sys-utils/swapon-common.c

   1 /*
   2  * SPDX-License-Identifier: GPL-2.0-or-later
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Copyright (C) 2012-2023 Karel Zak <kzak@redhat.com>
  10  *
  11  * Original implementation from Linux 0.99, without License and copyright in
  12  * the code. Karel Zak rewrote the code under GPL-2.0-or-later.
  13  */
  14 #include "c.h"
  15 #include "nls.h"
  16 #include "xalloc.h"
  17
  18 #include "swapon-common.h"
  19
  20 /*
  21  * content of /proc/swaps and /etc/fstab
  22  */
  23 static struct libmnt_table *swaps, *fstab;
  24
  25 struct libmnt_cache *mntcache;
  26
  27 static int table_parser_errcb(struct libmnt_table *tb __attribute__((__unused__)),
  28                         const char *filename, int line)
  29 {
  30         if (filename)
  31                 warnx(_("%s: parse error at line %d -- ignored"), filename, line);
  32         return 1;
  33 }
  34
  35 struct libmnt_table *get_fstab(const char *filename)
  36 {
  37         if (!fstab) {
  38                 fstab = mnt_new_table();
  39                 if (!fstab)
  40                         return NULL;
  41                 mnt_table_set_parser_errcb(fstab, table_parser_errcb);
  42                 mnt_table_set_cache(fstab, mntcache);
  43                 if (mnt_table_parse_fstab(fstab, filename) != 0)
  44                         return NULL;
  45         }
  46
  47         return fstab;
  48 }
  49
  50 struct libmnt_table *get_swaps(void)
  51 {
  52         if (!swaps) {
  53                 swaps = mnt_new_table();
  54                 if (!swaps)
  55                         return NULL;
  56                 mnt_table_set_cache(swaps, mntcache);
  57                 mnt_table_set_parser_errcb(swaps, table_parser_errcb);
  58                 if (mnt_table_parse_swaps(swaps, NULL) != 0)
  59                         return NULL;
  60         }
  61
  62         return swaps;
  63 }
  64
  65 void free_tables(void)
  66 {
  67         mnt_unref_table(swaps);
  68         mnt_unref_table(fstab);
  69 }
  70
  71 int match_swap(struct libmnt_fs *fs, void *data __attribute__((unused)))
  72 {
  73         return fs && mnt_fs_is_swaparea(fs);
  74 }
  75
  76 int is_active_swap(const char *filename)
  77 {
  78         struct libmnt_table *st = get_swaps();
  79         return st && mnt_table_find_source(st, filename, MNT_ITER_BACKWARD);
  80 }
  81
  82
  83 int cannot_find(const char *special)
  84 {
  85         warnx(_("cannot find the device for %s"), special);
  86         return -1;
  87 }
  88
  89 /*
  90  * Lists with -L and -U option
  91  */
  92 static const char **llist;
  93 static size_t llct;
  94 static const char **ulist;
  95 static size_t ulct;
  96
  97
  98 void add_label(const char *label)
  99 {
 100         llist = xreallocarray(llist, ++llct, sizeof(char *));
 101         llist[llct - 1] = label;
 102 }
 103
 104 const char *get_label(size_t i)
 105 {
 106         return i < llct ? llist[i] : NULL;
 107 }
 108
 109 size_t numof_labels(void)
 110 {
 111         return llct;
 112 }
 113
 114 void add_uuid(const char *uuid)
 115 {
 116         ulist = xreallocarray(ulist, ++ulct, sizeof(char *));
 117         ulist[ulct - 1] = uuid;
 118 }
 119
 120 const char *get_uuid(size_t i)
 121 {
 122         return i < ulct ? ulist[i] : NULL;
 123 }
 124
 125 size_t numof_uuids(void)
 126 {
 127         return ulct;
 128 }
 129