--- a/dovecot-example.conf	Tue Apr 10 17:37:50 2007 +0300
+++ b/dovecot-example.conf	Wed Apr 11 11:56:17 2007 +0300
@@ -1055,8 +1055,10 @@
   # ACL plugin. vfile backend reads ACLs from "dovecot-acl" file from maildir
   # directory. You can also optionally give a global ACL directory path where
   # ACLs are applied to all users' mailboxes. The global ACL directory contains
-  # one file for each mailbox, eg. INBOX or sub.mailbox.
-  #acl = vfile:/etc/dovecot-acls
+  # one file for each mailbox, eg. INBOX or sub.mailbox. cache_secs parameter
+  # specifies how many seconds to wait between stat()ing dovecot-acl file
+  # to see if it changed.
+  #acl = vfile:/etc/dovecot-acls:cache_secs=300
 
   # Convert plugin. If set, specifies the source storage path which is
   # converted to destination storage (mail_location) when the user logs in.

--- a/src/plugins/acl/acl-backend-vfile.c	Tue Apr 10 17:37:50 2007 +0300
+++ b/src/plugins/acl/acl-backend-vfile.c	Wed Apr 11 11:56:17 2007 +0300
@@ -9,15 +9,13 @@
 #include "acl-cache.h"
 #include "acl-api-private.h"
 
+#include <stdlib.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <sys/stat.h>
 
 #define ACL_FILENAME "dovecot-acl"
 
-/* Minimum time between stat()ing the ACL file to see if its timestamp has
-   changed. */
-#define ACL_VALIDITY_SECS 1
 /* Time difference to allow between this system's time and file server's time */
 #define ACL_SYNC_SECS 1
 
@@ -38,6 +36,7 @@
 struct acl_backend_vfile {
 	struct acl_backend backend;
 	const char *global_dir;
+	unsigned int cache_secs;
 };
 
 struct acl_object_vfile {
@@ -81,14 +80,30 @@
 {
 	struct acl_backend_vfile *backend =
 		(struct acl_backend_vfile *)_backend;
+	const char *const *tmp;
 
-	if (_backend->debug)
-		i_info("acl vfile: Global ACL directory: %s", data);
+	t_push();
+	tmp = t_strsplit(data, ":");
+	backend->global_dir = p_strdup(_backend->pool, *tmp);
 
-	backend->global_dir = p_strdup(_backend->pool, data);
+	while (*++tmp != NULL) {
+		if (strncmp(*tmp, "cache_secs=", 11) == 0)
+			backend->cache_secs = atoi(*tmp + 11);
+		else {
+			i_error("acl vfile: Unknown parameter: %s", *tmp);
+			t_pop();
+			return -1;
+		}
+	}
+	if (_backend->debug) {
+		i_info("acl vfile: Global ACL directory: %s",
+		       backend->global_dir);
+	}
+
 	_backend->cache =
 		acl_cache_init(_backend,
 			       sizeof(struct acl_backend_vfile_validity));
+	t_pop();
 	return 0;
 }
 
@@ -388,12 +403,14 @@
 acl_backend_vfile_refresh(struct acl_object *aclobj, const char *path,
 			  struct acl_vfile_validity *validity)
 {
+	struct acl_backend_vfile *backend =
+		(struct acl_backend_vfile *)aclobj->backend;
 	struct stat st;
 
 	if (validity == NULL)
 		return 1;
 	if (path == NULL ||
-	    validity->last_check + ACL_VALIDITY_SECS > ioloop_time)
+	    validity->last_check + backend->cache_secs > ioloop_time)
 		return 0;
 
 	validity->last_check = ioloop_time;