Commit b8e64b53 authored by Pavel Begunkov's avatar Pavel Begunkov Committed by Jens Axboe
Browse files

io_uring: track request creds with a flag 



Currently, if req->creds is not NULL, then there are creds assigned.
Track the invariant with a new flag in req->flags. No need to clear the
field at init, and also cleanup can be efficiently moved into
io_clean_op().

Signed-off-by: default avatarPavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/5f8baeb8d3b909487f555542350e2eac97005556.1623949695.git.asml.silence@gmail.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c10d1f98

fs/io_uring.c

+13 −8
Original line number Diff line number Diff line
@@ -718,6 +718,7 @@ enum { 
	REQ_F_COMPLETE_INLINE_BIT,

	REQ_F_REISSUE_BIT,

	REQ_F_DONT_REISSUE_BIT,

	REQ_F_CREDS_BIT,

	/* keep async read/write and isreg together and in order */

	REQ_F_ASYNC_READ_BIT,

	REQ_F_ASYNC_WRITE_BIT,
@@ -771,6 +772,8 @@ enum { 
	REQ_F_ASYNC_WRITE	= BIT(REQ_F_ASYNC_WRITE_BIT),

	/* regular file */

	REQ_F_ISREG		= BIT(REQ_F_ISREG_BIT),

	/* has creds assigned */

	REQ_F_CREDS		= BIT(REQ_F_CREDS_BIT),

};



struct async_poll {
@@ -1236,8 +1239,10 @@ static void io_prep_async_work(struct io_kiocb *req) 
	const struct io_op_def *def = &io_op_defs[req->opcode];

	struct io_ring_ctx *ctx = req->ctx;



	if (!req->creds)

	if (!(req->flags & REQ_F_CREDS)) {

		req->flags |= REQ_F_CREDS;

		req->creds = get_current_cred();

	}



	req->work.list.next = NULL;

	req->work.flags = 0;
@@ -1623,7 +1628,7 @@ static void io_req_complete_post(struct io_kiocb *req, long res, 
static inline bool io_req_needs_clean(struct io_kiocb *req)

{

	return req->flags & (REQ_F_BUFFER_SELECTED | REQ_F_NEED_CLEANUP |

				REQ_F_POLLED | REQ_F_INFLIGHT);

				REQ_F_POLLED | REQ_F_INFLIGHT | REQ_F_CREDS);

}



static void io_req_complete_state(struct io_kiocb *req, long res,
@@ -1747,10 +1752,6 @@ static void io_dismantle_req(struct io_kiocb *req) 
		percpu_ref_put(req->fixed_rsrc_refs);

	if (req->async_data)

		kfree(req->async_data);

	if (req->creds) {

		put_cred(req->creds);

		req->creds = NULL;

	}

}



/* must to be called somewhat shortly after putting a request */
@@ -6133,6 +6134,10 @@ static void io_clean_op(struct io_kiocb *req) 
		atomic_dec(&tctx->inflight_tracked);

		req->flags &= ~REQ_F_INFLIGHT;

	}

	if (req->flags & REQ_F_CREDS) {

		put_cred(req->creds);

		req->flags &= ~REQ_F_CREDS;

	}

}



static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)
@@ -6141,7 +6146,7 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) 
	const struct cred *creds = NULL;

	int ret;



	if (req->creds && req->creds != current_cred())

	if ((req->flags & REQ_F_CREDS) && req->creds != current_cred())

		creds = override_creds(req->creds);



	switch (req->opcode) {
@@ -6534,7 +6539,6 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, 
	atomic_set(&req->refs, 2);

	req->task = current;

	req->result = 0;

	req->creds = NULL;



	/* enforce forwards compatibility on users */

	if (unlikely(sqe_flags & ~SQE_VALID_FLAGS))
@@ -6556,6 +6560,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, 
		if (!req->creds)

			return -EINVAL;

		get_cred(req->creds);

		req->flags |= REQ_F_CREDS;

	}

	state = &ctx->submit_state;