From 288524b39b2a4c4d1669b16e4a6e0cefc7ed8912 Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sat, 28 Jul 2007 18:49:04 +0200 Subject: [PATCH] =?utf8?q?Attempt=20to=20copy=20a=20regular=20file,=20even?= =?utf8?q?=20if=20stat=20says=20it=20is=20empty.=20*=20NEWS:=20Document=20?= =?utf8?q?this=20bug=20fix.=20*=20src/copy.c=20(copy=5Freg):=20Read=20from?= =?utf8?q?=20a=20regular=20file,=20even=20if=20it=20appears=20(stat.st=5Fs?= =?utf8?q?ize=20=3D=3D=200)=20to=20be=20empty.=20=20This=20reverts=20an=20?= =?utf8?q?optimization=20introduced=20on=202005-11-23=20for=20coreutils-6.?= =?utf8?q?0.=20Otherwise,=20"cp=20/proc/cpuinfo=20/tmp"=20creates=20an=20e?= =?utf8?q?mpty=20file,=20on=20e.g.,=20linux-2.6.20.=20*=20tests/cp/proc-ze?= =?utf8?q?ro-len:=20New=20file.=20=20Test=20for=20the=20above.=20*=20tests?= =?utf8?q?/cp/Makefile.am=20(TESTS):=20Add=20proc-zero-len.=20Reported=20b?= =?utf8?q?y=20Dan=20Berrang=C3=A9.?= MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit --- ChangeLog | 13 ++++++++++ NEWS | 5 ++++ THANKS | 1 + src/copy.c | 1 - tests/cp/Makefile.am | 1 + tests/cp/proc-zero-len | 59 ++++++++++++++++++++++++++++++++++++++++++ 6 files changed, 79 insertions(+), 1 deletion(-) create mode 100755 tests/cp/proc-zero-len diff --git a/ChangeLog b/ChangeLog index 327e5342e0..23136e8d07 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,16 @@ +2007-07-28 Jim Meyering + + Attempt to copy a regular file, even if stat says it is empty. + * NEWS: Document this bug fix. + * src/copy.c (copy_reg): Read from a regular file, even if it + appears (stat.st_size == 0) to be empty. This reverts an + optimization introduced on 2005-11-23 for coreutils-6.0. + Otherwise, "cp /proc/cpuinfo /tmp" creates an empty file, + on e.g., linux-2.6.20. + * tests/cp/proc-zero-len: New file. Test for the above. + * tests/cp/Makefile.am (TESTS): Add proc-zero-len. + Reported by Dan Berrangé. + 2007-07-26 Bob Proulx sort: Improve sort --random-sort test. diff --git a/NEWS b/NEWS index fbefbf24c0..059980c02e 100644 --- a/NEWS +++ b/NEWS @@ -54,6 +54,11 @@ GNU coreutils NEWS -*- outline -*- ** Bug fixes + cp attempts to read a regular file, even if stat says it is empty. + Before, "cp /proc/cpuinfo c" would create an empty file when the kernel + reports stat.st_size == 0, while "cat /proc/cpuinfo > c" would "work", + and create a nonempty one. [bug introduced in coreutils-6.0] + cp no longer fails to write through a dangling symlink [bug introduced in coreutils-6.7]. cp --parents no longer mishandles symlinks to directories in file name diff --git a/THANKS b/THANKS index 601ca8fdfd..ae5269f31b 100644 --- a/THANKS +++ b/THANKS @@ -110,6 +110,7 @@ Dan Hagerty hag@gnu.ai.it.edu Dan Jacobson http://www.geocities.com/jidani Dan Pascu dan@services.iiruc.ro Daniel Bergstrom noa@melody.se +Daniel P. Berrangé berrange@redhat.com Dániel Varga danielv@axelero.hu Danny Levinson danny.levinson@overture.com Darren Salt ds@youmustbejoking.demon.co.uk diff --git a/src/copy.c b/src/copy.c index 965dd76d3f..ba79ed393f 100644 --- a/src/copy.c +++ b/src/copy.c @@ -418,7 +418,6 @@ copy_reg (char const *src_name, char const *dst_name, goto close_src_and_dst_desc; } - if (! (S_ISREG (src_open_sb.st_mode) && src_open_sb.st_size == 0)) { typedef uintptr_t word; off_t n_read_total = 0; diff --git a/tests/cp/Makefile.am b/tests/cp/Makefile.am index e3978c517d..ecb7181746 100644 --- a/tests/cp/Makefile.am +++ b/tests/cp/Makefile.am @@ -16,6 +16,7 @@ # along with this program. If not, see . TESTS = \ + proc-zero-len \ thru-dangling \ cp-a-selinux \ file-perm-race parent-perm-race \ diff --git a/tests/cp/proc-zero-len b/tests/cp/proc-zero-len new file mode 100755 index 0000000000..cd6f94c834 --- /dev/null +++ b/tests/cp/proc-zero-len @@ -0,0 +1,59 @@ +#!/bin/sh +# Ensure that cp copies contents of non-empty "regular" file with st_size==0 + +# Copyright (C) 2007 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 . + +if test "$VERBOSE" = yes; then + set -x + cp --version +fi + +. $srcdir/../envvar-check + +pwd=`pwd` +t0=`echo "$0"|sed 's,.*/,,'`.tmp; tmp=$t0/$$ +trap 'status=$?; cd "$pwd" && chmod -R u+rwx $t0 && rm -rf $t0 && exit $status' 0 +trap '(exit $?); exit $?' 1 2 13 15 + +framework_failure=0 +mkdir -p $tmp || framework_failure=1 +cd $tmp || framework_failure=1 +touch empty || framework_failure=1 + +if test $framework_failure = 1; then + echo "$0: failure in testing framework" 1>&2 + (exit 1); exit 1 +fi + +f=/proc/cpuinfo +test -r $f || f=empty + +fail=0 +cat $f > out || fail=1 + +# With coreutils-6.9, this would create a zero-length "exp" file. +cp $f exp || fail=1 + +# Don't simply compare contents; they might differ, +# e.g., if CPU freq changes between cat and cp invocations. +# Instead, simply compare whether they're both nonempty. +test -s out && { rm -f out; echo nonempty > out; } +test -s exp && { rm -f exp; echo nonempty > exp; } + +cmp out exp || fail=1 +test $fail = 1 && diff out exp 2> /dev/null + +(exit $fail); exit $fail -- 2.47.2