In free_percpu() we sometimes call pcpu_schedule_balance_work() to
queue a work item (which does a wakeup) while holding pcpu_lock.
This creates an unnecessary lock dependency between pcpu_lock and
the scheduler's pi_lock.  There are other places where we call
pcpu_schedule_balance_work() without hold pcpu_lock, and this case
doesn't need to be different.

Moving the call outside the lock prevents the following lockdep splat
when running tools/testing/selftests/bpf/{test_maps,test_progs} in
sequence with lockdep enabled:

======================================================
WARNING: possible circular locking dependency detected
5.1.0-dbg-DEV #1 Not tainted
------------------------------------------------------
kworker/23:255/18872 is trying to acquire lock:
000000000bc79290 (&(&pool->lock)->rlock){-.-.}, at: __queue_work+0xb2/0x520

but task is already holding lock:
00000000e3e7a6aa (pcpu_lock){..-.}, at: free_percpu+0x36/0x260

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #4 (pcpu_lock){..-.}:
       lock_acquire+0x9e/0x180
       _raw_spin_lock_irqsave+0x3a/0x50
       pcpu_alloc+0xfa/0x780
       __alloc_percpu_gfp+0x12/0x20
       alloc_htab_elem+0x184/0x2b0
       __htab_percpu_map_update_elem+0x252/0x290
       bpf_percpu_hash_update+0x7c/0x130
       __do_sys_bpf+0x1912/0x1be0
       __x64_sys_bpf+0x1a/0x20
       do_syscall_64+0x59/0x400
       entry_SYSCALL_64_after_hwframe+0x49/0xbe

-> #3 (&htab->buckets[i].lock){....}:
       lock_acquire+0x9e/0x180
       _raw_spin_lock_irqsave+0x3a/0x50
       htab_map_update_elem+0x1af/0x3a0

-> #2 (&rq->lock){-.-.}:
       lock_acquire+0x9e/0x180
       _raw_spin_lock+0x2f/0x40
       task_fork_fair+0x37/0x160
       sched_fork+0x211/0x310
       copy_process.part.43+0x7b1/0x2160
       _do_fork+0xda/0x6b0
       kernel_thread+0x29/0x30
       rest_init+0x22/0x260
       arch_call_rest_init+0xe/0x10
       start_kernel+0x4fd/0x520
       x86_64_start_reservations+0x24/0x26
       x86_64_start_kernel+0x6f/0x72
       secondary_startup_64+0xa4/0xb0

-> #1 (&p->pi_lock){-.-.}:
       lock_acquire+0x9e/0x180
       _raw_spin_lock_irqsave+0x3a/0x50
       try_to_wake_up+0x41/0x600
       wake_up_process+0x15/0x20
       create_worker+0x16b/0x1e0
       workqueue_init+0x279/0x2ee
       kernel_init_freeable+0xf7/0x288
       kernel_init+0xf/0x180
       ret_from_fork+0x24/0x30

-> #0 (&(&pool->lock)->rlock){-.-.}:
       __lock_acquire+0x101f/0x12a0
       lock_acquire+0x9e/0x180
       _raw_spin_lock+0x2f/0x40
       __queue_work+0xb2/0x520
       queue_work_on+0x38/0x80
       free_percpu+0x221/0x260
       pcpu_freelist_destroy+0x11/0x20
       stack_map_free+0x2a/0x40
       bpf_map_free_deferred+0x3c/0x50
       process_one_work+0x1f7/0x580
       worker_thread+0x54/0x410
       kthread+0x10f/0x150
       ret_from_fork+0x24/0x30

other info that might help us debug this:

Chain exists of:
  &(&pool->lock)->rlock --> &htab->buckets[i].lock --> pcpu_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(pcpu_lock);
                               lock(&htab->buckets[i].lock);
                               lock(pcpu_lock);
  lock(&(&pool->lock)->rlock);

 *** DEADLOCK ***

3 locks held by kworker/23:255/18872:
 #0: 00000000b36a6e16 ((wq_completion)events){+.+.},
     at: process_one_work+0x17a/0x580
 #1: 00000000dfd966f0 ((work_completion)(&map->work)){+.+.},
     at: process_one_work+0x17a/0x580
 #2: 00000000e3e7a6aa (pcpu_lock){..-.},
     at: free_percpu+0x36/0x260

stack backtrace:
CPU: 23 PID: 18872 Comm: kworker/23:255 Not tainted 5.1.0-dbg-DEV #1
Hardware name: ...
Workqueue: events bpf_map_free_deferred
Call Trace:
 dump_stack+0x67/0x95
 print_circular_bug.isra.38+0x1c6/0x220
 check_prev_add.constprop.50+0x9f6/0xd20
 __lock_acquire+0x101f/0x12a0
 lock_acquire+0x9e/0x180
 _raw_spin_lock+0x2f/0x40
 __queue_work+0xb2/0x520
 queue_work_on+0x38/0x80
 free_percpu+0x221/0x260
 pcpu_freelist_destroy+0x11/0x20
 stack_map_free+0x2a/0x40
 bpf_map_free_deferred+0x3c/0x50
 process_one_work+0x1f7/0x580
 worker_thread+0x54/0x410
 kthread+0x10f/0x150
 ret_from_fork+0x24/0x30
Signed-off-by: John Sperbeck <jsperbeck@google.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Just like blocks, chunks now maintain a scan_hint. This can be used to
skip some scanning by promoting the scan_hint to be the contig_hint.
The chunk's scan_hint is primarily updated on the backside and relies on
full scanning when a block becomes free or the free region spans across
blocks.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

As mentioned in the last patch, a chunk's hints are no different than a
block just responsible for more bits. This converts chunk level hints to
use a pcpu_block_md to maintain them. This lets us reuse the same hint
helper functions as a block. The left_free and right_free are unused by
the chunk's pcpu_block_md.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

In reality, a chunk is just a block covering a larger number of bits.
The hints themselves are one in the same. Rather than maintaining the
hints separately, first introduce nr_bits to genericize
pcpu_block_update() to correctly maintain block->right_free. The next
patch will convert chunk hints to be managed as a pcpu_block_md.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

Blocks now remember the latest scan_hint. This can be used on the
allocation path as when a contig_hint is broken, we can promote the
scan_hint to the contig_hint and scan forward from there. This works
because pcpu_block_refresh_hint() is only called on the allocation path
while block free regions are updated manually in
pcpu_block_update_hint_free().
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Percpu allocations attempt to do first fit by scanning forward from the
first_free of a block. However, fragmentation from allocation requests
can cause holes not seen by block hint update functions. To address
this, create a local version of bitmap_find_next_zero_area_off() that
remembers the largest area skipped over. The caveat is that it only sees
regions skipped over due to not fitting, not regions skipped due to
alignment.

Prior to updating the scan_hint, a scan backwards is done to try and
recover free bits skipped due to alignment. While this can cause
scanning to miss earlier possible free areas, smaller allocations will
eventually fill those holes due to first fit.
Signed-off-by: Dennis Zhou <dennis@kernel.org>

Fragmentation can cause both blocks and chunks to have an early
first_firee bit available, but only able to satisfy allocations much
later on. This patch introduces a scan_hint to help mitigate some
unnecessary scanning.

The scan_hint remembers the largest area prior to the contig_hint. If
the contig_hint == scan_hint, then scan_hint_start > contig_hint_start.
This is necessary for scan_hint discovery when refreshing a block.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

Previously, block size was flexible based on the constraint that the
GCD(PCPU_BITMAP_BLOCK_SIZE, PAGE_SIZE) > 1. However, this carried the
overhead that keeping a floating number of populated free pages required
scanning over the free regions of a chunk.

Setting the block size to be fixed at PAGE_SIZE lets us know when an
empty page becomes used as we will break a full contig_hint of a block.
This means we no longer have to scan the whole chunk upon breaking a
contig_hint which empty page management piggybacked off. A later patch
takes advantage of this to optimize the allocation path by only scanning
forward using the scan_hint introduced later too.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

In certain cases, requestors of percpu memory may want specific
alignments. However, it is possible to end up in situations where the
contig_hint matches, but the alignment does not. This causes excess
scanning of chunks that will fail. To prevent this, if a small
allocation fails (< 32B), the chunk is moved to the empty list. Once an
allocation is freed from that chunk, it is placed back into rotation.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

When a chunk becomes fragmented, it can end up having a large number of
small allocation areas free. The free_bytes sorting of chunks leads to
unnecessary checking of chunks that cannot satisfy the allocation.
Switch to contig_bits sorting to prevent scanning chunks that may not be
able to service the allocation request.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

While block hints were always accurate, it's possible when spanning
across blocks that we miss updating the chunk's contig_hint. Rather than
rely on correctness of the boundaries of hints, do a full overlap
comparison.

A future patch introduces the scan_hint which makes the contig_hint
slightly fuzzy as they can at times be smaller than the actual hint.
Signed-off-by: Dennis Zhou <dennis@kernel.org>

pcpu_find_block_fit() guarantees that a fit is found within
PCPU_BITMAP_BLOCK_BITS. Iteration is used to determine the first fit as
it compares against the block's contig_hint. This can lead to
incorrectly scanning past the end of the bitmap. The behavior was okay
given the check after for bit_off >= end and the correctness of the
hints from pcpu_find_block_fit().

This patch fixes this by bounding the end offset by the number of bits
in a chunk.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

When updating the chunk's contig_hint on the free path of a hint that
does not touch the page boundaries, it was incorrectly using the
starting offset of the free region and the block's contig_hint. This
could lead to incorrect assumptions about fit given a size and better
alignment of the start. Fix this by using (end - start) as this is only
called when updating a hint within a block.
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

Pull selinux fixes from Paul Moore:
 "Two small fixes for SELinux in v5.1: one adds a buffer length check to
  the SELinux SCTP code, the other ensures that the SELinux labeling for
  a NFS mount is not disabled if the filesystem is mounted twice"

* tag 'selinux-pr-20190312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock
  selinux: add the missing walk_size + len check in selinux_sctp_bind_connect

Merge tag 'apparmor-pr-2019-03-12' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor fixes from John Johansen:

 - fix double when failing to unpack secmark rules in policy

 - fix leak of dentry when profile is removed

* tag 'apparmor-pr-2019-03-12' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: fix double free when unpack of secmark rules fails
  apparmor: delete the dentry in aafs_remove() to avoid a leak
  apparmor: Fix warning about unused function apparmor_ipv6_postroute

Pull Kconfig updates from Masahiro Yamada:

 - rename lexer and parse files

 - fix 'Save as' menu of xconfig

* tag 'kconfig-v5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: fix 'Save As' menu of xconfig
  kconfig: rename zconf.y to parser.y
  kconfig: rename zconf.l to lexer.l

Merge tag 'pwm/for-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "The changes for this cycle are across the board.

  The bulk of it is cleanups, but there's also new device support in
  some drivers as well as more conversions to the atomic API"

* tag 'pwm/for-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (24 commits)
  pwm: atmel: Remove useless symbolic definitions
  pwm: bcm-kona: Update macros to remove braces around numbers
  pwm: imx27: Only enable the clocks once in .get_state()
  pwm: rcar: Improve calculation of divider
  pwm: rcar: Remove legacy APIs
  pwm: rcar: Use "atomic" API on rcar_pwm_resume()
  pwm: rcar: Add support "atomic" API
  pwm: atmel: Add support for SAM9X60's PWM controller
  pwm: atmel: Add PWM binding for SAM9X60
  pwm: atmel: Rename objects of type atmel_pwm_data
  pwm: atmel: Add support for controllers with 32 bit counters
  pwm: atmel: Add struct atmel_pwm_data
  pwm: Add MediaTek MT8183 display PWM driver support
  pwm: hibvt: Add hi3559v100 support
  dt-bindings: pwm: hibvt: Add hi3559v100 support
  pwm: hibvt: Use individual struct per of-data
  pwm: imx: Signedness bug in imx_pwm_get_state()
  pwm: imx: Split into two drivers
  pwm: imx: Don't print an error on -EPROBE_DEFER
  pwm: imx: Set driver data earlier simplifying the end of ->probe()
  ...

Pull mailbox updates from Jassi Brar:

 - mailbox-test: support multiple controller instances

 - misc cleanup: IMX, STM32 and Tegra

 - new driver: ZynqMP IPI

* tag 'mailbox-v5.1' of git://git.linaro.org/landing-teams/working/fujitsu/integration:
  mailbox: imx: keep MU irq working during suspend/resume
  dt-bindings: mailbox: Add Xilinx IPI Mailbox
  mailbox: ZynqMP IPI mailbox controller
  mailbox: stm32-ipcc: remove useless device_init_wakeup call
  mailbox: stm32-ipcc: do not enable wakeup source by default
  mailbox: mailbox-test: fix null pointer if no mmio
  mailbox: mailbox-test: fix debugfs in multi-instances
  mailbox: tegra-hsp: mark suspend function as __maybe_unused

Pull crypto fixes from Herbert Xu:
 "This fixes a bug in the newly added Exynos5433 AES code as well as an
  old one in the caam driver"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: caam - add missing put_device() call
  crypto: s5p-sss - fix AES support for Exynos5433

Pull libnvdimm updates from Dan Williams:
 "The bulk of this has been in -next since before the merge window
  opened, with no known collisions / issues reported.

  The only detail worth noting, outside the summary below, is that the
  "libnvdimm-start-pad" topic has been truncated to just cleanups and
  small fixes. The full topic branch would have doubled down on hacks
  around the "section alignment" limitation of the core-mm, instead
  effort is now being spent to address that root issue in the memory
  hotplug implementation for v5.2.

   - Fix nfit-bus command submission regression

   - Support retrieval of short-ARS results if the ARS state is
     "requires continuation", and even if the "no_init_ars" module
     parameter is specified

   - Allow busy-polling of the kernel ARS state by allowing root to
     reset the exponential back-off timer

   - Filter potentially stale ARS results by tracking query-ARS relative
     to the previous start-ARS

   - Enhance dax_device alignment checks

   - Add support for the Hyper-V family of device-specific-methods
     (DSMs)

   - Add several fixes and workarounds for Hyper-V compatibility

   - Fix support to cache the dirty-shutdown-count at init"

* tag 'libnvdimm-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (25 commits)
  libnvdimm/namespace: Clean up holder_class_store()
  libnvdimm/of_pmem: Fix platform_no_drv_owner.cocci warnings
  acpi/nfit: Update NFIT flags error message
  libnvdimm/btt: Fix LBA masking during 'free list' population
  libnvdimm/btt: Remove unnecessary code in btt_freelist_init
  libnvdimm/pfn: Remove dax_label_reserve
  dax: Check the end of the block-device capacity with dax_direct_access()
  nfit/ars: Avoid stale ARS results
  nfit/ars: Allow root to busy-poll the ARS state machine
  nfit/ars: Introduce scrub_flags
  nfit/ars: Remove ars_start_flags
  nfit/ars: Attempt short-ARS even in the no_init_ars case
  nfit/ars: Attempt a short-ARS whenever the ARS state is idle at boot
  acpi/nfit: Require opt-in for read-only label configurations
  libnvdimm/pmem: Honor force_raw for legacy pmem regions
  libnvdimm/pfn: Account for PAGE_SIZE > info-block-size in nd_pfn_init()
  libnvdimm: Fix altmap reservation size calculation
  libnvdimm, pfn: Fix over-trim in trim_pfn_device()
  acpi/nfit: Fix bus command validation
  libnvdimm/dimm: Add a no-BLK quirk based on NVDIMM family
  ...

Pull filesystem-dax updates from Dan Williams:

 - Fix handling of PMD-sized entries in the Xarray that lead to a crash
   scenario

 - Miscellaneous cleanups and small fixes

* tag 'fsdax-for-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: Flush partial PMDs correctly
  fs/dax: NIT fix comment regarding start/end vs range
  fs/dax: Convert to use vmf_error()

Pull UBI and UBIFS updates from Richard Weinberger:

 - A new interface for UBI to deal better with read disturb

 - Reject unsupported ioctl flags in UBIFS (xfstests found it)

* tag 'upstream-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubi: wl: Silence uninitialized variable warning
  ubifs: Reject unsupported ioctl flags explicitly
  ubi: Expose the bitrot interface
  ubi: Introduce in_pq()

Pull NFS server updates from Bruce Fields:
 "Miscellaneous NFS server fixes.

  Probably the most visible bug is one that could artificially limit
  NFSv4.1 performance by limiting the number of oustanding rpcs from a
  single client.

  Neil Brown also gets a special mention for fixing a 14.5-year-old
  memory-corruption bug in the encoding of NFSv3 readdir responses"

* tag 'nfsd-5.1' of git://linux-nfs.org/~bfields/linux:
  nfsd: allow nfsv3 readdir request to be larger.
  nfsd: fix wrong check in write_v4_end_grace()
  nfsd: fix memory corruption caused by readdir
  nfsd: fix performance-limiting session calculation
  svcrpc: fix UDP on servers with lots of threads
  svcrdma: Remove syslog warnings in work completion handlers
  svcrdma: Squelch compiler warning when SUNRPC_DEBUG is disabled
  svcrdma: Use struct_size() in kmalloc()
  svcrpc: fix unlikely races preventing queueing of sockets
  svcrpc: svc_xprt_has_something_to_do seems a little long
  SUNRPC: Don't allow compiler optimisation of svc_xprt_release_slot()
  nfsd: fix an IS_ERR() vs NULL check

Pull ext4 updates from Ted Ts'o:
 "A large number of bug fixes and cleanups.

  One new feature to allow users to more easily find the jbd2 journal
  thread for a particular ext4 file system"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
  jbd2: jbd2_get_transaction does not need to return a value
  jbd2: fix invalid descriptor block checksum
  ext4: fix bigalloc cluster freeing when hole punching under load
  ext4: add sysfs attr /sys/fs/ext4/<disk>/journal_task
  ext4: Change debugging support help prefix from EXT4 to Ext4
  ext4: fix compile error when using BUFFER_TRACE
  jbd2: fix compile warning when using JBUFFER_TRACE
  ext4: fix some error pointer dereferences
  ext4: annotate more implicit fall throughs
  ext4: annotate implicit fall throughs
  ext4: don't update s_rev_level if not required
  jbd2: fold jbd2_superblock_csum_{verify,set} into their callers
  jbd2: fix race when writing superblock
  ext4: fix crash during online resizing
  ext4: disallow files with EXT4_JOURNAL_DATA_FL from EXT4_IOC_SWAP_BOOT
  ext4: add mask of ext4 flags to swap
  ext4: update quota information while swapping boot loader inode
  ext4: cleanup pagecache before swap i_data
  ext4: fix check of inode in swap_inode_boot_loader
  ext4: unlock unused_pages timely when doing writeback
  ...

Pull ceph updates from Ilya Dryomov:
 "The highlights are:

   - rbd will now ignore discards that aren't aligned and big enough to
     actually free up some space (myself). This is controlled by the new
     alloc_size map option and can be disabled if needed.

   - support for rbd deep-flatten feature (myself). Deep-flatten allows
     "rbd flatten" to fully disconnect the clone image and its snapshots
     from the parent and make the parent snapshot removable.

   - a new round of cap handling improvements (Zheng Yan). The kernel
     client should now be much more prompt about releasing its caps and
     it is possible to put a limit on the number of caps held.

   - support for getting ceph.dir.pin extended attribute (Zheng Yan)"

* tag 'ceph-for-5.1-rc1' of git://github.com/ceph/ceph-client: (26 commits)
  Documentation: modern versions of ceph are not backed by btrfs
  rbd: advertise support for RBD_FEATURE_DEEP_FLATTEN
  rbd: whole-object write and zeroout should copyup when snapshots exist
  rbd: copyup with an empty snapshot context (aka deep-copyup)
  rbd: introduce rbd_obj_issue_copyup_ops()
  rbd: stop copying num_osd_ops in rbd_obj_issue_copyup()
  rbd: factor out __rbd_osd_req_create()
  rbd: clear ->xferred on error from rbd_obj_issue_copyup()
  rbd: remove experimental designation from kernel layering
  ceph: add mount option to limit caps count
  ceph: periodically trim stale dentries
  ceph: delete stale dentry when last reference is dropped
  ceph: remove dentry_lru file from debugfs
  ceph: touch existing cap when handling reply
  ceph: pass inclusive lend parameter to filemap_write_and_wait_range()
  rbd: round off and ignore discards that are too small
  rbd: handle DISCARD and WRITE_ZEROES separately
  rbd: get rid of obj_req->obj_request_count
  libceph: use struct_size() for kmalloc() in crush_decode()
  ceph: send cap releases more aggressively
  ...

Pull btrfs fixes from David Sterba:
 "Correctness and a deadlock fixes"

* tag 'for-5.1-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zstd: ensure reclaim timer is properly cleaned up
  btrfs: move ulist allocation out of transaction in quota enable
  btrfs: save drop_progress if we drop refs at all
  btrfs: check for refs on snapshot delete resume
  Btrfs: fix deadlock between clone/dedupe and rename
  Btrfs: fix corruption reading shared and compressed extents after hole punching

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:
   - Fixes for NFS I/O request leakages
   - Fix error handling paths in the NFS I/O recoalescing code
   - Reinitialise NFSv4.1 sequence results before retransmitting a
     request
   - Fix a soft lockup in the delegation recovery code
   - Bulk destroy of layouts needs to be safe w.r.t. umount
   - Prevent thundering herd issues when the SUNRPC socket is not
     connected
   - Respect RPC call timeouts when retrying transmission

  Features:
   - Convert rpc auth layer to use xdr_streams
   - Config option to disable insecure RPCSEC_GSS crypto types
   - Reduce size of RPC receive buffers
   - Readdirplus optimization by cache mechanism
   - Convert SUNRPC socket send code to use iov_iter()
   - SUNRPC micro-optimisations to avoid indirect calls
   - Add support for the pNFS LAYOUTERROR operation and use it with the
     pNFS/flexfiles driver
   - Add trace events to report non-zero NFS status codes
   - Various removals of unnecessary dprintks

  Bugfixes and cleanups:
   - Fix a number of sparse warnings and documentation format warnings
   - Fix nfs_parse_devname to not modify it's argument
   - Fix potential corruption of page being written through pNFS/blocks
   - fix xfstest generic/099 failures on nfsv3
   - Avoid NFSv4.1 "false retries" when RPC calls are interrupted
   - Abort I/O early if the pNFS/flexfiles layout segment was
     invalidated
   - Avoid unnecessary pNFS/flexfiles layout invalidations"

* tag 'nfs-for-5.1-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (90 commits)
  SUNRPC: Take the transport send lock before binding+connecting
  SUNRPC: Micro-optimise when the task is known not to be sleeping
  SUNRPC: Check whether the task was transmitted before rebind/reconnect
  SUNRPC: Remove redundant calls to RPC_IS_QUEUED()
  SUNRPC: Clean up
  SUNRPC: Respect RPC call timeouts when retrying transmission
  SUNRPC: Fix up RPC back channel transmission
  SUNRPC: Prevent thundering herd when the socket is not connected
  SUNRPC: Allow dynamic allocation of back channel slots
  NFSv4.1: Bump the default callback session slot count to 16
  SUNRPC: Convert remaining GFP_NOIO, and GFP_NOWAIT sites in sunrpc
  NFS/flexfiles: Clean up mirror DS initialisation
  NFS/flexfiles: Remove dead code in ff_layout_mirror_valid()
  NFS/flexfile: Simplify nfs4_ff_layout_select_ds_stateid()
  NFS/flexfile: Simplify nfs4_ff_layout_ds_version()
  NFS/flexfiles: Simplify ff_layout_get_ds_cred()
  NFS/flexfiles: Simplify nfs4_ff_find_or_create_ds_client()
  NFS/flexfiles: Simplify nfs4_ff_layout_select_ds_fh()
  NFS/flexfiles: Speed up read failover when DSes are down
  NFS/flexfiles: Don't invalidate DS deviceids for being unresponsive
  ...

Pull overlayfs updates from Miklos Szeredi:
 "Fix copy up of security related xattrs"

* tag 'ovl-update-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: Do not lose security.capability xattr over metadata file copy-up
  ovl: During copy up, first copy up data and then xattrs

Pull fuse updates from Miklos Szeredi:
 "Scalability and performance improvements, as well as minor bug fixes
  and cleanups"

* tag 'fuse-update-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (25 commits)
  fuse: cache readdir calls if filesystem opts out of opendir
  fuse: support clients that don't implement 'opendir'
  fuse: lift bad inode checks into callers
  fuse: multiplex cached/direct_io file operations
  fuse add copy_file_range to direct io fops
  fuse: use iov_iter based generic splice helpers
  fuse: Switch to using async direct IO for FOPEN_DIRECT_IO
  fuse: use atomic64_t for khctr
  fuse: clean up aborted
  fuse: Protect ff->reserved_req via corresponding fi->lock
  fuse: Protect fi->nlookup with fi->lock
  fuse: Introduce fi->lock to protect write related fields
  fuse: Convert fc->attr_version into atomic64_t
  fuse: Add fuse_inode argument to fuse_prepare_release()
  fuse: Verify userspace asks to requeue interrupt that we really sent
  fuse: Do some refactoring in fuse_dev_do_write()
  fuse: Wake up req->waitq of only if not background
  fuse: Optimize request_end() by not taking fiq->waitq.lock
  fuse: Kill fasync only if interrupt is queued in queue_interrupt()
  fuse: Remove stale comment in end_requests()
  ...

Pull vfs mount infrastructure updates from Al Viro:
 "The rest of core infrastructure; no new syscalls in that pile, but the
  old parts are switched to new infrastructure. At that point
  conversions of individual filesystems can happen independently; some
  are done here (afs, cgroup, procfs, etc.), there's also a large series
  outside of that pile dealing with NFS (quite a bit of option-parsing
  stuff is getting used there - it's one of the most convoluted
  filesystems in terms of mount-related logics), but NFS bits are the
  next cycle fodder.

  It got seriously simplified since the last cycle; documentation is
  probably the weakest bit at the moment - I considered dropping the
  commit introducing Documentation/filesystems/mount_api.txt (cutting
  the size increase by quarter ;-), but decided that it would be better
  to fix it up after -rc1 instead.

  That pile allows to do followup work in independent branches, which
  should make life much easier for the next cycle. fs/super.c size
  increase is unpleasant; there's a followup series that allows to
  shrink it considerably, but I decided to leave that until the next
  cycle"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits)
  afs: Use fs_context to pass parameters over automount
  afs: Add fs_context support
  vfs: Add some logging to the core users of the fs_context log
  vfs: Implement logging through fs_context
  vfs: Provide documentation for new mount API
  vfs: Remove kern_mount_data()
  hugetlbfs: Convert to fs_context
  cpuset: Use fs_context
  kernfs, sysfs, cgroup, intel_rdt: Support fs_context
  cgroup: store a reference to cgroup_ns into cgroup_fs_context
  cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper
  cgroup_do_mount(): massage calling conventions
  cgroup: stash cgroup_root reference into cgroup_fs_context
  cgroup2: switch to option-by-option parsing
  cgroup1: switch to option-by-option parsing
  cgroup: take options parsing into ->parse_monolithic()
  cgroup: fold cgroup1_mount() into cgroup1_get_tree()
  cgroup: start switching to fs_context
  ipc: Convert mqueue fs to fs_context
  proc: Add fs_context support to procfs
  ...

Pull iov_iter updates from Al Viro:
 "A couple of iov_iter patches - Christoph's crapectomy (the last
  remaining user of iov_for_each() went away with lustre, IIRC) and
  Eric'c optimization of sanity checks"

* 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  iov_iter: optimize page_copy_sane()
  uio: remove the unused iov_for_each macro

Pull misc vfs updates from Al Viro:
 "Assorted fixes (really no common topic here)"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: Make __vfs_write() static
  vfs: fix preadv64v2 and pwritev64v2 compat syscalls with offset == -1
  pipe: stop using ->can_merge
  splice: don't merge into linked buffers
  fs: move generic stat response attr handling to vfs_getattr_nosec
  orangefs: don't reinitialize result_mask in ->getattr
  fs/devpts: always delete dcache dentry-s in dput()

Merge misc updates from Andrew Morton:

 - a few misc things

 - the rest of MM

-  remove flex_arrays, replace with new simple radix-tree implementation

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (38 commits)
  Drop flex_arrays
  sctp: convert to genradix
  proc: commit to genradix
  generic radix trees
  selinux: convert to kvmalloc
  md: convert to kvmalloc
  openvswitch: convert to kvmalloc
  of: fix kmemleak crash caused by imbalance in early memory reservation
  mm: memblock: update comments and kernel-doc
  memblock: split checks whether a region should be skipped to a helper function
  memblock: remove memblock_{set,clear}_region_flags
  memblock: drop memblock_alloc_*_nopanic() variants
  memblock: memblock_alloc_try_nid: don't panic
  treewide: add checks for the return value of memblock_alloc*()
  swiotlb: add checks for the return value of memblock_alloc*()
  init/main: add checks for the return value of memblock_alloc*()
  mm/percpu: add checks for the return value of memblock_alloc*()
  sparc: add checks for the return value of memblock_alloc*()
  ia64: add checks for the return value of memblock_alloc*()
  arch: don't memset(0) memory returned by memblock_alloc()
  ...

All existing users have been converted to generic radix trees

Link: http://lkml.kernel.org/r/20181217131929.11727-8-kent.overstreet@gmail.comSigned-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

This also makes sctp_stream_alloc_(out|in) saner, in that they no longer
allocate new flex_arrays/genradixes, they just preallocate more
elements.

This code does however have a suspicious lack of locking.

Link: http://lkml.kernel.org/r/20181217131929.11727-7-kent.overstreet@gmail.comSigned-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The new generic radix trees have a simpler API and implementation, and
no limitations on number of elements, so all flex_array users are being
converted

Link: http://lkml.kernel.org/r/20181217131929.11727-6-kent.overstreet@gmail.comSigned-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Very simple radix tree implementation that supports storing arbitrary
size entries, up to PAGE_SIZE - upcoming patches will convert existing
flex_array users to genradixes.  The new genradix code has a much
simpler API and implementation, and doesn't have a hard limit on the
number of elements like flex_array does.

Link: http://lkml.kernel.org/r/20181217131929.11727-5-kent.overstreet@gmail.comSigned-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The flex arrays were being used for constant sized arrays, so there's no
benefit to using flex_arrays over something simpler.

Link: http://lkml.kernel.org/r/20181217131929.11727-4-kent.overstreet@gmail.comSigned-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The code really just wants a big flat buffer, so just do that.

Link: http://lkml.kernel.org/r/20181217131929.11727-3-kent.overstreet@gmail.comSigned-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Cc: Shaohua Li <shli@kernel.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Patch series "generic radix trees; drop flex arrays".

This patch (of 7):

There was no real need for this code to be using flexarrays, it's just
implementing a hash table - ideally it would be using rhashtables, but
that conversion would be significantly more complicated.

Link: http://lkml.kernel.org/r/20181217131929.11727-2-kent.overstreet@gmail.comSigned-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Cc: Pravin B Shelar <pshelar@ovn.org>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Shaohua Li <shli@kernel.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>