bcachefs: Fix some refcounting bugs

We really need debug mode assertions that ca->ref and ca->io_ref are
used correctly.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/alloc_background.c

@@ -371,7 +371,7 @@ int bch2_alloc_write(struct bch_fs *c, unsigned flags)
 
 			ret = bch2_alloc_write_key(&trans, iter, flags);
 			if (ret) {
-				percpu_ref_put(&ca->io_ref);
+				percpu_ref_put(&ca->ref);
 				goto err;
 			}
 			bch2_btree_iter_next_slot(iter);

fs/bcachefs/btree_gc.c

@@ -1023,7 +1023,7 @@ static void bch2_gc_free(struct bch_fs *c)
 static int bch2_gc_done(struct bch_fs *c,
 			bool initial, bool metadata_only)
 {
-	struct bch_dev *ca;
+	struct bch_dev *ca = NULL;
 	bool verify = !metadata_only && (!initial ||
 		       (c->sb.compat & (1ULL << BCH_COMPAT_alloc_info)));
 	unsigned i, dev;
@@ -1169,6 +1169,8 @@ static int bch2_gc_done(struct bch_fs *c,
 #undef copy_stripe_field
 #undef copy_field
 fsck_err:
+	if (ca)
+		percpu_ref_put(&ca->ref);
 	if (ret)
 		bch_err(c, "%s: ret %i", __func__, ret);
 	return ret;
@@ -1177,7 +1179,7 @@ static int bch2_gc_done(struct bch_fs *c,
 static int bch2_gc_start(struct bch_fs *c,
 			 bool metadata_only)
 {
-	struct bch_dev *ca;
+	struct bch_dev *ca = NULL;
 	unsigned i;
 	int ret;
 

fs/bcachefs/buckets.c

@@ -2071,7 +2071,7 @@ static int __bch2_trans_mark_dev_sb(struct btree_trans *trans,
 
 int bch2_trans_mark_dev_sb(struct bch_fs *c, struct bch_dev *ca)
 {
-	return bch2_trans_do(c, NULL, NULL, 0,
+	return bch2_trans_do(c, NULL, NULL, BTREE_INSERT_LAZY_RW,
 			__bch2_trans_mark_dev_sb(&trans, ca));
 }
 

fs/bcachefs/recovery.c

@@ -1328,8 +1328,10 @@ int bch2_fs_initialize(struct bch_fs *c)
 	err = "error marking superblock and journal";
 	for_each_member_device(ca, c, i) {
 		ret = bch2_trans_mark_dev_sb(c, ca);
-		if (ret)
+		if (ret) {
+			percpu_ref_put(&ca->ref);
 			goto err;
+		}
 	}
 
 	bch2_inode_init(c, &root_inode, 0, 0,

fs/bcachefs/super.c

@@ -629,9 +629,11 @@ static const char *bch2_fs_online(struct bch_fs *c)
 	down_write(&c->state_lock);
 
 	err = "error creating sysfs objects";
-	__for_each_member_device(ca, c, i, NULL)
-		if (bch2_dev_sysfs_online(c, ca))
+	for_each_member_device(ca, c, i)
+		if (bch2_dev_sysfs_online(c, ca)) {
+			percpu_ref_put(&ca->ref);
 			goto err;
+		}
 
 	list_add(&c->list, &bch_fs_list);
 	err = NULL;
@@ -1839,12 +1841,14 @@ struct bch_dev *bch2_dev_lookup(struct bch_fs *c, const char *path)
 	if (ret)
 		return ERR_PTR(ret);
 
-	for_each_member_device(ca, c, i)
+	rcu_read_lock();
+	for_each_member_device_rcu(ca, c, i, NULL)
 		if (ca->disk_sb.bdev->bd_dev == dev)
 			goto found;
-
 	ca = ERR_PTR(-ENOENT);
 found:
+	rcu_read_unlock();
+
 	return ca;
 }
 

fs/bcachefs/super.h

@@ -107,11 +107,8 @@ static inline struct bch_dev *__bch2_next_dev(struct bch_fs *c, unsigned *iter,
 	return ca;
 }
 
-#define __for_each_member_device(ca, c, iter, mask)			\
-	for ((iter) = 0; ((ca) = __bch2_next_dev((c), &(iter), mask)); (iter)++)
-
 #define for_each_member_device_rcu(ca, c, iter, mask)			\
-	__for_each_member_device(ca, c, iter, mask)
+	for ((iter) = 0; ((ca) = __bch2_next_dev((c), &(iter), mask)); (iter)++)
 
 static inline struct bch_dev *bch2_get_next_dev(struct bch_fs *c, unsigned *iter)
 {