summaryrefslogtreecommitdiffstats
path: root/lib/mountlist.c
blob: fac5c45e58b82f9258a4318a269d9d17ec06268c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
/* mountlist.c -- return a list of mounted file systems

   Copyright (C) 1991-1992, 1997-2022 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */

#include <config.h>

#include "mountlist.h"

#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>

#include "xalloc.h"

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#if HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif

#if MAJOR_IN_MKDEV
# include <sys/mkdev.h>
#elif MAJOR_IN_SYSMACROS
# include <sys/sysmacros.h>
#endif

#if defined MOUNTED_GETFSSTAT   /* OSF/1, also (obsolete) Apple Darwin 1.3 */
# if HAVE_SYS_UCRED_H
#  include <grp.h> /* needed on OSF V4.0 for definition of NGROUPS,
                      NGROUPS is used as an array dimension in ucred.h */
#  include <sys/ucred.h> /* needed by powerpc-apple-darwin1.3.7 */
# endif
# if HAVE_SYS_MOUNT_H
#  include <sys/mount.h>
# endif
# if HAVE_SYS_FS_TYPES_H
#  include <sys/fs_types.h> /* needed by powerpc-apple-darwin1.3.7 */
# endif
# if HAVE_STRUCT_FSSTAT_F_FSTYPENAME
#  define FS_TYPE(Ent) ((Ent).f_fstypename)
# else
#  define FS_TYPE(Ent) mnt_names[(Ent).f_type]
# endif
#endif /* MOUNTED_GETFSSTAT */

#ifdef MOUNTED_GETMNTENT1       /* glibc, HP-UX, IRIX, Cygwin, Android,
                                   also (obsolete) 4.3BSD, SunOS */
# include <mntent.h>
# include <sys/types.h>
# if defined __ANDROID__        /* Android */
   /* Bionic versions from between 2014-01-09 and 2015-01-08 define MOUNTED to
      an incorrect value; older Bionic versions don't define it at all.  */
#  undef MOUNTED
#  define MOUNTED "/proc/mounts"
# elif !defined MOUNTED
#  if defined _PATH_MOUNTED     /* GNU libc  */
#   define MOUNTED _PATH_MOUNTED
#  endif
#  if defined MNT_MNTTAB        /* HP-UX.  */
#   define MOUNTED MNT_MNTTAB
#  endif
# endif
#endif

#ifdef MOUNTED_GETMNTINFO       /* Mac OS X, FreeBSD, OpenBSD, also (obsolete) 4.4BSD */
# include <sys/mount.h>
#endif

#ifdef MOUNTED_GETMNTINFO2      /* NetBSD, Minix */
# include <sys/statvfs.h>
#endif

#ifdef MOUNTED_FS_STAT_DEV      /* Haiku, also (obsolete) BeOS */
# include <fs_info.h>
# include <dirent.h>
#endif

#ifdef MOUNTED_FREAD_FSTYP      /* (obsolete) SVR3 */
# include <mnttab.h>
# include <sys/fstyp.h>
# include <sys/statfs.h>
#endif

#ifdef MOUNTED_GETEXTMNTENT     /* Solaris >= 8 */
# include <sys/mnttab.h>
#endif

#ifdef MOUNTED_GETMNTENT2       /* Solaris < 8, also (obsolete) SVR4 */
# include <sys/mnttab.h>
#endif

#ifdef MOUNTED_VMOUNT           /* AIX */
# include <fshelp.h>
# include <sys/vfs.h>
#endif

#ifdef MOUNTED_INTERIX_STATVFS  /* Interix */
# include <sys/statvfs.h>
# include <dirent.h>
#endif

#if HAVE_SYS_MNTENT_H
/* This is to get MNTOPT_IGNORE on e.g. SVR4.  */
# include <sys/mntent.h>
#endif

#ifdef MOUNTED_GETMNTENT1
# if !HAVE_SETMNTENT            /* Android <= 4.4 */
#  define setmntent(fp,mode) fopen (fp, mode "e")
# endif
# if !HAVE_ENDMNTENT            /* Android <= 4.4 */
#  define endmntent(fp) fclose (fp)
# endif
#endif

#ifndef HAVE_HASMNTOPT
# define hasmntopt(mnt, opt) ((char *) 0)
#endif

#undef MNT_IGNORE
#ifdef MNTOPT_IGNORE
# if defined __sun && defined __SVR4
/* Solaris defines hasmntopt(struct mnttab *, char *)
   while it is otherwise hasmntopt(struct mnttab *, const char *).  */
#  define MNT_IGNORE(M) hasmntopt (M, (char *) MNTOPT_IGNORE)
# else
#  define MNT_IGNORE(M) hasmntopt (M, MNTOPT_IGNORE)
# endif
#else
# define MNT_IGNORE(M) 0
#endif

/* Each of the FILE streams in this file is only used in a single thread.  */
#include "unlocked-io.h"

/* The results of opendir() in this file are not used with dirfd and fchdir,
   therefore save some unnecessary work in fchdir.c.  */
#ifdef GNULIB_defined_opendir
# undef opendir
#endif
#ifdef GNULIB_defined_closedir
# undef closedir
#endif

#define ME_DUMMY_0(Fs_name, Fs_type)            \
  (strcmp (Fs_type, "autofs") == 0              \
   || strcmp (Fs_type, "proc") == 0             \
   || strcmp (Fs_type, "subfs") == 0            \
   /* for Linux 2.6/3.x */                      \
   || strcmp (Fs_type, "debugfs") == 0          \
   || strcmp (Fs_type, "devpts") == 0           \
   || strcmp (Fs_type, "fusectl") == 0          \
   || strcmp (Fs_type, "fuse.portal") == 0      \
   || strcmp (Fs_type, "mqueue") == 0           \
   || strcmp (Fs_type, "rpc_pipefs") == 0       \
   || strcmp (Fs_type, "sysfs") == 0            \
   /* FreeBSD, Linux 2.4 */                     \
   || strcmp (Fs_type, "devfs") == 0            \
   /* for NetBSD 3.0 */                         \
   || strcmp (Fs_type, "kernfs") == 0           \
   /* for Irix 6.5 */                           \
   || strcmp (Fs_type, "ignore") == 0)

/* Historically, we have marked as "dummy" any file system of type "none",
   but now that programs like du need to know about bind-mounted directories,
   we grant an exception to any with "bind" in its list of mount options.
   I.e., those are *not* dummy entries.  */
#ifdef MOUNTED_GETMNTENT1
# define ME_DUMMY(Fs_name, Fs_type, Bind)	\
  (ME_DUMMY_0 (Fs_name, Fs_type)		\
   || (strcmp (Fs_type, "none") == 0 && !Bind))
#else
# define ME_DUMMY(Fs_name, Fs_type)		\
  (ME_DUMMY_0 (Fs_name, Fs_type) || strcmp (Fs_type, "none") == 0)
#endif

#ifdef __CYGWIN__
# include <windows.h>
/* Don't assume that UNICODE is not defined.  */
# undef GetDriveType
# define GetDriveType GetDriveTypeA
# define ME_REMOTE me_remote
/* All cygwin mount points include ':' or start with '//'; so it
   requires a native Windows call to determine remote disks.  */
static bool
me_remote (char const *fs_name, _GL_UNUSED char const *fs_type)
{
  if (fs_name[0] && fs_name[1] == ':')
    {
      char drive[4];
      sprintf (drive, "%c:\\", fs_name[0]);
      switch (GetDriveType (drive))
        {
        case DRIVE_REMOVABLE:
        case DRIVE_FIXED:
        case DRIVE_CDROM:
        case DRIVE_RAMDISK:
          return false;
        }
    }
  return true;
}
#endif

#ifndef ME_REMOTE
/* A file system is "remote" if its Fs_name contains a ':'
   or if (it is of type (smbfs or cifs) and its Fs_name starts with '//')
   or if it is of any other of the listed types
   or Fs_name is equal to "-hosts" (used by autofs to mount remote fs).
   "VM" file systems like prl_fs or vboxsf are not considered remote here. */
# define ME_REMOTE(Fs_name, Fs_type)            \
    (strchr (Fs_name, ':') != NULL              \
     || ((Fs_name)[0] == '/'                    \
         && (Fs_name)[1] == '/'                 \
         && (strcmp (Fs_type, "smbfs") == 0     \
             || strcmp (Fs_type, "smb3") == 0   \
             || strcmp (Fs_type, "cifs") == 0)) \
     || strcmp (Fs_type, "acfs") == 0           \
     || strcmp (Fs_type, "afs") == 0            \
     || strcmp (Fs_type, "coda") == 0           \
     || strcmp (Fs_type, "auristorfs") == 0     \
     || strcmp (Fs_type, "fhgfs") == 0          \
     || strcmp (Fs_type, "gpfs") == 0           \
     || strcmp (Fs_type, "ibrix") == 0          \
     || strcmp (Fs_type, "ocfs2") == 0          \
     || strcmp (Fs_type, "vxfs") == 0           \
     || strcmp ("-hosts", Fs_name) == 0)
#endif

#if MOUNTED_GETMNTINFO          /* Mac OS X, FreeBSD, OpenBSD, also (obsolete) 4.4BSD */

# if ! HAVE_STRUCT_STATFS_F_FSTYPENAME
static char *
fstype_to_string (short int t)
{
  switch (t)
    {
#  ifdef MOUNT_PC
    case MOUNT_PC:
      return "pc";
#  endif
#  ifdef MOUNT_MFS
    case MOUNT_MFS:
      return "mfs";
#  endif
#  ifdef MOUNT_LO
    case MOUNT_LO:
      return "lo";
#  endif
#  ifdef MOUNT_TFS
    case MOUNT_TFS:
      return "tfs";
#  endif
#  ifdef MOUNT_TMP
    case MOUNT_TMP:
      return "tmp";
#  endif
#  ifdef MOUNT_UFS
   case MOUNT_UFS:
     return "ufs" ;
#  endif
#  ifdef MOUNT_NFS
   case MOUNT_NFS:
     return "nfs" ;
#  endif
#  ifdef MOUNT_MSDOS
   case MOUNT_MSDOS:
     return "msdos" ;
#  endif
#  ifdef MOUNT_LFS
   case MOUNT_LFS:
     return "lfs" ;
#  endif
#  ifdef MOUNT_LOFS
   case MOUNT_LOFS:
     return "lofs" ;
#  endif
#  ifdef MOUNT_FDESC
   case MOUNT_FDESC:
     return "fdesc" ;
#  endif
#  ifdef MOUNT_PORTAL
   case MOUNT_PORTAL:
     return "portal" ;
#  endif
#  ifdef MOUNT_NULL
   case MOUNT_NULL:
     return "null" ;
#  endif
#  ifdef MOUNT_UMAP
   case MOUNT_UMAP:
     return "umap" ;
#  endif
#  ifdef MOUNT_KERNFS
   case MOUNT_KERNFS:
     return "kernfs" ;
#  endif
#  ifdef MOUNT_PROCFS
   case MOUNT_PROCFS:
     return "procfs" ;
#  endif
#  ifdef MOUNT_AFS
   case MOUNT_AFS:
     return "afs" ;
#  endif
#  ifdef MOUNT_CD9660
   case MOUNT_CD9660:
     return "cd9660" ;
#  endif
#  ifdef MOUNT_UNION
   case MOUNT_UNION:
     return "union" ;
#  endif
#  ifdef MOUNT_DEVFS
   case MOUNT_DEVFS:
     return "devfs" ;
#  endif
#  ifdef MOUNT_EXT2FS
   case MOUNT_EXT2FS:
     return "ext2fs" ;
#  endif
    default:
      return "?";
    }
}
# endif

static char *
fsp_to_string (const struct statfs *fsp)
{
# if HAVE_STRUCT_STATFS_F_FSTYPENAME
  return (char *) (fsp->f_fstypename);
# else
  return fstype_to_string (fsp->f_type);
# endif
}

#endif /* MOUNTED_GETMNTINFO */

#ifdef MOUNTED_VMOUNT           /* AIX */
static char *
fstype_to_string (int t)
{
  struct vfs_ent *e;

  e = getvfsbytype (t);
  if (!e || !e->vfsent_name)
    return "none";
  else
    return e->vfsent_name;
}
#endif /* MOUNTED_VMOUNT */


#if defined MOUNTED_GETMNTENT1 || defined MOUNTED_GETMNTENT2

/* Return the device number from MOUNT_OPTIONS, if possible.
   Otherwise return (dev_t) -1.  */
static dev_t
dev_from_mount_options (char const *mount_options)
{
  /* GNU/Linux allows file system implementations to define their own
     meaning for "dev=" mount options, so don't trust the meaning
     here.  */
# ifndef __linux__

  static char const dev_pattern[] = ",dev=";
  char const *devopt = strstr (mount_options, dev_pattern);

  if (devopt)
    {
      char const *optval = devopt + sizeof dev_pattern - 1;
      char *optvalend;
      unsigned long int dev;
      errno = 0;
      dev = strtoul (optval, &optvalend, 16);
      if (optval != optvalend
          && (*optvalend == '\0' || *optvalend == ',')
          && ! (dev == ULONG_MAX && errno == ERANGE)
          && dev == (dev_t) dev)
        return dev;
    }

# endif
  (void) mount_options;
  return -1;
}

#endif

#if defined MOUNTED_GETMNTENT1 && (defined __linux__ || defined __ANDROID__) /* GNU/Linux, Android */

/* Unescape the paths in mount tables.
   STR is updated in place.  */

static void
unescape_tab (char *str)
{
  size_t i, j = 0;
  size_t len = strlen (str) + 1;
  for (i = 0; i < len; i++)
    {
      if (str[i] == '\\' && (i + 4 < len)
          && str[i + 1] >= '0' && str[i + 1] <= '3'
          && str[i + 2] >= '0' && str[i + 2] <= '7'
          && str[i + 3] >= '0' && str[i + 3] <= '7')
        {
          str[j++] = (str[i + 1] - '0') * 64 +
                     (str[i + 2] - '0') * 8 +
                     (str[i + 3] - '0');
          i += 3;
        }
      else
        str[j++] = str[i];
    }
}

/* Find the next space in STR, terminate the string there in place,
   and return that position.  Otherwise return NULL.  */

static char *
terminate_at_blank (char *str)
{
  char *s = strchr (str, ' ');
  if (s)
    *s = '\0';
  return s;
}
#endif

/* Return a list of the currently mounted file systems, or NULL on error.
   Add each entry to the tail of the list so that they stay in order.
   If NEED_FS_TYPE is true, ensure that the file system type fields in
   the returned list are valid.  Otherwise, they might not be.  */

struct mount_entry *
read_file_system_list (bool need_fs_type)
{
  struct mount_entry *mount_list;
  struct mount_entry *me;
  struct mount_entry **mtail = &mount_list;
  (void) need_fs_type;

#ifdef MOUNTED_GETMNTENT1       /* glibc, HP-UX, IRIX, Cygwin, Android,
                                   also (obsolete) 4.3BSD, SunOS */
  {
    FILE *fp;

# if defined __linux__ || defined __ANDROID__
    /* Try parsing mountinfo first, as that make device IDs available.
       Note we could use libmount routines to simplify this parsing a little
       (and that code is in previous versions of this function), however
       libmount depends on libselinux which pulls in many dependencies.  */
    char const *mountinfo = "/proc/self/mountinfo";
    fp = fopen (mountinfo, "re");
    if (fp != NULL)
      {
        char *line = NULL;
        size_t buf_size = 0;

        while (getline (&line, &buf_size, fp) != -1)
          {
            unsigned int devmaj, devmin;
            int rc, mntroot_s;

            rc = sscanf(line, "%*u "        /* id - discarded  */
                              "%*u "        /* parent - discarded  */
                              "%u:%u "      /* dev major:minor  */
                              "%n",         /* mountroot (start)  */
                              &devmaj, &devmin,
                              &mntroot_s);

            if (rc != 2 && rc != 3)  /* 3 if %n included in count.  */
              continue;

            /* find end of MNTROOT.  */
            char *mntroot = line + mntroot_s;
            char *blank = terminate_at_blank (mntroot);
            if (! blank)
              continue;

            /* find end of TARGET.  */
            char *target = blank + 1;
            blank = terminate_at_blank (target);
            if (! blank)
              continue;

            /* skip optional fields, terminated by " - "  */
            char *dash = strstr (blank + 1, " - ");
            if (! dash)
              continue;

            /* advance past the " - " separator.  */
            char *fstype = dash + 3;
            blank = terminate_at_blank (fstype);
            if (! blank)
              continue;

            /* find end of SOURCE.  */
            char *source = blank + 1;
            if (! terminate_at_blank (source))
              continue;

            /* manipulate the sub-strings in place.  */
            unescape_tab (source);
            unescape_tab (target);
            unescape_tab (mntroot);
            unescape_tab (fstype);

            me = xmalloc (sizeof *me);

            me->me_devname = xstrdup (source);
            me->me_mountdir = xstrdup (target);
            me->me_mntroot = xstrdup (mntroot);
            me->me_type = xstrdup (fstype);
            me->me_type_malloced = 1;
            me->me_dev = makedev (devmaj, devmin);
            /* we pass "false" for the "Bind" option as that's only
               significant when the Fs_type is "none" which will not be
               the case when parsing "/proc/self/mountinfo", and only
               applies for static /etc/mtab files.  */
            me->me_dummy = ME_DUMMY (me->me_devname, me->me_type, false);
            me->me_remote = ME_REMOTE (me->me_devname, me->me_type);

            /* Add to the linked list. */
            *mtail = me;
            mtail = &me->me_next;
          }

        free (line);

        if (ferror (fp))
          {
            int saved_errno = errno;
            fclose (fp);
            errno = saved_errno;
            goto free_then_fail;
          }

        if (fclose (fp) == EOF)
          goto free_then_fail;
      }
    else /* fallback to /proc/self/mounts (/etc/mtab).  */
# endif /* __linux __ || __ANDROID__ */
      {
        struct mntent *mnt;
        char const *table = MOUNTED;

        fp = setmntent (table, "r");
        if (fp == NULL)
          return NULL;

        while ((mnt = getmntent (fp)))
          {
            bool bind = hasmntopt (mnt, "bind");

            me = xmalloc (sizeof *me);
            me->me_devname = xstrdup (mnt->mnt_fsname);
            me->me_mountdir = xstrdup (mnt->mnt_dir);
            me->me_mntroot = NULL;
            me->me_type = xstrdup (mnt->mnt_type);
            me->me_type_malloced = 1;
            me->me_dummy = ME_DUMMY (me->me_devname, me->me_type, bind);
            me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
            me->me_dev = dev_from_mount_options (mnt->mnt_opts);

            /* Add to the linked list. */
            *mtail = me;
            mtail = &me->me_next;
          }

        if (endmntent (fp) == 0)
          goto free_then_fail;
      }
  }
#endif /* MOUNTED_GETMNTENT1. */

#ifdef MOUNTED_GETMNTINFO       /* Mac OS X, FreeBSD, OpenBSD, also (obsolete) 4.4BSD */
  {
    struct statfs *fsp;
    int entries;

    entries = getmntinfo (&fsp, MNT_NOWAIT);
    if (entries < 0)
      return NULL;
    for (; entries-- > 0; fsp++)
      {
        char *fs_type = fsp_to_string (fsp);

        me = xmalloc (sizeof *me);
        me->me_devname = xstrdup (fsp->f_mntfromname);
        me->me_mountdir = xstrdup (fsp->f_mntonname);
        me->me_mntroot = NULL;
        me->me_type = fs_type;
        me->me_type_malloced = 0;
        me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
        me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
        me->me_dev = (dev_t) -1;        /* Magic; means not known yet. */

        /* Add to the linked list. */
        *mtail = me;
        mtail = &me->me_next;
      }
  }
#endif /* MOUNTED_GETMNTINFO */

#ifdef MOUNTED_GETMNTINFO2      /* NetBSD, Minix */
  {
    struct statvfs *fsp;
    int entries;

    entries = getmntinfo (&fsp, MNT_NOWAIT);
    if (entries < 0)
      return NULL;
    for (; entries-- > 0; fsp++)
      {
        me = xmalloc (sizeof *me);
        me->me_devname = xstrdup (fsp->f_mntfromname);
        me->me_mountdir = xstrdup (fsp->f_mntonname);
        me->me_mntroot = NULL;
        me->me_type = xstrdup (fsp->f_fstypename);
        me->me_type_malloced = 1;
        me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
        me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
        me->me_dev = (dev_t) -1;        /* Magic; means not known yet. */

        /* Add to the linked list. */
        *mtail = me;
        mtail = &me->me_next;
      }
  }
#endif /* MOUNTED_GETMNTINFO2 */

#if defined MOUNTED_FS_STAT_DEV /* Haiku, also (obsolete) BeOS */
  {
    /* The next_dev() and fs_stat_dev() system calls give the list of
       all file systems, including the information returned by statvfs()
       (fs type, total blocks, free blocks etc.), but without the mount
       point. But on BeOS all file systems except / are mounted in the
       rootfs, directly under /.
       The directory name of the mount point is often, but not always,
       identical to the volume name of the device.
       We therefore get the list of subdirectories of /, and the list
       of all file systems, and match the two lists.  */

    DIR *dirp;
    struct rootdir_entry
      {
        char *name;
        dev_t dev;
        ino_t ino;
        struct rootdir_entry *next;
      };
    struct rootdir_entry *rootdir_list;
    struct rootdir_entry **rootdir_tail;
    int32 pos;
    dev_t dev;
    fs_info fi;

    /* All volumes are mounted in the rootfs, directly under /. */
    rootdir_list = NULL;
    rootdir_tail = &rootdir_list;
    dirp = opendir ("/");
    if (dirp)
      {
        struct dirent *d;

        while ((d = readdir (dirp)) != NULL)
          {
            char *name;
            struct stat statbuf;

            if (strcmp (d->d_name, "..") == 0)
              continue;

            if (strcmp (d->d_name, ".") == 0)
              name = xstrdup ("/");
            else
              {
                name = xmalloc (1 + strlen (d->d_name) + 1);
                name[0] = '/';
                strcpy (name + 1, d->d_name);
              }

            if (lstat (name, &statbuf) >= 0 && S_ISDIR (statbuf.st_mode))
              {
                struct rootdir_entry *re = xmalloc (sizeof *re);
                re->name = name;
                re->dev = statbuf.st_dev;
                re->ino = statbuf.st_ino;

                /* Add to the linked list.  */
                *rootdir_tail = re;
                rootdir_tail = &re->next;
              }
            else
              free (name);
          }
        closedir (dirp);
      }
    *rootdir_tail = NULL;

    for (pos = 0; (dev = next_dev (&pos)) >= 0; )
      if (fs_stat_dev (dev, &fi) >= 0)
        {
          /* Note: fi.dev == dev. */
          struct rootdir_entry *re;

          for (re = rootdir_list; re; re = re->next)
            if (re->dev == fi.dev && re->ino == fi.root)
              break;

          me = xmalloc (sizeof *me);
          me->me_devname = xstrdup (fi.device_name[0] != '\0'
                                    ? fi.device_name : fi.fsh_name);
          me->me_mountdir = xstrdup (re != NULL ? re->name : fi.fsh_name);
          me->me_mntroot = NULL;
          me->me_type = xstrdup (fi.fsh_name);
          me->me_type_malloced = 1;
          me->me_dev = fi.dev;
          me->me_dummy = 0;
          me->me_remote = (fi.flags & B_FS_IS_SHARED) != 0;

          /* Add to the linked list. */
          *mtail = me;
          mtail = &me->me_next;
        }
    *mtail = NULL;

    while (rootdir_list != NULL)
      {
        struct rootdir_entry *re = rootdir_list;
        rootdir_list = re->next;
        free (re->name);
        free (re);
      }
  }
#endif /* MOUNTED_FS_STAT_DEV */

#if defined MOUNTED_GETFSSTAT   /* OSF/1, also (obsolete) Apple Darwin 1.3 */
  {
    int numsys, counter;
    size_t bufsize;
    struct statfs *stats;

    numsys = getfsstat (NULL, 0L, MNT_NOWAIT);
    if (numsys < 0)
      return NULL;
    if (SIZE_MAX / sizeof *stats <= numsys)
      xalloc_die ();

    bufsize = (1 + numsys) * sizeof *stats;
    stats = xmalloc (bufsize);
    numsys = getfsstat (stats, bufsize, MNT_NOWAIT);

    if (numsys < 0)
      {
        free (stats);
        return NULL;
      }

    for (counter = 0; counter < numsys; counter++)
      {
        me = xmalloc (sizeof *me);
        me->me_devname = xstrdup (stats[counter].f_mntfromname);
        me->me_mountdir = xstrdup (stats[counter].f_mntonname);
        me->me_mntroot = NULL;
        me->me_type = xstrdup (FS_TYPE (stats[counter]));
        me->me_type_malloced = 1;
        me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
        me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
        me->me_dev = (dev_t) -1;        /* Magic; means not known yet. */

        /* Add to the linked list. */
        *mtail = me;
        mtail = &me->me_next;
      }

    free (stats);
  }
#endif /* MOUNTED_GETFSSTAT */

#if defined MOUNTED_FREAD_FSTYP /* (obsolete) SVR3 */
  {
    struct mnttab mnt;
    char *table = "/etc/mnttab";
    FILE *fp;

    fp = fopen (table, "re");
    if (fp == NULL)
      return NULL;

    while (fread (&mnt, sizeof mnt, 1, fp) > 0)
      {
        me = xmalloc (sizeof *me);
        me->me_devname = xstrdup (mnt.mt_dev);
        me->me_mountdir = xstrdup (mnt.mt_filsys);
        me->me_mntroot = NULL;
        me->me_dev = (dev_t) -1;        /* Magic; means not known yet. */
        me->me_type = "";
        me->me_type_malloced = 0;
        if (need_fs_type)
          {
            struct statfs fsd;
            char typebuf[FSTYPSZ];

            if (statfs (me->me_mountdir, &fsd, sizeof fsd, 0) != -1
                && sysfs (GETFSTYP, fsd.f_fstyp, typebuf) != -1)
              {
                me->me_type = xstrdup (typebuf);
                me->me_type_malloced = 1;
              }
          }
        me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
        me->me_remote = ME_REMOTE (me->me_devname, me->me_type);

        /* Add to the linked list. */
        *mtail = me;
        mtail = &me->me_next;
      }

    if (ferror (fp))
      {
        /* The last fread() call must have failed.  */
        int saved_errno = errno;
        fclose (fp);
        errno = saved_errno;
        goto free_then_fail;
      }

    if (fclose (fp) == EOF)
      goto free_then_fail;
  }
#endif /* MOUNTED_FREAD_FSTYP.  */

#ifdef MOUNTED_GETEXTMNTENT     /* Solaris >= 8 */
  {
    struct extmnttab mnt;
    const char *table = MNTTAB;
    FILE *fp;
    int ret;

    /* No locking is needed, because the contents of /etc/mnttab is generated
       by the kernel.  */

    errno = 0;
    fp = fopen (table, "re");
    if (fp == NULL)
      ret = errno;
    else
      {
        while ((ret = getextmntent (fp, &mnt, 1)) == 0)
          {
            me = xmalloc (sizeof *me);
            me->me_devname = xstrdup (mnt.mnt_special);
            me->me_mountdir = xstrdup (mnt.mnt_mountp);
            me->me_mntroot = NULL;
            me->me_type = xstrdup (mnt.mnt_fstype);
            me->me_type_malloced = 1;
            me->me_dummy = MNT_IGNORE (&mnt) != 0;
            me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
            me->me_dev = makedev (mnt.mnt_major, mnt.mnt_minor);

            /* Add to the linked list. */
            *mtail = me;
            mtail = &me->me_next;
          }

        ret = fclose (fp) == EOF ? errno : 0 < ret ? 0 : -1;
        /* Here ret = -1 means success, ret >= 0 means failure.  */
      }

    if (0 <= ret)
      {
        errno = ret;
        goto free_then_fail;
      }
  }
#endif /* MOUNTED_GETEXTMNTENT */

#ifdef MOUNTED_GETMNTENT2       /* Solaris < 8, also (obsolete) SVR4 */
  {
    struct mnttab mnt;
    const char *table = MNTTAB;
    FILE *fp;
    int ret;
    int lockfd = -1;

# if defined F_RDLCK && defined F_SETLKW
    /* MNTTAB_LOCK is a macro name of our own invention; it's not present in
       e.g. Solaris 2.6.  If the SVR4 folks ever define a macro
       for this file name, we should use their macro name instead.
       (Why not just lock MNTTAB directly?  We don't know.)  */
#  ifndef MNTTAB_LOCK
#   define MNTTAB_LOCK "/etc/.mnttab.lock"
#  endif
    lockfd = open (MNTTAB_LOCK, O_RDONLY | O_CLOEXEC);
    if (0 <= lockfd)
      {
        struct flock flock;
        flock.l_type = F_RDLCK;
        flock.l_whence = SEEK_SET;
        flock.l_start = 0;
        flock.l_len = 0;
        while (fcntl (lockfd, F_SETLKW, &flock) == -1)
          if (errno != EINTR)
            {
              int saved_errno = errno;
              close (lockfd);
              errno = saved_errno;
              return NULL;
            }
      }
    else if (errno != ENOENT)
      return NULL;
# endif

    errno = 0;
    fp = fopen (table, "re");
    if (fp == NULL)
      ret = errno;
    else
      {
        while ((ret = getmntent (fp, &mnt)) == 0)
          {
            me = xmalloc (sizeof *me);
            me->me_devname = xstrdup (mnt.mnt_special);
            me->me_mountdir = xstrdup (mnt.mnt_mountp);
            me->me_mntroot = NULL;
            me->me_type = xstrdup (mnt.mnt_fstype);
            me->me_type_malloced = 1;
            me->me_dummy = MNT_IGNORE (&mnt) != 0;
            me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
            me->me_dev = dev_from_mount_options (mnt.mnt_mntopts);

            /* Add to the linked list. */
            *mtail = me;
            mtail = &me->me_next;
          }

        ret = fclose (fp) == EOF ? errno : 0 < ret ? 0 : -1;
        /* Here ret = -1 means success, ret >= 0 means failure.  */
      }

    if (0 <= lockfd && close (lockfd) != 0)
      ret = errno;

    if (0 <= ret)
      {
        errno = ret;
        goto free_then_fail;
      }
  }
#endif /* MOUNTED_GETMNTENT2.  */

#ifdef MOUNTED_VMOUNT           /* AIX */
  {
    int bufsize;
    void *entries;
    char *thisent;
    struct vmount *vmp;
    int n_entries;
    int i;

    /* Ask how many bytes to allocate for the mounted file system info.  */
    entries = &bufsize;
    if (mntctl (MCTL_QUERY, sizeof bufsize, entries) != 0)
      return NULL;
    entries = xmalloc (bufsize);

    /* Get the list of mounted file systems.  */
    n_entries = mntctl (MCTL_QUERY, bufsize, entries);
    if (n_entries < 0)
      {
        free (entries);
        return NULL;
      }

    for (i = 0, thisent = entries;
         i < n_entries;
         i++, thisent += vmp->vmt_length)
      {
        char *options, *ignore;

        vmp = (struct vmount *) thisent;
        me = xmalloc (sizeof *me);
        if (vmp->vmt_flags & MNT_REMOTE)
          {
            char *host, *dir;

            me->me_remote = 1;
            /* Prepend the remote dirname.  */
            host = thisent + vmp->vmt_data[VMT_HOSTNAME].vmt_off;
            dir = thisent + vmp->vmt_data[VMT_OBJECT].vmt_off;
            me->me_devname = xmalloc (strlen (host) + strlen (dir) + 2);
            strcpy (me->me_devname, host);
            strcat (me->me_devname, ":");
            strcat (me->me_devname, dir);
          }
        else
          {
            me->me_remote = 0;
            me->me_devname = xstrdup (thisent +
                                      vmp->vmt_data[VMT_OBJECT].vmt_off);
          }
        me->me_mountdir = xstrdup (thisent + vmp->vmt_data[VMT_STUB].vmt_off);
        me->me_mntroot = NULL;
        me->me_type = xstrdup (fstype_to_string (vmp->vmt_gfstype));
        me->me_type_malloced = 1;
        options = thisent + vmp->vmt_data[VMT_ARGS].vmt_off;
        ignore = strstr (options, "ignore");
        me->me_dummy = (ignore
                        && (ignore == options || ignore[-1] == ',')
                        && (ignore[sizeof "ignore" - 1] == ','
                            || ignore[sizeof "ignore" - 1] == '\0'));
        me->me_dev = (dev_t) -1; /* vmt_fsid might be the info we want.  */

        /* Add to the linked list. */
        *mtail = me;
        mtail = &me->me_next;
      }
    free (entries);
  }
#endif /* MOUNTED_VMOUNT. */

#ifdef MOUNTED_INTERIX_STATVFS  /* Interix */
  {
    DIR *dirp = opendir ("/dev/fs");
    char node[9 + NAME_MAX];

    if (!dirp)
      goto free_then_fail;

    while (1)
      {
        struct statvfs dev;
        struct dirent entry;
        struct dirent *result;

        /* FIXME: readdir_r is planned to be withdrawn from POSIX and
           marked obsolescent in glibc.  Use readdir instead.  */
        if (readdir_r (dirp, &entry, &result) || result == NULL)
          break;

        strcpy (node, "/dev/fs/");
        strcat (node, entry.d_name);

        if (statvfs (node, &dev) == 0)
          {
            me = xmalloc (sizeof *me);
            me->me_devname = xstrdup (dev.f_mntfromname);
            me->me_mountdir = xstrdup (dev.f_mntonname);
            me->me_mntroot = NULL;
            me->me_type = xstrdup (dev.f_fstypename);
            me->me_type_malloced = 1;
            me->me_dummy = ME_DUMMY (me->me_devname, me->me_type);
            me->me_remote = ME_REMOTE (me->me_devname, me->me_type);
            me->me_dev = (dev_t) -1;        /* Magic; means not known yet. */

            /* Add to the linked list. */
            *mtail = me;
            mtail = &me->me_next;
          }
      }
    closedir (dirp);
  }
#endif /* MOUNTED_INTERIX_STATVFS */

  *mtail = NULL;
  return mount_list;


 free_then_fail: _GL_UNUSED_LABEL;
  {
    int saved_errno = errno;
    *mtail = NULL;

    while (mount_list)
      {
        me = mount_list->me_next;
        free_mount_entry (mount_list);
        mount_list = me;
      }

    errno = saved_errno;
    return NULL;
  }
}

/* Free a mount entry as returned from read_file_system_list ().  */

void
free_mount_entry (struct mount_entry *me)
{
  free (me->me_devname);
  free (me->me_mountdir);
  free (me->me_mntroot);
  if (me->me_type_malloced)
    free (me->me_type);
  free (me);
}