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e418bbc9 JA |
1 | #ifndef IOU_REQ_REF_H |
2 | #define IOU_REQ_REF_H | |
3 | ||
4 | #include <linux/atomic.h> | |
ab1c84d8 | 5 | #include <linux/io_uring_types.h> |
e418bbc9 JA |
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 | ||
14 | static 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 | ||
20 | static inline bool req_ref_put_and_test(struct io_kiocb *req) | |
21 | { | |
22 | if (likely(!(req->flags & REQ_F_REFCOUNT))) | |
23 | return true; | |
24 | ||
25 | WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); | |
26 | return atomic_dec_and_test(&req->refs); | |
27 | } | |
28 | ||
29 | static inline void req_ref_get(struct io_kiocb *req) | |
30 | { | |
31 | WARN_ON_ONCE(!(req->flags & REQ_F_REFCOUNT)); | |
32 | WARN_ON_ONCE(req_ref_zero_or_close_to_overflow(req)); | |
33 | atomic_inc(&req->refs); | |
34 | } | |
35 | ||
36 | static inline void __io_req_set_refcount(struct io_kiocb *req, int nr) | |
37 | { | |
38 | if (!(req->flags & REQ_F_REFCOUNT)) { | |
39 | req->flags |= REQ_F_REFCOUNT; | |
40 | atomic_set(&req->refs, nr); | |
41 | } | |
42 | } | |
43 | ||
44 | static inline void io_req_set_refcount(struct io_kiocb *req) | |
45 | { | |
46 | __io_req_set_refcount(req, 1); | |
47 | } | |
48 | #endif |