ceph: make CRUSH hash function a bucket property

Make the integer hash function a property of the bucket it is used on.  This
allows us to gracefully add support for new hash functions without starting
from scatch.

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 9 insertions, 7 deletions

diff --git a/fs/ceph/crush/mapper.c b/fs/ceph/crush/mapper.c
index 54f3f402af60..2523d448445c 100644
--- a/fs/ceph/crush/mapper.c
+++ b/fs/ceph/crush/mapper.c
@@ -78,7 +78,7 @@ static int bucket_perm_choose(struct crush_bucket *bucket,
 
                 /* optimize common r=0 case */
                 if (pr == 0) {
-                        s = crush_hash32_3(x, bucket->id, 0) %
+                        s = crush_hash32_3(bucket->hash, x, bucket->id, 0) %
                                 bucket->size;
                         bucket->perm[0] = s;
                         bucket->perm_n = 0xffff;   /* magic value, see below */
@@ -103,7 +103,7 @@ static int bucket_perm_choose(struct crush_bucket *bucket,
                 unsigned p = bucket->perm_n;
                 /* no point in swapping the final entry */
                 if (p < bucket->size - 1) {
-                        i = crush_hash32_3(x, bucket->id, p) %
+                        i = crush_hash32_3(bucket->hash, x, bucket->id, p) %
                                 (bucket->size - p);
                         if (i) {
                                 unsigned t = bucket->perm[p + i];
@@ -138,8 +138,8 @@ static int bucket_list_choose(struct crush_bucket_list *bucket,
         int i;
 
         for (i = bucket->h.size-1; i >= 0; i--) {
-                __u64 w = crush_hash32_4(x, bucket->h.items[i], r,
-                                         bucket->h.id);
+                __u64 w = crush_hash32_4(bucket->h.hash,x, bucket->h.items[i],
+                                         r, bucket->h.id);
                 w &= 0xffff;
                 dprintk("list_choose i=%d x=%d r=%d item %d weight %x "
                         "sw %x rand %llx",
@@ -198,7 +198,8 @@ static int bucket_tree_choose(struct crush_bucket_tree *bucket,
         while (!terminal(n)) {
                 /* pick point in [0, w) */
                 w = bucket->node_weights[n];
-                t = (__u64)crush_hash32_4(x, n, r, bucket->h.id) * (__u64)w;
+                t = (__u64)crush_hash32_4(bucket->h.hash, x, n, r,
+                                          bucket->h.id) * (__u64)w;
                 t = t >> 32;
 
                 /* descend to the left or right? */
@@ -224,7 +225,7 @@ static int bucket_straw_choose(struct crush_bucket_straw *bucket,
         __u64 draw;
 
         for (i = 0; i < bucket->h.size; i++) {
-                draw = crush_hash32_3(x, bucket->h.items[i], r);
+                draw = crush_hash32_3(bucket->h.hash, x, bucket->h.items[i], r);
                 draw &= 0xffff;
                 draw *= bucket->straws[i];
                 if (i == 0 || draw > high_draw) {
@@ -267,7 +268,8 @@ static int is_out(struct crush_map *map, __u32 *weight, int item, int x)
                 return 0;
         if (weight[item] == 0)
                 return 1;
-        if ((crush_hash32_2(x, item) & 0xffff) < weight[item])
+        if ((crush_hash32_2(CRUSH_HASH_RJENKINS1, x, item) & 0xffff)
+            < weight[item])
                 return 0;
         return 1;
 }