On 2023/09/22 2:38, Wenchao Hao wrote:
> This is just a cleanup for scsi_dev_queue_ready() to avoid
> redundant goto and if statement, it did not change the origin
> logic.
>
> Signed-off-by: Wenchao Hao <[email protected]>
> ---
> drivers/scsi/scsi_lib.c | 35 ++++++++++++++++++-----------------
> 1 file changed, 18 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index ca5eb058d5c7..f3e388127dbd 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1254,28 +1254,29 @@ static inline int scsi_dev_queue_ready(struct
> request_queue *q,
> int token;
>
> token = sbitmap_get(&sdev->budget_map);
> - if (atomic_read(&sdev->device_blocked)) {
> - if (token < 0)
> - goto out;
> + if (token < 0)
> + return -1;
This is changing how this function works...
>
> - if (scsi_device_busy(sdev) > 1)
> - goto out_dec;
> + /*
> + * device_blocked is not set at mostly time, so check it first
> + * and return token when it is not set.
> + */
> + if (!atomic_read(&sdev->device_blocked))
> + return token;
...because you reversed the tests order.
>
> - /*
> - * unblock after device_blocked iterates to zero
> - */
> - if (atomic_dec_return(&sdev->device_blocked) > 0)
> - goto out_dec;
> - SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
> - "unblocking device at zero depth\n"));
> + /*
> + * unblock after device_blocked iterates to zero
> + */
> + if (scsi_device_busy(sdev) > 1 ||
> + atomic_dec_return(&sdev->device_blocked) > 0) {
And here too, you are changing how the function works. The atomic_dec may not be
done if the first condition is true.
> + sbitmap_put(&sdev->budget_map, token);
> + return -1;
> }
>
> + SCSI_LOG_MLQUEUE(3, sdev_printk(KERN_INFO, sdev,
> + "unblocking device at zero depth\n"));
> +
> return token;
> -out_dec:
> - if (token >= 0)
> - sbitmap_put(&sdev->budget_map, token);
> -out:
> - return -1;
> }
>
> /*
--
Damien Le Moal
Western Digital Research
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