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mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 13:13:57 +08:00
linux-next/Documentation/ABI
Linus Torvalds 91f8575685 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client
Pull Ceph changes from Alex Elder:
 "This is a big pull.

  Most of it is culmination of Alex's work to implement RBD image
  layering, which is now complete (yay!).

  There is also some work from Yan to fix i_mutex behavior surrounding
  writes in cephfs, a sync write fix, a fix for RBD images that get
  resized while they are mapped, and a few patches from me that resolve
  annoying auth warnings and fix several bugs in the ceph auth code."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (254 commits)
  rbd: fix image request leak on parent read
  libceph: use slab cache for osd client requests
  libceph: allocate ceph message data with a slab allocator
  libceph: allocate ceph messages with a slab allocator
  rbd: allocate image object names with a slab allocator
  rbd: allocate object requests with a slab allocator
  rbd: allocate name separate from obj_request
  rbd: allocate image requests with a slab allocator
  rbd: use binary search for snapshot lookup
  rbd: clear EXISTS flag if mapped snapshot disappears
  rbd: kill off the snapshot list
  rbd: define rbd_snap_size() and rbd_snap_features()
  rbd: use snap_id not index to look up snap info
  rbd: look up snapshot name in names buffer
  rbd: drop obj_request->version
  rbd: drop rbd_obj_method_sync() version parameter
  rbd: more version parameter removal
  rbd: get rid of some version parameters
  rbd: stop tracking header object version
  rbd: snap names are pointer to constant data
  ...
2013-05-06 13:11:19 -07:00
..
obsolete Merge branches 'for-3.7/upstream-fixes', 'for-3.8/hidraw', 'for-3.8/i2c-hid', 'for-3.8/multitouch', 'for-3.8/roccat', 'for-3.8/sensors' and 'for-3.8/upstream' into for-linus 2012-12-12 21:41:55 +01:00
removed netfilter: remove ip_queue support 2012-05-08 20:25:42 +02:00
stable tpm: add documentation for sysfs interfaces 2013-02-05 09:38:21 -06:00
testing Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client 2013-05-06 13:11:19 -07:00
README Documentation: remove reference to feature-removal-schedule.txt 2012-12-17 17:15:12 -08:00

This directory attempts to document the ABI between the Linux kernel and
userspace, and the relative stability of these interfaces.  Due to the
everchanging nature of Linux, and the differing maturity levels, these
interfaces should be used by userspace programs in different ways.

We have four different levels of ABI stability, as shown by the four
different subdirectories in this location.  Interfaces may change levels
of stability according to the rules described below.

The different levels of stability are:

  stable/
	This directory documents the interfaces that the developer has
	defined to be stable.  Userspace programs are free to use these
	interfaces with no restrictions, and backward compatibility for
	them will be guaranteed for at least 2 years.  Most interfaces
	(like syscalls) are expected to never change and always be
	available.

  testing/
	This directory documents interfaces that are felt to be stable,
	as the main development of this interface has been completed.
	The interface can be changed to add new features, but the
	current interface will not break by doing this, unless grave
	errors or security problems are found in them.  Userspace
	programs can start to rely on these interfaces, but they must be
	aware of changes that can occur before these interfaces move to
	be marked stable.  Programs that use these interfaces are
	strongly encouraged to add their name to the description of
	these interfaces, so that the kernel developers can easily
	notify them if any changes occur (see the description of the
	layout of the files below for details on how to do this.)

  obsolete/
  	This directory documents interfaces that are still remaining in
	the kernel, but are marked to be removed at some later point in
	time.  The description of the interface will document the reason
	why it is obsolete and when it can be expected to be removed.

  removed/
	This directory contains a list of the old interfaces that have
	been removed from the kernel.

Every file in these directories will contain the following information:

What:		Short description of the interface
Date:		Date created
KernelVersion:	Kernel version this feature first showed up in.
Contact:	Primary contact for this interface (may be a mailing list)
Description:	Long description of the interface and how to use it.
Users:		All users of this interface who wish to be notified when
		it changes.  This is very important for interfaces in
		the "testing" stage, so that kernel developers can work
		with userspace developers to ensure that things do not
		break in ways that are unacceptable.  It is also
		important to get feedback for these interfaces to make
		sure they are working in a proper way and do not need to
		be changed further.


How things move between levels:

Interfaces in stable may move to obsolete, as long as the proper
notification is given.

Interfaces may be removed from obsolete and the kernel as long as the
documented amount of time has gone by.

Interfaces in the testing state can move to the stable state when the
developers feel they are finished.  They cannot be removed from the
kernel tree without going through the obsolete state first.

It's up to the developer to place their interfaces in the category they
wish for it to start out in.