1 files changed, 55 insertions, 66 deletions

diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c
index 1b4e1756b169..dd90d1236f4a 100644
--- a/drivers/md/dm-cache-target.c
+++ b/drivers/md/dm-cache-target.c
@@ -424,7 +424,6 @@ static void free_migration(struct dm_cache_migration *mg)
 		wake_up(&cache->migration_wait);
 
 	mempool_free(mg, cache->migration_pool);
-	wake_worker(cache);
 }
 
 static int prealloc_data_structs(struct cache *cache, struct prealloc *p)
@@ -919,14 +918,14 @@ static void defer_writethrough_bio(struct cache *cache, struct bio *bio)
 	wake_worker(cache);
 }
 
-static void writethrough_endio(struct bio *bio, int err)
+static void writethrough_endio(struct bio *bio)
 {
 	struct per_bio_data *pb = get_per_bio_data(bio, PB_DATA_SIZE_WT);
 
 	dm_unhook_bio(&pb->hook_info, bio);
 
-	if (err) {
-		bio_endio(bio, err);
+	if (bio->bi_error) {
+		bio_endio(bio);
 		return;
 	}
 
@@ -1064,14 +1063,6 @@ static void dec_io_migrations(struct cache *cache)
 	atomic_dec(&cache->nr_io_migrations);
 }
 
-static void __cell_release(struct cache *cache, struct dm_bio_prison_cell *cell,
-			   bool holder, struct bio_list *bios)
-{
-	(holder ? dm_cell_release : dm_cell_release_no_holder)
-		(cache->prison, cell, bios);
-	free_prison_cell(cache, cell);
-}
-
 static bool discard_or_flush(struct bio *bio)
 {
 	return bio->bi_rw & (REQ_FLUSH | REQ_FUA | REQ_DISCARD);
@@ -1079,14 +1070,13 @@ static bool discard_or_flush(struct bio *bio)
 
 static void __cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell)
 {
-	if (discard_or_flush(cell->holder))
+	if (discard_or_flush(cell->holder)) {
 		/*
-		 * We have to handle these bios
-		 * individually.
+		 * We have to handle these bios individually.
 		 */
-		__cell_release(cache, cell, true, &cache->deferred_bios);
-
-	else
+		dm_cell_release(cache->prison, cell, &cache->deferred_bios);
+		free_prison_cell(cache, cell);
+	} else
 		list_add_tail(&cell->user_list, &cache->deferred_cells);
 }
 
@@ -1113,7 +1103,7 @@ static void cell_defer(struct cache *cache, struct dm_bio_prison_cell *cell, boo
 static void cell_error_with_code(struct cache *cache, struct dm_bio_prison_cell *cell, int err)
 {
 	dm_cell_error(cache->prison, cell, err);
-	dm_bio_prison_free_cell(cache->prison, cell);
+	free_prison_cell(cache, cell);
 }
 
 static void cell_requeue(struct cache *cache, struct dm_bio_prison_cell *cell)
@@ -1123,8 +1113,11 @@ static void cell_requeue(struct cache *cache, struct dm_bio_prison_cell *cell)
 
 static void free_io_migration(struct dm_cache_migration *mg)
 {
-	dec_io_migrations(mg->cache);
+	struct cache *cache = mg->cache;
+
+	dec_io_migrations(cache);
 	free_migration(mg);
+	wake_worker(cache);
 }
 
 static void migration_failure(struct dm_cache_migration *mg)
@@ -1231,7 +1224,7 @@ static void migration_success_post_commit(struct dm_cache_migration *mg)
 			 * The block was promoted via an overwrite, so it's dirty.
 			 */
 			set_dirty(cache, mg->new_oblock, mg->cblock);
-			bio_endio(mg->new_ocell->holder, 0);
+			bio_endio(mg->new_ocell->holder);
 			cell_defer(cache, mg->new_ocell, false);
 		}
 		free_io_migration(mg);
@@ -1284,7 +1277,7 @@ static void issue_copy(struct dm_cache_migration *mg)
 	}
 }
 
-static void overwrite_endio(struct bio *bio, int err)
+static void overwrite_endio(struct bio *bio)
 {
 	struct dm_cache_migration *mg = bio->bi_private;
 	struct cache *cache = mg->cache;
@@ -1294,7 +1287,7 @@ static void overwrite_endio(struct bio *bio, int err)
 
 	dm_unhook_bio(&pb->hook_info, bio);
 
-	if (err)
+	if (bio->bi_error)
 		mg->err = true;
 
 	mg->requeue_holder = false;
@@ -1351,16 +1344,18 @@ static void issue_discard(struct dm_cache_migration *mg)
 {
 	dm_dblock_t b, e;
 	struct bio *bio = mg->new_ocell->holder;
+	struct cache *cache = mg->cache;
 
-	calc_discard_block_range(mg->cache, bio, &b, &e);
+	calc_discard_block_range(cache, bio, &b, &e);
 	while (b != e) {
-		set_discard(mg->cache, b);
+		set_discard(cache, b);
 		b = to_dblock(from_dblock(b) + 1);
 	}
 
-	bio_endio(bio, 0);
-	cell_defer(mg->cache, mg->new_ocell, false);
+	bio_endio(bio);
+	cell_defer(cache, mg->new_ocell, false);
 	free_migration(mg);
+	wake_worker(cache);
 }
 
 static void issue_copy_or_discard(struct dm_cache_migration *mg)
@@ -1631,7 +1626,7 @@ static void process_discard_bio(struct cache *cache, struct prealloc *structs,
 
 	calc_discard_block_range(cache, bio, &b, &e);
 	if (b == e) {
-		bio_endio(bio, 0);
+		bio_endio(bio);
 		return;
 	}
 
@@ -1729,6 +1724,8 @@ static void remap_cell_to_origin_clear_discard(struct cache *cache,
 		remap_to_origin(cache, bio);
 		issue(cache, bio);
 	}
+
+	free_prison_cell(cache, cell);
 }
 
 static void remap_cell_to_cache_dirty(struct cache *cache, struct dm_bio_prison_cell *cell,
@@ -1763,6 +1760,8 @@ static void remap_cell_to_cache_dirty(struct cache *cache, struct dm_bio_prison_
 		remap_to_cache(cache, bio, cblock);
 		issue(cache, bio);
 	}
+
+	free_prison_cell(cache, cell);
 }
 
 /*----------------------------------------------------------------*/
@@ -1947,6 +1946,7 @@ static int commit_if_needed(struct cache *cache)
 
 static void process_deferred_bios(struct cache *cache)
 {
+	bool prealloc_used = false;
 	unsigned long flags;
 	struct bio_list bios;
 	struct bio *bio;
@@ -1966,6 +1966,7 @@ static void process_deferred_bios(struct cache *cache)
 		 * this bio might require one, we pause until there are some
 		 * prepared mappings to process.
 		 */
+		prealloc_used = true;
 		if (prealloc_data_structs(cache, &structs)) {
 			spin_lock_irqsave(&cache->lock, flags);
 			bio_list_merge(&cache->deferred_bios, &bios);
@@ -1983,11 +1984,13 @@ static void process_deferred_bios(struct cache *cache)
 			process_bio(cache, &structs, bio);
 	}
 
-	prealloc_free_structs(cache, &structs);
+	if (prealloc_used)
+		prealloc_free_structs(cache, &structs);
 }
 
 static void process_deferred_cells(struct cache *cache)
 {
+	bool prealloc_used = false;
 	unsigned long flags;
 	struct dm_bio_prison_cell *cell, *tmp;
 	struct list_head cells;
@@ -2007,6 +2010,7 @@ static void process_deferred_cells(struct cache *cache)
 		 * this bio might require one, we pause until there are some
 		 * prepared mappings to process.
 		 */
+		prealloc_used = true;
 		if (prealloc_data_structs(cache, &structs)) {
 			spin_lock_irqsave(&cache->lock, flags);
 			list_splice(&cells, &cache->deferred_cells);
@@ -2017,7 +2021,8 @@ static void process_deferred_cells(struct cache *cache)
 		process_cell(cache, &structs, cell);
 	}
 
-	prealloc_free_structs(cache, &structs);
+	if (prealloc_used)
+		prealloc_free_structs(cache, &structs);
 }
 
 static void process_deferred_flush_bios(struct cache *cache, bool submit_bios)
@@ -2062,7 +2067,7 @@ static void process_deferred_writethrough_bios(struct cache *cache)
 
 static void writeback_some_dirty_blocks(struct cache *cache)
 {
-	int r = 0;
+	bool prealloc_used = false;
 	dm_oblock_t oblock;
 	dm_cblock_t cblock;
 	struct prealloc structs;
@@ -2072,15 +2077,12 @@ static void writeback_some_dirty_blocks(struct cache *cache)
 	memset(&structs, 0, sizeof(structs));
 
 	while (spare_migration_bandwidth(cache)) {
-		if (prealloc_data_structs(cache, &structs))
-			break;
-
-		r = policy_writeback_work(cache->policy, &oblock, &cblock, busy);
-		if (r)
-			break;
+		if (policy_writeback_work(cache->policy, &oblock, &cblock, busy))
+			break; /* no work to do */
 
-		r = get_cell(cache, oblock, &structs, &old_ocell);
-		if (r) {
+		prealloc_used = true;
+		if (prealloc_data_structs(cache, &structs) ||
+		    get_cell(cache, oblock, &structs, &old_ocell)) {
 			policy_set_dirty(cache->policy, oblock);
 			break;
 		}
@@ -2088,7 +2090,8 @@ static void writeback_some_dirty_blocks(struct cache *cache)
 		writeback(cache, &structs, oblock, cblock, old_ocell);
 	}
 
-	prealloc_free_structs(cache, &structs);
+	if (prealloc_used)
+		prealloc_free_structs(cache, &structs);
 }
 
 /*----------------------------------------------------------------
@@ -2213,8 +2216,10 @@ static void requeue_deferred_bios(struct cache *cache)
 	bio_list_merge(&bios, &cache->deferred_bios);
 	bio_list_init(&cache->deferred_bios);
 
-	while ((bio = bio_list_pop(&bios)))
-		bio_endio(bio, DM_ENDIO_REQUEUE);
+	while ((bio = bio_list_pop(&bios))) {
+		bio->bi_error = DM_ENDIO_REQUEUE;
+		bio_endio(bio);
+	}
 }
 
 static int more_work(struct cache *cache)
@@ -3119,7 +3124,7 @@ static int cache_map(struct dm_target *ti, struct bio *bio)
 			 * This is a duplicate writethrough io that is no
 			 * longer needed because the block has been demoted.
 			 */
-			bio_endio(bio, 0);
+			bio_endio(bio);
 			// FIXME: remap everything as a miss
 			cell_defer(cache, cell, false);
 			r = DM_MAPIO_SUBMITTED;
@@ -3496,7 +3501,7 @@ static void cache_resume(struct dm_target *ti)
  * <#demotions> <#promotions> <#dirty>
  * <#features> <features>*
  * <#core args> <core args>
- * <policy name> <#policy args> <policy args>* <cache metadata mode>
+ * <policy name> <#policy args> <policy args>* <cache metadata mode> <needs_check>
  */
 static void cache_status(struct dm_target *ti, status_type_t type,
 			 unsigned status_flags, char *result, unsigned maxlen)
@@ -3582,6 +3587,11 @@ static void cache_status(struct dm_target *ti, status_type_t type,
 		else
 			DMEMIT("rw ");
 
+		if (dm_cache_metadata_needs_check(cache->cmd))
+			DMEMIT("needs_check ");
+		else
+			DMEMIT("- ");
+
 		break;
 
 	case STATUSTYPE_TABLE:
@@ -3769,26 +3779,6 @@ static int cache_iterate_devices(struct dm_target *ti,
 	return r;
 }
 
-/*
- * We assume I/O is going to the origin (which is the volume
- * more likely to have restrictions e.g. by being striped).
- * (Looking up the exact location of the data would be expensive
- * and could always be out of date by the time the bio is submitted.)
- */
-static int cache_bvec_merge(struct dm_target *ti,
-			    struct bvec_merge_data *bvm,
-			    struct bio_vec *biovec, int max_size)
-{
-	struct cache *cache = ti->private;
-	struct request_queue *q = bdev_get_queue(cache->origin_dev->bdev);
-
-	if (!q->merge_bvec_fn)
-		return max_size;
-
-	bvm->bi_bdev = cache->origin_dev->bdev;
-	return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
-}
-
 static void set_discard_limits(struct cache *cache, struct queue_limits *limits)
 {
 	/*
@@ -3820,7 +3810,7 @@ static void cache_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 static struct target_type cache_target = {
 	.name = "cache",
-	.version = {1, 7, 0},
+	.version = {1, 8, 0},
 	.module = THIS_MODULE,
 	.ctr = cache_ctr,
 	.dtr = cache_dtr,
@@ -3832,7 +3822,6 @@ static struct target_type cache_target = {
 	.status = cache_status,
 	.message = cache_message,
 	.iterate_devices = cache_iterate_devices,
-	.merge = cache_bvec_merge,
 	.io_hints = cache_io_hints,
 };