[SCSI] Fix SCSI tape oops at module removal

Removing the SCSI tape module results in an oops in class_device_destroy if
any devices are present. The patch at the end of this message fixes the bug
by moving class_destroy() later in exit_st() so that the class still exists
when devices are removed. (The bug is old but class_simple_device_remove() did
nothing when the class did not exist.)

The patch also fixes a "class leak" in init_st() error path.

I would like to get this into 2.6.13 but it may be too late?

Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 2 insertions, 6 deletions

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 0291a8fb654d..0a7839db5752 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4149,12 +4149,10 @@ static int __init init_st(void)
                         do_create_driverfs_files();
                         return 0;
                 }
-                if (st_sysfs_class)
-                        class_destroy(st_sysfs_class);
                 unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
-
                                          ST_MAX_TAPE_ENTRIES);
         }
+        class_destroy(st_sysfs_class);
 
         printk(KERN_ERR "Unable to get major %d for SCSI tapes\n", SCSI_TAPE_MAJOR);
         return 1;
@@ -4162,13 +4160,11 @@ static int __init init_st(void)
 
 static void __exit exit_st(void)
 {
-        if (st_sysfs_class)
-                class_destroy(st_sysfs_class);
-        st_sysfs_class = NULL;
         do_remove_driverfs_files();
         scsi_unregister_driver(&st_template.gendrv);
         unregister_chrdev_region(MKDEV(SCSI_TAPE_MAJOR, 0),
                                  ST_MAX_TAPE_ENTRIES);
+        class_destroy(st_sysfs_class);
         kfree(scsi_tapes);
         printk(KERN_INFO "st: Unloaded.\n");
 }