On 6/24/2023 7:26 PM, Hou Tao wrote:
> From: Hou Tao <houtao1@xxxxxxxxxx>
>
> When doing mkfs.xfs on a pmem device, the following warning was
> reported and :
>
> ------------[ cut here ]------------
> WARNING: CPU: 2 PID: 384 at block/blk-core.c:751 submit_bio_noacct
> Modules linked in:
> CPU: 2 PID: 384 Comm: mkfs.xfs Not tainted 6.4.0-rc7+ #154
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
> RIP: 0010:submit_bio_noacct+0x340/0x520
> ......
> Call Trace:
> <TASK>
> ? asm_exc_invalid_op+0x1b/0x20
> ? submit_bio_noacct+0x340/0x520
> ? submit_bio_noacct+0xd5/0x520
> submit_bio+0x37/0x60
> async_pmem_flush+0x79/0xa0
> nvdimm_flush+0x17/0x40
> pmem_submit_bio+0x370/0x390
> __submit_bio+0xbc/0x190
> submit_bio_noacct_nocheck+0x14d/0x370
> submit_bio_noacct+0x1ef/0x520
> submit_bio+0x55/0x60
> submit_bio_wait+0x5a/0xc0
> blkdev_issue_flush+0x44/0x60
>
> The root cause is that submit_bio_noacct() needs bio_op() is either
> WRITE or ZONE_APPEND for flush bio and async_pmem_flush() doesn't assign
> REQ_OP_WRITE when allocating flush bio, so submit_bio_noacct just fail
> the flush bio.
>
> Simply fix it by adding the missing REQ_OP_WRITE for flush bio. And we
> could fix the flush order issue and do flush optimization later.
>
> Fixes: b4a6bb3a67aa ("block: add a sanity check for non-write flush/fua bios")
> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
> ---
> v3:
> * adjust the overly long lines in both commit message and code
>
> v2: https://lore.kernel.org/linux-block/20230621134340.878461-1-houtao@xxxxxxxxxxxxxxx
> * do a minimal fix first (Suggested by Christoph)
>
> v1: https://lore.kernel.org/linux-block/ZJLpYMC8FgtZ0k2k@xxxxxxxxxxxxx/T/#t
>
> Hi Jens & Dan,
>
> I found Pankaj was working on the optimization of virtio-pmem flush bio
> [0], but considering the last status update was 1/12/2022, so could you
> please pick the patch up for v6.4 and we can do the flush optimization
> later ?
>
> [0]: https://lore.kernel.org/lkml/20220111161937.56272-1-pankaj.gupta.linux@xxxxxxxxx/T/
>
I've failed to understand why we should wait for [0] ...
Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
-ck
