Btrfs: fix spinlock assertions on UP systems

btrfs_tree_locked was being used to make sure a given extent_buffer was
properly locked in a few places.  But, it wasn't correct for UP compiled
kernels.

This switches it to using assert_spin_locked instead, and renames it to
btrfs_assert_tree_locked to better reflect how it was really being used.
Signed-off-by: Chris Mason <chris.mason@oracle.com>

fs/btrfs/ctree.c

@@ -277,7 +277,7 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
 	if (*cow_ret == buf)
 		unlock_orig = 1;
 
-	WARN_ON(!btrfs_tree_locked(buf));
+	btrfs_assert_tree_locked(buf);
 
 	if (parent)
 		parent_start = parent->start;
@@ -2365,7 +2365,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (slot >= btrfs_header_nritems(upper) - 1)
 		return 1;
 
-	WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+	btrfs_assert_tree_locked(path->nodes[1]);
 
 	right = read_node_slot(root, upper, slot + 1);
 	btrfs_tree_lock(right);
@@ -2562,7 +2562,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (right_nritems == 0)
 		return 1;
 
-	WARN_ON(!btrfs_tree_locked(path->nodes[1]));
+	btrfs_assert_tree_locked(path->nodes[1]);
 
 	left = read_node_slot(root, path->nodes[1], slot - 1);
 	btrfs_tree_lock(left);
@@ -4101,7 +4101,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 
 		next = read_node_slot(root, c, slot);
 		if (!path->skip_locking) {
-			WARN_ON(!btrfs_tree_locked(c));
+			btrfs_assert_tree_locked(c);
 			btrfs_tree_lock(next);
 			btrfs_set_lock_blocking(next);
 		}
@@ -4126,7 +4126,7 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path)
 			reada_for_search(root, path, level, slot, 0);
 		next = read_node_slot(root, next, 0);
 		if (!path->skip_locking) {
-			WARN_ON(!btrfs_tree_locked(path->nodes[level]));
+			btrfs_assert_tree_locked(path->nodes[level]);
 			btrfs_tree_lock(next);
 			btrfs_set_lock_blocking(next);
 		}

fs/btrfs/disk-io.c

@@ -857,7 +857,7 @@ int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
 	struct inode *btree_inode = root->fs_info->btree_inode;
 	if (btrfs_header_generation(buf) ==
 	    root->fs_info->running_transaction->transid) {
-		WARN_ON(!btrfs_tree_locked(buf));
+		btrfs_assert_tree_locked(buf);
 
 		/* ugh, clear_extent_buffer_dirty can be expensive */
 		btrfs_set_lock_blocking(buf);
@@ -2361,7 +2361,7 @@ void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
 
 	btrfs_set_lock_blocking(buf);
 
-	WARN_ON(!btrfs_tree_locked(buf));
+	btrfs_assert_tree_locked(buf);
 	if (transid != root->fs_info->generation) {
 		printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
 		       "found %llu running %llu\n",

fs/btrfs/extent-tree.c

@@ -4418,13 +4418,13 @@ int btrfs_drop_subtree(struct btrfs_trans_handle *trans,
 	path = btrfs_alloc_path();
 	BUG_ON(!path);
 
-	BUG_ON(!btrfs_tree_locked(parent));
+	btrfs_assert_tree_locked(parent);
 	parent_level = btrfs_header_level(parent);
 	extent_buffer_get(parent);
 	path->nodes[parent_level] = parent;
 	path->slots[parent_level] = btrfs_header_nritems(parent);
 
-	BUG_ON(!btrfs_tree_locked(node));
+	btrfs_assert_tree_locked(node);
 	level = btrfs_header_level(node);
 	extent_buffer_get(node);
 	path->nodes[level] = node;

fs/btrfs/locking.c

@@ -220,8 +220,8 @@ int btrfs_tree_unlock(struct extent_buffer *eb)
 	return 0;
 }
 
-int btrfs_tree_locked(struct extent_buffer *eb)
+void btrfs_assert_tree_locked(struct extent_buffer *eb)
 {
-	return test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags) ||
-			spin_is_locked(&eb->lock);
+	if (!test_bit(EXTENT_BUFFER_BLOCKING, &eb->bflags))
+		assert_spin_locked(&eb->lock);
 }

fs/btrfs/locking.h

@@ -21,11 +21,11 @@
 
 int btrfs_tree_lock(struct extent_buffer *eb);
 int btrfs_tree_unlock(struct extent_buffer *eb);
-int btrfs_tree_locked(struct extent_buffer *eb);
 
 int btrfs_try_tree_lock(struct extent_buffer *eb);
 int btrfs_try_spin_lock(struct extent_buffer *eb);
 
 void btrfs_set_lock_blocking(struct extent_buffer *eb);
 void btrfs_clear_lock_blocking(struct extent_buffer *eb);
+void btrfs_assert_tree_locked(struct extent_buffer *eb);
 #endif