ceph/src/rbd.cc

// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
// vim: ts=8 sw=2 smarttab
/*
 * Ceph - scalable distributed file system
 *
 * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
 *
 * This is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software 
 * Foundation.  See file COPYING.
 * 
 */

#include "config.h"

#include "common/common_init.h"
#include "include/librados.hpp"
using namespace librados;
#include "include/byteorder.h"


#include <iostream>

#include <stdlib.h>
#include <time.h>
#include <sys/types.h>
#include <errno.h>

#include "include/rbd_types.h"

struct pools {
  pool_t md;
  pool_t data;
  pool_t dest;
};

typedef struct pools pools_t;

static Rados rados;
static string dir_oid = RBD_DIRECTORY;
static string dir_info_oid = RBD_INFO;

void usage()
{
  cout << "usage: rbdtool [-n <auth user>] [OPTIONS] <cmd> ...\n"
       << "where 'pool' is a rados pool name (default is 'rbd') and 'cmd' is one of:\n"
       << "  <ls | list> [pool-name]                   list rbd images\n"
       << "  info [image-name]                         show information about image size,\n"
       << "                                            striping, etc.\n"
       << "  create [image-name]                       create an empty image (requires size\n"
       << "                                            param)\n"
       << "  resize [image-name]                       resize (expand or contract) image\n"
       << "                                            (requires size param)\n"
       << "  rm [image-name]                           delete an image\n"
       << "  export [image-name] [dest-path]           export image to file\n"
       << "  import [path] [dst-image]                 import image from file (dest defaults\n"
       << "                                            as the filename part of file)\n"
       << "  <cp | copy> [src-image] [dest-image]      copy image to dest\n"
       << "  <mv | rename> [src-image] [dest-image]    copy image to dest\n"
       << "  snap ls [image-name]                      dump list of image snapshots\n"
       << "  snap create <--snap=name> [image-name]    create a snapshot\n"
       << "  snap rollback <--snap=name> [image-name]  rollback image head to snapshot\n"
       << "\n"
       << "Other input options:\n"
       << "  -p, --pool <pool>            source pool name\n"
       << "  --image <image-name>         image name\n"
       << "  --dest <name>                destination [pool and] image name\n"
       << "  --snap <snapname>            specify snapshot name\n"
       << "  --dest-pool <name>           destination pool name\n"
       << "  --path <path-name>           path name for import/export (if not specified)\n"
       << "  --size <size in MB>          size parameter for create and resize commands\n";
}

void usage_exit()
{
  assert(1);
  usage();
  exit(1);
}


static void init_rbd_header(struct rbd_obj_header_ondisk& ondisk,
			    size_t size, int *order, uint64_t bid)
{
  uint32_t hi = bid >> 32;
  uint32_t lo = bid & 0xFFFFFFFF;
  memset(&ondisk, 0, sizeof(ondisk));

  memcpy(&ondisk.text, RBD_HEADER_TEXT, sizeof(RBD_HEADER_TEXT));
  memcpy(&ondisk.signature, RBD_HEADER_SIGNATURE, sizeof(RBD_HEADER_SIGNATURE));
  memcpy(&ondisk.version, RBD_HEADER_VERSION, sizeof(RBD_HEADER_VERSION));

  snprintf(ondisk.block_name, sizeof(ondisk.block_name), "rb.%x.%x", hi, lo);

  if (!*order)
    *order = RBD_DEFAULT_OBJ_ORDER;

  ondisk.image_size = size;
  ondisk.options.order = *order;
  ondisk.options.crypt_type = RBD_CRYPT_NONE;
  ondisk.options.comp_type = RBD_COMP_NONE;
  ondisk.snap_seq = 0;
  ondisk.snap_count = 0;
  ondisk.reserved = 0;
  ondisk.snap_names_len = 0;
}

static void print_header(const char *imgname, rbd_obj_header_ondisk *header)
{
  int obj_order = header->options.order;
  cout << "rbd image '" << imgname << "':\n"
       << "\tsize " << prettybyte_t(header->image_size) << " in "
       << (header->image_size >> obj_order) << " objects\n"
       << "\torder " << obj_order
       << " (" << prettybyte_t(1 << obj_order) << " objects)"
       << std::endl;
}

static string get_block_oid(rbd_obj_header_ondisk *header, uint64_t num)
{
  char o[RBD_MAX_SEG_NAME_SIZE];
  sprintf(o, "%s.%012llx", header->block_name, (unsigned long long)num);
  return o;
}

static uint64_t get_max_block(rbd_obj_header_ondisk *header)
{
  uint64_t size = header->image_size;
  int obj_order = header->options.order;
  uint64_t block_size = 1 << obj_order;
  uint64_t numseg = (size + block_size - 1) >> obj_order;

  return numseg;
}

static uint64_t get_block_size(rbd_obj_header_ondisk *header)
{
  return 1 << header->options.order;
}

static uint64_t get_block_num(rbd_obj_header_ondisk *header, uint64_t ofs)
{
  int obj_order = header->options.order;
  uint64_t num = ofs >> obj_order;

  return num;
}

void trim_image(pools_t& pp, const char *imgname, rbd_obj_header_ondisk *header, uint64_t newsize)
{
  uint64_t numseg = get_max_block(header);
  uint64_t start = get_block_num(header, newsize);

  cout << "trimming image data from " << numseg << " to " << start << " objects..." << std::endl;
  for (uint64_t i=start; i<numseg; i++) {
    string oid = get_block_oid(header, i);
    rados.remove(pp.data, oid);
    if ((i & 127) == 0) {
      cout << "\r\t" << i << "/" << numseg;
      cout.flush();
    }
  }
}

static int init_rbd_info(struct rbd_info *info)
{
  memset(info, 0, sizeof(*info));
  return 0;
}

int read_rbd_info(pools_t& pp, string& info_oid, struct rbd_info *info)
{
  int r;
  bufferlist bl;

  r = rados.read(pp.md, info_oid, 0, bl, sizeof(*info));
  if (r < 0)
    return r;
  if (r == 0) {
    return init_rbd_info(info);
  }

  if (r < (int)sizeof(*info))
    return -EIO;

  memcpy(info, bl.c_str(), r);
  return 0;
}

static int touch_rbd_info(pool_t pool, string& info_oid)
{
  bufferlist bl;
  int r = rados.write(pool, info_oid, 0, bl, 0);
  if (r < 0)
    return r;
  return 0;
}

static int rbd_assign_bid(pool_t pool, string& info_oid, uint64_t *id)
{
  bufferlist bl, out;

  *id = 0;

  int r = touch_rbd_info(pool, info_oid);
  if (r < 0)
    return r;

  r = rados.exec(pool, info_oid, "rbd", "assign_bid", bl, out);
  if (r < 0)
    return r;

  bufferlist::iterator iter = out.begin();
  ::decode(*id, iter);

  return 0;
}


static int read_header_bl(pool_t pool, string& md_oid, bufferlist& header)
{
  int r;
#define READ_SIZE 4096
  do {
    bufferlist bl;
    r = rados.read(pool, md_oid, 0, bl, READ_SIZE);
    if (r < 0)
      return r;
    header.claim_append(bl);
   } while (r == READ_SIZE);

  return 0;
}

static int read_header(pool_t pool, string& md_oid, struct rbd_obj_header_ondisk *header)
{
  bufferlist header_bl;
  int r = read_header_bl(pool, md_oid, header_bl);
  if (r < 0)
    return r;
  if (header_bl.length() < (int)sizeof(*header))
    return -EIO;
  memcpy(header, header_bl.c_str(), sizeof(*header));

  return 0;
}

static int write_header(pools_t& pp, string& md_oid, bufferlist& header)
{
  bufferlist bl;
  int r = rados.write(pp.md, md_oid, 0, header, header.length());

  return r;
}

static int tmap_set(pools_t& pp, string& imgname)
{
  bufferlist cmdbl, emptybl;
  __u8 c = CEPH_OSD_TMAP_SET;
  ::encode(c, cmdbl);
  ::encode(imgname, cmdbl);
  ::encode(emptybl, cmdbl);
  return rados.tmap_update(pp.md, dir_oid, cmdbl);
}

static int tmap_rm(pools_t& pp, string& imgname)
{
  bufferlist cmdbl;
  __u8 c = CEPH_OSD_TMAP_RM;
  ::encode(c, cmdbl);
  ::encode(imgname, cmdbl);
  return rados.tmap_update(pp.md, dir_oid, cmdbl);
}

static int rollback_image(pools_t& pp, struct rbd_obj_header_ondisk *header,
                          SnapContext& snapc, uint64_t snapid)
{
  uint64_t numseg = get_max_block(header);

  for (uint64_t i = 0; i < numseg; i++) {
    int r;
    string oid = get_block_oid(header, i);
    r = rados.selfmanaged_snap_rollback_object(pp.data, oid, snapc, snapid);
    if (r < 0 && r != -ENOENT)
      return r;
  }
  return 0;
}

static int do_list(pools_t& pp, const char *poolname)
{
  bufferlist bl;
  int r = rados.read(pp.md, dir_oid, 0, bl, 0);
  if (r < 0)
    return r;

  bufferlist::iterator p = bl.begin();
  bufferlist header;
  map<string,bufferlist> m;
  ::decode(header, p);
  ::decode(m, p);
  for (map<string,bufferlist>::iterator q = m.begin(); q != m.end(); q++)
    cout << q->first << std::endl;
  return 0;
}

static int do_create(pool_t pool, string& md_oid, const char *imgname,
                     uint64_t size, int *order)
{

  // make sure it doesn't already exist
  int r = rados.stat(pool, md_oid, NULL, NULL);
  if (r == 0) {
    cerr << "rbd image header " << md_oid << " already exists" << std::endl;
    return -EEXIST;
  }

  uint64_t bid;
  r = rbd_assign_bid(pool, dir_info_oid, &bid);
  if (r < 0) {
    cerr << "failed to assign a block name for image" << std::endl;
    return r;
  }

  struct rbd_obj_header_ondisk header;
  init_rbd_header(header, size, order, bid);

  bufferlist bl;
  bl.append((const char *)&header, sizeof(header));

  print_header(imgname, &header);

  cout << "adding rbd image to directory..." << std::endl;
  bufferlist cmdbl, emptybl;
  __u8 c = CEPH_OSD_TMAP_SET;
  ::encode(c, cmdbl);
  ::encode(imgname, cmdbl);
  ::encode(emptybl, cmdbl);
  r = rados.tmap_update(pool, dir_oid, cmdbl);
  if (r < 0) {
    cerr << "error adding img to directory: " << strerror(-r)<< std::endl;
    return r;
  }

  cout << "creating rbd image..." << std::endl;
  r = rados.write(pool, md_oid, 0, bl, bl.length());
  if (r < 0) {
    cerr << "error writing header: " << strerror(-r) << std::endl;
    return r;
  }

  cout << "done." << std::endl;
  return 0;
}

static int do_rename(pools_t& pp, string& md_oid, const char *imgname, const char *dstname)
{
  string dst_md_oid = dstname;
  dst_md_oid += RBD_SUFFIX;
  string dstname_str = dstname;
  string imgname_str = imgname;
  bufferlist header;
  int r = read_header_bl(pp.md, md_oid, header);
  if (r < 0) {
    cerr << "error reading header: " << md_oid << ": " << strerror(-r) << std::endl;
    return r;
  }
  r = rados.stat(pp.md, dst_md_oid, NULL, NULL);
  if (r == 0) {
    cerr << "rbd image header " << dst_md_oid << " already exists" << std::endl;
    return -EEXIST;
  }
  r = write_header(pp, dst_md_oid, header);
  if (r < 0) {
    cerr << "error writing header: " << dst_md_oid << ": " << strerror(-r) << std::endl;
    return r;
  }
  r = tmap_set(pp, dstname_str);
  if (r < 0) {
    rados.remove(pp.md, dst_md_oid);
    cerr << "can't add " << dst_md_oid << " to directory" << std::endl;
    return r;
  }
  r = tmap_rm(pp, imgname_str);
  if (r < 0)
    cerr << "warning: couldn't remove old entry from directory (" << imgname_str << ")" << std::endl;

  r = rados.remove(pp.md, md_oid);
  if (r < 0)
    cerr << "warning: couldn't remove old metadata" << std::endl;

  return 0;
}


static int do_show_info(pools_t& pp, string& md_oid, const char *imgname)
{
  struct rbd_obj_header_ondisk header;
  int r = read_header(pp.md, md_oid, &header);
  if (r < 0)
    return r;

  print_header(imgname, &header);
  return 0;
}

static int do_delete(pools_t& pp, string& md_oid, const char *imgname)
{
  struct rbd_obj_header_ondisk header;
  int r = read_header(pp.md, md_oid, &header);
  if (r >= 0) {
    print_header(imgname, &header);
    trim_image(pp, imgname, &header, 0);
    cout << "\rremoving header..." << std::endl;
    rados.remove(pp.md, md_oid);
  }

  cout << "removing rbd image to directory..." << std::endl;
  bufferlist cmdbl;
  __u8 c = CEPH_OSD_TMAP_RM;
  ::encode(c, cmdbl);
  ::encode(imgname, cmdbl);
  r = rados.tmap_update(pp.md, dir_oid, cmdbl);
  if (r < 0) {
    cerr << "error removing img from directory: " << strerror(-r)<< std::endl;
    return r;
  }

  cout << "done." << std::endl;
  return 0;
}

static int do_resize(pools_t& pp, string& md_oid, const char *imgname, uint64_t size)
{
  struct rbd_obj_header_ondisk header;
  int r = read_header(pp.md, md_oid, &header);
  if (r < 0)
    return r;

  // trim
  if (size == header.image_size) {
    cout << "no change in size (" << size << " -> " << header.image_size << ")" << std::endl;
    print_header(imgname, &header);
    return 0;
  }

  if (size > header.image_size) {
    cout << "expanding image " << size << " -> " << header.image_size << " objects" << std::endl;
    header.image_size = size;
  } else {
    cout << "shrinking image " << size << " -> " << header.image_size << " objects" << std::endl;
    trim_image(pp, imgname, &header, size);
    header.image_size = size;
  }
  print_header(imgname, &header);

  // rewrite header
  bufferlist bl;
  bl.append((const char *)&header, sizeof(header));
  r = rados.write(pp.md, md_oid, 0, bl, bl.length());
  if (r < 0) {
    cerr << "error writing header: " << strerror(-r) << std::endl;
    return r;
  }

   cout << "done." << std::endl;
   return 0;
}

static int do_list_snaps(pools_t& pp, string& md_oid)
{
  bufferlist bl, bl2;

  int r = rados.exec(pp.md, md_oid, "rbd", "snap_list", bl, bl2);
  if (r < 0) {
    cerr << "list_snaps failed: " << strerror(-r) << std::endl;
    return r;
  }

  uint32_t num_snaps;
  uint64_t snap_seq;
  bufferlist::iterator iter = bl2.begin();
  ::decode(snap_seq, iter);
  ::decode(num_snaps, iter);
  for (uint32_t i=0; i < num_snaps; i++) {
    uint64_t id, image_size;
    string s;
    ::decode(id, iter);
    ::decode(image_size, iter);
    ::decode(s, iter);
    cout << id << "\t" << s << "\t" << image_size << std::endl;
  }
  return 0;
}

static int do_add_snap(pools_t& pp, string& md_oid, const char *snapname)
{
  bufferlist bl, bl2;
  uint64_t snap_id;

  int r = rados.selfmanaged_snap_create(pp.md, &snap_id);
  if (r < 0) {
    cerr << "failed to create snap id: " << strerror(-r) << std::endl;
    return r;
  }

  ::encode(snapname, bl);
  ::encode(snap_id, bl);

  r = rados.exec(pp.md, md_oid, "rbd", "snap_add", bl, bl2);
  if (r < 0) {
    cerr << "rbd.snap_add execution failed failed: " << strerror(-r) << std::endl;
    return r;
  }

  return 0;
}

static int do_get_snapc(pools_t& pp, string& md_oid, const char *snapname,
                        SnapContext& snapc, vector<snap_t>& snaps, uint64_t& snapid)
{
  bufferlist bl, bl2;

  int r = rados.exec(pp.md, md_oid, "rbd", "snap_list", bl, bl2);
  if (r < 0) {
    cerr << "list_snaps failed: " << strerror(-r) << std::endl;
    return r;
  }

  snaps.clear();

  uint32_t num_snaps;
  bufferlist::iterator iter = bl2.begin();
  ::decode(snapc.seq, iter);
  ::decode(num_snaps, iter);
  snapid = 0;
  for (uint32_t i=0; i < num_snaps; i++) {
    uint64_t id, image_size;
    string s;
    ::decode(id, iter);
    ::decode(image_size, iter);
    ::decode(s, iter);
    if (s.compare(snapname) == 0)
      snapid = id;
    snapc.snaps.push_back(id);
    snaps.push_back(id);
  }

  if (!snapc.is_valid()) {
    cerr << "image snap context is invalid! can't rollback" << std::endl;
    return -EIO;
  }

  if (!snapid) {
    return -ENOENT;
  }

  return 0;
}

static int do_rollback_snap(pools_t& pp, string& md_oid, SnapContext& snapc, uint64_t snapid)
{
  struct rbd_obj_header_ondisk header;
  int r = read_header(pp.md, md_oid, &header);
  if (r < 0) {
    cerr << "error reading header: " << md_oid << ": " << strerror(-r) << std::endl;
    return r;
  }
  r = rollback_image(pp, &header, snapc, snapid);
  if (r < 0)
    return r;

  return 0;
}

static int do_export(pools_t& pp, string& md_oid, const char *path)
{
  struct rbd_obj_header_ondisk header;
  int64_t ret;
  int r;

  ret = read_header(pp.md, md_oid, &header);
  if (ret < 0)
    return ret;

  uint64_t numseg = get_max_block(&header);
  uint64_t block_size = get_block_size(&header);
  int fd = open(path, O_WRONLY | O_CREAT | O_EXCL, 0644);
  uint64_t pos = 0;

  if (fd < 0)
    return -errno;

  for (uint64_t i = 0; i < numseg; i++) {
    bufferlist bl;
    string oid = get_block_oid(&header, i);
    r = rados.read(pp.data, oid, 0, bl, block_size);
    if (r < 0 && r == -ENOENT)
      r = 0;
    if (r < 0) {
      ret = r;
      goto done;
    }

    if (bl.length()) {
      ret = lseek64(fd, pos, SEEK_SET);
      if (ret < 0) {
	ret = -errno;
	cerr << "could not seek to pos " << pos << std::endl;
	goto done;
      }
      ret = write(fd, bl.c_str(), bl.length());
      if (ret < 0)
        goto done;
    }

    pos += block_size;
  }
  r = ftruncate(fd, header.image_size);
  if (r < 0)
    ret = -errno;

  ret = 0;

done:
  close(fd);
  return ret;
}

static const char *imgname_from_path(const char *path)
{
  const char *imgname;

  imgname = strrchr(path, '/');
  if (imgname)
    imgname++;
  else
    imgname = path;

  return imgname;
}

static void update_snap_name(char *imgname, char **snap)
{
  char *s;

  s = strrchr(imgname, '@');
  if (!s)
    return;

  *s = '\0';

  if (!snap)
    return;

  s++;
  if (*s)
    *snap = s;
}

static void set_pool_image_name(const char *orig_pool, const char *orig_img,
                                char **new_pool, char **new_img, char **snap)
{
  const char *sep;

  if (orig_pool)
    return;

  if (!orig_img) {
    *new_pool = strdup("rbd");
    return;
  }

  sep = strchr(orig_img, '/');
  if (!sep) {
    *new_pool= strdup("rbd");
    *new_img = strdup(orig_img);
    goto done_img;
  }

  *new_pool =  strdup(orig_img);
  sep = strchr(*new_pool, '/');
  assert (sep);

  *(char *)sep = '\0';
  *new_img = strdup(sep + 1);

done_img:
  update_snap_name(*new_img, snap);
}

static int do_import(pool_t pool, const char *imgname, int order, const char *path)
{
  int fd = open(path, O_RDONLY);
  int r;
  uint64_t size;
  uint64_t block_size;
  struct stat stat_buf;
  string md_oid;

  if (fd < 0) {
    r = -errno;
    cerr << "error opening " << path << std::endl;
    return r;
  }

  r = fstat(fd, &stat_buf);
  if (r < 0) {
    r = -errno;
    cerr << "stat error " << path << std::endl;
    return r;
  }
  size = (uint64_t)stat_buf.st_size;

  assert(imgname);

  md_oid = imgname;
  md_oid += RBD_SUFFIX;

  r = do_create(pool, md_oid, imgname, size, &order);
  if (r < 0) {
    cerr << "image creation failed" << std::endl;
    return r;
  }

  block_size = 1 << order;

  /* FIXME: use fiemap to read sparse files */
  struct rbd_obj_header_ondisk header;
  r = read_header(pool, md_oid, &header);
  if (r < 0) {
    cerr << "error reading header" << std::endl;
    return r;
  }

  uint64_t numseg = get_max_block(&header);
  uint64_t seg_pos = 0;
  for (uint64_t i=0; i<numseg; i++) {
    uint64_t seg_size = min(size - seg_pos, block_size);
    uint64_t seg_left = seg_size;

    while (seg_left) {
      uint64_t len = min(seg_left, block_size);
      bufferptr p(len);
      len = read(fd, p.c_str(), len);
      if (len < 0) {
        r = -errno;
        cerr << "error reading file\n" << std::endl;
        return r;
      }
      bufferlist bl;
      bl.append(p);
      string oid = get_block_oid(&header, i);
      r = rados.write(pool, oid, 0, bl, len);
      if (r < 0) {
        cerr << "error writing to image block" << std::endl;
        return r;
      }

      seg_left -= len;
    }

    seg_pos += seg_size;
  }

  return 0;
}

static int do_copy(pools_t& pp, const char *imgname, const char *destname)
{
  struct rbd_obj_header_ondisk header, dest_header;
  int64_t ret;
  int r;
  string md_oid, dest_md_oid;

  md_oid = imgname;
  md_oid += RBD_SUFFIX;

  dest_md_oid = destname;
  dest_md_oid += RBD_SUFFIX;

  ret = read_header(pp.md, md_oid, &header);
  if (ret < 0)
    return ret;

  uint64_t numseg = get_max_block(&header);
  uint64_t block_size = get_block_size(&header);
  int order = header.options.order;

  r = do_create(pp.dest, dest_md_oid, destname, header.image_size, &order);
  if (r < 0) {
    cerr << "header creation failed" << std::endl;
    return r;
  }

  ret = read_header(pp.dest, dest_md_oid, &dest_header);
  if (ret < 0) {
    cerr << "failed to read newly created header" << std::endl;
    return ret;
  }

  for (uint64_t i = 0; i < numseg; i++) {
    bufferlist bl;
    string oid = get_block_oid(&header, i);
    r = rados.read(pp.data, oid, 0, bl, block_size);
    if (r < 0 && r == -ENOENT)
      r = 0;
    if (r < 0)
      return r;

    if (bl.length()) {
      string dest_oid = get_block_oid(&dest_header, i);
      r = rados.write(pp.dest, dest_oid, 0, bl, bl.length());
      if (r < 0) {
        cerr << "failed to write block " << dest_oid << std::endl;
        return r;
      }
    }
  }

  return 0;
}

static void err_exit(pools_t& pp)
{
  if (pp.data)
    rados.close_pool(pp.data);
  if (pp.md)
    rados.close_pool(pp.md);
  rados.shutdown();
  exit(1);
}

enum {
  OPT_NO_CMD = 0,
  OPT_LIST,
  OPT_INFO,
  OPT_CREATE,
  OPT_RESIZE,
  OPT_RM,
  OPT_EXPORT,
  OPT_IMPORT,
  OPT_COPY,
  OPT_RENAME,
  OPT_SNAP_CREATE,
  OPT_SNAP_ROLLBACK,
  OPT_SNAP_LIST,
};

static int get_cmd(const char *cmd, bool *snapcmd)
{
  if (strcmp(cmd, "snap") == 0) {
    if (*snapcmd)
      return -EINVAL;
    *snapcmd = true;
    return 0;
  }

  if (!*snapcmd) {
    if (strcmp(cmd, "ls") == 0 ||
        strcmp(cmd, "list") == 0)
      return OPT_LIST;
    if (strcmp(cmd, "info") == 0)
      return OPT_INFO;
    if (strcmp(cmd, "create") == 0)
      return OPT_CREATE;
    if (strcmp(cmd, "resize") == 0)
      return OPT_RESIZE;
    if (strcmp(cmd, "rm") == 0)
      return OPT_RM;
    if (strcmp(cmd, "export") == 0)
      return OPT_EXPORT;
    if (strcmp(cmd, "import") == 0)
      return OPT_IMPORT;
    if (strcmp(cmd, "copy") == 0 ||
        strcmp(cmd, "cp") == 0)
      return OPT_COPY;
    if (strcmp(cmd, "rename") == 0 ||
        strcmp(cmd, "mv") == 0)
      return OPT_RENAME;
  } else {
    if (strcmp(cmd, "create") == 0||
        strcmp(cmd, "add") == 0)
      return OPT_SNAP_CREATE;
    if (strcmp(cmd, "rollback") == 0||
        strcmp(cmd, "revert") == 0)
      return OPT_SNAP_ROLLBACK;
    if (strcmp(cmd, "ls") == 0||
        strcmp(cmd, "list") == 0)
      return OPT_SNAP_LIST;
  }

  return -EINVAL;
}

static void set_conf_param(const char *param, const char **var1, const char **var2)
{
  if (!*var1)
    *var1 = param;
  else if (var2 && !*var2)
    *var2 = param;
  else
    usage_exit();
}

int main(int argc, const char **argv) 
{
  vector<const char*> args;
  DEFINE_CONF_VARS(usage_exit);
  argv_to_vec(argc, argv, args);
  env_to_vec(args);

  pool_t pool, md_pool, dest_pool;
  pools_t pp = { 0, 0, 0 };
  snap_t snapid = 0;
  vector<snap_t> snaps;
  SnapContext snapc;

  int opt_cmd = OPT_NO_CMD;

  common_set_defaults(false);
  common_init(args, "rbdtool", true);

  const char *poolname = NULL;
  uint64_t size = 0;
  int order = 0;
  const char *imgname = NULL, *snapname = NULL, *destname = NULL, *dest_poolname = NULL, *path = NULL;
  string md_oid;
  bool is_snap_cmd = false;

  FOR_EACH_ARG(args) {
    if (CONF_ARG_EQ("pool", 'p')) {
      CONF_SAFE_SET_ARG_VAL(&poolname, OPT_STR);
    } else if (CONF_ARG_EQ("dest-pool", '\0')) {
      CONF_SAFE_SET_ARG_VAL(&dest_poolname, OPT_STR);
    } else if (CONF_ARG_EQ("snap", '\0')) {
      CONF_SAFE_SET_ARG_VAL(&snapname, OPT_STR);
    } else if (CONF_ARG_EQ("image", 'i')) {
      CONF_SAFE_SET_ARG_VAL(&imgname, OPT_STR);
    } else if (CONF_ARG_EQ("size", 's')) {
      CONF_SAFE_SET_ARG_VAL(&size, OPT_LONGLONG);
      size <<= 20; // MB -> bytes
    } else if (CONF_ARG_EQ("order", '\0')) {
      CONF_SAFE_SET_ARG_VAL(&order, OPT_INT);
    } else if (CONF_ARG_EQ("path", '\0')) {
      CONF_SAFE_SET_ARG_VAL(&path, OPT_STR);
    } else if (CONF_ARG_EQ("dest", '\0')) {
      CONF_SAFE_SET_ARG_VAL(&destname, OPT_STR);
    } else {
      if (!opt_cmd) {
        opt_cmd = get_cmd(CONF_VAL, &is_snap_cmd);
        if (opt_cmd < 0) {
          cerr << "invalid command: " << CONF_VAL << std::endl;
          usage_exit();
        }
      } else {
        switch (opt_cmd) {
          case OPT_LIST:
            set_conf_param(CONF_VAL, &poolname, NULL);
            break;
          case OPT_INFO:
          case OPT_CREATE:
          case OPT_RESIZE:
          case OPT_RM:
          case OPT_SNAP_CREATE:
          case OPT_SNAP_ROLLBACK:
          case OPT_SNAP_LIST:
            set_conf_param(CONF_VAL, &imgname, NULL);
            break;
          case OPT_EXPORT:
            set_conf_param(CONF_VAL, &imgname, &path);
            break;
          case OPT_IMPORT:
            set_conf_param(CONF_VAL, &path, &destname);
            break;
          case OPT_COPY:
          case OPT_RENAME:
            set_conf_param(CONF_VAL, &imgname, &destname);
            break;
        }
      }
    }
    //  usage_exit();
  }
  if (!opt_cmd)
    usage_exit();

  if (opt_cmd == OPT_EXPORT && !imgname) {
    cerr << "error: image name was not specified" << std::endl;
    usage_exit();
  }

  if (opt_cmd == OPT_IMPORT && !path) {
    cerr << "error: path was not specified" << std::endl;
    usage_exit();
  }

  if (opt_cmd == OPT_IMPORT && !destname)
    destname = imgname_from_path(path);

  if (opt_cmd != OPT_LIST && opt_cmd != OPT_IMPORT && !imgname) {
    cerr << "error: image name was not specified" << std::endl;
    usage_exit();
  }

  set_pool_image_name(poolname, imgname, (char **)&poolname, (char **)&imgname, (char **)&snapname);
  set_pool_image_name(dest_poolname, destname, (char **)&dest_poolname, (char **)&destname, NULL);

  if ((opt_cmd == OPT_SNAP_CREATE || opt_cmd == OPT_SNAP_ROLLBACK) && !snapname) {
    cerr << "error: snap name was not specified" << std::endl;
    usage_exit();
  }

  if (!dest_poolname)
    dest_poolname = poolname;

  if (opt_cmd == OPT_EXPORT && !path)
    path = imgname;

  if (opt_cmd == OPT_COPY && !destname ) {
    cerr << "error: destination image name was not specified" << std::endl;
    usage_exit();
  }

  if (rados.initialize(argc, argv) < 0) {
     cerr << "error: couldn't initialize rados!" << std::endl;
     exit(1);
  }

  if (opt_cmd != OPT_LIST && opt_cmd != OPT_IMPORT) {
    md_oid = imgname;
    md_oid += RBD_SUFFIX;
  }

  int r = rados.open_pool(poolname, &md_pool);
  if (r < 0) {
    cerr << "error opening pool " << poolname << " (err=" << r << ")" << std::endl;
    err_exit(pp);
  }
  pp.md = md_pool;

  r = rados.open_pool(poolname, &pool);
  if (r < 0) {
    cerr << "error opening pool " << poolname << " (err=" << r << ")" << std::endl;
    err_exit(pp);
  }
  pp.data = pool;
  if (snapname) {
    r = do_get_snapc(pp, md_oid, snapname, snapc, snaps, snapid);
    if (r == -ENOENT) {
      if (opt_cmd == OPT_SNAP_CREATE)
        r = 0;
      else
        cerr << "snapshot not found: " << snapname << std::endl;
    }
    if (r < 0) {
      cerr << "error searching for snapshot: " << strerror(-r) << std::endl;
      err_exit(pp);
    }

    r = rados.set_snap_context(pool, snapc.seq, snaps);
    if (r < 0) {
      cerr << "error setting snapshot context: " << strerror(-r) << std::endl;
      err_exit(pp);
    }

    rados.set_snap(pool, snapid);
  }

  if (opt_cmd == OPT_COPY || opt_cmd == OPT_IMPORT) {
    r = rados.open_pool(dest_poolname, &dest_pool);
    if (r < 0) {
      cerr << "error opening pool " << dest_poolname << " (err=" << r << ")" << std::endl;
      err_exit(pp);
    }
    pp.dest = dest_pool;
  }

  if (opt_cmd == OPT_LIST) {
    r = do_list(pp, poolname);
    if (r < 0) {
      switch (r) {
      case -ENOENT:
        cerr << "pool " << poolname << " doesn't contain rbd images" << std::endl;
        break;
      default:
        cerr << "error: " << strerror(-r) << std::endl;
      }
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_CREATE) {
    if (!size) {
      cerr << "must specify size in MB to create an rbd image" << std::endl;
      usage();
      err_exit(pp);
    }
    if (order && (order < 12 || order > 25)) {
      cerr << "order must be between 12 (4 KB) and 25 (32 MB)" << std::endl;
      usage();
      err_exit(pp);
    }
    r = do_create(pp.md, md_oid, imgname, size, &order);
    if (r < 0) {
      cerr << "create error: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_RENAME) {
    r = do_rename(pp, md_oid, imgname, destname);
    if (r < 0) {
      cerr << "rename error: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_INFO) {
    r = do_show_info(pp, md_oid, imgname);
    if (r < 0) {
      cerr << "error: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_RM) {
    r = do_delete(pp, md_oid, imgname);
    if (r < 0) {
      cerr << "delete error: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_RESIZE) {
    r = do_resize(pp, md_oid, imgname, size);
    if (r < 0) {
      cerr << "resize error: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_SNAP_LIST) {
    if (!imgname) {
      usage();
      err_exit(pp);
    }
    r = do_list_snaps(pp, md_oid);
    if (r < 0) {
      cerr << "failed to list snapshots: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_SNAP_CREATE) {
    if (!imgname || !snapname) {
      usage();
      err_exit(pp);
    }
    r = do_add_snap(pp, md_oid, snapname);
    if (r < 0) {
      cerr << "failed to create snapshot: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_SNAP_ROLLBACK) {
    if (!imgname) {
      usage();
      err_exit(pp);
    }
    r = do_rollback_snap(pp, md_oid, snapc, snapid);
    if (r < 0) {
      cerr << "rollback failed: " << strerror(-r) << std::endl;
      usage();
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_EXPORT) {
    if (!path) {
      cerr << "pathname should be specified" << std::endl;
      err_exit(pp);
    }
    r = do_export(pp, md_oid, path);
    if (r < 0) {
      cerr << "export error: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_IMPORT) {
     if (!path) {
      cerr << "pathname should be specified" << std::endl;
      err_exit(pp);
    }
    r = do_import(pp.dest, destname, order, path);
    if (r < 0) {
      cerr << "import failed: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  } else if (opt_cmd == OPT_COPY) {
    r = do_copy(pp, imgname, destname);
    if (r < 0) {
      cerr << "copy failed: " << strerror(-r) << std::endl;
      err_exit(pp);
    }
  }

  rados.close_pool(pool);
  rados.close_pool(md_pool);
  rados.shutdown(); 
  return 0;
}