[PATCH] ext3 -nobh option causes oops

For files other than IFREG, nobh option doesn't make sense.  Modifications
to them are journalled and needs buffer heads to do that.  Without this
patch, we get kernel oops in page_buffers().

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
index ab034d3..c5ee9f0 100644
--- a/fs/ext3/inode.c
+++ b/fs/ext3/inode.c
@@ -1158,7 +1158,7 @@
 		ret = PTR_ERR(handle);
 		goto out;
 	}
-	if (test_opt(inode->i_sb, NOBH))
+	if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
 		ret = nobh_prepare_write(page, from, to, ext3_get_block);
 	else
 		ret = block_prepare_write(page, from, to, ext3_get_block);
@@ -1244,7 +1244,7 @@
 	if (new_i_size > EXT3_I(inode)->i_disksize)
 		EXT3_I(inode)->i_disksize = new_i_size;
 
-	if (test_opt(inode->i_sb, NOBH))
+	if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
 		ret = nobh_commit_write(file, page, from, to);
 	else
 		ret = generic_commit_write(file, page, from, to);
@@ -1494,7 +1494,7 @@
 		goto out_fail;
 	}
 
-	if (test_opt(inode->i_sb, NOBH))
+	if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
 		ret = nobh_writepage(page, ext3_get_block, wbc);
 	else
 		ret = block_write_full_page(page, ext3_get_block, wbc);