Re: [PATCH] sendfile removal

On Thu, May 31 2007, H. Peter Anvin wrote:
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.

I agree, but it's still a change in behaviour. Even if we consider the
app buggy (it is), can we potentially break it?

--
Jens Axboe

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