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Message-ID: <d62c3e97-bddf-4fd4-9099-2ff6954938b3@acm.org>
Date:   Wed, 18 Oct 2023 11:07:03 -0700
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Subject: Re: [PATCH v3 1/2] scsi: core: cleanup scsi_dev_queue_ready()
Content-Language: en-US
To:     Wenchao Hao <haowenchao2@huawei.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>
Cc:     "James E . J . Bottomley" <jejb@linux.ibm.com>,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        louhongxiang@huawei.com
References: <20231018113746.1940197-1-haowenchao2@huawei.com>
 <20231018113746.1940197-2-haowenchao2@huawei.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <20231018113746.1940197-2-haowenchao2@huawei.com>
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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 <haowenchao2@huawei.com>
> ---
>   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 <bvanassche@acm.org>