Mercurial > hg > octave-nkf > gnulib-hg
view lib/minmax.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 | 8250f2777afc |
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/* MIN, MAX macros. Copyright (C) 1995, 1998, 2001, 2003, 2005, 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 2, 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, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #ifndef _MINMAX_H #define _MINMAX_H /* Note: MIN, MAX are also defined in <sys/param.h> on some systems (glibc, IRIX, HP-UX, OSF/1). Therefore you might get warnings about MIN, MAX macro redefinitions on some systems; the workaround is to #include this file as the last one among the #include list. */ /* Before we define the following symbols we get the <limits.h> file since otherwise we get redefinitions on some systems if <limits.h> is included after this file. Likewise for <sys/param.h>. If more than one of these system headers define MIN and MAX, pick just one of the headers (because the definitions most likely are the same). */ #if HAVE_MINMAX_IN_LIMITS_H # include <limits.h> #elif HAVE_MINMAX_IN_SYS_PARAM_H # include <sys/param.h> #endif /* Note: MIN and MAX should be used with two arguments of the same type. They might not return the minimum and maximum of their two arguments, if the arguments have different types or have unusual floating-point values. For example, on a typical host with 32-bit 'int', 64-bit 'long long', and 64-bit IEEE 754 'double' types: MAX (-1, 2147483648) returns 4294967295. MAX (9007199254740992.0, 9007199254740993) returns 9007199254740992.0. MAX (NaN, 0.0) returns 0.0. MAX (+0.0, -0.0) returns -0.0. and in each case the answer is in some sense bogus. */ /* MAX(a,b) returns the maximum of A and B. */ #ifndef MAX # define MAX(a,b) ((a) > (b) ? (a) : (b)) #endif /* MIN(a,b) returns the minimum of A and B. */ #ifndef MIN # define MIN(a,b) ((a) < (b) ? (a) : (b)) #endif #endif /* _MINMAX_H */