Re: kernel oops when burning CDs

[Tachino Nobuhiro]

Hello,

At Mon, 4 Jun 2001 22:43:30 +0100 (BST),
Alan Cox wrote:
> 
> > I get an ooops and immediate kernel panic when I break (CTRL-C) cdrecord. I 
> > can reproduce it anytime. I use 2.4.5-ac series. Obviously, Linus' 2.4.5 is 
> > fine.
> > I know, I know. I was supposed to make a serios oops report, BUT I wasn't 
> 
> Write down the EIP and the call trace then look them up in System.map. Also
> include the hardware details. The -ac tree has a newer version of the scsi
> generic code. It fixes some oopses but in your case it apparently added a new
> failure case

  Oops occures in SG driver. This patch fixes the problem.

diff -r -u linux.org/drivers/scsi/sg.c linux/drivers/scsi/sg.c
--- linux.org/drivers/scsi/sg.c	Fri Jun  1 10:10:22 2001
+++ linux/drivers/scsi/sg.c	Fri Jun  1 17:08:00 2001
@@ -1114,7 +1114,8 @@
             sg_remove_sfp(sdp, sfp);
 	    sfp = NULL;
         }
-	__MOD_DEC_USE_COUNT(sg_template.module);
+	if (sg_template.module)
+		__MOD_DEC_USE_COUNT(sg_template.module);
 	if (sdp->device->host->hostt->module)
 	    __MOD_DEC_USE_COUNT(sdp->device->host->hostt->module);
     }
@@ -1311,7 +1312,8 @@
 			sg_finish_rem_req(srp);
 		}
 		if (sfp->closed) {
-		    __MOD_DEC_USE_COUNT(sg_template.module);
+		    if (sg_template.module)
+			__MOD_DEC_USE_COUNT(sg_template.module);
 		    if (sdp->device->host->hostt->module)
 			__MOD_DEC_USE_COUNT(sdp->device->host->hostt->module);
 		    __sg_remove_sfp(sdp, sfp);
@@ -2207,7 +2209,8 @@
     else {
         sfp->closed = 1; /* flag dirty state on this fd */
 	/* MOD_INC's to inhibit unloading sg and associated adapter driver */
-	__MOD_INC_USE_COUNT(sg_template.module);
+	if (sg_template.module)
+	    __MOD_INC_USE_COUNT(sg_template.module);
 	 if (sdp->device->host->hostt->module)
 	    __MOD_INC_USE_COUNT(sdp->device->host->hostt->module);
         SCSI_LOG_TIMEOUT(1, printk(