From f524d9c95fab54783d0038f7a3e8c014d5b56857 Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Fri, 28 Jan 2022 10:58:40 -0500
Subject: [PATCH] dm: revert partial fix for redundant bio-based IO accounting
Git-commit: f524d9c95fab54783d0038f7a3e8c014d5b56857
Patch-mainline: v5.17-rc2
References: git-fixes
Reverts a1e1cb72d9649 ("dm: fix redundant IO accounting for bios that
need splitting") because it was too narrow in scope (only addressed
redundant 'sectors[]' accounting and not ios, nsecs[], etc).
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220128155841.39644-3-snitzer@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
drivers/md/dm.c | 15 ---------------
1 file changed, 15 deletions(-)
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1510,9 +1510,6 @@ static void init_clone_info(struct clone
ci->sector = bio->bi_iter.bi_sector;
}
-#define __dm_part_stat_sub(part, field, subnd) \
- (part_stat_get(part, field) -= (subnd))
-
/*
* Entry point to split a bio into clones and submit them to the targets.
*/
@@ -1549,18 +1546,6 @@ static blk_qc_t __split_and_process_bio(
GFP_NOIO, &md->queue->bio_split);
ci.io->orig_bio = b;
- /*
- * Adjust IO stats for each split, otherwise upon queue
- * reentry there will be redundant IO accounting.
- * NOTE: this is a stop-gap fix, a proper fix involves
- * significant refactoring of DM core's bio splitting
- * (by eliminating DM's splitting and just using bio_split)
- */
- part_stat_lock();
- __dm_part_stat_sub(dm_disk(md)->part0,
- sectors[op_stat_group(bio_op(bio))], ci.sector_count);
- part_stat_unlock();
-
bio_chain(b, bio);
trace_block_split(b, bio->bi_iter.bi_sector);
ret = submit_bio_noacct(bio);