/*

 *  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.

 */

--- net-snmp-5.4.1.orig/agent/mibgroup/host/hr_filesys.c	2007-05-18 11:08:01.000000000 -0700

+++ net-snmp-5.4.1/agent/mibgroup/host/hr_filesys.c	2012-08-17 01:23:04.781860694 -0700

@@ -31,6 +31,10 @@

 #include <sys/mount.h>

 #endif

+#ifdef solaris2

+#include <sys/stat.h>

+#endif

+

 #include <ctype.h>

 #if HAVE_STRING_H

 #include <string.h>

@@ -85,7 +89,11 @@

 #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

@@ -563,6 +571,12 @@

 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);

@@ -603,10 +617,62 @@

         }

     }

 #else

-    HRFS_index = 1;

-    if (fp != NULL)

-        fclose(fp);

-    fp = fopen(ETC_MNTTAB, "r");

+    	HRFS_index = 1;

+	if (fp != NULL)

+        	fclose(fp);

+#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

+

 #endif

 }

@@ -699,21 +765,24 @@

 #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

-    HRFS_entry = getmntent(fp);

-    if (HRFS_entry == NULL)

-        return -1;

-#endif                          /* solaris2 */

+	if (fp == NULL)

+                return -1;

+        HRFS_entry = getmntent(fp);

+        if (HRFS_entry == NULL)

+                return -1;

-    for (cpp = HRFS_ignores; *cpp != NULL; ++cpp)

-        if (!strcmp(HRFS_entry->HRFS_type, *cpp))

-            return Get_Next_HR_FileSys();

+	for (cpp = HRFS_ignores; *cpp != NULL; ++cpp)

+		if (!strcmp(HRFS_entry->HRFS_type, *cpp))

+			return Get_Next_HR_FileSys();

     /*

      * Try and ensure that index values are persistent

@@ -728,6 +797,8 @@

     }

     return HRFS_index++;

+#endif

+

 #endif                          /* HAVE_GETFSSTAT */

 }

@@ -780,20 +851,34 @@

 End_HR_FileSys(void)

 {

 #ifdef HAVE_GETFSSTAT

-    if (fsstats)

-        free((char *) fsstats);

-    fsstats = NULL;

+	if (fsstats)

+		free((char *) fsstats);

+	fsstats = NULL;

 #elif defined(aix4) || defined(aix5)

-    if(aixmnt != NULL) {

-        free(aixmnt);

-        aixmnt = NULL;

-        aixcurr = NULL;

-        HRFS_entry = NULL;

-    }

-#else

-    if (fp != NULL)

-        fclose(fp);

-    fp = NULL;

+	if(aixmnt != NULL) {

+		free(aixmnt);

+		aixmnt = NULL;

+		aixcurr = NULL;

+		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

 }