Mercurial > hg > octave-nkf > gnulib-hg
view lib/binary-io.h @ 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 | f6ec6d171e52 |
children | 8250f2777afc |
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/* Binary mode I/O. Copyright (C) 2001, 2003, 2005, 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/>. */ #ifndef _BINARY_H #define _BINARY_H /* For systems that distinguish between text and binary I/O. O_BINARY is guaranteed by the gnulib <fcntl.h>. */ #include <fcntl.h> /* The MSVC7 <stdio.h> doesn't like to be included after '#define fileno ...', so we include it here first. */ #include <stdio.h> /* SET_BINARY (fd); changes the file descriptor fd to perform binary I/O. */ #if O_BINARY # if defined __EMX__ || defined __DJGPP__ || defined __CYGWIN__ # include <io.h> /* declares setmode() */ # else # define setmode _setmode # undef fileno # define fileno _fileno # endif # ifdef __DJGPP__ # include <unistd.h> /* declares isatty() */ /* Avoid putting stdin/stdout in binary mode if it is connected to the console, because that would make it impossible for the user to interrupt the program through Ctrl-C or Ctrl-Break. */ # define SET_BINARY(fd) ((void) (!isatty (fd) ? (setmode (fd, O_BINARY), 0) : 0)) # else # define SET_BINARY(fd) ((void) setmode (fd, O_BINARY)) # endif #else /* On reasonable systems, binary I/O is the default. */ # define SET_BINARY(fd) /* do nothing */ ((void) 0) #endif #endif /* _BINARY_H */