[PATCHSET 0/5 v3] brd: partition fixes

[Boaz Harrosh <boaz@plexistor.com>]

Jens Hi

Currently brd has multiple bugs when trying to use partitions. After this
set all known problems are solved. Please see individual patch for description
of the problem.

[v3]
Same exact code but some commit messages changed to try and explain better
what was fixed and why. (Rebased on 3.18-rc3 but nothing changed in brd.c
since then)

[v2]
Based on Jens's linux-next [30e996a] incorporating the brd patch by Dmitry Monakhov.
Dmitry has introduced a new part_show parameter, this parameter is now removed
and we always "part_show=1".
Scripts that did part_show=1 will work just the same but will display a
message in logs. This is harmless. (And scripts can be modified to
remove this parameter)

[v1]
Current situation is that any attempt to use partitions with brd device would
create the partition but then any use will trash the data.

See: http://www.spinics.net/lists/linux-scsi/msg76737.html

So these patches fixes up all the problems we saw with the code, but not sacrificing
any of the old fixtures. See [patch 4/5] for more explanations.

list of patches:
[PATCH 1/5] axonram: Fix bug in direct_access
[PATCH 2/5] block: Change direct_access calling convention

	These 2 above are from Matthew's DAX series latest version.
	Exactly as is, taken from the 01org/prd.git tree
	They are needed so to support direct_access with partitions.

[PATCH 3/5] brd: Fix all partitions BUGs

	This one fixes all the very HARD bugs, which today
	cause data corruption.

[PATCH 4/5] brd: Request from fdisk 4k alignment
[PATCH 5/5] brd: Add getgeo to block ops for fdisk

	And the last two are to try and make fdisk work
	properly with a direct_access() device.

One can fetch/view these patches from a public tree here:
  git: git://git.open-osd.org/pmem.git brd-partitions branch
  web: http://git.open-osd.org/gitweb.cgi?p=pmem.git;a=shortlog;h=refs/heads/brd-partitions

Thanks
Boaz