1. 11 Dec, 2006 16 commits
  2. 10 Dec, 2006 24 commits
    • Ralf Baechle's avatar
      [MIPS] Export local_flush_data_cache_page for sake of IDE. · 9202f325
      Ralf Baechle authored
      On a CPU with aliases the IDE core needs to flush caches in the special
      IDE variants of insw, insl etc.  If IDE support is built as a module this
      will only work if local_flush_data_cache_page happens is exported as a
      module.
      
      As per policy export local_flush_data_cache_page as GPL symbol only.
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      9202f325
    • Ralf Baechle's avatar
      [MIPS] Export pm_power_off · f8bf35a9
      Ralf Baechle authored
      This is required for ipmi_poweroff.c to work as a module.
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      f8bf35a9
    • Ralf Baechle's avatar
      [MIPS] Export csum_partial_copy_nocheck. · ae32ffd6
      Ralf Baechle authored
      ibmtr.c and typhoon.c use it.
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      ae32ffd6
    • Ralf Baechle's avatar
      [MIPS] Move die and die_if_kernel() from system.h to ptrace.h · 2d911e9a
      Ralf Baechle authored
      This eleminates the need to include ptrace.h into system.h and fixes a
      harmless namespace conflict on the PC symbol in bpck.c.
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      2d911e9a
    • Ralf Baechle's avatar
      [MIPS] Discard .exit.text at linktime. · 86384d54
      Ralf Baechle authored
      This fixes fairly unobvious breakage of various drivers.
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      86384d54
    • Ralf Baechle's avatar
    • Herbert Xu's avatar
      [CRYPTO] dm-crypt: Select CRYPTO_CBC · 3263263f
      Herbert Xu authored
      As CBC is the default chaining method for cryptoloop, we should select
      it from cryptoloop to ease the transition.  Spotted by Rene Herman.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      3263263f
    • Cal Peake's avatar
      [PATCH] add MODULE_* attributes to bit reversal library · 0258736a
      Cal Peake authored
      Add MODULE_* attributes to the new bit reversal library. Most notably
      MODULE_LICENSE which prevents superfluous kernel tainting.
      Signed-off-by: default avatarCal Peake <cp@absolutedigital.net>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      0258736a
    • Linus Torvalds's avatar
      Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6 · edb16bec
      Linus Torvalds authored
      * master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
        [SPARC64]: Fix several kprobes bugs.
        [SPARC64]: Update defconfig.
        [SPARC64]: dma remove extra brackets
        [SPARC{32,64}]: Propagate ptrace_traceme() return value.
        [SPARC64]: Replace kmalloc+memset with kzalloc
        [SPARC]: Check kzalloc() return value in SUN4D irq/iommu init.
        [SPARC]: Replace kmalloc+memset with kzalloc
        [SPARC64]: Run ctrl-alt-del action for sun4v powerdown request.
        [SPARC64]: Unaligned accesses to userspace are hard errors.
        [SPARC64]: Call do_mathemu on illegal instruction traps too.
        [SPARC64]: Update defconfig.
        [SPARC64]: Add irqtrace/stacktrace/lockdep support.
      edb16bec
    • Linus Torvalds's avatar
      Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb · bb7320d1
      Linus Torvalds authored
      * 'master' of master.kernel.org:/pub/scm/linux/kernel/git/mchehab/v4l-dvb: (132 commits)
        V4L/DVB 4949b: Fix container_of pointer retreival
        V4L/DVB (4949a): Fix INIT_WORK
        V4L/DVB (4949): Cxusb: codingstyle cleanups
        V4L/DVB (4948): Cxusb: Convert tuner functions to use dvb_pll_attach
        V4L/DVB (4947): Cx88: trivial cleanups
        V4L/DVB (4946): Cx88: Move cx88_dvb_bus_ctrl out of the card-specific area
        V4L/DVB (4945): Cx88: consolidate cx22702_config structs
        V4L/DVB (4944): Cx88: Convert DViCO FusionHDTV Hybrid to use dvb_pll_attach
        V4L/DVB (4943): Cx88: cleanup dvb_pll_attach for lgdt3302 tuners
        V4L/DVB (4953): Usbvision minor fixes
        V4L/DVB (4951): Add version.h, since it is required for VIDIOC_QUERYCAP
        V4L/DVB (4940): Or51211: Changed SNR and signal strength calculations
        V4L/DVB (4939): Or51132: Changed SNR and signal strength reporting
        V4L/DVB (4938): Cx88: Convert lgdt3302 tuning function to use dvb_pll_attach
        V4L/DVB (4941): Remove LINUX_VERSION_CODE and fix identations
        V4L/DVB (4942): Whitespace cleanups
        V4L/DVB (4937): Usbvision cleanup and code reorganization
        V4L/DVB (4936): Make MT4049FM5 tuner to set FM Gain to Normal
        V4L/DVB (4935): Added the capability of selecting fm gain by tuner
        V4L/DVB (4934): Usbvision radio requires GainNormal at e register
        ...
      bb7320d1
    • Avi Kivity's avatar
      [PATCH] kvm: userspace interface · 6aa8b732
      Avi Kivity authored
      web site: http://kvm.sourceforge.net
      
      mailing list: kvm-devel@lists.sourceforge.net
        (http://lists.sourceforge.net/lists/listinfo/kvm-devel)
      
      The following patchset adds a driver for Intel's hardware virtualization
      extensions to the x86 architecture.  The driver adds a character device
      (/dev/kvm) that exposes the virtualization capabilities to userspace.  Using
      this driver, a process can run a virtual machine (a "guest") in a fully
      virtualized PC containing its own virtual hard disks, network adapters, and
      display.
      
      Using this driver, one can start multiple virtual machines on a host.
      
      Each virtual machine is a process on the host; a virtual cpu is a thread in
      that process.  kill(1), nice(1), top(1) work as expected.  In effect, the
      driver adds a third execution mode to the existing two: we now have kernel
      mode, user mode, and guest mode.  Guest mode has its own address space mapping
      guest physical memory (which is accessible to user mode by mmap()ing
      /dev/kvm).  Guest mode has no access to any I/O devices; any such access is
      intercepted and directed to user mode for emulation.
      
      The driver supports i386 and x86_64 hosts and guests.  All combinations are
      allowed except x86_64 guest on i386 host.  For i386 guests and hosts, both pae
      and non-pae paging modes are supported.
      
      SMP hosts and UP guests are supported.  At the moment only Intel
      hardware is supported, but AMD virtualization support is being worked on.
      
      Performance currently is non-stellar due to the naive implementation of the
      mmu virtualization, which throws away most of the shadow page table entries
      every context switch.  We plan to address this in two ways:
      
      - cache shadow page tables across tlb flushes
      - wait until AMD and Intel release processors with nested page tables
      
      Currently a virtual desktop is responsive but consumes a lot of CPU.  Under
      Windows I tried playing pinball and watching a few flash movies; with a recent
      CPU one can hardly feel the virtualization.  Linux/X is slower, probably due
      to X being in a separate process.
      
      In addition to the driver, you need a slightly modified qemu to provide I/O
      device emulation and the BIOS.
      
      Caveats (akpm: might no longer be true):
      
      - The Windows install currently bluescreens due to a problem with the
        virtual APIC.  We are working on a fix.  A temporary workaround is to
        use an existing image or install through qemu
      - Windows 64-bit does not work.  That's also true for qemu, so it's
        probably a problem with the device model.
      
      [bero@arklinux.org: build fix]
      [simon.kagstrom@bth.se: build fix, other fixes]
      [uril@qumranet.com: KVM: Expose interrupt bitmap]
      [akpm@osdl.org: i386 build fix]
      [mingo@elte.hu: i386 fixes]
      [rdreier@cisco.com: add log levels to all printks]
      [randy.dunlap@oracle.com: Fix sparse NULL and C99 struct init warnings]
      [anthony@codemonkey.ws: KVM: AMD SVM: 32-bit host support]
      Signed-off-by: default avatarYaniv Kamay <yaniv@qumranet.com>
      Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
      Cc: Simon Kagstrom <simon.kagstrom@bth.se>
      Cc: Bernhard Rosenkraenzer <bero@arklinux.org>
      Signed-off-by: default avatarUri Lublin <uril@qumranet.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Roland Dreier <rolandd@cisco.com>
      Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
      Signed-off-by: default avatarAnthony Liguori <anthony@codemonkey.ws>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      6aa8b732
    • Daniel Walker's avatar
      [PATCH] clocksource: small cleanup · f5f1a24a
      Daniel Walker authored
      Mostly changing alignment.  Just some general cleanup.
      
      [akpm@osdl.org: build fix]
      Signed-off-by: default avatarDaniel Walker <dwalker@mvista.com>
      Acked-by: default avatarJohn Stultz <johnstul@us.ibm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f5f1a24a
    • Daniel Walker's avatar
      [PATCH] clocksource: add usage of CONFIG_SYSFS · 2b013700
      Daniel Walker authored
      Simply adds some ifdefs to remove clocksoure sysfs code when CONFIG_SYSFS
      isn't turn on.
      Signed-off-by: default avatarDaniel Walker <dwalker@mvista.com>
      Acked-by: default avatarJohn Stultz <johnstul@us.ibm.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      2b013700
    • Arjan van de Ven's avatar
      [PATCH] user of the jiffies rounding patch: Slab · 2b284214
      Arjan van de Ven authored
      This patch introduces users of the round_jiffies() function in the slab code.
      
      The slab code has a few "run every second" timers for background work; these
      are obviously not timing critical as long as they happen roughly at the right
      frequency.
      Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      2b284214
    • Arjan van de Ven's avatar
      [PATCH] user of the jiffies rounding code: JBD · 44d306e1
      Arjan van de Ven authored
      This patch introduces a user: of the round_jiffies() function; the "5 second"
      ext3/jbd wakeup.
      
      While "every 5 seconds" doesn't sound as a problem, there can be many of these
      (and these timers do add up over all the kernel).  The "5 second" wakeup isn't
      really timing sensitive; in addition even with rounding it'll still happen
      every 5 seconds (with the exception of the very first time, which is likely to
      be rounded up to somewhere closer to 6 seconds)
      Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      44d306e1
    • Arjan van de Ven's avatar
      [PATCH] round_jiffies infrastructure · 4c36a5de
      Arjan van de Ven authored
      Introduce a round_jiffies() function as well as a round_jiffies_relative()
      function.  These functions round a jiffies value to the next whole second.
      The primary purpose of this rounding is to cause all "we don't care exactly
      when" timers to happen at the same jiffy.
      
      This avoids multiple timers firing within the second for no real reason;
      with dynamic ticks these extra timers cause wakeups from deep sleep CPU
      sleep states and thus waste power.
      
      The exact wakeup moment is skewed by the cpu number, to avoid all cpus from
      waking up at the exact same time (and hitting the same lock/cachelines
      there)
      
      [akpm@osdl.org: fix variable type]
      Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      4c36a5de
    • Vadim Lobanov's avatar
      [PATCH] fdtable: Implement new pagesize-based fdtable allocator · 5466b456
      Vadim Lobanov authored
      This patch provides an improved fdtable allocation scheme, useful for
      expanding fdtable file descriptor entries.  The main focus is on the fdarray,
      as its memory usage grows 128 times faster than that of an fdset.
      
      The allocation algorithm sizes the fdarray in such a way that its memory usage
      increases in easy page-sized chunks. The overall algorithm expands the allowed
      size in powers of two, in order to amortize the cost of invoking vmalloc() for
      larger allocation sizes. Namely, the following sizes for the fdarray are
      considered, and the smallest that accommodates the requested fd count is
      chosen:
      
          pagesize / 4
          pagesize / 2
          pagesize      <- memory allocator switch point
          pagesize * 2
          pagesize * 4
          ...etc...
      
      Unlike the current implementation, this allocation scheme does not require a
      loop to compute the optimal fdarray size, and can be done in efficient
      straightline code.
      
      Furthermore, since the fdarray overflows the pagesize boundary long before any
      of the fdsets do, it makes sense to optimize run-time by allocating both
      fdsets in a single swoop.  Even together, they will still be, by far, smaller
      than the fdarray.  The fdtable->open_fds is now used as the anchor for the
      fdset memory allocation.
      Signed-off-by: default avatarVadim Lobanov <vlobanov@speakeasy.net>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5466b456
    • Vadim Lobanov's avatar
      [PATCH] fdtable: Remove the free_files field · 4fd45812
      Vadim Lobanov authored
      An fdtable can either be embedded inside a files_struct or standalone (after
      being expanded).  When an fdtable is being discarded after all RCU references
      to it have expired, we must either free it directly, in the standalone case,
      or free the files_struct it is contained within, in the embedded case.
      
      Currently the free_files field controls this behavior, but we can get rid of
      it entirely, as all the necessary information is already recorded.  We can
      distinguish embedded and standalone fdtables using max_fds, and if it is
      embedded we can divine the relevant files_struct using container_of().
      Signed-off-by: default avatarVadim Lobanov <vlobanov@speakeasy.net>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      4fd45812
    • Vadim Lobanov's avatar
      [PATCH] fdtable: Make fdarray and fdsets equal in size · bbea9f69
      Vadim Lobanov authored
      Currently, each fdtable supports three dynamically-sized arrays of data: the
      fdarray and two fdsets.  The code allows the number of fds supported by the
      fdarray (fdtable->max_fds) to differ from the number of fds supported by each
      of the fdsets (fdtable->max_fdset).
      
      In practice, it is wasteful for these two sizes to differ: whenever we hit a
      limit on the smaller-capacity structure, we will reallocate the entire fdtable
      and all the dynamic arrays within it, so any delta in the memory used by the
      larger-capacity structure will never be touched at all.
      
      Rather than hogging this excess, we shouldn't even allocate it in the first
      place, and keep the capacities of the fdarray and the fdsets equal.  This
      patch removes fdtable->max_fdset.  As an added bonus, most of the supporting
      code becomes simpler.
      Signed-off-by: default avatarVadim Lobanov <vlobanov@speakeasy.net>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      bbea9f69
    • Vadim Lobanov's avatar
      [PATCH] fdtable: Delete pointless code in dup_fd() · f3d19c90
      Vadim Lobanov authored
      The dup_fd() function creates a new files_struct and fdtable embedded inside
      that files_struct, and then possibly expands the fdtable using expand_files().
      
      The out_release error path is invoked when expand_files() returns an error
      code.  However, when this attempt to expand fails, the fdtable is left in its
      original embedded form, so it is pointless to try to free the associated
      fdarray and fdsets.
      Signed-off-by: default avatarVadim Lobanov <vlobanov@speakeasy.net>
      Cc: Dipankar Sarma <dipankar@in.ibm.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      f3d19c90
    • Zach Brown's avatar
      [PATCH] dio: lock refcount operations · 5eb6c7a2
      Zach Brown authored
      The wait_for_more_bios() function name was poorly chosen.  While looking to
      clean it up it I noticed that the dio struct refcounting between the bio
      completion and dio submission paths was racey.
      
      The bio submission path was simply freeing the dio struct if
      atomic_dec_and_test() indicated that it dropped the final reference.
      
      The aio bio completion path was dereferencing its dio struct pointer *after
      dropping its reference* based on the remaining number of references.
      
      These two paths could race and result in the aio bio completion path
      dereferencing a freed dio, though this was not observed in the wild.
      
      This moves the refcount under the bio lock so that bio completion can drop
      its reference and decide to wake all in one atomic step.
      
      Once testing and waking is locked dio_await_one() can test its sleeping
      condition and mark itself uninterruptible under the lock.  It gets simpler
      and wait_for_more_bios() disappears.
      
      The addition of the interrupt masking spin lock acquiry in dio_bio_submit()
      looks alarming.  This lock acquiry existed in that path before the recent
      dio completion patch set.  We shouldn't expect significant performance
      regression from returning to the behaviour that existed before the
      completion clean up work.
      
      This passed 4k block ext3 O_DIRECT fsx and aio-stress on an SMP machine.
      Signed-off-by: default avatarZach Brown <zach.brown@oracle.com>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Suparna Bhattacharya <suparna@in.ibm.com>
      Cc: Jeff Moyer <jmoyer@redhat.com>
      Cc: <xfs-masters@oss.sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      5eb6c7a2
    • Zach Brown's avatar
      [PATCH] dio: only call aio_complete() after returning -EIOCBQUEUED · 8459d86a
      Zach Brown authored
      The only time it is safe to call aio_complete() is when the ->ki_retry
      function returns -EIOCBQUEUED to the AIO core.  direct_io_worker() has
      historically done this by relying on its caller to translate positive return
      codes into -EIOCBQUEUED for the aio case.  It did this by trying to keep
      conditionals in sync.  direct_io_worker() knew when finished_one_bio() was
      going to call aio_complete().  It would reverse the test and wait and free the
      dio in the cases it thought that finished_one_bio() wasn't going to.
      
      Not surprisingly, it ended up getting it wrong.  'ret' could be a negative
      errno from the submission path but it failed to communicate this to
      finished_one_bio().  direct_io_worker() would return < 0, it's callers
      wouldn't raise -EIOCBQUEUED, and aio_complete() would be called.  In the
      future finished_one_bio()'s tests wouldn't reflect this and aio_complete()
      would be called for a second time which can manifest as an oops.
      
      The previous cleanups have whittled the sync and async completion paths down
      to the point where we can collapse them and clearly reassert the invariant
      that we must only call aio_complete() after returning -EIOCBQUEUED.
      direct_io_worker() will only return -EIOCBQUEUED when it is not the last to
      drop the dio refcount and the aio bio completion path will only call
      aio_complete() when it is the last to drop the dio refcount.
      direct_io_worker() can ensure that it is the last to drop the reference count
      by waiting for bios to drain.  It does this for sync ops, of course, and for
      partial dio writes that must fall back to buffered and for aio ops that saw
      errors during submission.
      
      This means that operations that end up waiting, even if they were issued as
      aio ops, will not call aio_complete() from dio.  Instead we return the return
      code of the operation and let the aio core call aio_complete().  This is
      purposely done to fix a bug where AIO DIO file extensions would call
      aio_complete() before their callers have a chance to update i_size.
      
      Now that direct_io_worker() is explicitly returning -EIOCBQUEUED its callers
      no longer have to translate for it.  XFS needs to be careful not to free
      resources that will be used during AIO completion if -EIOCBQUEUED is returned.
       We maintain the previous behaviour of trying to write fs metadata for O_SYNC
      aio+dio writes.
      Signed-off-by: default avatarZach Brown <zach.brown@oracle.com>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Suparna Bhattacharya <suparna@in.ibm.com>
      Acked-by: default avatarJeff Moyer <jmoyer@redhat.com>
      Cc: <xfs-masters@oss.sgi.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      8459d86a
    • Zach Brown's avatar
      [PATCH] dio: remove duplicate bio wait code · 20258b2b
      Zach Brown authored
      Now that we have a single refcount and waiting path we can reuse it in the
      async 'should_wait' path.  It continues to rely on the fragile link between
      the conditional in dio_complete_aio() which decides to complete the AIO and
      the conditional in direct_io_worker() which decides to wait and free.
      
      By waiting before dropping the reference we stop dio_bio_end_aio() from
      calling dio_complete_aio() which used to wake up the waiter after seeing the
      reference count drop to 0.  We hoist this wake up into dio_bio_end_aio() which
      now notices when it's left a single remaining reference that is held by the
      waiter.
      Signed-off-by: default avatarZach Brown <zach.brown@oracle.com>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Suparna Bhattacharya <suparna@in.ibm.com>
      Acked-by: default avatarJeff Moyer <jmoyer@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      20258b2b
    • Zach Brown's avatar
      [PATCH] dio: formalize bio counters as a dio reference count · 0273201e
      Zach Brown authored
      Previously we had two confusing counts of bio progress.  'bio_count' was
      decremented as bios were processed and freed by the dio core.  It was used to
      indicate final completion of the dio operation.  'bios_in_flight' reflected
      how many bios were between submit_bio() and bio->end_io.  It was used by the
      sync path to decide when to wake up and finish completing bios and was ignored
      by the async path.
      
      This patch collapses the two notions into one notion of a dio reference count.
       bios hold a dio reference when they're between submit_bio and bio->end_io.
      
      Since bios_in_flight was only used in the sync path it is now equivalent to
      dio->refcount - 1 which accounts for direct_io_worker() holding a reference
      for the duration of the operation.
      
      dio_bio_complete() -> finished_one_bio() was called from the sync path after
      finding bios on the list that the bio->end_io function had deposited.
      finished_one_bio() can not drop the dio reference on behalf of these bios now
      because bio->end_io already has.  The is_async test in finished_one_bio()
      meant that it never actually did anything other than drop the bio_count for
      sync callers.  So we remove its refcount decrement, don't call it from
      dio_bio_complete(), and hoist its call up into the async dio_bio_complete()
      caller after an explicit refcount decrement.  It is renamed dio_complete_aio()
      to reflect the remaining work it actually does.
      Signed-off-by: default avatarZach Brown <zach.brown@oracle.com>
      Cc: Badari Pulavarty <pbadari@us.ibm.com>
      Cc: Suparna Bhattacharya <suparna@in.ibm.com>
      Acked-by: default avatarJeff Moyer <jmoyer@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      0273201e