#ifndef IOU_REQ_REF_H #define IOU_REQ_REF_H #include <linux/atomic.h> #include <linux/io_uring_types.h> /* * Shamelessly stolen from the mm implementation of page reference checking, * see commit f958d7b528b1 for details. */ #define req_ref_zero_or_close_to_overflow(req) \ ((unsigned int) atomic_read(&(req->refs)) + 127u <= 127u) static inline bool req_ref_inc_not_zero(struct io_kiocb *req) { WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); return atomic_inc_not_zero(&req->refs); } static inline bool req_ref_put_and_test_atomic(struct io_kiocb *req) { WARN_ON_ONCE(!(data_race(req->flags) & REQ_F_REFCOUNT)); WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); return atomic_dec_and_test(&req->refs); } static inline bool req_ref_put_and_test(struct io_kiocb *req) { if (likely(!(req->flags & REQ_F_REFCOUNT))) return true; WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); return atomic_dec_and_test(&req->refs); } static inline void req_ref_get(struct io_kiocb *req) { WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); atomic_inc(&req->refs); } static inline void req_ref_put(struct io_kiocb *req) { WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); atomic_dec(&req->refs); } static inline void __io_req_set_refcount(struct io_kiocb *req, int nr) { if (!(req->flags & REQ_F_REFCOUNT)) { req->flags |= REQ_F_REFCOUNT; atomic_set(&req->refs, nr); } } static inline void io_req_set_refcount(struct io_kiocb *req) { __io_req_set_refcount(req, 1); } #endif