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Message-ID: <4b107020-2494-2470-ba1b-c2000eae1355@opensource.wdc.com>
Date:   Thu, 24 Feb 2022 21:49:31 +0900
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Subject: Re: [PATCH 2/2] scsi: libsas: Use bool for queue_work() return code
Content-Language: en-US
To:     John Garry <john.garry@huawei.com>, jejb@linux.ibm.com,
        martin.petersen@oracle.com
Cc:     chenxiang66@hisilicon.com, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org, linuxarm@huawei.com
References: <1645700699-82369-1-git-send-email-john.garry@huawei.com>
 <1645700699-82369-3-git-send-email-john.garry@huawei.com>
From:   Damien Le Moal <damien.lemoal@opensource.wdc.com>
Organization: Western Digital Research
In-Reply-To: <1645700699-82369-3-git-send-email-john.garry@huawei.com>
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Precedence: bulk

On 2/24/22 20:04, John Garry wrote:
> Function queue_work() returns a bool, so use a bool to hold this value
> for the return code, which should make the code a tiny bit more clear.
> 
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
>  drivers/scsi/libsas/sas_event.c    | 23 +++++++++--------------
>  drivers/scsi/libsas/sas_internal.h |  2 +-
>  2 files changed, 10 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/scsi/libsas/sas_event.c b/drivers/scsi/libsas/sas_event.c
> index 8ff58fd97837..e5eb24100e2d 100644
> --- a/drivers/scsi/libsas/sas_event.c
> +++ b/drivers/scsi/libsas/sas_event.c
> @@ -10,13 +10,13 @@
>  #include <scsi/scsi_host.h>
>  #include "sas_internal.h"
>  
> -int sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
> +bool sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
>  {
>  	/* it's added to the defer_q when draining so return succeed */
> -	int rc = 1;
> +	bool rc = true;
>  
>  	if (!test_bit(SAS_HA_REGISTERED, &ha->state))
> -		return 0;
> +		return false;
>  
>  	if (test_bit(SAS_HA_DRAINING, &ha->state)) {
>  		/* add it to the defer list, if not already pending */
> @@ -28,11 +28,11 @@ int sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
>  	return rc;

While at it, I would cleanup this function like this:

diff --git a/drivers/scsi/libsas/sas_event.c
b/drivers/scsi/libsas/sas_event.c
index 3613b9b315bc..38e6e91aaf36 100644
--- a/drivers/scsi/libsas/sas_event.c
+++ b/drivers/scsi/libsas/sas_event.c
@@ -12,20 +12,17 @@

 int sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw)
 {
-       /* it's added to the defer_q when draining so return succeed */
-       int rc = 1;
-
        if (!test_bit(SAS_HA_REGISTERED, &ha->state))
-               return 0;
+               return false;

        if (test_bit(SAS_HA_DRAINING, &ha->state)) {
                /* add it to the defer list, if not already pending */
                if (list_empty(&sw->drain_node))
                        list_add_tail(&sw->drain_node, &ha->defer_q);
-       } else
-               rc = queue_work(ha->event_q, &sw->work);
+               return true;
+       }

-       return rc;
+       return queue_work(ha->event_q, &sw->work);
 }

No local variable :)

>  }
>  
> -static int sas_queue_event(int event, struct sas_work *work,
> +static bool sas_queue_event(int event, struct sas_work *work,
>  			    struct sas_ha_struct *ha)
>  {
>  	unsigned long flags;
> -	int rc;
> +	bool rc;
>  
>  	spin_lock_irqsave(&ha->lock, flags);
>  	rc = sas_queue_work(ha, work);
> @@ -44,13 +44,12 @@ static int sas_queue_event(int event, struct sas_work *work,
>  void sas_queue_deferred_work(struct sas_ha_struct *ha)
>  {
>  	struct sas_work *sw, *_sw;
> -	int ret;
>  
>  	spin_lock_irq(&ha->lock);
>  	list_for_each_entry_safe(sw, _sw, &ha->defer_q, drain_node) {
>  		list_del_init(&sw->drain_node);
> -		ret = sas_queue_work(ha, sw);
> -		if (ret != 1) {
> +
> +		if (sas_queue_work(ha, sw) == false) {

if (!sas_queue_work(ha, sw)) ?

>  			pm_runtime_put(ha->dev);
>  			sas_free_event(to_asd_sas_event(&sw->work));
>  		}
> @@ -170,7 +169,6 @@ void sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event,
>  {
>  	struct sas_ha_struct *ha = phy->ha;
>  	struct asd_sas_event *ev;
> -	int ret;
>  
>  	BUG_ON(event >= PORT_NUM_EVENTS);
>  
> @@ -186,8 +184,7 @@ void sas_notify_port_event(struct asd_sas_phy *phy, enum port_event event,
>  	if (sas_defer_event(phy, ev))
>  		return;
>  
> -	ret = sas_queue_event(event, &ev->work, ha);
> -	if (ret != 1) {
> +	if (sas_queue_event(event, &ev->work, ha) == false) {

Same.

>  		pm_runtime_put(ha->dev);
>  		sas_free_event(ev);
>  	}
> @@ -199,7 +196,6 @@ void sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event,
>  {
>  	struct sas_ha_struct *ha = phy->ha;
>  	struct asd_sas_event *ev;
> -	int ret;
>  
>  	BUG_ON(event >= PHY_NUM_EVENTS);
>  
> @@ -215,8 +211,7 @@ void sas_notify_phy_event(struct asd_sas_phy *phy, enum phy_event event,
>  	if (sas_defer_event(phy, ev))
>  		return;
>  
> -	ret = sas_queue_event(event, &ev->work, ha);
> -	if (ret != 1) {
> +	if (sas_queue_event(event, &ev->work, ha) == false) {

And again.

>  		pm_runtime_put(ha->dev);
>  		sas_free_event(ev);
>  	}
> diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
> index 24843db2cb65..13d0ffaada93 100644
> --- a/drivers/scsi/libsas/sas_internal.h
> +++ b/drivers/scsi/libsas/sas_internal.h
> @@ -67,7 +67,7 @@ void sas_porte_broadcast_rcvd(struct work_struct *work);
>  void sas_porte_link_reset_err(struct work_struct *work);
>  void sas_porte_timer_event(struct work_struct *work);
>  void sas_porte_hard_reset(struct work_struct *work);
> -int sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw);
> +bool sas_queue_work(struct sas_ha_struct *ha, struct sas_work *sw);
>  
>  int sas_notify_lldd_dev_found(struct domain_device *);
>  void sas_notify_lldd_dev_gone(struct domain_device *);


-- 
Damien Le Moal
Western Digital Research