Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  backing-dev: ensure that a removed bdi no longer has super_block referencing it
  block: use after free bug in __blkdev_get
  block: silently error unsupported empty barriers too
diff --git a/block/blk-core.c b/block/blk-core.c
index ac0fa10..71da511 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1161,7 +1161,7 @@
 	const unsigned int ff = bio->bi_rw & REQ_FAILFAST_MASK;
 	int rw_flags;
 
-	if (bio_rw_flagged(bio, BIO_RW_BARRIER) && bio_has_data(bio) &&
+	if (bio_rw_flagged(bio, BIO_RW_BARRIER) &&
 	    (q->next_ordered == QUEUE_ORDERED_NONE)) {
 		bio_endio(bio, -EOPNOTSUPP);
 		return 0;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 9cf4b92..8bed055 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1248,8 +1248,8 @@
 			bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9);
 		}
 	} else {
-		put_disk(disk);
 		module_put(disk->fops->owner);
+		put_disk(disk);
 		disk = NULL;
 		if (bdev->bd_contains == bdev) {
 			if (bdev->bd_disk->fops->open) {
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 5a37e20..1065b71 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -610,6 +610,21 @@
 		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) {
@@ -682,6 +697,7 @@
 		spin_unlock(&inode_lock);
 	}
 
+	bdi_prune_sb(bdi);
 	bdi_unregister(bdi);
 
 	for (i = 0; i < NR_BDI_STAT_ITEMS; i++)