With write back cache, we use orig_page to do prexor. This patch
makes sure we read data into orig_page for it.

Flag R5_OrigPageUPTDODATE is added to show whether orig_page
has the latest data from raid disk.

We introduce a helper function uptodate_for_rmw() to simplify
the a couple conditions in handle_stripe_dirtying().
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Shaohua Li <shli@fb.com>

sector_t is unsigned long, it's never < 0
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Shaohua Li <shli@fb.com>

Pull sound fixes from Takashi Iwai:
 "This time we got a few more fixes than the previous rc's, and most of
  commits were about ASoC.

  The only significant change in the core side is the regression fix wrt
  the aux device list handling, and all the rest are driver-specific
  small / trivial fixes"

* tag 'sound-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: usb-audio: Add a quirk for Plantronics BT600
  ASoC: rt5645: set sel_i2s_pre_div1 to 2
  ASoC: dpcm: Avoid putting stream state to STOP when FE stream is paused
  ASoC: Intel: Skylake: Release FW ctx in cleanup
  ASoC: Intel: bytcr-rt5640: fix settings in internal clock mode
  ASoC: fsl_ssi: set fifo watermark to more reliable value
  ASoC: nau8825: fix invalid configuration in Pre-Scalar of FLL
  ASoC: nau8825: correct the function name of register
  ASoC: Intel: Skylake: Fix to fail safely if module not available in path
  ASoC: tlv320aic3x: Mark the RESET register as volatile
  ASoC: Fix binding and probing of auxiliary components
  ASoC: wm_adsp: Don't overrun firmware file buffer when reading region data
  ASoC: Intel: bytcr_rt5640: fallback mechanism if MCLK is not enabled
  ASoC: hdmi-codec: use unsigned type to structure members with bit-field
  ASoC: topology: kfree kcontrol->private_value before freeing kcontrol
  ASoC: rsnd: don't double free kctrl
  ASoC: dwc: Fix PIO mode initialization

Pull xfs fixes from Darrick Wong:
 "As promised last week, here's some stability fixes from Christoph and
  Jan Kara:

   - fix free space request handling when low on disk space

   - remove redundant log failure error messages

   - free truncated dirty pages instead of letting them build up
     forever"

* tag 'xfs-for-linus-4.10-rc4-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: Timely free truncated dirty pages
  xfs: don't print warnings when xfs_log_force fails
  xfs: don't rely on ->total in xfs_alloc_space_available
  xfs: adjust allocation length in xfs_alloc_space_available
  xfs: fix bogus minleft manipulations
  xfs: bump up reserved blocks in xfs_alloc_set_aside

Pull remoteproc fixes from Bjorn Andersson:
 "This fixes two regressions that have been reported to be introduced in
  v4.10-rc1.

   - correct an incorrect usage of the kref api

   - revert the change to make the resource table read-only. As the
     space each vdev resource is used as virtio device config space it
     must be shared with the remote"

* tag 'rproc-v4.10-fixes' of git://github.com/andersson/remoteproc:
  Revert "remoteproc: Merge table_ptr and cached_table pointers"
  remoteproc: fix vdev reference management

Pull rpmsg fixes from Bjorn Andersson:
 "This fixes a regression introduced in v4.10-rc1 that prohibits
  multiple channels with the same name but different endpoint addresses
  to be used"

* tag 'rpmsg-v4.10-fixes' of git://github.com/andersson/remoteproc:
  rpmsg: virtio_rpmsg_bus: fix channel creation

Pull HID fixes from Jiri Kosina:

 - device descriptor length validation fix to hid-cypress driver from
   Greg

 - introduction of a short delay into i2c-hid, which is not really
   mandated by the spec, but fixes Asus Touchpads

 - Petzl USB connectable flashlight quirk from myself

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: i2c-hid: Add sleep between POWER ON and RESET
  HID: hid-cypress: validate length of report
  HID: ignore Petzl USB headlamp

Merge branch 'scsi-target-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bvanassche/linux

Pull scsi target fixes from Bart Van Assche:

 - a series of bug fixes for the XCOPY implementation from David
   Disseldorp

 - one bug fix for the ibmvscsis driver, a driver that is used for
   communication between partitions on IBM POWER systems.

* 'scsi-target-for-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/bvanassche/linux:
  ibmvscsis: Fix srp_transfer_data fail return code
  target: support XCOPY requests without parameters
  target: check for XCOPY parameter truncation
  target: use XCOPY segment descriptor CSCD IDs
  target: check XCOPY segment descriptor CSCD IDs
  target: simplify XCOPY wwn->se_dev lookup helper
  target: return UNSUPPORTED TARGET/SEGMENT DESC TYPE CODE sense
  target: bounds check XCOPY total descriptor list length
  target: bounds check XCOPY segment descriptor list
  target: use XCOPY TOO MANY TARGET DESCRIPTORS sense
  target: add XCOPY target/segment desc sense codes

Pull md fixes from Shaohua Li:
 "Basically one fix for raid5 cache which is merged in this cycle,
  others are trival fixes"

* tag 'md/4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md:
  md/raid5: Use correct IS_ERR() variation on pointer check
  md: cleanup mddev flag clear for takeover
  md/r5cache: fix spelling mistake on "recoverying"
  md/r5cache: assign conf->log before r5l_load_log()
  md/r5cache: simplify handling of sh->log_start in recovery
  md/raid5-cache: removes unnecessary write-through mode judgments
  md/raid10: Refactor raid10_make_request
  md/raid1: Refactor raid1_make_request

Support for the Asus Touchpad was recently added. It turns out this
device can fail initialisation (and become unusable) when the RESET
command is sent too soon after the POWER ON command.

Unfortunately the i2c-hid specification does not specify the need for
a delay between these two commands. But it was discovered the Windows
driver has a 1ms delay.

As a result, this patch modifies the i2c-hid module to add a sleep
inbetween the POWER ON and RESET commands which lasts between 1ms and 5ms.

See https://github.com/vlasenko/hid-asus-dkms/issues/24 for further
details.
Signed-off-by: Brendan McGrath <redmcg@redmandi.dyndns.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Merge fixes from Andrew Morton:
 "27 fixes.

  There are three patches that aren't actually fixes. They're simple
  function renamings which are nice-to-have in mainline as ongoing net
  development depends on them."

* akpm: (27 commits)
  timerfd: export defines to userspace
  mm/hugetlb.c: fix reservation race when freeing surplus pages
  mm/slab.c: fix SLAB freelist randomization duplicate entries
  zram: support BDI_CAP_STABLE_WRITES
  zram: revalidate disk under init_lock
  mm: support anonymous stable page
  mm: add documentation for page fragment APIs
  mm: rename __page_frag functions to __page_frag_cache, drop order from drain
  mm: rename __alloc_page_frag to page_frag_alloc and __free_page_frag to page_frag_free
  mm, memcg: fix the active list aging for lowmem requests when memcg is enabled
  mm: don't dereference struct page fields of invalid pages
  mailmap: add codeaurora.org names for nameless email commits
  signal: protect SIGNAL_UNKILLABLE from unintentional clearing.
  mm: pmd dirty emulation in page fault handler
  ipc/sem.c: fix incorrect sem_lock pairing
  lib/Kconfig.debug: fix frv build failure
  mm: get rid of __GFP_OTHER_NODE
  mm: fix remote numa hits statistics
  mm: fix devm_memremap_pages crash, use mem_hotplug_{begin, done}
  ocfs2: fix crash caused by stale lvb with fsdlm plugin
  ...

Merge tag 'asoc-fix-v4.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus

ASoC: Fixes for v4.10

As well as the usual smattering of driver specific fixes collected since
the merge window this has one particularly important fix to the core for
handling of aux_devs which was broken during the merge window by some of
the componentization refactoring.

Commit 99579cce "xfs: skip dirty pages in ->releasepage()" started
to skip dirty pages in xfs_vm_releasepage() which also has the effect
that if a dirty page is truncated, it does not get freed by
block_invalidatepage() and is lingering in LRU list waiting for reclaim.
So a simple loop like:

while true; do
	dd if=/dev/zero of=file bs=1M count=100
	rm file
done

will keep using more and more memory until we hit low watermarks and
start pagecache reclaim which will eventually reclaim also the truncate
pages. Keeping these truncated (and thus never usable) pages in memory
is just a waste of memory, is unnecessarily stressing page cache
reclaim, and reportedly also leads to anonymous mmap(2) returning ENOMEM
prematurely.

So instead of just skipping dirty pages in xfs_vm_releasepage(), return
to old behavior of skipping them only if they have delalloc or unwritten
buffers and fix the spurious warnings by warning only if the page is
clean.

CC: stable@vger.kernel.org
CC: Brian Foster <bfoster@redhat.com>
CC: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Petr Tůma <petr.tuma@d3s.mff.cuni.cz>
Fixes: 99579cceSigned-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Pull networking fixes from David Miller:

 1) Fix rtlwifi crash, from Larry Finger.

 2) Memory disclosure in appletalk ipddp routing code, from Vlad
    Tsyrklevich.

 3) r8152 can erroneously split an RX packet into multiple URBs if the
    Rx FIFO is not empty when we suspend. Fix this by waiting for the
    FIFO to empty before suspending. From Hayes Wang.

 4) Two GRO fixes (enter slow path when not enough SKB tail room exists,
    disable frag0 optimizations when there are IPV6 extension headers)
    from Eric Dumazet and Herbert Xu.

 5) A series of mlx5e bug fixes (do source udp port offloading for
    tunnels properly, Ip fragment matching fixes, handling firmware
    errors properly when installing TC rules, etc.) from Saeed Mahameed,
    Or Gerlitz, Roi Dayan, Hadar Hen Zion, Gil Rockah, and Daniel
    Jurgens.

 6) Two VRF fixes from David Ahern (don't skip multipath selection for
    VRF paths, disallow VRF to be configured with table ID 0).

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (35 commits)
  net: vrf: do not allow table id 0
  net: phy: marvell: fix Marvell 88E1512 used in SGMII mode
  sctp: Fix spelling mistake: "Atempt" -> "Attempt"
  net: ipv4: Fix multipath selection with vrf
  cgroup: move CONFIG_SOCK_CGROUP_DATA to init/Kconfig
  gro: use min_t() in skb_gro_reset_offset()
  net/mlx5: Only cancel recovery work when cleaning up device
  net/mlx5e: Remove WARN_ONCE from adaptive moderation code
  net/mlx5e: Un-register uplink representor on nic_disable
  net/mlx5e: Properly handle FW errors while adding TC rules
  net/mlx5e: Fix kbuild warnings for uninitialized parameters
  net/mlx5e: Set inline mode requirements for matching on IP fragments
  net/mlx5e: Properly get address type of encapsulation IP headers
  net/mlx5e: TC ipv4 tunnel encap offload error flow fixes
  net/mlx5e: Warn when rejecting offload attempts of IP tunnels
  net/mlx5e: Properly handle offloading of source udp port for IP tunnels
  gro: Disable frag0 optimization on IPv6 ext headers
  gro: Enter slow-path if there is no tailroom
  mlx4: Return EOPNOTSUPP instead of ENOTSUPP
  net/af_iucv: don't use paged skbs for TX on HiperSockets
  ...

Pull crypto fix from Herbert Xu:
 "This fixes a regression in aesni that renders it useless if it's
  built-in with a modular pcbc configuration"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: aesni - Fix failure when built-in with modular pcbc

Frank reported that vrf devices can be created with a table id of 0.
This breaks many of the run time table id checks and should not be
allowed. Detect this condition at create time and fail with EINVAL.

Fixes: 193125db ("net: Introduce VRF device driver")
Reported-by: Frank Kellermann <frank.kellermann@atos.net>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When an Marvell 88E1512 PHY is connected to a nic in SGMII mode, the
fiber page is used for the SGMII host-side connection.  The PHY driver
notices that SUPPORTED_FIBRE is set, so it tries reading the fiber page
for the link status, and ends up reading the MAC-side status instead of
the outgoing (copper) link.  This leads to incorrect results reported
via ethtool.

If the PHY is connected via SGMII to the host, ignore the fiber page.
However, continue to allow the existing power management code to
suspend and resume the fiber page.

Fixes: 6cfb3bcc ("Marvell phy: check link status in case of fiber link.")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Trivial fix to spelling mistake in WARN_ONCE message
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

fib_select_path does not call fib_select_multipath if oif is set in the
flow struct. For VRF use cases oif is always set, so multipath route
selection is bypassed. Use the FLOWI_FLAG_SKIP_NH_OIF to skip the oif
check similar to what is done in fib_table_lookup.

Add saddr and proto to the flow struct for the fib lookup done by the
VRF driver to better match hash computation for a flow.

Fixes: 613d09b3 ("net: Use VRF device index for lookups on TX")
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We now 'select SOCK_CGROUP_DATA' but Kconfig complains that this is
not right when CONFIG_NET is disabled and there is no socket interface:

warning: (CGROUP_BPF) selects SOCK_CGROUP_DATA which has unmet direct dependencies (NET)

I don't know what the correct solution for this is, but simply removing
the dependency on NET from SOCK_CGROUP_DATA by moving it out of the
'if NET' section avoids the warning and does not produce other build
errors.

Fixes: 483c4933 ("cgroup: Fix CGROUP_BPF config")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

On 32bit arches, (skb->end - skb->data) is not 'unsigned int',
so we shall use min_t() instead of min() to avoid a compiler error.

Fixes: 1272ce87 ("gro: Enter slow-path if there is no tailroom")
Reported-by: kernel test robot <fengguang.wu@intel.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Saeed Mahameed says:

====================
Mellanox mlx5 fixes and cleanups 2017-01-10

This series includes some mlx5e general cleanups from Daniel, Gil, Hadar
and myself.
Also it includes some critical mlx5e TC offloads fixes from Or Gerlitz.

For -stable:
 - net/mlx5e: Remove WARN_ONCE from adaptive moderation code

   Although this fix doesn't affect any functionality, I thought it is
   better to clean this -WARN_ONCE- up for -stable in case someone hits
   such corner case.

Please apply and let me know if there's any problem.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Do not attempt to drain the health workqueue when unloading the device in
the recovery flow, this can cause a deadlock when the recovery work
tries to cancel itself with sync.

Because the work is no longer unconditionally canceled when unloading, it
must be explicitly canceled in the AER flow.

fixes: 689a248d ("net/mlx5: Cancel recovery work in remove flow")
Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When trying to do interface down or changing interface configuration
under heavy traffic, some of the adaptive moderation corner cases can
occur and leave a WARN_ONCE call trace in the kernel log.

Those WARN_ONCE are meant for debug only, and should have been inserted
only under debug. We avoid such call traces by removing those WARN_ONCE.

Fixes: cb3c7fd4 ("net/mlx5e: Support adaptive RX coalescing")
Signed-off-by: Gil Rockah <gilr@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The code before this patch registered uplink e-Switch representor
on nic_enable and unregistered on nic_cleanup, the right place
for this unregister is in nic_disable.

Fixes: 127ea380 ("net/mlx5: Add Representors registration API")
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Reviewed-by: Mohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the firmware returns an error (common example is an attempt to
add twice the same rule which is refused by the some FWs), we are not
properly derefing/cleaning few resources allocated on the way.
Examples are vport vlan deref under eswitch vlan offloads, and encap
entry/neighbour deref under eswitch encapsulation offloads, fix that.

Fixes: a54e20b4 ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads')
Fixes: 8b32580d ('net/mlx5e: Add TC vlan action for SRIOV offloads')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

kbuild warn about parameters that may be used uninitialized, fix it.

Fixes: a54e20b4 ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads')
Signed-off-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

For e-switch level matching on packets being an IP fragment, we
need to make sure the source vport inline mode is L3, fix that.

Fixes: 3f7d0eb4 ('net/mlx5e: Offload TC matching on packets being IP fragments')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As done elsewhere in our TC/flower offload code, the address type of
the encapsulation IP headers should be realized accroding to the
addr_type field of the encapsulation control dissector key, do that.

Fixes: bbd00f7e ('net/mlx5e: Add TC tunnel release action for SRIOV offloads')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When the route lookup fails we should return the actual error.

When the neigh isn't valid, we should return -EOPNOTSUPP as done
in similar cases along the code.

When the offload can't take place as of invalid neigh etc, we
must release the neigh.

Fixes: a54e20b4 ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We silently reject offloading of IPv6 tunnels, non vxlan tunnels,
vxlan tunnels where the dst port to match is not provided, etc.

Be a bit more verbose and print a warning so the user better
realizes what went wrong here and can fix it.

Fixes: a54e20b4 ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads')
Fixes: bbd00f7e ('net/mlx5e: Add TC tunnel release action for SRIOV offloads')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

We can offload the matching on source udp port of ip tunnels for
decapsulation. We can not offload setting source udp port for tunnels
as part of encapsulation. Fix both the code that deals with matching
offload (decap) and the code that deal with encap offload to align with
that.

Fixes: a54e20b4 ('net/mlx5e: Add basic TC tunnel set action for SRIOV offloads')
Fixes: bbd00f7e ('net/mlx5e: Add TC tunnel release action for SRIOV offloads')
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Hadar Hen Zion <hadarh@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Since userspace is expected to call timerfd syscalls directly with these
flags/ioctls, make sure we export them so they don't have to duplicate
the values themselves.

Link: http://lkml.kernel.org/r/20161219064052.7196-1-vapier@gentoo.orgSigned-off-by: Mike Frysinger <vapier@gentoo.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

return_unused_surplus_pages() decrements the global reservation count,
and frees any unused surplus pages that were backing the reservation.

Commit 7848a4bf ("mm/hugetlb.c: add cond_resched_lock() in
return_unused_surplus_pages()") added a call to cond_resched_lock in the
loop freeing the pages.

As a result, the hugetlb_lock could be dropped, and someone else could
use the pages that will be freed in subsequent iterations of the loop.
This could result in inconsistent global hugetlb page state, application
api failures (such as mmap) failures or application crashes.

When dropping the lock in return_unused_surplus_pages, make sure that
the global reservation count (resv_huge_pages) remains sufficiently
large to prevent someone else from claiming pages about to be freed.

Analyzed by Paul Cassella.

Fixes: 7848a4bf ("mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()")
Link: http://lkml.kernel.org/r/1483991767-6879-1-git-send-email-mike.kravetz@oracle.comSigned-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Paul Cassella <cassella@cray.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: <stable@vger.kernel.org>	[3.15+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch fixes a bug in the freelist randomization code.  When a high
random number is used, the freelist will contain duplicate entries.  It
will result in different allocations sharing the same chunk.

It will result in odd behaviours and crashes.  It should be uncommon but
it depends on the machines.  We saw it happening more often on some
machines (every few hours of running tests).

Fixes: c7ce4f60 ("mm: SLAB freelist randomization")
Link: http://lkml.kernel.org/r/20170103181908.143178-1-thgarnie@google.comSigned-off-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Thomas Garnier <thgarnie@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

zram has used per-cpu stream feature from v4.7.  It aims for increasing
cache hit ratio of scratch buffer for compressing.  Downside of that
approach is that zram should ask memory space for compressed page in
per-cpu context which requires stricted gfp flag which could be failed.
If so, it retries to allocate memory space out of per-cpu context so it
could get memory this time and compress the data again, copies it to the
memory space.

In this scenario, zram assumes the data should never be changed but it is
not true without stable page support.  So, If the data is changed under
us, zram can make buffer overrun so that zsmalloc free object chain is
broken so system goes crash like below

   https://bugzilla.suse.com/show_bug.cgi?id=997574

This patch adds BDI_CAP_STABLE_WRITES to zram for declaring "I am block
device needing *stable write*".

Fixes: da9556a2 ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-4-git-send-email-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Commit b4c5c609 ("zram: avoid lockdep splat by revalidate_disk")
moved revalidate_disk call out of init_lock to avoid lockdep
false-positive splat.  However, commit 08eee69f ("zram: remove
init_lock in zram_make_request") removed init_lock in IO path so there
is no worry about lockdep splat.  So, let's restore it.

This patch is needed to set BDI_CAP_STABLE_WRITES atomically in next
patch.

Fixes: da9556a2 ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/1482366980-3782-3-git-send-email-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

During developemnt for zram-swap asynchronous writeback, I found strange
corruption of compressed page, resulting in:

  Modules linked in: zram(E)
  CPU: 3 PID: 1520 Comm: zramd-1 Tainted: G            E   4.8.0-mm1-00320-ge0d4894c9c38-dirty #3274
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
  task: ffff88007620b840 task.stack: ffff880078090000
  RIP: set_freeobj.part.43+0x1c/0x1f
  RSP: 0018:ffff880078093ca8  EFLAGS: 00010246
  RAX: 0000000000000018 RBX: ffff880076798d88 RCX: ffffffff81c408c8
  RDX: 0000000000000018 RSI: 0000000000000000 RDI: 0000000000000246
  RBP: ffff880078093cb0 R08: 0000000000000000 R09: 0000000000000000
  R10: ffff88005bc43030 R11: 0000000000001df3 R12: ffff880076798d88
  R13: 000000000005bc43 R14: ffff88007819d1b8 R15: 0000000000000001
  FS:  0000000000000000(0000) GS:ffff88007e380000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00007fc934048f20 CR3: 0000000077b01000 CR4: 00000000000406e0
  Call Trace:
    obj_malloc+0x22b/0x260
    zs_malloc+0x1e4/0x580
    zram_bvec_rw+0x4cd/0x830 [zram]
    page_requests_rw+0x9c/0x130 [zram]
    zram_thread+0xe6/0x173 [zram]
    kthread+0xca/0xe0
    ret_from_fork+0x25/0x30

With investigation, it reveals currently stable page doesn't support
anonymous page.  IOW, reuse_swap_page can reuse the page without waiting
writeback completion so it can overwrite page zram is compressing.

Unfortunately, zram has used per-cpu stream feature from v4.7.
It aims for increasing cache hit ratio of scratch buffer for
compressing. Downside of that approach is that zram should ask
memory space for compressed page in per-cpu context which requires
stricted gfp flag which could be failed. If so, it retries to
allocate memory space out of per-cpu context so it could get memory
this time and compress the data again, copies it to the memory space.

In this scenario, zram assumes the data should never be changed
but it is not true unless stable page supports. So, If the data is
changed under us, zram can make buffer overrun because second
compression size could be bigger than one we got in previous trial
and blindly, copy bigger size object to smaller buffer which is
buffer overrun. The overrun breaks zsmalloc free object chaining
so system goes crash like above.

I think below is same problem.
https://bugzilla.suse.com/show_bug.cgi?id=997574

Unfortunately, reuse_swap_page should be atomic so that we cannot wait on
writeback in there so the approach in this patch is simply return false if
we found it needs stable page.  Although it increases memory footprint
temporarily, it happens rarely and it should be reclaimed easily althoug
it happened.  Also, It would be better than waiting of IO completion,
which is critial path for application latency.

Fixes: da9556a2 ("zram: user per-cpu compression streams")
Link: http://lkml.kernel.org/r/20161120233015.GA14113@bbox
Link: http://lkml.kernel.org/r/1482366980-3782-2-git-send-email-minchan@kernel.orgSigned-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Hyeoncheol Lee <cheol.lee@lge.com>
Cc: <yjay.kim@lge.com>
Cc: Sangseok Lee <sangseok.lee@lge.com>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This is a first pass at trying to add documentation for the page_frag
APIs.  They may still change over time but for now I thought I would try
to get these documented so that as more network drivers and stack calls
make use of them we have one central spot to document how they are meant
to be used.

Link: http://lkml.kernel.org/r/20170104024157.13451.6758.stgit@localhost.localdomainSigned-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This patch does two things.

First it goes through and renames the __page_frag prefixed functions to
__page_frag_cache so that we can be clear that we are draining or
refilling the cache, not the frags themselves.

Second we drop the order parameter from __page_frag_cache_drain since we
don't actually need to pass it since all fragments are either order 0 or
must be a compound page.

Link: http://lkml.kernel.org/r/20170104023954.13451.5678.stgit@localhost.localdomainSigned-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>