Re: [PATCH v2 5/5] generic: test invalid swap file activation

Darrick J. Wong
2018-05-18T14:37:16Z

On Wed, May 16, 2018 at 01:38:49PM -0700, Omar Sandoval wrote:
> From: Omar Sandoval <osandov@fb.com>
>
> Swap files cannot have holes, and they must at least two pages.
> swapon(8) and mkswap(8) have stricter restrictions, so add versions of
> those commands without any restrictions.
>
> Signed-off-by: Omar Sandoval <osandov@fb.com>
> ---
> .gitignore | 2 ++
> src/Makefile | 2 +-
> src/mkswap.c | 83 +++++++++++++++++++++++++++++++++++++++++++
> src/swapon.c | 24 +++++++++++++
> tests/generic/490 | 77 +++++++++++++++++++++++++++++++++++++++
> tests/generic/490.out | 5 +++
> tests/generic/group | 1 +
> 7 files changed, 193 insertions(+), 1 deletion(-)
> create mode 100644 src/mkswap.c
> create mode 100644 src/swapon.c
> create mode 100755 tests/generic/490
> create mode 100644 tests/generic/490.out
>
> diff --git a/.gitignore b/.gitignore
> index 53029e24..efc73a7c 100644
> --- a/.gitignore
> +++ b/.gitignore
> @@ -92,6 +92,7 @@
> /src/lstat64
> /src/makeextents
> /src/metaperf
> +/src/mkswap
> /src/mmapcat
> /src/multi_open_unlink
> /src/nametest
> @@ -111,6 +112,7 @@
> /src/seek_sanity_test
> /src/stale_handle
> /src/stat_test
> +/src/swapon
> /src/t_access_root
> /src/t_dir_offset
> /src/t_dir_offset2
> diff --git a/src/Makefile b/src/Makefile
> index c42d3bb1..01fe99ef 100644
> --- a/src/Makefile
> +++ b/src/Makefile
> @@ -26,7 +26,7 @@ LINUX_TARGETS = xfsctl bstat t_mtab getdevicesize preallo_rw_pattern_reader \
> renameat2 t_getcwd e4compact test-nextquota punch-alternating \
> attr-list-by-handle-cursor-test listxattr dio-interleaved t_dir_type \
> dio-invalidate-cache stat_test t_encrypted_d_revalidate \
> - attr_replace_test
> + attr_replace_test swapon mkswap
>
> SUBDIRS = log-writes perf
>
> diff --git a/src/mkswap.c b/src/mkswap.c
> new file mode 100644
> index 00000000..d0bce2bd
> --- /dev/null
> +++ b/src/mkswap.c
> @@ -0,0 +1,83 @@
> +/* mkswap(8) without any sanity checks */
> +
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <unistd.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +
> +struct swap_header {
> + char bootbits[1024];
> + uint32_t version;
> + uint32_t last_page;
> + uint32_t nr_badpages;
> + unsigned char sws_uuid[16];
> + unsigned char sws_volume[16];
> + uint32_t padding[117];
> + uint32_t badpages[1];
> +};
> +
> +int main(int argc, char **argv)
> +{
> + struct swap_header *hdr;
> + FILE *file;
> + struct stat st;
> + long page_size;
> + int ret;
> +
> + if (argc != 2) {
> + fprintf(stderr, "usage: %s PATH\n", argv[0]);
> + return EXIT_FAILURE;
> + }
> +
> + page_size = sysconf(_SC_PAGESIZE);
> + if (page_size == -1) {
> + perror("sysconf");
> + return EXIT_FAILURE;
> + }
> +
> + hdr = calloc(1, page_size);
> + if (!hdr) {
> + perror("calloc");
> + return EXIT_FAILURE;
> + }
> +
> + file = fopen(argv[1], "r+");
> + if (!file) {
> + perror("fopen");
> + free(hdr);
> + return EXIT_FAILURE;
> + }
> +
> + ret = fstat(fileno(file), &st);
> + if (ret) {
> + perror("fstat");
> + free(hdr);
> + fclose(file);
> + return EXIT_FAILURE;
> + }
> +
> + hdr->version = 1;
> + hdr->last_page = st.st_size / page_size - 1;
> + memset(&hdr->sws_uuid, 0x99, sizeof(hdr->sws_uuid));
> + memcpy((char *)hdr + page_size - 10, "SWAPSPACE2", 10);
> +
> + if (fwrite(hdr, page_size, 1, file) != 1) {
> + perror("fwrite");
> + free(hdr);
> + fclose(file);
> + return EXIT_FAILURE;
> + }
> +
> + if (fclose(file) == EOF) {
> + perror("fwrite");
> + free(hdr);
> + return EXIT_FAILURE;
> + }
> +
> + free(hdr);
> +
> + return EXIT_SUCCESS;
> +}
> diff --git a/src/swapon.c b/src/swapon.c
> new file mode 100644
> index 00000000..0cb7108a
> --- /dev/null
> +++ b/src/swapon.c
> @@ -0,0 +1,24 @@
> +/* swapon(8) without any sanity checks; simply calls swapon(2) directly. */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <sys/swap.h>
> +
> +int main(int argc, char **argv)
> +{
> + int ret;
> +
> + if (argc != 2) {
> + fprintf(stderr, "usage: %s PATH\n", argv[0]);
> + return EXIT_FAILURE;
> + }
> +
> + ret = swapon(argv[1], 0);
> + if (ret) {
> + perror("swapon");
> + return EXIT_FAILURE;
> + }
> +
> + return EXIT_SUCCESS;
> +}
> diff --git a/tests/generic/490 b/tests/generic/490
> new file mode 100755
> index 00000000..6ba2ecb3
> --- /dev/null
> +++ b/tests/generic/490
> @@ -0,0 +1,77 @@
> +#! /bin/bash
> +# FS QA Test 490
> +#
> +# Test invalid swap files.
> +#
> +#-----------------------------------------------------------------------
> +# Copyright (c) 2018 Facebook. All Rights Reserved.
> +#
> +# This program is free software; you can redistribute it and/or
> +# modify it under the terms of the GNU General Public License as
> +# published by the Free Software Foundation.
> +#
> +# This program is distributed in the hope that it would be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program; if not, write the Free Software Foundation,
> +# Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
> +#-----------------------------------------------------------------------
> +#
> +
> +seq=`basename $0`
> +seqres=$RESULT_DIR/$seq
> +echo "QA output created by $seq"
> +
> +here=`pwd`
> +tmp=/tmp/$$
> +status=1 # failure is the default!
> +trap "_cleanup; exit \$status" 0 1 2 3 15
> +
> +_cleanup()
> +{
> + cd /
> + rm -f $tmp.*
> +}
> +
> +# get standard environment, filters and checks
> +. ./common/rc
> +. ./common/filter
> +
> +# remove previous $seqres.full before test
> +rm -f $seqres.full
> +
> +_supported_fs generic
> +_supported_os Linux
> +_require_scratch_swapfile
> +_require_test_program mkswap
> +_require_test_program swapon
> +
> +_scratch_mkfs >> $seqres.full 2>&1
> +_scratch_mount
> +
> +echo "File with holes"
> +# We can't use _format_swapfile because we're using our custom mkswap and
> +# swapon.
> +touch "$SCRATCH_MNT/swap"
> +$CHATTR_PROG +C "$SCRATCH_MNT/swap"

FWIW I see:

/djwong/e2fsprogs/build-x64/misc/chattr: Operation not supported while setting flags on /opt/swap

on XFS (we don't support the nocow flag), so the stdout/stderr need to
be redirected elsewhere.

--D

> +chmod 0600 "$SCRATCH_MNT/swap"
> +$XFS_IO_PROG -c "truncate $(($(get_page_size) * 10))" "$SCRATCH_MNT/swap"
> +"$here/src/mkswap" "$SCRATCH_MNT/swap"
> +"$here/src/swapon" "$SCRATCH_MNT/swap"
> +swapoff "$SCRATCH_MNT/swap" >/dev/null 2>&1
> +
> +echo "Empty swap file (only swap header)"
> +rm -f "$SCRATCH_MNT/swap"
> +touch "$SCRATCH_MNT/swap"
> +$CHATTR_PROG +C "$SCRATCH_MNT/swap"
> +chmod 0600 "$SCRATCH_MNT/swap"
> +_pwrite_byte 0x61 0 $(get_page_size) "$SCRATCH_MNT/swap" >> $seqres.full
> +"$here/src/mkswap" "$SCRATCH_MNT/swap"
> +"$here/src/swapon" "$SCRATCH_MNT/swap"
> +swapoff "$SCRATCH_MNT/swap" >/dev/null 2>&1
> +
> +status=0
> +exit
> diff --git a/tests/generic/490.out b/tests/generic/490.out
> new file mode 100644
> index 00000000..96226c64
> --- /dev/null
> +++ b/tests/generic/490.out
> @@ -0,0 +1,5 @@
> +QA output created by 490
> +File with holes
> +swapon: Invalid argument
> +Empty swap file (only swap header)
> +swapon: Invalid argument
> diff --git a/tests/generic/group b/tests/generic/group
> index a5252aeb..422e21e2 100644
> --- a/tests/generic/group
> +++ b/tests/generic/group
> @@ -492,3 +492,4 @@
> 487 auto quick
> 488 auto quick swap
> 489 auto quick swap
> +490 auto quick swap
> --
> 2.17.0
>
> --
> To unsubscribe from this list: send the line "unsubscribe fstests" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html