From 24f8174646123c2833bc87967b366796231b04e0 Mon Sep 17 00:00:00 2001 From: Liping Zhang Date: Sun, 5 Feb 2017 21:57:34 +0800 Subject: xshared: do not lock again and again if "-w" option is not specified After running the following commands, some confusing messages was printed out: # while : ; do iptables -A INPUT & iptables -D INPUT & done [...] Another app is currently holding the xtables lock; still -9s 0us time ahead to have a chance to grab the lock... Another app is currently holding the xtables lock; still -29s 0us time ahead to have a chance to grab the lock... If "-w" option is not specified, the "wait" will be zero, so we should check whether the timer_left is less than wait_interval before we call select to sleep. Also remove unused "BASE_MICROSECONDS" and "struct timeval waited_time" introduced by commit e8f857a5a151 ("xtables: Add an interval option for xtables lock wait"). Fixes: e8f857a5a151 ("xtables: Add an interval option for xtables lock wait") Signed-off-by: Liping Zhang Signed-off-by: Pablo Neira Ayuso --- iptables/xshared.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) (limited to 'iptables/xshared.c') diff --git a/iptables/xshared.c b/iptables/xshared.c index cccb8aec..055acf20 100644 --- a/iptables/xshared.c +++ b/iptables/xshared.c @@ -17,7 +17,6 @@ #include "xshared.h" #define XT_LOCK_NAME "/run/xtables.lock" -#define BASE_MICROSECONDS 100000 /* * Print out any special helps. A user might like to be able to add a --help @@ -249,13 +248,11 @@ void xs_init_match(struct xtables_match *match) bool xtables_lock(int wait, struct timeval *wait_interval) { - struct timeval time_left, wait_time, waited_time; + struct timeval time_left, wait_time; int fd, i = 0; time_left.tv_sec = wait; time_left.tv_usec = 0; - waited_time.tv_sec = 0; - waited_time.tv_usec = 0; fd = open(XT_LOCK_NAME, O_CREAT, 0600); if (fd < 0) @@ -264,6 +261,9 @@ bool xtables_lock(int wait, struct timeval *wait_interval) while (1) { if (flock(fd, LOCK_EX | LOCK_NB) == 0) return true; + else if (wait >= 0 && timercmp(&time_left, wait_interval, <)) + return false; + if (++i % 10 == 0) { if (wait != -1) fprintf(stderr, "Another app is currently holding the xtables lock; " @@ -279,10 +279,7 @@ bool xtables_lock(int wait, struct timeval *wait_interval) if (wait == -1) continue; - timeradd(&waited_time, wait_interval, &waited_time); timersub(&time_left, wait_interval, &time_left); - if (!timerisset(&time_left)) - return false; } } -- cgit v1.2.3