ceph/src/tools/cephfs/JournalScanner.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) 2014 john spray <john.spray@inktank.com>
   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 #ifndef JOURNAL_SCANNER_H
  15 #define JOURNAL_SCANNER_H
  16
  17 // For Journaler::Header, can't forward-declare nested classes
  18 #include <osdc/Journaler.h>
  19
  20 namespace librados {
  21   class IoCtx;
  22 }
  23
  24 #include "JournalFilter.h"
  25
  26 /**
  27  * A simple sequential reader for metadata journals.  Unlike
  28  * the MDS Journaler class, this is written to detect, record,
  29  * and read past corruptions and missing objects.  It is also
  30  * less efficient but more plainly written.
  31  */
  32 class JournalScanner
  33 {
  34   private:
  35   librados::IoCtx &io;
  36
  37   // Input constraints
  38   const int rank;
  39   JournalFilter const filter;
  40
  41   void gap_advance();
  42
  43   public:
  44   JournalScanner(
  45       librados::IoCtx &io_,
  46       int rank_,
  47       JournalFilter const &filter_) :
  48     io(io_),
  49     rank(rank_),
  50     filter(filter_),
  51     pointer_present(false),
  52     pointer_valid(false),
  53     header_present(false),
  54     header_valid(false),
  55     header(NULL) {};
  56
  57   JournalScanner(
  58       librados::IoCtx &io_,
  59       int rank_) :
  60     io(io_),
  61     rank(rank_),
  62     pointer_present(false),
  63     pointer_valid(false),
  64     header_present(false),
  65     header_valid(false),
  66     header(NULL) {};
  67
  68   ~JournalScanner();
  69
  70   int scan(bool const full=true);
  71   int scan_pointer();
  72   int scan_header();
  73   int scan_events();
  74   void report(std::ostream &out) const;
  75
  76   std::string obj_name(uint64_t offset) const;
  77   std::string obj_name(inodeno_t ino, uint64_t offset) const;
  78
  79   // The results of the scan
  80   inodeno_t ino;  // Corresponds to JournalPointer.front
  81   class EventRecord {
  82     public:
  83     EventRecord() : log_event(NULL), raw_size(0) {}
  84     EventRecord(LogEvent *le, uint32_t rs) : log_event(le), raw_size(rs) {}
  85     LogEvent *log_event;
  86     uint32_t raw_size;  //< Size from start offset including all encoding overhead
  87   };
  88
  89   class EventError {
  90     public:
  91     int r;
  92     std::string description;
  93     EventError(int r_, const std::string &desc_)
  94       : r(r_), description(desc_) {}
  95   };
  96
  97   typedef std::map<uint64_t, EventRecord> EventMap;
  98   typedef std::map<uint64_t, EventError> ErrorMap;
  99   typedef std::pair<uint64_t, uint64_t> Range;
 100   bool pointer_present;
 101   bool pointer_valid;
 102   bool header_present;
 103   bool header_valid;
 104   Journaler::Header *header;
 105
 106   bool is_healthy() const;
 107   bool is_readable() const;
 108   std::vector<std::string> objects_valid;
 109   std::vector<uint64_t> objects_missing;
 110   std::vector<Range> ranges_invalid;
 111   std::vector<uint64_t> events_valid;
 112   EventMap events;
 113
 114   // For events present in ::events (i.e. scanned successfully),
 115   // any subsequent errors handling them (e.g. replaying)
 116   ErrorMap errors;
 117
 118
 119   private:
 120   // Forbid copy construction because I have ptr members
 121   JournalScanner(const JournalScanner &rhs);
 122 };
 123
 124 #endif // JOURNAL_SCANNER_H
 125