sm_statd.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 435 行

# ifndef lint
static char *sccsid = "@(#)sm_statd.c	4.1	(ULTRIX)	7/2/90";
# endif not lint

/****************************************************************
 *								*
 *  Licensed to Digital Equipment Corporation, Maynard, MA	*
 *		Copyright 1985 Sun Microsystems, Inc.		*
 *			All rights reserved.			*
 *								*
 ****************************************************************/
/**/
/*
 *	Modification history:
 *	~~~~~~~~~~~~~~~~~~~~
 *
 *	revision			comments
 *	--------	-----------------------------------------------
 *
 *	18-Jan-88	fries
 *			Added Header and Copyright notice.
 *
 *	
 */
#include <stdio.h>
#include <sys/types.h>
#include <sys/file.h>
#include <sys/dir.h>
#include <rpc/rpc.h>
#include <rpcsvc/sm_inter.h>
#include <errno.h>
#include "sm_statd.h"

#define MAXPGSIZE 8192
#define SM_INIT_ALARM 15
extern int debug;
extern int errno;
extern char STATE[20], CURRENT[20], BACKUP[20];
int LOCAL_STATE;

struct name_entry {
	char *name;
	int count;
	struct name_entry *prev;
	struct name_entry *nxt;
};
typedef struct name_entry name_entry;

name_entry *find_name();
name_entry *insert_name();
name_entry *record_q;
name_entry *recovery_q;

char hostname[MAXNAMLEN];

sm_notify(ntfp)
stat_chge *ntfp;
{
	if(debug) printf("sm_notify: %s state =%d\n", ntfp->name, ntfp->state);
	send_notice(ntfp->name, ntfp->state);
}

/*
 * called when statd first comes up; it searches /etc/sm to gather
 * all entries to notify its own failure
 */
statd_init()
{
	int cc, fd;
	char buf[MAXPGSIZE];
	long base;
	int nbytes;
	struct direct dir, *dirp;
	char *bufp;
	int len;
	name_entry *nl;
	char from[MAXNAMLEN], to[MAXNAMLEN], path[MAXNAMLEN];
	FILE *fp, *fopen();
	int err;

	if(debug) printf("enter statd_init\n");
	gethostname(hostname, MAXNAMLEN);
	if((fp = fopen(STATE, "a+")) == NULL) {
		fprintf(stderr, "fopen(stat file) error\n");
		exit(1);
	}
	if(fseek(fp, 0, 0) == -1) {
		perror("fseek");
		fprintf(stderr, "\n");
		exit(1);
	}
	if((cc = fscanf(fp, "%d", &LOCAL_STATE)) == EOF) {
		if(debug >= 2) printf("empty file\n");
		LOCAL_STATE = 0;
	}
	if(LOCAL_STATE % 2 == 0) 
		LOCAL_STATE = LOCAL_STATE +1;
	else
		LOCAL_STATE = LOCAL_STATE + 2;
	if(fseek(fp, 0, 0) == -1) {
		perror("fseek");
		fprintf(stderr, "\n");
		exit(1);
	}
	fprintf(fp, "%d", LOCAL_STATE);
	fflush(fp);
	if(fsync(fileno(fp)) == -1) {
		perror("fsync");
		fprintf(stderr, "\n");
		exit(1);
	}
	fclose(fp);
	if(debug) printf("local state = %d\n", LOCAL_STATE);
	
	if((mkdir(CURRENT, 00777)) == -1) {
		if(errno != EEXIST) {
			perror("mkdir current");
			fprintf(stderr, "\n");
			exit(1);
		}
	}
	if((mkdir(BACKUP, 00777)) == -1) {
		if(errno != EEXIST) {
			perror("mkdir backup");
			fprintf(stderr, "\n");
			exit(1);
		}
	}

	/* get all entries in CURRENT into BACKUP */
	if((fd = open(CURRENT, O_RDONLY, 00200)) == -1) {
		perror("open current directory");
		fprintf(stderr, "\n");
		exit(1);
	}
	if((cc = getdirentries(fd, buf, 8192, &base)) == -1) {
		perror("getdirentries");
		fprintf(stderr, "\n");
		exit(1);
	}
	bufp = buf;
	len = 0;
	while( cc > 0) {
		bufp = bufp + len;
		dirp = (struct direct *)bufp;
		len = dirp -> d_reclen;
/*
		printf("len = %d\n", len);
		printf("d_name = %s\n", dirp->d_name);
*/
		if(strcmp(dirp->d_name, ".") != 0  &&
		strcmp(dirp->d_name, "..") != 0) {
		/* rename all entries from CURRENT to BACKUP */
			strcpy(from , CURRENT);
			strcpy(to, BACKUP);
			strcat(from, "/");
			strcat(to, "/");
			strcat(from, dirp->d_name);
			strcat(to, dirp->d_name);
			if(rename(from, to) == -1) {
				perror("rename");
				fprintf(stderr, "\n");
				exit(1);
			}
			if(debug >= 2) printf("rename: %s to %s\n", from ,to);
		}
		cc = cc - len;
	}
	if(close(fd) == -1) {
		perror("close current directory\n");
		fprintf(stderr, "\n");
		exit(1);
	}

	/* get all entries in BACKUP into recovery_q */
	if((fd = open(BACKUP, O_RDONLY, 00200)) == -1) {
		perror("open backup directory");
		fprintf(stderr, "\n");
		exit(1);
	}
	if((cc = getdirentries(fd, buf, 8192, &base)) == -1) {
		perror("getdirentries");
		fprintf(stderr, "\n");
		exit(1);
	}
	bufp = buf;
	len = 0;
	while( cc > 0) {
		bufp = bufp + len;
		dirp = (struct direct *)bufp;
		len = dirp -> d_reclen;
		if(strcmp(dirp->d_name, ".") != 0  &&
		strcmp(dirp->d_name, "..") != 0) {
		/* get all entries from BACKUP to recovery_q */
			if((err = statd_call_statd(dirp->d_name))!=0 ) {
				insert_name(&recovery_q, dirp->d_name);
			}
			else { /* remove from BACKUP directory */
				strcpy(path, BACKUP);
				strcat(path, "/");
				strcat(path, dirp->d_name);
			if(debug >= 2) printf("remove monitor entry %s\n", path);
			if(unlink(path) == -1) {
				perror(path);
				fprintf(stderr, "\n");
				exit(1);
			}
			}
		}
		cc = cc - len;
	}
	if(close(fd) == -1) {
		perror("close current directory\n");
		fprintf(stderr, "\n");
		exit(1);
	}

	/* notify statd */
	if(recovery_q != NULL)
		alarm(SM_INIT_ALARM);
}

xdr_notify(xdrs, ntfp)
XDR *xdrs;
stat_chge *ntfp;
{
	if(!xdr_string(xdrs, &ntfp->name, MAXNAMLEN+1)) {
		return(FALSE);
	}
	if(!xdr_int(xdrs, &ntfp->state)) {
		return(FALSE);
	}
	return(TRUE);
}

statd_call_statd(name)
char *name;
{
	stat_chge ntf;
	int err;

	ntf.name =hostname;
	ntf.state = LOCAL_STATE;
	if(debug) printf("statd_call_statd at %s\n", name);
	if((err = call_tcp(name, SM_PROG, SM_VERS,
	SM_NOTIFY, xdr_notify, &ntf, xdr_void, NULL, 0))
	== (int) RPC_TIMEDOUT || err == (int) RPC_SUCCESS) {
		return(0);
	}
	else {
		fprintf(stderr, "statd cannot talk to statd at %s\n", name);
		return(-1);
	}
}


sm_try()
{
	name_entry *nl, *next;

	if(debug >= 2) printf("enter sm_try: recovery_q = %s\n", recovery_q->name);
	next = recovery_q;
	while((nl = next) != NULL) {
		next = next->nxt;
		if(statd_call_statd(nl->name) == 0) {
			/* remove entry from recovery_q */ 
			delete_name(&recovery_q, nl->name);
		}
	}
	if(recovery_q != NULL)
		alarm(SM_INIT_ALARM);
}

char *
xmalloc(len)
unsigned len;
{
	char *new;

	if((new = (char *)malloc(len)) == 0) {
		perror("malloc");
		fprintf(stderr, "\n");
		return(NULL);
	}
	else {
		bzero(new, len);
		return(new);
	}
}

/*
 * the following two routines are very similar to
 * insert_mon and delete_mon in sm_proc.c, except the structture
 * is different
 */
name_entry *
insert_name(namepp, name)
name_entry **namepp;
char *name;
{
	name_entry *new;

	new = (name_entry *) xmalloc(sizeof(struct name_entry)); 
	new->name = xmalloc(strlen(name) + 1);
	strcpy(new->name, name);
	new->nxt = *namepp;
	if(new->nxt != NULL)
		new->nxt->prev = new;
	*namepp = new; 
	return(new);
}

delete_name(namepp, name)
name_entry **namepp;
char *name;
{
	name_entry *nl;

	nl = *namepp;
	while(nl != NULL) {
		if(strcmp(nl->name, name) == 0) {/*found */
			if(nl->prev != NULL)
				nl->prev->nxt = nl->nxt;
			else 
				*namepp = nl->nxt;
			if(nl->nxt != NULL)
				nl->nxt->prev = nl->prev;
			free(nl->name);
			free(nl);
			return;
		}
		nl = nl->nxt;
	}
	return;
}

name_entry *
find_name(namep, name)
name_entry *namep;
char *name;
{
	name_entry *nl;

	nl = namep;
	while(nl != NULL) {
		if(strcmp(nl->name, name) == 0) {
			return(nl);
		}
		nl = nl->nxt;
	}
	return(NULL);
}

record_name(name, op)
char *name;
int op;
{
	name_entry *nl;
	int fd;
	char path[MAXNAMLEN];

	if(op == 1) { /* insert */
		if((nl = find_name(record_q, name)) == NULL) {
			nl = insert_name(&record_q, name);
			/* make an entry in current directory */
			strcpy(path, CURRENT);
			strcat(path, "/");
			strcat(path, name);
			if(debug >= 2) printf("create monitor entry %s\n", path);
			if((fd = open(path, O_CREAT, 00200)) == -1){
				fprintf(stderr, "open: \n");
				perror(path);
				fprintf(stderr, "\n");
				if(errno != EACCES)
					exit(1);
			}
			else {
				if(debug >= 2) printf("%s is created\n", path);
				if(close(fd)) {
					perror("close");
					fprintf(stderr, "\n");
					exit(1);
				}
			}
		}
		nl->count++;
	}
	else { /* delete */
		if((nl = find_name(record_q, name)) == NULL) {
			return;
		}
		nl->count--;
		if(nl->count == 0) {
			delete_name(&record_q, name);
		/* remove this entry from current directory */
			strcpy(path, CURRENT);
			strcat(path, "/");
			strcat(path, name);
			if(debug >= 2) printf("remove monitor entry %s\n", path);
			if(unlink(path) == -1) {
				perror(path);
				fprintf(stderr, "\n");
				exit(1);
			}

		}
	}
	
}

sm_crash()
{
	name_entry *nl, *next;

	if(record_q == NULL)
		return;
	next = record_q;	/* clean up record queue */
	while((nl = next) != NULL) {
		next = next->nxt;
		delete_name(&record_q, nl->name);
	}

	if(recovery_q != NULL) { /* clean up all onging recovery act*/
		if(debug) printf("sm_crash clean up\n");
		alarm(0);
		next = recovery_q;
		while( (nl = next) != NULL) {
			next = next ->nxt;
			delete_name(&recovery_q, nl->name);
		}
	}
	statd_init();
}