Description of problem:
Gluster v5.5 (oVirt 4.3.2) fails to create a snapshot when the gluster bricks have an ".automount" unit.

Version-Release number of selected component (if applicable):
glusterfs-5.5-1.el7.x86_64
glusterfs-api-5.5-1.el7.x86_64
glusterfs-api-devel-5.5-1.el7.x86_64
glusterfs-cli-5.5-1.el7.x86_64
glusterfs-client-xlators-5.5-1.el7.x86_64
glusterfs-coreutils-0.2.0-1.el7.x86_64
glusterfs-devel-5.5-1.el7.x86_64
glusterfs-events-5.5-1.el7.x86_64
glusterfs-extra-xlators-5.5-1.el7.x86_64
glusterfs-fuse-5.5-1.el7.x86_64
glusterfs-geo-replication-5.5-1.el7.x86_64
glusterfs-libs-5.5-1.el7.x86_64
glusterfs-rdma-5.5-1.el7.x86_64
glusterfs-resource-agents-5.5-1.el7.noarch
glusterfs-server-5.5-1.el7.x86_64
libvirt-daemon-driver-storage-gluster-4.5.0-10.el7_6.6.x86_64
nfs-ganesha-gluster-2.7.2-1.el7.x86_64
python2-gluster-5.5-1.el7.x86_64
vdsm-gluster-4.30.11-1.el7.x86_64


How reproducible:
Always.

Steps to Reproduce:
1.Create brick mount & automount units
Ex:
[root@ovirt1 system]# systemctl cat gluster_bricks-isos.mount
# /etc/systemd/system/gluster_bricks-isos.mount
[Unit]
Description=Mount glusterfs brick - ISOS
Requires = vdo.service
After = vdo.service
Before = glusterd.service
Conflicts = umount.target

[Mount]
What=/dev/mapper/gluster_vg_md0-gluster_lv_isos
Where=/gluster_bricks/isos
Type=xfs
Options=inode64,noatime,nodiratime

[Install]
WantedBy=glusterd.service
[root@ovirt1 system]# systemctl cat gluster_bricks-isos.automount
# /etc/systemd/system/gluster_bricks-isos.automount
[Unit]
Description=automount for gluster brick ISOS

[Automount]
Where=/gluster_bricks/isos

[Install]
WantedBy=multi-user.target

2.Create a gluster volume on the bricks.
Ex:
Volume Name: isos
Type: Replicate
Volume ID: 9b92b5bd-79f5-427b-bd8d-af28b038ed2a
Status: Started
Snapshot Count: 0
Number of Bricks: 1 x (2 + 1) = 3
Transport-type: tcp
Bricks:
Brick1: ovirt1:/gluster_bricks/isos/isos
Brick2: ovirt2:/gluster_bricks/isos/isos
Brick3: ovirt3.localdomain:/gluster_bricks/isos/isos (arbiter)
Options Reconfigured:
cluster.granular-entry-heal: enable
performance.strict-o-direct: on
network.ping-timeout: 30
storage.owner-gid: 36
storage.owner-uid: 36
user.cifs: off
features.shard: on
cluster.shd-wait-qlength: 10000
cluster.shd-max-threads: 8
cluster.locking-scheme: granular
cluster.data-self-heal-algorithm: full
cluster.server-quorum-type: server
cluster.quorum-type: auto
cluster.eager-lock: enable
network.remote-dio: off
performance.low-prio-threads: 32
performance.io-cache: off
performance.read-ahead: off
performance.quick-read: off
transport.address-family: inet
nfs.disable: on
performance.client-io-threads: off
cluster.enable-shared-storage: enable

3.Create snapshot:
gluster snapshot create isos-snap-2019-04-11 isos  description TEST

Actual results:
Error in logs and console:

[2019-04-12 07:56:54.526508] E [MSGID: 106077] [glusterd-snapshot.c:1882:glusterd_is_thinp_brick] 0-management: Failed to get pool name for device systemd-1
[2019-04-12 07:56:54.527509] E [MSGID: 106121] [glusterd-snapshot.c:2523:glusterd_snapshot_create_prevalidate] 0-management: Failed to pre validate
[2019-04-12 07:56:54.527525] E [MSGID: 106024] [glusterd-snapshot.c:2547:glusterd_snapshot_create_prevalidate] 0-management: Snapshot is supported only for thin provisioned LV. Ensure that all bricks of isos are thinly provisioned LV.
[2019-04-12 07:56:54.527539] W [MSGID: 106029] [glusterd-snapshot.c:8613:glusterd_snapshot_prevalidate] 0-management: Snapshot create pre-validation failed
[2019-04-12 07:56:54.527552] W [MSGID: 106121] [glusterd-mgmt.c:147:gd_mgmt_v3_pre_validate_fn] 0-management: Snapshot Prevalidate Failed
[2019-04-12 07:56:54.527568] E [MSGID: 106121] [glusterd-mgmt.c:1015:glusterd_mgmt_v3_pre_validate] 0-management: Pre Validation failed for operation Snapshot on local node
[2019-04-12 07:56:54.527583] E [MSGID: 106121] [glusterd-mgmt.c:2377:glusterd_mgmt_v3_initiate_snap_phases] 0-management: Pre Validation Failed

Expected results:
Gluster to exclude entries of type "autofs" in /proc/mounts and create the snapshot.

Additional info:
Disabling the automount units and restarting the mount units' fixes the issue.