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

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

1 files changed, 788 insertions, 0 deletions

diff --git a/src/mds/CDir.h b/src/mds/CDir.h
new file mode 100644
index 000000000..4e189e273
--- /dev/null
+++ b/src/mds/CDir.h
@@ -0,0 +1,788 @@
+// -*- 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_CDIR_H
+#define CEPH_CDIR_H
+
+#include <iosfwd>
+#include <list>
+#include <map>
+#include <set>
+#include <string>
+#include <string_view>
+
+#include "common/bloom_filter.hpp"
+#include "common/config.h"
+#include "include/buffer_fwd.h"
+#include "include/counter.h"
+#include "include/types.h"
+
+#include "CInode.h"
+#include "MDSCacheObject.h"
+#include "MDSContext.h"
+#include "cephfs_features.h"
+#include "SessionMap.h"
+#include "messages/MClientReply.h"
+
+class CDentry;
+class MDCache;
+
+std::ostream& operator<<(std::ostream& out, const class CDir& dir);
+
+class CDir : public MDSCacheObject, public Counter<CDir> {
+public:
+  MEMPOOL_CLASS_HELPERS();
+
+  typedef mempool::mds_co::map<dentry_key_t, CDentry*> dentry_key_map;
+  typedef mempool::mds_co::set<dentry_key_t> dentry_key_set;
+
+  using fnode_ptr = std::shared_ptr<fnode_t>;
+  using fnode_const_ptr = std::shared_ptr<const fnode_t>;
+
+  template <typename ...Args>
+  static fnode_ptr allocate_fnode(Args && ...args) {
+    static mempool::mds_co::pool_allocator<fnode_t> allocator;
+    return std::allocate_shared<fnode_t>(allocator, std::forward<Args>(args)...);
+  }
+
+  struct dentry_commit_item {
+    string key;
+    snapid_t first;
+    bool is_remote = false;
+
+    inodeno_t ino;
+    unsigned char d_type;
+    mempool::mds_co::string alternate_name;
+
+    bool snaprealm = false;
+    sr_t srnode;
+
+    mempool::mds_co::string symlink;
+    uint64_t features;
+    uint64_t dft_len;
+    CInode::inode_const_ptr inode;
+    CInode::xattr_map_const_ptr xattrs;
+    CInode::old_inode_map_const_ptr old_inodes;
+    snapid_t oldest_snap;
+    damage_flags_t damage_flags;
+  };
+
+  // -- freezing --
+  struct freeze_tree_state_t {
+    CDir *dir; // freezing/frozen tree root
+    int auth_pins = 0;
+    bool frozen = false;
+    freeze_tree_state_t(CDir *d) : dir(d) {}
+  };
+
+  class scrub_info_t {
+  public:
+    MEMPOOL_CLASS_HELPERS();
+    struct scrub_stamps {
+      version_t version = 0;
+      utime_t time;
+    };
+
+    scrub_info_t() {}
+
+    scrub_stamps last_recursive; // when we last finished a recursive scrub
+    scrub_stamps last_local; // when we last did a local scrub
+
+    bool directory_scrubbing = false; /// safety check
+    bool last_scrub_dirty = false; /// is scrub info dirty or is it flushed to fnode?
+
+    ScrubHeaderRef header;
+  };
+
+  // -- pins --
+  static const int PIN_DNWAITER =     1;
+  static const int PIN_INOWAITER =    2;
+  static const int PIN_CHILD =        3;
+  static const int PIN_FROZEN =       4;
+  static const int PIN_SUBTREE =      5;
+  static const int PIN_IMPORTING =    7;
+  static const int PIN_IMPORTBOUND =  9;
+  static const int PIN_EXPORTBOUND = 10;
+  static const int PIN_STICKY =      11;
+  static const int PIN_SUBTREETEMP = 12;  // used by MDCache::trim_non_auth()
+
+  // -- state --
+  static const unsigned STATE_COMPLETE =      (1<< 0);  // the complete contents are in cache
+  static const unsigned STATE_FROZENTREE =    (1<< 1);  // root of tree (bounded by exports)
+  static const unsigned STATE_FREEZINGTREE =  (1<< 2);  // in process of freezing
+  static const unsigned STATE_FROZENDIR =     (1<< 3);
+  static const unsigned STATE_FREEZINGDIR =   (1<< 4);
+  static const unsigned STATE_COMMITTING =    (1<< 5);  // mid-commit
+  static const unsigned STATE_FETCHING =      (1<< 6);  // currenting fetching
+  static const unsigned STATE_CREATING =      (1<< 7);
+  static const unsigned STATE_IMPORTBOUND =   (1<< 8);
+  static const unsigned STATE_EXPORTBOUND =   (1<< 9);
+  static const unsigned STATE_EXPORTING =     (1<<10);
+  static const unsigned STATE_IMPORTING =     (1<<11);
+  static const unsigned STATE_FRAGMENTING =   (1<<12);
+  static const unsigned STATE_STICKY =        (1<<13);  // sticky pin due to inode stickydirs
+  static const unsigned STATE_DNPINNEDFRAG =  (1<<14);  // dir is refragmenting
+  static const unsigned STATE_ASSIMRSTAT =    (1<<15);  // assimilating inode->frag rstats
+  static const unsigned STATE_DIRTYDFT =      (1<<16);  // dirty dirfragtree
+  static const unsigned STATE_BADFRAG =       (1<<17);  // bad dirfrag
+  static const unsigned STATE_TRACKEDBYOFT =  (1<<18);  // tracked by open file table
+  static const unsigned STATE_AUXSUBTREE =    (1<<19);  // no subtree merge
+
+  // common states
+  static const unsigned STATE_CLEAN =  0;
+
+  // these state bits are preserved by an import/export
+  // ...except if the directory is hashed, in which case none of them are!
+  static const unsigned MASK_STATE_EXPORTED = 
+  (STATE_COMPLETE|STATE_DIRTY|STATE_DIRTYDFT|STATE_BADFRAG);
+  static const unsigned MASK_STATE_IMPORT_KEPT = 
+  (						  
+   STATE_IMPORTING |
+   STATE_IMPORTBOUND |
+   STATE_EXPORTBOUND |
+   STATE_FROZENTREE |
+   STATE_STICKY |
+   STATE_TRACKEDBYOFT);
+  static const unsigned MASK_STATE_EXPORT_KEPT = 
+  (STATE_EXPORTING |
+   STATE_IMPORTBOUND |
+   STATE_EXPORTBOUND |
+   STATE_FROZENTREE |
+   STATE_FROZENDIR |
+   STATE_STICKY |
+   STATE_TRACKEDBYOFT);
+  static const unsigned MASK_STATE_FRAGMENT_KEPT = 
+  (STATE_DIRTY |
+   STATE_EXPORTBOUND |
+   STATE_IMPORTBOUND |
+   STATE_AUXSUBTREE |
+   STATE_REJOINUNDEF);
+
+  // -- rep spec --
+  static const int REP_NONE =     0;
+  static const int REP_ALL =      1;
+  static const int REP_LIST =     2;
+
+  static const unsigned EXPORT_NONCE  = 1;
+
+  // -- wait masks --
+  static const uint64_t WAIT_DENTRY       = (1<<0);  // wait for item to be in cache
+  static const uint64_t WAIT_COMPLETE     = (1<<1);  // wait for complete dir contents
+  static const uint64_t WAIT_FROZEN       = (1<<2);  // auth pins removed
+  static const uint64_t WAIT_CREATED	  = (1<<3);  // new dirfrag is logged
+
+  static const int WAIT_DNLOCK_OFFSET = 4;
+
+  static const uint64_t WAIT_ANY_MASK = (uint64_t)(-1);
+  static const uint64_t WAIT_ATSUBTREEROOT = (WAIT_SINGLEAUTH);
+
+  // -- dump flags --
+  static const int DUMP_PATH             = (1 << 0);
+  static const int DUMP_DIRFRAG          = (1 << 1);
+  static const int DUMP_SNAPID_FIRST     = (1 << 2);
+  static const int DUMP_VERSIONS         = (1 << 3);
+  static const int DUMP_REP              = (1 << 4);
+  static const int DUMP_DIR_AUTH         = (1 << 5);
+  static const int DUMP_STATES           = (1 << 6);
+  static const int DUMP_MDS_CACHE_OBJECT = (1 << 7);
+  static const int DUMP_ITEMS            = (1 << 8);
+  static const int DUMP_ALL              = (-1);
+  static const int DUMP_DEFAULT          = DUMP_ALL & (~DUMP_ITEMS);
+
+  CDir(CInode *in, frag_t fg, MDCache *mdc, bool auth);
+
+  std::string_view pin_name(int p) const override {
+    switch (p) {
+    case PIN_DNWAITER: return "dnwaiter";
+    case PIN_INOWAITER: return "inowaiter";
+    case PIN_CHILD: return "child";
+    case PIN_FROZEN: return "frozen";
+    case PIN_SUBTREE: return "subtree";
+    case PIN_IMPORTING: return "importing";
+    case PIN_IMPORTBOUND: return "importbound";
+    case PIN_EXPORTBOUND: return "exportbound";
+    case PIN_STICKY: return "sticky";
+    case PIN_SUBTREETEMP: return "subtreetemp";
+    default: return generic_pin_name(p);
+    }
+  }
+
+  bool is_lt(const MDSCacheObject *r) const override {
+    return dirfrag() < (static_cast<const CDir*>(r))->dirfrag();
+  }
+
+  void resync_accounted_fragstat();
+  void resync_accounted_rstat();
+  void assimilate_dirty_rstat_inodes(MutationRef& mut);
+  void assimilate_dirty_rstat_inodes_finish(EMetaBlob *blob);
+
+  void mark_exporting() {
+    state_set(CDir::STATE_EXPORTING);
+    inode->num_exporting_dirs++;
+  }
+  void clear_exporting() {
+    state_clear(CDir::STATE_EXPORTING);
+    inode->num_exporting_dirs--;
+  }
+
+  version_t get_version() const { return fnode->version; }
+  void update_projected_version() {
+    ceph_assert(projected_fnode.empty());
+    projected_version = fnode->version;
+  }
+  version_t get_projected_version() const { return projected_version; }
+
+  void reset_fnode(fnode_const_ptr&& ptr) {
+    fnode = std::move(ptr);
+  }
+  void set_fresh_fnode(fnode_const_ptr&& ptr);
+
+  const fnode_const_ptr& get_fnode() const {
+    return fnode;
+  }
+
+  // only used for updating newly allocated CDir
+  fnode_t* _get_fnode() {
+    if (fnode == empty_fnode)
+      reset_fnode(allocate_fnode());
+    return const_cast<fnode_t*>(fnode.get());
+  }
+
+  const fnode_const_ptr& get_projected_fnode() const {
+    if (projected_fnode.empty())
+      return fnode;
+    else
+      return projected_fnode.back();
+  }
+
+  // fnode should have already been projected in caller's context
+  fnode_t* _get_projected_fnode() {
+    ceph_assert(!projected_fnode.empty());
+    return const_cast<fnode_t*>(projected_fnode.back().get());
+  }
+
+  fnode_ptr project_fnode(const MutationRef& mut);
+
+  void pop_and_dirty_projected_fnode(LogSegment *ls, const MutationRef& mut);
+  bool is_projected() const { return !projected_fnode.empty(); }
+  version_t pre_dirty(version_t min=0);
+  void _mark_dirty(LogSegment *ls);
+  void _set_dirty_flag() {
+    if (!state_test(STATE_DIRTY)) {
+      state_set(STATE_DIRTY);
+      get(PIN_DIRTY);
+    }
+  }
+  void mark_dirty(LogSegment *ls, version_t pv=0);
+  void mark_clean();
+
+  bool is_new() { return item_new.is_on_list(); }
+  void mark_new(LogSegment *ls);
+
+  bool is_bad() { return state_test(STATE_BADFRAG); }
+
+  /**
+   * Call to start this CDir on a new scrub.
+   * @pre It is not currently scrubbing
+   * @pre The CDir is marked complete.
+   * @post It has set up its internal scrubbing state.
+   */
+  void scrub_initialize(const ScrubHeaderRef& header);
+  const ScrubHeaderRef& get_scrub_header() {
+    static const ScrubHeaderRef nullref;
+    return scrub_infop ? scrub_infop->header : nullref;
+  }
+
+  bool scrub_is_in_progress() const {
+    return (scrub_infop && scrub_infop->directory_scrubbing);
+  }
+
+  /**
+   * Call this once all CDentries have been scrubbed, according to
+   * scrub_dentry_next's listing. It finalizes the scrub statistics.
+   */
+  void scrub_finished();
+
+  void scrub_aborted();
+  /**
+   * Tell the CDir to do a local scrub of itself.
+   * @pre The CDir is_complete().
+   * @returns true if the rstats and directory contents match, false otherwise.
+   */
+  bool scrub_local();
+
+  const scrub_info_t *scrub_info() const {
+    if (!scrub_infop)
+      scrub_info_create();
+    return scrub_infop.get();
+  }
+
+  // -- accessors --
+  inodeno_t ino()     const { return inode->ino(); }          // deprecate me?
+  frag_t    get_frag()    const { return frag; }
+  dirfrag_t dirfrag() const { return dirfrag_t(inode->ino(), frag); }
+
+  CInode *get_inode()    { return inode; }
+  const CInode *get_inode() const { return inode; }
+  CDir *get_parent_dir() { return inode->get_parent_dir(); }
+
+  dentry_key_map::iterator begin() { return items.begin(); }
+  dentry_key_map::iterator end() { return items.end(); }
+  dentry_key_map::iterator lower_bound(dentry_key_t key) { return items.lower_bound(key); }
+
+  unsigned get_num_head_items() const { return num_head_items; }
+  unsigned get_num_head_null() const { return num_head_null; }
+  unsigned get_num_snap_items() const { return num_snap_items; }
+  unsigned get_num_snap_null() const { return num_snap_null; }
+  unsigned get_num_any() const { return num_head_items + num_head_null + num_snap_items + num_snap_null; }
+  
+  bool check_rstats(bool scrub=false);
+
+  void inc_num_dirty() { num_dirty++; }
+  void dec_num_dirty() { 
+    ceph_assert(num_dirty > 0);
+    num_dirty--; 
+  }
+  int get_num_dirty() const {
+    return num_dirty;
+  }
+
+  void adjust_num_inodes_with_caps(int d);
+
+  int64_t get_frag_size() const {
+    return get_projected_fnode()->fragstat.size();
+  }
+
+  // -- dentries and inodes --
+  CDentry* lookup_exact_snap(std::string_view dname, snapid_t last);
+  CDentry* lookup(std::string_view n, snapid_t snap=CEPH_NOSNAP);
+
+  CDentry* add_null_dentry(std::string_view dname,
+			   snapid_t first=2, snapid_t last=CEPH_NOSNAP);
+  CDentry* add_primary_dentry(std::string_view dname, CInode *in, mempool::mds_co::string alternate_name,
+			      snapid_t first=2, snapid_t last=CEPH_NOSNAP);
+  CDentry* add_remote_dentry(std::string_view dname, inodeno_t ino, unsigned char d_type,
+                             mempool::mds_co::string alternate_name,
+			     snapid_t first=2, snapid_t last=CEPH_NOSNAP);
+  void remove_dentry( CDentry *dn );         // delete dentry
+  void link_remote_inode( CDentry *dn, inodeno_t ino, unsigned char d_type);
+  void link_remote_inode( CDentry *dn, CInode *in );
+  void link_primary_inode( CDentry *dn, CInode *in );
+  void unlink_inode(CDentry *dn, bool adjust_lru=true);
+  void try_remove_unlinked_dn(CDentry *dn);
+
+  void add_to_bloom(CDentry *dn);
+  bool is_in_bloom(std::string_view name);
+  bool has_bloom() { return (bloom ? true : false); }
+  void remove_bloom() {
+    bloom.reset();
+  }
+
+  void try_remove_dentries_for_stray();
+  bool try_trim_snap_dentry(CDentry *dn, const std::set<snapid_t>& snaps);
+
+  void split(int bits, std::vector<CDir*>* subs, MDSContext::vec& waiters, bool replay);
+  void merge(const std::vector<CDir*>& subs, MDSContext::vec& waiters, bool replay);
+
+  bool should_split() const {
+    return g_conf()->mds_bal_split_size > 0 &&
+           (int)get_frag_size() > g_conf()->mds_bal_split_size;
+  }
+  bool should_split_fast() const;
+  bool should_merge() const;
+
+  mds_authority_t authority() const override;
+  mds_authority_t get_dir_auth() const { return dir_auth; }
+  void set_dir_auth(const mds_authority_t &a);
+  void set_dir_auth(mds_rank_t a) { set_dir_auth(mds_authority_t(a, CDIR_AUTH_UNKNOWN)); }
+  bool is_ambiguous_dir_auth() const {
+    return dir_auth.second != CDIR_AUTH_UNKNOWN;
+  }
+  bool is_full_dir_auth() const {
+    return is_auth() && !is_ambiguous_dir_auth();
+  }
+  bool is_full_dir_nonauth() const {
+    return !is_auth() && !is_ambiguous_dir_auth();
+  }
+  
+  bool is_subtree_root() const {
+    return dir_auth != CDIR_AUTH_DEFAULT;
+  }
+
+  bool contains(CDir *x);  // true if we are x or an ancestor of x 
+
+  // for giving to clients
+  void get_dist_spec(std::set<mds_rank_t>& ls, mds_rank_t auth) {
+    if (is_auth()) {
+      list_replicas(ls);
+      if (!ls.empty()) 
+	ls.insert(auth);
+    }
+  }
+
+  static void encode_dirstat(ceph::buffer::list& bl, const session_info_t& info, const DirStat& ds);
+
+  void _encode_base(ceph::buffer::list& bl) {
+    ENCODE_START(1, 1, bl);
+    encode(first, bl);
+    encode(*fnode, bl);
+    encode(dir_rep, bl);
+    encode(dir_rep_by, bl);
+    ENCODE_FINISH(bl);
+  }
+  void _decode_base(ceph::buffer::list::const_iterator& p) {
+    DECODE_START(1, p);
+    decode(first, p);
+    {
+      auto _fnode = allocate_fnode();
+      decode(*_fnode, p);
+      reset_fnode(std::move(_fnode));
+    }
+    decode(dir_rep, p);
+    decode(dir_rep_by, p);
+    DECODE_FINISH(p);
+  }
+
+  // -- state --
+  bool is_complete() { return state & STATE_COMPLETE; }
+  bool is_exporting() { return state & STATE_EXPORTING; }
+  bool is_importing() { return state & STATE_IMPORTING; }
+  bool is_dirty_dft() { return state & STATE_DIRTYDFT; }
+
+  int get_dir_rep() const { return dir_rep; }
+  bool is_rep() const { 
+    if (dir_rep == REP_NONE) return false;
+    return true;
+  }
+  bool can_rep() const;
+ 
+  // -- fetch --
+  object_t get_ondisk_object() { 
+    return file_object_t(ino(), frag);
+  }
+  void fetch(MDSContext *c, bool ignore_authpinnability=false);
+  void fetch(MDSContext *c, std::string_view want_dn, bool ignore_authpinnability=false);
+  void fetch(MDSContext *c, const std::set<dentry_key_t>& keys);
+
+#if 0  // unused?
+  void wait_for_commit(Context *c, version_t v=0);
+#endif
+  void commit_to(version_t want);
+  void commit(version_t want, MDSContext *c,
+	      bool ignore_authpinnability=false, int op_prio=-1);
+
+  // -- dirtyness --
+  version_t get_committing_version() const { return committing_version; }
+  version_t get_committed_version() const { return committed_version; }
+  void set_committed_version(version_t v) { committed_version = v; }
+
+  void mark_complete();
+
+  // -- reference counting --
+  void first_get() override;
+  void last_put() override;
+
+  bool is_waiting_for_dentry(std::string_view dname, snapid_t snap) {
+    return waiting_on_dentry.count(string_snap_t(dname, snap));
+  }
+  void add_dentry_waiter(std::string_view dentry, snapid_t snap, MDSContext *c);
+  void take_dentry_waiting(std::string_view dentry, snapid_t first, snapid_t last, MDSContext::vec& ls);
+  void take_sub_waiting(MDSContext::vec& ls);  // dentry or ino
+
+  void add_waiter(uint64_t mask, MDSContext *c) override;
+  void take_waiting(uint64_t mask, MDSContext::vec& ls) override;  // may include dentry waiters
+  void finish_waiting(uint64_t mask, int result = 0);    // ditto
+
+  // -- import/export --
+  mds_rank_t get_export_pin(bool inherit=true) const;
+  bool is_exportable(mds_rank_t dest) const;
+
+  void encode_export(ceph::buffer::list& bl);
+  void finish_export();
+  void abort_export() {
+    put(PIN_TEMPEXPORTING);
+  }
+  void decode_import(ceph::buffer::list::const_iterator& blp, LogSegment *ls);
+  void abort_import();
+
+  // -- auth pins --
+  bool can_auth_pin(int *err_ret=nullptr) const override;
+  int get_auth_pins() const { return auth_pins; }
+  int get_dir_auth_pins() const { return dir_auth_pins; }
+  void auth_pin(void *who) override;
+  void auth_unpin(void *who) override;
+
+  void adjust_nested_auth_pins(int dirinc, void *by);
+  void verify_fragstat();
+
+  void _walk_tree(std::function<bool(CDir*)> cb);
+
+  bool freeze_tree();
+  void _freeze_tree();
+  void unfreeze_tree();
+  void adjust_freeze_after_rename(CDir *dir);
+
+  bool freeze_dir();
+  void _freeze_dir();
+  void unfreeze_dir();
+
+  void maybe_finish_freeze();
+
+  std::pair<bool,bool> is_freezing_or_frozen_tree() const {
+    if (freeze_tree_state) {
+      if (freeze_tree_state->frozen)
+	return std::make_pair(false, true);
+      return std::make_pair(true, false);
+    }
+    return std::make_pair(false, false);
+  }
+
+  bool is_freezing() const override { return is_freezing_dir() || is_freezing_tree(); }
+  bool is_freezing_tree() const {
+    if (!num_freezing_trees)
+      return false;
+    return is_freezing_or_frozen_tree().first;
+  }
+  bool is_freezing_tree_root() const { return state & STATE_FREEZINGTREE; }
+  bool is_freezing_dir() const { return state & STATE_FREEZINGDIR; }
+
+  bool is_frozen() const override { return is_frozen_dir() || is_frozen_tree(); }
+  bool is_frozen_tree() const {
+    if (!num_frozen_trees)
+      return false;
+    return is_freezing_or_frozen_tree().second;
+  }
+  bool is_frozen_tree_root() const { return state & STATE_FROZENTREE; }
+  bool is_frozen_dir() const { return state & STATE_FROZENDIR; }
+
+  bool is_freezeable(bool freezing=false) const {
+    // no nested auth pins.
+    if (auth_pins - (freezing ? 1 : 0) > 0 ||
+	(freeze_tree_state && freeze_tree_state->auth_pins != auth_pins))
+      return false;
+
+    // inode must not be frozen.
+    if (!is_subtree_root() && inode->is_frozen())
+      return false;
+
+    return true;
+  }
+
+  bool is_freezeable_dir(bool freezing=false) const {
+    if ((auth_pins - freezing) > 0 || dir_auth_pins > 0)
+      return false;
+
+    // if not subtree root, inode must not be frozen (tree--frozen_dir is okay).
+    if (!is_subtree_root() && inode->is_frozen() && !inode->is_frozen_dir())
+      return false;
+
+    return true;
+  }
+
+  bool is_any_freezing_or_frozen_inode() const {
+    return num_frozen_inodes || !freezing_inodes.empty();
+  }
+  bool is_auth_pinned_by_lock_cache() const {
+    return frozen_inode_suppressed;
+  }
+  void disable_frozen_inode() {
+    ceph_assert(num_frozen_inodes == 0);
+    frozen_inode_suppressed++;
+  }
+  void enable_frozen_inode();
+
+  std::ostream& print_db_line_prefix(std::ostream& out) override;
+  void print(std::ostream& out) override;
+  void dump(ceph::Formatter *f, int flags = DUMP_DEFAULT) const;
+  void dump_load(ceph::Formatter *f);
+
+  // context
+  MDCache *mdcache;
+
+  CInode *inode;  // my inode
+  frag_t frag;   // my frag
+
+  snapid_t first = 2;
+  mempool::mds_co::compact_map<snapid_t,old_rstat_t> dirty_old_rstat;  // [value.first,key]
+
+  // my inodes with dirty rstat data
+  elist<CInode*> dirty_rstat_inodes;
+
+  elist<CDentry*> dirty_dentries;
+  elist<CDir*>::item item_dirty, item_new;
+
+  // lock caches that auth-pin me
+  elist<MDLockCache::DirItem*> lock_caches_with_auth_pins;
+
+  // all dirfrags within freezing/frozen tree reference the 'state'
+  std::shared_ptr<freeze_tree_state_t> freeze_tree_state;
+
+protected:
+  // friends
+  friend class Migrator;
+  friend class CInode;
+  friend class MDCache;
+  friend class MDiscover;
+  friend class MDBalancer;
+
+  friend class CDirDiscover;
+  friend class CDirExport;
+  friend class C_IO_Dir_TMAP_Fetched;
+  friend class C_IO_Dir_OMAP_Fetched;
+  friend class C_IO_Dir_OMAP_FetchedMore;
+  friend class C_IO_Dir_Committed;
+  friend class C_IO_Dir_Commit_Ops;
+
+  void _omap_fetch(MDSContext *fin, const std::set<dentry_key_t>& keys);
+  void _omap_fetch_more(version_t omap_version, bufferlist& hdrbl,
+			map<string, bufferlist>& omap, MDSContext *fin);
+  CDentry *_load_dentry(
+      std::string_view key,
+      std::string_view dname,
+      snapid_t last,
+      ceph::buffer::list &bl,
+      int pos,
+      const std::set<snapid_t> *snaps,
+      double rand_threshold,
+      bool *force_dirty);
+
+  /**
+   * Go bad due to a damaged dentry (register with damagetable and go BADFRAG)
+   */
+  void go_bad_dentry(snapid_t last, std::string_view dname);
+
+  /**
+   * Go bad due to a damaged header (register with damagetable and go BADFRAG)
+   */
+  void go_bad(bool complete);
+
+  void _omap_fetched(ceph::buffer::list& hdrbl, std::map<std::string, ceph::buffer::list>& omap,
+		     bool complete, int r);
+
+  // -- commit --
+  void _commit(version_t want, int op_prio);
+  void _omap_commit_ops(int r, int op_prio, int64_t metapool, version_t version, bool _new,
+			vector<dentry_commit_item> &to_set, bufferlist &dfts,
+			vector<string> &to_remove,
+			mempool::mds_co::compact_set<mempool::mds_co::string> &_stale);
+  void _encode_primary_inode_base(dentry_commit_item &item, bufferlist &dfts,
+                                  bufferlist &bl);
+  void _omap_commit(int op_prio);
+  void _parse_dentry(CDentry *dn, dentry_commit_item &item,
+                     const set<snapid_t> *snaps, bufferlist &bl);
+  void _committed(int r, version_t v);
+
+  static fnode_const_ptr empty_fnode;
+  // fnode is a pointer to constant fnode_t, the constant fnode_t can be shared
+  // by CDir and log events. To update fnode, read-copy-update should be used.
+
+  fnode_const_ptr fnode = empty_fnode;
+
+  version_t projected_version = 0;
+  mempool::mds_co::list<fnode_const_ptr> projected_fnode;
+
+  std::unique_ptr<scrub_info_t> scrub_infop;
+
+  // contents of this directory
+  dentry_key_map items;       // non-null AND null
+  unsigned num_head_items = 0;
+  unsigned num_head_null = 0;
+  unsigned num_snap_items = 0;
+  unsigned num_snap_null = 0;
+
+  int num_dirty = 0;
+
+  int num_inodes_with_caps = 0;
+
+  // state
+  version_t committing_version = 0;
+  version_t committed_version = 0;
+
+  mempool::mds_co::compact_set<mempool::mds_co::string> stale_items;
+
+  // lock nesting, freeze
+  static int num_frozen_trees;
+  static int num_freezing_trees;
+
+  // freezing/frozen inodes in this dirfrag
+  int num_frozen_inodes = 0;
+  int frozen_inode_suppressed = 0;
+  elist<CInode*> freezing_inodes;
+
+  int dir_auth_pins = 0;
+
+  // cache control  (defined for authority; hints for replicas)
+  __s32      dir_rep;
+  mempool::mds_co::compact_set<__s32> dir_rep_by;      // if dir_rep == REP_LIST
+
+  // popularity
+  dirfrag_load_vec_t pop_me;
+  dirfrag_load_vec_t pop_nested;
+  dirfrag_load_vec_t pop_auth_subtree;
+  dirfrag_load_vec_t pop_auth_subtree_nested;
+
+  ceph::coarse_mono_time last_popularity_sample = ceph::coarse_mono_clock::zero();
+
+  load_spread_t pop_spread;
+
+  elist<CInode*> pop_lru_subdirs;
+
+  std::unique_ptr<bloom_filter> bloom; // XXX not part of mempool::mds_co
+  /* If you set up the bloom filter, you must keep it accurate!
+   * It's deleted when you mark_complete() and is deliberately not serialized.*/
+
+  mempool::mds_co::compact_set<mempool::mds_co::string> wanted_items;
+  mempool::mds_co::compact_map<version_t, MDSContext::vec_alloc<mempool::mds_co::pool_allocator> > waiting_for_commit;
+
+  // -- waiters --
+  mempool::mds_co::compact_map< string_snap_t, MDSContext::vec_alloc<mempool::mds_co::pool_allocator> > waiting_on_dentry; // FIXME string_snap_t not in mempool
+
+private:
+  friend std::ostream& operator<<(std::ostream& out, const class CDir& dir);
+
+  void log_mark_dirty();
+
+  /**
+   * Create a scrub_info_t struct for the scrub_infop pointer.
+   */
+  void scrub_info_create() const;
+  /**
+   * Delete the scrub_infop if it's not got any useful data.
+   */
+  void scrub_maybe_delete_info();
+
+  void link_inode_work( CDentry *dn, CInode *in );
+  void unlink_inode_work( CDentry *dn );
+  void remove_null_dentries();
+  void purge_stale_snap_data(const std::set<snapid_t>& snaps);
+
+  void prepare_new_fragment(bool replay);
+  void prepare_old_fragment(std::map<string_snap_t, MDSContext::vec >& dentry_waiters, bool replay);
+  void steal_dentry(CDentry *dn);  // from another dir.  used by merge/split.
+  void finish_old_fragment(MDSContext::vec& waiters, bool replay);
+  void init_fragment_pins();
+  std::string get_path() const;
+
+  // -- authority --
+  /*
+   *     normal: <parent,unknown>   !subtree_root
+   * delegation: <mds,unknown>       subtree_root
+   *  ambiguous: <mds1,mds2>         subtree_root
+   *             <parent,mds2>       subtree_root
+   */
+  mds_authority_t dir_auth;
+};
+
+#endif