minix3/fs/ext2/main.c

#include "fs.h"
#include <assert.h>
#include <minix/callnr.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <minix/dmap.h>
#include <minix/endpoint.h>
#include <minix/vfsif.h>
#include <minix/optset.h>
#include "buf.h"
#include "inode.h"

/* Declare some local functions. */
static void get_work(message *m_in);
static void reply(endpoint_t who, message *m_out);

/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init_fresh(int type, sef_init_info_t *info);
static void sef_cb_signal_handler(int signo);

EXTERN int env_argc;
EXTERN char **env_argv;

static struct optset optset_table[] = {
  { "sb",		OPT_INT,    &opt.block_with_super,	0	},
  { "orlov",		OPT_BOOL,   &opt.use_orlov,		TRUE    },
  { "oldalloc",		OPT_BOOL,   &opt.use_orlov,		FALSE   },
  { "mfsalloc",		OPT_BOOL,   &opt.mfsalloc,		TRUE    },
  { "reserved",		OPT_BOOL,   &opt.use_reserved_blocks,	TRUE    },
  { "prealloc",		OPT_BOOL,   &opt.use_prealloc, 		TRUE	},
  { "noprealloc",	OPT_BOOL,   &opt.use_prealloc, 		FALSE	},
  { NULL,		0,	    NULL,			0								}
};

/*===========================================================================*
 *				main                                         *
 *===========================================================================*/
int main(int argc, char *argv[])
{
/* This is the main routine of this service. The main loop consists of
 * three major activities: getting new work, processing the work, and
 * sending the reply. The loop never terminates, unless a panic occurs.
 */
  int error = OK, ind, transid;
  unsigned short test_endian = 1;

  /* SEF local startup. */
  env_setargs(argc, argv);
  sef_local_startup();

  le_CPU = (*(unsigned char *) &test_endian == 0 ? 0 : 1);

  /* Server isn't tested on big endian CPU */
  ASSERT(le_CPU == 1);

  while(!unmountdone || !exitsignaled) {
	endpoint_t src;

	/* Wait for request message. */
	get_work(&fs_m_in);

	transid = TRNS_GET_ID(fs_m_in.m_type);
	fs_m_in.m_type = TRNS_DEL_ID(fs_m_in.m_type);
	if (fs_m_in.m_type == 0) {
		assert(!IS_VFS_FS_TRANSID(transid));
		fs_m_in.m_type = transid;       /* Backwards compat. */
		transid = 0;
	} else
		assert(IS_VFS_FS_TRANSID(transid));

	src = fs_m_in.m_source;
	caller_uid = INVAL_UID;	/* To trap errors */
	caller_gid = INVAL_GID;
	req_nr = fs_m_in.m_type;

	if (req_nr < FS_BASE) {
		fs_m_in.m_type += FS_BASE;
		req_nr = fs_m_in.m_type;
	}
	ind = req_nr - FS_BASE;

	if (ind < 0 || ind >= NREQS) {
		printf("mfs: bad request %d\n", req_nr);
		printf("ind = %d\n", ind);
		error = EINVAL;
	} else {
		error = (*fs_call_vec[ind])();
	}

	fs_m_out.m_type = error;
	if (IS_VFS_FS_TRANSID(transid)) {
		/* If a transaction ID was set, reset it */
		fs_m_out.m_type = TRNS_ADD_ID(fs_m_out.m_type, transid);
	}
	reply(src, &fs_m_out);

	if (error == OK)
		read_ahead(); /* do block read ahead */
  }

  return 0;
}

/*===========================================================================*
 *			       sef_local_startup			     *
 *===========================================================================*/
static void sef_local_startup()
{
  /* Register init callbacks. */
  sef_setcb_init_fresh(sef_cb_init_fresh);
  sef_setcb_init_restart(sef_cb_init_fail);

  /* No live update support for now. */

  /* Register signal callbacks. */
  sef_setcb_signal_handler(sef_cb_signal_handler);

  /* Let SEF perform startup. */
  sef_startup();
}

/*===========================================================================*
 *		            sef_cb_init_fresh                                *
 *===========================================================================*/
static int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *UNUSED(info))
{
/* Initialize the Minix file server. */
  int i;

  /* Defaults */
  opt.use_orlov = TRUE;
  opt.mfsalloc = FALSE;
  opt.use_reserved_blocks = FALSE;
  opt.block_with_super = 0;
  opt.use_prealloc = FALSE;

  /* If we have been given an options string, parse options from there. */
  for (i = 1; i < env_argc - 1; i++)
	if (!strcmp(env_argv[i], "-o"))
		optset_parse(optset_table, env_argv[++i]);

  lmfs_may_use_vmcache(1);

  /* Init inode table */
  for (i = 0; i < NR_INODES; ++i) {
	inode[i].i_count = 0;
	cch[i] = 0;
  }

  init_inode_cache();

  /* just a small number before we find out the block size at mount time */
  lmfs_buf_pool(10);

  return(OK);
}

/*===========================================================================*
 *		           sef_cb_signal_handler                             *
 *===========================================================================*/
static void sef_cb_signal_handler(int signo)
{
  /* Only check for termination signal, ignore anything else. */
  if (signo != SIGTERM) return;

  exitsignaled = 1;
  (void) fs_sync();

  /* If unmounting has already been performed, exit immediately.
   * We might not get another message.
   */
  if (unmountdone) exit(0);
}

/*===========================================================================*
 *				get_work				     *
 *===========================================================================*/
static void get_work(m_in)
message *m_in;				/* pointer to message */
{
  int r, srcok = 0;
  endpoint_t src;

  do {
	if ((r = sef_receive(ANY, m_in)) != OK) 	/* wait for message */
		panic("sef_receive failed: %d", r);
	src = m_in->m_source;

	if(src == VFS_PROC_NR) {
		if(unmountdone)
			printf("ext2: unmounted: unexpected message from FS\n");
		else
			srcok = 1;		/* Normal FS request. */

	} else
		printf("ext2: unexpected source %d\n", src);
  } while(!srcok);

   assert((src == VFS_PROC_NR && !unmountdone));
}


/*===========================================================================*
 *				reply					     *
 *===========================================================================*/
static void reply(
  endpoint_t who,
  message *m_out                       	/* report result */
)
{
  if (OK != ipc_send(who, m_out))    /* send the message */
	printf("ext2(%d) was unable to send reply\n", sef_self());
}