Bug 1783187

Created attachment 1644726 [details]
logs and xmls

Description of problem:
As subject

Version-Release number of selected component (if applicable):
libvirt-5.10.0-1.module+el8.2.0+5040+bd433686.x86_64
qemu-kvm-4.2.0-1.module+el8.2.0+4793+b09dd2fb.x86_64
glusterfs-6.0-24.el8.x86_64

Gluster server: glusterfs-server-6.0-21.el7rhgs.x86_64

How reproducible:
60%

Steps to Reproduce:
1. Start an VM
# virsh create domain.xml

2. Create a disk snapshot on gluster source
# cat snapshot.xml 
<domainsnapshot>
  <name>s1</name>
  <description>Snapshot of OS install and updates</description>
  <disks>
    <disk name='vda' type='network' device='disk'>
      <source protocol='gluster' name='gv/q35.s1'>
        <host name='10.66.85.42'/>
      </source>
      <target dev='vda' bus='virtio'/>
    </disk>
  </disks>
</domainsnapshot>

# virsh snapshot-create q35 snapshot.xml --no-metadata --disk-only
error: operation failed: failed to format image: 'Permission denied'

Then you may get a SIGSEGV:
# abrt-cli ls                             
id d87d01b28bb5b676870e86ab2159def43838dec6
reason:         gf_log_flush_msgs(): qemu-kvm killed by SIGSEGV
time:           Fri 13 Dec 2019 02:46:09 AM EST
cmdline:        /usr/libexec/qemu-kvm -name guest=q35,debug-threads=on -S -object secret,id=masterKey0,format=raw,file=/var/lib/libvirt/qemu/domain-2-q35/master-key.aes -machine pc-q35-rhel8.1.0,accel=kvm,usb=off,vmport=off,dump-guest-core=off -cpu Opteron_G3 -m 1024 -overcommit mem-lock=off -smp 1,sockets=1,cores=1,threads=1 -uuid 516b83cb-bd68-47cf-b577-9ed07741601e -no-user-config -nodefaults -chardev socket,id=charmonitor,fd=38,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc,driftfix=slew -global kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -global ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on -device ich9-usb-ehci1,id=usb,bus=pcie.0,addr=0x5.0x7 -device ich9-usb-uhci1,masterbus=usb.0,firstport=0,bus=pcie.0,multifunction=on,addr=0x5 -device ich9-usb-uhci2,masterbus=usb.0,firstport=2,bus=pcie.0,addr=0x5.0x1 -device ich9-usb-uhci3,masterbus=usb.0,firstport=4,bus=pcie.0,addr=0x5.0x2 -device virtio-scsi-pci,id=scsi0,bus=pcie.0,addr=0x6 -device virtio-serial-pci,id=virtio-serial0,bus=pcie.0,addr=0x7 -blockdev '{\"driver\":\"file\",\"filename\":\"/var/lib/libvirt/images/RHEL-8.2-x86_64-latest-clone.qcow2\",\"node-name\":\"libvirt-1-storage\",\"auto-read-only\":true,\"discard\":\"unmap\"}' -blockdev '{\"node-name\":\"libvirt-1-format\",\"read-only\":false,\"driver\":\"qcow2\",\"file\":\"libvirt-1-storage\",\"backing\":null}' -device virtio-blk-pci,scsi=off,bus=pcie.0,addr=0x9,drive=libvirt-1-format,id=virtio-disk0,bootindex=1 -netdev tap,fd=40,id=hostnet0 -device e1000,netdev=hostnet0,id=net0,mac=52:54:00:87:15:bd,bus=pcie.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -chardev spicevmc,id=charchannel0,name=vdagent -device virtserialport,bus=virtio-serial0.0,nr=13,chardev=charchannel0,id=channel0,name=com.redhat.spice.0 -device usb-tablet,id=input0,bus=usb.0,port=1 -spice port=5901,addr=0.0.0.0,disable-ticketing,image-compression=off,seamless-migration=on -device qxl-vga,id=video0,ram_size=67108864,vram_size=67108864,vram64_size_mb=0,vgamem_mb=16,max_outputs=1,bus=pcie.0,addr=0x2 -device intel-hda,id=sound0,bus=pcie.0,addr=0x4 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -chardev spicevmc,id=charredir0,name=usbredir -device usb-redir,chardev=charredir0,id=redir0,bus=usb.0,port=2 -chardev spicevmc,id=charredir1,name=usbredir -device usb-redir,chardev=charredir1,id=redir1,bus=usb.0,port=3 -device virtio-balloon-pci,id=balloon0,bus=pcie.0,addr=0x8 -sandbox on,obsolete=deny,elevateprivileges=deny,spawn=deny,resourcecontrol=deny -msg timestamp=on
package:        15:qemu-kvm-core-4.2.0-1.module+el8.2.0+4793+b09dd2fb
uid:            107 (qemu)
count:          1
Directory:      /var/spool/abrt/ccpp-2019-12-13-02:46:09-27855
Run 'abrt-cli report /var/spool/abrt/ccpp-2019-12-13-02:46:09-27855' for creating a case in Red Hat Customer Portal

Backtrace:
(gdb) bt
#0  0x00007f6e536d5b75 in __list_splice (list=0x5564a6844490, list=0x5564a6844490, head=0x7f6e2cff8660) at ./glusterfs/list.h:112
#1  0x00007f6e536d5b75 in list_splice_init (head=0x7f6e2cff8660, list=0x5564a6844490) at ./glusterfs/list.h:135
#2  0x00007f6e536d5b75 in gf_log_flush_msgs (ctx=ctx@entry=0x5564a6844120) at logging.c:1763
#3  0x00007f6e536d5ece in gf_log_flush_timeout_cbk (data=0x5564a6844120) at logging.c:1883
#4  0x00007f6e536e1655 in gf_timer_proc (data=0x5564a6545c40) at timer.c:185
#5  0x00007f6eca4a82de in start_thread (arg=<optimized out>) at pthread_create.c:486
#6  0x00007f6eca1d9e83 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95


Actual results:
As subject

Expected results:
NO SIGSEGV

Additional info:
Logs in attachment:
br0.log --> brick log of gluster server
glusterd.log --> glutserd log of gluster server
libvirtd.log --> log of libvirtd
gdb.txt --> the backtrace of coredump
qemu.log --> it should contain the gluster client log. But due to the error following, I cannot get it:
ERROR: failed to create logfile "/var/log/glusterfs/10.66.85.42-gv-27855.log" (Permission denied)

I will ask qemu or libvirt developers about how to get client log.