1. 03 Nov, 2015 3 commits
    • Dave Chinner's avatar
      xfs: Don't use unwritten extents for DAX · 1ca19157
      Dave Chinner authored
      DAX has a page fault serialisation problem with block allocation.
      Because it allows concurrent page faults and does not have a page
      lock to serialise faults to the same page, it can get two concurrent
      faults to the page that race.
      
      When two read faults race, this isn't a huge problem as the data
      underlying the page is not changing and so "detect and drop" works
      just fine. The issues are to do with write faults.
      
      When two write faults occur, we serialise block allocation in
      get_blocks() so only one faul will allocate the extent. It will,
      however, be marked as an unwritten extent, and that is where the
      problem lies - the DAX fault code cannot differentiate between a
      block that was just allocated and a block that was preallocated and
      needs zeroing. The result is that both write faults end up zeroing
      the block and attempting to convert it back to written.
      
      The problem is that the first fault can zero and convert before the
      second fault starts zeroing, resulting in the zeroing for the second
      fault overwriting the data that the first fault wrote with zeros.
      The second fault then attempts to convert the unwritten extent,
      which is then a no-op because it's already written. Data loss occurs
      as a result of this race.
      
      Because there is no sane locking construct in the page fault code
      that we can use for serialisation across the page faults, we need to
      ensure block allocation and zeroing occurs atomically in the
      filesystem. This means we can still take concurrent page faults and
      the only time they will serialise is in the filesystem
      mapping/allocation callback. The page fault code will always see
      written, initialised extents, so we will be able to remove the
      unwritten extent handling from the DAX code when all filesystems are
      converted.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
      
      1ca19157
    • Dave Chinner's avatar
      xfs: introduce BMAPI_ZERO for allocating zeroed extents · 3fbbbea3
      Dave Chinner authored
      To enable DAX to do atomic allocation of zeroed extents, we need to
      drive the block zeroing deep into the allocator. Because
      xfs_bmapi_write() can return merged extents on allocation that were
      only partially allocated (i.e. requested range spans allocated and
      hole regions, allocation into the hole was contiguous), we cannot
      zero the extent returned from xfs_bmapi_write() as that can
      overwrite existing data with zeros.
      
      Hence we have to drive the extent zeroing into the allocation code,
      prior to where we merge the extents into the BMBT and return the
      resultant map. This means we need to propagate this need down to
      the xfs_alloc_vextent() and issue the block zeroing at this point.
      
      While this functionality is being introduced for DAX, there is no
      reason why it is specific to DAX - we can per-zero blocks during the
      allocation transaction on any type of device. It's just slow (and
      usually slower than unwritten allocation and conversion) on
      traditional block devices so doesn't tend to get used. We can,
      however, hook hardware zeroing optimisations via sb_issue_zeroout()
      to this operation, so it may be useful in future and hence the
      "allocate zeroed blocks" API needs to be implementation neutral.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
      3fbbbea3
    • Dave Chinner's avatar
      xfs: fix inode size update overflow in xfs_map_direct() · 3e12dbbd
      Dave Chinner authored
      Both direct IO and DAX pass an offset and count into get_blocks that
      will overflow a s64 variable when an IO goes into the last supported
      block in a file (i.e. at offset 2^63 - 1FSB bytes). This can be seen
      from the tracing:
      
      xfs_get_blocks_alloc: [...] offset 0x7ffffffffffff000 count 4096
      xfs_gbmap_direct:     [...] offset 0x7ffffffffffff000 count 4096
      xfs_gbmap_direct_none:[...] offset 0x7ffffffffffff000 count 4096
      
      0x7ffffffffffff000 + 4096 = 0x8000000000000000, and hence that
      overflows the s64 offset and we fail to detect the need for a
      filesize update and an ioend is not allocated.
      
      This is *mostly* avoided for direct IO because such extending IOs
      occur with full block allocation, and so the "IS_UNWRITTEN()" check
      still evaluates as true and we get an ioend that way. However, doing
      single sector extending IOs to this last block will expose the fact
      that file size updates will not occur after the first allocating
      direct IO as the overflow will then be exposed.
      
      There is one further complexity: the DAX page fault path also
      exposes the same issue in block allocation. However, page faults
      cannot extend the file size, so in this case we want to allocate the
      block but do not want to allocate an ioend to enable file size
      update at IO completion. Hence we now need to distinguish between
      the direct IO patch allocation and dax fault path allocation to
      avoid leaking ioend structures.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarBrian Foster <bfoster@redhat.com>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
      3e12dbbd
  2. 20 Sep, 2015 10 commits
    • Linus Torvalds's avatar
      Linux 4.3-rc2 · 1f93e4a9
      Linus Torvalds authored
      1f93e4a9
    • Linus Torvalds's avatar
      Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm · 99bc7215
      Linus Torvalds authored
      Pull ARM fixes from Russell King:
       "Three fixes and a resulting cleanup for -rc2:
      
         - Andre Przywara reported that he was seeing a warning with the new
           cast inside DMA_ERROR_CODE's definition, and fixed the incorrect
           use.
      
         - Doug Anderson noticed that kgdb causes a "scheduling while atomic"
           bug.
      
         - OMAP5 folk noticed that their Thumb-2 compiled X servers crashed
           when enabling support to cover ARMv6 CPUs due to a kernel bug
           leaking some conditional context into the signal handler"
      
      * 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
        ARM: 8425/1: kgdb: Don't try to stop the machine when setting breakpoints
        ARM: 8437/1: dma-mapping: fix build warning with new DMA_ERROR_CODE definition
        ARM: get rid of needless #if in signal handling code
        ARM: fix Thumb2 signal handling when ARMv6 is enabled
      99bc7215
    • Linus Torvalds's avatar
      Merge tag 'linux-kselftest-4.3-rc2' of... · 30ec5682
      Linus Torvalds authored
      Merge tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
      
      Pull kselftest fixes from Shuah Khan:
       "This update contains 7 fixes for problems ranging from build failurs
        to incorrect error reporting"
      
      * tag 'linux-kselftest-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
        selftests: exec: revert to default emit rule
        selftests: change install command to rsync
        selftests: mqueue: simplify the Makefile
        selftests: mqueue: allow extra cflags
        selftests: rename jump label to static_keys
        selftests/seccomp: add support for s390
        seltests/zram: fix syntax error
      30ec5682
    • Linus Torvalds's avatar
      Merge tag 'pm+acpi-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm · 009884f3
      Linus Torvalds authored
      Pull power management and ACPI updates from Rafael Wysocki:
       "Included are: a somewhat late devfreq update which however is mostly
        fixes and cleanups with one new thing only (the PPMUv2 support on
        Exynos5433), an ACPI cpufreq driver fixup and two ACPI core cleanups
        related to preprocessor directives.
      
        Specifics:
      
         - Fix a memory allocation size in the devfreq core (Xiaolong Ye).
      
         - Fix a mistake in the exynos-ppmu DT binding (Javier Martinez
           Canillas).
      
         - Add support for PPMUv2 ((Platform Performance Monitoring Unit
           version 2.0) on the Exynos5433 SoCs (Chanwoo Choi).
      
         - Fix a type casting bug in the Exynos PPMU code (MyungJoo Ham).
      
         - Assorted devfreq code cleanups and optimizations (Javi Merino,
           MyungJoo Ham, Viresh Kumar).
      
         - Fix up the ACPI cpufreq driver to use a more lightweight way to get
           to its private data in the ->get() callback (Rafael J Wysocki).
      
         - Fix a CONFIG_ prefix bug in one of the ACPI drivers and make the
           ACPI subsystem use IS_ENABLED() instead of #ifdefs in function
           bodies (Sudeep Holla)"
      
      * tag 'pm+acpi-4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
        cpufreq: acpi-cpufreq: Use cpufreq_cpu_get_raw() in ->get()
        ACPI: Eliminate CONFIG_.*{, _MODULE} #ifdef in favor of IS_ENABLED()
        ACPI: int340x_thermal: add missing CONFIG_ prefix
        PM / devfreq: Fix incorrect type issue.
        PM / devfreq: tegra: Update governor to use devfreq_update_stats()
        PM / devfreq: comments for get_dev_status usage updated
        PM / devfreq: drop comment about thermal setting max_freq
        PM / devfreq: cache the last call to get_dev_status()
        PM / devfreq: Drop unlikely before IS_ERR(_OR_NULL)
        PM / devfreq: exynos-ppmu: bit-wise operation bugfix.
        PM / devfreq: exynos-ppmu: Update documentation to support PPMUv2
        PM / devfreq: exynos-ppmu: Add the support of PPMUv2 for Exynos5433
        PM / devfreq: event: Remove incorrect property in exynos-ppmu DT binding
      009884f3
    • Linus Torvalds's avatar
      Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux · d590b2d4
      Linus Torvalds authored
      Pull clk fixes from Stephen Boyd:
       "A few driver fixes for tegra, rockchip, and st SoCs and a two-liner in
        the framework to avoid oops when get_parent ops return out of range
        values on tegra platforms"
      
      * tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
        drivers: clk: st: Rename st_pll3200c32_407_c0_x into st_pll3200c32_cx_x
        clk: check for invalid parent index of orphans in __clk_init()
        clk: tegra: dfll: Properly protect OPP list
        clk: rockchip: add critical clock for rk3368
      d590b2d4
    • Linus Torvalds's avatar
      Merge tag 'led-fixes-for-v4.3-rc2' of... · e6827baf
      Linus Torvalds authored
      Merge tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds
      
      Pull LED fixes from Jacek Anaszewski:
       - fix module autoload for six OF platform drivers (aat1290, bcm6328,
         bcm6358, ktd2692, max77693, ns2)
       - aat1290: add missing static modifier
       - ipaq-micro: add missing LEDS_CLASS dependency
       - lp55xx: correct Kconfig dependecy for f/w user helper
      
      * tag 'led-fixes-for-v4.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/j.anaszewski/linux-leds:
        leds:lp55xx: Correct Kconfig dependency for f/w user helper
        leds: leds-ipaq-micro: Add LEDS_CLASS dependency
        leds: aat1290: add 'static' modifier to init_mm_current_scale
        leds: leds-ns2: Fix module autoload for OF platform driver
        leds: max77693: Fix module autoload for OF platform driver
        leds: ktd2692: Fix module autoload for OF platform driver
        leds: bcm6358: Fix module autoload for OF platform driver
        leds: bcm6328: Fix module autoload for OF platform driver
        leds: aat1290: Fix module autoload for OF platform driver
      e6827baf
    • Linus Torvalds's avatar
      Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma · dc847d5b
      Linus Torvalds authored
      Pull rdma fixes from Doug Ledford:
       "The new hfi1 driver in staging/rdma has had a number of fixup patches
        since being added to the tree.  This is the first batch of those fixes"
      
      * tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma:
        IB/hfi: Properly set permissions for user device files
        IB/hfi1: mask vs shift confusion
        IB/hfi1: clean up some defines
        IB/hfi1: info leak in get_ctxt_info()
        IB/hfi1: fix a locking bug
        IB/hfi1: checking for NULL instead of IS_ERR
        IB/hfi1: fix sdma_descq_cnt parameter parsing
        IB/hfi1: fix copy_to/from_user() error handling
        IB/hfi1: fix pstateinfo from returning improperly byteswapped value
      dc847d5b
    • Linus Torvalds's avatar
      Merge branch 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm · 2673ee56
      Linus Torvalds authored
      Pull libnvdimm fixes from Dan Williams:
      
       - a boot regression (since v4.2) fix for some ARM configurations from
         Tyler
      
       - regression (since v4.1) fixes for mkfs.xfs on a DAX enabled device
         from Jeff.  These are tagged for -stable.
      
       - a pair of locking fixes from Axel that are hidden from lockdep since
         they involve device_lock().  The "btt" one is tagged for -stable, the
         other only applies to the new "pfn" mechanism in v4.3.
      
       - a fix for the pmem ->rw_page() path to use wmb_pmem() from Ross.
      
      * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
        mm: fix type cast in __pfn_to_phys()
        pmem: add proper fencing to pmem_rw_page()
        libnvdimm: pfn_devs: Fix locking in namespace_store
        libnvdimm: btt_devs: Fix locking in namespace_store
        blockdev: don't set S_DAX for misaligned partitions
        dax: fix O_DIRECT I/O to the last block of a blockdev
      2673ee56
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.dk/linux-block · 133bb595
      Linus Torvalds authored
      Pull block updates from Jens Axboe:
       "This is a bit bigger than it should be, but I could (did) not want to
        send it off last week due to both wanting extra testing, and expecting
        a fix for the bounce regression as well.  In any case, this contains:
      
         - Fix for the blk-merge.c compilation warning on gcc 5.x from me.
      
         - A set of back/front SG gap merge fixes, from me and from Sagi.
           This ensures that we honor SG gapping for integrity payloads as
           well.
      
         - Two small fixes for null_blk from Matias, fixing a leak and a
           capacity propagation issue.
      
         - A blkcg fix from Tejun, fixing a NULL dereference.
      
         - A fast clone optimization from Ming, fixing a performance
           regression since the arbitrarily sized bio's were introduced.
      
         - Also from Ming, a regression fix for bouncing IOs"
      
      * 'for-linus' of git://git.kernel.dk/linux-block:
        block: fix bounce_end_io
        block: blk-merge: fast-clone bio when splitting rw bios
        block: blkg_destroy_all() should clear q->root_blkg and ->root_rl.blkg
        block: Copy a user iovec if it includes gaps
        block: Refuse adding appending a gapped integrity page to a bio
        block: Refuse request/bio merges with gaps in the integrity payload
        block: Check for gaps on front and back merges
        null_blk: fix wrong capacity when bs is not 512 bytes
        null_blk: fix memory leak on cleanup
        block: fix bogus compiler warnings in blk-merge.c
      133bb595
    • Chris Mason's avatar
      fs-writeback: unplug before cond_resched in writeback_sb_inodes · 590dca3a
      Chris Mason authored
      Commit 505a666e ("writeback: plug writeback in wb_writeback() and
      writeback_inodes_wb()") has us holding a plug during writeback_sb_inodes,
      which increases the merge rate when relatively contiguous small files
      are written by the filesystem.  It helps both on flash and spindles.
      
      For an fs_mark workload creating 4K files in parallel across 8 drives,
      this commit improves performance ~9% more by unplugging before calling
      cond_resched().  cond_resched() doesn't trigger an implicit unplug, so
      explicitly getting the IO down to the device before scheduling reduces
      latencies for anyone waiting on clean pages.
      
      It also cuts down on how often we use kblockd to unplug, which means
      less work bouncing from one workqueue to another.
      
      Many more details about how we got here:
      
        https://lkml.org/lkml/2015/9/11/570Signed-off-by: default avatarChris Mason <clm@fb.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      590dca3a
  3. 19 Sep, 2015 1 commit
  4. 18 Sep, 2015 26 commits