Hi Christophe,
This patch fixes 2 logging bugs:
o multipath command prints unexpected log message like
"libdevmapper: libdm-common.c(303): Created /dev/mapper/<mapname>"
o multipathd doesn't log messages like "--------shut down------"
during the exit path
Please apply.
What is the problem:
o multipath command and multipathd register dm_write_log() using
dm_log_init() and it can be called from libdevmapper codes like
dm_lib_release().
o dm_write_log() references the global "conf" to find the verbosity,
but it is freed before dm_lib_release() calls dm_write_log().
o So dm_write_log() reads garbage value like big vervosity.
What does the patch do:
o multipath command sets NULL to "conf" after freeing it.
This prevents dm_write_log() from reading garbage data.
o multipath command and multipathd free "conf" after all logging
are completed, because the logging functions reference it
to find the verbosity.
Thanks,
Kiyoshi Ueda
diff -rupN git-20080326/multipath/main.c log-fix/multipath/main.c
--- git-20080326/multipath/main.c 2008-03-26 18:03:17.000000000 -0400
+++ log-fix/multipath/main.c 2008-03-26 18:42:21.000000000 -0400
@@ -421,9 +421,17 @@ main (int argc, char *argv[])
out:
sysfs_cleanup();
- free_config(conf);
dm_lib_release();
dm_lib_exit();
+
+ /*
+ * Freeing config must be done after dm_lib_exit(), because
+ * the logging function (dm_write_log()), which is called there,
+ * references the config.
+ */
+ free_config(conf);
+ conf = NULL;
+
#ifdef _DEBUG_
dbg_free_final(NULL);
#endif
diff -rupN git-20080326/multipathd/main.c log-fix/multipathd/main.c
--- git-20080326/multipathd/main.c 2008-03-26 18:03:16.000000000 -0400
+++ log-fix/multipathd/main.c 2008-03-26 18:43:16.000000000 -0400
@@ -1365,8 +1365,6 @@ child (void * param)
vecs->lock = NULL;
FREE(vecs);
vecs = NULL;
- free_config(conf);
- conf = NULL;
condlog(2, "--------shut down-------");
@@ -1376,6 +1374,14 @@ child (void * param)
dm_lib_release();
dm_lib_exit();
+ /*
+ * Freeing config must be done after condlog() and dm_lib_exit(),
+ * because logging functions like dlog() and dm_write_log()
+ * reference the config.
+ */
+ free_config(conf);
+ conf = NULL;
+
#ifdef _DEBUG_
dbg_free_final(NULL);
#endif
--
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