From: Bernhard Voelker Date: Tue, 14 Aug 2012 07:22:13 +0000 (+0200) Subject: df: fail when the mount list is required but cannot be read X-Git-Tag: v8.19~11 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=46afefaaa8ea95b5eb63a62792774cd18738234a;p=thirdparty%2Fcoreutils.git df: fail when the mount list is required but cannot be read * src/df.c (main): Add conditions to fail when the mount list cannot be read: this includes the cases when a file name argument is given and any of -a, -l, -t or -x is used. * doc/coreutils.texi: Document the additional error conditions. * tests/df/no-mtab-status: Add a new test. * tests/Makefile.am: Reference the new test. * NEWS: Mention the fix. --- diff --git a/NEWS b/NEWS index 385617e867..46d0a41314 100644 --- a/NEWS +++ b/NEWS @@ -2,6 +2,11 @@ GNU coreutils NEWS -*- outline -*- * Noteworthy changes in release ?.? (????-??-??) [?] + df now fails when the list of mounted file systems (/etc/mtab) cannot + be read, yet the file system type information is needed to process + certain options like -a, -l, -t and -x. + [This bug was present in "the beginning".] + * Noteworthy changes in release 8.18 (2012-08-12) [stable] diff --git a/doc/coreutils.texi b/doc/coreutils.texi index 516ec7311e..744b41a9fe 100644 --- a/doc/coreutils.texi +++ b/doc/coreutils.texi @@ -10754,6 +10754,11 @@ inspect the exit status of a command like @samp{df -t ext3 -t reiserfs @var{dir}} to test whether @var{dir} is on a file system of type @samp{ext3} or @samp{reiserfs}. +Since the list of file systems (@var{mtab}) is needed to determine the +file system type, failure includes the cases when that list cannot +be read and one or more of the options @option{-a}, @option{-l}, @option{-t} +or @option{-x} is used together with a file name argument. + @node du invocation @section @command{du}: Estimate file space usage diff --git a/src/df.c b/src/df.c index 4f3b56b25e..9d956cd037 100644 --- a/src/df.c +++ b/src/df.c @@ -1100,10 +1100,19 @@ main (int argc, char **argv) if (mount_list == NULL) { /* Couldn't read the table of mounted file systems. - Fail if df was invoked with no file name arguments; - Otherwise, merely give a warning and proceed. */ - int status = (optind < argc ? 0 : EXIT_FAILURE); - const char *warning = (optind < argc ? _("Warning: ") : ""); + Fail if df was invoked with no file name arguments, + or when either of -a, -l, -t or -x is used with file name + arguments. Otherwise, merely give a warning and proceed. */ + int status = 0; + if ( ! (optind < argc) + || (show_all_fs + || show_local_fs + || fs_select_list != NULL + || fs_exclude_list != NULL)) + { + status = EXIT_FAILURE; + } + const char *warning = (status == 0 ? _("Warning: ") : ""); error (status, errno, "%s%s", warning, _("cannot read table of mounted file systems")); } diff --git a/tests/Makefile.am b/tests/Makefile.am index edc04b4fb9..273405f595 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -376,6 +376,7 @@ TESTS = \ df/df-P \ df/unreadable \ df/total-unprocessed \ + df/no-mtab-status \ dd/direct \ dd/misc \ dd/nocache \ diff --git a/tests/df/no-mtab-status b/tests/df/no-mtab-status new file mode 100755 index 0000000000..6e078541fe --- /dev/null +++ b/tests/df/no-mtab-status @@ -0,0 +1,79 @@ +#!/bin/sh +# Test df's behaviour when the mount list cannot be read. +# This test is skipped on systems that lack LD_PRELOAD support; that's fine. + +# Copyright (C) 2012 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 . + +. "${srcdir=.}/init.sh"; path_prepend_ ../src +print_ver_ df + +df || skip_ "df fails" + +# Simulate "mtab" failure. +cat > k.c <<'EOF' || framework_failure_ +#include +#include + +struct mntent *getmntent (FILE *fp) +{ + /* Prove that LD_PRELOAD works. */ + static int done = 0; + if (!done) + { + fclose (fopen ("x", "w")); + ++done; + } + /* Now simulate the failure. */ + errno = ENOENT; + return NULL; +} +EOF + +# Then compile/link it: +$CC -shared -fPIC -ldl -O2 k.c -o k.so \ + || framework_failure_ 'failed to compile with -shared -fPIC' + +# Test if LD_PRELOAD works: +LD_PRELOAD=./k.so df +test -f x || skip_ "internal test failure: maybe LD_PRELOAD doesn't work?" + +# These tests are supposed to succeed: +LD_PRELOAD=./k.so df '.' || fail=1 +LD_PRELOAD=./k.so df -i '.' || fail=1 +LD_PRELOAD=./k.so df -T '.' || fail=1 +LD_PRELOAD=./k.so df -Ti '.' || fail=1 +LD_PRELOAD=./k.so df --total '.' || fail=1 + +# These tests are supposed to fail: +LD_PRELOAD=./k.so df && fail=1 +LD_PRELOAD=./k.so df -i && fail=1 +LD_PRELOAD=./k.so df -T && fail=1 +LD_PRELOAD=./k.so df -Ti && fail=1 +LD_PRELOAD=./k.so df --total && fail=1 + +LD_PRELOAD=./k.so df -a && fail=1 +LD_PRELOAD=./k.so df -a '.' && fail=1 + +LD_PRELOAD=./k.so df -l && fail=1 +LD_PRELOAD=./k.so df -l '.' && fail=1 + +LD_PRELOAD=./k.so df -t hello && fail=1 +LD_PRELOAD=./k.so df -t hello '.' && fail=1 + +LD_PRELOAD=./k.so df -x hello && fail=1 +LD_PRELOAD=./k.so df -x hello '.' && fail=1 + +Exit $fail