Created attachment 902381 [details]
Core file

Description of problem:
All my clients segfaulted as part of the rebalance associated with remove-brick

This also occurred before I could look at it during a plain rebalance.

Version-Release number of selected component (if applicable):
3.4.3

How reproducible:
Unknown

Steps to Reproduce:
1. With a volume mounted and VMs using the images on that volume, remove-brick
2. wait

Actual results:
all client segfault

Expected results:
no clients segfault

Additional info:
Thread 7 (Thread 0x7fa0e2370700 (LWP 18049)):
#0  0x00007fa0e44f99f7 in do_sigwait () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007fa0e44f9a79 in sigwait () from /lib/x86_64-linux-gnu/libpthread.so.0
#2  0x00007fa0e4fdbe30 in glusterfs_sigwaiter (arg=<optimized out>) at glusterfsd.c:1604
#3  0x00007fa0e44f1e9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#4  0x00007fa0e421e3fd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 6 (Thread 0x7fa0e136e700 (LWP 18051)):
#0  0x00007fa0e44f60fe in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007fa0e4b789e3 in syncenv_task (proc=0x7fa0e67e4780) at syncop.c:460
#2  0x00007fa0e4b78df0 in syncenv_processor (thdata=0x7fa0e67e4780) at syncop.c:538
#3  0x00007fa0e44f1e9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#4  0x00007fa0e421e3fd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 5 (Thread 0x7fa0e1b6f700 (LWP 18050)):
#0  0x00007fa0e44f60fe in pthread_cond_timedwait@@GLIBC_2.3.2 () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007fa0e4b789e3 in syncenv_task (proc=0x7fa0e67e43c0) at syncop.c:460
#2  0x00007fa0e4b78df0 in syncenv_processor (thdata=0x7fa0e67e43c0) at syncop.c:538
#3  0x00007fa0e44f1e9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#4  0x00007fa0e421e3fd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 4 (Thread 0x7fa0e00ca700 (LWP 18052)):
#0  0x00007fa0e44f952d in nanosleep () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007fa0e4b59bec in gf_timer_proc (ctx=0x7fa0e67bc010) at timer.c:173
#2  0x00007fa0e44f1e9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#3  0x00007fa0e421e3fd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#4  0x0000000000000000 in ?? ()

Thread 3 (Thread 0x7fa0e4fc1700 (LWP 18047)):
#0  0x00007fa0e421ea93 in epoll_wait () from /lib/x86_64-linux-gnu/libc.so.6
#1  0x00007fa0e4b8f557 in event_dispatch_epoll (event_pool=0x7fa0e67d7dd0) at event-epoll.c:428
#2  0x00007fa0e4fd9873 in main (argc=4, argv=0x7fffacbea278) at glusterfsd.c:1934

Thread 2 (Thread 0x7fa0d77fe700 (LWP 18055)):
#0  0x00007fa0e44f8d2d in read () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007fa0e2379a33 in read (__nbytes=16, __buf=0x7fa0d77fdda0, __fd=<optimized out>) at /usr/include/x86_64-linux-gnu/bits/unistd.h:45
#2  notify_kernel_loop (data=<optimized out>) at fuse-bridge.c:3592
#3  0x00007fa0e44f1e9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#4  0x00007fa0e421e3fd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#5  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fa0d7fff700 (LWP 18054)):
#0  0x00007fa0e44f6a50 in pthread_spin_lock () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x00007fa0e4b680d3 in fd_ref (fd=0x7fa0e697e8dc) at fd.c:447
#2  0x00007fa0e237c83d in fuse_write (this=0x7fa0e67d8a90, finh=0x7fa0d00059c0, msg=0x7fa0d5c7e000) at fuse-bridge.c:2226
#3  0x00007fa0e23911f4 in fuse_thread_proc (data=0x7fa0e67d8a90) at fuse-bridge.c:4607
#4  0x00007fa0e44f1e9a in start_thread () from /lib/x86_64-linux-gnu/libpthread.so.0
#5  0x00007fa0e421e3fd in clone () from /lib/x86_64-linux-gnu/libc.so.6
#6  0x0000000000000000 in ?? ()