Re: scsi: bsg-lib: drop device reference on error path

From: Chaitanya Kulkarni
Date: Wed Apr 17 2019 - 05:19:00 EST


Hi Pan,

Thanks for the patch, purely cosmetics comments below.

On 4/16/19 8:27 PM, Pan Bian wrote:
> The function put_device is not called to drop the device reference taken
> by get_device on error paths. This patch fixes the bug.
>
> Fixes: cd2f076f1d7("bsg: convert to use blk-mq")
> Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
> ---
> block/bsg-lib.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/block/bsg-lib.c b/block/bsg-lib.c
> index 005e2b7..fe9e0cc 100644
> --- a/block/bsg-lib.c
> +++ b/block/bsg-lib.c
> @@ -281,21 +281,24 @@ static blk_status_t bsg_queue_rq(struct blk_mq_hw_ctx *hctx,
> struct bsg_set *bset =
> container_of(q->tag_set, struct bsg_set, tag_set);
> int ret;
> + blk_status_t status = BLK_STS_IOERR;
>
Not sure if we need status variable as the code written here pretty
straight forward.
> blk_mq_start_request(req);
>
> if (!get_device(dev))
> - return BLK_STS_IOERR;
> + return status;
>
Also if we are still considering having status variable then we should
add "err:" label at the end of function just before return and use that
for an error instead of having multiple returns.
> if (!bsg_prepare_job(dev, req))
> - return BLK_STS_IOERR;
> + goto out;
>
> ret = bset->job_fn(blk_mq_rq_to_pdu(req));
> if (ret)
> - return BLK_STS_IOERR;
> + goto out;
>
> + status = BLK_STS_OK;
> +out:
> put_device(dev);
> - return BLK_STS_OK;
> + return status;
> }
>
> /* called right after the request is allocated for the request_queue */
>