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io_uring: check for need to re-wait in polled async handling

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We added this for just the regular poll requests in commit a6ba632d2c
("io_uring: retry poll if we got woken with non-matching mask"), we
should do the same for the poll handler used pollable async requests.
Move the re-wait check and arm into a helper, and call it from
io_async_task_func() as well.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Jens Axboe 2020-04-13 11:09:12 -06:00
parent 8835758085
commit 74ce6ce43d
1 changed files with 29 additions and 14 deletions
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43
fs/io_uring.c
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@ -4156,6 +4156,26 @@ static int __io_async_wake(struct io_kiocb *req, struct io_poll_iocb *poll,
return 1;
}
static bool io_poll_rewait(struct io_kiocb *req, struct io_poll_iocb *poll)
__acquires(&req->ctx->completion_lock)
{
struct io_ring_ctx *ctx = req->ctx;
if (!req->result && !READ_ONCE(poll->canceled)) {
struct poll_table_struct pt = { ._key = poll->events };
req->result = vfs_poll(req->file, &pt) & poll->events;
}
spin_lock_irq(&ctx->completion_lock);
if (!req->result && !READ_ONCE(poll->canceled)) {
add_wait_queue(poll->head, &poll->wait);
return true;
}
return false;
}
static void io_async_task_func(struct callback_head *cb)
{
struct io_kiocb *req = container_of(cb, struct io_kiocb, task_work);
@ -4164,14 +4184,16 @@ static void io_async_task_func(struct callback_head *cb)
trace_io_uring_task_run(req->ctx, req->opcode, req->user_data);
WARN_ON_ONCE(!list_empty(&req->apoll->poll.wait.entry));
if (hash_hashed(&req->hash_node)) {
spin_lock_irq(&ctx->completion_lock);
hash_del(&req->hash_node);
if (io_poll_rewait(req, &apoll->poll)) {
spin_unlock_irq(&ctx->completion_lock);
return;
}
if (hash_hashed(&req->hash_node))
hash_del(&req->hash_node);
spin_unlock_irq(&ctx->completion_lock);
/* restore ->work in case we need to retry again */
memcpy(&req->work, &apoll->work, sizeof(req->work));
@ -4436,18 +4458,11 @@ static void io_poll_task_handler(struct io_kiocb *req, struct io_kiocb **nxt)
struct io_ring_ctx *ctx = req->ctx;
struct io_poll_iocb *poll = &req->poll;
if (!req->result && !READ_ONCE(poll->canceled)) {
struct poll_table_struct pt = { ._key = poll->events };
req->result = vfs_poll(req->file, &pt) & poll->events;
}
spin_lock_irq(&ctx->completion_lock);
if (!req->result && !READ_ONCE(poll->canceled)) {
add_wait_queue(poll->head, &poll->wait);
if (io_poll_rewait(req, poll)) {
spin_unlock_irq(&ctx->completion_lock);
return;
}
hash_del(&req->hash_node);
io_poll_complete(req, req->result, 0);
req->flags |= REQ_F_COMP_LOCKED;