There's no good reason to keep efi_enabled() under CONFIG_X86 anymore,
since nothing about the implementation is specific to x86.

Set EFI feature flags in the ia64 boot path instead of claiming to
support all features. The old behaviour was actually buggy since
efi.memmap never points to a valid memory map, so we shouldn't be
claiming to support EFI_MEMMAP.

Fortunately, this bug was never triggered because EFI_MEMMAP isn't used
outside of arch/x86 currently, but that may not always be the case.
Reviewed-and-tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

As we grow support for more EFI architectures they're going to want the
ability to query which EFI features are available on the running system.
Instead of storing this information in an architecture-specific place,
stick it in the global 'struct efi', which is already the central
location for EFI state.

While we're at it, let's change the return value of efi_enabled() to be
bool and replace all references to 'facility' with 'feature', which is
the usual word used to describe the attributes of the running system.
Signed-off-by: NMatt Fleming <matt.fleming@intel.com>

On some architectures (for example, arm), we don't end up indirectly
pulling in the declaration of kzalloc() and kfree(), and so building
anything that includes <linux/mlx5/driver.h> breaks.  Fix this by adding
an explicit include to get the declaration.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

I started noticing problems with KVM guest destruction on Linux
3.12+, where guest memory wasn't being cleaned up. I bisected it
down to the commit introducing the new 'asm goto'-based atomics,
and found this quirk was later applied to those.

Unfortunately, even with GCC 4.8.2 (which ostensibly fixed the
known 'asm goto' bug) I am still getting some kind of
miscompilation. If I enable the asm_volatile_goto quirk for my
compiler, KVM guests are destroyed correctly and the memory is
cleaned up.

So make the quirk unconditional for now, until bug is found
and fixed.
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NSteven Noonan <steven@uplinklabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1392274867-15236-1-git-send-email-steven@uplinklabs.net
Link: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670Signed-off-by: NIngo Molnar <mingo@kernel.org>

Immutable biovecs changed the way bio segments are treated in such a way that
bio_for_each_segment() cannot now do what we want for discard/write same bios,
since bi_size means something completely different for them.

Fortunately discard and write same bios never have more than a single biovec, so
bio_for_each_segment() is unnecessary and not terribly meaningful for them, but
we still have to special case them in a few places.
Signed-off-by: NKent Overstreet <kmo@daterainc.com>
Tested-by: NRichard W.M. Jones <rjones@redhat.com>
Signed-off-by: NJens Axboe <axboe@fb.com>

Use what we already do for arch_disable_smp_support() to fix these:

  arch/x86/kernel/smpboot.c:1155:6: warning: symbol 'arch_enable_nonboot_cpus_begin' was not declared. Should it be static?
  arch/x86/kernel/smpboot.c:1160:6: warning: symbol 'arch_enable_nonboot_cpus_end' was not declared. Should it be static?
  kernel/cpu.c:512:13: warning: symbol 'arch_enable_nonboot_cpus_begin' was not declared. Should it be static?
  kernel/cpu.c:516:13: warning: symbol 'arch_enable_nonboot_cpus_end' was not declared. Should it be static?
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
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>

Witch to using a preallocated flush_rq for blk-mq similar to what's done
with the old request path.  This allows us to set up the request properly
with a tag from the actually allowed range and ->rq_disk as needed by
some drivers.  To make life easier we also switch to dynamic allocation
of ->flush_rq for the old path.

This effectively reverts most of

    "blk-mq: fix for flush deadlock"

and

    "blk-mq: Don't reserve a tag for flush request"
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Rework I/O completions to work more like the old code path.  blk_mq_end_io
now stays out of the business of deferring completions to others CPUs
and calling blk_mark_rq_complete.  The latter is very important to allow
completing requests that have timed out and thus are already marked completed,
the former allows using the IPI callout even for driver specific completions
instead of having to reimplement them.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

Add prototype declaration to header file include/linux/bio.h because it
is used by more than one file.

This eliminates the following warning in bio-integrity.c:
fs/bio-integrity.c:214:14: warning: no previous prototype for ‘bio_integrity_tag_size’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NJens Axboe <axboe@fb.com>

It actually goes back to 2004 ([PATCH] Concurrent O_SYNC write support)
when sync_page_range() had been introduced; generic_file_write{,v}() correctly
synced
	pos_after_write - written .. pos_after_write - 1
but generic_file_aio_write() synced
	pos_before_write .. pos_before_write + written - 1
instead.  Which is not the same thing with O_APPEND, obviously.
A couple of years later correct variant had been killed off when
everything switched to use of generic_file_aio_write().

All users of generic_file_aio_write() are affected, and the same bug
has been copied into other instances of ->aio_write().

The fix is trivial; the only subtle point is that generic_write_sync()
ought to be inlined to avoid calculations useless for the majority of
calls.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Some drivers use request_any_context_irq() but there isn't a
devm_* function for it. Add one so that these drivers don't need
to explicitly free the irq on driver detach.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Link: http://lkml.kernel.org/r/1388709460-19222-3-git-send-email-sboyd@codeaurora.orgSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

This reverts commit 35773dac.  It's a
hack that caused regressions in the usb-storage and userspace USB
drivers that use usbfs and libusb.  Commit 70cabb7d992f "xhci 1.0: Limit
arbitrarily-aligned scatter gather." should fix the issues seen with the
ax88179_178a driver on xHCI 1.0 hosts, without causing regressions.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: stable@vger.kernel.org # 3.12

This is neede for proper SG_IO operation as well as various uses of
blk_execute_rq from the SCSI midlayer.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@fb.com>

During the initial VMBUS connect phase, starting with WS2012 R2, we should
specify the VPCU in the guest that should receive the notification. Fix this
issue. This fix is required to properly connect to the host in the kexeced
kernel.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>        [3.9+]
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit c1be5232 ("Fix micro UAR allocator") broke binary compatibility
between libmlx5 and mlx5_ib since it defines a different value to the number
of micro UARs per page, leading to wrong calculation in libmlx5. This patch
defines struct mlx5_ib_alloc_ucontext_req_v2 as an extension to struct
mlx5_ib_alloc_ucontext_req.  The extended size is determined in mlx5_ib_alloc_ucontext()
and in case of old library we use uuarn 0 which works fine -- this is
acheived due to create_user_qp() falling back from high to medium then to
low class where low class will return 0.  For new libraries we use the
more sophisticated allocation algorithm.
Signed-off-by: NEli Cohen <eli@mellanox.com>
Reviewed-by: NYann Droneaud <ydroneaud@opteya.com>
Signed-off-by: NRoland Dreier <roland@purestorage.com>

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>

Make sure that the forward declared structs in gpio/consumer.h are also visible
on the else branch of the CONFIG_GPIOLIB #ifdef.

Fixes the following warnings and their associated errors when CONFIG_GPIOLIB is
not selected:
	include/linux/gpio/consumer.h:67:14: warning: 'struct device' declared inside parameter list
	include/linux/gpio/consumer.h:67:14: warning: its scope is only this definition or declaration, which is probably not what you want
	[...]
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NAlexandre Courbot <acourbot@nvidia.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.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>

If the of_device_id table inside a device driver is protected by #ifdef
CONFIG_OF, the driver still has to provide a dummy declaration of the
table, or wrap it inside of_match_ptr(), when calling of_match_device()
in the CONFIG_OF=n case, else the driver fails to compile with e.g.

drivers/spi/spi-rspi.c: In function 'rspi_probe':
drivers/spi/spi-rspi.c:1203:26: error: 'rspi_of_match' undeclared (first use in this function)
drivers/spi/spi-rspi.c:1203:26: note: each undeclared identifier is reported only once for each function it appears in

Make of_match_device() nullify the table pointer if CONFIG_OF=n to fix
this.
Reported-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: NGeert Uytterhoeven <geert+renesas@linux-m68k.org>
Signed-off-by: NRob Herring <robh@kernel.org>

Commit 00b2c76a "include/linux/of.h: make for_each_child_of_node()
reference its args when CONFIG_OF=n" fixed warnings for unused
variables, but introduced variable "used uninitialized" warnings.
Simply initializing the variables would result in "set but not used"
warnings with W=1.

Fix both types of warnings by making all the for_each macros
unconditional and rely on the dummy static inline functions to
initialize and reference any variables.
Reported-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NRob Herring <robh@kernel.org>
Acked-by: NGrant Likely <grant.likely@linaro.org>

Add devm_phy_optional_get and phy_optional_get, which should be used
when the phy is optional. They does not return an error when the phy
does not exist, rather they returns NULL, which is considered as a valid
phy, but results in NOPs when used with the consumer API.
Signed-off-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Acked-by: NKishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: NJason Cooper <jason@lakedaemon.net>

nfs41_wake_and_assign_slot() relies on the task->tk_msg.rpc_argp and
task->tk_msg.rpc_resp always pointing to the session sequence arguments.

nfs4_proc_open_confirm tries to pull a fast one by reusing the open
sequence structure, thus causing corruption of the NFSv4 slot table.

Cc: stable@vger.kernel.org # 3.12+
Signed-off-by: NTrond Myklebust <trond.myklebust@primarydata.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

On x86, SLUB creates and handles <=8192-byte allocations internally.
It passes larger ones up to the allocator.  Saying "up to order 2" is,
at best, ambiguous.  Is that order-1?  Or (order-2 bytes)?  Make
it more clear.

SLOB commits a similar sin.  It *handles* page-size requests, but the
comment says that it passes up "all page size and larger requests".

SLOB also swaps around the order of the very-similarly-named
KMALLOC_SHIFT_HIGH and KMALLOC_SHIFT_MAX #defines.  Make it
consistent with the order of the other two allocators.

Cc: Matt Mackall <mpm@selenic.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: NChristoph Lameter <cl@linux-foundation.org>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

Add my copyright to the zsmalloc source code which I maintain.
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch moves zsmalloc under mm directory.

Before that, description will explain why we have needed custom
allocator.

Zsmalloc is a new slab-based memory allocator for storing compressed
pages.  It is designed for low fragmentation and high allocation success
rate on large object, but <= PAGE_SIZE allocations.

zsmalloc differs from the kernel slab allocator in two primary ways to
achieve these design goals.

zsmalloc never requires high order page allocations to back slabs, or
"size classes" in zsmalloc terms.  Instead it allows multiple
single-order pages to be stitched together into a "zspage" which backs
the slab.  This allows for higher allocation success rate under memory
pressure.

Also, zsmalloc allows objects to span page boundaries within the zspage.
This allows for lower fragmentation than could be had with the kernel
slab allocator for objects between PAGE_SIZE/2 and PAGE_SIZE.  With the
kernel slab allocator, if a page compresses to 60% of it original size,
the memory savings gained through compression is lost in fragmentation
because another object of the same size can't be stored in the leftover
space.

This ability to span pages results in zsmalloc allocations not being
directly addressable by the user.  The user is given an
non-dereferencable handle in response to an allocation request.  That
handle must be mapped, using zs_map_object(), which returns a pointer to
the mapped region that can be used.  The mapping is necessary since the
object data may reside in two different noncontigious pages.

The zsmalloc fulfills the allocation needs for zram perfectly

[sjenning@linux.vnet.ibm.com: borrow Seth's quote]
Signed-off-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NNitin Gupta <ngupta@vflare.org>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Bob Liu <bob.liu@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Luigi Semenzato <semenzato@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make smp_call_function_single and friends more efficient by using a
lockless list.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now we have memblock_virt_alloc_low to replace original bootmem api in
swiotlb.

But we should not use BOOTMEM_LOW_LIMIT for arch that does not support
CONFIG_NOBOOTMEM, as old api take 0.

| #define alloc_bootmem_low(x) \
|        __alloc_bootmem_low(x, SMP_CACHE_BYTES, 0)
|#define alloc_bootmem_low_pages_nopanic(x) \
|        __alloc_bootmem_low_nopanic(x, PAGE_SIZE, 0)

and we have
 #define BOOTMEM_LOW_LIMIT __pa(MAX_DMA_ADDRESS)
for CONFIG_NOBOOTMEM.

Restore goal to 0 to fix ia64 crash, that Tony found.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Reported-by: NTony Luck <tony.luck@gmail.com>
Tested-by: NTony Luck <tony.luck@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Self generated skbuffs in net/can/bcm.c are setting a skb->sk reference but
no explicit destructor which is enforced since Linux 3.11 with commit
376c7311 (net: add a temporary sanity check in skb_orphan()).

This patch adds some helper functions to make sure that a destructor is
properly defined when a sock reference is assigned to a CAN related skb.
To create an unshared skb owned by the original sock a common helper function
has been introduced to replace open coded functions to create CAN echo skbs.
Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Tested-by: NAndre Naujoks <nautsch2@gmail.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reserving a tag (request) for flush to avoid dead lock is a overkill. A
tag is valuable resource. We can track the number of flush requests and
disallow having too many pending flush requests allocated. With this
patch, blk_mq_alloc_request_pinned() could do a busy nop (but not a dead
loop) if too many pending requests are allocated and new flush request
is allocated. But this should not be a problem, too many pending flush
requests are very rare case.

I verified this can fix the deadlock caused by too many pending flush
requests.
Signed-off-by: NShaohua Li <shli@fusionio.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Commit d5dc77bf ("consolidate compat lookup_dcookie()") coverted all
architectures to the new compat_sys_lookup_dcookie() syscall.

The "len" paramater of the new compat syscall must have the type
compat_size_t in order to enforce zero extension for architectures where
the ABI requires that the caller of a function performed zero and/or
sign extension to 64 bit of all parameters.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org>	[v3.10+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We got a report that the pwritev syscall does not work correctly in
compat mode on s390.

It turned out that with commit 72ec3516 ("switch compat readv/writev
variants to COMPAT_SYSCALL_DEFINE") we lost the zero extension of a
couple of syscall parameters because the some parameter types haven't
been converted from unsigned long to compat_ulong_t.

This is needed for architectures where the ABI requires that the caller
of a function performed zero and/or sign extension to 64 bit of all
parameters.
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@vger.kernel.org>	[v3.10+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The VM is currently heavily tuned to avoid swapping.  Whether that is
good or bad is a separate discussion, but as long as the VM won't swap
to make room for dirty cache, we can not consider anonymous pages when
calculating the amount of dirtyable memory, the baseline to which
dirty_background_ratio and dirty_ratio are applied.

A simple workload that occupies a significant size (40+%, depending on
memory layout, storage speeds etc.) of memory with anon/tmpfs pages and
uses the remainder for a streaming writer demonstrates this problem.  In
that case, the actual cache pages are a small fraction of what is
considered dirtyable overall, which results in an relatively large
portion of the cache pages to be dirtied.  As kswapd starts rotating
these, random tasks enter direct reclaim and stall on IO.

Only consider free pages and file pages dirtyable.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Reported-by: NTejun Heo <tj@kernel.org>
Tested-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NRik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Reviewed-by: NMichal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJean Delvare <khali@linux-fr.org>

The event returned from fsnotify_add_notify_event() cannot ever be used
safely as the event may be freed by the time the function returns (after
dropping notification_mutex). So change the prototype to just return
whether the event was added or merged into some existing event.
Reported-and-tested-by: NJiri Kosina <jkosina@suse.cz>
Reported-and-tested-by: NDave Jones <davej@fedoraproject.org>
Signed-off-by: NJan Kara <jack@suse.cz>

Btrfs needs a simple way to know if it needs to let go of it's read lock on a
rwsem.  Introduce rwsem_is_contended to check to see if there are any waiters on
this rwsem currently.  This is just a hueristic, it is meant to be light and not
100% accurate and called by somebody already holding on to the rwsem in either
read or write.  Thanks,
Signed-off-by: NJosef Bacik <jbacik@fusionio.com>
Signed-off-by: NChris Mason <clm@fb.com>
Acked-by: NIngo Molnar <mingo@kernel.org>

I observed that there are for_each macros that do an extra memory access
beyond the defined area.
Normally this does not cause problems.
But, this can cause exceptions. For example: if the area is allocated at
the end of a page and the next page is not accessible.

For correctness, I suggest changing the arguments of the 'for loop' like
others 'for_each' do in the kernel.
Signed-off-by: NJose Alonso <joalonsof@gmail.com>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Reduce data size a little.
Reduce checkpatch noise.

$ size kernel/softirq.o*
   text	   data	    bss	    dec	    hex	filename
  11554	   6013	   4008	  21575	   5447	kernel/softirq.o.new
  11474	   6093	   4008	  21575	   5447	kernel/softirq.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

@splice_desc.total_len is 32 bit(unsigned int) which is used to store the
size passed from userspace which is 64 bit(size_t) so that the size is
unexpectedly truncated

That means vmsplice can not work if the size passed from userspace is >=
4G, for example, we noticed in vmsplice, splice-reader does not do
anything and splice-writer is waiting for available buffer forever if the
size is 4G

Fix it by extending @splice_desc.total_len to 64 bits as well
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This field is only used to reset the ids seq number if it exceeds the
smaller of INT_MAX/SEQ_MULTIPLIER and USHRT_MAX, and can therefore be
moved out of the structure and into its own macro.  Since each
ipc_namespace contains a table of 3 pointers to struct ipc_ids we can
save space in instruction text:

   text    data     bss     dec     hex filename
  56232    2348      24   58604    e4ec ipc/built-in.o
  56216    2348      24   58588    e4dc ipc/built-in.o-after
Signed-off-by: NDavidlohr Bueso <davidlohr@hp.com>
Reviewed-by: NJonathan Gonzalez <jgonzalez@linets.cl>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Rik van Riel <riel@redhat.com>
Acked-by: NManfred Spraul <manfred@colorfullife.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>