From b3e8cb104e3ab59c96b09dd0213a8863c1b6578b Mon Sep 17 00:00:00 2001 From: FUJITA Tomonori Date: Fri, 15 Aug 2008 11:33:58 +0900 Subject: [PATCH] dm snapshot: add shared_snapshot_target Signed-off-by: FUJITA Tomonori --- drivers/md/dm-snap.c | 199 +++++++++++++++++++++++++++++++++++++++++++++----- 1 files changed, 181 insertions(+), 18 deletions(-) diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index ae8bb34..aceb143 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -1145,11 +1145,9 @@ static void snapshot_resume(struct dm_target *ti) up_write(&s->lock); } -static int snapshot_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) +static int do_snapshot_status(struct dm_snapshot *snap, status_type_t type, + char *result, unsigned int maxlen, u64 snapid) { - struct dm_snapshot *snap = ti->private; - switch (type) { case STATUSTYPE_INFO: if (!snap->valid) @@ -1175,16 +1173,31 @@ static int snapshot_status(struct dm_target *ti, status_type_t type, * to make private copies if the output is to * make sense. */ - snprintf(result, maxlen, "%s %s %c %llu", - snap->origin->name, snap->cow->name, - snap->type, - (unsigned long long)snap->chunk_size); + if (snap->type == 'S') + snprintf(result, maxlen, "%s %s %c %llu %llu", + snap->origin->name, snap->cow->name, + snap->type, + (unsigned long long)snap->chunk_size, + snapid); + else + snprintf(result, maxlen, "%s %s %c %llu", + snap->origin->name, snap->cow->name, + snap->type, + (unsigned long long)snap->chunk_size); break; } return 0; } +static int snapshot_status(struct dm_target *ti, status_type_t type, + char *result, unsigned int maxlen) +{ + struct dm_snapshot *snap = ti->private; + + return do_snapshot_status(snap, type, result, maxlen, 0); +} + /*----------------------------------------------------------------- * Origin methods *---------------------------------------------------------------*/ @@ -1398,7 +1411,6 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result, /* * shared exception origin code */ - struct dm_shared_origin { struct dm_dev *origin; @@ -1525,6 +1537,134 @@ static int shared_origin_message(struct dm_target *ti, unsigned argc, return snap->store.message(&snap->store, argc, argv); } +/* + * shared exception snapshot code + */ + +struct dm_shared_snapshot { + struct dm_dev *origin; + + struct dm_snapshot *snap; + u64 snapid; +}; + +/* + * Construct a shared origin mapping: + */ +static int shared_snapshot_ctr(struct dm_target *ti, unsigned int argc, + char **argv) +{ + int r; + struct dm_shared_origin *dso; + struct dm_shared_snapshot *dss; + struct dm_snapshot *origin_snap; + struct dm_dev *dev; + struct origin *o; + u64 id; + + if (argc != 2) { + ti->error = "snapshot: incorrect number of arguments"; + return -EINVAL; + } + + dss = kzalloc(sizeof(*dss), GFP_KERNEL); + if (!dss) + return -ENOMEM; + + id = simple_strtoul(argv[1], NULL, 10); + if (id >= 64) { + r = -EINVAL; + ti->error = "Invalid snapid"; + goto out; + } + + r = dm_get_device(ti, argv[0], 0, ti->len, FMODE_READ, &dev); + if (r) { + ti->error = "Cannot get origin device"; + goto out; + } + + r = -EINVAL; + down_read(&_origins_lock); + o = __lookup_origin(dev->bdev); + if (o && !list_empty(&o->snapshots)) { + int nr; + unsigned long map[DIV_ROUND_UP(MAX_SNAPSHOTS, BITS_PER_LONG)]; + struct exception_store *store; + + memset(map, 0, sizeof(map)); + + origin_snap = list_first_entry(&o->snapshots, + struct dm_snapshot, list); + store = &origin_snap->store; + dso = origin_snap->ti->private; + + down_write(&store->snap->lock); + nr = store->get_snapshot_info(store, map, sizeof(map)); + up_write(&store->snap->lock); + + if (test_bit(id, map)) { + dm_table_get(origin_snap->ti->table); + ti->private = dss; + dss->snap = origin_snap; + dss->snapid = id; + dss->origin = dev; + + ti->split_io = origin_snap->chunk_size; + r = 0; + + printk("%s %d: %lld\n", __FUNCTION__, __LINE__, + (unsigned long long)id); + + } else { + ti->error = "non-exist snapshot"; + r = -EINVAL; + } + } + up_read(&_origins_lock); + + if (r) + dm_put_device(ti, dev); +out: + if (r) + kfree(dss); + + return r; +} + +static void shared_snapshot_dtr(struct dm_target *ti) +{ + struct dm_shared_snapshot *dss = ti->private; + + dm_table_put(dss->snap->ti->table); + dm_put_device(ti, dss->origin); + kfree(dss); +} + +static int shared_snapshot_map(struct dm_target *ti, struct bio *bio, + union map_info *map_context) +{ + struct dm_shared_snapshot *dss = ti->private; + + return do_snapshot_map(dss->snap, bio, map_context, dss->snapid); +} + +static int shared_snapshot_end_io(struct dm_target *ti, struct bio *bio, + int error, union map_info *map_context) +{ + struct dm_shared_snapshot *dss = ti->private; + + return do_snapshot_end_io(dss->snap, bio, error, map_context); +} + +static int shared_snapshot_status(struct dm_target *ti, status_type_t type, + char *result, unsigned int maxlen) +{ + struct dm_shared_snapshot *dss = ti->private; + + return do_snapshot_status(dss->snap, type, result, maxlen, dss->snapid); +} + static struct target_type origin_target = { .name = "snapshot-origin", .version = {1, 6, 0}, @@ -1559,6 +1699,17 @@ static struct target_type shared_origin_target = { .message = shared_origin_message, }; +static struct target_type shared_snapshot_target = { + .name = "s-snap", + .version = {1, 0, 0}, + .module = THIS_MODULE, + .ctr = shared_snapshot_ctr, + .dtr = shared_snapshot_dtr, + .map = shared_snapshot_map, + .end_io = shared_snapshot_end_io, + .status = shared_snapshot_status, +}; + static int __init dm_snapshot_init(void) { int r; @@ -1575,37 +1726,43 @@ static int __init dm_snapshot_init(void) goto bad1; } + r = dm_register_target(&shared_snapshot_target); + if (r) { + DMERR("shared snapshot target register failed %d", r); + goto bad2; + } + r = dm_register_target(&shared_origin_target); if (r) { DMERR("shared origin target register failed %d", r); - goto bad2; + goto bad3; } r = init_origin_hash(); if (r) { DMERR("init_origin_hash failed."); - goto bad3; + goto bad4; } exception_cache = KMEM_CACHE(dm_snap_exception, 0); if (!exception_cache) { DMERR("Couldn't create exception cache."); r = -ENOMEM; - goto bad4; + goto bad5; } pending_cache = KMEM_CACHE(dm_snap_pending_exception, 0); if (!pending_cache) { DMERR("Couldn't create pending cache."); r = -ENOMEM; - goto bad5; + goto bad6; } 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 bad6; + goto bad7; } ksnapd = create_singlethread_workqueue("ksnapd"); @@ -1619,14 +1776,16 @@ static int __init dm_snapshot_init(void) bad_pending_pool: kmem_cache_destroy(tracked_chunk_cache); - bad6: + bad7: kmem_cache_destroy(pending_cache); - bad5: + bad6: kmem_cache_destroy(exception_cache); - bad4: + bad5: exit_origin_hash(); - bad3: + bad4: dm_unregister_target(&shared_origin_target); + bad3: + dm_unregister_target(&shared_snapshot_target); bad2: dm_unregister_target(&origin_target); bad1: @@ -1648,6 +1807,10 @@ static void __exit dm_snapshot_exit(void) if (r) DMERR("origin unregister failed %d", r); + r = dm_unregister_target(&shared_snapshot_target); + if (r) + DMERR("shared snapshot unregister failed %d", r); + r = dm_unregister_target(&shared_origin_target); if (r) DMERR("shared origin unregister failed %d", r); -- 1.5.5.GIT