io: Return UNSUPPORTED if filesystem do not support 64 bit timestamps

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. This patch adds a new libsupport function, 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
2021-03-11 09:30:33 -03:00 · 2021-03-11 09:30:33 -03:00 · b2970919ba
parent 20bee71348
commit b2970919ba
6 changed files with 101 additions and 3 deletions
--- 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 \
--- 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 */
--- a/support/support_path_support_time64.c
+++ 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
+}
--- 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);
+
  struct stat64 st;
  int result;
  time_t t;
--- 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);
+
  struct stat64 st;
  int result;
  time_t t;
--- 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);
+
  struct stat64 st;
  int result;
  time_t t;