Merge tag 'for-5.18/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - Significant refactoring and fixing of how DM core does bio-based IO
   accounting with focus on fixing wildly inaccurate IO stats for
   dm-crypt (and other DM targets that defer bio submission in their own
   workqueues). End result is proper IO accounting, made possible by
   targets being updated to use the new dm_submit_bio_remap() interface.

 - Add hipri bio polling support (REQ_POLLED) to bio-based DM.

 - Reduce dm_io and dm_target_io structs so that a single dm_io (which
   contains dm_target_io and first clone bio) weighs in at 256 bytes.
   For reference the bio struct is 128 bytes.

 - Various other small cleanups, fixes or improvements in DM core and
   targets.

 - Update MAINTAINERS with my kernel.org email address to allow
   distinction between my "upstream" and "Red" Hats.

* tag 'for-5.18/dm-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (46 commits)
  dm: consolidate spinlocks in dm_io struct
  dm: reduce size of dm_io and dm_target_io structs
  dm: switch dm_target_io booleans over to proper flags
  dm: switch dm_io booleans over to proper flags
  dm: update email address in MAINTAINERS
  dm: return void from __send_empty_flush
  dm: factor out dm_io_complete
  dm cache: use dm_submit_bio_remap
  dm: simplify dm_sumbit_bio_remap interface
  dm thin: use dm_submit_bio_remap
  dm: add WARN_ON_ONCE to dm_submit_bio_remap
  dm: support bio polling
  block: add ->poll_bio to block_device_operations
  dm mpath: use DMINFO instead of printk with KERN_INFO
  dm: stop using bdevname
  dm-zoned: remove the ->name field in struct dmz_dev
  dm: remove unnecessary local variables in __bind
  dm: requeue IO if mapping table not yet available
  dm io: remove stale comment block for dm_io()
  dm thin metadata: remove unused dm_thin_remove_block and __remove
  ...

2 files changed, 13 insertions, 5 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 9c14deab3af4..d4ae6ac53ffc 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -688,7 +688,7 @@ static void __submit_bio(struct bio *bio)
  *
  * bio_list_on_stack[0] contains bios submitted by the current ->submit_bio.
  * bio_list_on_stack[1] contains bios that were submitted before the current
- *	->submit_bio_bio, but that haven't been processed yet.
+ *	->submit_bio, but that haven't been processed yet.
  */
 static void __submit_bio_noacct(struct bio *bio)
 {
@@ -955,7 +955,7 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags)
 {
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	blk_qc_t cookie = READ_ONCE(bio->bi_cookie);
-	int ret;
+	int ret = 0;
 
 	if (cookie == BLK_QC_T_NONE ||
 	    !test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
@@ -965,10 +965,14 @@ int bio_poll(struct bio *bio, struct io_comp_batch *iob, unsigned int flags)
 
 	if (blk_queue_enter(q, BLK_MQ_REQ_NOWAIT))
 		return 0;
-	if (WARN_ON_ONCE(!queue_is_mq(q)))
-		ret = 0;	/* not yet implemented, should not happen */
-	else
+	if (queue_is_mq(q)) {
 		ret = blk_mq_poll(q, cookie, iob, flags);
+	} else {
+		struct gendisk *disk = q->disk;
+
+		if (disk && disk->fops->poll_bio)
+			ret = disk->fops->poll_bio(bio, iob, flags);
+	}
 	blk_queue_exit(q);
 	return ret;
 }
diff --git a/block/genhd.c b/block/genhd.c
index 37eb41ee4086..c9a4fc90d3e9 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -412,6 +412,10 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
 	struct device *ddev = disk_to_dev(disk);
 	int ret;
 
+	/* Only makes sense for bio-based to set ->poll_bio */
+	if (queue_is_mq(disk->queue) && disk->fops->poll_bio)
+		return -EINVAL;
+
 	/*
 	 * The disk queue should now be all set with enough information about
 	 * the device for the elevator code to pick an adequate default