00d7d6cef6
option - it was going to return a special flag back to caller and expecting caller to call it again with special parameter! Also caller was charged with calling mount() syscall... mount: mtab support was non-functional. Enabling it revealed serious bug which is not fixed yet.
602 lines
15 KiB
C
602 lines
15 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini mount implementation for busybox
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*
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* Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
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* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
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* Copyright (C) 2005-2006 by Rob Landley <rob@landley.net>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*/
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/* todo:
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* bb_getopt_ulflags();
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*/
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/* Design notes: There is no spec for mount. Remind me to write one.
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mount_main() calls singlemount() which calls mount_it_now().
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mount_main() can loop through /etc/fstab for mount -a
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singlemount() can loop through /etc/filesystems for fstype detection.
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mount_it_now() does the actual mount.
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*/
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#include "busybox.h"
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#include <mntent.h>
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// Not real flags, but we want to be able to check for this.
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#define MOUNT_NOAUTO (1<<29)
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#define MOUNT_SWAP (1<<30)
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/* Standard mount options (from -o options or --options), with corresponding
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* flags */
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struct {
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char *name;
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long flags;
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} static mount_options[] = {
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// MS_FLAGS set a bit. ~MS_FLAGS disable that bit. 0 flags are NOPs.
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USE_FEATURE_MOUNT_LOOP(
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{"loop", 0},
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)
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USE_FEATURE_MOUNT_FSTAB(
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{"defaults", 0},
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{"quiet", 0},
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{"noauto",MOUNT_NOAUTO},
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{"swap",MOUNT_SWAP},
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)
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USE_FEATURE_MOUNT_FLAGS(
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// vfs flags
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{"nosuid", MS_NOSUID},
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{"suid", ~MS_NOSUID},
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{"dev", ~MS_NODEV},
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{"nodev", MS_NODEV},
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{"exec", ~MS_NOEXEC},
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{"noexec", MS_NOEXEC},
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{"sync", MS_SYNCHRONOUS},
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{"async", ~MS_SYNCHRONOUS},
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{"atime", ~MS_NOATIME},
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{"noatime", MS_NOATIME},
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{"diratime", ~MS_NODIRATIME},
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{"nodiratime", MS_NODIRATIME},
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{"loud", ~MS_SILENT},
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// action flags
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{"bind", MS_BIND},
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{"move", MS_MOVE},
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{"shared", MS_SHARED},
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{"slave", MS_SLAVE},
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{"private", MS_PRIVATE},
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{"unbindable", MS_UNBINDABLE},
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{"rshared", MS_SHARED|MS_RECURSIVE},
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{"rslave", MS_SLAVE|MS_RECURSIVE},
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{"rprivate", MS_SLAVE|MS_RECURSIVE},
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{"runbindable", MS_UNBINDABLE|MS_RECURSIVE},
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)
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// Always understood.
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{"ro", MS_RDONLY}, // vfs flag
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{"rw", ~MS_RDONLY}, // vfs flag
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{"remount", MS_REMOUNT}, // action flag
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};
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/* Append mount options to string */
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static void append_mount_options(char **oldopts, char *newopts)
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{
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if(*oldopts && **oldopts) {
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char *temp = xasprintf("%s,%s",*oldopts,newopts);
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free(*oldopts);
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*oldopts = temp;
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} else {
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if (ENABLE_FEATURE_CLEAN_UP) free(*oldopts);
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*oldopts = xstrdup(newopts);
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}
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}
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/* Use the mount_options list to parse options into flags.
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* Also return list of unrecognized options if unrecognized!=NULL */
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static int parse_mount_options(char *options, char **unrecognized)
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{
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int flags = MS_SILENT;
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// Loop through options
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for (;;) {
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int i;
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char *comma = strchr(options, ',');
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if (comma) *comma = 0;
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// Find this option in mount_options
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for (i = 0; i < (sizeof(mount_options) / sizeof(*mount_options)); i++) {
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if (!strcasecmp(mount_options[i].name, options)) {
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long fl = mount_options[i].flags;
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if(fl < 0) flags &= fl;
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else flags |= fl;
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break;
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}
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}
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// If unrecognized not NULL, append unrecognized mount options */
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if (unrecognized
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&& i == (sizeof(mount_options) / sizeof(*mount_options)))
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{
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// Add it to strflags, to pass on to kernel
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i = *unrecognized ? strlen(*unrecognized) : 0;
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*unrecognized = xrealloc(*unrecognized, i+strlen(options)+2);
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// Comma separated if it's not the first one
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if (i) (*unrecognized)[i++] = ',';
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strcpy((*unrecognized)+i, options);
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}
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// Advance to next option, or finish
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if(comma) {
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*comma = ',';
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options = ++comma;
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} else break;
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}
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return flags;
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}
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// Return a list of all block device backed filesystems
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static llist_t *get_block_backed_filesystems(void)
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{
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char *fs, *buf,
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*filesystems[] = {"/etc/filesystems", "/proc/filesystems", 0};
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llist_t *list = 0;
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int i;
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FILE *f;
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for(i = 0; filesystems[i]; i++) {
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if(!(f = fopen(filesystems[i], "r"))) continue;
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for(fs = buf = 0; (fs = buf = bb_get_chomped_line_from_file(f));
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free(buf))
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{
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if(!strncmp(buf,"nodev",5) && isspace(buf[5])) continue;
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while(isspace(*fs)) fs++;
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if(*fs=='#' || *fs=='*') continue;
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if(!*fs) continue;
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llist_add_to_end(&list,xstrdup(fs));
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}
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if (ENABLE_FEATURE_CLEAN_UP) fclose(f);
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}
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return list;
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}
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llist_t *fslist = 0;
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#if ENABLE_FEATURE_CLEAN_UP
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static void delete_block_backed_filesystems(void)
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{
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llist_free(fslist, free);
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}
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#else
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void delete_block_backed_filesystems(void);
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#endif
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#if ENABLE_FEATURE_MTAB_SUPPORT
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static int useMtab = 1;
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static int fakeIt;
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#else
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#define useMtab 0
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#define fakeIt 0
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#endif
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// Perform actual mount of specific filesystem at specific location.
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int mount_it_now(struct mntent *mp, int vfsflags, char *filteropts)
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{
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int rc;
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if (fakeIt) { return 0; }
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// Mount, with fallback to read-only if necessary.
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for(;;) {
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rc = mount(mp->mnt_fsname, mp->mnt_dir, mp->mnt_type,
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vfsflags, filteropts);
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if(!rc || (vfsflags&MS_RDONLY) || (errno!=EACCES && errno!=EROFS))
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break;
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bb_error_msg("%s is write-protected, mounting read-only",
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mp->mnt_fsname);
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vfsflags |= MS_RDONLY;
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}
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// Abort entirely if permission denied.
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if (rc && errno == EPERM)
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bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
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/* If the mount was successful, and we're maintaining an old-style
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* mtab file by hand, add the new entry to it now. */
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if(ENABLE_FEATURE_MTAB_SUPPORT && useMtab && !rc) {
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FILE *mountTable = setmntent(bb_path_mtab_file, "a+");
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int i;
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if(!mountTable)
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bb_error_msg("no %s",bb_path_mtab_file);
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// Add vfs string flags
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for(i=0; mount_options[i].flags != MS_REMOUNT; i++)
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if (mount_options[i].flags > 0)
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append_mount_options(&(mp->mnt_opts), mount_options[i].name);
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// Remove trailing / (if any) from directory we mounted on
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i = strlen(mp->mnt_dir);
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if(i>1 && mp->mnt_dir[i-1] == '/') mp->mnt_dir[i-1] = 0;
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// Write and close.
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if(!mp->mnt_type || !*mp->mnt_type) mp->mnt_type="--bind";
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// addmntent(mountTable, mp);
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if(0) bb_error_msg("buggy: addmntent(fsname='%s' dir='%s' type='%s' opts='%s')",
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mp->mnt_fsname,
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mp->mnt_dir,
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mp->mnt_type,
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mp->mnt_opts
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);
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endmntent(mountTable);
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if (ENABLE_FEATURE_CLEAN_UP)
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if(strcmp(mp->mnt_type,"--bind")) mp->mnt_type = 0;
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}
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return rc;
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}
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// Mount one directory. Handles CIFS, NFS, loopback, autobind, and filesystem
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// type detection. Returns 0 for success, nonzero for failure.
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static int singlemount(struct mntent *mp, int ignore_busy)
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{
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int rc = -1, vfsflags;
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char *loopFile = 0, *filteropts = 0;
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llist_t *fl = 0;
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struct stat st;
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vfsflags = parse_mount_options(mp->mnt_opts, &filteropts);
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// Treat fstype "auto" as unspecified.
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if (mp->mnt_type && !strcmp(mp->mnt_type,"auto")) mp->mnt_type = 0;
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// Might this be an CIFS filesystem?
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if(ENABLE_FEATURE_MOUNT_CIFS &&
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(!mp->mnt_type || !strcmp(mp->mnt_type,"cifs")) &&
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(mp->mnt_fsname[0]==mp->mnt_fsname[1] && (mp->mnt_fsname[0]=='/' || mp->mnt_fsname[0]=='\\')))
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{
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struct hostent *he;
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char ip[32], *s;
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rc = 1;
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// Replace '/' with '\' and verify that unc points to "//server/share".
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for (s = mp->mnt_fsname; *s; ++s)
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if (*s == '/') *s = '\\';
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// get server IP
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s = strrchr(mp->mnt_fsname, '\\');
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if (s == mp->mnt_fsname+1) goto report_error;
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*s = 0;
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he = gethostbyname(mp->mnt_fsname+2);
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*s = '\\';
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if (!he) goto report_error;
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// Insert ip=... option into string flags. (NOTE: Add IPv6 support.)
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sprintf(ip, "ip=%d.%d.%d.%d", he->h_addr[0], he->h_addr[1],
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he->h_addr[2], he->h_addr[3]);
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parse_mount_options(ip, &filteropts);
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// compose new unc '\\server-ip\share'
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s = xasprintf("\\\\%s%s",ip+3,strchr(mp->mnt_fsname+2,'\\'));
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if (ENABLE_FEATURE_CLEAN_UP) free(mp->mnt_fsname);
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mp->mnt_fsname = s;
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// lock is required
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vfsflags |= MS_MANDLOCK;
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mp->mnt_type = "cifs";
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rc = mount_it_now(mp, vfsflags, filteropts);
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goto report_error;
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}
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// Might this be an NFS filesystem?
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if (ENABLE_FEATURE_MOUNT_NFS &&
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(!mp->mnt_type || !strcmp(mp->mnt_type,"nfs")) &&
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strchr(mp->mnt_fsname, ':') != NULL)
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{
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rc = nfsmount(mp, vfsflags, filteropts);
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goto report_error;
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}
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// Look at the file. (Not found isn't a failure for remount, or for
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// a synthetic filesystem like proc or sysfs.)
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if (!lstat(mp->mnt_fsname, &st) && !(vfsflags & (MS_REMOUNT | MS_BIND | MS_MOVE)))
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{
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// Do we need to allocate a loopback device for it?
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if (ENABLE_FEATURE_MOUNT_LOOP && S_ISREG(st.st_mode)) {
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loopFile = bb_simplify_path(mp->mnt_fsname);
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mp->mnt_fsname = 0;
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switch(set_loop(&(mp->mnt_fsname), loopFile, 0)) {
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case 0:
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case 1:
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break;
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default:
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bb_error_msg( errno == EPERM || errno == EACCES
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? bb_msg_perm_denied_are_you_root
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: "cannot setup loop device");
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return errno;
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}
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// Autodetect bind mounts
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} else if (S_ISDIR(st.st_mode) && !mp->mnt_type)
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vfsflags |= MS_BIND;
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}
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/* If we know the fstype (or don't need to), jump straight
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* to the actual mount. */
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if (mp->mnt_type || (vfsflags & (MS_REMOUNT | MS_BIND | MS_MOVE)))
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rc = mount_it_now(mp, vfsflags, filteropts);
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// Loop through filesystem types until mount succeeds or we run out
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else {
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/* Initialize list of block backed filesystems. This has to be
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* done here so that during "mount -a", mounts after /proc shows up
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* can autodetect. */
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if (!fslist) {
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fslist = get_block_backed_filesystems();
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if (ENABLE_FEATURE_CLEAN_UP && fslist)
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atexit(delete_block_backed_filesystems);
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}
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for (fl = fslist; fl; fl = fl->link) {
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mp->mnt_type = fl->data;
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if (!(rc = mount_it_now(mp,vfsflags, filteropts))) break;
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mp->mnt_type = 0;
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}
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}
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// If mount failed, clean up loop file (if any).
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if (ENABLE_FEATURE_MOUNT_LOOP && rc && loopFile) {
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del_loop(mp->mnt_fsname);
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if (ENABLE_FEATURE_CLEAN_UP) {
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free(loopFile);
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free(mp->mnt_fsname);
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}
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}
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report_error:
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if (ENABLE_FEATURE_CLEAN_UP) free(filteropts);
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if (rc && errno == EBUSY && ignore_busy) rc = 0;
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if (rc < 0)
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/* perror here sometimes says "mounting ... on ... failed: Success" */
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bb_error_msg("mounting %s on %s failed", mp->mnt_fsname, mp->mnt_dir);
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return rc;
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}
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// Parse options, if necessary parse fstab/mtab, and call singlemount for
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// each directory to be mounted.
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int mount_main(int argc, char **argv)
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{
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char *cmdopts = xstrdup(""), *fstabname, *fstype=0, *storage_path=0;
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FILE *fstab;
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int i, opt, all = FALSE, rc = 0;
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struct mntent mtpair[2], *mtcur = mtpair;
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/* parse long options, like --bind and --move. Note that -o option
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* and --option are synonymous. Yes, this means --remount,rw works. */
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for (i = opt = 0; i < argc; i++) {
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if (argv[i][0] == '-' && argv[i][1] == '-') {
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append_mount_options(&cmdopts,argv[i]+2);
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} else argv[opt++] = argv[i];
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}
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argc = opt;
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// Parse remaining options
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while ((opt = getopt(argc, argv, "o:t:rwavnf")) > 0) {
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switch (opt) {
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case 'o':
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append_mount_options(&cmdopts, optarg);
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break;
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case 't':
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fstype = optarg;
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break;
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case 'r':
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append_mount_options(&cmdopts, "ro");
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break;
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case 'w':
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append_mount_options(&cmdopts, "rw");
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break;
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case 'a':
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all = TRUE;
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break;
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case 'n':
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USE_FEATURE_MTAB_SUPPORT(useMtab = FALSE;)
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break;
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case 'f':
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USE_FEATURE_MTAB_SUPPORT(fakeIt = FALSE;)
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break;
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case 'v':
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break; // ignore -v
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default:
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bb_show_usage();
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}
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}
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|
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// Three or more non-option arguments? Die with a usage message.
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if (optind-argc>2) bb_show_usage();
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// If we have no arguments, show currently mounted filesystems
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|
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if (optind == argc) {
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if (!all) {
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FILE *mountTable = setmntent(bb_path_mtab_file, "r");
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|
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if(!mountTable) bb_error_msg_and_die("no %s",bb_path_mtab_file);
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while (getmntent_r(mountTable,mtpair,bb_common_bufsiz1,
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sizeof(bb_common_bufsiz1)))
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{
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// Don't show rootfs.
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if (!strcmp(mtpair->mnt_fsname, "rootfs")) continue;
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if (!fstype || !strcmp(mtpair->mnt_type, fstype))
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printf("%s on %s type %s (%s)\n", mtpair->mnt_fsname,
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mtpair->mnt_dir, mtpair->mnt_type,
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mtpair->mnt_opts);
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}
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if (ENABLE_FEATURE_CLEAN_UP) endmntent(mountTable);
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return EXIT_SUCCESS;
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}
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} else storage_path = bb_simplify_path(argv[optind]);
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// When we have two arguments, the second is the directory and we can
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// skip looking at fstab entirely. We can always abspath() the directory
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// argument when we get it.
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if (optind+2 == argc) {
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mtpair->mnt_fsname = argv[optind];
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mtpair->mnt_dir = argv[optind+1];
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mtpair->mnt_type = fstype;
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mtpair->mnt_opts = cmdopts;
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rc = singlemount(mtpair, 0);
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goto clean_up;
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}
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// If we have a shared subtree flag, don't worry about fstab or mtab.
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i = parse_mount_options(cmdopts,0);
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if (ENABLE_FEATURE_MOUNT_FLAGS &&
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(i & (MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE )))
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{
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|
rc = mount("", argv[optind], "", i, "");
|
|
if (rc) bb_perror_msg_and_die("%s", argv[optind]);
|
|
goto clean_up;
|
|
}
|
|
|
|
// Open either fstab or mtab
|
|
|
|
if (parse_mount_options(cmdopts,0) & MS_REMOUNT)
|
|
fstabname = bb_path_mtab_file;
|
|
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++;
|
|
}
|
|
}
|
|
}
|
|
if (ENABLE_FEATURE_CLEAN_UP) endmntent(fstab);
|
|
|
|
clean_up:
|
|
|
|
if (ENABLE_FEATURE_CLEAN_UP) {
|
|
free(storage_path);
|
|
free(cmdopts);
|
|
}
|
|
|
|
return rc;
|
|
}
|