diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2006-12-27 07:35:09 +0300 |
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committer | Denis Vlasenko <vda.linux@googlemail.com> | 2006-12-27 07:35:09 +0300 |
commit | 7b76233290bd9dead1848f28ed6d0edfcceb8e09 (patch) | |
tree | b963999fc54eddb65f1929b894f868e24851fc9c /util-linux/umount.c |
Correcting tag name to be like previous ones1_3_0
Diffstat (limited to 'util-linux/umount.c')
-rw-r--r-- | util-linux/umount.c | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/util-linux/umount.c b/util-linux/umount.c new file mode 100644 index 000000000..6ba72aed1 --- /dev/null +++ b/util-linux/umount.c @@ -0,0 +1,151 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini umount implementation for busybox + * + * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org> + * Copyright (C) 2005 by Rob Landley <rob@landley.net> + * + * Licensed under GPL version 2, see file LICENSE in this tarball for details. + */ + +#include "busybox.h" +#include <mntent.h> +#include <getopt.h> + +#define OPTION_STRING "flDnravd" +#define OPT_FORCE 1 +#define OPT_LAZY 2 +#define OPT_DONTFREELOOP 4 +#define OPT_NO_MTAB 8 +#define OPT_REMOUNT 16 +#define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? 32 : 0) + +int umount_main(int argc, char **argv) +{ + int doForce; + char path[2*PATH_MAX]; + struct mntent me; + FILE *fp; + int status = EXIT_SUCCESS; + unsigned opt; + struct mtab_list { + char *dir; + char *device; + struct mtab_list *next; + } *mtl, *m; + + /* Parse any options */ + + opt = getopt32(argc, argv, OPTION_STRING); + + argc -= optind; + argv += optind; + + doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY)); + + /* Get a list of mount points from mtab. We read them all in now mostly + * for umount -a (so we don't have to worry about the list changing while + * we iterate over it, or about getting stuck in a loop on the same failing + * entry. Notice that this also naturally reverses the list so that -a + * umounts the most recent entries first. */ + + m = mtl = 0; + + /* If we're umounting all, then m points to the start of the list and + * the argument list should be empty (which will match all). */ + + fp = setmntent(bb_path_mtab_file, "r"); + if (!fp) { + if (opt & OPT_ALL) + bb_error_msg_and_die("cannot open %s", bb_path_mtab_file); + } else { + while (getmntent_r(fp, &me, path, sizeof(path))) { + m = xmalloc(sizeof(struct mtab_list)); + m->next = mtl; + m->device = xstrdup(me.mnt_fsname); + m->dir = xstrdup(me.mnt_dir); + mtl = m; + } + endmntent(fp); + } + + /* If we're not umounting all, we need at least one argument. */ + if (!(opt & OPT_ALL)) { + m = 0; + if (!argc) bb_show_usage(); + } + + // Loop through everything we're supposed to umount, and do so. + for (;;) { + int curstat; + char *zapit = *argv; + + // Do we already know what to umount this time through the loop? + if (m) safe_strncpy(path, m->dir, PATH_MAX); + // For umount -a, end of mtab means time to exit. + else if (opt & OPT_ALL) break; + // Get next command line argument (and look it up in mtab list) + else if (!argc--) break; + else { + argv++; + realpath(zapit, path); + for (m = mtl; m; m = m->next) + if (!strcmp(path, m->dir) || !strcmp(path, m->device)) + break; + } + // If we couldn't find this sucker in /etc/mtab, punt by passing our + // command line argument straight to the umount syscall. Otherwise, + // umount the directory even if we were given the block device. + if (m) zapit = m->dir; + + // Let's ask the thing nicely to unmount. + curstat = umount(zapit); + + // Force the unmount, if necessary. + if (curstat && doForce) { + curstat = umount2(zapit, doForce); + if (curstat) + bb_error_msg("forced umount of %s failed!", zapit); + } + + // If still can't umount, maybe remount read-only? + if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) { + curstat = mount(m->device, zapit, NULL, MS_REMOUNT|MS_RDONLY, NULL); + bb_error_msg(curstat ? "cannot remount %s read-only" : + "%s busy - remounted read-only", m->device); + } + + if (curstat) { + status = EXIT_FAILURE; + bb_perror_msg("cannot umount %s", zapit); + } else { + /* De-allocate the loop device. This ioctl should be ignored on + * any non-loop block devices. */ + if (ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONTFREELOOP) && m) + del_loop(m->device); + if (ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m) + erase_mtab(m->dir); + } + + // Find next matching mtab entry for -a or umount /dev + // Note this means that "umount /dev/blah" will unmount all instances + // of /dev/blah, not just the most recent. + while (m && (m = m->next)) + if ((opt & OPT_ALL) || !strcmp(path, m->device)) + break; + } + + // Free mtab list if necessary + + if (ENABLE_FEATURE_CLEAN_UP) { + while (mtl) { + m = mtl->next; + free(mtl->device); + free(mtl->dir); + free(mtl); + mtl = m; + } + } + + return status; +} |