Description of problem: While writing a file using dd and simultaneously doing graph-change, the fuse client crashed


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


How reproducible: Consistently


Steps to Reproduce:
1. dd if=/dev/urandom of=/mnt/gluster/ddfile bs=64k count=10240

2. while true; do gluster volume set test2 performance.write-behind off; sleep 1; gluster volume set test2 performance.write-behind on; sleep 1; done

  
Actual results:

(gdb) bt
#0  0x00007f4e6aa18253 in gf_timer_call_cancel (ctx=0x1cea010, event=0x1d0f1d0) at timer.c:126
#1  0x00007f4e6a7df2a1 in rpc_clnt_disable (rpc=0x1d666f0) at rpc-clnt.c:1637
#2  0x00007f4e65e7ce99 in notify (this=0x1d13cf0, event=17, data=0x1d15ab0) at client.c:2168
#3  0x00007f4e6aa0003a in xlator_notify (xl=0x1d13cf0, event=17, data=0x1d15ab0) at xlator.c:457
#4  0x00007f4e6aa1318a in default_notify (this=0x1d15ab0, event=17, data=0x1d16bc0) at defaults.c:1316
#5  0x00007f4e65c4fe28 in afr_notify (this=0x1d15ab0, event=17, data=0x1d16bc0, data2=0x11) at afr-common.c:3739
#6  0x00007f4e65c50ea9 in notify (this=0x1d15ab0, event=17, data=0x1d16bc0) at afr.c:51
#7  0x00007f4e6aa0003a in xlator_notify (xl=0x1d15ab0, event=17, data=0x1d16bc0) at xlator.c:457
#8  0x00007f4e6aa1318a in default_notify (this=0x1d16bc0, event=17, data=0x1d17d40) at defaults.c:1316
#9  0x00007f4e6aa0003a in xlator_notify (xl=0x1d16bc0, event=17, data=0x1d17d40) at xlator.c:457
#10 0x00007f4e6aa1318a in default_notify (this=0x1d17d40, event=17, data=0x1d18de0) at defaults.c:1316
#11 0x00007f4e6aa0003a in xlator_notify (xl=0x1d17d40, event=17, data=0x1d18de0) at xlator.c:457
#12 0x00007f4e6aa1318a in default_notify (this=0x1d18de0, event=17, data=0x1d19ec0) at defaults.c:1316
#13 0x00007f4e6aa0003a in xlator_notify (xl=0x1d18de0, event=17, data=0x1d19ec0) at xlator.c:457
#14 0x00007f4e6aa1318a in default_notify (this=0x1d19ec0, event=17, data=0x1d1afe0) at defaults.c:1316
#15 0x00007f4e6aa0003a in xlator_notify (xl=0x1d19ec0, event=17, data=0x1d1afe0) at xlator.c:457
#16 0x00007f4e6aa1318a in default_notify (this=0x1d1afe0, event=17, data=0x1d1c0a0) at defaults.c:1316
#17 0x00007f4e6aa0003a in xlator_notify (xl=0x1d1afe0, event=17, data=0x1d1c0a0) at xlator.c:457
#18 0x00007f4e6aa1318a in default_notify (this=0x1d1c0a0, event=17, data=0x1d1d250) at defaults.c:1316
#19 0x00007f4e64f71e1c in notify (this=0x1d1c0a0, event=17, data=0x1d1d250) at io-stats.c:2718
#20 0x00007f4e6aa0003a in xlator_notify (xl=0x1d1c0a0, event=17, data=0x1d1d250) at xlator.c:457
#21 0x00007f4e6aa1318a in default_notify (this=0x1d1d250, event=17, data=0x1d1d250) at defaults.c:1316
#22 0x00007f4e6aa0003a in xlator_notify (xl=0x1d1d250, event=17, data=0x1d1d250) at xlator.c:457
#23 0x00007f4e684f94f8 in fuse_graph_sync (this=0x1d02100) at fuse-bridge.c:3871
#24 0x00007f4e684f996f in fuse_thread_proc (data=0x1d02100) at fuse-bridge.c:3975
#25 0x00007f4e6a39aefc in start_thread (arg=0x7f4e63d70700) at pthread_create.c:304
#26 0x00007f4e6a0d589d in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:112
#27 0x0000000000000000 in ?? ()

(gdb) p *event
$11 = {next = 0x0, prev = 0x0, at = {tv_sec = 0, tv_usec = 0}, callbk = 0, data = 0x0, xl = 0x0}