diff mbox series

[v2,1/2] scsi: core: cleanup scsi_dev_queue_ready()

Message ID 20231016020847.1270258-2-haowenchao2@huawei.com
State New
Headers
Series cleanup patch |

Commit Message

Wenchao Hao Oct. 16, 2023, 2:08 a.m. UTC 
  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 <haowenchao2@huawei.com>
---
 drivers/scsi/scsi_lib.c | 35 ++++++++++++++++++-----------------
 1 file changed, 18 insertions(+), 17 deletions(-)

Comments

Bart Van Assche Oct. 17, 2023, 9:15 p.m. UTC | #1 
On 10/15/23 19:08, Wenchao Hao wrote:
> +	/*
> +	 * 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;

This patch looks like an improvement to me. But I don't think that the
above comment is useful. I propose to move it into the patch
description.

> -		/*
> -		 * 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) {
 > +		sbitmap_put(&sdev->budget_map, token);
 > +		return -1;
 >   	}

Please make the above comment match the new code, e.g. by changing it
into the following: "Only unblock if no other commands are pending and
if device_blocked has decreased to zero".

Thanks,

Bart.
Wenchao Hao Oct. 18, 2023, 2:22 a.m. UTC | #2 
On 2023/10/18 5:15, Bart Van Assche wrote:
> On 10/15/23 19:08, Wenchao Hao wrote:
>> +    /*
>> +     * 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;
> 
> This patch looks like an improvement to me. But I don't think that the
> above comment is useful. I propose to move it into the patch
> description.
> 
>> -        /*
>> -         * 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) {
>  > +        sbitmap_put(&sdev->budget_map, token);
>  > +        return -1;
>  >       }
> 
> Please make the above comment match the new code, e.g. by changing it
> into the following: "Only unblock if no other commands are pending and
> if device_blocked has decreased to zero".
> 

OK, would update.

Thanks.

> Thanks,
> 
> Bart.
>
diff mbox series

Patch

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 40f407ffd26f..b179c24f9c76 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1250,28 +1250,29 @@  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;
 
-		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;
 
-		/*
-		 * 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) {
+		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;
 }
 
 /*