distribute client crashed in dht_stat_merge. Sanity script was running and server up and down was being done when the crash happened. This is the backtrace of the core generated.

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This GDB was configured as "x86_64-slackware-linux"...

warning: Can't read pathname for load map: Input/output error.
Reading symbols from /opt/glusterfs/3.0.5rc6/lib/libglusterfs.so.0...done.
Loaded symbols for /opt/glusterfs/3.0.5rc6/lib/libglusterfs.so.0
Reading symbols from /lib64/libdl.so.2...done.
Loaded symbols for /lib64/libdl.so.2
Reading symbols from /lib64/libpthread.so.0...done.
Loaded symbols for /lib64/libpthread.so.0
Reading symbols from /lib64/libc.so.6...done.
Loaded symbols for /lib64/libc.so.6
Reading symbols from /lib64/ld-linux-x86-64.so.2...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
Reading symbols from /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/xlator/protocol/client.so...done.
Loaded symbols for /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/xlator/protocol/client.so
Reading symbols from /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/xlator/cluster/distribute.so...done.
Loaded symbols for /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/xlator/cluster/distribute.so
Reading symbols from /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/xlator/mount/fuse.so...done.
Loaded symbols for /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/xlator/mount/fuse.so
Reading symbols from /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/transport/socket.so...done.
Loaded symbols for /opt/glusterfs/3.0.5rc6/lib/glusterfs/3.0.5rc6/transport/socket.so
Reading symbols from /lib64/libnss_files.so.2...done.
Loaded symbols for /lib64/libnss_files.so.2
Reading symbols from /usr/lib64/libgcc_s.so.1...done.
Loaded symbols for /usr/lib64/libgcc_s.so.1
Core was generated by `/opt/glusterfs/3.0.5rc6/sbin/glusterfs -f client1.vol /mnt/hd/ -l /tmp/tests_cl'.
Program terminated with signal 11, Segmentation fault.
[New process 4211]
[New process 4212]
[New process 4217]
#0  0x00007f740da1685e in dht_stat_merge (this=0x611200, to=0x7f740020aba8, from=0x7fff00000000, subvol=0x6103f0)
    at ../../../../../xlators/cluster/dht/src/dht-helper.c:328
328		to->st_dev      = from->st_dev;
(gdb) bt
#0  0x00007f740da1685e in dht_stat_merge (this=0x611200, to=0x7f740020aba8, from=0x7fff00000000, subvol=0x6103f0)
    at ../../../../../xlators/cluster/dht/src/dht-helper.c:328
#1  0x00007f740da18802 in dht_selfheal_dir_mkdir_cbk (frame=0x7f7400209730, cookie=0x745f10, this=0x611200, op_ret=-1, op_errno=22, 
    inode=0x7f740009fd50, stbuf=0x0, preparent=0x0, postparent=0x7fff00000000)
    at ../../../../../xlators/cluster/dht/src/dht-selfheal.c:220
#2  0x00007f740dc4dbe6 in client_mkdir (frame=0x745f10, this=0x6103f0, loc=0x7f740020a878, mode=16877)
    at ../../../../../xlators/protocol/client/src/client-protocol.c:1062
#3  0x00007f740da18bdf in dht_selfheal_dir_mkdir (frame=0x7f7400209730, loc=0x7f740020a878, layout=0x7f74000a0050, force=1)
    at ../../../../../xlators/cluster/dht/src/dht-selfheal.c:271
#4  0x00007f740da19634 in dht_selfheal_restore (frame=0x7f7400209730, dir_cbk=0x7f740da2fcde <dht_rmdir_selfheal_cbk>, 
    loc=0x7f740020a878, layout=0x7f74000a0050) at ../../../../../xlators/cluster/dht/src/dht-selfheal.c:531
#5  0x00007f740da30020 in dht_rmdir_cbk (frame=0x7f7400209730, cookie=0x850330, this=0x611200, op_ret=0, op_errno=22, 
    preparent=0x7fff98ed3e90, postparent=0x7fff98ed3e00) at ../../../../../xlators/cluster/dht/src/dht-common.c:3264
#6  0x00007f740dc5c8a3 in client_rmdir_cbk (frame=0x850330, hdr=0x868510, hdrlen=268, iobuf=0x0)
    at ../../../../../xlators/protocol/client/src/client-protocol.c:4883
#7  0x00007f740dc619dc in protocol_client_interpret (this=0x6108a0, trans=0x613c40, hdr_p=0x868510 "", hdrlen=268, iobuf=0x0)
    at ../../../../../xlators/protocol/client/src/client-protocol.c:6571
#8  0x00007f740dc626a2 in protocol_client_pollin (this=0x6108a0, trans=0x613c40)
    at ../../../../../xlators/protocol/client/src/client-protocol.c:6869
#9  0x00007f740dc62d16 in notify (this=0x6108a0, event=2, data=0x613c40)
    at ../../../../../xlators/protocol/client/src/client-protocol.c:6988
#10 0x00007f740ee142fa in xlator_notify (xl=0x6108a0, event=2, data=0x613c40) at ../../../libglusterfs/src/xlator.c:929
#11 0x00007f740cdec257 in socket_event_poll_in (this=0x613c40) at ../../../../transport/socket/src/socket.c:771
#12 0x00007f740cdec551 in socket_event_handler (fd=12, idx=0, data=0x613c40, poll_in=1, poll_out=0, poll_err=0)
    at ../../../../transport/socket/src/socket.c:871
#13 0x00007f740ee38f1f in event_dispatch_epoll_handler (event_pool=0x60a320, events=0x6171a0, i=0)
    at ../../../libglusterfs/src/event.c:804
#14 0x00007f740ee390ee in event_dispatch_epoll (event_pool=0x60a320) at ../../../libglusterfs/src/event.c:867
#15 0x00007f740ee393ff in event_dispatch (event_pool=0x60a320) at ../../../libglusterfs/src/event.c:975
#16 0x000000000040634b in main (argc=6, argv=0x7fff98ed4b48) at ../../../glusterfsd/src/glusterfsd.c:1425
(gdb) p from
$1 = (struct stat *) 0x7fff00000000
(gdb) p *from
Cannot access memory at address 0x7fff00000000
(gdb) f 2
#2  0x00007f740dc4dbe6 in client_mkdir (frame=0x745f10, this=0x6103f0, loc=0x7f740020a878, mode=16877)
    at ../../../../../xlators/protocol/client/src/client-protocol.c:1062
1062	        STACK_UNWIND (frame, -1, EINVAL, loc->inode, NULL);
(gdb) q


In client_mkdir STACK_UNWIND_STRICT should be used instead if STACK_UNWIND which makes postparent to have some wrong address in dht_selfheal_dir_mkdir_cbk