ceph/src/librbd/Utils.cc

   1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
   2 // vim: ts=8 sw=2 smarttab
   3
   4 #include <boost/algorithm/string.hpp>
   5 #include <boost/lexical_cast.hpp>
   6
   7 #include "librbd/Utils.h"
   8 #include "include/rbd_types.h"
   9 #include "include/stringify.h"
  10 #include "include/rbd/features.h"
  11 #include "common/dout.h"
  12
  13 #define dout_subsys ceph_subsys_rbd
  14 #undef dout_prefix
  15 #define dout_prefix *_dout << "librbd: "
  16
  17 namespace librbd {
  18 namespace util {
  19
  20 const std::string group_header_name(const std::string &group_id)
  21 {
  22   return RBD_GROUP_HEADER_PREFIX + group_id;
  23 }
  24
  25 const std::string id_obj_name(const std::string &name)
  26 {
  27   return RBD_ID_PREFIX + name;
  28 }
  29
  30 const std::string header_name(const std::string &image_id)
  31 {
  32   return RBD_HEADER_PREFIX + image_id;
  33 }
  34
  35 const std::string old_header_name(const std::string &image_name)
  36 {
  37   return image_name + RBD_SUFFIX;
  38 }
  39
  40 std::string unique_lock_name(const std::string &name, void *address) {
  41   return name + " (" + stringify(address) + ")";
  42 }
  43
  44 librados::AioCompletion *create_rados_callback(Context *on_finish) {
  45   return create_rados_callback<Context, &Context::complete>(on_finish);
  46 }
  47
  48 std::string generate_image_id(librados::IoCtx &ioctx) {
  49   librados::Rados rados(ioctx);
  50
  51   uint64_t bid = rados.get_instance_id();
  52   uint32_t extra = rand() % 0xFFFFFFFF;
  53
  54   ostringstream bid_ss;
  55   bid_ss << std::hex << bid << std::hex << extra;
  56   std::string id = bid_ss.str();
  57
  58   // ensure the image id won't overflow the fixed block name size
  59   if (id.length() > RBD_MAX_IMAGE_ID_LENGTH) {
  60     id = id.substr(id.length() - RBD_MAX_IMAGE_ID_LENGTH);
  61   }
  62
  63   return id;
  64 }
  65
  66 uint64_t get_rbd_default_features(CephContext* cct)
  67 {
  68   auto str_val = cct->_conf->get_val<std::string>("rbd_default_features");
  69   return boost::lexical_cast<uint64_t>(str_val);
  70 }
  71
  72 bool calc_sparse_extent(const bufferptr &bp,
  73                         size_t sparse_size,
  74                         uint64_t length,
  75                         size_t *write_offset,
  76                         size_t *write_length,
  77                         size_t *offset) {
  78   size_t extent_size;
  79   if (*offset + sparse_size > length) {
  80     extent_size = length - *offset;
  81   } else {
  82     extent_size = sparse_size;
  83   }
  84
  85   bufferptr extent(bp, *offset, extent_size);
  86   *offset += extent_size;
  87
  88   bool extent_is_zero = extent.is_zero();
  89   if (!extent_is_zero) {
  90     *write_length += extent_size;
  91   }
  92   if (extent_is_zero && *write_length == 0) {
  93     *write_offset += extent_size;
  94   }
  95
  96   if ((extent_is_zero || *offset == length) && *write_length != 0) {
  97     return true;
  98   }
  99   return false;
 100 }
 101 } // namespace util
 102
 103 } // namespace librbd