| commit 24f8174646123c2833bc87967b366796231b04e0 |
| Author: Liping Zhang <zlpnobody@gmail.com> |
| Date: Sun Feb 5 21:57:34 2017 +0800 |
| |
| 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 <zlpnobody@gmail.com> |
| Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> |
| |
| diff --git a/iptables/xshared.c b/iptables/xshared.c |
| index cccb8ae..055acf2 100644 |
| |
| |
| @@ -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; |
| } |
| } |
| |