dm: fix bio_set allocation

The use of bioset_init_from_src mean that the pre-allocated pools weren't
used for anything except parameter passing, and the integrity pool
creation got completely lost for the actual live mapped_device.  Fix that
by assigning the actual preallocated dm_md_mempools to the mapped_device
and using that for I/O instead of creating new mempools.

Fixes: 2a2a4c510b76 ("dm: use bioset_init_from_src() to copy bio_set")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Mike Snitzer <snitzer@kernel.org>

5 files changed, 35 insertions, 75 deletions

diff --git a/drivers/md/dm-core.h b/drivers/md/dm-core.h
index d21648a923ea..54c0473a51dd 100644
--- a/drivers/md/dm-core.h
+++ b/drivers/md/dm-core.h
@@ -33,6 +33,14 @@ struct dm_kobject_holder {
  * access their members!
  */
 
+/*
+ * For mempools pre-allocation at the table loading time.
+ */
+struct dm_md_mempools {
+	struct bio_set bs;
+	struct bio_set io_bs;
+};
+
 struct mapped_device {
 	struct mutex suspend_lock;
 
@@ -110,8 +118,7 @@ struct mapped_device {
 	/*
 	 * io objects are allocated from here.
 	 */
-	struct bio_set io_bs;
-	struct bio_set bs;
+	struct dm_md_mempools *mempools;
 
 	/* kobject and completion */
 	struct dm_kobject_holder kobj_holder;
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 6087cdcaad46..a83b98a8d2a9 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -319,7 +319,7 @@ static int setup_clone(struct request *clone, struct request *rq,
 {
 	int r;
 
-	r = blk_rq_prep_clone(clone, rq, &tio->md->bs, gfp_mask,
+	r = blk_rq_prep_clone(clone, rq, &tio->md->mempools->bs, gfp_mask,
 			      dm_rq_bio_constructor, tio);
 	if (r)
 		return r;
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 0e833a154b31..bd539afbfe88 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1038,17 +1038,6 @@ static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *
 	return 0;
 }
 
-void dm_table_free_md_mempools(struct dm_table *t)
-{
-	dm_free_md_mempools(t->mempools);
-	t->mempools = NULL;
-}
-
-struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
-{
-	return t->mempools;
-}
-
 static int setup_indexes(struct dm_table *t)
 {
 	int i;
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index dfb0a551bd88..8b21155d3c4f 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -136,14 +136,6 @@ static int get_swap_bios(void)
 	return latch;
 }
 
-/*
- * For mempools pre-allocation at the table loading time.
- */
-struct dm_md_mempools {
-	struct bio_set bs;
-	struct bio_set io_bs;
-};
-
 struct table_device {
 	struct list_head list;
 	refcount_t count;
@@ -581,7 +573,7 @@ static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio)
 	struct dm_target_io *tio;
 	struct bio *clone;
 
-	clone = bio_alloc_clone(NULL, bio, GFP_NOIO, &md->io_bs);
+	clone = bio_alloc_clone(NULL, bio, GFP_NOIO, &md->mempools->io_bs);
 	/* Set default bdev, but target must bio_set_dev() before issuing IO */
 	clone->bi_bdev = md->disk->part0;
 
@@ -628,7 +620,8 @@ static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti,
 	} else {
 		struct mapped_device *md = ci->io->md;
 
-		clone = bio_alloc_clone(NULL, ci->bio, gfp_mask, &md->bs);
+		clone = bio_alloc_clone(NULL, ci->bio, gfp_mask,
+					&md->mempools->bs);
 		if (!clone)
 			return NULL;
 		/* Set default bdev, but target must bio_set_dev() before issuing IO */
@@ -1876,8 +1869,7 @@ static void cleanup_mapped_device(struct mapped_device *md)
 {
 	if (md->wq)
 		destroy_workqueue(md->wq);
-	bioset_exit(&md->bs);
-	bioset_exit(&md->io_bs);
+	dm_free_md_mempools(md->mempools);
 
 	if (md->dax_dev) {
 		dax_remove_host(md->disk);
@@ -2049,48 +2041,6 @@ static void free_dev(struct mapped_device *md)
 	kvfree(md);
 }
 
-static int __bind_mempools(struct mapped_device *md, struct dm_table *t)
-{
-	struct dm_md_mempools *p = dm_table_get_md_mempools(t);
-	int ret = 0;
-
-	if (dm_table_bio_based(t)) {
-		/*
-		 * The md may already have mempools that need changing.
-		 * If so, reload bioset because front_pad may have changed
-		 * because a different table was loaded.
-		 */
-		bioset_exit(&md->bs);
-		bioset_exit(&md->io_bs);
-
-	} else if (bioset_initialized(&md->bs)) {
-		/*
-		 * There's no need to reload with request-based dm
-		 * because the size of front_pad doesn't change.
-		 * Note for future: If you are to reload bioset,
-		 * prep-ed requests in the queue may refer
-		 * to bio from the old bioset, so you must walk
-		 * through the queue to unprep.
-		 */
-		goto out;
-	}
-
-	BUG_ON(!p ||
-	       bioset_initialized(&md->bs) ||
-	       bioset_initialized(&md->io_bs));
-
-	ret = bioset_init_from_src(&md->bs, &p->bs);
-	if (ret)
-		goto out;
-	ret = bioset_init_from_src(&md->io_bs, &p->io_bs);
-	if (ret)
-		bioset_exit(&md->bs);
-out:
-	/* mempool bind completed, no longer need any mempools in the table */
-	dm_table_free_md_mempools(t);
-	return ret;
-}
-
 /*
  * Bind a table to the device.
  */
@@ -2144,12 +2094,28 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t,
 		 * immutable singletons - used to optimize dm_mq_queue_rq.
 		 */
 		md->immutable_target = dm_table_get_immutable_target(t);
-	}
 
-	ret = __bind_mempools(md, t);
-	if (ret) {
-		old_map = ERR_PTR(ret);
-		goto out;
+		/*
+		 * There is no need to reload with request-based dm because the
+		 * size of front_pad doesn't change.
+		 *
+		 * Note for future: If you are to reload bioset, prep-ed
+		 * requests in the queue may refer to bio from the old bioset,
+		 * so you must walk through the queue to unprep.
+		 */
+		if (!md->mempools) {
+			md->mempools = t->mempools;
+			t->mempools = NULL;
+		}
+	} else {
+		/*
+		 * The md may already have mempools that need changing.
+		 * If so, reload bioset because front_pad may have changed
+		 * because a different table was loaded.
+		 */
+		dm_free_md_mempools(md->mempools);
+		md->mempools = t->mempools;
+		t->mempools = NULL;
 	}
 
 	ret = dm_table_set_restrictions(t, md->queue, limits);
diff --git a/drivers/md/dm.h b/drivers/md/dm.h
index 3f89664fea01..a8405ce305a9 100644
--- a/drivers/md/dm.h
+++ b/drivers/md/dm.h
@@ -71,8 +71,6 @@ struct dm_target *dm_table_get_immutable_target(struct dm_table *t);
 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t);
 bool dm_table_bio_based(struct dm_table *t);
 bool dm_table_request_based(struct dm_table *t);
-void dm_table_free_md_mempools(struct dm_table *t);
-struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t);
 
 void dm_lock_md_type(struct mapped_device *md);
 void dm_unlock_md_type(struct mapped_device *md);