autofs-5.0.5 - wait for master source mutex
From: Ian Kent <raven@themaw.net>
Occasionally we might not be able to get the master source write
lock when a read lock is held. We can wait a little while to see
if it gets released without causing a problem.
---
lib/master.c | 15 ++++++++++++++-
1 files changed, 14 insertions(+), 1 deletions(-)
diff --git a/lib/master.c b/lib/master.c
index 5846f72..53dfa27 100644
--- a/lib/master.c
+++ b/lib/master.c
@@ -536,13 +536,26 @@ void send_map_update_request(struct autofs_point *ap)
void master_source_writelock(struct master_mapent *entry)
{
+ int retries = 5; /* 1 second maximum */
int status;
- status = pthread_rwlock_wrlock(&entry->source_lock);
+ while (retries--) {
+ status = pthread_rwlock_wrlock(&entry->source_lock);
+ if (status != EAGAIN)
+ break;
+ else {
+ struct timespec t = { 0, 200000000 };
+ struct timespec r;
+ while (nanosleep(&t, &r) == -1 && errno == EINTR)
+ memcpy(&t, &r, sizeof(struct timespec));
+ }
+ }
+
if (status) {
logmsg("master_mapent source write lock failed");
fatal(status);
}
+
return;
}