[PATCH 000 of 8] md/bitmap: Introduction - rework management of bitmap files.

[NeilBrown <neilb@suse.de>]

I thought it was time to review the md/bitmap code - partly because I
wasn't comfortable with how it was handling writing to files.  The more
I learnt about the VM/VFS, the more I realised it was wrong....

I found plenty to do...

The last patch in this series of 8 is the big one.  It substantially
changes the way bitmap files are handled.  The key change is that it
now works more like swapfile: bmap() is used to find where the blocks
are and write goes direct to storage bypassing the filesystem.

These are *not* for 2.6.17, but should be ok for when 2.6.18 opens.

I've done some testing and it seems to work OK, but it is a big change
and more testing wouldn't be a bad thing :-)

 [PATCH 001 of 8] md/bitmap: Fix online removal of file-backed bitmaps
 [PATCH 002 of 8] md/bitmap: Remove bitmap writeback daemon.
 [PATCH 003 of 8] md/bitmap: Cleaner separation of page attribute handlers in md/bitmap.
 [PATCH 004 of 8] md/bitmap: Use set_bit etc for bitmap page attributes.
 [PATCH 005 of 8] md/bitmap: Remove unnecessary page reference manipulations from md/bitmap code.
 [PATCH 006 of 8] md/bitmap: Remove dead code from md/bitmap.
 [PATCH 007 of 8] md/bitmap: Tidy up i_writecount handling in md/bitmap
 [PATCH 008 of 8] md/bitmap: Change md/bitmap file handling to use bmap to file blocks.