Btrfs: Fix cache_block_group to catch holes at the start of the group
Cache block group was overly complex and missed free blocks at the very start
of the group. This patch simplifies things significantly.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index b074ad1..9151850 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -39,6 +39,7 @@
u64 i;
u64 last = 0;
u64 hole_size;
+ u64 first_free;
int found = 0;
root = root->fs_info->extent_root;
@@ -51,16 +52,22 @@
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
+
path->reada = 2;
+ first_free = block_group->key.objectid;
key.objectid = block_group->key.objectid;
key.flags = 0;
key.offset = 0;
+
btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY);
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+
if (ret < 0)
return ret;
+
if (ret && path->slots[0] > 0)
path->slots[0]--;
+
while(1) {
leaf = btrfs_buffer_leaf(path->nodes[0]);
slot = path->slots[0];
@@ -71,50 +78,48 @@
if (ret == 0) {
continue;
} else {
- if (found) {
- hole_size = block_group->key.objectid +
- block_group->key.offset - last;
- } else {
- last = block_group->key.objectid;
- hole_size = block_group->key.offset;
- }
- for (i = 0; i < hole_size; i++) {
- set_radix_bit(extent_radix,
- last + i);
- }
break;
}
}
+
btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
+ if (key.objectid < block_group->key.objectid) {
+ if (key.objectid + key.offset > first_free)
+ first_free = key.objectid + key.offset;
+ goto next;
+ }
+
if (key.objectid >= block_group->key.objectid +
block_group->key.offset) {
- if (found) {
- hole_size = block_group->key.objectid +
- block_group->key.offset - last;
- } else {
- last = block_group->key.objectid;
- hole_size = block_group->key.offset;
+ break;
+ }
+
+ if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
+ if (!found) {
+ last = first_free;
+ found = 1;
}
+ hole_size = key.objectid - last;
for (i = 0; i < hole_size; i++) {
set_radix_bit(extent_radix, last + i);
}
- break;
+ last = key.objectid + key.offset;
}
- if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) {
- if (!found) {
- last = key.objectid + key.offset;
- found = 1;
- } else {
- hole_size = key.objectid - last;
- for (i = 0; i < hole_size; i++) {
- set_radix_bit(extent_radix, last + i);
- }
- last = key.objectid + key.offset;
- }
- }
+next:
path->slots[0]++;
}
+ if (!found)
+ last = first_free;
+ if (block_group->key.objectid +
+ block_group->key.offset > last) {
+ hole_size = block_group->key.objectid +
+ block_group->key.offset - last;
+ for (i = 0; i < hole_size; i++) {
+ set_radix_bit(extent_radix,
+ last + i);
+ }
+ }
block_group->cached = 1;
err:
btrfs_free_path(path);