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Btrfs: Fix cache_block_group to catch holes at the start of the group

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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>
This commit is contained in:
Yan 2007-09-14 16:15:28 -04:00 committed by David Woodhouse
parent 6af858b24c
commit 7d7d6068be
1 changed files with 35 additions and 30 deletions
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65
fs/btrfs/extent-tree.c
View file

@ -39,6 +39,7 @@ static int cache_block_group(struct btrfs_root *root,
u64 i;
u64 last = 0;
u64 hole_size;
u64 first_free;
int found = 0;
root = root->fs_info->extent_root;
@ -51,16 +52,22 @@ static int cache_block_group(struct btrfs_root *root,
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 @@ static int cache_block_group(struct btrfs_root *root,
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;
}
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;
}
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);