Adding upstream version 16.2.11+ds.upstream/16.2.11+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

17 files changed, 1590 insertions, 0 deletions

diff --git a/src/mds/events/ECommitted.h b/src/mds/events/ECommitted.h
new file mode 100644
index 000000000..41b120813
--- /dev/null
+++ b/src/mds/events/ECommitted.h
@@ -0,0 +1,43 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_ECOMMITTED_H
+#define CEPH_MDS_ECOMMITTED_H
+
+#include "../LogEvent.h"
+#include "EMetaBlob.h"
+
+class ECommitted : public LogEvent {
+public:
+  metareqid_t reqid;
+
+  ECommitted() : LogEvent(EVENT_COMMITTED) { }
+  explicit ECommitted(metareqid_t r) :
+    LogEvent(EVENT_COMMITTED), reqid(r) { }
+
+  void print(ostream& out) const override {
+    out << "ECommitted " << reqid;
+  }
+
+  void encode(bufferlist &bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator &bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<ECommitted*>& ls);
+
+  void update_segment() override {}
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(ECommitted)
+
+#endif
diff --git a/src/mds/events/EExport.h b/src/mds/events/EExport.h
new file mode 100644
index 000000000..589062db2
--- /dev/null
+++ b/src/mds/events/EExport.h
@@ -0,0 +1,58 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_EEXPORT_H
+#define CEPH_EEXPORT_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+#include "../MDSRank.h"
+
+#include "EMetaBlob.h"
+#include "../LogEvent.h"
+
+class EExport : public LogEvent {
+public:
+  EMetaBlob metablob; // exported dir
+protected:
+  dirfrag_t      base;
+  set<dirfrag_t> bounds;
+  mds_rank_t target;
+  
+public:
+  EExport() :
+    LogEvent(EVENT_EXPORT), target(MDS_RANK_NONE) { }
+  EExport(MDLog *mdlog, CDir *dir, mds_rank_t t) :
+    LogEvent(EVENT_EXPORT),
+    base(dir->dirfrag()), target(t) { }
+  
+  set<dirfrag_t> &get_bounds() { return bounds; }
+  
+  void print(ostream& out) const override {
+    out << "EExport " << base << " to mds." << target << " " << metablob;
+  }
+
+  EMetaBlob *get_metablob() override { return &metablob; }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator &bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EExport*>& ls);
+  void replay(MDSRank *mds) override;
+
+};
+WRITE_CLASS_ENCODER_FEATURES(EExport)
+
+#endif
diff --git a/src/mds/events/EFragment.h b/src/mds/events/EFragment.h
new file mode 100644
index 000000000..1cbbf7a8a
--- /dev/null
+++ b/src/mds/events/EFragment.h
@@ -0,0 +1,81 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_EFRAGMENT_H
+#define CEPH_MDS_EFRAGMENT_H
+
+#include "../LogEvent.h"
+#include "EMetaBlob.h"
+
+struct dirfrag_rollback {
+  CDir::fnode_const_ptr fnode;
+  dirfrag_rollback() { }
+  void encode(bufferlist& bl) const;
+  void decode(bufferlist::const_iterator& bl);
+};
+WRITE_CLASS_ENCODER(dirfrag_rollback)
+
+class EFragment : public LogEvent {
+public:
+  EMetaBlob metablob;
+  __u8 op{0};
+  inodeno_t ino;
+  frag_t basefrag;
+  __s32 bits{0};         // positive for split (from basefrag), negative for merge (to basefrag)
+  frag_vec_t orig_frags;
+  bufferlist rollback;
+
+  EFragment() : LogEvent(EVENT_FRAGMENT) { }
+  EFragment(MDLog *mdlog, int o, dirfrag_t df, int b) :
+    LogEvent(EVENT_FRAGMENT),
+    op(o), ino(df.ino), basefrag(df.frag), bits(b) { }
+
+  void print(ostream& out) const override {
+    out << "EFragment " << op_name(op) << " " << ino << " " << basefrag << " by " << bits << " " << metablob;
+  }
+
+  enum {
+    OP_PREPARE = 1,
+    OP_COMMIT = 2,
+    OP_ROLLBACK = 3,
+    OP_FINISH = 4 // finish deleting orphan dirfrags
+  };
+  static std::string_view op_name(int o) {
+    switch (o) {
+    case OP_PREPARE: return "prepare";
+    case OP_COMMIT: return "commit";
+    case OP_ROLLBACK: return "rollback";
+    case OP_FINISH: return "finish";
+    default: return "???";
+    }
+  }
+
+  void add_orig_frag(frag_t df, dirfrag_rollback *drb=NULL) {
+    using ceph::encode;
+    orig_frags.push_back(df);
+    if (drb)
+      encode(*drb, rollback);
+  }
+
+  EMetaBlob *get_metablob() override { return &metablob; }
+
+  void encode(bufferlist &bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator &bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EFragment*>& ls);
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(EFragment)
+
+#endif
diff --git a/src/mds/events/EImportFinish.h b/src/mds/events/EImportFinish.h
new file mode 100644
index 000000000..24bb1cd13
--- /dev/null
+++ b/src/mds/events/EImportFinish.h
@@ -0,0 +1,53 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_EIMPORTFINISH_H
+#define CEPH_EIMPORTFINISH_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+#include "../MDSRank.h"
+#include "../LogEvent.h"
+
+class EImportFinish : public LogEvent {
+ protected:
+  dirfrag_t base; // imported dir
+  bool success;
+
+ public:
+  EImportFinish(CDir *dir, bool s) : LogEvent(EVENT_IMPORTFINISH), 
+				     base(dir->dirfrag()),
+				     success(s) { }
+  EImportFinish() : LogEvent(EVENT_IMPORTFINISH), base(), success(false) { }
+  
+  void print(ostream& out) const override {
+    out << "EImportFinish " << base;
+    if (success)
+      out << " success";
+    else
+      out << " failed";
+  }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator &bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EImportFinish*>& ls);
+  
+  void replay(MDSRank *mds) override;
+
+};
+WRITE_CLASS_ENCODER_FEATURES(EImportFinish)
+
+#endif
diff --git a/src/mds/events/EImportStart.h b/src/mds/events/EImportStart.h
new file mode 100644
index 000000000..d4673a84a
--- /dev/null
+++ b/src/mds/events/EImportStart.h
@@ -0,0 +1,61 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_EIMPORTSTART_H
+#define CEPH_EIMPORTSTART_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+class MDLog;
+class MDSRank;
+
+#include "EMetaBlob.h"
+#include "../LogEvent.h"
+
+class EImportStart : public LogEvent {
+protected:
+  dirfrag_t base;
+  vector<dirfrag_t> bounds;
+  mds_rank_t from;
+
+public:
+  EMetaBlob metablob;
+  bufferlist client_map;  // encoded map<__u32,entity_inst_t>
+  version_t cmapv{0};
+
+  EImportStart(MDLog *log, dirfrag_t di, const vector<dirfrag_t>& b, mds_rank_t f) :
+    LogEvent(EVENT_IMPORTSTART),
+    base(di), bounds(b), from(f) { }
+  EImportStart() :
+    LogEvent(EVENT_IMPORTSTART), from(MDS_RANK_NONE) { }
+  
+  void print(ostream& out) const override {
+    out << "EImportStart " << base << " from mds." << from << " " << metablob;
+  }
+
+  EMetaBlob *get_metablob() override { return &metablob; }
+  
+  void encode(bufferlist &bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator &bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EImportStart*>& ls);
+  
+  void update_segment() override;
+  void replay(MDSRank *mds) override;
+
+};
+WRITE_CLASS_ENCODER_FEATURES(EImportStart)
+
+#endif
diff --git a/src/mds/events/EMetaBlob.h b/src/mds/events/EMetaBlob.h
new file mode 100644
index 000000000..d555627a3
--- /dev/null
+++ b/src/mds/events/EMetaBlob.h
@@ -0,0 +1,613 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_EMETABLOB_H
+#define CEPH_MDS_EMETABLOB_H
+
+#include <string_view>
+
+#include "../CInode.h"
+#include "../CDir.h"
+#include "../CDentry.h"
+#include "../LogSegment.h"
+
+#include "include/interval_set.h"
+#include "common/strescape.h"
+
+class MDSRank;
+class MDLog;
+class LogSegment;
+struct MDPeerUpdate;
+
+/*
+ * a bunch of metadata in the journal
+ */
+
+/* notes:
+ *
+ * - make sure you adjust the inode.version for any modified inode you
+ *   journal.  CDir and CDentry maintain a projected_version, but CInode
+ *   doesn't, since the journaled inode usually has to be modified 
+ *   manually anyway (to delay the change in the MDS's cache until after
+ *   it is journaled).
+ *
+ */
+
+
+class EMetaBlob {
+
+public:
+  /* fullbit - a regular dentry + inode
+   *
+   * We encode this one a bit weirdly, just because (also, it's marginally faster
+   * on multiple encodes, which I think can happen):
+   * Encode a bufferlist on struct creation with all data members, without a struct_v.
+   * When encode is called, encode struct_v and then append the bufferlist.
+   * Decode straight into the appropriate variables.
+   *
+   * So, if you add members, encode them in the constructor and then change
+   * the struct_v in the encode function!
+   */
+  struct fullbit {
+    static const int STATE_DIRTY =	 (1<<0);
+    static const int STATE_DIRTYPARENT = (1<<1);
+    static const int STATE_DIRTYPOOL   = (1<<2);
+    static const int STATE_NEED_SNAPFLUSH = (1<<3);
+    static const int STATE_EPHEMERAL_RANDOM = (1<<4);
+    std::string  dn;         // dentry
+    std::string alternate_name;
+    snapid_t dnfirst, dnlast;
+    version_t dnv{0};
+    CInode::inode_const_ptr inode;      // if it's not XXX should not be part of mempool; wait for std::pmr to simplify
+    CInode::xattr_map_const_ptr xattrs;
+    fragtree_t dirfragtree;
+    std::string symlink;
+    snapid_t oldest_snap;
+    bufferlist snapbl;
+    __u8 state{0};
+    CInode::old_inode_map_const_ptr old_inodes; // XXX should not be part of mempool; wait for std::pmr to simplify
+
+    fullbit(std::string_view d, std::string_view an, snapid_t df, snapid_t dl,
+	    version_t v, const CInode::inode_const_ptr& i, const fragtree_t &dft,
+	    const CInode::xattr_map_const_ptr& xa, std::string_view sym,
+	    snapid_t os, const bufferlist &sbl, __u8 st,
+	    const CInode::old_inode_map_const_ptr& oi) :
+      dn(d), alternate_name(an), dnfirst(df), dnlast(dl), dnv(v), inode(i), xattrs(xa),
+      oldest_snap(os), state(st), old_inodes(oi)
+    {
+      if (i->is_symlink())
+	symlink = sym;
+      if (i->is_dir())
+	dirfragtree = dft;
+      snapbl = sbl;
+    }
+    explicit fullbit(bufferlist::const_iterator &p) {
+      decode(p);
+    }
+    fullbit() = default;
+    fullbit(const fullbit&) = delete;
+    ~fullbit() {}
+    fullbit& operator=(const fullbit&) = delete;
+
+    void encode(bufferlist& bl, uint64_t features) const;
+    void decode(bufferlist::const_iterator &bl);
+    void dump(Formatter *f) const;
+    static void generate_test_instances(std::list<EMetaBlob::fullbit*>& ls);
+
+    void update_inode(MDSRank *mds, CInode *in);
+    bool is_dirty() const { return (state & STATE_DIRTY); }
+    bool is_dirty_parent() const { return (state & STATE_DIRTYPARENT); }
+    bool is_dirty_pool() const { return (state & STATE_DIRTYPOOL); }
+    bool need_snapflush() const { return (state & STATE_NEED_SNAPFLUSH); }
+    bool is_export_ephemeral_random() const { return (state & STATE_EPHEMERAL_RANDOM); }
+
+    void print(ostream& out) const {
+      out << " fullbit dn " << dn << " [" << dnfirst << "," << dnlast << "] dnv " << dnv
+	  << " inode " << inode->ino
+	  << " state=" << state;
+      if (!alternate_name.empty()) {
+          out << " altn " << binstrprint(alternate_name, 8);
+      }
+      out << std::endl;
+    }
+    string state_string() const {
+      string state_string;
+      bool marked_already = false;
+      if (is_dirty()) {
+	state_string.append("dirty");
+	marked_already = true;
+      }
+      if (is_dirty_parent()) {
+	state_string.append(marked_already ? "+dirty_parent" : "dirty_parent");
+	if (is_dirty_pool())
+	  state_string.append("+dirty_pool");
+      }
+      return state_string;
+    }
+  };
+  WRITE_CLASS_ENCODER_FEATURES(fullbit)
+  
+  /* remotebit - a dentry + remote inode link (i.e. just an ino)
+   */
+  struct remotebit {
+    std::string dn;
+    std::string alternate_name;
+    snapid_t dnfirst = 0, dnlast = 0;
+    version_t dnv = 0;
+    inodeno_t ino = 0;
+    unsigned char d_type = '\0';
+    bool dirty = false;
+
+    remotebit(std::string_view d, std::string_view an, snapid_t df, snapid_t dl, version_t v, inodeno_t i, unsigned char dt, bool dr) : 
+      dn(d), alternate_name(an), dnfirst(df), dnlast(dl), dnv(v), ino(i), d_type(dt), dirty(dr) { }
+    explicit remotebit(bufferlist::const_iterator &p) { decode(p); }
+    remotebit() = default;
+
+    void encode(bufferlist& bl) const;
+    void decode(bufferlist::const_iterator &bl);
+    void print(ostream& out) const {
+      out << " remotebit dn " << dn << " [" << dnfirst << "," << dnlast << "] dnv " << dnv
+	  << " ino " << ino
+	  << " dirty=" << dirty;
+      if (!alternate_name.empty()) {
+        out << " altn " << binstrprint(alternate_name, 8);
+      }
+      out << std::endl;
+    }
+    void dump(Formatter *f) const;
+    static void generate_test_instances(std::list<remotebit*>& ls);
+  };
+  WRITE_CLASS_ENCODER(remotebit)
+
+  /*
+   * nullbit - a null dentry
+   */
+  struct nullbit {
+    std::string dn;
+    snapid_t dnfirst, dnlast;
+    version_t dnv;
+    bool dirty;
+
+    nullbit(std::string_view d, snapid_t df, snapid_t dl, version_t v, bool dr) :
+      dn(d), dnfirst(df), dnlast(dl), dnv(v), dirty(dr) { }
+    explicit nullbit(bufferlist::const_iterator &p) { decode(p); }
+    nullbit(): dnfirst(0), dnlast(0), dnv(0), dirty(false) {}
+
+    void encode(bufferlist& bl) const;
+    void decode(bufferlist::const_iterator &bl);
+    void dump(Formatter *f) const;
+    static void generate_test_instances(std::list<nullbit*>& ls);
+    void print(ostream& out) const {
+      out << " nullbit dn " << dn << " [" << dnfirst << "," << dnlast << "] dnv " << dnv
+	  << " dirty=" << dirty << std::endl;
+    }
+  };
+  WRITE_CLASS_ENCODER(nullbit)
+
+
+  /* dirlump - contains metadata for any dir we have contents for.
+   */
+public:
+  struct dirlump {
+    static const int STATE_COMPLETE =    (1<<1);
+    static const int STATE_DIRTY =       (1<<2);  // dirty due to THIS journal item, that is!
+    static const int STATE_NEW =         (1<<3);  // new directory
+    static const int STATE_IMPORTING =	 (1<<4);  // importing directory
+    static const int STATE_DIRTYDFT =	 (1<<5);  // dirty dirfragtree
+
+    //version_t  dirv;
+    CDir::fnode_const_ptr fnode;
+    __u32 state;
+    __u32 nfull, nremote, nnull;
+
+  private:
+    mutable bufferlist dnbl;
+    mutable bool dn_decoded;
+    mutable list<fullbit> dfull;
+    mutable vector<remotebit> dremote;
+    mutable vector<nullbit> dnull;
+
+  public:
+    dirlump() : state(0), nfull(0), nremote(0), nnull(0), dn_decoded(true) { }
+    dirlump(const dirlump&) = delete;
+    dirlump& operator=(const dirlump&) = delete;
+    
+    bool is_complete() const { return state & STATE_COMPLETE; }
+    void mark_complete() { state |= STATE_COMPLETE; }
+    bool is_dirty() const { return state & STATE_DIRTY; }
+    void mark_dirty() { state |= STATE_DIRTY; }
+    bool is_new() const { return state & STATE_NEW; }
+    void mark_new() { state |= STATE_NEW; }
+    bool is_importing() { return state & STATE_IMPORTING; }
+    void mark_importing() { state |= STATE_IMPORTING; }
+    bool is_dirty_dft() { return state & STATE_DIRTYDFT; }
+    void mark_dirty_dft() { state |= STATE_DIRTYDFT; }
+
+    const list<fullbit>			&get_dfull() const { return dfull; }
+    list<fullbit>			&_get_dfull() { return dfull; }
+    const vector<remotebit>		&get_dremote() const { return dremote; }
+    const vector<nullbit>		&get_dnull() const { return dnull; }
+
+    template< class... Args>
+    void add_dfull(Args&&... args) {
+      dfull.emplace_back(std::forward<Args>(args)...);
+    }
+    template< class... Args>
+    void add_dremote(Args&&... args) {
+      dremote.emplace_back(std::forward<Args>(args)...);
+    }
+    template< class... Args>
+    void add_dnull(Args&&... args) {
+      dnull.emplace_back(std::forward<Args>(args)...);
+    }
+
+    void print(dirfrag_t dirfrag, ostream& out) const {
+      out << "dirlump " << dirfrag << " v " << fnode->version
+	  << " state " << state
+	  << " num " << nfull << "/" << nremote << "/" << nnull
+	  << std::endl;
+      _decode_bits();
+      for (const auto& p : dfull)
+	p.print(out);
+      for (const auto& p : dremote)
+	p.print(out);
+      for (const auto& p : dnull)
+	p.print(out);
+    }
+
+    string state_string() const {
+      string state_string;
+      bool marked_already = false;
+      if (is_complete()) {
+	state_string.append("complete");
+	marked_already = true;
+      }
+      if (is_dirty()) {
+	state_string.append(marked_already ? "+dirty" : "dirty");
+	marked_already = true;
+      }
+      if (is_new()) {
+	state_string.append(marked_already ? "+new" : "new");
+      }
+      return state_string;
+    }
+
+    // if this changes, update the versioning in encode for it!
+    void _encode_bits(uint64_t features) const {
+      using ceph::encode;
+      if (!dn_decoded) return;
+      encode(dfull, dnbl, features);
+      encode(dremote, dnbl);
+      encode(dnull, dnbl);
+    }
+    void _decode_bits() const { 
+      using ceph::decode;
+      if (dn_decoded) return;
+      auto p = dnbl.cbegin();
+      decode(dfull, p);
+      decode(dremote, p);
+      decode(dnull, p);
+      dn_decoded = true;
+    }
+
+    void encode(bufferlist& bl, uint64_t features) const;
+    void decode(bufferlist::const_iterator &bl);
+    void dump(Formatter *f) const;
+    static void generate_test_instances(std::list<dirlump*>& ls);
+  };
+  WRITE_CLASS_ENCODER_FEATURES(dirlump)
+
+  // my lumps.  preserve the order we added them in a list.
+  vector<dirfrag_t>         lump_order;
+  map<dirfrag_t, dirlump> lump_map;
+  list<fullbit> roots;
+public:
+  vector<pair<__u8,version_t> > table_tids;  // tableclient transactions
+
+  inodeno_t opened_ino;
+public:
+  inodeno_t renamed_dirino;
+  vector<frag_t> renamed_dir_frags;
+private:
+  
+  // ino (pre)allocation.  may involve both inotable AND session state.
+  version_t inotablev, sessionmapv;
+  inodeno_t allocated_ino;            // inotable
+  interval_set<inodeno_t> preallocated_inos; // inotable + session
+  inodeno_t used_preallocated_ino;    //            session
+  entity_name_t client_name;          //            session
+
+  // inodes i've truncated
+  vector<inodeno_t> truncate_start;        // start truncate
+  map<inodeno_t, LogSegment::seq_t> truncate_finish;  // finished truncate (started in segment blah)
+
+public:
+  vector<inodeno_t> destroyed_inodes;
+private:
+
+  // idempotent op(s)
+  vector<pair<metareqid_t,uint64_t> > client_reqs;
+  vector<pair<metareqid_t,uint64_t> > client_flushes;
+
+ public:
+  void encode(bufferlist& bl, uint64_t features) const;
+  void decode(bufferlist::const_iterator& bl);
+  void get_inodes(std::set<inodeno_t> &inodes) const;
+  void get_paths(std::vector<std::string> &paths) const;
+  void get_dentries(std::map<dirfrag_t, std::set<std::string> > &dentries) const;
+  entity_name_t get_client_name() const {return client_name;}
+
+  void dump(Formatter *f) const;
+  static void generate_test_instances(std::list<EMetaBlob*>& ls);
+  // soft stateadd
+  uint64_t last_subtree_map;
+  uint64_t event_seq;
+
+  // for replay, in certain cases
+  //LogSegment *_segment;
+
+  EMetaBlob() : opened_ino(0), renamed_dirino(0),
+                inotablev(0), sessionmapv(0), allocated_ino(0),
+                last_subtree_map(0), event_seq(0)
+                {}
+  EMetaBlob(const EMetaBlob&) = delete;
+  ~EMetaBlob() { }
+  EMetaBlob& operator=(const EMetaBlob&) = delete;
+
+  void print(ostream& out) {
+    for (const auto &p : lump_order)
+      lump_map[p].print(p, out);
+  }
+
+  void add_client_req(metareqid_t r, uint64_t tid=0) {
+    client_reqs.push_back(pair<metareqid_t,uint64_t>(r, tid));
+  }
+  void add_client_flush(metareqid_t r, uint64_t tid=0) {
+    client_flushes.push_back(pair<metareqid_t,uint64_t>(r, tid));
+  }
+
+  void add_table_transaction(int table, version_t tid) {
+    table_tids.push_back(pair<__u8, version_t>(table, tid));
+  }
+
+  void add_opened_ino(inodeno_t ino) {
+    ceph_assert(!opened_ino);
+    opened_ino = ino;
+  }
+
+  void set_ino_alloc(inodeno_t alloc,
+		     inodeno_t used_prealloc,
+		     interval_set<inodeno_t>& prealloc,
+		     entity_name_t client,
+		     version_t sv, version_t iv) {
+    allocated_ino = alloc;
+    used_preallocated_ino = used_prealloc;
+    preallocated_inos = prealloc;
+    client_name = client;
+    sessionmapv = sv;
+    inotablev = iv;
+  }
+
+  void add_truncate_start(inodeno_t ino) {
+    truncate_start.push_back(ino);
+  }
+  void add_truncate_finish(inodeno_t ino, uint64_t segoff) {
+    truncate_finish[ino] = segoff;
+  }
+  
+  bool rewrite_truncate_finish(MDSRank const *mds, std::map<uint64_t, uint64_t> const &old_to_new);
+
+  void add_destroyed_inode(inodeno_t ino) {
+    destroyed_inodes.push_back(ino);
+  }
+  
+  void add_null_dentry(CDentry *dn, bool dirty) {
+    add_null_dentry(add_dir(dn->get_dir(), false), dn, dirty);
+  }
+  void add_null_dentry(dirlump& lump, CDentry *dn, bool dirty) {
+    // add the dir
+    lump.nnull++;
+    lump.add_dnull(dn->get_name(), dn->first, dn->last,
+		   dn->get_projected_version(), dirty);
+  }
+
+  void add_remote_dentry(CDentry *dn, bool dirty) {
+    add_remote_dentry(add_dir(dn->get_dir(), false), dn, dirty, 0, 0);
+  }
+  void add_remote_dentry(CDentry *dn, bool dirty, inodeno_t rino, int rdt) {
+    add_remote_dentry(add_dir(dn->get_dir(), false), dn, dirty, rino, rdt);
+  }
+  void add_remote_dentry(dirlump& lump, CDentry *dn, bool dirty, 
+			 inodeno_t rino=0, unsigned char rdt=0) {
+    if (!rino) {
+      rino = dn->get_projected_linkage()->get_remote_ino();
+      rdt = dn->get_projected_linkage()->get_remote_d_type();
+    }
+    lump.nremote++;
+    lump.add_dremote(dn->get_name(), dn->get_alternate_name(), dn->first, dn->last,
+		     dn->get_projected_version(), rino, rdt, dirty);
+  }
+
+  // return remote pointer to to-be-journaled inode
+  void add_primary_dentry(CDentry *dn, CInode *in, bool dirty,
+			  bool dirty_parent=false, bool dirty_pool=false,
+			  bool need_snapflush=false) {
+    __u8 state = 0;
+    if (dirty) state |= fullbit::STATE_DIRTY;
+    if (dirty_parent) state |= fullbit::STATE_DIRTYPARENT;
+    if (dirty_pool) state |= fullbit::STATE_DIRTYPOOL;
+    if (need_snapflush) state |= fullbit::STATE_NEED_SNAPFLUSH;
+    add_primary_dentry(add_dir(dn->get_dir(), false), dn, in, state);
+  }
+  void add_primary_dentry(dirlump& lump, CDentry *dn, CInode *in, __u8 state) {
+    if (!in) 
+      in = dn->get_projected_linkage()->get_inode();
+
+    if (in->is_ephemeral_rand()) {
+      state |= fullbit::STATE_EPHEMERAL_RANDOM;
+    }
+
+    const auto& pi = in->get_projected_inode();
+    ceph_assert(pi->version > 0);
+
+    if ((state & fullbit::STATE_DIRTY) && pi->is_backtrace_updated())
+      state |= fullbit::STATE_DIRTYPARENT;
+
+    bufferlist snapbl;
+    const sr_t *sr = in->get_projected_srnode();
+    if (sr)
+      sr->encode(snapbl);
+
+    lump.nfull++;
+    lump.add_dfull(dn->get_name(), dn->get_alternate_name(), dn->first, dn->last, dn->get_projected_version(),
+		   pi, in->dirfragtree, in->get_projected_xattrs(), in->symlink,
+		   in->oldest_snap, snapbl, state, in->get_old_inodes());
+
+    // make note of where this inode was last journaled
+    in->last_journaled = event_seq;
+    //cout << "journaling " << in->inode.ino << " at " << my_offset << std::endl;
+  }
+
+  // convenience: primary or remote?  figure it out.
+  void add_dentry(CDentry *dn, bool dirty) {
+    dirlump& lump = add_dir(dn->get_dir(), false);
+    add_dentry(lump, dn, dirty, false, false);
+  }
+  void add_import_dentry(CDentry *dn) {
+    bool dirty_parent = false;
+    bool dirty_pool = false;
+    if (dn->get_linkage()->is_primary()) {
+      dirty_parent = dn->get_linkage()->get_inode()->is_dirty_parent();
+      dirty_pool = dn->get_linkage()->get_inode()->is_dirty_pool();
+    }
+    dirlump& lump = add_dir(dn->get_dir(), false);
+    add_dentry(lump, dn, dn->is_dirty(), dirty_parent, dirty_pool);
+  }
+  void add_dentry(dirlump& lump, CDentry *dn, bool dirty, bool dirty_parent, bool dirty_pool) {
+    // primary or remote
+    if (dn->get_projected_linkage()->is_remote()) {
+      add_remote_dentry(dn, dirty);
+      return;
+    } else if (dn->get_projected_linkage()->is_null()) {
+      add_null_dentry(dn, dirty);
+      return;
+    }
+    ceph_assert(dn->get_projected_linkage()->is_primary());
+    add_primary_dentry(dn, 0, dirty, dirty_parent, dirty_pool);
+  }
+
+  void add_root(bool dirty, CInode *in) {
+    in->last_journaled = event_seq;
+    //cout << "journaling " << in->inode.ino << " at " << my_offset << std::endl;
+
+    const auto& pi = in->get_projected_inode();
+    const auto& px = in->get_projected_xattrs();
+    const auto& pdft = in->dirfragtree;
+
+    bufferlist snapbl;
+    const sr_t *sr = in->get_projected_srnode();
+    if (sr)
+      sr->encode(snapbl);
+
+    for (auto p = roots.begin(); p != roots.end(); ++p) {
+      if (p->inode->ino == in->ino()) {
+	roots.erase(p);
+	break;
+      }
+    }
+
+    string empty;
+    roots.emplace_back(empty, "", in->first, in->last, 0, pi, pdft, px, in->symlink,
+		       in->oldest_snap, snapbl, (dirty ? fullbit::STATE_DIRTY : 0),
+		       in->get_old_inodes());
+  }
+  
+  dirlump& add_dir(CDir *dir, bool dirty, bool complete=false) {
+    return add_dir(dir->dirfrag(), dir->get_projected_fnode(),
+		   dirty, complete);
+  }
+  dirlump& add_new_dir(CDir *dir) {
+    return add_dir(dir->dirfrag(), dir->get_projected_fnode(),
+		   true, true, true); // dirty AND complete AND new
+  }
+  dirlump& add_import_dir(CDir *dir) {
+    // dirty=false would be okay in some cases
+    return add_dir(dir->dirfrag(), dir->get_projected_fnode(),
+		   dir->is_dirty(), dir->is_complete(), false, true, dir->is_dirty_dft());
+  }
+  dirlump& add_fragmented_dir(CDir *dir, bool dirty, bool dirtydft) {
+    return add_dir(dir->dirfrag(), dir->get_projected_fnode(),
+		   dirty, false, false, false, dirtydft);
+  }
+  dirlump& add_dir(dirfrag_t df, const CDir::fnode_const_ptr& pf, bool dirty,
+		   bool complete=false, bool isnew=false,
+		   bool importing=false, bool dirty_dft=false) {
+    if (lump_map.count(df) == 0)
+      lump_order.push_back(df);
+
+    dirlump& l = lump_map[df];
+    l.fnode = pf;
+    if (complete) l.mark_complete();
+    if (dirty) l.mark_dirty();
+    if (isnew) l.mark_new();
+    if (importing) l.mark_importing();
+    if (dirty_dft) l.mark_dirty_dft();
+    return l;
+  }
+  
+  static const int TO_AUTH_SUBTREE_ROOT = 0;  // default.
+  static const int TO_ROOT = 1;
+  
+  void add_dir_context(CDir *dir, int mode = TO_AUTH_SUBTREE_ROOT);
+
+  bool empty() {
+    return roots.empty() && lump_order.empty() && table_tids.empty() &&
+	   truncate_start.empty() && truncate_finish.empty() &&
+	   destroyed_inodes.empty() && client_reqs.empty() &&
+	   opened_ino == 0 && inotablev == 0 && sessionmapv == 0;
+  }
+
+  void print(ostream& out) const {
+    out << "[metablob";
+    if (!lump_order.empty()) 
+      out << " " << lump_order.front() << ", " << lump_map.size() << " dirs";
+    if (!table_tids.empty())
+      out << " table_tids=" << table_tids;
+    if (allocated_ino || preallocated_inos.size()) {
+      if (allocated_ino)
+	out << " alloc_ino=" << allocated_ino;
+      if (preallocated_inos.size())
+	out << " prealloc_ino=" << preallocated_inos;
+      if (used_preallocated_ino)
+	out << " used_prealloc_ino=" << used_preallocated_ino;
+      out << " v" << inotablev;
+    }
+    out << "]";
+  }
+
+  void update_segment(LogSegment *ls);
+  void replay(MDSRank *mds, LogSegment *ls, MDPeerUpdate *su=NULL);
+};
+WRITE_CLASS_ENCODER_FEATURES(EMetaBlob)
+WRITE_CLASS_ENCODER_FEATURES(EMetaBlob::fullbit)
+WRITE_CLASS_ENCODER(EMetaBlob::remotebit)
+WRITE_CLASS_ENCODER(EMetaBlob::nullbit)
+WRITE_CLASS_ENCODER_FEATURES(EMetaBlob::dirlump)
+
+inline ostream& operator<<(ostream& out, const EMetaBlob& t) {
+  t.print(out);
+  return out;
+}
+
+#endif
diff --git a/src/mds/events/ENoOp.h b/src/mds/events/ENoOp.h
new file mode 100644
index 000000000..1bf5161e8
--- /dev/null
+++ b/src/mds/events/ENoOp.h
@@ -0,0 +1,35 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_ENOOP_H
+#define CEPH_MDS_ENOOP_H
+
+#include "../LogEvent.h"
+
+class ENoOp : public LogEvent {
+  uint32_t pad_size;
+
+public:
+  ENoOp() : LogEvent(EVENT_NOOP), pad_size(0) { }
+  explicit ENoOp(uint32_t size_) : LogEvent(EVENT_NOOP), pad_size(size_){ }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override {}
+
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(ENoOp)
+
+#endif
diff --git a/src/mds/events/EOpen.h b/src/mds/events/EOpen.h
new file mode 100644
index 000000000..06bfd3e88
--- /dev/null
+++ b/src/mds/events/EOpen.h
@@ -0,0 +1,61 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_EOPEN_H
+#define CEPH_MDS_EOPEN_H
+
+#include "../LogEvent.h"
+#include "EMetaBlob.h"
+
+class EOpen : public LogEvent {
+public:
+  EMetaBlob metablob;
+  vector<inodeno_t> inos;
+  vector<vinodeno_t> snap_inos;
+
+  EOpen() : LogEvent(EVENT_OPEN) { }
+  explicit EOpen(MDLog *mdlog) :
+    LogEvent(EVENT_OPEN) { }
+
+  void print(ostream& out) const override {
+    out << "EOpen " << metablob << ", " << inos.size() << " open files";
+  }
+
+  EMetaBlob *get_metablob() override { return &metablob; }
+
+  void add_clean_inode(CInode *in) {
+    if (!in->is_base()) {
+      metablob.add_dir_context(in->get_projected_parent_dn()->get_dir());
+      metablob.add_primary_dentry(in->get_projected_parent_dn(), 0, false);
+      if (in->last == CEPH_NOSNAP)
+	inos.push_back(in->ino());
+      else
+	snap_inos.push_back(in->vino());
+    }
+  }
+  void add_ino(inodeno_t ino) {
+    inos.push_back(ino);
+  }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EOpen*>& ls);
+
+  void update_segment() override;
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(EOpen)
+
+#endif
diff --git a/src/mds/events/EPeerUpdate.h b/src/mds/events/EPeerUpdate.h
new file mode 100644
index 000000000..38f53735e
--- /dev/null
+++ b/src/mds/events/EPeerUpdate.h
@@ -0,0 +1,157 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef CEPH_MDS_EPEERUPDATE_H
+#define CEPH_MDS_EPEERUPDATE_H
+
+#include <string_view>
+
+#include "../LogEvent.h"
+#include "EMetaBlob.h"
+
+/*
+ * rollback records, for remote/peer updates, which may need to be manually
+ * rolled back during journal replay.  (or while active if leader fails, but in
+ * that case these records aren't needed.)
+ */
+struct link_rollback {
+  metareqid_t reqid;
+  inodeno_t ino;
+  bool was_inc;
+  utime_t old_ctime;
+  utime_t old_dir_mtime;
+  utime_t old_dir_rctime;
+  bufferlist snapbl;
+
+  link_rollback() : ino(0), was_inc(false) {}
+
+  void encode(bufferlist& bl) const;
+  void decode(bufferlist::const_iterator& bl);
+  void dump(Formatter *f) const;
+  static void generate_test_instances(std::list<link_rollback*>& ls);
+};
+WRITE_CLASS_ENCODER(link_rollback)
+
+/*
+ * this is only used on an empty dir with a dirfrag on a remote node.
+ * we are auth for nothing.  all we need to do is relink the directory
+ * in the hierarchy properly during replay to avoid breaking the
+ * subtree map.
+ */
+struct rmdir_rollback {
+  metareqid_t reqid;
+  dirfrag_t src_dir;
+  string src_dname;
+  dirfrag_t dest_dir;
+  string dest_dname;
+  bufferlist snapbl;
+
+  void encode(bufferlist& bl) const;
+  void decode(bufferlist::const_iterator& bl);
+  void dump(Formatter *f) const;
+  static void generate_test_instances(std::list<rmdir_rollback*>& ls);
+};
+WRITE_CLASS_ENCODER(rmdir_rollback)
+
+struct rename_rollback {
+  struct drec {
+    dirfrag_t dirfrag;
+    utime_t dirfrag_old_mtime;
+    utime_t dirfrag_old_rctime;
+    inodeno_t ino, remote_ino;
+    string dname;
+    char remote_d_type;
+    utime_t old_ctime;
+
+    drec() : remote_d_type((char)S_IFREG) {}
+
+    void encode(bufferlist& bl) const;
+    void decode(bufferlist::const_iterator& bl);
+    void dump(Formatter *f) const;
+    static void generate_test_instances(std::list<drec*>& ls);
+  };
+  WRITE_CLASS_MEMBER_ENCODER(drec)
+
+  metareqid_t reqid;
+  drec orig_src, orig_dest;
+  drec stray; // we know this is null, but we want dname, old mtime/rctime
+  utime_t ctime;
+  bufferlist srci_snapbl;
+  bufferlist desti_snapbl;
+
+  void encode(bufferlist& bl) const;
+  void decode(bufferlist::const_iterator& bl);
+  void dump(Formatter *f) const;
+  static void generate_test_instances(std::list<rename_rollback*>& ls);
+};
+WRITE_CLASS_ENCODER(rename_rollback::drec)
+WRITE_CLASS_ENCODER(rename_rollback)
+
+
+class EPeerUpdate : public LogEvent {
+public:
+  const static int OP_PREPARE = 1;
+  const static int OP_COMMIT = 2;
+  const static int OP_ROLLBACK = 3;
+
+  const static int LINK = 1;
+  const static int RENAME = 2;
+  const static int RMDIR = 3;
+
+  /*
+   * we journal a rollback metablob that contains the unmodified metadata
+   * too, because we may be updating previously dirty metadata, which
+   * will allow old log segments to be trimmed.  if we end of rolling back,
+   * those updates could be lost.. so we re-journal the unmodified metadata,
+   * and replay will apply _either_ commit or rollback.
+   */
+  EMetaBlob commit;
+  bufferlist rollback;
+  string type;
+  metareqid_t reqid;
+  mds_rank_t leader;
+  __u8 op;  // prepare, commit, abort
+  __u8 origop; // link | rename
+
+  EPeerUpdate() : LogEvent(EVENT_PEERUPDATE), leader(0), op(0), origop(0) { }
+  EPeerUpdate(MDLog *mdlog, std::string_view s, metareqid_t ri, int leadermds, int o, int oo) :
+    LogEvent(EVENT_PEERUPDATE),
+    type(s),
+    reqid(ri),
+    leader(leadermds),
+    op(o), origop(oo) { }
+
+  void print(ostream& out) const override {
+    if (type.length())
+      out << type << " ";
+    out << " " << (int)op;
+    if (origop == LINK) out << " link";
+    if (origop == RENAME) out << " rename";
+    out << " " << reqid;
+    out << " for mds." << leader;
+    out << commit;
+  }
+
+  EMetaBlob *get_metablob() override { return &commit; }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EPeerUpdate*>& ls);
+
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(EPeerUpdate)
+
+#endif
diff --git a/src/mds/events/EPurged.h b/src/mds/events/EPurged.h
new file mode 100644
index 000000000..cda1b2ecf
--- /dev/null
+++ b/src/mds/events/EPurged.h
@@ -0,0 +1,46 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation.  See file COPYING.
+ *
+ */
+
+#ifndef CEPH_MDS_EPURGE_H
+#define CEPH_MDS_EPURGE_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+#include "../LogEvent.h"
+
+class EPurged : public LogEvent {
+public:
+  EPurged() : LogEvent(EVENT_PURGED) { }
+  EPurged(const interval_set<inodeno_t>& _inos, LogSegment::seq_t _seq, version_t iv)
+    : LogEvent(EVENT_PURGED), inos(_inos), seq(_seq), inotablev(iv) {
+  }
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  void print(ostream& out) const override {
+    out << "Eurged " << inos.size() << " inos, inotable v" << inotablev;
+  }
+
+  void update_segment() override;
+  void replay(MDSRank *mds) override;
+
+protected:
+  interval_set<inodeno_t> inos;
+  LogSegment::seq_t seq;
+  version_t inotablev{0};
+};
+WRITE_CLASS_ENCODER_FEATURES(EPurged)
+
+#endif // CEPH_MDS_EPURGE_H
diff --git a/src/mds/events/EResetJournal.h b/src/mds/events/EResetJournal.h
new file mode 100644
index 000000000..302227fc6
--- /dev/null
+++ b/src/mds/events/EResetJournal.h
@@ -0,0 +1,39 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+
+#ifndef CEPH_MDS_ERESETJOURNAL_H
+#define CEPH_MDS_ERESETJOURNAL_H
+
+#include "../LogEvent.h"
+
+// generic log event
+class EResetJournal : public LogEvent {
+ public:
+  EResetJournal() : LogEvent(EVENT_RESETJOURNAL) { }
+  ~EResetJournal() override {}
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EResetJournal*>& ls);
+  void print(ostream& out) const override {
+    out << "EResetJournal";
+  }
+
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(EResetJournal)
+
+#endif
diff --git a/src/mds/events/ESession.h b/src/mds/events/ESession.h
new file mode 100644
index 000000000..c6586e3b5
--- /dev/null
+++ b/src/mds/events/ESession.h
@@ -0,0 +1,71 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_ESESSION_H
+#define CEPH_MDS_ESESSION_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+#include "../LogEvent.h"
+
+class ESession : public LogEvent {
+ protected:
+  entity_inst_t client_inst;
+  bool open;    // open or close
+  version_t cmapv{0};  // client map version
+
+  interval_set<inodeno_t> inos_to_free;
+  version_t inotablev{0};
+
+  interval_set<inodeno_t> inos_to_purge;
+  
+  // Client metadata stored during open
+  client_metadata_t client_metadata;
+
+ public:
+  ESession() : LogEvent(EVENT_SESSION), open(false) { }
+  ESession(const entity_inst_t& inst, bool o, version_t v,
+	   const client_metadata_t& cm) :
+    LogEvent(EVENT_SESSION),
+    client_inst(inst), open(o), cmapv(v), inotablev(0),
+    client_metadata(cm) { }
+  ESession(const entity_inst_t& inst, bool o, version_t v,
+	   const interval_set<inodeno_t>& to_free, version_t iv,
+	   const interval_set<inodeno_t>& to_purge) :
+    LogEvent(EVENT_SESSION), client_inst(inst), open(o), cmapv(v),
+    inos_to_free(to_free), inotablev(iv), inos_to_purge(to_purge) {}
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<ESession*>& ls);
+
+  void print(ostream& out) const override {
+    if (open)
+      out << "ESession " << client_inst << " open cmapv " << cmapv;
+    else
+      out << "ESession " << client_inst << " close cmapv " << cmapv;
+    if (inos_to_free.size() || inos_to_purge.size())
+      out << " (" << inos_to_free.size() << " to free, v" << inotablev
+	  << ", " << inos_to_purge.size() << " to purge)";
+  }
+  
+  void update_segment() override;
+  void replay(MDSRank *mds) override;
+  entity_inst_t get_client_inst() const {return client_inst;}
+};
+WRITE_CLASS_ENCODER_FEATURES(ESession)
+
+#endif
diff --git a/src/mds/events/ESessions.h b/src/mds/events/ESessions.h
new file mode 100644
index 000000000..fad702120
--- /dev/null
+++ b/src/mds/events/ESessions.h
@@ -0,0 +1,61 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_ESESSIONS_H
+#define CEPH_MDS_ESESSIONS_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+#include "../LogEvent.h"
+
+class ESessions : public LogEvent {
+protected:
+  version_t cmapv;  // client map version
+  bool old_style_encode;
+
+public:
+  map<client_t,entity_inst_t> client_map;
+  map<client_t,client_metadata_t> client_metadata_map;
+
+  ESessions() : LogEvent(EVENT_SESSIONS), cmapv(0), old_style_encode(false) { }
+  ESessions(version_t pv, map<client_t,entity_inst_t>&& cm,
+	    map<client_t,client_metadata_t>&& cmm) :
+    LogEvent(EVENT_SESSIONS),
+    cmapv(pv), old_style_encode(false),
+    client_map(std::move(cm)),
+    client_metadata_map(std::move(cmm)) {}
+
+  void mark_old_encoding() { old_style_encode = true; }
+
+  void encode(bufferlist &bl, uint64_t features) const override;
+  void decode_old(bufferlist::const_iterator &bl);
+  void decode_new(bufferlist::const_iterator &bl);
+  void decode(bufferlist::const_iterator &bl) override {
+    if (old_style_encode) decode_old(bl);
+    else decode_new(bl);
+  }
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<ESessions*>& ls);
+
+  void print(ostream& out) const override {
+    out << "ESessions " << client_map.size() << " opens cmapv " << cmapv;
+  }
+  
+  void update_segment() override;
+  void replay(MDSRank *mds) override;  
+};
+WRITE_CLASS_ENCODER_FEATURES(ESessions)
+
+#endif
diff --git a/src/mds/events/ESubtreeMap.h b/src/mds/events/ESubtreeMap.h
new file mode 100644
index 000000000..3dc824087
--- /dev/null
+++ b/src/mds/events/ESubtreeMap.h
@@ -0,0 +1,48 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_ESUBTREEMAP_H
+#define CEPH_MDS_ESUBTREEMAP_H
+
+#include "../LogEvent.h"
+#include "EMetaBlob.h"
+
+class ESubtreeMap : public LogEvent {
+public:
+  EMetaBlob metablob;
+  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), event_seq(0) { }
+  
+  void print(ostream& out) const override {
+    out << "ESubtreeMap " << subtrees.size() << " subtrees " 
+	<< ", " << ambiguous_subtrees.size() << " ambiguous "
+	<< metablob;
+  }
+
+  EMetaBlob *get_metablob() override { return &metablob; }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<ESubtreeMap*>& ls);
+
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(ESubtreeMap)
+
+#endif
diff --git a/src/mds/events/ETableClient.h b/src/mds/events/ETableClient.h
new file mode 100644
index 000000000..3f6e454e6
--- /dev/null
+++ b/src/mds/events/ETableClient.h
@@ -0,0 +1,49 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_ETABLECLIENT_H
+#define CEPH_MDS_ETABLECLIENT_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+#include "../mds_table_types.h"
+#include "../LogEvent.h"
+
+struct ETableClient : public LogEvent {
+  __u16 table;
+  __s16 op;
+  version_t tid;
+
+  ETableClient() : LogEvent(EVENT_TABLECLIENT), table(0), op(0), tid(0) { }
+  ETableClient(int t, int o, version_t ti) :
+    LogEvent(EVENT_TABLECLIENT),
+    table(t), op(o), tid(ti) { }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<ETableClient*>& ls);
+
+  void print(ostream& out) const override {
+    out << "ETableClient " << get_mdstable_name(table) << " " << get_mdstableserver_opname(op);
+    if (tid) out << " tid " << tid;
+  }  
+
+  //void update_segment();
+  void replay(MDSRank *mds) override;  
+};
+WRITE_CLASS_ENCODER_FEATURES(ETableClient)
+
+#endif
diff --git a/src/mds/events/ETableServer.h b/src/mds/events/ETableServer.h
new file mode 100644
index 000000000..59fe8ff1c
--- /dev/null
+++ b/src/mds/events/ETableServer.h
@@ -0,0 +1,59 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_ETABLESERVER_H
+#define CEPH_MDS_ETABLESERVER_H
+
+#include "common/config.h"
+#include "include/types.h"
+
+#include "../mds_table_types.h"
+#include "../LogEvent.h"
+
+struct ETableServer : public LogEvent {
+  __u16 table;
+  __s16 op;
+  uint64_t reqid;
+  mds_rank_t bymds;
+  bufferlist mutation;
+  version_t tid;
+  version_t version;
+
+  ETableServer() : LogEvent(EVENT_TABLESERVER), table(0), op(0),
+		   reqid(0), bymds(MDS_RANK_NONE), tid(0), version(0) { }
+  ETableServer(int t, int o, uint64_t ri, mds_rank_t m, version_t ti, version_t v) :
+    LogEvent(EVENT_TABLESERVER),
+    table(t), op(o), reqid(ri), bymds(m), tid(ti), version(v) { }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<ETableServer*>& ls);
+
+  void print(ostream& out) const override {
+    out << "ETableServer " << get_mdstable_name(table) 
+	<< " " << get_mdstableserver_opname(op);
+    if (reqid) out << " reqid " << reqid;
+    if (bymds >= 0) out << " mds." << bymds;
+    if (tid) out << " tid " << tid;
+    if (version) out << " version " << version;
+    if (mutation.length()) out << " mutation=" << mutation.length() << " bytes";
+  }  
+
+  void update_segment() override;
+  void replay(MDSRank *mds) override;  
+};
+WRITE_CLASS_ENCODER_FEATURES(ETableServer)
+
+#endif
diff --git a/src/mds/events/EUpdate.h b/src/mds/events/EUpdate.h
new file mode 100644
index 000000000..d320014a1
--- /dev/null
+++ b/src/mds/events/EUpdate.h
@@ -0,0 +1,55 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software 
+ * Foundation.  See file COPYING.
+ * 
+ */
+
+#ifndef CEPH_MDS_EUPDATE_H
+#define CEPH_MDS_EUPDATE_H
+
+#include <string_view>
+
+#include "../LogEvent.h"
+#include "EMetaBlob.h"
+
+class EUpdate : public LogEvent {
+public:
+  EMetaBlob metablob;
+  string type;
+  bufferlist client_map;
+  version_t cmapv;
+  metareqid_t reqid;
+  bool had_peers;
+
+  EUpdate() : LogEvent(EVENT_UPDATE), cmapv(0), had_peers(false) { }
+  EUpdate(MDLog *mdlog, std::string_view s) :
+    LogEvent(EVENT_UPDATE),
+    type(s), cmapv(0), had_peers(false) { }
+  
+  void print(ostream& out) const override {
+    if (type.length())
+      out << "EUpdate " << type << " ";
+    out << metablob;
+  }
+
+  EMetaBlob *get_metablob() override { return &metablob; }
+
+  void encode(bufferlist& bl, uint64_t features) const override;
+  void decode(bufferlist::const_iterator& bl) override;
+  void dump(Formatter *f) const override;
+  static void generate_test_instances(std::list<EUpdate*>& ls);
+
+  void update_segment() override;
+  void replay(MDSRank *mds) override;
+};
+WRITE_CLASS_ENCODER_FEATURES(EUpdate)
+
+#endif