[PATCH] libfs: return error code on failed attr set

[Wu Fengguang <fengguang.wu@intel.com>]

Currently all simple_attr.set handlers return 0 on success and negative
codes on error. Fix simple_attr_write() to return these error codes.

CC: Theodore Ts'o <tytso@mit.edu>
CC: Al Viro <viro@zeniv.linux.org.uk>
CC: Christoph Hellwig <hch@lst.de>
CC: Nick Piggin <npiggin@suse.de>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
---
 fs/libfs.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- linux-mm.orig/fs/libfs.c	2009-09-08 16:28:59.000000000 +0800
+++ linux-mm/fs/libfs.c	2009-09-08 16:29:50.000000000 +0800
@@ -822,10 +822,11 @@ ssize_t simple_attr_write(struct file *f
 	if (copy_from_user(attr->set_buf, buf, size))
 		goto out;
 
-	ret = len; /* claim we got the whole input */
 	attr->set_buf[size] = '\0';
 	val = simple_strtol(attr->set_buf, NULL, 0);
-	attr->set(attr->data, val);
+	ret = attr->set(attr->data, val);
+	if (ret == 0)
+		ret = len; /* on success, claim we got the whole input */
 out:
 	mutex_unlock(&attr->mutex);
 	return ret;