On Wed, Aug 31, 2011 at 17:34, Paul Eggert <egg...@cs.ucla.edu> wrote:
> On 08/31/11 07:06, Kevin Brott wrote:
> > If we do not use fstatat then tar builds and passes almost all of the
> checks (only the two sparse file ones fail).
> > If we use fstatat, then almost all of the checks fail - because the
> resulting binary is dropping zero-byte files into the archives, and doesn't
> function.
> >
> > So either there is a bug or enough of a fundamental difference in the way
> AIX 7.1's new fstatat call works, that it's not usable with the way the
> existing GNU tar code is trying to use it.
>
> It semmed pretty clear there is a bug there.
> Unfortunately, the test program does not seem to expose the bug.
>
> How about this test program instead? Please run it in a directory
> where conftest.file has been created via "echo xxx >conftest.file".
>
> If this test program works on AIX 7.1, can you modify it in a minor
> way so that it correctly exposes the AIX bug? There must be some
> way to do it, since 'tar' is doing it.
>
> #include <fcntl.h>
> #include <sys/stat.h>
>
> int
> main (void)
> {
> struct stat a;
> struct stat b;
> int fd = open (".", O_RDONLY);
>
> if (fd < 0)
> return 10;
> if (fstatat (fd, "conftest.file", &a,
> AT_SYMLINK_NOFOLLOW)
> != 0)
> return 1;
> if (lstat ("conftest.file", &b) != 0)
> return 2;
> if (a.st_size != b.st_size) return 3;
> if (a.st_dev != b.st_dev) return 4;
> if (a.st_ino != b.st_ino) return 5;
> if (a.st_mode != b.st_mode) return 6;
> if (a.st_nlink != b.st_nlink) return 7;
> if (a.st_uid != b.st_uid) return 8;
> if (a.st_gid != b.st_gid) return 9;
> /* Don't check time members, to avoid caching issues. */
> return 0;
> }
>
$ echo xxx > conftest.file
$ cat conftest.file
xxx
$ xlc -o test source.c
$ ./test ; echo $?
0
$ truss -f ./test
12058888: execve("./test", 0x2FF22AA4, 0x200132A8) argc: 1
12058888: 16908635: kopen(".", O_RDONLY) = 3
12058888: 16908635: statxat(3, "conftest.file", 0x2FF22910, 76, 01) = 0
12058888: 16908635: statx("conftest.file", 0x2FF22988, 76, 01) = 0
12058888: 16908635: kfcntl(1, F_GETFL, 0x2FF22FFC) = 67110914
12058888: 16908635: kfcntl(2, F_GETFL, 0x2FF22FFC) = 67110914
12058888: 16908635: _exit(0)
I'm going to rebuild the non-working version of tar and the mostly-working
version and have them both create a two-file archive and truss both runs.
Maybe someone less clueless than I will be able to see where the failure is.
--
# include <stddisclaimer.h>
/* Kevin Brott <kevin.br...@gmail.com> */
