cciss: Fix problem with remove_from_scan_list on driver unload
cciss: Fix problem with remove_from_scan_list that on driver unload
it doesn't remove the controller from the scan list correctly if
the controller is currently being scanned for new devices.
Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 92b1263..81c2187 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3513,28 +3513,33 @@
* @h: Pointer to the controller.
*
* Removes the controller from the rescan queue if present. Blocks if
- * the controller is currently conducting a rescan.
+ * the controller is currently conducting a rescan. The controller
+ * can be in one of three states:
+ * 1. Doesn't need a scan
+ * 2. On the scan list, but not scanning yet (we remove it)
+ * 3. Busy scanning (and not on the list). In this case we want to wait for
+ * the scan to complete to make sure the scanning thread for this
+ * controller is completely idle.
**/
static void remove_from_scan_list(struct ctlr_info *h)
{
struct ctlr_info *test_h, *tmp_h;
- int scanning = 0;
mutex_lock(&scan_mutex);
list_for_each_entry_safe(test_h, tmp_h, &scan_q, scan_list) {
- if (test_h == h) {
+ if (test_h == h) { /* state 2. */
list_del(&h->scan_list);
complete_all(&h->scan_wait);
mutex_unlock(&scan_mutex);
return;
}
}
- if (&h->busy_scanning)
- scanning = 0;
- mutex_unlock(&scan_mutex);
-
- if (scanning)
+ if (h->busy_scanning) { /* state 3. */
+ mutex_unlock(&scan_mutex);
wait_for_completion(&h->scan_wait);
+ } else { /* state 1, nothing to do. */
+ mutex_unlock(&scan_mutex);
+ }
}
/**