os, osd, tools: Add backportable compatibility checking for sharded objectswip-compat-cuttlefish

OSD
  New CEPH_OSD_FEATURE_INCOMPAT_SHARDS
FileStore
  NEW CEPH_FS_FEATURE_INCOMPAT_SHARDS
  Add FSSuperblock with feature CompatSet in it
  Store sharded_objects state using CompatSet
  Add set_allow_sharded_objects() and get_allow_sharded_objects() to FileStore/ObjectStore
  Add read_superblock()/write_superblock() internal filestore functions
ceph_filestore_dump
  Add OSDsuperblock to export format
  Use CompatSet from OSD code itself in filestore-dump tool
  Always check compatibility of OSD features with on-disk features
  On import verify compatibility of on-disk features with export data
  Bump super_ver due to export format change

Backport: dumpling, cuttlefish

Signed-off-by: David Zafman <david.zafman@inktank.com>
(cherry picked from commit 5b70c2b0108f744c171364f26475fb7baaa8b6fe)

Conflicts:

	src/os/FileStore.cc
	src/os/FileStore.h
	src/osd/OSD.cc
	src/osd/OSD.h

1 files changed, 14 insertions, 4 deletions

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index a93545d4437..1e91d5a2096 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -129,7 +129,9 @@ static ostream& _prefix(std::ostream* _dout, int whoami, OSDMapRef osdmap) {
 
 const coll_t coll_t::META_COLL("meta");
 
-static CompatSet get_osd_compat_set() {
+//Initial features in new superblock.
+//Features here are also automatically upgraded
+CompatSet OSD::get_osd_initial_compat_set() {
   CompatSet::FeatureSet ceph_osd_feature_compat;
   CompatSet::FeatureSet ceph_osd_feature_ro_compat;
   CompatSet::FeatureSet ceph_osd_feature_incompat;
@@ -147,6 +149,13 @@ static CompatSet get_osd_compat_set() {
 		   ceph_osd_feature_incompat);
 }
 
+//Features are added here that this OSD supports.
+CompatSet OSD::get_osd_compat_set() {
+  CompatSet compat =  get_osd_initial_compat_set();
+  //Any features here can be set in code, but not in initial superblock
+  return compat;
+}
+
 OSDService::OSDService(OSD *osd) :
   osd(osd),
   whoami(osd->whoami), store(osd->store), clog(osd->clog),
@@ -611,7 +620,7 @@ int OSD::mkfs(const std::string &dev, const std::string &jdev, uuid_d fsid, int
       sb.cluster_fsid = fsid;
       sb.osd_fsid = store->get_fsid();
       sb.whoami = whoami;
-      sb.compat_features = get_osd_compat_set();
+      sb.compat_features = get_osd_initial_compat_set();
 
       // benchmark?
       if (g_conf->osd_auto_weight) {
@@ -1080,11 +1089,12 @@ int OSD::init()
       return r;
   }
 
-  if (osd_compat.compare(superblock.compat_features) != 0) {
+  CompatSet initial = get_osd_initial_compat_set();
+  if (initial.compare(superblock.compat_features) != 0) {
     // We need to persist the new compat_set before we
     // do anything else
     dout(5) << "Upgrading superblock compat_set" << dendl;
-    superblock.compat_features = osd_compat;
+    superblock.compat_features = initial;
     ObjectStore::Transaction t;
     write_superblock(t);
     r = store->apply_transaction(t);