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-rw-r--r--client/mtab.c220
1 files changed, 0 insertions, 220 deletions
diff --git a/client/mtab.c b/client/mtab.c
deleted file mode 100644
index 70789bcb9d..0000000000
--- a/client/mtab.c
+++ /dev/null
@@ -1,220 +0,0 @@
-/*
- * mtab locking routines for use with mount.cifs and umount.cifs
- * Copyright (C) 2008 Jeff Layton (jlayton@samba.org)
- *
- * 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
- * the Free Software Foundation; either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
-*/
-
-/*
- * This code was copied from the util-linux-ng sources and modified:
- *
- * git://git.kernel.org/pub/scm/utils/util-linux-ng/util-linux-ng.git
- *
- * ...specifically from mount/fstab.c. That file has no explicit license. The
- * "default" license for anything in that tree is apparently GPLv2+, so I
- * believe we're OK to copy it here.
- *
- * Jeff Layton <jlayton@samba.org>
- */
-
-#include <unistd.h>
-#include <errno.h>
-#include <stdio.h>
-#include <sys/time.h>
-#include <sys/stat.h>
-#include <time.h>
-#include <fcntl.h>
-#include <mntent.h>
-#include <stdlib.h>
-#include <signal.h>
-#include "mount.h"
-
-
-/* Updating mtab ----------------------------------------------*/
-
-/* Flag for already existing lock file. */
-static int we_created_lockfile = 0;
-static int lockfile_fd = -1;
-
-/* Flag to indicate that signals have been set up. */
-static int signals_have_been_setup = 0;
-
-static void
-handler (int sig) {
- exit(EX_USER);
-}
-
-static void
-setlkw_timeout (int sig) {
- /* nothing, fcntl will fail anyway */
-}
-
-/* Remove lock file. */
-void
-unlock_mtab (void) {
- if (we_created_lockfile) {
- close(lockfile_fd);
- lockfile_fd = -1;
- unlink (_PATH_MOUNTED_LOCK);
- we_created_lockfile = 0;
- }
-}
-
-/* Create the lock file.
- The lock file will be removed if we catch a signal or when we exit. */
-/* The old code here used flock on a lock file /etc/mtab~ and deleted
- this lock file afterwards. However, as rgooch remarks, that has a
- race: a second mount may be waiting on the lock and proceed as
- soon as the lock file is deleted by the first mount, and immediately
- afterwards a third mount comes, creates a new /etc/mtab~, applies
- flock to that, and also proceeds, so that the second and third mount
- now both are scribbling in /etc/mtab.
- The new code uses a link() instead of a creat(), where we proceed
- only if it was us that created the lock, and hence we always have
- to delete the lock afterwards. Now the use of flock() is in principle
- superfluous, but avoids an arbitrary sleep(). */
-
-/* Where does the link point to? Obvious choices are mtab and mtab~~.
- HJLu points out that the latter leads to races. Right now we use
- mtab~.<pid> instead. Use 20 as upper bound for the length of %d. */
-#define MOUNTLOCK_LINKTARGET _PATH_MOUNTED_LOCK "%d"
-#define MOUNTLOCK_LINKTARGET_LTH (sizeof(_PATH_MOUNTED_LOCK)+20)
-
-/*
- * The original mount locking code has used sleep(1) between attempts and
- * maximal number of attemps has been 5.
- *
- * There was very small number of attempts and extremely long waiting (1s)
- * that is useless on machines with large number of concurret mount processes.
- *
- * Now we wait few thousand microseconds between attempts and we have global
- * time limit (30s) rather than limit for number of attempts. The advantage
- * is that this method also counts time which we spend in fcntl(F_SETLKW) and
- * number of attempts is not so much restricted.
- *
- * -- kzak@redhat.com [2007-Mar-2007]
- */
-
-/* maximum seconds between first and last attempt */
-#define MOUNTLOCK_MAXTIME 30
-
-/* sleep time (in microseconds, max=999999) between attempts */
-#define MOUNTLOCK_WAITTIME 5000
-
-int
-lock_mtab (void) {
- int i;
- struct timespec waittime;
- struct timeval maxtime;
- char linktargetfile[MOUNTLOCK_LINKTARGET_LTH];
-
- if (!signals_have_been_setup) {
- int sig = 0;
- struct sigaction sa;
-
- sa.sa_handler = handler;
- sa.sa_flags = 0;
- sigfillset (&sa.sa_mask);
-
- while (sigismember (&sa.sa_mask, ++sig) != -1
- && sig != SIGCHLD) {
- if (sig == SIGALRM)
- sa.sa_handler = setlkw_timeout;
- else
- sa.sa_handler = handler;
- sigaction (sig, &sa, (struct sigaction *) 0);
- }
- signals_have_been_setup = 1;
- }
-
- sprintf(linktargetfile, MOUNTLOCK_LINKTARGET, getpid ());
-
- i = open (linktargetfile, O_WRONLY|O_CREAT, S_IRUSR|S_IWUSR);
- if (i < 0) {
- /* linktargetfile does not exist (as a file)
- and we cannot create it. Read-only filesystem?
- Too many files open in the system?
- Filesystem full? */
- return EX_FILEIO;
- }
- close(i);
-
- gettimeofday(&maxtime, NULL);
- maxtime.tv_sec += MOUNTLOCK_MAXTIME;
-
- waittime.tv_sec = 0;
- waittime.tv_nsec = (1000 * MOUNTLOCK_WAITTIME);
-
- /* Repeat until it was us who made the link */
- while (!we_created_lockfile) {
- struct timeval now;
- struct flock flock;
- int errsv, j;
-
- j = link(linktargetfile, _PATH_MOUNTED_LOCK);
- errsv = errno;
-
- if (j == 0)
- we_created_lockfile = 1;
-
- if (j < 0 && errsv != EEXIST) {
- (void) unlink(linktargetfile);
- return EX_FILEIO;
- }
-
- lockfile_fd = open (_PATH_MOUNTED_LOCK, O_WRONLY);
-
- if (lockfile_fd < 0) {
- /* Strange... Maybe the file was just deleted? */
- gettimeofday(&now, NULL);
- if (errno == ENOENT && now.tv_sec < maxtime.tv_sec) {
- we_created_lockfile = 0;
- continue;
- }
- (void) unlink(linktargetfile);
- return EX_FILEIO;
- }
-
- flock.l_type = F_WRLCK;
- flock.l_whence = SEEK_SET;
- flock.l_start = 0;
- flock.l_len = 0;
-
- if (j == 0) {
- /* We made the link. Now claim the lock. If we can't
- * get it, continue anyway
- */
- fcntl (lockfile_fd, F_SETLK, &flock);
- (void) unlink(linktargetfile);
- } else {
- /* Someone else made the link. Wait. */
- gettimeofday(&now, NULL);
- if (now.tv_sec < maxtime.tv_sec) {
- alarm(maxtime.tv_sec - now.tv_sec);
- if (fcntl (lockfile_fd, F_SETLKW, &flock) == -1) {
- (void) unlink(linktargetfile);
- return EX_FILEIO;
- }
- alarm(0);
- nanosleep(&waittime, NULL);
- } else {
- (void) unlink(linktargetfile);
- return EX_FILEIO;
- }
- close(lockfile_fd);
- }
- }
- return 0;
-}
-