sysfs: Use only return value from is_visible for the file mode

Up to now, is_visible can only be used to either remove visibility
of a file entirely or to add permissions, but not to reduce permissions.
This makes it impossible, for example, to use DEVICE_ATTR_RW to define
file attributes and reduce permissions to read-only.

This behavior is undesirable and unnecessarily complicates code which
needs to reduce permissions; instead of just returning the desired
permissions, it has to ensure that the permissions in the attribute
variable declaration only reflect the minimal permissions ever needed.

Change semantics of is_visible to only use the permissions returned
from it instead of oring the returned value with the hard-coded
permissions.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Guenter Roeck 2015-03-12 09:58:26 -04:00 committed by Greg Kroah-Hartman
parent bc465aa9d0
commit da4759c73b

View File

@ -41,7 +41,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
if (grp->attrs) {
for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
umode_t mode = 0;
umode_t mode = (*attr)->mode;
/*
* In update mode, we're changing the permissions or
@ -56,8 +56,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
continue;
}
error = sysfs_add_file_mode_ns(parent, *attr, false,
(*attr)->mode | mode,
NULL);
mode, NULL);
if (unlikely(error))
break;
}