b4d0d230cc
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public licence as published by the free software foundation either version 2 of the licence or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 114 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520170857.552531963@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
130 lines
2.6 KiB
C
130 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* fd-based mount test.
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*
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* Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <sys/prctl.h>
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#include <sys/wait.h>
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#include <linux/mount.h>
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#include <linux/unistd.h>
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#define E(x) do { if ((x) == -1) { perror(#x); exit(1); } } while(0)
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static void check_messages(int fd)
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{
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char buf[4096];
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int err, n;
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err = errno;
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for (;;) {
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n = read(fd, buf, sizeof(buf));
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if (n < 0)
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break;
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n -= 2;
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switch (buf[0]) {
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case 'e':
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fprintf(stderr, "Error: %*.*s\n", n, n, buf + 2);
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break;
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case 'w':
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fprintf(stderr, "Warning: %*.*s\n", n, n, buf + 2);
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break;
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case 'i':
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fprintf(stderr, "Info: %*.*s\n", n, n, buf + 2);
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break;
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}
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}
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errno = err;
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}
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static __attribute__((noreturn))
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void mount_error(int fd, const char *s)
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{
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check_messages(fd);
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fprintf(stderr, "%s: %m\n", s);
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exit(1);
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}
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/* Hope -1 isn't a syscall */
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#ifndef __NR_fsopen
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#define __NR_fsopen -1
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#endif
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#ifndef __NR_fsmount
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#define __NR_fsmount -1
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#endif
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#ifndef __NR_fsconfig
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#define __NR_fsconfig -1
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#endif
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#ifndef __NR_move_mount
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#define __NR_move_mount -1
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#endif
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static inline int fsopen(const char *fs_name, unsigned int flags)
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{
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return syscall(__NR_fsopen, fs_name, flags);
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}
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static inline int fsmount(int fsfd, unsigned int flags, unsigned int ms_flags)
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{
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return syscall(__NR_fsmount, fsfd, flags, ms_flags);
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}
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static inline int fsconfig(int fsfd, unsigned int cmd,
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const char *key, const void *val, int aux)
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{
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return syscall(__NR_fsconfig, fsfd, cmd, key, val, aux);
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}
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static inline int move_mount(int from_dfd, const char *from_pathname,
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int to_dfd, const char *to_pathname,
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unsigned int flags)
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{
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return syscall(__NR_move_mount,
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from_dfd, from_pathname,
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to_dfd, to_pathname, flags);
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}
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#define E_fsconfig(fd, cmd, key, val, aux) \
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do { \
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if (fsconfig(fd, cmd, key, val, aux) == -1) \
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mount_error(fd, key ?: "create"); \
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} while (0)
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int main(int argc, char *argv[])
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{
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int fsfd, mfd;
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/* Mount a publically available AFS filesystem */
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fsfd = fsopen("afs", 0);
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if (fsfd == -1) {
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perror("fsopen");
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exit(1);
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}
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E_fsconfig(fsfd, FSCONFIG_SET_STRING, "source", "#grand.central.org:root.cell.", 0);
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E_fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0);
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mfd = fsmount(fsfd, 0, MOUNT_ATTR_RDONLY);
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if (mfd < 0)
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mount_error(fsfd, "fsmount");
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E(close(fsfd));
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if (move_mount(mfd, "", AT_FDCWD, "/mnt", MOVE_MOUNT_F_EMPTY_PATH) < 0) {
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perror("move_mount");
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exit(1);
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}
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E(close(mfd));
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exit(0);
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}
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