Btrfs: join tree mod log code with the code holding back delayed refs
We've got two mechanisms both required for reliable backref resolving (tree
mod log and holding back delayed refs). You cannot make use of one without
the other. So instead of requiring the user of this mechanism to setup both
correctly, we join them into a single interface.
Additionally, we stop inserting non-blockers into fs_info->tree_mod_seq_list
as we did before, which was of no value.
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index a383c18..7d80ddd 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -773,9 +773,8 @@
*/
static int find_parent_nodes(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 delayed_ref_seq, u64 time_seq,
- struct ulist *refs, struct ulist *roots,
- const u64 *extent_item_pos)
+ u64 time_seq, struct ulist *refs,
+ struct ulist *roots, const u64 *extent_item_pos)
{
struct btrfs_key key;
struct btrfs_path *path;
@@ -837,7 +836,7 @@
btrfs_put_delayed_ref(&head->node);
goto again;
}
- ret = __add_delayed_refs(head, delayed_ref_seq,
+ ret = __add_delayed_refs(head, time_seq,
&prefs_delayed);
mutex_unlock(&head->mutex);
if (ret) {
@@ -981,8 +980,7 @@
*/
static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 delayed_ref_seq, u64 time_seq,
- struct ulist **leafs,
+ u64 time_seq, struct ulist **leafs,
const u64 *extent_item_pos)
{
struct ulist *tmp;
@@ -997,7 +995,7 @@
return -ENOMEM;
}
- ret = find_parent_nodes(trans, fs_info, bytenr, delayed_ref_seq,
+ ret = find_parent_nodes(trans, fs_info, bytenr,
time_seq, *leafs, tmp, extent_item_pos);
ulist_free(tmp);
@@ -1024,8 +1022,7 @@
*/
int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info, u64 bytenr,
- u64 delayed_ref_seq, u64 time_seq,
- struct ulist **roots)
+ u64 time_seq, struct ulist **roots)
{
struct ulist *tmp;
struct ulist_node *node = NULL;
@@ -1043,7 +1040,7 @@
ULIST_ITER_INIT(&uiter);
while (1) {
- ret = find_parent_nodes(trans, fs_info, bytenr, delayed_ref_seq,
+ ret = find_parent_nodes(trans, fs_info, bytenr,
time_seq, tmp, *roots, NULL);
if (ret < 0 && ret != -ENOENT) {
ulist_free(tmp);
@@ -1376,11 +1373,9 @@
struct ulist *roots = NULL;
struct ulist_node *ref_node = NULL;
struct ulist_node *root_node = NULL;
- 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;
pr_debug("resolving all inodes for extent %llu\n",
extent_item_objectid);
@@ -1391,16 +1386,11 @@
trans = btrfs_join_transaction(fs_info->extent_root);
if (IS_ERR(trans))
return PTR_ERR(trans);
-
- delayed_refs = &trans->transaction->delayed_refs;
- 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, tree_mod_seq_elem.seq, &refs,
+ tree_mod_seq_elem.seq, &refs,
&extent_item_pos);
if (ret)
goto out;
@@ -1408,8 +1398,7 @@
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,
- tree_mod_seq_elem.seq, &roots);
+ tree_mod_seq_elem.seq, &roots);
if (ret)
break;
ULIST_ITER_INIT(&root_uiter);
@@ -1431,7 +1420,6 @@
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);
}