/*
 *  Version 2 - Modified the patch file to make it work for the newer
 *  revision in net-snmp 5.7.2. Some fragments of the patch had gone
 *  into the community net-snmp source. So this patch file has been
 *  updated with the correct diffs.
 *
 *  This patch fixes the performance issue observed while retrieving the
 *  hrStorage parameters in systems with large number of mountpoints
 *  parameters using snmpwalk.
 *
 *  This issue is happening due to the overhead of large number of
 *  ioctl() system calls in getmntent() function called by the
 *  Get_Next_HR_FileSys() function.
 *
 *  We see that in the Get_Next_HR_FileSys() function, inorder to access
 *  the last mountpoint, the /etc/mnttab is opened and we walk through 
 *  all the mnttab entries for all filesystems till the end. This is the 
 *  reason we find a large number of the MNTIOC_GETMNTENT ioctl() calls.  
 *
 *  To reduce the overhead of the getmntent() calls, we maintain a cache
 *  of all the /etc/mnttab entries and walk through the cache instead of 
 *  opening /etc/mnttab and walking all the entries for each mountpoint.
 *  This functionality is provided by the load_mnttab_cache_solaris()
 *  function called from the Init_HR_FileSys() function.
 */

--- net-snmp/agent/mibgroup/host/hr_filesys.c	Sun Dec 30 22:37:05 2012
+++ net-snmp/agent/mibgroup/host/hr_filesys.c	Mon Dec 31 00:55:29 2012
@@ -46,6 +46,10 @@
 #include <sys/mount.h>
 #endif
 
+#ifdef solaris2
+#include <sys/stat.h>
+#endif
+
 #include <ctype.h>
 #if HAVE_STRING_H
 #include <string.h>
@@ -108,7 +112,11 @@
 #ifdef solaris2
 
 struct mnttab   HRFS_entry_struct;
-struct mnttab  *HRFS_entry = &HRFS_entry_struct;
+struct mnttab  *HRFS_entry;
+struct mnttab	*HRFS_list;
+static int fscount;
+static time_t last_access=-1;
+
 #define	HRFS_name	mnt_special
 #define	HRFS_mount	mnt_mountp
 #define	HRFS_type	mnt_fstype
@@ -619,6 +627,12 @@
 void
 Init_HR_FileSys(void)
 {
+#ifdef solaris2
+	char buf[512]={NULL};
+	int lines=0, i=0;
+	struct stat file_stat;
+#endif
+
 #if HAVE_GETFSSTAT
 #if defined(HAVE_STATVFS) && defined(__NetBSD__)
     fscount = getvfsstat(NULL, 0, ST_NOWAIT);
@@ -662,7 +676,59 @@
     HRFS_index = 1;
     if (fp != NULL)
         fclose(fp);
-    fp = fopen(ETC_MNTTAB, "r");
+#ifdef solaris2
+	HRFS_index = 0;
+	stat(ETC_MNTTAB, &file_stat);
+	if (last_access == -1 || last_access != file_stat.st_mtime) { 
+    		fp = fopen(ETC_MNTTAB, "r");
+		if(fp == NULL)
+		{
+			DEBUGMSGTL(("host/hr_filesys", "fopen failed for mnttab.\n"));
+			return;
+		}
+
+		while ( (fgets((char *)&buf,sizeof(buf),fp)) != NULL) {
+			lines++;
+		}	
+		fclose(fp);
+	
+		HRFS_list = (struct mnttab *) malloc (sizeof(struct mnttab) * lines);
+		
+		if(HRFS_list == NULL)
+		{
+			DEBUGMSGTL(("host/hr_filesys", "Memory allocation for mnttab cache failed.\n"));
+			return;
+		}				
+
+    		fp = fopen(ETC_MNTTAB, "r");
+		
+		if(fp == NULL)
+                {
+			DEBUGMSGTL(("host/hr_filesys", "fopen failed for mnttab.\n"));
+			free(HRFS_list);
+			return;
+                }
+
+		fscount = lines;
+		while (i < fscount)
+    		{
+			if (getmntent(fp, &HRFS_entry_struct) == 0)
+        		{
+				HRFS_list[i].mnt_special = strdup(HRFS_entry_struct.mnt_special);
+				HRFS_list[i].mnt_mountp = strdup(HRFS_entry_struct.mnt_mountp);
+				HRFS_list[i].mnt_fstype = strdup(HRFS_entry_struct.mnt_fstype);
+				HRFS_list[i].mnt_mntopts = strdup(HRFS_entry_struct.mnt_mntopts);
+        			i++;
+        		}
+    		}
+	
+		HRFS_entry = HRFS_list;
+		last_access = file_stat.st_mtime;
+	}
+#else    
+	fp = fopen(ETC_MNTTAB, "r");
+#endif
+
     if (!fp) {
       netsnmp_config_error("Can't open mnttab %s\n", ETC_MNTTAB);
     }
@@ -758,17 +824,20 @@
 #else
     const char    **cpp;
 
-    if (fp == NULL)
-        return -1;
 
 #ifdef solaris2
-    if (getmntent(fp, HRFS_entry) != 0)
-        return -1;
+
+	if (HRFS_index >= fscount)
+		return -1;
+	HRFS_entry = &HRFS_list[HRFS_index];
+		return ++HRFS_index;
+
 #else
+	if (fp == NULL)
+                return -1;
     HRFS_entry = getmntent(fp);
     if (HRFS_entry == NULL)
         return -1;
-#endif                          /* solaris2 */
 
     for (cpp = HRFS_ignores; *cpp != NULL; ++cpp)
         if (!strcmp(HRFS_entry->HRFS_type, *cpp))
@@ -787,6 +856,8 @@
     }
 
     return HRFS_index++;
+#endif
+
 #endif                          /* HAVE_GETFSSTAT */
 }
 
@@ -854,10 +925,24 @@
         HRFS_entry = NULL;
     }
 #else
+    int i=0;
     if (fp != NULL)
         fclose(fp);
     fp = NULL;
+
+#ifdef solaris2
+	while (i < fscount) {
+		free(HRFS_list[i].mnt_special);
+		free(HRFS_list[i].mnt_mountp);
+		free(HRFS_list[i].mnt_fstype);
+		free(HRFS_list[i].mnt_mntopts);
+		i++;
+	}
+	if (HRFS_list != NULL)
+		free(HRFS_list);
 #endif
+
+#endif
 }