1. 07 May, 2015 18 commits
  2. 27 Apr, 2015 9 commits
    • Linus Torvalds's avatar
      Linux 4.1-rc1 · b787f68c
      Linus Torvalds authored
      b787f68c
    • Andy Lutomirski's avatar
      x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue · 61f01dd9
      Andy Lutomirski authored
      AMD CPUs don't reinitialize the SS descriptor on SYSRET, so SYSRET with
      SS == 0 results in an invalid usermode state in which SS is apparently
      equal to __USER_DS but causes #SS if used.
      
      Work around the issue by setting SS to __KERNEL_DS __switch_to, thus
      ensuring that SYSRET never happens with SS set to NULL.
      
      This was exposed by a recent vDSO cleanup.
      
      Fixes: e7d6eefa x86/vdso32/syscall.S: Do not load __USER32_DS to %ss
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: Peter Anvin <hpa@zytor.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Denys Vlasenko <vda.linux@googlemail.com>
      Cc: Brian Gerst <brgerst@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      61f01dd9
    • Linus Torvalds's avatar
      Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux · 1190944f
      Linus Torvalds authored
      Pull intel drm fixes from Dave Airlie.
      
      * 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
        drm/i915: vlv: fix save/restore of GFX_MAX_REQ_COUNT reg
        drm/i915: Workaround to avoid lite restore with HEAD==TAIL
        drm/i915: cope with large i2c transfers
      1190944f
    • Linus Torvalds's avatar
      Merge git://git.infradead.org/intel-iommu · 9f86262d
      Linus Torvalds authored
      Pull intel iommu updates from David Woodhouse:
       "This lays a little of the groundwork for upcoming Shared Virtual
        Memory support — fixing some bogus #defines for capability bits and
        adding the new ones, and starting to use the new wider page tables
        where we can, in anticipation of actually filling in the new fields
        therein.
      
        It also allows graphics devices to be assigned to VM guests again.
        This got broken in 3.17 by disallowing assignment of RMRR-afflicted
        devices.  Like USB, we do understand why there's an RMRR for graphics
        devices — and unlike USB, it's actually sane.  So we can make an
        exception for graphics devices, just as we do USB controllers.
      
        Finally, tone down the warning about the X2APIC_OPT_OUT bit, due to
        persistent requests.  X2APIC_OPT_OUT was added to the spec as a nasty
        hack to allow broken BIOSes to forbid us from using X2APIC when they
        do stupid and invasive things and would break if we did.
      
        Someone noticed that since Windows doesn't have full IOMMU support for
        DMA protection, setting the X2APIC_OPT_OUT bit made Windows avoid
        initialising the IOMMU on the graphics unit altogether.
      
        This means that it would be available for use in "driver mode", where
        the IOMMU registers are made available through a BAR of the graphics
        device and the graphics driver can do SVM all for itself.
      
        So they started setting the X2APIC_OPT_OUT bit on *all* platforms with
        SVM capabilities.  And even the platforms which *might*, if the
        planets had been aligned correctly, possibly have had SVM capability
        but which in practice actually don't"
      
      * git://git.infradead.org/intel-iommu:
        iommu/vt-d: support extended root and context entries
        iommu/vt-d: Add new extended capabilities from v2.3 VT-d specification
        iommu/vt-d: Allow RMRR on graphics devices too
        iommu/vt-d: Print x2apic opt out info instead of printing a warning
        iommu/vt-d: kill bogus ecap_niotlb_iunits()
      9f86262d
    • Linus Torvalds's avatar
      Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux · 85f2901b
      Linus Torvalds authored
      Pull i2c fixes from Wolfram Sang:
       "This has a mixture of merge window cleanups and bugfixes"
      
      * 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
        i2c: st: add include for pinctrl
        i2c: mux: use proper dev when removing "channel-X" symlinks
        i2c: digicolor: remove duplicate include
        i2c: Mark adapter devices with pm_runtime_no_callbacks
        i2c: pca-platform: fix broken email address
        i2c: mxs: fix broken email address
        i2c: rk3x: report number of messages transmitted
      85f2901b
    • Linus Torvalds's avatar
      Merge branch 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs · f583381f
      Linus Torvalds authored
      Pull btrfs fixes from Chris Mason:
       "Filipe hit two problems in my block group cache patches.  We finalized
        the fixes last week and ran through more tests"
      
      * 'for-linus-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
        Btrfs: prevent list corruption during free space cache processing
        Btrfs: fix inode cache writeout
      f583381f
    • Dave Airlie's avatar
      Merge tag 'drm-intel-next-fixes-2015-04-25' of... · 59fd7e4b
      Dave Airlie authored
      Merge tag 'drm-intel-next-fixes-2015-04-25' of git://anongit.freedesktop.org/drm-intel into drm-fixes
      
      three fixes for i915.
      
      * tag 'drm-intel-next-fixes-2015-04-25' of git://anongit.freedesktop.org/drm-intel:
        drm/i915: vlv: fix save/restore of GFX_MAX_REQ_COUNT reg
        drm/i915: Workaround to avoid lite restore with HEAD==TAIL
        drm/i915: cope with large i2c transfers
      59fd7e4b
    • Linus Torvalds's avatar
      Merge tag 'nfs-for-4.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · 59953fba
      Linus Torvalds authored
      Pull NFS client updates from Trond Myklebust:
       "Another set of mainly bugfixes and a couple of cleanups.  No new
        functionality in this round.
      
        Highlights include:
      
        Stable patches:
         - Fix a regression in /proc/self/mountstats
         - Fix the pNFS flexfiles O_DIRECT support
         - Fix high load average due to callback thread sleeping
      
        Bugfixes:
         - Various patches to fix the pNFS layoutcommit support
         - Do not cache pNFS deviceids unless server notifications are enabled
         - Fix a SUNRPC transport reconnection regression
         - make debugfs file creation failure non-fatal in SUNRPC
         - Another fix for circular directory warnings on NFSv4 "junctioned"
           mountpoints
         - Fix locking around NFSv4.2 fallocate() support
         - Truncating NFSv4 file opens should also sync O_DIRECT writes
         - Prevent infinite loop in rpcrdma_ep_create()
      
        Features:
         - Various improvements to the RDMA transport code's handling of
           memory registration
         - Various code cleanups"
      
      * tag 'nfs-for-4.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (55 commits)
        fs/nfs: fix new compiler warning about boolean in switch
        nfs: Remove unneeded casts in nfs
        NFS: Don't attempt to decode missing directory entries
        Revert "nfs: replace nfs_add_stats with nfs_inc_stats when add one"
        NFS: Rename idmap.c to nfs4idmap.c
        NFS: Move nfs_idmap.h into fs/nfs/
        NFS: Remove CONFIG_NFS_V4 checks from nfs_idmap.h
        NFS: Add a stub for GETDEVICELIST
        nfs: remove WARN_ON_ONCE from nfs_direct_good_bytes
        nfs: fix DIO good bytes calculation
        nfs: Fetch MOUNTED_ON_FILEID when updating an inode
        sunrpc: make debugfs file creation failure non-fatal
        nfs: fix high load average due to callback thread sleeping
        NFS: Reduce time spent holding the i_mutex during fallocate()
        NFS: Don't zap caches on fallocate()
        xprtrdma: Make rpcrdma_{un}map_one() into inline functions
        xprtrdma: Handle non-SEND completions via a callout
        xprtrdma: Add "open" memreg op
        xprtrdma: Add "destroy MRs" memreg op
        xprtrdma: Add "reset MRs" memreg op
        ...
      59953fba
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 9ec3a646
      Linus Torvalds authored
      Pull fourth vfs update from Al Viro:
       "d_inode() annotations from David Howells (sat in for-next since before
        the beginning of merge window) + four assorted fixes"
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        RCU pathwalk breakage when running into a symlink overmounting something
        fix I_DIO_WAKEUP definition
        direct-io: only inc/dec inode->i_dio_count for file systems
        fs/9p: fix readdir()
        VFS: assorted d_backing_inode() annotations
        VFS: fs/inode.c helpers: d_inode() annotations
        VFS: fs/cachefiles: d_backing_inode() annotations
        VFS: fs library helpers: d_inode() annotations
        VFS: assorted weird filesystems: d_inode() annotations
        VFS: normal filesystems (and lustre): d_inode() annotations
        VFS: security/: d_inode() annotations
        VFS: security/: d_backing_inode() annotations
        VFS: net/: d_inode() annotations
        VFS: net/unix: d_backing_inode() annotations
        VFS: kernel/: d_inode() annotations
        VFS: audit: d_backing_inode() annotations
        VFS: Fix up some ->d_inode accesses in the chelsio driver
        VFS: Cachefiles should perform fs modifications on the top layer only
        VFS: AF_UNIX sockets should call mknod on the top layer only
      9ec3a646
  3. 26 Apr, 2015 8 commits
    • Linus Torvalds's avatar
      Merge tag 'pm+acpi-4.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · c8b3fd0c
      Linus Torvalds authored
      Pull more power management and ACPI updates from Rafael Wysocki:
       "These are fixes mostly (intel_pstate, ACPI core, ACPI EC driver,
        cpupower tool), a new CPU ID for the Intel RAPL driver and one
        intel_pstate driver improvement that didn't make it to my previous
        pull requests due to timing.
      
        Specifics:
      
         - Fix a build warning in the intel_pstate driver showing up in
           non-SMP builds (Borislav Petkov)
      
         - Change one of the intel_pstate's P-state selection parameters for
           Baytrail and Cherrytrail CPUs to significantly improve performance
           at the cost of a small increase in energy consumption (Kristen
           Carlson Accardi)
      
         - Fix a NULL pointer dereference in the ACPI EC driver due to an
           unsafe list walk in the query handler removal routine (Chris
           Bainbridge)
      
         - Get rid of a false-positive lockdep warning in the ACPI container
           hot-remove code (Rafael J Wysocki)
      
         - Prevent the ACPI device enumeration code from creating device
           objects of a wrong type in some cases (Rafael J Wysocki)
      
         - Add Skylake processors support to the Intel RAPL power capping
           driver (Brian Bian)
      
         - Drop the stale MAINTAINERS entry for the ACPI dock driver that is
           regarded as part of the ACPI core and maintained along with it now
           (Chao Yu)
      
         - Fix cpupower tool breakage caused by a library API change in libpci
           3.3.0 (Lucas Stach)"
      
      * tag 'pm+acpi-4.1-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        ACPI / scan: Add a scan handler for PRP0001
        ACPI / scan: Annotate physical_node_lock in acpi_scan_is_offline()
        ACPI / EC: fix NULL pointer dereference in acpi_ec_remove_query_handler()
        MAINTAINERS: remove maintainship entry of docking station driver
        powercap / RAPL: Add support for Intel Skylake processors
        cpufreq: intel_pstate: Fix an annoying !CONFIG_SMP warning
        intel_pstate: Change the setpoint for Atom params
        cpupower: fix breakage from libpci API change
      c8b3fd0c
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 · d89b3e19
      Linus Torvalds authored
      Pull crypto fixes from Herbert Xu:
       "This push fixes a build problem with img-hash under non-standard
        configurations and a serious regression with sha512_ssse3 which can
        lead to boot failures"
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
        crypto: img-hash - CRYPTO_DEV_IMGTEC_HASH should depend on HAS_DMA
        crypto: x86/sha512_ssse3 - fixup for asm function prototype change
      d89b3e19
    • Linus Torvalds's avatar
      Merge tag 'platform-drivers-x86-v4.1-1' of... · 78d42567
      Linus Torvalds authored
      Merge tag 'platform-drivers-x86-v4.1-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86
      
      Pull x86 platform driver updates from Darren Hart:
       "This series includes significant updates to the toshiba_acpi driver
        and the reintroduction of the dell-laptop keyboard backlight additions
        I had to revert previously.  Also included are various fixes for
        typos, warnings, correctness, and minor bugs.
      
        Specifics:
      
        dell-laptop:
           - add support for keyboard backlight.
      
        toshiba_acpi:
           - adaptive keyboard, hotkey, USB sleep and charge, and backlight
             updates.  Update sysfs documentation.
      
        toshiba_bluetooth:
           - fix enabling/disabling loop on recent devices
      
        apple-gmux:
           - lock iGP IO to protect from vgaarb changes
      
        other:
           - Fix typos, clear gcc warnings, clarify pr_* messages, correct
             return types, update MAINTAINERS"
      
      * tag 'platform-drivers-x86-v4.1-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86: (25 commits)
        toshiba_acpi: Do not register vendor backlight when acpi_video bl is available
        MAINTAINERS: Add me on list of Dell laptop drivers
        platform: x86: dell-laptop: Add support for keyboard backlight
        Documentation/ABI: Update sysfs-driver-toshiba_acpi entry
        toshiba_acpi: Fix pr_* messages from USB Sleep Functions
        toshiba_acpi: Update and fix USB Sleep and Charge modes
        wmi: Use bool function return values of true/false not 1/0
        toshiba_bluetooth: Fix enabling/disabling loop on recent devices
        toshiba_bluetooth: Clean up *_add function and disable BT device at removal
        toshiba_bluetooth: Add three new functions to the driver
        toshiba_acpi: Fix the enabling of the Special Functions
        toshiba_acpi: Use the Hotkey Event Type function for keymap choosing
        toshiba_acpi: Add Hotkey Event Type function and definitions
        x86/wmi: delete unused wmi_data_lock mutex causing gcc warning
        apple-gmux: lock iGP IO to protect from vgaarb changes
        MAINTAINERS: Add missing Toshiba devices and add myself as maintainer
        toshiba_acpi: Update events in toshiba_acpi_notify
        intel-oaktrail: Fix trivial typo in comment
        thinkpad_acpi: off by one in adaptive_keyboard_hotkey_notify_hotkey()
        thinkpad_acpi: signedness bugs getting current_mode
        ...
      78d42567
    • Linus Torvalds's avatar
      Merge tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform · 36a8032d
      Linus Torvalds authored
      Pull chrome platform updates from Olof Johansson:
       "Here's a set of updates to the Chrome OS platform drivers for this
        merge window.
      
        Main new things this cycle is:
      
         - Driver changes to expose the lightbar to users.  With this, you can
           make your own blinkenlights on Chromebook Pixels.
      
         - Changes in the way that the atmel_mxt trackpads are probed.  The
           laptop driver is trying to be smart and not instantiate the devices
           that don't answer to probe.  For the trackpad that can come up in
           two modes (bootloader or regular), this gets complicated since the
           driver already knows how to handle the two modes including the
           actual addresses used.  So now the laptop driver needs to know more
           too, instantiating the regular address even if the bootloader one
           is the probe that passed.
      
         - mfd driver improvements by Javier Martines Canillas, and a few
           bugfixes from him, kbuild and myself"
      
      * tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform:
        platform/chrome: chromeos_laptop - instantiate Atmel at primary address
        platform/chrome: cros_ec_lpc - Depend on X86 || COMPILE_TEST
        platform/chrome: cros_ec_lpc - Include linux/io.h header file
        platform/chrome: fix platform_no_drv_owner.cocci warnings
        platform/chrome: cros_ec_lightbar - fix duplicate const warning
        platform/chrome: cros_ec_dev - fix Unknown escape '%' warning
        platform/chrome: Expose Chrome OS Lightbar to users
        platform/chrome: Create sysfs attributes for the ChromeOS EC
        mfd: cros_ec: Instantiate ChromeOS EC character device
        platform/chrome: Add Chrome OS EC userspace device interface
        platform/chrome: Add cros_ec_lpc driver for x86 devices
        mfd: cros_ec: Add char dev and virtual dev pointers
        mfd: cros_ec: Use fixed size arrays to transfer data with the EC
      36a8032d
    • Linus Torvalds's avatar
      Merge tag 'cris-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris · 7f9f4430
      Linus Torvalds authored
      Pull arch/cris updates from Jesper Nilsson:
       "Some much needed love for the CRIS-port.
      
        There's a bunch of changes this time, giving the CRISv32 port a bit of
        modern makeover with device-tree, irq domain and gpiolib support, and
        more switchover to generic frameworks.
      
        Some small fixes and removal of the theoretical SMP support brings up
        the rear"
      
      * tag 'cris-for-4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/jesper/cris:
        cris: fix integer overflow in ELF_ET_DYN_BASE
        CRISv32: use GENERIC_SCHED_CLOCK
        CRISv32: use MMIO clocksource
        CRISv32: use generic clockevents
        CRIS: use generic headers via Kbuild
        CRIS: use generic cmpxchg.h
        CRIS: use generic atomic.h
        CRIS: use generic atomic bitops
        CRISv10: remove redundant macros from system.h
        CRIS: remove SMP code
        CRISv32: don't enable irqs in INIT_THREAD
        CRISv32: handle multiple signals
        CRISv32: prevent bogus restarts on sigreturn
        CRISv32: don't attempt syscall restart on irq exit
        Add binding documentation for CRIS
        CRIS: add Axis 88 board device tree
        CRISv32: add device tree support
        CRISv32: add irq domains support
        CRIS: enable GPIOLIB
      7f9f4430
    • Linus Torvalds's avatar
      Merge tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux · 63905bba
      Linus Torvalds authored
      Pull powerpc fixes from Michael Ellerman:
      
       - fix for mm_dec_nr_pmds() from Scott.
      
       - fixes for oopses seen with KVM + THP from Aneesh.
      
       - build fixes from Aneesh & Shreyas.
      
      * tag 'powerpc-4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mpe/linux:
        powerpc/mm: Fix build error with CONFIG_PPC_TRANSACTIONAL_MEM disabled
        powerpc/kvm: Fix ppc64_defconfig + PPC_POWERNV=n build error
        powerpc/mm/thp: Return pte address if we find trans_splitting.
        powerpc/mm/thp: Make page table walk safe against thp split/collapse
        KVM: PPC: Remove page table walk helpers
        KVM: PPC: Use READ_ONCE when dereferencing pte_t pointer
        powerpc/hugetlb: Call mm_dec_nr_pmds() in hugetlb_free_pmd_range()
      63905bba
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm · eadf16a9
      Linus Torvalds authored
      Pull second batch of KVM changes from Paolo Bonzini:
       "This mostly includes the PPC changes for 4.1, which this time cover
        Book3S HV only (debugging aids, minor performance improvements and
        some cleanups).  But there are also bug fixes and small cleanups for
        ARM, x86 and s390.
      
        The task_migration_notifier revert and real fix is still pending
        review, but I'll send it as soon as possible after -rc1"
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (29 commits)
        KVM: arm/arm64: check IRQ number on userland injection
        KVM: arm: irqfd: fix value returned by kvm_irq_map_gsi
        KVM: VMX: Preserve host CR4.MCE value while in guest mode.
        KVM: PPC: Book3S HV: Use msgsnd for signalling threads on POWER8
        KVM: PPC: Book3S HV: Translate kvmhv_commence_exit to C
        KVM: PPC: Book3S HV: Streamline guest entry and exit
        KVM: PPC: Book3S HV: Use bitmap of active threads rather than count
        KVM: PPC: Book3S HV: Use decrementer to wake napping threads
        KVM: PPC: Book3S HV: Don't wake thread with no vcpu on guest IPI
        KVM: PPC: Book3S HV: Get rid of vcore nap_count and n_woken
        KVM: PPC: Book3S HV: Move vcore preemption point up into kvmppc_run_vcpu
        KVM: PPC: Book3S HV: Minor cleanups
        KVM: PPC: Book3S HV: Simplify handling of VCPUs that need a VPA update
        KVM: PPC: Book3S HV: Accumulate timing information for real-mode code
        KVM: PPC: Book3S HV: Create debugfs file for each guest's HPT
        KVM: PPC: Book3S HV: Add ICP real mode counters
        KVM: PPC: Book3S HV: Move virtual mode ICP functions to real-mode
        KVM: PPC: Book3S HV: Convert ICS mutex lock to spin lock
        KVM: PPC: Book3S HV: Add guest->host real mode completion counters
        KVM: PPC: Book3S HV: Add helpers for lock/unlock hpte
        ...
      eadf16a9
    • Stephen Rothwell's avatar
  4. 25 Apr, 2015 1 commit
    • Dmitry Torokhov's avatar
      platform/chrome: chromeos_laptop - instantiate Atmel at primary address · 96cba9b0
      Dmitry Torokhov authored
      The new Atmel MXT driver expects i2c client's address contain the
      primary (main address) of the chip, and calculates the expected
      bootloader address form the primary address. Unfortunately chrome_laptop
      does probe the devices and if touchpad (or touchscreen, or both) comes
      up in bootloader mode the i2c device gets instantiated with the
      bootloader address which confuses the driver.
      
      To work around this issue let's probe the primary address first. If the
      device is not detected at the primary address we'll probe alternative
      addresses as "dummy" devices. If any of them are found, destroy the
      dummy client and instantiate client with proper name at primary address
      still.
      Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      96cba9b0
  5. 24 Apr, 2015 4 commits
    • Al Viro's avatar
      RCU pathwalk breakage when running into a symlink overmounting something · 3cab989a
      Al Viro authored
      Calling unlazy_walk() in walk_component() and do_last() when we find
      a symlink that needs to be followed doesn't acquire a reference to vfsmount.
      That's fine when the symlink is on the same vfsmount as the parent directory
      (which is almost always the case), but it's not always true - one _can_
      manage to bind a symlink on top of something.  And in such cases we end up
      with excessive mntput().
      
      Cc: stable@vger.kernel.org # since 2.6.39
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      3cab989a
    • Eric Sandeen's avatar
      fix I_DIO_WAKEUP definition · ac74d8d6
      Eric Sandeen authored
      I_DIO_WAKEUP is never directly used, but fix it up anyway.
      Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      ac74d8d6
    • Jens Axboe's avatar
      direct-io: only inc/dec inode->i_dio_count for file systems · fe0f07d0
      Jens Axboe authored
      do_blockdev_direct_IO() increments and decrements the inode
      ->i_dio_count for each IO operation. It does this to protect against
      truncate of a file. Block devices don't need this sort of protection.
      
      For a capable multiqueue setup, this atomic int is the only shared
      state between applications accessing the device for O_DIRECT, and it
      presents a scaling wall for that. In my testing, as much as 30% of
      system time is spent incrementing and decrementing this value. A mixed
      read/write workload improved from ~2.5M IOPS to ~9.6M IOPS, with
      better latencies too. Before:
      
      clat percentiles (usec):
       |  1.00th=[   33],  5.00th=[   34], 10.00th=[   34], 20.00th=[   34],
       | 30.00th=[   34], 40.00th=[   34], 50.00th=[   35], 60.00th=[   35],
       | 70.00th=[   35], 80.00th=[   35], 90.00th=[   37], 95.00th=[   80],
       | 99.00th=[   98], 99.50th=[  151], 99.90th=[  155], 99.95th=[  155],
       | 99.99th=[  165]
      
      After:
      
      clat percentiles (usec):
       |  1.00th=[   95],  5.00th=[  108], 10.00th=[  129], 20.00th=[  149],
       | 30.00th=[  155], 40.00th=[  161], 50.00th=[  167], 60.00th=[  171],
       | 70.00th=[  177], 80.00th=[  185], 90.00th=[  201], 95.00th=[  270],
       | 99.00th=[  390], 99.50th=[  398], 99.90th=[  418], 99.95th=[  422],
       | 99.99th=[  438]
      
      In other setups, Robert Elliott reported seeing good performance
      improvements:
      
      https://lkml.org/lkml/2015/4/3/557
      
      The more applications accessing the device, the worse it gets.
      
      Add a new direct-io flags, DIO_SKIP_DIO_COUNT, which tells
      do_blockdev_direct_IO() that it need not worry about incrementing
      or decrementing the inode i_dio_count for this caller.
      
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: Elliott, Robert (Server Storage) <elliott@hp.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarJens Axboe <axboe@fb.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      fe0f07d0
    • Johannes Berg's avatar
      fs/9p: fix readdir() · 8e3c5005
      Johannes Berg authored
      Al Viro's IOV changes broke 9p readdir() because the new code
      didn't abort the read when it returned nothing. The original
      code checked if the combined error/length was <= 0 but in the
      new code that accidentally got changed to just an error check.
      
      Add back the return from the function when nothing is read.
      
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Fixes: e1200fe6 ("9p: switch p9_client_read() to passing struct iov_iter *")
      Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      8e3c5005