diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index d557264ee974deab61c33736d93af24ffb2a93d2..fe69edda11fbad5201dffc3d4848af5b49fab1c6 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3276,7 +3276,7 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans,
 			   struct btrfs_root *root, unsigned long count);
 int btrfs_async_run_delayed_refs(struct btrfs_root *root,
 				 unsigned long count, int wait);
-int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len);
+int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len);
 int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 			     struct btrfs_root *root, u64 bytenr,
 			     u64 offset, int metadata, u64 *refs, u64 *flags);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 1ad0f47ac850bce13c5bc369416eff171604768c..1bf9f897065dc886ce4463b3d63f5e507c2b953c 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3817,19 +3817,19 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 	struct btrfs_super_block *sb = fs_info->super_copy;
 	int ret = 0;
 
-	if (sb->root_level > BTRFS_MAX_LEVEL) {
-		printk(KERN_ERR "BTRFS: tree_root level too big: %d > %d\n",
-				sb->root_level, BTRFS_MAX_LEVEL);
+	if (btrfs_super_root_level(sb) >= BTRFS_MAX_LEVEL) {
+		printk(KERN_ERR "BTRFS: tree_root level too big: %d >= %d\n",
+				btrfs_super_root_level(sb), BTRFS_MAX_LEVEL);
 		ret = -EINVAL;
 	}
-	if (sb->chunk_root_level > BTRFS_MAX_LEVEL) {
-		printk(KERN_ERR "BTRFS: chunk_root level too big: %d > %d\n",
-				sb->chunk_root_level, BTRFS_MAX_LEVEL);
+	if (btrfs_super_chunk_root_level(sb) >= BTRFS_MAX_LEVEL) {
+		printk(KERN_ERR "BTRFS: chunk_root level too big: %d >= %d\n",
+				btrfs_super_chunk_root_level(sb), BTRFS_MAX_LEVEL);
 		ret = -EINVAL;
 	}
-	if (sb->log_root_level > BTRFS_MAX_LEVEL) {
-		printk(KERN_ERR "BTRFS: log_root level too big: %d > %d\n",
-				sb->log_root_level, BTRFS_MAX_LEVEL);
+	if (btrfs_super_log_root_level(sb) >= BTRFS_MAX_LEVEL) {
+		printk(KERN_ERR "BTRFS: log_root level too big: %d >= %d\n",
+				btrfs_super_log_root_level(sb), BTRFS_MAX_LEVEL);
 		ret = -EINVAL;
 	}
 
@@ -3837,15 +3837,15 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 	 * The common minimum, we don't know if we can trust the nodesize/sectorsize
 	 * items yet, they'll be verified later. Issue just a warning.
 	 */
-	if (!IS_ALIGNED(sb->root, 4096))
+	if (!IS_ALIGNED(btrfs_super_root(sb), 4096))
 		printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
 				sb->root);
-	if (!IS_ALIGNED(sb->chunk_root, 4096))
+	if (!IS_ALIGNED(btrfs_super_chunk_root(sb), 4096))
 		printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
 				sb->chunk_root);
-	if (!IS_ALIGNED(sb->log_root, 4096))
+	if (!IS_ALIGNED(btrfs_super_log_root(sb), 4096))
 		printk(KERN_WARNING "BTRFS: tree_root block unaligned: %llu\n",
-				sb->log_root);
+				btrfs_super_log_root(sb));
 
 	if (memcmp(fs_info->fsid, sb->dev_item.fsid, BTRFS_UUID_SIZE) != 0) {
 		printk(KERN_ERR "BTRFS: dev_item UUID does not match fsid: %pU != %pU\n",
@@ -3857,13 +3857,13 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 	 * Hint to catch really bogus numbers, bitflips or so, more exact checks are
 	 * done later
 	 */
-	if (sb->num_devices > (1UL << 31))
+	if (btrfs_super_num_devices(sb) > (1UL << 31))
 		printk(KERN_WARNING "BTRFS: suspicious number of devices: %llu\n",
-				sb->num_devices);
+				btrfs_super_num_devices(sb));
 
-	if (sb->bytenr != BTRFS_SUPER_INFO_OFFSET) {
+	if (btrfs_super_bytenr(sb) != BTRFS_SUPER_INFO_OFFSET) {
 		printk(KERN_ERR "BTRFS: super offset mismatch %llu != %u\n",
-				sb->bytenr, BTRFS_SUPER_INFO_OFFSET);
+				btrfs_super_bytenr(sb), BTRFS_SUPER_INFO_OFFSET);
 		ret = -EINVAL;
 	}
 
@@ -3871,14 +3871,15 @@ static int btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
 	 * The generation is a global counter, we'll trust it more than the others
 	 * but it's still possible that it's the one that's wrong.
 	 */
-	if (sb->generation < sb->chunk_root_generation)
+	if (btrfs_super_generation(sb) < btrfs_super_chunk_root_generation(sb))
 		printk(KERN_WARNING
 			"BTRFS: suspicious: generation < chunk_root_generation: %llu < %llu\n",
-			sb->generation, sb->chunk_root_generation);
-	if (sb->generation < sb->cache_generation && sb->cache_generation != (u64)-1)
+			btrfs_super_generation(sb), btrfs_super_chunk_root_generation(sb));
+	if (btrfs_super_generation(sb) < btrfs_super_cache_generation(sb)
+	    && btrfs_super_cache_generation(sb) != (u64)-1)
 		printk(KERN_WARNING
 			"BTRFS: suspicious: generation < cache_generation: %llu < %llu\n",
-			sb->generation, sb->cache_generation);
+			btrfs_super_generation(sb), btrfs_super_cache_generation(sb));
 
 	return ret;
 }
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index d565895710126f813fd8a6c88c520ffe0fcffd3c..47c1ba14108254a6eb47f44472cd63a337d76c95 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -710,8 +710,8 @@ void btrfs_clear_space_info_full(struct btrfs_fs_info *info)
 	rcu_read_unlock();
 }
 
-/* simple helper to search for an existing extent at a given offset */
-int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
+/* simple helper to search for an existing data extent at a given offset */
+int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len)
 {
 	int ret;
 	struct btrfs_key key;
@@ -726,12 +726,6 @@ int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len)
 	key.type = BTRFS_EXTENT_ITEM_KEY;
 	ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path,
 				0, 0);
-	if (ret > 0) {
-		btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
-		if (key.objectid == start &&
-		    key.type == BTRFS_METADATA_ITEM_KEY)
-			ret = 0;
-	}
 	btrfs_free_path(path);
 	return ret;
 }
@@ -786,7 +780,6 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 	else
 		key.type = BTRFS_EXTENT_ITEM_KEY;
 
-again:
 	ret = btrfs_search_slot(trans, root->fs_info->extent_root,
 				&key, path, 0, 0);
 	if (ret < 0)
@@ -802,13 +795,6 @@ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans,
 			    key.offset == root->nodesize)
 				ret = 0;
 		}
-		if (ret) {
-			key.objectid = bytenr;
-			key.type = BTRFS_EXTENT_ITEM_KEY;
-			key.offset = root->nodesize;
-			btrfs_release_path(path);
-			goto again;
-		}
 	}
 
 	if (ret == 0) {
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index a2b97ef10317081aebaa09aedeaddf4dec71a492..54bd91ece35b6c7a1f5b2cdce9e7be8c80d99e6f 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2151,6 +2151,7 @@ static void __exit exit_btrfs_fs(void)
 	extent_map_exit();
 	extent_io_exit();
 	btrfs_interface_exit();
+	btrfs_end_io_wq_exit();
 	unregister_filesystem(&btrfs_fs_type);
 	btrfs_exit_sysfs();
 	btrfs_cleanup_fs_uuids();
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 1475979e5718ab8727ad47f8c52898257c76b0ed..286213cec86132188a9db6e687769902f06613a9 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -672,7 +672,7 @@ static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
 			 * is this extent already allocated in the extent
 			 * allocation tree?  If so, just add a reference
 			 */
-			ret = btrfs_lookup_extent(root, ins.objectid,
+			ret = btrfs_lookup_data_extent(root, ins.objectid,
 						ins.offset);
 			if (ret == 0) {
 				ret = btrfs_inc_extent_ref(trans, root,