X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=backref.c;h=27309e07a1e99d07faff8d36e7fb3092616d17e0;hb=2c2db167c79bee6c0ce88f55f964135908654f74;hp=127951c5d3f9d13586a2af38d61b1b655d805879;hpb=3ae36b3b0f13326df8b38ff4a4df1ce47fccd417;p=platform%2Fupstream%2Fbtrfs-progs.git

diff --git a/backref.c b/backref.c
index 127951c..27309e0 100644
--- a/backref.c
+++ b/backref.c
@@ -130,13 +130,22 @@ struct __prelim_ref {
 	u64 wanted_disk_byte;
 };
 
+static struct __prelim_ref *list_first_pref(struct list_head *head)
+{
+	return list_first_entry(head, struct __prelim_ref, list);
+}
+
 struct pref_state {
 	struct list_head pending;
+	struct list_head pending_missing_keys;
+	struct list_head pending_indirect_refs;
 };
 
 static void init_pref_state(struct pref_state *prefstate)
 {
 	INIT_LIST_HEAD(&prefstate->pending);
+	INIT_LIST_HEAD(&prefstate->pending_missing_keys);
+	INIT_LIST_HEAD(&prefstate->pending_indirect_refs);
 }
 
 /*
@@ -183,7 +192,7 @@ static int __add_prelim_ref(struct pref_state *prefstate, u64 root_id,
 			    u64 parent, u64 wanted_disk_byte, int count,
 			    gfp_t gfp_mask)
 {
-	struct list_head *head = &prefstate->pending;
+	struct list_head *head;
 	struct __prelim_ref *ref;
 
 	if (root_id == BTRFS_DATA_RELOC_TREE_OBJECTID)
@@ -194,16 +203,23 @@ static int __add_prelim_ref(struct pref_state *prefstate, u64 root_id,
 		return -ENOMEM;
 
 	ref->root_id = root_id;
-	if (key)
+	if (key) {
 		ref->key_for_search = *key;
-	else
+		head = &prefstate->pending;
+	} else if (parent) {
 		memset(&ref->key_for_search, 0, sizeof(ref->key_for_search));
+		head = &prefstate->pending;
+	} else {
+		memset(&ref->key_for_search, 0, sizeof(ref->key_for_search));
+		head = &prefstate->pending_missing_keys;
+	}
 
 	ref->inode_list = NULL;
 	ref->level = level;
 	ref->count = count;
 	ref->parent = parent;
 	ref->wanted_disk_byte = wanted_disk_byte;
+
 	list_add_tail(&ref->list, head);
 
 	return 0;
@@ -359,11 +375,10 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
 				   struct btrfs_path *path, u64 time_seq,
 				   const u64 *extent_item_pos, u64 total_refs)
 {
-	struct list_head *head = &prefstate->pending;
+	struct list_head *head = &prefstate->pending_indirect_refs;
 	int err;
 	int ret = 0;
 	struct __prelim_ref *ref;
-	struct __prelim_ref *ref_safe;
 	struct __prelim_ref *new_ref;
 	struct ulist *parents;
 	struct ulist_node *node;
@@ -373,16 +388,11 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
 	if (!parents)
 		return -ENOMEM;
 
-	/*
-	 * _safe allows us to insert directly after the current item without
-	 * iterating over the newly inserted items.
-	 * we're also allowed to re-assign ref during iteration.
-	 */
-	list_for_each_entry_safe(ref, ref_safe, head, list) {
-		if (ref->parent)	/* already direct */
-			continue;
-		if (ref->count == 0)
-			continue;
+	while (!list_empty(head)) {
+		ref = list_first_pref(head);
+		list_move(&ref->list, &prefstate->pending);
+		ASSERT(!ref->parent);	/* already direct */
+		ASSERT(ref->count);
 		err = __resolve_indirect_ref(fs_info, path, time_seq, ref,
 					     parents, extent_item_pos,
 					     total_refs);
@@ -415,7 +425,7 @@ static int __resolve_indirect_refs(struct btrfs_fs_info *fs_info,
 			new_ref->parent = node->val;
 			new_ref->inode_list = (struct extent_inode_elem *)
 							(uintptr_t)node->aux;
-			list_add(&new_ref->list, &ref->list);
+			list_add_tail(&new_ref->list, &prefstate->pending);
 		}
 		ulist_reinit(parents);
 	}
@@ -449,18 +459,16 @@ static inline int ref_for_same_block(struct __prelim_ref *ref1,
 static int __add_missing_keys(struct btrfs_fs_info *fs_info,
 			      struct pref_state *prefstate)
 {
-	struct list_head *head = &prefstate->pending;
-	struct list_head *pos;
 	struct extent_buffer *eb;
 
-	list_for_each(pos, head) {
+	while (!list_empty(&prefstate->pending_missing_keys)) {
 		struct __prelim_ref *ref;
-		ref = list_entry(pos, struct __prelim_ref, list);
 
-		if (ref->parent)
-			continue;
-		if (ref->key_for_search.type)
-			continue;
+		ref = list_first_pref(&prefstate->pending_missing_keys);
+
+		ASSERT(ref->root_id);
+		ASSERT(!ref->parent);
+		ASSERT(!ref->key_for_search.type);
 		BUG_ON(!ref->wanted_disk_byte);
 		eb = read_tree_block(fs_info, ref->wanted_disk_byte, 0);
 		if (!extent_buffer_uptodate(eb)) {
@@ -472,6 +480,7 @@ static int __add_missing_keys(struct btrfs_fs_info *fs_info,
 		else
 			btrfs_node_key_to_cpu(eb, &ref->key_for_search, 0);
 		free_extent_buffer(eb);
+		list_move(&ref->list, &prefstate->pending);
 	}
 	return 0;
 }
@@ -802,9 +811,11 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 
 	__merge_refs(&prefstate, 2);
 
+	BUG_ON(!list_empty(&prefstate.pending_missing_keys));
+	BUG_ON(!list_empty(&prefstate.pending_indirect_refs));
+
 	while (!list_empty(&prefstate.pending)) {
-		ref = list_first_entry(&prefstate.pending,
-				       struct __prelim_ref, list);
+		ref = list_first_pref(&prefstate.pending);
 		WARN_ON(ref->count < 0);
 		if (roots && ref->count && ref->root_id && ref->parent == 0) {
 			/* no parent == root of tree */
@@ -854,8 +865,7 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 out:
 	btrfs_free_path(path);
 	while (!list_empty(&prefstate.pending)) {
-		ref = list_first_entry(&prefstate.pending,
-				       struct __prelim_ref, list);
+		ref = list_first_pref(&prefstate.pending);
 		list_del(&ref->list);
 		kfree(ref);
 	}