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Date:   Sun, 14 Feb 2021 22:57:51 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: [PATCH RFC] namei: don't drop link paths acquired under
 LOOKUP_RCU
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On Sun, Feb 14, 2021 at 09:45:39AM -0700, Jens Axboe wrote:

> >> +out3:
> >> +	nd->depth = 0;	// as we hadn't gotten to legitimize_links()
> >>  out2:
> >>  	nd->path.mnt = NULL;
> >>  out1:
> > 
> > Alternatively, we could use the fact that legitimize_links() is not
> > called anywhere other than these two places and have LOOKUP_CACHED
> > checked there.  As in
> 
> Both fix the issue for me, just tested them. The second one seems
> cleaner to me, would probably be nice to have a comment on that in
> either the two callers or at least in legitimize_links() though.

Hmm...  Do you have anything on top of that branch?  If you do, there's
no way to avoid leaving bisect hazard; if not, I'd rather fold a fix
into the broken commit...