Messages in this thread | | | From | AceLan Kao <> | Date | Sat, 26 Aug 2023 12:31:15 +0800 | Subject | Re: Infiniate systemd loop when power off the machine with multiple MD RAIDs |
| |
Hi Song,
Song Liu <song@kernel.org> 於 2023年8月23日 週三 下午9:25寫道: > > Hi AceLan, > > On Wed, Aug 23, 2023 at 1:03 AM AceLan Kao <acelan@gmail.com> wrote: > > > [...] > > > > > > My suggestion is delete the list node under this scenario, did you try > > > above? > > Still no luck, the patch doesn't work, the sympton is the same. > [...] > > > > > > Is the issue still reproducible with remove below from cmd? > > > > > > echo "repair" | sudo tee /sys/class/block/md12?/md/sync_action > > > > > > Just want to know if resync thread is related with the issue or not. > > Probably not, we can reproduce the issue without resync, just feel > > it's easier to reproduce the issue, so I put the command in my script. > > > > Could you please run the follow two experiments? > > 1. Confirm 12a6caf273240a triggers this. Specifically: > git checkout 12a6caf273240a => repros > git checkout 12a6caf273240a~1 => cannot repro Yes, I'm pretty sure about this, that's my bisect result and I just confirmed it again. I also tried reverting 12a6caf273240a and the issue is gone.
> > 2. Try with the following change (add debug messages), which hopefully > shows which command is holding a reference on mddev->openers. > > Thanks, > Song > > diff --git i/drivers/md/md.c w/drivers/md/md.c > index 78be7811a89f..3e9b718b32c1 100644 > --- i/drivers/md/md.c > +++ w/drivers/md/md.c > @@ -7574,11 +7574,15 @@ static int md_ioctl(struct block_device *bdev, > blk_mode_t mode, > if (mddev->pers && atomic_read(&mddev->openers) > 1) { > mutex_unlock(&mddev->open_mutex); > err = -EBUSY; > + pr_warn("%s return -EBUSY for %s with > mddev->openers = %d\n", > + __func__, mdname(mddev), > atomic_read(&mddev->openers)); > goto out; > } > if (test_and_set_bit(MD_CLOSING, &mddev->flags)) { > mutex_unlock(&mddev->open_mutex); > err = -EBUSY; > + pr_warn("%s return -EBUSY for %s with > MD_CLOSING bit set\n", > + __func__, mdname(mddev)); > goto out; > } > did_set_md_closing = true; > @@ -7789,6 +7793,8 @@ static int md_open(struct gendisk *disk, blk_mode_t mode) > goto out_unlock; > > atomic_inc(&mddev->openers); > + pr_info("%s:%s openers++ = %d by %s\n", __func__, mdname(mddev), > + atomic_read(&mddev->openers), current->comm); > mutex_unlock(&mddev->open_mutex); > > disk_check_media_change(disk); > @@ -7807,6 +7813,8 @@ static void md_release(struct gendisk *disk) > > BUG_ON(!mddev); > atomic_dec(&mddev->openers); > + pr_info("%s:%s openers-- = %d by %s\n", __func__, mdname(mddev), > + atomic_read(&mddev->openers), current->comm); > mddev_put(mddev); > } It's pretty strange that I can't reproduce the issue after applied the patch.
I tried to figure out which part affect the issue and found when I comment out the pr_info() In md_release(), the issue could be reproduced.
-- Chia-Lin Kao(AceLan) http://blog.acelan.idv.tw/ E-Mail: acelan.kaoATcanonical.com (s/AT/@/)
| |