[PATCH v2 2/2] io_uring: io_queue_link*() right after submit

From: Pavel Begunkov
Date: Tue Nov 05 2019 - 16:22:43 EST


After a call to io_submit_sqe(), it's already known whether it needs
to queue a link or not. Do it there, as it's simplier and doesn't keep
an extra variable across the loop.

Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
---
fs/io_uring.c | 22 ++++++++++------------
1 file changed, 10 insertions(+), 12 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index ebe2a4edd644..82c2da99cb5c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2687,7 +2687,6 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
struct io_submit_state state, *statep = NULL;
struct io_kiocb *link = NULL;
struct io_kiocb *shadow_req = NULL;
- bool prev_was_link = false;
int i, submitted = 0;
bool mm_fault = false;

@@ -2710,17 +2709,6 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
}
}

- /*
- * If previous wasn't linked and we have a linked command,
- * that's the end of the chain. Submit the previous link.
- */
- if (!prev_was_link && link) {
- io_queue_link_head(ctx, link, &link->submit, shadow_req);
- link = NULL;
- shadow_req = NULL;
- }
- prev_was_link = (s.sqe->flags & IOSQE_IO_LINK) != 0;
-
if (link && (s.sqe->flags & IOSQE_IO_DRAIN)) {
if (!shadow_req) {
shadow_req = io_get_req(ctx, NULL);
@@ -2741,6 +2729,16 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
trace_io_uring_submit_sqe(ctx, s.sqe->user_data, true, async);
io_submit_sqe(ctx, &s, statep, &link);
submitted++;
+
+ /*
+ * If previous wasn't linked and we have a linked command,
+ * that's the end of the chain. Submit the previous link.
+ */
+ if (!(s.sqe->flags & IOSQE_IO_LINK) && link) {
+ io_queue_link_head(ctx, link, &link->submit, shadow_req);
+ link = NULL;
+ shadow_req = NULL;
+ }
}

if (link)
--
2.23.0