xfs online resizing support

[sgzijl]

Added new feature xfs online resizing. Last PR didn't pass test (blkid invoked twice, expected once), which seems to be fixed now (locally).

[c33s]

there is a major problem with this commit, the commands for creating and changing an xfs filesystem work different:

mkfs.xfs <device>
xfs_growfs <mount-point>

mkfs.xfs requires a device like /dev/vg_group/mytest and xfs_growfs requires a mount point like /mnt/mytest

so if a filesystem is defined like that (device):

filesystem { "/dev/vg_group/mytest": ensure => present, fs_type => 'xfs' }

mkfs.xfs works but xfs_growfs fails with the message xfs_growfs: /dev/vg_group/mytest is not a mounted XFS filesystem

defining the filesystem as mount point:

filesystem { "/mnt/mytest": ensure => present, fs_type => 'xfs' }

mkfs.xfs fails with mkfs.xfs /mnt/mytest' returned 1: /mnt/mytest: No such file or directory

[sgzijl]

@c33s are you trying to resize an unmounted xfs filesystem? with xfs resizing only works on mounted filesystems. it doesn't matter whether you specify the device or mount point (tested on Centos6).