, both in md and raid5.  Subsequent patches
with restore the plugging functionality.

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/drivers/md/md.c b/drivers/md/md.c
index b12b3776c0c0c8ca46b998cac6df78845363f7ee..fb11170c717ebf496e2024ce86274156e9ed0e03 100644 (file)
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -445,50 +445,6 @@ void md_flush_request(mddev_t *mddev, struct bio *bio)
 }
 EXPORT_SYMBOL(md_flush_request);
 
-/* Support for plugging.
- * This mirrors the plugging support in request_queue, but does not
- * require having a whole queue
- */
-static void plugger_work(struct work_struct *work)
-{
-       struct plug_handle *plug =
-               container_of(work, struct plug_handle, unplug_work);
-       plug->unplug_fn(plug);
-}
-static void plugger_timeout(unsigned long data)
-{
-       struct plug_handle *plug = (void *)data;
-       kblockd_schedule_work(NULL, &plug->unplug_work);
-}
-void plugger_init(struct plug_handle *plug,
-                 void (*unplug_fn)(struct plug_handle *))
-{
-       plug->unplug_flag = 0;
-       plug->unplug_fn = unplug_fn;
-       init_timer(&plug->unplug_timer);
-       plug->unplug_timer.function = plugger_timeout;
-       plug->unplug_timer.data = (unsigned long)plug;
-       INIT_WORK(&plug->unplug_work, plugger_work);
-}
-EXPORT_SYMBOL_GPL(plugger_init);
-
-void plugger_set_plug(struct plug_handle *plug)
-{
-       if (!test_and_set_bit(PLUGGED_FLAG, &plug->unplug_flag))
-               mod_timer(&plug->unplug_timer, jiffies + msecs_to_jiffies(3)+1);
-}
-EXPORT_SYMBOL_GPL(plugger_set_plug);
-
-int plugger_remove_plug(struct plug_handle *plug)
-{
-       if (test_and_clear_bit(PLUGGED_FLAG, &plug->unplug_flag)) {
-               del_timer(&plug->unplug_timer);
-               return 1;
-       } else
-               return 0;
-}
-EXPORT_SYMBOL_GPL(plugger_remove_plug);
-
 
 static inline mddev_t *mddev_get(mddev_t *mddev)
 {
@@ -4723,7 +4679,6 @@ static void md_clean(mddev_t *mddev)
        mddev->bitmap_info.chunksize = 0;
        mddev->bitmap_info.daemon_sleep = 0;
        mddev->bitmap_info.max_write_behind = 0;
-       mddev->plug = NULL;
 }
 
 static void __md_stop_writes(mddev_t *mddev)
@@ -6688,12 +6643,6 @@ int md_allow_write(mddev_t *mddev)
 }
 EXPORT_SYMBOL_GPL(md_allow_write);
 
-void md_unplug(mddev_t *mddev)
-{
-       if (mddev->plug)
-               mddev->plug->unplug_fn(mddev->plug);
-}
-
 #define SYNC_MARKS     10
 #define        SYNC_MARK_STEP  (3*HZ)
 void md_do_sync(mddev_t *mddev)

diff --git a/drivers/md/md.h b/drivers/md/md.h
index 52b407369e13f0c82b7fa23f3ee2ca7d41483bbb..fad90228672f5bcb89d57b98f6a122b9274cd355 100644 (file)
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -29,26 +29,6 @@
 typedef struct mddev_s mddev_t;
 typedef struct mdk_rdev_s mdk_rdev_t;
 
-/* generic plugging support - like that provided with request_queue,
- * but does not require a request_queue
- */
-struct plug_handle {
-       void                    (*unplug_fn)(struct plug_handle *);
-       struct timer_list       unplug_timer;
-       struct work_struct      unplug_work;
-       unsigned long           unplug_flag;
-};
-#define        PLUGGED_FLAG 1
-void plugger_init(struct plug_handle *plug,
-                 void (*unplug_fn)(struct plug_handle *));
-void plugger_set_plug(struct plug_handle *plug);
-int plugger_remove_plug(struct plug_handle *plug);
-static inline void plugger_flush(struct plug_handle *plug)
-{
-       del_timer_sync(&plug->unplug_timer);
-       cancel_work_sync(&plug->unplug_work);
-}
-
 /*
  * MD's 'extended' device
  */
@@ -336,7 +316,6 @@ struct mddev_s
        struct list_head                all_mddevs;
 
        struct attribute_group          *to_remove;
-       struct plug_handle              *plug; /* if used by personality */
 
        struct bio_set                  *bio_set;
 
@@ -516,7 +495,6 @@ extern int md_integrity_register(mddev_t *mddev);
 extern void md_integrity_add_rdev(mdk_rdev_t *rdev, mddev_t *mddev);
 extern int strict_strtoul_scaled(const char *cp, unsigned long *res, int scale);
 extern void restore_bitmap_write_access(struct file *file);
-extern void md_unplug(mddev_t *mddev);
 
 extern void mddev_init(mddev_t *mddev);
 extern int md_run(mddev_t *mddev);

diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ce6960b1c682290157c85e871e00d90427515311..a1755a6a3e5f8b04eecf2f3189ad8d8199039570 100644 (file)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -199,14 +199,12 @@ static void __release_stripe(raid5_conf_t *conf, struct stripe_head *sh)
                BUG_ON(!list_empty(&sh->lru));
                BUG_ON(atomic_read(&conf->active_stripes)==0);
                if (test_bit(STRIPE_HANDLE, &sh->state)) {
-                       if (test_bit(STRIPE_DELAYED, &sh->state)) {
+                       if (test_bit(STRIPE_DELAYED, &sh->state))
                                list_add_tail(&sh->lru, &conf->delayed_list);
-                               plugger_set_plug(&conf->plug);
-                       } else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
-                                  sh->bm_seq - conf->seq_write > 0) {
+                       else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
+                                  sh->bm_seq - conf->seq_write > 0)
                                list_add_tail(&sh->lru, &conf->bitmap_list);
-                               plugger_set_plug(&conf->plug);
-                       } else {
+                       else {
                                clear_bit(STRIPE_BIT_DELAY, &sh->state);
                                list_add_tail(&sh->lru, &conf->handle_list);
                        }
@@ -461,7 +459,7 @@ get_active_stripe(raid5_conf_t *conf, sector_t sector,
                                                     < (conf->max_nr_stripes *3/4)
                                                     || !conf->inactive_blocked),
                                                    conf->device_lock,
-                                                   md_raid5_kick_device(conf));
+                                                   md_wakeup_thread(conf->mddev->thread));
                                conf->inactive_blocked = 0;
                        } else
                                init_stripe(sh, sector, previous);
@@ -1470,7 +1468,7 @@ 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,
-                                   blk_flush_plug(current));
+                                   );
                osh = get_free_stripe(conf);
                spin_unlock_irq(&conf->device_lock);
                atomic_set(&nsh->count, 1);
@@ -3623,8 +3621,7 @@ static void raid5_activate_delayed(raid5_conf_t *conf)
                                atomic_inc(&conf->preread_active_stripes);
                        list_add_tail(&sh->lru, &conf->hold_list);
                }
-       } else
-               plugger_set_plug(&conf->plug);
+       }
 }
 
 static void activate_bit_delay(raid5_conf_t *conf)
@@ -3641,21 +3638,6 @@ static void activate_bit_delay(raid5_conf_t *conf)
        }
 }
 
-void md_raid5_kick_device(raid5_conf_t *conf)
-{
-       blk_flush_plug(current);
-       raid5_activate_delayed(conf);
-       md_wakeup_thread(conf->mddev->thread);
-}
-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_kick_device(conf);
-}
-
 int md_raid5_congested(mddev_t *mddev, int bits)
 {
        raid5_conf_t *conf = mddev->private;
@@ -4057,7 +4039,7 @@ static int make_request(mddev_t *mddev, struct bio * bi)
                                 * add failed due to overlap.  Flush everything
                                 * and wait a while
                                 */
-                               md_raid5_kick_device(conf);
+                               md_wakeup_thread(mddev->thread);
                                release_stripe(sh);
                                schedule();
                                goto retry;
@@ -5144,8 +5126,6 @@ static int run(mddev_t *mddev)
                       mdname(mddev));
        md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
 
-       plugger_init(&conf->plug, raid5_unplug);
-       mddev->plug = &conf->plug;
        if (mddev->queue) {
                int chunk_size;
                /* read-ahead size must cover two whole stripes, which
@@ -5195,7 +5175,6 @@ static int stop(mddev_t *mddev)
        mddev->thread = NULL;
        if (mddev->queue)
                mddev->queue->backing_dev_info.congested_fn = NULL;
-       plugger_flush(&conf->plug); /* the unplug fn references 'conf'*/
        free_conf(conf);
        mddev->private = NULL;
        mddev->to_remove = &raid5_attrs_group;

diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h
index 8d563a4f022a778a6d9354a3c1bf514c6f5e10b6..3ca77a2613ba0a544ffa9c4aca4e12122d77cc96 100644 (file)
--- a/drivers/md/raid5.h
+++ b/drivers/md/raid5.h
@@ -400,8 +400,6 @@ struct raid5_private_data {
                                            * Cleared when a sync completes.
                                            */
 
-       struct plug_handle      plug;
-
        /* per cpu variables */
        struct raid5_percpu {
                struct page     *spare_page; /* Used when checking P/Q in raid6 */