From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Martin Wilck <mwilck@suse.com>
Date: Tue, 15 Dec 2020 17:09:49 +0100
Subject: [PATCH] multipath-tools: avoid access to /etc/localtime

If the root file system is multipathed, and IO is queued because all paths
are failed, multipathd may block trying to access the root FS, and thus be
unable to reinstate paths. One file that is frequently accessed is
/etc/localtime. Avoid that by printing monotonic timestamps instead.

Reviewed-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
---
 libmultipath/debug.c     | 14 ++++++++------
 libmultipath/devmapper.c | 12 ++++++------
 libmultipath/log.c       |  1 -
 multipathd/main.c        |  3 ---
 4 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/libmultipath/debug.c b/libmultipath/debug.c
index 429f2699..510e15e5 100644
--- a/libmultipath/debug.c
+++ b/libmultipath/debug.c
@@ -14,6 +14,8 @@
 #include "config.h"
 #include "defaults.h"
 #include "debug.h"
+#include "time-util.h"
+#include "util.h"
 
 int logsink;
 int libmp_verbosity = DEFAULT_VERBOSITY;
@@ -25,13 +27,13 @@ void dlog(int prio, const char * fmt, ...)
 	va_start(ap, fmt);
 	if (logsink != LOGSINK_SYSLOG) {
 		if (logsink == LOGSINK_STDERR_WITH_TIME) {
-			time_t t = time(NULL);
-			struct tm *tb = localtime(&t);
-			char buff[16];
+			struct timespec ts;
+			char buff[32];
 
-			strftime(buff, sizeof(buff),
-				 "%b %d %H:%M:%S", tb);
-			buff[sizeof(buff)-1] = '\0';
+			get_monotonic_time(&ts);
+			safe_sprintf(buff, "%ld.%06ld",
+				     (long)ts.tv_sec,
+				     ts.tv_nsec/1000);
 			fprintf(stderr, "%s | ", buff);
 		}
 		vfprintf(stderr, fmt, ap);
diff --git a/libmultipath/devmapper.c b/libmultipath/devmapper.c
index 4977b311..095cbc0c 100644
--- a/libmultipath/devmapper.c
+++ b/libmultipath/devmapper.c
@@ -27,6 +27,7 @@
 #include "config.h"
 #include "wwids.h"
 #include "version.h"
+#include "time-util.h"
 
 #include "log_pthread.h"
 #include <sys/types.h>
@@ -106,13 +107,12 @@ dm_write_log (int level, const char *file, int line, const char *f, ...)
 	va_start(ap, f);
 	if (logsink != LOGSINK_SYSLOG) {
 		if (logsink == LOGSINK_STDERR_WITH_TIME) {
-			time_t t = time(NULL);
-			struct tm *tb = localtime(&t);
-			char buff[16];
-
-			strftime(buff, sizeof(buff), "%b %d %H:%M:%S", tb);
-			buff[sizeof(buff)-1] = '\0';
+			struct timespec ts;
+			char buff[32];
 
+			get_monotonic_time(&ts);
+			safe_sprintf(buff, "%ld.%06ld",
+				     (long)ts.tv_sec, ts.tv_nsec/1000);
 			fprintf(stderr, "%s | ", buff);
 		}
 		fprintf(stderr, "libdevmapper: %s(%i): ", file, line);
diff --git a/libmultipath/log.c b/libmultipath/log.c
index 95c8f01a..6498c88c 100644
--- a/libmultipath/log.c
+++ b/libmultipath/log.c
@@ -120,7 +120,6 @@ void log_reset (char *program_name)
 	pthread_cleanup_push(cleanup_mutex, &logq_lock);
 
 	closelog();
-	tzset();
 	openlog(program_name, 0, LOG_DAEMON);
 
 	pthread_cleanup_pop(1);
diff --git a/multipathd/main.c b/multipathd/main.c
index 2eab4854..4417860b 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -2706,9 +2706,6 @@ reconfigure (struct vectors * vecs)
 	delete_all_foreign();
 
 	reset_checker_classes();
-	/* Re-read any timezone changes */
-	tzset();
-
 	if (bindings_read_only)
 		conf->bindings_read_only = bindings_read_only;
 	check_alias_settings(conf);