From 4bda89b77c7b03c06ad7b45f3dcc9c8e3a52bc1c Mon Sep 17 00:00:00 2001
From: Pavel Begunkov <asml.silence@gmail.com>
Date: Sun, 15 Aug 2021 10:40:24 +0100
Subject: [PATCH 09/11] io_uring: simplify io_prep_linked_timeout
Git-commit: 4d13d1a4d1e1807e04b846b48934e87016027f90
Patch-mainline: v5.15-rc1
References: bnc#1205205

The link test in io_prep_linked_timeout() is pretty bulky, replace it
with a flag. It's better for normal path and linked requests, and also
will be used further for request failing.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3703770bfae8bc1ff370e43ef5767940202cab42.1628981736.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
---
 fs/io_uring.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c0735fec44d2..d3bf1edb2985 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -710,6 +710,7 @@ enum {
 	REQ_F_DONT_REISSUE_BIT,
 	REQ_F_CREDS_BIT,
 	REQ_F_REFCOUNT_BIT,
+	REQ_F_ARM_LTIMEOUT_BIT,
 	/* keep async read/write and isreg together and in order */
 	REQ_F_NOWAIT_READ_BIT,
 	REQ_F_NOWAIT_WRITE_BIT,
@@ -765,6 +766,8 @@ enum {
 	REQ_F_CREDS		= BIT(REQ_F_CREDS_BIT),
 	/* skip refcounting if not set */
 	REQ_F_REFCOUNT		= BIT(REQ_F_REFCOUNT_BIT),
+	/* there is a linked timeout that has to be armed */
+	REQ_F_ARM_LTIMEOUT	= BIT(REQ_F_ARM_LTIMEOUT_BIT),
 };
 
 struct async_poll {
@@ -1303,23 +1306,18 @@ static void io_req_track_inflight(struct io_kiocb *req)
 
 static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req)
 {
-	struct io_kiocb *nxt = req->link;
-
-	if (req->flags & REQ_F_LINK_TIMEOUT)
-		return NULL;
+	req->flags &= ~REQ_F_ARM_LTIMEOUT;
+	req->flags |= REQ_F_LINK_TIMEOUT;
 
 	/* linked timeouts should have two refs once prep'ed */
 	io_req_set_refcount(req);
-	__io_req_set_refcount(nxt, 2);
-
-	nxt->timeout.head = req;
-	req->flags |= REQ_F_LINK_TIMEOUT;
-	return nxt;
+	__io_req_set_refcount(req->link, 2);
+	return req->link;
 }
 
 static inline struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
 {
-	if (likely(!req->link || req->link->opcode != IORING_OP_LINK_TIMEOUT))
+	if (likely(!(req->flags & REQ_F_ARM_LTIMEOUT)))
 		return NULL;
 	return __io_prep_linked_timeout(req);
 }
@@ -5769,6 +5767,8 @@ static int io_timeout_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 			return -EINVAL;
 		if (link->last->opcode == IORING_OP_LINK_TIMEOUT)
 			return -EINVAL;
+		req->timeout.head = link->last;
+		link->last->flags |= REQ_F_ARM_LTIMEOUT;
 	}
 	return 0;
 }
-- 
2.35.3