Introduce BPF_MAP_TYPE_PERCPU_HASH map type which is used to do
accurate counters without need to use BPF_XADD instruction which turned
out to be too costly for high-performance network monitoring.
In the typical use case the 'key' is the flow tuple or other long
living object that sees a lot of events per second.

bpf_map_lookup_elem() returns per-cpu area.
Example:
struct {
  u32 packets;
  u32 bytes;
} * ptr = bpf_map_lookup_elem(&map, &key);
/* ptr points to this_cpu area of the value, so the following
 * increments will not collide with other cpus
 */
ptr->packets ++;
ptr->bytes += skb->len;

bpf_update_elem() atomically creates a new element where all per-cpu
values are zero initialized and this_cpu value is populated with
given 'value'.
Note that non-per-cpu hash map always allocates new element
and then deletes old after rcu grace period to maintain atomicity
of update. Per-cpu hash map updates element values in-place.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

netdev_rss_key is written to once and thereafter is read by
drivers when they are initialising. The fact that it is mostly
read and not written to makes it a candidate for a __read_mostly
declaration.
Signed-off-by: NKim Jones <kim-marie.jones@intel.com>
Signed-off-by: NAlan Carey <alan.carey@intel.com>
Acked-by: NRami Rosen <rami.rosen@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RFC 7413 (TCP Fast Open) 4.2.2 states that the SYNACK message
MAY include data and/or FIN

This patch adds support for the client side :

If we receive a SYNACK with payload or FIN, queue the skb instead
of ignoring it.

Since we already support the same for SYN, we refactor the existing
code and reuse it. Note we need to clone the skb, so this operation
might fail under memory pressure.

Sara Dickinson pointed out FreeBSD server Fast Open implementation
was planned to generate such SYNACK in the future.

The server side might be implemented on linux later.
Reported-by: NSara Dickinson <sara@sinodun.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CC: Jiri Pirko <jiri@resnulli.us>
CC: netdev@vger.kernel.org
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds an rx_nohandler stat counter, along with a sysfs statistics
node, and copies the counter out via netlink as well.

CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@mellanox.com>
CC: Daniel Borkmann <daniel@iogearbox.net>
CC: Tom Herbert <tom@herbertland.com>
CC: Jay Vosburgh <j.vosburgh@gmail.com>
CC: Veaceslav Falico <vfalico@gmail.com>
CC: Andy Gospodarek <gospo@cumulusnetworks.com>
CC: netdev@vger.kernel.org
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A dma_addr_t is potentially smaller than a phys_addr_t on some archs.
Don't truncate the address when doing the pfn conversion.

Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Reported-by: NMatthew Wilcox <willy@linux.intel.com>
[willy: fix pfn_t_to_phys as well]
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Avoid populating pagecache when the block device is in DAX mode.
Otherwise these page cache entries collide with the fsync/msync
implementation and break data durability guarantees.

Cc: Jan Kara <jack@suse.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Tested-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NMatthew Wilcox <willy@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Dynamically enabling DAX requires that the page cache first be flushed
and invalidated.  This must occur atomically with the change of DAX mode
otherwise we confuse the fsync/msync tracking and violate data
durability guarantees.  Eliminate the possibilty of DAX-disabled to
DAX-enabled transitions for now and revisit this for the next cycle.

Cc: Jan Kara <jack@suse.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Similar to the file I/O path, re-direct all I/O to the DAX path for I/O
to a block-device special file.  Both regular files and device special
files can use the common filp->f_mapping->host lookup to determing is
DAX is enabled.

Otherwise, we confuse the DAX code that does not expect to find live
data in the page cache:

    ------------[ cut here ]------------
    WARNING: CPU: 0 PID: 7676 at mm/filemap.c:217
    __delete_from_page_cache+0x9f6/0xb60()
    Modules linked in:
    CPU: 0 PID: 7676 Comm: a.out Not tainted 4.4.0+ #276
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
     00000000ffffffff ffff88006d3f7738 ffffffff82999e2d 0000000000000000
     ffff8800620a0000 ffffffff86473d20 ffff88006d3f7778 ffffffff81352089
     ffffffff81658d36 ffffffff86473d20 00000000000000d9 ffffea0000009d60
    Call Trace:
     [<     inline     >] __dump_stack lib/dump_stack.c:15
     [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
     [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
     [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
     [<ffffffff81658d36>] __delete_from_page_cache+0x9f6/0xb60 mm/filemap.c:217
     [<ffffffff81658fb2>] delete_from_page_cache+0x112/0x200 mm/filemap.c:244
     [<ffffffff818af369>] __dax_fault+0x859/0x1800 fs/dax.c:487
     [<ffffffff8186f4f6>] blkdev_dax_fault+0x26/0x30 fs/block_dev.c:1730
     [<     inline     >] wp_pfn_shared mm/memory.c:2208
     [<ffffffff816e9145>] do_wp_page+0xc85/0x14f0 mm/memory.c:2307
     [<     inline     >] handle_pte_fault mm/memory.c:3323
     [<     inline     >] __handle_mm_fault mm/memory.c:3417
     [<ffffffff816ecec3>] handle_mm_fault+0x2483/0x4640 mm/memory.c:3446
     [<ffffffff8127eff6>] __do_page_fault+0x376/0x960 arch/x86/mm/fault.c:1238
     [<ffffffff8127f738>] trace_do_page_fault+0xe8/0x420 arch/x86/mm/fault.c:1331
     [<ffffffff812705c4>] do_async_page_fault+0x14/0xd0 arch/x86/kernel/kvm.c:264
     [<ffffffff86338f78>] async_page_fault+0x28/0x30 arch/x86/entry/entry_64.S:986
     [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a
    arch/x86/entry/entry_64.S:185
    ---[ end trace dae21e0f85f1f98c ]---

Fixes: 5a023cdb ("block: enable dax for raw block devices")
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Reported-by: NKirill A. Shutemov <kirill@shutemov.name>
Suggested-by: NJan Kara <jack@suse.cz>
Reviewed-by: NJan Kara <jack@suse.cz>
Suggested-by: NMatthew Wilcox <willy@linux.intel.com>
Tested-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The current implementation of ip6_dst_lookup_tail basically
ignore the egress ifindex match: if the saddr is set,
ip6_route_output() purposefully ignores flowi6_oif, due
to the commit d46a9d67 ("net: ipv6: Dont add RT6_LOOKUP_F_IFACE
flag if saddr set"), if the saddr is 'any' the first route lookup
in ip6_dst_lookup_tail fails, but upon failure a second lookup will
be performed with saddr set, thus ignoring the ifindex constraint.

This commit adds an output route lookup function variant, which
allows the caller to specify lookup flags, and modify
ip6_dst_lookup_tail() to enforce the ifindex match on the second
lookup via said helper.

ip6_route_output() becames now a static inline function build on
top of ip6_route_output_flags(); as a side effect, out-of-tree
modules need now a GPL license to access the output route lookup
functionality.
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJörg Thalheim <joerg@higgsboson.tk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update the comments around struct iommu_ops to match
current state and fix a few typos while at it.
Signed-off-by: NMagnus Damm <damm+renesas@opensource.se>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Having proper defines makes the code a bit readable, it also avoids
duplicating hard-coded values since these are also needed when
auto-allocating PSM values (in a subsequent patch).
Signed-off-by: NJohan Hedberg <johan.hedberg@intel.com>
Signed-off-by: NMarcel Holtmann <marcel@holtmann.org>

The orphan cleanup workqueue doesn't always catch orphans, for example,
if they never schedule after they are orphaned. IOW, the event leak is
still very real. It also wouldn't work for kernel counters.

Doing it synchonously is a little hairy due to lock inversion issues,
but is made to work.

Patch based on work by Alexander Shishkin.
Suggested-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Signed-off-by: NIngo Molnar <mingo@kernel.org>

Robustify refcounting.
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20160126045947.GA40151@ast-mbp.thefacebook.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

After we use refcnt to check if transport is alive, the dead can be
removed from sctp_transport.

The traversal of transport_addr_list in procfs dump is using
list_for_each_entry_rcu, no need to check if it has been freed.

sctp_generate_t3_rtx_event and sctp_generate_heartbeat_event is
protected by sock lock, it's not necessary to check dead, either.
also, the timers are cancelled when sctp_transport_free() is
called, that it doesn't wait for refcnt to reach 0 to cancel them.
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now when __sctp_lookup_association is running in BH, it will try to
check if t->dead is set, but meanwhile other CPUs may be freeing this
transport and this assoc and if it happens that
__sctp_lookup_association checked t->dead a bit too early, it may think
that the association is still good while it was already freed.

So we fix this race by using atomic_add_unless in sctp_transport_hold.
After we get one transport from hashtable, we will hold it only when
this transport's refcnt is not 0, so that we can make sure t->asoc
cannot be freed before we hold the asoc again.

Note that sctp association is not freed using RCU so we can't use
atomic_add_unless() with it as it may just be too late for that either.

Fixes: 4f008781 ("sctp: apply rhashtable api to send/recv path")
Reported-by: NVlad Yasevich <vyasevich@gmail.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Let cleancache_fs_enabled() call cleancache_fs_enabled_mapping()
directly.

Remove redundant variable ret in cleancache_get_page().
Signed-off-by: NChen Gang <gang.chen.5i5j@gmail.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

The cleancache_ops structure is never modified, so declare it as const.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Allow a signal to interrupt the wait for a tty reopen; eg., if
the tty has starting final close and is waiting for the device to
drain.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Cc: stable <stable@vger.kernel.org> # 4.4
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Export further minor feature bitmasks and the varyings count from
the GPU specifications registers to userspace.
Acked-by: NChristian Gmeiner <christian.gmeiner@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>

Let's take the (outlandish) example of an interrupt controller
capable of handling both wired interrupts and PCI MSIs.

With the current code, the PCI MSI domain is going to be tagged
with DOMAIN_BUS_PCI_MSI, and the wired domain with DOMAIN_BUS_ANY.

Things get hairy when we start looking up the domain for a wired
interrupt (typically when creating it based on some firmware
information - DT or ACPI).

In irq_create_fwspec_mapping(), we perform the lookup using
DOMAIN_BUS_ANY, which is actually used as a wildcard. This gives
us one chance out of two to end up with the wrong domain, and
we try to configure a wired interrupt with the MSI domain.
Everything grinds to a halt pretty quickly.

What we really need to do is to start looking for a domain that
would uniquely identify a wired interrupt domain, and only use
DOMAIN_BUS_ANY as a fallback.

In order to solve this, let's introduce a new DOMAIN_BUS_WIRED
token, which is going to be used exactly as described above.
Of course, this depends on the irqchip to setup the domain
bus_token, and nobody had to implement this so far.

Only so far.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Link: http://lkml.kernel.org/r/1453816347-32720-2-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

timeline was wrongly assigned with ->get_driver_name().

Link: http://lkml.kernel.org/r/1453376895-30747-1-git-send-email-gustavo@padovan.orgSigned-off-by: NGustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The napi_synchronize() function is defined twice: The definition
for SMP builds waits for other CPUs to be done, while the uniprocessor
variant just contains a barrier and ignores its argument.

In the mvneta driver, this leads to a warning about an unused variable
when we lookup the NAPI struct of another CPU and then don't use it:

ethernet/marvell/mvneta.c: In function 'mvneta_percpu_notifier':
ethernet/marvell/mvneta.c:2910:30: error: unused variable 'other_port' [-Werror=unused-variable]

There are no other CPUs on a UP build, so that code never runs, but
gcc does not know this.

The nicest solution seems to be to turn the napi_synchronize() helper
into an inline function for the UP case as well, as that leads gcc to
not complain about the argument being unused. Once we do that, we can
also combine the two cases into a single function definition and use
if(IS_ENABLED()) rather than #ifdef to make it look a bit nicer.

The warning first came up in linux-4.4, but I failed to catch it
earlier.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: f8642885 ("net: mvneta: Statically assign queues to CPUs")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The "dual_image" and "inactive_flag" fields should be merged into a single
"image_sequence" field.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11834/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The extended flash address needs to be subtracted from bcm_tag flash
image offsets. Move this value to the bcm_tag header file.

Renamed define name to consistently use bcm963xx for flash layout
which should be considered a property of the board and not the SoC
(i.e. bcm63xx could theoretically be used on a board without CFE
or any flash).
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11833/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Move Broadcom BCM963xx image tag data structure to include/linux/
so that drivers outside of mach-bcm63xx can use it.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11832/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Broadcom BCM963xx boards have multiple nvram variants across different
SoCs with additional checksum fields added whenever the size of the
nvram was extended.

Add this structure as a header file so that multiple drivers can use it.
Signed-off-by: NSimon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11830/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This adds support for the Microchip PIC32 MIPS microcontroller with the
specific variant PIC32MZDA. PIC32MZDA is based on the MIPS m14KEc core
and boots using device tree.

This includes an early pin setup and early clock setup needed prior to
device tree being initialized. In additon, an interface is provided to
synchronize access to registers shared across several peripherals.
Signed-off-by: NJoshua Henderson <joshua.henderson@microchip.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12097/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

To properly handle fsync/msync in an efficient way DAX needs to track
dirty pages so it is able to flush them durably to media on demand.

The tracking of dirty pages is done via the radix tree in struct
address_space.  This radix tree is already used by the page writeback
infrastructure for tracking dirty pages associated with an open file,
and it already has support for exceptional (non struct page*) entries.
We build upon these features to add exceptional entries to the radix
tree for DAX dirty PMD or PTE pages at fault time.

[dan.j.williams@intel.com: fix dax_pmd_dbg build warning]
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add find_get_entries_tag() to the family of functions that include
find_get_entries(), find_get_pages() and find_get_pages_tag().  This is
needed for DAX dirty page handling because we need a list of both page
offsets and radix tree entries ('indices' and 'entries' in this
function) that are marked with the PAGECACHE_TAG_TOWRITE tag.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add support for tracking dirty DAX entries in the struct address_space
radix tree.  This tree is already used for dirty page writeback, and it
already supports the use of exceptional (non struct page*) entries.

In order to properly track dirty DAX pages we will insert new
exceptional entries into the radix tree that represent dirty DAX PTE or
PMD pages.  These exceptional entries will also contain the writeback
addresses for the PTE or PMD faults that we can use at fsync/msync time.

There are currently two types of exceptional entries (shmem and shadow)
that can be placed into the radix tree, and this adds a third.  We rely
on the fact that only one type of exceptional entry can be found in a
given radix tree based on its usage.  This happens for free with DAX vs
shmem but we explicitly prevent shadow entries from being added to radix
trees for DAX mappings.

The only shadow entries that would be generated for DAX radix trees
would be to track zero page mappings that were created for holes.  These
pages would receive minimal benefit from having shadow entries, and the
choice to have only one type of exceptional entry in a given radix tree
makes the logic simpler both in clear_exceptional_entry() and in the
rest of DAX.
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

__arch_wb_cache_pmem() was already an internal implementation detail of
the x86 PMEM API, but this functionality needs to be exported as part of
the general PMEM API to handle the fsync/msync case for DAX mmaps.

One thing worth noting is that we really do want this to be part of the
PMEM API as opposed to a stand-alone function like clflush_cache_range()
because of ordering restrictions.  By having wb_cache_pmem() as part of
the PMEM API we can leave it unordered, call it multiple times to write
back large amounts of memory, and then order the multiple calls with a
single wmb_pmem().
Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This crash is caused by NULL pointer deference, in page_to_pfn() marco,
when page == NULL :

  Unable to handle kernel NULL pointer dereference at virtual address 00000000
  Internal error: Oops: 94000006 [#1] SMP
  Modules linked in:
  CPU: 1 PID: 26 Comm: khugepaged Tainted: G        W       4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3
  PC is at khugepaged+0x378/0x1af8
  LR is at khugepaged+0x418/0x1af8
  Process khugepaged (pid: 26, stack limit = 0xffffffc079638020)
  Call trace:
    khugepaged+0x378/0x1af8
    kthread+0xdc/0xf4
    ret_from_fork+0xc/0x40
  Code: 35001700 f0002c60 aa0703e3 f9009fa0 (f94000e0)
  ---[ end trace 637503d8e28ae69e  ]---
  Kernel panic - not syncing: Fatal exception
  CPU2: stopping
  CPU: 2 PID: 0 Comm: swapper/2 Tainted: G      D W       4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3
  Hardware name: linux,dummy-virt (DT)

[akpm@linux-foundation.org: fix fat-fingered merge resolution]
Signed-off-by: Nyalin wang <yalin.wang2010@gmail.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After THP refcounting rework we have only two possible return values
from pmd_trans_huge_lock(): success and failure.  Return-by-pointer for
ptl doesn't make much sense in this case.

Let's convert pmd_trans_huge_lock() to return ptl on success and NULL on
failure.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Suggested-by: NLinus Torvalds <torvalds@linux-foundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The cgroup methods are no longer used after baac50bb ("net:
tcp_memcontrol: simplify linkage between socket and page counter").
The hunk to delete them was included in the original patch but must
have gotten lost during conflict resolution on the way upstream.

Fixes: baac50bb ("net: tcp_memcontrol: simplify linkage between socket and page counter")
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There are a number of problems with revoking a "was sending" message:

(1) We never make any attempt to revoke data - only kvecs contibute to
con->out_skip.  However, once the header (envelope) is written to the
socket, our peer learns data_len and sets itself to expect at least
data_len bytes to follow front or front+middle.  If ceph_msg_revoke()
is called while the messenger is sending message's data portion,
anything we send after that call is counted by the OSD towards the now
revoked message's data portion.  The effects vary, the most common one
is the eventual hang - higher layers get stuck waiting for the reply to
the message that was sent out after ceph_msg_revoke() returned and
treated by the OSD as a bunch of data bytes.  This is what Matt ran
into.

(2) Flat out zeroing con->out_kvec_bytes worth of bytes to handle kvecs
is wrong.  If ceph_msg_revoke() is called before the tag is sent out or
while the messenger is sending the header, we will get a connection
reset, either due to a bad tag (0 is not a valid tag) or a bad header
CRC, which kind of defeats the purpose of revoke.  Currently the kernel
client refuses to work with header CRCs disabled, but that will likely
change in the future, making this even worse.

(3) con->out_skip is not reset on connection reset, leading to one or
more spurious connection resets if we happen to get a real one between
con->out_skip is set in ceph_msg_revoke() and before it's cleared in
write_partial_skip().

Fixing (1) and (3) is trivial.  The idea behind fixing (2) is to never
zero the tag or the header, i.e. send out tag+header regardless of when
ceph_msg_revoke() is called.  That way the header is always correct, no
unnecessary resets are induced and revoke stands ready for disabled
CRCs.  Since ceph_msg_revoke() rips out con->out_msg, introduce a new
"message out temp" and copy the header into it before sending.

Cc: stable@vger.kernel.org # 4.0+
Reported-by: NMatt Conner <matt.conner@keepertech.com>
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Tested-by: NMatt Conner <matt.conner@keepertech.com>
Reviewed-by: NSage Weil <sage@redhat.com>

This patch makes ceph_frag_contains_value return bool to improve
readability due to this particular function only using either one or
zero as its return value.

No functional change.
Signed-off-by: NYaowei Bai <baiyaowei@cmss.chinamobile.com>
Signed-off-by: NYan, Zheng <zyan@redhat.com>