1. 01 Oct, 2014 9 commits
    • Dave Chinner's avatar
      xfs: introduce xfs_buf_submit[_wait] · 595bff75
      Dave Chinner authored
      There is a lot of cookie-cutter code that looks like:
      	if (shutdown)
      		handle buffer error
      	error = xfs_buf_iowait(bp)
      	if (error)
      		handle buffer error
      spread through XFS. There's significant complexity now in
      xfs_buf_iorequest() to specifically handle this sort of synchronous
      IO pattern, but there's all sorts of nasty surprises in different
      error handling code dependent on who owns the buffer references and
      the locks.
      Pull this pattern into a single helper, where we can hide all the
      synchronous IO warts and hence make the error handling for all the
      callers much saner. This removes the need for a special extra
      reference to protect IO completion processing, as we can now hold a
      single reference across dispatch and waiting, simplifying the sync
      IO smeantics and error handling.
      In doing this, also rename xfs_buf_iorequest to xfs_buf_submit and
      make it explicitly handle on asynchronous IO. This forces all users
      to be switched specifically to one interface or the other and
      removes any ambiguity between how the interfaces are to be used. It
      also means that xfs_buf_iowait() goes away.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: kill xfs_bioerror_relse · 8b131973
      Dave Chinner authored
      There is only one caller now - xfs_trans_read_buf_map() - and it has
      very well defined call semantics - read, synchronous, and b_iodone
      is NULL. Hence it's pretty clear what error handling is necessary
      for this case. The bigger problem of untangling
      xfs_trans_read_buf_map error handling is left to a future patch.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: xfs_bioerror can die. · 27187754
      Dave Chinner authored
      Internal buffer write error handling is a mess due to the unnatural
      split between xfs_bioerror and xfs_bioerror_relse().
      xfs_bwrite() only does sync IO and determines the handler to
      call based on b_iodone, so for this caller the only difference
      between xfs_bioerror() and xfs_bioerror_release() is the XBF_DONE
      flag. We don't care what the XBF_DONE flag state is because we stale
      the buffer in both paths - the next buffer lookup will clear
      XBF_DONE because XBF_STALE is set. Hence we can use common
      error handling for xfs_bwrite().
      __xfs_buf_delwri_submit() is a similar - it's only ever called
      on writes - all sync or async - and again there's no reason to
      handle them any differently at all.
      Clean up the nasty error handling and remove xfs_bioerror().
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: kill xfs_bdstrat_cb · 8dac3921
      Dave Chinner authored
      Only has two callers, and is just a shutdown check and error handler
      around xfs_buf_iorequest. However, the error handling is a mess of
      read and write semantics, and both internal callers only call it for
      writes. Hence kill the wrapper, and follow up with a patch to
      sanitise the error handling.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: rework xfs_buf_bio_endio error handling · 61be9c52
      Dave Chinner authored
      Currently the report of a bio error from completion
      immediately marks the buffer with an error. The issue is that this
      is racy w.r.t. synchronous IO - the submitter can see b_error being
      set before the IO is complete, and hence we cannot differentiate
      between submission failures and completion failures.
      Add an internal b_io_error field protected by the b_lock to catch IO
      completion errors, and only propagate that to the buffer during
      final IO completion handling. Hence we can tell in xfs_buf_iorequest
      if we've had a submission failure bey checking bp->b_error before
      dropping our b_io_remaining reference - that reference will prevent
      b_io_error values from being propagated to b_error in the event that
      completion races with submission.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: xfs_buf_ioend and xfs_buf_iodone_work duplicate functionality · e8aaba9a
      Dave Chinner authored
      We do some work in xfs_buf_ioend, and some work in
      xfs_buf_iodone_work, but much of that functionality is the same.
      This work can all be done in a single function, leaving
      xfs_buf_iodone just a wrapper to determine if we should execute it
      by workqueue or directly. hence rename xfs_buf_iodone_work to
      xfs_buf_ioend(), and add a new xfs_buf_ioend_async() for places that
      need async processing.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: synchronous buffer IO needs a reference · e11bb805
      Dave Chinner authored
      When synchronous IO runs IO completion work, it does so without an
      IO reference or a hold reference on the buffer. The IO "hold
      reference" is owned by the submitter, and released when the
      submission is complete. The IO reference is released when both the
      submitter and the bio end_io processing is run, and so if the io
      completion work is run from IO completion context, it is run without
      an IO reference.
      Hence we can get the situation where the submitter can submit the
      IO, see an error on the buffer and unlock and free the buffer while
      there is still IO in progress. This leads to use-after-free and
      memory corruption.
      Fix this by taking a "sync IO hold" reference that is owned by the
      IO and not released until after the buffer completion calls are run
      to wake up synchronous waiters. This means that the buffer will not
      be freed in any circumstance until all IO processing is completed.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: Don't use xfs_buf_iowait in the delwri buffer code · cf53e99d
      Dave Chinner authored
      For the special case of delwri buffer submission and waiting, we
      don't need to issue IO synchronously at all. The second pass to call
      xfs_buf_iowait() can be replaced with  blocking on xfs_buf_lock() -
      the buffer will be unlocked when the async IO is complete.
      This formalises a sane the method of waiting for async IO - take an
      extra reference, submit the IO, call xfs_buf_lock() when you want to
      wait for IO completion. i.e.:
      	bp = xfs_buf_find();
      	bp->b_flags |= XBF_ASYNC;
      	error = bp->b_error;
      While this is somewhat racy for gathering IO errors, none of the
      code that calls xfs_buf_delwri_submit() will race against other
      users of the buffers being submitted. Even if they do, we don't
      really care if the error is detected by the delwri code or the user
      we raced against. Either way, the error will be detected and
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
    • Dave Chinner's avatar
      xfs: force the log before shutting down · a870fe6d
      Dave Chinner authored
      When we have marked the filesystem for shutdown, we want to prevent
      any further buffer IO from being submitted. However, we currently
      force the log after marking the filesystem as shut down, hence
      allowing IO to the log *after* we have marked both the filesystem
      and the log as in an error state.
      Clean this up by forcing the log before we mark the filesytem with
      an error. This replaces the pure CIL flush that we currently have
      which works around this same issue (i.e the CIL can't be flushed
      once the shutdown flags are set) and hence enables us to clean up
      the logic substantially.
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
  2. 25 Aug, 2014 5 commits
    • Linus Torvalds's avatar
      Linux 3.17-rc2 · 52addcf9
      Linus Torvalds authored
    • Linus Torvalds's avatar
      Merge tag 'nfs-for-3.17-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs · f01bfc97
      Linus Torvalds authored
      Pull NFS client fixes from Trond Myklebust:
         - more fixes for read/write codepath regressions
           * sleeping while holding the inode lock
           * stricter enforcement of page contiguity when coalescing requests
           * fix up error handling in the page coalescing code
         - don't busy wait on SIGKILL in the file locking code"
      * tag 'nfs-for-3.17-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
        nfs: Don't busy-wait on SIGKILL in __nfs_iocounter_wait
        nfs: can_coalesce_requests must enforce contiguity
        nfs: disallow duplicate pages in pgio page vectors
        nfs: don't sleep with inode lock in lock_and_join_requests
        nfs: fix error handling in lock_and_join_requests
        nfs: use blocking page_group_lock in add_request
        nfs: fix nonblocking calls to nfs_page_group_lock
        nfs: change nfs_page_group_lock argument
    • Linus Torvalds's avatar
      Merge tag 'renesas-sh-drivers-for-v3.17' of... · dd5957b7
      Linus Torvalds authored
      Merge tag 'renesas-sh-drivers-for-v3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas
      Pull SH driver fix from Simon Horman:
       "Confine SH_INTC to platforms that need it"
      * tag 'renesas-sh-drivers-for-v3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
        sh: intc: Confine SH_INTC to platforms that need it
    • Linus Torvalds's avatar
      Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus · 497c01dd
      Linus Torvalds authored
      Pull MIPS fixes from Ralf Baechle:
       "Pretty much all across the field so with this we should be in
        reasonable shape for the upcoming -rc2"
      * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
        MIPS: OCTEON: make get_system_type() thread-safe
        MIPS: CPS: Initialize EVA before bringing up VPEs from secondary cores
        MIPS: Malta: EVA: Rename 'eva_entry' to 'platform_eva_init'
        MIPS: EVA: Add new EVA header
        MIPS: scall64-o32: Fix indirect syscall detection
        MIPS: syscall: Fix AUDIT value for O32 processes on MIPS64
        MIPS: Loongson: Fix COP2 usage for preemptible kernel
        MIPS: NL: Fix nlm_xlp_defconfig build error
        MIPS: Remove race window in page fault handling
        MIPS: Malta: Improve system memory detection for '{e, }memsize' >= 2G
        MIPS: Alchemy: Fix db1200 PSC clock enablement
        MIPS: BCM47XX: Fix reboot problem on BCM4705/BCM4785
        MIPS: Remove duplicated include from numa.c
        MIPS: Add common plat_irq_dispatch declaration
        MIPS: MSP71xx: remove unused plat_irq_dispatch() argument
        MIPS: GIC: Remove useless parens from GICBIS().
        MIPS: perf: Mark pmu interupt IRQF_NO_THREAD
    • Linus Torvalds's avatar
      Merge tag 'trace-fixes-v3.17-rc1' of... · 01e9982a
      Linus Torvalds authored
      Merge tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
      Pull fix for ftrace function tracer/profiler conflict from Steven Rostedt:
       "The rewrite of the ftrace code that makes it possible to allow for
        separate trampolines had a design flaw with the interaction between
        the function and function_graph tracers.
        The main flaw was the simplification of the use of multiple tracers
        having the same filter (like function and function_graph, that use the
        set_ftrace_filter file to filter their code).  The design assumed that
        the two tracers could never run simultaneously as only one tracer can
        be used at a time.  The problem with this assumption was that the
        function profiler could be implemented on top of the function graph
        tracer, and the function profiler could run at the same time as the
        function tracer.  This caused the assumption to be broken and when
        ftrace detected this failed assumpiton it would spit out a nasty
        warning and shut itself down.
        Instead of using a single ftrace_ops that switches between the
        function and function_graph callbacks, the two tracers can again use
        their own ftrace_ops.  But instead of having a complex hierarchy of
        ftrace_ops, the filter fields are placed in its own structure and the
        ftrace_ops can carefully use the same filter.  This change took a bit
        to be able to allow for this and currently only the global_ops can
        share the same filter, but this new design can easily be modified to
        allow for any ftrace_ops to share its filter with another ftrace_ops.
        The first four patches deal with the change of allowing the ftrace_ops
        to share the filter (and this needs to go to 3.16 as well).
        The fifth patch fixes a bug that was also caused by the new changes
        but only for archs other than x86, and only if those archs implement a
        direct call to the function_graph tracer which they do not do yet but
        will in the future.  It does not need to go to stable, but needs to be
        fixed before the other archs update their code to allow direct calls
        to the function_graph trampoline"
      * tag 'trace-fixes-v3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
        ftrace: Use current addr when converting to nop in __ftrace_replace_code()
        ftrace: Fix function_profiler and function tracer together
        ftrace: Fix up trampoline accounting with looping on hash ops
        ftrace: Update all ftrace_ops for a ftrace_hash_ops update
        ftrace: Allow ftrace_ops to use the hashes from other ops
  3. 24 Aug, 2014 12 commits
  4. 23 Aug, 2014 5 commits
    • Heiko Stuebner's avatar
      MAINTAINERS: add new Rockchip SoC list · 00250b52
      Heiko Stuebner authored
      Add the new list that Rockchip-specific patches should also be directed to.
      Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
    • Heiko Stuebner's avatar
      ARM: dts: rockchip: readd missing mmc0 pinctrl settings · 1302d32c
      Heiko Stuebner authored
      During the restructuring of the Rockchip Cortex-A9 dtsi files it seems
      like the pinctrl settings vanished at some point from the mmc0 support.
      This of course renders them unusable, so readd the necessary pinctrl
      Signed-off-by: default avatarHeiko Stuebner <heiko@sntech.de>
    • Olof Johansson's avatar
      Merge tag 'sunxi-dt-for-3.17-2' of... · 2136edf3
      Olof Johansson authored
      Merge tag 'sunxi-dt-for-3.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux into fixes
      Merge "Allwinner DT changes, take 2" from Maxime Ripard:
      Only a single patch in here that fixes a DTC warning.
      * tag 'sunxi-dt-for-3.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mripard/linux
        ARM: dt: sun6i: Add #address-cells and #size-cells to i2c controller nodes
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
    • Steven Rostedt (Red Hat)'s avatar
      ftrace: Use current addr when converting to nop in __ftrace_replace_code() · 39b5552c
      Steven Rostedt (Red Hat) authored
      In __ftrace_replace_code(), when converting the call to a nop in a function
      it needs to compare against the "curr" (current) value of the ftrace ops, and
      not the "new" one. It currently does not affect x86 which is the only arch
      to do the trampolines with function graph tracer, but when other archs that do
      depend on this code implement the function graph trampoline, it can crash.
      Here's an example when ARM uses the trampolines (in the future):
       ------------[ cut here ]------------
       WARNING: CPU: 0 PID: 9 at kernel/trace/ftrace.c:1716 ftrace_bug+0x17c/0x1f4()
       Modules linked in: omap_rng rng_core ipv6
       CPU: 0 PID: 9 Comm: migration/0 Not tainted 3.16.0-test-10959-gf0094b28-dirty #52
       [<c02188f4>] (unwind_backtrace) from [<c021343c>] (show_stack+0x20/0x24)
       [<c021343c>] (show_stack) from [<c095a674>] (dump_stack+0x78/0x94)
       [<c095a674>] (dump_stack) from [<c02532a0>] (warn_slowpath_common+0x7c/0x9c)
       [<c02532a0>] (warn_slowpath_common) from [<c02532ec>] (warn_slowpath_null+0x2c/0x34)
       [<c02532ec>] (warn_slowpath_null) from [<c02cbac4>] (ftrace_bug+0x17c/0x1f4)
       [<c02cbac4>] (ftrace_bug) from [<c02cc44c>] (ftrace_replace_code+0x80/0x9c)
       [<c02cc44c>] (ftrace_replace_code) from [<c02cc658>] (ftrace_modify_all_code+0xb8/0x164)
       [<c02cc658>] (ftrace_modify_all_code) from [<c02cc718>] (__ftrace_modify_code+0x14/0x1c)
       [<c02cc718>] (__ftrace_modify_code) from [<c02c7244>] (multi_cpu_stop+0xf4/0x134)
       [<c02c7244>] (multi_cpu_stop) from [<c02c6e90>] (cpu_stopper_thread+0x54/0x130)
       [<c02c6e90>] (cpu_stopper_thread) from [<c0271cd4>] (smpboot_thread_fn+0x1ac/0x1bc)
       [<c0271cd4>] (smpboot_thread_fn) from [<c026ddf0>] (kthread+0xe0/0xfc)
       [<c026ddf0>] (kthread) from [<c020f318>] (ret_from_fork+0x14/0x20)
       ---[ end trace dc9ce72c5b617d8f ]---
      [   65.047264] ftrace failed to modify [<c0208580>] asm_do_IRQ+0x10/0x1c
      [   65.054070]  actual: 85:1b:00:eb
      Fixes: 7413af1f
       "ftrace: Make get_ftrace_addr() and get_ftrace_addr_old() global"
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
    • Steven Rostedt (Red Hat)'s avatar
      ftrace: Fix function_profiler and function tracer together · 5f151b24
      Steven Rostedt (Red Hat) authored
      The latest rewrite of ftrace removed the separate ftrace_ops of
      the function tracer and the function graph tracer and had them
      share the same ftrace_ops. This simplified the accounting by removing
      the multiple layers of functions called, where the global_ops func
      would call a special list that would iterate over the other ops that
      were registered within it (like function and function graph), which
      itself was registered to the ftrace ops list of all functions
      currently active. If that sounds confusing, the code that implemented
      it was also confusing and its removal is a good thing.
      The problem with this change was that it assumed that the function
      and function graph tracer can never be used at the same time.
      This is mostly true, but there is an exception. That is when the
      function profiler uses the function graph tracer to profile.
      The function profiler can be activated the same time as the function
      tracer, and this breaks the assumption and the result is that ftrace
      will crash (it detects the error and shuts itself down, it does not
      cause a kernel oops).
      To solve this issue, a previous change allowed the hash tables
      for the functions traced by a ftrace_ops to be a pointer and let
      multiple ftrace_ops share the same hash. This allows the function
      and function_graph tracer to have separate ftrace_ops, but still
      share the hash, which is what is done.
      Now the function and function graph tracers have separate ftrace_ops
      again, and the function tracer can be run while the function_profile
      is active.
      Cc: stable@vger.kernel.org # 3.16 (apply after 3.17-rc4 is out)
      Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
  5. 22 Aug, 2014 9 commits