Re: [PATCH] sendfile removal

From: Jens Axboe
Date: Thu May 31 2007 - 06:54:31 EST


On Thu, May 31 2007, Eric Dumazet wrote:
> On Thu, 31 May 2007 12:33:16 +0200
> Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:
>
> > Hi,
> >
> > This patch removes the ->sendfile() hook from the file_operations
> > structure, and replaces the sys_sendfile() mechanism to be based on
> > ->splice_read() instead. There should be no functional changes.
> >
>
> > - 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.

Encourage those people to use splice() instead :-)

--
Jens Axboe

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