mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2025-02-26 08:19:49 +07:00
fe272570d0
commit dc5d17a3c39b06aef866afca19245a9cfb533a79 upstream.
One customer reports a crash problem which causes by flush request. It
triggers a warning before crash.
/* new request after previous flush is completed */
if (ktime_after(req_start, mddev->prev_flush_start)) {
WARN_ON(mddev->flush_bio);
mddev->flush_bio = bio;
bio = NULL;
}
The WARN_ON is triggered. We use spin lock to protect prev_flush_start and
flush_bio in md_flush_request. But there is no lock protection in
md_submit_flush_data. It can set flush_bio to NULL first because of
compiler reordering write instructions.
For example, flush bio1 sets flush bio to NULL first in
md_submit_flush_data. An interrupt or vmware causing an extended stall
happen between updating flush_bio and prev_flush_start. Because flush_bio
is NULL, flush bio2 can get the lock and submit to underlayer disks. Then
flush bio1 updates prev_flush_start after the interrupt or extended stall.
Then flush bio3 enters in md_flush_request. The start time req_start is
behind prev_flush_start. The flush_bio is not NULL(flush bio2 hasn't
finished). So it can trigger the WARN_ON now. Then it calls INIT_WORK
again. INIT_WORK() will re-initialize the list pointers in the
work_struct, which then can result in a corrupted work list and the
work_struct queued a second time. With the work list corrupted, it can
lead in invalid work items being used and cause a crash in
process_one_work.
We need to make sure only one flush bio can be handled at one same time.
So add spin lock in md_submit_flush_data to protect prev_flush_start and
flush_bio in an atomic way.
Reviewed-by: David Jeffery <djeffery@redhat.com>
Signed-off-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|---|---|---|
| .. | ||
| bcache | ||
| persistent-data | ||
| dm-bio-prison-v1.c | ||
| dm-bio-prison-v1.h | ||
| dm-bio-prison-v2.c | ||
| dm-bio-prison-v2.h | ||
| dm-bio-record.h | ||
| dm-bufio.c | ||
| dm-builtin.c | ||
| dm-cache-background-tracker.c | ||
| dm-cache-background-tracker.h | ||
| dm-cache-block-types.h | ||
| dm-cache-metadata.c | ||
| dm-cache-metadata.h | ||
| dm-cache-policy-internal.h | ||
| dm-cache-policy-smq.c | ||
| dm-cache-policy.c | ||
| dm-cache-policy.h | ||
| dm-cache-target.c | ||
| dm-clone-metadata.c | ||
| dm-clone-metadata.h | ||
| dm-clone-target.c | ||
| dm-core.h | ||
| dm-crypt.c | ||
| dm-delay.c | ||
| dm-dust.c | ||
| dm-ebs-target.c | ||
| dm-era-target.c | ||
| dm-exception-store.c | ||
| dm-exception-store.h | ||
| dm-flakey.c | ||
| dm-historical-service-time.c | ||
| dm-init.c | ||
| dm-integrity.c | ||
| dm-io.c | ||
| dm-ioctl.c | ||
| dm-kcopyd.c | ||
| dm-linear.c | ||
| dm-log-userspace-base.c | ||
| dm-log-userspace-transfer.c | ||
| dm-log-userspace-transfer.h | ||
| dm-log-writes.c | ||
| dm-log.c | ||
| dm-mpath.c | ||
| dm-mpath.h | ||
| dm-path-selector.c | ||
| dm-path-selector.h | ||
| dm-queue-length.c | ||
| dm-raid1.c | ||
| dm-raid.c | ||
| dm-region-hash.c | ||
| dm-round-robin.c | ||
| dm-rq.c | ||
| dm-rq.h | ||
| dm-service-time.c | ||
| dm-snap-persistent.c | ||
| dm-snap-transient.c | ||
| dm-snap.c | ||
| dm-stats.c | ||
| dm-stats.h | ||
| dm-stripe.c | ||
| dm-switch.c | ||
| dm-sysfs.c | ||
| dm-table.c | ||
| dm-target.c | ||
| dm-thin-metadata.c | ||
| dm-thin-metadata.h | ||
| dm-thin.c | ||
| dm-uevent.c | ||
| dm-uevent.h | ||
| dm-unstripe.c | ||
| dm-verity-fec.c | ||
| dm-verity-fec.h | ||
| dm-verity-target.c | ||
| dm-verity-verify-sig.c | ||
| dm-verity-verify-sig.h | ||
| dm-verity.h | ||
| dm-writecache.c | ||
| dm-zero.c | ||
| dm-zoned-metadata.c | ||
| dm-zoned-reclaim.c | ||
| dm-zoned-target.c | ||
| dm-zoned.h | ||
| dm.c | ||
| dm.h | ||
| Kconfig | ||
| Makefile | ||
| md-autodetect.c | ||
| md-bitmap.c | ||
| md-bitmap.h | ||
| md-cluster.c | ||
| md-cluster.h | ||
| md-faulty.c | ||
| md-linear.c | ||
| md-linear.h | ||
| md-multipath.c | ||
| md-multipath.h | ||
| md.c | ||
| md.h | ||
| raid0.c | ||
| raid0.h | ||
| raid1-10.c | ||
| raid1.c | ||
| raid1.h | ||
| raid5-cache.c | ||
| raid5-log.h | ||
| raid5-ppl.c | ||
| raid5.c | ||
| raid5.h | ||
| raid10.c | ||
| raid10.h | ||