2023-10-18 11:38:32

by Wenchao Hao

Subject: [PATCH v3 1/2] scsi: core: cleanup scsi_dev_queue_ready()

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 | 32 +++++++++++++++-----------------
1 file changed, 15 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index aca57c3ab626..cf3864f72093 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1251,28 +1251,26 @@ 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;

- if (scsi_device_busy(sdev) > 1)
- goto out_dec;
+ if (!atomic_read(&sdev->device_blocked))
+ return token;

- /*
- * 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"));
+ /*
+ * Only unblock if no other commands are pending and
+ * if device_blocked has decreased to zero
+ */
+ if (scsi_device_busy(sdev) > 1 ||
+ atomic_dec_return(&sdev->device_blocked) > 0) {
+ 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;
}

/*
--
2.32.0

2023-10-18 18:07:37

by Bart Van Assche

Subject: Re: [PATCH v3 1/2] scsi: core: cleanup scsi_dev_queue_ready()

On 10/18/23 04:37, 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 | 32 +++++++++++++++-----------------
> 1 file changed, 15 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index aca57c3ab626..cf3864f72093 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -1251,28 +1251,26 @@ 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;
>
> - if (scsi_device_busy(sdev) > 1)
> - goto out_dec;
> + if (!atomic_read(&sdev->device_blocked))
> + return token;
>
> - /*
> - * 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"));
> + /*
> + * Only unblock if no other commands are pending and
> + * if device_blocked has decreased to zero
> + */
> + if (scsi_device_busy(sdev) > 1 ||
> + atomic_dec_return(&sdev->device_blocked) > 0) {
> + 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;
> }
>
> /*

Thanks for having made this function easier to read.

Reviewed-by: Bart Van Assche <[email protected]>