Commit 52b1fdca authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: handle completed ordered extents in btrfs_split_ordered_extent 



To delay splitting ordered_extents to I/O completion time we need to be
able to handle fully completed ordered extents in
btrfs_split_ordered_extent.  Besides a bit of accounting this primarily
involved moving over the csums to the split bio for the range that it
covers, which is simple enough because we always have one
btrfs_ordered_sum per bio.

Reviewed-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 816f589b

fs/btrfs/ordered-data.c

+32 −8
Original line number Diff line number Diff line
@@ -1141,9 +1141,11 @@ struct btrfs_ordered_extent *btrfs_split_ordered_extent( 
	struct btrfs_fs_info *fs_info = root->fs_info;

	u64 file_offset = ordered->file_offset;

	u64 disk_bytenr = ordered->disk_bytenr;

	unsigned long flags = ordered->flags & BTRFS_ORDERED_TYPE_FLAGS;

	unsigned long flags = ordered->flags;

	struct btrfs_ordered_sum *sum, *tmpsum;

	struct btrfs_ordered_extent *new;

	struct rb_node *node;

	u64 offset = 0;



	trace_btrfs_ordered_extent_split(inode, ordered);
@@ -1155,15 +1157,15 @@ struct btrfs_ordered_extent *btrfs_split_ordered_extent( 
	 */

	if (WARN_ON_ONCE(len >= ordered->num_bytes))

		return ERR_PTR(-EINVAL);

	/* We cannot split once ordered extent is past end_bio. */

	/* We cannot split partially completed ordered extents. */

	if (ordered->bytes_left) {

		ASSERT(!(flags & ~BTRFS_ORDERED_TYPE_FLAGS));

		if (WARN_ON_ONCE(ordered->bytes_left != ordered->disk_num_bytes))

			return ERR_PTR(-EINVAL);

	}

	/* We cannot split a compressed ordered extent. */

	if (WARN_ON_ONCE(ordered->disk_num_bytes != ordered->num_bytes))

		return ERR_PTR(-EINVAL);

	/* Checksum list should be empty. */

	if (WARN_ON_ONCE(!list_empty(&ordered->list)))

		return ERR_PTR(-EINVAL);



	new = alloc_ordered_extent(inode, file_offset, len, len, disk_bytenr,

				   len, 0, flags, ordered->compress_type);
@@ -1186,7 +1188,29 @@ struct btrfs_ordered_extent *btrfs_split_ordered_extent( 
	ordered->disk_bytenr += len;

	ordered->num_bytes -= len;

	ordered->disk_num_bytes -= len;



	if (test_bit(BTRFS_ORDERED_IO_DONE, &ordered->flags)) {

		ASSERT(ordered->bytes_left == 0);

		new->bytes_left = 0;

	} else {

		ordered->bytes_left -= len;

	}



	if (test_bit(BTRFS_ORDERED_TRUNCATED, &ordered->flags)) {

		if (ordered->truncated_len > len) {

			ordered->truncated_len -= len;

		} else {

			new->truncated_len = ordered->truncated_len;

			ordered->truncated_len = 0;

		}

	}



	list_for_each_entry_safe(sum, tmpsum, &ordered->list, list) {

		if (offset == len)

			break;

		list_move_tail(&sum->list, &new->list);

		offset += sum->len;

	}



	/* Re-insert the node */

	node = tree_insert(&tree->tree, ordered->file_offset, &ordered->rb_node);