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-rw-r--r--usr.sbin/autofs/autounmountd.c353
1 files changed, 353 insertions, 0 deletions
diff --git a/usr.sbin/autofs/autounmountd.c b/usr.sbin/autofs/autounmountd.c
new file mode 100644
index 000000000000..0230510d6e78
--- /dev/null
+++ b/usr.sbin/autofs/autounmountd.c
@@ -0,0 +1,353 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2014 The FreeBSD Foundation
+ *
+ * This software was developed by Edward Tomasz Napierala under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ */
+
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/mount.h>
+#include <sys/time.h>
+#include <assert.h>
+#include <errno.h>
+#include <libutil.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "common.h"
+
+#define AUTOUNMOUNTD_PIDFILE "/var/run/autounmountd.pid"
+
+struct automounted_fs {
+ TAILQ_ENTRY(automounted_fs) af_next;
+ time_t af_mount_time;
+ bool af_mark;
+ fsid_t af_fsid;
+ char af_mountpoint[MNAMELEN];
+};
+
+static TAILQ_HEAD(, automounted_fs) automounted;
+
+static struct automounted_fs *
+automounted_find(fsid_t fsid)
+{
+ struct automounted_fs *af;
+
+ TAILQ_FOREACH(af, &automounted, af_next) {
+ if (fsidcmp(&af->af_fsid, &fsid) == 0)
+ return (af);
+ }
+
+ return (NULL);
+}
+
+static struct automounted_fs *
+automounted_add(fsid_t fsid, const char *mountpoint)
+{
+ struct automounted_fs *af;
+
+ af = calloc(1, sizeof(*af));
+ if (af == NULL)
+ log_err(1, "calloc");
+ af->af_mount_time = time(NULL);
+ af->af_fsid = fsid;
+ strlcpy(af->af_mountpoint, mountpoint, sizeof(af->af_mountpoint));
+
+ TAILQ_INSERT_TAIL(&automounted, af, af_next);
+
+ return (af);
+}
+
+static void
+automounted_remove(struct automounted_fs *af)
+{
+
+ TAILQ_REMOVE(&automounted, af, af_next);
+ free(af);
+}
+
+static void
+refresh_automounted(void)
+{
+ struct automounted_fs *af, *tmpaf;
+ struct statfs *mntbuf;
+ int i, nitems;
+
+ nitems = getmntinfo(&mntbuf, MNT_WAIT);
+ if (nitems <= 0)
+ log_err(1, "getmntinfo");
+
+ log_debugx("refreshing list of automounted filesystems");
+
+ TAILQ_FOREACH(af, &automounted, af_next)
+ af->af_mark = false;
+
+ for (i = 0; i < nitems; i++) {
+ if (strcmp(mntbuf[i].f_fstypename, "autofs") == 0) {
+ log_debugx("skipping %s, filesystem type is autofs",
+ mntbuf[i].f_mntonname);
+ continue;
+ }
+
+ if ((mntbuf[i].f_flags & MNT_AUTOMOUNTED) == 0) {
+ log_debugx("skipping %s, not automounted",
+ mntbuf[i].f_mntonname);
+ continue;
+ }
+
+ af = automounted_find(mntbuf[i].f_fsid);
+ if (af == NULL) {
+ log_debugx("new automounted filesystem found on %s "
+ "(FSID:%d:%d)", mntbuf[i].f_mntonname,
+ mntbuf[i].f_fsid.val[0], mntbuf[i].f_fsid.val[1]);
+ af = automounted_add(mntbuf[i].f_fsid,
+ mntbuf[i].f_mntonname);
+ } else {
+ log_debugx("already known automounted filesystem "
+ "found on %s (FSID:%d:%d)", mntbuf[i].f_mntonname,
+ mntbuf[i].f_fsid.val[0], mntbuf[i].f_fsid.val[1]);
+ }
+ af->af_mark = true;
+ }
+
+ TAILQ_FOREACH_SAFE(af, &automounted, af_next, tmpaf) {
+ if (af->af_mark)
+ continue;
+ log_debugx("lost filesystem mounted on %s (FSID:%d:%d)",
+ af->af_mountpoint, af->af_fsid.val[0], af->af_fsid.val[1]);
+ automounted_remove(af);
+ }
+}
+
+static int
+unmount_by_fsid(const fsid_t fsid, const char *mountpoint)
+{
+ char *fsid_str;
+ int error, ret;
+
+ ret = asprintf(&fsid_str, "FSID:%d:%d", fsid.val[0], fsid.val[1]);
+ if (ret < 0)
+ log_err(1, "asprintf");
+
+ error = unmount(fsid_str, MNT_NONBUSY | MNT_BYFSID);
+ if (error != 0) {
+ if (errno == EBUSY) {
+ log_debugx("cannot unmount %s (%s): %s",
+ mountpoint, fsid_str, strerror(errno));
+ } else {
+ log_warn("cannot unmount %s (%s)",
+ mountpoint, fsid_str);
+ }
+ } else
+ rpc_umntall();
+
+ free(fsid_str);
+
+ return (error);
+}
+
+static time_t
+expire_automounted(time_t expiration_time)
+{
+ struct automounted_fs *af, *tmpaf;
+ time_t now;
+ time_t mounted_for, mounted_max = -1;
+ int error;
+
+ now = time(NULL);
+
+ log_debugx("expiring automounted filesystems");
+
+ TAILQ_FOREACH_SAFE(af, &automounted, af_next, tmpaf) {
+ mounted_for = difftime(now, af->af_mount_time);
+
+ if (mounted_for < expiration_time) {
+ log_debugx("skipping %s (FSID:%d:%d), mounted "
+ "for %jd seconds", af->af_mountpoint,
+ af->af_fsid.val[0], af->af_fsid.val[1],
+ (intmax_t)mounted_for);
+
+ if (mounted_for > mounted_max)
+ mounted_max = mounted_for;
+
+ continue;
+ }
+
+ log_debugx("filesystem mounted on %s (FSID:%d:%d), "
+ "was mounted for %ld seconds; unmounting",
+ af->af_mountpoint, af->af_fsid.val[0], af->af_fsid.val[1],
+ (long)mounted_for);
+ error = unmount_by_fsid(af->af_fsid, af->af_mountpoint);
+ if (error != 0) {
+ if (mounted_for > mounted_max)
+ mounted_max = mounted_for;
+ }
+ }
+
+ return (mounted_max);
+}
+
+static void
+usage_autounmountd(void)
+{
+
+ fprintf(stderr, "usage: autounmountd [-r time][-t time][-dv]\n");
+ exit(1);
+}
+
+static void
+do_wait(int kq, time_t sleep_time)
+{
+ struct timespec timeout;
+ struct kevent unused;
+ int nevents;
+
+ if (sleep_time != -1) {
+ assert(sleep_time > 0);
+ timeout.tv_sec = sleep_time;
+ timeout.tv_nsec = 0;
+
+ log_debugx("waiting for filesystem event for %ld seconds",
+ (long)sleep_time);
+ nevents = kevent(kq, NULL, 0, &unused, 1, &timeout);
+ } else {
+ log_debugx("waiting for filesystem event");
+ nevents = kevent(kq, NULL, 0, &unused, 1, NULL);
+ }
+ if (nevents < 0) {
+ if (errno == EINTR)
+ return;
+ log_err(1, "kevent");
+ }
+
+ if (nevents == 0) {
+ log_debugx("timeout reached");
+ assert(sleep_time > 0);
+ } else {
+ log_debugx("got filesystem event");
+ }
+}
+
+int
+main_autounmountd(int argc, char **argv)
+{
+ struct kevent event;
+ struct pidfh *pidfh;
+ pid_t otherpid;
+ const char *pidfile_path = AUTOUNMOUNTD_PIDFILE;
+ int ch, debug = 0, error, kq;
+ time_t expiration_time = 600, retry_time = 600, mounted_max, sleep_time;
+ bool dont_daemonize = false;
+
+ while ((ch = getopt(argc, argv, "dr:t:v")) != -1) {
+ switch (ch) {
+ case 'd':
+ dont_daemonize = true;
+ debug++;
+ break;
+ case 'r':
+ retry_time = atoi(optarg);
+ break;
+ case 't':
+ expiration_time = atoi(optarg);
+ break;
+ case 'v':
+ debug++;
+ break;
+ case '?':
+ default:
+ usage_autounmountd();
+ }
+ }
+ argc -= optind;
+ if (argc != 0)
+ usage_autounmountd();
+
+ if (retry_time <= 0)
+ log_errx(1, "retry time must be greater than zero");
+ if (expiration_time <= 0)
+ log_errx(1, "expiration time must be greater than zero");
+
+ log_init(debug);
+
+ pidfh = pidfile_open(pidfile_path, 0600, &otherpid);
+ if (pidfh == NULL) {
+ if (errno == EEXIST) {
+ log_errx(1, "daemon already running, pid: %jd.",
+ (intmax_t)otherpid);
+ }
+ log_err(1, "cannot open or create pidfile \"%s\"",
+ pidfile_path);
+ }
+
+ if (dont_daemonize == false) {
+ if (daemon(0, 0) == -1) {
+ log_warn("cannot daemonize");
+ pidfile_remove(pidfh);
+ exit(1);
+ }
+ }
+
+ pidfile_write(pidfh);
+
+ TAILQ_INIT(&automounted);
+
+ kq = kqueue();
+ if (kq < 0)
+ log_err(1, "kqueue");
+
+ EV_SET(&event, 0, EVFILT_FS, EV_ADD | EV_CLEAR, VQ_MOUNT | VQ_UNMOUNT, 0, NULL);
+ error = kevent(kq, &event, 1, NULL, 0, NULL);
+ if (error < 0)
+ log_err(1, "kevent");
+
+ for (;;) {
+ refresh_automounted();
+ mounted_max = expire_automounted(expiration_time);
+ if (mounted_max == -1) {
+ sleep_time = mounted_max;
+ log_debugx("no filesystems to expire");
+ } else if (mounted_max < expiration_time) {
+ sleep_time = difftime(expiration_time, mounted_max);
+ log_debugx("some filesystems expire in %ld seconds",
+ (long)sleep_time);
+ } else {
+ sleep_time = retry_time;
+ log_debugx("some expired filesystems remain mounted, "
+ "will retry in %ld seconds", (long)sleep_time);
+ }
+
+ do_wait(kq, sleep_time);
+ }
+
+ return (0);
+}
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