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Commit 42bc954f authored by Mikulas Patocka's avatar Mikulas Patocka Committed by Alasdair G Kergon
Browse files

dm snapshot: use per_bio_data 



Replace tracked_chunk_pool with per_bio_data in dm-snap.

Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent e42c3f91

drivers/md/dm-snap.c

+8 −35
Original line number Diff line number Diff line
@@ -79,7 +79,6 @@ struct dm_snapshot { 


	/* Chunks with outstanding reads */

	spinlock_t tracked_chunk_lock;

	mempool_t *tracked_chunk_pool;

	struct hlist_head tracked_chunk_hash[DM_TRACKED_CHUNK_HASH_SIZE];



	/* The on disk metadata handler */
@@ -191,13 +190,11 @@ struct dm_snap_tracked_chunk { 
	chunk_t chunk;

};



static struct kmem_cache *tracked_chunk_cache;



static struct dm_snap_tracked_chunk *track_chunk(struct dm_snapshot *s,

						 struct bio *bio,

						 chunk_t chunk)

{

	struct dm_snap_tracked_chunk *c = mempool_alloc(s->tracked_chunk_pool,

							GFP_NOIO);

	struct dm_snap_tracked_chunk *c = dm_per_bio_data(bio, sizeof(struct dm_snap_tracked_chunk));



	c->chunk = chunk;
@@ -217,8 +214,6 @@ static void stop_tracking_chunk(struct dm_snapshot *s, 
	spin_lock_irqsave(&s->tracked_chunk_lock, flags);

	hlist_del(&c->node);

	spin_unlock_irqrestore(&s->tracked_chunk_lock, flags);



	mempool_free(c, s->tracked_chunk_pool);

}



static int __chunk_is_tracked(struct dm_snapshot *s, chunk_t chunk)
@@ -1119,14 +1114,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 
		goto bad_pending_pool;

	}



	s->tracked_chunk_pool = mempool_create_slab_pool(MIN_IOS,

							 tracked_chunk_cache);

	if (!s->tracked_chunk_pool) {

		ti->error = "Could not allocate tracked_chunk mempool for "

			    "tracking reads";

		goto bad_tracked_chunk_pool;

	}



	for (i = 0; i < DM_TRACKED_CHUNK_HASH_SIZE; i++)

		INIT_HLIST_HEAD(&s->tracked_chunk_hash[i]);
@@ -1134,6 +1121,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) 


	ti->private = s;

	ti->num_flush_requests = num_flush_requests;

	ti->per_bio_data_size = sizeof(struct dm_snap_tracked_chunk);



	/* Add snapshot to the list of snapshots for this origin */

	/* Exceptions aren't triggered till snapshot_resume() is called */
@@ -1182,9 +1170,6 @@ bad_read_metadata: 
	unregister_snapshot(s);



bad_load_and_register:

	mempool_destroy(s->tracked_chunk_pool);



bad_tracked_chunk_pool:

	mempool_destroy(s->pending_pool);



bad_pending_pool:
@@ -1289,8 +1274,6 @@ static void snapshot_dtr(struct dm_target *ti) 
		BUG_ON(!hlist_empty(&s->tracked_chunk_hash[i]));

#endif



	mempool_destroy(s->tracked_chunk_pool);



	__free_exceptions(s);



	mempool_destroy(s->pending_pool);
@@ -1669,7 +1652,7 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio, 
		}

	} else {

		bio->bi_bdev = s->origin->bdev;

		map_context->ptr = track_chunk(s, chunk);

		map_context->ptr = track_chunk(s, bio, chunk);

	}



out_unlock:
@@ -1732,7 +1715,7 @@ static int snapshot_merge_map(struct dm_target *ti, struct bio *bio, 
		remap_exception(s, e, bio, chunk);



		if (bio_rw(bio) == WRITE)

			map_context->ptr = track_chunk(s, chunk);

			map_context->ptr = track_chunk(s, bio, chunk);

		goto out_unlock;

	}
@@ -2192,7 +2175,7 @@ static int origin_iterate_devices(struct dm_target *ti, 


static struct target_type origin_target = {

	.name    = "snapshot-origin",

	.version = {1, 7, 1},

	.version = {1, 8, 0},

	.module  = THIS_MODULE,

	.ctr     = origin_ctr,

	.dtr     = origin_dtr,
@@ -2205,7 +2188,7 @@ static struct target_type origin_target = { 


static struct target_type snapshot_target = {

	.name    = "snapshot",

	.version = {1, 10, 0},

	.version = {1, 11, 0},

	.module  = THIS_MODULE,

	.ctr     = snapshot_ctr,

	.dtr     = snapshot_dtr,
@@ -2219,7 +2202,7 @@ static struct target_type snapshot_target = { 


static struct target_type merge_target = {

	.name    = dm_snapshot_merge_target_name,

	.version = {1, 1, 0},

	.version = {1, 2, 0},

	.module  = THIS_MODULE,

	.ctr     = snapshot_ctr,

	.dtr     = snapshot_dtr,
@@ -2280,17 +2263,8 @@ static int __init dm_snapshot_init(void) 
		goto bad_pending_cache;

	}



	tracked_chunk_cache = KMEM_CACHE(dm_snap_tracked_chunk, 0);

	if (!tracked_chunk_cache) {

		DMERR("Couldn't create cache to track chunks in use.");

		r = -ENOMEM;

		goto bad_tracked_chunk_cache;

	}



	return 0;



bad_tracked_chunk_cache:

	kmem_cache_destroy(pending_cache);

bad_pending_cache:

	kmem_cache_destroy(exception_cache);

bad_exception_cache:
@@ -2316,7 +2290,6 @@ static void __exit dm_snapshot_exit(void) 
	exit_origin_hash();

	kmem_cache_destroy(pending_cache);

	kmem_cache_destroy(exception_cache);

	kmem_cache_destroy(tracked_chunk_cache);



	dm_exception_store_exit();

}