Gentle ping!
Dan, Vishal for suggestion/review on this patch and request for merging.
+Cc Michael for awareness, as virtio-pmem device is currently broken.
Thanks,
Pankaj
> From: Hou Tao <houtao1@xxxxxxxxxx>
>
> When doing mkfs.xfs on a pmem device, the following warning was
> reported:
>
> ------------[ 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>
> ? 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.
>
> Cc: stable@xxxxxxxxxxxxxxx # 6.3+
> Fixes: b4a6bb3a67aa ("block: add a sanity check for non-write flush/fua bios")
> Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
> Reviewed-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
> Tested-by: Pankaj Gupta <pankaj.gupta@xxxxxxx>
> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
> ---
> v4:
> * add stable Cc
> * collect Rvb and Tested-by tags
>
> v3: https://lore.kernel.org/linux-block/20230625022633.2753877-1-houtao@xxxxxxxxxxxxxxx
> * 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
>
> drivers/nvdimm/nd_virtio.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c
> index c6a648fd8744..1f8c667c6f1e 100644
> --- a/drivers/nvdimm/nd_virtio.c
> +++ b/drivers/nvdimm/nd_virtio.c
> @@ -105,7 +105,8 @@ int async_pmem_flush(struct nd_region *nd_region, struct bio *bio)
> * parent bio. Otherwise directly call nd_region flush.
> */
> if (bio && bio->bi_iter.bi_sector != -1) {
> - struct bio *child = bio_alloc(bio->bi_bdev, 0, REQ_PREFLUSH,
> + struct bio *child = bio_alloc(bio->bi_bdev, 0,
> + REQ_OP_WRITE | REQ_PREFLUSH,
> GFP_ATOMIC);
>
> if (!child)
> --
> 2.29.2
>
