Try to make a "type-punned pointer" warning go away for somebody on the
[oweals/busybox.git] / util-linux / mount.c
index 562b7e8218b680896c96ec29f47fe19c6bb6a4cf..f665a08758e2377809a04ba726448bba79c777f2 100644 (file)
+/* vi: set sw=4 ts=4: */
 /*
  * Mini mount implementation for busybox
  *
  * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 2005-2006 by Rob Landley <rob@landley.net>
  *
- * 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 2 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * 3/21/1999   Charles P. Wright <cpwright@cpwright.com>
- *             searches through fstab when -a is passed
- *             will try mounting stuff with all fses when passed -t auto
- *
- * 1999-04-17  Dave Cinege...Rewrote -t auto. Fixed ro mtab.
- *
- * 1999-10-07  Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
- *              Rewrote of a lot of code. Removed mtab usage (I plan on
- *              putting it back as a compile-time option some time), 
- *              major adjustments to option parsing, and some serious 
- *              dieting all around.
+ * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ */
+
+/* todo:
+ * bb_getopt_ulflags();
+ */
+
+/* Design notes: There is no spec for mount.  Remind me to write one.
+
+   mount_main() calls singlemount() which calls mount_it_now().
+
+   mount_main() can loop through /etc/fstab for mount -a
+   singlemount() can loop through /etc/filesystems for fstype detection.
+   mount_it_now() does the actual mount.
 */
 
-#include "internal.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <errno.h>
-#include <string.h>
-#include <stdio.h>
+#include "busybox.h"
 #include <mntent.h>
-#include <sys/mount.h>
-#include <ctype.h>
-#include <fstab.h>
-
-static const char mount_usage[] = "Usage:\tmount [flags]\n"
-    "\tmount [flags] device directory [-o options,more-options]\n"
-    "\n"
-    "Flags:\n"
-    "\t-a:\tMount all file systems in fstab.\n"
-    "\t-o option:\tOne of many filesystem options, listed below.\n"
-    "\t-r:\tMount the filesystem read-only.\n"
-    "\t-t filesystem-type:\tSpecify the filesystem type.\n"
-    "\t-w:\tMount for reading and writing (default).\n"
-    "\n"
-    "Options for use with the \"-o\" flag:\n"
-    "\tasync / sync:\tWrites are asynchronous / synchronous.\n"
-    "\tdev / nodev:\tAllow use of special device files / disallow them.\n"
-    "\texec / noexec:\tAllow use of executable files / disallow them.\n"
-    "\tsuid / nosuid:\tAllow set-user-id-root programs / disallow them.\n"
-    "\tremount: Re-mount a currently-mounted filesystem, changing its flags.\n"
-    "\tro / rw: Mount for read-only / read-write.\n"
-    "\t"
-    "There are EVEN MORE flags that are specific to each filesystem.\n"
-    "You'll have to see the written documentation for those.\n";
-
-struct mount_options {
-    const char *name;
-    unsigned long and;
-    unsigned long or;
-};
 
-static const struct mount_options mount_options[] = {
-    {"async", ~MS_SYNCHRONOUS, 0},
-    {"defaults", ~0, 0},
-    {"dev", ~MS_NODEV, 0},
-    {"exec", ~MS_NOEXEC, 0},
-    {"nodev", ~0, MS_NODEV},
-    {"noexec", ~0, MS_NOEXEC},
-    {"nosuid", ~0, MS_NOSUID},
-    {"remount", ~0, MS_REMOUNT},
-    {"ro", ~0, MS_RDONLY},
-    {"rw", ~MS_RDONLY, 0},
-    {"suid", ~MS_NOSUID, 0},
-    {"sync", ~0, MS_SYNCHRONOUS},
-    {0, 0, 0}
+// These two aren't always defined in old headers
+#ifndef MS_BIND
+#define MS_BIND                4096
+#endif
+#ifndef MS_MOVE
+#define MS_MOVE                8192
+#endif
+#ifndef MS_SILENT
+#define MS_SILENT      32768
+#endif
+
+// Not real flags, but we want to be able to check for this.
+#define MOUNT_NOAUTO    (1<<29)
+#define MOUNT_SWAP      (1<<30)
+/* Standard mount options (from -o options or --options), with corresponding
+ * flags */
+
+struct {
+       const char *name;
+       long flags;
+} static const mount_options[] = {
+       // NOP flags.
+
+       {"loop", 0},
+       {"defaults", 0},
+       {"quiet", 0},
+
+       // vfs flags
+
+       {"ro", MS_RDONLY},
+       {"rw", ~MS_RDONLY},
+       {"nosuid", MS_NOSUID},
+       {"suid", ~MS_NOSUID},
+       {"dev", ~MS_NODEV},
+       {"nodev", MS_NODEV},
+       {"exec", ~MS_NOEXEC},
+       {"noexec", MS_NOEXEC},
+       {"sync", MS_SYNCHRONOUS},
+       {"async", ~MS_SYNCHRONOUS},
+       {"atime", ~MS_NOATIME},
+       {"noatime", MS_NOATIME},
+       {"diratime", ~MS_NODIRATIME},
+       {"nodiratime", MS_NODIRATIME},
+       {"loud", ~MS_SILENT},
+
+       // action flags
+
+       {"remount", MS_REMOUNT},
+       {"bind", MS_BIND},
+       {"move", MS_MOVE},
+       {"noauto",MOUNT_NOAUTO},
+       {"swap",MOUNT_SWAP}
 };
 
+/* Append mount options to string */
+static void append_mount_options(char **oldopts, char *newopts)
+{
+       if(*oldopts && **oldopts) {
+               char *temp=xasprintf("%s,%s",*oldopts,newopts);
+               free(*oldopts);
+               *oldopts=temp;
+       } else {
+               if (ENABLE_FEATURE_CLEAN_UP) free(*oldopts);
+               *oldopts = xstrdup(newopts);
+       }
+}
 
-/* Seperate standard mount options from the nonstandard string options */
-static void
-parse_mount_options ( char *options, unsigned long *flags, char *strflags)
+/* Use the mount_options list to parse options into flags.
+ * Return list of unrecognized options in *strflags if strflags!=NULL */
+static int parse_mount_options(char *options, char **unrecognized)
 {
-    while (options) {
-       int gotone=FALSE;
-       char *comma = strchr (options, ',');
-       const struct mount_options* f = mount_options;
-       if (comma)
-           *comma = '\0';
-
-       while (f->name != 0) {
-           if (strcasecmp (f->name, options) == 0) {
-               *flags &= f->and;
-               *flags |= f->or;
-               gotone=TRUE;
-               break;
-           }
-           f++;
+       int flags = MS_SILENT;
+
+       // Loop through options
+       for (;;) {
+               int i;
+               char *comma = strchr(options, ',');
+
+               if (comma) *comma = 0;
+
+               // Find this option in mount_options
+               for (i = 0; i < (sizeof(mount_options) / sizeof(*mount_options)); i++) {
+                       if (!strcasecmp(mount_options[i].name, options)) {
+                               long fl = mount_options[i].flags;
+                               if(fl < 0) flags &= fl;
+                               else flags |= fl;
+                               break;
+                       }
+               }
+               // If unrecognized not NULL, append unrecognized mount options */
+               if (unrecognized
+                               && i == (sizeof(mount_options) / sizeof(*mount_options)))
+               {
+                       // Add it to strflags, to pass on to kernel
+                       i = *unrecognized ? strlen(*unrecognized) : 0;
+                       *unrecognized = xrealloc(*unrecognized, i+strlen(options)+2);
+
+                       // Comma separated if it's not the first one
+                       if (i) (*unrecognized)[i++] = ',';
+                       strcpy((*unrecognized)+i, options);
+               }
+
+               // Advance to next option, or finish
+               if(comma) {
+                       *comma = ',';
+                       options = ++comma;
+               } else break;
        }
-       if (*strflags && strflags!= '\0' && gotone==FALSE) {
-           char *temp=strflags;
-           temp += strlen (strflags);
-           *temp++ = ',';
-           *temp++ = '\0';
+
+       return flags;
+}
+
+// Return a list of all block device backed filesystems
+
+static llist_t *get_block_backed_filesystems(void)
+{
+       char *fs, *buf,
+                *filesystems[] = {"/etc/filesystems", "/proc/filesystems", 0};
+       llist_t *list = 0;
+       int i;
+       FILE *f;
+
+       for(i = 0; filesystems[i]; i++) {
+               if(!(f = fopen(filesystems[i], "r"))) continue;
+
+               for(fs = buf = 0; (fs = buf = bb_get_chomped_line_from_file(f));
+                       free(buf))
+               {
+                       if(!strncmp(buf,"nodev",5) && isspace(buf[5])) continue;
+
+                       while(isspace(*fs)) fs++;
+                       if(*fs=='#' || *fs=='*') continue;
+                       if(!*fs) continue;
+
+                       llist_add_to_end(&list,xstrdup(fs));
+               }
+               if (ENABLE_FEATURE_CLEAN_UP) fclose(f);
        }
-       if (gotone==FALSE) {
-           strcat (strflags, options);
-           gotone=FALSE;
+
+       return list;
+}
+
+llist_t *fslist = 0;
+
+#if ENABLE_FEATURE_CLEAN_UP
+static void delete_block_backed_filesystems(void)
+{
+       llist_free(fslist, free);
+}
+#else
+void delete_block_backed_filesystems(void);
+#endif
+
+#if ENABLE_FEATURE_MTAB_SUPPORT
+static int useMtab;
+static int fakeIt;
+#else
+#define useMtab 0
+#define fakeIt 0
+#endif
+
+// Perform actual mount of specific filesystem at specific location.
+
+static int mount_it_now(struct mntent *mp, int vfsflags, char *filteropts)
+{
+       int rc;
+
+       if (fakeIt) { return 0; }
+
+       // Mount, with fallback to read-only if necessary.
+
+       for(;;) {
+               rc = mount(mp->mnt_fsname, mp->mnt_dir, mp->mnt_type,
+                               vfsflags, filteropts);
+               if(!rc || (vfsflags&MS_RDONLY) || (errno!=EACCES && errno!=EROFS))
+                       break;
+               bb_error_msg("%s is write-protected, mounting read-only",
+                               mp->mnt_fsname);
+               vfsflags |= MS_RDONLY;
        }
-       if (comma) {
-           *comma = ',';
-           options = ++comma;
-       } else {
-           break;
+
+       // Abort entirely if permission denied.
+
+       if (rc && errno == EPERM)
+               bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
+
+       /* If the mount was successful, and we're maintaining an old-style
+        * mtab file by hand, add the new entry to it now. */
+
+       if(ENABLE_FEATURE_MTAB_SUPPORT && useMtab && !rc) {
+               FILE *mountTable = setmntent(bb_path_mtab_file, "a+");
+               int i;
+
+               if(!mountTable)
+                       bb_error_msg("No %s\n",bb_path_mtab_file);
+
+               // Add vfs string flags
+
+               for(i=0; mount_options[i].flags != MS_REMOUNT; i++)
+                       if (mount_options[i].flags > 0)
+                               append_mount_options(&(mp->mnt_opts),
+// Shut up about the darn const.  It's not important.  I don't care.
+                                               (char *)mount_options[i].name);
+
+               // Remove trailing / (if any) from directory we mounted on
+
+               i = strlen(mp->mnt_dir);
+               if(i>1 && mp->mnt_dir[i-1] == '/') mp->mnt_dir[i-1] = 0;
+
+               // Write and close.
+
+               if(!mp->mnt_type || !*mp->mnt_type) mp->mnt_type="--bind";
+               addmntent(mountTable, mp);
+               endmntent(mountTable);
+               if (ENABLE_FEATURE_CLEAN_UP)
+                       if(strcmp(mp->mnt_type,"--bind")) mp->mnt_type = 0;
        }
-    }
+
+       return rc;
 }
 
-int
-mount_one (
-          char *blockDevice, char *directory, char *filesystemType,
-          unsigned long flags, char *string_flags)
+
+// Mount one directory.  Handles NFS, loopback, autobind, and filesystem type
+// detection.  Returns 0 for success, nonzero for failure.
+
+static int singlemount(struct mntent *mp, int ignore_busy)
 {
-    int status = 0;
+       int rc = -1, vfsflags;
+       char *loopFile = 0, *filteropts = 0;
+       llist_t *fl = 0;
+       struct stat st;
+
+       vfsflags = parse_mount_options(mp->mnt_opts, &filteropts);
 
-    char buf[255];
+       // Treat fstype "auto" as unspecified.
 
-    if (strcmp(filesystemType, "auto") == 0) {
-       FILE *f = fopen ("/proc/filesystems", "r");
+       if (mp->mnt_type && !strcmp(mp->mnt_type,"auto")) mp->mnt_type = 0;
 
-       if (f == NULL)
-           return( FALSE);
+       // Might this be an NFS filesystem?
 
-       while (fgets (buf, sizeof (buf), f) != NULL) {
-           filesystemType = buf;
-           if (*filesystemType == '\t') {      // Not a nodev filesystem
+       if (ENABLE_FEATURE_MOUNT_NFS &&
+               (!mp->mnt_type || !strcmp(mp->mnt_type,"nfs")) &&
+               strchr(mp->mnt_fsname, ':') != NULL)
+       {
+               if (nfsmount(mp->mnt_fsname, mp->mnt_dir, &vfsflags, &filteropts, 1)) {
+                       bb_perror_msg("nfsmount failed");
+                       goto report_error;
+               } else {
+                       // Strangely enough, nfsmount() doesn't actually mount() anything.
+                       mp->mnt_type = "nfs";
+                       rc = mount_it_now(mp, vfsflags, filteropts);
+                       if (ENABLE_FEATURE_CLEAN_UP) free(filteropts);
+                       
+                       goto report_error;
+               }
+       }
 
-               // Add NULL termination to each line
-               while (*filesystemType && *filesystemType != '\n')
-                   filesystemType++;
-               *filesystemType = '\0';
+       // Look at the file.  (Not found isn't a failure for remount, or for
+       // a synthetic filesystem like proc or sysfs.)
 
-               filesystemType = buf;
-               filesystemType++;       // hop past tab
+       if (lstat(mp->mnt_fsname, &st));
+       else if (!(vfsflags & (MS_REMOUNT | MS_BIND | MS_MOVE))) {
+               // Do we need to allocate a loopback device for it?
 
-               status = mount (blockDevice, directory, filesystemType,
-                               flags | MS_MGC_VAL, string_flags);
-               if (status == 0)
-                   break;
-           }
+               if (ENABLE_FEATURE_MOUNT_LOOP && S_ISREG(st.st_mode)) {
+                       loopFile = bb_simplify_path(mp->mnt_fsname);
+                       mp->mnt_fsname = 0;
+                       switch(set_loop(&(mp->mnt_fsname), loopFile, 0)) {
+                               case 0:
+                               case 1:
+                                       break;
+                               default:
+                                       bb_error_msg( errno == EPERM || errno == EACCES
+                                               ? bb_msg_perm_denied_are_you_root
+                                               : "Couldn't setup loop device");
+                                       return errno;
+                       }
+
+               // Autodetect bind mounts
+
+               } else if (S_ISDIR(st.st_mode) && !mp->mnt_type) vfsflags |= MS_BIND;
+       }
+
+       /* If we know the fstype (or don't need to), jump straight
+        * to the actual mount. */
+
+       if (mp->mnt_type || (vfsflags & (MS_REMOUNT | MS_BIND | MS_MOVE)))
+               rc = mount_it_now(mp, vfsflags, filteropts);
+
+       // Loop through filesystem types until mount succeeds or we run out
+
+       else {
+
+               /* Initialize list of block backed filesystems.  This has to be
+                * done here so that during "mount -a", mounts after /proc shows up
+                * can autodetect. */
+
+               if (!fslist) {
+                       fslist = get_block_backed_filesystems();
+                       if (ENABLE_FEATURE_CLEAN_UP && fslist)
+                               atexit(delete_block_backed_filesystems);
+               }
+
+               for (fl = fslist; fl; fl = fl->link) {
+                       mp->mnt_type = fl->data;
+
+                       if (!(rc = mount_it_now(mp,vfsflags, filteropts))) break;
+
+                       mp->mnt_type = 0;
+               }
+       }
+
+       if (ENABLE_FEATURE_CLEAN_UP) free(filteropts);
+
+       // If mount failed, clean up loop file (if any).
+
+       if (ENABLE_FEATURE_MOUNT_LOOP && rc && loopFile) {
+               del_loop(mp->mnt_fsname);
+               if (ENABLE_FEATURE_CLEAN_UP) {
+                       free(loopFile);
+                       free(mp->mnt_fsname);
+               }
        }
-       fclose (f);
-    } else {
-       status = mount (blockDevice, directory, filesystemType,
-                       flags | MS_MGC_VAL, string_flags);
-    }
-
-    if (status) {
-       fprintf (stderr, "Mounting %s on %s failed: %s\n",
-                blockDevice, directory, strerror(errno));
-       return (FALSE);
-    }
-    return (TRUE);
+report_error:
+       if (rc && errno == EBUSY && ignore_busy) rc = 0;
+       if (rc < 0)
+               bb_perror_msg("Mounting %s on %s failed", mp->mnt_fsname, mp->mnt_dir);
+
+       return rc;
 }
 
-extern int mount_main (int argc, char **argv)
+// Parse options, if necessary parse fstab/mtab, and call singlemount for
+// each directory to be mounted.
+
+int mount_main(int argc, char **argv)
 {
-    char string_flags[1024]="";
-    unsigned long flags = 0;
-    char *filesystemType = "auto";
-    char *device = NULL;
-    char *directory = NULL;
-    struct stat statBuf;
-    int all = 0;
-    int i;
-
-    if (stat("/etc/fstab", &statBuf) < 0) 
-       fprintf(stderr, "/etc/fstab file missing -- Please install one.\n\n");
-
-    if (argc == 1) {
-       FILE *mountTable;
-       if ((mountTable = setmntent ("/proc/mounts", "r"))) {
-           struct mntent *m;
-           while ((m = getmntent (mountTable)) != 0) {
-               struct fstab* fstabItem;
-               char *blockDevice = m->mnt_fsname;
-               /* Note that if /etc/fstab is missing, libc can't fix up /dev/root for us */
-               if (strcmp (blockDevice, "/dev/root") == 0) {
-                   fstabItem = getfsfile ("/");
-                   if (fstabItem != NULL)
-                       blockDevice = fstabItem->fs_spec;
-               }
-               printf ("%s on %s type %s (%s)\n", blockDevice, m->mnt_dir,
-                       m->mnt_type, m->mnt_opts);
-           }
-           endmntent (mountTable);
+       char *cmdopts = xstrdup(""), *fstabname, *fstype=0, *storage_path=0;
+       FILE *fstab;
+       int i, opt, all = FALSE, rc = 0;
+       struct mntent mtpair[2], *mtcur = mtpair;
+
+       /* parse long options, like --bind and --move.  Note that -o option
+        * and --option are synonymous.  Yes, this means --remount,rw works. */
+
+       for (i = opt = 0; i < argc; i++) {
+               if (argv[i][0] == '-' && argv[i][1] == '-') {
+                       append_mount_options(&cmdopts,argv[i]+2);
+               } else argv[opt++] = argv[i];
        }
-       exit( TRUE);
-    }
-
-
-    /* Parse options */
-    i = --argc;
-    argv++;
-    while (i > 0 && **argv) {
-       if (**argv == '-') {
-           while (i>0 && *++(*argv)) switch (**argv) {
-           case 'o':
-               if (--i == 0) {
-                   fprintf (stderr, "%s\n", mount_usage);
-                   exit( FALSE);
+       argc = opt;
+
+       // Parse remaining options
+
+       while ((opt = getopt(argc, argv, "o:t:rwavnf")) > 0) {
+               switch (opt) {
+                       case 'o':
+                               append_mount_options(&cmdopts, optarg);
+                               break;
+                       case 't':
+                               fstype = optarg;
+                               break;
+                       case 'r':
+                               append_mount_options(&cmdopts, "ro");
+                               break;
+                       case 'w':
+                               append_mount_options(&cmdopts, "rw");
+                               break;
+                       case 'a':
+                               all = TRUE;
+                               break;
+                       case 'n':
+                               USE_FEATURE_MTAB_SUPPORT(useMtab = FALSE;)
+                               break;
+                       case 'f':
+                               USE_FEATURE_MTAB_SUPPORT(fakeIt = FALSE;)
+                               break;
+                       case 'v':
+                               break;          // ignore -v
+                       default:
+                               bb_show_usage();
                }
-               parse_mount_options (*(++argv), &flags, string_flags);
-               --i;
-               ++argv;
-               break;
-           case 'r':
-               flags |= MS_RDONLY;
-               break;
-           case 't':
-               if (--i == 0) {
-                   fprintf (stderr, "%s\n", mount_usage);
-                   exit( FALSE);
+       }
+
+       // Three or more non-option arguments?  Die with a usage message.
+
+       if (optind-argc>2) bb_show_usage();
+
+       // If we have no arguments, show currently mounted filesystems
+
+       if (optind == argc) {
+               if (!all) {
+                       FILE *mountTable = setmntent(bb_path_mtab_file, "r");
+
+                       if(!mountTable) bb_error_msg_and_die("No %s",bb_path_mtab_file);
+
+                       while (getmntent_r(mountTable,mtpair,bb_common_bufsiz1,
+                                                               sizeof(bb_common_bufsiz1)))
+                       {
+                               // Don't show rootfs.
+                               if (!strcmp(mtpair->mnt_fsname, "rootfs")) continue;
+
+                               if (!fstype || !strcmp(mtpair->mnt_type, fstype))
+                                       printf("%s on %s type %s (%s)\n", mtpair->mnt_fsname,
+                                                       mtpair->mnt_dir, mtpair->mnt_type,
+                                                       mtpair->mnt_opts);
+                       }
+                       if (ENABLE_FEATURE_CLEAN_UP) endmntent(mountTable);
+                       return EXIT_SUCCESS;
                }
-               filesystemType = *(++argv);
-               --i;
-               ++argv;
-               break;
-           case 'w':
-               flags &= ~MS_RDONLY;
-               break;
-           case 'a':
-               all = 1;
-               break;
-           case 'v':
-           case 'h':
-           case '-':
-               fprintf (stderr, "%s\n", mount_usage);
-               exit( TRUE);
-               break;
-           }
-       } else {
-           if (device == NULL)
-               device=*argv;
-           else if (directory == NULL)
-               directory=*argv;
-           else {
-               fprintf (stderr, "%s\n", mount_usage);
-               exit( TRUE);
-           }
        }
-       i--;
-       argv++;
-    }
 
-    if (all == 1) {
-       struct mntent *m;
-       FILE *f = setmntent ("/etc/fstab", "r");
+       // When we have two arguments, the second is the directory and we can
+       // skip looking at fstab entirely.  We can always abspath() the directory
+       // argument when we get it.
 
-       if (f == NULL) {
-           perror("/etc/fstab");
-           exit( FALSE); 
+       if (optind+2 == argc) {
+               mtpair->mnt_fsname = argv[optind];
+               mtpair->mnt_dir = argv[optind+1];
+               mtpair->mnt_type = fstype;
+               mtpair->mnt_opts = cmdopts;
+               rc = singlemount(mtpair, 0);
+               goto clean_up;
        }
-       while ((m = getmntent (f)) != NULL) {
-           // If the file system isn't noauto, and isn't mounted on /, mount 
-           // it
-           if ((!strstr (m->mnt_opts, "noauto"))
-               && (m->mnt_dir[1] != '\0') && !((m->mnt_type[0] == 's')
-                                               && (m->mnt_type[1] == 'w'))
-               && !((m->mnt_type[0] == 'n') && (m->mnt_type[1] == 'f'))) {
-               mount_one (m->mnt_fsname, m->mnt_dir, m->mnt_type, flags,
-                          m->mnt_opts);
-           }
+
+       // If we have at least one argument, it's the storage location
+
+       if (optind < argc) storage_path = bb_simplify_path(argv[optind]);
+
+       // Open either fstab or mtab
+
+       if (parse_mount_options(cmdopts,0) & MS_REMOUNT)
+               fstabname = (char *)bb_path_mtab_file;  // Again with the evil const.
+       else fstabname="/etc/fstab";
+
+       if (!(fstab=setmntent(fstabname,"r")))
+               bb_perror_msg_and_die("Cannot read %s",fstabname);
+
+       // Loop through entries until we find what we're looking for.
+
+       memset(mtpair,0,sizeof(mtpair));
+       for (;;) {
+               struct mntent *mtnext = mtpair + (mtcur==mtpair ? 1 : 0);
+
+               // Get next fstab entry
+
+               if (!getmntent_r(fstab, mtcur, bb_common_bufsiz1
+                                       + (mtcur==mtpair ? sizeof(bb_common_bufsiz1)/2 : 0),
+                               sizeof(bb_common_bufsiz1)/2))
+               {
+                       // Were we looking for something specific?
+
+                       if (optind != argc) {
+
+                               // If we didn't find anything, complain.
+
+                               if (!mtnext->mnt_fsname)
+                                       bb_error_msg_and_die("Can't find %s in %s",
+                                               argv[optind], fstabname);
+
+                               // Mount the last thing we found.
+
+                               mtcur = mtnext;
+                               mtcur->mnt_opts = xstrdup(mtcur->mnt_opts);
+                               append_mount_options(&(mtcur->mnt_opts),cmdopts);
+                               rc = singlemount(mtcur, 0);
+                               free(mtcur->mnt_opts);
+                       }
+                       goto clean_up;
+               }
+
+               /* If we're trying to mount something specific and this isn't it,
+                * skip it.  Note we must match both the exact text in fstab (ala
+                * "proc") or a full path from root */
+
+               if (optind != argc) {
+
+                       // Is this what we're looking for?
+
+                       if(strcmp(argv[optind],mtcur->mnt_fsname) &&
+                          strcmp(storage_path,mtcur->mnt_fsname) &&
+                          strcmp(argv[optind],mtcur->mnt_dir) &&
+                          strcmp(storage_path,mtcur->mnt_dir)) continue;
+
+                       // Remember this entry.  Something later may have overmounted
+                       // it, and we want the _last_ match.
+
+                       mtcur = mtnext;
+
+               // If we're mounting all.
+
+               } else {
+
+                       // Do we need to match a filesystem type?
+                       if (fstype && strcmp(mtcur->mnt_type,fstype)) continue;
+
+                       // Skip noauto and swap anyway.
+
+                       if (parse_mount_options(mtcur->mnt_opts,0)
+                               & (MOUNT_NOAUTO | MOUNT_SWAP)) continue;
+
+                       // Mount this thing.
+
+                       if (singlemount(mtcur, 1)) {
+                               /* Count number of failed mounts */
+                               rc++;
+                       }
+               }
        }
-       endmntent (f);
-    } else {
-       if (device && directory) {
-           exit (mount_one (device, directory, filesystemType, 
-                       flags, string_flags));
-       } else {
-           fprintf (stderr, "%s\n", mount_usage);
-           exit( FALSE);
+       if (ENABLE_FEATURE_CLEAN_UP) endmntent(fstab);
+
+clean_up:
+
+       if (ENABLE_FEATURE_CLEAN_UP) {
+               free(storage_path);
+               free(cmdopts);
        }
-    }
-    exit( TRUE);
+
+       return rc;
 }