1 files changed, 57 insertions, 60 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index aded3ef..10db21f 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -220,7 +220,8 @@ static int __add_prelim_ref(struct list_head *head, u64 root_id,
 
 static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
 			   struct ulist *parents, struct __prelim_ref *ref,
-			   int level, u64 time_seq, const u64 *extent_item_pos)
+			   int level, u64 time_seq, const u64 *extent_item_pos,
+			   u64 total_refs)
 {
 	int ret = 0;
 	int slot;
@@ -249,7 +250,7 @@ static int add_all_parents(struct btrfs_root *root, struct btrfs_path *path,
 	if (path->slots[0] >= btrfs_header_nritems(path->nodes[0]))
 		ret = btrfs_next_old_leaf(root, path, time_seq);
 
-	while (!ret && count < ref->count) {
+	while (!ret && count < total_refs) {
 		eb = path->nodes[0];
 		slot = path->slots[0];
 
@@ -306,7 +307,7 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 				  struct btrfs_path *path, u64 time_seq,
 				  struct __prelim_ref *ref,
 				  struct ulist *parents,
-				  const u64 *extent_item_pos)
+				  const u64 *extent_item_pos, u64 total_refs)
 {
 	struct btrfs_root *root;
 	struct btrfs_key root_key;
@@ -329,7 +330,10 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 		goto out;
 	}
 
-	root_level = btrfs_old_root_level(root, time_seq);
+	if (path->search_commit_root)
+		root_level = btrfs_header_level(root->commit_root);
+	else
+		root_level = btrfs_old_root_level(root, time_seq);
 
 	if (root_level + 1 == level) {
 		srcu_read_unlock(&fs_info->subvol_srcu, index);
@@ -361,7 +365,7 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
 	}
 
 	ret = add_all_parents(root, path, parents, ref, level, time_seq,
-			      extent_item_pos);
+			      extent_item_pos, total_refs);
 out:
 	path->lowest_level = 0;
 	btrfs_release_path(path);
@@ -374,7 +378,7 @@ out:
 static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
 				   struct btrfs_path *path, u64 time_seq,
 				   struct list_head *head,
-				   const u64 *extent_item_pos)
+				   const u64 *extent_item_pos, u64 total_refs)
 {
 	int err;
 	int ret = 0;
@@ -400,7 +404,8 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
 		if (ref->count == 0)
 			continue;
 		err = __resolve_indirect_ref(fs_info, path, time_seq, ref,
-					     parents, extent_item_pos);
+					     parents, extent_item_pos,
+					     total_refs);
 		/*
 		 * we can only tolerate ENOENT,otherwise,we should catch error
 		 * and return directly.
@@ -557,7 +562,7 @@ static void __merge_refs(struct list_head *head, int mode)
  * smaller or equal that seq to the list
  */
 static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
-			      struct list_head *prefs)
+			      struct list_head *prefs, u64 *total_refs)
 {
 	struct btrfs_delayed_extent_op *extent_op = head->extent_op;
 	struct rb_node *n = &head->node.rb_node;
@@ -593,6 +598,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
 		default:
 			BUG_ON(1);
 		}
+		*total_refs += (node->ref_mod * sgn);
 		switch (node->type) {
 		case BTRFS_TREE_BLOCK_REF_KEY: {
 			struct btrfs_delayed_tree_ref *ref;
@@ -653,7 +659,8 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq,
  */
 static int __add_inline_refs(struct btrfs_fs_info *fs_info,
 			     struct btrfs_path *path, u64 bytenr,
-			     int *info_level, struct list_head *prefs)
+			     int *info_level, struct list_head *prefs,
+			     u64 *total_refs)
 {
 	int ret = 0;
 	int slot;
@@ -677,6 +684,7 @@ static int __add_inline_refs(struct btrfs_fs_info *fs_info,
 
 	ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
 	flags = btrfs_extent_flags(leaf, ei);
+	*total_refs += btrfs_extent_refs(leaf, ei);
 	btrfs_item_key_to_cpu(leaf, &found_key, slot);
 
 	ptr = (unsigned long)(ei + 1);
@@ -859,6 +867,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 	struct list_head prefs;
 	struct __prelim_ref *ref;
 	struct extent_inode_elem *eie = NULL;
+	u64 total_refs = 0;
 
 	INIT_LIST_HEAD(&prefs);
 	INIT_LIST_HEAD(&prefs_delayed);
@@ -873,8 +882,10 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 	path = btrfs_alloc_path();
 	if (!path)
 		return -ENOMEM;
-	if (!trans)
+	if (!trans) {
 		path->search_commit_root = 1;
+		path->skip_locking = 1;
+	}
 
 	/*
 	 * grab both a lock on the path and a lock on the delayed ref head.
@@ -915,7 +926,7 @@ again:
 			}
 			spin_unlock(&delayed_refs->lock);
 			ret = __add_delayed_refs(head, time_seq,
-						 &prefs_delayed);
+						 &prefs_delayed, &total_refs);
 			mutex_unlock(&head->mutex);
 			if (ret)
 				goto out;
@@ -936,7 +947,8 @@ again:
 		    (key.type == BTRFS_EXTENT_ITEM_KEY ||
 		     key.type == BTRFS_METADATA_ITEM_KEY)) {
 			ret = __add_inline_refs(fs_info, path, bytenr,
-						&info_level, &prefs);
+						&info_level, &prefs,
+						&total_refs);
 			if (ret)
 				goto out;
 			ret = __add_keyed_refs(fs_info, path, bytenr,
@@ -956,7 +968,7 @@ again:
 	__merge_refs(&prefs, 1);
 
 	ret = __resolve_indirect_refs(fs_info, path, time_seq, &prefs,
-				      extent_item_pos);
+				      extent_item_pos, total_refs);
 	if (ret)
 		goto out;
 
@@ -965,7 +977,7 @@ again:
 	while (!list_empty(&prefs)) {
 		ref = list_first_entry(&prefs, struct __prelim_ref, list);
 		WARN_ON(ref->count < 0);
-		if (ref->count && ref->root_id && ref->parent == 0) {
+		if (roots && ref->count && ref->root_id && ref->parent == 0) {
 			/* no parent == root of tree */
 			ret = ulist_add(roots, ref->root_id, 0, GFP_NOFS);
 			if (ret < 0)
@@ -1061,22 +1073,14 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
 				u64 time_seq, struct ulist **leafs,
 				const u64 *extent_item_pos)
 {
-	struct ulist *tmp;
 	int ret;
 
-	tmp = ulist_alloc(GFP_NOFS);
-	if (!tmp)
-		return -ENOMEM;
 	*leafs = ulist_alloc(GFP_NOFS);
-	if (!*leafs) {
-		ulist_free(tmp);
+	if (!*leafs)
 		return -ENOMEM;
-	}
 
 	ret = find_parent_nodes(trans, fs_info, bytenr,
-				time_seq, *leafs, tmp, extent_item_pos);
-	ulist_free(tmp);
-
+				time_seq, *leafs, NULL, extent_item_pos);
 	if (ret < 0 && ret != -ENOENT) {
 		free_leaf_list(*leafs);
 		return ret;
@@ -1098,9 +1102,9 @@ static int btrfs_find_all_leafs(struct btrfs_trans_handle *trans,
  *
  * returns 0 on success, < 0 on error.
  */
-int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
-				struct btrfs_fs_info *fs_info, u64 bytenr,
-				u64 time_seq, struct ulist **roots)
+static int __btrfs_find_all_roots(struct btrfs_trans_handle *trans,
+				  struct btrfs_fs_info *fs_info, u64 bytenr,
+				  u64 time_seq, struct ulist **roots)
 {
 	struct ulist *tmp;
 	struct ulist_node *node = NULL;
@@ -1136,6 +1140,20 @@ int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
 	return 0;
 }
 
+int btrfs_find_all_roots(struct btrfs_trans_handle *trans,
+			 struct btrfs_fs_info *fs_info, u64 bytenr,
+			 u64 time_seq, struct ulist **roots)
+{
+	int ret;
+
+	if (!trans)
+		down_read(&fs_info->commit_root_sem);
+	ret = __btrfs_find_all_roots(trans, fs_info, bytenr, time_seq, roots);
+	if (!trans)
+		up_read(&fs_info->commit_root_sem);
+	return ret;
+}
+
 /*
  * this makes the path point to (inum INODE_ITEM ioff)
  */
@@ -1333,38 +1351,13 @@ int extent_from_logical(struct btrfs_fs_info *fs_info, u64 logical,
 	if (ret < 0)
 		return ret;
 
-	while (1) {
-		u32 nritems;
-		if (path->slots[0] == 0) {
-			btrfs_set_path_blocking(path);
-			ret = btrfs_prev_leaf(fs_info->extent_root, path);
-			if (ret != 0) {
-				if (ret > 0) {
-					pr_debug("logical %llu is not within "
-						 "any extent\n", logical);
-					ret = -ENOENT;
-				}
-				return ret;
-			}
-		} else {
-			path->slots[0]--;
-		}
-		nritems = btrfs_header_nritems(path->nodes[0]);
-		if (nritems == 0) {
-			pr_debug("logical %llu is not within any extent\n",
-				 logical);
-			return -ENOENT;
-		}
-		if (path->slots[0] == nritems)
-			path->slots[0]--;
-
-		btrfs_item_key_to_cpu(path->nodes[0], found_key,
-				      path->slots[0]);
-		if (found_key->type == BTRFS_EXTENT_ITEM_KEY ||
-		    found_key->type == BTRFS_METADATA_ITEM_KEY)
-			break;
+	ret = btrfs_previous_extent_item(fs_info->extent_root, path, 0);
+	if (ret) {
+		if (ret > 0)
+			ret = -ENOENT;
+		return ret;
 	}
-
+	btrfs_item_key_to_cpu(path->nodes[0], found_key, path->slots[0]);
 	if (found_key->type == BTRFS_METADATA_ITEM_KEY)
 		size = fs_info->extent_root->leafsize;
 	else if (found_key->type == BTRFS_EXTENT_ITEM_KEY)
@@ -1540,6 +1533,8 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
 		if (IS_ERR(trans))
 			return PTR_ERR(trans);
 		btrfs_get_tree_mod_seq(fs_info, &tree_mod_seq_elem);
+	} else {
+		down_read(&fs_info->commit_root_sem);
 	}
 
 	ret = btrfs_find_all_leafs(trans, fs_info, extent_item_objectid,
@@ -1550,8 +1545,8 @@ int iterate_extent_inodes(struct btrfs_fs_info *fs_info,
 
 	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,
-					   tree_mod_seq_elem.seq, &roots);
+		ret = __btrfs_find_all_roots(trans, fs_info, ref_node->val,
+					     tree_mod_seq_elem.seq, &roots);
 		if (ret)
 			break;
 		ULIST_ITER_INIT(&root_uiter);
@@ -1573,6 +1568,8 @@ out:
 	if (!search_commit_root) {
 		btrfs_put_tree_mod_seq(fs_info, &tree_mod_seq_elem);
 		btrfs_end_transaction(trans, fs_info->extent_root);
+	} else {
+		up_read(&fs_info->commit_root_sem);
 	}
 
 	return ret;