xfs: split out transaction reservation code

The transaction reservation size calculations is used by both kernel
and userspace, but most of the transaction code in xfs_trans.c is
kernel specific. Split all the transaction reservation code out into
it's own files to make sharing with userspace simpler. This just
leaves kernel-only definitions in xfs_trans.h, so it doesn't need to
be shared with userspace anymore, either.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index 4a45080..dc72b6b 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -47,6 +47,7 @@
 				   xfs_mru_cache.o \
 				   xfs_rename.o \
 				   xfs_super.o \
+				   xfs_trans.o \
 				   xfs_utils.o \
 				   xfs_vnodeops.o \
 				   xfs_xattr.o \
@@ -76,7 +77,7 @@
 				   xfs_log_recover.o \
 				   xfs_mount.o \
 				   xfs_symlink.o \
-				   xfs_trans.o
+				   xfs_trans_resv.o
 
 # low-level transaction/log code
 xfs-y				+= xfs_log.o \