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authorTejun Heo <tj@kernel.org>2013-11-24 03:01:46 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-28 01:01:03 +0400
commitc84a3b27798dfce928b867fa1c9f3c3fd66f0a31 (patch)
tree87a706232ee20ce8262b4a34bbf9eaf06b3ddfe6 /fs/sysfs/sysfs.h
parent6ce4eac1f600b34f2f7f58f9cd8f0503d79e42ae (diff)
downloadlinux-c84a3b27798dfce928b867fa1c9f3c3fd66f0a31.tar.xz
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 cb26a311578e ("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. a1212d278c05 ("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>
Diffstat (limited to 'fs/sysfs/sysfs.h')
-rw-r--r--fs/sysfs/sysfs.h25
1 files changed, 7 insertions, 18 deletions
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 0af09fbfb3f6..e116c21a27bf 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -90,11 +90,8 @@ struct sysfs_dirent {
#define SYSFS_COPY_NAME (SYSFS_DIR | SYSFS_KOBJ_LINK)
#define SYSFS_ACTIVE_REF (SYSFS_KOBJ_ATTR | SYSFS_KOBJ_BIN_ATTR)
-/* identify any namespace tag on sysfs_dirents */
-#define SYSFS_NS_TYPE_MASK 0xf00
-#define SYSFS_NS_TYPE_SHIFT 8
-
-#define SYSFS_FLAG_MASK ~(SYSFS_NS_TYPE_MASK|SYSFS_TYPE_MASK)
+#define SYSFS_FLAG_MASK ~SYSFS_TYPE_MASK
+#define SYSFS_FLAG_NS 0x01000
#define SYSFS_FLAG_REMOVED 0x02000
static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
@@ -102,15 +99,6 @@ static inline unsigned int sysfs_type(struct sysfs_dirent *sd)
return sd->s_flags & SYSFS_TYPE_MASK;
}
-/*
- * Return any namespace tags on this dirent.
- * enum kobj_ns_type is defined in linux/kobject.h
- */
-static inline enum kobj_ns_type sysfs_ns_type(struct sysfs_dirent *sd)
-{
- return (sd->s_flags & SYSFS_NS_TYPE_MASK) >> SYSFS_NS_TYPE_SHIFT;
-}
-
#ifdef CONFIG_DEBUG_LOCK_ALLOC
#define sysfs_dirent_init_lockdep(sd) \
@@ -155,12 +143,13 @@ struct sysfs_addrm_cxt {
*/
/*
- * Each sb is associated with a set of namespace tags (i.e.
- * the network namespace of the task which mounted this sysfs
- * instance).
+ * Each sb is associated with one namespace tag, currently the network
+ * namespace of the task which mounted this sysfs instance. If multiple
+ * tags become necessary, make the following an array and compare
+ * sysfs_dirent tag against every entry.
*/
struct sysfs_super_info {
- void *ns[KOBJ_NS_TYPES];
+ void *ns;
};
#define sysfs_info(SB) ((struct sysfs_super_info *)(SB->s_fs_info))
extern struct sysfs_dirent sysfs_root;