dm: refactor dm_md_mempool allocation

The current split between dm_table_alloc_md_mempools and
dm_alloc_md_mempools is rather arbitrary, so merge the two
into one easy to follow function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

drivers/md/dm-core.h

@@ -230,6 +230,9 @@ struct dm_target_io {
 	sector_t old_sector;
 	struct bio clone;
 };
+#define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
+#define DM_IO_BIO_OFFSET \
+	(offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
 
 /*
  * dm_target_io flags

drivers/md/dm-table.c

@@ -6,6 +6,7 @@
  */
 
 #include "dm-core.h"
+#include "dm-rq.h"
 
 #include <linux/module.h>
 #include <linux/vmalloc.h>
@@ -1010,32 +1011,56 @@ static bool dm_table_supports_poll(struct dm_table *t);
 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
 {
 	enum dm_queue_mode type = dm_table_get_type(t);
-	unsigned per_io_data_size = 0;
-	unsigned min_pool_size = 0;
-	struct dm_target *ti;
-	unsigned i;
-	bool poll_supported = false;
+	unsigned int per_io_data_size = 0, front_pad, io_front_pad;
+	unsigned int min_pool_size = 0, pool_size;
+	struct dm_md_mempools *pools;
 
 	if (unlikely(type == DM_TYPE_NONE)) {
 		DMWARN("no table type is set, can't allocate mempools");
 		return -EINVAL;
 	}
 
-	if (__table_type_bio_based(type)) {
-		for (i = 0; i < t->num_targets; i++) {
-			ti = t->targets + i;
-			per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
-			min_pool_size = max(min_pool_size, ti->num_flush_bios);
-		}
-		poll_supported = dm_table_supports_poll(t);
+	pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
+	if (!pools)
+		return -ENOMEM;
+
+	if (type == DM_TYPE_REQUEST_BASED) {
+		pool_size = dm_get_reserved_rq_based_ios();
+		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
+		goto init_bs;
 	}
 
-	t->mempools = dm_alloc_md_mempools(md, type, per_io_data_size, min_pool_size,
-					   t->integrity_supported, poll_supported);
-	if (!t->mempools)
-		return -ENOMEM;
+	for (unsigned int i = 0; i < t->num_targets; i++) {
+		struct dm_target *ti = t->targets + i;
 
+		per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
+		min_pool_size = max(min_pool_size, ti->num_flush_bios);
+	}
+	pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
+	front_pad = roundup(per_io_data_size,
+		__alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
+
+	io_front_pad = roundup(per_io_data_size,
+		__alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
+	if (bioset_init(&pools->io_bs, pool_size, io_front_pad,
+			dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0))
+		goto out_free_pools;
+	if (t->integrity_supported &&
+	    bioset_integrity_create(&pools->io_bs, pool_size))
+		goto out_free_pools;
+init_bs:
+	if (bioset_init(&pools->bs, pool_size, front_pad, 0))
+		goto out_free_pools;
+	if (t->integrity_supported &&
+	    bioset_integrity_create(&pools->bs, pool_size))
+		goto out_free_pools;
+
+	t->mempools = pools;
 	return 0;
+
+out_free_pools:
+	dm_free_md_mempools(pools);
+	return -ENOMEM;
 }
 
 static int setup_indexes(struct dm_table *t)

drivers/md/dm.c

@@ -88,10 +88,6 @@ struct clone_info {
 	bool submit_as_polled:1;
 };
 
-#define DM_TARGET_IO_BIO_OFFSET (offsetof(struct dm_target_io, clone))
-#define DM_IO_BIO_OFFSET \
-	(offsetof(struct dm_target_io, clone) + offsetof(struct dm_io, tio))
-
 static inline struct dm_target_io *clone_to_tio(struct bio *clone)
 {
 	return container_of(clone, struct dm_target_io, clone);
@@ -2978,54 +2974,6 @@ int dm_noflush_suspending(struct dm_target *ti)
 }
 EXPORT_SYMBOL_GPL(dm_noflush_suspending);
 
-struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
-					    unsigned per_io_data_size, unsigned min_pool_size,
-					    bool integrity, bool poll)
-{
-	struct dm_md_mempools *pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
-	unsigned int pool_size = 0;
-	unsigned int front_pad, io_front_pad;
-	int ret;
-
-	if (!pools)
-		return NULL;
-
-	switch (type) {
-	case DM_TYPE_BIO_BASED:
-	case DM_TYPE_DAX_BIO_BASED:
-		pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
-		front_pad = roundup(per_io_data_size, __alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
-		io_front_pad = roundup(per_io_data_size,  __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
-		ret = bioset_init(&pools->io_bs, pool_size, io_front_pad, poll ? BIOSET_PERCPU_CACHE : 0);
-		if (ret)
-			goto out;
-		if (integrity && bioset_integrity_create(&pools->io_bs, pool_size))
-			goto out;
-		break;
-	case DM_TYPE_REQUEST_BASED:
-		pool_size = max(dm_get_reserved_rq_based_ios(), min_pool_size);
-		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
-		/* per_io_data_size is used for blk-mq pdu at queue allocation */
-		break;
-	default:
-		BUG();
-	}
-
-	ret = bioset_init(&pools->bs, pool_size, front_pad, 0);
-	if (ret)
-		goto out;
-
-	if (integrity && bioset_integrity_create(&pools->bs, pool_size))
-		goto out;
-
-	return pools;
-
-out:
-	dm_free_md_mempools(pools);
-
-	return NULL;
-}
-
 void dm_free_md_mempools(struct dm_md_mempools *pools)
 {
 	if (!pools)

drivers/md/dm.h

@@ -218,9 +218,6 @@ void dm_kcopyd_exit(void);
 /*
  * Mempool operations
  */
-struct dm_md_mempools *dm_alloc_md_mempools(struct mapped_device *md, enum dm_queue_mode type,
-					    unsigned per_io_data_size, unsigned min_pool_size,
-					    bool integrity, bool poll);
 void dm_free_md_mempools(struct dm_md_mempools *pools);
 
 /*