Re: System freeze when accessing st.ko and /dev/st0

[Brian King <brking@us.ibm.com>]

[-- Attachment #1: Type: text/plain, Size: 755 bytes --]

Mike Anderson wrote:
> Brian King [brking@us.ibm.com] wrote:
> 
>>I have been debugging this same problem in sg today. It appears as if
>>kobj_unmap is never getting called when a device is deleted. When I
>>added a call to kobj_unmap, the problem went away. I'm currently working
>>on a patch for this.
>>
>>-Brian
> 
> 
> Are you indicating that we need a direct call to kobj_unmap along with
> the call to cdev_unmap?

No. We just need a call to cdev_unmap, which isn't getting done. The attached
patch should fix this for both sg and st. I have tested both and it works for me.
Phil, can you please apply and let me know if it fixes your problem? It should
apply against 2.6.2.

Thanks


-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

[-- Attachment #2: patch-2.6.2-sg_st-cdev_unmap --]
[-- Type: text/plain, Size: 1024 bytes --]

diff -Naur linux-2.6.2/drivers/scsi/sg.c linux-2.6.2-cdev_unmap/drivers/scsi/sg.c
--- linux-2.6.2/drivers/scsi/sg.c	Fri Feb  6 14:12:22 2004
+++ linux-2.6.2-cdev_unmap/drivers/scsi/sg.c	Fri Feb  6 14:12:35 2004
@@ -1513,6 +1513,7 @@
 	if (sdp) {
 		sysfs_remove_link(&scsidp->sdev_gendev.kobj, "generic");
 		sysfs_remove_link(&sdp->cdev->kobj, "device");
+		cdev_unmap(MKDEV(SCSI_GENERIC_MAJOR, sdp->disk->first_minor), 1);
 		cdev_del(sdp->cdev);
 		sdp->cdev = NULL;
 		devfs_remove("%s/generic", scsidp->devfs_name);
diff -Naur linux-2.6.2/drivers/scsi/st.c linux-2.6.2-cdev_unmap/drivers/scsi/st.c
--- linux-2.6.2/drivers/scsi/st.c	Fri Jan  9 00:59:45 2004
+++ linux-2.6.2-cdev_unmap/drivers/scsi/st.c	Fri Feb  6 14:18:57 2004
@@ -3964,6 +3964,7 @@
 				for (j=0; j < 2; j++) {
 					sysfs_remove_link(&tpnt->modes[mode].cdevs[j]->kobj,
 							  "device");
+					cdev_unmap(MKDEV(SCSI_TAPE_MAJOR, TAPE_MINOR(i, mode, j)), 1);
 					cdev_del(tpnt->modes[mode].cdevs[j]);
 					tpnt->modes[mode].cdevs[j] = NULL;
 				}