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#!/bin/sh
# Copyright (C) 2012-2022 Free Software Foundation, Inc.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program 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 General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <https://www.gnu.org/licenses/>.
. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
print_ver_ dd
is_local_dir_ . || very_expensive_
require_sparse_support_
# Ensure basic sparse generation works
truncate -s1M sparse
dd bs=32K if=sparse of=sparse.dd conv=sparse
test $(stat -c %s sparse) = $(stat -c %s sparse.dd) || fail=1
# Demonstrate that conv=sparse with oflag=append,
# will do ineffective seeks in the output
printf 'a\000\000b' > file.in
printf 'ab' > exp
dd if=file.in bs=1 conv=sparse oflag=append > out
compare exp out || fail=1
# Demonstrate conv=sparse with conv=notrunc,
# where data in file.out is not overwritten with NULs
printf '____' > out
printf 'a__b' > exp
dd if=file.in bs=1 conv=sparse,notrunc of=out
compare exp out || fail=1
# Ensure we fall back to write if seek fails
dd if=file.in bs=1 conv=sparse | cat > file.out
cmp file.in file.out || fail=1
# Setup for block size tests: create a 3MiB file with a 1MiB
# stretch of NUL bytes in the middle.
rm -f file.in
dd if=/dev/urandom of=file.in bs=1M count=3 iflag=fullblock || fail=1
dd if=/dev/zero of=file.in bs=1M count=1 seek=1 conv=notrunc || fail=1
kb_alloc() { du -k "$1"|cut -f1; }
# sync out data for async allocators like NFS/BTRFS
# sync file.in || fail=1
# If our just-created input file appears to be too small,
# skip the remaining tests. On at least Solaris 10 with NFS,
# file.in is reported to occupy <= 1KiB for about 50 seconds
# after its creation.
if test $(kb_alloc file.in) -gt 3000; then
# Ensure NUL blocks smaller than the *output* block size are not made sparse.
# Here, with a 2MiB block size, dd's conv=sparse must *not* introduce a hole.
dd if=file.in of=file.out ibs=1M obs=2M conv=sparse || fail=1
# Intermittently BTRFS returns 0 allocation for file.out unless synced
sync file.out || framework_failure_
test 2500 -lt $(kb_alloc file.out) || fail=1
# Note we recreate a sparse file first to avoid
# speculative preallocation seen in XFS, where a write() that
# extends a file can preallocate some extra space that
# a subsequent seek will not convert to a hole.
rm -f file.out
truncate --size=3M file.out
# Ensure that this 1MiB *output* block of NULs *is* converted to a hole.
dd if=file.in of=file.out ibs=2M obs=1M conv=sparse,notrunc
if test $(kb_alloc file.out) -ge 2500; then
# Double check the failure by creating a sparse file in
# the traditional manner for comparison, as we're not guaranteed
# that seek=1M will create a hole. apfs on darwin 19.2.0 for example
# was seen to not to create holes < 16MiB.
dd if=file.in of=manual.out bs=1M count=1 || fail=1
dd if=file.in of=manual.out bs=1M count=1 seek=2 conv=notrunc || fail=1
test $(kb_alloc file.out) -eq $(kb_alloc manual.out) || fail=1
fi
fi
Exit $fail
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