ceph/src/mds/snap.h

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3 /*
   4  * Ceph - scalable distributed file system
   5  *
   6  * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
   7  *
   8  * This is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License version 2.1, as published by the Free Software
  11  * Foundation.  See file COPYING.
  12  *
  13  */
  14
  15 #ifndef CEPH_MDS_SNAP_H
  16 #define CEPH_MDS_SNAP_H
  17
  18 #include <map>
  19 #include <string_view>
  20
  21 #include "mdstypes.h"
  22 #include "common/snap_types.h"
  23
  24 #include "Capability.h"
  25
  26 /*
  27  * generic snap descriptor.
  28  */
  29 struct SnapInfo {
  30   void encode(ceph::buffer::list &bl) const;
  31   void decode(ceph::buffer::list::const_iterator &bl);
  32   void dump(ceph::Formatter *f) const;
  33   static void generate_test_instances(std::list<SnapInfo*>& ls);
  34
  35   std::string_view get_long_name() const;
  36
  37   snapid_t snapid;
  38   inodeno_t ino;
  39   utime_t stamp;
  40   std::string name;
  41
  42   mutable std::string long_name; ///< cached _$ino_$name
  43   std::map<std::string,std::string> metadata;
  44 };
  45 WRITE_CLASS_ENCODER(SnapInfo)
  46
  47 inline bool operator==(const SnapInfo &l, const SnapInfo &r)
  48 {
  49   return l.snapid == r.snapid && l.ino == r.ino &&
  50          l.stamp == r.stamp && l.name == r.name;
  51 }
  52
  53 std::ostream& operator<<(std::ostream& out, const SnapInfo &sn);
  54
  55 /*
  56  * SnapRealm - a subtree that shares the same set of snapshots.
  57  */
  58 struct SnapRealm;
  59
  60 struct snaplink_t {
  61   void encode(ceph::buffer::list &bl) const;
  62   void decode(ceph::buffer::list::const_iterator &bl);
  63   void dump(ceph::Formatter *f) const;
  64   static void generate_test_instances(std::list<snaplink_t*>& ls);
  65
  66   inodeno_t ino;
  67   snapid_t first;
  68 };
  69 WRITE_CLASS_ENCODER(snaplink_t)
  70
  71 std::ostream& operator<<(std::ostream& out, const snaplink_t &l);
  72
  73 // carry data about a specific version of a SnapRealm
  74 struct sr_t {
  75   void mark_parent_global() { flags |= PARENT_GLOBAL; }
  76   void clear_parent_global() { flags &= ~PARENT_GLOBAL; }
  77   bool is_parent_global() const { return flags & PARENT_GLOBAL; }
  78
  79   void mark_subvolume() { flags |= SUBVOLUME; }
  80   void clear_subvolume() { flags &= ~SUBVOLUME; }
  81   bool is_subvolume() const { return flags & SUBVOLUME; }
  82
  83   void encode(ceph::buffer::list &bl) const;
  84   void decode(ceph::buffer::list::const_iterator &bl);
  85   void dump(ceph::Formatter *f) const;
  86   static void generate_test_instances(std::list<sr_t*>& ls);
  87
  88   snapid_t seq = 0;                     // basically, a version/seq # for changes to _this_ realm.
  89   snapid_t created = 0;                 // when this realm was created.
  90   snapid_t last_created = 0;            // last snap created in _this_ realm.
  91   snapid_t last_destroyed = 0;          // seq for last removal
  92   snapid_t current_parent_since = 1;
  93   std::map<snapid_t, SnapInfo> snaps;
  94   std::map<snapid_t, snaplink_t> past_parents;  // key is "last" (or NOSNAP)
  95   std::set<snapid_t> past_parent_snaps;
  96   utime_t last_modified;                // timestamp when this realm
  97                                         // was last changed.
  98   uint64_t change_attr = 0;             // tracks changes to snap
  99                                         // realm attrs.
 100
 101   __u32 flags = 0;
 102   enum {
 103     PARENT_GLOBAL       = 1 << 0,
 104     SUBVOLUME           = 1 << 1,
 105   };
 106 };
 107 WRITE_CLASS_ENCODER(sr_t)
 108
 109 class MDCache;
 110 #endif