bcachefs: Improve error handling for for_each_btree_key_continue()

Change it to match for_each_btree_key()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_iter.h

@@ -246,6 +246,11 @@ static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 		: bch2_btree_iter_next(iter);
 }
 
+static inline int bkey_err(struct bkey_s_c k)
+{
+	return PTR_ERR_OR_ZERO(k.k);
+}
+
 #define for_each_btree_key(_trans, _iter, _btree_id,			\
 			   _start, _flags, _k, _ret)			\
 	for ((_ret) = PTR_ERR_OR_ZERO((_iter) =				\
@@ -257,16 +262,11 @@ static inline struct bkey_s_c __bch2_btree_iter_next(struct btree_iter *iter,
 	     (_ret) = PTR_ERR_OR_ZERO(((_k) =				\
 			__bch2_btree_iter_next(_iter, _flags)).k))
 
-#define for_each_btree_key_continue(_iter, _flags, _k)			\
+#define for_each_btree_key_continue(_iter, _flags, _k, _ret)		\
 	for ((_k) = __bch2_btree_iter_peek(_iter, _flags);		\
-	     !IS_ERR_OR_NULL((_k).k);					\
+	     !((_ret) = bkey_err(_k)) && (_k).k;			\
 	     (_k) = __bch2_btree_iter_next(_iter, _flags))
 
-static inline int bkey_err(struct bkey_s_c k)
-{
-	return PTR_ERR_OR_ZERO(k.k);
-}
-
 /* new multiple iterator interface: */
 
 int bch2_trans_iter_put(struct btree_trans *, struct btree_iter *);

fs/bcachefs/fsck.c

@@ -248,7 +248,7 @@ static int hash_check_duplicates(struct btree_trans *trans,
 	iter = bch2_trans_copy_iter(trans, h->chain);
 	BUG_ON(IS_ERR(iter));
 
-	for_each_btree_key_continue(iter, 0, k2) {
+	for_each_btree_key_continue(iter, 0, k2, ret) {
 		if (bkey_cmp(k2.k->p, k.k->p) >= 0)
 			break;
 
@@ -458,7 +458,7 @@ static int check_extents(struct bch_fs *c)
 	iter = bch2_trans_get_iter(&trans, BTREE_ID_EXTENTS,
 				   POS(BCACHEFS_ROOT_INO, 0), 0);
 retry:
-	for_each_btree_key_continue(iter, 0, k) {
+	for_each_btree_key_continue(iter, 0, k, ret) {
 		ret = walk_inode(&trans, &w, k.k->p.inode);
 		if (ret)
 			break;
@@ -553,7 +553,7 @@ static int check_dirents(struct bch_fs *c)
 	iter = bch2_trans_get_iter(&trans, BTREE_ID_DIRENTS,
 				   POS(BCACHEFS_ROOT_INO, 0), 0);
 retry:
-	for_each_btree_key_continue(iter, 0, k) {
+	for_each_btree_key_continue(iter, 0, k, ret) {
 		struct bkey_s_c_dirent d;
 		struct bch_inode_unpacked target;
 		bool have_target;
@@ -707,7 +707,7 @@ static int check_xattrs(struct bch_fs *c)
 	iter = bch2_trans_get_iter(&trans, BTREE_ID_XATTRS,
 				   POS(BCACHEFS_ROOT_INO, 0), 0);
 retry:
-	for_each_btree_key_continue(iter, 0, k) {
+	for_each_btree_key_continue(iter, 0, k, ret) {
 		ret = walk_inode(&trans, &w, k.k->p.inode);
 		if (ret)
 			break;
@@ -995,7 +995,7 @@ static int check_directory_structure(struct bch_fs *c,
 
 	iter = bch2_trans_get_iter(&trans, BTREE_ID_INODES, POS_MIN, 0);
 retry:
-	for_each_btree_key_continue(iter, 0, k) {
+	for_each_btree_key_continue(iter, 0, k, ret) {
 		if (k.k->type != KEY_TYPE_inode)
 			continue;
 
@@ -1021,7 +1021,7 @@ static int check_directory_structure(struct bch_fs *c,
 			had_unreachable = true;
 		}
 	}
-	ret = bch2_trans_iter_free(&trans, iter);
+	bch2_trans_iter_free(&trans, iter);
 	if (ret)
 		goto err;
 

fs/bcachefs/str_hash.h

@@ -187,6 +187,7 @@ int bch2_hash_needs_whiteout(struct btree_trans *trans,
 {
 	struct btree_iter *iter;
 	struct bkey_s_c k;
+	int ret;
 
 	iter = bch2_trans_copy_iter(trans, start);
 	if (IS_ERR(iter))
@@ -194,7 +195,7 @@ int bch2_hash_needs_whiteout(struct btree_trans *trans,
 
 	bch2_btree_iter_next_slot(iter);
 
-	for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k) {
+	for_each_btree_key_continue(iter, BTREE_ITER_SLOTS, k, ret) {
 		if (k.k->type != desc.key_type &&
 		    k.k->type != KEY_TYPE_whiteout)
 			break;
@@ -206,7 +207,8 @@ int bch2_hash_needs_whiteout(struct btree_trans *trans,
 		}
 	}
 
-	return bch2_trans_iter_free(trans, iter);
+	bch2_trans_iter_free(trans, iter);
+	return ret;
 }
 
 static __always_inline