Btrfs: use the tree modification log for backref resolving
This enables backref resolving on life trees while they are changing. This
is a prerequisite for quota groups and just nice to have for everything
else.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index fd13101..0ac47f2 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -231,6 +231,7 @@
*/
static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
int search_commit_root,
+ u64 time_seq,
struct __prelim_ref *ref,
struct ulist *parents,
const u64 *extent_item_pos)
@@ -266,7 +267,7 @@
goto out;
path->lowest_level = level;
- ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, 0, 0);
+ ret = btrfs_search_old_slot(root, &ref->key_for_search, path, time_seq);
pr_debug("search slot in root %llu (level %d, ref count %d) returned "
"%d for key (%llu %u %llu)\n",
(unsigned long long)ref->root_id, level, ref->count, ret,
@@ -305,7 +306,7 @@
* resolve all indirect backrefs from the list
*/
static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
- int search_commit_root,
+ int search_commit_root, u64 time_seq,
struct list_head *head,
const u64 *extent_item_pos)
{
@@ -333,7 +334,8 @@
if (ref->count == 0)
continue;
err = __resolve_indirect_ref(fs_info, search_commit_root,
- ref, parents, extent_item_pos);
+ time_seq, ref, parents,
+ extent_item_pos);
if (err) {
if (ret == 0)
ret = err;
@@ -750,7 +752,8 @@
*/
static int find_parent_nodes(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 seq, struct ulist *refs, struct ulist *roots,
+ u64 delayed_ref_seq, u64 time_seq,
+ struct ulist *refs, struct ulist *roots,
const u64 *extent_item_pos)
{
struct btrfs_key key;
@@ -813,7 +816,8 @@
btrfs_put_delayed_ref(&head->node);
goto again;
}
- ret = __add_delayed_refs(head, seq, &prefs_delayed);
+ ret = __add_delayed_refs(head, delayed_ref_seq,
+ &prefs_delayed);
if (ret) {
spin_unlock(&delayed_refs->lock);
goto out;
@@ -854,8 +858,8 @@
if (ret)
goto out;
- ret = __resolve_indirect_refs(fs_info, search_commit_root, &prefs,
- extent_item_pos);
+ ret = __resolve_indirect_refs(fs_info, search_commit_root, time_seq,
+ &prefs, extent_item_pos);
if (ret)
goto out;
@@ -945,7 +949,8 @@
*/
static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 seq, struct ulist **leafs,
+ u64 delayed_ref_seq, u64 time_seq,
+ struct ulist **leafs,
const u64 *extent_item_pos)
{
struct ulist *tmp;
@@ -960,8 +965,8 @@
return -ENOMEM;
}
- ret = find_parent_nodes(trans, fs_info, bytenr, seq, *leafs, tmp,
- extent_item_pos);
+ ret = find_parent_nodes(trans, fs_info, bytenr, delayed_ref_seq,
+ time_seq, *leafs, tmp, extent_item_pos);
ulist_free(tmp);
if (ret < 0 && ret != -ENOENT) {
@@ -987,7 +992,8 @@
*/
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 seq, struct ulist **roots)
+ u64 delayed_ref_seq, u64 time_seq,
+ struct ulist **roots)
{
struct ulist *tmp;
struct ulist_node *node = NULL;
@@ -1005,8 +1011,8 @@
ULIST_ITER_INIT(&uiter);
while (1) {
- ret = find_parent_nodes(trans, fs_info, bytenr, seq,
- tmp, *roots, NULL);
+ ret = find_parent_nodes(trans, fs_info, bytenr, delayed_ref_seq,
+ time_seq, tmp, *roots, NULL);
if (ret < 0 && ret != -ENOENT) {
ulist_free(tmp);
ulist_free(*roots);
@@ -1338,7 +1344,8 @@
struct ulist *roots = NULL;
struct ulist_node *ref_node = NULL;
struct ulist_node *root_node = NULL;
- struct seq_list seq_elem;
+ struct seq_list seq_elem = {};
+ struct seq_list tree_mod_seq_elem = {};
struct ulist_iterator ref_uiter;
struct ulist_iterator root_uiter;
struct btrfs_delayed_ref_root *delayed_refs = NULL;
@@ -1357,17 +1364,20 @@
spin_lock(&delayed_refs->lock);
btrfs_get_delayed_seq(delayed_refs, &seq_elem);
spin_unlock(&delayed_refs->lock);
+ btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
}
ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,
- seq_elem.seq, &refs, &extent_item_pos);
+ seq_elem.seq, tree_mod_seq_elem.seq, &refs,
+ &extent_item_pos);
if (ret)
goto out;
ULIST_ITER_INIT(&ref_uiter);
while (!ret && (ref_node = ulist_next(refs, &ref_uiter))) {
ret = btrfs_find_all_roots(trans, fs_info, ref_node->val,
- seq_elem.seq, &roots);
+ seq_elem.seq,
+ tree_mod_seq_elem.seq, &roots);
if (ret)
break;
ULIST_ITER_INIT(&root_uiter);
@@ -1388,6 +1398,7 @@
ulist_free(roots);
out:
if (!search_commit_root) {
+ btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
btrfs_put_delayed_seq(delayed_refs, &seq_elem);
btrfs_end_transaction(trans, fs_info->extent_root);
}