Mercurial > hg > octave-nkf > gnulib-hg
view lib/mknod.c @ 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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/* Create a device inode. Copyright (C) 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/>. */ /* written by Eric Blake */ #include <config.h> #include <sys/stat.h> #include <errno.h> #include <string.h> #if !HAVE_MKNOD /* Mingw lacks mknod; always fail with ENOSYS. */ int mknod (char const *name _GL_UNUSED, mode_t mode _GL_UNUSED, dev_t dev _GL_UNUSED) { errno = ENOSYS; return -1; } #else /* HAVE_MKNOD */ # undef mknod /* Create a file system node FILE, with access permissions and file type in MODE, and device type in DEV. Usually, non-root applications can only create named fifos (mode includes S_IFIFO), with DEV set to 0. Also work around trailing slash bugs. */ int rpl_mknod (char const *name, mode_t mode, dev_t dev) { # if MKFIFO_TRAILING_SLASH_BUG /* Trailing slash only makes sense for directories. Of course, using mknod to create a directory is not very portable, so it may still fail later on. */ if (!S_ISDIR (mode)) { size_t len = strlen (name); if (len && name[len - 1] == '/') { struct stat st; if (stat (name, &st) == 0) errno = EEXIST; return -1; } } # endif # if MKNOD_FIFO_BUG /* POSIX requires mknod to create fifos for non-privileged processes, but BSD implementations fail with EPERM. */ if (S_ISFIFO (mode) && dev == 0) return mkfifo (name, mode & ~S_IFIFO); # endif return mknod (name, mode, dev); } #endif /* HAVE_MKNOD */