Description of problem:
In the ocf:heartbeat:exportfs resource agent, the use of a character class list in square brackets causes the monitor operation to fail. According to `man 5 exports`, this is valid wildcard syntax for an export.

    wildcards
                  Machine names may contain the wildcard characters * and ?, or may contain character class lists within [square brackets].

The start operation works fine and creates the export.
    # pcs resource create myexport ocf:heartbeat:exportfs directory=/mnt clientspec='192.168.22.2[23]' fsid=1001 --group testgroup

    # pcs resource show myexport
     Resource: myexport (class=ocf provider=heartbeat type=exportfs)
      Attributes: clientspec=192.168.22.2[23] directory=/mnt fsid=1001
      Operations: monitor interval=10 timeout=20 (myexport-monitor-interval-10)
                  start interval=0s timeout=40 (myexport-start-interval-0s)
                  stop interval=0s timeout=120 (myexport-stop-interval-0s)

    # exportfs -v
    /mnt          	192.168.22.2[23](ro,sync,wdelay,hide,no_subtree_check,fsid=1001,sec=sys,secure,root_squash,no_all_squash)

However, the monitor operation fails continuously. The resource loops through a sequence of "start success, monitor failure, stop success, start success, monitor failure..."

    # pcs status
    ...
     Resource Group: testgroup
         myLVM	(ocf::heartbeat:LVM):	Started fastvm-centos-7-4-23
         myFS	(ocf::heartbeat:Filesystem):	Started fastvm-centos-7-4-23
         myNFS	(ocf::heartbeat:nfsserver):	Started fastvm-centos-7-4-23
         myexport	(ocf::heartbeat:exportfs):	FAILED fastvm-centos-7-4-23

    Failed Actions:
    * myexport_monitor_10000 on fastvm-centos-7-4-23 'not running' (7): call=19020, status=complete, exitreason='none',
        last-rc-change='Wed Mar 14 19:22:00 2018', queued=0ms, exec=23ms

The exportfs_monitor() function calls the is_exported() function:
    204 is_exported() {
    205         local dir=$1
    206         local spec=$2
    207 
    208         # IPv6 addressed are encased in brackets that need to be removed
    209         spec=$(echo $spec | sed 's/\[//;s/\]//')
    210 
    211         exportfs |
    212                 sed -e '$! N; s/\n[[:space:]]\+/ /; t; s/[[:space:]]\+\([^[:space:]]\+\)\(\n\|$\)/ \1\2/g; P;D;' |
    213                 grep -q -x -F "$dir $spec"
    214 }

The problem is in line 209. The function strips square bracket characters from the spec before using it as a search pattern. This is because square brackets are placed around IPv6 addresses as a special designator when CREATING the export (i.e., in clientspec) but are not present when DISPLAYING an IPv6 export. For example:
    # exportfs [fe80::]/64:/var/tmp
    # exportfs -v
    /var/tmp      	fe80::/64(ro,sync,wdelay,hide,no_subtree_check,sec=sys,secure,root_squash,no_all_squash)

So it's necessary to strip square brackets before grepping for an IPv6 export.

However, this breaks IPv4 exportfs clientspecs with character class list wildcards.


Version-Release number of selected component (if applicable):
resource-agents-3.9.5-105.el7_4.6
resource-agents-3.9.5-124.el7


How reproducible:
Always


Steps to Reproduce:
# pcs resource create myLVM ocf:heartbeat:LVM volgrpname=clus_vg --group testgroup
# mkfs.xfs /dev/clus_vg/lv1
# pcs resource create myFS ocf:heartbeat:Filesystem device=/dev/clus_vg/lv1 directory=/mnt fstype=xfs --group testgroup
# pcs resource create myNFS ocf:heartbeat:nfsserver --group testgroup
# pcs resource create myexport ocf:heartbeat:exportfs directory=/mnt clientspec='192.168.22.2[23]' options=ro fsid=1001 --group testgroup


Actual results:
    # pcs status
    ...
     Resource Group: testgroup
         myLVM	(ocf::heartbeat:LVM):	Started fastvm-centos-7-4-23
         myFS	(ocf::heartbeat:Filesystem):	Started fastvm-centos-7-4-23
         myNFS	(ocf::heartbeat:nfsserver):	Started fastvm-centos-7-4-23
         myexport	(ocf::heartbeat:exportfs):	FAILED fastvm-centos-7-4-23

    Failed Actions:
    * myexport_monitor_10000 on fastvm-centos-7-4-23 'not running' (7): call=19020, status=complete, exitreason='none',
        last-rc-change='Wed Mar 14 19:22:00 2018', queued=0ms, exec=23ms


Expected results:
    # pcs status
    ...
     Resource Group: testgroup
         myLVM	(ocf::heartbeat:LVM):	Started fastvm-centos-7-4-23
         myFS	(ocf::heartbeat:Filesystem):	Started fastvm-centos-7-4-23
         myNFS	(ocf::heartbeat:nfsserver):	Started fastvm-centos-7-4-23
         myexport	(ocf::heartbeat:exportfs):	Started fastvm-centos-7-4-23


Additional info: