From 460af1f9d9e62acce4a21f9bd00b5bcd5963bcd4 Mon Sep 17 00:00:00 2001 From: Yu Kuai Date: Mon, 29 May 2023 21:11:06 +0800 Subject: md/raid1-10: limit the number of plugged bio bio can be added to plug infinitely, and following writeback test can trigger huge amount of plugged bio: Test script: modprobe brd rd_nr=4 rd_size=10485760 mdadm -CR /dev/md0 -l10 -n4 /dev/ram[0123] --assume-clean --bitmap=internal echo 0 > /proc/sys/vm/dirty_background_ratio fio -filename=/dev/md0 -ioengine=libaio -rw=write -bs=4k -numjobs=1 -iodepth=128 -name=test Test result: Monitor /sys/block/md0/inflight will found that inflight keep increasing until fio finish writing, after running for about 2 minutes: [root@fedora ~]# cat /sys/block/md0/inflight 0 4474191 Fix the problem by limiting the number of plugged bio based on the number of copies for original bio. Signed-off-by: Yu Kuai Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230529131106.2123367-8-yukuai1@huaweicloud.com --- drivers/md/raid1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/raid1.c') diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index 334ed76d3c5a..dd25832eb045 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1565,7 +1565,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, r1_bio->sector); /* flush_pending_writes() needs access to the rdev so...*/ mbio->bi_bdev = (void *)rdev; - if (!raid1_add_bio_to_plug(mddev, mbio, raid1_unplug)) { + if (!raid1_add_bio_to_plug(mddev, mbio, raid1_unplug, disks)) { spin_lock_irqsave(&conf->device_lock, flags); bio_list_add(&conf->pending_bio_list, mbio); spin_unlock_irqrestore(&conf->device_lock, flags); -- cgit v1.2.3