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/> Looks good. You may add: Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx> It'd be nice to get a verification that this is indeed tested on the latest upstream and does not regress the tests that run the open_by_handle program. Thanks, Amir. > > 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) { > + 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"); > + else > + 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 (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; > + } > + > + if (!skip_mntid_unique && statx_mntid_unique != 0) { > + struct handle dummy_fh; > + uint64_t mntid_unique = 0; > + > + /* > + * 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; > + ret = name_to_handle_at(AT_FDCWD, fname, &dummy_fh.fh, (int *) &mntid_unique, AT_HANDLE_MNT_ID_UNIQUE); > + if (ret < 0) { > + if (errno != EINVAL) { > + fprintf(stderr, "%s: name_to_handle_at(AT_HANDLE_MNT_ID_UNIQUE): %m\n", fname); > + return EXIT_FAILURE; > + } > + /* > + * EINVAL means AT_HANDLE_MNT_ID_UNIQUE is not supported, so skip > + * the check in that case. > + */ > + printf("name_to_handle_at(AT_HANDLE_MNT_ID_UNIQUE) not supported by running kernel -- skipping unique mount ID test\n"); > + skip_mntid_unique = true; > + } else { > + 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; > + } > + } > + } > + > + return 0; > +} > + > int main(int argc, char **argv) > { > int i, c; > @@ -132,7 +226,7 @@ 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; > @@ -307,21 +401,9 @@ 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); > + if (ret < 0) > return EXIT_FAILURE; > - } > } > if (keepopen) { > /* Open without close to keep unlinked files around */ > @@ -349,21 +431,9 @@ 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); > + if (ret < 0) > return EXIT_FAILURE; > - } > } > if (out_fd) { > ret = write(out_fd, (char *)&dir_handle, sizeof(*handle)); > -- > 2.46.0 >
