cdrom: revert commit 22a9189 (cdrom: use kmalloced buffers instead of buffers on stack)
The commit 22a9189fd073db3d03a4cf8b8c098aa207602de1 (cdrom: use
kmalloced buffers instead of buffers on stack) is introduced to use
kmalloced buffers for packet commands to avoid stack corruption on non
coherent platforms.
SCSI cdrom uses blk_rq_map_kern, which properly avoids DMA on the
stack by using the bounce buffers. IDE cdrom also has the mechnism to
avoids DMA on the stack. So we don't need this extra complexitiy in
cdrom.c, such as allocating just 8 bytes. The lower layers can handle
it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Tejun Heo <htejun@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
blk_rq_map_kern can handle the stack buffers correctly (avoid DMA
from/to the stack buffers by using the bounce buffer) so we don't need
to complicate the code by allocating just 8 bytes.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Tejun Heo <htejun@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
block: blk_rq_map_kern uses the bounce buffers for stack buffers
blk_rq_map_kern is used for kernel internal I/Os. Some callers use
this function with stack buffers but DMA to/from the stack buffers
leads to memory corruption on a non-coherent platform.
This patch make blk_rq_map_kern uses the bounce buffers if a caller
passes a stack buffer (on the all platforms for simplicity).
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Tejun Heo <htejun@gmail.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This adds blk_queue_update_dma_pad to prevent LLDs from overwriting
the dma pad mask wrongly (we added blk_queue_update_dma_alignment due
to the same reason).
This also converts libata to use blk_queue_update_dma_pad instead of
blk_queue_dma_pad.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Tejun Heo <htejun@gmail.com> Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Alan Cox [Fri, 4 Jul 2008 07:51:21 +0000 (09:51 +0200)]
paride: push ioctl down into driver
Leaves us with lock_kernel for two methods. Also remove a bogus printk
with no printk level and return -ENOTTY not -EINVAL for correctness.
Signed-off-by: Alan Cox <alan@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
(Jens: added smp_lock.h include to pt.c, otherwise it wont compile because
of missing {un}lock_kernel() definition)
Add bvec_merge_data to handle stacked devices and ->merge_bvec()
When devices are stacked, one device's merge_bvec_fn may need to perform
the mapping and then call one or more functions for its underlying devices.
The following bio fields are used:
bio->bi_sector
bio->bi_bdev
bio->bi_size
bio->bi_rw using bio_data_dir()
This patch creates a new struct bvec_merge_data holding a copy of those
fields to avoid having to change them directly in the struct bio when
going down the stack only to have to change them back again on the way
back up. (And then when the bio gets mapped for real, the whole
exercise gets repeated, but that's a problem for another day...)
Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Neil Brown <neilb@suse.de> Cc: Milan Broz <mbroz@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Adel Gadllah [Thu, 26 Jun 2008 11:48:27 +0000 (13:48 +0200)]
allow userspace to modify scsi command filter on per device basis
This patch exports the per-gendisk command filter to user space through
sysfs, so it can be changed by the system administrator.
All users of the old cmd filter have been converted to use the new one.
Original patch from Peter Jones.
Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com> Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Some block devices support verifying the integrity of requests by way
of checksums or other protection information that is submitted along
with the I/O.
This patch implements support for generating and verifying integrity
metadata, as well as correctly merging, splitting and cloning bios and
requests that have this extra information attached.
See Documentation/block/data-integrity.txt for more information.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Move struct bio_set and biovec_slab definitions to bio.h so they can
be used outside of bio.c.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Ian Campbell [Tue, 17 Jun 2008 08:47:08 +0000 (10:47 +0200)]
xen: Avoid allocations causing swap activity on the resume path
Avoid allocations causing swap activity on the resume path by
preventing the allocations from doing IO and allowing them
to access the emergency pools.
These paths are used when a frontend device is trying to connect
to its backend driver over Xenbus. These reconnections are triggered
on demand by IO, so by definition there is already IO underway,
and further IO would naturally deadlock. On resume, this path
is triggered when the running system tries to continue using its
devices. If it cannot then the resume will fail; to try to avoid this
we let it dip into the emergency pools.
xen/blkfront: Add the CDROM_GET_CAPABILITY ioctl to blkfront.
Return 0 instead of -EINVAL if the blkfront device is a cdrom,
i.e. had the VDISK_CDROM attribute. This allows udev's cdrom_id
to correctly detect the device as a cdrom device.
Jens Axboe [Thu, 12 Jun 2008 18:12:36 +0000 (20:12 +0200)]
block: kill request_queue_t
Everything was moved to struct request_queue a few kernel revisions
ago, maintaining the deprecated typedef to avoid breaking things.
Now the time has come to get rid of that typedef.
Alan D. Brunelle [Wed, 11 Jun 2008 07:12:52 +0000 (09:12 +0200)]
Added in user-injected messages into blk traces
This allows a user to annotate the blk trace stream: writing a suitable
message to {/sys/kernel/debug}/block/<dsf>/msg will have it propagated
into the trace stream.
Signed-off-by: Alan D. Brunelle <alan.brunelle@hp.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Jens Axboe [Thu, 29 May 2008 07:35:22 +0000 (09:35 +0200)]
as-iosched: properly protect ioc_gone and ioc count
If we have multiple tasks freeing io contexts when as-iosched
is being unloaded, we could complete() ioc_gone twice. Fix that by
protecting ioc_gone complete() and clearing with a spinlock for
just that purpose. Doesn't matter from a performance perspective,
since it'll only enter that path when ioc_gone != NULL (when as-iosched
is being rmmod'ed).
Jens Axboe [Thu, 29 May 2008 07:32:08 +0000 (09:32 +0200)]
cfq-iosched: properly protect ioc_gone and ioc count
If we have multiple tasks freeing cfq_io_contexts when cfq-iosched
is being unloaded, we could complete() ioc_gone twice. Fix that by
protecting ioc_gone complete() and clearing with a spinlock for
just that purpose. Doesn't matter from a performance perspective,
since it'll only enter that path when ioc_gone != NULL (when cfq-iosched
is being rmmod'ed).
Merge branch 'i2c-fix' of git://aeryn.fluff.org.uk/bjdooks/linux
* 'i2c-fix' of git://aeryn.fluff.org.uk/bjdooks/linux:
I2C: S3C2410: Add MODULE_ALIAS() for s3c2440 device.
I2C: S3C2410: Fixup error codes returned rom a transfer.
I2C: S3C2410: Check ACK on byte transmission
Merge branch 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block
* 'for-2.6.26' of git://git.kernel.dk/linux-2.6-block:
Properly notify block layer of sync writes
block: Fix the starving writes bug in the anticipatory IO scheduler
* git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb:
V4L/DVB (8178): uvc: Fix compilation breakage for the other drivers, if uvc is selected
V4L/DVB (8145a): USB Video Class driver
* master.kernel.org:/home/rmk/linux-2.6-arm:
[ARM] 5131/1: Annotate platform_secondary_init with trace_hardirqs_off
[ARM] 5117/1: pxafb: fix __devinit/exit annotations
[ARM] Export dma_sync_sg_for_device()
[ARM] 5109/1: Mark rtc sa1100 driver as wakeup source before registering it
[ARM] 5116/1: pxafb: cleanup and fix order of failure handling
[ARM] 5115/1: pxafb: fix ifdef for command line option handling
ARM: OMAP: Correcting the gpmc prefetch control register address
ARM: OMAP: DMA: Don't mark channel active in omap_enable_channel_irq
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: fix divide error when trying to configure rt_period to zero
Merge branch 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6
* 'i2c-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6:
i2c: Fix bad hint about irqs in i2c.h
i2c: Documentation: fix device matching description
Merge branch 'for-2.6.26' of git://neil.brown.name/md
* 'for-2.6.26' of git://neil.brown.name/md:
Fix error paths if md_probe fails.
Don't acknowlege that stripe-expand is complete until it really is.
Ensure interrupted recovery completed properly (v1 metadata plus bitmap)
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc:
powerpc/mpc5200: Fix lite5200b suspend/resume
powerpc/legacy_serial: Bail if reg-offset/shift properties are present
powerpc/bootwrapper: update for initrd with simpleImage
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (55 commits)
net: fib_rules: fix error code for unsupported families
netdevice: Fix wrong string handle in kernel command line parsing
net: Tyop of sk_filter() comment
netlink: Unneeded local variable
net-sched: fix filter destruction in atm/hfsc qdisc destruction
net-sched: change tcf_destroy_chain() to clear start of filter list
ipv4: fix sysctl documentation of time related values
mac80211: don't accept WEP keys other than WEP40 and WEP104
hostap: fix sparse warnings
hostap: don't report useless WDS frames by default
textsearch: fix Boyer-Moore text search bug
netfilter: nf_conntrack_tcp: fixing to check the lower bound of valid ACK
ipv6 route: Convert rt6_device_match() to use RT6_LOOKUP_F_xxx flags.
netlabel: Fix a problem when dumping the default IPv6 static labels
net/inet_lro: remove setting skb->ip_summed when not LRO-able
inet fragments: fix race between inet_frag_find and inet_frag_secret_rebuild
CONNECTOR: add a proc entry to list connectors
netlink: Fix some doc comments in net/netlink/attr.c
tcp: /proc/net/tcp rto,ato values not scaled properly (v2)
include/linux/netdevice.h: don't export MAX_HEADER to userspace
...
When scheduled swaps occur, we need to blit between front & back
buffers. If the buffers are tiled, we need to set the appropriate
XY_SRC_COPY tile bit, but only on 965 chips, since it will cause
corruption on pre-965 (e.g. 945).
Bug reported by and fix tested by Tomas Janousek <tomi@nomi.cz>.
| linux/drivers/input/ff-core.c: In function 'input_ff_upload':
| linux/drivers/input/ff-core.c:172: error: dereferencing pointer to incomplete type
| linux/drivers/input/ff-core.c: In function 'erase_effect':
| linux/drivers/input/ff-core.c:197: error: dereferencing pointer to incomplete type
| linux/drivers/input/ff-core.c:204: error: dereferencing pointer to incomplete type
| make[4]: *** [drivers/input/ff-core.o] Error 1
As the incomplete type is `struct task_struct', including <linux/sched.h> fixes
it.
Alex Chiang [Wed, 2 Jul 2008 02:02:23 +0000 (20:02 -0600)]
PCI: acpiphp: cleanup notify handler on all root bridges
During the development of the physical PCI slot patch series, Gary Hade
kept on reporting strange oopses due to interactions between pci_slot
and acpiphp.
http://lkml.org/lkml/2007/11/28/319
find_root_bridges() unconditionally installs
handle_hotplug_event_bridge() as an ACPI_SYSTEM_NOTIFY handler for all
root bridges.
However, during module cleanup, remove_bridge() will only remove the
notify handler iff the root bridge had a hot-pluggable slot directly
underneath. That is:
root bridge -> hotplug slot
But, if the topology looks like either of the following:
Then we currently do not remove the notify handler from that root
bridge.
This can cause a kernel oops if we modprobe acpiphp later and it gets
loaded somewhere else in memory. If the root bridge then receives a
hotplug event, it will then attempt to call a stale, non-existent notify
handler and we blow up.
Much thanks goes to Gary Hade for his persistent debugging efforts.
Signed-off-by: Alex Chiang <achiang@hp.com> Signed-off-by: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
For Broadcom 5706, 5708, 5709 rev. A nics, any read beyond the
VPD end tag will hang the device. This problem was initially
observed when a vpd entry was created in sysfs
('/sys/bus/pci/devices/<id>/vpd'). A read to this sysfs entry
will dump 32k of data. Reading a full 32k will cause an access
beyond the VPD end tag causing the device to hang. Once the device
is hung, the bnx2 driver will not be able to reset the device.
We believe that it is legal to read beyond the end tag and
therefore the solution is to limit the read/write length.
A majority of this patch is from Matthew Wilcox who gave code for
reworking the PCI vpd size information. A PCI quirk added for the
Broadcom NIC's to limit the read/write's.
Signed-off-by: Benjamin Li <benli@broadcom.com> Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Milan Broz [Wed, 2 Jul 2008 08:34:28 +0000 (09:34 +0100)]
dm crypt: use cond_resched
Add cond_resched() to prevent monopolising CPU when processing large bios.
dm-crypt processes encryption of bios in sector units. If the bio request
is big it can spend a long time in the encryption call.
Signed-off-by: Milan Broz <mbroz@redhat.com> Tested-by: Yan Li <elliot.li.tech@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Wang Chen [Wed, 2 Jul 2008 02:57:19 +0000 (19:57 -0700)]
netdevice: Fix wrong string handle in kernel command line parsing
v1->v2: Use strlcpy() to ensure s[i].name be null-termination.
1. In netdev_boot_setup_add(), a long name will leak.
ex. : dev=21,0x1234,0x1234,0x2345,eth123456789verylongname.........
2. In netdev_boot_setup_check(), mismatch will happen if s[i].name
is a substring of dev->name.
ex. : dev=...eth1 dev=...eth11
[ With feedback from Ben Hutchings. ]
Signed-off-by: Wang Chen <wangchen@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
ipv4: fix sysctl documentation of time related values
These sysctl values are time related and all use the same routine
(proc_dointvec_jiffies) that internally converts from seconds to jiffies.
The code is fine, the documentation is just wrong.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Tim Yamin [Tue, 17 Jun 2008 08:33:14 +0000 (09:33 +0100)]
powerpc/mpc5200: Fix lite5200b suspend/resume
Suspend/resume ("echo mem > /sys/power/state") does not work with
vanilla kernels -- the system does not suspend correctly and just
hangs. This patch fixes this so suspend/resume works:
1) of_iomap does not map the whole 0xC000 of the MPC5200 immr so
saving registers does not work.
2) PCI registers need to be saved and restored.
Signed-off-by: Tim Yamin <plasm@roo.me.uk> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
John Linn [Tue, 1 Jul 2008 17:52:41 +0000 (10:52 -0700)]
powerpc/legacy_serial: Bail if reg-offset/shift properties are present
The legacy serial driver does not work with an 8250 type UART that is
described in the device tree with the reg-offset and reg-shift
properties. This change makes legacy_serial ignore these devices.
Signed-off-by: John Linn <john.linn@xilinx.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Wolfram Sang [Tue, 1 Jul 2008 20:38:18 +0000 (22:38 +0200)]
i2c: Fix bad hint about irqs in i2c.h
i2c.h mentions -1 as a not-issued irq. This false hint was taken by
of_i2c and caused crashes. Don't give any advice as 'no irq' is not
consistent across all architectures yet and it is not needed internally
by the i2c-core.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
The matching process described for new style clients in
Documentation/i2c/writing-clients is classed as out-of-date
as it requires the presence of an .id_table entry in the
driver's i2c_driver entry.
Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
Ben Hutchings [Tue, 1 Jul 2008 16:18:17 +0000 (17:18 +0100)]
PCI: Restrict VPD read permission to root
Some PCI devices will lock up if we attempt to read from VPD addresses
beyond some device-dependent limit. Until we can identify these
devices and adjust the file size accordingly, only let root read VPD
through sysfs to prevent a DoS by normal users.
Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Ben Dooks [Tue, 1 Jul 2008 10:59:41 +0000 (11:59 +0100)]
I2C: S3C2410: Check ACK on byte transmission
We should check for the reception of an ACK after transmitting each
data byte. The address send has been correctly checking this, but the
data write byte state should have also been checking for these failures.
As part of the same fix, we remove the ACK checking from the receive
path where it should not have been checking for an ACK which our hardware
was sending.
Gautham R Shenoy [Fri, 27 Jun 2008 04:47:38 +0000 (10:17 +0530)]
rcu: fix hotplug vs rcu race
Dhaval Giani reported this warning during cpu hotplug stress-tests:
| On running kernel compiles in parallel with cpu hotplug:
|
| WARNING: at arch/x86/kernel/smp.c:118
| native_smp_send_reschedule+0x21/0x36()
| Modules linked in:
| Pid: 27483, comm: cc1 Not tainted 2.6.26-rc7 #1
| [...]
| [<c0110355>] native_smp_send_reschedule+0x21/0x36
| [<c014fe8f>] force_quiescent_state+0x47/0x57
| [<c014fef0>] call_rcu+0x51/0x6d
| [<c01713b3>] __fput+0x130/0x158
| [<c0171231>] fput+0x17/0x19
| [<c016fd99>] filp_close+0x4d/0x57
| [<c016fdff>] sys_close+0x5c/0x97
IMHO the warning is a spurious one.
cpu_online_map is updated by the _cpu_down() using stop_machine_run().
Since force_quiescent_state is invoked from irqs disabled section,
stop_machine_run() won't be executing while a cpu is executing
force_quiescent_state(). Hence the cpu_online_map is stable while we're
in the irq disabled section.
However, a cpu might have been offlined _just_ before we disabled irqs
while entering force_quiescent_state(). And rcu subsystem might not yet
have handled the CPU_DEAD notification, leading to the offlined cpu's
bit being set in the rcp->cpumask.
Hence cpumask = (rcp->cpumask & cpu_online_map) to prevent sending
smp_reschedule() to an offlined CPU.
Here's the timeline:
CPU_A CPU_B
--------------------------------------------------------------
cpu_down(): .
. .
. .
stop_machine(): /* disables preemption, .
* and irqs */ .
. .
. .
take_cpu_down(); .
. .
. .
. .
cpu_disable(); /*this removes cpu .
*from cpu_online_map .
*/ .
. .
. .
restart_machine(); /* enables irqs */ .
------WINDOW DURING WHICH rcp->cpumask is stale ---------------
. call_rcu();
. /* disables irqs here */
. .force_quiescent_state();
.CPU_DEAD: .for_each_cpu(rcp->cpumask)
. . smp_send_reschedule();
. .
. . WARN_ON() for offlined CPU!
.
.
.
rcu_cpu_notify:
.
-------- WINDOW ENDS ------------------------------------------
rcu_offline_cpu() /* Which calls cpu_quiet()
* which removes
* cpu from rcp->cpumask.
*/
If a new batch was started just before calling stop_machine_run(), the
"tobe-offlined" cpu is still present in rcp-cpumask.
During a cpu-offline, from take_cpu_down(), we queue an rt-prio idle
task as the next task to be picked by the scheduler. We also call
cpu_disable() which will disable any further interrupts and remove the
cpu's bit from the cpu_online_map.
Once the stop_machine_run() successfully calls take_cpu_down(), it calls
schedule(). That's the last time a schedule is called on the offlined
cpu, and hence the last time when rdp->passed_quiesc will be set to 1
through rcu_qsctr_inc().
But the cpu_quiet() will be on this cpu will be called only when the
next RCU_SOFTIRQ occurs on this CPU. So at this time, the offlined CPU
is still set in rcp->cpumask.
Now coming back to the idle_task which truely offlines the CPU, it does
check for a pending RCU and raises the softirq, since it will find
rdp->passed_quiesc to be 0 in this case. However, since the cpu is
offline I am not sure if the softirq will trigger on the CPU.
Even if it doesn't the rcu_offline_cpu() will find that rcp->completed
is not the same as rcp->cur, which means that our cpu could be holding
up the grace period progression. Hence we call cpu_quiet() and move
ahead.
But because of the window explained in the timeline, we could still have
a call_rcu() before the RCU subsystem executes it's CPU_DEAD
notification, and we send smp_send_reschedule() to offlined cpu while
trying to force the quiescent states. The appended patch adds comments
and prevents checking for offlined cpu everytime.
cpu_online_map is updated by the _cpu_down() using stop_machine_run().
Since force_quiescent_state is invoked from irqs disabled section,
stop_machine_run() won't be executing while a cpu is executing
force_quiescent_state(). Hence the cpu_online_map is stable while we're
in the irq disabled section.
fsync_buffers_list() and sync_dirty_buffer() both issue async writes and
then immediately wait on them. Conceptually, that makes them sync writes
and we should treat them as such so that the IO schedulers can handle
them appropriately.
This patch fixes a write starvation issue that Lin Ming reported, where
xx is stuck for more than 2 minutes because of a large number of
synchronous IO in the system:
Lin Ming confirms that this patch fixes the issue. I've run tests with
it for the past week and no ill effects have been observed, so I'm
proposing it for inclusion into 2.6.26.
Divyesh Shah [Mon, 16 Jun 2008 16:37:08 +0000 (18:37 +0200)]
block: Fix the starving writes bug in the anticipatory IO scheduler
AS scheduler alternates between issuing read and write batches. It does
the batch switch only after all requests from the previous batch are
completed.
When switching to a write batch, if there is an on-going read request,
it waits for its completion and indicates its intention of switching by
setting ad->changed_batch and the new direction but does not update the
batch_expire_time for the new write batch which it does in the case of
no previous pending requests.
On completion of the read request, it sees that we were waiting for the
switch and schedules work for kblockd right away and resets the
ad->changed_data flag.
Now when kblockd enters dispatch_request where it is expected to pick
up a write request, it in turn ends the write batch because the
batch_expire_timer was not updated and shows the expire timestamp for
the previous batch.
This results in the write starvation for all the cases where there is
the intention for switching to a write batch, but there is a previous
in-flight read request and the batch gets reverted to a read_batch
right away.
This also holds true in the reverse case (switching from a write batch
to a read batch with an in-flight write request).
I've checked that this bug exists on 2.6.11, 2.6.18, 2.6.24 and
linux-2.6-block git HEAD. I've tested the fix on x86 platforms with
SCSI drives where the driver asks for the next request while a current
request is in-flight.
This patch is based off linux-2.6-block git HEAD.
Bug reproduction:
A simple scenario which reproduces this bug is:
- dd if=/dev/hda3 of=/dev/null &
- lilo
The lilo takes forever to complete.
This can also be reproduced fairly easily with the earlier dd and
another test
program doing msync().
The example test program below should print out a message after every
iteration
but it simply hangs forever. With this bugfix it makes forward progress.
====
Example test program using msync() (thanks to suleiman AT google DOT
com)
I'm checking as soon as possible for the period not being zero since, if
it is, going ahead is useless. This way we also save a mutex_lock() and
a read_lock() wrt doing it inside tg_set_bandwidth() or
__rt_schedulable().
Tony Luck [Mon, 30 Jun 2008 22:03:14 +0000 (15:03 -0700)]
[IA64] Bugfix for system with 32 cpus
On a system where there are no hot pluggable cpus "additional_cpus"
is still set to -1 at the point where we call per_cpu_scan_finalize().
If we didn't find an SRAT table and so pick the default "32" for the
number of cpus, when we get to:
high_cpu = min(high_cpu + reserve_cpus, NR_CPUS);
we will end up initializing for just 31 cpus ... and so we will
die horribly when bringing up cpu#32.
Laurent Pinchart [Mon, 30 Jun 2008 18:04:50 +0000 (15:04 -0300)]
V4L/DVB (8145a): USB Video Class driver
This driver supports video input devices compliant with the USB Video Class
specification. This means lots of currently manufactured webcams, and probably
most of the future ones.
mac80211: don't accept WEP keys other than WEP40 and WEP104
This patch makes mac80211 refuse a WEP key whose length is not WEP40 nor
WEP104.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Pavel Roskin [Fri, 27 Jun 2008 20:19:58 +0000 (16:19 -0400)]
hostap: fix sparse warnings
Rewrite AID calculation in handle_pspoll() to avoid truncating bits.
Make hostap_80211_header_parse() static, don't export it. Avoid
shadowing variables.
Signed-off-by: Pavel Roskin <proski@gnu.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Joonwoo Park [Mon, 30 Jun 2008 19:42:23 +0000 (12:42 -0700)]
textsearch: fix Boyer-Moore text search bug
The current logic has a bug which cannot find matching pattern, if the
pattern is matched from the first character of target string.
for example:
pattern=abc, string=abcdefg
pattern=a, string=abcdefg
Searching algorithm should return 0 for those things.
Signed-off-by: Joonwoo Park <joonwpark81@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Jozsef Kadlecsik [Mon, 30 Jun 2008 19:41:30 +0000 (12:41 -0700)]
netfilter: nf_conntrack_tcp: fixing to check the lower bound of valid ACK
Lost connections was reported by Thomas Bätzler (running 2.6.25 kernel) on
the netfilter mailing list (see the thread "Weird nat/conntrack Problem
with PASV FTP upload"). He provided tcpdump recordings which helped to
find a long lingering bug in conntrack.
In TCP connection tracking, checking the lower bound of valid ACK could
lead to mark valid packets as INVALID because:
- We have got a "higher or equal" inequality, but the test checked
the "higher" condition only; fixed.
- If the packet contains a SACK option, it could occur that the ACK
value was before the left edge of our (S)ACK "window": if a previous
packet from the other party intersected the right edge of the window
of the receiver, we could move forward the window parameters beyond
accepting a valid ack. Therefore in this patch we check the rightmost
SACK edge instead of the ACK value in the lower bound of valid (S)ACK
test.
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Catalin Marinas [Fri, 27 Jun 2008 14:15:12 +0000 (15:15 +0100)]
[ARM] 5131/1: Annotate platform_secondary_init with trace_hardirqs_off
This patch annotates the platform_secondary_init function in
arch/arm/mach-realview/platsmp.c with trace_hardirqs_off to avoid a
warning when LOCKDEP and TRACE_IRQFLAGS are enabled.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Linus Torvalds [Mon, 30 Jun 2008 15:56:57 +0000 (08:56 -0700)]
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:
ptrace GET/SET FPXREGS broken
x86: fix cpu hotplug crash
x86: section/warning fixes
x86: shift bits the right way in native_read_tscp
Dmitry Torokhov [Thu, 26 Jun 2008 15:30:02 +0000 (11:30 -0400)]
Input: fix locking in force-feedback core
The newly added event_lock spinlock in the input core disallows sleeping
and therefore using mutexes in event handlers. Convert force-feedback
core to rely on event_lock instead of mutex to protect slots allocated
for fore-feedback effects. The original mutex is still used to serialize
uploading and erasing of effects.
struct user_fxsr_struct {
unsigned short cwd;
unsigned short swd;
unsigned short twd;
unsigned short fop;
long fip;
long fcs;
long foo;
long fos;
long mxcsr;
long reserved;
long st_space[32]; /* 8*16 bytes for each FP-reg = 128 bytes */
long xmm_space[32]; /* 8*16 bytes for each XMM-reg = 128 bytes */
long padding[56];
};
int main(void)
{
pid_t pid;
pid = fork();
switch(pid){
case -1:/* error */
break;
case 0:/* child */
child();
break;
default:
parent(pid);
break;
}
return 0;
}
int child(void)
{
ptrace(PTRACE_TRACEME);
kill(getpid(), SIGSTOP);
sleep(10);
return 0;
}
int parent(pid_t pid)
{
int ret;
struct user_fxsr_struct fpxregs;
In function _cpu_up, the panic happens when calling
__raw_notifier_call_chain at the second time. Kernel doesn't panic when
calling it at the first time. If just say because of nr_cpu_ids, that's
not right.
By checking the source code, I found that function do_boot_cpu is the culprit.
Consider below call chain:
_cpu_up=>__cpu_up=>smp_ops.cpu_up=>native_cpu_up=>do_boot_cpu.
So do_boot_cpu is called in the end. In do_boot_cpu, if
boot_error==true, cpu_clear(cpu, cpu_possible_map) is executed. So later
on, when _cpu_up calls __raw_notifier_call_chain at the second time to
report CPU_UP_CANCELED, because this cpu is already cleared from
cpu_possible_map, get_cpu_sysdev returns NULL.
Many resources are related to cpu_possible_map, so it's better not to
change it.
Below patch against 2.6.26-rc7 fixes it by removing the bit clearing in
cpu_possible_map.
projects / linux-2.6 / log