vdev.h

/*
   vdev: a virtual device manager for *nix
   Copyright (C) 2014  Jude Nelson

   This program is dual-licensed: you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 3 or later as 
   published by the Free Software Foundation. For the terms of this 
   license, see LICENSE.GPLv3+ or <http://www.gnu.org/licenses/>.

   You are free to use this program under the terms of the GNU General
   Public License, 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.

   Alternatively, you are free to use this program under the terms of the 
   Internet Software Consortium License, but WITHOUT ANY WARRANTY; without
   even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   For the terms of this license, see LICENSE.ISC or 
   <http://www.isc.org/downloads/software-support-policy/isc-license/>.
*/

#ifndef _VDEV_H_
#define _VDEV_H_

#include "libvdev/config.h"
#include "libvdev/util.h"
#include "os/common.h"
#include "device.h"
#include "workqueue.h"

#ifndef VDEV_CONFIG_FILE
#define VDEV_CONFIG_FILE "/etc/vdev/vdevd.conf"
#endif

// global vdev state 
struct vdev_state {
   
   // configuration (covered by reload_lock)
   struct vdev_config* config;
   
   // arguments 
   int argc;
   char** argv;
   
   // mountpoint; where /dev is
   char* mountpoint;
   
   // OS context
   struct vdev_os_context* os;
   
   // actions (covered by reload_lock)
   struct vdev_action* acts;
   size_t num_acts;
   
   // pending requests
   struct vdev_pending_context* pending;
   
   // device processing workqueue (back-end)
   struct vdev_wq device_wq;
   
   // are we taking events from the OS? (back-end)
   bool running;
   
   // coldplug only?
   bool coldplug_only;
   
   // fd to signal the end of coldplug 
   int coldplug_finished_fd;

   // error thread that listens to an error FIFO
   // that helper processes use to send error
   // messages to vdev's log
   bool error_thread_running; 
   pthread_t error_thread;

   // fd to the error pipe, to be passed to subprocesses
   // in place of stderr
   int error_fd;

   // reload lock--held when reloading the config 
   pthread_mutex_t reload_lock;
};

typedef char* cstr;

C_LINKAGE_BEGIN

int vdev_init( struct vdev_state* vdev, int argc, char** argv );
int vdev_start( struct vdev_state* vdev );
int vdev_main( struct vdev_state* vdev, int flush_fd );
int vdev_reload( struct vdev_state* vdev );
int vdev_stop( struct vdev_state* vdev );
int vdev_shutdown( struct vdev_state* vdev, bool unlink_pidfile );

int vdev_reload_lock( struct vdev_state* vdev );
int vdev_reload_unlock( struct vdev_state* vdev );

int vdev_error_fifo_path( char const* mountpoint, char* path, size_t path_len );
int vdev_signal_coldplug_finished( struct vdev_state* state, int status );

int vdev_preseed_run( struct vdev_state* state );
int vdev_remove_unplugged_devices( struct vdev_state* state );

SGLIB_DEFINE_VECTOR_PROTOTYPES( cstr );

C_LINKAGE_END

#endif