linux/include
Tejun Heo 8e3f6541d4 cgroup: implement cgroup_add_cftypes() and friends
Currently, cgroup directories are populated by subsys->populate()
callback explicitly creating files on each cgroup creation.  This
level of flexibility isn't needed or desirable.  It provides largely
unused flexibility which call for abuses while severely limiting what
the core layer can do through the lack of structure and conventions.

Per each cgroup file type, the only distinction that cgroup users is
making is whether a cgroup is root or not, which can easily be
expressed with flags.

This patch introduces cgroup_add_cftypes().  These deal with cftypes
instead of individual files - controllers indicate that certain types
of files exist for certain subsystem.  Newly added CFTYPE_*_ON_ROOT
flags indicate whether a cftype should be excluded or created only on
the root cgroup.

cgroup_add_cftypes() can be called any time whether the target
subsystem is currently attached or not.  cgroup core will create files
on the existing cgroups as necessary.

Also, cgroup_subsys->base_cftypes is added to ease registration of the
base files for the subsystem.  If non-NULL on subsys init, the cftypes
pointed to by ->base_cftypes are automatically registered on subsys
init / load.

Further patches will convert the existing users and remove the file
based interface.  Note that this interface allows dynamic addition of
files to an active controller.  This will be used for sub-controller
modularity and unified hierarchy in the longer term.

This patch implements the new mechanism but doesn't apply it to any
user.

v2: replaced DECLARE_CGROUP_CFTYPES[_COND]() with
    cgroup_subsys->base_cftypes, which works better for cgroup_subsys
    which is loaded as module.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
2012-04-01 12:09:55 -07:00
..
acpi Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2012-03-30 16:45:39 -07:00
asm-generic Merge branch 'x86-x32-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-29 18:12:23 -07:00
crypto crypto: remove the second argument of k[un]map_atomic() 2012-03-20 21:48:16 +08:00
drm The following text was taken from the original review request: 2012-03-24 10:08:39 -07:00
keys
linux cgroup: implement cgroup_add_cftypes() and friends 2012-04-01 12:09:55 -07:00
math-emu
media The following text was taken from the original review request: 2012-03-24 10:41:37 -07:00
misc
mtd
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-03-27 16:52:32 -07:00
pcmcia
rdma Merge branches 'cma', 'cxgb3', 'cxgb4', 'ehca', 'iser', 'mad', 'nes', 'qib', 'srp' and 'srpt' into for-next 2012-03-19 09:50:33 -07:00
rxrpc
scsi SCSI updates on 20120331 2012-03-31 13:31:23 -07:00
sound The following text was taken from the original review request: 2012-03-24 10:41:37 -07:00
target target: Use array_zalloc for device_list 2012-03-15 19:15:51 -07:00
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2012-03-30 12:44:29 -07:00
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xen Disintegrate and delete asm/system.h 2012-03-28 15:58:21 -07:00
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