opening symlinks with O_CREAT under latest 2.5.74

[Petr Vandrovec]

Hi,
  couple of things stopped working on my box
where I have /dev/vc/XX as symlinks to /dev/ttyXX, and some
things use /dev/vc/XX and some /dev/ttyXX. After last update
hour ago things which use /dev/vc/XX stopped working for
non-root - they now fail with EACCES error if they attempt
to redirect its input or output through '>' or '<>' bash
redirection operators:

$ touch /tmp/xx
$ ln -s /tmp/xx yy
$ cat > yy
-bash: yy: Permission denied

Strace says:

[pid  3268] open("yy", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0666) = -1 EACCES (Permission denied)

This command succeeds on kernel from thursday. Simillar problem is
that

$ rm /tmp/xx
$ ln -s /tmp/xx yy
$ cat > yy
-bash: yy: No such file or directory

while it creates /tmp/xx file on older kernels.

  Currently I suspect Trond's LOOKUP_CONTINUE change in 
'[PATCH] Add open intent information to the 'struct nameidata', but I
did not tried reverting it yet to find whether it is culprit or no. But
other changes than these four from Trond looks completely innocent.
					Thanks,
						Petr Vandrovec
						[e-mail]