xref: /linux-6.15/include/linux/crush/mapper.h (revision cfd6ed45)
1 #ifndef CEPH_CRUSH_MAPPER_H
2 #define CEPH_CRUSH_MAPPER_H
3 
4 /*
5  * CRUSH functions for find rules and then mapping an input to an
6  * output set.
7  *
8  * LGPL2
9  */
10 
11 #include "crush.h"
12 
13 extern int crush_find_rule(const struct crush_map *map, int ruleset, int type, int size);
14 extern int crush_do_rule(const struct crush_map *map,
15 			 int ruleno,
16 			 int x, int *result, int result_max,
17 			 const __u32 *weights, int weight_max,
18 			 void *cwin);
19 
20 /*
21  * Returns the exact amount of workspace that will need to be used
22  * for a given combination of crush_map and result_max. The caller can
23  * then allocate this much on its own, either on the stack, in a
24  * per-thread long-lived buffer, or however it likes.
25  */
26 static inline size_t crush_work_size(const struct crush_map *map,
27 				     int result_max)
28 {
29 	return map->working_size + result_max * 3 * sizeof(__u32);
30 }
31 
32 void crush_init_workspace(const struct crush_map *map, void *v);
33 
34 #endif
35