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-rw-r--r--user/stressfs.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/user/stressfs.c b/user/stressfs.c
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+++ b/user/stressfs.c
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+// Demonstrate that moving the "acquire" in iderw after the loop that
+// appends to the idequeue results in a race.
+
+// For this to work, you should also add a spin within iderw's
+// idequeue traversal loop. Adding the following demonstrated a panic
+// after about 5 runs of stressfs in QEMU on a 2.1GHz CPU:
+// for (i = 0; i < 40000; i++)
+// asm volatile("");
+
+#include "kernel/types.h"
+#include "kernel/stat.h"
+#include "user/user.h"
+#include "kernel/fs.h"
+#include "kernel/fcntl.h"
+
+int
+main(int argc, char *argv[])
+{
+ int fd, i;
+ char path[] = "stressfs0";
+ char data[512];
+
+ printf(1, "stressfs starting\n");
+ memset(data, 'a', sizeof(data));
+
+ for(i = 0; i < 4; i++)
+ if(fork() > 0)
+ break;
+
+ printf(1, "write %d\n", i);
+
+ path[8] += i;
+ fd = open(path, O_CREATE | O_RDWR);
+ for(i = 0; i < 20; i++)
+// printf(fd, "%d\n", i);
+ write(fd, data, sizeof(data));
+ close(fd);
+
+ printf(1, "read\n");
+
+ fd = open(path, O_RDONLY);
+ for (i = 0; i < 20; i++)
+ read(fd, data, sizeof(data));
+ close(fd);
+
+ wait();
+
+ exit();
+}