mount.cifs: use monotonic time for timeouts

this is especially important during the boot process, where the clock is often
being set initially and clock jumps are more common.

diff --git a/mtab.c b/mtab.c
index de1aabd6f87d71f5fbf7d37bb03a1222a25fb4a2..64e725071f1c717729675412d2c1c8e7aecc77a1 100644 (file)
--- a/mtab.c
+++ b/mtab.c
@@ -39,6 +39,7 @@
 #include <stdlib.h>
 #include <signal.h>
 #include "mount.h"
+#include "config.h"
 
 
 /* Updating mtab ----------------------------------------------*/
@@ -60,6 +61,22 @@ setlkw_timeout (int sig __attribute__((unused))) {
      /* nothing, fcntl will fail anyway */
 }
 
+/* use monotonic time for timeouts */
+struct timeval
+mono_time(void) {
+       struct timeval ret;
+#if defined(HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC)
+       struct timespec ts;
+       if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
+               ret.tv_sec = ts.tv_sec;
+               ret.tv_usec = ts.tv_nsec/1000;
+               return ret;
+       }
+#endif
+       gettimeofday(&ret,NULL);
+       return ret;
+}
+
 /* Remove lock file.  */
 void
 unlock_mtab (void) {
@@ -150,7 +167,7 @@ lock_mtab (void) {
        }
        close(i);
 
-       gettimeofday(&maxtime, NULL);
+       maxtime = mono_time();
        maxtime.tv_sec += MOUNTLOCK_MAXTIME;
 
        waittime.tv_sec = 0;
@@ -177,7 +194,7 @@ lock_mtab (void) {
 
                if (lockfile_fd < 0) {
                        /* Strange... Maybe the file was just deleted? */
-                       gettimeofday(&now, NULL);
+                       now = mono_time();
                        if (errno == ENOENT && now.tv_sec < maxtime.tv_sec) {
                                we_created_lockfile = 0;
                                continue;
@@ -199,7 +216,7 @@ lock_mtab (void) {
                        (void) unlink(linktargetfile);
                } else {
                        /* Someone else made the link. Wait. */
-                       gettimeofday(&now, NULL);
+                       now = mono_time();
                        if (now.tv_sec < maxtime.tv_sec) {
                                alarm(maxtime.tv_sec - now.tv_sec);
                                if (fcntl (lockfile_fd, F_SETLKW, &flock) == -1) {