210 	struct dm_snapshot *snap;  member
448 static int __find_snapshots_sharing_cow(struct dm_snapshot *snap,  in __find_snapshots_sharing_cow()  argument
458 	o = __lookup_origin(snap->origin->bdev);  in __find_snapshots_sharing_cow()
465 		if (!bdev_equal(s->cow->bdev, snap->cow->bdev))  in __find_snapshots_sharing_cow()
489 static int __validate_exception_handover(struct dm_snapshot *snap)  in __validate_exception_handover()  argument
495 	if ((__find_snapshots_sharing_cow(snap, &snap_src, &snap_dest,  in __validate_exception_handover()
498 		snap->ti->error = "Snapshot cow pairing for exception table handover failed";  in __validate_exception_handover()
512 	if (!dm_target_is_snapshot_merge(snap->ti))  in __validate_exception_handover()
519 		snap->ti->error = "A snapshot is already merging.";  in __validate_exception_handover()
525 		snap->ti->error = "Snapshot exception store does not support snapshot-merge.";  in __validate_exception_handover()
551 static int register_snapshot(struct dm_snapshot *snap)  in register_snapshot()  argument
554 	struct block_device *bdev = snap->origin->bdev;  in register_snapshot()
563 	r = __validate_exception_handover(snap);  in register_snapshot()
583 	__insert_snapshot(o, snap);  in register_snapshot()
746 	pe->snap = s;  in alloc_pending_exception()
753 	struct dm_snapshot *s = pe->snap;  in free_pending_exception()
855 	struct dm_snapshot *snap;  in __minimum_chunk_size()  local
859 		list_for_each_entry(snap, &o->snapshots, list)  in __minimum_chunk_size()
861 						  snap->store->chunk_size);  in __minimum_chunk_size()
1453 	snap_dest->store->snap = snap_dest;  in __handover_exceptions()
1454 	snap_src->store->snap = snap_src;  in __handover_exceptions()
1645 	struct dm_snapshot *s = pe->snap;  in pending_complete()
1731 	struct dm_snapshot *s = pe->snap;  in complete_exception()
1745 	struct dm_snapshot *s = pe->snap;  in copy_callback()
1794 	struct dm_snapshot *s = pe->snap;  in start_copy()
1824 	struct dm_snapshot *s = pe->snap;  in start_full_bio()
2317 	struct dm_snapshot *snap = ti->private;  in snapshot_status()  local
2323 		down_write(&snap->lock);  in snapshot_status()
2325 		if (!snap->valid)  in snapshot_status()
2327 		else if (snap->merge_failed)  in snapshot_status()
2329 		else if (snap->snapshot_overflowed)  in snapshot_status()
2332 			if (snap->store->type->usage) {  in snapshot_status()
2335 				snap->store->type->usage(snap->store,  in snapshot_status()
2347 		up_write(&snap->lock);  in snapshot_status()
2357 		DMEMIT("%s %s", snap->origin->name, snap->cow->name);  in snapshot_status()
2358 		sz += snap->store->type->status(snap->store, type, result + sz,  in snapshot_status()
2360 		num_features = snap->discard_zeroes_cow + snap->discard_passdown_origin;  in snapshot_status()
2363 			if (snap->discard_zeroes_cow)  in snapshot_status()
2365 			if (snap->discard_passdown_origin)  in snapshot_status()
2372 		DMEMIT(",snap_origin_name=%s", snap->origin->name);  in snapshot_status()
2373 		DMEMIT(",snap_cow_name=%s", snap->cow->name);  in snapshot_status()
2374 		DMEMIT(",snap_valid=%c", snap->valid ? 'y' : 'n');  in snapshot_status()
2375 		DMEMIT(",snap_merge_failed=%c", snap->merge_failed ? 'y' : 'n');  in snapshot_status()
2376 		DMEMIT(",snapshot_overflowed=%c", snap->snapshot_overflowed ? 'y' : 'n');  in snapshot_status()
2385 	struct dm_snapshot *snap = ti->private;  in snapshot_iterate_devices()  local
2388 	r = fn(ti, snap->origin, 0, ti->len, data);  in snapshot_iterate_devices()
2391 		r = fn(ti, snap->cow, 0, get_dev_size(snap->cow->bdev), data);  in snapshot_iterate_devices()
2398 	struct dm_snapshot *snap = ti->private;  in snapshot_io_hints()  local
2400 	if (snap->discard_zeroes_cow) {  in snapshot_io_hints()
2405 		(void) __find_snapshots_sharing_cow(snap, &snap_src, &snap_dest, NULL);  in snapshot_io_hints()
2407 			snap = snap_src;  in snapshot_io_hints()
2410 		limits->discard_granularity = snap->store->chunk_size;  in snapshot_io_hints()
2411 		limits->max_discard_sectors = snap->store->chunk_size;  in snapshot_io_hints()
2436 	struct dm_snapshot *snap;  in __origin_write()  local
2445 	list_for_each_entry(snap, snapshots, list) {  in __origin_write()
2450 		if (dm_target_is_snapshot_merge(snap->ti))  in __origin_write()
2454 		if (sector >= dm_table_get_size(snap->ti->table))  in __origin_write()
2461 		chunk = sector_to_chunk(snap->store, sector);  in __origin_write()
2462 		dm_exception_table_lock_init(snap, chunk, &lock);  in __origin_write()
2464 		down_read(&snap->lock);  in __origin_write()
2468 		if (!snap->valid || !snap->active)  in __origin_write()
2471 		pe = __lookup_pending_exception(snap, chunk);  in __origin_write()
2478 			e = dm_lookup_exception(&snap->complete, chunk);  in __origin_write()
2483 			pe = alloc_pending_exception(snap);  in __origin_write()
2486 			pe2 = __lookup_pending_exception(snap, chunk);  in __origin_write()
2489 				e = dm_lookup_exception(&snap->complete, chunk);  in __origin_write()
2495 				pe = __insert_pending_exception(snap, pe, chunk);  in __origin_write()
2498 					up_read(&snap->lock);  in __origin_write()
2500 					invalidate_snapshot(snap, -ENOMEM);  in __origin_write()
2533 		up_read(&snap->lock);  in __origin_write()