Re: [PATCH 2/3] scsi: read host_busy via scsi_host_busy()

[Ming Lei]

On Fri, Apr 27, 2018 at 03:51:46PM +, Bart Van Assche wrote:
> On Fri, 2018-04-20 at 14:57 +0800, Ming Lei wrote:
> >  show_host_busy(struct device *dev, struct device_attribute *attr, char 
> > *buf)
> >  {
> > struct Scsi_Host *shost = class_to_shost(dev);
> > -   return snprintf(buf, 20, "%d\n", atomic_read(>host_busy));
> > +   return snprintf(buf, 20, "%d\n", scsi_host_busy(shost));
> >  }
> >  static DEVICE_ATTR(host_busy, S_IRUGO, show_host_busy, NULL);
> 
> The ", 20" part is cargo-cult programming. Since you have to touch this code,
> please either use "sprintf(buf, ...)" or use "scnprintf(buf, PAGE_SIZE, ...)".

This patch is only to replace atomic_read(>host_busy) with
scsi_host_busy(shost) which returns 'int' too, so nothing related
with snprintf(buf, 20,..).

No mention the string with 20 length is enough to hold integer, so it
isn't needed too. 

So I don't see any reason to do that in this patch.

Thanks, 
Ming

Re: [PATCH 2/3] scsi: read host_busy via scsi_host_busy()

[Bart Van Assche]

On Fri, 2018-04-20 at 14:57 +0800, Ming Lei wrote:
>  show_host_busy(struct device *dev, struct device_attribute *attr, char *buf)
>  {
>   struct Scsi_Host *shost = class_to_shost(dev);
> - return snprintf(buf, 20, "%d\n", atomic_read(>host_busy));
> + return snprintf(buf, 20, "%d\n", scsi_host_busy(shost));
>  }
>  static DEVICE_ATTR(host_busy, S_IRUGO, show_host_busy, NULL);

The ", 20" part is cargo-cult programming. Since you have to touch this code,
please either use "sprintf(buf, ...)" or use "scnprintf(buf, PAGE_SIZE, ...)".

Thanks,

Bart.

[PATCH 2/3] scsi: read host_busy via scsi_host_busy()

[Ming Lei]

No functional change, just replace the direct read of scsi_host->host_busy
with scsi_host_busy().

Cc: Omar Sandoval ,
Cc: "Martin K. Petersen" ,
Cc: James Bottomley ,
Cc: Christoph Hellwig ,
Cc: Don Brace 
Cc: Kashyap Desai 
Cc: Mike Snitzer 
Cc: Hannes Reinecke 
Cc: Laurence Oberman 
Signed-off-by: Ming Lei 
---
 drivers/scsi/advansys.c   | 8 
 drivers/scsi/libsas/sas_scsi_host.c   | 4 ++--
 drivers/scsi/megaraid/megaraid_sas_base.c | 2 +-
 drivers/scsi/mpt3sas/mpt3sas_base.c   | 4 ++--
 drivers/scsi/qlogicpti.c  | 2 +-
 drivers/scsi/scsi.c   | 2 +-
 drivers/scsi/scsi_error.c | 6 +++---
 drivers/scsi/scsi_sysfs.c | 2 +-
 8 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
index 24e57e770432..38ee024cbfc7 100644
--- a/drivers/scsi/advansys.c
+++ b/drivers/scsi/advansys.c
@@ -2416,8 +2416,8 @@ static void asc_prt_scsi_host(struct Scsi_Host *s)
struct asc_board *boardp = shost_priv(s);
 
printk("Scsi_Host at addr 0x%p, device %s\n", s, dev_name(boardp->dev));
-   printk(" host_busy %u, host_no %d,\n",
-  atomic_read(>host_busy), s->host_no);
+   printk(" host_busy %d, host_no %d,\n",
+  scsi_host_busy(s), s->host_no);
 
printk(" base 0x%lx, io_port 0x%lx, irq %d,\n",
   (ulong)s->base, (ulong)s->io_port, boardp->irq);
@@ -3182,8 +3182,8 @@ static void asc_prt_driver_conf(struct seq_file *m, 
struct Scsi_Host *shost)
shost->host_no);
 
seq_printf(m,
-  " host_busy %u, max_id %u, max_lun %llu, max_channel %u\n",
-  atomic_read(>host_busy), shost->max_id,
+  " host_busy %d, max_id %u, max_lun %llu, max_channel %u\n",
+  scsi_host_busy(shost), shost->max_id,
   shost->max_lun, shost->max_channel);
 
seq_printf(m,
diff --git a/drivers/scsi/libsas/sas_scsi_host.c 
b/drivers/scsi/libsas/sas_scsi_host.c
index ceab5e5c41c2..33229348dcb6 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -759,7 +759,7 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
spin_unlock_irq(shost->host_lock);
 
SAS_DPRINTK("Enter %s busy: %d failed: %d\n",
-   __func__, atomic_read(>host_busy), 
shost->host_failed);
+   __func__, scsi_host_busy(shost), shost->host_failed);
/*
 * Deal with commands that still have SAS tasks (i.e. they didn't
 * complete via the normal sas_task completion mechanism),
@@ -801,7 +801,7 @@ void sas_scsi_recover_host(struct Scsi_Host *shost)
goto retry;
 
SAS_DPRINTK("--- Exit %s: busy: %d failed: %d tries: %d\n",
-   __func__, atomic_read(>host_busy),
+   __func__, scsi_host_busy(shost),
shost->host_failed, tries);
 }
 
diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c 
b/drivers/scsi/megaraid/megaraid_sas_base.c
index b89c6e6c0589..008a3bdfa948 100644
--- a/drivers/scsi/megaraid/megaraid_sas_base.c
+++ b/drivers/scsi/megaraid/megaraid_sas_base.c
@@ -2822,7 +2822,7 @@ static int megasas_reset_bus_host(struct scsi_cmnd *scmd)
"SCSI command pointer: (%p)\t SCSI host state: %d\t"
" SCSI host busy: %d\t FW outstanding: %d\n",
scmd, scmd->device->host->shost_state,
-   atomic_read((atomic_t *)>device->host->host_busy),
+   scsi_host_busy(scmd->device->host),
atomic_read(>fw_outstanding));
 
/*
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c 
b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 61f93a134956..b7325355df8e 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -3260,7 +3260,7 @@ _base_recovery_check(struct MPT3SAS_ADAPTER *ioc)
 * See _wait_for_commands_to_complete() call with regards to this code.
 */
if (ioc->shost_recovery && ioc->pending_io_count) {
-   ioc->pending_io_count = atomic_read(>shost->host_busy);
+   ioc->pending_io_count = scsi_host_busy(ioc->shost);
if (ioc->pending_io_count == 0)
wake_up(>reset_wq);
}
@@ -6658,7 +6658,7 @@ mpt3sas_wait_for_commands_to_complete(struct 
MPT3SAS_ADAPTER *ioc)
return;
 
/* pending command count */
-   ioc->pending_io_count = atomic_read(>shost->host_busy);
+   ioc->pending_io_count = scsi_host_busy(ioc->shost);
 
if (!ioc->pending_io_count)
return;
diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index