[LTP] [PATCH v4 1/2] OVL_MNT: add helpers to setup overlayfs mountpoint

[Petr Vorel]

Hi Murphy, Amir, Cyril,

just a suggestion to apply diff below:

1) mount_overlay(): you don't actually use lineno and safe in error messages
tst_fs_setup.c: In function ‘mount_overlay’:
tst_fs_setup.c:26:31: warning: unused parameter ‘file’ [-Wunused-parameter]
 int mount_overlay(const char *file, const int lineno, int safe)
                   ~~~~~~~~~~~~^~~~
tst_fs_setup.c:26:47: warning: unused parameter ‘lineno’ [-Wunused-parameter]
 int mount_overlay(const char *file, const int lineno, int safe)

2) mount_overlay(): return ret from mount (usually -1) instead of 1 (in case
anybody is interested).

3) mount_overlay(): earlier return 0 after checking ENODEV saves us one shift
right (but might look as error, as tst_res() is usually followed by return).

4) create_overlay_dirs(): checks for OVL_LOWER and thus can be called in
mount_overlay() without any check. This saves us calling it before
{SAFE,TST}_MOUNT_OVERLAY() in execveat03.c and readahead02.c

5) removed unused headers (<stdint.h>, <stdio.h>, <stdlib.h>, <sys/vfs.h>),
is any of them needed and the need masked by it's include in tst_test.h?

5) other cleanup

TODO:
I'm still not sure about ovl_mounted. There is static int mntpoint_mounted in
lib/tst_test.c, which does umount.  tst_test->mntpoint, I guess we should use
it. WDYT?

Kind regards,
Petr
---
* diff to first commit:
diff --git lib/tst_fs_setup.c lib/tst_fs_setup.c
index de09c7135..60dedc283 100644
--- lib/tst_fs_setup.c
+++ lib/tst_fs_setup.c
@@ -1,46 +1,46 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * DESCRIPTION
- *	A place for setup filesystem helpers.
- */
 
-#include <stdint.h>
+#include <dirent.h>
 #include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <sys/vfs.h>
 #include <sys/mount.h>
 
 #define TST_NO_DEFAULT_MAIN
 #include "tst_test.h"
 #include "tst_fs.h"
 
+#define TST_FS_SETUP_OVERLAYFS_MSG "overlayfs is not configured in this kernel"
+#define TST_FS_SETUP_OVERLAYFS_CONFIG "lowerdir="OVL_LOWER",upperdir="OVL_UPPER",workdir="OVL_WORK
+
 void create_overlay_dirs(void)
 {
-	SAFE_MKDIR(OVL_LOWER, 0755);
-	SAFE_MKDIR(OVL_UPPER, 0755);
-	SAFE_MKDIR(OVL_WORK, 0755);
-	SAFE_MKDIR(OVL_MNT, 0755);
+	DIR* dir = opendir(OVL_BASE_MNTPOINT);
+	if (!dir) {
+		SAFE_MKDIR(OVL_LOWER, 0755);
+		SAFE_MKDIR(OVL_UPPER, 0755);
+		SAFE_MKDIR(OVL_WORK, 0755);
+		SAFE_MKDIR(OVL_MNT, 0755);
+	}
 }
 
 int mount_overlay(const char *file, const int lineno, int safe)
 {
-	int ret = 0;
-	char *cfgmsg = "overlayfs is not configured in this kernel.";
-
-	ret = mount("overlay", OVL_MNT, "overlay", 0, "lowerdir="OVL_LOWER
-		    ",upperdir="OVL_UPPER",workdir="OVL_WORK);
-	if (ret < 0) {
-		if (errno == ENODEV) {
-			if (safe) {
-				tst_brk(TCONF, cfgmsg);
-			} else {
-				tst_res(TINFO, cfgmsg);
-				return 1;
-			}
+	int ret;
+
+	create_overlay_dirs();
+
+	ret = mount("overlay", OVL_MNT, "overlay", 0, TST_FS_SETUP_OVERLAYFS_CONFIG);
+
+	if (!ret)
+		return 0;
+
+	if (errno == ENODEV) {
+		if (safe) {
+			tst_brk(TCONF, "%s:%d: " TST_FS_SETUP_OVERLAYFS_MSG, file, lineno);
 		} else {
-			tst_brk(TBROK | TERRNO, "overlayfs mount failed");
+			tst_res(TINFO, "%s:%d: " TST_FS_SETUP_OVERLAYFS_MSG, file, lineno);
 		}
+	} else {
+		tst_brk(TBROK | TERRNO, "overlayfs mount failed");
 	}
-	return 0;
+	return ret;
 }

* diff to second commit:
diff --git testcases/kernel/syscalls/execveat/execveat03.c testcases/kernel/syscalls/execveat/execveat03.c
index 446ff4f1d..eb088bc4c 100644
--- testcases/kernel/syscalls/execveat/execveat03.c
+++ testcases/kernel/syscalls/execveat/execveat03.c
@@ -88,8 +88,6 @@ static void verify_execveat(void)
 static void setup(void)
 {
 	check_execveat();
-
-	create_overlay_dirs();
 	SAFE_MOUNT_OVERLAY();
 	ovl_mounted = 1;
 }
diff --git testcases/kernel/syscalls/inotify/inotify08.c testcases/kernel/syscalls/inotify/inotify08.c
index 929ed08f1..9433315e2 100644
--- testcases/kernel/syscalls/inotify/inotify08.c
+++ testcases/kernel/syscalls/inotify/inotify08.c
@@ -165,7 +165,7 @@ static void setup(void)
 	if (fd_notify < 0) {
 		if (errno == ENOSYS) {
 			tst_brk(TCONF,
-				"inotify is not configured in this kernel.");
+				"inotify is not configured in this kernel");
 		} else {
 			tst_brk(TBROK | TERRNO,
 				"inotify_init () failed");
diff --git testcases/kernel/syscalls/readahead/readahead02.c testcases/kernel/syscalls/readahead/readahead02.c
index db95c2b01..f6e07173d 100644
--- testcases/kernel/syscalls/readahead/readahead02.c
+++ testcases/kernel/syscalls/readahead/readahead02.c
@@ -388,7 +388,6 @@ static void setup(void)
 	setup_readahead_length();
 	tst_res(TINFO, "readahead length: %d", readahead_length);
 
-	create_overlay_dirs();
 	ovl_mounted = TST_MOUNT_OVERLAY();
 }