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 #include "librbd/ImageCtx.h"
  13
  14 #define dout_subsys ceph_subsys_rbd
  15 #undef dout_prefix
  16 #define dout_prefix *_dout << "librbd: "
  17
  18 namespace librbd {
  19 namespace util {
  20
  21 const std::string group_header_name(const std::string &group_id)
  22 {
  23   return RBD_GROUP_HEADER_PREFIX + group_id;
  24 }
  25
  26 const std::string id_obj_name(const std::string &name)
  27 {
  28   return RBD_ID_PREFIX + name;
  29 }
  30
  31 const std::string header_name(const std::string &image_id)
  32 {
  33   return RBD_HEADER_PREFIX + image_id;
  34 }
  35
  36 const std::string old_header_name(const std::string &image_name)
  37 {
  38   return image_name + RBD_SUFFIX;
  39 }
  40
  41 std::string unique_lock_name(const std::string &name, void *address) {
  42   return name + " (" + stringify(address) + ")";
  43 }
  44
  45 librados::AioCompletion *create_rados_callback(Context *on_finish) {
  46   return create_rados_callback<Context, &Context::complete>(on_finish);
  47 }
  48
  49 std::string generate_image_id(librados::IoCtx &ioctx) {
  50   librados::Rados rados(ioctx);
  51
  52   uint64_t bid = rados.get_instance_id();
  53   uint32_t extra = rand() % 0xFFFFFFFF;
  54
  55   ostringstream bid_ss;
  56   bid_ss << std::hex << bid << std::hex << extra;
  57   std::string id = bid_ss.str();
  58
  59   // ensure the image id won't overflow the fixed block name size
  60   if (id.length() > RBD_MAX_IMAGE_ID_LENGTH) {
  61     id = id.substr(id.length() - RBD_MAX_IMAGE_ID_LENGTH);
  62   }
  63
  64   return id;
  65 }
  66
  67 uint64_t get_rbd_default_features(CephContext* cct)
  68 {
  69   auto str_val = cct->_conf->get_val<std::string>("rbd_default_features");
  70   return boost::lexical_cast<uint64_t>(str_val);
  71 }
  72
  73 bool calc_sparse_extent(const bufferptr &bp,
  74                         size_t sparse_size,
  75                         uint64_t length,
  76                         size_t *write_offset,
  77                         size_t *write_length,
  78                         size_t *offset) {
  79   size_t extent_size;
  80   if (*offset + sparse_size > length) {
  81     extent_size = length - *offset;
  82   } else {
  83     extent_size = sparse_size;
  84   }
  85
  86   bufferptr extent(bp, *offset, extent_size);
  87   *offset += extent_size;
  88
  89   bool extent_is_zero = extent.is_zero();
  90   if (!extent_is_zero) {
  91     *write_length += extent_size;
  92   }
  93   if (extent_is_zero && *write_length == 0) {
  94     *write_offset += extent_size;
  95   }
  96
  97   if ((extent_is_zero || *offset == length) && *write_length != 0) {
  98     return true;
  99   }
 100   return false;
 101 }
 102
 103 bool is_metadata_config_override(const std::string& metadata_key,
 104                                  std::string* config_key) {
 105   size_t prefix_len = librbd::ImageCtx::METADATA_CONF_PREFIX.size();
 106   if (metadata_key.size() > prefix_len &&
 107       metadata_key.compare(0, prefix_len,
 108                            librbd::ImageCtx::METADATA_CONF_PREFIX) == 0) {
 109     *config_key = metadata_key.substr(prefix_len,
 110                                       metadata_key.size() - prefix_len);
 111     return true;
 112   }
 113   return false;
 114 }
 115
 116 } // namespace util
 117 } // namespace librbd