[RFC v2] io: Return UNSUPPORTED if filesystem do not support 64 bit timestamps
Carlos O'Donell
carlos@redhat.com
Thu Mar 11 23:06:34 GMT 2021
On 3/11/21 2:29 PM, Adhemerval Zanella via Libc-alpha wrote:
> Some Linux filesystems might not fully support 64 bit timestamps [1],
> which make some Linux specific tests to fail when they check for the
> functionality.
LGTM.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> This patch adds a new libsupport functions, support_path_support_time64,
> that returns whether the target file supports or not 64 bit timestamps.
> The support is checked by issuing a utimensat and verifying both the
> last access and last modification time against a statx call.
>
> The tests that might fail are also adjusted to check the file support
> as well:
>
> $ dd if=/dev/zero of=loopbackfile.img bs=100M count=1
> 1+0 records in
> 1+0 records out
> 104857600 bytes (105 MB, 100 MiB) copied, 0,0589568 s, 1,8 GB/s
> $ sudo losetup -fP loopbackfile.img
> $ mkfs.xfs loopbackfile.img
> meta-data=loopbackfile.img isize=512 agcount=4, agsize=6400 blks
> = sectsz=512 attr=2, projid32bit=1
> = crc=1 finobt=1, sparse=1, rmapbt=0
> = reflink=1
> data = bsize=4096 blocks=25600, imaxpct=25
> = sunit=0 swidth=0 blks
> naming =version 2 bsize=4096 ascii-ci=0, ftype=1
> log =internal log bsize=4096 blocks=1368, version=2
> = sectsz=512 sunit=0 blks, lazy-count=1
> realtime =none extsz=4096 blocks=0, rtextents=0
> $ mkdir loopfs
> $ sudo mount -o loop /dev/loop0 loopfs/
> $ sudo chown -R azanella:azanella loopfs
> $ TMPDIR=loopfs/ ./testrun.sh misc/tst-utimes
> error: ../sysdeps/unix/sysv/linux/tst-utimes.c:55: File loopfs//utimesfECsK1 does not support 64-bit timestamps
>
> [1] https://bugzilla.redhat.com/show_bug.cgi?id=1795576
> ---
> support/Makefile | 1 +
> support/support.h | 5 ++
> support/support_path_support_time64.c | 76 ++++++++++++++++++++++++++
> sysdeps/unix/sysv/linux/tst-futimens.c | 8 ++-
> sysdeps/unix/sysv/linux/tst-utime.c | 7 ++-
> sysdeps/unix/sysv/linux/tst-utimes.c | 7 ++-
> 6 files changed, 101 insertions(+), 3 deletions(-)
> create mode 100644 support/support_path_support_time64.c
>
> diff --git a/support/Makefile b/support/Makefile
> index 8d63fbd5da..5904cdd412 100644
> --- a/support/Makefile
> +++ b/support/Makefile
> @@ -59,6 +59,7 @@ libsupport-routines = \
> support_format_hostent \
> support_format_netent \
> support_isolate_in_subprocess \
> + support_path_support_time64 \
> support_process_state \
> support_ptrace \
> support_openpty \
> diff --git a/support/support.h b/support/support.h
> index 9cbc455720..2e477c9e7c 100644
> --- a/support/support.h
> +++ b/support/support.h
> @@ -23,6 +23,7 @@
> #ifndef SUPPORT_H
> #define SUPPORT_H
>
> +#include <stdbool.h>
> #include <stddef.h>
> #include <sys/cdefs.h>
> /* For mode_t. */
> @@ -129,6 +130,10 @@ extern void support_copy_file (const char *from, const char *to);
> extern ssize_t support_copy_file_range (int, off64_t *, int, off64_t *,
> size_t, unsigned int);
>
> +/* Return true is PATH supports 64-bit time_t interfaces for file
> + operations (such as fstatat or utimensat). */
> +extern bool support_path_support_time64 (const char *path);
> +
> __END_DECLS
>
> #endif /* SUPPORT_H */
> diff --git a/support/support_path_support_time64.c b/support/support_path_support_time64.c
> new file mode 100644
> index 0000000000..74af7d4973
> --- /dev/null
> +++ b/support/support_path_support_time64.c
> @@ -0,0 +1,76 @@
> +/* Check if path supports 64-bit time interfaces.
> + Copyright (C) 2021 Free Software Foundation, Inc.
> + This file is part of the GNU C Library.
> +
> + The GNU C Library is free software; you can redistribute it and/or
> + modify it under the terms of the GNU Lesser General Public
> + License as published by the Free Software Foundation; either
> + version 2.1 of the License, or (at your option) any later version.
> +
> + The GNU C Library is distributed in the hope that it will be useful,
> + but WITHOUT ANY WARRANTY; without even the implied warranty of
> + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
> + Lesser General Public License for more details.
> +
> + You should have received a copy of the GNU Lesser General Public
> + License along with the GNU C Library; if not, see
> + <https://www.gnu.org/licenses/>. */
> +
> +#include <fcntl.h>
> +#include <support/check.h>
> +#include <support/support.h>
> +#include <sys/stat.h>
> +#ifdef __linux__
> +#include <sysdep.h>
> +#endif
> +
> +#ifdef __linux__
> +static int
> +utimesat_call (const char *path, const struct __timespec64 tsp[2])
> +{
> +# ifndef __NR_utimensat_time64
> +# define __NR_utimensat_time64 __NR_utimensat
> +# endif
> + return INLINE_SYSCALL_CALL (utimensat_time64, AT_FDCWD, path, &tsp[0], 0);
> +}
> +#endif
> +
> +bool
> +support_path_support_time64 (const char *path)
> +{
> +#ifdef __linux__
> + /* Obtain the original timestamps to restore at the end. */
> + struct statx ostx;
> + TEST_VERIFY_EXIT (statx (AT_FDCWD, path, 0, STATX_BASIC_STATS, &ostx) == 0);
> +
> + const struct __timespec64 tsp[] =
> + {
> + /* 1s and 2s after y2038 limit. */
> + { 0x80000001ULL, 0 },
> + { 0x80000002ULL, 0 }
> + };
> + /* Return is kernel does not support __NR_utimensat_time64. */
> + if (utimesat_call (path, tsp) == -1)
> + return false;
> +
> + /* Verify if the last access and last modification time match the ones
> + obtained with statx. */
> + struct statx stx;
> + TEST_VERIFY_EXIT (statx (AT_FDCWD, path, 0, STATX_BASIC_STATS, &stx) == 0);
> +
> + bool support = stx.stx_atime.tv_sec == tsp[0].tv_sec
> + && stx.stx_mtime.tv_sec == tsp[1].tv_sec;
> +
> + /* Reset to original timestamps. */
> + const struct __timespec64 otsp[] =
> + {
> + { ostx.stx_atime.tv_sec, ostx.stx_atime.tv_nsec },
> + { ostx.stx_mtime.tv_sec, ostx.stx_mtime.tv_nsec },
> + };
> + TEST_VERIFY_EXIT (utimesat_call (path, otsp) == 0);
> +
> + return support;
> +#else
> + return true;
> +#endif
> +}
> diff --git a/sysdeps/unix/sysv/linux/tst-futimens.c b/sysdeps/unix/sysv/linux/tst-futimens.c
> index 8f48cfee63..785cd87557 100644
> --- a/sysdeps/unix/sysv/linux/tst-futimens.c
> +++ b/sysdeps/unix/sysv/linux/tst-futimens.c
> @@ -21,10 +21,12 @@
> #include <stdlib.h>
> #include <sys/stat.h>
> #include <support/check.h>
> +#include <support/support.h>
> #include <support/xunistd.h>
> #include <support/temp_file.h>
>
> static int temp_fd = -1;
> +static char *testfile;
>
> /* struct timespec array with Y2038 threshold minus 2 and 1 seconds. */
> const struct timespec t1[2] = { { 0x7FFFFFFE, 0 }, { 0x7FFFFFFF, 0 } };
> @@ -39,13 +41,17 @@ const struct timespec t3[2] = { { 0x7FFFFFFE, 0 }, { 0x80000002ULL, 0 } };
> static void
> do_prepare (int argc, char *argv[])
> {
> - temp_fd = create_temp_file ("futimensat", NULL);
> + temp_fd = create_temp_file ("futimensat", &testfile);
> TEST_VERIFY_EXIT (temp_fd > 0);
> }
>
> static int
> test_futimens_helper (const struct timespec *ts)
> {
> + if (!support_path_support_time64 (testfile))
> + FAIL_UNSUPPORTED ("File %s does not support 64-bit timestamps",
> + testfile);
OK. XFAIL thes test.
> +
> struct stat64 st;
> int result;
> time_t t;
> diff --git a/sysdeps/unix/sysv/linux/tst-utime.c b/sysdeps/unix/sysv/linux/tst-utime.c
> index 6735421657..21e4e41dea 100644
> --- a/sysdeps/unix/sysv/linux/tst-utime.c
> +++ b/sysdeps/unix/sysv/linux/tst-utime.c
> @@ -23,11 +23,12 @@
> #include <sys/types.h>
> #include <utime.h>
> #include <support/check.h>
> +#include <support/support.h>
> #include <support/xunistd.h>
> #include <support/temp_file.h>
>
> static int temp_fd = -1;
> -char *testfile;
> +static char *testfile;
>
> /* struct utimbuf with Y2038 threshold minus 2 and 1 seconds. */
> const static struct utimbuf t1 = { 0x7FFFFFFE, 0x7FFFFFFF };
> @@ -49,6 +50,10 @@ do_prepare (int argc, char *argv[])
> static int
> test_utime_helper (const struct utimbuf *ut)
> {
> + if (!support_path_support_time64 (testfile))
> + FAIL_UNSUPPORTED ("File %s does not support 64-bit timestamps",
> + testfile);
OK. XFAIL the test.
> +
> struct stat64 st;
> int result;
> time_t t;
> diff --git a/sysdeps/unix/sysv/linux/tst-utimes.c b/sysdeps/unix/sysv/linux/tst-utimes.c
> index 8c7b006a22..0f23e44897 100644
> --- a/sysdeps/unix/sysv/linux/tst-utimes.c
> +++ b/sysdeps/unix/sysv/linux/tst-utimes.c
> @@ -22,11 +22,12 @@
> #include <sys/stat.h>
> #include <sys/time.h>
> #include <support/check.h>
> +#include <support/support.h>
> #include <support/xunistd.h>
> #include <support/temp_file.h>
>
> static int temp_fd = -1;
> -char *testfile;
> +static char *testfile;
>
> /* struct timeval array with Y2038 threshold minus 2 and 1 seconds. */
> const static struct timeval t1[2] = { { 0x7FFFFFFE, 0 }, { 0x7FFFFFFF, 0 } };
> @@ -50,6 +51,10 @@ do_prepare (int argc, char *argv[])
> static int
> test_utime_helper (const struct timeval *tv)
> {
> + if (!support_path_support_time64 (testfile))
> + FAIL_UNSUPPORTED ("File %s does not support 64-bit timestamps",
> + testfile);
OK. XFAIL the test.
> +
> struct stat64 st;
> int result;
> time_t t;
>
--
Cheers,
Carlos.
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