[PATCH v2 4/5] io_uring: remove extra nxt check after punt

Pavel Begunkov
2020-02-28T23:38:43Z

After __io_queue_sqe() ended up in io_queue_async_work(), it's already
known that there is no @nxt req, so skip the check and return from the
function.

Also, @nxt initialisation now can be done just before
io_put_req_find_next(), as there is no jumping until it's checked.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
fs/io_uring.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5a579f686f9e..cefbae582b5f 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4857,7 +4857,7 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_kiocb *linked_timeout;
- struct io_kiocb *nxt = NULL;
+ struct io_kiocb *nxt;
const struct cred *old_creds = NULL;
int ret;

@@ -4884,7 +4884,7 @@ static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
if (io_arm_poll_handler(req)) {
if (linked_timeout)
io_queue_linked_timeout(linked_timeout);
- goto done_req;
+ goto exit;
}
punt:
if (io_op_defs[req->opcode].file_table) {
@@ -4898,10 +4898,11 @@ static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
* submit reference when the iocb is actually submitted.
*/
io_queue_async_work(req);
- goto done_req;
+ goto exit;
}

err:
+ nxt = NULL;
/* drop submission reference */
io_put_req_find_next(req, &nxt);

@@ -4918,15 +4919,14 @@ static void __io_queue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe)
req_set_fail_links(req);
io_put_req(req);
}
-done_req:
if (nxt) {
req = nxt;
- nxt = NULL;

if (req->flags & REQ_F_FORCE_ASYNC)
goto punt;
goto again;
}
+exit:
if (old_creds)
revert_creds(old_creds);
}
--
2.24.0