2 files changed, 46 insertions, 6 deletions

diff --git a/net/ceph/crush/mapper.c b/net/ceph/crush/mapper.c
index d7edc24333b8..35fce755ce10 100644
--- a/net/ceph/crush/mapper.c
+++ b/net/ceph/crush/mapper.c
@@ -306,7 +306,6 @@ static int crush_choose(const struct crush_map *map,
         int item = 0;
         int itemtype;
         int collide, reject;
-        const unsigned int orig_tries = 5; /* attempts before we fall back to search */
 
         dprintk("CHOOSE%s bucket %d x %d outpos %d numrep %d\n", recurse_to_leaf ? "_LEAF" : "",
                 bucket->id, x, outpos, numrep);
@@ -351,8 +350,9 @@ static int crush_choose(const struct crush_map *map,
                                         reject = 1;
                                         goto reject;
                                 }
-                                if (flocal >= (in->size>>1) &&
-                                    flocal > orig_tries)
+                                if (map->choose_local_fallback_tries > 0 &&
+                                    flocal >= (in->size>>1) &&
+                                    flocal > map->choose_local_fallback_tries)
                                         item = bucket_perm_choose(in, x, r);
                                 else
                                         item = crush_bucket_choose(in, x, r);
@@ -422,13 +422,14 @@ reject:
                                         ftotal++;
                                         flocal++;
 
-                                        if (collide && flocal < 3)
+                                        if (collide && flocal <= map->choose_local_tries)
                                                 /* retry locally a few times */
                                                 retry_bucket = 1;
-                                        else if (flocal <= in->size + orig_tries)
+                                        else if (map->choose_local_fallback_tries > 0 &&
+                                                 flocal <= in->size + map->choose_local_fallback_tries)
                                                 /* exhaustive bucket search */
                                                 retry_bucket = 1;
-                                        else if (ftotal < 20)
+                                        else if (ftotal <= map->choose_total_tries)
                                                 /* then retry descent */
                                                 retry_descent = 1;
                                         else
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 9600674c2c39..3124b71a8883 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -135,6 +135,21 @@ bad:
         return -EINVAL;
 }
 
+static int skip_name_map(void **p, void *end)
+{
+        int len;
+        ceph_decode_32_safe(p, end, len ,bad);
+        while (len--) {
+                int strlen;
+                *p += sizeof(u32);
+                ceph_decode_32_safe(p, end, strlen, bad);
+                *p += strlen;
+}
+        return 0;
+bad:
+        return -EINVAL;
+}
+
 static struct crush_map *crush_decode(void *pbyval, void *end)
 {
         struct crush_map *c;
@@ -143,6 +158,7 @@ static struct crush_map *crush_decode(void *pbyval, void *end)
         void **p = &pbyval;
         void *start = pbyval;
         u32 magic;
+        u32 num_name_maps;
 
         dout("crush_decode %p to %p len %d\n", *p, end, (int)(end - *p));
 
@@ -150,6 +166,11 @@ static struct crush_map *crush_decode(void *pbyval, void *end)
         if (c == NULL)
                 return ERR_PTR(-ENOMEM);
 
+        /* set tunables to default values */
+        c->choose_local_tries = 2;
+        c->choose_local_fallback_tries = 5;
+        c->choose_total_tries = 19;
+
         ceph_decode_need(p, end, 4*sizeof(u32), bad);
         magic = ceph_decode_32(p);
         if (magic != CRUSH_MAGIC) {
@@ -297,7 +318,25 @@ static struct crush_map *crush_decode(void *pbyval, void *end)
         }
 
         /* ignore trailing name maps. */
+        for (num_name_maps = 0; num_name_maps < 3; num_name_maps++) {
+                err = skip_name_map(p, end);
+                if (err < 0)
+                        goto done;
+        }
+
+        /* tunables */
+        ceph_decode_need(p, end, 3*sizeof(u32), done);
+        c->choose_local_tries = ceph_decode_32(p);
+        c->choose_local_fallback_tries =  ceph_decode_32(p);
+        c->choose_total_tries = ceph_decode_32(p);
+        dout("crush decode tunable choose_local_tries = %d",
+             c->choose_local_tries);
+        dout("crush decode tunable choose_local_fallback_tries = %d",
+             c->choose_local_fallback_tries);
+        dout("crush decode tunable choose_total_tries = %d",
+             c->choose_total_tries);
 
+done:
         dout("crush_decode success\n");
         return c;