libmount/src/init.c

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 /*
   3  * This file is part of libmount from util-linux project.
   4  *
   5  * Copyright (C) 2008-2018 Karel Zak <kzak@redhat.com>
   6  *
   7  * libmount is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU Lesser General Public License as published by
   9  * the Free Software Foundation; either version 2.1 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 /**
  14  * SECTION: init
  15  * @title: Library initialization
  16  * @short_description: initialize debugging
  17  */
  18
  19 #include <stdarg.h>
  20
  21 #include "mountP.h"
  22
  23 UL_DEBUG_DEFINE_MASK(libmount);
  24 UL_DEBUG_DEFINE_MASKNAMES(libmount) =
  25 {
  26         { "all", MNT_DEBUG_ALL,         "info about all subsystems" },
  27         { "cache", MNT_DEBUG_CACHE,     "paths and tags cache" },
  28         { "cxt", MNT_DEBUG_CXT,         "library context (handler)" },
  29         { "diff", MNT_DEBUG_DIFF,       "mountinfo changes tracking" },
  30         { "fs", MNT_DEBUG_FS,           "FS abstraction" },
  31         { "help", MNT_DEBUG_HELP,       "this help" },
  32         { "hook", MNT_DEBUG_HOOK,       "hooks functionality" },
  33         { "locks", MNT_DEBUG_LOCKS,     "mtab and utab locking" },
  34         { "loop", MNT_DEBUG_LOOP,       "loop devices routines" },
  35         { "options", MNT_DEBUG_OPTIONS, "mount options parsing" },
  36         { "optlist", MNT_DEBUG_OPTLIST, "mount options container" },
  37         { "tab", MNT_DEBUG_TAB,         "fstab, mtab, mountinfo routines" },
  38         { "update", MNT_DEBUG_UPDATE,   "mtab, utab updates" },
  39         { "utils", MNT_DEBUG_UTILS,     "misc library utils" },
  40         { "monitor", MNT_DEBUG_MONITOR, "mount tables monitor" },
  41         { "btrfs", MNT_DEBUG_BTRFS,     "btrfs specific routines" },
  42         { "verity", MNT_DEBUG_VERITY,   "verity specific routines" },
  43
  44         { NULL, 0 }
  45 };
  46
  47 /**
  48  * mnt_init_debug:
  49  * @mask: debug mask (0xffff to enable full debugging)
  50  *
  51  * If the @mask is not specified, then this function reads
  52  * the LIBMOUNT_DEBUG environment variable to get the mask.
  53  *
  54  * Already initialized debugging stuff cannot be changed. Calling
  55  * this function twice has no effect.
  56  */
  57 void mnt_init_debug(int mask)
  58 {
  59         if (libmount_debug_mask)
  60                 return;
  61
  62         __UL_INIT_DEBUG_FROM_ENV(libmount, MNT_DEBUG_, mask, LIBMOUNT_DEBUG);
  63
  64         if (libmount_debug_mask != MNT_DEBUG_INIT
  65             && libmount_debug_mask != (MNT_DEBUG_HELP|MNT_DEBUG_INIT)) {
  66                 const char *ver = NULL;
  67                 const char **features = NULL, **p;
  68
  69                 mnt_get_library_version(&ver);
  70                 mnt_get_library_features(&features);
  71
  72                 DBG(INIT, ul_debug("library debug mask: 0x%06x", libmount_debug_mask));
  73                 DBG(INIT, ul_debug("library version: %s", ver));
  74                 p = features;
  75                 while (p && *p)
  76                         DBG(INIT, ul_debug("    feature: %s", *p++));
  77         }
  78
  79         ON_DBG(HELP, ul_debug_print_masks("LIBMOUNT_DEBUG",
  80                                 UL_DEBUG_MASKNAMES(libmount)));
  81 }
  82
  83 #ifdef TEST_PROGRAM
  84
  85 #include <errno.h>
  86 #include <stdlib.h>
  87 int main(int argc, char *argv[])
  88 {
  89         if (argc == 2) {
  90                 int mask;
  91
  92                 errno = 0;
  93                 mask = strtoul(argv[1], 0, 0);
  94
  95                 if (errno)
  96                         return 1;
  97
  98                 mnt_init_debug(mask);
  99         }
 100         else if (argc == 1) {
 101                 mnt_init_debug(0);
 102         } else
 103                 return 1;
 104
 105         return 0;
 106 }
 107 #endif /* TEST_PROGRAM */
 108