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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
line wrap: on
line source

/* A dummy file, to prevent empty libraries from breaking builds.
   Copyright (C) 2004, 2007, 2009-2011 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/>.  */

/* Some systems, reportedly OpenBSD and Mac OS X, refuse to create
   libraries without any object files.  You might get an error like:

   > ar cru .libs/libgl.a
   > ar: no archive members specified

   Compiling this file, and adding its object file to the library, will
   prevent the library from being empty.  */

/* Some systems, such as Solaris with cc 5.0, refuse to work with libraries
   that don't export any symbol.  You might get an error like:

   > cc ... libgnu.a
   > ild: (bad file) garbled symbol table in archive ../gllib/libgnu.a

   Compiling this file, and adding its object file to the library, will
   prevent the library from exporting no symbols.  */

#ifdef __sun
/* This declaration ensures that the library will export at least 1 symbol.  */
int gl_dummy_symbol;
#else
/* This declaration is solely to ensure that after preprocessing
   this file is never empty.  */
typedef int dummy;
#endif