Description of problem:
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smbd process crashes and there are multiple core dumps while doing following operations in parallel.

Create a 2x2 volume and do multiple(3) cifs mount of the volume.

1.From mount point1: /mnt/cifs1/
./iozone -i 0 -w -+n -c -C -e -s 200M -r 64k -t 50 -F /mnt/cifs5/file{1..50}.ioz
2.From smbclient execute the following:
for i in `seq 1 50`; do echo file.ioz; done  | xargs -n 1 -P 50 -I {} smbclient -msmb3 //10.70.X.Y/gluster-testvol/ foobar -c "get {} /dev/null"
3.From mount point2 : /mnt/cifs2
Do rename of files that are being created by iozone.
4.From mount point3: /mnt/cifs3
Execute ll

ll on the mount point hangs.

On the servers smbd process crashes and dumps multiple cores:

Trace is as follows:

Aug 31 18:01:27 dhcp47-64 smbd[443]: [2016/08/31 18:01:27.946414,  0] ../source3/modules/vfs_glusterfs.c:258(vfs_gluster_connect)
Aug 31 18:01:27 dhcp47-64 smbd[443]:  testvol: Initialized volume from server localhost
Aug 31 18:01:27 dhcp47-64 smbd[443]: [2016/08/31 18:01:27.954382,  0] ../source3/smbd/oplock.c:193(update_num_read_oplocks)
Aug 31 18:01:27 dhcp47-64 smbd[443]:  PANIC: assert failed at ../source3/smbd/oplock.c(193): d->num_share_modes == 1
Aug 31 18:01:27 dhcp47-64 smbd[443]: [2016/08/31 18:01:27.954468,  0] ../source3/lib/util.c:791(smb_panic_s3)
Aug 31 18:01:27 dhcp47-64 smbd[443]:  PANIC (pid 443): assert failed: d->num_share_modes == 1
Aug 31 18:01:27 dhcp47-64 smbd[443]: [2016/08/31 18:01:27.955187,  0] ../source3/lib/util.c:902(log_stack_trace)
Aug 31 18:01:27 dhcp47-64 smbd[443]:  BACKTRACE: 28 stack frames:
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #0 /lib64/libsmbconf.so.0(log_stack_trace+0x1a) [0x7f8709347eaa]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #1 /lib64/libsmbconf.so.0(smb_panic_s3+0x20) [0x7f8709347f80]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #2 /lib64/libsamba-util.so.0(smb_panic+0x2f) [0x7f870b83957f]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #3 /usr/lib64/samba/libsmbd-base-samba4.so(update_num_read_oplocks+0xf9) [0x7f870b428489]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #4 /usr/lib64/samba/libsmbd-base-samba4.so(+0x1173c6) [0x7f870b3cd3c6]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #5 /usr/lib64/samba/libsmbd-base-samba4.so(+0x119e29) [0x7f870b3cfe29]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #6 /usr/lib64/samba/libsmbd-base-samba4.so(create_file_default+0x1cf) [0x7f870b3d0e7f]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #7 /usr/lib64/samba/libsmbd-base-samba4.so(+0x1fbc1e) [0x7f870b4b1c1e]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #8 /usr/lib64/samba/libsmbd-base-samba4.so(smb_vfs_call_create_file+0xd8) [0x7f870b3d7b28]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #9 /usr/lib64/samba/libsmbd-base-samba4.so(smbd_do_setfilepathinfo+0x1ec6) [0x7f870b3bd7e6]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #10 /usr/lib64/samba/libsmbd-base-samba4.so(+0x108ebb) [0x7f870b3beebb]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #11 /usr/lib64/samba/libsmbd-base-samba4.so(reply_trans2+0x8cd) [0x7f870b3c212d]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #12 /usr/lib64/samba/libsmbd-base-samba4.so(+0x132e90) [0x7f870b3e8e90]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #13 /usr/lib64/samba/libsmbd-base-samba4.so(+0x134c30) [0x7f870b3eac30]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #14 /usr/lib64/samba/libsmbd-base-samba4.so(+0x136321) [0x7f870b3ec321]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #15 /lib64/libsmbconf.so.0(run_events_poll+0x16c) [0x7f870935d39c]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #16 /lib64/libsmbconf.so.0(+0x355f0) [0x7f870935d5f0]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #17 /lib64/libtevent.so.0(_tevent_loop_once+0x8d) [0x7f8707d8440d]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #18 /lib64/libtevent.so.0(tevent_common_loop_wait+0x1b) [0x7f8707d845ab]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #19 /usr/lib64/samba/libsmbd-base-samba4.so(smbd_process+0x701) [0x7f870b3ed671]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #20 /usr/sbin/smbd(+0xc304) [0x7f870bed7304]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #21 /lib64/libsmbconf.so.0(run_events_poll+0x16c) [0x7f870935d39c]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #22 /lib64/libsmbconf.so.0(+0x355f0) [0x7f870935d5f0]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #23 /lib64/libtevent.so.0(_tevent_loop_once+0x8d) [0x7f8707d8440d]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #24 /lib64/libtevent.so.0(tevent_common_loop_wait+0x1b) [0x7f8707d845ab]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #25 /usr/sbin/smbd(main+0x15d4) [0x7f870bed2ad4]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #26 /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f87079e0b15]
Aug 31 18:01:27 dhcp47-64 smbd[443]:   #27 /usr/sbin/smbd(+0x7ea9) [0x7f870bed2ea9]


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

samba-common-libs-4.4.3-8.el7rhgs.x86_64
samba-common-4.4.3-8.el7rhgs.noarch
samba-vfs-glusterfs-4.4.3-8.el7rhgs.x86_64
samba-debuginfo-4.4.3-8.el7rhgs.x86_64
samba-libs-4.4.3-8.el7rhgs.x86_64
samba-client-libs-4.4.3-8.el7rhgs.x86_64
samba-4.4.3-8.el7rhgs.x86_64
samba-client-4.4.3-8.el7rhgs.x86_64
samba-common-tools-4.4.3-8.el7rhgs.x86_64

How reproducible:
Tried twice with the similar tests.

Steps to Reproduce:
1.As explained above in the description
2.
3.

Actual results:
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ll on cifs mount hangs as smbd process crashes and dumps too many cores.

Expected results:
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ll on mount point should not hang , and smbd process should not crash.


Additional info:
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core file and logs will be updated shortly.