src/partition/makefs.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <fcntl.h>
   4 #include <sys/prctl.h>
   5 #include <sys/stat.h>
   6 #include <sys/types.h>
   7 #include <unistd.h>
   8
   9 #include "alloc-util.h"
  10 #include "blockdev-util.h"
  11 #include "dissect-image.h"
  12 #include "fd-util.h"
  13 #include "main-func.h"
  14 #include "process-util.h"
  15 #include "signal-util.h"
  16 #include "string-util.h"
  17
  18 static int makefs(const char *type, const char *device) {
  19         const char *mkfs;
  20         pid_t pid;
  21         int r;
  22
  23         if (streq(type, "swap"))
  24                 mkfs = "/sbin/mkswap";
  25         else
  26                 mkfs = strjoina("/sbin/mkfs.", type);
  27         if (access(mkfs, X_OK) != 0)
  28                 return log_error_errno(errno, "%s is not executable: %m", mkfs);
  29
  30         r = safe_fork("(mkfs)", FORK_RESET_SIGNALS|FORK_DEATHSIG|FORK_RLIMIT_NOFILE_SAFE|FORK_LOG, &pid);
  31         if (r < 0)
  32                 return r;
  33         if (r == 0) {
  34                 const char *cmdline[3] = { mkfs, device, NULL };
  35
  36                 /* Child */
  37
  38                 execv(cmdline[0], (char**) cmdline);
  39                 _exit(EXIT_FAILURE);
  40         }
  41
  42         return wait_for_terminate_and_check(mkfs, pid, WAIT_LOG);
  43 }
  44
  45 static int run(int argc, char *argv[]) {
  46         _cleanup_free_ char *device = NULL, *type = NULL, *detected = NULL;
  47         _cleanup_close_ int lock_fd = -1;
  48         struct stat st;
  49         int r;
  50
  51         log_setup_service();
  52
  53         if (argc != 3)
  54                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
  55                                        "This program expects two arguments.");
  56
  57         /* type and device must be copied because makefs calls safe_fork, which clears argv[] */
  58         type = strdup(argv[1]);
  59         if (!type)
  60                 return log_oom();
  61
  62         device = strdup(argv[2]);
  63         if (!device)
  64                 return log_oom();
  65
  66         if (stat(device, &st) < 0)
  67                 return log_error_errno(errno, "Failed to stat \"%s\": %m", device);
  68
  69         if (S_ISBLK(st.st_mode)) {
  70                 /* Lock the device so that udev doesn't interfere with our work */
  71
  72                 lock_fd = lock_whole_block_device(st.st_rdev, LOCK_EX);
  73                 if (lock_fd < 0)
  74                         return log_error_errno(lock_fd, "Failed to lock whole block device of \"%s\": %m", device);
  75         } else
  76                 log_info("%s is not a block device.", device);
  77
  78         r = probe_filesystem(device, &detected);
  79         if (r == -EUCLEAN)
  80                 return log_error_errno(r, "Ambiguous results of probing for file system on \"%s\", refusing to proceed.", device);
  81         if (r < 0)
  82                 return log_error_errno(r, "Failed to probe \"%s\": %m", device);
  83         if (detected) {
  84                 log_info("'%s' is not empty (contains file system of type %s), exiting.", device, detected);
  85                 return 0;
  86         }
  87
  88         return makefs(type, device);
  89 }
  90
  91 DEFINE_MAIN_FUNCTION(run);