[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/linux-2.6/xfs_fs_subr.c b/fs/xfs/linux-2.6/xfs_fs_subr.c
index dc05628..2eb87cd 100644
--- a/fs/xfs/linux-2.6/xfs_fs_subr.c
+++ b/fs/xfs/linux-2.6/xfs_fs_subr.c
@@ -35,7 +35,7 @@
 		truncate_inode_pages(ip->i_mapping, first);
 }
 
-void
+int
 fs_flushinval_pages(
 	bhv_desc_t	*bdp,
 	xfs_off_t	first,
@@ -44,13 +44,16 @@
 {
 	bhv_vnode_t	*vp = BHV_TO_VNODE(bdp);
 	struct inode	*ip = vn_to_inode(vp);
+	int		ret = 0;
 
 	if (VN_CACHED(vp)) {
 		if (VN_TRUNC(vp))
 			VUNTRUNCATE(vp);
-		filemap_write_and_wait(ip->i_mapping);
-		truncate_inode_pages(ip->i_mapping, first);
+		ret = filemap_write_and_wait(ip->i_mapping);
+		if (!ret)
+			truncate_inode_pages(ip->i_mapping, first);
 	}
+	return ret;
 }
 
 int
@@ -63,14 +66,18 @@
 {
 	bhv_vnode_t	*vp = BHV_TO_VNODE(bdp);
 	struct inode	*ip = vn_to_inode(vp);
+	int		ret = 0;
+	int		ret2;
 
 	if (VN_DIRTY(vp)) {
 		if (VN_TRUNC(vp))
 			VUNTRUNCATE(vp);
-		filemap_fdatawrite(ip->i_mapping);
+		ret = filemap_fdatawrite(ip->i_mapping);
 		if (flags & XFS_B_ASYNC)
-			return 0;
-		filemap_fdatawait(ip->i_mapping);
+			return ret;
+		ret2 = filemap_fdatawait(ip->i_mapping);
+		if (!ret)
+			ret = ret2;
 	}
-	return 0;
+	return ret;
 }