[PATCH AUTOSEL 5.15 11/11] block/rnbd: replace REQ_OP_FLUSH with REQ_OP_WRITE

From: Sasha Levin
Date: Sat May 20 2023 - 14:25:55 EST


From: Guoqing Jiang <guoqing.jiang@xxxxxxxxx>

[ Upstream commit 5e6e08087a4acb4ee3574cea32dbff0f63c7f608 ]

Since flush bios are implemented as writes with no data and
the preflush flag per Christoph's comment [1].

And we need to change it in rnbd accordingly. Otherwise, I
got splatting when create fs from rnbd client.

[ 464.028545] ------------[ cut here ]------------
[ 464.028553] WARNING: CPU: 0 PID: 65 at block/blk-core.c:751 submit_bio_noacct+0x32c/0x5d0
[ ... ]
[ 464.028668] CPU: 0 PID: 65 Comm: kworker/0:1H Tainted: G OE 6.4.0-rc1 #9
[ 464.028671] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-0-g2dd4b9b-rebuilt.opensuse.org 04/01/2014
[ 464.028673] Workqueue: ib-comp-wq ib_cq_poll_work [ib_core]
[ 464.028717] RIP: 0010:submit_bio_noacct+0x32c/0x5d0
[ 464.028720] Code: 03 0f 85 51 fe ff ff 48 8b 43 18 8b 88 04 03 00 00 85 c9 0f 85 3f fe ff ff e9 be fd ff ff 0f b6 d0 3c 0d 74 26 83 fa 01 74 21 <0f> 0b b8 0a 00 00 00 e9 56 fd ff ff 4c 89 e7 e8 70 a1 03 00 84 c0
[ 464.028722] RSP: 0018:ffffaf3680b57c68 EFLAGS: 00010202
[ 464.028724] RAX: 0000000000060802 RBX: ffffa09dcc18bf00 RCX: 0000000000000000
[ 464.028726] RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffffa09dde081d00
[ 464.028727] RBP: ffffaf3680b57c98 R08: ffffa09dde081d00 R09: ffffa09e38327200
[ 464.028729] R10: 0000000000000000 R11: 0000000000000000 R12: ffffa09dde081d00
[ 464.028730] R13: ffffa09dcb06e1e8 R14: 0000000000000000 R15: 0000000000200000
[ 464.028733] FS: 0000000000000000(0000) GS:ffffa09e3bc00000(0000) knlGS:0000000000000000
[ 464.028735] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 464.028736] CR2: 000055a4e8206c40 CR3: 0000000119f06000 CR4: 00000000003506f0
[ 464.028738] Call Trace:
[ 464.028740] <TASK>
[ 464.028746] submit_bio+0x1b/0x80
[ 464.028748] rnbd_srv_rdma_ev+0x50d/0x10c0 [rnbd_server]
[ 464.028754] ? percpu_ref_get_many.constprop.0+0x55/0x140 [rtrs_server]
[ 464.028760] ? __this_cpu_preempt_check+0x13/0x20
[ 464.028769] process_io_req+0x1dc/0x450 [rtrs_server]
[ 464.028775] rtrs_srv_inv_rkey_done+0x67/0xb0 [rtrs_server]
[ 464.028780] __ib_process_cq+0xbc/0x1f0 [ib_core]
[ 464.028793] ib_cq_poll_work+0x2b/0xa0 [ib_core]
[ 464.028804] process_one_work+0x2a9/0x580

[1]. https://lore.kernel.org/all/ZFHgefWofVt24tRl@xxxxxxxxxxxxx/

Signed-off-by: Guoqing Jiang <guoqing.jiang@xxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Chaitanya Kulkarni <kch@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230512034631.28686-1-guoqing.jiang@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/block/rnbd/rnbd-proto.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/rnbd/rnbd-proto.h b/drivers/block/rnbd/rnbd-proto.h
index c1bc5c0fef71d..e0fe0a9aa3708 100644
--- a/drivers/block/rnbd/rnbd-proto.h
+++ b/drivers/block/rnbd/rnbd-proto.h
@@ -241,7 +241,7 @@ static inline u32 rnbd_to_bio_flags(u32 rnbd_opf)
bio_opf = REQ_OP_WRITE;
break;
case RNBD_OP_FLUSH:
- bio_opf = REQ_OP_FLUSH | REQ_PREFLUSH;
+ bio_opf = REQ_OP_WRITE | REQ_PREFLUSH;
break;
case RNBD_OP_DISCARD:
bio_opf = REQ_OP_DISCARD;
--
2.39.2