io_uring: introduce req_need_defer()

Makes the code easier to read.

Signed-off-by: Bob Liu <bob.liu@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 297b9e80dc5c54be62c2a6c1c3c5b3e0cf2c4e0c..9500780bcaeacb9e3a0089d04cf408c101a9de4f 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -448,7 +448,7 @@ static struct io_ring_ctx *io_ring_ctx_alloc(struct io_uring_params *p)
        return NULL;
 }
 
-static inline bool __io_sequence_defer(struct io_kiocb *req)
+static inline bool __req_need_defer(struct io_kiocb *req)
 {
        struct io_ring_ctx *ctx = req->ctx;
 
@@ -456,12 +456,12 @@ static inline bool __io_sequence_defer(struct io_kiocb *req)
                                        + atomic_read(&ctx->cached_cq_overflow);
 }
 
-static inline bool io_sequence_defer(struct io_kiocb *req)
+static inline bool req_need_defer(struct io_kiocb *req)
 {
-       if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) != REQ_F_IO_DRAIN)
-               return false;
+       if ((req->flags & (REQ_F_IO_DRAIN|REQ_F_IO_DRAINED)) == REQ_F_IO_DRAIN)
+               return __req_need_defer(req);
 
-       return __io_sequence_defer(req);
+       return false;
 }
 
 static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
@@ -469,7 +469,7 @@ static struct io_kiocb *io_get_deferred_req(struct io_ring_ctx *ctx)
        struct io_kiocb *req;
 
        req = list_first_entry_or_null(&ctx->defer_list, struct io_kiocb, list);
-       if (req && !io_sequence_defer(req)) {
+       if (req && !req_need_defer(req)) {
                list_del_init(&req->list);
                return req;
        }
@@ -482,7 +482,7 @@ static struct io_kiocb *io_get_timeout_req(struct io_ring_ctx *ctx)
        struct io_kiocb *req;
 
        req = list_first_entry_or_null(&ctx->timeout_list, struct io_kiocb, list);
-       if (req && !__io_sequence_defer(req)) {
+       if (req && !__req_need_defer(req)) {
                list_del_init(&req->list);
                return req;
        }
@@ -2436,7 +2436,8 @@ static int io_req_defer(struct io_kiocb *req)
        struct io_uring_sqe *sqe_copy;
        struct io_ring_ctx *ctx = req->ctx;
 
-       if (!io_sequence_defer(req) && list_empty(&ctx->defer_list))
+       /* Still need defer if there is pending req in defer list. */
+       if (!req_need_defer(req) && list_empty(&ctx->defer_list))
                return 0;
 
        sqe_copy = kmalloc(sizeof(*sqe_copy), GFP_KERNEL);
@@ -2444,7 +2445,7 @@ static int io_req_defer(struct io_kiocb *req)
                return -EAGAIN;
 
        spin_lock_irq(&ctx->completion_lock);
-       if (!io_sequence_defer(req) && list_empty(&ctx->defer_list)) {
+       if (!req_need_defer(req) && list_empty(&ctx->defer_list)) {
                spin_unlock_irq(&ctx->completion_lock);
                kfree(sqe_copy);
                return 0;