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bug#13347: stat/fstat inappropriately used in cp, install, rm, sort, cho
From: |
Burkhardt, Glenn UTAS |
Subject: |
bug#13347: stat/fstat inappropriately used in cp, install, rm, sort, chown for Windows 7 platforms |
Date: |
Thu, 3 Jan 2013 17:10:45 +0000 |
MINGW32_NT-6.1 BOS0DT-1QLS1R1 1.0.17(0.48/3/2) 2011-04-24 23:39 i686 Msys
gcc version 4.7.0 (GCC)
Windows 7 Enterprise SP1
coreutils-5.97
I noticed this when trying to use the "cp" command in a Clearcase locally
hosted dynamic view. When trying to copy a view private file, the 'cp' command
would fail with a message like
skipping file `jj', as it was replaced while being copied
The problem is that the 'cp' command uses 'stat' on the source file initially,
and then, when it's ready to copy, uses 'fstat' on it again, after the file has
been opened for reading (about line 237 in copy.c from coreutils-5.97). This
works on a file that's on a local hard drive, but not on a Clearcase locally
hosted dynamic view. The 'install' command has the same problem.
This test really shouldn't be done on a Windows platform. Microsoft's
documentation describes different values for stat.st_dev returned by the
'stat()' and 'fstat()' functions. There's also a note that the stat.st_ino
value is meaningless for NTFS filesystems. Although MinGW releases a very old
version of 'coreutils', the current 8.9 version will have the same problem.
The definition of the macro SAME_INODE is unchanged.
But then it gets interesting. The 'cp' command is built with a different
version of 'stat' and 'fstat' than one normally gets with a MinGW build
environment. The coreutils need the Msys build environment, and the
'stat/fstat' functions are pulled from libmsys-1.0.dll.a. A build in regular
MinGW environment with the current compiler gets the functions from
libmoldname.a. So were the coreutils built with gcc-4.7.0, and no
libmsys-1.0.dll.a, the copy command would fail for files on the local hard
drive, since stat.st_dev is different for stat() and fstat().
I've attached a small test program to show the stat()/fstat() output, and a
patch for system.h in coreutils that allows a working version of 'cp.exe' and
'install.exe' to be built.
Please also see the bug report to the MinGW bug tracker, ID 3590842:
http://sourceforge.net/tracker/?func=detail&aid=3590842&group_id=2435&atid=102435
system.h.patch
Description: system.h.patch
test-stat.c
Description: test-stat.c
- bug#13347: stat/fstat inappropriately used in cp, install, rm, sort, chown for Windows 7 platforms,
Burkhardt, Glenn UTAS <=