These come from Linux v6.11-rc5.
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
---
src/open_by_handle.c | 4 +++-
src/statx.h | 22 ++++++++++++++++++++--
2 files changed, 23 insertions(+), 3 deletions(-)
diff --git a/src/open_by_handle.c b/src/open_by_handle.c
index 0f74ed08b1f0..d9c802ca9bd1 100644
--- a/src/open_by_handle.c
+++ b/src/open_by_handle.c
@@ -82,12 +82,14 @@ Examples:
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
-#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#include <linux/limits.h>
#include <libgen.h>
+#include <sys/stat.h>
+#include "statx.h"
+
#define MAXFILES 1024
struct handle {
diff --git a/src/statx.h b/src/statx.h
index 3f239d791dfe..935cb2ed415e 100644
--- a/src/statx.h
+++ b/src/statx.h
@@ -102,7 +102,7 @@ struct statx {
__u64 stx_ino; /* Inode number */
__u64 stx_size; /* File size */
__u64 stx_blocks; /* Number of 512-byte blocks allocated */
- __u64 __spare1[1];
+ __u64 stx_attributes_mask; /* Mask to show what's supported in stx_attributes */
/* 0x40 */
struct statx_timestamp stx_atime; /* Last access time */
struct statx_timestamp stx_btime; /* File creation time */
@@ -114,7 +114,18 @@ struct statx {
__u32 stx_dev_major; /* ID of device containing file [uncond] */
__u32 stx_dev_minor;
/* 0x90 */
- __u64 __spare2[14]; /* Spare space for future expansion */
+ __u64 stx_mnt_id;
+ __u32 stx_dio_mem_align; /* Memory buffer alignment for direct I/O */
+ __u32 stx_dio_offset_align; /* File offset alignment for direct I/O */
+ /* 0xa0 */
+ __u64 stx_subvol; /* Subvolume identifier */
+ __u32 stx_atomic_write_unit_min; /* Min atomic write unit in bytes */
+ __u32 stx_atomic_write_unit_max; /* Max atomic write unit in bytes */
+ /* 0xb0 */
+ __u32 stx_atomic_write_segments_max; /* Max atomic write segment count */
+ __u32 __spare1[1];
+ /* 0xb8 */
+ __u64 __spare3[9]; /* Spare space for future expansion */
/* 0x100 */
};
@@ -139,6 +150,13 @@ struct statx {
#define STATX_BLOCKS 0x00000400U /* Want/got stx_blocks */
#define STATX_BASIC_STATS 0x000007ffU /* The stuff in the normal stat struct */
#define STATX_BTIME 0x00000800U /* Want/got stx_btime */
+#define STATX_MNT_ID 0x00001000U /* Got stx_mnt_id */
+#define STATX_DIOALIGN 0x00002000U /* Want/got direct I/O alignment info */
+#define STATX_MNT_ID_UNIQUE 0x00004000U /* Want/got extended stx_mount_id */
+#define STATX_SUBVOL 0x00008000U /* Want/got stx_subvol */
+#define STATX_WRITE_ATOMIC 0x00010000U /* Want/got atomic_write_* fields */
+
+#define STATX__RESERVED 0x80000000U /* Reserved for future struct statx expansion */
#define STATX_ALL 0x00000fffU /* All currently supported flags */
/*
--
2.46.0Now 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@cyphar.com/
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
---
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;
+ }
+ 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;
+ }
+ }
+
+ 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
# Check non-stale handles to files that were hardlinked and original deleted
create_test_files $testdir
--
2.46.0On Wed, Aug 28, 2024 at 12:37 PM Aleksa Sarai <cyphar@cyphar.com> 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@cyphar.com/
> Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
> ---
> 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...
> + }
> + 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?
Thanks,
Amir.
On 2024-08-30, Amir Goldstein <amir73il@gmail.com> wrote:
> On Wed, Aug 28, 2024 at 12:37 PM Aleksa Sarai <cyphar@cyphar.com> 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@cyphar.com/
> > Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
> > ---
> > 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/>
© 2016 - 2025 Red Hat, Inc.