ceph/src/tools/rados/PoolDump.cc

   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) 2015 Red Hat
   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 #include "include/rados/librados.hpp"
  16 #include "common/errno.h"
  17
  18 #include "PoolDump.h"
  19
  20 using namespace librados;
  21
  22 #define dout_context g_ceph_context
  23 #define dout_subsys ceph_subsys_rados
  24
  25 /**
  26  * Export RADOS objects from a live cluster
  27  * to a serialized format via a file descriptor.
  28  *
  29  * @returns 0 on success, else error code
  30  */
  31 int PoolDump::dump(IoCtx *io_ctx)
  32 {
  33   ceph_assert(io_ctx != NULL);
  34
  35   int r = 0;
  36   write_super();
  37
  38   r = write_simple(TYPE_POOL_BEGIN, file_fd);
  39   if (r != 0) {
  40     return r;
  41   }
  42
  43   io_ctx->set_namespace(all_nspaces);
  44   librados::NObjectIterator i = io_ctx->nobjects_begin();
  45
  46   librados::NObjectIterator i_end = io_ctx->nobjects_end();
  47   for (; i != i_end; ++i) {
  48     const std::string oid = i->get_oid();
  49     dout(10) << "OID '" << oid << "'" << dendl;
  50
  51     // Compose OBJECT_BEGIN
  52     // ====================
  53     object_begin obj_begin;
  54     obj_begin.hoid.hobj.oid = i->get_oid();
  55     obj_begin.hoid.hobj.nspace = i->get_nspace();
  56     obj_begin.hoid.hobj.set_key(i->get_locator());
  57
  58     // Only output head, RadosImport only wants that
  59     obj_begin.hoid.hobj.snap = CEPH_NOSNAP;
  60
  61     // Skip setting object_begin.oi, RadosImport doesn't care
  62
  63     r = write_section(TYPE_OBJECT_BEGIN, obj_begin, file_fd);
  64     if (r != 0) {
  65       return r;
  66     }
  67
  68     // Compose TYPE_DATA chunks
  69     // ========================
  70     const uint32_t op_size = 4096 * 1024;
  71     uint64_t offset = 0;
  72     io_ctx->set_namespace(i->get_nspace());
  73     io_ctx->locator_set_key(i->get_locator());
  74     while (true) {
  75       bufferlist outdata;
  76       r = io_ctx->read(oid, outdata, op_size, offset);
  77       if (r <= 0) {
  78         // Error or no data
  79         break;
  80       }
  81
  82       r = write_section(TYPE_DATA,
  83           data_section(offset, outdata.length(), outdata), file_fd);
  84       if (r != 0) {
  85         // Output stream error
  86         return r;
  87       }
  88
  89       if (outdata.length() < op_size) {
  90         // No more data
  91         break;
  92       }
  93       offset += outdata.length();
  94     }
  95
  96     // Compose TYPE_ATTRS chunk
  97     // ========================
  98     std::map<std::string, bufferlist> raw_xattrs;
  99     std::map<std::string, bufferlist> xattrs;
 100     r = io_ctx->getxattrs(oid, raw_xattrs);
 101     if (r < 0) {
 102       cerr << "error getting xattr set " << oid << ": " << cpp_strerror(r)
 103            << std::endl;
 104       return r;
 105     }
 106     // Prepend "_" to mimic how user keys are represented in a pg export
 107     for (std::map<std::string, bufferlist>::iterator i = raw_xattrs.begin();
 108          i != raw_xattrs.end(); ++i) {
 109       std::pair< std::string, bufferlist> item(std::string("_") + std::string(i->first.c_str()), i->second);
 110       xattrs.insert(item);
 111     }
 112     r = write_section(TYPE_ATTRS, attr_section(xattrs), file_fd);
 113     if (r != 0) {
 114       return r;
 115     }
 116
 117     // Compose TYPE_OMAP_HDR section
 118     // =============================
 119     bufferlist omap_header;
 120     r = io_ctx->omap_get_header(oid, &omap_header);
 121     if (r < 0) {
 122       cerr << "error getting omap header " << oid
 123            << ": " << cpp_strerror(r) << std::endl;
 124       return r;
 125     }
 126     r = write_section(TYPE_OMAP_HDR, omap_hdr_section(omap_header), file_fd);
 127     if (r != 0) {
 128       return r;
 129     }
 130
 131     // Compose TYPE_OMAP
 132     int MAX_READ = 512;
 133     string last_read = "";
 134     do {
 135       map<string, bufferlist> values;
 136       r = io_ctx->omap_get_vals(oid, last_read, MAX_READ, &values);
 137       if (r < 0) {
 138         cerr << "error getting omap keys " << oid << ": "
 139              << cpp_strerror(r) << std::endl;
 140         return r;
 141       }
 142       if (values.size()) {
 143         last_read = values.rbegin()->first;
 144       } else {
 145         break;
 146       }
 147
 148       r = write_section(TYPE_OMAP, omap_section(values), file_fd);
 149       if (r != 0) {
 150         return r;
 151       }
 152       r = values.size();
 153     } while (r == MAX_READ);
 154
 155     // Close object
 156     // =============
 157     r = write_simple(TYPE_OBJECT_END, file_fd);
 158     if (r != 0) {
 159       return r;
 160     }
 161   }
 162
 163   r = write_simple(TYPE_POOL_END, file_fd);
 164 #if defined(__linux__)
 165   if (file_fd != STDOUT_FILENO)
 166     posix_fadvise(file_fd, 0, 0, POSIX_FADV_DONTNEED);
 167 #endif
 168   return r;
 169 }