On 2024-09-04, Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> On Wed, Sep 4, 2024 at 7:57 PM Aleksa Sarai <cyphar@xxxxxxxxxx> wrote:
> >
> > In order to make sure we are actually testing AT_HANDLE_MNT_ID_UNIQUE,
> > add a test (based on generic/426) which runs the open_by_handle in a
> > mode where it will error out if there is a problem with getting mount
> > IDs. The test is skipped if the kernel doesn't support the necessary
> > features.
> >
> > Suggested-by: Amir Goldstein <amir73il@xxxxxxxxx>
> > Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx>
>
> Apart from one minor nits below, you may add:
>
> Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
>
> > ---
> > common/rc | 24 ++++++++++++++++
> > src/open_by_handle.c | 63 ++++++++++++++++++++++++++++++++++-------
> > tests/generic/756 | 65 +++++++++++++++++++++++++++++++++++++++++++
> > tests/generic/756.out | 5 ++++
> > 4 files changed, 147 insertions(+), 10 deletions(-)
> > create mode 100755 tests/generic/756
> > create mode 100644 tests/generic/756.out
> >
> > diff --git a/common/rc b/common/rc
> > index 9da9fe188297..0beaf2ff1126 100644
> > --- a/common/rc
> > +++ b/common/rc
> > @@ -5178,6 +5178,30 @@ _require_fibmap()
> > rm -f $file
> > }
> >
> > +_require_statx_unique_mountid()
> > +{
> > + # statx(STATX_MNT_ID=0x1000) was added in Linux 5.8.
> > + # statx(STATX_MNT_ID_UNIQUE=0x4000) was added in Linux 6.9.
> > + # We only need to check the latter.
> > +
> > + export STATX_MNT_ID_UNIQUE=0x4000
> > + local statx_mask=$(
> > + ${XFS_IO_PROG} -c "statx -m $STATX_MNT_ID_UNIQUE -r" "$TEST_DIR" |
> > + sed -En 's/stat\.mask = (0x[0-9a-f]+)/\1/p'
> > + )
> > +
> > + [[ $(( statx_mask & STATX_MNT_ID_UNIQUE )) == $((STATX_MNT_ID_UNIQUE)) ]] ||
> > + _notrun "statx does not support STATX_MNT_ID_UNIQUE on this kernel"
> > +}
> > +
> > +_require_open_by_handle_unique_mountid()
> > +{
> > + _require_test_program "open_by_handle"
> > +
> > + $here/src/open_by_handle -C AT_HANDLE_MNT_ID_UNIQUE 2>&1 \
> > + || _notrun "name_to_handle_at does not support AT_HANDLE_MNT_ID_UNIQUE"
> > +}
> > +
> > _try_wipe_scratch_devs()
> > {
> > test -x "$WIPEFS_PROG" || return 0
> > diff --git a/src/open_by_handle.c b/src/open_by_handle.c
> > index 920ec7d9170b..b5c1a30abbbc 100644
> > --- a/src/open_by_handle.c
> > +++ b/src/open_by_handle.c
> > @@ -106,9 +106,11 @@ struct handle {
> >
> > void usage(void)
> > {
> > - fprintf(stderr, "usage: open_by_handle [-cludmrwapknhs] [<-i|-o> <handles_file>] <test_dir> [num_files]\n");
> > + fprintf(stderr, "usage: open_by_handle [-cludmMrwapknhs] [<-i|-o> <handles_file>] <test_dir> [num_files]\n");
> > + fprintf(stderr, " open_by_handle -C <feature>\n");
> > fprintf(stderr, "\n");
> > fprintf(stderr, "open_by_handle -c <test_dir> [N] - create N test files under test_dir, try to get file handles and exit\n");
> > + fprintf(stderr, "open_by_handle -c <test_dir> [N] - create N test files under test_dir, try to get file handles and exit\n");
> > fprintf(stderr, "open_by_handle <test_dir> [N] - get file handles of test files, drop caches and try to open by handle\n");
> > fprintf(stderr, "open_by_handle -n <test_dir> [N] - get file handles of test files and try to open by handle without drop caches\n");
> > fprintf(stderr, "open_by_handle -k <test_dir> [N] - get file handles of files that are kept open, drop caches and try to open by handle\n");
> > @@ -117,19 +119,23 @@ void usage(void)
> > fprintf(stderr, "open_by_handle -a <test_dir> [N] - write data to test files after open by handle\n");
> > fprintf(stderr, "open_by_handle -l <test_dir> [N] - create hardlinks to test files, drop caches and try to open by handle\n");
> > fprintf(stderr, "open_by_handle -u <test_dir> [N] - unlink (hardlinked) test files, drop caches and try to open by handle\n");
> > - fprintf(stderr, "open_by_handle -U <test_dir> [N] - verify the mount ID returned with AT_HANDLE_MNT_ID_UNIQUE is correct\n");
>
> I guess this was not supposed to be in the first patch
Yeah, it got mixed up when splitting the patch. I'll fix it up.
> > fprintf(stderr, "open_by_handle -d <test_dir> [N] - unlink test files and hardlinks, drop caches and try to open by handle\n");
> > fprintf(stderr, "open_by_handle -m <test_dir> [N] - rename test files, drop caches and try to open by handle\n");
> > + fprintf(stderr, "open_by_handle -M <test_dir> [N] - do not silently skip the mount ID verifications\n");
> > fprintf(stderr, "open_by_handle -p <test_dir> - create/delete and try to open by handle also test_dir itself\n");
> > fprintf(stderr, "open_by_handle -i <handles_file> <test_dir> [N] - read test files handles from file and try to open by handle\n");
> > fprintf(stderr, "open_by_handle -o <handles_file> <test_dir> [N] - get file handles of test files and write handles to file\n");
> > fprintf(stderr, "open_by_handle -s <test_dir> [N] - wait in sleep loop after opening files by handle to keep them open\n");
> > fprintf(stderr, "open_by_handle -z <test_dir> [N] - query filesystem required buffer size\n");
> > + fprintf(stderr, "\n");
> > + fprintf(stderr, "open_by_handle -C <feature> - check if <feature> is supported by the kernel.\n");
> > + fprintf(stderr, " <feature> can be any of the following values:\n");
> > + fprintf(stderr, " - AT_HANDLE_MNT_ID_UNIQUE\n");
> > exit(EXIT_FAILURE);
> > }
> >
> > static int do_name_to_handle_at(const char *fname, struct file_handle *fh,
> > - int bufsz)
> > + int bufsz, bool force_check_mountid)
> > {
> > int ret;
> > int mntid_short;
> > @@ -145,10 +151,15 @@ static int do_name_to_handle_at(const char *fname, struct file_handle *fh,
> > fprintf(stderr, "%s: statx(STATX_MNT_ID): %m\n", fname);
> > return EXIT_FAILURE;
> > }
> > - if (!(statxbuf.stx_mask & STATX_MNT_ID))
> > + if (!(statxbuf.stx_mask & STATX_MNT_ID)) {
> > + if (force_check_mountid) {
> > + fprintf(stderr, "%s: statx(STATX_MNT_ID) not supported by running kernel\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > skip_mntid = true;
> > - else
> > + } else {
> > statx_mntid_short = statxbuf.stx_mnt_id;
> > + }
> > }
> >
> > if (!skip_mntid_unique) {
> > @@ -160,10 +171,15 @@ static int do_name_to_handle_at(const char *fname, struct file_handle *fh,
> > * STATX_MNT_ID_UNIQUE was added fairly recently in Linux 6.8, so if the
> > * kernel doesn't give us a unique mount ID just skip it.
> > */
> > - if (!(statxbuf.stx_mask & STATX_MNT_ID_UNIQUE))
> > + if (!(statxbuf.stx_mask & STATX_MNT_ID_UNIQUE)) {
> > + if (force_check_mountid) {
> > + fprintf(stderr, "%s: statx(STATX_MNT_ID_UNIQUE) not supported by running kernel\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > skip_mntid_unique = true;
> > - else
> > + } else {
> > statx_mntid_unique = statxbuf.stx_mnt_id;
> > + }
> > }
> >
> > fh->handle_bytes = bufsz;
> > @@ -204,6 +220,10 @@ static int do_name_to_handle_at(const char *fname, struct file_handle *fh,
> > return EXIT_FAILURE;
> > }
> > /* EINVAL means AT_HANDLE_MNT_ID_UNIQUE is not supported */
> > + if (force_check_mountid) {
> > + fprintf(stderr, "%s: name_to_handle_at(AT_HANDLE_MNT_ID_UNIQUE) not supported by running kernel\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > skip_mntid_unique = true;
> > } else {
> > if (mntid_unique != statx_mntid_unique) {
> > @@ -216,6 +236,22 @@ static int do_name_to_handle_at(const char *fname, struct file_handle *fh,
> > return 0;
> > }
> >
> > +static int check_feature(const char *feature)
> > +{
> > + if (!strcmp(feature, "AT_HANDLE_MNT_ID_UNIQUE")) {
> > + int ret = name_to_handle_at(AT_FDCWD, ".", NULL, NULL, AT_HANDLE_MNT_ID_UNIQUE);
> > + /* If AT_HANDLE_MNT_ID_UNIQUE is supported, we get EFAULT. */
> > + if (ret < 0 && errno == EINVAL) {
> > + fprintf(stderr, "name_to_handle_at(AT_HANDLE_MNT_ID_UNIQUE) not supported by running kernel\n");
> > + return EXIT_FAILURE;
> > + }
> > + return 0;
> > + }
> > +
> > + fprintf(stderr, "unknown feature name '%s'\n", feature);
> > + return EXIT_FAILURE;
> > +}
> > +
> > int main(int argc, char **argv)
> > {
> > int i, c;
> > @@ -235,16 +271,20 @@ int main(int argc, char **argv)
> > int create = 0, delete = 0, nlink = 1, move = 0;
> > int rd = 0, wr = 0, wrafter = 0, parent = 0;
> > int keepopen = 0, drop_caches = 1, sleep_loop = 0;
> > + int force_check_mountid = 0;
> > int bufsz = MAX_HANDLE_SZ;
> >
> > if (argc < 2)
> > usage();
> >
> > - while ((c = getopt(argc, argv, "cludmrwapknhi:o:sz")) != -1) {
> > + while ((c = getopt(argc, argv, "cC:ludmMrwapknhi:o:sz")) != -1) {
> > switch (c) {
> > case 'c':
> > create = 1;
> > break;
> > + case 'C':
> > + /* Check kernel feature support. */
> > + return check_feature(optarg);
> > case 'w':
> > /* Write data before open_by_handle_at() */
> > wr = 1;
> > @@ -271,6 +311,9 @@ int main(int argc, char **argv)
> > case 'm':
> > move = 1;
> > break;
> > + case 'M':
> > + force_check_mountid = 1;
> > + break;
> > case 'p':
> > parent = 1;
> > break;
> > @@ -403,7 +446,7 @@ int main(int argc, char **argv)
> > return EXIT_FAILURE;
> > }
> > } else {
> > - ret = do_name_to_handle_at(fname, &handle[i].fh, bufsz);
> > + ret = do_name_to_handle_at(fname, &handle[i].fh, bufsz, force_check_mountid);
> > if (ret)
> > return EXIT_FAILURE;
> > }
> > @@ -433,7 +476,7 @@ int main(int argc, char **argv)
> > return EXIT_FAILURE;
> > }
> > } else {
> > - ret = do_name_to_handle_at(test_dir, &dir_handle.fh, bufsz);
> > + ret = do_name_to_handle_at(test_dir, &dir_handle.fh, bufsz, force_check_mountid);
> > if (ret)
> > return EXIT_FAILURE;
> > }
> > diff --git a/tests/generic/756 b/tests/generic/756
> > new file mode 100755
> > index 000000000000..c7a82cfd25f4
> > --- /dev/null
> > +++ b/tests/generic/756
> > @@ -0,0 +1,65 @@
> > +#! /bin/bash
> > +# SPDX-License-Identifier: GPL-2.0
> > +# Copyright (C) 2017 CTERA Networks. All Rights Reserved.
> > +# Copyright (C) 2024 Aleksa Sarai <cyphar@xxxxxxxxxx>
> > +#
> > +# FS QA Test No. 756
> > +#
> > +# Check stale handles pointing to unlinked files and non-stale handles pointing
> > +# to linked files while verifying that u64 mount IDs are correctly returned.
> > +#
> > +. ./common/preamble
> > +_begin_fstest auto quick exportfs
> > +
> > +# Import common functions.
> > +. ./common/filter
> > +
> > +
> > +# Modify as appropriate.
> > +_require_test
> > +# _require_exportfs and already requires open_by_handle, but let's not count on it
> > +_require_test_program "open_by_handle"
> > +_require_exportfs
> > +# We need both STATX_MNT_ID_UNIQUE and AT_HANDLE_MNT_ID_UNIQUE.
> > +_require_statx_unique_mountid
> > +_require_open_by_handle_unique_mountid
> > +
> > +NUMFILES=1024
> > +testdir=$TEST_DIR/$seq-dir
> > +mkdir -p $testdir
> > +
> > +# Create empty test files in test dir
> > +create_test_files()
> > +{
> > + local dir=$1
> > +
> > + mkdir -p $dir
> > + rm -f $dir/*
> > + $here/src/open_by_handle -c $dir $NUMFILES
> > +}
> > +
> > +# Test encode/decode file handles
> > +test_file_handles()
> > +{
> > + local dir=$1
> > + local opt=$2
> > +
> > + echo test_file_handles $* | _filter_test_dir
> > + $here/src/open_by_handle $opt $dir $NUMFILES
> > +}
> > +
> > +# Check stale handles to deleted files
> > +create_test_files $testdir
> > +test_file_handles $testdir -Md
> > +
> > +# Check non-stale handles to linked files
> > +create_test_files $testdir
> > +test_file_handles $testdir -M
> > +
> > +# Check non-stale handles to files that were hardlinked and original deleted
> > +create_test_files $testdir
> > +test_file_handles $testdir -Ml
> > +test_file_handles $testdir -Mu
> > +
> > +status=0
> > +exit
> > diff --git a/tests/generic/756.out b/tests/generic/756.out
> > new file mode 100644
> > index 000000000000..48aed88d87b9
> > --- /dev/null
> > +++ b/tests/generic/756.out
> > @@ -0,0 +1,5 @@
> > +QA output created by 756
> > +test_file_handles TEST_DIR/756-dir -Md
> > +test_file_handles TEST_DIR/756-dir -M
> > +test_file_handles TEST_DIR/756-dir -Ml
> > +test_file_handles TEST_DIR/756-dir -Mu
> > --
> > 2.46.0
> >
--
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>
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