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;
*/
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.
*/
*/
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)
int i;
int r = -EINVAL;
char *origin_path, *cow_path;
+ dev_t origin_dev, cow_dev;
unsigned args_used, num_flush_requests = 1;
fmode_t origin_mode = FMODE_READ;
ti->error = "Cannot get origin device";
goto bad_origin;
}
+ origin_dev = s->origin->bdev->bd_dev;
cow_path = argv[0];
argv++;
argc--;
+ cow_dev = dm_get_dev_t(cow_path);
+ if (cow_dev && cow_dev == origin_dev) {
+ ti->error = "COW device cannot be the same as origin device";
+ r = -EINVAL;
+ goto bad_cow;
+ }
+
r = dm_get_device(ti, cow_path, dm_table_get_mode(ti->table), &s->cow);
if (r) {
ti->error = "Cannot get COW device";
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);
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;
}
dm_table_event(s->ti->table);
}
-static void pending_complete(struct dm_snap_pending_exception *pe, int success)
+static void pending_complete(void *context, int success)
{
+ struct dm_snap_pending_exception *pe = context;
struct dm_exception *e;
struct dm_snapshot *s = pe->snap;
struct bio *origin_bios = NULL;
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);
}
retry_origin_bios(s, origin_bios);
+
+ free_pending_exception(pe);
}
-static void commit_callback(void *context, int success)
+static void complete_exception(struct dm_snap_pending_exception *pe)
{
- struct dm_snap_pending_exception *pe = context;
+ struct dm_snapshot *s = pe->snap;
- pending_complete(pe, success);
+ /* Update the metadata if we are persistent */
+ s->store->type->commit_exception(s->store, &pe->e, !pe->copy_error,
+ pending_complete, pe);
}
/*
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);
+ }
}
/*
return NULL;
}
+ pe->exception_sequence = s->exception_start_sequence++;
+
dm_insert_exception(&s->pending, &pe->e);
return pe;
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;
maxlen - sz);
break;
}
-
- return 0;
}
static int snapshot_iterate_devices(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;
snprintf(result, maxlen, "%s", dev->name);
break;
}
-
- return 0;
}
static int origin_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
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,
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,
return r;
}
- r = dm_register_target(&snapshot_target);
- if (r < 0) {
- DMERR("snapshot target register failed %d", r);
- goto bad_register_snapshot_target;
- }
-
- r = dm_register_target(&origin_target);
- if (r < 0) {
- DMERR("Origin target register failed %d", r);
- goto bad_register_origin_target;
- }
-
- r = dm_register_target(&merge_target);
- if (r < 0) {
- DMERR("Merge target register failed %d", r);
- goto bad_register_merge_target;
- }
-
r = init_origin_hash();
if (r) {
DMERR("init_origin_hash failed.");
goto bad_tracked_chunk_cache;
}
+ r = dm_register_target(&snapshot_target);
+ if (r < 0) {
+ DMERR("snapshot target register failed %d", r);
+ goto bad_register_snapshot_target;
+ }
+
+ r = dm_register_target(&origin_target);
+ if (r < 0) {
+ DMERR("Origin target register failed %d", r);
+ goto bad_register_origin_target;
+ }
+
+ r = dm_register_target(&merge_target);
+ if (r < 0) {
+ DMERR("Merge target register failed %d", r);
+ goto bad_register_merge_target;
+ }
+
return 0;
+bad_register_merge_target:
+ dm_unregister_target(&origin_target);
+bad_register_origin_target:
+ dm_unregister_target(&snapshot_target);
+bad_register_snapshot_target:
+ kmem_cache_destroy(tracked_chunk_cache);
bad_tracked_chunk_cache:
kmem_cache_destroy(pending_cache);
bad_pending_cache:
bad_exception_cache:
exit_origin_hash();
bad_origin_hash:
- dm_unregister_target(&merge_target);
-bad_register_merge_target:
- dm_unregister_target(&origin_target);
-bad_register_origin_target:
- dm_unregister_target(&snapshot_target);
-bad_register_snapshot_target:
dm_exception_store_exit();
return r;
MODULE_DESCRIPTION(DM_NAME " snapshot target");
MODULE_AUTHOR("Joe Thornber");
MODULE_LICENSE("GPL");
+MODULE_ALIAS("dm-snapshot-origin");
+MODULE_ALIAS("dm-snapshot-merge");
git.openpandora.org / pandora-kernel.git / blobdiff