linux.git/fs/sysfs/sysfs.h, branch v3.1

->permission() sanitizing: don't pass flags to ->permission()

2011-07-20T05:43:24+00:00

not used by the instances anymore.

Signed-off-by: Al Viro

Delay struct net freeing while there's a sysfs instance refering to it

2011-06-12T21:45:41+00:00

	* new refcount in struct net, controlling actual freeing of the memory
	* new method in kobj_ns_type_operations (->drop_ns())
	* ->current_ns() semantics change - it's supposed to be followed by
corresponding ->drop_ns().  For struct net in case of CONFIG_NET_NS it bumps
the new refcount; net_drop_ns() decrements it and calls net_free() if the
last reference has been dropped.  Method renamed to ->grab_current_ns().
	* old net_free() callers call net_drop_ns() instead.
	* sysfs_exit_ns() is gone, along with a large part of callchain
leading to it; now that the references stored in ->ns[...] stay valid we
do not need to hunt them down and replace them with NULL.  That fixes
problems in sysfs_lookup() and sysfs_readdir(), along with getting rid
of sb->s_instances abuse.

	Note that struct net *shutdown* logics has not changed - net_cleanup()
is called exactly when it used to be called.  The only thing postponed by
having a sysfs instance refering to that struct net is actual freeing of
memory occupied by struct net.

Signed-off-by: Al Viro

headers: kobject.h redux

2011-01-10T16:51:44+00:00

Remove kobject.h from files which don't need it, notably,
sched.h and fs.h.

Signed-off-by: Alexey Dobriyan 
Signed-off-by: Linus Torvalds

fs: provide rcu-walk aware permission i_ops

2011-01-07T06:50:29+00:00

Signed-off-by: Nick Piggin

switch sysfs to ->evict_inode()

2010-08-09T20:47:53+00:00

Signed-off-by: Al Viro

sysfs: Comment sysfs directory tagging logic

2010-05-21T16:37:31+00:00

Add some in-line comments to explain the new infrastructure, which
was introduced to support sysfs directory tagging with namespaces.
I think an overall description someplace might be good too, but it
didn't really seem to fit into Documentation/filesystems/sysfs.txt,
which appears more geared toward users, rather than maintainers, of
sysfs.

(Tejun, please let me know if I can make anything clearer or failed
altogether to comment something that should be commented.)

Signed-off-by: Serge E. Hallyn 
Cc: Eric W. Biederman 
Cc: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

sysfs: Implement sysfs tagged directory support.

2010-05-21T16:37:31+00:00

The problem.  When implementing a network namespace I need to be able
to have multiple network devices with the same name.  Currently this
is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and
potentially a few other directories of the form /sys/ ... /net/*.

What this patch does is to add an additional tag field to the
sysfs dirent structure.  For directories that should show different
contents depending on the context such as /sys/class/net/, and
/sys/devices/virtual/net/ this tag field is used to specify the
context in which those directories should be visible.  Effectively
this is the same as creating multiple distinct directories with
the same name but internally to sysfs the result is nicer.

I am calling the concept of a single directory that looks like multiple
directories all at the same path in the filesystem tagged directories.

For the networking namespace the set of directories whose contents I need
to filter with tags can depend on the presence or absence of hotplug
hardware or which modules are currently loaded.  Which means I need
a simple race free way to setup those directories as tagged.

To achieve a reace free design all tagged directories are created
and managed by sysfs itself.

Users of this interface:
- define a type in the sysfs_tag_type enumeration.
- call sysfs_register_ns_types with the type and it's operations
- sysfs_exit_ns when an individual tag is no longer valid

- Implement mount_ns() which returns the ns of the calling process
  so we can attach it to a sysfs superblock.
- Implement ktype.namespace() which returns the ns of a syfs kobject.

Everything else is left up to sysfs and the driver layer.

For the network namespace mount_ns and namespace() are essentially
one line functions, and look to remain that.

Tags are currently represented a const void * pointers as that is
both generic, prevides enough information for equality comparisons,
and is trivial to create for current users, as it is just the
existing namespace pointer.

The work needed in sysfs is more extensive.  At each directory
or symlink creating I need to check if the directory it is being
created in is a tagged directory and if so generate the appropriate
tag to place on the sysfs_dirent.  Likewise at each symlink or
directory removal I need to check if the sysfs directory it is
being removed from is a tagged directory and if so figure out
which tag goes along with the name I am deleting.

Currently only directories which hold kobjects, and
symlinks are supported.  There is not enough information
in the current file attribute interfaces to give us anything
to discriminate on which makes it useless, and there are
no potential users which makes it an uninteresting problem
to solve.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Benjamin Thery 
Signed-off-by: Greg Kroah-Hartman

sysfs: Basic support for multiple super blocks

2010-05-21T16:37:30+00:00

Add all of the necessary bioler plate to support
multiple superblocks in sysfs.

Signed-off-by: Eric W. Biederman 
Acked-by: Serge Hallyn 
Signed-off-by: Greg Kroah-Hartman

sysfs: Kill unused sysfs_sb variable.

2010-03-08T01:04:52+00:00

Now that there are no more users we can remove
the sysfs_sb variable.

Acked-by: Tejun Heo 
Acked-by: Serge Hallyn 
Signed-off-by: Eric W. Biederman 
Signed-off-by: Greg Kroah-Hartman

sysfs: Pass super_block to sysfs_get_inode

2010-03-08T01:04:52+00:00

Currently sysfs_get_inode magically returns an inode on
sysfs_sb.  Make the super_block parameter explicit and
the code becomes clearer.

Acked-by: Tejun Heo 
Acked-by: Serge Hallyn 
Signed-off-by: Eric W. Biederman 
Signed-off-by: Greg Kroah-Hartman