bcachefs: Make sure to go rw if lazy in fsck

The paths where we delete or truncate inodes don't pass commit flags for
BTREE_INSERT_LAZY_RW, so just go rw if necessary in the fsck code.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/fsck.c

@@ -1265,6 +1265,8 @@ static int check_inode(struct btree_trans *trans,
 		      u.bi_inum))) {
 		bch_verbose(c, "deleting inode %llu", u.bi_inum);
 
+		bch2_fs_lazy_rw(c);
+
 		ret = bch2_inode_rm(c, u.bi_inum);
 		if (ret)
 			bch_err(c, "error in fsck: error %i while deleting inode", ret);
@@ -1277,6 +1279,8 @@ static int check_inode(struct btree_trans *trans,
 		      u.bi_inum))) {
 		bch_verbose(c, "truncating inode %llu", u.bi_inum);
 
+		bch2_fs_lazy_rw(c);
+
 		/*
 		 * XXX: need to truncate partial blocks too here - or ideally
 		 * just switch units to bytes and that issue goes away

fs/bcachefs/super.h

@@ -221,6 +221,15 @@ void bch2_fs_read_only(struct bch_fs *);
 int bch2_fs_read_write(struct bch_fs *);
 int bch2_fs_read_write_early(struct bch_fs *);
 
+/*
+ * Only for use in the recovery/fsck path:
+ */
+static inline void bch2_fs_lazy_rw(struct bch_fs *c)
+{
+	if (percpu_ref_is_zero(&c->writes))
+		bch2_fs_read_write_early(c);
+}
+
 void bch2_fs_stop(struct bch_fs *);
 
 int bch2_fs_start(struct bch_fs *);