Now cc Jens actually. On 10/4/21 11:34 PM, Guoqing Jiang wrote:
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@xxxxxxxxxxxxxxx # v5.12+ Cc: Jens Stutte <jens@xxxxxxxxxxxxxxxxxx> Reported-by: Jens Stutte <jens@xxxxxxxxxxxxxxxxxx> Signed-off-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx> --- 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 19598bd38939..6ba12f0f0f03 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1496,7 +1496,7 @@ 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
