btrfs: return the new ordered_extent from btrfs_split_ordered_extent

Return the ordered_extent split from the passed in one.  This will be
needed to be able to store an ordered_extent in the btrfs_bio.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/inode.c

@@ -2719,6 +2719,7 @@ int btrfs_extract_ordered_extent(struct btrfs_bio *bbio,
 {
 	u64 start = (u64)bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
 	u64 len = bbio->bio.bi_iter.bi_size;
+	struct btrfs_ordered_extent *new;
 	int ret;
 
 	/* Must always be called for the beginning of an ordered extent. */
@@ -2740,7 +2741,12 @@ int btrfs_extract_ordered_extent(struct btrfs_bio *bbio,
 			return ret;
 	}
 
-	return btrfs_split_ordered_extent(ordered, len);
+	new = btrfs_split_ordered_extent(ordered, len);
+	if (IS_ERR(new))
+		return PTR_ERR(new);
+	btrfs_put_ordered_extent(new);
+
+	return 0;
 }
 
 /*

fs/btrfs/ordered-data.c

@@ -1116,7 +1116,8 @@ bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
 }
 
 /* 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 btrfs_ordered_extent *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;
@@ -1135,16 +1136,16 @@ int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 len)
 	 * reduce the original extent to a zero length either.
 	 */
 	if (WARN_ON_ONCE(len >= ordered->num_bytes))
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	/* We cannot split once ordered extent is past end_bio. */
 	if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	/* We cannot split a compressed ordered extent. */
 	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 	/* Checksum list should be empty. */
 	if (WARN_ON_ONCE(!list_empty(&ordered->list)))
-		return -EINVAL;
+		return ERR_PTR(-EINVAL);
 
 	spin_lock_irq(&tree->lock);
 	/* Remove from tree once */
@@ -1171,13 +1172,13 @@ int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 len)
 
 	/*
 	 * The splitting extent is already counted and will be added again in
-	 * btrfs_add_ordered_extent(). Subtract len to avoid double counting.
+	 * btrfs_alloc_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);
+	return btrfs_alloc_ordered_extent(BTRFS_I(inode), file_offset, len, len,
+					  disk_bytenr, len, 0, flags,
+					  ordered->compress_type);
 }
 
 int __init ordered_data_init(void)

fs/btrfs/ordered-data.h

@@ -206,7 +206,8 @@ void btrfs_lock_and_flush_ordered_range(struct btrfs_inode *inode, u64 start,
 					struct extent_state **cached_state);
 bool btrfs_try_lock_ordered_range(struct btrfs_inode *inode, u64 start, u64 end,
 				  struct extent_state **cached_state);
-int btrfs_split_ordered_extent(struct btrfs_ordered_extent *ordered, u64 len);
+struct btrfs_ordered_extent *btrfs_split_ordered_extent(
+			struct btrfs_ordered_extent *ordered, u64 len);
 int __init ordered_data_init(void);
 void __cold ordered_data_exit(void);