utils: add development helper to quickly dump a directories contents

src/lxc/utils.c

@@ -1855,3 +1855,53 @@ bool multiply_overflow(int64_t base, uint64_t mult, int64_t *res)
 	*res = base * mult;
 	return true;
 }
+
+int print_r(int fd, const char *path)
+{
+	__do_close int dfd = -EBADF;
+	__do_closedir DIR *dir = NULL;
+	int ret = 0;
+	struct dirent *direntp;
+	struct stat st;
+
+	if (is_empty_string(path))
+		dfd = dup(fd);
+	else
+		dfd = openat(fd, path, O_CLOEXEC | O_DIRECTORY);
+	if (dfd < 0)
+		return -1;
+
+	dir = fdopendir(dfd);
+	if (!dir)
+		return -1;
+	/* Transfer ownership to fdopendir(). */
+	move_fd(dfd);
+
+	while ((direntp = readdir(dir))) {
+		if (!strcmp(direntp->d_name, ".") ||
+		    !strcmp(direntp->d_name, ".."))
+			continue;
+
+		ret = fstatat(dfd, direntp->d_name, &st, AT_SYMLINK_NOFOLLOW);
+		if (ret < 0 && errno != ENOENT)
+			break;
+
+		ret = 0;
+		if (S_ISDIR(st.st_mode))
+			ret = print_r(dfd, direntp->d_name);
+		else
+			INFO("mode(%o):uid(%d):gid(%d) -> %s/%s\n",
+			     (st.st_mode & ~S_IFMT), st.st_uid, st.st_gid, path,
+			     direntp->d_name);
+		if (ret < 0 && errno != ENOENT)
+			break;
+	}
+
+	ret = fstatat(fd, path, &st, AT_SYMLINK_NOFOLLOW);
+	if (ret)
+		return -1;
+	else
+		INFO("mode(%o):uid(%d):gid(%d) -> %s",
+		     (st.st_mode & ~S_IFMT), st.st_uid, st.st_gid, path);
+	return ret;
+}

src/lxc/utils.h

@@ -243,5 +243,6 @@ __hidden extern int safe_mount_beneath(const char *beneath, const char *src, con
 				       const char *fstype, unsigned int flags, const void *data);
 __hidden extern int safe_mount_beneath_at(int beneat_fd, const char *src, const char *dst,
 					  const char *fstype, unsigned int flags, const void *data);
+__hidden __lxc_unused int print_r(int fd, const char *path);
 
 #endif /* __LXC_UTILS_H */