mds: introduce sequence number for log events

Use the sequence number to index log segments. Later commit will defer
encoding/submitting log events to separate thread, log events' offsets
are unknown before they are encoded.

Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>

diff --git a/src/mds/LogSegment.h b/src/mds/LogSegment.h
index a2b8ace387c80065d58351a5b87b40224b52fb1d..1df103b0514c6c3f286625674fcc7463334da1f6 100644 (file)
--- a/src/mds/LogSegment.h
+++ b/src/mds/LogSegment.h
@@ -35,9 +35,9 @@ struct MDSlaveUpdate;
 
 class LogSegment {
  public:
+  const uint64_t seq;
   uint64_t offset, end;
   int num_events;
-  uint64_t trimmable_at;
 
   // dirty items
   elist<CDir*>    dirty_dirfrags, new_dirfrags;
@@ -70,8 +70,8 @@ class LogSegment {
   void try_to_expire(MDS *mds, C_GatherBuilder &gather_bld, int op_prio);
 
   // cons
-  LogSegment(loff_t off) :
-    offset(off), end(off), num_events(0), trimmable_at(0),
+  LogSegment(uint64_t _seq, loff_t off=-1) :
+    seq(_seq), offset(off), end(off), num_events(0),
     dirty_dirfrags(member_offset(CDir, item_dirty)),
     new_dirfrags(member_offset(CDir, item_new)),
     dirty_inodes(member_offset(CInode, item_dirty)),

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index e3e352a80669e2e20d419116e15676bf08cc2821..80cfd8958fffc0cdb2305e469b02702dd3013cf9 100644 (file)
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -6115,7 +6115,7 @@ void MDCache::truncate_inode_finish(CInode *in, LogSegment *ls)
   CDentry *dn = in->get_projected_parent_dn();
   le->metablob.add_dir_context(dn->get_dir());
   le->metablob.add_primary_dentry(dn, in, true);
-  le->metablob.add_truncate_finish(in->ino(), ls->offset);
+  le->metablob.add_truncate_finish(in->ino(), ls->seq);
 
   journal_dirty_inode(mut.get(), &le->metablob, in);
   mds->mdlog->submit_entry(le, new C_MDC_TruncateLogged(this, in, mut));

diff --git a/src/mds/MDLog.cc b/src/mds/MDLog.cc
index 11019633956a2ec511bde8681e1288abb9e90150..1a7d3c99def3e6d50cbc7f556b2496e3862d47c1 100644 (file)
--- a/src/mds/MDLog.cc
+++ b/src/mds/MDLog.cc
@@ -171,6 +171,14 @@ void MDLog::start_entry(LogEvent *e)
   assert(cur_event == NULL);
   cur_event = e;
   e->set_start_off(get_write_pos());
+
+  event_seq++;
+
+  EMetaBlob *metablob = e->get_metablob();
+  if (metablob) {
+    metablob->event_seq = event_seq;
+    metablob->last_subtree_map = get_last_segment_seq();
+  }
 }
 
 void MDLog::cancel_entry(LogEvent *le)
@@ -294,9 +302,10 @@ void MDLog::start_new_segment()
 
 void MDLog::prepare_new_segment()
 {
-  dout(7) << __func__ << " at " << journaler->get_write_pos() << dendl;
+  uint64_t seq = event_seq + 1;
+  dout(7) << __func__ << " seq " << seq << dendl;
 
-  segments[journaler->get_write_pos()] = new LogSegment(journaler->get_write_pos());
+  segments[seq] = new LogSegment(seq, journaler->get_write_pos());
 
   logger->inc(l_mdl_segadd);
   logger->set(l_mdl_seg, segments.size());
@@ -310,7 +319,9 @@ void MDLog::prepare_new_segment()
 void MDLog::journal_segment_subtree_map(Context *onsync)
 {
   dout(7) << __func__ << dendl;
-  submit_entry(mds->mdcache->create_subtree_map(), onsync);
+  ESubtreeMap *sle = mds->mdcache->create_subtree_map();
+  sle->event_seq = get_last_segment_seq();
+  submit_entry(sle, onsync);
 }
 
 void MDLog::trim(int m)
@@ -430,7 +441,7 @@ void MDLog::_trim_expired_segments()
     logger->inc(l_mdl_segtrm);
     logger->inc(l_mdl_evtrm, ls->num_events);
     
-    segments.erase(ls->offset);
+    segments.erase(ls->seq);
     delete ls;
     trimmed = true;
   }
@@ -835,8 +846,15 @@ void MDLog::_replay_thread()
     // new segment?
     if (le->get_type() == EVENT_SUBTREEMAP ||
        le->get_type() == EVENT_RESETJOURNAL) {
-      segments[pos] = new LogSegment(pos);
+      ESubtreeMap *sle = dynamic_cast<ESubtreeMap*>(le);
+      if (sle && sle->event_seq > 0)
+       event_seq = sle->event_seq;
+      else
+       event_seq = pos;
+      segments[event_seq] = new LogSegment(event_seq, pos);
       logger->set(l_mdl_seg, segments.size());
+    } else {
+      event_seq++;
     }
 
     // have we seen an import map yet?

diff --git a/src/mds/MDLog.h b/src/mds/MDLog.h
index a04b2f8251bb5c2f62c67343bb45e46ed1b9a0b0..318c6344e7dc00990e5b2c547692c7084f46aa3a 100644 (file)
--- a/src/mds/MDLog.h
+++ b/src/mds/MDLog.h
@@ -117,6 +117,7 @@ protected:
   map<uint64_t,LogSegment*> segments;
   set<LogSegment*> expiring_segments;
   set<LogSegment*> expired_segments;
+  uint64_t event_seq;
   int expiring_events;
   int expired_events;
 
@@ -126,6 +127,10 @@ protected:
   friend class MDCache;
 
 public:
+  uint64_t get_last_segment_seq() {
+    assert(!segments.empty());
+    return segments.rbegin()->first;
+  }
   uint64_t get_last_segment_offset() {
     assert(!segments.empty());
     return segments.rbegin()->first;
@@ -168,7 +173,7 @@ public:
                  replay_thread(this),
                  already_replayed(false),
                  recovery_thread(this),
-                 expiring_events(0), expired_events(0),
+                 event_seq(0), expiring_events(0), expired_events(0),
                  cur_event(NULL) { }             
   ~MDLog();
 
@@ -176,7 +181,7 @@ public:
   // -- segments --
   void start_new_segment();
   void prepare_new_segment();
-  void journal_segment_subtree_map(Context *onsync=0);
+  void journal_segment_subtree_map(Context *onsync);
 
   LogSegment *peek_current_segment() {
     return segments.empty() ? NULL : segments.rbegin()->second;
@@ -187,9 +192,9 @@ public:
     return segments.rbegin()->second;
   }
 
-  LogSegment *get_segment(uint64_t off) {
-    if (segments.count(off))
-      return segments[off];
+  LogSegment *get_segment(uint64_t seq) {
+    if (segments.count(seq))
+      return segments[seq];
     return NULL;
   }
 

diff --git a/src/mds/events/EMetaBlob.h b/src/mds/events/EMetaBlob.h
index be0021d75ac0639edbe5abc12358b397608914d8..86889c58e282a5472ee17d3b5b2a5fdbfa49596b 100644 (file)
--- a/src/mds/events/EMetaBlob.h
+++ b/src/mds/events/EMetaBlob.h
@@ -326,7 +326,7 @@ private:
   static void generate_test_instances(list<EMetaBlob*>& ls);
   // soft stateadd
   uint64_t last_subtree_map;
-  uint64_t my_offset;
+  uint64_t event_seq;
 
   // for replay, in certain cases
   //LogSegment *_segment;
@@ -425,7 +425,7 @@ private:
       in = dn->get_projected_linkage()->get_inode();
 
     // make note of where this inode was last journaled
-    in->last_journaled = my_offset;
+    in->last_journaled = event_seq;
     //cout << "journaling " << in->inode.ino << " at " << my_offset << std::endl;
 
     inode_t *pi = in->get_projected_inode();
@@ -478,7 +478,7 @@ private:
 
   void add_root(bool dirty, CInode *in, inode_t *pi=0, fragtree_t *pdft=0, bufferlist *psnapbl=0,
                    map<string,bufferptr> *px=0) {
-    in->last_journaled = my_offset;
+    in->last_journaled = event_seq;
     //cout << "journaling " << in->inode.ino << " at " << my_offset << std::endl;
 
     if (!pi) pi = in->get_projected_inode();

diff --git a/src/mds/events/ESubtreeMap.h b/src/mds/events/ESubtreeMap.h
index 1349dfce91146868199dcdf4b51162a3d7039359..4dea7ecc7991e5cb41b9c63800230e0b79333949 100644 (file)
--- a/src/mds/events/ESubtreeMap.h
+++ b/src/mds/events/ESubtreeMap.h
@@ -24,8 +24,9 @@ public:
   map<dirfrag_t, vector<dirfrag_t> > subtrees;
   set<dirfrag_t> ambiguous_subtrees;
   uint64_t expire_pos;
+  uint64_t event_seq;
 
-  ESubtreeMap() : LogEvent(EVENT_SUBTREEMAP), expire_pos(0) { }
+  ESubtreeMap() : LogEvent(EVENT_SUBTREEMAP), expire_pos(0), event_seq(0) { }
   
   void print(ostream& out) const {
     out << "ESubtreeMap " << subtrees.size() << " subtrees " 

diff --git a/src/mds/journal.cc b/src/mds/journal.cc
index 5a3d1045b49735d706e83657bafec6b6481bb9ee..1db55d11e6ad1a99c6320f14b2c0bdcfe8f17c27 100644 (file)
--- a/src/mds/journal.cc
+++ b/src/mds/journal.cc
@@ -291,10 +291,8 @@ void LogSegment::try_to_expire(MDS *mds, C_GatherBuilder &gather_bld, int op_pri
 // EMetaBlob
 
 EMetaBlob::EMetaBlob(MDLog *mdlog) : opened_ino(0), renamed_dirino(0),
-                                    inotablev(0), sessionmapv(0),
-                                    allocated_ino(0),
-                                    last_subtree_map(mdlog ? mdlog->get_last_segment_offset() : 0),
-                                    my_offset(mdlog ? mdlog->get_write_pos() : 0) //, _segment(0)
+                                    inotablev(0), sessionmapv(0), allocated_ino(0),
+                                    last_subtree_map(0), event_seq(0)
 { }
 
 void EMetaBlob::add_dir_context(CDir *dir, int mode)
@@ -339,7 +337,7 @@ void EMetaBlob::add_dir_context(CDir *dir, int mode)
       }
       
       // was the inode journaled in this blob?
-      if (my_offset && diri->last_journaled == my_offset) {
+      if (event_seq && diri->last_journaled == event_seq) {
        dout(20) << "EMetaBlob::add_dir_context(" << dir << ") already have diri this blob " << *diri << dendl;
        break;
       }
@@ -2415,18 +2413,19 @@ void ESlaveUpdate::replay(MDS *mds)
 
 void ESubtreeMap::encode(bufferlist& bl) const
 {
-  ENCODE_START(5, 5, bl);
+  ENCODE_START(6, 5, bl);
   ::encode(stamp, bl);
   ::encode(metablob, bl);
   ::encode(subtrees, bl);
   ::encode(ambiguous_subtrees, bl);
   ::encode(expire_pos, bl);
+  ::encode(event_seq, bl);
   ENCODE_FINISH(bl);
 }
  
 void ESubtreeMap::decode(bufferlist::iterator &bl)
 {
-  DECODE_START_LEGACY_COMPAT_LEN(5, 5, 5, bl);
+  DECODE_START_LEGACY_COMPAT_LEN(6, 5, 5, bl);
   if (struct_v >= 2)
     ::decode(stamp, bl);
   ::decode(metablob, bl);
@@ -2435,6 +2434,8 @@ void ESubtreeMap::decode(bufferlist::iterator &bl)
     ::decode(ambiguous_subtrees, bl);
   if (struct_v >= 3)
     ::decode(expire_pos, bl);
+  if (struct_v >= 6)
+    ::decode(event_seq, bl);
   DECODE_FINISH(bl);
 }