X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=umount.c;h=3e23b9705edf3e660f277fca16eadf945d496ded;hb=4949faf4b2090ca23c2aeb34535fdbe57754913a;hp=04cd8a080815e9a80b3e3bd3031068656d0ecedd;hpb=3c163822d88105450806fdb6a29fdfc2511267d1;p=oweals%2Fbusybox.git diff --git a/umount.c b/umount.c index 04cd8a080..3e23b9705 100644 --- a/umount.c +++ b/umount.c @@ -1,7 +1,10 @@ +/* vi: set sw=4 ts=4: */ /* * Mini umount implementation for busybox * - * Copyright (C) 1998 by Erik Andersen + * + * Copyright (C) 1999,2000,2001 by Lineo, inc. + * Written by Erik Andersen , * * 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 @@ -19,77 +22,268 @@ * */ -#include "internal.h" #include -#include #include -#include #include +#include +#include +#include "busybox.h" + + +static const int MNT_FORCE = 1; +static const int MS_MGC_VAL = 0xc0ed0000; /* Magic number indicatng "new" flags */ +static const int MS_REMOUNT = 32; /* Alter flags of a mounted FS. */ +static const int MS_RDONLY = 1; /* Mount read-only. */ + +extern int mount (__const char *__special_file, __const char *__dir, + __const char *__fstype, unsigned long int __rwflag, + __const void *__data); +extern int umount (__const char *__special_file); +extern int umount2 (__const char *__special_file, int __flags); + +struct _mtab_entry_t { + char *device; + char *mountpt; + struct _mtab_entry_t *next; +}; + +static struct _mtab_entry_t *mtab_cache = NULL; + + + +#if defined BB_FEATURE_MOUNT_FORCE +static int doForce = FALSE; +#endif +#if defined BB_FEATURE_MOUNT_LOOP +static int freeLoop = TRUE; +#endif +#if defined BB_FEATURE_MTAB_SUPPORT +static int useMtab = TRUE; +#endif +static int umountAll = FALSE; +static int doRemount = FALSE; +extern const char mtab_file[]; /* Defined in utility.c */ + + + +/* These functions are here because the getmntent functions do not appear + * to be re-entrant, which leads to all sorts of problems when we try to + * use them recursively - randolph + * + * TODO: Perhaps switch to using Glibc's getmntent_r + * -Erik + */ +void mtab_read(void) +{ + struct _mtab_entry_t *entry = NULL; + struct mntent *e; + FILE *fp; + + if (mtab_cache != NULL) + return; + + if ((fp = setmntent(mtab_file, "r")) == NULL) { + error_msg("Cannot open %s", mtab_file); + return; + } + while ((e = getmntent(fp))) { + entry = xmalloc(sizeof(struct _mtab_entry_t)); + entry->device = strdup(e->mnt_fsname); + entry->mountpt = strdup(e->mnt_dir); + entry->next = mtab_cache; + mtab_cache = entry; + } + endmntent(fp); +} + +char *mtab_getinfo(const char *match, const char which) +{ + struct _mtab_entry_t *cur = mtab_cache; + + while (cur) { + if (strcmp(cur->mountpt, match) == 0 || + strcmp(cur->device, match) == 0) { + if (which == MTAB_GETMOUNTPT) { + return cur->mountpt; + } else { +#if !defined BB_FEATURE_MTAB_SUPPORT + if (strcmp(cur->device, "/dev/root") == 0) { + /* Adjusts device to be the real root device, + * or leaves device alone if it can't find it */ + find_real_root_device_name( cur->device); + return ( cur->device); + } +#endif + return cur->device; + } + } + cur = cur->next; + } + return NULL; +} + +char *mtab_first(void **iter) +{ + struct _mtab_entry_t *mtab_iter; + + if (!iter) + return NULL; + mtab_iter = mtab_cache; + *iter = (void *) mtab_iter; + return mtab_next(iter); +} + +char *mtab_next(void **iter) +{ + char *mp; + + if (iter == NULL || *iter == NULL) + return NULL; + mp = ((struct _mtab_entry_t *) (*iter))->mountpt; + *iter = (void *) ((struct _mtab_entry_t *) (*iter))->next; + return mp; +} -const char umount_usage[] = "\tumount {filesystem|directory}\n" -"or to unmount all mounted file systems:\n\tumount -a\n"; +/* Don't bother to clean up, since exit() does that + * automagically, so we can save a few bytes */ +#ifdef BB_FEATURE_CLEAN_UP +void mtab_free(void) +{ + struct _mtab_entry_t *this, *next; + + this = mtab_cache; + while (this) { + next = this->next; + if (this->device) + free(this->device); + if (this->mountpt) + free(this->mountpt); + free(this); + this = next; + } +} +#endif -static int -umount_all() +static int do_umount(const char *name) { int status; - struct mntent *m; - FILE *mountTable; - - if ((mountTable = setmntent ("/proc/mounts", "r"))) { - while ((m = getmntent (mountTable)) != 0) { - char *blockDevice = m->mnt_fsname; - if (strcmp (blockDevice, "/dev/root") == 0) - blockDevice = (getfsfile ("/"))->fs_spec; - status=umount (m->mnt_dir); - if (status!=0) { - /* Don't bother retrying the umount on busy devices */ - if (errno==EBUSY) { - perror(m->mnt_dir); + char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE); + + if (blockDevice && strcmp(blockDevice, name) == 0) + name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT); + + status = umount(name); + +#if defined BB_FEATURE_MOUNT_LOOP + if (freeLoop == TRUE && blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9)) + /* this was a loop device, delete it */ + del_loop(blockDevice); +#endif +#if defined BB_FEATURE_MOUNT_FORCE + if (status != 0 && doForce == TRUE) { + status = umount2(blockDevice, MNT_FORCE); + if (status != 0) { + error_msg_and_die("forced umount of %s failed!", blockDevice); + } + } +#endif + if (status != 0 && doRemount == TRUE && errno == EBUSY) { + status = mount(blockDevice, name, NULL, + MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL); + if (status == 0) { + error_msg("%s busy - remounted read-only", blockDevice); + } else { + error_msg("Cannot remount %s read-only", blockDevice); + } + } + if (status == 0) { +#if defined BB_FEATURE_MTAB_SUPPORT + if (useMtab == TRUE) + erase_mtab(name); +#endif + return (TRUE); + } + return (FALSE); +} + +static int umount_all(void) +{ + int status = TRUE; + char *mountpt; + void *iter; + + for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) { + /* Never umount /proc on a umount -a */ + if (strstr(mountpt, "proc")!= NULL) continue; - } - printf ("Trying to umount %s failed: %s\n", - m->mnt_dir, strerror(errno)); - printf ("Instead trying to umount %s\n", blockDevice); - status=umount (blockDevice); - if (status!=0) { - printf ("Couldn't umount %s on %s (type %s): %s\n", - blockDevice, m->mnt_dir, m->mnt_type, strerror(errno)); - } + if (!do_umount(mountpt)) { + /* Don't bother retrying the umount on busy devices */ + if (errno == EBUSY) { + perror_msg("%s", mountpt); + status = FALSE; + continue; + } + if (!do_umount(mountpt)) { + printf("Couldn't umount %s on %s: %s\n", + mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE), + strerror(errno)); + status = FALSE; + } } - } - endmntent (mountTable); - } - return( TRUE); + } + return (status); } -extern int -umount_main(int argc, char * * argv) +extern int umount_main(int argc, char **argv) { + if (argc < 2) { + show_usage(); + } +#ifdef BB_FEATURE_CLEAN_UP + atexit(mtab_free); +#endif + + /* Parse any options */ + while (--argc > 0 && **(++argv) == '-') { + while (*++(*argv)) + switch (**argv) { + case 'a': + umountAll = TRUE; + break; +#if defined BB_FEATURE_MOUNT_LOOP + case 'l': + freeLoop = FALSE; + break; +#endif +#ifdef BB_FEATURE_MTAB_SUPPORT + case 'n': + useMtab = FALSE; + break; +#endif +#ifdef BB_FEATURE_MOUNT_FORCE + case 'f': + doForce = TRUE; + break; +#endif + case 'r': + doRemount = TRUE; + break; + case 'v': + break; /* ignore -v */ + default: + show_usage(); + } + } - if (argc < 2) { - fprintf(stderr, "Usage: %s", umount_usage); - exit(FALSE); - } - argc--; - argv++; - - /* Parse any options */ - while (**argv == '-') { - while (*++(*argv)) switch (**argv) { - case 'a': - exit ( umount_all() ); - break; - default: - fprintf(stderr, "Usage: %s\n", umount_usage); - exit( FALSE); + mtab_read(); + if (umountAll == TRUE) { + if (umount_all() == TRUE) + return EXIT_SUCCESS; + else + return EXIT_FAILURE; } - } - if ( umount(*argv) == 0 ) - exit (TRUE); - else { - perror("umount"); - exit( FALSE); - } + if (do_umount(*argv) == TRUE) + return EXIT_SUCCESS; + perror_msg_and_die("%s", *argv); }