1#!/bin/sh
2
3# Copyright (C) 2012-2023 Free Software Foundation, Inc.
4
5# This program is free software: you can redistribute it and/or modify
6# it under the terms of the GNU General Public License as published by
7# the Free Software Foundation, either version 3 of the License, or
8# (at your option) any later version.
9
10# This program 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
13# GNU General Public License for more details.
14
15# You should have received a copy of the GNU General Public License
16# along with this program.  If not, see <https://www.gnu.org/licenses/>.
17
18. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
19print_ver_ dd
20is_local_dir_ . || very_expensive_
21require_sparse_support_
22
23# Ensure basic sparse generation works
24truncate -s1M sparse
25dd bs=32K if=sparse of=sparse.dd conv=sparse
26test $(stat -c %s sparse) = $(stat -c %s sparse.dd) || fail=1
27
28# Demonstrate that conv=sparse with oflag=append,
29# will do ineffective seeks in the output
30printf 'a\000\000b' > file.in
31printf 'ab' > exp
32dd if=file.in bs=1 conv=sparse oflag=append > out
33compare exp out || fail=1
34
35# Demonstrate conv=sparse with conv=notrunc,
36# where data in file.out is not overwritten with NULs
37printf '____' > out
38printf 'a__b' > exp
39dd if=file.in bs=1 conv=sparse,notrunc of=out
40compare exp out || fail=1
41
42# Ensure we fall back to write if seek fails
43dd if=file.in bs=1 conv=sparse | cat > file.out
44cmp file.in file.out || fail=1
45
46# Setup for block size tests: create a 3MiB file with a 1MiB
47# stretch of NUL bytes in the middle.
48rm -f file.in
49dd if=/dev/urandom of=file.in bs=1M count=3 iflag=fullblock || fail=1
50dd if=/dev/zero    of=file.in bs=1M count=1 seek=1 conv=notrunc || fail=1
51
52kb_alloc() { du -k "$1"|cut -f1; }
53
54# sync out data for async allocators like NFS/BTRFS
55# sync file.in || fail=1
56
57# If our just-created input file appears to be too small,
58# skip the remaining tests.  On at least Solaris 10 with NFS,
59# file.in is reported to occupy <= 1KiB for about 50 seconds
60# after its creation.
61if test $(kb_alloc file.in) -gt 3000; then
62
63  # Ensure NUL blocks smaller than the *output* block size are not made sparse.
64  # Here, with a 2MiB block size, dd's conv=sparse must *not* introduce a hole.
65  dd if=file.in of=file.out ibs=1M obs=2M conv=sparse || fail=1
66
67  # Intermittently BTRFS returns 0 allocation for file.out unless synced
68  sync file.out || framework_failure_
69  test 2500 -lt $(kb_alloc file.out) || fail=1
70
71  # Note we recreate a sparse file first to avoid
72  # speculative preallocation seen in XFS, where a write() that
73  # extends a file can preallocate some extra space that
74  # a subsequent seek will not convert to a hole.
75  rm -f file.out
76  truncate --size=3M file.out
77
78  # Ensure that this 1MiB *output* block of NULs *is* converted to a hole.
79  dd if=file.in of=file.out ibs=2M obs=1M conv=sparse,notrunc
80  if test $(kb_alloc file.out) -ge 2500; then
81    # Double check the failure by creating a sparse file in
82    # the traditional manner for comparison, as we're not guaranteed
83    # that seek=1M will create a hole.  apfs on darwin 19.2.0 for example
84    # was seen to not to create holes < 16MiB.
85    dd if=file.in of=manual.out bs=1M count=1 || fail=1
86    dd if=file.in of=manual.out bs=1M count=1 seek=2 conv=notrunc || fail=1
87
88    test $(kb_alloc file.out) -eq $(kb_alloc manual.out) || fail=1
89  fi
90
91fi
92
93Exit $fail
94