Mercurial > hg > octave-nkf > gnulib-hg
view lib/open-safer.c @ 15988:cd7ac59d8eb5
fts: close parent dir FD before returning from post-traversal fts_read
The problem: the fts-using "mkdir -p A/B; rm -rf A" would attempt to
unlink A, even though an FD open on A remained. This is suboptimal
(holding a file descriptor open longer than needed), but otherwise not
a problem on Unix-like kernels. However, on Cygwin with certain Novell
file systems, (see http://cygwin.com/ml/cygwin/2011-10/msg00365.html),
that represents a real problem: it causes the removal of A to fail
with e.g., "rm: cannot remove `A': Device or resource busy"
fts visits each directory twice and keeps a cache (fts_fd_ring) of
directory file descriptors. After completing the final, FTS_DP,
visit of a directory, RESTORE_INITIAL_CWD intended to clear the FD
cache, but then proceeded to add a new FD to it via the subsequent
FCHDIR (which calls cwd_advance_fd and i_ring_push). Before, the
final file descriptor would be closed only via fts_close's call to
fd_ring_clear. Now, it is usually closed earlier, via the final
FTS_DP-returning fts_read call.
* lib/fts.c (restore_initial_cwd): New function, converted from
the macro. Call fd_ring_clear *after* FCHDIR, not before it.
Update callers.
Reported by Franz Sirl via the above URL, with analysis by Eric Blake
in http://thread.gmane.org/gmane.comp.lib.gnulib.bugs/28739
author | Jim Meyering <meyering@redhat.com> |
---|---|
date | Sun, 23 Oct 2011 22:42:25 +0200 |
parents | 97fc9a21a8fb |
children | 8250f2777afc |
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/* Invoke open, but avoid some glitches. Copyright (C) 2005-2006, 2008-2011 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/>. */ /* Written by Paul Eggert. */ #include <config.h> #include "fcntl-safer.h" #include <fcntl.h> #include <stdarg.h> #include "unistd-safer.h" int open_safer (char const *file, int flags, ...) { mode_t mode = 0; if (flags & O_CREAT) { va_list ap; va_start (ap, flags); /* We have to use PROMOTED_MODE_T instead of mode_t, otherwise GCC 4 creates crashing code when 'mode_t' is smaller than 'int'. */ mode = va_arg (ap, PROMOTED_MODE_T); va_end (ap); } return fd_safer (open (file, flags, mode)); }