btrfs: fold btrfs_clone_ordered_extent into btrfs_split_ordered_extent

The function btrfs_clone_ordered_extent is very specific to the usage in
btrfs_split_ordered_extent.  Now that only a single call to
btrfs_clone_ordered_extent is left, just fold it into
btrfs_split_ordered_extent to make the operation more clear.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/ordered-data.c

@@ -1116,38 +1116,21 @@ bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
 	return false;
 }
 
-
-static int clone_ordered_extent(struct btrfs_ordered_extent *ordered, u64 pos,
-				u64 len)
-{
-	struct inode *inode = ordered->inode;
-	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
-	u64 file_offset = ordered->file_offset + pos;
-	u64 disk_bytenr = ordered->disk_bytenr + pos;
-	unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
-
-	/*
-	 * The splitting extent is already counted and will be added again in
-	 * btrfs_add_ordered_extent_*(). Subtract len to avoid double counting.
-	 */
-	percpu_counter_add_batch(&fs_info->ordered_bytes, -len,
-				 fs_info->delalloc_batch);
-	WARN_ON_ONCE(flags & (1 << BTRFS_ORDERED_COMPRESSED));
-	return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
-					disk_bytenr, len, 0, flags,
-					ordered->compress_type);
-}
-
 /* Split out a new ordered extent for this first @len bytes of @ordered. */
 int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 len)
 {
 	struct inode *inode = ordered->inode;
 	struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
 	struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+	u64 file_offset = ordered->file_offset;
+	u64 disk_bytenr = ordered->disk_bytenr;
+	unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;
 	struct rb_node *node;
 
 	trace_btrfs_ordered_extent_split(BTRFS_I(inode), ordered);
 
+	ASSERT(!(flags & (1U << BTRFS_ORDERED_COMPRESSED)));
+
 	/*
 	 * The entire bio must be covered by the ordered extent, but we can't
 	 * reduce the original extent to a zero length either.
@@ -1187,7 +1170,15 @@ int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 len)
 
 	spin_unlock_irq(&tree->lock);
 
-	return clone_ordered_extent(ordered, 0, len);
+	/*
+	 * The splitting extent is already counted and will be added again in
+	 * btrfs_add_ordered_extent(). Subtract len to avoid double counting.
+	 */
+	percpu_counter_add_batch(&fs_info->ordered_bytes, -len, fs_info->delalloc_batch);
+
+	return btrfs_add_ordered_extent(BTRFS_I(inode), file_offset, len, len,
+					disk_bytenr, len, 0, flags,
+					ordered->compress_type);
 }
 
 int __init ordered_data_init(void)