. loops checked for PID_FREE . exit broken down in exit and cleanup functions; when reboot happens, cleanup is done but not exit (as processes have not actually exited), this keeps drivers working . fixed a few uninitialized and unused variables scripts: . new packaging system
293 lines
9.2 KiB
C
293 lines
9.2 KiB
C
/* This file contains the main program of the File System. It consists of
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* a loop that gets messages requesting work, carries out the work, and sends
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* replies.
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*
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* The entry points into this file are:
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* main: main program of the File System
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* reply: send a reply to a process after the requested work is done
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*
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*/
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struct super_block; /* proto.h needs to know this */
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#include "fs.h"
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#include <fcntl.h>
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#include <string.h>
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#include <stdio.h>
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#include <signal.h>
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#include <stdlib.h>
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#include <sys/ioc_memory.h>
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#include <sys/svrctl.h>
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#include <sys/select.h>
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/keymap.h>
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#include <minix/const.h>
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#include <minix/endpoint.h>
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#include "buf.h"
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#include "file.h"
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#include "fproc.h"
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#include "inode.h"
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#include "param.h"
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#include "super.h"
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FORWARD _PROTOTYPE( void fs_init, (void) );
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FORWARD _PROTOTYPE( void get_work, (void) );
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FORWARD _PROTOTYPE( void init_root, (void) );
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/*===========================================================================*
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* main *
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*===========================================================================*/
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PUBLIC int main()
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{
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/* This is the main program of the file system. The main loop consists of
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* three major activities: getting new work, processing the work, and sending
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* the reply. This loop never terminates as long as the file system runs.
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*/
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int error;
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fs_init();
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/* This is the main loop that gets work, processes it, and sends replies. */
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while (TRUE) {
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get_work(); /* sets who and call_nr */
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fp = &fproc[who_p]; /* pointer to proc table struct */
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super_user = (fp->fp_effuid == SU_UID ? TRUE : FALSE); /* su? */
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/* Check for special control messages first. */
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if (call_nr == PROC_EVENT) {
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/* Assume FS got signal. Synchronize, but don't exit. */
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do_sync();
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} else if (call_nr == SYN_ALARM) {
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/* Alarm timer expired. Used only for select(). Check it. */
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fs_expire_timers(m_in.NOTIFY_TIMESTAMP);
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} else if ((call_nr & NOTIFY_MESSAGE)) {
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/* Device notifies us of an event. */
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dev_status(&m_in);
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} else {
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/* Call the internal function that does the work. */
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if (call_nr < 0 || call_nr >= NCALLS) {
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error = ENOSYS;
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/* Not supposed to happen. */
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printf("FS, warning illegal %d system call by %d\n", call_nr, who_e);
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} else if (fp->fp_pid == PID_FREE) {
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error = ENOSYS;
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printf("FS, bad process, who = %d, call_nr = %d, endpt1 = %d\n",
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who_e, call_nr, m_in.endpt1);
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} else {
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error = (*call_vec[call_nr])();
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}
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/* Copy the results back to the user and send reply. */
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if (error != SUSPEND) { reply(who_e, error); }
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if (rdahed_inode != NIL_INODE) {
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read_ahead(); /* do block read ahead */
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}
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}
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}
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return(OK); /* shouldn't come here */
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}
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/*===========================================================================*
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* get_work *
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*===========================================================================*/
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PRIVATE void get_work()
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{
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/* Normally wait for new input. However, if 'reviving' is
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* nonzero, a suspended process must be awakened.
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*/
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register struct fproc *rp;
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if (reviving != 0) {
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/* Revive a suspended process. */
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for (rp = &fproc[0]; rp < &fproc[NR_PROCS]; rp++)
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if (rp->fp_pid != PID_FREE && rp->fp_revived == REVIVING) {
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who_p = (int)(rp - fproc);
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who_e = rp->fp_endpoint;
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call_nr = rp->fp_fd & BYTE;
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m_in.fd = (rp->fp_fd >>8) & BYTE;
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m_in.buffer = rp->fp_buffer;
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m_in.nbytes = rp->fp_nbytes;
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rp->fp_suspended = NOT_SUSPENDED; /*no longer hanging*/
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rp->fp_revived = NOT_REVIVING;
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reviving--;
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return;
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}
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panic(__FILE__,"get_work couldn't revive anyone", NO_NUM);
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}
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for(;;) {
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/* Normal case. No one to revive. */
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if (receive(ANY, &m_in) != OK)
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panic(__FILE__,"fs receive error", NO_NUM);
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who_e = m_in.m_source;
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who_p = _ENDPOINT_P(who_e);
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if(who_p < -NR_TASKS || who_p >= NR_PROCS)
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panic(__FILE__,"receive process out of range", who_p);
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if(who_p >= 0 && fproc[who_p].fp_endpoint == NONE) {
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printf("FS: ignoring request from %d, endpointless slot %d (%d)\n",
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m_in.m_source, who_p, m_in.m_type);
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continue;
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}
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if(who_p >= 0 && fproc[who_p].fp_endpoint != who_e) {
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printf("FS: receive endpoint inconsistent (%d, %d, %d).\n",
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who_e, fproc[who_p].fp_endpoint, who_e);
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panic(__FILE__, "FS: inconsistent endpoint ", NO_NUM);
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continue;
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}
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call_nr = m_in.m_type;
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return;
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}
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}
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/*===========================================================================*
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* buf_pool *
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*===========================================================================*/
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PRIVATE void buf_pool(void)
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{
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/* Initialize the buffer pool. */
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register struct buf *bp;
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bufs_in_use = 0;
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front = &buf[0];
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rear = &buf[NR_BUFS - 1];
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for (bp = &buf[0]; bp < &buf[NR_BUFS]; bp++) {
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bp->b_blocknr = NO_BLOCK;
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bp->b_dev = NO_DEV;
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bp->b_next = bp + 1;
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bp->b_prev = bp - 1;
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}
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buf[0].b_prev = NIL_BUF;
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buf[NR_BUFS - 1].b_next = NIL_BUF;
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for (bp = &buf[0]; bp < &buf[NR_BUFS]; bp++) bp->b_hash = bp->b_next;
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buf_hash[0] = front;
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}
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/*===========================================================================*
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* reply *
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*===========================================================================*/
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PUBLIC void reply(whom, result)
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int whom; /* process to reply to */
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int result; /* result of the call (usually OK or error #) */
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{
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/* Send a reply to a user process. If the send fails, just ignore it. */
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int s;
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m_out.reply_type = result;
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s = send(whom, &m_out);
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if (s != OK) printf("FS: couldn't send reply %d to %d: %d\n",
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result, whom, s);
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}
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/*===========================================================================*
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* fs_init *
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*===========================================================================*/
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PRIVATE void fs_init()
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{
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/* Initialize global variables, tables, etc. */
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register struct inode *rip;
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register struct fproc *rfp;
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message mess;
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int s;
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/* Initialize the process table with help of the process manager messages.
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* Expect one message for each system process with its slot number and pid.
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* When no more processes follow, the magic process number NONE is sent.
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* Then, stop and synchronize with the PM.
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*/
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do {
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if (OK != (s=receive(PM_PROC_NR, &mess)))
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panic(__FILE__,"FS couldn't receive from PM", s);
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if (NONE == mess.PR_ENDPT) break;
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rfp = &fproc[mess.PR_SLOT];
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rfp->fp_pid = mess.PR_PID;
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rfp->fp_endpoint = mess.PR_ENDPT;
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rfp->fp_realuid = (uid_t) SYS_UID;
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rfp->fp_effuid = (uid_t) SYS_UID;
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rfp->fp_realgid = (gid_t) SYS_GID;
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rfp->fp_effgid = (gid_t) SYS_GID;
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rfp->fp_umask = ~0;
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} while (TRUE); /* continue until process NONE */
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mess.m_type = OK; /* tell PM that we succeeded */
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s=send(PM_PROC_NR, &mess); /* send synchronization message */
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/* All process table entries have been set. Continue with FS initialization.
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* Certain relations must hold for the file system to work at all. Some
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* extra block_size requirements are checked at super-block-read-in time.
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*/
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if (OPEN_MAX > 127) panic(__FILE__,"OPEN_MAX > 127", NO_NUM);
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if (NR_BUFS < 6) panic(__FILE__,"NR_BUFS < 6", NO_NUM);
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if (V1_INODE_SIZE != 32) panic(__FILE__,"V1 inode size != 32", NO_NUM);
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if (V2_INODE_SIZE != 64) panic(__FILE__,"V2 inode size != 64", NO_NUM);
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if (OPEN_MAX > 8 * sizeof(long))
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panic(__FILE__,"Too few bits in fp_cloexec", NO_NUM);
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/* The following initializations are needed to let dev_opcl succeed .*/
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fp = (struct fproc *) NULL;
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who_e = who_p = FS_PROC_NR;
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buf_pool(); /* initialize buffer pool */
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build_dmap(); /* build device table and map boot driver */
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init_root(); /* init root device and load super block */
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init_select(); /* init select() structures */
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/* The root device can now be accessed; set process directories. */
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for (rfp=&fproc[0]; rfp < &fproc[NR_PROCS]; rfp++) {
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FD_ZERO(&(rfp->fp_filp_inuse));
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if (rfp->fp_pid != PID_FREE) {
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rip = get_inode(root_dev, ROOT_INODE);
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dup_inode(rip);
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rfp->fp_rootdir = rip;
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rfp->fp_workdir = rip;
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} else rfp->fp_endpoint = NONE;
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}
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}
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/*===========================================================================*
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* init_root *
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*===========================================================================*/
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PRIVATE void init_root()
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{
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int bad;
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register struct super_block *sp;
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register struct inode *rip = NIL_INODE;
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int s;
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/* Open the root device. */
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root_dev = DEV_IMGRD;
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if ((s=dev_open(root_dev, FS_PROC_NR, R_BIT|W_BIT)) != OK)
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panic(__FILE__,"Cannot open root device", s);
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#if ENABLE_CACHE2
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/* The RAM disk is a second level block cache while not otherwise used. */
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init_cache2(ram_size);
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#endif
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/* Initialize the super_block table. */
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for (sp = &super_block[0]; sp < &super_block[NR_SUPERS]; sp++)
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sp->s_dev = NO_DEV;
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/* Read in super_block for the root file system. */
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sp = &super_block[0];
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sp->s_dev = root_dev;
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/* Check super_block for consistency. */
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bad = (read_super(sp) != OK);
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if (!bad) {
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rip = get_inode(root_dev, ROOT_INODE); /* inode for root dir */
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if ( (rip->i_mode & I_TYPE) != I_DIRECTORY || rip->i_nlinks < 3) bad++;
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}
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if (bad) panic(__FILE__,"Invalid root file system", NO_NUM);
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sp->s_imount = rip;
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dup_inode(rip);
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sp->s_isup = rip;
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sp->s_rd_only = 0;
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return;
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}
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