[PATCH 1/1] io_uring: remove index from sqe_submit

[PATCH 1/1] io_uring: remove index from sqe_submit

[Pavel Begunkov]

submit->index is used only for inbound check in submission path (i.e.
head < ctx->sq_entries). However, it always will be true, as
1. it's already validated by io_get_sqring()
2. ctx->sq_entries can't be changedd inbetween, because of held
ctx->uring_lock and ctx->refs.

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

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 949faf14345e..710a0e8c1334 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -276,7 +276,6 @@ struct io_ring_ctx {
 struct sqe_submit {
 	const struct io_uring_sqe	*sqe;
 	struct file			*ring_file;
-	unsigned short			index;
 	bool				has_user : 1;
 	bool				in_async : 1;
 	bool				needs_fixed_file : 1;
@@ -2169,9 +2168,6 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
 
 	req->user_data = READ_ONCE(s->sqe->user_data);
 
-	if (unlikely(s->index >= ctx->sq_entries))
-		return -EINVAL;
-
 	opcode = READ_ONCE(s->sqe->opcode);
 	switch (opcode) {
 	case IORING_OP_NOP:
@@ -2625,7 +2621,6 @@ static bool io_get_sqring(struct io_ring_ctx *ctx, struct sqe_submit *s)
 	head = READ_ONCE(sq_array[head & ctx->sq_mask]);
 	if (head < ctx->sq_entries) {
 		s->ring_file = NULL;
-		s->index = head;
 		s->sqe = &ctx->sq_sqes[head];
 		s->sequence = ctx->cached_sq_head;
 		ctx->cached_sq_head++;
-- 
2.23.0

Re: [PATCH 1/1] io_uring: remove index from sqe_submit

[Jens Axboe]

On 10/27/19 9:52 AM, Pavel Begunkov wrote:
> submit->index is used only for inbound check in submission path (i.e.
> head < ctx->sq_entries). However, it always will be true, as
> 1. it's already validated by io_get_sqring()
> 2. ctx->sq_entries can't be changedd inbetween, because of held
> ctx->uring_lock and ctx->refs.

Applied, thanks.

-- 
Jens Axboe