Re: [PATCH 1/1] dpt_i2o: delete unnecessary null test on array

Julia Lawall
2014-08-09T06:26:15Z

>From nobody Sat Aug 9 08:17:15 CEST 2014
From: Julia Lawall <Julia.Lawall@lip6.fr>
To: Adaptec OEM Raid Solutions <aacraid@adaptec.com>
Cc: "James E.J. Bottomley" <JBottomley@parallels.com>,linux-scsi@vger.kernel.org,linux-kernel@vger.kernel.org
Subject: [PATCH] dpt_i2o: delete unnecessary null test on array

From: Julia Lawall <Julia.Lawall@lip6.fr>

Convert a NULL test on an array to a NULL test on its element. Delete a
redundant test and clean up the code a little.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r@
type T;
T [] e;
position p;
@@
e ==@p NULL

@ disable fld_to_ptr@
expression e;
identifier f;
position r.p;
@@
* e.f ==@p NULL
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>

---
v2: Test instead the array element, and clean up the code a bit.

drivers/scsi/dpt_i2o.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/scsi/dpt_i2o.c b/drivers/scsi/dpt_i2o.c
index 67283ef..4647c93 100644
--- a/drivers/scsi/dpt_i2o.c
+++ b/drivers/scsi/dpt_i2o.c
@@ -1169,15 +1169,14 @@ static struct adpt_device* adpt_find_device(adpt_hba* pHba, u32 chan, u32 id, u6
if(chan < 0 || chan >= MAX_CHANNEL)
return NULL;

- if( pHba->channel[chan].device == NULL){
- printk(KERN_DEBUG"Adaptec I2O RAID: Trying to find device before they are allocated\n");
+ d = pHba->channel[chan].device[id];
+ if (!d) {
+ printk(KERN_DEBUG "Adaptec I2O RAID: Trying to find device before they are allocated\n");
return NULL;
}

- d = pHba->channel[chan].device[id];
- if(!d || d->tid == 0) {
+ if (d->tid == 0)
return NULL;
- }

/* If it is the only lun at that address then this should match*/
if(d->scsi_lun == lun){