On Sat, Jun 25, 2022 at 01:53:21AM -0700, Jeremy Bongio wrote:
> Adds a utility to get/set 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@xxxxxxxxx>
> ---
Hi Jeremy,
Thanks for the patch, some picky review points as below:
> src/Makefile | 4 +-
> src/global.h | 2 +
> src/uuid_ioctl.c | 106 +++++++++++++++++++++++++++++++++++++++++++++
> tests/ext4/056 | 59 +++++++++++++++++++++++++
> tests/ext4/056.out | 1 +
> 5 files changed, 170 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/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/global.h b/src/global.h
> index b4407099..747d95f8 100644
> --- a/src/global.h
> +++ b/src/global.h
> @@ -184,4 +184,6 @@ roundup_64(unsigned long long x, unsigned int y)
> return rounddown_64(x + y - 1, y);
> }
>
> +#define BUILD_BUG_ON(condition) ((void)sizeof(char[1 - 2*!!(condition)]))
> +
> #endif /* GLOBAL_H */
> diff --git a/src/uuid_ioctl.c b/src/uuid_ioctl.c
> new file mode 100644
> index 00000000..51480689
> --- /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>
> +#include "global.h"
> +
> +struct fsuuid {
> + size_t len;
> + __u8 *b;
> +};
> +
> +#ifndef EXT4_IOC_GETFSUUID
> +#define EXT4_IOC_GETFSUUID _IOR('f', 44, struct fsuuid)
> +#endif
> +
> +#ifndef EXT4_IOC_SETFSUUID
> +#define EXT4_IOC_SETFSUUID _IOW('f', 45, struct fsuuid)
> +#endif
> +
> +int main(int argc, char **argv)
> +{
> + int error, fd;
> + struct fsuuid fsuuid;
^
Bad indent at here, please check the indent of this program.
> +
> + if (argc < 3) {
> + fprintf(stderr, "Invalid arguments\n");
> + return 1;
> + }
> +
> + fd = open(argv[2], O_RDONLY);
> + if (!fd) {
> + perror(argv[2]);
> + return 1;
> + }
> +
> + BUILD_BUG_ON(sizeof(uuid_t) % 16);
> + fsuuid.len = 16;
> + fsuuid.b = calloc(fsuuid.len, sizeof(__u8));
> +
> + if (strcmp(argv[1], "get") == 0) {
> + uuid_t uuid;
> + char uuid_str[37];
> +
> + if (ioctl(fd, EXT4_IOC_GETFSUUID, &fsuuid)) {
> + close(fd);
> + fprintf(stderr, "%s while trying to get fs uuid\n",
> + strerror(errno));
> + return 1;
> + }
> +
> + memcpy(&uuid, fsuuid.b, sizeof(uuid));
> + uuid_unparse(uuid, uuid_str);
> + printf("%s", uuid_str);
> + } else if (strcmp(argv[1], "set") == 0) {
> + if (argc != 4) {
> + fprintf(stderr, "UUID argument missing.\n");
> + return 1;
> + }
> +
> + if (strlen(argv[3]) != 36) {
> + fprintf(stderr, "Invalid UUID. The UUID should be in "
> + "canonical format. Example: "
> + "8c628557-6987-42b2-ba16-b7cc79ddfb43\n");
> + return 1;
> + }
> +
> + uuid_t uuid;
> + error = uuid_parse(argv[3], uuid);
> + if (error < 0) {
> + fprintf(stderr, "%s: invalid UUID.\n", argv[0]);
> + return 1;
> + }
> +
> + memcpy(fsuuid.b, uuid, sizeof(uuid));
> + if(ioctl(fd, EXT4_IOC_SETFSUUID, &fsuuid)) {
> + close(fd);
> + fprintf(stderr, "%s while trying to set fs uuid\n",
> + strerror(errno));
> + return 1;
> + }
> + } else {
> + fprintf(stderr, "Invalid command\n");
> + }
> +
> + close(fd);
> + return 0;
> +}
> diff --git a/tests/ext4/056 b/tests/ext4/056
> new file mode 100755
> index 00000000..46631d46
> --- /dev/null
> +++ b/tests/ext4/056
> @@ -0,0 +1,59 @@
> +#! /bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +# Copyright (c) 2000-2005 Silicon Graphics, Inc. All Rights Reserved.
> +#
> +# Test the set/get UUID ioctl.
> +#
> +
> +. ./common/preamble
> +_begin_fstest auto ioctl resize
Why this case is "resize" related?
> +
> +tmpfile="/tmp/$$."
> +trap "rm -f $tmpfile; exit" 0 1 2 3 15
We have default "trap" when you source ./common/preamble. If you need a custom
cleanup by youself, you can define a new one in this case (refer to other cases
which has their own _cleanup).
> +
> +# Import common functions.
> +. ./common/filter
> +
> +# real QA test starts here
> +_supported_fs ext4
> +_require_scratch
> +_require_test_program uuid_ioctl
> +
> +UUID_IOCTL=$here/src/uuid_ioctl
> +
> +# if the ioctl is not supported by the kernel, then skip test.
> +current_uid=$($UUID_IOCTL get $SCRATCH_MNT)
> +if [[ "$current_uid" = "Inappropriate ioctl for device while trying to set fs uuid" ]]; then
> + _notrun "UUID ioctls are not supported by kernel."
^
It's not fault, but we recommended the tab width is 8, for fstests bash script.
> +fi
> +
> +# Create filesystem and mount
> +_scratch_mkfs_ext4 -O metadata_csum_seed >> $seqres.full 2>&1
^
Generally we make sure $seqres.full is null (rm -f $seqres.full) or truncated
at first. So an easier way is using "> $seqres.full" at the first place which
trys to write $seqres.full, to clean .full file.
> +_scratch_mount >> $seqres.full
> +
> +# Begin fsstress while modifying UUID
> +fsstress_args=$(_scale_fsstress_args -d $SCRATCH_MNT -p 15 -n 999999)
> +"$FSSTRESS_PROG" $fsstress_args > /dev/null &
Better to use "2>&1" if you don't want this case fails on some weird fsstress
error output. Or ">>$seqres.full 2>&1" if you'd like to know what happened
on fsstress.
Do I miss something? I didn't find any place try to make sure above fsstress
process is killed/end (by using kill and wait).
> +
> +test_uuid_ioctl()
> +{
> + for n in $(seq 1 20); do
> + new_uuid=$(uuidgen)
I think uuidgen isn't a tool which is 100% installed on all linux system. So
_require_command $UUIDGEN_PROG uuidgen
> +
> + echo "Setting UUID to ${new_uuid}" >> $seqres.full 2>&1
> + $UUID_IOCTL set $SCRATCH_MNT $new_uuid >> $seqres.full 2>&1
> +
> + current_uuid=$($UUID_IOCTL get $SCRATCH_MNT)
> + echo "$UUID_IOCTL get $SCARTCH_MNT: $current_uuid" >> $seqres.full 2>&1
> + if [[ "$current_uuid" != "$new_uuid" ]]; then
> + echo "UUID does not equal what was sent with the ioctl"
> + exit
I think break is enough, but exit is fine too.
> + fi
> + done
> +}
> +
> +test_uuid_ioctl
I'm wondering why not run the code in test_uuid_ioctl directly. Looks like you
just make them into a function, then run this function once. It doesn't use
local variables, or be called many times, or have many complicated lines. Or
you'd like to package the codes in "for n in $(seq 1 20)" loop?
> +
> +# success, all done
> +status=0
> +exit
> diff --git a/tests/ext4/056.out b/tests/ext4/056.out
> new file mode 100644
> index 00000000..06f52bb4
> --- /dev/null
> +++ b/tests/ext4/056.out
> @@ -0,0 +1 @@
> +QA output created by 056
Silence is golden ?
Thanks,
Zorro
> --
> 2.37.0.rc0.161.g10f37bed90-goog
>
