Btrfs: make free space caching faster with many non-inline extent references

So to cache free space, we iterate every extent item to gather free space info.

When we have say 10,000 non-inline extent refs(such as BTRFS_EXTENT_DATA_REF),
it takes quite a long time, and since inline extent refs and non-inline ones have
same objectid in their keys, we can just re-search the tree with the next address
to skip non-inline references.

(This is found by dedup feature because dedup extents can end up with many
non-inline extent refs.)

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit is contained in:
Liu Bo 2013-07-11 17:51:15 +08:00 committed by Chris Mason
parent ee3441b490
commit 52ee28d249

View File

@ -420,6 +420,7 @@ static noinline void caching_thread(struct btrfs_work *work)
/* need to make sure the commit_root doesn't disappear */
down_read(&fs_info->extent_commit_sem);
next:
ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0);
if (ret < 0)
goto err;
@ -459,6 +460,16 @@ static noinline void caching_thread(struct btrfs_work *work)
continue;
}
if (key.objectid < last) {
key.objectid = last;
key.offset = 0;
key.type = BTRFS_EXTENT_ITEM_KEY;
caching_ctl->progress = last;
btrfs_release_path(path);
goto next;
}
if (key.objectid < block_group->key.objectid) {
path->slots[0]++;
continue;