mirror of
git://git.sv.gnu.org/coreutils.git
synced 2026-02-12 02:12:06 +02:00
ed0c3c33c6
On XFS, when creating the ~2G test file 'big' in a for-loop by
appending 20M each time, the file ends up using ~4G - visible in
'st_blocks'. The unused space would be reclaimed later.
This feature is called "speculative preallocation" which aims at
avoiding fragmentation.
According to the XFS FAQ [1], there are two particular aspects of
XFS speculative preallocation that are triggering this:
1. "Applications that repeatedly trigger preallocation and reclaim
cycles [after file close] can cause fragmentation.
Therefore, this pattern is detected and causes the preallocation
to persist beyond the lifecycle of the file descriptor."
2. "Preallocation sizes grow as files grow larger."
[1] http://xfs.org/index.php/XFS_FAQ
Avoid one of the above by only doing a single close (reclaim cycle).
* tests/du/2g.sh: Similar to the fix for a dd test (see commit
v8.22-65-g7c03fe2), avoid speculative preallocation by creating
the 'big' file in one go instead of appending to it in the loop.
Remove debugging statements as the output with 'set -x' is
sufficient nowadays.
66 lines
1.8 KiB
Bash
Executable File
66 lines
1.8 KiB
Bash
Executable File
#!/bin/sh
|
|
# Ensure that du can handle a 2GB file (i.e., a file of size 2^31 bytes)
|
|
# Before coreutils-5.93, on systems with a signed, 32-bit stat.st_blocks
|
|
# one of du's computations would overflow.
|
|
|
|
# Copyright (C) 2005-2014 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 <http://www.gnu.org/licenses/>.
|
|
|
|
. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
|
|
print_ver_ du
|
|
|
|
# Creating a 2GB file counts as 'very expensive'.
|
|
very_expensive_
|
|
|
|
|
|
# Get number of free kilobytes on current partition, so we can
|
|
# skip this test if there is insufficient free space.
|
|
free_kb=$(df -k --output=avail . | tail -n1)
|
|
case "$free_kb" in
|
|
[0-9]*) ;;
|
|
*) skip_ "invalid size from df: $free_kb";;
|
|
esac
|
|
|
|
# Require about 3GB free.
|
|
min_kb=3000000
|
|
test $min_kb -lt $free_kb ||
|
|
{
|
|
skip_ \
|
|
"too little free space on current partition: $free_kb (need $min_kb KB)"
|
|
}
|
|
|
|
big=big
|
|
rm -f $big
|
|
{
|
|
for i in $(seq 100); do
|
|
# Note: 2147483648 == 2^31. Print floor(2^31/100) per iteration.
|
|
printf %21474836s x || fail=1
|
|
done
|
|
# After the final iteration, append the remaining 48 bytes.
|
|
printf %48s x || fail=1
|
|
} > $big || fail=1
|
|
|
|
du -k $big > out1 || fail=1
|
|
rm -f $big
|
|
sed 's/^2[0-9][0-9][0-9][0-9][0-9][0-9] '$big'$/~2M/' out1 > out
|
|
|
|
cat <<\EOF > exp || fail=1
|
|
~2M
|
|
EOF
|
|
|
|
compare exp out || fail=1
|
|
|
|
Exit $fail
|