code to prepare for an upcoming mod which will introduce multi-level
in-core extent allocations. Although the in-core extent management is
using a new code path in this mod, the functionality remains the same. 
Major changes include:	- Introduce 10 new subroutines which re-orgainze
the existing code but	do NOT change functionality:	    
xfs_iext_get_ext()	   xfs_iext_insert()	     xfs_iext_add()	  
 xfs_iext_remove()	   xfs_iext_remove_inline()	   
xfs_iext_remove_direct()	 xfs_iext_realloc_direct()	  
xfs_iext_direct_to_inline()	    xfs_iext_inline_to_direct()        
xfs_iext_destroy() - Remove 2 subroutines (functionality moved to new
subroutines above):	    xfs_iext_realloc() -replaced by xfs_iext_add()
and xfs_iext_remove()	      xfs_bmap_insert_exlist() - replaced by
xfs_iext_insert()	  xfs_bmap_delete_exlist() - replaced by
xfs_iext_remove() - Replace all hard-coded (indexed) extent assignments
with a call to	 xfs_iext_get_ext() - Replace all extent record pointer
arithmetic (ep++, ep--, base + lastx,..)   with calls to
xfs_iext_get_ext() - Update comments to remove the idea of a single
"extent list" and   introduce "extent record" terminology instead

SGI-PV: 928864
SGI-Modid: xfs-linux-melb:xfs-kern:207390a
Signed-off-by: NMandy Kirkconnell <alkirkco@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

equivalents.

SGI-PV: 907752
SGI-Modid: xfs-linux-melb:xfs-kern:24961a
Signed-off-by: NNathan Scott <nathans@sgi.com>

sources.

SGI-PV: 907752
SGI-Modid: xfs-linux-melb:xfs-kern:24659a
Signed-off-by: NNathan Scott <nathans@sgi.com>

consistent.

SGI-PV: 941645
SGI-Modid: xfs-linux-melb:xfs-kern:202961a
Signed-off-by: NNathan Scott <nathans@sgi.com>

well.  Also provides a mechanism for inheriting this property from the
parent directory for new files.

SGI-PV: 945264
SGI-Modid: xfs-linux-melb:xfs-kern:24367a
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 943272
SGI-Modid: xfs-linux:xfs-kern:201006a
Signed-off-by: NChristoph Hellwig <hch@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 943908
SGI-Modid: xfs-linux:xfs-kern:200874a
Signed-off-by: NYingping Lu <yingping@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

xfs_bmap -a.

SGI-PV: 944075
SGI-Modid: xfs-linux:xfs-kern:200860a
Signed-off-by: NYingping Lu <yingping@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 941645
SGI-Modid: xfs-linux:xfs-kern:23925a
Signed-off-by: NNathan Scott <nathans@sgi.com>

boilerplate.

SGI-PV: 913862
SGI-Modid: xfs-linux:xfs-kern:23903a
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 943122
SGI-Modid: xfs-linux:xfs-kern:23901a
Signed-off-by: NNathan Scott <nathans@sgi.com>

the data/attr forks now grow up/down from either end of the literal area,
rather than dividing the literal area into two chunks and growing both
upward.  Means we can now make much more efficient use of the attribute
space, incl. fitting DMF attributes inline in 256 byte inodes, and large
jumps in dbench3 performance numbers.  It is self enabling, but can be
forced on/off via the attr2/noattr2 mount options.

SGI-PV: 941645
SGI-Modid: xfs-linux:xfs-kern:23835a
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 942243
SGI-Modid: xfs-linux:xfs-kern:198658a
Signed-off-by: NChristoph Hellwig <hch@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

are getting ENOSPC errors on writes. When we fail to allocate space for
indirect blocks in xfs_bmapi() make sure we release the direct block
allocation before returning.

SGI-PV: 938502
SGI-Modid: xfs-linux:xfs-kern:22986a
Signed-off-by: NDavid Chinner <dgc@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

not enabled though.

SGI-PV: 938145
SGI-Modid: xfs-linux:xfs-kern:22900a
Signed-off-by: NNathan Scott <nathans@sgi.com>

SGI-PV: 936255
SGI-Modid: xfs-linux:xfs-kern:192760a
Signed-off-by: NChristoph Hellwig <hch@sgi.com>
Signed-off-by: NNathan Scott <nathans@sgi.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!