stressfs.c (1030B)
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. Adding the following demonstrated a panic 6 // after about 5 runs of stressfs in QEMU on a 2.1GHz CPU: 7 // for (i = 0; i < 40000; i++) 8 // asm volatile(""); 9 10 #include "types.h" 11 #include "stat.h" 12 #include "user.h" 13 #include "fs.h" 14 #include "fcntl.h" 15 16 int 17 main(int argc, char *argv[]) 18 { 19 int fd, i; 20 char path[] = "stressfs0"; 21 char data[512]; 22 23 printf(1, "stressfs starting\n"); 24 memset(data, 'a', sizeof(data)); 25 26 for(i = 0; i < 4; i++) 27 if(fork() > 0) 28 break; 29 30 printf(1, "write %d\n", i); 31 32 path[8] += i; 33 fd = open(path, O_CREATE | O_RDWR); 34 for(i = 0; i < 20; i++) 35 // printf(fd, "%d\n", i); 36 write(fd, data, sizeof(data)); 37 close(fd); 38 39 printf(1, "read\n"); 40 41 fd = open(path, O_RDONLY); 42 for (i = 0; i < 20; i++) 43 read(fd, data, sizeof(data)); 44 close(fd); 45 46 wait(); 47 48 exit(); 49 }