Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core-2.6: (38 commits)
  net: Expose all network devices in a namespaces in sysfs
  hotplug: netns aware uevent_helper
  kobj: Send hotplug events in the proper namespace.
  netlink: Implment netlink_broadcast_filtered
  net/sysfs: Fix the bitrot in network device kobject namespace support
  netns: Teach network device kobjects which namespace they are in.
  kobject: Send hotplug events in all network namespaces
  driver-core: fix Typo in drivers/base/core.c for CONFIG_MODULE
  pci: check caps from sysfs file open to read device dependent config space
  sysfs: add struct file* to bin_attr callbacks
  sysfs: Remove usage of S_BIAS to avoid merge conflict with the vfs tree
  sysfs: Don't use enums in inline function declaration.
  sysfs-namespaces: add a high-level Documentation file
  sysfs: Comment sysfs directory tagging logic
  driver core: Implement ns directory support for device classes.
  sysfs: Implement sysfs_delete_link
  sysfs: Add support for tagged directories with untagged members.
  sysfs: Implement sysfs tagged directory support.
  kobj: Add basic infrastructure for dealing with namespaces.
  sysfs: Remove double free sysfs_get_sb
  ...

1 files changed, 42 insertions, 0 deletions

diff --git a/Documentation/filesystems/sysfs-tagging.txt b/Documentation/filesystems/sysfs-tagging.txt
new file mode 100644
index 00000000000..caaaf1266d8
--- /dev/null
+++ b/Documentation/filesystems/sysfs-tagging.txt
@@ -0,0 +1,42 @@
+Sysfs tagging
+-------------
+
+(Taken almost verbatim from Eric Biederman's netns tagging patch
+commit msg)
+
+The problem.  Network devices show up in sysfs and with the network
+namespace active multiple devices with the same name can show up in
+the same directory, ouch!
+
+To avoid that problem and allow existing applications in network
+namespaces to see the same interface that is currently presented in
+sysfs, sysfs now has tagging directory support.
+
+By using the network namespace pointers as tags to separate out the
+the sysfs directory entries we ensure that we don't have conflicts
+in the directories and applications only see a limited set of
+the network devices.
+
+Each sysfs directory entry may be tagged with zero or one
+namespaces.  A sysfs_dirent is augmented with a void *s_ns.  If a
+directory entry is tagged, then sysfs_dirent->s_flags will have a
+flag between KOBJ_NS_TYPE_NONE and KOBJ_NS_TYPES, and s_ns will
+point to the namespace to which it belongs.
+
+Each sysfs superblock's sysfs_super_info contains an array void
+*ns[KOBJ_NS_TYPES].  When a a task in a tagging namespace
+kobj_nstype first mounts sysfs, a new superblock is created.  It
+will be differentiated from other sysfs mounts by having its
+s_fs_info->ns[kobj_nstype] set to the new namespace.  Note that
+through bind mounting and mounts propagation, a task can easily view
+the contents of other namespaces' sysfs mounts.  Therefore, when a
+namespace exits, it will call kobj_ns_exit() to invalidate any
+sysfs_dirent->s_ns pointers pointing to it.
+
+Users of this interface:
+- define a type in the kobj_ns_type enumeration.
+- call kobj_ns_type_register() with its kobj_ns_type_operations which has
+  - current_ns() which returns current's namespace
+  - netlink_ns() which returns a socket's namespace
+  - initial_ns() which returns the initial namesapce
+- call kobj_ns_exit() when an individual tag is no longer valid