To use spin_{un}lock_irq is dangerous if caller disabled interrupt.
During aio buffer migration, we have a possibility to see the following
call stack.

aio_migratepage  [disable interrupt]
  migrate_page_copy
    clear_page_dirty_for_io
      set_page_dirty
        __set_page_dirty_buffers
          __set_page_dirty
            spin_lock_irq

This mean, current aio migration is a deadlockable.  spin_lock_irqsave
is a safer alternative and we should use it.
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reported-by: David Rientjes rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The following path will cause array out of bound.

memblock_add_region() will always set nid in memblock.reserved to
MAX_NUMNODES.  In numa_register_memblks(), after we set all nid to
correct valus in memblock.reserved, we called setup_node_data(), and
used memblock_alloc_nid() to allocate memory, with nid set to
MAX_NUMNODES.

The nodemask_t type can be seen as a bit array.  And the index is 0 ~
MAX_NUMNODES-1.

After that, when we call node_set() in numa_clear_kernel_node_hotplug(),
the nodemask_t got an index of value MAX_NUMNODES, which is out of [0 ~
MAX_NUMNODES-1].

See below:

numa_init()
 |---> numa_register_memblks()
 |      |---> memblock_set_node(memory)		set correct nid in memblock.memory
 |      |---> memblock_set_node(reserved)	set correct nid in memblock.reserved
 |      |......
 |      |---> setup_node_data()
 |             |---> memblock_alloc_nid()	here, nid is set to MAX_NUMNODES (1024)
 |......
 |---> numa_clear_kernel_node_hotplug()
        |---> node_set()			here, we have an index 1024, and overflowed

This patch moves nid setting to numa_clear_kernel_node_hotplug() to fix
this problem.
Reported-by: NDave Jones <davej@redhat.com>
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Tested-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Reported-by: NDave Jones <davej@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Tested-by: NDave Jones <davej@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

On-stack variable numa_kernel_nodes in numa_clear_kernel_node_hotplug()
was not initialized.  So we need to initialize it.

[akpm@linux-foundation.org: use NODE_MASK_NONE, per David]
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Tested-by: NGu Zheng <guz.fnst@cn.fujitsu.com>
Reported-by: NDave Jones <davej@redhat.com>
Reported-by: NDavid Rientjes <rientjes@google.com>
Tested-by: NDave Jones <davej@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

During aio stress test, we observed the following lockdep warning.  This
mean AIO+numa_balancing is currently deadlockable.

The problem is, aio_migratepage disable interrupt, but
__set_page_dirty_nobuffers unintentionally enable it again.

Generally, all helper function should use spin_lock_irqsave() instead of
spin_lock_irq() because they don't know caller at all.

   other info that might help us debug this:
    Possible unsafe locking scenario:

          CPU0
          ----
     lock(&(&ctx->completion_lock)->rlock);
     <Interrupt>
       lock(&(&ctx->completion_lock)->rlock);

    *** DEADLOCK ***

      dump_stack+0x19/0x1b
      print_usage_bug+0x1f7/0x208
      mark_lock+0x21d/0x2a0
      mark_held_locks+0xb9/0x140
      trace_hardirqs_on_caller+0x105/0x1d0
      trace_hardirqs_on+0xd/0x10
      _raw_spin_unlock_irq+0x2c/0x50
      __set_page_dirty_nobuffers+0x8c/0xf0
      migrate_page_copy+0x434/0x540
      aio_migratepage+0xb1/0x140
      move_to_new_page+0x7d/0x230
      migrate_pages+0x5e5/0x700
      migrate_misplaced_page+0xbc/0xf0
      do_numa_page+0x102/0x190
      handle_pte_fault+0x241/0x970
      handle_mm_fault+0x265/0x370
      __do_page_fault+0x172/0x5a0
      do_page_fault+0x1a/0x70
      page_fault+0x28/0x30
Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <jweiner@redhat.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

swapoff clear swap_info's SWP_USED flag prematurely and free its
resources after that.  A concurrent swapon will reuse this swap_info
while its previous resources are not cleared completely.

These late freed resources are:
 - p->percpu_cluster
 - swap_cgroup_ctrl[type]
 - block_device setting
 - inode->i_flags &= ~S_SWAPFILE

This patch clears the SWP_USED flag after all its resources are freed,
so that swapon can reuse this swap_info by alloc_swap_info() safely.

[akpm@linux-foundation.org: tidy up code comment]
Signed-off-by: NWeijie Yang <weijie.yang@samsung.com>
Acked-by: NHugh Dickins <hughd@google.com>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a patch to improve swap readahead algorithm.  It's from Hugh and
I slightly changed it.

Hugh's original changelog:

swapin readahead does a blind readahead, whether or not the swapin is
sequential.  This may be ok on harddisk, because large reads have
relatively small costs, and if the readahead pages are unneeded they can
be reclaimed easily - though, what if their allocation forced reclaim of
useful pages? But on SSD devices large reads are more expensive than
small ones: if the readahead pages are unneeded, reading them in caused
significant overhead.

This patch adds very simplistic random read detection.  Stealing the
PageReadahead technique from Konstantin Khlebnikov's patch, avoiding the
vma/anon_vma sophistications of Shaohua Li's patch, swapin_nr_pages()
simply looks at readahead's current success rate, and narrows or widens
its readahead window accordingly.  There is little science to its
heuristic: it's about as stupid as can be whilst remaining effective.

The table below shows elapsed times (in centiseconds) when running a
single repetitive swapping load across a 1000MB mapping in 900MB ram
with 1GB swap (the harddisk tests had taken painfully too long when I
used mem=500M, but SSD shows similar results for that).

Vanilla is the 3.6-rc7 kernel on which I started; Shaohua denotes his
Sep 3 patch in mmotm and linux-next; HughOld denotes my Oct 1 patch
which Shaohua showed to be defective; HughNew this Nov 14 patch, with
page_cluster as usual at default of 3 (8-page reads); HughPC4 this same
patch with page_cluster 4 (16-page reads); HughPC0 with page_cluster 0
(1-page reads: no readahead).

HDD for swapping to harddisk, SSD for swapping to VertexII SSD.  Seq for
sequential access to the mapping, cycling five times around; Rand for
the same number of random touches.  Anon for a MAP_PRIVATE anon mapping;
Shmem for a MAP_SHARED anon mapping, equivalent to tmpfs.

One weakness of Shaohua's vma/anon_vma approach was that it did not
optimize Shmem: seen below.  Konstantin's approach was perhaps mistuned,
50% slower on Seq: did not compete and is not shown below.

HDD        Vanilla Shaohua HughOld HughNew HughPC4 HughPC0
Seq Anon     73921   76210   75611   76904   78191  121542
Seq Shmem    73601   73176   73855   72947   74543  118322
Rand Anon   895392  831243  871569  845197  846496  841680
Rand Shmem 1058375 1053486  827935  764955  764376  756489

SSD        Vanilla Shaohua HughOld HughNew HughPC4 HughPC0
Seq Anon     24634   24198   24673   25107   21614   70018
Seq Shmem    24959   24932   25052   25703   22030   69678
Rand Anon    43014   26146   28075   25989   26935   25901
Rand Shmem   45349   45215   28249   24268   24138   24332

These tests are, of course, two extremes of a very simple case: under
heavier mixed loads I've not yet observed any consistent improvement or
degradation, and wider testing would be welcome.

Shaohua Li:

Test shows Vanilla is slightly better in sequential workload than Hugh's
patch.  I observed with Hugh's patch sometimes the readahead size is
shrinked too fast (from 8 to 1 immediately) in sequential workload if
there is no hit.  And in such case, continuing doing readahead is good
actually.

I don't prepare a sophisticated algorithm for the sequential workload
because so far we can't guarantee sequential accessed pages are swap out
sequentially.  So I slightly change Hugh's heuristic - don't shrink
readahead size too fast.

Here is my test result (unit second, 3 runs average):
	Vanilla		Hugh		New
Seq	356		370		360
Random	4525		2447		2444

Attached graph is the swapin/swapout throughput I collected with 'vmstat
2'.  The first part is running a random workload (till around 1200 of
the x-axis) and the second part is running a sequential workload.
swapin and swapout throughput are almost identical in steady state in
both workloads.  These are expected behavior.  while in Vanilla, swapin
is much bigger than swapout especially in random workload (because wrong
readahead).

Original patches by: Shaohua Li and Konstantin Khlebnikov.

[fengguang.wu@intel.com: swapin_nr_pages() can be static]
Signed-off-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NShaohua Li <shli@fusionio.com>
Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Even if using the same jbd2 handle, we cannot rollback a transaction.
So once some error occurs after successfully allocating clusters, the
allocated clusters will never be used and it means they are lost.  For
example, call ocfs2_claim_clusters successfully when expanding a file,
but failed in ocfs2_insert_extent.  So we need free the allocated
clusters if they are not used indeed.
Signed-off-by: NZongxun Wang <wangzongxun@huawei.com>
Signed-off-by: NJoseph Qi <joseph.qi@huawei.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clean up descriptions of memmap= boot options.

Add periods (full stops), drop commas, change "used" to "reserved" or
"marked".
Signed-off-by: NRandy Dunlap <rdunlap@infradead.org>
Cc: Andiry Xu <andiry.xu@gmail.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull irq updates from Thomas Gleixner:
 "This lot provides:

   * Bugfixes for armada irq controller
   * Updates to renesas irq chip
   * Support for the TI-NSPIRE irq controller

  Not strictly a bug fix only pull request, but important updates for
  some of the arm Socs which I completely forgot to send last week.

  Seems like my obliviousness is getting worse, I just can't remember
  when it started"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Add support for TI-NSPIRE irqchip
  irqchip: renesas-irqc: Enable mask on suspend
  irqchip: renesas-irqc: Use lazy disable
  irqchip: armada-370-xp: fix MSI race condition
  irqchip: armada-370-xp: fix IPI race condition

Pull Xen fixes from Konrad Rzeszutek Wilk:
 "Bug-fixes:
   - Revert "xen/grant-table: Avoid m2p_override during mapping" as it
     broke Xen ARM build.
   - Fix CR4 not being set on AP processors in Xen PVH mode"

* tag 'stable/for-linus-3.14-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/pvh: set CR4 flags for APs
  Revert "xen/grant-table: Avoid m2p_override during mapping"

Pull ia64 update from Tony Luck:
 "Wire up new sched_setattr and sched_getattr syscalls"

* tag 'please-pull-ia64-syscalls' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
  [IA64] Wire up new sched_setattr and sched_getattr syscalls

Pull NVMe driver update from Matthew Wilcox:
 "Looks like I missed the merge window ...  but these are almost all
  bugfixes anyway (the ones that aren't have been baking for months)"

* git://git.infradead.org/users/willy/linux-nvme:
  NVMe: Namespace use after free on surprise removal
  NVMe: Correct uses of INIT_WORK
  NVMe: Include device and queue numbers in interrupt name
  NVMe: Add a pci_driver shutdown method
  NVMe: Disable admin queue on init failure
  NVMe: Dynamically allocate partition numbers
  NVMe: Async IO queue deletion
  NVMe: Surprise removal handling
  NVMe: Abort timed out commands
  NVMe: Schedule reset for failed controllers
  NVMe: Device resume error handling
  NVMe: Cache dev->pci_dev in a local pointer
  NVMe: Fix lockdep warnings
  NVMe: compat SG_IO ioctl
  NVMe: remove deprecated IRQF_DISABLED
  NVMe: Avoid shift operation when writing cq head doorbell

Pull regulator fixes from Mark Brown:
 "A couple of driver fixes here but the main thing is a fix to the
  checks for deferred probe non-DT systems with fully specified
  regulators which had been broken by a device tree fix which meant that
  we wouldn't insert optional regulators.

  This had slipped through the cracks since very few systems do that in
  the first place and those that do it in mainline don't need optional
  regulators anyway"

* tag 'regulator-v3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: s2mps11: Fix NULL pointer of_node value when using platform data
  regulator: core: Correct default return value for full constraints
  regulator: ab3100: cast fix

Pull crypto fixes from Herbert Xu:
 "This fixes a number of concurrency issues on s390 where multiple users
  of the same crypto transform may clobber each other's results"

* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: s390 - fix des and des3_ede ctr concurrency issue
  crypto: s390 - fix des and des3_ede cbc concurrency issue
  crypto: s390 - fix concurrency issue in aes-ctr mode

It can take some time to validate the image, make sure
{allyes|allmod}config doesn't enable it.

I'd say randconfig will cover it often enough, and the failure is also
borderline build coverage related: you cannot really make the decoder
test fail via source level changes, only with changes in the build
environment, so I agree with Andi that we can disable this one too.
Signed-off-by: NIngo Molnar <mingo@kernel.org>
Acked-by: Paul Gortmaker paul.gortmaker@windriver.com>
Suggested-and-acked-by: Andi Kleen andi@firstfloor.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This changes 'do_execve()' to get the executable name as a 'struct
filename', and to free it when it is done.  This is what the normal
users want, and it simplifies and streamlines their error handling.

The controlled lifetime of the executable name also fixes a
use-after-free problem with the trace_sched_process_exec tracepoint: the
lifetime of the passed-in string for kernel users was not at all
obvious, and the user-mode helper code used UMH_WAIT_EXEC to serialize
the pathname allocation lifetime with the execve() having finished,
which in turn meant that the trace point that happened after
mm_release() of the old process VM ended up using already free'd memory.

To solve the kernel string lifetime issue, this simply introduces
"getname_kernel()" that works like the normal user-space getname()
function, except with the source coming from kernel memory.

As Oleg points out, this also means that we could drop the tcomm[] array
from 'struct linux_binprm', since the pathname lifetime now covers
setup_new_exec().  That would be a separate cleanup.
Reported-by: NIgor Zhbanov <i.zhbanov@samsung.com>
Tested-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull btrfs fixes from Chris Mason:
 "Filipe is fixing compile and boot problems with our crc32c rework, and
  Josef has disabled snapshot aware defrag for now.

  As the number of snapshots increases, we're hitting OOM.  For the
  short term we're disabling things until a bigger fix is ready"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: use late_initcall instead of module_init
  Btrfs: use btrfs_crc32c everywhere instead of libcrc32c
  Btrfs: disable snapshot aware defrag for now

Pull NFS client bugfixes from Trond Myklebust:
 "Highlights:

   - Fix NFSv3 acl regressions
   - Fix NFSv4 memory corruption due to slot table abuse in
     nfs4_proc_open_confirm
   - nfs4_destroy_session must call rpc_destroy_waitqueue"

* tag 'nfs-for-3.14-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  fs: get_acl() must be allowed to return EOPNOTSUPP
  NFSv3: Fix return value of nfs3_proc_setacls
  NFSv3: Remove unused function nfs3_proc_set_default_acl
  NFSv4.1: nfs4_destroy_session must call rpc_destroy_waitqueue
  NFSv4: Fix memory corruption in nfs4_proc_open_confirm
  nfs: fix setting of ACLs on file creation.

It really isn't very interesting to have DEBUG_INFO when doing compile
coverage stuff (you wouldn't want to run the result anyway, that's kind
of the whole point of COMPILE_TEST), and it currently makes the build
take longer and use much more disk space for "all{yes,mod}config".

There's somewhat active discussion about this still, and we might end up
with some new config option for things like this (Andi points out that
the silly X86_DECODER_SELFTEST option also slows down the normal
coverage tests hugely), but I'm starting the ball rolling with this
simple one-liner.

DEBUG_INFO isn't that noticeable if you have tons of memory and a good
IO subsystem, but it hurts you a lot if you don't - for very little
upside for the common use.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Merge remote-tracking branches 'regulator/fix/ab3100' and 'regulator/fix/s2mps11' into regulator-linus

posix_acl_xattr_get requires get_acl() to return EOPNOTSUPP if the
filesystem cannot support acls. This is needed for NFS, which can't
know whether or not the server supports acls until it tries to get/set
one.
This patch converts posix_acl_chmod and posix_acl_create to deal with
EOPNOTSUPP return values from get_acl().
Reported-by: NRussell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/20140130140834.GW15937@n2100.arm.linux.org.uk
Cc: Al Viro viro@zeniv.linux.org.uk>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Tested-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

During bootup in the 'probe_page_size_mask' these CR4 flags are
set in there. But for AP processors they are not set as we do not
use 'secondary_startup_64' which the baremetal kernels uses.
Instead do it in this function which we use in Xen PVH during our
startup for AP processors.

As such fix it up to make sure we have that flag set.
Signed-off-by: NMukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

nfs3_proc_setacls is used internally by the NFSv3 create operations
to set the acl after the file has been created. If the operation
fails because the server doesn't support acls, then it must return '0',
not -EOPNOTSUPP.
Reported-by: NRussell King <linux@arm.linux.org.uk>
Link: http://lkml.kernel.org/r/20140201010328.GI15937@n2100.arm.linux.org.uk
Cc: Christoph Hellwig <hch@lst.de>
Tested-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

It seems that when init_btrfs_fs() is called, crc32c/crc32c-intel might
not always be already initialized, which results in the call to crypto_alloc_shash()
returning -ENOENT, as experienced by Ahmet who reported this.

Therefore make sure init_btrfs_fs() is called after crc32c is initialized (which
is at initialization level 6, module_init), by using late_initcall (which is at
initialization level 7) instead of module_init for btrfs.
Reported-and-Tested-by: NAhmet Inan <ainan@mathematik.uni-freiburg.de>
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

After the commit titled "Btrfs: fix btrfs boot when compiled as built-in",
LIBCRC32C requirement was removed from btrfs' Kconfig. This made it not
possible to build a kernel with btrfs enabled (either as module or built-in)
if libcrc32c is not enabled as well. So just replace all uses of libcrc32c
with the equivalent function in btrfs hash.h - btrfs_crc32c.
Signed-off-by: NFilipe David Borba Manana <fdmanana@gmail.com>
Signed-off-by: NChris Mason <clm@fb.com>

It's just broken and it's taking a lot of effort to fix it, so for now just
disable it so people can defrag in peace.  Thanks,

Cc: stable@vger.kernel.org
Signed-off-by: NJosef Bacik <jbacik@fb.com>
Signed-off-by: NChris Mason <clm@fb.com>

This reverts commit 08ece5bb.

As it breaks ARM builds and needs more attention
on the ARM side.
Acked-by: NDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Pull parisc updates from Helge Deller:
 "The three major changes in this patchset is a implementation for
  flexible userspace memory maps, cache-flushing fixes (again), and a
  long-discussed ABI change to make EWOULDBLOCK the same value as
  EAGAIN.

  parisc has been the only platform where we had EWOULDBLOCK != EAGAIN
  to keep HP-UX compatibility.  Since we will probably never implement
  full HP-UX support, we prefer to drop this compatibility to make it
  easier for us with Linux userspace programs which mostly never checked
  for both values.  We don't expect major fall-outs because of this
  change, and if we face some, we will simply rebuild the necessary
  applications in the debian archives"

* 'parisc-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: add flexible mmap memory layout support
  parisc: Make EWOULDBLOCK be equal to EAGAIN on parisc
  parisc: convert uapi/asm/stat.h to use native types only
  parisc: wire up sched_setattr and sched_getattr
  parisc: fix cache-flushing
  parisc/sti_console: prefer Linux fonts over built-in ROM fonts

HPFS needs to load 4 consecutive 512-byte sectors when accessing the
directory nodes or bitmaps.  We can't switch to 2048-byte block size
because files are allocated in the units of 512-byte sectors.

Previously, the driver would allocate a 2048-byte area using kmalloc,
copy the data from four buffers to this area and eventually copy them
back if they were modified.

In the current implementation of the buffer cache, buffers are allocated
in the pagecache.  That means that 4 consecutive 512-byte buffers are
stored in consecutive areas in the kernel address space.  So, we don't
need to allocate extra memory and copy the content of the buffers there.

This patch optimizes the code to avoid copying the buffers.  It checks
if the four buffers are stored in contiguous memory - if they are not,
it falls back to allocating a 2048-byte area and copying data there.
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Previously, hpfs scanned all bitmaps each time the user asked for free
space using statfs.  This patch changes it so that hpfs scans the
bitmaps only once, remembes the free space and on next invocation of
statfs it returns the value instantly.

New versions of wine are hammering on the statfs syscall very heavily,
making some games unplayable when they're stored on hpfs, with load
times in minutes.

This should be backported to the stable kernels because it fixes
user-visible problem (excessive level load times in wine).
Signed-off-by: NMikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for the flexible mmap memory layout (as described in
http://lwn.net/Articles/91829). This is especially very interesting on
parisc since we currently only support 32bit userspace (even with a
64bit Linux kernel).
Signed-off-by: NHelge Deller <deller@gmx.de>

On Linux, only parisc uses a different value for EWOULDBLOCK which
causes a lot of troubles for applications not checking for both values.
Since the hpux compat is long dead, make EWOULDBLOCK behave the same as
all other architectures.
Signed-off-by: NGuy Martin <gmsoft@tuxicoman.be>
Signed-off-by: NHelge Deller <deller@gmx.de>

The stat.h header file is exported to userspace. Some userspace
applications failed to compile due to missing/unknown types, so we
better convert it to use native types only (like it's done on other
architectures too).
Signed-off-by: NHelge Deller <deller@gmx.de>

Signed-off-by: NHelge Deller <deller@gmx.de>

This commit:
f8dae006: parisc: Ensure full cache coherency for kmap/kunmap
caused negative caching side-effects, e.g. hanging processes with expect and
too many inequivalent alias messages from flush_dcache_page() on Debian 5 systems.

This patch now partly reverts it and has been in production use on our debian buildd
makeservers since a week without any major problems.
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: NHelge Deller <deller@gmx.de>

The built-in ROM fonts lack many necessary ASCII characters, which is
why it makes sens to prefer the Linux fonts instead if they are
available.  This makes consoles on STI graphics cards which are not
supported by the stifb driver (e.g. Visualize FXe) looks much nicer.
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v3.13