[PATCH 2/3] io_uring: abstract out main poll wake handler

Jens Axboe
2020-02-12T20:25:21Z

In preparation for having multiple poll waitqueues, abstract out the
main wake handler so we can call it with the desired data.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 74 +++++++++++++++++++++++++++------------------------
1 file changed, 39 insertions(+), 35 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 08ffeb7df4f5..9cd2ce3b8ad9 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3622,17 +3622,11 @@ static void io_poll_trigger_evfd(struct io_wq_work **workptr)
io_put_req(req);
}

-static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
- void *key)
+static void __io_poll_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
+ __poll_t mask)
{
- struct io_kiocb *req = wait->private;
- struct io_poll_iocb *poll = &req->poll;
struct io_ring_ctx *ctx = req->ctx;
- __poll_t mask = key_to_poll(key);
-
- /* for instances that support it check for an event match first: */
- if (mask && !(mask & poll->events))
- return 0;
+ unsigned long flags;

list_del_init(&poll->wait.entry);

@@ -3642,40 +3636,50 @@ static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
* If we have a link timeout we're going to need the completion_lock
* for finalizing the request, mark us as having grabbed that already.
*/
- if (mask) {
- unsigned long flags;
+ if (llist_empty(&ctx->poll_llist) && !req->io &&
+ spin_trylock_irqsave(&ctx->completion_lock, flags)) {
+ bool trigger_ev;

- if (llist_empty(&ctx->poll_llist) &&
- spin_trylock_irqsave(&ctx->completion_lock, flags)) {
- bool trigger_ev;
-
- hash_del(&req->hash_node);
- io_poll_complete(req, mask, 0);
+ hash_del(&req->hash_node);
+ io_poll_complete(req, mask, 0);

- trigger_ev = io_should_trigger_evfd(ctx);
- if (trigger_ev && eventfd_signal_count()) {
- trigger_ev = false;
- req->work.func = io_poll_trigger_evfd;
- } else {
- req->flags |= REQ_F_COMP_LOCKED;
- io_put_req(req);
- req = NULL;
- }
- spin_unlock_irqrestore(&ctx->completion_lock, flags);
- __io_cqring_ev_posted(ctx, trigger_ev);
+ trigger_ev = io_should_trigger_evfd(ctx);
+ if (trigger_ev && eventfd_signal_count()) {
+ trigger_ev = false;
+ req->work.func = io_poll_trigger_evfd;
} else {
- req->result = mask;
- req->llist_node.next = NULL;
- /* if the list wasn't empty, we're done */
- if (!llist_add(&req->llist_node, &ctx->poll_llist))
- req = NULL;
- else
- req->work.func = io_poll_flush;
+ req->flags |= REQ_F_COMP_LOCKED;
+ io_put_req(req);
+ req = NULL;
}
+ spin_unlock_irqrestore(&ctx->completion_lock, flags);
+ __io_cqring_ev_posted(ctx, trigger_ev);
+ } else {
+ req->result = mask;
+ req->llist_node.next = NULL;
+ /* if the list wasn't empty, we're done */
+ if (!llist_add(&req->llist_node, &ctx->poll_llist))
+ req = NULL;
+ else
+ req->work.func = io_poll_flush;
}
+
if (req)
io_queue_async_work(req);
+}
+
+static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
+ void *key)
+{
+ struct io_kiocb *req = wait->private;
+ struct io_poll_iocb *poll = &req->poll;
+ __poll_t mask = key_to_poll(key);
+
+ /* for instances that support it check for an event match first: */
+ if (mask && !(mask & poll->events))
+ return 0;

+ __io_poll_wake(req, &req->poll, mask);
return 1;
}

--
2.25.0