[RFC v5] UBI: Fastmap support (aka checkpointing)

[Richard Weinberger]

This is a bug-fix release. v4 handled static volumes wrong.
v6 will address everything that Artem pointed out.

v1: https://lwn.net/Articles/481612/
v2: https://lwn.net/Articles/496586/
v3: Didn't release it to linux-mtd
v4: http://article.gmane.org/gmane.linux.kernel/1297626

Changes since v1:
       - renamed it to UBIVIS (at least in Kconfig)
       - UBIVIS parameters are now configurable via Kconfig
       - several bugs have been fixed (design and implementation bugs)
       - added lots of comments to make the review process easier
       - made checkpatch.pl happy

Changes since v2:
       - minor bugs have been fixed
       - renamed it to UBI fastmap (as Artem requested)

Changes since v3:
       - changed the on-flash layout (added padding fields, turned the
         EBA storage into an array)
       - fixed some corner cases (the protection queue needed some extra work)
       - removed the data type hint logic
       - rebased to Artems mtd tree

Changes since v4:
       - fixed static volume handling (used_ebs and last_data_bytes contained
         bad values in some cases)
	
git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubi2.git ubi2/v5

[PATCH 1/7] [RFC] UBI: Export next_sqnum()
[PATCH 2/7] [RFC] UBI: Export compare_lebs()
[PATCH 3/7] [RFC] UBI: Add fastmap on-flash layout
[PATCH 4/7] [RFC] UBI: Add fastmap structs to ubi_device
[PATCH 5/7] [RFC] UBI: Make wl subsystem fastmap aware
[PATCH 6/7] [RFC] UBI: Implement fastmapping support
[PATCH 7/7] [RFC] UBI: Wire up fastmap support

Thanks,
//richard