Btrfs: check if there is enough space for balancing smarter

When checking if there is enough space for balancing a block group,
since we do not take raid types into consideration, we do not account
corrent amounts of space that we needed.  This makes us do some extra
work before we get ENOSPC.

Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
liubo 2011-08-03 10:15:25 +00:00 committed by Chris Mason
parent 38c01b9605
commit cdcb725c05

View File

@ -6728,6 +6728,10 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
struct btrfs_space_info *space_info; struct btrfs_space_info *space_info;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
struct btrfs_device *device; struct btrfs_device *device;
u64 min_free;
int index;
int dev_nr = 0;
int dev_min = 1;
int full = 0; int full = 0;
int ret = 0; int ret = 0;
@ -6737,8 +6741,10 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
if (!block_group) if (!block_group)
return -1; return -1;
min_free = btrfs_block_group_used(&block_group->item);
/* no bytes used, we're good */ /* no bytes used, we're good */
if (!btrfs_block_group_used(&block_group->item)) if (!min_free)
goto out; goto out;
space_info = block_group->space_info; space_info = block_group->space_info;
@ -6754,10 +6760,9 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
* all of the extents from this block group. If we can, we're good * all of the extents from this block group. If we can, we're good
*/ */
if ((space_info->total_bytes != block_group->key.offset) && if ((space_info->total_bytes != block_group->key.offset) &&
(space_info->bytes_used + space_info->bytes_reserved + (space_info->bytes_used + space_info->bytes_reserved +
space_info->bytes_pinned + space_info->bytes_readonly + space_info->bytes_pinned + space_info->bytes_readonly +
btrfs_block_group_used(&block_group->item) < min_free < space_info->total_bytes)) {
space_info->total_bytes)) {
spin_unlock(&space_info->lock); spin_unlock(&space_info->lock);
goto out; goto out;
} }
@ -6774,9 +6779,29 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
if (full) if (full)
goto out; goto out;
/*
* index:
* 0: raid10
* 1: raid1
* 2: dup
* 3: raid0
* 4: single
*/
index = get_block_group_index(block_group);
if (index == 0) {
dev_min = 4;
min_free /= 2;
} else if (index == 1) {
dev_min = 2;
} else if (index == 2) {
min_free *= 2;
} else if (index == 3) {
dev_min = fs_devices->rw_devices;
min_free /= dev_min;
}
mutex_lock(&root->fs_info->chunk_mutex); mutex_lock(&root->fs_info->chunk_mutex);
list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) {
u64 min_free = btrfs_block_group_used(&block_group->item);
u64 dev_offset; u64 dev_offset;
/* /*
@ -6787,7 +6812,11 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
ret = find_free_dev_extent(NULL, device, min_free, ret = find_free_dev_extent(NULL, device, min_free,
&dev_offset, NULL); &dev_offset, NULL);
if (!ret) if (!ret)
dev_nr++;
if (dev_nr >= dev_min)
break; break;
ret = -1; ret = -1;
} }
} }