Assembe: fix bug in force_array - it wasn't forcing properly.

Since 'best' was expanded to hold replacement devices, we might
need to go up to raid_disks*2 to find devices to force.

Also fix another place when considering replacement drives would
be wrong (the 'chosen' device should never be a replacement).

Reported-by: John Yates <jyates65@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>
Fix typos in mdadm.8.in

I found a small bug in the documentation of mdadm.  I fixed it in my
local git clone of git://neil.brown.name/mdadm  Here is the change:


Signed-off-by: NeilBrown <neilb@suse.de>
Add support for --add-spare

--add-spare is like --add, but a --re-add is never attempted.
So it is equivalent to two separate commands:

 --zero-metadata
 --add

Signed-off-by: NeilBrown <neilb@suse.de>
ddf tests: fix get_rootdev

Getting the major number from the hex device number should take
all-but-the-last-two digits, rather than just the first two digits.

Signed-off-by: NeilBrown <neilb@suse.de>
IMSM metadata really should be ignored when found on partitions.

commit b31df43682216d1c65813eae49ebdd8253db8907
changed load_super_imsm to not insist on finding a partition if
ignore_hw_compat was set.
Unfortunately this is set for '--assemble' so arrays could get
assembled badly.

The comment says this was to allow e.g. --examine of image files.
A better fixes for this is to change test_partitions to not report
a regular file as being a partition.
The errors from the BLKPG ioctl are:

 ENOTTY : not a block device.
 EINVAL : not a whole device (probably a partition)
 ENXIO  : partition doesn't exist (so not a partition)

Reported-by: "David F." <df7729@gmail.com>
Signed-off-by: NeilBrown <neilb@suse.de>