Commit graph

311749 commits

Author SHA1 Message Date
Alan Cox
b63b5e819d mmc: core: correct invalid error checking
The effect of the existing code is that we continue blindly when we
should warn about an invalid allocation unit.

Reported-by: dcb314@hotmail.com
Resolves-bug: https://bugzilla.kernel.org/show_bug.cgi?id=44061
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:24 -04:00
Philip Rakity
68737043bb mmc: only support voltage (vdd) that regulator agrees with
If we are using a regulator the SD Host Controller and the
regulator should agree about the voltages supported.  Use
the common subset that is supported.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:24 -04:00
Philip Rakity
0aa6770000 mmc: sdhci: only set 200mA support for 1.8v if 200mA is available
max_current_caps can return 0 if not available from the sd controller.
If no regulator is present or the regulator specifies a current
less then 200ma, we no longer still set the 200mA caps bit anyway.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Reviewed-by: Aaron Lu <aaron_lu@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:23 -04:00
Philip Rakity
bad37e1ac6 mmc: sdhci: if MAX_CURRENT is 0, try getting current from regulator
The sd host controller spec indicates the the MAX_CURRENT value may
be returned as 0.  In this case other methods need to be used to
return the current.  If 0 is returned and there is a regulator,
ask the regulator for how much current is available.

Signed-off-by: Philip Rakity <prakity@marvell.com>
Signed-off-by: Mark F. Brown <mark.brown314@gmail.com>
Reviewed-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:22 -04:00
Guennadi Liakhovetski
e480606ad4 mmc: sh_mmcif: support generic card-detection
Extend the sh_mmcif driver to support GPIO card detection, provided by the
slot function module. The original .get_cd() platform callback is also
preserved for now.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:22 -04:00
Guennadi Liakhovetski
d9adcc1286 mmc: prohibit card detection when host is not ready
Currently mmc host drivers have to decide whether to enable card
detection before calling mmc_add_host() -- in which case a card
insertion event can arrive before the host has been completely
initialised -- or after mmc_add_host(), in which case the initial
card detection can be problematic.

This patch adds an explicit indication of when card detection should
not be carried out. With it in place enabling card detection before
calling mmc_add_host() should be safe. Similarly, disabling it again
after calling mmc_remove_host() will avoid any races.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:21 -04:00
Guennadi Liakhovetski
bf68a812f0 mmc: sh-mmcif: add OF support, make platform data optional
Add primitive OF support to the sh-mmcif driver, which also makes it
necessary to be able to run without platform data.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:21 -04:00
Guennadi Liakhovetski
c7bb4487a3 mmc: sdhi: add OF support, make platform data optional
Add primitive support for OF to the SDHI TMIO glue, which also makes it
necessary to be able to run without platform data.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:20 -04:00
Guennadi Liakhovetski
3071cafb7f mmc: tmio: use generic GPIO CD and WP handlers
The tmio-mmc driver is already using the generic GPIO CD handler in IRQ
mode. This patch adds support for CD polling mode and also checks for
availability of a WP GPIO.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:20 -04:00
Guennadi Liakhovetski
d7d8d500bc mmc: sh_mobile_sdhi: support caps2 flags
Let SDHI platforms specify mmc_host::caps2 flags in their platform data.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:19 -04:00
Guennadi Liakhovetski
02cb3221d5 mmc: tmio: support caps2 flags
Allow tmio mmc glue drivers to pass mmc_host::caps2 flags down to
the mmc layer.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:18 -04:00
Guennadi Liakhovetski
5aa7dad305 mmc: core: add WP pin handler to slot functions
Card Write-Protect pin is often implemented, using a GPIO, which makes
it simple to provide a generic handler for it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:18 -04:00
Guennadi Liakhovetski
a7d1a1ebd8 mmc: core: convert slot functions to managed allocation
This prepares for the addition of further slot functions.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:17 -04:00
Guennadi Liakhovetski
befe4048d8 mmc: add CD GPIO polling support to slot functions
A simple extension of mmc slot functions add support for CD GPIO polling
for cases where the GPIO cannot produce interrupts, or where this is not
desired for some reason.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:17 -04:00
Guennadi Liakhovetski
5c08d7fae0 mmc: add two capability flags for CD and WP signal polarity
To handle CD and WP SD/MMC slot pins we need generic flags to specify their
polarity.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:16 -04:00
Guennadi Liakhovetski
27410ee7e3 mmc: core: use a more generic name for slot function types and fields
struct mmc_host::hotplug is becoming a generic hook for slot functions.
Rename it accordingly.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:16 -04:00
Guennadi Liakhovetski
7d17baa05d mmc: sh_mmcif: add regulator support
Add regulator support to the sh_mmcif driver, but also preserve the current
power-callback.

Also note, that the card power is not switched off during clock gating
periods, hence there's no need to power it on every time the card is
re-activated.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:15 -04:00
Guennadi Liakhovetski
e2ee996eaa mmc: sh_mmcif: remove redundant .down_pwr() callback
From the original version of sh_mmcif the .set_pwr() callback has only been
used to turn the card's power on, and the .down_pwr() callback has been
used to turn it off. .set_pwr() can be used for both these tasks, which is
also how it is implemented by the only user of this API: the SH7724 ecovec
board.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:14 -04:00
Guennadi Liakhovetski
a660926710 mmc: sh_mmcif: re-read the clock frequency every time it is turned on
With aggressive clock gating the clock can be disabled during interface
inactivity. During this time its frequency can be changed by another its
user. Therefore when the interface is activated again and the clock is
re-enabled, its frequency has to be re-read.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:14 -04:00
Guennadi Liakhovetski
b289174ff7 mmc: sh_mmcif: fix clock management
Regardless of whether the MMC bus clock is the same as the PM clock on
this specific interface, it has to be managed separately. Its proper
management should also include enabling and disabling of the clock,
whenever the interface is becoming active or going idle respectively.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:13 -04:00
Guennadi Liakhovetski
e1aae2eb3f mmc: sh_mmcif: simplify and use meaningful label names in error-handling
A check for NULL platform data can be conveniently made in the very
beginning of probing. Replace numbered error-handling labels in .probe()
with meaningful names to make any future reorganisation simpler.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:13 -04:00
Guennadi Liakhovetski
944640d0ff mmc: tmio: remove a duplicated comment line
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:12 -04:00
Guennadi Liakhovetski
71da63e767 mmc: sdhi: do not install dummy callbacks
Currently the SDHI glue for the TMIO MMC driver installs dummy .get_cd() and
.set_pwr() callbacks even if the platform didn't supply them. This is not
necessary, since the TMIO MMC driver itself checks for NULL callbacks. This
is also dubious if the platform provides a regulator for SD-card power
switching. It is better to only install those callbacks, if they are really
provided by the platform.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:11 -04:00
Guennadi Liakhovetski
b958a67c6b mmc: tmio: add regulator support
Currently the TMIO MMC driver derives the OCR mask from the platform data
and uses a platform callback to turn card power on and off. This patch adds
regulator support to the driver.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:11 -04:00
Guennadi Liakhovetski
56c4928793 mmc: sdhi: implement tmio-mmc clock enable-update and disable callbacks
Instead of delivering one static clock frequency value, read from the
hardware during probing, enable the tmio-mmc driver to re-read the
frequency dynamically.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:10 -04:00
Guennadi Liakhovetski
8c102a9646 mmc: tmio: add callbacks to enable-update and disable the interface clock
Every time the clock is enabled after possibly being disabled, we have
to re-read its frequency and update our configuration.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:10 -04:00
Guennadi Liakhovetski
e0337cc8b0 mmc: tmio: don't needlessly enable interrupts during probing
We don't have to force-enable MMC interrupts in our .probe() method,
mmc_add_host() will trigger card detection, that will enable all the
necessary interrupts.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:09 -04:00
Jonathan Kliegman
3bfe619dc3 mmc: dw_mmc: Fix null dma_ops access when use_dma is false
host->dma_ops is not valid if host->usa dma is 0 so protect
host->dma_ops reference in dw_mci_resume

Signed-off-by: Jonathan Kliegman <kliegs@chromium.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:09 -04:00
Guennadi Liakhovetski
e137788dd1 mmc: add a function to get regulators, supplying card's power
Add a function to get regulators, supplying card's Vdd and Vccq on a
specific host. If a Vdd supplying regulator is found, the function checks,
whether a valid OCR mask can be obtained from it. The Vccq regulator is
optional. A failure to get it is not fatal.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Reviwed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:08 -04:00
Laurent Pinchart
6de707f200 mmc: tmio: Don't access hardware registers after stopping clocks
The tmio_mmc_set_ios() function configures the MMC power, clock and bus
width. When the mmc core requests the driver to power off the card, we
inform runtime PM, that the controller can be suspended. This can lead
to the MSTP clock being turned off.

Writing to any 16-bit hardware registers with the MSTP clock off leads
to timeouts and errors being printed to the kernel log. This can occur
both when stopping the MMC clock and when configuring the bus width.

To fix this, stop the MMC clock before calling put_runtime_pm(), and
skip bus width configuration when power is off.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Tested-by: Simon Horman <horms@verge.net.au>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:07 -04:00
Laurent Pinchart
7541ca9847 mmc: sh_mmcif: Support MMC_SLEEP_AWAKE command
The MMC_SLEEP_AWAKE and SD_IO_SEND_OP_COND commands share the same
opcode. SD_IO_SEND_OP_COND isn't supported by the SH MMCIF, but
MMC_SLEEP_AWAKE is. Discriminate between the two commands using the
command flags, and reject SD_IO_SEND_OP_COND only.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:07 -04:00
Girish K S
94c6cee91b mmc: dw_mmc: Add check for IDMAC configuration
In the current dwmmc driver there is support for selecting IDMAC from
the menu config option. If the support for IDMAC is enabled in the menu
config and the hardware configuration register's DMA_INTERFACE field is
0, the driver will still try to do the DMA initialization.

The dw_mci_idmac_init function currently implemented returns only success
indicating that the DMA initialization is always successful. This patch
adds a check for existence of the DMA IP to allow the DMA initialization.

Signed-off-by: Girish K S <girish.shivananjappa@linaro.org>
Acked-by: Will Newton <will.newton@imgtec.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-21 00:02:06 -04:00
Chris Ball
b650352dd3 mmc: sdhci-pxa: Add device tree support
Tested on an OLPC XO-1.75.  (MMP2, sdhci-pxav3, CONFIG_MACH_MMP2_DT=y)

Signed-off-by: Chris Ball <cjb@laptop.org>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
2012-07-21 00:01:47 -04:00
Chris Ball
ed3efc1ccc mmc: dt: Add reg/interrupts to mmc.txt for clarity.
Even though these aren't parsed by the MMC driver, make clear that
they're required by the OF core.  (Also, a few typo fixes.)

Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:04:07 -04:00
Chris Ball
4efafee02f mmc: dt: Deduplicate binding docs by referencing mmc.txt
Now that we have common bindings for MMC, rewrite the individual
bindings to inherit from mmc.txt and describe their differences.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:04:06 -04:00
Chris Ball
45a6b32e24 mmc: core: Export regulator_* functions as GPL
The regulator API functions we're wrapping are exported as GPL, so our
wrappers for the same functions should be too.

Reported-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:04:06 -04:00
Subhash Jadavani
ecf8b5d0a3 mmc: block: replace __blk_end_request() with blk_end_request()
For completing any block request, MMC block driver is calling:
	spin_lock_irq(queue)
	__blk_end_request()
	spin_unlock_irq(queue)

But if we analyze the sources of latency in kernel using ftrace,
__blk_end_request() function at times may take up to 6.5ms with
spinlock held and irq disabled.

__blk_end_request() calls couple of functions and ftrace output
shows that blk_update_bidi_request() function is almost taking 6ms.
There are 2 function to end the current request: ___blk_end_request()
and blk_end_request(). Both these functions do same thing except
that blk_end_request() function doesn't take up the spinlock
while calling the blk_update_bidi_request().

This patch replaces all __blk_end_request() calls with
blk_end_request() and __blk_end_request_all() calls with
blk_end_request_all().

Testing done: 20 process concurrent read/write on sd card
and eMMC. Ran this test for almost a day on multicore system
and no errors observed.

This change is not meant for improving MMC throughput; it's basically
about becoming fair to other threads/interrupts in the system. By
holding spin lock and interrupts disabled for longer duration, we
won't allow other threads/interrupts to run at all.  Actually slight
performance degradation at file system level can be expected as we
are not holding the spin lock during blk_update_bidi_request() which
means our mmcqd thread may get preempted for other high priority
thread or any interrupt in the system.

These are performance numbers (100MB file write) with eMMC running
in DDR mode:

Without this patch:
	Name of the Test   Value   Unit
	LMDD Read Test     53.79   MBPS
	LMDD Write Test    18.86   MBPS
	IOZONE  Read Test  51.65   MBPS
	IOZONE  Write Test 24.36   MBPS

With this patch:
	Name of the Test    Value  Unit
	LMDD Read Test      52.94  MBPS
	LMDD Write Test     16.70  MBPS
	IOZONE  Read Test   52.08  MBPS
	IOZONE  Write Test  23.29  MBPS

Read numbers are fine. Write numbers are bit down (especially LMDD
write), may be because write requests normally have large transfer
size and which means there are chances that while mmcq is executing
blk_update_bidi_request(), it may get interrupted by interrupts or
other high priority thread.

Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:04:05 -04:00
Venkatraman S
6af9e96e05 mmc: core: Fix the HPI execution sequence
mmc_execute_hpi should send the HPI command only once, and only
if the card is in PRG state.

According to eMMC spec, the command's completion time is
not dependent on OUT_OF_INTERRUPT_TIME. Only the transition
out of PRG STATE is guarded by OUT_OF_INTERRUPT_TIME - which
is defined to begin at the end of sending the command itself.

Specify the default timeout for the actual sending of HPI
command, and then use OUT_OF_INTERRUPT_TIME to wait for
the transition out of PRG state.

Reported-by: Alex Lemberg <Alex.Lemberg@sandisk.com>
Signed-off-by: Venkatraman S <svenkatr@ti.com>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:04:04 -04:00
Guennadi Liakhovetski
fd0ea65d3e mmc: extend and rename cd-gpio helpers to handle more slot GPIO functions
GPIOs can be used in MMC/SD-card slots not only for hotplug detection, but
also to implement the write-protection pin. Rename cd-gpio helpers to
slot-gpio to make addition of further slot GPIO functions possible.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:04:04 -04:00
Guennadi Liakhovetski
0f506a9669 mmc: tmio: use MMC opcode defines instead of numbers
mmc.h defines macros for most frequently used MMC opcodes. Use them instead
of hard-coded numbers.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:04:03 -04:00
Guennadi Liakhovetski
623b51fc86 mmc: cd-gpio: pass IRQF_ONESHOT to request_threaded_irq()
Fix a boot regression on Mackerel boards with sh_mobile_sdhi
in existing kernels causing:

genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq XXX

caused by 1c6c6952 (genirq: Reject bogus threaded irq requests).

This is backported from Guennadi's patch:
"mmc: extend and rename cd-gpio helpers to handle more slot GPIO functions"

Reported-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 23:03:57 -04:00
Venkatraman S
87f761b6c0 mmc: core: Revert "skip card initialization if power class selection fails"
This reverts commit 3d93576e(skip card initialization if
power class selection fails).
Problem has been reported when this is used with eMMC4.41
card with Tegra Platform. Till the issue is root caused,
bus width selection failure should not be treated as fatal.

Reported-by: Marc Dietrich <marvin24@gmx.de>
Signed-Off-by: Venkatraman S <svenkatr@ti.com>
CC: Ulf Hansson <ulf.hansson@stericsson.com>
CC: Subhash Jadavani <subhashj@codeaurora.org>
CC: Saugata Das <saugata.das@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-07-10 22:47:13 -04:00
Tejun Heo
5db9a4d99b cgroup: fix cgroup hierarchy umount race
48ddbe1946 "cgroup: make css->refcnt clearing on cgroup removal
optional" allowed a css to linger after the associated cgroup is
removed.  As a css holds a reference on the cgroup's dentry, it means
that cgroup dentries may linger for a while.

Destroying a superblock which has dentries with positive refcnts is a
critical bug and triggers BUG() in vfs code.  As each cgroup dentry
holds an s_active reference, any lingering cgroup has both its dentry
and the superblock pinned and thus preventing premature release of
superblock.

Unfortunately, after 48ddbe1946, there's a small window while
releasing a cgroup which is directly under the root of the hierarchy.
When a cgroup directory is released, vfs layer first deletes the
corresponding dentry and then invokes dput() on the parent, which may
recurse further, so when a cgroup directly below root cgroup is
released, the cgroup is first destroyed - which releases the s_active
it was holding - and then the dentry for the root cgroup is dput().

This creates a window where the root dentry's refcnt isn't zero but
superblock's s_active is.  If umount happens before or during this
window, vfs will see the root dentry with non-zero refcnt and trigger
BUG().

Before 48ddbe1946, this problem didn't exist because the last dentry
reference was guaranteed to be put synchronously from rmdir(2)
invocation which holds s_active around the whole process.

Fix it by holding an extra superblock->s_active reference across
dput() from css release, which is the dput() path added by 48ddbe1946
and the only one which doesn't hold an extra s_active ref across the
final cgroup dput().

Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <4FEEA5CB.8070809@huawei.com>
Reported-by: shyju pv <shyju.pv@huawei.com>
Tested-by: shyju pv <shyju.pv@huawei.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Li Zefan <lizefan@huawei.com>
2012-07-07 16:08:18 -07:00
Tejun Heo
7db5b3ca0e Revert "cgroup: superblock can't be released with active dentries"
This reverts commit fa980ca87d.  The
commit was an attempt to fix a race condition where a cgroup hierarchy
may be unmounted with positive dentry reference on root cgroup.  While
the commit made the race condition slightly more difficult to trigger,
the race was still there and could be reliably triggered using a
different test case.

Revert the incorrect fix.  The next commit will describe the race and
fix it correctly.

Signed-off-by: Tejun Heo <tj@kernel.org>
LKML-Reference: <4FEEA5CB.8070809@huawei.com>
Reported-by: shyju pv <shyju.pv@huawei.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Li Zefan <lizefan@huawei.com>
2012-07-07 15:55:47 -07:00
Linus Torvalds
cd6407fe22 Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM fixes from Russell King:
 "Last merge window, we had some updates from Al cleaning up the signal
  restart handling.  These have caused some problems on ARM, and while
  Al has some fixes, we have some concerns with Al's patches but we've
  been unsuccesful with discussing this.

  We have got to the point where we need to do something, and we've
  decided that the best solution is to revert the appropriate commits
  until Al is able to reply to us.

  Also included here are four patches to fix warnings that I've noticed
  in my build system, and one fix for kprobes test code."

* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
  ARM: fix warning caused by wrongly typed arm_dma_limit
  ARM: fix warnings about atomic64_read
  ARM: 7440/1: kprobes: only test 'sub pc, pc, #1b-2b+8-2' on ARMv6
  ARM: 7441/1: perf: return -EOPNOTSUPP if requested mode exclusion is unavailable
  ARM: 7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK"
  ARM: 7442/1: Revert "remove unused restart trampoline"
  ARM: fix set_domain() macro
  ARM: fix mach-versatile/pci.c warning
2012-07-07 11:20:59 -07:00
Linus Torvalds
26c439d400 Fixes an incorrect access mode check when preparing to open a file in the lower
filesystem. This isn't an urgent fix, but it is simple and the check was
 obviously incorrect.
 
 Also fixes a couple important bugs in the eCryptfs miscdev interface. These
 changes are low risk due to the small number of users that use the miscdev
 interface. I was able to keep the changes minimal and I have some cleaner, more
 complete changes queued up for the next merge window that will build on these
 patches.
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Merge tag 'ecryptfs-3.5-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs

Pull eCryptfs fixes from Tyler Hicks:
 "Fixes an incorrect access mode check when preparing to open a file in
  the lower filesystem.  This isn't an urgent fix, but it is simple and
  the check was obviously incorrect.

  Also fixes a couple important bugs in the eCryptfs miscdev interface.
  These changes are low risk due to the small number of users that use
  the miscdev interface.  I was able to keep the changes minimal and I
  have some cleaner, more complete changes queued up for the next merge
  window that will build on these patches."

* tag 'ecryptfs-3.5-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs:
  eCryptfs: Gracefully refuse miscdev file ops on inherited/passed files
  eCryptfs: Fix lockdep warning in miscdev operations
  eCryptfs: Properly check for O_RDONLY flag before doing privileged open
2012-07-06 15:32:18 -07:00
Linus Torvalds
c8912f2be3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull target fixes from Nicholas Bellinger:
 "Two minor target fixes.  There is really nothing exciting and/or
  controversial this time around.

  There's one fix from MDR for a RCU debug warning message within tcm_fc
  code (CC'ed to stable), and a small AC fix for qla_target.c based upon
  a recent Coverity static report.

  Also, there is one other outstanding virtio-scsi LUN scanning bugfix
  that has been uncovered with the in-flight tcm_vhost driver over the
  last days, and that needs to make it into 3.5 final too.  This patch
  has been posted to linux-scsi again here:

    http://marc.info/?l=linux-scsi&m=134160609212542&w=2

  and I've asked James to include it in his next PULL request."

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  qla2xxx: print the right array elements in qlt_async_event
  tcm_fc: Resolve suspicious RCU usage warnings
2012-07-06 13:59:50 -07:00
Tyler Hicks
8dc6780587 eCryptfs: Gracefully refuse miscdev file ops on inherited/passed files
File operations on /dev/ecryptfs would BUG() when the operations were
performed by processes other than the process that originally opened the
file. This could happen with open files inherited after fork() or file
descriptors passed through IPC mechanisms. Rather than calling BUG(), an
error code can be safely returned in most situations.

In ecryptfs_miscdev_release(), eCryptfs still needs to handle the
release even if the last file reference is being held by a process that
didn't originally open the file. ecryptfs_find_daemon_by_euid() will not
be successful, so a pointer to the daemon is stored in the file's
private_data. The private_data pointer is initialized when the miscdev
file is opened and only used when the file is released.

https://launchpad.net/bugs/994247

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
2012-07-06 15:51:12 -05:00
Alan Cox
4f1d0f1971 qla2xxx: print the right array elements in qlt_async_event
Based upon Alan's patch from Coverity scan id 793583, these debug
messages in qlt_async_event() should be starting from byte 0, which is
always the Asynchronous Event Status Code from the parent switch statement.

Also, rename reason_code -> login_code following the language used in
2500 FW spec for Port Database Changed (0x8014) -> Port Database Changed
Event Mailbox Register for mailbox[2].

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Chad Dupuis <chad.dupuis@qlogic.com>
Cc: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-07-06 13:09:23 -07:00
Mark Rustad
863555be0c tcm_fc: Resolve suspicious RCU usage warnings
Use rcu_dereference_protected to tell rcu that the ft_lport_lock
is held during ft_lport_create. This resolved "suspicious RCU usage"
warnings when debugging options are turned on.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-07-06 12:52:09 -07:00