tests: example: add new test for increment epoch

This patch modifies the notify_inval_entry.c example so that it includes
an extra option to use fuse_lowlevel_notify_increment_epoch().  The test
test_notify_inval_entry() was also modified to test this extra option.

Signed-off-by: Luis Henriques <luis@igalia.com>

2 files changed, 43 insertions, 11 deletions

diff --git a/example/notify_inval_entry.c b/example/notify_inval_entry.c
index 1060d50..728a9dc 100644
--- a/example/notify_inval_entry.c
+++ b/example/notify_inval_entry.c
@@ -67,6 +67,12 @@
  * To use the function fuse_lowlevel_notify_expire_entry() instead of
  * fuse_lowlevel_notify_inval_entry(), use the command line option --only-expire
  *
+ * Another possible command-line option is --inc-epoch, which will use the FUSE
+ * low-level function fuse_lowlevel_notify_increment_epoch() instead.  This will
+ * function will force the invalidation of all dentries next time they are
+ * revalidated.  Note that --inc-epoch and --only-expire options are mutually
+ * exclusive.
+ *
  * ## Compilation ##
  *
  *     gcc -Wall notify_inval_entry.c `pkg-config fuse3 --cflags --libs` -o notify_inval_entry
@@ -103,12 +109,14 @@ struct options {
     float timeout;
     int update_interval;
     int only_expire;
+    int inc_epoch;
 };
 static struct options options = {
     .timeout = 5,
     .no_notify = 0,
     .update_interval = 1,
     .only_expire = 0,
+    .inc_epoch = 0,
 };
 
 #define OPTION(t, p)                           \
@@ -118,6 +126,7 @@ static const struct fuse_opt option_spec[] = {
     OPTION("--update-interval=%d", update_interval),
     OPTION("--timeout=%f", timeout),
     OPTION("--only-expire", only_expire),
+    OPTION("--inc-epoch", inc_epoch),
     FUSE_OPT_END
 };
 
@@ -263,7 +272,7 @@ static void update_fs(void) {
 static void* update_fs_loop(void *data) {
     struct fuse_session *se = (struct fuse_session*) data;
     char *old_name;
-
+    int ret = 0;
 
     while(!fuse_session_exited(se)) {
         old_name = strdup(file_name);
@@ -271,24 +280,27 @@ static void* update_fs_loop(void *data) {
 
         if (!options.no_notify && lookup_cnt) {
             if(options.only_expire) { // expire entry
-                int ret = fuse_lowlevel_notify_expire_entry
-                   (se, FUSE_ROOT_ID, old_name, strlen(old_name));
+                ret = fuse_lowlevel_notify_expire_entry
+                    (se, FUSE_ROOT_ID, old_name, strlen(old_name));
 
                 // no kernel support
                 if (ret == -ENOSYS) {
                     printf("fuse_lowlevel_notify_expire_entry not supported by kernel\n");
-                    printf("Exiting...\n");
-
-                    fuse_session_exit(se);
-                    // Make sure to exit now, rather than on next request from userspace
-                    pthread_kill(main_thread, SIGPIPE);
-
                     break;
                 }
+
                 // 1) ret == 0: successful expire of an existing entry
                 // 2) ret == -ENOENT: kernel has already expired the entry /
                 //                    entry does not exist anymore in the kernel
                 assert(ret == 0 || ret == -ENOENT);
+            } else if (options.inc_epoch) { // increment epoch
+                ret = fuse_lowlevel_notify_increment_epoch(se);
+
+                if (ret == -ENOSYS) {
+                    printf("fuse_lowlevel_notify_increment_epoch not supported by kernel\n");
+                    break;
+                }
+                assert(ret == 0);
             } else { // invalidate entry
                 assert(fuse_lowlevel_notify_inval_entry
                       (se, FUSE_ROOT_ID, old_name, strlen(old_name)) == 0);
@@ -297,6 +309,15 @@ static void* update_fs_loop(void *data) {
         free(old_name);
         sleep(options.update_interval);
     }
+
+    if (ret == -ENOSYS) {
+        printf("Exiting...\n");
+
+        fuse_session_exit(se);
+        // Make sure to exit now, rather than on next request from userspace
+        pthread_kill(main_thread, SIGPIPE);
+    }
+
     return NULL;
 }
 
@@ -307,7 +328,8 @@ static void show_help(const char *progname)
                "    --timeout=<secs>       Timeout for kernel caches\n"
                "    --update-interval=<secs>  Update-rate of file system contents\n"
                "    --no-notify            Disable kernel notifications\n"
-               "    --only-expire            Expire entries instead of invalidating them\n"
+               "    --only-expire          Expire entries instead of invalidating them\n"
+               "    --inc-epoch            Increment epoch, invalidating all dentries\n"
                "\n");
 }
 
@@ -336,6 +358,11 @@ int main(int argc, char *argv[]) {
         ret = 0;
         goto err_out1;
     }
+    if (options.only_expire && options.inc_epoch) {
+        printf("'only-expire' and 'inc-epoch' options are exclusive\n");
+        ret = 0;
+        goto err_out1;
+    }
 
     /* Initial contents */
     update_fs();
diff --git a/test/test_examples.py b/test/test_examples.py
index 2e23697..2658081 100755
--- a/test/test_examples.py
+++ b/test/test_examples.py
@@ -376,7 +376,8 @@ def test_null(tmpdir, output_checker):
 
 @pytest.mark.skipif(fuse_proto < (7,12),
                     reason='not supported by running kernel')
-@pytest.mark.parametrize("only_expire", ("invalidate_entries", "expire_entries"))
+@pytest.mark.parametrize("only_expire", ("invalidate_entries",
+                                         "expire_entries", "inc_epoch"))
 @pytest.mark.parametrize("notify", (True, False))
 def test_notify_inval_entry(tmpdir, only_expire, notify, output_checker):
     mnt_dir = str(tmpdir)
@@ -390,6 +391,10 @@ def test_notify_inval_entry(tmpdir, only_expire, notify, output_checker):
         cmdline.append('--only-expire')
         if "FUSE_CAP_EXPIRE_ONLY" not in fuse_caps:
             pytest.skip('only-expire not supported by running kernel')
+    elif only_expire == "inc_epoch":
+        cmdline.append('--inc-epoch')
+        if fuse_proto < (7,44):
+            pytest.skip('inc-epoch not supported by running kernel')
     mount_process = subprocess.Popen(cmdline, stdout=output_checker.fd,
                                      stderr=output_checker.fd)
     try: