Commit graph

29402 commits

Author SHA1 Message Date
Dan Williams
a08abd8ca8 async_tx: structify submission arguments, add scribble
Prepare the api for the arrival of a new parameter, 'scribble'.  This
will allow callers to identify scratchpad memory for dma address or page
address conversions.  As this adds yet another parameter, take this
opportunity to convert the common submission parameters (flags,
dependency, callback, and callback argument) into an object that is
passed by reference.

Also, take this opportunity to fix up the kerneldoc and add notes about
the relevant ASYNC_TX_* flags for each routine.

[ Impact: moves api pass-by-value parameters to a pass-by-reference struct ]

Signed-off-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03 14:07:35 -07:00
Dan Williams
88ba2aa586 async_tx: kill ASYNC_TX_DEP_ACK flag
In support of inter-channel chaining async_tx utilizes an ack flag to
gate whether a dependent operation can be chained to another.  While the
flag is not set the chain can be considered open for appending.  Setting
the ack flag closes the chain and flags the descriptor for garbage
collection.  The ASYNC_TX_DEP_ACK flag essentially means "close the
chain after adding this dependency".  Since each operation can only have
one child the api now implicitly sets the ack flag at dependency
submission time.  This removes an unnecessary management burden from
clients of the api.

[ Impact: clean up and enforce one dependency per operation ]

Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-06-03 14:07:34 -07:00
Dan Williams
099f53cb50 async_tx: rename zero_sum to val
'zero_sum' does not properly describe the operation of generating parity
and checking that it validates against an existing buffer.  Change the
name of the operation to 'val' (for 'validate').  This is in
anticipation of the p+q case where it is a requirement to identify the
target parity buffers separately from the source buffers, because the
target parity buffers will not have corresponding pq coefficients.

Reviewed-by: Andre Noll <maan@systemlinux.org>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-04-08 14:28:37 -07:00
Dan Williams
fd74ea6588 Merge branch 'dmaengine' into async-tx-raid6 2009-04-08 14:28:13 -07:00
Hans-Christian Egtvedt
d9de451989 dw_dmac: add cyclic API to DW DMA driver
This patch adds a cyclic DMA interface to the DW DMA driver. This is
very useful if you want to use the DMA controller in combination with a
sound device which uses cyclic buffers.

Using a DMA channel for cyclic DMA will disable the possibility to use
it as a normal DMA engine until the user calls the cyclic free function
on the DMA channel. Also a cyclic DMA list can not be prepared if the
channel is already active.

Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-04-01 15:42:34 -07:00
Dan Williams
f701d589aa md/raid6: move raid6 data processing to raid6_pq.ko
Move the raid6 data processing routines into a standalone module
(raid6_pq) to prepare them to be called from async_tx wrappers and other
non-md drivers/modules.  This precludes a circular dependency of raid456
needing the async modules for data processing while those modules in
turn depend on raid456 for the base level synchronous raid6 routines.

To support this move:
1/ The exportable definitions in raid6.h move to include/linux/raid/pq.h
2/ The raid6_call, recovery calls, and table symbols are exported
3/ Extra #ifdef __KERNEL__ statements to enable the userspace raid6test to
   compile

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 15:09:39 +11:00
NeilBrown
43b2e5d86d md: move md_k.h from include/linux/raid/ to drivers/md/
It really is nicer to keep related code together..

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
NeilBrown
bff61975b3 md: move lots of #include lines out of .h files and into .c
This makes the includes more explicit, and is preparation for moving
md_k.h to drivers/md/md.h

Remove include/raid/md.h as its only remaining use was to #include
other files.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
NeilBrown
92022950c6 md: move most content from md.h to md_k.h
The extern function definitions are kernel-internal definitions, so
they belong in md_k.h

The MD_*_VERSION values could reasonably go in a number of places,
but md_u.h seems most reasonable.

This leaves almost nothing in md.h.  It will go soon.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:33:13 +11:00
NeilBrown
8b2b5c217c md: move LEVEL_* definition from md_k.h to md_u.h
.. as they are part of the user-space interface.
Also move MdpMinorShift into there so we can remove duplication.

Lastly move mdp_major in.  It is less obviously part of the user-space
interface, but do_mounts_md.c uses it, and it is acting a bit like
user-space.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:03 +11:00
Christoph Hellwig
ef740c372d md: move headers out of include/linux/raid/
Move the headers with the local structures for the disciplines and
bitmap.h into drivers/md/ so that they are more easily grepable for
hacking and not far away.  md.h is left where it is for now as there
are some uses from the outside.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:03 +11:00
NeilBrown
eea1bf384e md: Fix is_mddev_idle test (again).
There are two problems with is_mddev_idle.

1/ sync_io is 'atomic_t' and hence 'int'.  curr_events and all the
   rest are 'long'.
   So if sync_io were to wrap on a 64bit host, the value of
   curr_events would go very negative suddenly, and take a very
   long time to return to positive.

   So do all calculations as 'int'.  That gives us plenty of precision
   for what we need.

2/ To initialise rdev->last_events we simply call is_mddev_idle, on
   the assumption that it will make sure that last_events is in a
   suitable range.  It used to do this, but now it does not.
   So now we need to be more explicit about initialisation.

Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31 14:27:02 +11:00
Atsushi Nemoto
0f571515c3 dmaengine: Add privatecnt to revert DMA_PRIVATE property
Currently dma_request_channel() set DMA_PRIVATE capability but never
clear it.  So if a public channel was once grabbed by
dma_request_channel(), the device stay PRIVATE forever.  Add
privatecnt member to dma_device to correctly revert it.

[lg@denx.de: fix bad usage of 'chan' in dma_async_device_register]
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-26 09:48:09 -07:00
Dan Williams
729b5d1b8e dmaengine: allow dma support for async_tx to be toggled
Provide a config option for blocking the allocation of dma channels to
the async_tx api.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-25 09:13:25 -07:00
Dan Williams
06164f3194 async_tx: provide __async_inline for HAS_DMA=n archs
To allow an async_tx routine to be compiled away on HAS_DMA=n arch it
needs to be declared __always_inline otherwise the compiler may emit
code and cause a link error.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-25 09:13:25 -07:00
Dan Williams
54aee6a5f5 dmaengine: kill some unused headers
The dmaengine redux left some unneeded headers in
include/linux/dmaengine.h, clean them up.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-25 09:13:24 -07:00
Linus Torvalds
0b80e3adc2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  cpumask: mm_cpumask for accessing the struct mm_struct's cpu_vm_mask.
  cpumask: tsk_cpumask for accessing the struct task_struct's cpus_allowed.
2009-03-12 16:34:59 -07:00
Rusty Russell
45e575ab9b cpumask: mm_cpumask for accessing the struct mm_struct's cpu_vm_mask.
This allows us to change the representation (to a dangling bitmap or
cpumask_var_t) without breaking all the callers: they can use
mm_cpumask() now and won't see a difference as the changes roll into
linux-next.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-12 14:35:44 +10:30
Rusty Russell
76e6eee033 cpumask: tsk_cpumask for accessing the struct task_struct's cpus_allowed.
This allows us to change the representation (to a dangling bitmap or
cpumask_var_t) without breaking all the callers: they can use
tsk_cpumask() now and won't see a difference as the changes roll into
linux-next.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-12 14:35:44 +10:30
Pantelis Koukousoulas
260cf8a2cb drm: fix EDID parser problem with positive/negative hsync/vsync
Comparing the layouts of struct detail_pixel_timing with
x.org's struct detailed_timings and how those are handled,
it appears that the hsync_positive and vsync_positive
fields are backwards.

This patch fixes https://bugs.freedesktop.org/show_bug.cgi?id=20019
for me. It was tested on 2 monitors, LG FLATRON L225WS 22" and
a YAKUMO 17" for which more details are unknown.

Signed-off-by: Pantelis Koukousoulas <pktoss@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2009-03-11 12:18:48 +10:00
Linus Torvalds
99adcd9d67 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq:
  [CPUFREQ] Add p4-clockmod sysfs-ui removal to feature-removal schedule.
  Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."
2009-03-09 13:23:59 -07:00
Dave Jones
129f8ae9b1 Revert "[CPUFREQ] Disable sysfs ui for p4-clockmod."
This reverts commit e088e4c9cd.

Removing the sysfs interface for p4-clockmod was flagged as a
regression in bug 12826.

Course of action:
 - Find out the remaining causes of overheating, and fix them
   if possible. ACPI should be doing the right thing automatically.
   If it isn't, we need to fix that.
 - mark p4-clockmod ui as deprecated
 - try again with the removal in six months.

It's not really feasible to printk about the deprecation, because
it needs to happen at all the sysfs entry points, which means adding
a lot of strcmp("p4-clockmod".. calls to the core, which.. bleuch.

Signed-off-by: Dave Jones <davej@redhat.com>
2009-03-09 15:07:33 -04:00
Linus Torvalds
df0b4a5080 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (29 commits)
  p54: fix race condition in memory management
  cfg80211: test before subtraction on unsigned
  iwlwifi: fix error flow in iwl*_pci_probe
  rt2x00 : more devices to rt73usb.c
  rt2x00 : more devices to rt2500usb.c
  bonding: Fix device passed into ->ndo_neigh_setup().
  vlan: Fix vlan-in-vlan crashes.
  net: Fix missing dev->neigh_setup in register_netdevice().
  tmspci: fix request_irq race
  pkt_sched: act_police: Fix a rate estimator test.
  tg3: Fix 5906 link problems
  SCTP: change sctp_ctl_sock_init() to try IPv4 if IPv6 fails
  IPv6: add "disable" module parameter support to ipv6.ko
  sungem: another error printed one too early
  aoe: error printed 1 too early
  net pcmcia: worklimit reaches -1
  net: more timeouts that reach -1
  net: fix tokenring license
  dm9601: new vendor/product IDs
  netlink: invert error code in netlink_set_err()
  ...
2009-03-09 09:15:40 -07:00
Linus Torvalds
5dc18f51a2 Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
  dmatest: fix use after free in dmatest_exit
  ipu_idmac: fix spinlock type
  iop-adma, mv_xor: fix mem leak on self-test setup failure
  fsldma: fix off by one in dma_halt
  I/OAT: fail self-test if callback test reaches timeout
  I/OAT: update driver version and copyright dates
  I/OAT: list usage cleanup
  I/OAT: set tcp_dma_copybreak to 256k for I/OAT ver.3
  I/OAT: cancel watchdog before dma remove
  I/OAT: fail initialization on zero channels detection
  I/OAT: do not set DCACTRL_CMPL_WRITE_ENABLE for I/OAT ver.3
  I/OAT: add verification for proper APICID_TAG_MAP setting by BIOS
  dmaengine: update kerneldoc
2009-03-08 10:23:05 -07:00
Linus Torvalds
fd6ec5f3ac Merge git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
  ata: add CFA specific identify data words
  remove stale comment from <linux/hdreg.h>
  AT91: initialize Compact Flash on AT91SAM9263 cpu
  ide: add at91_ide driver
  ide: allow to wrap interrupt handler
  ide-iops: fix odd-length ATAPI PIO transfers
  ide: NULL noise: drivers/ide/ide-*.c
  ide: expiry() returns int, negative expiry() return values won't be noticed
2009-03-08 10:22:22 -07:00
Linus Torvalds
83d5a32510 Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  libata: Don't trust current capacity values in identify words 57-58
  libata: make sure port is thawed when skipping resets
  sata_nv: fix module parameter description
  ahci: Add the Device IDs for MCP89 and remove IDs of MCP7B to/from ahci.c
  libata: don't use on-stack sense buffer
  libata: align ap->sector_buf
  libata: fix dma_unmap_sg misuse
  libata: change drive ready wait after hard reset to 5s
2009-03-08 10:22:01 -07:00
Linus Torvalds
2a50b2560e Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: serio - fix protocol number for TouchIT213
2009-03-08 10:14:19 -07:00
Dmitry Torokhov
ab96ddec72 Input: serio - fix protocol number for TouchIT213
Protocol 0x37 has been reserved for iNexio devices and Sahara
was supposed to get 0x38.

Reported-by: Claudio Nieder <private@claudio.ch>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2009-03-07 18:41:38 -08:00
Sergei Shtylyov
d42ad15b75 ata: add CFA specific identify data words
Declare CFA specific identify data words 162 and 163 for future use.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
[bart: update patch summary/description]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-03-05 17:20:55 +01:00
Bartlomiej Zolnierkiewicz
ebcad5aaea remove stale comment from <linux/hdreg.h>
HDIO_GET_IDENTITY returns 256 words currently.

Noticed by Norman Diamond.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-03-05 16:10:59 +01:00
Stanislaw Gruszka
849d713000 ide: allow to wrap interrupt handler
Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl>
Cc: Andrew Victor <linux@maxim.org.za>
[bart: minor checkpatch.pl / CodingStyle fixups]
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-03-05 16:10:57 +01:00
Tejun Heo
84bda12af3 libata: align ap->sector_buf
ap->sector_buf is used as DMA target and should at least be aligned on
cacheline.  This caused problems on some embedded machines.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-03-05 07:25:02 -05:00
FUJITA Tomonori
5825627c94 libata: fix dma_unmap_sg misuse
libata passes the returned value of dma_map_sg() to
dma_unmap_sg(),which is the misuse of dma_unmap_sg().

DMA-mapping.txt says:

To unmap a scatterlist, just call:

	pci_unmap_sg(pdev, sglist, nents, direction);

Again, make sure DMA activity has already finished.

PLEASE NOTE:  The 'nents' argument to the pci_unmap_sg call must be
              the _same_ one you passed into the pci_map_sg call,
	      it should _NOT_ be the 'count' value _returned_ from the
              pci_map_sg call.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-03-05 07:24:57 -05:00
Stuart Hayes
e7d3ef13d5 libata: change drive ready wait after hard reset to 5s
This fixes problems during resume with drives that take longer than 1s to
be ready.  The ATA-6 spec appears to allow 5 seconds for a drive to be
ready.

On one affected system, this patch changes "PM: resume devices took..."
message from 17 seconds to 4 seconds, and gets rid of a lot of ugly
timeout/error messages.

Without this patch, the libata code moves on after 1s, tries to send a
soft reset (which the drive doesn't see because it isn't ready) which also
times out, then an IDENTIFY command is sent to the drive which times out,
and finally the error handler will try to send another hard reset which
will finally get things working.

Signed-off-by: Stuart Hayes <stuart_hayes@dell.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2009-03-05 07:24:42 -05:00
David S. Miller
77827a7cf3 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2009-03-04 23:59:54 -08:00
David S. Miller
9d40bbda59 vlan: Fix vlan-in-vlan crashes.
As analyzed by Patrick McHardy, vlan needs to reset it's
netdev_ops pointer in it's ->init() function but this
leaves the compat method pointers stale.

Add a netdev_resync_ops() and call it from the vlan code.

Any other driver which changes ->netdev_ops after register_netdevice()
will need to call this new function after doing so too.

With help from Patrick McHardy.

Tested-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-04 23:46:25 -08:00
Linus Torvalds
219f170a85 Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  sched: don't allow setuid to succeed if the user does not have rt bandwidth
  sched_rt: don't start timer when rt bandwidth disabled
2009-03-03 14:33:20 -08:00
Linus Torvalds
b24746c7be Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: Teach RCU that idle task is not quiscent state at boot
2009-03-03 14:32:04 -08:00
Eric W. Biederman
17edde5209 netns: Remove net_alive
It turns out that net_alive is unnecessary, and the original problem
that led to it being added was simply that the icmp code thought
it was a network device and wound up being unable to handle packets
while there were still packets in the network namespace.

Now that icmp and tcp have been fixed to properly register themselves
this problem is no longer present and we have a stronger guarantee
that packets will not arrive in a network namespace then that provided
by net_alive in netif_receive_skb.  So remove net_alive allowing
packet reception run a little faster.

Additionally document the strong reason why network namespace cleanup
is safe so that if something happens again someone else will have
a chance of figuring it out.

Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-03 01:14:27 -08:00
Linus Torvalds
2d44947a56 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  fix warning in io_mapping_map_wc()
  x86: i915 needs pgprot_writecombine() and is_io_mapping_possible()
2009-03-02 15:47:01 -08:00
Pallipadi, Venkatesh
5ce04e3de8 fix warning in io_mapping_map_wc()
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-02 09:43:32 +01:00
Chris Leech
709ab3261e net headers: export dcbnl.h
The DCB netlink interface is required for building the userspace tools
available at e1000.sourceforge.net

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-01 00:19:36 -08:00
Chris Leech
5c25222180 net headers: cleanup dcbnl.h
1) add an include for <linux/types.h>
2) change dcbmsg.dcb_family from unsigned char to __u8 to be more
   consistent with use of kernel types

Signed-off-by: Chris Leech <christopher.leech@intel.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-03-01 00:19:35 -08:00
David S. Miller
18963caaf5 Merge branch 'master' of /home/davem/src/GIT/linux-2.6/ 2009-02-28 15:36:58 -08:00
Linus Torvalds
535d8e8f19 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: enable DMAR by default
  xen: disable interrupts early, as start_kernel expects
  gpu/drm, x86, PAT: io_mapping_create_wc and resource_size_t
  gpu/drm, x86, PAT: Handle io_mapping_create_wc() errors in a clean way
  x86, Voyager: fix compile by lifting the degeneracy of phys_cpu_present_map
  x86, doc: fix references to Documentation/x86/i386/boot.txt
2009-02-27 16:43:05 -08:00
David Howells
5170836679 Fix recursive lock in free_uid()/free_user_ns()
free_uid() and free_user_ns() are corecursive when CONFIG_USER_SCHED=n,
but free_user_ns() is called from free_uid() by way of uid_hash_remove(),
which requires uidhash_lock to be held.  free_user_ns() then calls
free_uid() to complete the destruction.

Fix this by deferring the destruction of the user_namespace.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-27 16:26:21 -08:00
Dhaval Giani
54e9912428 sched: don't allow setuid to succeed if the user does not have rt bandwidth
Impact: fix hung task with certain (non-default) rt-limit settings

Corey Hickey reported that on using setuid to change the uid of a
rt process, the process would be unkillable and not be running.
This is because there was no rt runtime for that user group. Add
in a check to see if a user can attach an rt task to its task group.
On failure, return EINVAL, which is also returned in
CONFIG_CGROUP_SCHED.

Reported-by: Corey Hickey <bugfood-ml@fatooh.org>
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-27 11:11:53 +01:00
Jens Axboe
1e42807918 block: reduce stack footprint of blk_recount_segments()
blk_recalc_rq_segments() requires a request structure passed in, which
we don't have from blk_recount_segments(). So the latter allocates one on
the stack, using > 400 bytes of stack for that. This can cause us to spill
over one page of stack from ext4 at least:

 0)     4560     400   blk_recount_segments+0x43/0x62
 1)     4160      32   bio_phys_segments+0x1c/0x24
 2)     4128      32   blk_rq_bio_prep+0x2a/0xf9
 3)     4096      32   init_request_from_bio+0xf9/0xfe
 4)     4064     112   __make_request+0x33c/0x3f6
 5)     3952     144   generic_make_request+0x2d1/0x321
 6)     3808      64   submit_bio+0xb9/0xc3
 7)     3744      48   submit_bh+0xea/0x10e
 8)     3696     368   ext4_mb_init_cache+0x257/0xa6a [ext4]
 9)     3328     288   ext4_mb_regular_allocator+0x421/0xcd9 [ext4]
10)     3040     160   ext4_mb_new_blocks+0x211/0x4b4 [ext4]
11)     2880     336   ext4_ext_get_blocks+0xb61/0xd45 [ext4]
12)     2544      96   ext4_get_blocks_wrap+0xf2/0x200 [ext4]
13)     2448      80   ext4_da_get_block_write+0x6e/0x16b [ext4]
14)     2368     352   mpage_da_map_blocks+0x7e/0x4b3 [ext4]
15)     2016     352   ext4_da_writepages+0x2ce/0x43c [ext4]
16)     1664      32   do_writepages+0x2d/0x3c
17)     1632     144   __writeback_single_inode+0x162/0x2cd
18)     1488      96   generic_sync_sb_inodes+0x1e3/0x32b
19)     1392      16   sync_sb_inodes+0xe/0x10
20)     1376      48   writeback_inodes+0x69/0xb3
21)     1328     208   balance_dirty_pages_ratelimited_nr+0x187/0x2f9
22)     1120     224   generic_file_buffered_write+0x1d4/0x2c4
23)      896     176   __generic_file_aio_write_nolock+0x35f/0x393
24)      720      80   generic_file_aio_write+0x6c/0xc8
25)      640      80   ext4_file_write+0xa9/0x137 [ext4]
26)      560     320   do_sync_write+0xf0/0x137
27)      240      48   vfs_write+0xb3/0x13c
28)      192      64   sys_write+0x4c/0x74
29)      128     128   system_call_fastpath+0x16/0x1b

Split the segment counting out into a __blk_recalc_rq_segments() helper
to avoid allocating an onstack request just for checking the physical
segment count.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-26 10:45:48 +01:00
Paul E. McKenney
a682604838 rcu: Teach RCU that idle task is not quiscent state at boot
This patch fixes a bug located by Vegard Nossum with the aid of
kmemcheck, updated based on review comments from Nick Piggin,
Ingo Molnar, and Andrew Morton.  And cleans up the variable-name
and function-name language.  ;-)

The boot CPU runs in the context of its idle thread during boot-up.
During this time, idle_cpu(0) will always return nonzero, which will
fool Classic and Hierarchical RCU into deciding that a large chunk of
the boot-up sequence is a big long quiescent state.  This in turn causes
RCU to prematurely end grace periods during this time.

This patch changes the rcutree.c and rcuclassic.c rcu_check_callbacks()
function to ignore the idle task as a quiescent state until the
system has started up the scheduler in rest_init(), introducing a
new non-API function rcu_idle_now_means_idle() to inform RCU of this
transition.  RCU maintains an internal rcu_idle_cpu_truthful variable
to track this state, which is then used by rcu_check_callback() to
determine if it should believe idle_cpu().

Because this patch has the effect of disallowing RCU grace periods
during long stretches of the boot-up sequence, this patch also introduces
Josh Triplett's UP-only optimization that makes synchronize_rcu() be a
no-op if num_online_cpus() returns 1.  This allows boot-time code that
calls synchronize_rcu() to proceed normally.  Note, however, that RCU
callbacks registered by call_rcu() will likely queue up until later in
the boot sequence.  Although rcuclassic and rcutree can also use this
same optimization after boot completes, rcupreempt must restrict its
use of this optimization to the portion of the boot sequence before the
scheduler starts up, given that an rcupreempt RCU read-side critical
section may be preeempted.

In addition, this patch takes Nick Piggin's suggestion to make the
system_state global variable be __read_mostly.

Changes since v4:

o	Changes the name of the introduced function and variable to
	be less emotional.  ;-)

Changes since v3:

o	WARN_ON(nr_context_switches() > 0) to verify that RCU
	switches out of boot-time mode before the first context
	switch, as suggested by Nick Piggin.

Changes since v2:

o	Created rcu_blocking_is_gp() internal-to-RCU API that
	determines whether a call to synchronize_rcu() is itself
	a grace period.

o	The definition of rcu_blocking_is_gp() for rcuclassic and
	rcutree checks to see if but a single CPU is online.

o	The definition of rcu_blocking_is_gp() for rcupreempt
	checks to see both if but a single CPU is online and if
	the system is still in early boot.

	This allows rcupreempt to again work correctly if running
	on a single CPU after booting is complete.

o	Added check to rcupreempt's synchronize_sched() for there
	being but one online CPU.

Tested all three variants both SMP and !SMP, booted fine, passed a short
rcutorture test on both x86 and Power.

Located-by: Vegard Nossum <vegard.nossum@gmail.com>
Tested-by: Vegard Nossum <vegard.nossum@gmail.com>
Tested-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-26 04:08:14 +01:00
Bartlomiej Zolnierkiewicz
8fed436841 ide: fix refcounting in device drivers
During host driver module removal del_gendisk() results in a final
put on drive->gendev and freeing the drive by drive_release_dev().

Convert device drivers from using struct kref to use struct device
so device driver's object holds reference on ->gendev and prevents
drive from prematurely going away.

Also fix ->remove methods to not erroneously drop reference on a
host driver by using only put_device() instead of ide*_put().

Reported-by: Stanislaw Gruszka <stf_xl@wp.pl>
Tested-by: Stanislaw Gruszka <stf_xl@wp.pl>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
2009-02-25 20:28:24 +01:00