tree 516eb00e50add1fe1cce74e8967857af5d41083e
parent 769ba8d92025fa390f3097e658b8ed6e032d68e9
author Boaz Harrosh <bharrosh@panasas.com> 1318426927 +0200
committer Boaz Harrosh <bharrosh@panasas.com> 1319502148 -0700

exofs: Support for RAID5 read-4-write interface.

The ore need suplied a r4w_get_page/r4w_put_page API
from Filesystem so it can get cache pages to read-into when
writing parial stripes.

Also I commented out and NULLed the .writepage (singular)
vector. Because it gives terrible write pattern to raid
and is apparently not needed. Even in OOM conditions the
system copes (even better) with out it.

TODO: How to specify to write_cache_pages() to start
      or include a certain page?

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>