--- /dev/null
+/*
+ * Copyright (C) 2010 Karel Zak <kzak@redhat.com>
+ *
+ * This file may be redistributed under the terms of the
+ * GNU Lesser General Public License.
+ */
+
+/**
+ * SECTION: mtab
+ * @title: mtab managment
+ * @short_description: userspace mount information management
+ *
+ * The libmount library allows to use more modes for mtab management:
+ *
+ * - /etc/mtab is regular file
+ *
+ * then libmount manages the file in classical way (all mounts are
+ * added to the file)
+ *
+ * - /etc/mtab is symlink
+ *
+ * then libmount ignores mtab at all
+ *
+ * - /etc/mtab is symlink and /var/run/mount/ directory exists
+ *
+ * then libmount stores userspace specific mount options to the
+ * /var/run/mount/mountinfo file (the file format compatible to
+ * /proc/self/mountinfo)
+ *
+ *
+ * The mtab is always updated in two steps. The first step is to prepare a new
+ * mtab entry -- mnt_mtab_prepare_update(), this step has to be done before
+ * mount(2) syscall. The second step is to update the mtab file --
+ * mnt_update_mtab(), this step should be done after mount(2) syscall.
+ *
+ * The mnt_update_mtab() behaviour is undefined if mnt_mtab_prepare_update() has
+ * not been used.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include "c.h"
+#include "mountP.h"
+#include "mangle.h"
+#include "pathnames.h"
+
+
+
+/*
+ * mtab update description
+ */
+struct _mnt_mtab {
+ int action; /* MNT_ACT_{MOUNT,UMOUNT} */
+ int mountflags; /* MS_* flags */
+ char *filename; /* usually /etc/mtab or /var/run/mount/mountinfo */
+ char *old_target; /* for MS_MOVE */
+ int format; /* MNT_FMT_{MTAB,MOUNTINFO} */
+ int nolock; /* don't alloca private mnt_lock */
+ mnt_fs *fs; /* entry */
+ mnt_lock *lc; /* lock or NULL */
+};
+
+/**
+ * mnt_new_mtab:
+ * @action: MNT_ACT_{MOUNT,UMOUNT}
+ *
+ * Returns: newly allocated mtab description
+ */
+mnt_mtab *mnt_new_mtab(int action)
+{
+ mnt_mtab *mt;
+
+ mt = calloc(1, sizeof(struct _mnt_mtab));
+ if (!mt)
+ return NULL;
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: allocate\n", mt));
+
+ mt->action = action;
+ mt->fs = mnt_new_fs();
+ if (!mt->fs)
+ goto err;
+ return mt;
+err:
+ mnt_free_fs(mt->fs);
+ free(mt);
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab: failed to allocate handler\n"));
+
+ return NULL;
+}
+
+/**
+ * mnt_free_mtab:
+ * @mt: mtab
+ *
+ * Deallocates mnt_mtab handler.
+ */
+void mnt_free_mtab(mnt_mtab *mt)
+{
+ if (!mt)
+ return;
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: deallacate\n", mt));
+
+ mnt_free_lock(mt->lc);
+ free(mt->filename);
+ free(mt);
+}
+
+/**
+ * mnt_mtab_set_filename:
+ * @mt: mtab
+ * @filename: path to mtab (default is /etc/mtab or /var/run/mount/mountinfo)
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_filename(mnt_mtab *mt, const char *filename)
+{
+ char *p = NULL;
+ assert(mt);
+
+ if (!mt)
+ return -1;
+ if (filename) {
+ p = strdup(filename);
+ if (!p)
+ return -1;
+ }
+ free(mt->filename);
+ mt->filename = p;
+ return 0;
+}
+
+/**
+ * mnt_mtab_set_action:
+ * @mt: mtab
+ * @action: MNT_ACT_{MOUNT,UMOUNT}
+ *
+ * Overwrites the previously defined action by mnt_new_mtab().
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_action(mnt_mtab *mt, int action)
+{
+ assert(mt);
+ if (!mt)
+ return -1;
+ mt->action = action;
+ return 0;
+}
+
+/**
+ * mnt_mtab_set_format:
+ * @mt: mtab
+ * @format: MNT_FMT_{MTAB,MOUNTINFO}
+ *
+ * Sets mtab file format, default is MNT_FMT_MTAB for paths that end with
+ * "mtab" and MNT_FMT_MOUNTINFO for paths that end with "mountinfo".
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_format(mnt_mtab *mt, int format)
+{
+ assert(mt);
+ if (!mt)
+ return -1;
+ mt->format = format;
+ return 0;
+}
+
+/**
+ * mnt_mtab_set_optstr:
+ * @mt: mtab
+ * @optstr: mount options that will be used for mount(2)
+ *
+ * Note that mnt_mtab_prepare_update() will remove options that does not belong
+ * to mtab.
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_optstr(mnt_mtab *mt, const char *optstr)
+{
+ if (!mt)
+ return -1;
+ return mnt_fs_set_optstr(mt->fs, optstr);
+}
+
+/**
+ * mnt_mtab_set_mountflags:
+ * @mt: mtab
+ * @flags: MS_{REMOUNT,MOVE}
+ *
+ * Sets mount flags for mount/umount action. The flags are also
+ * extracted from mount options by mnt_mtab_prepare_update().
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_mountflags(mnt_mtab *mt, int flags)
+{
+ assert(mt);
+ if (!mt)
+ return -1;
+ mt->mountflags = flags;
+ return 0;
+}
+
+/**
+ * mnt_mtab_get_lock:
+ * @mt: mtab
+ *
+ * This function should not be called before mnt_mtab_prepare_update(). The lock
+ * is initialized when mtab update is required only.
+ *
+ * Note that after mnt_mtab_disable_lock(mt, TRUE) or after mnt_free_mtab()
+ * the lock will be automaticaly deallocated.
+ *
+ * Returns: libmount lock handler or NULL if locking is disabled.
+ */
+mnt_lock *mnt_mtab_get_lock(mnt_mtab *mt)
+{
+ return mt ? mt->lc : NULL;
+}
+
+/**
+ * mnt_mtab_disable_lock:
+ * @mt: mtab
+ * @disable: TRUE/FALSE
+ *
+ * Enable or disable mtab locking, the locking is enabled by default.
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_disable_lock(mnt_mtab *mt, int disable)
+{
+ if (!mt)
+ return -1;
+ if (disable) {
+ mnt_free_lock(mt->lc);
+ mt->lc = NULL;
+ }
+ mt->nolock = disable;
+ return 0;
+}
+
+/**
+ * mnt_mtab_set_source:
+ * @mt: mtab
+ * @source: device or directory name
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_source(mnt_mtab *mt, const char *source)
+{
+ return mt ? mnt_fs_set_source(mt->fs, source) : -1;
+}
+
+/**
+ * mnt_mtab_set_target:
+ * @mt: mtab
+ * @target: mountpoint
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_target(mnt_mtab *mt, const char *target)
+{
+ return mt ? mnt_fs_set_target(mt->fs, target) : -1;
+}
+
+/**
+ * mnt_mtab_set_old_target:
+ * @mt: mtab
+ * @target: old mountpoint
+ *
+ * Sets the original target for the MS_MOVE operation.
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_old_target(mnt_mtab *mt, const char *target)
+{
+ if (!mt)
+ return -1;
+ mt->old_target = strdup(target);
+ if (!mt->old_target)
+ return -1;
+ return 0;
+}
+
+/**
+ * mnt_mtab_set_fstype:
+ * @mt: mtab
+ * @fstype: filesystem type (e.g. "ext3")
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_mtab_set_fstype(mnt_mtab *mt, const char *fstype)
+{
+ if (!mt)
+ return -1;
+ return mnt_fs_set_fstype(mt->fs, fstype);
+}
+
+
+/*
+ * The format is same as /proc/self/mountinfo, but it contains userspace
+ * mount options and some unncessary fields are ignored.
+ */
+static int fprintf_mountinfo_fs(FILE *f, mnt_fs *fs)
+{
+ char *root = NULL, *target = NULL, *optstr = NULL,
+ *fstype = NULL, *source = NULL;
+ int rc = -1;
+ dev_t devno;
+
+ assert(fs);
+ assert(f);
+
+ if (!fs || !f)
+ return -1;
+ devno = mnt_fs_get_devno(fs);
+ source = mangle(mnt_fs_get_source(fs));
+ root = mangle(mnt_fs_get_root(fs));
+ target = mangle(mnt_fs_get_target(fs));
+ fstype = mangle(mnt_fs_get_fstype(fs));
+ optstr = mangle(mnt_fs_get_optstr(fs));
+
+ if (!root || !target || !optstr)
+ goto done;
+
+ rc = fprintf(f, "%i %i %u:%u %s %s %s - %s %s %s\n",
+ mnt_fs_get_id(fs),
+ mnt_fs_get_parent_id(fs),
+ major(devno), minor(devno),
+ root,
+ target,
+ optstr,
+ fstype ? fstype : "auto",
+ source ? source : "none",
+ "none");
+ rc = 0;
+done:
+ free(root);
+ free(target);
+ free(optstr);
+ free(fstype);
+ free(source);
+ return rc;
+}
+
+static int fprintf_mtab_fs(FILE *f, mnt_fs *fs)
+{
+ char *m1 = NULL, *m2 = NULL, *m3 = NULL, *m4 = NULL;
+ int rc = -1;
+
+ assert(fs);
+ assert(f);
+
+ if (!fs || !f)
+ return -1;
+
+ m1 = mangle(mnt_fs_get_source(fs));
+ m2 = mangle(mnt_fs_get_target(fs));
+ m3 = mangle(mnt_fs_get_fstype(fs));
+ m4 = mangle(mnt_fs_get_optstr(fs));
+
+ if (!m1 || !m2 || !m3 || !m4)
+ goto done;
+
+ rc = fprintf(f, "%s %s %s %s %d %d\n",
+ m1, m2, m3, m4,
+ mnt_fs_get_freq(fs),
+ mnt_fs_get_passno(fs));
+ rc = 0;
+done:
+ free(m1);
+ free(m2);
+ free(m3);
+ free(m4);
+
+ return rc;
+}
+
+static int update_file(const char *filename, int fmt, mnt_tab *tb)
+{
+ mnt_iter itr;
+ mnt_fs *fs;
+ FILE *f = NULL;
+ char tmpname[PATH_MAX];
+ struct stat st;
+ int fd;
+ int (*line_fn)(FILE *, mnt_fs *);
+
+ assert(tb);
+ if (!tb)
+ goto error;
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %s: update from tab %p\n", filename, tb));
+
+ if (snprintf(tmpname, sizeof(tmpname), "%s.tmp", filename)
+ >= sizeof(tmpname))
+ goto error;
+
+ f = fopen(tmpname, "w");
+ if (!f)
+ goto error;
+
+ line_fn = fmt == MNT_FMT_MTAB ? fprintf_mtab_fs : fprintf_mountinfo_fs;
+
+ mnt_reset_iter(&itr, MNT_ITER_FORWARD);
+ while(mnt_tab_next_fs(tb, &itr, &fs) == 0)
+ line_fn(f, fs);
+
+ fd = fileno(f);
+
+ if (fchmod(fd, S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) < 0)
+ goto error;
+
+ /* Copy uid/gid from the present file before renaming. */
+ if (stat(filename, &st) == 0) {
+ if (fchown(fd, st.st_uid, st.st_gid) < 0)
+ goto error;
+ }
+
+ fclose(f);
+ f = NULL;
+
+ if (rename(tmpname, filename) < 0)
+ goto error;
+
+ return 0;
+error:
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %s: update from tab %p failed\n", filename, tb));
+ if (f)
+ fclose(f);
+ return -1;
+}
+
+static int set_fs_root(mnt_mtab *mt, mnt_fs *fs)
+{
+ char *root = NULL, *mnt = NULL;
+ const char *fstype;
+ char *optstr;
+ mnt_tab *tb = NULL;
+
+ if (mt->mountflags & MS_REMOUNT)
+ return 0;
+
+ optstr = (char *) mnt_fs_get_optstr(fs);
+ fstype = mnt_fs_get_fstype(fs);
+
+ /*
+ * bind-mount -- get fs-root and source device for the source filesystem
+ */
+ if (mt->mountflags & MS_BIND) {
+ const char *src, *src_root;
+ mnt_fs *src_fs;
+
+ src = mnt_fs_get_srcpath(fs);
+ if (!src)
+ goto err;
+ mnt = mnt_get_mountpoint(src);
+ if (!mnt)
+ goto err;
+ root = mnt_get_fs_root(src, mnt);
+
+ tb = mnt_new_tab_from_file(_PATH_PROC_MOUNTINFO);
+ if (!tb)
+ goto dflt;
+ src_fs = mnt_tab_find_target(tb, mnt, MNT_ITER_BACKWARD);
+ if (!src_fs)
+ goto dflt;
+
+ /* set device name and fs */
+ src = mnt_fs_get_srcpath(src_fs);
+ mnt_fs_set_source(fs, src);
+
+ mnt_fs_set_fstype(fs, mnt_fs_get_fstype(src_fs));
+
+ /* on btrfs the subvolume is used as fs-root in
+ * /proc/self/mountinfo, so we have get the original subvolume
+ * name from src_fs and prepend the subvolume name to the
+ * fs-root path
+ */
+ src_root = mnt_fs_get_root(src_fs);
+ if (src_root && !startswith(root, src_root)) {
+ size_t sz = strlen(root) + strlen(src_root) + 1;
+ char *tmp = malloc(sz);
+
+ if (!tmp)
+ goto err;
+ snprintf(tmp, sz, "%s%s", src_root, root);
+ free(root);
+ root = tmp;
+ }
+ }
+
+ /*
+ * btrfs-subvolume mount -- get subvolume name and use it as a root-fs path
+ */
+ else if (fstype && !strcmp(fstype, "btrfs")) {
+ char *vol = NULL, *p;
+ size_t sz, volsz = 0;
+
+ if (mnt_optstr_get_option(optstr, "subvol", &vol, &volsz))
+ goto dflt;
+
+ sz = volsz;
+ if (*vol != '/')
+ sz++;
+ root = malloc(sz + 1);
+ if (!root)
+ goto err;
+ p = root;
+ if (*vol != '/')
+ *p++ = '/';
+ memcpy(p, vol, volsz);
+ *(root + sz) = '\0';
+ }
+
+dflt:
+ mnt_free_tab(tb);
+ if (!root)
+ root = strdup("/");
+ if (!root)
+ goto err;
+ fs->root = root;
+ free(mnt);
+ return 0;
+err:
+ free(root);
+ free(mnt);
+ return -1;
+}
+
+/**
+ * mnt_mtab_prepare_update:
+ * @mt: mtab
+ *
+ * Prepares internal data for mtab update:
+ * - set mtab filename if mnt_mtab_set_filename() was't called
+ * - set mtab file format if mnt_mtab_set_format() was't called
+ * - (bitwise) OR mountflags from mount options
+ * - for /var/run/mount/mountinfo:
+ * * evaluate if mtab update is necessary
+ * * set fs root and devname for bind mount and btrfs subvolumes
+ * - allocate mtab_lock if necessary
+ *
+ * This function has to be always called before mount(2). The mnt_update_mtab()
+ * should not be called is mnt_mtab_prepare_update() returns non-zero value.
+ *
+ * Returns: 0 on success, 1 if update is unncessary, -1 in case of error
+ */
+int mnt_mtab_prepare_update(mnt_mtab *mt)
+{
+ char *u = NULL;
+ const char *o = NULL;
+
+ assert(mt);
+
+ if (!mt)
+ return -1;
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: prepare update (target %s, source %s, optstr %s)\n",
+ mt, mnt_fs_get_target(mt->fs), mnt_fs_get_source(mt->fs),
+ mnt_fs_get_optstr(mt->fs)));
+
+ if (!mt->filename) {
+ const char *p = mnt_get_writable_mtab_path();
+ if (!p) {
+ if (errno)
+ goto err; /* EACCES? */
+ goto nothing; /* no mtab */
+ }
+ mt->filename = strdup(p);
+ if (!mt->filename)
+ goto err;
+ }
+ if (!mt->format)
+ mt->format = endswith(mt->filename, "mountinfo") ?
+ MNT_FMT_MOUNTINFO : MNT_FMT_MTAB;
+
+
+ /* TODO: cannonicalize source and target paths on mnt->fs */
+
+ o = mnt_fs_get_optstr(mt->fs);
+ if (o)
+ mt->mountflags |= mnt_optstr_get_mountflags(o);
+
+ /* umount */
+ if (mt->action == MNT_ACT_UMOUNT)
+ return 0;
+
+ /*
+ * A) classic /etc/mtab
+ */
+ if (mt->format != MNT_FMT_MOUNTINFO)
+ return 0;
+
+ /*
+ * B) /var/run/mount/mountinfo
+ */
+ if (mt->mountflags & MS_REMOUNT) {
+ /* remount */
+ if (mnt_split_optstr(o, &u, NULL, NULL, MNT_NOMTAB, 0))
+ goto err;
+ if (mnt_fs_set_optstr(mt->fs, u))
+ goto err;
+
+ } else {
+ if (!o)
+ goto nothing; /* no options */
+ if (mnt_split_optstr(o, &u, NULL, NULL, MNT_NOMTAB, 0))
+ goto err;
+ if (!u)
+ goto nothing; /* no userpsace options */
+ if (set_fs_root(mt, mt->fs))
+ goto err;
+ mnt_fs_set_optstr(mt->fs, u);
+ }
+
+ if (!mt->nolock && !mt->lc) {
+ mt->lc = mnt_new_lock(mt->filename, 0);
+ if (!mt->lc)
+ goto err;
+ }
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: prepare update: success\n", mt));
+ free(u);
+ return 0;
+err:
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: prepare update: failed\n", mt));
+ free(u);
+ return -1;
+nothing:
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: prepare update: unnecessary\n", mt));
+ free(u);
+ return 1;
+}
+
+static int add_entry(mnt_mtab *mt)
+{
+ FILE *f;
+ int rc = -1;
+
+ assert(mt);
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: add entry\n", mt));
+ if (mt->lc)
+ mnt_lock_file(mt->lc);
+ f = fopen(mt->filename, "a+");
+ if (f) {
+ if (mt->format == MNT_FMT_MOUNTINFO)
+ rc = fprintf_mountinfo_fs(f, mt->fs);
+ else
+ rc = fprintf_mtab_fs(f, mt->fs);
+ fclose(f);
+ }
+ if (mt->lc)
+ mnt_unlock_file(mt->lc);
+ return rc;
+}
+
+static int remove_entry(mnt_mtab *mt)
+{
+ const char *target;
+ mnt_tab *tb = NULL;
+ mnt_fs *fs = NULL;
+ int rc = -1;
+
+ assert(mt);
+ assert(mt->filename);
+
+ target = mnt_fs_get_target(mt->fs);
+ assert(target);
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: remove entry (target %s)\n", mt, target));
+
+ if (mt->lc)
+ mnt_lock_file(mt->lc);
+ tb = mnt_new_tab_from_file(mt->filename);
+ if (!tb)
+ goto done;
+ fs = mnt_tab_find_target(tb, target, MNT_ITER_BACKWARD);
+ if (!fs) {
+ rc = 0; /* no error if the file does not contain the target */
+ goto done;
+ }
+ mnt_tab_remove_fs(tb, fs);
+
+ if (!update_file(mt->filename, mt->format, tb))
+ rc = 0;
+done:
+ if (mt->lc)
+ mnt_unlock_file(mt->lc);
+ mnt_free_tab(tb);
+ mnt_free_fs(fs);
+ return rc;
+}
+
+static int modify_target(mnt_mtab *mt)
+{
+ mnt_tab *tb = NULL;
+ mnt_fs *fs = NULL;
+ int rc = -1;
+
+ assert(mt);
+ assert(mt->old_target);
+ assert(mt->filename);
+ assert(mnt_fs_get_target(mt->fs));
+
+ if (!mt->old_target)
+ return -1;
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: modify target (%s->%s)\n", mt,
+ mt->old_target, mnt_fs_get_target(mt->fs)));
+
+ if (mt->lc)
+ mnt_lock_file(mt->lc);
+ tb = mnt_new_tab_from_file(mt->filename);
+ if (!tb)
+ goto done;
+ fs = mnt_tab_find_target(tb, mt->old_target, MNT_ITER_BACKWARD);
+ if (!fs) {
+ rc = 0; /* no error if the file does not contain the target */
+ goto done;
+ }
+
+ mnt_fs_set_target(fs, mnt_fs_get_target(mt->fs));
+
+ if (!update_file(mt->filename, mt->format, tb))
+ rc = 0;
+done:
+ if (mt->lc)
+ mnt_unlock_file(mt->lc);
+ mnt_free_tab(tb);
+ return rc;
+}
+
+static int modify_options(mnt_mtab *mt)
+{
+ mnt_tab *tb = NULL;
+ mnt_fs *fs = NULL, *rem_fs = NULL;
+ int rc = -1;
+ const char *target = mnt_fs_get_target(mt->fs);
+
+ assert(target);
+ assert(mt->filename);
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: modify options (target %s)\n", mt, target));
+
+ if (mt->lc)
+ mnt_lock_file(mt->lc);
+ tb = mnt_new_tab_from_file(mt->filename);
+ if (!tb)
+ goto done;
+ fs = mnt_tab_find_target(tb, target, MNT_ITER_BACKWARD);
+ if (!fs) {
+ rc = 0; /* no error if the file does not contain the target */
+ goto done;
+ }
+ if (mt->format == MNT_FMT_MOUNTINFO && !mnt_fs_get_optstr(mt->fs)) {
+ mnt_tab_remove_fs(tb, fs);
+ rem_fs = fs;
+ } else
+ mnt_fs_set_optstr(fs, mnt_fs_get_optstr(mt->fs));
+
+ if (!update_file(mt->filename, mt->format, tb))
+ rc = 0;
+done:
+ if (mt->lc)
+ mnt_unlock_file(mt->lc);
+ mnt_free_tab(tb);
+ mnt_free_fs(rem_fs);
+ return rc;
+}
+
+/**
+ * mnt_update_mtab:
+ * @mt: mtab
+ *
+ * Updates the mtab file. The behavior of this function is undefined if
+ * mnt_mtab_prepare_update() has not been called.
+ *
+ * Returns: 0 on success, -1 in case of error.
+ */
+int mnt_update_mtab(mnt_mtab *mt)
+{
+ assert(mt);
+ assert(mt->filename);
+ assert(mt->format);
+
+ if (!mt)
+ return -1;
+
+ DBG(DEBUG_MTAB, fprintf(stderr,
+ "libmount: mtab %p: update (target %s)\n", mt,
+ mnt_fs_get_target(mt->fs)));
+ /*
+ * umount
+ */
+ if (mt->action == MNT_ACT_UMOUNT)
+ return remove_entry(mt);
+ /*
+ * mount
+ */
+ if (mt->action == MNT_ACT_MOUNT) {
+ if (mt->mountflags & MS_REMOUNT)
+ return modify_options(mt);
+
+ if (mt->mountflags & MS_MOVE)
+ return modify_target(mt);
+
+ return add_entry(mt); /* mount */
+ }
+ return -1;
+}
+
+#ifdef TEST_PROGRAM
+
+#include <errno.h>
+
+mnt_lock *lock;
+
+static void lock_fallback(void)
+{
+ if (lock)
+ mnt_unlock_file(lock);
+}
+
+static int update(mnt_mtab *mt)
+{
+ int rc;
+
+ /*
+ * Note that mount(2) syscal should be called *after*
+ * mnt_mtab_prepare_update() and *before* mnt_update_mtab()
+ */
+ rc = mnt_mtab_prepare_update(mt);
+ if (!rc) {
+ /* setup lock fallback */
+ lock = mnt_mtab_get_lock(mt);
+ atexit(lock_fallback);
+
+ return mnt_update_mtab(mt);
+ }
+ if (rc == 1) {
+ printf("mtab: update is not reuquired\n");
+ return 0;
+ }
+ fprintf(stderr, "mtab: failed to prepare update\n");
+ return -1;
+}
+
+int test_add(struct mtest *ts, int argc, char *argv[])
+{
+ mnt_mtab *mt;
+ int rc = -1;
+
+ if (argc < 5)
+ return -1;
+ mt = mnt_new_mtab(MNT_ACT_MOUNT);
+ if (!mt)
+ return -1;
+ mnt_mtab_set_source(mt, argv[1]);
+ mnt_mtab_set_target(mt, argv[2]);
+ mnt_mtab_set_fstype(mt, argv[3]);
+ mnt_mtab_set_optstr(mt, argv[4]);
+
+ rc = update(mt);
+
+ mnt_free_mtab(mt);
+ return rc;
+}
+
+int test_remove(struct mtest *ts, int argc, char *argv[])
+{
+ mnt_mtab *mt;
+ int rc = -1;
+
+ if (argc < 2)
+ return -1;
+ mt = mnt_new_mtab(MNT_ACT_UMOUNT);
+ if (!mt)
+ return -1;
+ mnt_mtab_set_target(mt, argv[1]);
+
+ rc = update(mt);
+
+ mnt_free_mtab(mt);
+ return rc;
+}
+
+int test_move(struct mtest *ts, int argc, char *argv[])
+{
+ mnt_mtab *mt;
+ int rc = -1;
+
+ if (argc < 3)
+ return -1;
+ mt = mnt_new_mtab(MNT_ACT_MOUNT);
+ if (!mt)
+ return -1;
+ mnt_mtab_set_mountflags(mt, MS_MOVE);
+ mnt_mtab_set_old_target(mt, argv[1]);
+ mnt_mtab_set_target(mt, argv[2]);
+
+ rc = update(mt);
+
+ mnt_free_mtab(mt);
+ return rc;
+}
+
+int test_remount(struct mtest *ts, int argc, char *argv[])
+{
+ mnt_mtab *mt;
+ int rc = -1;
+
+ if (argc < 3)
+ return -1;
+ mt = mnt_new_mtab(MNT_ACT_MOUNT);
+ if (!mt)
+ return -1;
+ mnt_mtab_set_mountflags(mt, MS_REMOUNT);
+ mnt_mtab_set_target(mt, argv[1]);
+ mnt_mtab_set_optstr(mt, argv[2]);
+
+ rc = update(mt);
+
+ mnt_free_mtab(mt);
+ return rc;
+}
+
+int main(int argc, char *argv[])
+{
+ struct mtest tss[] = {
+ { "--add", test_add, "<src> <target> <type> <options> add line to mtab" },
+ { "--remove", test_remove, "<target> MS_REMOUNT mtab change" },
+ { "--move", test_move, "<old_target> <target> MS_MOVE mtab change" },
+ { "--remount",test_remount, "<target> <options> MS_REMOUNT mtab change" },
+ { NULL }
+ };
+
+ return mnt_run_test(tss, argc, argv);
+}
+
+#endif /* TEST_PROGRAM */
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