--- a/src/lib-storage/mail-autoexpunge.c	Thu Jun 22 02:33:03 2017 +0300
+++ b/src/lib-storage/mail-autoexpunge.c	Thu Jun 22 02:44:12 2017 +0300
@@ -2,7 +2,6 @@
 
 #include "lib.h"
 #include "ioloop.h"
-#include "file-create-locked.h"
 #include "mailbox-list-iter.h"
 #include "mail-storage-private.h"
 #include "mail-namespace.h"
@@ -14,9 +13,7 @@
 static bool
 mailbox_autoexpunge_lock(struct mail_user *user, struct file_lock **lock)
 {
-	struct file_create_settings lock_set;
-	bool created;
-	const char *home, *path, *error;
+	const char *error;
 	int ret;
 
 	if (*lock != NULL)
@@ -30,33 +27,19 @@
 	   so that multiple processes won't do the same work unnecessarily,
 	   and 2) it helps to avoid duplicate mails being added with
 	   lazy_expunge. */
-	if ((ret = mail_user_get_home(user, &home)) < 0) {
-		/* home lookup failed - shouldn't really happen */
+	ret = mail_user_lock_file_create(user, AUTOEXPUNGE_LOCK_FNAME,
+					 0, lock, &error);
+	if (ret < 0) {
+		i_error("autoexpunge: Couldn't create %s lock: %s",
+			AUTOEXPUNGE_LOCK_FNAME, error);
+		/* do autoexpunging anyway */
 		return TRUE;
-	}
-	if (ret == 0) {
-		i_warning("autoexpunge: User has no home directory, can't lock");
+	} else if (ret == 0) {
+		/* another process is autoexpunging, so we don't need to. */
+		return FALSE;
+	} else {
 		return TRUE;
 	}
-
-	const struct mail_storage_settings *mail_set =
-		mail_user_set_get_storage_set(user);
-	i_zero(&lock_set);
-	lock_set.lock_method = mail_set->parsed_lock_method;
-	path = t_strdup_printf("%s/"AUTOEXPUNGE_LOCK_FNAME, home);
-	if (file_create_locked(path, &lock_set, lock, &created, &error) == -1) {
-		if (errno == EAGAIN) {
-			/* another process is autoexpunging, so we don't
-			   need to. */
-			return FALSE;
-		}
-		i_error("autoexpunge: Couldn't lock %s: %s", path, error);
-		/* do autoexpunging anyway */
-		return TRUE;
-	}
-	file_lock_set_unlink_on_free(*lock, TRUE);
-	file_lock_set_close_on_free(*lock, TRUE);
-	return TRUE;
 }
 
 static int

--- a/src/lib-storage/mail-user.c	Thu Jun 22 02:33:03 2017 +0300
+++ b/src/lib-storage/mail-user.c	Thu Jun 22 02:44:12 2017 +0300
@@ -7,6 +7,7 @@
 #include "net.h"
 #include "module-dir.h"
 #include "home-expand.h"
+#include "file-create-locked.h"
 #include "safe-mkstemp.h"
 #include "str.h"
 #include "strescape.h"
@@ -496,6 +497,42 @@
 	str_append_c(dest, '.');
 }
 
+int mail_user_lock_file_create(struct mail_user *user, const char *lock_fname,
+			       unsigned int lock_secs,
+			       struct file_lock **lock_r, const char **error_r)
+{
+	bool created;
+	const char *home, *path, *error;
+	int ret;
+
+	if ((ret = mail_user_get_home(user, &home)) < 0) {
+		/* home lookup failed - shouldn't really happen */
+		*error_r = "Failed to lookup home directory";
+		errno = EINVAL;
+		return -1;
+	}
+	if (ret == 0) {
+		*error_r = "User has no home directory";
+		errno = EINVAL;
+		return -1;
+	}
+
+	const struct mail_storage_settings *mail_set =
+		mail_user_set_get_storage_set(user);
+	struct file_create_settings lock_set = {
+		.lock_timeout_secs = lock_secs,
+		.lock_method = mail_set->parsed_lock_method,
+	};
+	path = t_strdup_printf("%s/%s", home, lock_fname);
+	if (file_create_locked(path, &lock_set, lock_r, &created, &error) == -1) {
+		*error_r = t_strdup_printf("file_create_locked(%s) failed: %s", path, error);
+		return errno == EAGAIN ? 0 : -1;
+	}
+	file_lock_set_unlink_on_free(*lock_r, TRUE);
+	file_lock_set_close_on_free(*lock_r, TRUE);
+	return 1;
+}
+
 const char *mail_user_get_anvil_userip_ident(struct mail_user *user)
 {
 	if (user->remote_ip == NULL)

--- a/src/lib-storage/mail-user.h	Thu Jun 22 02:33:03 2017 +0300
+++ b/src/lib-storage/mail-user.h	Thu Jun 22 02:44:12 2017 +0300
@@ -152,6 +152,10 @@
    The file prefix doesn't contain any uniqueness. */
 void mail_user_set_get_temp_prefix(string_t *dest,
 				   const struct mail_user_settings *set);
+/* Returns 1 on success, 0 if lock_secs is reached, -1 on error */
+int mail_user_lock_file_create(struct mail_user *user, const char *lock_fname,
+			       unsigned int lock_secs,
+			       struct file_lock **lock_r, const char **error_r);
 
 /* Returns TRUE if plugin is loaded for the user. */
 bool mail_user_is_plugin_loaded(struct mail_user *user, struct module *module);