On Mon, Sep 2, 2024 at 6:46 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/20240828-exportfs-u64-mount-id-v3-0-10c2c4c16708@xxxxxxxxxx/ > Signed-off-by: Aleksa Sarai <cyphar@xxxxxxxxxx> > --- > v2: > - Remove -M argument and always do the mount ID tests. [Amir Goldstein] > - Do not error out if the kernel doesn't support STATX_MNT_ID_UNIQUE > or AT_HANDLE_MNT_ID_UNIQUE. [Amir Goldstein] > - v1: <https://lore.kernel.org/all/20240828103706.2393267-1-cyphar@xxxxxxxxxx/> > > src/open_by_handle.c | 128 +++++++++++++++++++++++++++++++++---------- > 1 file changed, 99 insertions(+), 29 deletions(-) > > diff --git a/src/open_by_handle.c b/src/open_by_handle.c > index d9c802ca9bd1..0ad591da632e 100644 > --- a/src/open_by_handle.c > +++ b/src/open_by_handle.c > @@ -86,10 +86,16 @@ Examples: > #include <errno.h> > #include <linux/limits.h> > #include <libgen.h> > +#include <stdint.h> > +#include <stdbool.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 { > @@ -120,6 +126,94 @@ void usage(void) > exit(EXIT_FAILURE); > } > > +int do_name_to_handle_at(const char *fname, struct file_handle *fh, int bufsz) > +{ > + int ret; > + int mntid_short; > + > + static bool skip_mntid_unique; > + > + uint64_t statx_mntid_short = 0, statx_mntid_unique = 0; > + struct statx statxbuf; > + > + /* Get both the short and unique mount id. */ > + if (statx(AT_FDCWD, fname, 0, STATX_MNT_ID, &statxbuf) < 0) { This fails build on top of latest for-next branch with commit 873e36c9 - statx.h: update to latest kernel UAPI It can be fixed by changing to use the private xfstests_statx() implementation, same as in stat_test.c. I am not sure how elegant this is, but that's the easy fix. > + 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 (!skip_mntid_unique) { > + 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; > + } > + /* > + * 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 ((skip_mntid_unique |= !(statxbuf.stx_mask & STATX_MNT_ID_UNIQUE))) > + printf("statx(STATX_MNT_ID_UNIQUE) not supported by running kernel -- skipping unique mount ID test\n"); This verbose print breaks all existing "exportfs" tests which do not expect it in the golden output. I understand that silently ignoring the failure is not good, but I also would like to add this test coverage to all the existing tests. One solution is to resurrect the command line option -M from v1, but instead of meaning "test unique mount id" let it mean "do not allow to skip unique mount id" test. Then you can add a new test that runs open_by_handle -M, but also implement a helper _require_unique_mntid similar to _require_btime which is needed for the new test to run only on new kernels. I'm sorry for this complication, but fstest is a testsuite that runs on disto and stable kernels as well and we need to allow test coverage of new features along with stability of the test env. Thanks, Amir.
