Tejun Heo c84a3b2779 sysfs: drop kobj_ns_type handling, take #2 ... The way namespace tags are implemented in sysfs is more complicated than necessary. As each tag is a pointer value and required to be non-NULL under a namespace enabled parent, there's no need to record separately what type each tag is. If multiple namespace types are needed, which currently aren't, we can simply compare the tag to a set of allowed tags in the superblock assuming that the tags, being pointers, won't have the same value across multiple types. This patch rips out kobj_ns_type handling from sysfs. sysfs now has an enable switch to turn on namespace under a node. If enabled, all children are required to have non-NULL namespace tags and filtered against the super_block's tag. kobject namespace determination is now performed in lib/kobject.c::create_dir() making sysfs_read_ns_type() unnecessary. The sanity checks are also moved. create_dir() is restructured to ease such addition. This removes most kobject namespace knowledge from sysfs proper which will enable proper separation and layering of sysfs. This is the second try. The first one was cb26a31157 ("sysfs: drop kobj_ns_type handling") which tried to automatically enable namespace if there are children with non-NULL namespace tags; however, it was broken for symlinks as they should inherit the target's tag iff namespace is enabled in the parent. This led to namespace filtering enabled incorrectly for wireless net class devices through phy80211 symlinks and thus network configuration failure. a1212d278c ("Revert "sysfs: drop kobj_ns_type handling"") reverted the commit. This shouldn't introduce any behavior changes, for real. v2: Dummy implementation of sysfs_enable_ns() for !CONFIG_SYSFS was missing and caused build failure. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2013-11-27 13:01:03 -08:00
..
dir.c	sysfs: drop kobj_ns_type handling, take #2	2013-11-27 13:01:03 -08:00
file.c	sysfs: use generic_file_llseek() for sysfs_file_operations	2013-11-01 12:13:37 -07:00
group.c	sysfs: introduce [__]sysfs_remove()	2013-10-03 16:38:52 -07:00
inode.c	sysfs: move sysfs_hash_and_remove() to fs/sysfs/dir.c	2013-10-29 15:12:07 -07:00
Kconfig	kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT	2011-01-20 17:02:05 -08:00
Makefile	sysfs: merge regular and bin file handling	2013-10-05 17:27:40 -07:00
mount.c	sysfs: drop kobj_ns_type handling, take #2	2013-11-27 13:01:03 -08:00
symlink.c	sysfs: drop kobj_ns_type handling, take #2	2013-11-27 13:01:03 -08:00
sysfs.h	sysfs: drop kobj_ns_type handling, take #2	2013-11-27 13:01:03 -08:00