io_uring: refactor io_req_defer()

Rename io_req_defer() into io_drain_req() and refactor it uncoupling it
from io_queue_sqe() error handling and preparing for coming
optimisations. Also, prioritise non IOSQE_ASYNC path.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4f17dd56e7fbe52d1866f8acd8efe3284d2bebcb.1623709150.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2021-06-14 23:37:30 +01:00 committed by Jens Axboe
parent 0499e582aa
commit 76cc33d791

View file

@ -5998,7 +5998,7 @@ static u32 io_get_sequence(struct io_kiocb *req)
return ctx->cached_sq_head - nr_reqs;
}
static int io_req_defer(struct io_kiocb *req)
static bool io_drain_req(struct io_kiocb *req)
{
struct io_ring_ctx *ctx = req->ctx;
struct io_defer_entry *de;
@ -6008,27 +6008,29 @@ static int io_req_defer(struct io_kiocb *req)
/* Still need defer if there is pending req in defer list. */
if (likely(list_empty_careful(&ctx->defer_list) &&
!(req->flags & REQ_F_IO_DRAIN)))
return 0;
return false;
seq = io_get_sequence(req);
/* Still a chance to pass the sequence check */
if (!req_need_defer(req, seq) && list_empty_careful(&ctx->defer_list))
return 0;
return false;
ret = io_req_prep_async(req);
if (ret)
return ret;
io_prep_async_link(req);
de = kmalloc(sizeof(*de), GFP_KERNEL);
if (!de)
return -ENOMEM;
if (!de) {
io_req_complete_failed(req, ret);
return true;
}
spin_lock_irq(&ctx->completion_lock);
if (!req_need_defer(req, seq) && list_empty(&ctx->defer_list)) {
spin_unlock_irq(&ctx->completion_lock);
kfree(de);
io_queue_async_work(req);
return -EIOCBQUEUED;
return true;
}
trace_io_uring_defer(ctx, req, req->user_data);
@ -6036,7 +6038,7 @@ static int io_req_defer(struct io_kiocb *req)
de->seq = seq;
list_add_tail(&de->list, &ctx->defer_list);
spin_unlock_irq(&ctx->completion_lock);
return -EIOCBQUEUED;
return true;
}
static void io_clean_op(struct io_kiocb *req)
@ -6447,21 +6449,18 @@ static void __io_queue_sqe(struct io_kiocb *req)
static void io_queue_sqe(struct io_kiocb *req)
{
int ret;
if (io_drain_req(req))
return;
ret = io_req_defer(req);
if (ret) {
if (ret != -EIOCBQUEUED) {
fail_req:
io_req_complete_failed(req, ret);
}
} else if (req->flags & REQ_F_FORCE_ASYNC) {
ret = io_req_prep_async(req);
if (unlikely(ret))
goto fail_req;
io_queue_async_work(req);
} else {
if (likely(!(req->flags & REQ_F_FORCE_ASYNC))) {
__io_queue_sqe(req);
} else {
int ret = io_req_prep_async(req);
if (unlikely(ret))
io_req_complete_failed(req, ret);
else
io_queue_async_work(req);
}
}