Hi Leon,
On Tue, Feb 1, 2022 at 2:15 PM jkhsjdhjs <jkhsjdhjs@xxxxxxxxxxx> wrote:
>
> Dear Song Liu,
>
> my kernel (5.17-rc2) experiences a NULL pointer dereference when
> activating an LDM (Windows Logical Disk Manager) on Arch Linux using
> ldmtool [1]. I have attached the relevant excerpt of dmesg. This bug
> causes my LDM RAID to fail activating (see ldmtool-status.txt and
> lsblk.txt). Since this worked fine with 5.16 I bisected the kernel and
> found, that commit f51d46d0e7cb5b8494aa534d276a9d8915a2443d [2]
> introduced the issue.
>
> I'm not sure what else to add, if there's more information I can
> provide, please tell me. Otherwise I'll happily assist in fixing this
> issue - if there's something I can do.
Thanks for the report! And sorry for the bug.
For the next step, could you please test whether the following change
fixes the issue?
Best,
Song
diff --git i/drivers/md/md.c w/drivers/md/md.c
index 854cbf4234aa..18e987c644c6 100644
--- i/drivers/md/md.c
+++ w/drivers/md/md.c
@@ -5868,10 +5868,6 @@ int md_run(struct mddev *mddev)
nowait = nowait && blk_queue_nowait(bdev_get_queue(rdev->bdev));
}
- /* Set the NOWAIT flags if all underlying devices support it */
- if (nowait)
- blk_queue_flag_set(QUEUE_FLAG_NOWAIT, mddev->queue);
-
if (!bioset_initialized(&mddev->bio_set)) {
err = bioset_init(&mddev->bio_set, BIO_POOL_SIZE, 0,
BIOSET_NEED_BVECS);
if (err)
@@ -6009,6 +6005,10 @@ int md_run(struct mddev *mddev)
else
blk_queue_flag_clear(QUEUE_FLAG_NONROT, mddev->queue);
blk_queue_flag_set(QUEUE_FLAG_IO_STAT, mddev->queue);
+
+ /* Set the NOWAIT flags if all underlying devices support it */
+ if (nowait)
+ blk_queue_flag_set(QUEUE_FLAG_NOWAIT, mddev->queue);
}
if (pers->sync_request) {
if (mddev->kobj.sd &&
