1 files changed, 37 insertions, 48 deletions

diff --git a/fs/bcachefs/snapshot.h b/fs/bcachefs/snapshot.h
index 382a171f5413..6766bf673ed9 100644
--- a/fs/bcachefs/snapshot.h
+++ b/fs/bcachefs/snapshot.h
@@ -46,12 +46,9 @@ static inline const struct snapshot_t *snapshot_t(struct bch_fs *c, u32 id)
 
 static inline u32 bch2_snapshot_tree(struct bch_fs *c, u32 id)
 {
-	rcu_read_lock();
+	guard(rcu)();
 	const struct snapshot_t *s = snapshot_t(c, id);
-	id = s ? s->tree : 0;
-	rcu_read_unlock();
-
-	return id;
+	return s ? s->tree : 0;
 }
 
 static inline u32 __bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
@@ -62,11 +59,8 @@ static inline u32 __bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
 
 static inline u32 bch2_snapshot_parent_early(struct bch_fs *c, u32 id)
 {
-	rcu_read_lock();
-	id = __bch2_snapshot_parent_early(c, id);
-	rcu_read_unlock();
-
-	return id;
+	guard(rcu)();
+	return __bch2_snapshot_parent_early(c, id);
 }
 
 static inline u32 __bch2_snapshot_parent(struct bch_fs *c, u32 id)
@@ -88,20 +82,15 @@ static inline u32 __bch2_snapshot_parent(struct bch_fs *c, u32 id)
 
 static inline u32 bch2_snapshot_parent(struct bch_fs *c, u32 id)
 {
-	rcu_read_lock();
-	id = __bch2_snapshot_parent(c, id);
-	rcu_read_unlock();
-
-	return id;
+	guard(rcu)();
+	return __bch2_snapshot_parent(c, id);
 }
 
 static inline u32 bch2_snapshot_nth_parent(struct bch_fs *c, u32 id, u32 n)
 {
-	rcu_read_lock();
+	guard(rcu)();
 	while (n--)
 		id = __bch2_snapshot_parent(c, id);
-	rcu_read_unlock();
-
 	return id;
 }
 
@@ -110,13 +99,11 @@ u32 bch2_snapshot_skiplist_get(struct bch_fs *, u32);
 
 static inline u32 bch2_snapshot_root(struct bch_fs *c, u32 id)
 {
-	u32 parent;
+	guard(rcu)();
 
-	rcu_read_lock();
+	u32 parent;
 	while ((parent = __bch2_snapshot_parent(c, id)))
 		id = parent;
-	rcu_read_unlock();
-
 	return id;
 }
 
@@ -128,11 +115,8 @@ static inline enum snapshot_id_state __bch2_snapshot_id_state(struct bch_fs *c,
 
 static inline enum snapshot_id_state bch2_snapshot_id_state(struct bch_fs *c, u32 id)
 {
-	rcu_read_lock();
-	enum snapshot_id_state ret = __bch2_snapshot_id_state(c, id);
-	rcu_read_unlock();
-
-	return ret;
+	guard(rcu)();
+	return __bch2_snapshot_id_state(c, id);
 }
 
 static inline bool bch2_snapshot_exists(struct bch_fs *c, u32 id)
@@ -142,12 +126,9 @@ static inline bool bch2_snapshot_exists(struct bch_fs *c, u32 id)
 
 static inline int bch2_snapshot_is_internal_node(struct bch_fs *c, u32 id)
 {
-	rcu_read_lock();
+	guard(rcu)();
 	const struct snapshot_t *s = snapshot_t(c, id);
-	int ret = s ? s->children[0] : -BCH_ERR_invalid_snapshot_node;
-	rcu_read_unlock();
-
-	return ret;
+	return s ? s->children[0] : -BCH_ERR_invalid_snapshot_node;
 }
 
 static inline int bch2_snapshot_is_leaf(struct bch_fs *c, u32 id)
@@ -160,13 +141,8 @@ static inline int bch2_snapshot_is_leaf(struct bch_fs *c, u32 id)
 
 static inline u32 bch2_snapshot_depth(struct bch_fs *c, u32 parent)
 {
-	u32 depth;
-
-	rcu_read_lock();
-	depth = parent ? snapshot_t(c, parent)->depth + 1 : 0;
-	rcu_read_unlock();
-
-	return depth;
+	guard(rcu)();
+	return parent ? snapshot_t(c, parent)->depth + 1 : 0;
 }
 
 bool __bch2_snapshot_is_ancestor(struct bch_fs *, u32, u32);
@@ -180,20 +156,14 @@ static inline bool bch2_snapshot_is_ancestor(struct bch_fs *c, u32 id, u32 ances
 
 static inline bool bch2_snapshot_has_children(struct bch_fs *c, u32 id)
 {
-	rcu_read_lock();
+	guard(rcu)();
 	const struct snapshot_t *t = snapshot_t(c, id);
-	bool ret = t && (t->children[0]|t->children[1]) != 0;
-	rcu_read_unlock();
-
-	return ret;
+	return t && (t->children[0]|t->children[1]) != 0;
 }
 
 static inline bool snapshot_list_has_id(snapshot_id_list *s, u32 id)
 {
-	darray_for_each(*s, i)
-		if (*i == id)
-			return true;
-	return false;
+	return darray_find(*s, id) != NULL;
 }
 
 static inline bool snapshot_list_has_ancestor(struct bch_fs *c, snapshot_id_list *s, u32 id)
@@ -258,6 +228,25 @@ static inline int bch2_check_key_has_snapshot(struct btree_trans *trans,
 		: __bch2_check_key_has_snapshot(trans, iter, k);
 }
 
+int __bch2_get_snapshot_overwrites(struct btree_trans *,
+				   enum btree_id, struct bpos,
+				   snapshot_id_list *);
+
+/*
+ * Get a list of snapshot IDs that have overwritten a given key:
+ */
+static inline int bch2_get_snapshot_overwrites(struct btree_trans *trans,
+					       enum btree_id btree, struct bpos pos,
+					       snapshot_id_list *s)
+{
+	darray_init(s);
+
+	return bch2_snapshot_has_children(trans->c, pos.snapshot)
+		? __bch2_get_snapshot_overwrites(trans, btree, pos, s)
+		: 0;
+
+}
+
 int bch2_snapshot_node_set_deleted(struct btree_trans *, u32);
 
 int __bch2_key_has_snapshot_overwrites(struct btree_trans *, enum btree_id, struct bpos);