static __init int bdi_class_init(void)
{
bdi_class = class_create(THIS_MODULE, "bdi");
+ if (IS_ERR(bdi_class))
+ return PTR_ERR(bdi_class);
+
bdi_class->dev_attrs = bdi_dev_attrs;
bdi_debug_init();
return 0;
/*
* Finally, kill the kernel threads. We don't need to be RCU
- * safe anymore, since the bdi is gone from visibility.
+ * safe anymore, since the bdi is gone from visibility. Force
+ * unfreeze of the thread before calling kthread_stop(), otherwise
+ * it would never exet if it is currently stuck in the refrigerator.
*/
- list_for_each_entry(wb, &bdi->wb_list, list)
+ list_for_each_entry(wb, &bdi->wb_list, list) {
+ thaw_process(wb->task);
kthread_stop(wb->task);
+ }
+}
+
+/*
+ * This bdi is going away now, make sure that no super_blocks point to it
+ */
+static void bdi_prune_sb(struct backing_dev_info *bdi)
+{
+ struct super_block *sb;
+
+ spin_lock(&sb_lock);
+ list_for_each_entry(sb, &super_blocks, s_list) {
+ if (sb->s_bdi == bdi)
+ sb->s_bdi = NULL;
+ }
+ spin_unlock(&sb_lock);
}
void bdi_unregister(struct backing_dev_info *bdi)
{
if (bdi->dev) {
+ bdi_prune_sb(bdi);
+
if (!bdi_cap_flush_forker(bdi))
bdi_wb_shutdown(bdi);
bdi_debug_unregister(bdi);