From: Hou Tao <houtao1@xxxxxxxxxx>
The following warning was reported when doing fsync on a pmem device:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 384 at block/blk-core.c:751 submit_bio_noacct+0x340/0x520
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>
---
v2:
* 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 fix and 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 fix
and optimization later ?
[0]: https://lore.kernel.org/lkml/20220111161937.56272-1-pankaj.gupta.linux@xxxxxxxxx/T/
drivers/nvdimm/nd_virtio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvdimm/nd_virtio.c b/drivers/nvdimm/nd_virtio.c
index c6a648fd8744..97098099f8a3 100644
--- a/drivers/nvdimm/nd_virtio.c
+++ b/drivers/nvdimm/nd_virtio.c
@@ -105,7 +105,7 @@ 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
