dm snapshot: use per_bio_data

Replace tracked_chunk_pool with per_bio_data in dm-snap.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
This commit is contained in:
Mikulas Patocka 2012-12-21 20:23:38 +00:00 committed by Alasdair G Kergon
parent e42c3f914d
commit 42bc954f2a

View File

@ -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();
}