[Gluster-devel] QEMU with GlusterFS backend segfaults when running FIO

[Bharata B Rao]

I see similar failures when installing a distribution (and not
necessarily running FIO) on a VM image present on BD backend too...

On Mon, Oct 29, 2012 at 3:16 PM, Bharata B Rao <bharata.rao at gmail.com> wrote:
> Hi,
>
> With GlusterFS block backend in QEMU, running FIO from inside VM
> causes a segfault like this...
>
> (gdb) bt
> #0  0x00007ffff5ff03e8 in __memcpy_ssse3_back () from /lib64/libc.so.6
> #1  0x00007fffeb95cd5e in iov_unload (buf=0x7fffeaeec000 "",
> vector=0x7fff24001610, count=1)
>     at ../../../../libglusterfs/src/common-utils.h:343
> #2  0x00007fffeb95f1c1 in __wb_collapse_small_writes
> (holder=0x7fff08001c40, req=
>     0x7fff24001c70) at write-behind.c:903
> #3  0x00007fffeb95f427 in __wb_preprocess_winds (wb_inode=0x7fff14000a10)
>     at write-behind.c:979
> #4  0x00007fffeb95f6e5 in wb_process_queue (wb_inode=0x7fff14000a10)
> at write-behind.c:1064
> #5  0x00007fffeb95fbbe in wb_writev (frame=0x5555565cdac4,
> this=0x7fffd4003e80, fd=
>     0x555556b55d6c, vector=0x555559e15180, count=1, offset=2493120512,
> flags=0, iobref=
>     0x7fff240014c0, xdata=0x0) at write-behind.c:1160
> #6  0x00007fffeb75394b in ra_writev (frame=0x5555565d2cbc,
> this=0x7fffd40049e0, fd=
>     0x555556b55d6c, vector=0x555559e15180, count=1, offset=2493120512,
> flags=0, iobref=
>     0x7fff240014c0, xdata=0x0) at read-ahead.c:682
> #7  0x00007fffeb5429c9 in ioc_writev (frame=0x5555565cd564,
> this=0x7fffd4005380, fd=
>     0x555556b55d6c, vector=0x555559e15180, count=1, offset=2493120512,
> flags=0, iobref=
>     0x7fff240014c0, xdata=0x0) at io-cache.c:1250
> #8  0x00007fffeb328c78 in qr_writev (frame=0x5555565cdecc,
> this=0x7fffd4005e30, fd=
>     0x555556b55d6c, vector=0x555559e15180, count=1, off=2493120512,
> wr_flags=0, iobref=
>     0x7fff240014c0, xdata=0x0) at quick-read.c:1525
> #9  0x00007fffeb11925f in mdc_writev (frame=0x5555565ce17c,
> this=0x7fffd4006880, fd=
>     0x555556b55d6c, vector=0x555559e15180, count=1, offset=2493120512,
> flags=0, iobref=
>     0x7fff240014c0, xdata=0x0) at md-cache.c:1420
> #10 0x00007fffeaf0789b in io_stats_writev (frame=0x5555565cd96c,
> this=0x7fffd40072d0, fd=
>     0x555556b55d6c, vector=0x555559e15180, count=1, offset=2493120512,
> flags=0, iobref=
>     0x7fff240014c0, xdata=0x0) at io-stats.c:2091
> #11 0x00007ffff5c79ed0 in syncop_writev (subvol=0x7fffd40072d0,
> fd=0x555556b55d6c, vector=
>     0x555559e15180, count=1, offset=2493120512, iobref=0x7fff240014c0, flags=0)
>     at syncop.c:1096
> #12 0x00007ffff72ac51e in glfs_pwritev (glfd=0x555556b6ef50,
> iovec=0x5555565691e0, iovcnt=
>     6, offset=2493120512, flags=0) at glfs-fops.c:543
> #13 0x00007ffff72ac04c in glfs_io_async_task (data=0x555556a1e660) at
> glfs-fops.c:396
> #14 0x00007ffff5c732ab in synctask_wrap (old_task=0x5555571145e0) at
> syncop.c:125
> #15 0x00007ffff5ef0360 in ?? () from /lib64/libc.so.6
> #16 0x0000000000000000 in ?? ()
>
> git bisect points to
>
> commit c903de38da917239fe905fc6efa1f413d120fc04
> Author: Anand Avati <avati at redhat.com>
> Date:   Thu Sep 13 22:26:59 2012 -0700
>
>     write-behind: implement causal ordering and other cleanup
>
> I hadn't seen this earlier since I had resorted to
> performance.write-behind=off setting for my test volume.
>
> Regards,
> Bharata.
> --
> http://bharata.sulekha.com/blog/posts.htm, http://raobharata.wordpress.com/



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