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Commit Graph

90 Commits

Author SHA1 Message Date
John W. Linville
38a0084063 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem 2012-07-12 13:44:50 -04:00
Ben Hutchings
2c53040f01 net: Fix (nearly-)kernel-doc comments for various functions
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 23:13:45 -07:00
Johannes Berg
fc8a7321d3 mac80211: don't expose ieee80211_add_srates_ie()
This and ieee80211_add_ext_srates_ie() aren't
exported, so can't be used by drivers anyway,
but there's also no reason that they should be
so make them private to mac80211 and use sdata
instead of vif arguments.

Acked-by: Arik Nemtsov <arik@wizery.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-06-28 10:35:50 +02:00
Johannes Berg
bdcbd8e0e3 mac80211: clean up debugging
There are a few things that make the logging and
debugging in mac80211 less useful than it should
be right now:
 * a lot of messages should be pr_info, not pr_debug
 * wholesale use of pr_debug makes it require *both*
   Kconfig and dynamic configuration
 * there are still a lot of ifdefs
 * the style is very inconsistent, sometimes the
   sdata->name is printed in front

Clean up everything, introducing new macros and
separating out the station MLME debugging into
a new Kconfig symbol.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2012-06-24 11:32:29 +02:00
Joe Perches
f0d232080f net: mac80211: Convert printk(KERN_DEBUG to pr_debug
Standardize the debugging to be able to use dynamic_debug.

Coalesce formats, align arguments.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-06-05 15:27:16 -04:00
Ashok Nagarajan
cbf9322eb1 mac80211: Modify mesh_set_ht_prot_mode() to have less identation
Determining types of peers is modified to have less indentation. This change is
suggested by Johannes. This patch also corrects the reference in comment to
IEEE 802.11-2012 version.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-05-16 13:24:25 -04:00
Thomas Pedersen
f5c5681424 mac80211: send peer candidate event for new sta only
Only send a cfg80211 new peer candidate notification if userspace has
yet to allocate this station entry.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-05-15 17:27:54 -04:00
Ashok Nagarajan
70c33eaae7 {nl,cfg,mac}80211: Allow user to see/configure HT protection mode
This patch introduces a new mesh configuration parameter "ht_opmode" and will
allow user to check the current HT protection mode selected. Users could
configure the protection mode by the command "iw mesh_iface set mesh_param
mesh_ht_protection_mode=2". The default protection mode of mesh is set to
non-HT mixed mode.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Reviewed-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-05-08 21:53:59 -04:00
Ashok Nagarajan
57aac7c51c mac80211: Implement HT mixed protection mode
Section 9.23.3.5 of IEEE 80211s standard describes the protection rules for
HT mesh STA in a MBSS. Three HT protection modes are supported for now:

non-HT mixed mode - is selected if any non-HT peers are present in our MBSS.
20MHz-protection mode - is selected if all peers in our 20/40MHz MBSS support
			HT and atleast one HT20 peer is present.
no-protection mode - is selected otherwise.

This is a limited implementation of 9.23.3.5, which only considers mesh peers
when determining the HT protection mode. Station's channel_type needs to be
maintained.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Reviewed-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-05-08 21:53:57 -04:00
Thomas Pedersen
c7d258288f mac80211: don't transmit 40MHz frames to 20MHz peer
If a mesh peer indicates it is operating as 20MHz-only in its HT
operation IE, have the rate control algorithm respect this by disabling
the equivalent bit in the ieee80211_sta HT capabilities.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-05-08 21:53:42 -04:00
Thomas Pedersen
e87278e730 mac80211: insert mesh peer after init
Drivers need the station rate info when inserting a new sta_info. The
patch "mac80211: refactor mesh peer initialization" wrongly assumed the
rate info could be applied after insertion. After further review, this
is clearly not the case.

This fixes a regression where HT parameters were not applied before
inserting the sta_info, causing performance degradation.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-05-08 21:53:42 -04:00
Thomas Pedersen
e76781e48f mac80211: don't set mesh peer ht caps if ht disabled
Blindly setting ht caps on a mesh peer's station entry would result in
MCS rates being used by the rate control algorithm even if no ht had
been configured. Fix this by checking the channel type before assigning
ht capabilites.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-23 15:34:07 -04:00
Thomas Pedersen
f743ff4907 mac80211: refactor mesh peer rate handling
To avoid passing supp_rates and basic_rates around all the time, just
derive these when needed in mesh_matches_local() and mesh_peer_init().

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-23 15:34:07 -04:00
Thomas Pedersen
54ab1ffb6c mac80211: refactor mesh peer initialization
This patch unifies the previous two paths toward mesh peer creation a
bit. It also fixes a bug where a peer's changing rates or HT mode
wouldn't register on leaving and then returning to the mesh with a sta
entry still present.

Also clean up locking and clear possibly stale ht cap.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-23 15:34:07 -04:00
Ashok Nagarajan
fe40cb6274 mac80211: Check basic rates when peering
Section 13.2.3 of IEEE 80211s standard requires BSSBasicRateSet of mesh nodes
to be identical to establish peer link.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:47 -04:00
Ashok Nagarajan
9ebb61a23d mac80211: Modify sta_get_rates to give basic rates
Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:47 -04:00
Ashok Nagarajan
657c3e0c41 mac80211: Indicate basic rates when adding rate IEs
Basic rates are added with supported rates IE and extended supported
rates IE.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:46 -04:00
Johannes Berg
074d46d1d2 wireless: rename ht_info to ht_operation
Since some of the HT code pre-dates 802.11n-2009
some names are wrong. The one that bothers me most
is that "HT operation" is called "HT information"
in our code and that causes confusion.

Rename "HT information" to "HT operation" and also
the control_chan field to primary_chan to match
the name used in the spec.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-09 16:05:55 -04:00
Ashok Nagarajan
3d4f969972 mac80211: Fix potential null pointer dereferencing
The patch "{nl,cfg,mac}80211: Implement RSSI threshold for mesh peering"
has a potential null pointer dereferencing problem. Thanks to Dan Carpenter
for pointing out. This patch will fix the issue.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-03-07 13:51:47 -05:00
Ashok Nagarajan
5533513784 {nl,cfg,mac}80211: Implement RSSI threshold for mesh peering
Mesh peer links are established only if average rssi of the peer
candidate satisfies the threshold. This is not in 802.11s specification
but was requested by David Fulgham, an open80211s user. This is a way to avoid
marginal peer links with stations that are barely within range.

This patch adds a new mesh configuration parameter, mesh_rssi_threshold. This
feature is supported only for hardwares that report signal in dBm.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-03-05 15:23:15 -05:00
John W. Linville
874239f51f Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless 2012-02-01 10:48:50 -05:00
Johannes Berg
83d5cc0124 mac80211: station state transition error handling
In the future, when we start notifying drivers,
state transitions could potentially fail. To make
it easier to distinguish between programming bugs
and driver failures:
 * rename sta_info_move_state() to
   sta_info_pre_move_state() which can only be
   called before the station is inserted (and
   check this with a new station flag).
 * rename sta_info_move_state_checked() to just
   plain sta_info_move_state(), as it will be
   the regular function that can fail for more
   than just one reason (bad transition or an
   error from the driver)

This makes the programming model easier -- one of
the functions can only be called before insertion
and can't fail, the other can fail.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-01-30 15:41:25 -05:00
Javier Cardona
65e8b0ccb6 mac80211: Use the right headroom size for mesh mgmt frames
Use local->tx_headroom instad of local->hw.extra_tx_headroom.
local->tx_headroom is the max of hw.extra_tx_headroom required by the
driver and the headroom required by mac80211 for status reporting.  On
drivers where hw.extra_tx_headroom is smaller than what mac80211
requires (e.g. ath5k), we would not reserve sufficient buffer space to
report tx status.

Also, don't reserve local->tx_headroom + local->hw.extra_tx_headroom.

Reported-by: Simon Morgenthaler <s.morgenthaler@students.unibe.ch>
Reported-by: Kai Scharwies <kai@scharwies.de>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-01-18 14:38:06 -05:00
Johannes Berg
d9a7ddb05e mac80211: refactor station state transitions
Station entries can have various states, the most
important ones being auth, assoc and authorized.
This patch prepares us for telling the driver about
these states, we don't want to confuse drivers with
strange transitions, so with this we enforce that
they move in the right order between them (back and
forth); some transitions might happen before the
driver even knows about the station, but at least
runtime transitions will be ordered correctly.

As a consequence, IBSS and MESH stations will now
have the ASSOC flag set (so they can transition to
AUTHORIZED), and we can get rid of a special case
in TX processing.

When freeing a station, unwind the state so that
other parts of the code (or drivers later) can rely
on the transitions.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-12-15 14:46:34 -05:00
Ben Greear
ef96a84202 mac80211: Support ht-cap over-rides.
This implements ht-cap over-rides for mac80211 drivers.
HT may be disabled, making an /a/b/g/n station act like an
a/b/g station.  HT40 may be disabled forcing the station to
be HT20 even if the AP and local hardware support HT40.

MAX-AMSDU may be disabled.
AMPDU-Density may be increased.
AMPDU-Factor may be decreased.

This has been successfully tested with ath9k using patched
wpa_supplicant and iw.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-21 16:22:06 -05:00
Thomas Pedersen
739522baa1 mac80211: set HT capabilities for mesh peer
Set peer's HT capabilities, and disallow peering if we're on a different
channel type.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Ashok Nagarajan <anagar6@uic.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-08 15:54:33 -05:00
Thomas Pedersen
176f36086e mac80211: add HT IEs to mesh frames
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Ashok Nagarajan <anagar6@uic.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-08 15:54:33 -05:00
Thomas Pedersen
3b69a9c5f2 mac80211: comment allocation of mesh frames
Remove most references to magic numbers, save a few bytes and hopefully
improve readability.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-11-08 15:54:31 -05:00
Johannes Berg
c2c98fdeb5 mac80211: optimise station flags
The flaglock in struct sta_info has long been
something that I wanted to get rid of, this
finally does the conversion to atomic bitops.

The conversion itself is straight-forward in
most places, a few things needed to change a
bit since we can no longer use multiple bits
at the same time.

On x86-64, this is a fairly significant code
size reduction:
   text	   data	    bss	    dec	    hex
 427861	  23648	   1008	 452517	  6e7a5	before
 425383	  23648	    976	 450007	  6ddd7	after

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-09-30 15:57:19 -04:00
Arik Nemtsov
768db3438b mac80211: standardize adding supported rates IEs
Relocate the mesh implementation of adding the (extended) supported
rates IE to util.c, anticipating its use by other parts of mac80211.

Signed-off-by: Arik Nemtsov <arik@wizery.com>
Cc: Kalyan C Gaddam <chakkal@iit.edu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-09-30 15:57:06 -04:00
Thomas Pedersen
ba4a14e102 mac80211: notify peer when shutting down peer link
Send a Mesh Peering Close frame when we deactivate a mesh peer link.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-09-21 16:19:41 -04:00
Javier Cardona
5fbdf4a2df mac80211: Mark all mesh stations as QoS capable
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-09-14 13:56:51 -04:00
Thomas Pedersen
8db098507c mac80211: update mesh peering frame format
This patch updates the mesh peering frames to the format specified in
the recently ratified 802.11s standard. Several changes took place to
make this happen:

	- Change RX path to handle new self-protected frames
	- Add new Peering management IE
	- Remove old Peer Link IE
	- Remove old plink_action field in ieee80211_mgmt header

These changes by themselves would either break peering, or work by
coincidence, so squash them all into this patch.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-08-22 14:46:00 -04:00
Thomas Pedersen
54ef656b05 mac80211: update mesh peering frame codes
Have the mesh peering frames use the self-protected action and reason codes
specified in 802.11s and defined in ieee80211.h. Remove the local enums.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-08-22 14:46:00 -04:00
Thomas Pedersen
082ebb0c25 mac80211: fix mesh beacon format
Correct ordering of IEs in the mesh beacon while removing unneeded IEs
from mesh peering frames. Set privacy bit in capability info if security
is enabled. Add utility functions to aid in construction
of IEs and reduce code duplication.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-08-22 14:45:59 -04:00
Javier Cardona
57cf8043a6 nl80211: Move peer link state definition to nl80211
These definitions need to be exposed now that we can set the peer link
states via NL80211_ATTR_STA_PLINK_STATE.  They were already being
(opaquely) reported by NL80211_STA_INFO_PLINK_STATE.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-05-16 14:10:49 -04:00
Javier Cardona
915b5c50f8 open80211s: Stop using zero for address 3 in mesh plink mgmt frames
Previous versions of 11s draft used the all zeroes address.  Current
draft uses the same address as address 2.

Also, use the ANA-approved action category code for peer establishment frames.

Note: This breaks compatibility with previous mesh protocol instances.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-05-11 14:37:48 -04:00
Javier Cardona
d3aaec8ab7 mac80211: Drop MESH_PLINK category and use new ANA-approved MESH_ACTION
Note: This breaks compatibility with previous mesh protocol instances.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-05-11 14:37:47 -04:00
Javier Cardona
b130e5cec9 nl80211: Introduce NL80211_MESH_SETUP_USERSPACE_AMPE
Introduce a new configuration option to support AMPE from userspace.

Prior to this series we only supported authentication in userspace: an
authentication daemon would authenticate peer candidates in userspace
and hand them over to the kernel.  From that point the mesh stack would
take over and establish a peer link (Mesh Peering Management).

These patches introduce support for Authenticated Mesh Peering Exchange
in userspace.  The userspace daemon implements the AMPE protocol and on
successfull completion create mesh peers and install encryption keys.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-05-11 14:37:47 -04:00
Javier Cardona
1570ca5927 mac80211: send notification on new peer candidate for our secure mesh
Also, advertise support for mesh authentication.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-04-12 16:58:24 -04:00
Javier Cardona
96b78dff03 nl80211/mac80211: Perform PLINK_ACTION on new station
Modify the NEW_STATION command to accept PLINK_ACTIONS, in case
userspace wants to create stations and initiate a peer link right away
(for authenticated stations) or create a blocked station (for
debugging).

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-04-12 16:57:39 -04:00
Javier Cardona
53e805111b mac80211: ignore peer link requests from unauthenticated stations.
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-04-12 16:57:38 -04:00
Javier Cardona
5cff5e01e8 mac80211: ignore peers if security is enabled for this mesh
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-04-12 16:57:37 -04:00
Javier Cardona
581a8b0fee nl80211: rename NL80211_MESH_SETUP_VENDOR_PATH_SEL_IE
To NL80211_MESH_SETUP_IE. This reflects our ability to insert any ie
into a mesh beacon, not simply path selection ies.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2011-04-12 16:57:37 -04:00
Javier Cardona
c80d545da3 mac80211: Let userspace enable and configure vendor specific path selection.
Userspace will now be allowed to toggle between the default path
selection algorithm (HWMP, implemented in the kernel), and a vendor
specific alternative.  Also in the same patch, allow userspace to add
information elements to mesh beacons.  This is accordance with the
Extensible Path Selection Framework specified in version 7.0 of the
802.11s draft.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-12-20 14:46:57 -05:00
Christian Lamparter
d12c74528e mac80211: fix possible null-pointer de-reference
This patch not only fixes a null-pointer de-reference
that would be triggered by a PLINK_OPEN frame with mis-
matching/incompatible mesh configuration, but also
responds correctly to non-compatible PLINK_OPEN frames
by generating a PLINK_CLOSE with the right reason code.

The original bug was detected by smatch.
( http://repo.or.cz/w/smatch.git )

net/mac80211/mesh_plink.c +574 mesh_rx_plink_frame(168)
error: we previously assumed 'sta' could be null.

Cc: <stable@kernel.org>
Reviewed-and-Tested-by: Steve deRosier <steve@cozybit.com>
Reviewed-and-Tested-by: Javier Cardona <javier@cozybit.com>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-10-11 15:04:20 -04:00
John W. Linville
c937019761 mac80211: avoid scheduling while atomic in mesh_rx_plink_frame
While mesh_rx_plink_frame holds sta->lock...

mesh_rx_plink_frame ->
	mesh_plink_inc_estab_count ->
		ieee80211_bss_info_change_notify

...but ieee80211_bss_info_change_notify is allowed to sleep.  A driver
taking advantage of that allowance can cause a scheduling while
atomic bug.  Similar paths exist for mesh_plink_dec_estab_count,
so work around those as well.

http://bugzilla.kernel.org/show_bug.cgi?id=16099

Also, correct a minor kerneldoc comment error (mismatched function names).

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Cc: stable@kernel.org
2010-06-24 15:42:30 -04:00
John W. Linville
5c01d56693 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next-2.6 into for-davem
Conflicts:
	Documentation/feature-removal-schedule.txt
	drivers/net/wireless/ath/ath5k/phy.c
	drivers/net/wireless/wl12xx/wl1271_main.c
2010-04-15 16:21:34 -04:00
Javier Cardona
97ad9139fd mac80211: Moved mesh action codes to a more visible location
Grouped mesh action codes together with the other action codes in
ieee80211.h.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-04-08 15:24:07 -04:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00