Re: [PATCH] virtio_blk: corrent types for status handling

From: Max Gurtovoy
Date: Mon Oct 25 2021 - 04:25:30 EST



On 10/25/2021 10:58 AM, Michael S. Tsirkin wrote:
virtblk_setup_cmd returns blk_status_t in an int, callers then assign it
back to a blk_status_t variable. blk_status_t is either u32 or (more
typically) u8 so it works, but is inelegant and causes sparse warnings.

Pass the status in blk_status_t in a consistent way.

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Fixes: b2c5221fd074 ("virtio-blk: avoid preallocating big SGL for data")
Cc: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>
Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
---
drivers/block/virtio_blk.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index c336d9bb9105..c7d05ff24084 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -208,8 +208,9 @@ static void virtblk_cleanup_cmd(struct request *req)
kfree(bvec_virt(&req->special_vec));
}
-static int virtblk_setup_cmd(struct virtio_device *vdev, struct request *req,
- struct virtblk_req *vbr)
+static blk_status_t virtblk_setup_cmd(struct virtio_device *vdev,
+ struct request *req,
+ struct virtblk_req *vbr)
{
bool unmap = false;
u32 type;
@@ -317,14 +318,15 @@ static blk_status_t virtio_queue_rq(struct blk_mq_hw_ctx *hctx,
unsigned long flags;
unsigned int num;
int qid = hctx->queue_num;
- int err;
bool notify = false;
+ blk_status_t status;
+ int err;
BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
- err = virtblk_setup_cmd(vblk->vdev, req, vbr);
- if (unlikely(err))
- return err;
+ status = virtblk_setup_cmd(vblk->vdev, req, vbr);
+ if (unlikely(status))
+ return status;

Maybe we can compare the returned status to BLK_STS_OK. But I see we don't do it also in NVMe subsystem so I guess we can assume BLK_STS_OK == 0 forever.

Jens/Christoph, any thoughts on that ?


Anyway Looks good.

Thanks for the fix,

Reviewed-by: Max Gurtovoy <mgurtovoy@xxxxxxxxxx>

blk_mq_start_request(req);