1 #ifndef IOU_REQ_REF_H 2 #define IOU_REQ_REF_H 3 4 #include <linux/atomic.h> 5 #include <linux/io_uring_types.h> 6 7 /* 8 * Shamelessly stolen from the mm implementation of page reference checking, 9 * see commit f958d7b528b1 for details. 10 */ 11 #define req_ref_zero_or_close_to_overflow(req) \ 12 ((unsigned int) atomic_read(&(req->refs)) + 127u <= 127u) 13 req_ref_inc_not_zero(struct io_kiocb * req)14static inline bool req_ref_inc_not_zero(struct io_kiocb *req) 15 { 16 WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); 17 return atomic_inc_not_zero(&req->refs); 18 } 19 req_ref_put_and_test_atomic(struct io_kiocb * req)20static inline bool req_ref_put_and_test_atomic(struct io_kiocb *req) 21 { 22 WARN_ON_ONCE(!(data_race(req->flags) & REQ_F_REFCOUNT)); 23 WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); 24 return atomic_dec_and_test(&req->refs); 25 } 26 req_ref_put_and_test(struct io_kiocb * req)27static inline bool req_ref_put_and_test(struct io_kiocb *req) 28 { 29 if (likely(!(req->flags & REQ_F_REFCOUNT))) 30 return true; 31 32 WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); 33 return atomic_dec_and_test(&req->refs); 34 } 35 req_ref_get(struct io_kiocb * req)36static inline void req_ref_get(struct io_kiocb *req) 37 { 38 WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); 39 WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); 40 atomic_inc(&req->refs); 41 } 42 __io_req_set_refcount(struct io_kiocb * req,int nr)43static inline void __io_req_set_refcount(struct io_kiocb *req, int nr) 44 { 45 if (!(req->flags & REQ_F_REFCOUNT)) { 46 req->flags |= REQ_F_REFCOUNT; 47 atomic_set(&req->refs, nr); 48 } 49 } 50 io_req_set_refcount(struct io_kiocb * req)51static inline void io_req_set_refcount(struct io_kiocb *req) 52 { 53 __io_req_set_refcount(req, 1); 54 } 55 #endif 56