>
>
> getenv() and setenv() are not required by posix to be thread safe (see
> man pthreads). I assume there is a good reason for this.
>
> >From my interpretation of that man page, it appears syslog() is required
> to be thread safe. I took a look at glibc2.9 and it does indeed use
> strftime_l inside its syslog calls (which is on the non-threadsafe
> list).
>
> One workaround is simply to remove the use of the syslog libc API and
> implement it directly. I am not too enthusiastic about the current
> syslog implementation in libc after reading through the code (memory
> allocations, etc). This was done in the past but at some point was
> reverted.
>
> The issue remains regarding the proper use of getenv() and setenv()
> inside corosync. Ideally we wouldn't use thread unsafe apis, but we do
> and getenv/setenv seem pretty important. I thought of using weak (or
> maybe its called lazy) bindings to override getenv and setenv, but these
> apis appear to not support lazy(/or weak i forget term) bindings.
>
> To correct this problem fully I suggest the following changes:
> 1) write our own syslog implementation which connects to the syslog
> daemon socket and uses the write system call to write the output.
> Examples of this are in older versions of openais
> 2) add getenv() and setenv() apis to the coroapi definitions
> these getenv/setenv call the libc getenv/setenv with a mutex held to
> mutually exclude the environment. Pacemaker and internal corosync code
> can then call these getenv/setenv calls where necessary to ensure
> correct operation.
>
> There may be some issue with pacemaker using setenv after forking which
> could then operate on an invalid mutex that I would like Andrew's
> feedback regarding.
>
> bzs:
>
> https://bugzilla.redhat.com/show_bug.cgi?id=561180
>
> https://bugzilla.redhat.com/show_bug.cgi?id=561181
>
> Feel free to add your analysis
>
> Regards
> -steve
>
Thank you very much. I added a test program and some comments on bugzilla.
Also I tested my two proposals since I need some fix right now. It worked
OK. Only thing I needed to export HA_cluster_type=openais. I added this to
/etc/init.d/corosync before start(). I could change the pacemaker source to
use openais by default if HA_cluster_type is not set, then I don't need to
export. But it's OK. Until the fix is available, I will use my workaround.
hj
Index: corosync/exec/main.c
===================================================================
--- corosync/exec/main.c (revision 406)
+++ corosync/exec/main.c (working copy)
@@ -756,6 +756,10 @@
corosync_exit_error (AIS_DONE_INIT_SERVICES);
}
evil_init (api);
+
+ /* Create logsys worker thread after pcmk_startup() finishes
+ to prevent a seg fault from setenv()/getenv() */
+ logsys_fork_completed();
}
int main (int argc, char **argv)
@@ -994,7 +998,6 @@
if (background) {
corosync_tty_detach ();
}
- logsys_fork_completed();
/*
* Sleep for a while to let other nodes in the cluster
Index: pacemaker/lib/ais/plugin.c
===================================================================
--- pacemaker/lib/ais/plugin.c (revision 406)
+++ pacemaker/lib/ais/plugin.c (working copy)
@@ -325,11 +325,11 @@
get_config_opt(pcmk_api, local_handle, "debug", &value, "on");
if(ais_get_boolean(value)) {
plugin_log_level = LOG_DEBUG;
- setenv("HA_debug", "1", 1);
+ /*setenv("HA_debug", "1", 1);*/
} else {
plugin_log_level = LOG_INFO;
- setenv("HA_debug", "0", 1);
+ /*setenv("HA_debug", "0", 1);*/
}
get_config_opt(pcmk_api, local_handle, "to_file", &value, "off");
@@ -346,13 +346,13 @@
if(value == NULL) {
ais_err("Logging to a file requested but no log file specified");
} else {
- setenv("HA_logfile", value, 1);
+ /*setenv("HA_logfile", value, 1);*/
}
}
get_config_opt(pcmk_api, local_handle, "syslog_facility", &value, "daemon");
- setenv("HA_logfacility", value, 1);
- setenv("HA_LOGFACILITY", value, 1);
+ /*setenv("HA_logfacility", value, 1);*/
+ /*setenv("HA_LOGFACILITY", value, 1);*/
config_find_done(pcmk_api, local_handle);
@@ -371,7 +371,7 @@
local_cname_len = strlen(local_cname);
get_config_opt(pcmk_api, local_handle, "use_logd", &value, "no");
- setenv("HA_use_logd", value, 1);
+ /*setenv("HA_use_logd", value, 1);*/
get_config_opt(pcmk_api, local_handle, "use_mgmtd", &value, "no");
if(ais_get_boolean(value) == FALSE) {
@@ -511,8 +511,8 @@
membership_notify_list = g_hash_table_new(g_direct_hash, g_direct_equal);
ipc_client_list = g_hash_table_new(g_direct_hash, g_direct_equal);
- setenv("HA_COMPRESSION", "bz2", 1);
- setenv("HA_cluster_type", "openais", 1);
+ /*setenv("HA_COMPRESSION", "bz2", 1);
+ setenv("HA_cluster_type", "openais", 1);*/
ais_info("CRM: Initialized");
log_printf(LOG_INFO, "Logging: Initialized %s\n", __PRETTY_FUNCTION__);
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