Mercurial > hg > octave-nkf > gnulib-hg
view lib/dosname.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 | 9f47f8c334f2 |
| children | 8250f2777afc |
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/* File names on MS-DOS/Windows systems. Copyright (C) 2000-2001, 2004-2006, 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/>. From Paul Eggert and Jim Meyering. */ #ifndef _DOSNAME_H #define _DOSNAME_H #if (defined _WIN32 || defined __WIN32__ || \ defined __MSDOS__ || defined __CYGWIN__ || \ defined __EMX__ || defined __DJGPP__) /* This internal macro assumes ASCII, but all hosts that support drive letters use ASCII. */ # define _IS_DRIVE_LETTER(C) (((unsigned int) (C) | ('a' - 'A')) - 'a' \ <= 'z' - 'a') # define FILE_SYSTEM_PREFIX_LEN(Filename) \ (_IS_DRIVE_LETTER ((Filename)[0]) && (Filename)[1] == ':' ? 2 : 0) # ifndef __CYGWIN__ # define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 1 # endif # define ISSLASH(C) ((C) == '/' || (C) == '\\') #else # define FILE_SYSTEM_PREFIX_LEN(Filename) 0 # define ISSLASH(C) ((C) == '/') #endif #ifndef FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE # define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 0 #endif #if FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE # define IS_ABSOLUTE_FILE_NAME(F) ISSLASH ((F)[FILE_SYSTEM_PREFIX_LEN (F)]) # else # define IS_ABSOLUTE_FILE_NAME(F) \ (ISSLASH ((F)[0]) || FILE_SYSTEM_PREFIX_LEN (F) != 0) #endif #define IS_RELATIVE_FILE_NAME(F) (! IS_ABSOLUTE_FILE_NAME (F)) #endif /* DOSNAME_H_ */