src/shared/dm-util.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <fcntl.h>
   4 #include <linux/dm-ioctl.h>
   5 #include <sys/ioctl.h>
   6
   7 #include "dm-util.h"
   8 #include "fd-util.h"
   9 #include "string-util.h"
  10
  11 int dm_deferred_remove_cancel(const char *name) {
  12         _cleanup_close_ int fd = -EBADF;
  13         struct message {
  14                 struct dm_ioctl dm_ioctl;
  15                 struct dm_target_msg dm_target_msg;
  16                 char msg_text[STRLEN("@cancel_deferred_remove") + 1];
  17         } _packed_ message = {
  18                 .dm_ioctl = {
  19                         .version = {
  20                                 DM_VERSION_MAJOR,
  21                                 DM_VERSION_MINOR,
  22                                 DM_VERSION_PATCHLEVEL
  23                         },
  24                         .data_size = sizeof(struct message),
  25                         .data_start = sizeof(struct dm_ioctl),
  26                 },
  27                 .msg_text = "@cancel_deferred_remove",
  28         };
  29
  30         assert(name);
  31
  32         if (strlen(name) >= sizeof(message.dm_ioctl.name))
  33                 return -ENODEV; /* A device with a name longer than this cannot possibly exist */
  34
  35         strncpy_exact(message.dm_ioctl.name, name, sizeof(message.dm_ioctl.name));
  36
  37         fd = open("/dev/mapper/control", O_RDWR|O_CLOEXEC);
  38         if (fd < 0)
  39                 return -errno;
  40
  41         if (ioctl(fd, DM_TARGET_MSG, &message))
  42                 return -errno;
  43
  44         return 0;
  45 }