From: Guoqing Jiang <guoqing.jiang@linux.dev> mainline inclusion from mainline-v5.16-rc1 commit fd3b6975e9c11c4fa00965f82a0bfbb3b7b44101 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I566T6 CVE: NA Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- Commit 6607cd319b6b91bff94e90f798a61c031650b514 ("raid1: ensure write behind bio has less than BIO_MAX_VECS sectors") tried to guarantee the size of behind bio is not bigger than BIO_MAX_VECS sectors. Unfortunately the same calltrace still could happen since an array could enable write-behind without write mostly device. To match the manpage of mdadm (which says "write-behind is only attempted on drives marked as write-mostly"), we need to check WriteMostly flag to avoid such unexpected behavior. [1]. https://bugzilla.kernel.org/show_bug.cgi?id=213181#c25 Cc: stable@vger.kernel.org # v5.12+ Cc: Jens Stutte <jens@chianterastutte.eu> Reported-by: Jens Stutte <jens@chianterastutte.eu> Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Luo Meng <luomeng12@huawei.com> Reviewed-by: Jason Yan <yanaijie@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- drivers/md/raid1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 5e17699cf47c..7c7f03f07f03 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1492,7 +1492,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, if (!r1_bio->bios[i]) continue; - if (first_clone) { + if (first_clone && test_bit(WriteMostly, &rdev->flags)) { /* do behind I/O ? * Not if there are too many, or cannot * allocate memory, or a reader on WriteMostly -- 2.20.1