path: root/sbuild/sbuild-chroot-lvm-snapshot.cc

/* Copyright © 2005-2008  Roger Leigh <rleigh@debian.org>
 *
 * schroot is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * schroot is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 *
 *********************************************************************/

#include <config.h>

#include "sbuild-chroot-lvm-snapshot.h"
#include "sbuild-chroot-block-device.h"
#include "sbuild-format-detail.h"
#include "sbuild-lock.h"

#include <cerrno>
#include <iostream>

#include <boost/format.hpp>

using std::endl;
using boost::format;
using namespace sbuild;

chroot_lvm_snapshot::chroot_lvm_snapshot ():
  chroot_block_device_base(),
  chroot_source(),
  snapshot_device(),
  snapshot_options()
{
}

chroot_lvm_snapshot::~chroot_lvm_snapshot ()
{
}

sbuild::chroot::ptr
chroot_lvm_snapshot::clone () const
{
  return ptr(new chroot_lvm_snapshot(*this));
}

sbuild::chroot::ptr
chroot_lvm_snapshot::clone_source () const
{
  ptr clone(new chroot_block_device(*this));

  clone_source_setup(clone);

  return clone;
}

std::string const&
chroot_lvm_snapshot::get_snapshot_device () const
{
  return this->snapshot_device;
}

void
chroot_lvm_snapshot::set_snapshot_device (std::string const& snapshot_device)
{
  if (!is_absname(snapshot_device))
    throw error(snapshot_device, DEVICE_ABS);

  this->snapshot_device = snapshot_device;
}

std::string const&
chroot_lvm_snapshot::get_snapshot_options () const
{
  return this->snapshot_options;
}

void
chroot_lvm_snapshot::set_snapshot_options (std::string const& snapshot_options)
{
  this->snapshot_options = snapshot_options;
}

void
chroot_lvm_snapshot::set_mount_device (std::string const& mount_device)
{
  // Setting the mount device is not permitted for lvm_snapshot chroots.
}

std::string const&
chroot_lvm_snapshot::get_mount_device () const
{
  return this->snapshot_device;
}

std::string const&
chroot_lvm_snapshot::get_chroot_type () const
{
  static const std::string type("lvm-snapshot");

  return type;
}

void
chroot_lvm_snapshot::setup_env (environment& env)
{
  chroot_block_device_base::setup_env(env);
  chroot_source::setup_env(env);

  env.add("CHROOT_LVM_SNAPSHOT_NAME", sbuild::basename(get_snapshot_device()));
  env.add("CHROOT_LVM_SNAPSHOT_DEVICE", get_snapshot_device());
  env.add("CHROOT_LVM_SNAPSHOT_OPTIONS", get_snapshot_options());
}

void
chroot_lvm_snapshot::setup_lock (chroot::setup_type type,
				 bool               lock,
				 int                status)
{
  std::string device;

  /* Lock is removed by setup script on setup stop.  Unlocking here
     would fail: the LVM snapshot device no longer exists. */
  if (!(type == SETUP_STOP && lock == false))
    {
      if (type == SETUP_START)
	device = get_device();
      else
	device = get_snapshot_device();

      if (device.empty())
	throw error(CHROOT_DEVICE);

      try
	{
	  stat file_status(device);
	  if (!file_status.is_block())
	    {
	      throw error(get_device(), DEVICE_NOTBLOCK);
	    }
	  else
	    {
	      /* Lock is preserved while running a command. */
	      if ((type == EXEC_START && lock == false) ||
		  (type == EXEC_STOP && lock == true))
		return;

	      sbuild::device_lock dlock(device);
	      if (lock)
		{
		  try
		    {
		      dlock.set_lock(lock::LOCK_EXCLUSIVE, 15);
		    }
		  catch (sbuild::lock::error const& e)
		    {
		      throw error(get_device(), DEVICE_LOCK, e);
		    }
		}
	      else
		{
		  try
		    {
		      dlock.unset_lock();
		    }
		  catch (sbuild::lock::error const& e)
		    {
		      throw error(get_device(), DEVICE_UNLOCK, e);
		    }
		}
	    }
	}
      catch (sbuild::stat::error const& e) // Failed to stat
	{
	  // Don't throw if stopping a session and the device stat
	  // failed.  This is because the setup scripts shouldn't fail
	  // to be run if the LVM snapshot no longer exists, which
	  // would prevent the session from being ended.
	  if (type != SETUP_STOP)
	    throw;
	}
    }

  /* Create or unlink session information. */
  if ((type == SETUP_START && lock == true) ||
      (type == SETUP_STOP && lock == false && status == 0))
    {
      bool start = (type == SETUP_START);
      setup_session_info(start);
    }
}

sbuild::chroot::session_flags
chroot_lvm_snapshot::get_session_flags () const
{
  session_flags flags = SESSION_CREATE | chroot_source::get_session_flags();
  if (get_active())
    flags = flags | SESSION_PURGE;

  return flags;
}

void
chroot_lvm_snapshot::get_details (format_detail& detail) const
{
  chroot_block_device_base::get_details(detail);
  chroot_source::get_details(detail);

  if (!this->snapshot_device.empty())
    detail.add(_("LVM Snapshot Device"), get_snapshot_device());
  if (!this->snapshot_options.empty())
    detail.add(_("LVM Snapshot Options"), get_snapshot_options());
}

void
chroot_lvm_snapshot::get_keyfile (keyfile& keyfile) const
{
  chroot_block_device_base::get_keyfile(keyfile);
  chroot_source::get_keyfile(keyfile);

  if (get_active())
    keyfile::set_object_value(*this,
			      &chroot_lvm_snapshot::get_snapshot_device,
			      keyfile, get_keyfile_name(),
			      "lvm-snapshot-device");

  if (!get_active())
    keyfile::set_object_value(*this,
			      &chroot_lvm_snapshot::get_snapshot_options,
			      keyfile, get_keyfile_name(),
			      "lvm-snapshot-options");
}

void
chroot_lvm_snapshot::set_keyfile (keyfile const& keyfile,
				  string_list&   used_keys)
{
  chroot_block_device_base::set_keyfile(keyfile, used_keys);
  chroot_source::set_keyfile(keyfile, used_keys);

  keyfile::get_object_value(*this, &chroot_lvm_snapshot::set_snapshot_device,
			    keyfile, get_keyfile_name(), "lvm-snapshot-device",
			    get_active() ?
			    keyfile::PRIORITY_REQUIRED :
			    keyfile::PRIORITY_DISALLOWED);
  used_keys.push_back("lvm-snapshot-device");

  keyfile::get_object_value(*this, &chroot_lvm_snapshot::set_snapshot_options,
			    keyfile, get_keyfile_name(), "lvm-snapshot-options",
			    get_active() ?
			    keyfile::PRIORITY_DEPRECATED :
			    keyfile::PRIORITY_REQUIRED); // Only needed for creating snapshot, not using snapshot
  used_keys.push_back("lvm-snapshot-options");
}