io_uring: move inflight un-tracking into cleanup

REQ_F_INFLIGHT deaccounting doesn't do any spinlocking or resource
freeing anymore, so it's safe to move it into the normal cleanup flow,
i.e. into io_clean_op(), so making it cleaner.

Also move io_req_needs_clean() to be first in io_dismantle_req() so it
doesn't reload req->flags.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/90653a3a5de4107e3a00536fa4c2ea5f2c38a4ac.1618916549.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -1601,7 +1601,7 @@ 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_POLLED | REQ_F_INFLIGHT);
 }
 
 static void io_req_complete_state(struct io_kiocb *req, long res,
@@ -1717,17 +1717,10 @@ static void io_dismantle_req(struct io_kiocb *req)
 {
 	unsigned int flags = req->flags;
 
+	if (io_req_needs_clean(req))
+		io_clean_op(req);
 	if (!(flags & REQ_F_FIXED_FILE))
 		io_put_file(req->file);
-	if (io_req_needs_clean(req) || (req->flags & REQ_F_INFLIGHT)) {
-		io_clean_op(req);
-		if (req->flags & REQ_F_INFLIGHT) {
-			struct io_uring_task *tctx = req->task->io_uring;
-
-			atomic_dec(&tctx->inflight_tracked);
-			req->flags &= ~REQ_F_INFLIGHT;
-		}
-	}
 	if (req->fixed_rsrc_refs)
 		percpu_ref_put(req->fixed_rsrc_refs);
 	if (req->async_data)
@@ -6057,6 +6050,12 @@ static void io_clean_op(struct io_kiocb *req)
 		kfree(req->apoll);
 		req->apoll = NULL;
 	}
+	if (req->flags & REQ_F_INFLIGHT) {
+		struct io_uring_task *tctx = req->task->io_uring;
+
+		atomic_dec(&tctx->inflight_tracked);
+		req->flags &= ~REQ_F_INFLIGHT;
+	}
 }
 
 static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags)