view lib/canonicalize.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 97fc9a21a8fb
children 0b2b4b60945f
line wrap: on
line source

/* Return the canonical absolute name of a given file.
   Copyright (C) 1996-2007, 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/>.  */

#ifndef CANONICALIZE_H_
# define CANONICALIZE_H_

#include <stdlib.h> /* for canonicalize_file_name */

enum canonicalize_mode_t
  {
    /* All components must exist.  */
    CAN_EXISTING = 0,

    /* All components excluding last one must exist.  */
    CAN_ALL_BUT_LAST = 1,

    /* No requirements on components existence.  */
    CAN_MISSING = 2
  };
typedef enum canonicalize_mode_t canonicalize_mode_t;

/* Return a malloc'd string containing the canonical absolute name of
   the named file.  This acts like canonicalize_file_name, except that
   whether components must exist depends on the canonicalize_mode_t
   argument.  */
char *canonicalize_filename_mode (const char *, canonicalize_mode_t);

#endif /* !CANONICALIZE_H_ */