Commit Graph

2400 Commits

Author SHA1 Message Date
Jens Axboe
35d37c6635 Revert "blk-mq: Micro-optimize bt_get()"
This reverts commit 52f7eb945f.

The optimization is only really safe for a single queue, otherwise
'bs' and 'bt' can indeed change, and if we don't do a finish_wait()
for each loop, we'll potentially change the wait structure and
corrupt task wait list.

Reported-by: Jan Kara <jack@suse.cz>
2014-12-15 08:30:26 -07:00
Linus Torvalds
caf292ae5b Merge branch 'for-3.19/core' of git://git.kernel.dk/linux-block
Pull block driver core update from Jens Axboe:
 "This is the pull request for the core block IO changes for 3.19.  Not
  a huge round this time, mostly lots of little good fixes:

   - Fix a bug in sysfs blktrace interface causing a NULL pointer
     dereference, when enabled/disabled through that API.  From Arianna
     Avanzini.

   - Various updates/fixes/improvements for blk-mq:

        - A set of updates from Bart, mostly fixing buts in the tag
          handling.

        - Cleanup/code consolidation from Christoph.

        - Extend queue_rq API to be able to handle batching issues of IO
          requests. NVMe will utilize this shortly. From me.

        - A few tag and request handling updates from me.

        - Cleanup of the preempt handling for running queues from Paolo.

        - Prevent running of unmapped hardware queues from Ming Lei.

        - Move the kdump memory limiting check to be in the correct
          location, from Shaohua.

        - Initialize all software queues at init time from Takashi. This
          prevents a kobject warning when CPUs are brought online that
          weren't online when a queue was registered.

   - Single writeback fix for I_DIRTY clearing from Tejun.  Queued with
     the core IO changes, since it's just a single fix.

   - Version X of the __bio_add_page() segment addition retry from
     Maurizio.  Hope the Xth time is the charm.

   - Documentation fixup for IO scheduler merging from Jan.

   - Introduce (and use) generic IO stat accounting helpers for non-rq
     drivers, from Gu Zheng.

   - Kill off artificial limiting of max sectors in a request from
     Christoph"

* 'for-3.19/core' of git://git.kernel.dk/linux-block: (26 commits)
  bio: modify __bio_add_page() to accept pages that don't start a new segment
  blk-mq: Fix uninitialized kobject at CPU hotplugging
  blktrace: don't let the sysfs interface remove trace from running list
  blk-mq: Use all available hardware queues
  blk-mq: Micro-optimize bt_get()
  blk-mq: Fix a race between bt_clear_tag() and bt_get()
  blk-mq: Avoid that __bt_get_word() wraps multiple times
  blk-mq: Fix a use-after-free
  blk-mq: prevent unmapped hw queue from being scheduled
  blk-mq: re-check for available tags after running the hardware queue
  blk-mq: fix hang in bt_get()
  blk-mq: move the kdump check to blk_mq_alloc_tag_set
  blk-mq: cleanup tag free handling
  blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
  blk: introduce generic io stat accounting help function
  blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
  genhd: check for int overflow in disk_expand_part_tbl()
  blk-mq: add blk_mq_free_hctx_request()
  blk-mq: export blk_mq_free_request()
  blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
  ...
2014-12-13 14:14:23 -08:00
Maurizio Lombardi
fcbf6a087a bio: modify __bio_add_page() to accept pages that don't start a new segment
The original behaviour is to refuse to add a new page if the maximum
number of segments has been reached, regardless of the fact the page we
are going to add can be merged into the last segment or not.

Unfortunately, when the system runs under heavy memory fragmentation
conditions, a driver may try to add multiple pages to the last segment.
The original code won't accept them and EBUSY will be reported to
userspace.

This patch modifies the function so it refuses to add a page only in case
the latter starts a new segment and the maximum number of segments has
already been reached.

The bug can be easily reproduced with the st driver:

1) set CONFIG_SCSI_MPT2SAS_MAX_SGE or CONFIG_SCSI_MPT3SAS_MAX_SGE  to 16
2) modprobe st buffer_kbs=1024
3) #dd if=/dev/zero of=/dev/st0 bs=1M count=10
   dd: error writing `/dev/st0': Device or resource busy

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Ming Lei <ming.lei@canonical.com>
Cc: Jet Chen <jet.chen@intel.com>
Cc: Tomas Henzl <thenzl@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-11 09:11:52 -07:00
Linus Torvalds
92a578b064 ACPI and power management updates for 3.19-rc1
This time we have some more new material than we used to have during
 the last couple of development cycles.
 
 The most important part of it to me is the introduction of a unified
 interface for accessing device properties provided by platform
 firmware.  It works with Device Trees and ACPI in a uniform way and
 drivers using it need not worry about where the properties come
 from as long as the platform firmware (either DT or ACPI) makes
 them available.  It covers both devices and "bare" device node
 objects without struct device representation as that turns out to
 be necessary in some cases.  This has been in the works for quite
 a few months (and development cycles) and has been approved by
 all of the relevant maintainers.
 
 On top of that, some drivers are switched over to the new interface
 (at25, leds-gpio, gpio_keys_polled) and some additional changes are
 made to the core GPIO subsystem to allow device drivers to manipulate
 GPIOs in the "canonical" way on platforms that provide GPIO information
 in their ACPI tables, but don't assign names to GPIO lines (in which
 case the driver needs to do that on the basis of what it knows about
 the device in question).  That also has been approved by the GPIO
 core maintainers and the rfkill driver is now going to use it.
 
 Second is support for hardware P-states in the intel_pstate driver.
 It uses CPUID to detect whether or not the feature is supported by
 the processor in which case it will be enabled by default.  However,
 it can be disabled entirely from the kernel command line if necessary.
 
 Next is support for a platform firmware interface based on ACPI
 operation regions used by the PMIC (Power Management Integrated
 Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
 That interface is used for manipulating power resources and for
 thermal management: sensor temperature reporting, trip point setting
 and so on.
 
 Also the ACPI core is now going to support the _DEP configuration
 information in a limited way.  Basically, _DEP it supposed to reflect
 off-the-hierarchy dependencies between devices which may be very
 indirect, like when AML for one device accesses locations in an
 operation region handled by another device's driver (usually, the
 device depended on this way is a serial bus or GPIO controller).
 The support added this time is sufficient to make the ACPI battery
 driver work on Asus T100A, but it is general enough to be able to
 cover some other use cases in the future.
 
 Finally, we have a new cpufreq driver for the Loongson1B processor.
 
 In addition to the above, there are fixes and cleanups all over the
 place as usual and a traditional ACPICA update to a recent upstream
 release.
 
 As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver
 for Intel platforms should be able to handle power management of
 the DMA engine correctly, the cpufreq-dt driver should interact
 with the thermal subsystem in a better way and the ACPI backlight
 driver should handle some more corner cases, among other things.
 
 On top of the ACPICA update there are fixes for race conditions
 in the ACPICA's interrupt handling code which might lead to some
 random and strange looking failures on some systems.
 
 In the cleanups department the most visible part is the series
 of commits targeted at getting rid of the CONFIG_PM_RUNTIME
 configuration option.  That was triggered by a discussion
 regarding the generic power domains code during which we realized
 that trying to support certain combinations of PM config options
 was painful and not really worth it, because nobody would use them
 in production anyway.  For this reason, we decided to make
 CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and that lead to the
 conclusion that the latter became redundant and CONFIG_PM could
 be used instead of it.  The material here makes that replacement
 in a major part of the tree, but there will be at least one more
 batch of that in the second part of the merge window.
 
 Specifics:
 
  - Support for retrieving device properties information from ACPI
    _DSD device configuration objects and a unified device properties
    interface for device drivers (and subsystems) on top of that.
    As stated above, this works with Device Trees and ACPI and allows
    device drivers to be written in a platform firmware (DT or ACPI)
    agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers
    are now going to use this new interface and the GPIO subsystem
    is additionally modified to allow device drivers to assign names
    to GPIO resources returned by ACPI _CRS objects (in case _DSD is
    not present or does not provide the expected data).  The changes
    in this set are mostly from Mika Westerberg, Rafael J Wysocki,
    Aaron Lu, and Darren Hart with some fixes from others (Fabio Estevam,
    Geert Uytterhoeven).
 
  - Support for Hardware Managed Performance States (HWP) as described
    in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
    driver.  CPUID is used to detect whether or not the feature is
    supported by the processor.  If supported, it will be enabled
    automatically unless the intel_pstate=no_hwp switch is present in
    the kernel command line.  From Dirk Brandewie.
 
  - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).
 
  - Support for firmware interface based on ACPI operation regions
    used by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
    platforms for power resource control and thermal management
    (Aaron Lu).
 
  - Limited support for retrieving off-the-hierarchy dependencies
    between devices from ACPI _DEP device configuration objects
    and deferred probing support for the ACPI battery driver based
    on the _DEP information to make that driver work on Asus T100A
    (Lan Tianyu).
 
  - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).
 
  - ACPICA update to upstream revision 20141107 which only affects
    tools (Bob Moore).
 
  - Fixes for race conditions in the ACPICA's interrupt handling
    code and in the ACPI code related to system suspend and resume
    (Lv Zheng and Rafael J Wysocki).
 
  - ACPI core fix for an RCU-related issue in the ioremap() regions
    management code that slowed down significantly after CPUs had
    been allowed to enter idle states even if they'd had RCU callbakcs
    queued and triggered some problems in certain proprietary graphics
    driver (and elsewhere).  The fix replaces synchronize_rcu() in
    that code with synchronize_rcu_expedited() which makes the issue
    go away.  From Konstantin Khlebnikov.
 
  - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
    management of the DMA engine included into the LPSS correctly.
    The problem is that the DMA engine doesn't have ACPI PM support
    of its own and it simply is turned off when the last LPSS device
    having ACPI PM support goes into D3cold.  To work around that,
    the PM domain used by the ACPI LPSS driver is redesigned so at
    least one device with ACPI PM support will be on as long as the
    DMA engine is in use.  From Andy Shevchenko.
 
  - ACPI backlight driver fix to avoid using it on "Win8-compatible"
    systems where it doesn't work and where it was used by default by
    mistake (Aaron Lu).
 
  - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
    Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and
    Ashwin Chaugule (mostly related to the upcoming ARM64 support).
 
  - Intel RAPL (Running Average Power Limit) power capping driver
    fixes and improvements including new processor IDs (Jacob Pan).
 
  - Generic power domains modification to power up domains after
    attaching devices to them to meet the expectations of device
    drivers and bus types assuming devices to be accessible at
    probe time (Ulf Hansson).
 
  - Preliminary support for controlling device clocks from the
    generic power domains core code and modifications of the
    ARM/shmobile platform to use that feature (Ulf Hansson).
 
  - Assorted minor fixes and cleanups of the generic power
    domains core code (Ulf Hansson, Geert Uytterhoeven).
 
  - Assorted minor fixes and cleanups of the device clocks control
    code in the PM core (Geert Uytterhoeven, Grygorii Strashko).
 
  - Consolidation of device power management Kconfig options by making
    CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
    which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
    is the first batch of the changes needed for this purpose.
 
  - Core device runtime power management support code cleanup related
    to the execution of callbacks (Andrzej Hajda).
 
  - cpuidle ARM support improvements (Lorenzo Pieralisi).
 
  - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and
    a new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
    Bartlomiej Zolnierkiewicz).
 
  - New cpufreq driver callback (->ready) to be executed when the
    cpufreq core is ready to use a given policy object and cpufreq-dt
    driver modification to use that callback for cooling device
    registration (Viresh Kumar).
 
  - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu,
    James Geboski, Tomeu Vizoso).
 
  - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
    cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
    Stefan Wahren, Petr Cvek).
 
  - OPP (Operating Performance Points) framework modification to
    allow OPPs to be removed too and update of a few cpufreq drivers
    (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
    during initialization) on driver removal (Viresh Kumar).
 
  - Hibernation core fixes and cleanups (Tina Ruchandani and
    Markus Elfring).
 
  - PM Kconfig fix related to CPU power management (Pankaj Dubey).
 
  - cpupower tool fix (Prarit Bhargava).
 
 /
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Merge tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management updates from Rafael Wysocki:
 "This time we have some more new material than we used to have during
  the last couple of development cycles.

  The most important part of it to me is the introduction of a unified
  interface for accessing device properties provided by platform
  firmware.  It works with Device Trees and ACPI in a uniform way and
  drivers using it need not worry about where the properties come from
  as long as the platform firmware (either DT or ACPI) makes them
  available.  It covers both devices and "bare" device node objects
  without struct device representation as that turns out to be necessary
  in some cases.  This has been in the works for quite a few months (and
  development cycles) and has been approved by all of the relevant
  maintainers.

  On top of that, some drivers are switched over to the new interface
  (at25, leds-gpio, gpio_keys_polled) and some additional changes are
  made to the core GPIO subsystem to allow device drivers to manipulate
  GPIOs in the "canonical" way on platforms that provide GPIO
  information in their ACPI tables, but don't assign names to GPIO lines
  (in which case the driver needs to do that on the basis of what it
  knows about the device in question).  That also has been approved by
  the GPIO core maintainers and the rfkill driver is now going to use
  it.

  Second is support for hardware P-states in the intel_pstate driver.
  It uses CPUID to detect whether or not the feature is supported by the
  processor in which case it will be enabled by default.  However, it
  can be disabled entirely from the kernel command line if necessary.

  Next is support for a platform firmware interface based on ACPI
  operation regions used by the PMIC (Power Management Integrated
  Circuit) chips on the Intel Baytrail-T and Baytrail-T-CR platforms.
  That interface is used for manipulating power resources and for
  thermal management: sensor temperature reporting, trip point setting
  and so on.

  Also the ACPI core is now going to support the _DEP configuration
  information in a limited way.  Basically, _DEP it supposed to reflect
  off-the-hierarchy dependencies between devices which may be very
  indirect, like when AML for one device accesses locations in an
  operation region handled by another device's driver (usually, the
  device depended on this way is a serial bus or GPIO controller).  The
  support added this time is sufficient to make the ACPI battery driver
  work on Asus T100A, but it is general enough to be able to cover some
  other use cases in the future.

  Finally, we have a new cpufreq driver for the Loongson1B processor.

  In addition to the above, there are fixes and cleanups all over the
  place as usual and a traditional ACPICA update to a recent upstream
  release.

  As far as the fixes go, the ACPI LPSS (Low-power Subsystem) driver for
  Intel platforms should be able to handle power management of the DMA
  engine correctly, the cpufreq-dt driver should interact with the
  thermal subsystem in a better way and the ACPI backlight driver should
  handle some more corner cases, among other things.

  On top of the ACPICA update there are fixes for race conditions in the
  ACPICA's interrupt handling code which might lead to some random and
  strange looking failures on some systems.

  In the cleanups department the most visible part is the series of
  commits targeted at getting rid of the CONFIG_PM_RUNTIME configuration
  option.  That was triggered by a discussion regarding the generic
  power domains code during which we realized that trying to support
  certain combinations of PM config options was painful and not really
  worth it, because nobody would use them in production anyway.  For
  this reason, we decided to make CONFIG_PM_SLEEP select
  CONFIG_PM_RUNTIME and that lead to the conclusion that the latter
  became redundant and CONFIG_PM could be used instead of it.  The
  material here makes that replacement in a major part of the tree, but
  there will be at least one more batch of that in the second part of
  the merge window.

  Specifics:

   - Support for retrieving device properties information from ACPI _DSD
     device configuration objects and a unified device properties
     interface for device drivers (and subsystems) on top of that.  As
     stated above, this works with Device Trees and ACPI and allows
     device drivers to be written in a platform firmware (DT or ACPI)
     agnostic way.  The at25, leds-gpio and gpio_keys_polled drivers are
     now going to use this new interface and the GPIO subsystem is
     additionally modified to allow device drivers to assign names to
     GPIO resources returned by ACPI _CRS objects (in case _DSD is not
     present or does not provide the expected data).  The changes in
     this set are mostly from Mika Westerberg, Rafael J Wysocki, Aaron
     Lu, and Darren Hart with some fixes from others (Fabio Estevam,
     Geert Uytterhoeven).

   - Support for Hardware Managed Performance States (HWP) as described
     in Volume 3, section 14.4, of the Intel SDM in the intel_pstate
     driver.  CPUID is used to detect whether or not the feature is
     supported by the processor.  If supported, it will be enabled
     automatically unless the intel_pstate=no_hwp switch is present in
     the kernel command line.  From Dirk Brandewie.

   - New Intel Broadwell-H ID for intel_pstate (Dirk Brandewie).

   - Support for firmware interface based on ACPI operation regions used
     by the PMIC chips on the Intel Baytrail-T and Baytrail-T-CR
     platforms for power resource control and thermal management (Aaron
     Lu).

   - Limited support for retrieving off-the-hierarchy dependencies
     between devices from ACPI _DEP device configuration objects and
     deferred probing support for the ACPI battery driver based on the
     _DEP information to make that driver work on Asus T100A (Lan
     Tianyu).

   - New cpufreq driver for the Loongson1B processor (Kelvin Cheung).

   - ACPICA update to upstream revision 20141107 which only affects
     tools (Bob Moore).

   - Fixes for race conditions in the ACPICA's interrupt handling code
     and in the ACPI code related to system suspend and resume (Lv Zheng
     and Rafael J Wysocki).

   - ACPI core fix for an RCU-related issue in the ioremap() regions
     management code that slowed down significantly after CPUs had been
     allowed to enter idle states even if they'd had RCU callbakcs
     queued and triggered some problems in certain proprietary graphics
     driver (and elsewhere).  The fix replaces synchronize_rcu() in that
     code with synchronize_rcu_expedited() which makes the issue go
     away.  From Konstantin Khlebnikov.

   - ACPI LPSS (Low-Power Subsystem) driver fix to handle power
     management of the DMA engine included into the LPSS correctly.  The
     problem is that the DMA engine doesn't have ACPI PM support of its
     own and it simply is turned off when the last LPSS device having
     ACPI PM support goes into D3cold.  To work around that, the PM
     domain used by the ACPI LPSS driver is redesigned so at least one
     device with ACPI PM support will be on as long as the DMA engine is
     in use.  From Andy Shevchenko.

   - ACPI backlight driver fix to avoid using it on "Win8-compatible"
     systems where it doesn't work and where it was used by default by
     mistake (Aaron Lu).

   - Assorted minor ACPI core fixes and cleanups from Tomasz Nowicki,
     Sudeep Holla, Huang Rui, Hanjun Guo, Fabian Frederick, and Ashwin
     Chaugule (mostly related to the upcoming ARM64 support).

   - Intel RAPL (Running Average Power Limit) power capping driver fixes
     and improvements including new processor IDs (Jacob Pan).

   - Generic power domains modification to power up domains after
     attaching devices to them to meet the expectations of device
     drivers and bus types assuming devices to be accessible at probe
     time (Ulf Hansson).

   - Preliminary support for controlling device clocks from the generic
     power domains core code and modifications of the ARM/shmobile
     platform to use that feature (Ulf Hansson).

   - Assorted minor fixes and cleanups of the generic power domains core
     code (Ulf Hansson, Geert Uytterhoeven).

   - Assorted minor fixes and cleanups of the device clocks control code
     in the PM core (Geert Uytterhoeven, Grygorii Strashko).

   - Consolidation of device power management Kconfig options by making
     CONFIG_PM_SLEEP select CONFIG_PM_RUNTIME and removing the latter
     which is now redundant (Rafael J Wysocki and Kevin Hilman).  That
     is the first batch of the changes needed for this purpose.

   - Core device runtime power management support code cleanup related
     to the execution of callbacks (Andrzej Hajda).

   - cpuidle ARM support improvements (Lorenzo Pieralisi).

   - cpuidle cleanup related to the CPUIDLE_FLAG_TIME_VALID flag and a
     new MAINTAINERS entry for ARM Exynos cpuidle (Daniel Lezcano and
     Bartlomiej Zolnierkiewicz).

   - New cpufreq driver callback (->ready) to be executed when the
     cpufreq core is ready to use a given policy object and cpufreq-dt
     driver modification to use that callback for cooling device
     registration (Viresh Kumar).

   - cpufreq core fixes and cleanups (Viresh Kumar, Vince Hsu, James
     Geboski, Tomeu Vizoso).

   - Assorted fixes and cleanups in the cpufreq-pcc, intel_pstate,
     cpufreq-dt, pxa2xx cpufreq drivers (Lenny Szubowicz, Ethan Zhao,
     Stefan Wahren, Petr Cvek).

   - OPP (Operating Performance Points) framework modification to allow
     OPPs to be removed too and update of a few cpufreq drivers
     (cpufreq-dt, exynos5440, imx6q, cpufreq) to remove OPPs (added
     during initialization) on driver removal (Viresh Kumar).

   - Hibernation core fixes and cleanups (Tina Ruchandani and Markus
     Elfring).

   - PM Kconfig fix related to CPU power management (Pankaj Dubey).

   - cpupower tool fix (Prarit Bhargava)"

* tag 'pm+acpi-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (120 commits)
  i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
  dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  tools: cpupower: fix return checks for sysfs_get_idlestate_count()
  drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
  MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  leds: leds-gpio: Fix multiple instances registration without 'label' property
  iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
  block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
  PM: Merge the SET*_RUNTIME_PM_OPS() macros
  ...
2014-12-10 21:17:00 -08:00
Takashi Iwai
06a41a99d1 blk-mq: Fix uninitialized kobject at CPU hotplugging
When a CPU is hotplugged, the current blk-mq spews a warning like:

  kobject '(null)' (ffffe8ffffc8b5d8): tried to add an uninitialized object, something is seriously wrong.
  CPU: 1 PID: 1386 Comm: systemd-udevd Not tainted 3.18.0-rc7-2.g088d59b-default #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_171129-lamiak 04/01/2014
   0000000000000000 0000000000000002 ffffffff81605f07 ffffe8ffffc8b5d8
   ffffffff8132c7a0 ffff88023341d370 0000000000000020 ffff8800bb05bd58
   ffff8800bb05bd08 000000000000a0a0 000000003f441940 0000000000000007
  Call Trace:
   [<ffffffff81005306>] dump_trace+0x86/0x330
   [<ffffffff81005644>] show_stack_log_lvl+0x94/0x170
   [<ffffffff81006d21>] show_stack+0x21/0x50
   [<ffffffff81605f07>] dump_stack+0x41/0x51
   [<ffffffff8132c7a0>] kobject_add+0xa0/0xb0
   [<ffffffff8130aee1>] blk_mq_register_hctx+0x91/0xb0
   [<ffffffff8130b82e>] blk_mq_sysfs_register+0x3e/0x60
   [<ffffffff81309298>] blk_mq_queue_reinit_notify+0xf8/0x190
   [<ffffffff8107cfdc>] notifier_call_chain+0x4c/0x70
   [<ffffffff8105fd23>] cpu_notify+0x23/0x50
   [<ffffffff81060037>] _cpu_up+0x157/0x170
   [<ffffffff810600d9>] cpu_up+0x89/0xb0
   [<ffffffff815fa5b5>] cpu_subsys_online+0x35/0x80
   [<ffffffff814323cd>] device_online+0x5d/0xa0
   [<ffffffff81432485>] online_store+0x75/0x80
   [<ffffffff81236a5a>] kernfs_fop_write+0xda/0x150
   [<ffffffff811c5532>] vfs_write+0xb2/0x1f0
   [<ffffffff811c5f42>] SyS_write+0x42/0xb0
   [<ffffffff8160c4ed>] system_call_fastpath+0x16/0x1b
   [<00007f0132fb24e0>] 0x7f0132fb24e0

This is indeed because of an uninitialized kobject for blk_mq_ctx.
The blk_mq_ctx kobjects are initialized in blk_mq_sysfs_init(), but it
goes loop over hctx_for_each_ctx(), i.e. it initializes only for
online CPUs.  Thus, when a CPU is hotplugged, the ctx for the newly
onlined CPU is registered without initialization.

This patch fixes the issue by initializing the all ctx kobjects
belonging to each queue.

Bugzilla: https://bugzilla.novell.com/show_bug.cgi?id=908794
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-10 08:57:31 -07:00
Bart Van Assche
959f5f5b2f blk-mq: Use all available hardware queues
Suppose that a system has two CPU sockets, three cores per socket,
that it does not support hyperthreading and that four hardware
queues are provided by a block driver. With the current algorithm
this will lead to the following assignment of CPU cores to hardware
queues:

  HWQ 0: 0 1
  HWQ 1: 2 3
  HWQ 2: 4 5
  HWQ 3: (none)

This patch changes the queue assignment into:

  HWQ 0: 0 1
  HWQ 1: 2
  HWQ 2: 3 4
  HWQ 3: 5

In other words, this patch has the following three effects:
- All four hardware queues are used instead of only three.
- CPU cores are spread more evenly over hardware queues. For the
  above example the range of the number of CPU cores associated
  with a single HWQ is reduced from [0..2] to [1..2].
- If the number of HWQ's is a multiple of the number of CPU sockets
  it is now guaranteed that all CPU cores associated with a single
  HWQ reside on the same CPU socket.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 09:08:21 -07:00
Bart Van Assche
52f7eb945f blk-mq: Micro-optimize bt_get()
Remove a superfluous finish_wait() call. Convert the two bt_wait_ptr()
calls into a single call.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robert Elliott <elliott@hp.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 09:07:28 -07:00
Bart Van Assche
c38d185d4a blk-mq: Fix a race between bt_clear_tag() and bt_get()
What we need is the following two guarantees:
* Any thread that observes the effect of the test_and_set_bit() by
  __bt_get_word() also observes the preceding addition of 'current'
  to the appropriate wait list. This is guaranteed by the semantics
  of the spin_unlock() operation performed by prepare_and_wait().
  Hence the conversion of test_and_set_bit_lock() into
  test_and_set_bit().
* The wait lists are examined by bt_clear() after the tag bit has
  been cleared. clear_bit_unlock() guarantees that any thread that
  observes that the bit has been cleared also observes the store
  operations preceding clear_bit_unlock(). However,
  clear_bit_unlock() does not prevent that the wait lists are examined
  before that the tag bit is cleared. Hence the addition of a memory
  barrier between clear_bit() and the wait list examination.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robert Elliott <elliott@hp.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 09:07:16 -07:00
Bart Van Assche
9e98e9d7cf blk-mq: Avoid that __bt_get_word() wraps multiple times
If __bt_get_word() is called with last_tag != 0, if the first
find_next_zero_bit() fails, if after wrap-around the
test_and_set_bit() call fails and find_next_zero_bit() succeeds,
if the next test_and_set_bit() call fails and subsequently
find_next_zero_bit() does not find a zero bit, then another
wrap-around will occur. Avoid this by introducing an additional
local variable.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robert Elliott <elliott@hp.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 09:07:14 -07:00
Bart Van Assche
45a9c9d909 blk-mq: Fix a use-after-free
blk-mq users are allowed to free the memory request_queue.tag_set
points at after blk_cleanup_queue() has finished but before
blk_release_queue() has started. This can happen e.g. in the SCSI
core. The SCSI core namely embeds the tag_set structure in a SCSI
host structure. The SCSI host structure is freed by
scsi_host_dev_release(). This function is called after
blk_cleanup_queue() finished but can be called before
blk_release_queue().

This means that it is not safe to access request_queue.tag_set from
inside blk_release_queue(). Hence remove the blk_sync_queue() call
from blk_release_queue(). This call is not necessary - outstanding
requests must have finished before blk_release_queue() is
called. Additionally, move the blk_mq_free_queue() call from
blk_release_queue() to blk_cleanup_queue() to avoid that struct
request_queue.tag_set gets accessed after it has been freed.

This patch avoids that the following kernel oops can be triggered
when deleting a SCSI host for which scsi-mq was enabled:

Call Trace:
 [<ffffffff8109a7c4>] lock_acquire+0xc4/0x270
 [<ffffffff814ce111>] mutex_lock_nested+0x61/0x380
 [<ffffffff812575f0>] blk_mq_free_queue+0x30/0x180
 [<ffffffff8124d654>] blk_release_queue+0x84/0xd0
 [<ffffffff8126c29b>] kobject_cleanup+0x7b/0x1a0
 [<ffffffff8126c140>] kobject_put+0x30/0x70
 [<ffffffff81245895>] blk_put_queue+0x15/0x20
 [<ffffffff8125c409>] disk_release+0x99/0xd0
 [<ffffffff8133d056>] device_release+0x36/0xb0
 [<ffffffff8126c29b>] kobject_cleanup+0x7b/0x1a0
 [<ffffffff8126c140>] kobject_put+0x30/0x70
 [<ffffffff8125a78a>] put_disk+0x1a/0x20
 [<ffffffff811d4cb5>] __blkdev_put+0x135/0x1b0
 [<ffffffff811d56a0>] blkdev_put+0x50/0x160
 [<ffffffff81199eb4>] kill_block_super+0x44/0x70
 [<ffffffff8119a2a4>] deactivate_locked_super+0x44/0x60
 [<ffffffff8119a87e>] deactivate_super+0x4e/0x70
 [<ffffffff811b9833>] cleanup_mnt+0x43/0x90
 [<ffffffff811b98d2>] __cleanup_mnt+0x12/0x20
 [<ffffffff8107252c>] task_work_run+0xac/0xe0
 [<ffffffff81002c01>] do_notify_resume+0x61/0xa0
 [<ffffffff814d2c58>] int_signal+0x12/0x17

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robert Elliott <elliott@hp.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: <stable@vger.kernel.org> # v3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-09 09:07:13 -07:00
Linus Torvalds
f3f62a38ce SCSI for-linus on 20141208
This patch is the usual mix of driver updates (srp, ipr, scsi_debug, NCR5380,
 fnic, 53c974, ses, wd719x, hpsa, megaraid_sas).  Of those, wd7a9x is new and
 53c974 is a rewrite of the old tmscsim driver and the extensive work by Finn
 Thain rewrites all the NCR5380 based drivers.  There's also extensive
 infrastructure updates: a new logging infrastructure for sense information and
 a rewrite of the tagged command queue API and an assortment of minor updates.
 
 Signed-off-by: James Bottomley <JBottomley@Parallels.com>
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Merge tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI updates from James Bottomley:
 "This patch is the usual mix of driver updates (srp, ipr, scsi_debug,
  NCR5380, fnic, 53c974, ses, wd719x, hpsa, megaraid_sas).

  Of those, wd7a9x is new and 53c974 is a rewrite of the old tmscsim
  driver and the extensive work by Finn Thain rewrites all the NCR5380
  based drivers.

  There's also extensive infrastructure updates: a new logging
  infrastructure for sense information and a rewrite of the tagged
  command queue API and an assortment of minor updates"

* tag 'scsi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (183 commits)
  scsi: set fmt to NULL scsi_extd_sense_format() by default
  libsas: remove task_collector mode
  wd719x: remove dma_cache_sync call
  scsi_debug: add Report supported opcodes+tmfs; Compare and write
  scsi_debug: change SCSI command parser to table driven
  scsi_debug: add Capacity Changed Unit Attention
  scsi_debug: append inject error flags onto scsi_cmnd object
  scsi_debug: pinpoint invalid field in sense data
  wd719x: Add firmware documentation
  wd719x: Introduce Western Digital WD7193/7197/7296 PCI SCSI card driver
  eeprom-93cx6: Add (read-only) support for 8-bit mode
  esas2r: fix an oversight in setting return value
  esas2r: fix an error path in esas2r_ioctl_handler
  esas2r: fir error handling in do_fm_api
  scsi: add SPC-3 command definitions
  scsi: rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16
  scsi: remove scsi_driver owner field
  scsi: move scsi_dispatch_cmd to scsi_lib.c
  scsi: stop passing a gfp_mask argument down the command setup path
  scsi: remove scsi_next_command
  ...
2014-12-08 21:19:19 -08:00
Ming Lei
19c66e59ce blk-mq: prevent unmapped hw queue from being scheduled
When one hardware queue has no mapped software queues, it
shouldn't have been scheduled. Otherwise WARNING or OOPS
can triggered.

blk_mq_hw_queue_mapped() helper is introduce for fixing
the problem.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-08 21:37:08 -07:00
Rafael J. Wysocki
e3d857e1ae Merge branch 'pm-runtime'
* pm-runtime: (25 commits)
  i2c-omap / PM: Drop CONFIG_PM_RUNTIME from i2c-omap.c
  dmaengine / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drivers: sh / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  e1000e / igb / PM: Eliminate CONFIG_PM_RUNTIME
  MMC / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  MFD / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  misc / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  media / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  input / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  iio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hsi / OMAP / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  i2c-hid / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  drm / exynos / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  gpio / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  hwrandom / exynos / PM: Use CONFIG_PM in #ifdef
  block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
  USB / PM: Drop CONFIG_PM_RUNTIME from the USB core
  PM: Merge the SET*_RUNTIME_PM_OPS() macros
  PM / Kconfig: Do not select PM directly from Kconfig files
  PCI / PM: Drop CONFIG_PM_RUNTIME from the PCI core
  ...
2014-12-08 20:00:44 +01:00
Jens Axboe
080ff35114 blk-mq: re-check for available tags after running the hardware queue
If we run out of tags and have to sleep, we run the hardware queue
to kick pending IO into gear. During that run, we may have completed
requests, so re-check if we have free tags before going to sleep.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-08 08:49:06 -07:00
Bart Van Assche
b32232073e blk-mq: fix hang in bt_get()
Avoid that if there are fewer hardware queues than CPU threads that
bt_get() can hang. The symptoms of the hang were as follows:

* All tags allocated for a particular hardware queue.
* (nr_tags) pending commands for that hardware queue.
* No pending commands for the software queues associated with that
  hardware queue.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-08 08:46:34 -07:00
James Bottomley
dc843ef00e Merge remote-tracking branch 'scsi-queue/core-for-3.19' into for-linus 2014-12-08 07:40:20 -08:00
Rafael J. Wysocki
47fafbc701 block / PM: Replace CONFIG_PM_RUNTIME with CONFIG_PM
After commit b2b49ccbdd (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is
selected) PM_RUNTIME is always set if PM is set, so #ifdef blocks
depending on CONFIG_PM_RUNTIME may now be changed to depend on
CONFIG_PM.

Replace CONFIG_PM_RUNTIME with CONFIG_PM in the block device core.

Reviewed-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-04 01:00:23 +01:00
Darrick J. Wong
594416a720 block: fix regression where bio_integrity_process uses wrong bio_vec iterator
bio integrity handling is broken on a system with LVM layered atop a
DIF/DIX SCSI drive because device mapper clones the bio, modifies the
clone, and sends the clone to the lower layers for processing.
However, the clone bio has bi_vcnt == 0, which means that when the sd
driver calls bio_integrity_process to attach DIX data, the
for_each_segment_all() call (which uses bi_vcnt) returns immediately
and random garbage is sent to the disk on a disk write.  The disk of
course returns an error.

Therefore, teach bio_integrity_process() to use bio_for_each_segment()
to iterate the bio_vecs, since the per-bio iterator tracks which
bio_vecs are associated with that particular bio.  The integrity
handling code is effectively part of the "driver" (it's not the bio
owner), so it must use the correct iterator function.

v2: Fix a compiler warning about abandoned local variables.  This
patch supersedes "block: bio_integrity_process uses wrong bio_vec
iterator".  Patch applies against 3.18-rc6.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-12-02 08:15:21 -07:00
Shaohua Li
6637fadf25 blk-mq: move the kdump check to blk_mq_alloc_tag_set
We call blk_mq_alloc_tag_set() first then blk_mq_init_queue(). The requests are
allocated in the former function. So the kdump check should be moved to there
to really save memory.

Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-30 18:35:39 -07:00
Jens Axboe
70114c393c blk-mq: cleanup tag free handling
We only call __blk_mq_put_tag() and __blk_mq_put_reserved_tag()
from blk_mq_put_tag(), so just inline the two calls instead of
having them as separate functions.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-24 15:52:30 -07:00
Jens Axboe
a33c1ba291 blk-mq: use 'nr_cpu_ids' as highest CPU ID count for hwq <-> cpu map
We currently use num_possible_cpus(), but that breaks on sparc64 where
the CPU ID space is discontig. Use nr_cpu_ids as the highest CPU ID
instead, so we don't end up reading from invalid memory.

Cc: stable@kernel.org # 3.13+
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-24 15:02:42 -07:00
Hannes Reinecke
eb846d9f14 scsi: rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16
SPC-3 defines SERVICE ACTION IN(12) and SERVICE ACTION IN(16).
So rename SERVICE_ACTION_IN to SERVICE_ACTION_IN_16 to be
consistent with SPC and to allow for better distinction.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Tested-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Robert Elliott <elliott@hp.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-24 20:01:40 +01:00
Gu Zheng
394ffa503b blk: introduce generic io stat accounting help function
Many block drivers accounting io stat based on bio (e.g. NVMe...),
the blk_account_io_start/end() which is based on request
does not make sense to them, so here we introduce the similar help
function named generic_start/end_io_acct base on raw sectors, and it can
simplify some driver's open io accounting code.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-24 08:04:44 -07:00
Christoph Hellwig
b657d7e632 blk-mq: handle the single queue case in blk_mq_hctx_next_cpu
Don't duplicate the code to handle the not cpu bounce case in the
caller, do it inside blk_mq_hctx_next_cpu instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-24 08:02:07 -07:00
Jens Axboe
5fabcb4c33 genhd: check for int overflow in disk_expand_part_tbl()
We can get here from blkdev_ioctl() -> blkpg_ioctl() -> add_partition()
with a user passed in partno value. If we pass in 0x7fffffff, the
new target in disk_expand_part_tbl() overflows the 'int' and we
access beyond the end of ptbl->part[] and even write to it when we
do the rcu_assign_pointer() to assign the new partition.

Reported-by: David Ramos <daramos@stanford.edu>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-19 13:09:07 -07:00
Jens Axboe
7c7f2f2bc9 blk-mq: add blk_mq_free_hctx_request()
It's silly to use blk_mq_free_request() which in turn maps the
request to the hardware queue, for places where we already know
what the hardware queue is. This saves us an extra mapping of a
hardware queue on request completion, if the caller knows this
information already.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-17 10:41:57 -07:00
Jens Axboe
1a3b595a28 blk-mq: export blk_mq_free_request()
Drivers that know they are blk-mq should just use this function
instead of calling through blk_put_request().

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-17 10:40:48 -07:00
Christoph Hellwig
125c99bc8b scsi: add new scsi-command flag for tagged commands
Currently scsi piggy backs on the block layer to define the concept
of a tagged command.  But we want to be able to have block-level host-wide
tags assigned even for untagged commands like the initial INQUIRY, so add
a new SCSI-level flag for commands that are tagged at the scsi level, so
that even commands without that set can have tags assigned to them.  Note
that this alredy is the case for the blk-mq code path, and this just lets
the old path catch up with it.

We also set this flag based upon sdev->simple_tags instead of the block
queue flag, so that it is entirely independent of the block layer tagging,
and thus always correct even if a driver doesn't use block level tagging
yet.

Also remove the old blk_rq_tagged; it was only used by SCSI drivers, and
removing it forces them to look for the proper replacement.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
2014-11-12 11:19:40 +01:00
Bart Van Assche
205fb5f5ba blk-mq: add blk_mq_unique_tag()
The queuecommand() callback functions in SCSI low-level drivers
need to know which hardware context has been selected by the
block layer. Since this information is not available in the
request structure, and since passing the hctx pointer directly to
the queuecommand callback function would require modification of
all SCSI LLDs, add a function to the block layer that allows to
query the hardware context index.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2014-11-12 11:16:09 +01:00
Ming Lei
7f60dcaaf9 block: blk-merge: fix blk_recount_segments()
For cloned bio, bio->bi_vcnt can't be used at all, and we
have resort to bio_segments() to figure out how many
segment there are in the bio.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-11 16:24:15 -07:00
Paolo Bonzini
2a90d4aae5 blk-mq: use get_cpu/put_cpu instead of preempt_disable/preempt_enable
blk-mq is using preempt_disable/enable in order to ensure that the
queue runners are placed on the right CPU.  This does not work with
the RT patches, because __blk_mq_run_hw_queue takes a non-raw
spinlock with the preemption-disabled region.  If there is contention
on the lock, this violates the rules for preemption-disabled regions.

While this should be easily fixable within the RT patches just by doing
migrate_disable/enable, we can do better and document _why_ this
particular region runs with disabled preemption.  After the previous
patch, it is trivial to switch it to get/put_cpu; the RT patches then
can change it to get_cpu_light, which lets virtio-blk run under RT
kernels.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Clark Williams <williams@redhat.com>
Tested-by: Clark Williams <williams@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-11 11:04:49 -07:00
Paolo Bonzini
398205b839 blk_mq: call preempt_disable/enable in blk_mq_run_hw_queue, and only if needed
preempt_disable/enable surrounds every call to blk_mq_run_hw_queue,
except the one in blk-flush.c.  In fact that one is always asynchronous,
and it does not need smp_processor_id().

We can do the same for all other calls, avoiding preempt_disable when
async is true.  This avoids peppering blk-mq.c with preemption-disabled
regions.

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: Clark Williams <williams@redhat.com>
Tested-by: Clark Williams <williams@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-11 11:04:47 -07:00
Tony Battersby
92697dc947 scsi: Fix more error handling in SCSI_IOCTL_SEND_COMMAND
Fix an error path in SCSI_IOCTL_SEND_COMMAND that calls
blk_put_request(rq) on an invalid IS_ERR(rq) pointer.

Fixes: a492f07545 ("block,scsi: fixup blk_get_request dead queue scenarios")
Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-10 15:41:47 -07:00
Tejun Heo
f3af020b9a blk-mq: make mq_queue_reinit_notify() freeze queues in parallel
q->mq_usage_counter is a percpu_ref which is killed and drained when
the queue is frozen.  On a CPU hotplug event, blk_mq_queue_reinit()
which involves freezing the queue is invoked on all existing queues.
Because percpu_ref killing and draining involve a RCU grace period,
doing the above on one queue after another may take a long time if
there are many queues on the system.

This patch splits out initiation of freezing and waiting for its
completion, and updates blk_mq_queue_reinit_notify() so that the
queues are frozen in parallel instead of one after another.  Note that
freezing and unfreezing are moved from blk_mq_queue_reinit() to
blk_mq_queue_reinit_notify().

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-11-04 14:49:31 -07:00
Jan Kara
ece9c72acc block: Fix computation of merged request priority
Priority of a merged request is computed by ioprio_best(). If one of the
requests has undefined priority (IOPRIO_CLASS_NONE) and another request
has priority from IOPRIO_CLASS_BE, the function will return the
undefined priority which is wrong. Fix the function to properly return
priority of a request with the defined priority.

Fixes: d58cdfb89c
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-31 08:30:43 -06:00
Jens Axboe
e167dfb53c blk-mq: add BLK_MQ_F_DEFER_ISSUE support flag
Drivers can now tell blk-mq if they take advantage of the deferred
issue through 'last' or not. If they do, don't do queue-direct
for sync IO. This is a preparation patch for the nvme conversion.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-29 11:18:26 -06:00
Jens Axboe
74c450521d blk-mq: add a 'list' parameter to ->queue_rq()
Since we have the notion of a 'last' request in a chain, we can use
this to have the hardware optimize the issuing of requests. Add
a list_head parameter to queue_rq that the driver can use to
temporarily store hw commands for issue when 'last' is true. If we
are doing a chain of requests, pass in a NULL list for the first
request to force issue of that immediately, then batch the remainder
for deferred issue until the last request has been sent.

Instead of adding yet another argument to the hot ->queue_rq path,
encapsulate the passed arguments in a blk_mq_queue_data structure.
This is passed as a constant, and has been tested as faster than
passing 4 (or even 3) args through ->queue_rq. Update drivers for
the new ->queue_rq() prototype. There are no functional changes
in this patch for drivers - if they don't use the passed in list,
then they will just queue requests individually like before.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-29 11:14:52 -06:00
Sudip Mukherjee
d32f6b5752 block: fix wrong error return in elevator_init()
while compiling integer err was showing as a set but unused variable.
elevator_init_fn can be either cfq_init_queue or deadline_init_queue
or noop_init_queue.
all three of these functions are returning -ENOMEM if they fail to
allocate the queue.
so we should actually be returning the error code rather than
returning 0 always.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-23 12:35:42 -06:00
Jan Kara
84ce0f0e94 scsi: Fix error handling in SCSI_IOCTL_SEND_COMMAND
When sg_scsi_ioctl() fails to prepare request to submit in
blk_rq_map_kern() we jump to a label where we just end up copying
(luckily zeroed-out) kernel buffer to userspace instead of reporting
error. Fix the problem by jumping to the right label.

CC: Jens Axboe <axboe@kernel.dk>
CC: linux-scsi@vger.kernel.org
CC: stable@vger.kernel.org
Coverity-id: 1226871
Signed-off-by: Jan Kara <jack@suse.cz>

Fixed up the, now unused, out label.

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-22 20:13:39 -06:00
Ming Lei
76d8137a31 blk-merge: recaculate segment if it isn't less than max segments
The problem is introduced by commit 764f612c6c3c231b(blk-merge:
don't compute bi_phys_segments from bi_vcnt for cloned bio),
and merge is needed if number of current segment isn't less than
max segments.

Strictly speaking, bio->bi_vcnt shouldn't be used here since
it may not be accurate in cases of both cloned bio or bio cloned
from, but bio_segments() is a bit expensive, and bi_vcnt is still
the biggest number, so the approach should work.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-21 19:00:32 -06:00
Christoph Hellwig
34b48db66e block: remove artifical max_hw_sectors cap
Set max_sectors to the value the drivers provides as hardware limit by
default.  Linux had proper I/O throttling for a long time and doesn't
rely on a artifically small maximum I/O size anymore.  By not limiting
the I/O size by default we remove an annoying tuning step required for
most Linux installation.

Note that both the user, and if absolutely required the driver can still
impose a limit for FS requests below max_hw_sectors_kb.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-21 14:02:54 -06:00
Linus Torvalds
d3dc366bba Merge branch 'for-3.18/core' of git://git.kernel.dk/linux-block
Pull core block layer changes from Jens Axboe:
 "This is the core block IO pull request for 3.18.  Apart from the new
  and improved flush machinery for blk-mq, this is all mostly bug fixes
  and cleanups.

   - blk-mq timeout updates and fixes from Christoph.

   - Removal of REQ_END, also from Christoph.  We pass it through the
     ->queue_rq() hook for blk-mq instead, freeing up one of the request
     bits.  The space was overly tight on 32-bit, so Martin also killed
     REQ_KERNEL since it's no longer used.

   - blk integrity updates and fixes from Martin and Gu Zheng.

   - Update to the flush machinery for blk-mq from Ming Lei.  Now we
     have a per hardware context flush request, which both cleans up the
     code should scale better for flush intensive workloads on blk-mq.

   - Improve the error printing, from Rob Elliott.

   - Backing device improvements and cleanups from Tejun.

   - Fixup of a misplaced rq_complete() tracepoint from Hannes.

   - Make blk_get_request() return error pointers, fixing up issues
     where we NULL deref when a device goes bad or missing.  From Joe
     Lawrence.

   - Prep work for drastically reducing the memory consumption of dm
     devices from Junichi Nomura.  This allows creating clone bio sets
     without preallocating a lot of memory.

   - Fix a blk-mq hang on certain combinations of queue depths and
     hardware queues from me.

   - Limit memory consumption for blk-mq devices for crash dump
     scenarios and drivers that use crazy high depths (certain SCSI
     shared tag setups).  We now just use a single queue and limited
     depth for that"

* 'for-3.18/core' of git://git.kernel.dk/linux-block: (58 commits)
  block: Remove REQ_KERNEL
  blk-mq: allocate cpumask on the home node
  bio-integrity: remove the needless fail handle of bip_slab creating
  block: include func name in __get_request prints
  block: make blk_update_request print prefix match ratelimited prefix
  blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio
  block: fix alignment_offset math that assumes io_min is a power-of-2
  blk-mq: Make bt_clear_tag() easier to read
  blk-mq: fix potential hang if rolling wakeup depth is too high
  block: add bioset_create_nobvec()
  block: use bio_clone_fast() in blk_rq_prep_clone()
  block: misplaced rq_complete tracepoint
  sd: Honor block layer integrity handling flags
  block: Replace strnicmp with strncasecmp
  block: Add T10 Protection Information functions
  block: Don't merge requests if integrity flags differ
  block: Integrity checksum flag
  block: Relocate bio integrity flags
  block: Add a disk flag to block integrity profile
  block: Add prefix to block integrity profile flags
  ...
2014-10-18 11:53:51 -07:00
Jens Axboe
a86073e48a blk-mq: allocate cpumask on the home node
All other allocs are done on the specific node, somehow the
cpumask for hw queue runs was missed. Fix that by using
zalloc_cpumask_var_node() in blk_mq_init_queue().

Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-13 15:41:54 -06:00
Gu Zheng
b65c7491cb bio-integrity: remove the needless fail handle of bip_slab creating
bip_slab is created with SLAB_PANIC, so the fail handler is unneeded.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-13 15:09:38 -06:00
Robert Elliott
7b2b10e0e2 block: include func name in __get_request prints
In __get_request calls to printk_ratelimited, include the function name so
the callbacks suppressed message matches the messages that are printed,
and add "dev" before the device name so it matches other block layer
messages.

Signed-off-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-13 08:34:23 -06:00
Robert Elliott
ef3ecb66bc block: make blk_update_request print prefix match ratelimited prefix
In blk_update_request, change the printk_ratelimited
prefix from end_request to blk_update_request so it
matches the name printed if rate limiting occurs.

Old:
[10234.933106] blk_update_request: 174 callbacks suppressed
[10234.934940] end_request: critical target error, dev sdr, sector 16
[10234.949788] end_request: critical target error, dev sdr, sector 16

New:
[16863.445173] blk_update_request: 398 callbacks suppressed
[16863.447029] blk_update_request: critical target error, dev sdr, sector
1442066176
[16863.449383] blk_update_request: critical target error, dev sdr, sector
802802888
[16863.451680] blk_update_request: critical target error, dev sdr, sector
1609535456

Signed-off-by: Robert Elliott <elliott@hp.com>
Reviewed-by: Webb Scales <webbnh@hp.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-13 08:34:21 -06:00
Linus Torvalds
c798360cd1 Merge branch 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo:
 "A lot of activities on percpu front.  Notable changes are...

   - percpu allocator now can take @gfp.  If @gfp doesn't contain
     GFP_KERNEL, it tries to allocate from what's already available to
     the allocator and a work item tries to keep the reserve around
     certain level so that these atomic allocations usually succeed.

     This will replace the ad-hoc percpu memory pool used by
     blk-throttle and also be used by the planned blkcg support for
     writeback IOs.

     Please note that I noticed a bug in how @gfp is interpreted while
     preparing this pull request and applied the fix 6ae833c7fe
     ("percpu: fix how @gfp is interpreted by the percpu allocator")
     just now.

   - percpu_ref now uses longs for percpu and global counters instead of
     ints.  It leads to more sparse packing of the percpu counters on
     64bit machines but the overhead should be negligible and this
     allows using percpu_ref for refcnting pages and in-memory objects
     directly.

   - The switching between percpu and single counter modes of a
     percpu_ref is made independent of putting the base ref and a
     percpu_ref can now optionally be initialized in single or killed
     mode.  This allows avoiding percpu shutdown latency for cases where
     the refcounted objects may be synchronously created and destroyed
     in rapid succession with only a fraction of them reaching fully
     operational status (SCSI probing does this when combined with
     blk-mq support).  It's also planned to be used to implement forced
     single mode to detect underflow more timely for debugging.

  There's a separate branch percpu/for-3.18-consistent-ops which cleans
  up the duplicate percpu accessors.  That branch causes a number of
  conflicts with s390 and other trees.  I'll send a separate pull
  request w/ resolutions once other branches are merged"

* 'for-3.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (33 commits)
  percpu: fix how @gfp is interpreted by the percpu allocator
  blk-mq, percpu_ref: start q->mq_usage_counter in atomic mode
  percpu_ref: make INIT_ATOMIC and switch_to_atomic() sticky
  percpu_ref: add PERCPU_REF_INIT_* flags
  percpu_ref: decouple switching to percpu mode and reinit
  percpu_ref: decouple switching to atomic mode and killing
  percpu_ref: add PCPU_REF_DEAD
  percpu_ref: rename things to prepare for decoupling percpu/atomic mode switch
  percpu_ref: replace pcpu_ prefix with percpu_
  percpu_ref: minor code and comment updates
  percpu_ref: relocate percpu_ref_reinit()
  Revert "blk-mq, percpu_ref: implement a kludge for SCSI blk-mq stall during probe"
  Revert "percpu: free percpu allocation info for uniprocessor system"
  percpu-refcount: make percpu_ref based on longs instead of ints
  percpu-refcount: improve WARN messages
  percpu: fix locking regression in the failure path of pcpu_alloc()
  percpu-refcount: add @gfp to percpu_ref_init()
  proportions: add @gfp to init functions
  percpu_counter: add @gfp to percpu_counter_init()
  percpu_counter: make percpu_counters_lock irq-safe
  ...
2014-10-10 07:26:02 -04:00
Ming Lei
764f612c6c blk-merge: don't compute bi_phys_segments from bi_vcnt for cloned bio
It isn't correct to figure out req->bi_phys_segments from bio->bi_vcnt
if the bio is cloned.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Tested-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-09 13:11:44 -06:00
Mike Snitzer
b8839b8c55 block: fix alignment_offset math that assumes io_min is a power-of-2
The math in both blk_stack_limits() and queue_limit_alignment_offset()
assume that a block device's io_min (aka minimum_io_size) is always a
power-of-2.  Fix the math such that it works for non-power-of-2 io_min.

This issue (of alignment_offset != 0) became apparent when testing
dm-thinp with a thinp blocksize that matches a RAID6 stripesize of
1280K.  Commit fdfb4c8c1 ("dm thin: set minimum_io_size to pool's data
block size") unlocked the potential for alignment_offset != 0 due to
the dm-thin-pool's io_min possibly being a non-power-of-2.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2014-10-09 09:41:40 -06:00
Linus Torvalds
28596c9722 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
Pull "trivial tree" updates from Jiri Kosina:
 "Usual pile from trivial tree everyone is so eagerly waiting for"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
  Remove MN10300_PROC_MN2WS0038
  mei: fix comments
  treewide: Fix typos in Kconfig
  kprobes: update jprobe_example.c for do_fork() change
  Documentation: change "&" to "and" in Documentation/applying-patches.txt
  Documentation: remove obsolete pcmcia-cs from Changes
  Documentation: update links in Changes
  Documentation: Docbook: Fix generated DocBook/kernel-api.xml
  score: Remove GENERIC_HAS_IOMAP
  gpio: fix 'CONFIG_GPIO_IRQCHIP' comments
  tty: doc: Fix grammar in serial/tty
  dma-debug: modify check_for_stack output
  treewide: fix errors in printk
  genirq: fix reference in devm_request_threaded_irq comment
  treewide: fix synchronize_rcu() in comments
  checkstack.pl: port to AArch64
  doc: queue-sysfs: minor fixes
  init/do_mounts: better syntax description
  MIPS: fix comment spelling
  powerpc/simpleboot: fix comment
  ...
2014-10-07 21:16:26 -04:00