From 3c7ba57050ae84679a81dde6bbce876826c25420 Mon Sep 17 00:00:00 2001
From: Bernd Schubert <bschubert@ddn.com>
Date: Tue, 26 Dec 2023 11:53:55 +0100
Subject: [PATCH] examples/notify_store_retrieve: Add a clean shutdown

On shutdown update_fs_loop() was failing frequently in github
test with ENOENT, but only ENODEV was tested for and only for the.
With clean shutdown there is no need to test for such errors at all.
---
 example/notify_store_retrieve.c | 31 ++++++++++++++++++++-----------
 1 file changed, 20 insertions(+), 11 deletions(-)

diff --git a/example/notify_store_retrieve.c b/example/notify_store_retrieve.c
index 0a165c5..c4d0087 100644
--- a/example/notify_store_retrieve.c
+++ b/example/notify_store_retrieve.c
@@ -70,6 +70,7 @@
 #include <stddef.h>
 #include <unistd.h>
 #include <pthread.h>
+#include <stdbool.h>
 
 /* We can't actually tell the kernel that there is no
    timeout, so we just send a big value */
@@ -86,6 +87,12 @@ static size_t file_size;
    received it back correctly (==2) */
 static int retrieve_status = 0;
 
+static bool is_umount = false;
+
+/* updater thread tid */
+static pthread_t updater;
+
+
 /* Command line parsing */
 struct options {
     int no_notify;
@@ -268,6 +275,15 @@ static void tfs_retrieve_reply(fuse_req_t req, void *cookie, fuse_ino_t ino,
     fuse_reply_none(req);
 }
 
+static void tfs_destroy(void *userdata)
+{
+	(void)userdata;
+
+	is_umount = true;
+
+	pthread_join(updater, NULL);
+}
+
 
 static const struct fuse_lowlevel_ops tfs_oper = {
     .lookup	= tfs_lookup,
@@ -277,6 +293,7 @@ static const struct fuse_lowlevel_ops tfs_oper = {
     .read	= tfs_read,
     .forget     = tfs_forget,
     .retrieve_reply = tfs_retrieve_reply,
+    .destroy    = tfs_destroy,
 };
 
 static void update_fs(void) {
@@ -296,7 +313,7 @@ static void* update_fs_loop(void *data) {
     struct fuse_bufvec bufv;
     int ret;
 
-    while(1) {
+    while(!is_umount) {
         update_fs();
         if (!options.no_notify && lookup_cnt) {
             /* Only send notification if the kernel
@@ -311,11 +328,7 @@ static void* update_fs_loop(void *data) {
             /* This shouldn't fail, but apparently it sometimes
                does - see https://github.com/libfuse/libfuse/issues/105 */
             ret = fuse_lowlevel_notify_store(se, FILE_INO, 0, &bufv, 0);
-            if (-ret == ENODEV) {
-                // File system was unmounted
-                break;
-            }
-            else if (ret != 0) {
+            if (ret != 0 && !is_umount) {
                 fprintf(stderr, "ERROR: fuse_lowlevel_notify_store() failed with %s (%d)\n",
                         strerror(-ret), -ret);
                 abort();
@@ -325,10 +338,7 @@ static void* update_fs_loop(void *data) {
                kernel to send us back the stored data */
             ret = fuse_lowlevel_notify_retrieve(se, FILE_INO, MAX_STR_LEN,
                                                 0, (void*) strdup(file_contents));
-            if (-ret == ENODEV) { // File system was unmounted
-                break;
-            }
-            assert(ret == 0);
+            assert(ret == 0 || is_umount);
             if(retrieve_status == 0)
                 retrieve_status = 1;
         }
@@ -351,7 +361,6 @@ int main(int argc, char *argv[]) {
     struct fuse_session *se;
     struct fuse_cmdline_opts opts;
     struct fuse_loop_config config;
-    pthread_t updater;
     int ret = -1;
 
     if (fuse_opt_parse(&args, &options, option_spec, NULL) == -1)
-- 
2.30.2