crush/mapper: clarify numrep vs endpos

Pass numrep (the width of the result) separately from the number of results
we want *this* iteration.  This makes things less awkward when we do a
recursive call (for chooseleaf) and want only one item.

Signed-off-by: Sage Weil <sage@inktank.com>

diff --git a/src/crush/mapper.c b/src/crush/mapper.c
index 1459e4ae6e334457b1d759acf80c40d3fc31a894..61ea18753e4881670653fefaa2fbbf4db2c0832a 100644 (file)
--- a/src/crush/mapper.c
+++ b/src/crush/mapper.c
@@ -456,13 +456,13 @@ reject:
 static void crush_choose_indep(const struct crush_map *map,
                              struct crush_bucket *bucket,
                              const __u32 *weight, int weight_max,
-                             int x, int numrep, int type,
                              int *out, int outpos,
                              int recurse_to_leaf,
                              int *out2)
+                              int x, int left, int numrep, int type,
 {
        struct crush_bucket *in = bucket;
-       int left = numrep - outpos;
+       int endpos = outpos + left;
        int rep;
        unsigned int ftotal;
        int r;
@@ -475,14 +475,14 @@ static void crush_choose_indep(const struct crush_map *map,
                bucket->id, x, outpos, numrep);
 
        /* initially my result is undefined */
-       for (rep = outpos; rep < numrep; rep++) {
+       for (rep = outpos; rep < endpos; rep++) {
                out[rep] = CRUSH_ITEM_UNDEF;
                if (out2)
                        out2[rep] = CRUSH_ITEM_UNDEF;
        }
 
        for (ftotal = 0; left > 0 && ftotal < map->choose_total_tries; ftotal++) {
-               for (rep = outpos; rep < numrep; rep++) {
+               for (rep = outpos; rep < endpos; rep++) {
                        if (out[rep] != CRUSH_ITEM_UNDEF)
                                continue;
 
@@ -550,7 +550,7 @@ static void crush_choose_indep(const struct crush_map *map,
 
                                /* collision? */
                                collide = 0;
-                               for (i = outpos; i < numrep; i++) {
+                               for (i = outpos; i < endpos; i++) {
                                        if (out[i] == item) {
                                                collide = 1;
                                                break;
@@ -564,9 +564,9 @@ static void crush_choose_indep(const struct crush_map *map,
                                                crush_choose_indep(map,
                                                                   map->buckets[-1-item],
                                                                   weight, weight_max,
-                                                                  x, rep+1, 0,
                                                                   out2, rep,
                                                                   0, NULL);
+                                                  x, 1, numrep, 0,
                                                if (out2[rep] == CRUSH_ITEM_NONE) {
                                                        /* placed nothing; no leaf */
                                                        break;
@@ -589,7 +589,7 @@ static void crush_choose_indep(const struct crush_map *map,
                        }
                }
        }
-       for (rep = outpos; rep < numrep; rep++) {
+       for (rep = outpos; rep < endpos; rep++) {
                if (out[rep] == CRUSH_ITEM_UNDEF) {
                        out[rep] = CRUSH_ITEM_NONE;
                }
@@ -694,7 +694,7 @@ int crush_do_rule(const struct crush_map *map,
                                                map,
                                                map->buckets[-1-w[i]],
                                                weight, weight_max,
-                                               x, numrep,
+                                               x, numrep, numrep,
                                                curstep->arg2,
                                                o+osize, j,
                                                recurse_to_leaf,