Merge tag 'block-5.10-2020-12-12' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "This should be it for 5.10.

  Mike and Song looked into the warning case, and thankfully it appears
  the fix was pretty trivial - we can just change the md device chunk
  type to unsigned int to get rid of it. They cannot currently be < 0,
  and nobody is checking for that either.

  We're reverting the discard changes as the corruption reports came in
  very late, and there's just no time to attempt to deal with it at this
  point. Reverting the changes in question is the right call for 5.10"

* tag 'block-5.10-2020-12-12' of git://git.kernel.dk/linux-block:
  md: change mddev 'chunk_sectors' from int to unsigned
  Revert "md: add md_submit_discard_bio() for submitting discard bio"
  Revert "md/raid10: extend r10bio devs to raid disks"
  Revert "md/raid10: pull codes that wait for blocked dev into one function"
  Revert "md/raid10: improve raid10 discard request"
  Revert "md/raid10: improve discard request for far layout"
  Revert "dm raid: remove unnecessary discard limits for raid10"

Author: torvalds

drivers/md/dm-raid.c

@@ -3728,6 +3728,17 @@ static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 	blk_limits_io_min(limits, chunk_size_bytes);
 	blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
+
+	/*
+	 * RAID10 personality requires bio splitting,
+	 * RAID0/1/4/5/6 don't and process large discard bios properly.
+	 */
+	if (rs_is_raid10(rs)) {
+		limits->discard_granularity = max(chunk_size_bytes,
+						  limits->discard_granularity);
+		limits->max_discard_sectors = min_not_zero(rs->md.chunk_sectors,
+							   limits->max_discard_sectors);
+	}
 }
 
 static void raid_postsuspend(struct dm_target *ti)

drivers/md/md.c

@@ -8582,26 +8582,6 @@ void md_write_end(struct mddev *mddev)
 
 EXPORT_SYMBOL(md_write_end);
 
-/* This is used by raid0 and raid10 */
-void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev,
-			struct bio *bio, sector_t start, sector_t size)
-{
-	struct bio *discard_bio = NULL;
-
-	if (__blkdev_issue_discard(rdev->bdev, start, size,
-		GFP_NOIO, 0, &discard_bio) || !discard_bio)
-		return;
-
-	bio_chain(discard_bio, bio);
-	bio_clone_blkg_association(discard_bio, bio);
-	if (mddev->gendisk)
-		trace_block_bio_remap(bdev_get_queue(rdev->bdev),
-			discard_bio, disk_devt(mddev->gendisk),
-			bio->bi_iter.bi_sector);
-	submit_bio_noacct(discard_bio);
-}
-EXPORT_SYMBOL(md_submit_discard_bio);
-
 /* md_allow_write(mddev)
  * Calling this ensures that the array is marked 'active' so that writes
  * may proceed without blocking.  It is important to call this before

drivers/md/md.h

@@ -311,7 +311,7 @@ struct mddev {
 	int				external;	/* metadata is
 							 * managed externally */
 	char				metadata_type[17]; /* externally set*/
-	int				chunk_sectors;
+	unsigned int			chunk_sectors;
 	time64_t			ctime, utime;
 	int				level, layout;
 	char				clevel[16];
@@ -339,7 +339,7 @@ struct mddev {
 	 */
 	sector_t			reshape_position;
 	int				delta_disks, new_level, new_layout;
-	int				new_chunk_sectors;
+	unsigned int			new_chunk_sectors;
 	int				reshape_backwards;
 
 	struct md_thread		*thread;	/* management thread */
@@ -713,8 +713,6 @@ extern void md_write_end(struct mddev *mddev);
 extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
 extern void md_error(struct mddev *mddev, struct md_rdev *rdev);
 extern void md_finish_reshape(struct mddev *mddev);
-extern void md_submit_discard_bio(struct mddev *mddev, struct md_rdev *rdev,
-			struct bio *bio, sector_t start, sector_t size);
 
 extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio);
 extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,

drivers/md/raid0.c

@@ -477,6 +477,7 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
 
 	for (disk = 0; disk < zone->nb_dev; disk++) {
 		sector_t dev_start, dev_end;
+		struct bio *discard_bio = NULL;
 		struct md_rdev *rdev;
 
 		if (disk < start_disk_index)
@@ -499,9 +500,18 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
 
 		rdev = conf->devlist[(zone - conf->strip_zone) *
 			conf->strip_zone[0].nb_dev + disk];
-		md_submit_discard_bio(mddev, rdev, bio,
+		if (__blkdev_issue_discard(rdev->bdev,
 			dev_start + zone->dev_start + rdev->data_offset,
-			dev_end - dev_start);
+			dev_end - dev_start, GFP_NOIO, 0, &discard_bio) ||
+		    !discard_bio)
+			continue;
+		bio_chain(discard_bio, bio);
+		bio_clone_blkg_association(discard_bio, bio);
+		if (mddev->gendisk)
+			trace_block_bio_remap(bdev_get_queue(rdev->bdev),
+				discard_bio, disk_devt(mddev->gendisk),
+				bio->bi_iter.bi_sector);
+		submit_bio_noacct(discard_bio);
 	}
 	bio_endio(bio);
 }