70 lines
2.2 KiB
Diff
70 lines
2.2 KiB
Diff
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From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Martin Wilck <mwilck@suse.com>
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Date: Tue, 15 Sep 2020 12:46:36 +0200
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Subject: [PATCH] multipathd: generalize and fix wait_for_state_change_if()
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It's unlikely but not impossible that other threads change the state
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while we're waiting, and if we grab the lock again, it's still not
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what we wanted. We need to continue waiting until either the condition
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is met, or time timeout expired.
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Moreover, generalize this code so that it can also be used in
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set_config_state().
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Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
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Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
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---
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multipathd/main.c | 25 ++++++++++++++++++-------
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1 file changed, 18 insertions(+), 7 deletions(-)
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diff --git a/multipathd/main.c b/multipathd/main.c
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index d081b3e9..1fb0ee62 100644
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--- a/multipathd/main.c
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+++ b/multipathd/main.c
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@@ -223,6 +223,23 @@ static void config_cleanup(__attribute__((unused)) void *arg)
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pthread_mutex_unlock(&config_lock);
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}
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+#define __wait_for_state_change(condition, ms) \
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+ ({ \
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+ struct timespec tmo; \
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+ int rc = 0; \
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+ \
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+ if (condition) { \
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+ get_monotonic_time(&tmo); \
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+ tmo.tv_nsec += (ms) * 1000 * 1000; \
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+ normalize_timespec(&tmo); \
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+ do \
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+ rc = pthread_cond_timedwait( \
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+ &config_cond, &config_lock, &tmo); \
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+ while (rc == 0 && (condition)); \
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+ } \
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+ rc; \
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+ })
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+
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/*
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* If the current status is @oldstate, wait for at most @ms milliseconds
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* for the state to change, and return the new state, which may still be
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@@ -232,20 +249,14 @@ enum daemon_status wait_for_state_change_if(enum daemon_status oldstate,
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unsigned long ms)
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{
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enum daemon_status st;
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- struct timespec tmo;
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if (oldstate == DAEMON_SHUTDOWN)
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return DAEMON_SHUTDOWN;
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pthread_mutex_lock(&config_lock);
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pthread_cleanup_push(config_cleanup, NULL);
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+ __wait_for_state_change(running_state == oldstate, ms);
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st = running_state;
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- if (st == oldstate && clock_gettime(CLOCK_MONOTONIC, &tmo) == 0) {
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- tmo.tv_nsec += ms * 1000 * 1000;
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- normalize_timespec(&tmo);
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- (void)pthread_cond_timedwait(&config_cond, &config_lock, &tmo);
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- st = running_state;
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- }
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pthread_cleanup_pop(1);
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return st;
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}
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