[XFS] propogate return codes from flush routines

This patch handles error return values in fs_flush_pages and
fs_flushinval_pages. It changes the prototype of fs_flushinval_pages so we
can propogate the errors and handle them at higher layers. I also modified
xfs_itruncate_start so that it could propogate the error further.

SGI-PV: 961990
SGI-Modid: xfs-linux-melb:xfs-kern:28231a

Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Stewart Smith <stewart@flamingspork.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/xfs_vfsops.c b/fs/xfs/xfs_vfsops.c
index 22a0927..2e830e7 100644
--- a/fs/xfs/xfs_vfsops.c
+++ b/fs/xfs/xfs_vfsops.c
@@ -1147,7 +1147,7 @@
 			if (XFS_FORCED_SHUTDOWN(mp)) {
 				bhv_vop_toss_pages(vp, 0, -1, FI_REMAPF);
 			} else {
-				bhv_vop_flushinval_pages(vp, 0, -1, FI_REMAPF);
+				error = bhv_vop_flushinval_pages(vp, 0, -1, FI_REMAPF);
 			}
 
 			xfs_ilock(ip, XFS_ILOCK_SHARED);