Re: [PATCH xfstests v1 2/2] open_by_handle: add tests for u64 mount ID

From: Aleksa Sarai
Date: Sun Sep 01 2024 - 08:58:34 EST

Next message: Menglong Dong: "Re: [PATCH net-next v2 07/12] net: vxlan: add skb drop reasons to vxlan_rcv()"
Previous message: Menglong Dong: "Re: [PATCH net-next v2 06/12] net: vxlan: make vxlan_set_mac() return drop reasons"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

On 2024-08-30, Amir Goldstein <amir73il@xxxxxxxxx> wrote:
> On Wed, Aug 28, 2024 at 12:37 PM Aleksa Sarai <cyphar@xxxxxxxxxx> wrote:
> >
> > Now that open_by_handle_at(2) can return u64 mount IDs, do some tests to
> > make sure they match properly as part of the regular open_by_handle
> > tests.
> >
> > Link: https://lore.kernel.org/all/20240801-exportfs-u64-mount-id-v3-0-be5d6283144a@xxxxxxxxxx/
> > Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx>
> > ---
> > src/open_by_handle.c | 123 ++++++++++++++++++++++++++++++++-----------
> > tests/generic/426 | 1 +
> > 2 files changed, 93 insertions(+), 31 deletions(-)
> >
> > diff --git a/src/open_by_handle.c b/src/open_by_handle.c
> > index d9c802ca9bd1..cbd68aeadac1 100644
> > --- a/src/open_by_handle.c
> > +++ b/src/open_by_handle.c
> > @@ -86,10 +86,15 @@ Examples:
> > #include <errno.h>
> > #include <linux/limits.h>
> > #include <libgen.h>
> > +#include <stdint.h>
> >
> > #include <sys/stat.h>
> > #include "statx.h"
> >
> > +#ifndef AT_HANDLE_MNT_ID_UNIQUE
> > +# define AT_HANDLE_MNT_ID_UNIQUE 0x001
> > +#endif
> > +
> > #define MAXFILES 1024
> >
> > struct handle {
> > @@ -99,7 +104,7 @@ 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, "\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");
> > @@ -111,6 +116,7 @@ void usage(void)
> > 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 -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] - confirm that the mount id returned by name_to_handle_at matches the mount id in statx\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 -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");
> > @@ -120,6 +126,81 @@ void usage(void)
> > exit(EXIT_FAILURE);
> > }
> >
> > +int do_name_to_handle_at(const char *fname, struct file_handle *fh, int bufsz,
> > + int checkmountid)
> > +{
> > + int ret;
> > + int mntid_short;
> > +
> > + uint64_t mntid_unique;
> > + uint64_t statx_mntid_short = 0, statx_mntid_unique = 0;
> > + struct handle dummy_fh;
> > +
> > + if (checkmountid) {
> > + struct statx statxbuf;
> > +
> > + /* Get both the short and unique mount id. */
> > + if (statx(AT_FDCWD, fname, 0, STATX_MNT_ID, &statxbuf) < 0) {
> > + fprintf(stderr, "%s: statx(STATX_MNT_ID): %m\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > + if (!(statxbuf.stx_mask & STATX_MNT_ID)) {
> > + fprintf(stderr, "%s: no STATX_MNT_ID in stx_mask\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > + statx_mntid_short = statxbuf.stx_mnt_id;
> > +
> > + if (statx(AT_FDCWD, fname, 0, STATX_MNT_ID_UNIQUE, &statxbuf) < 0) {
> > + fprintf(stderr, "%s: statx(STATX_MNT_ID_UNIQUE): %m\n", fname);
> > + return EXIT_FAILURE;
>
> This failure will break the test on LTS kernels - we don't want that.
> Instead I think you should:
> - drop the -M option
> - get statx_mntid_unique here IF kernel supports STATX_MNT_ID_UNIQUE
> and then...

Ah okay, I wasn't sure if the xfstests policy was like selftests where
only the latest kernel matters. I'll send a v2 with the suggestions you
mentioned.

However, presumably this means we would also not do the
STATX_MNT_ID_UNIQUE check if name_to_handle_at(AT_HANDLE_MNT_ID_UNIQUE)
returns -EINVAL, right?

> > + }
> > + if (!(statxbuf.stx_mask & STATX_MNT_ID_UNIQUE)) {
> > + fprintf(stderr, "%s: no STATX_MNT_ID_UNIQUE in stx_mask\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > + statx_mntid_unique = statxbuf.stx_mnt_id;
> > + }
> > +
> > + fh->handle_bytes = bufsz;
> > + ret = name_to_handle_at(AT_FDCWD, fname, fh, &mntid_short, 0);
> > + if (bufsz < fh->handle_bytes) {
> > + /* Query the filesystem required bufsz and the file handle */
> > + if (ret != -1 || errno != EOVERFLOW) {
> > + fprintf(stderr, "%s: unexpected result from name_to_handle_at: %d (%m)\n", fname, ret);
> > + return EXIT_FAILURE;
> > + }
> > + ret = name_to_handle_at(AT_FDCWD, fname, fh, &mntid_short, 0);
> > + }
> > + if (ret < 0) {
> > + fprintf(stderr, "%s: name_to_handle: %m\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > +
> > + if (checkmountid) {
> > + if (mntid_short != (int) statx_mntid_short) {
> > + fprintf(stderr, "%s: name_to_handle_at returned a different mount ID to STATX_MNT_ID: %u != %lu\n", fname, mntid_short, statx_mntid_short);
> > + return EXIT_FAILURE;
> > + }
> > +
> > + /*
> > + * Get the unique mount ID. We don't need to get another copy of the
> > + * handle so store it in a dummy struct.
> > + */
> > + dummy_fh.fh.handle_bytes = fh->handle_bytes;
> > + if (name_to_handle_at(AT_FDCWD, fname, &dummy_fh.fh, (int *) &mntid_unique, AT_HANDLE_MNT_ID_UNIQUE) < 0) {
> > + fprintf(stderr, "%s: name_to_handle_at(AT_HANDLE_MNT_ID_UNIQUE): %m\n", fname);
> > + return EXIT_FAILURE;
> > + }
> > +
> > + if (mntid_unique != statx_mntid_unique) {
> > + fprintf(stderr, "%s: name_to_handle_at(AT_HANDLE_MNT_ID_UNIQUE) returned a different mount ID to STATX_MNT_ID_UNIQUE: %lu != %lu\n", fname, mntid_unique, statx_mntid_unique);
> > + return EXIT_FAILURE;
> > + }
>
> - check statx_mntid_unique here IFF statx_mntid_unique is set
> - always check statx_mntid_short (what could be a reason to not check it?)
>
> > + }
> > +
> > + return 0;
> > +}
> > +
> > int main(int argc, char **argv)
> > {
> > int i, c;
> > @@ -132,19 +213,20 @@ int main(int argc, char **argv)
> > char fname2[PATH_MAX];
> > char *test_dir;
> > char *mount_dir;
> > - int mount_fd, mount_id;
> > + int mount_fd;
> > char *infile = NULL, *outfile = NULL;
> > int in_fd = 0, out_fd = 0;
> > int numfiles = 1;
> > 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 checkmountid = 0;
> > int bufsz = MAX_HANDLE_SZ;
> >
> > if (argc < 2)
> > usage();
> >
> > - while ((c = getopt(argc, argv, "cludmrwapknhi:o:sz")) != -1) {
> > + while ((c = getopt(argc, argv, "cludMmrwapknhi:o:sz")) != -1) {
> > switch (c) {
> > case 'c':
> > create = 1;
> > @@ -172,6 +254,9 @@ int main(int argc, char **argv)
> > delete = 1;
> > nlink = 0;
> > break;
> > + case 'M':
> > + checkmountid = 1;
> > + break;
> > case 'm':
> > move = 1;
> > break;
> > @@ -307,21 +392,9 @@ int main(int argc, char **argv)
> > return EXIT_FAILURE;
> > }
> > } else {
> > - handle[i].fh.handle_bytes = bufsz;
> > - ret = name_to_handle_at(AT_FDCWD, fname, &handle[i].fh, &mount_id, 0);
> > - if (bufsz < handle[i].fh.handle_bytes) {
> > - /* Query the filesystem required bufsz and the file handle */
> > - if (ret != -1 || errno != EOVERFLOW) {
> > - fprintf(stderr, "Unexpected result from name_to_handle_at(%s)\n", fname);
> > - return EXIT_FAILURE;
> > - }
> > - ret = name_to_handle_at(AT_FDCWD, fname, &handle[i].fh, &mount_id, 0);
> > - }
> > - if (ret < 0) {
> > - strcat(fname, ": name_to_handle");
> > - perror(fname);
> > + ret = do_name_to_handle_at(fname, &handle[i].fh, bufsz, checkmountid);
> > + if (ret < 0)
> > return EXIT_FAILURE;
> > - }
> > }
> > if (keepopen) {
> > /* Open without close to keep unlinked files around */
> > @@ -349,21 +422,9 @@ int main(int argc, char **argv)
> > return EXIT_FAILURE;
> > }
> > } else {
> > - dir_handle.fh.handle_bytes = bufsz;
> > - ret = name_to_handle_at(AT_FDCWD, test_dir, &dir_handle.fh, &mount_id, 0);
> > - if (bufsz < dir_handle.fh.handle_bytes) {
> > - /* Query the filesystem required bufsz and the file handle */
> > - if (ret != -1 || errno != EOVERFLOW) {
> > - fprintf(stderr, "Unexpected result from name_to_handle_at(%s)\n", dname);
> > - return EXIT_FAILURE;
> > - }
> > - ret = name_to_handle_at(AT_FDCWD, test_dir, &dir_handle.fh, &mount_id, 0);
> > - }
> > - if (ret < 0) {
> > - strcat(dname, ": name_to_handle");
> > - perror(dname);
> > + ret = do_name_to_handle_at(test_dir, &dir_handle.fh, bufsz, checkmountid);
> > + if (ret < 0)
> > return EXIT_FAILURE;
> > - }
> > }
> > if (out_fd) {
> > ret = write(out_fd, (char *)&dir_handle, sizeof(*handle));
> > diff --git a/tests/generic/426 b/tests/generic/426
> > index 25909f220e1e..df481c58562c 100755
> > --- a/tests/generic/426
> > +++ b/tests/generic/426
> > @@ -51,6 +51,7 @@ test_file_handles $testdir -d
> > # Check non-stale handles to linked files
> > create_test_files $testdir
> > test_file_handles $testdir
> > +test_file_handles $testdir -M
>
> I see no reason to add option -M and add a second invocation.
>
> Something I am missing?

Given how many other custom modes there were, I assumed that providing
it as an additional flag would've been preferred. I'll just make it
automatic.

Thanks!

>
> Thanks,
> Amir.

--
Aleksa Sarai
Senior Software Engineer (Containers)
SUSE Linux GmbH
<https://www.cyphar.com/>

Attachment: signature.asc
Description: PGP signature

Next message: Menglong Dong: "Re: [PATCH net-next v2 07/12] net: vxlan: add skb drop reasons to vxlan_rcv()"
Previous message: Menglong Dong: "Re: [PATCH net-next v2 06/12] net: vxlan: make vxlan_set_mac() return drop reasons"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]