X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fmd%2Fdm-snap.c;h=6b94c3ce42edce10e07e70169106f6cc7d1529f6;hb=e41f30294b426c6337aa182dc5adc4fea8d2a68a;hp=6f758870fc19cf0e66db3055dab36ab96e038fee;hpb=7e66eaf14e19c032433be7c4df3c892fa2a5282f;p=pandora-kernel.git diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c index 6f758870fc19..6b94c3ce42ed 100644 --- a/drivers/md/dm-snap.c +++ b/drivers/md/dm-snap.c @@ -66,6 +66,18 @@ struct dm_snapshot { atomic_t pending_exceptions_count; + /* Protected by "lock" */ + sector_t exception_start_sequence; + + /* Protected by kcopyd single-threaded callback */ + sector_t exception_complete_sequence; + + /* + * A list of pending exceptions that completed out of order. + * Protected by kcopyd single-threaded callback. + */ + struct list_head out_of_order_list; + mempool_t *pending_pool; struct dm_exception_table pending; @@ -171,6 +183,14 @@ struct dm_snap_pending_exception { */ int started; + /* There was copying error. */ + int copy_error; + + /* A sequence number, it is used for in-order completion. */ + sector_t exception_sequence; + + struct list_head out_of_order_entry; + /* * For writing a complete chunk, bypassing the copy. */ @@ -721,17 +741,16 @@ static int calc_max_buckets(void) */ static int init_hash_tables(struct dm_snapshot *s) { - sector_t hash_size, cow_dev_size, origin_dev_size, max_buckets; + sector_t hash_size, cow_dev_size, max_buckets; /* * Calculate based on the size of the original volume or * the COW volume... */ cow_dev_size = get_dev_size(s->cow->bdev); - origin_dev_size = get_dev_size(s->origin->bdev); max_buckets = calc_max_buckets(); - hash_size = min(origin_dev_size, cow_dev_size) >> s->store->chunk_shift; + hash_size = cow_dev_size >> s->store->chunk_shift; hash_size = min(hash_size, max_buckets); if (hash_size < 64) @@ -1091,6 +1110,9 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) s->valid = 1; s->active = 0; atomic_set(&s->pending_exceptions_count, 0); + s->exception_start_sequence = 0; + s->exception_complete_sequence = 0; + INIT_LIST_HEAD(&s->out_of_order_list); init_rwsem(&s->lock); INIT_LIST_HEAD(&s->list); spin_lock_init(&s->pe_lock); @@ -1117,6 +1139,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv) s->pending_pool = mempool_create_slab_pool(MIN_IOS, pending_cache); if (!s->pending_pool) { ti->error = "Could not allocate mempool for pending exceptions"; + r = -ENOMEM; goto bad_pending_pool; } @@ -1421,8 +1444,6 @@ out: full_bio->bi_end_io = pe->full_bio_end_io; full_bio->bi_private = pe->full_bio_private; } - free_pending_exception(pe); - increment_pending_exceptions_done_count(); up_write(&s->lock); @@ -1439,6 +1460,8 @@ out: } retry_origin_bios(s, origin_bios); + + free_pending_exception(pe); } static void commit_callback(void *context, int success) @@ -1448,6 +1471,19 @@ static void commit_callback(void *context, int success) pending_complete(pe, success); } +static void complete_exception(struct dm_snap_pending_exception *pe) +{ + struct dm_snapshot *s = pe->snap; + + if (unlikely(pe->copy_error)) + pending_complete(pe, 0); + + else + /* Update the metadata if we are persistent */ + s->store->type->commit_exception(s->store, &pe->e, + commit_callback, pe); +} + /* * Called when the copy I/O has finished. kcopyd actually runs * this code so don't block. @@ -1457,13 +1493,32 @@ static void copy_callback(int read_err, unsigned long write_err, void *context) struct dm_snap_pending_exception *pe = context; struct dm_snapshot *s = pe->snap; - if (read_err || write_err) - pending_complete(pe, 0); + pe->copy_error = read_err || write_err; - else - /* Update the metadata if we are persistent */ - s->store->type->commit_exception(s->store, &pe->e, - commit_callback, pe); + if (pe->exception_sequence == s->exception_complete_sequence) { + s->exception_complete_sequence++; + complete_exception(pe); + + while (!list_empty(&s->out_of_order_list)) { + pe = list_entry(s->out_of_order_list.next, + struct dm_snap_pending_exception, out_of_order_entry); + if (pe->exception_sequence != s->exception_complete_sequence) + break; + s->exception_complete_sequence++; + list_del(&pe->out_of_order_entry); + complete_exception(pe); + } + } else { + struct list_head *lh; + struct dm_snap_pending_exception *pe2; + + list_for_each_prev(lh, &s->out_of_order_list) { + pe2 = list_entry(lh, struct dm_snap_pending_exception, out_of_order_entry); + if (pe2->exception_sequence < pe->exception_sequence) + break; + } + list_add(&pe->out_of_order_entry, lh); + } } /* @@ -1558,6 +1613,8 @@ __find_pending_exception(struct dm_snapshot *s, return NULL; } + pe->exception_sequence = s->exception_start_sequence++; + dm_insert_exception(&s->pending, &pe->e); return pe; @@ -1845,8 +1902,8 @@ static void snapshot_merge_resume(struct dm_target *ti) start_merge(s); } -static int snapshot_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) +static void snapshot_status(struct dm_target *ti, status_type_t type, + char *result, unsigned maxlen) { unsigned sz = 0; struct dm_snapshot *snap = ti->private; @@ -1892,8 +1949,6 @@ static int snapshot_status(struct dm_target *ti, status_type_t type, maxlen - sz); break; } - - return 0; } static int snapshot_iterate_devices(struct dm_target *ti, @@ -2148,8 +2203,8 @@ static void origin_resume(struct dm_target *ti) ti->split_io = get_origin_minimum_chunksize(dev->bdev); } -static int origin_status(struct dm_target *ti, status_type_t type, char *result, - unsigned int maxlen) +static void origin_status(struct dm_target *ti, status_type_t type, + char *result, unsigned maxlen) { struct dm_dev *dev = ti->private; @@ -2162,8 +2217,6 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result, snprintf(result, maxlen, "%s", dev->name); break; } - - return 0; } static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm, @@ -2191,7 +2244,7 @@ static int origin_iterate_devices(struct dm_target *ti, static struct target_type origin_target = { .name = "snapshot-origin", - .version = {1, 7, 1}, + .version = {1, 7, 2}, .module = THIS_MODULE, .ctr = origin_ctr, .dtr = origin_dtr, @@ -2204,7 +2257,7 @@ static struct target_type origin_target = { static struct target_type snapshot_target = { .name = "snapshot", - .version = {1, 10, 0}, + .version = {1, 10, 2}, .module = THIS_MODULE, .ctr = snapshot_ctr, .dtr = snapshot_dtr, @@ -2327,3 +2380,5 @@ module_exit(dm_snapshot_exit); MODULE_DESCRIPTION(DM_NAME " snapshot target"); MODULE_AUTHOR("Joe Thornber"); MODULE_LICENSE("GPL"); +MODULE_ALIAS("dm-snapshot-origin"); +MODULE_ALIAS("dm-snapshot-merge");