Re: [PATCH 5/6] vfs: reorganize do_lookup

[Al Viro <viro@ZenIV.linux.org.uk>]

On Tue, Apr 03, 2012 at 10:13:18AM +0200, Miklos Szeredi wrote:

> The do_last() reorganization in the atomic-open series needs to be split
> up, I realize.  Do you have any other high level comments about that
> series?

Yes.
	a) Please, pull removal of open-from-d_revalidate() as far in front
of the queue as possible, *along* *with* -EOPENSTALE stuff.  Without the
latter the former is simply broken - we might have hit -ESTALE before and
LOOKUP_REVAL might have already been set, so just failing ->open() with
ESTALE may end up not repeating it.
	TBH, had that thing been in front of the queue, I would've put
it into the last pull request; that particular idiocy (NFS4 doing open
from all methods involved, except for ->open()) had been a serious source
of annoyance for a long time.  It really needs killing...

	b) opendata is simply bogus.  You need to pass caller-allocated
struct file in any case, right?  So why not use it to pass what you
need to pass?  We want to be able to tell "it's a symlink, here's the
vfsmount/dentry, now sod off and handle it yourself"?  Sure, but struct
file *already* contains struct path and that's not something that might
disappear on future kernel changes ;-)