dm delay: use per-bio data instead of a mempool and slab cache (42065460) · Commits · 戴 / test

drivers/md/dm-delay.c

+7 −28

Original line number	Diff line number	Diff line
		@@ -24,7 +24,6 @@ struct delay_c {
		struct work_struct flush_expired_bios;
		struct list_head delayed_bios;
		atomic_t may_delay;
		mempool_t *delayed_pool;

		struct dm_dev *dev_read;
		sector_t start_read;
		@@ -40,14 +39,11 @@ struct delay_c {
		struct dm_delay_info {
		struct delay_c *context;
		struct list_head list;
		struct bio *bio;
		unsigned long expires;
		};

		static DEFINE_MUTEX(delayed_bios_lock);

		static struct kmem_cache *delayed_cache;

		static void handle_delayed_timer(unsigned long data)
		{
		struct delay_c dc = (struct delay_c )data;
		@@ -87,13 +83,14 @@ static struct bio flush_delayed_bios(struct delay_c dc, int flush_all)
		mutex_lock(&delayed_bios_lock);
		list_for_each_entry_safe(delayed, next, &dc->delayed_bios, list) {
		if (flush_all \|\| time_after_eq(jiffies, delayed->expires)) {
		struct bio *bio = dm_bio_from_per_bio_data(delayed,
		sizeof(struct dm_delay_info));
		list_del(&delayed->list);
		bio_list_add(&flush_bios, delayed->bio);
		if ((bio_data_dir(delayed->bio) == WRITE))
		bio_list_add(&flush_bios, bio);
		if ((bio_data_dir(bio) == WRITE))
		delayed->context->writes--;
		else
		delayed->context->reads--;
		mempool_free(delayed, dc->delayed_pool);
		continue;
		}

		@@ -185,12 +182,6 @@ static int delay_ctr(struct dm_target ti, unsigned int argc, char *argv)
		}

		out:
		dc->delayed_pool = mempool_create_slab_pool(128, delayed_cache);
		if (!dc->delayed_pool) {
		DMERR("Couldn't create delayed bio pool.");
		goto bad_dev_write;
		}

		dc->kdelayd_wq = alloc_workqueue("kdelayd", WQ_MEM_RECLAIM, 0);
		if (!dc->kdelayd_wq) {
		DMERR("Couldn't start kdelayd");
		@@ -206,12 +197,11 @@ out:

		ti->num_flush_bios = 1;
		ti->num_discard_bios = 1;
		ti->per_bio_data_size = sizeof(struct dm_delay_info);
		ti->private = dc;
		return 0;

		bad_queue:
		mempool_destroy(dc->delayed_pool);
		bad_dev_write:
		if (dc->dev_write)
		dm_put_device(ti, dc->dev_write);
		bad_dev_read:
		@@ -232,7 +222,6 @@ static void delay_dtr(struct dm_target *ti)
		if (dc->dev_write)
		dm_put_device(ti, dc->dev_write);

		mempool_destroy(dc->delayed_pool);
		kfree(dc);
		}

		@@ -244,10 +233,9 @@ static int delay_bio(struct delay_c dc, int delay, struct bio bio)
		if (!delay \|\| !atomic_read(&dc->may_delay))
		return 1;

		delayed = mempool_alloc(dc->delayed_pool, GFP_NOIO);
		delayed = dm_per_bio_data(bio, sizeof(struct dm_delay_info));

		delayed->context = dc;
		delayed->bio = bio;
		delayed->expires = expires = jiffies + (delay * HZ / 1000);

		mutex_lock(&delayed_bios_lock);
		@@ -356,13 +344,7 @@ static struct target_type delay_target = {

		static int __init dm_delay_init(void)
		{
		int r = -ENOMEM;

		delayed_cache = KMEM_CACHE(dm_delay_info, 0);
		if (!delayed_cache) {
		DMERR("Couldn't create delayed bio cache.");
		goto bad_memcache;
		}
		int r;

		r = dm_register_target(&delay_target);
		if (r < 0) {
		@@ -373,15 +355,12 @@ static int __init dm_delay_init(void)
		return 0;

		bad_register:
		kmem_cache_destroy(delayed_cache);
		bad_memcache:
		return r;
		}

		static void __exit dm_delay_exit(void)
		{
		dm_unregister_target(&delay_target);
		kmem_cache_destroy(delayed_cache);
		}

		/* Module hooks */

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