[sheepdog] [PATCH v2 0/3] sheep: writeback cache semantics in backend store

[Hitoshi Mitake]

>
> I have got a core dump by following one liner:
>
> $ while (($?==0));do sudo ./check -corosync 26;done
>
> (gdb) bt
> #0  0x00007fa3fc81dba5 in raise (sig=<value optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
> #1  0x00007fa3fc8216b0 in abort () at abort.c:92
> #2  0x00007fa3fc85765b in __libc_message (do_abort=<value optimized out>, fmt=<value optimized out>)
>      at ../sysdeps/unix/sysv/linux/libc_fatal.c:189
> #3  0x00007fa3fc8616d6 in malloc_printerr (action=3, str=0x7fa3fc935758 "double free or corruption (!prev)",
>      ptr=<value optimized out>) at malloc.c:6283
> #4  0x00007fa3fc867ea3 in __libc_free (mem=<value optimized out>) at malloc.c:3738
> #5  0x0000000000407c88 in put_request (req=0x21b1c00) at request.c:513
> #6  0x000000000040d083 in bs_thread_request_done (fd=<value optimized out>, events=<value optimized out>, data=<value optimized out>)
>      at work.c:137
> #7  0x00000000004199c6 in event_loop (timeout=<value optimized out>) at event.c:179
> #8  0x000000000040437d in main (argc=<value optimized out>, argv=0x7fffad763628) at sheep.c:453
> (gdb) info threads
>    4 Thread 8362  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
>    3 Thread 8361  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
>    2 Thread 8363  pthread_cond_wait@@GLIBC_2.3.2 () at ../nptl/sysdeps/unix/sysv/linux/x86_64/pthread_cond_wait.S:162
> * 1 Thread 8333  0x00007fa3fc81dba5 in raise (sig=<value optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
>
>
> When I run without your patch set, I don't meet this seg fault.
>

Thanks for your information. I could also reproduce test fail with 026.
It seems to be a timing bug, I'm trying to debug it.

Thanks,
Hitoshi