stressfs.c

   1 // Demonstrate that moving the "acquire" in iderw after the loop that
   2 // appends to the idequeue results in a race.
   3
   4 // For this to work, you should also add a spin within iderw's
   5 // idequeue traversal loop.  Spinning 40000 times demonstrated the bug
   6 // after about 5 runs of stressfs in QEMU on a 2.1GHz CPU.
   7
   8 #include "types.h"
   9 #include "stat.h"
  10 #include "user.h"
  11 #include "fs.h"
  12 #include "fcntl.h"
  13
  14 int
  15 main(int argc, char *argv[])
  16 {
  17   int fd, i;
  18   char path[] = "stressfs0";
  19
  20   printf(1, "stressfs starting\n");
  21
  22   for(i = 0; i < 4; i++)
  23     if(fork() > 0)
  24       break;
  25
  26   printf(1, "%d\n", i);
  27
  28   path[8] += i;
  29   fd = open(path, O_CREATE | O_RDWR);
  30   for(i = 0; i < 100; i++)
  31     printf(fd, "%d\n", i);
  32   close(fd);
  33
  34   wait();
  35
  36   exit();
  37 }