From 2df8b310bcfe76827fd71092f58a2493ee6590b0 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 26 Jan 2026 15:36:22 +0100 Subject: [PATCH] dm: use bio_clone_blkg_association The origin bio carries blk-cgroup information which could be set from foreground(task_css(css) - wbc->wb->blkcg_css), so the blkcg won't control buffer io since commit ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone"). The synchronous io is still under control by blkcg, because 'bio->bi_blkg' is set by io submitting task which has been added into 'cgroup.procs'. Fix it by using bio_clone_blkg_association when submitting a cloned bio. Link: https://bugzilla.kernel.org/show_bug.cgi?id=220985 Fixes: ca522482e3eaf ("dm: pass NULL bdev to bio_alloc_clone") Reported-by: Zhihao Cheng Signed-off-by: Mikulas Patocka Tested-by: Zhihao Cheng --- drivers/md/dm.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/dm.c b/drivers/md/dm.c index ea2c43cddde1f..e178fe19973ea 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -1364,6 +1364,8 @@ void dm_submit_bio_remap(struct bio *clone, struct bio *tgt_clone) if (!tgt_clone) tgt_clone = clone; + bio_clone_blkg_association(tgt_clone, io->orig_bio); + /* * Account io->origin_bio to DM dev on behalf of target * that took ownership of IO with DM_MAPIO_SUBMITTED. -- 2.47.3