On 2/17/25 15:06, Jens Axboe wrote:
On 2/17/25 7:12 AM, Pavel Begunkov wrote:
On 2/17/25 13:58, Jens Axboe wrote:
On 2/17/25 6:37 AM, Pavel Begunkov wrote:
At the moment we can't sanely handle queuing an async request from a
multishot context, so disable them. It shouldn't matter as pollable
files / socekts don't normally do async.
Having something pollable that can return -EIOCBQUEUED is odd, but
that's just a side comment.
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 96b42c331267..4bda46c5eb20 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -878,7 +878,15 @@ static int __io_read(struct io_kiocb *req, unsigned int issue_flags)
if (unlikely(ret))
return ret;
- ret = io_iter_do_read(rw, &io->iter);
+ if (unlikely(req->opcode == IORING_OP_READ_MULTISHOT)) {
+ void *cb_copy = rw->kiocb.ki_complete;
+
+ rw->kiocb.ki_complete = NULL;
+ ret = io_iter_do_read(rw, &io->iter);
+ rw->kiocb.ki_complete = cb_copy;
+ } else {
+ ret = io_iter_do_read(rw, &io->iter);
+ }
This looks a bit odd. Why can't io_read_mshot() just clear
->ki_complete?
Forgot about that one, as for restoring it back, io_uring compares
or calls ->ki_complete in a couple of places, this way the patch
is more contained. It can definitely be refactored on top.
I'd be tempted to do that for the fix too, the patch as-is is a
bit of an eye sore... Hmm.
It is an eyesore, sure, but I think a simple/concise eyesore is
better as a fix than having to change a couple more blocks across
rw.c. It probably wouldn't be too many changes, but I can't say
I'm concerned about this version too much as long as it can be
reshuffled later.
--
Pavel Begunkov
