Implement a safe version of llist_for_each_entry, and use it in
blkif_free. Previously grants where freed while iterating the list,
which lead to dereferences when trying to fetch the next item.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
[v2: Move the llist_for_each_entry_safe in llist.h]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Change foreach_grant iterator to a safe version, that allows freeing
the element while iterating. Also move the free code in
free_persistent_gnts to prevent freeing the element before the rb_next
call.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad@kernel.org>
Cc: xen-devel@lists.xen.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Move the code that frees persistent grants from the red-black tree
to a function. This will make it easier for other consumers to move
this to a common place.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This patch contains fixes for persistent grants implementation v2:
* handle == 0 is a valid handle, so initialize grants in blkback
setting the handle to BLKBACK_INVALID_HANDLE instead of 0. Reported
by Konrad Rzeszutek Wilk.
* new_map is a boolean, use "true" or "false" instead of 1 and 0.
Reported by Konrad Rzeszutek Wilk.
* blkfront announces the persistent-grants feature as
feature-persistent-grants, use feature-persistent instead which is
consistent with blkback and the public Xen headers.
* Add a consistency check in blkfront to make sure we don't try to
access segments that have not been set.
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
[v1: The new_map int->bool had already been changed]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This patch implements persistent grants for the xen-blk{front,back}
mechanism. The effect of this change is to reduce the number of unmap
operations performed, since they cause a (costly) TLB shootdown. This
allows the I/O performance to scale better when a large number of VMs
are performing I/O.
Previously, the blkfront driver was supplied a bvec[] from the request
queue. This was granted to dom0; dom0 performed the I/O and wrote
directly into the grant-mapped memory and unmapped it; blkfront then
removed foreign access for that grant. The cost of unmapping scales
badly with the number of CPUs in Dom0. An experiment showed that when
Dom0 has 24 VCPUs, and guests are performing parallel I/O to a
ramdisk, the IPIs from performing unmap's is a bottleneck at 5 guests
(at which point 650,000 IOPS are being performed in total). If more
than 5 guests are used, the performance declines. By 10 guests, only
400,000 IOPS are being performed.
This patch improves performance by only unmapping when the connection
between blkfront and back is broken.
On startup blkfront notifies blkback that it is using persistent
grants, and blkback will do the same. If blkback is not capable of
persistent mapping, blkfront will still use the same grants, since it
is compatible with the previous protocol, and simplifies the code
complexity in blkfront.
To perform a read, in persistent mode, blkfront uses a separate pool
of pages that it maps to dom0. When a request comes in, blkfront
transmutes the request so that blkback will write into one of these
free pages. Blkback keeps note of which grefs it has already
mapped. When a new ring request comes to blkback, it looks to see if
it has already mapped that page. If so, it will not map it again. If
the page hasn't been previously mapped, it is mapped now, and a record
is kept of this mapping. Blkback proceeds as usual. When blkfront is
notified that blkback has completed a request, it memcpy's from the
shared memory, into the bvec supplied. A record that the {gref, page}
tuple is mapped, and not inflight is kept.
Writes are similar, except that the memcpy is peformed from the
supplied bvecs, into the shared pages, before the request is put onto
the ring.
Blkback stores a mapping of grefs=>{page mapped to by gref} in
a red-black tree. As the grefs are not known apriori, and provide no
guarantees on their ordering, we have to perform a search
through this tree to find the page, for every gref we receive. This
operation takes O(log n) time in the worst case. In blkfront grants
are stored using a single linked list.
The maximum number of grants that blkback will persistenly map is
currently set to RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST, to
prevent a malicios guest from attempting a DoS, by supplying fresh
grefs, causing the Dom0 kernel to map excessively. If a guest
is using persistent grants and exceeds the maximum number of grants to
map persistenly the newly passed grefs will be mapped and unmaped.
Using this approach, we can have requests that mix persistent and
non-persistent grants, and we need to handle them correctly.
This allows us to set the maximum number of persistent grants to a
lower value than RING_SIZE * BLKIF_MAX_SEGMENTS_PER_REQUEST, although
setting it will lead to unpredictable performance.
In writing this patch, the question arrises as to if the additional
cost of performing memcpys in the guest (to/from the pool of granted
pages) outweigh the gains of not performing TLB shootdowns. The answer
to that question is `no'. There appears to be very little, if any
additional cost to the guest of using persistent grants. There is
perhaps a small saving, from the reduced number of hypercalls
performed in granting, and ending foreign access.
Signed-off-by: Oliver Chick <oliver.chick@citrix.com>
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v1: Fixed up the misuse of bool as int]
Pull ktest confusion fix from Steven Rostedt:
"With the v3.7-rc2 kernel, the network cards on my target boxes were
not being brought up.
I found that the modules for the network was not being installed.
This was due to the config CONFIG_MODULES_USE_ELF_RELA that came
before CONFIG_MODULES, and confused ktest in thinking that
CONFIG_MODULES=y was not found.
Ktest needs to test all configs and not just stop if something starts
with CONFIG_MODULES."
* tag 'ktest-v3.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-ktest:
ktest: Fix ktest confusion with CONFIG_MODULES_USE_ELF_RELA
Pull minor spi MXS fixes from Mark Brown:
"These fixes are both pretty minor ones and are driver local."
* tag 'spi-mxs' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/misc:
spi: mxs: Terminate DMA in case of DMA timeout
spi: mxs: Assign message status after transfer finished
Pull arm-soc fixes from Arnd Bergmann:
"Bug fixes for a number of ARM platforms, mostly OMAP, imx and at91.
These come a little later than I had hoped but unfortunately we had a
few of these patches cause regressions themselves and had to work out
how to deal with those in the meantime."
* tag 'fixes-for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (38 commits)
Revert "ARM i.MX25: Fix PWM per clock lookups"
ARM: versatile: fix versatile_defconfig
ARM: mvebu: update defconfig with 3.7 changes
ARM: at91: fix at91x40 build
ARM: socfpga: Fix socfpga compilation with early_printk() enabled
ARM: SPEAr: Remove unused empty files
MAINTAINERS: Add arm-soc tree entry
ARM: dts: mxs: add the "clock-names" for gpmi-nand
ARM: ux500: Correct SDI5 address and add some format changes
ARM: ux500: Specify AMBA Primecell IDs for Nomadik I2C in DT
ARM: ux500: Fix build error relating to IRQCHIP_SKIP_SET_WAKE
ARM: at91: drop duplicated config SOC_AT91SAM9 entry
ARM: at91/i2c: change id to let i2c-at91 work
ARM: at91/i2c: change id to let i2c-gpio work
ARM: at91/dts: at91sam9g20ek_common: Fix typos in buttons labels.
ARM: at91: fix external interrupt specification in board code
ARM: at91: fix external interrupts in non-DT case
ARM: at91: at91sam9g10: fix SOC type detection
ARM: at91/tc: fix typo in the DT document
ARM: AM33XX: Fix configuration of dmtimer parent clock by dmtimer driverDate:Wed, 17 Oct 2012 13:55:55 -0500
...
Functions generic_file_splice_read and generic_file_splice_write access
the pagecache directly. For block devices these functions must be locked
so that block size is not changed while they are in progress.
This patch is an additional fix for commit b87570f5d3 ("Fix a crash
when block device is read and block size is changed at the same time")
that locked aio_read, aio_write and mmap against block size change.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use rcu_read_lock_sched / rcu_read_unlock_sched / synchronize_sched
instead of rcu_read_lock / rcu_read_unlock / synchronize_rcu.
This is an optimization. The RCU-protected region is very small, so
there will be no latency problems if we disable preempt in this region.
So we use rcu_read_lock_sched / rcu_read_unlock_sched that translates
to preempt_disable / preempt_disable. It is smaller (and supposedly
faster) than preemptible rcu_read_lock / rcu_read_unlock.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch introduces new barrier pair light_mb() and heavy_mb() for
percpu rw semaphores.
This patch fixes a bug in percpu-rw-semaphores where a barrier was
missing in percpu_up_write.
This patch improves performance on the read path of
percpu-rw-semaphores: on non-x86 cpus, there was a smp_mb() in
percpu_up_read. This patch changes it to a compiler barrier and removes
the "#if defined(X86) ..." condition.
From: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 92063cee11, it
was applied prematurely, causing this build error for
imx_v4_v5_defconfig:
arch/arm/mach-imx/clk-imx25.c: In function 'mx25_clocks_init':
arch/arm/mach-imx/clk-imx25.c:206:26: error: 'pwm_ipg_per' undeclared (first use in this function)
arch/arm/mach-imx/clk-imx25.c:206:26: note: each undeclared identifier is reported only once for each function it appears in
Sascha Hauer explains:
> There are several gates missing in clk-imx25.c. I have a patch which
> adds support for them and I seem to have missed that the above depends
> on it.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
With the introduction of CONFIG_ARCH_MULTIPLATFORM, versatile is
no longer the default platform, so we need to enable
CONFIG_ARCH_VERSATILE explicitly in order for that to be selected
rather than the multiplatform configuration.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The split of 370 and XP into two Kconfig options and the multiplatform
kernel support has changed a few Kconfig symbols, so let's update the
mvebu_defconfig file with the latest changes.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
patch 738a0fd7 "ARM: at91: fix external interrupts in non-DT case"
fixed a run-time error on some at91 platforms but did not apply
the same change to at91x40, which now doesn't build.
This changes at91x40 in the same way that the other platforms
were changed.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Pull networking fixes from David Miller:
"This is what we usually expect at this stage of the game, lots of
little things, mostly in drivers. With the occasional 'oops didn't
mean to do that' kind of regressions in the core code."
1) Uninitialized data in __ip_vs_get_timeouts(), from Arnd Bergmann
2) Reject invalid ACK sequences in Fast Open sockets, from Jerry Chu.
3) Lost error code on return from _rtl_usb_receive(), from Christian
Lamparter.
4) Fix reset resume on USB rt2x00, from Stanislaw Gruszka.
5) Release resources on error in pch_gbe driver, from Veaceslav Falico.
6) Default hop limit not set correctly in ip6_template_metrics[], fix
from Li RongQing.
7) Gianfar PTP code requests wrong kind of resource during probe, fix
from Wei Yang.
8) Fix VHOST net driver on big-endian, from Michael S Tsirkin.
9) Mallenox driver bug fixes from Jack Morgenstein, Or Gerlitz, Moni
Shoua, Dotan Barak, and Uri Habusha.
10) usbnet leaks memory on TX path, fix from Hemant Kumar.
11) Use socket state test, rather than presence of FIN bit packet, to
determine FIONREAD/SIOCINQ value. Fix from Eric Dumazet.
12) Fix cxgb4 build failure, from Vipul Pandya.
13) Provide a SYN_DATA_ACKED state to complement SYN_FASTOPEN in socket
info dumps. From Yuchung Cheng.
14) Fix leak of security path in kfree_skb_partial(). Fix from Eric
Dumazet.
15) Handle RX FIFO overflows more resiliently in pch_gbe driver, from
Veaceslav Falico.
16) Fix MAINTAINERS file pattern for networking drivers, from Jean
Delvare.
17) Add iPhone5 IDs to IPHETH driver, from Jay Purohit.
18) VLAN device type change restriction is too strict, and should not
trigger for the automatically generated vlan0 device. Fix from Jiri
Pirko.
19) Make PMTU/redirect flushing work properly again in ipv4, from
Steffen Klassert.
20) Fix memory corruptions by using kfree_rcu() in netlink_release().
From Eric Dumazet.
21) More qmi_wwan device IDs, from Bjørn Mork.
22) Fix unintentional change of SNAT/DNAT hooks in generic NAT
infrastructure, from Elison Niven.
23) Fix 3.6.x regression in xt_TEE netfilter module, from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (57 commits)
tilegx: fix some issues in the SW TSO support
qmi_wwan/cdc_ether: move Novatel 551 and E362 to qmi_wwan
net: usb: Fix memory leak on Tx data path
net/mlx4_core: Unmap UAR also in the case of error flow
net/mlx4_en: Don't use vlan tag value as an indication for vlan presence
net/mlx4_en: Fix double-release-range in tx-rings
bas_gigaset: fix pre_reset handling
vhost: fix mergeable bufs on BE hosts
gianfar_ptp: use iomem, not ioports resource tree in probe
ipv6: Set default hoplimit as zero.
NET_VENDOR_TI: make available for am33xx as well
pch_gbe: fix error handling in pch_gbe_up()
b43: Fix oops on unload when firmware not found
mwifiex: clean up scan state on error
mwifiex: return -EBUSY if specific scan request cannot be honored
brcmfmac: fix potential NULL dereference
Revert "ath9k_hw: Updated AR9003 tx gain table for 5GHz"
ath9k_htc: Add PID/VID for a Ubiquiti WiFiStation
rt2x00: usb: fix reset resume
rtlwifi: pass rx setup error code to caller
...
Pull slave-dmaengine fixes from Vinod Koul:
"Three fixes for slave dmanegine.
Two are for typo omissions in sifr dmaengine driver and the last one
is for the imx driver fixing a missing unlock"
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
dmaengine: sirf: fix a typo in moving running dma_desc to active queue
dmaengine: sirf: fix a typo in dma_prep_interleaved
dmaengine: imx-dma: fix missing unlock on error in imxdma_xfer_desc()
Pull power management and ACPI fixes from Rafael J Wysocki:
- Fix for a memory leak in acpi_bind_one() from Jesper Juhl.
- Fix for an error code path memory leak in pm_genpd_attach_cpuidle()
from Jonghwan Choi.
- Fix for smp_processor_id() usage in preemptible code in powernow-k8
from Andreas Herrmann.
- Fix for a suspend-related memory leak in cpufreq stats from Xiaobing
Tu.
- Freezer fix for failure to clear PF_NOFREEZE along with PF_KTHREAD in
flush_old_exec() from Oleg Nesterov.
- acpi_processor_notify() fix from Alan Cox.
* tag 'pm+acpi-for-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: missing break
freezer: exec should clear PF_NOFREEZE along with PF_KTHREAD
Fix memory leak in cpufreq stats.
cpufreq / powernow-k8: Remove usage of smp_processor_id() in preemptible code
PM / Domains: Fix memory leak on error path in pm_genpd_attach_cpuidle
ACPI: Fix memory leak in acpi_bind_one()
Pull infiniband fixes from Roland Dreier:
"Small batch of fixes for 3.7:
- Fix crash in error path in cxgb4
- Fix build error on 32 bits in mlx4
- Fix SR-IOV bugs in mlx4"
* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
mlx4_core: Perform correct resource cleanup if mlx4_QUERY_ADAPTER() fails
mlx4_core: Remove annoying debug messages from SR-IOV flow
RDMA/cxgb4: Don't free chunk that we have failed to allocate
IB/mlx4: Synchronize cleanup of MCGs in MCG paravirtualization
IB/mlx4: Fix QP1 P_Key processing in the Primary Physical Function (PPF)
IB/mlx4: Fix build error on platforms where UL is not 64 bits
Pull USB fixes from Greg Kroah-Hartman:
"Here are a bunch of USB fixes for the 3.7-rc tree.
There's a lot of small USB serial driver fixes, and one larger one
(the mos7840 driver changes are mostly just moving code around to fix
problems.) Thanks to Johan Hovold for finding the problems and fixing
them all up.
Other than those, there is the usual new device ids, xhci bugfixes,
and gadget driver fixes, nothing out of the ordinary.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'usb-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (49 commits)
xhci: trivial: Remove assigned but unused ep_ctx.
xhci: trivial: Remove assigned but unused slot_ctx.
xhci: Fix missing break in xhci_evaluate_context_result.
xhci: Fix potential NULL ptr deref in command cancellation.
ehci: Add yet-another Lucid nohandoff pci quirk
ehci: fix Lucid nohandoff pci quirk to be more generic with BIOS versions
USB: mos7840: fix port_probe flow
USB: mos7840: fix port-data memory leak
USB: mos7840: remove invalid disconnect handling
USB: mos7840: remove NULL-urb submission
USB: qcserial: fix interface-data memory leak in error path
USB: option: fix interface-data memory leak in error path
USB: ipw: fix interface-data memory leak in error path
USB: mos7840: fix port-device leak in error path
USB: mos7840: fix urb leak at release
USB: sierra: fix port-data memory leak
USB: sierra: fix memory leak in probe error path
USB: sierra: fix memory leak in attach error path
USB: usb-wwan: fix multiple memory leaks in error paths
USB: keyspan: fix NULL-pointer dereferences and memory leaks
...
Pull serial fix from Greg Kroah-Hartman:
"Here is one patch, a revert of a omap serial driver patch that was
causing problems, for your 3.7-rc tree.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'tty-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "serial: omap: fix software flow control"
Pull staging driver fixes from Greg Kroah-Hartman:
"Here are some staging driver fixes for your 3.7-rc tree.
Nothing major here, a number of iio driver fixups that were causing
problems, some comedi driver bugfixes, and a bunch of tidspbridge
warning squashing and other regressions fixed from the 3.6 release.
All have been in the linux-next releases for a bit.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'staging-3.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (32 commits)
staging: tidspbridge: delete unused mmu functions
staging: tidspbridge: ioremap physical address of the stack segment in shm
staging: tidspbridge: ioremap dsp sync addr
staging: tidspbridge: change type to __iomem for per and core addresses
staging: tidspbridge: drop const from custom mmu implementation
staging: tidspbridge: request the right irq for mmu
staging: ipack: add missing include (implicit declaration of function 'kfree')
staging: ramster: depends on NET
staging: omapdrm: fix allocation size for page addresses array
staging: zram: Fix handling of incompressible pages
Staging: android: binder: Allow using highmem for binder buffers
Staging: android: binder: Fix memory leak on thread/process exit
staging: comedi: ni_labpc: fix possible NULL deref during detach
staging: comedi: das08: fix possible NULL deref during detach
staging: comedi: amplc_pc263: fix possible NULL deref during detach
staging: comedi: amplc_pc236: fix possible NULL deref during detach
staging: comedi: amplc_pc236: fix invalid register access during detach
staging: comedi: amplc_dio200: fix possible NULL deref during detach
staging: comedi: 8255_pci: fix possible NULL deref during detach
staging: comedi: ni_daq_700: fix dio subdevice regression
...
Pull driver core fixes from Greg Kroah-Hartman:
"Here are a number of firmware core fixes for 3.7, and some other minor
fixes. And some documentation updates thrown in for good measure.
All have been in the linux-next tree for a while.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
* tag 'driver-core-3.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
Documentation:Chinese translation of Documentation/arm64/memory.txt
Documentation:Chinese translation of Documentation/arm64/booting.txt
Documentation:Chinese translation of Documentation/IRQ.txt
firmware loader: document kernel direct loading
sysfs: sysfs_pathname/sysfs_add_one: Use strlcat() instead of strcat()
dynamic_debug: Remove unnecessary __used
firmware loader: sync firmware cache by async_synchronize_full_domain
firmware loader: let direct loading back on 'firmware_buf'
firmware loader: fix one reqeust_firmware race
firmware loader: cancel uncache work before caching firmware
Roger Pau Monne
Linus Torvalds
Mikulas Patocka
Arnd Bergmann
Thomas Petazzoni