[RFC PATCH v3 4/8] selftests/fuse: factor-out test fixture setup/teardown

[Luis Henriques]

In order to reduce new tests setup/teardown code duplication, factor-out
these functions from the existing acl_cache test into a new fuse_common.c
file that can be reused in other tests.

Signed-off-by: Luis Henriques <luis@xxxxxxxxxx>
---
 .../selftests/filesystems/fuse/Makefile       |  8 ++-
 .../filesystems/fuse/fuse_acl_cache_test.c    | 62 +++----------------
 .../selftests/filesystems/fuse/fuse_common.c  | 60 ++++++++++++++++++
 .../selftests/filesystems/fuse/fuse_common.h  | 25 ++++++++
 4 files changed, 100 insertions(+), 55 deletions(-)
 create mode 100644 tools/testing/selftests/filesystems/fuse/fuse_common.c
 create mode 100644 tools/testing/selftests/filesystems/fuse/fuse_common.h

diff --git a/tools/testing/selftests/filesystems/fuse/Makefile b/tools/testing/selftests/filesystems/fuse/Makefile
index a3ee9b3a2f5d..7744f796eb06 100644
--- a/tools/testing/selftests/filesystems/fuse/Makefile
+++ b/tools/testing/selftests/filesystems/fuse/Makefile
@@ -21,8 +21,12 @@ ifeq ($(VAR_LDLIBS),)
 VAR_LDLIBS := -lfuse3 -pthread
 endif
 
+CFLAGS += $(VAR_CFLAGS)
+LDLIBS += $(VAR_LDLIBS)
+
 $(OUTPUT)/fuse_mnt: CFLAGS += $(VAR_CFLAGS)
 $(OUTPUT)/fuse_mnt: LDLIBS += $(VAR_LDLIBS)
 
-$(OUTPUT)/fuse_acl_cache_test: CFLAGS += $(VAR_CFLAGS)
-$(OUTPUT)/fuse_acl_cache_test: LDLIBS += $(VAR_LDLIBS)
+$(OUTPUT)/fuse_acl_cache_test: fuse_common.c fuse_acl_cache_test.c
+
+EXTRA_CLEAN := fuse_common.o
diff --git a/tools/testing/selftests/filesystems/fuse/fuse_acl_cache_test.c b/tools/testing/selftests/filesystems/fuse/fuse_acl_cache_test.c
index 2411a6e285f1..12cbf9753d03 100644
--- a/tools/testing/selftests/filesystems/fuse/fuse_acl_cache_test.c
+++ b/tools/testing/selftests/filesystems/fuse/fuse_acl_cache_test.c
@@ -33,23 +33,15 @@
  */
 
 #define _GNU_SOURCE
-#include <errno.h>
 #include <fcntl.h>
 #include <linux/limits.h>
-#include <pthread.h>
 #include <stdint.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/stat.h>
 #include <sys/xattr.h>
-#include <unistd.h>
-
-#define FUSE_USE_VERSION 31
-#include <fuse_lowlevel.h>
 
 #include "kselftest_harness.h"
 
+#include "fuse_common.h"
+
 /* ---- ACL binary encoding ------------------------------------------------ */
 /*
  * POSIX ACL v2 xattr format (little-endian):
@@ -176,69 +168,33 @@ static const struct fuse_lowlevel_ops fs_ops = {
 	.getxattr = fs_getxattr,
 };
 
-/* ---- Daemon thread ------------------------------------------------------- */
-
-static void *run_daemon(void *arg)
-{
-	fuse_session_loop((struct fuse_session *)arg);
-	return NULL;
-}
-
 /* ---- kselftest harness --------------------------------------------------- */
 
 FIXTURE(acl_cache) {
 	struct fuse_session *se;
-	char                 mountpoint[PATH_MAX];
+	char                 mountpoint[MOUNTPOINT_SZ];
 	char                 file_path[PATH_MAX];
 	pthread_t            thread;
 };
 
 FIXTURE_SETUP(acl_cache)
 {
-	char *fuse_argv[] = { "fuse_acl_cache_test", NULL };
-	struct fuse_args args = FUSE_ARGS_INIT(1, fuse_argv);
+	char err[MAX_ERR_MSG];
 
-	g_ds.acl            = acl_a;
-	g_ds.acl_size       = sizeof(acl_a);
+	g_ds.acl = acl_a;
+	g_ds.acl_size = sizeof(acl_a);
 	g_ds.getxattr_count = 0;
 
-	strcpy(self->mountpoint, "/tmp/acl_cache_test_XXXXXX");
-	if (!mkdtemp(self->mountpoint))
-		SKIP(return, "mkdtemp: %s", strerror(errno));
+	if (fs_setup(&self->se, self->mountpoint, &fs_ops, &self->thread, err))
+		SKIP(return, err);
 
 	snprintf(self->file_path, sizeof(self->file_path),
 		 "%s/" FILE_NAME, self->mountpoint);
-
-	self->se = fuse_session_new(&args, &fs_ops, sizeof(fs_ops), NULL);
-	if (!self->se) {
-		rmdir(self->mountpoint);
-		SKIP(return, "fuse_session_new failed");
-	}
-
-	if (fuse_session_mount(self->se, self->mountpoint)) {
-		fuse_session_destroy(self->se);
-		rmdir(self->mountpoint);
-		SKIP(return, "fuse_session_mount failed "
-			     "(missing fusermount3 or insufficient privileges)");
-	}
-
-	if (pthread_create(&self->thread, NULL, run_daemon, self->se)) {
-		fuse_session_unmount(self->se);
-		fuse_session_destroy(self->se);
-		rmdir(self->mountpoint);
-		SKIP(return, "pthread_create: %s", strerror(errno));
-	}
-
-	fuse_opt_free_args(&args);
 }
 
 FIXTURE_TEARDOWN(acl_cache)
 {
-	fuse_session_exit(self->se);
-	fuse_session_unmount(self->se);
-	pthread_join(self->thread, NULL);
-	fuse_session_destroy(self->se);
-	rmdir(self->mountpoint);
+	fs_teardown(self->se, self->thread, self->mountpoint);
 }
 
 static int do_force_statx(const char *path)
diff --git a/tools/testing/selftests/filesystems/fuse/fuse_common.c b/tools/testing/selftests/filesystems/fuse/fuse_common.c
new file mode 100644
index 000000000000..3a91cac25b81
--- /dev/null
+++ b/tools/testing/selftests/filesystems/fuse/fuse_common.c
@@ -0,0 +1,60 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "fuse_common.h"
+
+static void *run_daemon(void *arg)
+{
+	fuse_session_loop((struct fuse_session *)arg);
+	return NULL;
+}
+
+int fs_setup(struct fuse_session **se, char *mountpoint,
+	     const struct fuse_lowlevel_ops *fs_ops,
+	     pthread_t *thread, char *err)
+{
+	char *fuse_argv[] = { "fuse_test", NULL };
+	struct fuse_args args = FUSE_ARGS_INIT(1, fuse_argv);
+
+	strcpy(mountpoint, MOUNTPOINT_TEMPLATE);
+	if (!mkdtemp(mountpoint)) {
+		snprintf(err, MAX_ERR_MSG, "mkdtemp: %s", strerror(errno));
+		return -1;
+	}
+
+	*se = fuse_session_new(&args, fs_ops, sizeof(*fs_ops), NULL);
+	if (!*se) {
+		rmdir(mountpoint);
+		snprintf(err, MAX_ERR_MSG, "fuse_session_new failed");
+		return -1;
+	}
+
+	if (fuse_session_mount(*se, mountpoint)) {
+		fuse_session_destroy(*se);
+		rmdir(mountpoint);
+		snprintf(err, MAX_ERR_MSG, "fuse_session_mount failed "
+			"(missing fusermount3 or insufficient privileges)");
+		return -1;
+	}
+
+	if (pthread_create(thread, NULL, run_daemon, *se)) {
+		fuse_session_unmount(*se);
+		fuse_session_destroy(*se);
+		rmdir(mountpoint);
+		snprintf(err, MAX_ERR_MSG, "pthread_create: %s", strerror(errno));
+		return -1;
+	}
+
+	fuse_opt_free_args(&args);
+
+	return 0;
+}
+
+void fs_teardown(struct fuse_session *se, pthread_t thread, char *mountpoint)
+{
+	fuse_session_exit(se);
+	fuse_session_unmount(se);
+	pthread_join(thread, NULL);
+	fuse_session_destroy(se);
+	rmdir(mountpoint);
+}
+
diff --git a/tools/testing/selftests/filesystems/fuse/fuse_common.h b/tools/testing/selftests/filesystems/fuse/fuse_common.h
new file mode 100644
index 000000000000..77d5eb58550d
--- /dev/null
+++ b/tools/testing/selftests/filesystems/fuse/fuse_common.h
@@ -0,0 +1,25 @@
+#ifndef __SELFTEST_FUSE_COMMON_H__
+#define __SELFTEST_FUSE_COMMON_H__
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define FUSE_USE_VERSION 31
+#include <fuse_lowlevel.h>
+
+#define MAX_ERR_MSG 256
+
+#define MOUNTPOINT_TEMPLATE "/tmp/fuse_test_XXXXXX"
+#define MOUNTPOINT_SZ 64
+
+int fs_setup(struct fuse_session **se, char *mountpoint,
+	     const struct fuse_lowlevel_ops *fs_ops,
+	     pthread_t *thread, char *err);
+void fs_teardown(struct fuse_session *se, pthread_t thread, char *mountpoint);
+
+#endif /* __SELFTEST_FUSE_COMMON_H__ */