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	Wed, 17 Feb 2016 18:15:26 -0500
Date: Wed, 17 Feb 2016 23:15:24 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Martin Brandenburg <martin@omnibond.com>
Cc: Mike Marshall <hubcap@omnibond.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>
Subject: Re: Orangefs ABI documentation
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On Wed, Feb 17, 2016 at 11:09:00PM +0000, Al Viro wrote:

> However, that doesn't prevent all unpleasantness here - giving up just as
> it's being copied to userland and going into restart.  Ho-hum...  How about
> the following:
> 	* move increment of op->attempts into the same place where we
> set "given up"
> 	* in addition to the check for "given up" in the request-picking loop
> (as above), fetch op->attempts before dropping op->lock
> 	* after having retaken op->lock (after copy_to_user()) recheck
> op->attempts instead of checking for "given up".

	Crap...  There's a similar problem on the other end - in
orangefs_devreq_write_iter() between the time when op has been fetched
from the hash and the time we finish copying reply from userland.  Same
kind of "what it clear_... gets all way through and we resubmit it before
we get around to checking the given_up flag" problem...

	Let me think a bit...