[PATCH] namei fixes

OK, here comes a patch series that hopefully should close all
too-early-mntput() races in fs/namei.c.  Entire area is convoluted as hell, so
I'm splitting that series into _very_ small chunks.

Patches alread in the tree close only (very wide) races in following symlinks
(see "busy inodes after umount" thread some time ago).  Unfortunately, quite a
few narrower races of the same nature were not closed.  Hopefully this should
take care of all of them.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>