Under normal circumstances nilfs_sync_fs() writes out the super block,
which causes a flush of the underlying block device.  But this depends
on the THE_NILFS_SB_DIRTY flag, which is only set if the pointer to the
last segment crosses a segment boundary.  So if only a small amount of
data is written before the call to nilfs_sync_fs(), no flush of the
block device occurs.

In the above case an additional call to blkdev_issue_flush() is needed.
To prevent unnecessary overhead, the new flag nilfs->ns_flushed_device
is introduced, which is cleared whenever new logs are written and set
whenever the block device is flushed.  For convenience the function
nilfs_flush_device() is added, which contains the above logic.
Signed-off-by: NAndreas Rohner <andreas.rohner@gmx.net>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The Linux kernel coding style guidelines suggest not using typedefs for
structure types.  This patch gets rid of the typedef for befs_btree_node.

The following Coccinelle semantic patch detects the case.

@tn1@
type td;
@@

typedef struct { ... } td;

@script:python tf@
td << tn1.td;
tdres;
@@

coccinelle.tdres = td;

@@
type tn1.td;
identifier tf.tdres;
@@

-typedef
 struct
+  tdres
   { ... }
-td
 ;

@@
type tn1.td;
identifier tf.tdres;
@@

-td
+ struct tdres
Signed-off-by: NHimangi Saraogi <himangi774@gmail.com>
Acked-by: NJulia Lawall <julia.lawall@lip6.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit b5ada460 ("drivers/rtc/rtc-cmos.c: fix compilation warning
when !CONFIG_PM_SLEEP") broke wakeup from S5 by making cmos_poweroff a
nop unless CONFIG_PM_SLEEP was defined.

Fix this by restricting the #ifdef to cmos_resume and restoring the old
dependency on CONFIG_PM for cmos_suspend and cmos_poweroff.
Signed-off-by: NDaniel Glöckner <daniel-gl@gmx.net>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some drivers need 'devm_ioremap_resource' or 'devm_ioremap' which need
HAS_IOMEM, so let them depend on it.

The related error (with allmodconfig under score):

    MODPOST 1365 modules
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-xgene.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-stk17ta8.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1742.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1553.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1511.ko] undefined!
  ERROR: "devm_ioremap_resource" [drivers/rtc/rtc-ds1286.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-rp5c01.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-msm6242.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-m48t59.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-m48t35.ko] undefined!
  ERROR: "devm_ioremap" [drivers/rtc/rtc-bq4802.ko] undefined!
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Instead of pushing each byte let's reduce stack usage by using %*ph specifier.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

As pointed out by Sergei Shtylyov, the pcf8563_irq function contains a
bug in the error handling: an interrupt handler is not supposed to
return an errno value but an 'enum irqreturn'.

Let's fix this by returning IRQ_NONE in case of a communication error.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

gcc-4.9 found a potential condition under which the 'pending' variable
may be used uninitialized:

  drivers/rtc/rtc-pcf8563.c: In function 'pcf8563_irq':
  drivers/rtc/rtc-pcf8563.c:173:5: warning: 'pending' may be used uninitialized in this function [-Wmaybe-uninitialized]

This is because in the pcf8563_get_alarm_mode() function, we check any
nonzero return of pcf8563_read_block_data, but in the irq function we
only check for negative values, so a possible positive value does not
get detected if the compiler chooses not to inline the entire call
chain.

Checking for any non-zero value in the interrupt handler as well is just
as correct and lets the compiler know what we are doing, without needing
a bogus initialization.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The MAX7802 PMIC has a Real-Time-Clock (RTC) with two alarms.  This
patch adds support for the RTC and is based on a driver added by Simon
Glass to the Chrome OS kernel 3.8 tree.

[akpm@linux-foundation.org: add comment clarifying ffs() use]
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Cc: Simon Glass <sjg@chromium.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

max77686_rtc_calculate_wday() is used to calculate the day of the week
to be filled in struct rtc_time but that function only calculates the
number of bits shifted.  So the ffs() function can be used to find the
first bit set instead of a special function.

[akpm@linux-foundation.org: add comment clarifying ffs() use]
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If devm_rtc_device_register() fails a dev_err() is already reported so
there is no need to do an additional dev_info().
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The max77686 mfd driver adds a regmap IRQ chip which creates an IRQ
domain that is used to map the virtual RTC alarm1 interrupt.

The RTC driver assumes that this will always be true since the PMIC IRQ
is a required property according to the max77686 DT binding doc.  If an
"interrupts" property is not defined for a max77686 PMIC, then the mfd
probe function will fail and the RTC platform driver will never be
probed.

But even when it is not possible to probe the rtc-max77686 driver
without a regmap IRQ chip, it's better to explicitly check if the IRQ
chip data is not NULL and gracefully fail instead of getting an OOPS.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reported-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The MAX77686 RTC chip has two features called SMPL (Sudden Momentary
Power Loss) and WTSR (Watchdog Timeout and Software Resets).  Support
for these features seems to be implemented in the driver but compilation
is disabled using a C pre-processor conditional.

This code has been disabled since the driver was original merged in
commit fca1dd03 ("rtc: max77686: add Maxim 77686 driver").

So, since this code has never been built, let's just remove it.
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This series add support for the Real Time clock present in the Maxim 77802
Power Managment IC.  The version number is quite high because it
previously was part of a bigger series [0] that aimed to add support for
all the devices in the max77802 PMIC.  But now that the max77802
dependencies were already merged for 3.17, the series were split but I
kept the version numbering.

While working on the max77802 rtc support a lot of feedback was given and
the issues pointed out also apply to a driver for a similar PMIC RTC
(max77686).  So patches 01/06 to 05/06 in the series are cleanups for the
max77686 driver and patch 06/06 adds the support for the max77802 RTC.

The series were tested on an Exynos5250 Snow (max77686) and
Exynos5420 Peach Pit (max77802) machines.

This patch (of 6):

The max77686 includes an RTC that keeps power during suspend.  It's
convenient to be able to use it as a wakeup source.
Signed-off-by: NDoug Anderson <dianders@chromium.org>
Signed-off-by: NJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Reviewed-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

BQ32000 have "trickle chargers".  Introduce a device tree binding for
specifying the trickle charger configuration for that.
Signed-off-by: NPavel Machek <pavel@denx.de>
Reviewed-by: NJason Cooper <jason@lakedameon.net>
Cc: Matti Vaittinen <matti.vaittinen@nsn.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

BQ32000 devices have "trickle chargers".  Introduce a code to enable the
charger, based on device tree.

Without charger, RTC does not keep time after power off.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NPavel Machek <pavel@denx.de>
Cc: Jason Cooper <jason@lakedameon.net>
Cc: Matti Vaittinen <matti.vaittinen@nsn.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some DS13XX devices have "trickle chargers".  Introduce a device tree
binding for specifying the trickle charger configuration for ds1339.

Only ds1339 dt binding is supported because this is the only chip I have.
I _assume_ the code would have worked on other allready supported chips.
However I cannot check the resistor values for the other chips or test
them.  For other chips the driver code works as earlier Eg.  it does not
check the dt bindings at all
Signed-off-by: NMatti Vaittinen <matti.vaittinen@nsn.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Pavel Machek <pavel@denx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some DS13XX devices have "trickle chargers".  Introduce a device tree
binding for the resistor and diode configuration for enabling trickle
charger.
Signed-off-by: NMatti Vaittinen <matti.vaittinen@nsn.com>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Pavel Machek <pavel@denx.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is the initial version of the RK808 PMIC.  This is a power management
IC for multimedia products.  It provides regulators that are able to
supply power to processor cores and other components.  The chip provides
other modules including RTC, Clockout.
Signed-off-by: NChris Zhong <zyw@rock-chips.com>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Tested-by: NDoug Anderson <dianders@chromium.org>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Samuel Ortiz <sameo@linux.intel.com> says:
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Kever Yang <kever.yang@rock-chips.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is the initial version of the RK808 PMIC.  This is a power management
IC for multimedia products.  It provides regulators that are able to
supply power to processor cores and other components.  The chip provides
other modules including RTC, Clockout.

Add RTC driver for supporting RTC device present inside RK808 PMIC.

[akpm@linux-foundation.org: make tm_def static]
Signed-off-by: NChris Zhong <zyw@rock-chips.com>
Signed-off-by: NZhang Qing <zhangqing@rock-chips.com>
Tested-by: NHeiko Stuebner <heiko@sntech.de>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
Tested-by: NDoug Anderson <dianders@chromium.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Samuel Ortiz <sameo@linux.intel.com> says:
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Olof Johansson <olof@lixom.net>
Cc: Dmitry Torokhov <dtor@chromium.org>
Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Cc: Kever Yang <kever.yang@rock-chips.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

of_device_ids (i.e. compatible strings and the respective data) are not
supposed to change at runtime.  All functions working with of_device_ids
provided by <linux/of.h> work with const of_device_ids.  This allows to
mark all struct of_device_id below drivers/rtc const, too.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix wrong compatible string of Exynos3250 RTC (Real-Time Clock) dt node.
The RTC of Exynos3250 must need additional source clock (XrtcXTI).
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for RTC of Exynos3250 SoC.  The Exynos3250 needs source
clock(32.768KHz) for RTC block.  If source clock of RTC is registerd on
clock list of common clk framework, Exynos RTC drvier have to control
this clock.

Clock list for s3c-rtc device:
- rtc : CLK_RTC of CLK_GATE_IP_PERIR is gate clock for RTC.
- rtc_src : XrtcXTI is 32.768.kHz source clock for RTC.
 (XRTCXTI: Specifies a clock from 32.768 kHz crystal pad with XRTCXTI and
 XRTCXTO pins. RTC uses this clock as the source of a real-time clock.)
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add s3c_rtc_data structure to variant data according to SoC type.  The
s3c_rtc_data structure includes some functions to control RTC operation
and specific data dependent on SoC type.
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove warning message when checking codeing style with checkpatch script
and reduce un-necessary i2c read operation on s3c_rtc_enable.

    WARNING: line over 80 characters
    #406: FILE: drivers/rtc/rtc-s3c.c:406:
    +		if ((readw(info->base + S3C2410_RTCCON) & S3C2410_RTCCON_RTCEN) == 0) {

    WARNING: line over 80 characters
    #414: FILE: drivers/rtc/rtc-s3c.c:414:
    +		if ((readw(info->base + S3C2410_RTCCON) & S3C2410_RTCCON_CNTSEL)) {

    WARNING: line over 80 characters
    #422: FILE: drivers/rtc/rtc-s3c.c:422:
    +		if ((readw(info->base + S3C2410_RTCCON) & S3C2410_RTCCON_CLKRST)) {

    WARNING: Missing a blank line after declarations
    #451: FILE: drivers/rtc/rtc-s3c.c:451:
    +	struct s3c_rtc_drv_data *data;
    +	if (pdev->dev.of_node) {

    WARNING: Missing a blank line after declarations
    #453: FILE: drivers/rtc/rtc-s3c.c:453:
    +		const struct of_device_id *match;
    +		match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);

    WARNING: DT compatible string "samsung,s3c2416-rtc" appears un-documented -- check ./Documentation/devicetree/bindings/
    #650: FILE: drivers/rtc/rtc-s3c.c:650:
    +		.compatible = "samsung,s3c2416-rtc",

    WARNING: DT compatible string "samsung,s3c2443-rtc" appears un-documented -- check ./Documentation/devicetree/bindings/
    #653: FILE: drivers/rtc/rtc-s3c.c:653:
    +		.compatible = "samsung,s3c2443-rtc",
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Define s3c_rtc structure including necessary variables for S3C RTC device
instead of global variables.  This patch improves the readability by
removing global variables.
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use c99 initializers for structures.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@decl@
identifier i1,fld;
type T;
field list[n] fs;
@@

struct i1 {
 fs
 T fld;
 ...};

@bad@
identifier decl.i1,i2;
expression e;
initializer list[decl.n] is;
@@

struct i1 i2 = { is,
+ .fld = e
- e
 ,...};
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This documents autofs from the perspective of what the module actually
supports rather than how automount is expected to use it.

It is formatted using "markdown" and works best with Markdown.pl
(markdown_py doesn't like some constructs).

[rdunlap@infradead.org: copy editing]
Signed-off-by: NNeilBrown <neilb@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Acked-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If rcu-walk mode we don't *have* to return -EISDIR for non-mount-traps
as we will simply drop into REF-walk and handling DCACHE_NEED_AUTOMOUNT
dentrys the slow way.  But it is better if we do when possible.

In 'oz_mode', use the same condition as ref-walk: if not a mountpoint,
then it must be -EISDIR.

In regular mode there are most tests needed.  Most of them can be
performed without taking any spinlocks.  If we find a directory that
isn't obviously empty, and isn't mounted on, we need to call
'simple_empty()' which does take a spinlock.  If this turned out to hurt
performance, some other approach could be found to signal when a
directory is known to be empty.
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NIan Kent <raven@themaw.net>
Tested-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

->fs_lock protects AUTOFS_INF_EXPIRING.  We need to be sure that once
the flag is set, no new references beneath the dentry are taken.  So
rcu-walk currently needs to take fs_lock before checking the flag.  This
hurts performance.

Change the expiry to a two-stage process.  First set AUTOFS_INF_NO_RCU
which forces any path walk into ref-walk mode, then drop the lock and
call synchronize_rcu().  Once that returns we can be sure no rcu-walk is
active beneath the dentry and we can check reference counts again.

Now during an RCU-walk we can test AUTOFS_INF_EXPIRING without taking
the lock as along as we test AUTOFS_INF_NO_RCU too.  If either are set,
we must abort the RCU-walk If neither are set, we know that refcounts
will be tested again after we finish the RCU-walk so we are safe to
continue.

->fs_lock is still taken in d_manage() to check for a non-trap
directory.  That will be resolved in the next patch.
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NIan Kent <raven@themaw.net>
Tested-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Have a "test" function change the value it is testing can be confusing,
particularly as a future patch will be calling this function twice.

So move the update for 'last_used' to avoid repeat expiry to the place
where the final determination on what to expire is known.
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NIan Kent <raven@themaw.net>
Tested-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Future patch will potentially call this twice, so make it separate.
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NIan Kent <raven@themaw.net>
Tested-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This series teaches autofs about RCU-walk so that we don't drop straight
into REF-walk when we hit an autofs directory, and so that we avoid
spinlocks as much as possible when performing an RCU-walk.

This is needed so that the benefits of the recent NFS support for
RCU-walk are fully available when NFS filesystems are automounted.

Patches have been carefully reviewed and tested both with test suites
and in production - thanks a lot to Ian Kent for his support there.

This patch (of 6):

Any attempt to look up a pathname that passes though an autofs4 mount is
currently forced out of RCU-walk into REF-walk.

This can significantly hurt performance of many-thread work loads on
many-core systems, especially if the automounted filesystem supports
RCU-walk but doesn't get to benefit from it.

So if autofs4_d_manage is called with rcu_walk set, only fail with -ECHILD
if it is necessary to wait longer than a spinlock.
Signed-off-by: NNeilBrown <neilb@suse.de>
Reviewed-by: NIan Kent <raven@themaw.net>
Tested-by: NIan Kent <raven@themaw.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

sys_tz is already declared in include/linux/time.h
Signed-off-by: NFabian Frederick <fabf@skynet.be>
Cc: Petr Vandrovec <petr@vandrovec.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reduce boilerplate code by using __seq_open_private() instead of
seq_open() in kallsyms_open().
Signed-off-by: NRob Jones <rob.jones@codethink.co.uk>
Cc: Gideon Israel Dsouza <gidisrael@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

gcc-4.9 on ARM gives us a mysterious warning about the binfmt_misc
parse_command function:

  fs/binfmt_misc.c: In function 'parse_command.part.3':
  fs/binfmt_misc.c:405:7: warning: array subscript is above array bounds [-Warray-bounds]

I've managed to trace this back to the ARM implementation of memset,
which is called from copy_from_user in case of a fault and which does

 #define memset(p,v,n)                                                  \
        ({                                                              \
                void *__p = (p); size_t __n = n;                        \
                if ((__n) != 0) {                                       \
                        if (__builtin_constant_p((v)) && (v) == 0)      \
                                __memzero((__p),(__n));                 \
                        else                                            \
                                memset((__p),(v),(__n));                \
                }                                                       \
                (__p);                                                  \
        })

Apparently gcc gets confused by the check for "size != 0" and believes
that the size might be zero when it gets to the line that does "if
(s[count-1] == '\n')", so it would access data outside of the array.

gcc is clearly wrong here, since this condition was already checked
earlier in the function and the 'size' value can not change in the
meantime.

Fortunately, we can work around it and get rid of the warning by
rearranging the function to check for zero size after doing the
copy_from_user.  It is still safe to pass a zero size into
copy_from_user, so it does not cause any side effects.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Line wrap the content to 80 cols, and add more details to various fields
to match the code.  Drop reference to a website that does not exist
anymore.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current code places a 256 byte limit on the registration format.
This ends up being fairly limited when you try to do matching against a
binary format like ELF:

 - the magic & mask formats cannot have any embedded NUL chars
   (string_unescape_inplace halts at the first NUL)
 - each escape sequence quadruples the size: \x00 is needed for NUL
 - trying to match bytes at the start of the file as well as further
   on leads to a lot of \x00 sequences in the mask
 - magic & mask have to be the same length (when decoded)
 - still need bytes for the other fields
 - impossible!

Let's look at a concrete (and common) example: using QEMU to run MIPS
ELFs.  The name field uses 11 bytes "qemu-mipsel".  The interp uses 20
bytes "/usr/bin/qemu-mipsel".  The type & flags takes up 4 bytes.  We
need 7 bytes for the delimiter (usually ":").  We can skip offset.  So
already we're down to 107 bytes to use with the magic/mask instead of
the real limit of 128 (BINPRM_BUF_SIZE).  If people use shell code to
register (which they do the majority of the time), they're down to ~26
possible bytes since the escape sequence must be \x##.

The ELF format looks like (both 32 & 64 bit):

	e_ident: 16 bytes
	e_type: 2 bytes
	e_machine: 2 bytes

Those 20 bytes are enough for most architectures because they have so few
formats in the first place, thus they can be uniquely identified.  That
also means for shell users, since 20 is smaller than 26, they can sanely
register a handler.

But for some targets (like MIPS), we need to poke further.  The ELF fields
continue on:

	e_entry: 4 or 8 bytes
	e_phoff: 4 or 8 bytes
	e_shoff: 4 or 8 bytes
	e_flags: 4 bytes

We only care about e_flags here as that includes the bits to identify
whether the ELF is O32/N32/N64.  But now we have to consume another 16
bytes (for 32 bit ELFs) or 28 bytes (for 64 bit ELFs) just to match the
flags.  If every byte is escaped, we send 288 more bytes to the kernel
((20 {e_ident,e_type,e_machine} + 12 {e_entry,e_phoff,e_shoff} + 4
{e_flags}) * 2 {mask,magic} * 4 {escape}) and we've clearly blown our
budget.

Even if we try to be clever and do the decoding ourselves (rather than
relying on the kernel to process \x##), we still can't hit the mark --
string_unescape_inplace treats mask & magic as C strings so NUL cannot
be embedded.  That leaves us with having to pass \x00 for the 12/24
entry/phoff/shoff bytes (as those will be completely random addresses),
and that is a minimum requirement of 48/96 bytes for the mask alone.
Add up the rest and we blow through it (this is for 64 bit ELFs):
magic: 20 {e_ident,e_type,e_machine} + 24 {e_entry,e_phoff,e_shoff} +
       4 {e_flags} = 48              # ^^ See note below.
mask: 20 {e_ident,e_type,e_machine} + 96 {e_entry,e_phoff,e_shoff} +
       4 {e_flags} = 120
Remember above we had 107 left over, and now we're at 168.  This is of
course the *best* case scenario -- you'll also want to have NUL bytes
in the magic & mask too to match literal zeros.

Note: the reason we can use 24 in the magic is that we can work off of the
fact that for bytes the mask would clobber, we can stuff any value into
magic that we want.  So when mask is \x00, we don't need the magic to also
be \x00, it can be an unescaped raw byte like '!'.  This lets us handle
more formats (barely) under the current 256 limit, but that's a pretty
tall hoop to force people to jump through.

With all that said, let's bump the limit from 256 bytes to 1920.  This way
we support escaping every byte of the mask & magic field (which is 1024
bytes by themselves -- 128 * 4 * 2), and we leave plenty of room for other
fields.  Like long paths to the interpreter (when you have source in your
/really/long/homedir/qemu/foo).  Since the current code stuffs more than
one structure into the same buffer, we leave a bit of space to easily
round up to 2k.  1920 is just as arbitrary as 256 ;).
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Warn on probable misuses of logging functions with KERN_<LEVEL>
like pr_err(KERN_ERR "foo\n");
Signed-off-by: NJoe Perches <joe@perches.com>
Suggested-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add an exception to the return before else warning when the line
following it is also a return like:

	if (foo)
		return bar;
	else
		return baz;

This form of a test then return is at least as readable as

	if (foo)
		return bar;
	return baz;

so don't emit a warning on the first form.
Signed-off-by: NJoe Perches <joe@perches.com>
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Cc: Elshad Mustafayev <elshadimo@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Check for misspellings, based on Debian's lintian list.  Several false
positives were removed, and several additional words added that were
common in the kernel:

	backword backwords
	invalide valide
	recieves
	singed unsinged

While going back and fixing existing spelling mistakes isn't a high
priority, it'd be nice to try to catch them before they hit the tree.

In the 13830 commits between 3.15 and 3.16, the script would have noticed
560 spelling mistakes. The top 25 are shown here:

$ git log --pretty=oneline v3.15..v3.16 | wc -l
13830
$ git log --format='%H' v3.15..v3.16 | \
   while read commit ; do \
     echo "commit $commit" ; \
     git log --format=email --stat -p -1 $commit | \
       ./scripts/checkpatch.pl --types=typo_spelling --no-summary - ; \
   done | tee spell_v3.15..v3.16.txt | grep "may be misspelled" | \
   awk '{print $2}' | tr A-Z a-z | sort | uniq -c | sort -rn
     21 'seperate'
     17 'endianess'
     15 'sucess'
     13 'noticable'
     11 'occured'
     11 'accomodate'
     10 'interrup'
      9 'prefered'
      8 'unecessary'
      8 'explicitely'
      7 'supress'
      7 'overriden'
      7 'immediatly'
      7 'funtion'
      7 'defult'
      7 'childs'
      6 'succesful'
      6 'splitted'
      6 'specifc'
      6 'reseting'
      6 'recieve'
      6 'changable'
      5 'tmis'
      5 'singed'
      5 'preceeding'

Thanks to Joe Perches for rewrites, suggestions, additional misspelling
entries, and testing.
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NJoe Perches <joe@perches.com>
Cc: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>