libceph: introduce get_osdmap_client_data_v()

Full and incremental osdmaps are structured identically and have
identical headers.  Add a helper to decode both "old" (16-bit version,
v6) and "new" (8-bit struct_v+struct_compat+struct_len, v7) osdmap
enconding headers and switch to it.

Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Alex Elder <elder@linaro.org>

diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 6497322..be2a65f 100644 (file)
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -683,6 +683,63 @@ static int osdmap_set_max_osd(struct ceph_osdmap *map, int max)
        return 0;
 }
 
+#define OSDMAP_WRAPPER_COMPAT_VER      7
+#define OSDMAP_CLIENT_DATA_COMPAT_VER  1
+
+/*
+ * Return 0 or error.  On success, *v is set to 0 for old (v6) osdmaps,
+ * to struct_v of the client_data section for new (v7 and above)
+ * osdmaps.
+ */
+static int get_osdmap_client_data_v(void **p, void *end,
+                                   const char *prefix, u8 *v)
+{
+       u8 struct_v;
+
+       ceph_decode_8_safe(p, end, struct_v, e_inval);
+       if (struct_v >= 7) {
+               u8 struct_compat;
+
+               ceph_decode_8_safe(p, end, struct_compat, e_inval);
+               if (struct_compat > OSDMAP_WRAPPER_COMPAT_VER) {
+                       pr_warning("got v %d cv %d > %d of %s ceph_osdmap\n",
+                                  struct_v, struct_compat,
+                                  OSDMAP_WRAPPER_COMPAT_VER, prefix);
+                       return -EINVAL;
+               }
+               *p += 4; /* ignore wrapper struct_len */
+
+               ceph_decode_8_safe(p, end, struct_v, e_inval);
+               ceph_decode_8_safe(p, end, struct_compat, e_inval);
+               if (struct_compat > OSDMAP_CLIENT_DATA_COMPAT_VER) {
+                       pr_warning("got v %d cv %d > %d of %s ceph_osdmap client data\n",
+                                  struct_v, struct_compat,
+                                  OSDMAP_CLIENT_DATA_COMPAT_VER, prefix);
+                       return -EINVAL;
+               }
+               *p += 4; /* ignore client data struct_len */
+       } else {
+               u16 version;
+
+               *p -= 1;
+               ceph_decode_16_safe(p, end, version, e_inval);
+               if (version < 6) {
+                       pr_warning("got v %d < 6 of %s ceph_osdmap\n", version,
+                                  prefix);
+                       return -EINVAL;
+               }
+
+               /* old osdmap enconding */
+               struct_v = 0;
+       }
+
+       *v = struct_v;
+       return 0;
+
+e_inval:
+       return -EINVAL;
+}
+
 static int __decode_pools(void **p, void *end, struct ceph_osdmap *map,
                          bool incremental)
 {
@@ -798,7 +855,7 @@ static int decode_new_pg_temp(void **p, void *end, struct ceph_osdmap *map)
  */
 static int osdmap_decode(void **p, void *end, struct ceph_osdmap *map)
 {
-       u16 version;
+       u8 struct_v;
        u32 epoch = 0;
        void *start = *p;
        u32 max;
@@ -807,15 +864,9 @@ static int osdmap_decode(void **p, void *end, struct ceph_osdmap *map)
 
        dout("%s %p to %p len %d\n", __func__, *p, end, (int)(end - *p));
 
-       ceph_decode_16_safe(p, end, version, e_inval);
-       if (version > 6) {
-               pr_warning("got unknown v %d > 6 of osdmap\n", version);
-               goto e_inval;
-       }
-       if (version < 6) {
-               pr_warning("got old v %d < 6 of osdmap\n", version);
-               goto e_inval;
-       }
+       err = get_osdmap_client_data_v(p, end, "full", &struct_v);
+       if (err)
+               goto bad;
 
        /* fsid, epoch, created, modified */
        ceph_decode_need(p, end, sizeof(map->fsid) + sizeof(u32) +
@@ -943,15 +994,13 @@ struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end,
        __s32 new_flags, max;
        void *start = *p;
        int err;
-       u16 version;
+       u8 struct_v;
 
        dout("%s %p to %p len %d\n", __func__, *p, end, (int)(end - *p));
 
-       ceph_decode_16_safe(p, end, version, e_inval);
-       if (version != 6) {
-               pr_warning("got unknown v %d != 6 of inc osdmap\n", version);
-               goto e_inval;
-       }
+       err = get_osdmap_client_data_v(p, end, "inc", &struct_v);
+       if (err)
+               goto bad;
 
        /* fsid, epoch, modified, new_pool_max, new_flags */
        ceph_decode_need(p, end, sizeof(fsid) + sizeof(u32) + sizeof(modified) +