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: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Zhao Lei 2015-02-16 18:52:17 +08:00 committed by Chris Mason
parent 94b947b2f3
commit f2ab76188e
1 changed files with 13 additions and 11 deletions

View File

@ -1134,11 +1134,11 @@ int find_free_dev_extent(struct btrfs_trans_handle *trans,
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
again:
max_hole_start = search_start;
max_hole_size = 0;
hole_size = 0;
again:
if (search_start >= search_end || device->is_tgtdev_for_dev_replace) {
ret = -ENOSPC;
goto out;
@ -1231,21 +1231,23 @@ int find_free_dev_extent(struct btrfs_trans_handle *trans,
* allocated dev extents, and when shrinking the device,
* search_end may be smaller than search_start.
*/
if (search_end > search_start)
if (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) {
max_hole_start = search_start;
max_hole_size = hole_size;
}
if (contains_pending_extent(trans, device, &search_start, hole_size)) {
btrfs_release_path(path);
goto again;
}
/* See above. */
if (hole_size < num_bytes)
if (max_hole_size < num_bytes)
ret = -ENOSPC;
else
ret = 0;