From ae32c8a9193e09e405aa140ccc38fa557bcec215 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Tue, 31 Jan 2012 12:54:03 +0000
Subject: [PATCH] Upcoming change in sysfs will break the way libsensors
 detects if sysfs is mounted. Adjust the implementation so that it still works
 after said change.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/trunk@6017 7894878c-1315-0410-8ee3-d5d059ff63e0
---
 CHANGES     | 1 +
 lib/sysfs.c | 8 +++++---
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/CHANGES b/CHANGES
index 7a27669b..8dbf85d4 100644
--- a/CHANGES
+++ b/CHANGES
@@ -3,6 +3,7 @@ lm-sensors CHANGES file
 
 SVN HEAD
   libsensors: Added support for new sysfs attributes
+              Change sysfs detection to survive upcoming kernel changes
   sensors: Added support for new sysfs attributes
            Display both instantaneous and average power if available.
            Report thermal sensor type 1 as CPU diode
diff --git a/lib/sysfs.c b/lib/sysfs.c
index 94cea355..9068a71a 100644
--- a/lib/sysfs.c
+++ b/lib/sysfs.c
@@ -24,6 +24,7 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/vfs.h>
 #include <unistd.h>
 #include <string.h>
 #include <stdlib.h>
@@ -40,6 +41,7 @@
 /****************************************************************************/
 
 #define ATTR_MAX	128
+#define SYSFS_MAGIC	0x62656572
 
 /*
  * Read an attribute from sysfs
@@ -593,11 +595,11 @@ exit_free:
 /* returns !0 if sysfs filesystem was found, 0 otherwise */
 int sensors_init_sysfs(void)
 {
-	struct stat statbuf;
+	struct statfs statfsbuf;
 
 	snprintf(sensors_sysfs_mount, NAME_MAX, "%s", "/sys");
-	if (stat(sensors_sysfs_mount, &statbuf) < 0
-	 || statbuf.st_nlink <= 2)	/* Empty directory */
+	if (statfs(sensors_sysfs_mount, &statfsbuf) < 0
+	 || statfsbuf.f_type != SYSFS_MAGIC)
 		return 0;
 
 	return 1;