posix/tst-preadwrite64.c

   1 /* Tests for pread64 and pwrite64.
   2    Copyright (C) 2000-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #define _FILE_OFFSET_BITS 64
  20 #include "tst-preadwrite-common.c"
  21
  22 static int
  23 do_test (void)
  24 {
  25   ssize_t ret;
  26
  27   ret = do_test_with_offset (0);
  28   if (ret == -1)
  29     return 1;
  30
  31   /* Create a sparse file larger than 4GB to check if offset is handled
  32      correctly in p{write,read}64. */
  33   off_t base_offset = UINT32_MAX + 2048LL;
  34   ret = do_test_with_offset (base_offset);
  35   if (ret == -1)
  36     return 1;
  37
  38   struct stat st;
  39   if (fstat (fd, &st) == -1)
  40     {
  41       printf ("error: fstat on temporary file failed: %m");
  42       return 1;
  43     }
  44
  45   /* The file size should >= base_offset plus bytes read.  */
  46   off_t expected_value = base_offset + ret;
  47   if (st.st_size < expected_value)
  48     {
  49       printf ("error: file size less than expected (%jd > %jd)\n",
  50               (intmax_t) expected_value, (intmax_t) st.st_size);
  51       return 1;
  52     }
  53
  54   return 0;
  55 }