/*
    raidtest - a program to integritytest a Linux software raid
    Copyright (C) 2005  Kasper Dupont

    This program 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 2 of the License, or
    with permission from the author any later version.

    This program 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, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    $Id: $
*/

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>

void errstop(const char *s)
{
  perror(s);
  exit(EXIT_FAILURE);
}

void formaterror()
{
  fprintf(stderr,"Unexpected format in /proc/mdstat\n");
  exit(EXIT_FAILURE);
}

#define MAXDEV 99
int fds[MAXDEV];
char buffers[MAXDEV][1024];

void testit(int mdnum, int level, int blocks, int devices, char *devnames)
{
  int i,b;
  //printf("md%d raid%d %d blocks %d devices\n",mdnum,level,blocks,devices);
  if (level==5) {
    int d=devices-1;
    if (blocks % d) {
      fprintf(stderr,"md%d: %d not divisible by %d\n",mdnum,blocks,d);
      return;
    }
    blocks/=d;
  }

  for (i=0;i<devices;++i) {
    char tmp[42];
    char *p1,*p2;
    sprintf(tmp,"[%d]",i);
    p1=strstr(devnames,tmp);
    if (!p1) {
      fprintf(stderr,"md%d: device %d missing\n",mdnum,i);
      return;
    }
    *p1=0;
    p2=strrchr(devnames,' ');
    if (!p2) formaterror();
    fds[i]=open(p2+1,O_RDONLY);
    if (fds[i]==-1) {
      perror(p2+1);
      return;
    }
    *p1='*';
    //printf("%d %s",i,strstr(devnames,tmp));
  }

  for (b=0;b<blocks;++b) {
    for (i=0;i<devices;++i) {
      switch(read(fds[i],buffers[i],1024)) {
      case -1:
	perror("read");
      default:
	fprintf(stderr,"md%d: Unexpected end of device\n",mdnum);
	return;
      case 1024:
	break;
      }
    }
    switch(level) {
    case 1:
      for (i=1;i<devices;++i)
	if (memcmp(buffers[0],buffers[i],1024)) {
	  fprintf(stderr,"md%d: Integrity check failed\n",mdnum);
	  return;
	}
      break;
    case 5:
      {
	char v;
	int j;
	for (j=0;j<1024;++j) {
	  v=0;
	  for (i=0;i<devices;++i) v^=buffers[i][j];
	  if (v) {
	    fprintf(stderr,"md%d: Integrity check failed\n",mdnum);
	    return;
	  }
	}
      }
    }
    if (!(b&0xfff))
      fprintf(stderr,"\x0dmd%d: %d%% ",mdnum,b/(blocks/100));
  }
  fprintf(stderr,"\x0d           \x0d");
}

int main()
{
  int i;
  char buf[4100];
  char buf2[4100];
  FILE *mdstat=fopen("/proc/mdstat","r");
  if (!mdstat) errstop("/proc/mdstat");

  if (chdir("/dev")) errstop("/dev");
  for(i=0;i<MAXDEV;++i) fds[i]=-1;

  while(fgets(buf,4096,mdstat)) {
    if(!strncmp(buf,"md",2)) {
      char *p,*devnames;
      int mdnum=atoi(buf+2);
      int level,blocks,devtotal,devup;
      //printf("md%d\n",mdnum);
      p=strstr(buf,"raid");
      if (!p) formaterror();
      level=atoi(p+4);
      //printf("raid%d\n",level);

      if ((level != 1) && (level != 5)) {
	fprintf(stderr,"md%d: RAID level %d unsupported\n",mdnum,level);
      } else {
	devnames=strchr(p,' ');
	if (!devnames) formaterror();
	if(!fgets(buf2,4096,mdstat)) formaterror();
	blocks=atoi(buf2);
	if (blocks<1) formaterror();
	p=strchr(buf2,'[');
	if (!p) formaterror();
	devtotal=atoi(p+1);
	p=strchr(p,'/');
	if (!p) formaterror();
	devup=atoi(p+1);
	if ((level==1) && (devup>1) && (devup<devtotal)) devtotal=devup;
	if (devup<devtotal) {
	  fprintf(stderr,"md%d has too few disks\n",mdnum);
	} else {
	  testit(mdnum,level,blocks,devtotal,devnames);
	  for(i=0;i<MAXDEV;++i)
	    if (fds[i]!=-1) {
	      close(fds[i]);
	      fds[i]=-1;
	    }
	}
      }
    }
  }

  return 0;
}