osd_types: fix object_info_t backwards compatibility

Shipping an object_info_t to a replica with the dirty
flag set would cause the replica to interpret that
object as being lost.  Instead, we always encode
lost into the slot where dumpling expects to find
it and add another field at the end of the encoding.

Backport: emperor
Fixes: #6761
Signed-off-by: Samuel Just <sam.just@inktank.com>
Reviewed-by: Greg Farnum <greg@inktank.com>

diff --git a/src/osd/osd_types.cc b/src/osd/osd_types.cc
index 05b83c4af21bd86f6bf6d2c77f1b2d517d0dc21c..4a9a96c0b9023081aabe90b62eca0156263f5a56 100644 (file)
--- a/src/osd/osd_types.cc
+++ b/src/osd/osd_types.cc
@@ -2913,7 +2913,7 @@ void object_info_t::encode(bufferlist& bl) const
        ++i) {
     old_watchers.insert(make_pair(i->first.second, i->second));
   }
-  ENCODE_START(12, 8, bl);
+  ENCODE_START(13, 8, bl);
   ::encode(soid, bl);
   ::encode(myoloc, bl);        //Retained for compatibility
   ::encode(category, bl);
@@ -2928,23 +2928,23 @@ void object_info_t::encode(bufferlist& bl) const
     ::encode(snaps, bl);
   ::encode(truncate_seq, bl);
   ::encode(truncate_size, bl);
-  __u8 flags_lo = flags & 0xff;
-  __u8 flags_hi = (flags & 0xff00) >> 8;
-  ::encode(flags_lo, bl);
+  ::encode(is_lost(), bl);
   ::encode(old_watchers, bl);
   /* shenanigans to avoid breaking backwards compatibility in the disk format.
    * When we can, switch this out for simply putting the version_t on disk. */
   eversion_t user_eversion(0, user_version);
   ::encode(user_eversion, bl);
-  ::encode(flags_hi, bl);
+  ::encode(test_flag(FLAG_USES_TMAP), bl);
   ::encode(watchers, bl);
+  __u32 _flags = flags;
+  ::encode(_flags, bl);
   ENCODE_FINISH(bl);
 }
 
 void object_info_t::decode(bufferlist::iterator& bl)
 {
   object_locator_t myoloc;
-  DECODE_START_LEGACY_COMPAT_LEN(12, 8, 8, bl);
+  DECODE_START_LEGACY_COMPAT_LEN(13, 8, 8, bl);
   map<entity_name_t, watch_info_t> old_watchers;
   if (struct_v >= 2 && struct_v <= 5) {
     sobject_t obj;
@@ -2975,6 +2975,9 @@ void object_info_t::decode(bufferlist::iterator& bl)
   ::decode(truncate_seq, bl);
   ::decode(truncate_size, bl);
   if (struct_v >= 3) {
+    // if this is struct_v >= 13, we will overwrite this
+    // below since this field is just here for backwards
+    // compatibility
     __u8 lo;
     ::decode(lo, bl);
     flags = (flag_t)lo;
@@ -2988,9 +2991,10 @@ void object_info_t::decode(bufferlist::iterator& bl)
     user_version = user_eversion.version;
   }
   if (struct_v >= 9) {
-    __u8 hi;
-    ::decode(hi, bl);
-    flags = (flag_t)(flags | ((unsigned)hi << 8));
+    bool uses_tmap = false;
+    ::decode(uses_tmap, bl);
+    if (uses_tmap)
+      set_flag(FLAG_USES_TMAP);
   } else {
     set_flag(FLAG_USES_TMAP);
   }
@@ -3007,6 +3011,11 @@ void object_info_t::decode(bufferlist::iterator& bl)
          make_pair(i->second.cookie, i->first), i->second));
     }
   }
+  if (struct_v >= 13) {
+    __u32 _flags;
+    ::decode(_flags, bl);
+    flags = (flag_t)_flags;
+  }
   DECODE_FINISH(bl);
 }