mon/MonitorStore: store global version (gv) alongside paxos values

Keep a parallel set of files mapping paxos states (NNN of foo/NNN) to a
global version number, stored at foo_gv/NNN.  Provide per-state accessors
and wire into put_bl_sn_map() and trim().

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

diff --git a/src/mon/MonitorStore.cc b/src/mon/MonitorStore.cc
index 774898251be9a115a3f202372cb83e21f10b74ff..0fdb28259b67afb210ecd26e6f2b3b41e0971fc9 100644 (file)
--- a/src/mon/MonitorStore.cc
+++ b/src/mon/MonitorStore.cc
@@ -204,6 +204,22 @@ void MonitorStore::put_int(version_t val, const char *a, const char *b)
   }
 }
 
+// kludge to associate a global version number with each per-machine paxos state
+version_t MonitorStore::get_global_version(const char *a, version_t b)
+{
+  char fn[1024], fn2[1024];
+  snprintf(fn, sizeof(fn), "%s_gv", a);
+  snprintf(fn2, sizeof(fn2), "%llu", (long long unsigned)b);
+  return get_int(fn, fn2);
+}
+
+void MonitorStore::put_global_version(const char *a, version_t b, version_t gv)
+{
+  char fn[1024], fn2[1024];
+  snprintf(fn, sizeof(fn), "%s_gv", a);
+  snprintf(fn2, sizeof(fn2), "%llu", (long long unsigned)b);
+  put_int(gv, fn, fn2);
+}
 
 // ----------------------------------------
 // buffers
@@ -239,6 +255,14 @@ int MonitorStore::erase_ss(const char *a, const char *b)
     strcpy(fn, dr);
   }
   int r = ::unlink(fn);
+
+  if (b) {
+    // wipe out _gv file too, if any.  this is sloppy, but will work.
+    char gvf[1024];
+    snprintf(gvf, sizeof(gvf), "%s/%s_gv/%s", dir.c_str(), a, b);
+    ::unlink(gvf);  // ignore error; it may not be there.
+  }
+
   ::rmdir(dr);  // sloppy attempt to clean up empty dirs
   return r;
 }
@@ -351,7 +375,8 @@ int MonitorStore::write_bl_ss(bufferlist& bl, const char *a, const char *b, bool
 
 int MonitorStore::put_bl_sn_map(const char *a,
                                map<version_t,bufferlist>::iterator start,
-                               map<version_t,bufferlist>::iterator end)
+                               map<version_t,bufferlist>::iterator end,
+                               map<version_t,version_t> *gvmap)
 {
   version_t first = start->first;
   map<version_t,bufferlist>::iterator lastp = end;
@@ -367,6 +392,8 @@ int MonitorStore::put_bl_sn_map(const char *a,
       int err = put_bl_sn(p->second, a, p->first);
       if (err < 0)
        return err;
+      if (gvmap && gvmap->count(p->first) && (*gvmap)[p->first] > 0)
+       put_global_version(a, p->first, (*gvmap)[p->first]);
     }
     return 0;
   }
@@ -393,6 +420,12 @@ int MonitorStore::put_bl_sn_map(const char *a,
     ::close(fd);
     if (err < 0)
       return -errno;
+
+    // this doesn't try to be efficient.. too bad for you!  it may also
+    // extend beyond commmitted, but that's okay; we only look at these
+    // if the actual state files exist too.
+    if (gvmap && gvmap->count(p->first) && (*gvmap)[p->first])
+      put_global_version(a, p->first, (*gvmap)[p->first]);
   }
 
   // sync them all

diff --git a/src/mon/MonitorStore.h b/src/mon/MonitorStore.h
index 4510cde6b8fe981eb7867041e63c2b1d6b7bfcd9..cf748360456ea92df4f5af618d6b51ea50a0d4cc 100644 (file)
--- a/src/mon/MonitorStore.h
+++ b/src/mon/MonitorStore.h
@@ -42,6 +42,9 @@ public:
   version_t get_int(const char *a, const char *b=0);
   void put_int(version_t v, const char *a, const char *b=0);
 
+  version_t get_global_version(const char *a, version_t b);
+  void put_global_version(const char *a, version_t b, version_t gv);
+
   // buffers
   // ss and sn varieties.
   bool exists_bl_ss(const char *a, const char *b=0);
@@ -76,7 +79,8 @@ public:
    */
   int put_bl_sn_map(const char *a,
                    map<version_t,bufferlist>::iterator start,
-                   map<version_t,bufferlist>::iterator end);
+                   map<version_t,bufferlist>::iterator end,
+                   map<version_t,version_t> *gvmap);
 
   int erase_ss(const char *a, const char *b);
   int erase_sn(const char *a, version_t b) {