diff options
Diffstat (limited to 'include/linux/crush/crush.h')
| -rw-r--r-- | include/linux/crush/crush.h | 41 |
1 files changed, 34 insertions, 7 deletions
diff --git a/include/linux/crush/crush.h b/include/linux/crush/crush.h index be8f12b8f195..fbecbd089d75 100644 --- a/include/linux/crush/crush.h +++ b/include/linux/crush/crush.h @@ -135,13 +135,6 @@ struct crush_bucket { __u32 size; /* num items */ __s32 *items; - /* - * cached random permutation: used for uniform bucket and for - * the linear search fallback for the other bucket types. - */ - __u32 perm_x; /* @x for which *perm is defined */ - __u32 perm_n; /* num elements of *perm that are permuted/defined */ - __u32 *perm; }; struct crush_bucket_uniform { @@ -211,6 +204,21 @@ struct crush_map { * device fails. */ __u8 chooseleaf_stable; + /* + * This value is calculated after decode or construction by + * the builder. It is exposed here (rather than having a + * 'build CRUSH working space' function) so that callers can + * reserve a static buffer, allocate space on the stack, or + * otherwise avoid calling into the heap allocator if they + * want to. The size of the working space depends on the map, + * while the size of the scratch vector passed to the mapper + * depends on the size of the desired result set. + * + * Nothing stops the caller from allocating both in one swell + * foop and passing in two points, though. + */ + size_t working_size; + #ifndef __KERNEL__ /* * version 0 (original) of straw_calc has various flaws. version 1 @@ -248,4 +256,23 @@ static inline int crush_calc_tree_node(int i) return ((i+1) << 1)-1; } +/* + * These data structures are private to the CRUSH implementation. They + * are exposed in this header file because builder needs their + * definitions to calculate the total working size. + * + * Moving this out of the crush map allow us to treat the CRUSH map as + * immutable within the mapper and removes the requirement for a CRUSH + * map lock. + */ +struct crush_work_bucket { + __u32 perm_x; /* @x for which *perm is defined */ + __u32 perm_n; /* num elements of *perm that are permuted/defined */ + __u32 *perm; /* Permutation of the bucket's items */ +}; + +struct crush_work { + struct crush_work_bucket **work; /* Per-bucket working store */ +}; + #endif |