A value is assigned to 'nr_entries' but is never used, remove it.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Subtracting sizes is a fragile approach because the result is only
correct if the compiler has not added any padding at the end of the
structure. Hence use offsetof() instead of size subtraction. An
additional advantage of offsetof() is that it makes the intent more
clear.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Use a single statement to declare and initialize 'use_blk_mq' instead
of two statements.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

After QUEUE_FLAG_DYING has been set any code that is waiting in
get_request() should be woken up.  But to get this behaviour
blk_set_queue_dying() must be used instead of only setting
QUEUE_FLAG_DYING.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

If the first allocation attempt using GFP_NOWAIT fails, drop the lock
and retry using GFP_NOIO allocation (lock is dropped because the
allocation can take some time).

Note that we won't do GFP_NOIO allocation when we loop for the second
time, because the lock shouldn't be dropped between __wait_for_free_buffer
and __get_unclaimed_buffer.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

dm_bufio_shrink_count() is called from do_shrink_slab to find out how many
freeable objects are there. The reported value doesn't have to be precise,
so we don't need to take the dm-bufio lock.
Suggested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

We've seen in-field reports showing _lots_ (18 in one case, 41 in
another) of tasks all sitting there blocked on:

  mutex_lock+0x4c/0x68
  dm_bufio_shrink_count+0x38/0x78
  shrink_slab.part.54.constprop.65+0x100/0x464
  shrink_zone+0xa8/0x198

In the two cases analyzed, we see one task that looks like this:

  Workqueue: kverityd verity_prefetch_io

  __switch_to+0x9c/0xa8
  __schedule+0x440/0x6d8
  schedule+0x94/0xb4
  schedule_timeout+0x204/0x27c
  schedule_timeout_uninterruptible+0x44/0x50
  wait_iff_congested+0x9c/0x1f0
  shrink_inactive_list+0x3a0/0x4cc
  shrink_lruvec+0x418/0x5cc
  shrink_zone+0x88/0x198
  try_to_free_pages+0x51c/0x588
  __alloc_pages_nodemask+0x648/0xa88
  __get_free_pages+0x34/0x7c
  alloc_buffer+0xa4/0x144
  __bufio_new+0x84/0x278
  dm_bufio_prefetch+0x9c/0x154
  verity_prefetch_io+0xe8/0x10c
  process_one_work+0x240/0x424
  worker_thread+0x2fc/0x424
  kthread+0x10c/0x114

...and that looks to be the one holding the mutex.

The problem has been reproduced on fairly easily:
0. Be running Chrome OS w/ verity enabled on the root filesystem
1. Pick test patch: http://crosreview.com/412360
2. Install launchBalloons.sh and balloon.arm from
     http://crbug.com/468342
   ...that's just a memory stress test app.
3. On a 4GB rk3399 machine, run
     nice ./launchBalloons.sh 4 900 100000
   ...that tries to eat 4 * 900 MB of memory and keep accessing.
4. Login to the Chrome web browser and restore many tabs

With that, I've seen printouts like:
  DOUG: long bufio 90758 ms
...and stack trace always show's we're in dm_bufio_prefetch().

The problem is that we try to allocate memory with GFP_NOIO while
we're holding the dm_bufio lock.  Instead we should be using
GFP_NOWAIT.  Using GFP_NOIO can cause us to sleep while holding the
lock and that causes the above problems.

The current behavior explained by David Rientjes:

  It will still try reclaim initially because __GFP_WAIT (or
  __GFP_KSWAPD_RECLAIM) is set by GFP_NOIO.  This is the cause of
  contention on dm_bufio_lock() that the thread holds.  You want to
  pass GFP_NOWAIT instead of GFP_NOIO to alloc_buffer() when holding a
  mutex that can be contended by a concurrent slab shrinker (if
  count_objects didn't use a trylock, this pattern would trivially
  deadlock).

This change significantly increases responsiveness of the system while
in this state.  It makes a real difference because it unblocks kswapd.
In the bug report analyzed, kswapd was hung:

   kswapd0         D ffffffc000204fd8     0    72      2 0x00000000
   Call trace:
   [<ffffffc000204fd8>] __switch_to+0x9c/0xa8
   [<ffffffc00090b794>] __schedule+0x440/0x6d8
   [<ffffffc00090bac0>] schedule+0x94/0xb4
   [<ffffffc00090be44>] schedule_preempt_disabled+0x28/0x44
   [<ffffffc00090d900>] __mutex_lock_slowpath+0x120/0x1ac
   [<ffffffc00090d9d8>] mutex_lock+0x4c/0x68
   [<ffffffc000708e7c>] dm_bufio_shrink_count+0x38/0x78
   [<ffffffc00030b268>] shrink_slab.part.54.constprop.65+0x100/0x464
   [<ffffffc00030dbd8>] shrink_zone+0xa8/0x198
   [<ffffffc00030e578>] balance_pgdat+0x328/0x508
   [<ffffffc00030eb7c>] kswapd+0x424/0x51c
   [<ffffffc00023f06c>] kthread+0x10c/0x114
   [<ffffffc000203dd0>] ret_from_fork+0x10/0x40

By unblocking kswapd memory pressure should be reduced.
Suggested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Use a single loop instead of two loops to determine whether or not
all_blk_mq has to be set.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

When dm_table_set_type() is used by a target to establish a DM table's
type (e.g. DM_TYPE_MQ_REQUEST_BASED in the case of DM multipath) the
DM core must go on to verify that the devices in the table are
compatible with the established type.

Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature")
Cc: stable@vger.kernel.org # 4.8+
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

An earlier DM multipath table could have been build ontop of underlying
devices that were all using blk-mq.  In that case, if that active
multipath table is replaced with an empty DM multipath table (that
reflects all paths have failed) then it is important that the
'all_blk_mq' state of the active table is transfered to the new empty DM
table.  Otherwise dm-rq.c:dm_old_prep_tio() will incorrectly clone a
request that isn't needed by the DM multipath target when it is to issue
IO to an underlying blk-mq device.

Fixes: e83068a5 ("dm mpath: add optional "queue_mode" feature")
Cc: stable@vger.kernel.org # 4.8+
Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Tested-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Purely cleanup, avoids potential for strange coding bugs.  But in
reality if __multipath_map() fails the caller has no business looking at
*__clone.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

None of the callers of pg_init_all_paths() check its return value.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

This avoids the potential for invalid memory access, if/when there are
no priority groups, in response to invalid arguments being sent by the
user via DM message (e.g. "switch_group", "disable_group" or
"enable_group").
Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Avoids false positive of no hardware handler being specified (which is
implied by a NULL m->hw_handler_name).
Signed-off-by: tang.junhui <tang.junhui@zte.com.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Fix to return error code -EINVAL instead of 0, as is done elsewhere in
this function.

Fixes: e80d1c80 ("dm: do not override error code returned from dm_get_device()")
Cc: stable@vger.kernel.org # 4.3+
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The crypt_iv_operations are never modified, so declare them
as const.

Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

When target 1.9.1 gets takeover/reshape requests on devices with old superblock
format not supporting such conversions and rejects them in super_init_validation(),
it logs bogus error message (e.g. Reshape when a takeover is requested).

Whilst on it, add messages for disk adding/removing and stripe sectors
reshape requests, use the newer rs_{takeover,reshape}_requested() API,
address a raid10 false positive in checking array positions and
remove rs_set_new() because device members are already set proper.
Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Fixes userspace compilation errors like:

linux/dm-log-userspace.h:416:2: error: unknown type name ‘uint64_t’
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

In the past, dm-crypt used per-cpu crypto context. This has been removed
in the kernel 3.15 and the crypto context is shared between all cpus. This
patch renames the function crypt_setkey_allcpus to crypt_setkey, because
there is really no activity that is done for all cpus.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

In crypt_set_key(), if a failure occurs while replacing the old key
(e.g. tfm->setkey() fails) the key must not have DM_CRYPT_KEY_VALID flag
set.  Otherwise, the crypto layer would have an invalid key that still
has DM_CRYPT_KEY_VALID flag set.

Cc: stable@vger.kernel.org
Signed-off-by: Ondrej Kozina <okozina@redhat.com>
Reviewed-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Use bio_add_page(), the standard interface for adding a page to a bio,
rather than open-coding the same.

It should be noted that the 'clone' bio that is allocated using
bio_alloc_bioset(), in crypt_alloc_buffer(), does _not_ set the
bio's BIO_CLONED flag.  As such, bio_add_page()'s early return for true
bio clones (those with BIO_CLONED set) isn't applicable.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Firstly we have mature bvec/bio iterator helper for iterate each
page in one bio, not necessary to reinvent a wheel to do that.

Secondly the coming multipage bvecs requires this patch.

Also add comments about the direct access to bvec table.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Avoid accessing .bi_vcnt directly, because the bio can be split from
block layer and .bi_vcnt should never have been used here.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

It is required to hold the queue lock when calling blk_run_queue_async()
to avoid that a race between blk_run_queue_async() and
blk_cleanup_queue() is triggered.

Cc: stable@vger.kernel.org
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

The block manager's locking is useful for catching cycles that may
result from certain btree metadata corruption.  But in general it serves
as a developer tool to catch bugs in code.  Unless you're finding that
DM thin provisioning is hanging due to infinite loops within the block
manager's access to btree nodes you can safely disable this feature.
Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de> # do/while(0) macro fix
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Pull KVM fixes from Paolo Bonzini:
 "ARM fixes.  There are a couple pending x86 patches but they'll have to
  wait for next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: arm/arm64: vgic: Kick VCPUs when queueing already pending IRQs
  KVM: arm/arm64: vgic: Prevent access to invalid SPIs
  arm/arm64: KVM: Perform local TLB invalidation when multiplexing vcpus on a single CPU

Merge media fixes from Mauro Carvalho Chehab:
 "This contains two patches fixing problems with my patch series meant
  to make USB drivers to work again after the DMA on stack changes.

  The last patch on this series is actually not related to DMA on stack.
  It solves a longstanding bug affecting module unload, causing
  module_put() to be called twice. It was reported by the user who
  reported and tested the issues with the gp8psk driver with the DMA
  fixup patches. As we're late at -rc cycle, maybe you prefer to not
  apply it right now. If this is the case, I'll add to the pile of
  patches for 4.10.

  Exceptionally this time, I'm sending the patches via e-mail, because
  I'm on another trip, and won't be able to use the usual procedure
  until Monday. Also, it is only three patches, and you followed already
  the discussions about the first one"

* emailed patches from Mauro Carvalho Chehab <mchehab@osg.samsung.com>:
  gp8psk: Fix DVB frontend attach
  gp8psk: fix gp8psk_usb_in_op() logic
  dvb-usb: move data_mutex to struct dvb_usb_device

Pull char/misc fixes from Greg KH:
 "Here are three small driver fixes for some reported issues for
  4.9-rc5.

  One for the hyper-v subsystem, fixing up a naming issue that showed up
  in 4.9-rc1, one mei driver fix, and one fix for parallel ports,
  resolving a reported regression.

  All have been in linux-next with no reported issues"

* tag 'char-misc-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  ppdev: fix double-free of pp->pdev->name
  vmbus: make sysfs names consistent with PCI
  mei: bus: fix received data size check in NFC fixup

Pull driver core fixes from Greg KH:
 "Here are two driver core fixes for 4.9-rc5.

  The first resolves an issue with some drivers not liking to be unbound
  and bound again (if CONFIG_DEBUG_TEST_DRIVER_REMOVE is enabled), which
  solves some reported problems with graphics and storage drivers. The
  other resolves a smatch error with the 4.9-rc1 driver core changes
  around this feature.

  Both have been in linux-next with no reported issues"

* tag 'driver-core-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: fix smatch warning on dev->bus check
  driver core: skip removal test for non-removable drivers

Pull staging/IIO fixes from Grek KH:
 "Here are a few small staging and iio driver fixes for reported issues.

  The last one was cherry-picked from my -next branch to resolve a build
  warning that Arnd fixed, in his quest to be able to turn
  -Wmaybe-uninitialized back on again. That patch, and all of the
  others, have been in linux-next for a while with no reported issues"

* tag 'staging-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: maxim_thermocouple: detect invalid storage size in read()
  staging: nvec: remove managed resource from PS2 driver
  Revert "staging: nvec: ps2: change serio type to passthrough"
  drivers: staging: nvec: remove bogus reset command for PS/2 interface
  staging: greybus: arche-platform: fix device reference leak
  staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return value
  staging: sm750fb: Fix bugs introduced by early commits
  iio: hid-sensors: Increase the precision of scale to fix wrong reading interpretation.
  iio: orientation: hid-sensor-rotation: Add PM function (fix non working driver)
  iio: st_sensors: fix scale configuration for h3lis331dl
  staging: iio: ad5933: avoid uninitialized variable in error case

Pull USB / PHY fixes from Greg KH:
 "Here are a number of small USB and PHY driver fixes for 4.9-rc5

  Nothing major, just small fixes for reported issues, all of these have
  been in linux-next for a while with no reported issues"

* tag 'usb-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: cdc-acm: fix TIOCMIWAIT
  cdc-acm: fix uninitialized variable
  drivers/usb: Skip auto handoff for TI and RENESAS usb controllers
  usb: musb: remove duplicated actions
  usb: musb: da8xx: Don't print phy error on -EPROBE_DEFER
  phy: sun4i: check PMU presence when poking unknown bit of pmu
  phy-rockchip-pcie: remove deassert of phy_rst from exit callback
  phy: da8xx-usb: rename the ohci device to ohci-da8xx
  phy: Add reset callback for not generic phy
  uwb: fix device reference leaks
  usb: gadget: u_ether: remove interrupt throttling
  usb: dwc3: st: add missing <linux/pinctrl/consumer.h> include
  usb: dwc3: Fix error handling for core init

Pull more block fixes from Jens Axboe:
 "Since I mistakenly left out the lightnvm regression fix yesterday and
  the aoeblk seems adequately tested at this point, might as well send
  out another pull to make -rc5"

* 'for-linus' of git://git.kernel.dk/linux-block:
  aoe: fix crash in page count manipulation
  lightnvm: invalid offset calculation for lba_shift

Pull SCSI fixes from James Bottomley:
 "The megaraid_sas patch in here fixes a major regression in the last
  fix set that made all megaraid_sas cards unusable. It turns out no-one
  had actually tested such an "obvious" fix, sigh. The fix for the fix
  has been tested ...

  The next most serious is the vmw_pvscsi abort problem which basically
  means that aborts don't work on the vmware paravirt devices and error
  handling always escalates to reset.

  The rest are an assortment of missed reference counting in certain
  paths and corner case bugs that show up on some architectures"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: megaraid_sas: fix macro MEGASAS_IS_LOGICAL to avoid regression
  scsi: qla2xxx: fix invalid DMA access after command aborts in PCI device remove
  scsi: qla2xxx: do not queue commands when unloading
  scsi: libcxgbi: fix incorrect DDP resource cleanup
  scsi: qla2xxx: Fix scsi scan hang triggered if adapter fails during init
  scsi: scsi_dh_alua: Fix a reference counting bug
  scsi: vmw_pvscsi: return SUCCESS for successful command aborts
  scsi: mpt3sas: Fix for block device of raid exists even after deleting raid disk
  scsi: scsi_dh_alua: fix missing kref_put() in alua_rtpg_work()

Pull clk fixes from Stephen Boyd:
 "The typical collection of minor bug fixes in clk drivers. We don't
  have anything in the core framework here, just driver fixes.

  There's a boot fix for Samsung devices and a safety measure for qoriq
  to prevent CPUs from running too fast. There's also a fix for i.MX6Q
  to properly handle audio clock rates. We also have some "that's
  obviously wrong" fixes like bad NULL pointer checks in the MPP driver
  and a poor usage of __pa in the xgene clk driver that are fixed here"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: mmp: pxa910: fix return value check in pxa910_clk_init()
  clk: mmp: pxa168: fix return value check in pxa168_clk_init()
  clk: mmp: mmp2: fix return value check in mmp2_clk_init()
  clk: qoriq: Don't allow CPU clocks higher than starting value
  clk: imx: fix integer overflow in AV PLL round rate
  clk: xgene: Don't call __pa on ioremaped address
  clk/samsung: Use CLK_OF_DECLARE_DRIVER initialization method for CLKOUT
  clk: rockchip: don't return NULL when failing to register ddrclk branch

The DVB binding schema at the DVB core assumes that the frontend is a
separate driver.  Faling to do that causes OOPS when the module is
removed, as it tries to do a symbol_put_addr on an internal symbol,
causing craches like:

    WARNING: CPU: 1 PID: 28102 at kernel/module.c:1108 module_put+0x57/0x70
    Modules linked in: dvb_usb_gp8psk(-) dvb_usb dvb_core nvidia_drm(PO) nvidia_modeset(PO) snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd soundcore nvidia(PO) [last unloaded: rc_core]
    CPU: 1 PID: 28102 Comm: rmmod Tainted: P        WC O 4.8.4-build.1 #1
    Hardware name: MSI MS-7309/MS-7309, BIOS V1.12 02/23/2009
    Call Trace:
       dump_stack+0x44/0x64
       __warn+0xfa/0x120
       module_put+0x57/0x70
       module_put+0x57/0x70
       warn_slowpath_null+0x23/0x30
       module_put+0x57/0x70
       gp8psk_fe_set_frontend+0x460/0x460 [dvb_usb_gp8psk]
       symbol_put_addr+0x27/0x50
       dvb_usb_adapter_frontend_exit+0x3a/0x70 [dvb_usb]

From Derek's tests:
    "Attach bug is fixed, tuning works, module unloads without
     crashing. Everything seems ok!"
Reported-by: Derek <user.vdr@gmail.com>
Tested-by: Derek <user.vdr@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>