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>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 059dfa0..a3e71b5 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6728,6 +6728,10 @@
struct btrfs_space_info *space_info;
struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
struct btrfs_device *device;
+ u64 min_free;
+ int index;
+ int dev_nr = 0;
+ int dev_min = 1;
int full = 0;
int ret = 0;
@@ -6737,8 +6741,10 @@
if (!block_group)
return -1;
+ min_free = btrfs_block_group_used(&block_group->item);
+
/* no bytes used, we're good */
- if (!btrfs_block_group_used(&block_group->item))
+ if (!min_free)
goto out;
space_info = block_group->space_info;
@@ -6754,10 +6760,9 @@
* all of the extents from this block group. If we can, we're good
*/
if ((space_info->total_bytes != block_group->key.offset) &&
- (space_info->bytes_used + space_info->bytes_reserved +
- space_info->bytes_pinned + space_info->bytes_readonly +
- btrfs_block_group_used(&block_group->item) <
- space_info->total_bytes)) {
+ (space_info->bytes_used + space_info->bytes_reserved +
+ space_info->bytes_pinned + space_info->bytes_readonly +
+ min_free < space_info->total_bytes)) {
spin_unlock(&space_info->lock);
goto out;
}
@@ -6774,9 +6779,29 @@
if (full)
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);
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;
/*
@@ -6787,7 +6812,11 @@
ret = find_free_dev_extent(NULL, device, min_free,
&dev_offset, NULL);
if (!ret)
+ dev_nr++;
+
+ if (dev_nr >= dev_min)
break;
+
ret = -1;
}
}