libfs: return error code on failed attr set

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

Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
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: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 2 deletions

diff --git a/fs/libfs.c b/fs/libfs.c
index 662a28e4f667..219576c52d80 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -739,10 +739,11 @@ ssize_t simple_attr_write(struct file *file, const char __user *buf,
         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;