fanotify01: Test setting two marks on different filesystems

When tested fs has zero fsid (e.g. fuse) and events are reported
with fsid+fid, watching different filesystems with the same group is
not supported.

Try to setup a bogus mark on test tmp dir, in addition to the mark
on the tested filesystem, to check if marks on different filesystems
are supported.

Run on all filesystem to test both fs with zero fsid (e.g. fuse) and
fs with valid fsid.

Link: https://lore.kernel.org/ltp/20240125110510.751445-1-amir73il@gmail.com/
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>

Author: amir73il

testcases/kernel/syscalls/fanotify/fanotify.h

@@ -166,20 +166,23 @@ static inline int fanotify_flags_supported_on_fs(unsigned int init_flags,
 {
 	int fd;
 	int rval = 0;
+	int err = 0;
 
 	fd = fanotify_init(init_flags, O_RDONLY);
-
 	if (fd < 0) {
+		err = errno;
 		if (errno == ENOSYS)
 			tst_brk(TCONF, "fanotify not configured in kernel");
 		if (errno != EINVAL)
 			tst_brk(TBROK | TERRNO,
 				"fanotify_init(%x, O_RDONLY) failed",
 				init_flags);
+		errno = err;
 		return -1;
 	}
 
 	if (fname && fanotify_mark(fd, FAN_MARK_ADD | mark_flags, event_flags, AT_FDCWD, fname) < 0) {
+		err = errno;
 		if (errno == ENODEV || errno == EOPNOTSUPP || errno == EXDEV) {
 			rval = strcmp(fname, OVL_MNT) ? -2 : -3;
 		} else if (errno != EINVAL) {
@@ -194,6 +197,7 @@ static inline int fanotify_flags_supported_on_fs(unsigned int init_flags,
 
 	SAFE_CLOSE(fd);
 
+	errno = err;
 	return rval;
 }
 

testcases/kernel/syscalls/fanotify/fanotify01.c

@@ -77,6 +77,7 @@ static char buf[BUF_SIZE];
 static int fd_notify;
 static int fan_report_fid_unsupported;
 static int mount_mark_fid_unsupported;
+static int inode_mark_fid_xdev;
 static int filesystem_mark_unsupported;
 
 static unsigned long long event_set[EVENT_MAX];
@@ -328,6 +329,17 @@ static void test_fanotify(unsigned int n)
 
 	}
 
+
+	/*
+	 * Try to setup a bogus mark on test tmp dir, to check if marks on
+	 * different filesystems are supported.
+	 * When tested fs has zero fsid (e.g. fuse) and events are reported
+	 * with fsid+fid, watching different filesystems is not supported.
+	 */
+	ret = report_fid ? inode_mark_fid_xdev : 0;
+	TST_EXP_FD_OR_FAIL(fanotify_mark(fd_notify, FAN_MARK_ADD, FAN_CLOSE_WRITE,
+					 AT_FDCWD, "."), ret);
+
 	/* Remove mark to clear FAN_MARK_IGNORED_SURV_MODIFY */
 	SAFE_FANOTIFY_MARK(fd_notify, FAN_MARK_REMOVE | mark->flag,
 			  FAN_ACCESS | FAN_MODIFY | FAN_CLOSE | FAN_OPEN,
@@ -352,6 +364,20 @@ static void setup(void)
 	mount_mark_fid_unsupported = fanotify_flags_supported_on_fs(FAN_REPORT_FID,
 								    FAN_MARK_MOUNT,
 								    FAN_OPEN, fname);
+	/*
+	 * When mount mark is not supported due to zero fsid (e.g. fuse) or if TMPDIR has
+	 * non-uniform fsid (e.g. btrfs subvol), multi fs inode marks are not supported.
+	 */
+	if (mount_mark_fid_unsupported && errno == ENODEV) {
+		tst_res(TINFO, "filesystem %s does not support reporting events with fid from multi fs",
+				tst_device->fs_type);
+		inode_mark_fid_xdev = EXDEV;
+	}
+
+	if (fanotify_flags_supported_on_fs(FAN_REPORT_FID, FAN_MARK_MOUNT, FAN_OPEN, ".")) {
+		inode_mark_fid_xdev = errno;
+		tst_res(TINFO, "TMPDIR does not support reporting events with fid from multi fs");
+	}
 }
 
 static void cleanup(void)
@@ -368,6 +394,7 @@ static struct tst_test test = {
 	.needs_root = 1,
 	.mount_device = 1,
 	.mntpoint = MOUNT_PATH,
+	.all_filesystems = 1,
 };
 
 #else