btrfs: merge btrfs_del_delalloc_inode() helpers

The helpers btrfs_del_delalloc_inode() and __btrfs_del_delalloc_inode()
don't follow the pattern when the "__" helper does a special case and
are in fact reversed regarding the naming. We can merge them into one as
there's only one place that needs to be open coded.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/btrfs_inode.h

@@ -446,7 +446,7 @@ noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,
 			      u64 *orig_start, u64 *orig_block_len,
 			      u64 *ram_bytes, bool nowait, bool strict);
 
-void __btrfs_del_delalloc_inode(struct btrfs_inode *inode);
+void btrfs_del_delalloc_inode(struct btrfs_inode *inode);
 struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry);
 int btrfs_set_inode_index(struct btrfs_inode *dir, u64 *index);
 int btrfs_unlink_inode(struct btrfs_trans_handle *trans,

fs/btrfs/disk-io.c

@@ -4629,7 +4629,7 @@ static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
 		struct inode *inode = NULL;
 		btrfs_inode = list_first_entry(&splice, struct btrfs_inode,
 					       delalloc_inodes);
-		__btrfs_del_delalloc_inode(btrfs_inode);
+		btrfs_del_delalloc_inode(btrfs_inode);
 		spin_unlock(&root->delalloc_lock);
 
 		/*

fs/btrfs/inode.c

@@ -2410,7 +2410,7 @@ static void btrfs_add_delalloc_inode(struct btrfs_inode *inode)
 	spin_unlock(&root->delalloc_lock);
 }
 
-void __btrfs_del_delalloc_inode(struct btrfs_inode *inode)
+void btrfs_del_delalloc_inode(struct btrfs_inode *inode)
 {
 	struct btrfs_root *root = inode->root;
 	struct btrfs_fs_info *fs_info = root->fs_info;
@@ -2436,13 +2436,6 @@ void __btrfs_del_delalloc_inode(struct btrfs_inode *inode)
 	}
 }
 
-static void btrfs_del_delalloc_inode(struct btrfs_inode *inode)
-{
-	spin_lock(&inode->root->delalloc_lock);
-	__btrfs_del_delalloc_inode(inode);
-	spin_unlock(&inode->root->delalloc_lock);
-}
-
 /*
  * Properly track delayed allocation bytes in the inode and to maintain the
  * list of inodes that have pending delalloc work to be done.
@@ -2565,8 +2558,11 @@ void btrfs_clear_delalloc_extent(struct btrfs_inode *inode,
 		 * and are therefore protected against concurrent calls of this
 		 * function and btrfs_set_delalloc_extent().
 		 */
-		if (!btrfs_is_free_space_inode(inode) && new_delalloc_bytes == 0)
+		if (!btrfs_is_free_space_inode(inode) && new_delalloc_bytes == 0) {
+			spin_lock(&root->delalloc_lock);
 			btrfs_del_delalloc_inode(inode);
+			spin_unlock(&root->delalloc_lock);
+		}
 	}
 
 	if ((state->state & EXTENT_DELALLOC_NEW) &&