[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_inode.h b/fs/xfs/xfs_inode.h
index bc82372..699960f 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -481,7 +481,7 @@
 uint		xfs_dic2xflags(struct xfs_dinode_core *);
 int		xfs_ifree(struct xfs_trans *, xfs_inode_t *,
 			   struct xfs_bmap_free *);
-void		xfs_itruncate_start(xfs_inode_t *, uint, xfs_fsize_t);
+int		xfs_itruncate_start(xfs_inode_t *, uint, xfs_fsize_t);
 int		xfs_itruncate_finish(struct xfs_trans **, xfs_inode_t *,
 				     xfs_fsize_t, int, int);
 int		xfs_iunlink(struct xfs_trans *, xfs_inode_t *);