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From: Li Zhong <zhong@linux.vnet.ibm.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: JBottomley@parallels.com, linux-scsi@vger.kernel.org,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH scsi] Add NULL checking of return value from scsi_cmd_to_driver()
Date: Mon, 24 Sep 2012 13:30:26 +0800	[thread overview]
Message-ID: <1348464626.2475.13.camel@ThinkPad-T420> (raw)

Just noticed that after commit 919f797, it is possible that 
scsi_cmd_to_driver() returns NULL. This patch adds the NULL checking for drv 
returned from the above function. 

Maybe it is not possible at run time, but from the code itself, we'd better
have this check?  

This patch actually is a delta of my previous patch 
[https://lkml.org/lkml/2012/4/11/814] and commit 919f797

Signed-off-by: Li Zhong <zhong@linux.vnet.ibm.com>
---

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 2936b44..b9dd7f0 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -832,7 +832,7 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
         if (cmd->request->cmd_type != REQ_TYPE_BLOCK_PC) {
 		int old_good_bytes = good_bytes;
 		drv = scsi_cmd_to_driver(cmd);
-		if (drv->done)
+		if (drv && drv->done)
 			good_bytes = drv->done(cmd);
 		/*
 		 * USB may not give sense identifying bad sector and



             reply	other threads:[~2012-09-24  5:30 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-24  5:30 Li Zhong [this message]
2012-09-24  5:44 ` [PATCH scsi] Add NULL checking of return value from scsi_cmd_to_driver() James Bottomley
2012-09-24  7:03   ` Li Zhong
2012-09-24  7:35     ` James Bottomley
2012-09-24  9:25       ` Li Zhong
2012-09-24  9:33         ` James Bottomley
2012-09-27  2:02       ` Martin K. Petersen
2012-09-27  4:44         ` James Bottomley
2012-09-27  9:51           ` [PATCH scsi] Short the path length of scsi_cmd_to_driver() Li Zhong
2012-09-27 17:43             ` Martin K. Petersen
2012-09-28  7:13               ` Li Zhong
2012-09-28  7:45               ` James Bottomley
2012-09-27 17:41           ` [PATCH scsi] Add NULL checking of return value from scsi_cmd_to_driver() Martin K. Petersen
2012-09-28  7:48             ` James Bottomley
2012-09-29  4:23               ` [PATCH v2 scsi] Short the path length of scsi_cmd_to_driver() Li Zhong
2012-10-02 22:22                 ` Martin K. Petersen

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