On Linux, we must use 'kpartx' after partitioning the raw disk file
to create a loop device with partitions (partitioning a raw disk file
does not create the parition files/devices).
+ In Linux, the 'disk part' is called a 'partition' and is labeled
  with a '<device>p<nr>' instead of '<device>s<nr>' (slice).
+ Overwrite some variables defined in the config file.
+  Cleanup (reorder/'prettify') the definition of the META_* variables.
+ In Linux we create a ext2 filesystem by default, not ufs.
Some tests works on Linux but fail on BSD. Use log_{must,mustnot} appropriately.
Since Linux don't have 'coreadm', we use the procedure used on Linux instead.
+ This means using the /proc filesystem and ulimit.
* In setup_snap_env(), support 'newfs' on Linux (really mke2fs) which behave a little different
* In cleanup_env(), look for any mounted zvols - !!!NEEDS BSD VERIFICATION!!!
The Linux equivalence of 'mount -F zfs' is 'mount -t zfs'.
+ The 'dev' ('devices') option never show up in a mount list
  Test this by trying to create a 'zero' device.
unshare doesn't exist on Linux, instead exportfs is used. But it have
quite different usage. And can't run as normal user...
Remove leading slash to disk images in TESTDIR (ended up with double
which made the test fail).
The expected return value from 'mmap_exec' on Linux is 22, not 13.
Change hardcoded '/dev/{dsk,rdsk' to variable 'DEV_{DSK,RDSK}DIR'.
Linux does not separate them and puts everything in '/dev'.
In Linux, we need to add the '-d $TEST_BASE_DIR' to 'zpool import' for it to find the raw disk files.
sleep 1 - On Linux, we need to add a 'sleep 1' between creating a ZVOL and accessing it
to make sure udevd have had time to create the device node.