linux-stable/io_uring/refs.h

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#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(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