Commit da4759c7 authored Mar 12, 2015 by Guenter Roeck Committed by Greg Kroah-Hartman Mar 25, 2015

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>

parent bc465aa9

fs/sysfs/group.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -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;
		}

Admin message