[PATCH v2] ext4/056: add a check to make sure ext4 uuid ioctls get/set during fsstress.

Jeremy Bongio
2022-07-01T20:14:35Z

Adds a utility to set/get uuid through ext4 ioctl. Executes the ioctls
while running fsstress. These ioctls are used by tune2fs to safely change
the uuid without racing other filesystem modifications.

Signed-off-by: Jeremy Bongio <bongiojp@gmail.com>
---
.gitignore | 1 +
src/Makefile | 4 +-
src/uuid_ioctl.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
tests/ext4/056 | 55 +++++++++++++++++++++++
tests/ext4/056.out | 2 +
5 files changed, 166 insertions(+), 2 deletions(-)
create mode 100644 src/uuid_ioctl.c
create mode 100755 tests/ext4/056
create mode 100644 tests/ext4/056.out

diff --git a/.gitignore b/.gitignore
index ba0c572b..dab24d68 100644
--- a/.gitignore
+++ b/.gitignore
@@ -169,6 +169,7 @@ tags
/src/unwritten_mmap
/src/unwritten_sync
/src/usemem
+/src/uuid_ioctl
/src/writemod
/src/writev_on_pagefault
/src/xfsctl
diff --git a/src/Makefile b/src/Makefile
index 111ce1d9..e33e04de 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -31,14 +31,14 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
dio-invalidate-cache stat_test t_encrypted_d_revalidate \
attr_replace_test swapon mkswap t_attr_corruption t_open_tmpfiles \
fscrypt-crypt-util bulkstat_null_ocount splice-test chprojid_fail \
- detached_mounts_propagation ext4_resize
+ detached_mounts_propagation ext4_resize uuid_ioctl

EXTRA_EXECS = dmerror fill2attr fill2fs fill2fs_check scaleread.sh \
btrfs_crc32c_forged_name.py

SUBDIRS = log-writes perf

-LLDLIBS = $(LIBHANDLE) $(LIBACL) -lpthread -lrt
+LLDLIBS = $(LIBHANDLE) $(LIBACL) -lpthread -lrt -luuid

ifeq ($(HAVE_XLOG_ASSIGN_LSN), true)
LINUX_TARGETS += loggen
diff --git a/src/uuid_ioctl.c b/src/uuid_ioctl.c
new file mode 100644
index 00000000..a4937478
--- /dev/null
+++ b/src/uuid_ioctl.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Test program which uses the raw ext4 set_fsuuid ioctl directly.
+ * SYNOPSIS:
+ * $0 COMMAND MOUNT_POINT [UUID]
+ *
+ * COMMAND must be either "get" or "set".
+ * The UUID must be a 16 octet represented as 32 hexadecimal digits in canonical
+ * textual representation, e.g. output from `uuidgen`.
+ *
+ */
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <uuid/uuid.h>
+#include <linux/fs.h>
+
+struct fsuuid {
+ __u32 fu_len;
+ __u32 fu_flags;
+ __u8 fu_uuid[];
+};
+
+#define EXT4_IOC_SETFSUUID_FLAG_BLOCKING 0x1
+
+#ifndef EXT4_IOC_GETFSUUID
+#define EXT4_IOC_GETFSUUID _IOR('f', 44, struct fsuuid)
+#endif
+
+#ifndef EXT4_IOC_SETFSUUID
+#define EXT4_IOC_SETFSUUID _IOW('f', 44, struct fsuuid)
+#endif
+
+int main(int argc, char **argv)
+{
+ int error, fd;
+ struct fsuuid *fsuuid = NULL;
+
+ if (argc < 3) {
+ fprintf(stderr, "Invalid arguments\n");
+ return 1;
+ }
+
+ fd = open(argv[2], O_RDONLY);
+ if (!fd) {
+ perror(argv[2]);
+ return 1;
+ }
+
+ fsuuid = malloc(sizeof(*fsuuid) + sizeof(uuid_t));
+ if (!fsuuid) {
+ perror("malloc");
+ return 1;
+ }
+ fsuuid->fu_len = sizeof(uuid_t);
+
+ if (strcmp(argv[1], "get") == 0) {
+ uuid_t uuid;
+ char uuid_str[37];
+
+ if (ioctl(fd, EXT4_IOC_GETFSUUID, fsuuid)) {
+ fprintf(stderr, "%s while trying to get fs uuid\n",
+ strerror(errno));
+ return 1;
+ }
+
+ memcpy(&uuid, fsuuid->fu_uuid, sizeof(uuid));
+ uuid_unparse(uuid, uuid_str);
+ printf("%s", uuid_str);
+ } else if (strcmp(argv[1], "set") == 0) {
+ uuid_t uuid;
+
+ if (argc != 4) {
+ fprintf(stderr, "UUID argument missing.\n");
+ return 1;
+ }
+
+ error = uuid_parse(argv[3], uuid);
+ if (error < 0) {
+ fprintf(stderr, "Invalid UUID. The UUID should be in "
+ "canonical format. Example: "
+ "8c628557-6987-42b2-ba16-b7cc79ddfb43\n");
+ return 1;
+ }
+
+ memcpy(&fsuuid->fu_uuid, uuid, sizeof(uuid));
+ fsuuid->fu_flags = EXT4_IOC_SETFSUUID_FLAG_BLOCKING;
+ if (ioctl(fd, EXT4_IOC_SETFSUUID, fsuuid)) {
+ fprintf(stderr, "%s while trying to set fs uuid\n",
+ strerror(errno));
+ return 1;
+ }
+ } else {
+ fprintf(stderr, "Invalid command\n");
+ return 1;
+ }
+
+ return 0;
+}
diff --git a/tests/ext4/056 b/tests/ext4/056
new file mode 100755
index 00000000..ebefb136
--- /dev/null
+++ b/tests/ext4/056
@@ -0,0 +1,55 @@
+#! /bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Test the set/get UUID ioctl.
+#
+
+. ./common/preamble
+_begin_fstest auto ioctl
+
+# Import common functions.
+. ./common/filter
+
+# real QA test starts here
+_supported_fs ext4
+_require_scratch
+_require_test_program uuid_ioctl
+_require_command $UUIDGEN_PROG uuidgen
+
+UUID_IOCTL=$here/src/uuid_ioctl
+
+# if the ioctl is not supported by the kernel, then skip test.
+current_uuid=$($UUID_IOCTL get $SCRATCH_MNT 2>&1)
+if [[ "$current_uuid" =~ ^Inappropriate[[:space:]]ioctl ]]; then
+ _notrun "UUID ioctls are not supported by kernel."
+fi
+
+# Create filesystem and mount
+_scratch_mkfs_ext4 -O metadata_csum_seed >> $seqres.full 2>&1
+_scratch_mount >> $seqres.full
+
+# Begin fsstress while modifying UUID
+fsstress_args=$(_scale_fsstress_args -d $SCRATCH_MNT -p 15 -n 999999)
+$FSSTRESS_PROG $fsstress_args > /dev/null 2>&1 &
+fsstress_pid=$!
+
+for n in $(seq 1 20); do
+ new_uuid=$($UUIDGEN_PROG)
+
+ echo "Setting UUID to ${new_uuid}" >> $seqres.full 2>&1
+ $UUID_IOCTL set $SCRATCH_MNT $new_uuid
+
+ current_uuid=$($UUID_IOCTL get $SCRATCH_MNT)
+ echo "$UUID_IOCTL get $SCARTCH_MNT: $current_uuid" >> $seqres.full 2>&1
+ if [[ "$current_uuid" != "$new_uuid" ]]; then
+ echo "Current UUID ($current_uuid) does not equal what "
+ "was sent with the ioctl ($new_uuid)"
+ fi
+done
+
+# success, all done
+echo "Silence is golden"
+kill $fsstress_pid >/dev/null 2>&1
+wait
+status=0
+exit
diff --git a/tests/ext4/056.out b/tests/ext4/056.out
new file mode 100644
index 00000000..6142fcd2
--- /dev/null
+++ b/tests/ext4/056.out
@@ -0,0 +1,2 @@
+QA output created by 056
+Silence is golden
--
2.37.0.rc0.161.g10f37bed90-goog