Messages in this thread | | | From | Linus Torvalds <> | Date | Fri, 10 Feb 2023 14:08:35 -0800 | Subject | Re: copy on write for splice() from file to pipe? |
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On Fri, Feb 10, 2023 at 1:51 PM Jens Axboe <axboe@kernel.dk> wrote: > > Speaking of splice/io_uring, Ming posted this today: > > https://lore.kernel.org/io-uring/20230210153212.733006-1-ming.lei@redhat.com/
Ugh. Some of that is really ugly. Both 'ignore_sig' and 'ack_page_consuming' just look wrong. Pure random special cases.
And that 'ignore_sig' is particularly ugly, since the only thing that sets it also sets SPLICE_F_NONBLOCK.
And the *only* thing that actually then checks that field is 'splice_from_pipe_next()', where there are exactly two signal_pending() checks that it adds to, and
(a) the first one is to protect from endless loops
(b) the second one is irrelevant when SPLICE_F_NONBLOCK is set
So honestly, just NAK on that series.
I think that instead of 'ignore_sig' (which shouldn't exist), that first 'signal_pending()' check in splice_from_pipe_next() should just be changed into a 'fatal_signal_pending()'.
But that 'ack_page_consuming' thing looks even more disgusting, and since I'm not sure why it even exists, I don't know what it's doing wrong.
Let's agree not to make splice() worse, while people are talking about how bad it already is, ok?
Linus
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