[thirdparty/util-linux.git] / mount-deprecated / mount.c

/*
 * A mount(8) for Linux.
 *
 * Modifications by many people. Distributed under GPL.
 */

#include <unistd.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <getopt.h>
#include <stdio.h>

#include <pwd.h>
#include <grp.h>

#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <sys/mount.h>

#include <mntent.h>

#ifdef HAVE_LIBSELINUX
#include <selinux/selinux.h>
#include <selinux/context.h>
#endif

#include "pathnames.h"
#include "fsprobe.h"
#include "devname.h"
#include "mount_constants.h"
#include "sundries.h"
#include "mount_mntent.h"
#include "fstab.h"
#include "loopdev.h"
#include "linux_version.h"
#include "getusername.h"
#include "env.h"
#include "nls.h"
#include "blkdev.h"
#include "strutils.h"
#include "closestream.h"
#include "xgetpass.h"

#define DO_PS_FIDDLING

#ifdef DO_PS_FIDDLING
#include "setproctitle.h"
#endif

/* True for fake mount (-f).  */
static int fake = 0;

/* True if we are allowed to call /sbin/mount.${FSTYPE} */
static int external_allowed = 1;

/* Don't write an entry in /etc/mtab (-n).  */
static int nomtab = 0;

/* True for explicit readonly (-r).  */
static int readonly = 0;

/* Nonzero for sloppy (-s).  */
static int sloppy = 0;

/* True for explicit read/write (-w).  */
static int readwrite = 0;

/* True for all mount (-a).  */
static int mount_all = 0;

/* True for fork() during all mount (-F).  */
static int optfork = 0;

/* Add volumelabel in a listing of mounted devices (-l). */
static int list_with_volumelabel = 0;

/* Nonzero for mount {bind|move|make-shared|make-private|
 *                              make-unbindable|make-slave}
 */
static int mounttype = 0;

/* True if (ruid != euid) or (0 != ruid), i.e. only "user" mounts permitted.  */
static int restricted = 1;

/* Contains the fd to read the passphrase from, if any. */
static int pfd = -1;

/* mount(2) options */
struct mountargs {
       const char *spec;
       const char *node;
       const char *type;
       int flags;
       void *data;
};

/* Map from -o and fstab option strings to the flag argument to mount(2).  */
struct opt_map {
  const char *opt;              /* option name */
  int  skip;                    /* skip in mtab option string */
  int  inv;                     /* true if flag value should be inverted */
  int  mask;                    /* flag mask value */
  int  cmask;                   /* comments mask */
};

/* Custom mount options for our own purposes.  */
/* Maybe these should now be freed for kernel use again */
#define MS_NOAUTO       0x80000000
#define MS_USERS        0x40000000
#define MS_USER         0x20000000
#define MS_OWNER        0x10000000
#define MS_GROUP        0x08000000
#define MS_COMMENT      0x02000000
#define MS_LOOP         0x00010000

#define MS_COMMENT_NOFAIL       (1 << 1)
#define MS_COMMENT_NETDEV       (1 << 2)

/* Options that we keep the mount system call from seeing.  */
#define MS_NOSYS        (MS_NOAUTO|MS_USERS|MS_USER|MS_COMMENT|MS_LOOP)

/* Options that we keep from appearing in the options field in the mtab.  */
#define MS_NOMTAB       (MS_REMOUNT|MS_NOAUTO|MS_USERS|MS_USER)

#define MS_PROPAGATION  (MS_SHARED|MS_SLAVE|MS_UNBINDABLE|MS_PRIVATE)

/* Options that we make ordinary users have by default.  */
#define MS_SECURE       (MS_NOEXEC|MS_NOSUID|MS_NODEV)

/* Options that we make owner-mounted devices have by default */
#define MS_OWNERSECURE  (MS_NOSUID|MS_NODEV)

static const struct opt_map opt_map[] = {
  { "defaults", 0, 0, 0         },      /* default options */
  { "ro",       1, 0, MS_RDONLY },      /* read-only */
  { "rw",       1, 1, MS_RDONLY },      /* read-write */
  { "exec",     0, 1, MS_NOEXEC },      /* permit execution of binaries */
  { "noexec",   0, 0, MS_NOEXEC },      /* don't execute binaries */
  { "suid",     0, 1, MS_NOSUID },      /* honor suid executables */
  { "nosuid",   0, 0, MS_NOSUID },      /* don't honor suid executables */
  { "dev",      0, 1, MS_NODEV  },      /* interpret device files  */
  { "nodev",    0, 0, MS_NODEV  },      /* don't interpret devices */
  { "sync",     0, 0, MS_SYNCHRONOUS},  /* synchronous I/O */
  { "async",    0, 1, MS_SYNCHRONOUS},  /* asynchronous I/O */
  { "dirsync",  0, 0, MS_DIRSYNC},      /* synchronous directory modifications */
  { "remount",  0, 0, MS_REMOUNT},      /* Alter flags of mounted FS */
  { "bind",     0, 0, MS_BIND   },      /* Remount part of tree elsewhere */
  { "rbind",    0, 0, MS_BIND|MS_REC }, /* Idem, plus mounted subtrees */
  { "auto",     0, 1, MS_NOAUTO },      /* Can be mounted using -a */
  { "noauto",   0, 0, MS_NOAUTO },      /* Can  only be mounted explicitly */
  { "users",    0, 0, MS_USERS  },      /* Allow ordinary user to mount */
  { "nousers",  0, 1, MS_USERS  },      /* Forbid ordinary user to mount */
  { "user",     0, 0, MS_USER   },      /* Allow ordinary user to mount */
  { "nouser",   0, 1, MS_USER   },      /* Forbid ordinary user to mount */
  { "owner",    0, 0, MS_OWNER  },      /* Let the owner of the device mount */
  { "noowner",  0, 1, MS_OWNER  },      /* Device owner has no special privs */
  { "group",    0, 0, MS_GROUP  },      /* Let the group of the device mount */
  { "nogroup",  0, 1, MS_GROUP  },      /* Device group has no special privs */
  { "_netdev",  0, 0, MS_COMMENT, MS_COMMENT_NETDEV },  /* Device requires network */
  { "comment",  0, 0, MS_COMMENT},      /* fstab comment only (kudzu,_netdev)*/

  /* add new options here */
#ifdef MS_NOSUB
  { "sub",      0, 1, MS_NOSUB  },      /* allow submounts */
  { "nosub",    0, 0, MS_NOSUB  },      /* don't allow submounts */
#endif
#ifdef MS_SILENT
  { "silent",   0, 0, MS_SILENT    },   /* be quiet  */
  { "loud",     0, 1, MS_SILENT    },   /* print out messages. */
#endif
#ifdef MS_MANDLOCK
  { "mand",     0, 0, MS_MANDLOCK },    /* Allow mandatory locks on this FS */
  { "nomand",   0, 1, MS_MANDLOCK },    /* Forbid mandatory locks on this FS */
#endif
  { "loop",     1, 0, MS_LOOP   },      /* use a loop device */
#ifdef MS_NOATIME
  { "atime",    0, 1, MS_NOATIME },     /* Update access time */
  { "noatime",  0, 0, MS_NOATIME },     /* Do not update access time */
#endif
#ifdef MS_I_VERSION
  { "iversion", 0, 0, MS_I_VERSION },   /* Update inode I_version time */
  { "noiversion", 0, 1, MS_I_VERSION }, /* Don't update inode I_version time */
#endif
#ifdef MS_NODIRATIME
  { "diratime", 0, 1, MS_NODIRATIME },  /* Update dir access times */
  { "nodiratime", 0, 0, MS_NODIRATIME },/* Do not update dir access times */
#endif
#ifdef MS_RELATIME
  { "relatime", 0, 0, MS_RELATIME },   /* Update access times relative to
                                          mtime/ctime */
  { "norelatime", 0, 1, MS_RELATIME }, /* Update access time without regard
                                          to mtime/ctime */
#endif
#ifdef MS_STRICTATIME
  { "strictatime", 0, 0, MS_STRICTATIME }, /* Strict atime semantics */
  { "nostrictatime", 0, 1, MS_STRICTATIME }, /* kernel default atime */
#endif
  { "nofail",   0, 0, MS_COMMENT, MS_COMMENT_NOFAIL },  /* Do not fail if ENOENT on dev */
  { NULL,       0, 0, 0         }
};

static int opt_nofail;
static int invuser_flags;
static int comment_flags;

static const char *opt_loopdev, *opt_vfstype, *opt_offset, *opt_sizelimit,
        *opt_encryption, *opt_speed, *opt_comment, *opt_uhelper, *opt_helper;

static int is_readonly(const char *node);
static int mounted (const char *spec0, const char *node0, struct mntentchn *fstab_mc);
static int check_special_mountprog(const char *spec, const char *node,
                const char *type, int flags, char *extra_opts, int *status);

static struct string_opt_map {
  char *tag;
  int skip;
  const char **valptr;
} string_opt_map[] = {
  { "loop=",    0, &opt_loopdev },
  { "vfs=",     1, &opt_vfstype },
  { "offset=",  0, &opt_offset },
  { "sizelimit=",  0, &opt_sizelimit },
  { "encryption=", 0, &opt_encryption },
  { "speed=", 0, &opt_speed },
  { "comment=", 1, &opt_comment },
  { "uhelper=", 0, &opt_uhelper },
  { "helper=", 0, &opt_helper },
  { NULL, 0, NULL }
};

static void
clear_string_opts(void) {
        struct string_opt_map *m;

        for (m = &string_opt_map[0]; m->tag; m++)
                *(m->valptr) = NULL;
}

static void
clear_flags_opts(void) {
        invuser_flags = 0;
        comment_flags = 0;
        opt_nofail = 0;
}

static int
parse_string_opt(char *s) {
        struct string_opt_map *m;
        int lth;

        for (m = &string_opt_map[0]; m->tag; m++) {
                lth = strlen(m->tag);
                if (!strncmp(s, m->tag, lth)) {
                        *(m->valptr) = xstrdup(s + lth);
                        return 1;
                }
        }
        return 0;
}

/* Report on a single mount.  */
static void
print_one (const struct my_mntent *me) {

        char *fsname = NULL;

        if (mount_quiet)
                return;

        /* users assume backing file name rather than /dev/loopN in
         * mount(8) output if the device has been initialized by mount(8).
         */
        if (strncmp(me->mnt_fsname, "/dev/loop", 9) == 0 &&
            loopdev_is_autoclear(me->mnt_fsname))
                fsname = loopdev_get_backing_file(me->mnt_fsname);

        if (!fsname)
                fsname = (char *) me->mnt_fsname;

        printf ("%s on %s", fsname, me->mnt_dir);
        if (me->mnt_type != NULL && *(me->mnt_type) != '\0')
                printf (" type %s", me->mnt_type);
        if (me->mnt_opts != NULL)
                printf (" (%s)", me->mnt_opts);
        if (list_with_volumelabel && is_pseudo_fs(me->mnt_type) == 0) {
                const char *devname = spec_to_devname(me->mnt_fsname);

                if (devname) {
                        const char *label;

                        label = fsprobe_get_label_by_devname(devname);
                        my_free(devname);

                        if (label) {
                                printf (" [%s]", label);
                                my_free(label);
                        }
                }
        }
        printf ("\n");
}

/* Report on everything in mtab (of the specified types if any).  */
static int
print_all (char *types) {
     struct mntentchn *mc, *mc0;

     mc0 = mtab_head();
     for (mc = mc0->nxt; mc && mc != mc0; mc = mc->nxt) {
          if (matching_type (mc->m.mnt_type, types))
               print_one (&(mc->m));
     }

     if (!mtab_does_not_exist() && !mtab_is_a_symlink() && is_readonly(_PATH_MOUNTED))
          printf(_("\n"
        "mount: warning: /etc/mtab is not writable (e.g. read-only filesystem).\n"
        "       It's possible that information reported by mount(8) is not\n"
        "       up to date. For actual information about system mount points\n"
        "       check the /proc/mounts file.\n\n"));

     exit (0);
}

/* reallocates its first arg */
static char *
append_opt(char *s, const char *opt, const char *val)
{
        if (!opt)
                return s;
        if (!s) {
                if (!val)
                       return xstrdup(opt);             /* opt */

                return xstrconcat3(NULL, opt, val);     /* opt=val */
        }
        if (!val)
                return xstrconcat3(s, ",", opt);        /* s,opt */

        return xstrconcat4(s, ",", opt, val);           /* s,opt=val */
}

static char *
append_numopt(char *s, const char *opt, unsigned int num)
{
        char buf[32];

        snprintf(buf, sizeof(buf), "%u", num);
        return append_opt(s, opt, buf);
}

#ifdef HAVE_LIBSELINUX
/* strip quotes from a "string"
 * Warning: This function modify the "str" argument.
 */
static char *
strip_quotes(char *str)
{
        char *end = NULL;

        if (*str != '"')
                return str;

        end = strrchr(str, '"');
        if (end == NULL || end == str)
                die (EX_USAGE, _("mount: improperly quoted option string '%s'"), str);

        *end = '\0';
        return str+1;
}

/* translates SELinux context from human to raw format and
 * appends it to the mount extra options.
 *
 * returns -1 on error and 0 on success
 */
static int
append_context(const char *optname, char *optdata, char **extra_opts)
{
        security_context_t raw = NULL;
        char *data = NULL;

        if (is_selinux_enabled() != 1)
                /* ignore the option if we running without selinux */
                return 0;

        if (optdata==NULL || *optdata=='\0' || optname==NULL)
                return -1;

        /* TODO: use strip_quotes() for all mount options? */
        data = *optdata =='"' ? strip_quotes(optdata) : optdata;

        if (selinux_trans_to_raw_context(
                        (security_context_t) data, &raw) == -1 ||
                        raw == NULL)
                return -1;

        if (verbose)
                printf(_("mount: translated %s '%s' to '%s'\n"),
                                optname, data, (char *) raw);

        *extra_opts = append_opt(*extra_opts, optname, NULL);
        *extra_opts = xstrconcat4(*extra_opts, "\"", (char *) raw, "\"");

        freecon(raw);
        return 0;
}

/* returns newly allocated string without *context= options */
static char *remove_context_options(char *opts)
{
        char *begin = NULL, *end = NULL, *p;
        int open_quote = 0, changed = 0;

        if (!opts)
                return NULL;

        opts = xstrdup(opts);

        for (p = opts; p && *p; p++) {
                if (!begin)
                        begin = p;              /* begin of the option item */
                if (*p == '"')
                        open_quote ^= 1;        /* reverse the status */
                if (open_quote)
                        continue;               /* still in quoted block */
                if (*p == ',')
                        end = p;                /* terminate the option item */
                else if (*(p + 1) == '\0')
                        end = p + 1;            /* end of optstr */
                if (!begin || !end)
                        continue;

                if (strncmp(begin, "context=", 8) == 0 ||
                    strncmp(begin, "fscontext=", 10) == 0 ||
                    strncmp(begin, "defcontext=", 11) == 0 ||
                    strncmp(begin, "rootcontext=", 12) == 0 ||
                    strncmp(begin, "seclabel", 8) == 0) {
                        size_t sz;

                        if ((begin == opts || *(begin - 1) == ',') && *end == ',')
                                end++;
                        sz = strlen(end);

                        memmove(begin, end, sz + 1);
                        if (!*begin && *(begin - 1) == ',')
                                *(begin - 1) = '\0';

                        p = begin;
                        changed = 1;
                }
                begin = end = NULL;
        }

        if (changed && verbose)
                printf (_("mount: SELinux *context= options are ignore on remount.\n"));

        return opts;
}

static int has_context_option(char *opts)
{
        if (get_option("context=", opts, NULL) ||
            get_option("fscontext=", opts, NULL) ||
            get_option("defcontext=", opts, NULL) ||
            get_option("rootcontext=", opts, NULL))
                return 1;

        return 0;
}

#endif

/*
 * Look for OPT in opt_map table and return mask value.
 * If OPT isn't found, tack it onto extra_opts (which is non-NULL).
 * For the options uid= and gid= replace user or group name by its value.
 */
static inline void
parse_opt(char *opt, int *mask, int *inv_user, char **extra_opts) {
        const struct opt_map *om;

        for (om = opt_map; om->opt != NULL; om++)
                if (streq (opt, om->opt)) {
                        if (om->inv)
                                *mask &= ~om->mask;
                        else
                                *mask |= om->mask;
                        if (om->inv && ((*mask & MS_USER) || (*mask & MS_USERS))
                            && (om->mask & MS_SECURE))
                                *inv_user |= om->mask;
                        if ((om->mask == MS_USER || om->mask == MS_USERS)
                            && !om->inv)
                                *mask |= MS_SECURE;
                        if ((om->mask == MS_OWNER || om->mask == MS_GROUP)
                            && !om->inv)
                                *mask |= MS_OWNERSECURE;
#ifdef MS_SILENT
                        if (om->mask == MS_SILENT && om->inv)  {
                                mount_quiet = 1;
                                verbose = 0;
                        }
#endif
                        if (om->mask == MS_COMMENT) {
                                comment_flags |= om->cmask;
                                if (om->cmask == MS_COMMENT_NOFAIL)
                                        opt_nofail = 1;
                        }
                        return;
                }

        /* convert nonnumeric ids to numeric */
        if (!strncmp(opt, "uid=", 4) && !isdigit(opt[4])) {
                struct passwd *pw = getpwnam(opt+4);

                if (pw) {
                        *extra_opts = append_numopt(*extra_opts,
                                                "uid=", pw->pw_uid);
                        return;
                }
        }
        if (!strncmp(opt, "gid=", 4) && !isdigit(opt[4])) {
                struct group *gr = getgrnam(opt+4);

                if (gr) {
                        *extra_opts = append_numopt(*extra_opts,
                                                "gid=", gr->gr_gid);
                        return;
                }
        }

#ifdef HAVE_LIBSELINUX
        if (strncmp(opt, "context=", 8) == 0 && *(opt+8)) {
                if (append_context("context=", opt+8, extra_opts) == 0)
                        return;
        }
        if (strncmp(opt, "fscontext=", 10) == 0 && *(opt+10)) {
                if (append_context("fscontext=", opt+10, extra_opts) == 0)
                        return;
        }
        if (strncmp(opt, "defcontext=", 11) == 0 && *(opt+11)) {
                if (append_context("defcontext=", opt+11, extra_opts) == 0)
                        return;
        }
        if (strncmp(opt, "rootcontext=", 12) == 0 && *(opt+12)) {
                if (append_context("rootcontext=", opt+12, extra_opts) == 0)
                        return;
        }
#endif
        *extra_opts = append_opt(*extra_opts, opt, NULL);
}


/* Take -o options list and compute 4th and 5th args to mount(2).  flags
   gets the standard options (indicated by bits) and extra_opts all the rest */
static void
parse_opts (const char *options, int *flags, char **extra_opts) {
        *flags = 0;
        *extra_opts = NULL;

        clear_string_opts();
        clear_flags_opts();

        if (options != NULL) {
                char *opts = xstrdup(options);
                int open_quote = 0;
                char *opt, *p;

                for (p=opts, opt=NULL; p && *p; p++) {
                        if (!opt)
                                opt = p;                /* begin of the option item */
                        if (*p == '"')
                                open_quote ^= 1;        /* reverse the status */
                        if (open_quote)
                                continue;               /* still in quoted block */
                        if (*p == ',')
                                *p = '\0';              /* terminate the option item */
                        /* end of option item or last item */
                        if (*p == '\0' || *(p+1) == '\0') {
                                if (!parse_string_opt(opt))
                                        parse_opt(opt, flags, &invuser_flags, extra_opts);
                                opt = NULL;
                        }
                }
                free(opts);
        }

        if (readonly)
                *flags |= MS_RDONLY;
        if (readwrite)
                *flags &= ~MS_RDONLY;

        *flags |= mounttype;

        /* The propagation flags should not be used together with any
         * other flags (except MS_REC and MS_SILENT) */
        if (*flags & MS_PROPAGATION)
                *flags &= (MS_PROPAGATION | MS_REC | MS_SILENT);
}

/* Try to build a canonical options string.  */
static char *
fix_opts_string (int flags, const char *extra_opts,
                 const char *user, int inv_user)
{
        const struct opt_map *om;
        const struct string_opt_map *m;
        char *new_opts;

        new_opts = append_opt(NULL, (flags & MS_RDONLY) ? "ro" : "rw", NULL);
        for (om = opt_map; om->opt != NULL; om++) {
                if (om->skip)
                        continue;
                if (om->inv || !om->mask || (flags & om->mask) != om->mask)
                        continue;
                if (om->mask == MS_COMMENT && !(comment_flags & om->cmask))
                        continue;
                new_opts = append_opt(new_opts, om->opt, NULL);
                flags &= ~om->mask;
        }
        for (m = &string_opt_map[0]; m->tag; m++) {
                if (!m->skip && *(m->valptr))
                        new_opts = append_opt(new_opts, m->tag, *(m->valptr));
        }
        if (extra_opts && *extra_opts)
                new_opts = append_opt(new_opts, extra_opts, NULL);

        if (user)
                new_opts = append_opt(new_opts, "user=", user);

        if (inv_user) {
                for (om = opt_map; om->opt != NULL; om++) {
                        if (om->mask && om->inv
                            && (inv_user & om->mask) == om->mask) {
                                new_opts = append_opt(new_opts, om->opt, NULL);
                                inv_user &= ~om->mask;
                        }
                }
        }

        return new_opts;
}

static int
already (const char *spec0, const char *node0) {
        struct mntentchn *mc;
        int ret = 1;
        char *spec = canonicalize_spec(spec0);
        char *node = canonicalize(node0);

        if ((mc = getmntfile(node)) != NULL)
                error (_("mount: according to mtab, "
                         "%s is already mounted on %s"),
                       mc->m.mnt_fsname, node);
        else if (spec && strcmp (spec, "none") &&
                 (mc = getmntfile(spec)) != NULL)
                error (_("mount: according to mtab, %s is mounted on %s"),
                       spec, mc->m.mnt_dir);
        else
                ret = 0;

        free(spec);
        free(node);

        return ret;
}

/* Create mtab with a root entry.  */
static void
create_mtab (void) {
        struct mntentchn *fstab;
        struct my_mntent mnt;
        int flags;
        mntFILE *mfp;

        lock_mtab();

        mfp = my_setmntent (_PATH_MOUNTED, "a+");
        if (mfp == NULL || mfp->mntent_fp == NULL) {
                int errsv = errno;
                die (EX_FILEIO, _("mount: can't open %s for writing: %s"),
                     _PATH_MOUNTED, strerror (errsv));
        }

        /* Find the root entry by looking it up in fstab */
        if ((fstab = getfs_by_dir ("/")) || (fstab = getfs_by_dir ("root"))) {
                char *extra_opts;
                parse_opts (fstab->m.mnt_opts, &flags, &extra_opts);
                mnt.mnt_dir = "/";
                mnt.mnt_fsname = spec_to_devname(fstab->m.mnt_fsname);
                mnt.mnt_type = fstab->m.mnt_type;
                mnt.mnt_opts = fix_opts_string (flags, extra_opts, NULL, 0);
                mnt.mnt_freq = mnt.mnt_passno = 0;
                free(extra_opts);

                if (my_addmntent (mfp, &mnt) == 1) {
                        int errsv = errno;
                        die (EX_FILEIO, _("mount: error writing %s: %s"),
                             _PATH_MOUNTED, strerror (errsv));
                }
        }
        if (fchmod (fileno (mfp->mntent_fp), 0644) < 0)
                if (errno != EROFS) {
                        int errsv = errno;
                        die (EX_FILEIO,
                             _("mount: error changing mode of %s: %s"),
                             _PATH_MOUNTED, strerror (errsv));
                }
        my_endmntent (mfp);

        unlock_mtab();

        reset_mtab_info();
}

/* count successful mount system calls */
static int mountcount = 0;

/*
 * do_mount_syscall()
 *      Mount a single file system. Keep track of successes.
 * returns: 0: OK, -1: error in errno
 */
static int
do_mount_syscall (struct mountargs *args) {
        int flags = args->flags;

        if ((flags & MS_MGC_MSK) == 0)
                flags |= MS_MGC_VAL;

        if (verbose > 2)
                printf("mount: mount(2) syscall: source: \"%s\", target: \"%s\", "
                        "filesystemtype: \"%s\", mountflags: %d, data: %s\n",
                        args->spec, args->node, args->type, flags, (char *) args->data);

        return mount (args->spec, args->node, args->type, flags, args->data);
}

/*
 * do_mount()
 *      Mount a single file system, possibly invoking an external handler to
 *      do so. Keep track of successes.
 * returns: 0: OK, -1: error in errno
 */
static int
do_mount (struct mountargs *args, int *special, int *status) {
        int ret;
        if (check_special_mountprog(args->spec, args->node, args->type,
                                    args->flags, args->data, status)) {
                *special = 1;
                ret = 0;
        } else {
                ret = do_mount_syscall(args);
        }
        if (ret == 0)
                mountcount++;
        return ret;
}

/*
 * check_special_mountprog()
 *      If there is a special mount program for this type, exec it.
 * returns: 0: no exec was done, 1: exec was done, status has result
 */
static int
check_special_mountprog(const char *spec, const char *node, const char *type, int flags,
                        char *extra_opts, int *status) {
        char search_path[] = FS_SEARCH_PATH;
        char *path, mountprog[150];
        struct stat statbuf;
        int res;

        if (!external_allowed)
                return 0;

        if (type == NULL || strcmp(type, "none") == 0)
                return 0;

        path = strtok(search_path, ":");
        while (path) {
                int type_opt = 0;

                res = snprintf(mountprog, sizeof(mountprog), "%s/mount.%s",
                               path, type);
                path = strtok(NULL, ":");
                if (res < 0 || (size_t) res >= sizeof(mountprog))
                        continue;

                res = stat(mountprog, &statbuf);
                if (res == -1 && errno == ENOENT && strchr(type, '.')) {
                        /* If type ends with ".subtype" try without it */
                        *strrchr(mountprog, '.') = '\0';
                        type_opt = 1;
                        res = stat(mountprog, &statbuf);
                }
                if (res)
                        continue;

                if (verbose)
                        fflush(stdout);

                switch (fork()) {
                case 0: { /* child */
                        char *oo, *mountargs[12];
                        int i = 0;

                        if (setgid(getgid()) < 0)
                                die(EX_FAIL, _("mount: cannot set group id: %m"));

                        if (setuid(getuid()) < 0)
                                die(EX_FAIL, _("mount: cannot set user id: %m"));

                        oo = fix_opts_string(flags, extra_opts, NULL, invuser_flags);
                        mountargs[i++] = mountprog;                     /* 1 */
                        mountargs[i++] = (char *) spec;                 /* 2 */
                        mountargs[i++] = (char *) node;                 /* 3 */
                        if (sloppy && strncmp(type, "nfs", 3) == 0)
                                mountargs[i++] = "-s";                  /* 4 */
                        if (fake)
                                mountargs[i++] = "-f";                  /* 5 */
                        if (nomtab)
                                mountargs[i++] = "-n";                  /* 6 */
                        if (verbose)
                                mountargs[i++] = "-v";                  /* 7 */
                        if (oo && *oo) {
                                mountargs[i++] = "-o";                  /* 8 */
                                mountargs[i++] = oo;                    /* 9 */
                        }
                        if (type_opt) {
                                mountargs[i++] = "-t";                  /* 10 */
                                mountargs[i++] = (char *) type;         /* 11 */
                        }
                        mountargs[i] = NULL;                            /* 12 */

                        if (verbose > 2) {
                                i = 0;
                                while (mountargs[i]) {
                                        printf("mount: external mount: argv[%d] = \"%s\"\n",
                                                i, mountargs[i]);
                                        i++;
                                }
                                fflush(stdout);
                        }

                        execv(mountprog, mountargs);
                        exit(1);        /* exec failed */
                }

                default: { /* parent */
                        int st;
                        wait(&st);
                        *status = (WIFEXITED(st) ? WEXITSTATUS(st) : EX_SYSERR);
                        return 1;
                }

                case -1: { /* error */
                        int errsv = errno;
                        error(_("mount: cannot fork: %s"), strerror(errsv));
                }
                }
        }

        return 0;
}


/* list of already tested filesystems by procfsloop_mount() */
static struct tried {
        struct tried *next;
        char *type;
} *tried = NULL;

static int
was_tested(const char *fstype) {
        struct tried *t;

        for (t = tried; t; t = t->next) {
                if (!strcmp(t->type, fstype))
                        return 1;
        }
        return 0;
}

static void
set_tested(const char *fstype) {
        struct tried *t = xmalloc(sizeof(struct tried));

        t->next = tried;
        t->type = xstrdup(fstype);
        tried = t;
}

static void
free_tested(void) {
        struct tried *t, *tt;

        t = tried;
        while(t) {
                free(t->type);
                tt = t->next;
                free(t);
                t = tt;
        }
        tried = NULL;
}

static char *
procfsnext(FILE *procfs) {
   char line[100];
   char fsname[100];

   while (fgets(line, sizeof(line), procfs)) {
      if (sscanf (line, "nodev %[^#\n]\n", fsname) == 1) continue;
      if (sscanf (line, " %[^# \n]\n", fsname) != 1) continue;
      return xstrdup(fsname);
   }
   return 0;
}

/* Only use /proc/filesystems here, this is meant to test what
   the kernel knows about, so /etc/filesystems is irrelevant.
   Return: 1: yes, 0: no, -1: cannot open procfs */
static int
known_fstype_in_procfs(const char *type)
{
    FILE *procfs;
    char *fsname;
    int ret = -1;

    procfs = fopen(_PATH_PROC_FILESYSTEMS, "r");
    if (procfs) {
        ret = 0;
        while ((fsname = procfsnext(procfs)) != NULL)
            if (!strcmp(fsname, type)) {
                ret = 1;
                break;
            }
        fclose(procfs);
        procfs = NULL;
    }
    return ret;
}

/* Try all types in FILESYSTEMS, except those in *types,
   in case *types starts with "no" */
/* return: 0: OK, -1: error in errno, 1: type not found */
/* when 0 or -1 is returned, *types contains the type used */
/* when 1 is returned, *types is NULL */
static int
procfsloop_mount(int (*mount_fn)(struct mountargs *, int *, int *),
                         struct mountargs *args,
                         const char **types,
                         int *special, int *status)
{
        char *files[2] = { _PATH_FILESYSTEMS, _PATH_PROC_FILESYSTEMS };
        FILE *procfs;
        char *fsname;
        const char *notypes = NULL;
        int no = 0;
        int ret = 1;
        int errsv = 0;
        int i;

        if (*types && !strncmp(*types, "no", 2)) {
                no = 1;
                notypes = (*types) + 2;
        }
        *types = NULL;

        /* Use _PATH_PROC_FILESYSTEMS only when _PATH_FILESYSTEMS
         * (/etc/filesystems) does not exist.  In some cases trying a
         * filesystem that the kernel knows about on the wrong data will crash
         * the kernel; in such cases _PATH_FILESYSTEMS can be used to list the
         * filesystems that we are allowed to try, and in the order they should
         * be tried.  End _PATH_FILESYSTEMS with a line containing a single '*'
         * only, if _PATH_PROC_FILESYSTEMS should be tried afterwards.
         */
        for (i=0; i<2; i++) {
                procfs = fopen(files[i], "r");
                if (!procfs)
                        continue;
                while ((fsname = procfsnext(procfs)) != NULL) {
                        if (!strcmp(fsname, "*")) {
                                fclose(procfs);
                                goto nexti;
                        }
                        if (was_tested (fsname))
                                continue;
                        if (no && matching_type(fsname, notypes))
                                continue;
                        set_tested (fsname);
                        args->type = fsname;
                        if (verbose)
                                printf(_("Trying %s\n"), fsname);
                        if ((*mount_fn) (args, special, status) == 0) {
                                *types = fsname;
                                ret = 0;
                                break;
                        } else if (errno != EINVAL &&
                                   known_fstype_in_procfs(fsname) == 1) {
                                *types = "guess";
                                ret = -1;
                                errsv = errno;
                                break;
                        }
                }
                free_tested();
                fclose(procfs);
                errno = errsv;
                return ret;
        nexti:;
        }
        return 1;
}

static const char *
guess_fstype_by_devname(const char *devname, int *ambivalent)
{
   const char *type = fsprobe_get_fstype_by_devname_ambi(devname, ambivalent);

   if (verbose) {
      printf (_("mount: you didn't specify a filesystem type for %s\n"), devname);

      if (!type)
         printf (_("       I will try all types mentioned in %s or %s\n"),
                      _PATH_FILESYSTEMS, _PATH_PROC_FILESYSTEMS);
      else if (!strcmp(type, MNTTYPE_SWAP))
         printf (_("       and it looks like this is swapspace\n"));
      else
         printf (_("       I will try type %s\n"), type);
   }
   return type;
}

/*
 * guess_fstype_and_mount()
 *      Mount a single file system. Guess the type when unknown.
 * returns: 0: OK, -1: error in errno, 1: other error
 *      don't exit on non-fatal errors.
 *      on return types is filled with the type used.
 */
static int
guess_fstype_and_mount(const char *spec, const char *node, const char **types,
                       int flags, char *mount_opts, int *special, int *status) {
   struct mountargs args = { spec, node, NULL, flags & ~MS_NOSYS, mount_opts };
   int ambivalent = 0;

   if (*types && strcasecmp (*types, "auto") == 0)
      *types = NULL;

   if (!*types && !(flags & MS_REMOUNT)) {
      *types = guess_fstype_by_devname(spec, &ambivalent);
      if (*types) {
          if (!strcmp(*types, MNTTYPE_SWAP)) {
              error(_("%s looks like swapspace - not mounted"), spec);
              *types = NULL;
              return 1;
          } else {
              args.type = *types;
              return do_mount (&args, special, status);
          }
      } else if (ambivalent) {
          error(_("mount: %s: more filesystems detected. This should not happen,\n"
                  "       use -t <type> to explicitly specify the filesystem type or\n"
                  "       use wipefs(8) to clean up the device.\n"), spec);
          return 1;
      }
   }

   /* Accept a comma-separated list of types, and try them one by one */
   /* A list like "nonfs,.." indicates types not to use */
   if (*types && strncmp(*types, "no", 2) && strchr(*types,',')) {
      char *t = strdup(*types);
      char *p;

      while((p = strchr(t,',')) != NULL) {
         *p = 0;
         args.type = *types = t;
         if (do_mount (&args, special, status) == 0)
            return 0;
         t = p+1;
      }
      /* do last type below */
      *types = t;
   }

   if (*types || (flags & MS_REMOUNT)) {
      args.type = *types;
      return do_mount (&args, special, status);
   }

   return procfsloop_mount(do_mount, &args, types, special, status);
}

/*
 * restricted_check()
 *      Die if the user is not allowed to do this.
 */
static void
restricted_check(const char *spec, const char *node, int *flags, char **user) {
  if (restricted) {
      /*
       * MS_OWNER: Allow owners to mount when fstab contains
       * the owner option.  Note that this should never be used
       * in a high security environment, but may be useful to give
       * people at the console the possibility of mounting a floppy.
       * MS_GROUP: Allow members of device group to mount. (Martin Dickopp)
       */
      if (*flags & (MS_OWNER | MS_GROUP)) {
          struct stat sb;

          if (!strncmp(spec, "/dev/", 5) && stat(spec, &sb) == 0) {

              if (*flags & MS_OWNER) {
                  if (getuid() == sb.st_uid)
                      *flags |= MS_USER;
              }

              if (*flags & MS_GROUP) {
                  if (getgid() == sb.st_gid)
                      *flags |= MS_USER;
                  else {
                      int n = getgroups(0, NULL);

                      if (n > 0) {
                              gid_t *groups = xmalloc(n * sizeof(*groups));
                              if (getgroups(n, groups) == n) {
                                      int i;
                                      for (i = 0; i < n; i++) {
                                              if (groups[i] == sb.st_gid) {
                                                      *flags |= MS_USER;
                                                      break;
                                              }
                                      }
                              }
                              free(groups);
                      }
                  }
              }
          }
      }

      /* James Kehl <mkehl@gil.com.au> came with a similar patch:
         allow an arbitrary user to mount when he is the owner of
         the mount-point and has write-access to the device.
         This is even less secure. Let me skip it for the time being;
         there should be an explicit fstab line allowing such things. */

      if (!(*flags & (MS_USER | MS_USERS))) {
          if (already (spec, node))
            die (EX_USAGE, _("mount failed"));
          else
            die (EX_USAGE, _("mount: only root can mount %s on %s"), spec, node);
      }
      if (*flags & MS_USER)
          *user = getusername();
  }

  *flags &= ~(MS_OWNER | MS_GROUP);
}

/* Check, if there already exists a mounted loop device on the mountpoint node
 * with the same parameters.
 */
static int
is_mounted_same_loopfile(const char *node0, const char *loopfile, unsigned long long offset)
{
        struct mntentchn *mnt = NULL;
        char *node;
        int res = 0;

        node = canonicalize(node0);

        /* Search for mountpoint node in mtab,
         * procceed if any of these has the loop option set or
         * the device is a loop device
         */
        mnt = getmntdirbackward(node, mnt);
        if (!mnt) {
                free(node);
                return 0;
        }
        for(; mnt && res == 0; mnt = getmntdirbackward(node, mnt)) {
                char *p;

                if (strncmp(mnt->m.mnt_fsname, "/dev/loop", 9) == 0)
                        res = loopdev_is_used((char *) mnt->m.mnt_fsname,
                                        loopfile, offset, LOOPDEV_FL_OFFSET);

                else if (mnt->m.mnt_opts &&
                         (p = strstr(mnt->m.mnt_opts, "loop=")))
                {
                        char *dev = xstrdup(p+5);
                        if ((p = strchr(dev, ',')))
                                *p = '\0';
                        res =  loopdev_is_used(dev,
                                        loopfile, offset, LOOPDEV_FL_OFFSET);
                        free(dev);
                }
        }

        free(node);
        return res;
}

static int
parse_offset(const char **opt, uintmax_t *val)
{
        char *tmp;

        if (strtosize(*opt, val))
                return -1;

        tmp = xmalloc(32);
        snprintf(tmp, 32, "%jd", *val);
        my_free(*opt);
        *opt = tmp;
        return 0;
}

static int
loop_check(const char **spec, const char **type, int *flags,
           int *loop, const char **loopdev, const char **loopfile,
           const char *node) {
  int looptype;
  uintmax_t offset = 0, sizelimit = 0;
  struct loopdev_cxt lc;
  char *pwd = NULL;
  int ret = EX_FAIL;

  /*
   * In the case of a loop mount, either type is of the form lo@/dev/loop5
   * or the option "-o loop=/dev/loop5" or just "-o loop" is given, or
   * mount just has to figure things out for itself from the fact that
   * spec is not a block device. We do not test for a block device
   * immediately: maybe later other types of mountable objects will occur.
   */

  *loopdev = opt_loopdev;

  looptype = (*type && strncmp("lo@", *type, 3) == 0);
  if (looptype) {
    if (*loopdev)
      error(_("mount: loop device specified twice"));
    *loopdev = *type + 3;
    *type = opt_vfstype;
  } else if (opt_vfstype) {
    if (*type)
      error(_("mount: type specified twice"));
    else
      *type = opt_vfstype;
  }

  *loop = ((*flags & MS_LOOP) || *loopdev || opt_offset || opt_sizelimit || opt_encryption);
  *loopfile = *spec;

  /* Automatically create a loop device from a regular file if a filesystem
   * is not specified or the filesystem is known for libblkid (these
   * filesystems work with block devices only).
   *
   * Note that there is not a restriction (on kernel side) that prevents regular
   * file as a mount(2) source argument. A filesystem that is able to mount
   * regular files could be implemented.
   */
  if (!*loop && !(*flags & (MS_BIND | MS_MOVE | MS_PROPAGATION)) &&
      (!*type || strcmp(*type, "auto") == 0 || fsprobe_known_fstype(*type))) {

    struct stat st;
    if (stat(*loopfile, &st) == 0)
      *loop = S_ISREG(st.st_mode);
  }

  if (*loop) {
    *flags |= MS_LOOP;
    if (fake) {
      if (verbose)
        printf(_("mount: skipping the setup of a loop device\n"));
    } else {
      int loop_opts = 0;

      /* since 2.6.37 we don't have to store backing filename to mtab
       * because kernel provides the name in /sys
       */
      if (get_linux_version() >= KERNEL_VERSION(2, 6, 37) ||
          mtab_is_writable() == 0) {

        if (verbose)
          printf(_("mount: enabling autoclear loopdev flag\n"));
        loop_opts = LO_FLAGS_AUTOCLEAR;
      }

      if (*flags & MS_RDONLY)
        loop_opts |= LO_FLAGS_READ_ONLY;

      if (opt_offset && parse_offset(&opt_offset, &offset)) {
        error(_("mount: invalid offset '%s' specified"), opt_offset);
        return EX_FAIL;
      }
      if (opt_sizelimit && parse_offset(&opt_sizelimit, &sizelimit)) {
        error(_("mount: invalid sizelimit '%s' specified"), opt_sizelimit);
        return EX_FAIL;
      }

      if (is_mounted_same_loopfile(node, *loopfile, offset)) {
        error(_("mount: according to mtab %s is already mounted on %s as loop"), *loopfile, node);
        return EX_FAIL;
      }

      if (opt_encryption) {
#ifdef MCL_FUTURE
        if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
          error(_("mount: couldn't lock into memory"));
          return EX_FAIL;
        }
#endif
        pwd = xgetpass(pfd, _("Password: "));
      }

      loopcxt_init(&lc, 0);
      /*loopcxt_enable_debug(&lc, 1);*/

      if (*loopdev && **loopdev)
        loopcxt_set_device(&lc, *loopdev);      /* use loop=<devname> */

      do {
        int rc;

        if ((!*loopdev || !**loopdev) && loopcxt_find_unused(&lc) == 0)
            *loopdev = loopcxt_strdup_device(&lc);

        if (!*loopdev) {
          error(_("mount: failed to found free loop device"));
          loopcxt_deinit(&lc);
          goto err;     /* no more loop devices */
        }
        if (verbose)
          printf(_("mount: going to use the loop device %s\n"), *loopdev);

        rc = loopcxt_set_backing_file(&lc, *loopfile);

        if (!rc && offset)
          rc = loopcxt_set_offset(&lc, offset);
        if (!rc && sizelimit)
          rc = loopcxt_set_sizelimit(&lc, sizelimit);
        if (!rc && opt_encryption && pwd)
          loopcxt_set_encryption(&lc, opt_encryption, pwd);
        if (!rc)
          loopcxt_set_flags(&lc, loop_opts);

        if (rc) {
           error(_("mount: %s: failed to set loopdev attributes"), *loopdev);
           loopcxt_deinit(&lc);
           goto err;
        }

        /* setup the device */
        rc = loopcxt_setup_device(&lc);
        if (!rc)
          break;        /* success */

        if (rc != -EBUSY) {
          error(_("mount: %s: failed setting up loop device: %m"), *loopfile);
          if (!opt_loopdev) {
            my_free(*loopdev);
            *loopdev = NULL;
          }
          loopcxt_deinit(&lc);
          goto err;
        }

        if (!opt_loopdev) {
          if (verbose)
            printf(_("mount: stolen loop=%s ...trying again\n"), *loopdev);
            my_free(*loopdev);
            *loopdev = NULL;
            continue;
        }
        error(_("mount: stolen loop=%s"), *loopdev);
        loopcxt_deinit(&lc);
        goto err;

      } while (!*loopdev);

      if (verbose > 1)
        printf(_("mount: setup loop device successfully\n"));
      *spec = *loopdev;

      if (loopcxt_is_readonly(&lc))
        *flags |= MS_RDONLY;

      if (loopcxt_is_autoclear(&lc))
        /* Prevent recording loop dev in mtab for cleanup on umount */
        *loop = 0;

      /* We have to keep the device open until mount(2), otherwise it will
       * be auto-cleared by kernel (because LO_FLAGS_AUTOCLEAR) */
      loopcxt_set_fd(&lc, -1, 0);
      loopcxt_deinit(&lc);
    }
  }

  ret = 0;
err:
  if (pwd) {
    char *p = pwd;
    while (*p)
      *p++ = '\0';
    free(pwd);
  }
  return ret;
}


static void
update_mtab_entry(const char *spec, const char *node, const char *type,
                  const char *opts, int flags, int freq, int pass) {
        struct my_mntent mnt;

        mnt.mnt_fsname = is_pseudo_fs(type) ? xstrdup(spec) : canonicalize(spec);
        mnt.mnt_dir = canonicalize (node);
        mnt.mnt_type = type;
        mnt.mnt_opts = opts;
        mnt.mnt_freq = freq;
        mnt.mnt_passno = pass;

        /* We get chatty now rather than after the update to mtab since the
           mount succeeded, even if the write to /etc/mtab should fail.  */
        if (verbose)
                print_one (&mnt);

        if (!nomtab && mtab_does_not_exist()) {
                if (verbose > 1)
                        printf(_("mount: no %s found - creating it..\n"),
                               _PATH_MOUNTED);
                create_mtab ();

        }

        if (!nomtab && mtab_is_writable()) {
                if (flags & MS_REMOUNT)
                        update_mtab (mnt.mnt_dir, &mnt);
                else if (flags & MS_MOVE)
                        update_mtab(mnt.mnt_fsname, &mnt);
                else
                        update_mtab(NULL, &mnt);
        }
        my_free(mnt.mnt_fsname);
        my_free(mnt.mnt_dir);
}

static void
set_pfd(char *s) {
        if (!isdigit(*s))
                die(EX_USAGE,
                    _("mount: argument to -p or --pass-fd must be a number"));
        pfd = atoi(optarg);
}

static void
cdrom_setspeed(const char *spec) {
#define CDROM_SELECT_SPEED      0x5322  /* Set the CD-ROM speed */
        if (opt_speed) {
                int cdrom;
                int speed = atoi(opt_speed);

                if ((cdrom = open(spec, O_RDONLY | O_NONBLOCK)) < 0)
                        die(EX_FAIL,
                            _("mount: cannot open %s for setting speed"),
                            spec);
                if (ioctl(cdrom, CDROM_SELECT_SPEED, speed) < 0)
                        die(EX_FAIL, _("mount: cannot set speed: %m"));
                close(cdrom);
        }
}

/*
 * Check if @path is on read-only filesystem independently on file permissions.
 */
static int
is_readonly(const char *path)
{
        if (access(path, W_OK) == 0)
                return 0;
        if (errno == EROFS)
                return 1;
        if (errno != EACCES)
                return 0;

#ifdef HAVE_FUTIMENS
        /*
         * access(2) returns EACCES on read-only FS:
         *
         * - for set-uid application if one component of the path is not
         *   accessible for the current rUID. (Note that euidaccess(2) does not
         *   check for EROFS at all).
         *
         * - for read-write filesystem with read-only VFS node (aka -o remount,ro,bind)
         */
        {
                struct timespec times[2];

                times[0].tv_nsec = UTIME_NOW;   /* atime */
                times[1].tv_nsec = UTIME_OMIT;  /* mtime */

                if (utimensat(AT_FDCWD, path, times, 0) == -1)
                        return errno == EROFS;
        }
#endif
        return 0;
}

/*
 * try_mount_one()
 *      Try to mount one file system.
 *
 * returns: 0: OK, EX_SYSERR, EX_FAIL, return code from nfsmount,
 *      return status from wait
 */
static int
try_mount_one (const char *spec0, const char *node0, const char *types0,
               const char *opts0, int freq, int pass, int ro) {
  int res = 0, status = 0, special = 0;
  int mnt5_res = 0;             /* only for gcc */
  int mnt_err;
  int flags;
  char *extra_opts;             /* written in mtab */
  char *mount_opts;             /* actually used on system call */
  const char *opts, *spec, *node, *types;
  char *user = 0;
  int loop = 0;
  const char *loopdev = 0, *loopfile = 0;
  struct stat statbuf;

  /* copies for freeing on exit */
  const char *opts1, *spec1, *node1, *types1;

  if (verbose > 2) {
          printf("mount: spec:  \"%s\"\n", spec0);
          printf("mount: node:  \"%s\"\n", node0);
          printf("mount: types: \"%s\"\n", types0);
          printf("mount: opts:  \"%s\"\n", opts0);
  }

  spec = spec1 = xstrdup(spec0);
  node = node1 = xstrdup(node0);
  types = types1 = xstrdup(types0);
  opts = opts1 = xstrdup(opts0);

  parse_opts (opts, &flags, &extra_opts);
  mount_opts = xstrdup(extra_opts);

  /* quietly succeed for fstab entries that don't get mounted automatically */
  if (mount_all && (flags & MS_NOAUTO))
      goto out;

  restricted_check(spec, node, &flags, &user);

  /* The "mount -f" checks for for existing record in /etc/mtab (with
   * regular non-fake mount this is usually done by kernel)
   */
  if (!(flags & MS_REMOUNT) && fake && mounted (spec, node, NULL))
      die(EX_USAGE, _("mount: according to mtab, "
                      "%s is already mounted on %s\n"),
                      spec, node);

  if (opt_speed)
      cdrom_setspeed(spec);

  if (!(flags & MS_REMOUNT)) {
      /*
       * Don't set up a (new) loop device if we only remount - this left
       * stale assignments of files to loop devices. Nasty when used for
       * encryption.
       */
      res = loop_check(&spec, &types, &flags, &loop, &loopdev, &loopfile, node);
      if (res)
          goto out;
  }

  if (loop)
      opt_loopdev = loopdev;

  if (flags & (MS_BIND | MS_MOVE | MS_PROPAGATION))
      types = "none";

#ifdef HAVE_LIBSELINUX
  if (flags & MS_REMOUNT) {
      /*
       * Linux kernel does not accept any selinux context option on remount
       */
      if (mount_opts) {
          char *tmp = mount_opts;
          mount_opts = remove_context_options(mount_opts);
          my_free(tmp);
      }

  } else if (types && strcmp(types, "tmpfs") == 0 && is_selinux_enabled() > 0 &&
           !has_context_option(mount_opts)) {
      /*
       * Add rootcontext= mount option for tmpfs
       * https://bugzilla.redhat.com/show_bug.cgi?id=476964
       */
      security_context_t sc = NULL;

      if (getfilecon(node, &sc) > 0 && strcmp("unlabeled", sc))
              append_context("rootcontext=", (char *) sc, &mount_opts);
      freecon(sc);
  }
#endif

  /*
   * Call mount.TYPE for types that require a separate mount program.
   * For the moment these types are ncpfs and smbfs. Maybe also vxfs.
   * All such special things must occur isolated in the types string.
   */
  if (check_special_mountprog(spec, node, types, flags, mount_opts, &status)) {
      res = status;
      goto out;
  }

  block_signals (SIG_BLOCK);

  if (!fake) {
    mnt5_res = guess_fstype_and_mount (spec, node, &types, flags & ~MS_NOSYS,
                                       mount_opts, &special, &status);

    if (special) {
      block_signals (SIG_UNBLOCK);
      res = status;
      goto out;
    }
  }

  /* Kernel allows to use MS_RDONLY for bind mounts, but the read-only request
   * could be silently ignored. Check it to avoid 'ro' in mtab and 'rw' in
   * /proc/mounts.
   */
  if (!fake && mnt5_res == 0 &&
      (flags & MS_BIND) && (flags & MS_RDONLY) && !is_readonly(node)) {

      printf(_("mount: warning: %s seems to be mounted read-write.\n"), node);
      flags &= ~MS_RDONLY;
  }

  /* Kernel can silently add MS_RDONLY flag when mounting file system that
   * does not have write support. Check this to avoid 'ro' in /proc/mounts
   * and 'rw' in mtab.
   */
  if (!fake && mnt5_res == 0 &&
      !(flags & (MS_RDONLY | MS_PROPAGATION | MS_MOVE)) &&
      is_readonly(node)) {

      printf(_("mount: warning: %s seems to be mounted read-only.\n"), node);
      flags |= MS_RDONLY;
  }

  if (fake || mnt5_res == 0) {
      char *mo = fix_opts_string (flags & ~MS_NOMTAB, extra_opts, user, 0);
      const char *tp = types ? types : "unknown";

      /* Mount succeeded, report this (if verbose) and write mtab entry.  */
      if (!(mounttype & MS_PROPAGATION))
              update_mtab_entry(loop ? loopfile : spec,
                        node,
                        tp,
                        mo,
                        flags,
                        freq,
                        pass);

      block_signals (SIG_UNBLOCK);
      free(mo);

      res = 0;
      goto out;
  }

  mnt_err = errno;

  if (loop)
        loopdev_delete(spec);

  block_signals (SIG_UNBLOCK);

  /* Mount failed, complain, but don't die.  */

  if (types == 0) {
    if (restricted)
      error (_("mount: I could not determine the filesystem type, "
               "and none was specified"));
    else
      error (_("mount: you must specify the filesystem type"));
  } else if (mnt5_res != -1) {
      /* should not happen */
      error (_("mount: mount failed"));
  } else {
   switch (mnt_err) {
    case EPERM:
      if (geteuid() == 0) {
           if (stat (node, &statbuf) || !S_ISDIR(statbuf.st_mode))
                error (_("mount: mount point %s is not a directory"), node);
           else
                error (_("mount: permission denied"));
      } else
        error (_("mount: must be superuser to use mount"));
      break;
    case EBUSY:
      if (flags & MS_REMOUNT) {
        error (_("mount: %s is busy"), node);
      } else if (!strcmp(types, "proc") && !strcmp(node, "/proc")) {
        /* heuristic: if /proc/version exists, then probably proc is mounted */
        if (stat ("/proc/version", &statbuf))   /* proc mounted? */
           error (_("mount: %s is busy"), node);   /* no */
        else if (!mount_all || verbose)            /* yes, don't mention it */
           error (_("mount: proc already mounted"));
      } else {
        error (_("mount: %s already mounted or %s busy"), spec, node);
        already (spec, node);
      }
      break;
    case ENOENT:
      if (lstat (node, &statbuf))
           error (_("mount: mount point %s does not exist"), node);
      else if (stat (node, &statbuf))
           error (_("mount: mount point %s is a symbolic link to nowhere"),
                  node);
      else if (stat (spec, &statbuf)) {
           if (opt_nofail)
                goto out;
           error (_("mount: special device %s does not exist"), spec);
      } else {
           errno = mnt_err;
           perror("mount");
      }
      break;
    case ENOTDIR:
      if (stat (node, &statbuf) || ! S_ISDIR(statbuf.st_mode))
           error (_("mount: mount point %s is not a directory"), node);
      else if (stat (spec, &statbuf) && errno == ENOTDIR) {
           if (opt_nofail)
              goto out;
           error (_("mount: special device %s does not exist\n"
                    "       (a path prefix is not a directory)\n"), spec);
      } else {
           errno = mnt_err;
           perror("mount");
      }
      break;
    case EINVAL:
    { int fd;
      unsigned long long size = 0;

      if (flags & MS_REMOUNT) {
        error (_("mount: %s not mounted or bad option"), node);
      } else {
        error (_("mount: wrong fs type, bad option, bad superblock on %s,\n"
               "       missing codepage or helper program, or other error"),
               spec);

        if (stat(spec, &statbuf) < 0) {
          if (errno == ENOENT)         /* network FS? */
            error(_(
               "       (for several filesystems (e.g. nfs, cifs) you might\n"
               "       need a /sbin/mount.<type> helper program)"));

        } else if (S_ISBLK(statbuf.st_mode)
                         && (fd = open(spec, O_RDONLY | O_NONBLOCK)) >= 0) {

          if (blkdev_get_size(fd, &size) == 0) {
            if (size == 0 && !loop)
              error(_(
                 "       (could this be the IDE device where you in fact use\n"
                 "       ide-scsi so that sr0 or sda or so is needed?)"));

            if (size && size <= 2)
              error(_(
                  "       (aren't you trying to mount an extended partition,\n"
                  "       instead of some logical partition inside?)"));

            close(fd);
          }
        }
        error(_(
                "       In some cases useful info is found in syslog - try\n"
                "       dmesg | tail  or so\n"));
      }
      break;
    }
    case EMFILE:
      error (_("mount table full")); break;
    case EIO:
      error (_("mount: %s: can't read superblock"), spec); break;
    case ENODEV:
    {
      int pfs = known_fstype_in_procfs(types);

      if (pfs == 1 || !strcmp(types, "guess"))
        error(_("mount: %s: unknown device"), spec);
      else if (pfs == 0) {
        char *lowtype, *p;
        int u;

        error (_("mount: unknown filesystem type '%s'"), types);

        /* maybe this loser asked for FAT or ISO9660 or isofs */
        lowtype = xstrdup(types);
        u = 0;
        for(p=lowtype; *p; p++) {
          if(tolower(*p) != *p) {
            *p = tolower(*p);
            u++;
          }
        }
        if (u && known_fstype_in_procfs(lowtype) == 1)
          error (_("mount: probably you meant %s"), lowtype);
        else if (!strncmp(lowtype, "iso", 3) &&
                        known_fstype_in_procfs("iso9660") == 1)
          error (_("mount: maybe you meant 'iso9660'?"));
        else if (!strncmp(lowtype, "fat", 3) &&
                        known_fstype_in_procfs("vfat") == 1)
          error (_("mount: maybe you meant 'vfat'?"));
        free(lowtype);
      } else
        error (_("mount: %s has wrong device number or fs type %s not supported"),
               spec, types);
      break;
    }
    case ENOTBLK:
      if (opt_nofail)
        goto out;
      if (stat (spec, &statbuf)) /* strange ... */
        error (_("mount: %s is not a block device, and stat fails?"), spec);
      else if (S_ISBLK(statbuf.st_mode))
        error (_("mount: the kernel does not recognize %s as a block device\n"
               "       (maybe `modprobe driver'?)"), spec);
      else if (S_ISREG(statbuf.st_mode))
        error (_("mount: %s is not a block device (maybe try `-o loop'?)"),
                 spec);
      else
        error (_("mount: %s is not a block device"), spec);
      break;
    case ENXIO:
      if (opt_nofail)
        goto out;
      error (_("mount: %s is not a valid block device"), spec); break;
    case EACCES:  /* pre-linux 1.1.38, 1.1.41 and later */
    case EROFS:   /* linux 1.1.38 and later */
    { char *bd = (loop ? "" : _("block device "));
      if (ro || (flags & MS_RDONLY)) {
          error (_("mount: cannot mount %s%s read-only"),
                 bd, spec);
          break;
      } else if (readwrite) {
          error (_("mount: %s%s is write-protected but explicit `-w' flag given"),
                 bd, spec);
          break;
      } else if (flags & MS_REMOUNT) {
          error (_("mount: cannot remount %s%s read-write, is write-protected"),
                 bd, spec);
          break;
      } else {
         opts = opts0;
         types = types0;

         if (opts) {
             char *opts2 = append_opt(xstrdup(opts), "ro", NULL);
             my_free(opts1);
             opts = opts1 = opts2;
         } else
             opts = "ro";
         if (types && !strcmp(types, "guess"))
             types = 0;
         error (_("mount: %s%s is write-protected, mounting read-only"),
                bd, spec0);
         res = try_mount_one (spec0, node0, types, opts, freq, pass, 1);
         goto out;
      }
      break;
    }
    case ENOMEDIUM:
      error(_("mount: no medium found on %s"), spec);
      break;
    default:
      error ("mount: %s", strerror (mnt_err)); break;
    }
  }
  res = EX_FAIL;

 out:

#if defined(HAVE_LIBSELINUX) && defined(HAVE_SECURITY_GET_INITIAL_CONTEXT)
  if (res != EX_FAIL && verbose && is_selinux_enabled() > 0) {
      security_context_t raw = NULL, def = NULL;

      if (getfilecon(node, &raw) > 0 &&
                     security_get_initial_context("file", &def) == 0) {

          if (!selinux_file_context_cmp(raw, def))
              printf(_("mount: %s does not contain SELinux labels.\n"
                   "       You just mounted an file system that supports labels which does not\n"
                   "       contain labels, onto an SELinux box. It is likely that confined\n"
                   "       applications will generate AVC messages and not be allowed access to\n"
                   "       this file system.  For more details see restorecon(8) and mount(8).\n"),
                   node);
      }
      freecon(raw);
      freecon(def);
  }
#endif

  my_free(mount_opts);
  my_free(extra_opts);
  my_free(spec1);
  my_free(node1);
  my_free(opts1);
  my_free(types1);

  return res;
}

static char *
subst_string(const char *s, const char *sub, int sublen, const char *repl) {
        char *n;

        n = (char *) xmalloc(strlen(s)-sublen+strlen(repl)+1);
        strncpy (n, s, sub-s);
        strcpy (n + (sub-s), repl);
        strcat (n, sub+sublen);
        return n;
}

static char *
usersubst(const char *opts) {
        char *s, *w;
        char id[40];

        if (!opts)
                return NULL;

        s = "uid=useruid";
        if (opts && (w = strstr(opts, s)) != NULL) {
                sprintf(id, "uid=%u", getuid());
                opts = subst_string(opts, w, strlen(s), id);
        }
        s = "gid=usergid";
        if (opts && (w = strstr(opts, s)) != NULL) {
                sprintf(id, "gid=%u", getgid());
                opts = subst_string(opts, w, strlen(s), id);
        }
        return xstrdup(opts);
}

static int
is_existing_file (const char *s) {
        struct stat statbuf;

        return (stat(s, &statbuf) == 0);
}

/*
 * Return 0 for success (either mounted sth or -a and NOAUTO was given)
 */
static int
mount_one (const char *spec, const char *node, const char *types,
           const char *fstabopts, char *cmdlineopts, int freq, int pass) {
        const char *nspec = NULL;
        char *opts;

        /* Substitute values in opts, if required */
        opts = usersubst(fstabopts);

        /* Merge the fstab and command line options.  */
        opts = append_opt(opts, cmdlineopts, NULL);

        if (types == NULL && !mounttype && !is_existing_file(spec)) {
                if (strchr (spec, ':') != NULL) {
                        types = "nfs";
                        if (verbose)
                                printf(_("mount: no type was given - "
                                         "I'll assume nfs because of "
                                         "the colon\n"));
                } else if(!strncmp(spec, "//", 2)) {
                        types = "cifs";
                        if (verbose)
                                printf(_("mount: no type was given - "
                                         "I'll assume cifs because of "
                                         "the // prefix\n"));
                }
        }

        /* Handle possible LABEL= and UUID= forms of spec */
        if (types == NULL || (strncmp(types, "9p", 2) &&
                              strncmp(types, "nfs", 3) &&
                              strncmp(types, "cifs", 4) &&
                              strncmp(types, "smbfs", 5))) {
                if (!is_pseudo_fs(types))
                        nspec = spec_to_devname(spec);
                if (nspec)
                        spec = nspec;
        }

        return try_mount_one (spec, node, types, opts, freq, pass, 0);
}

static int
mounted (const char *spec0, const char *node0,
         struct mntentchn *fstab_mc __attribute__((__unused__))) {

        struct mntentchn *mc, *mc0;
        const char *spec, *node;
        int ret = 0;

        /* Handle possible UUID= and LABEL= in spec */
        spec = spec_to_devname(spec0);
        if (!spec)
                return ret;

        node = canonicalize(node0);


        mc0 = mtab_head();
        for (mc = mc0->nxt; mc && mc != mc0; mc = mc->nxt)
                if (streq (spec, mc->m.mnt_fsname) &&
                    streq (node, mc->m.mnt_dir)) {
                        ret = 1;
                        break;
                }

        my_free(spec);
        my_free(node);

        return ret;
}

/* returns 0 if not mounted, 1 if mounted and -1 in case of error */
static int
is_fstab_entry_mounted(struct mntentchn *mc, int verbose)
{
        struct stat st;

        if (mounted(mc->m.mnt_fsname, mc->m.mnt_dir, mc))
                goto yes;

        /* extra care for loop devices */
        if ((mc->m.mnt_opts && strstr(mc->m.mnt_opts, "loop=")) ||
            (stat(mc->m.mnt_fsname, &st) == 0 && S_ISREG(st.st_mode))) {

                char *p = get_option_value(mc->m.mnt_opts, "offset=");
                uintmax_t offset = 0;

                if (p && strtosize(p, &offset) != 0) {
                        if (verbose)
                                printf(_("mount: ignore %s "
                                        "(unparsable offset= option)\n"),
                                        mc->m.mnt_fsname);
                        return -1;
                }
                free(p);
                if (is_mounted_same_loopfile(mc->m.mnt_dir, mc->m.mnt_fsname, offset))
                        goto yes;
        }

        return 0;
yes:
        if (verbose)
                printf(_("mount: %s already mounted on %s\n"),
                               mc->m.mnt_fsname, mc->m.mnt_dir);
        return 1;
}

/* avoid using stat() on things we are not going to mount anyway.. */
static int
has_noauto (const char *opts) {
        char *s;

        if (!opts)
                return 0;
        s = strstr(opts, "noauto");
        if (!s)
                return 0;
        return (s == opts || s[-1] == ',') && (s[6] == 0 || s[6] == ',');
}

/* Mount all filesystems of the specified types except swap and root.  */
/* With the --fork option: fork and let different incarnations of
   mount handle different filesystems.  However, try to avoid several
   simultaneous mounts on the same physical disk, since that is very slow. */
#define DISKMAJOR(m)    (((int) m) & ~0xf)

static int
do_mount_all (char *types, char *options, char *test_opts) {
        struct mntentchn *mc, *mc0, *mtmp;
        int status = 0;
        struct stat statbuf;
        struct child {
                pid_t pid;
                char *group;
                struct mntentchn *mec;
                struct mntentchn *meclast;
                struct child *nxt;
        } childhead, *childtail, *cp;
        char major[22];
        char *g, *colon;

        /* build a chain of what we have to do, or maybe
           several chains, one for each major or NFS host */
        childhead.nxt = 0;
        childtail = &childhead;
        mc0 = fstab_head();
        for (mc = mc0->nxt; mc && mc != mc0; mc = mc->nxt) {
                if (has_noauto (mc->m.mnt_opts))
                        continue;
                if (matching_type (mc->m.mnt_type, types)
                    && matching_opts (mc->m.mnt_opts, test_opts)
                    && !streq (mc->m.mnt_dir, "/")
                    && !streq (mc->m.mnt_dir, "root")
                    && !is_fstab_entry_mounted(mc, verbose)) {

                        mtmp = (struct mntentchn *) xmalloc(sizeof(*mtmp));
                        *mtmp = *mc;
                        mtmp->nxt = 0;
                        g = NULL;
                        if (optfork) {
                                if (stat(mc->m.mnt_fsname, &statbuf) == 0 &&
                                    S_ISBLK(statbuf.st_mode)) {
                                        sprintf(major, "#%x",
                                                DISKMAJOR(statbuf.st_rdev));
                                        g = major;
                                }
                                if (strcmp(mc->m.mnt_type, "nfs") == 0) {
                                        g = xstrdup(mc->m.mnt_fsname);
                                        colon = strchr(g, ':');
                                        if (colon)
                                                *colon = '\0';
                                }
                        }
                        if (g) {
                                for (cp = childhead.nxt; cp; cp = cp->nxt)
                                        if (cp->group &&
                                            strcmp(cp->group, g) == 0) {
                                                cp->meclast->nxt = mtmp;
                                                cp->meclast = mtmp;
                                                goto fnd;
                                        }
                        }
                        cp = (struct child *) xmalloc(sizeof *cp);
                        cp->nxt = 0;
                        cp->mec = cp->meclast = mtmp;
                        cp->group = xstrdup(g);
                        cp->pid = 0;
                        childtail->nxt = cp;
                        childtail = cp;
                fnd:;

                }
        }

        /* now do everything */
        for (cp = childhead.nxt; cp; cp = cp->nxt) {
                pid_t p = -1;
                if (optfork) {
                        p = fork();
                        if (p == -1) {
                                int errsv = errno;
                                error(_("mount: cannot fork: %s"),
                                      strerror (errsv));
                        }
                        else if (p != 0)
                                cp->pid = p;
                }

                /* if child, or not forked, do the mounting */
                if (p == 0 || p == -1) {
                        for (mc = cp->mec; mc; mc = mc->nxt) {
                                status |= mount_one (mc->m.mnt_fsname,
                                                     mc->m.mnt_dir,
                                                     mc->m.mnt_type,
                                                     mc->m.mnt_opts,
                                                     options, 0, 0);
                        }
                        if (mountcount)
                                status |= EX_SOMEOK;
                        if (p == 0)
                                exit(status);
                }
        }

        /* wait for children, if any */
        while ((cp = childhead.nxt) != NULL) {
                childhead.nxt = cp->nxt;
                if (cp->pid) {
                        int ret;
                keep_waiting:
                        if(waitpid(cp->pid, &ret, 0) == -1) {
                                if (errno == EINTR)
                                        goto keep_waiting;
                                perror("waitpid");
                        } else if (WIFEXITED(ret))
                                status |= WEXITSTATUS(ret);
                        else
                                status |= EX_SYSERR;
                }
        }
        if (mountcount)
                status |= EX_SOMEOK;
        return status;
}

static struct option longopts[] = {
        { "all", 0, 0, 'a' },
        { "fake", 0, 0, 'f' },
        { "fork", 0, 0, 'F' },
        { "help", 0, 0, 'h' },
        { "no-mtab", 0, 0, 'n' },
        { "read-only", 0, 0, 'r' },
        { "ro", 0, 0, 'r' },
        { "verbose", 0, 0, 'v' },
        { "version", 0, 0, 'V' },
        { "read-write", 0, 0, 'w' },
        { "rw", 0, 0, 'w' },
        { "options", 1, 0, 'o' },
        { "test-opts", 1, 0, 'O' },
        { "pass-fd", 1, 0, 'p' },
        { "types", 1, 0, 't' },
        { "bind", 0, 0, 'B' },
        { "move", 0, 0, 'M' },
        { "guess-fstype", 1, 0, 134 },
        { "rbind", 0, 0, 'R' },
        { "make-shared", 0, 0, 136 },
        { "make-slave", 0, 0, 137 },
        { "make-private", 0, 0, 138 },
        { "make-unbindable", 0, 0, 139 },
        { "make-rshared", 0, 0, 140 },
        { "make-rslave", 0, 0, 141 },
        { "make-rprivate", 0, 0, 142 },
        { "make-runbindable", 0, 0, 143 },
        { "no-canonicalize", 0, 0, 144 },
        { "internal-only", 0, 0, 'i' },
        { NULL, 0, 0, 0 }
};

/* Keep the usage message at max 22 lines, each at most 70 chars long.
   The user should not need a pager to read it. */
static void
usage (FILE *fp, int n) {
        fprintf(fp, _(
          "Usage: mount -V                 : print version\n"
          "       mount -h                 : print this help\n"
          "       mount                    : list mounted filesystems\n"
          "       mount -l                 : idem, including volume labels\n"
          "So far the informational part. Next the mounting.\n"
          "The command is `mount [-t fstype] something somewhere'.\n"
          "Details found in /etc/fstab may be omitted.\n"
          "       mount -a [-t|-O] ...     : mount all stuff from /etc/fstab\n"
          "       mount device             : mount device at the known place\n"
          "       mount directory          : mount known device here\n"
          "       mount -t type dev dir    : ordinary mount command\n"
          "Note that one does not really mount a device, one mounts\n"
          "a filesystem (of the given type) found on the device.\n"
          "One can also mount an already visible directory tree elsewhere:\n"
          "       mount --bind olddir newdir\n"
          "or move a subtree:\n"
          "       mount --move olddir newdir\n"
          "One can change the type of mount containing the directory dir:\n"
          "       mount --make-shared dir\n"
          "       mount --make-slave dir\n"
          "       mount --make-private dir\n"
          "       mount --make-unbindable dir\n"
          "One can change the type of all the mounts in a mount subtree\n"
          "containing the directory dir:\n"
          "       mount --make-rshared dir\n"
          "       mount --make-rslave dir\n"
          "       mount --make-rprivate dir\n"
          "       mount --make-runbindable dir\n"
          "A device can be given by name, say /dev/hda1 or /dev/cdrom,\n"
          "or by label, using  -L label  or by uuid, using  -U uuid .\n"
          "Other options: [-nfFrsvw] [-o options] [-p passwdfd].\n"
          "For many more details, say  man 8 mount .\n"
        ));

        unlock_mtab();
        exit (n);
}

/* returns mount entry from fstab */
static struct mntentchn *
getfs(const char *spec, const char *uuid, const char *label)
{
        struct mntentchn *mc = NULL;
        const char *devname = NULL;

        if (!spec && !uuid && !label)
                return NULL;

        /*
         * A) 99% of all cases, the spec on cmdline matches
         *    with spec in fstab
         */
        if (uuid)
                mc = getfs_by_uuid(uuid);
        else if (label)
                mc = getfs_by_label(label);
        else {
                mc = getfs_by_dir(spec);

                if (!mc)
                        mc = getfs_by_spec(spec);
        }
        if (mc)
                return mc;

        /*
         * B) UUID or LABEL on cmdline, but devname in fstab
         */
        if (uuid)
                devname = fsprobe_get_devname_by_uuid(uuid);
        else if (label)
                devname = fsprobe_get_devname_by_label(label);
        else
                devname = spec_to_devname(spec);

        if (devname)
                mc = getfs_by_devname(devname);

        /*
         * C) mixed
         */
        if (!mc && devname) {
                const char *id = NULL;

                if (!label && (!spec || strncmp(spec, "LABEL=", 6))) {
                        id = fsprobe_get_label_by_devname(devname);
                        if (id)
                                mc = getfs_by_label(id);
                }
                if (!mc && !uuid && (!spec || strncmp(spec, "UUID=", 5))) {
                        id = fsprobe_get_uuid_by_devname(devname);
                        if (id)
                                mc = getfs_by_uuid(id);
                }
                my_free(id);

                if (mc) {
                        /* use real device name to avoid repetitional
                         * conversion from LABEL/UUID to devname
                         */
                        my_free(mc->m.mnt_fsname);
                        mc->m.mnt_fsname = xstrdup(devname);
                }
        }

        /*
         * D) remount -- try /etc/mtab
         *    Earlier mtab was tried first, but this would sometimes try the
         *    wrong mount in case mtab had the root device entry wrong.  Try
         *    the last occurrence first, since that is the visible mount.
         */
        if (!mc && (devname || spec))
                mc = getmntfilebackward (devname ? devname : spec, NULL);

        my_free(devname);
        return mc;
}


static void
print_version(int rc) {
        printf( "mount from %s (with "
#ifdef HAVE_LIBBLKID
                "libblkid"
#else
                "libvolume_id"
#endif
#ifdef HAVE_LIBSELINUX
                " and selinux"
#endif
                " support)\n", PACKAGE_STRING);
        exit(rc);
}

int
main(int argc, char *argv[]) {
        int c, result = 0, specseen;
        char *options = NULL, *test_opts = NULL, *node;
        const char *spec = NULL;
        char *label = NULL;
        char *uuid = NULL;
        char *types = NULL;
        char *p;
        struct mntentchn *mc;
        int fd;

        sanitize_env();
        setlocale(LC_ALL, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
        atexit(close_stdout);

        progname = argv[0];
        if ((p = strrchr(progname, '/')) != NULL)
                progname = p+1;

        umask(022);

        /* People report that a mount called from init without console
           writes error messages to /etc/mtab
           Let us try to avoid getting fd's 0,1,2 */
        while((fd = open("/dev/null", O_RDWR)) == 0 || fd == 1 || fd == 2) ;
        if (fd > 2)
                close(fd);

        fsprobe_init();

#ifdef DO_PS_FIDDLING
        initproctitle(argc, argv);
#endif

        while ((c = getopt_long (argc, argv, "aBfFhilL:Mno:O:p:rRsU:vVwt:",
                                 longopts, NULL)) != -1) {
                switch (c) {
                case 'a':              /* mount everything in fstab */
                        ++mount_all;
                        break;
                case 'B': /* bind */
                        mounttype = MS_BIND;
                        break;
                case 'f':              /* fake: don't actually call mount(2) */
                        ++fake;
                        break;
                case 'F':
                        ++optfork;
                        break;
                case 'h':               /* help */
                        usage (stdout, 0);
                        break;
                case 'i':
                        external_allowed = 0;
                        break;
                case 'l':
                        list_with_volumelabel = 1;
                        break;
                case 'L':
                        label = optarg;
                        break;
                case 'M': /* move */
                        mounttype = MS_MOVE;
                        break;
                case 'n':               /* do not write /etc/mtab */
                        ++nomtab;
                        break;
                case 'o':               /* specify mount options */
                        options = append_opt(options, optarg, NULL);
                        break;
                case 'O':               /* with -t: mount only if (not) opt */
                        test_opts = append_opt(test_opts, optarg, NULL);
                        break;
                case 'p':               /* fd on which to read passwd */
                        set_pfd(optarg);
                        break;
                case 'r':               /* mount readonly */
                        readonly = 1;
                        readwrite = 0;
                        break;
                case 'R': /* rbind */
                        mounttype = (MS_BIND | MS_REC);
                        break;
                case 's':               /* allow sloppy mount options */
                        sloppy = 1;
                        break;
                case 't':               /* specify file system types */
                        types = optarg;
                        break;
                case 'U':
                        uuid = optarg;
                        break;
                case 'v':               /* be chatty - more so if repeated */
                        ++verbose;
                        break;
                case 'V':               /* version */
                        print_version(EXIT_SUCCESS);
                        break;
                case 'w':               /* mount read/write */
                        readwrite = 1;
                        readonly = 0;
                        break;
                case 0:
                        break;

                case 134:
                        /* undocumented, may go away again:
                           call: mount --guess-fstype device
                           use only for testing purposes -
                           the guessing is not reliable at all */
                    {
                        const char *fstype;
                        fstype = fsprobe_get_fstype_by_devname(optarg);
                        printf("%s\n", fstype ? fstype : "unknown");
                        exit(fstype ? 0 : EX_FAIL);
                    }

                case 136:
                        mounttype = MS_SHARED;
                        break;

                case 137:
                        mounttype = MS_SLAVE;
                        break;

                case 138:
                        mounttype = MS_PRIVATE;
                        break;

                case 139:
                        mounttype = MS_UNBINDABLE;
                        break;

                case 140:
                        mounttype = (MS_SHARED | MS_REC);
                        break;

                case 141:
                        mounttype = (MS_SLAVE | MS_REC);
                        break;

                case 142:
                        mounttype = (MS_PRIVATE | MS_REC);
                        break;

                case 143:
                        mounttype = (MS_UNBINDABLE | MS_REC);
                        break;
                case 144:
                        nocanonicalize = 1;
                        break;
                case '?':
                default:
                        usage (stderr, EX_USAGE);
                }
        }

        if (verbose > 2) {
                printf("mount: fstab path: \"%s\"\n", _PATH_MNTTAB);
                printf("mount: mtab path:  \"%s\"\n", _PATH_MOUNTED);
                printf("mount: lock path:  \"%s\"\n", _PATH_MOUNTED_LOCK);
                printf("mount: temp path:  \"%s\"\n", _PATH_MOUNTED_TMP);
                printf("mount: UID:        %u\n", getuid());
                printf("mount: eUID:       %u\n", geteuid());
        }

        argc -= optind;
        argv += optind;

        specseen = (uuid || label) ? 1 : 0;     /* yes, .. i know */

        if (argc+specseen == 0 && !mount_all) {
                if (options || mounttype)
                        usage (stderr, EX_USAGE);
                return print_all (types);
        }

        {
                const uid_t ruid = getuid();
                const uid_t euid = geteuid();

                /* if we're really root and aren't running setuid */
                if (((uid_t)0 == ruid) && (ruid == euid)) {
                        restricted = 0;
                }

                if (restricted &&
                    (types || options || readwrite || nomtab || mount_all ||
                     nocanonicalize || fake || mounttype ||
                     (argc + specseen) != 1)) {

                        if (ruid == 0 && euid != 0)
                                /* user is root, but setuid to non-root */
                                die (EX_USAGE, _("mount: only root can do that "
                                        "(effective UID is %u)"), euid);

                        die (EX_USAGE, _("mount: only root can do that"));
                }
        }

        atexit(unlock_mtab);

        switch (argc+specseen) {
        case 0:
                /* mount -a */
                result = do_mount_all (types, options, test_opts);
                if (result == 0 && verbose && !fake)
                        error(_("nothing was mounted"));
                break;

        case 1:
                /* mount [-nfrvw] [-o options] special | node
                 * mount -L label  (or -U uuid)
                 * (/etc/fstab is necessary)
                 */
                if (types != NULL)
                        usage (stderr, EX_USAGE);

                if (uuid || label)
                        mc = getfs(NULL, uuid, label);
                else
                        mc = getfs(*argv, NULL, NULL);

                if (!mc) {
                        if (uuid || label)
                                die (EX_USAGE, _("mount: no such partition found"));

                        die (EX_USAGE,
                             _("mount: can't find %s in %s or %s"),
                             *argv, _PATH_MNTTAB, _PATH_MOUNTED);
                }

                result = mount_one (xstrdup (mc->m.mnt_fsname),
                                    xstrdup (mc->m.mnt_dir),
                                    xstrdup (mc->m.mnt_type),
                                    mc->m.mnt_opts, options, 0, 0);
                break;

        case 2:
                /* mount special node  (/etc/fstab is not necessary) */
                if (specseen) {
                        /* mount -L label node   (or -U uuid) */
                        spec = uuid ?   fsprobe_get_devname_by_uuid(uuid) :
                                        fsprobe_get_devname_by_label(label);
                        node = argv[0];
                } else {
                        /* mount special node */
                        spec = argv[0];
                        node = argv[1];
                }
                if (!spec)
                        die (EX_USAGE, _("mount: no such partition found"));

                result = mount_one (spec, node, types, NULL, options, 0, 0);
                break;

        default:
                usage (stderr, EX_USAGE);
        }

        if (result == EX_SOMEOK)
                result = 0;

        fsprobe_exit();

        exit (result);
}