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Date: Sun, 24 Jan 2016 00:16:15 +0000
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Mike Marshall <hubcap@omnibond.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>
Subject: Re: Orangefs ABI documentation
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On Sat, Jan 23, 2016 at 05:36:41PM -0500, Mike Marshall wrote:
> AV> IOW, would the following do the right thing?
> AV> That would've left us with only one caller of
> AV> handle_io_error()...
> 
> It works.  With your simplified code all
> the needed things still happen: complete and
> bufmap_put...
> 
> I've never had an error there unless I forgot
> to turn on the client-core...
> 
> You must be looking for a way to get rid of
> another macro <g>...

That as well, but mostly I want to sort the situation with cancels out and
get a better grasp on when can that code be reached.  BTW, an error at that
spot is trivial to arrange - just pass read() a destination with munmapped
page in the middle and it'll trigger just fine.  IOW,
	p = mmap(NULL, 65536, PROT_READ|PROT_WRITE,
		 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
	munmap(p + 16384, 16384);
	read(fd, p, 65536);
with fd being a file on orangefs should step into that.