ocfs2: use allocation reservations during file write

Add a per-inode reservations structure and pass it through to the
reservations code.

Signed-off-by: Mark Fasheh <mfasheh@suse.com>

diff --cc fs/ocfs2/alloc.c
Simple merge

diff --cc fs/ocfs2/aops.c
Simple merge

diff --cc fs/ocfs2/file.c
Simple merge

diff --cc fs/ocfs2/inode.c
Simple merge

diff --cc fs/ocfs2/inode.h
Simple merge

diff --cc fs/ocfs2/super.c
Simple merge