Re: [PATCH] block/blk-cgroup-rwstat: use data_race() for online test
"Yu Kuai" <[email protected]> Mon, 3 Aug 2026 13:29:35 +0800
| Newsgroups | org.kernel.vger.cgroups,org.kernel.vger.linux-block,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
=E5=9C=A8 2026/8/2 23:04, Tao Cui =E5=86=99=E9=81=93: > From: Tao Cui<[email protected]> > > blkg_rwstat_recursive_sum() reads pos_blkg->online without the queue > lock that its doc comment requires, since blkcg_print_blkgs() stopped > holding it in 56cc24f59c14. Concurrent blkg_create/destroy flips > ->online, tripping KCSAN. The race is harmless (RCU-protected, stale > online only causes minor stat noise). Use data_race() to annotate > the intentional lockless read. > > Signed-off-by: Tao Cui<[email protected]> > --- > block/blk-cgroup-rwstat.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Yu Kuai <[email protected]> --=20 Thanks, Kuai