[PATCH] sysfs: (driver/block) if show/store is missing return -EIO

sysfs: fix drivers/block so if an attribute doesn't implement
       show or store method read/write will return -EIO
       instead of 0 or -EINVAL.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/block/cfq-iosched.c b/drivers/block/cfq-iosched.c
index 2210bacad56a..3ac47dde64da 100644
--- a/drivers/block/cfq-iosched.c
+++ b/drivers/block/cfq-iosched.c
@@ -1775,7 +1775,7 @@ cfq_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
         struct cfq_fs_entry *entry = to_cfq(attr);
 
         if (!entry->show)
-                return 0;
+                return -EIO;
 
         return entry->show(e->elevator_data, page);
 }
@@ -1788,7 +1788,7 @@ cfq_attr_store(struct kobject *kobj, struct attribute *attr,
         struct cfq_fs_entry *entry = to_cfq(attr);
 
         if (!entry->store)
-                return -EINVAL;
+                return -EIO;
 
         return entry->store(e->elevator_data, page, length);
 }