md/raid5: add simple plugging infrastructure.
md/raid5 uses the plugging infrastructure provided by the block layer
and 'struct request_queue'. However when we plug raid5 under dm there
is no request queue so we cannot use that.
So create a similar infrastructure that is much lighter weight and use
it for raid5.
Signed-off-by: NeilBrown <neilb@suse.de>
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index ad6694f..84bb9ae 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -201,11 +201,11 @@
if (test_bit(STRIPE_HANDLE, &sh->state)) {
if (test_bit(STRIPE_DELAYED, &sh->state)) {
list_add_tail(&sh->lru, &conf->delayed_list);
- blk_plug_device(conf->mddev->queue);
+ plugger_set_plug(&conf->plug);
} else if (test_bit(STRIPE_BIT_DELAY, &sh->state) &&
sh->bm_seq - conf->seq_write > 0) {
list_add_tail(&sh->lru, &conf->bitmap_list);
- blk_plug_device(conf->mddev->queue);
+ plugger_set_plug(&conf->plug);
} else {
clear_bit(STRIPE_BIT_DELAY, &sh->state);
list_add_tail(&sh->lru, &conf->handle_list);
@@ -434,7 +434,7 @@
}
static void unplug_slaves(mddev_t *mddev);
-static void raid5_unplug_device(struct request_queue *q);
+static void raid5_unplug_device(raid5_conf_t *conf);
static struct stripe_head *
get_active_stripe(raid5_conf_t *conf, sector_t sector,
@@ -464,7 +464,7 @@
< (conf->max_nr_stripes *3/4)
|| !conf->inactive_blocked),
conf->device_lock,
- raid5_unplug_device(conf->mddev->queue)
+ raid5_unplug_device(conf)
);
conf->inactive_blocked = 0;
} else
@@ -3618,7 +3618,7 @@
list_add_tail(&sh->lru, &conf->hold_list);
}
} else
- blk_plug_device(conf->mddev->queue);
+ plugger_set_plug(&conf->plug);
}
static void activate_bit_delay(raid5_conf_t *conf)
@@ -3659,23 +3659,33 @@
rcu_read_unlock();
}
-static void raid5_unplug_device(struct request_queue *q)
+static void raid5_unplug_device(raid5_conf_t *conf)
{
- mddev_t *mddev = q->queuedata;
- raid5_conf_t *conf = mddev->private;
unsigned long flags;
spin_lock_irqsave(&conf->device_lock, flags);
- if (blk_remove_plug(q)) {
+ if (plugger_remove_plug(&conf->plug)) {
conf->seq_flush++;
raid5_activate_delayed(conf);
}
- md_wakeup_thread(mddev->thread);
+ md_wakeup_thread(conf->mddev->thread);
spin_unlock_irqrestore(&conf->device_lock, flags);
- unplug_slaves(mddev);
+ unplug_slaves(conf->mddev);
+}
+
+static void raid5_unplug(struct plug_handle *plug)
+{
+ raid5_conf_t *conf = container_of(plug, raid5_conf_t, plug);
+ raid5_unplug_device(conf);
+}
+
+static void raid5_unplug_queue(struct request_queue *q)
+{
+ mddev_t *mddev = q->queuedata;
+ raid5_unplug_device(mddev->private);
}
int md_raid5_congested(mddev_t *mddev, int bits)
@@ -4085,7 +4095,7 @@
* add failed due to overlap. Flush everything
* and wait a while
*/
- raid5_unplug_device(mddev->queue);
+ raid5_unplug_device(conf);
release_stripe(sh);
schedule();
goto retry;
@@ -5178,6 +5188,7 @@
mdname(mddev));
md_set_array_sectors(mddev, raid5_size(mddev, 0, 0));
+ plugger_init(&conf->plug, raid5_unplug);
if (mddev->queue) {
/* read-ahead size must cover two whole stripes, which
* is 2 * (datadisks) * chunksize where 'n' is the
@@ -5197,7 +5208,7 @@
mddev->queue->queue_lock = &conf->device_lock;
- mddev->queue->unplug_fn = raid5_unplug_device;
+ mddev->queue->unplug_fn = raid5_unplug_queue;
chunk_size = mddev->chunk_sectors << 9;
blk_queue_io_min(mddev->queue, chunk_size);
@@ -5229,7 +5240,7 @@
mddev->thread = NULL;
if (mddev->queue)
mddev->queue->backing_dev_info.congested_fn = NULL;
- blk_sync_queue(mddev->queue); /* the unplug fn references 'conf'*/
+ plugger_flush(&conf->plug); /* the unplug fn references 'conf'*/
free_conf(conf);
mddev->private = NULL;
mddev->to_remove = &raid5_attrs_group;