btrfs: pass an ordered_extent to btrfs_extract_ordered_extent

To prepare for a new caller that already has the ordered_extent
available, change btrfs_extract_ordered_extent to take an argument
for it.  Add a wrapper for the bio case that still has to do the
lookup (for now).
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Tested-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/bio.c

@@ -61,6 +61,20 @@ struct btrfs_bio *btrfs_bio_alloc(unsigned int nr_vecs, blk_opf_t opf,
 	return bbio;
 }
 
+static blk_status_t btrfs_bio_extract_ordered_extent(struct btrfs_bio *bbio)
+{
+	struct btrfs_ordered_extent *ordered;
+	int ret;
+
+	ordered = btrfs_lookup_ordered_extent(bbio->inode, bbio->file_offset);
+	if (WARN_ON_ONCE(!ordered))
+		return BLK_STS_IOERR;
+	ret = btrfs_extract_ordered_extent(bbio, ordered);
+	btrfs_put_ordered_extent(ordered);
+
+	return errno_to_blk_status(ret);
+}
+
 static struct btrfs_bio *btrfs_split_bio(struct btrfs_fs_info *fs_info,
 					 struct btrfs_bio *orig_bbio,
 					 u64 map_length, bool use_append)
@@ -653,7 +667,7 @@ static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num)
 		if (use_append) {
 			bio->bi_opf &= ~REQ_OP_WRITE;
 			bio->bi_opf |= REQ_OP_ZONE_APPEND;
-			ret = btrfs_extract_ordered_extent(bbio);
+			ret = btrfs_bio_extract_ordered_extent(bbio);
 			if (ret)
 				goto fail_put_bio;
 		}

fs/btrfs/btrfs_inode.h

@@ -407,7 +407,8 @@ static inline void btrfs_inode_split_flags(u64 inode_item_flags,
 
 int btrfs_check_sector_csum(struct btrfs_fs_info *fs_info, struct page *page,
 			    u32 pgoff, u8 *csum, const u8 * const csum_expected);
-blk_status_t btrfs_extract_ordered_extent(struct btrfs_bio *bbio);
+int btrfs_extract_ordered_extent(struct btrfs_bio *bbio,
+				 struct btrfs_ordered_extent *ordered);
 bool btrfs_data_csum_ok(struct btrfs_bio *bbio, struct btrfs_device *dev,
 			u32 bio_offset, struct bio_vec *bv);
 noinline int can_nocow_extent(struct inode *inode, u64 offset, u64 *len,

fs/btrfs/inode.c

@@ -2601,37 +2601,27 @@ static int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 p
 	return ret;
 }
 
-blk_status_t btrfs_extract_ordered_extent(struct btrfs_bio *bbio)
+int btrfs_extract_ordered_extent(struct btrfs_bio *bbio,
+				 struct btrfs_ordered_extent *ordered)
 {
 	u64 start = (u64)bbio->bio.bi_iter.bi_sector << SECTOR_SHIFT;
 	u64 len = bbio->bio.bi_iter.bi_size;
 	struct btrfs_inode *inode = bbio->inode;
-	struct btrfs_ordered_extent *ordered;
-	u64 ordered_len;
+	u64 ordered_len = ordered->num_bytes;
 	int ret = 0;
 
-	ordered = btrfs_lookup_ordered_extent(inode, bbio->file_offset);
-	if (WARN_ON_ONCE(!ordered))
-		return BLK_STS_IOERR;
-	ordered_len = ordered->num_bytes;
-
 	/* Must always be called for the beginning of an ordered extent. */
-	if (WARN_ON_ONCE(start != ordered->disk_bytenr)) {
-		ret = -EINVAL;
-		goto out;
-	}
+	if (WARN_ON_ONCE(start != ordered->disk_bytenr))
+		return -EINVAL;
 
 	/* No need to split if the ordered extent covers the entire bio. */
 	if (ordered->disk_num_bytes == len)
-		goto out;
+		return 0;
 
 	ret = btrfs_split_ordered_extent(ordered, len);
 	if (ret)
-		goto out;
-	ret = split_extent_map(inode, bbio->file_offset, ordered_len, len);
-out:
-	btrfs_put_ordered_extent(ordered);
-	return errno_to_blk_status(ret);
+		return ret;
+	return split_extent_map(inode, bbio->file_offset, ordered_len, len);
 }
 
 /*