Commit f2ab7618 authored by Zhao Lei's avatar Zhao Lei Committed by Chris Mason
Browse files

btrfs: Fix tail space processing in find_free_dev_extent() 



It is another reason for NO_SPACE case.

When we found enough free space in loop and saved them to
max_hole_start/size before, and tail space contains pending extent,
origional innocent max_hole_start/size are reset in retry.

As a result, find_free_dev_extent() returns less space than it can,
and cause NO_SPACE in user program.

Reviewed-by: default avatarLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: default avatarChris Mason <clm@fb.com>
parent 94b947b2

fs/btrfs/volumes.c

+13 −11
Original line number Original line Diff line number Diff line
@@ -1134,11 +1134,11 @@ int find_free_dev_extent(struct btrfs_trans_handle *trans, 
	path = btrfs_alloc_path();

	path = btrfs_alloc_path();

	if (!path)

	if (!path)

		return -ENOMEM;

		return -ENOMEM;

again:



	max_hole_start = search_start;

	max_hole_start = search_start;

	max_hole_size = 0;

	max_hole_size = 0;

	hole_size = 0;





again:

	if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {

	if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {

		ret = -ENOSPC;

		ret = -ENOSPC;

		goto out;

		goto out;
@@ -1231,21 +1231,23 @@ next: 
	 * allocated dev extents, and when shrinking the device,

	 * allocated dev extents, and when shrinking the device,

	 * search_end may be smaller than search_start.

	 * search_end may be smaller than search_start.

	 */

	 */

	if (search_end > search_start)

	if (search_end > search_start) {

		hole_size = search_end - search_start;

		hole_size = search_end - search_start;





		if (contains_pending_extent(trans, device, &search_start,

					    hole_size)) {

			btrfs_release_path(path);

			goto again;

		}



		if (hole_size > max_hole_size) {

		if (hole_size > max_hole_size) {

			max_hole_start = search_start;

			max_hole_start = search_start;

			max_hole_size = hole_size;

			max_hole_size = hole_size;

		}

		}



	if (contains_pending_extent(trans, device, &search_start, hole_size)) {

		btrfs_release_path(path);

		goto again;

	}

	}





	/* See above. */

	/* See above. */

	if (hole_size < num_bytes)

	if (max_hole_size < num_bytes)

		ret = -ENOSPC;

		ret = -ENOSPC;

	else

	else

		ret = 0;

		ret = 0;

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