Message-ID: <465F9BEF.20504@zytor.com>
Date: Thu, 31 May 2007 21:09:19 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Jens Axboe <jens.axboe@oracle.com>
CC: Eric Dumazet <dada1@cosmosbay.com>, linux-kernel@vger.kernel.org,
       cotte@de.ibm.com, hugh@veritas.com, neilb@suse.de, zanussi@us.ibm.com,
       Linus Torvalds <torvalds@osdl.org>, hch@infradead.org
Subject: Re: [PATCH] sendfile removal
References: <20070531103316.GO32105@kernel.dk> <20070531124753.a99f713c.dada1@cosmosbay.com> <20070531105321.GQ32105@kernel.dk>
In-Reply-To: <20070531105321.GQ32105@kernel.dk>
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Jens Axboe wrote:
>>   
>>> -	retval = in_file->f_op->sendfile(in_file, ppos, count, file_send_actor, out_file);
>>> +	fl = 0;
>>> +	if (in_file->f_flags & O_NONBLOCK)
>>> +		fl = SPLICE_F_NONBLOCK;
>>> +
>>> +	retval = do_splice_direct(in_file, ppos, out_file, count, fl);
>> I like this, but are you sure it wont break user land ?
>>
>> Some applications might react badly if sendfile() returns EAGAIN ?
> 
> Yeah, I didn't actually intend for that to sneak in. I'd think that
> userspace should handle it if they opened the file O_NONBLOCK (or used
> fcntl()), but it's a change in behaviour none the less and probably not
> a good idea.
> 

I would personally argue that sendfile() blocking on an O_NONBLOCK
desriptor, as opposed to returning EAGAIN, is a bug, and a fairly
serious such.

	-hpa
-
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