nfs: few fixes and enhancements #37

Job	Run time
Build kdevops Container (debian)	2m 16s
Build kdevops Container (opensuse)	2m 8s
Build kdevops Container (fedora)	2m 1s
Linux A/B Tests (fedora)	43s
Linux A/B Tests (debian)	1m 7s
Linux A/B Tests (opensuse)	50s
Quick Config Tests (blktests_nvme) on debian	53s
Quick Config Tests (blktests_nvme) on fedora	43s
Quick Config Tests (blktests_nvme) on opensuse	54s
Quick Config Tests (xfs_reflink_4k) on opensuse	57s
Quick Config Tests (xfs_reflink_4k) on fedora	45s
Quick Config Tests (lbs-xfs) on fedora	43s
Quick Config Tests (xfs_reflink_4k) on debian	55s
Quick Config Tests (lbs-xfs) on debian	56s
Quick Config Tests (linux-ab-testing) on fedora	44s
Quick Config Tests (lbs-xfs) on opensuse	49s
Quick Config Tests (linux-ab-testing) on debian	52s
Quick Config Tests (linux-ab-testing) on opensuse	46s
	19m 2s

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