tests/dd/nocache_eof.sh

   1 #!/bin/sh
   2 # Ensure dd invalidates to EOF when appropriate
   3
   4 # Copyright (C) 2017-2024 Free Software Foundation, Inc.
   5
   6 # This program is free software: you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation, either version 3 of the License, or
   9 # (at your option) any later version.
  10
  11 # This program is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  18
  19 . "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
  20 print_ver_ dd
  21 require_strace_ fadvise64,fadvise64_64
  22
  23 head -c1234567 /dev/zero > in.f || framework_failure_
  24
  25 # Check basic operation or skip.
  26 # We could check for 'Operation not supported' error here,
  27 # but that was seen to be brittle. HPUX returns ENOTTY for example.
  28 # So assume that if this basic operation fails, it's due to lack
  29 # of support by the system.
  30 dd if=in.f iflag=nocache count=0 ||
  31   skip_ 'this file system lacks support for posix_fadvise()'
  32
  33 strace_dd() {
  34   strace -o dd.strace -e fadvise64,fadvise64_64 dd status=none "$@" || fail=1
  35 }
  36
  37 advised_to_eof() {
  38   grep -F ' 0, POSIX_FADV_DONTNEED' dd.strace >/dev/null
  39 }
  40
  41 # The commented fadvise64 calls are what are expected with
  42 # a 4KiB page size and 128KiB IO_BUFSIZE.
  43
  44 strace_dd if=in.f of=out.f bs=1M oflag=nocache,sync
  45 #fadvise64(1, 0, 1048576, POSIX_FADV_DONTNEED) = 0
  46 #fadvise64(1, 1048576, 131072, POSIX_FADV_DONTNEED) = 0
  47 #fadvise64(1, 1179648, 0, POSIX_FADV_DONTNEED) = 0
  48 advised_to_eof || fail=1
  49
  50 strace_dd if=in.f count=0 iflag=nocache
  51 #fadvise64(0, 0, 0, POSIX_FADV_DONTNEED) = 0
  52 advised_to_eof || fail=1
  53
  54 strace_dd if=in.f of=/dev/null iflag=nocache skip=10 count=300
  55 #fadvise64(0, 5120, 131072, POSIX_FADV_DONTNEED) = 0
  56 #fadvise64(0, 136192, 22528, POSIX_FADV_DONTNEED) = 0
  57 returns_ 1 advised_to_eof || fail=1
  58
  59 strace_dd if=in.f of=/dev/null iflag=nocache bs=1M count=3000
  60 #fadvise64(0, 0, 1048576, POSIX_FADV_DONTNEED) = 0
  61 #fadvise64(0, 1048576, 131072, POSIX_FADV_DONTNEED) = 0
  62 #fadvise64(0, 1179648, 0, POSIX_FADV_DONTNEED) = 0
  63 advised_to_eof || fail=1
  64
  65 strace_dd if=in.f of=/dev/null bs=1M count=1 iflag=nocache
  66 #fadvise64(0, 0, 1048576, POSIX_FADV_DONTNEED) = 0
  67 returns_ 1 advised_to_eof || fail=1
  68
  69 strace_dd if=in.f of=out.f bs=1M iflag=nocache oflag=nocache,sync
  70 #fadvise64(0, 0, 1048576, POSIX_FADV_DONTNEED) = 0
  71 #fadvise64(1, 0, 1048576, POSIX_FADV_DONTNEED) = 0
  72 #fadvise64(0, 1048576, 131072, POSIX_FADV_DONTNEED) = 0
  73 #fadvise64(1, 1048576, 131072, POSIX_FADV_DONTNEED) = 0
  74 #fadvise64(0, 1179648, 0, POSIX_FADV_DONTNEED) = 0
  75 #fadvise64(1, 1179648, 0, POSIX_FADV_DONTNEED) = 0
  76 advised_to_eof || fail=1
  77
  78 # Ensure sub page size offsets are handled.
  79 # I.e., only page aligned offsets are sent to fadvise.
  80 if ! strace -o dd.strace -e fadvise64,fadvise64_64 dd status=none \
  81  if=in.f of=out.f bs=1M oflag=direct oseek=512B; then
  82   warn_ '512 byte aligned O_DIRECT is not supported on this (file) system'
  83   # The current file system may not support O_DIRECT,
  84   # or older XFS had a page size alignment requirement
  85 else
  86   #The first call is redundant but inconsequential
  87   #fadvise64(1, 1048576, 0, POSIX_FADV_DONTNEED) = 0
  88   #fadvise64(1, 1048576, 0, POSIX_FADV_DONTNEED) = 0
  89   advised_to_eof || fail=1
  90
  91   strace_dd if=in.f of=out.f bs=1M oflag=direct
  92   #fadvise64(1, 1048576, 0, POSIX_FADV_DONTNEED) = 0
  93   #fadvise64(1, 1048576, 0, POSIX_FADV_DONTNEED) = 0
  94   advised_to_eof || fail=1
  95 fi
  96
  97 Exit $fail