Currently in F2FS, page faults and operations that truncate the pagecahe
or data blocks, are completely unsynchronized. This can result in page
fault faulting in a page into a range that we are changing after
truncating, and thus we can end up with a page mapped to disk blocks that
will be shortly freed. Filesystem corruption will shortly follow.

This patch fixes the problem by creating new rw semaphore i_mmap_sem in
f2fs_inode_info and grab it for functions removing blocks from extent tree
and for read over page faults. The mechanism is similar to that in ext4.
Signed-off-by: Qiuyang Sun <sunqiuyang@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

The index of segment which the next nat block is in has only one different
bit than the current one, so to get the next nat address, we can simply
alter that one bit.
Signed-off-by: Fan Li <fanofcode.li@samsung.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Make sure number of entires doesn't exceed max journal size.

Cc: stable@vger.kernel.org
Signed-off-by: Jin Qian <jinqian@android.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Mount fs with option noflush_merge, boot failed for illegal address
fcc in function f2fs_issue_flush:

        if (!test_opt(sbi, FLUSH_MERGE)) {
                ret = submit_flush_wait(sbi);
                atomic_inc(&fcc->issued_flush);   ->  Here, fcc illegal
                return ret;
        }
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

It's not necessary to specify 'int' casting for PTR_ERR.
Signed-off-by: Zhang Shengju <zhangshengju@cmss.chinamobile.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

For example,

f2fs_create
 - new_node_page is failed
 - handle_failed_inode
  - skip to add it into orphan list, since ni.blk_addr == NULL_ADDR
   : set_inode_flag(inode, FI_FREE_NID)

f2fs_evict_inode
 - EIO due to fault injection
 - f2fs_bug_on() is triggered

So, we don't need to call f2fs_bug_on in this case.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

clear_prefree_segments() issues small discards after discarding full
segments. These small discards may not be section aligned, so not zone
aligned on a zoned block device, causing __f2fs_iissue_discard_zone() to fail.
Fix this by not issuing small discards for a volume mounted with the BLKZONED
feature enabled.

Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Since only an open file can be written to, and we only allow open()ing
an encrypted file when its key is available, there is no need to check
for the key again before permitting each ->write_iter().

This code was also broken in that it wouldn't actually have failed if
the key was in fact unavailable.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Since only an open file can be mmap'ed, and we only allow open()ing an
encrypted file when its key is available, there is no need to check for
the key again before permitting each mmap().

This f2fs copy of this code was also broken in that it wouldn't actually
have failed if the key was in fact unavailable.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: David Gstir <david@sigma-star.at>
Acked-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Wait discard IO completion outside cmd_lock to avoid long latency
of holding cmd_lock in IO busy scenario.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

There could be more than one waiter waiting discard IO completion, so we
need use complete_all() instead of complete() in f2fs_submit_discard_endio
to avoid hungtask.

Fixes: 	ec9895ad ("f2fs: don't hold cmd_lock during waiting discard
command")
Cc: <stable@vger.kernel.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Serialize data/node IOs by using fifo list instead of mutex lock,
it will help to enhance concurrency of f2fs, meanwhile keeping LFS
IO semantics.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Split wio_mutex to adjust different temperature bio cache.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Came across a hungtask caused by huge number of rb tree traversing
during adding discard addrs in cp. This patch combine these consistence
checks and move it to discard thread.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Thread A:					Thread B:

-f2fs_remount
    -sbi->mount_opt.opt = 0;
						<--- -f2fs_iget
						         -do_read_inode
							     -f2fs_init_extent_tree
							         -F2FS_I(inode)->extent_tree is NULL
        -default_options && parse_options
	    -remount return
						<---  -f2fs_map_blocks
						          -f2fs_lookup_extent_tree
                                                              -f2fs_bug_on(sbi, !et);

The same problem with f2fs_new_inode.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This allows to freeze gc and discard threads.

Cc: stable@vger.kernel.org
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch add a new method get_ssr_cost to select
SSR segment more accurately.
Signed-off-by: Yunlei He <heyunlei@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Currently, if we do get_node_of_data before f2fs_lock_op, there may be dead lock
as follows, where process A would be in infinite loop, and B will NOT be awaked.

Process A(cp):            Process B:
f2fs_lock_all(sbi)
                        get_dnode_of_data <---- lock dn.node_page
flush_nodes             f2fs_lock_op

So, this patch adds f2fs_trylock_op to avoid f2fs_lock_op done by IPU.
Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Split DATA/NODE type bio cache according to different temperature,
so write IOs with the same temperature can be merged in corresponding
bio cache as much as possible, otherwise, different temperature write
IOs submitting into one bio cache will always cause split of bio.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch just changes using fio instead of parameters.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Merged IO flow doesn't need to care about read IOs.

f2fs_submit_merged_bio -> f2fs_submit_merged_write
f2fs_submit_merged_bios -> f2fs_submit_merged_writes
f2fs_submit_merged_bio_cond -> f2fs_submit_merged_write_cond
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch avoids to use f2fs_submit_merged_bio for read, which was the only
read case.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

By default, f2fs_gc returns -EINVAL in general error cases, e.g., no victim
was selected. However, the default errno may be overwritten in two cases:
gc_more and BG_GC -> FG_GC. We should return consistent errno in such cases.
Signed-off-by: Weichao Guo <guoweichao@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Last kernel has already support new syscall statx() in commit a528d35e
("statx: Add a system call to make enhanced file info available"), with
this interface we can show more file info including file creation and some
attribute flags to user.

This patch tries to support this functionality.
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

This patch fixes missing inode flag loaded from disk, reported by Tom.

[tom@localhost ~]$ sudo mount /dev/loop0 /mnt/
[tom@localhost ~]$ sudo chown tom:tom /mnt/
[tom@localhost ~]$ touch /mnt/testfile
[tom@localhost ~]$ sudo chattr +i /mnt/testfile
[tom@localhost ~]$ echo test > /mnt/testfile
bash: /mnt/testfile: Operation not permitted
[tom@localhost ~]$ rm /mnt/testfile
rm: cannot remove '/mnt/testfile': Operation not permitted
[tom@localhost ~]$ sudo umount /mnt/
[tom@localhost ~]$ sudo mount /dev/loop0 /mnt/
[tom@localhost ~]$ lsattr /mnt/testfile
----i-------------- /mnt/testfile
[tom@localhost ~]$ echo test > /mnt/testfile
[tom@localhost ~]$ rm /mnt/testfile
[tom@localhost ~]$ sudo umount /mnt/

Cc: stable@vger.kernel.org
Reported-by: Tom Yan <tom.ty89@outlook.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Make sure segno and blkoff read from raw image are valid.

Cc: stable@vger.kernel.org
Signed-off-by: Jin Qian <jinqian@google.com>
[Jaegeuk Kim: adjust minor coding style]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Pull KVM updates from Paolo Bonzini:
 "ARM:
   - HYP mode stub supports kexec/kdump on 32-bit
   - improved PMU support
   - virtual interrupt controller performance improvements
   - support for userspace virtual interrupt controller (slower, but
     necessary for KVM on the weird Broadcom SoCs used by the Raspberry
     Pi 3)

  MIPS:
   - basic support for hardware virtualization (ImgTec P5600/P6600/I6400
     and Cavium Octeon III)

  PPC:
   - in-kernel acceleration for VFIO

  s390:
   - support for guests without storage keys
   - adapter interruption suppression

  x86:
   - usual range of nVMX improvements, notably nested EPT support for
     accessed and dirty bits
   - emulation of CPL3 CPUID faulting

  generic:
   - first part of VCPU thread request API
   - kvm_stat improvements"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
  kvm: nVMX: Don't validate disabled secondary controls
  KVM: put back #ifndef CONFIG_S390 around kvm_vcpu_kick
  Revert "KVM: Support vCPU-based gfn->hva cache"
  tools/kvm: fix top level makefile
  KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
  KVM: Documentation: remove VM mmap documentation
  kvm: nVMX: Remove superfluous VMX instruction fault checks
  KVM: x86: fix emulation of RSM and IRET instructions
  KVM: mark requests that need synchronization
  KVM: return if kvm_vcpu_wake_up() did wake up the VCPU
  KVM: add explicit barrier to kvm_vcpu_kick
  KVM: perform a wake_up in kvm_make_all_cpus_request
  KVM: mark requests that do not need a wakeup
  KVM: remove #ifndef CONFIG_S390 around kvm_vcpu_wake_up
  KVM: x86: always use kvm_make_request instead of set_bit
  KVM: add kvm_{test,clear}_request to replace {test,clear}_bit
  s390: kvm: Cpu model support for msa6, msa7 and msa8
  KVM: x86: remove irq disablement around KVM_SET_CLOCK/KVM_GET_CLOCK
  kvm: better MWAIT emulation for guests
  KVM: x86: virtualize cpuid faulting
  ...

Pull ARM updates from Russell King:
 "Lots of little things this time:

   - allow modules to be autoloaded according to the HWCAP feature bits
     (used primarily for crypto modules)

   - split module core and init PLT sections, since the core code and
     init code could be placed far apart, and the PLT sections need to
     be local to the code block.

   - three patches from Chris Brandt to allow Cortex-A9 L2 cache
     optimisations to be disabled where a SoC didn't wire up the out of
     band signals.

   - NoMMU compliance fixes, avoiding corruption of vector table which
     is not being used at this point, and avoiding possible register
     state corruption when switching mode.

   - fixmap memory attribute compliance update.

   - remove unnecessary locking from update_sections_early()

   - ftrace fix for DEBUG_RODATA with !FRAME_POINTER"

* 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm:
  ARM: 8672/1: mm: remove tasklist locking from update_sections_early()
  ARM: 8671/1: V7M: Preserve registers across switch from Thread to Handler mode
  ARM: 8670/1: V7M: Do not corrupt vector table around v7m_invalidate_l1 call
  ARM: 8668/1: ftrace: Fix dynamic ftrace with DEBUG_RODATA and !FRAME_POINTER
  ARM: 8667/3: Fix memory attribute inconsistencies when using fixmap
  ARM: 8663/1: wire up HWCAP/HWCAP2 feature bits to the CPU modalias
  ARM: 8666/1: mm: dump: Add domain to output
  ARM: 8662/1: module: split core and init PLT sections
  ARM: 8661/1: dts: r7s72100: add l2 cache
  ARM: 8660/1: shmobile: r7s72100: Enable L2 cache
  ARM: 8659/1: l2c: allow CA9 optimizations to be disabled

Pull Xtensa updates from Max Filippov:

 - clearly mark references to spilled register locations with SPILL_SLOT
   macros

 - clean up xtensa ptrace: use generic tracehooks, move internal kernel
   definitions from uapi/asm to asm, make locally-used functions static,
   fix code style and alignment

 - use command line parameters passed to ISS as kernel command line.

* tag 'xtensa-20170507' of git://github.com/jcmvbkbc/linux-xtensa:
  xtensa: clean up access to spilled registers locations
  xtensa: use generic tracehooks
  xtensa: move internal ptrace definitions from uapi/asm to asm
  xtensa: clean up xtensa/kernel/ptrace.c
  xtensa: drop unused fast_io_protect function
  xtensa: use ITLB_HIT_BIT instead of hardcoded number
  xtensa: ISS: update kernel command line in platform_setup
  xtensa: ISS: add argc/argv simcall definitions
  xtensa: ISS: cleanup setup.c

Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've focused on enhancing performance with regards to
  block allocation, GC, and discard/in-place-update IO controls. There
  are a bunch of clean-ups as well as minor bug fixes.

  Enhancements:
   - disable heap-based allocation by default
   - issue small-sized discard commands by default
   - change the policy of data hotness for logging
   - distinguish IOs in terms of size and wbc type
   - start SSR earlier to avoid foreground GC
   - enhance data structures managing discard commands
   - enhance in-place update flow
   - add some more fault injection routines
   - secure one more xattr entry

  Bug fixes:
   - calculate victim cost for GC correctly
   - remain correct victim segment number for GC
   - race condition in nid allocator and initializer
   - stale pointer produced by atomic_writes
   - fix missing REQ_SYNC for flush commands
   - handle missing errors in more corner cases"

* tag 'for-f2fs-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (111 commits)
  f2fs: fix a mount fail for wrong next_scan_nid
  f2fs: enhance scalability of trace macro
  f2fs: relocate inode_{,un}lock in F2FS_IOC_SETFLAGS
  f2fs: Make flush bios explicitely sync
  f2fs: show available_nids in f2fs/status
  f2fs: flush dirty nats periodically
  f2fs: introduce CP_TRIMMED_FLAG to avoid unneeded discard
  f2fs: allow cpc->reason to indicate more than one reason
  f2fs: release cp and dnode lock before IPU
  f2fs: shrink size of struct discard_cmd
  f2fs: don't hold cmd_lock during waiting discard command
  f2fs: nullify fio->encrypted_page for each writes
  f2fs: sanity check segment count
  f2fs: introduce valid_ipu_blkaddr to clean up
  f2fs: lookup extent cache first under IPU scenario
  f2fs: reconstruct code to write a data page
  f2fs: introduce __wait_discard_cmd
  f2fs: introduce __issue_discard_cmd
  f2fs: enable small discard by default
  f2fs: delay awaking discard thread
  ...

Pull fscrypt updates from Ted Ts'o:
 "Only bug fixes and cleanups for this merge window"

* tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt:
  fscrypt: correct collision claim for digested names
  MAINTAINERS: fscrypt: update mailing list, patchwork, and git
  ext4: clean up ext4_match() and callers
  f2fs: switch to using fscrypt_match_name()
  ext4: switch to using fscrypt_match_name()
  fscrypt: introduce helper function for filename matching
  fscrypt: avoid collisions when presenting long encrypted filenames
  f2fs: check entire encrypted bigname when finding a dentry
  ubifs: check for consistent encryption contexts in ubifs_lookup()
  f2fs: sync f2fs_lookup() with ext4_lookup()
  ext4: remove "nokey" check from ext4_lookup()
  fscrypt: fix context consistency check when key(s) unavailable
  fscrypt: Remove __packed from fscrypt_policy
  fscrypt: Move key structure and constants to uapi
  fscrypt: remove fscrypt_symlink_data_len()
  fscrypt: remove unnecessary checks for NULL operations

Pull ext4 updates from Ted Ts'o:

 - add GETFSMAP support

 - some performance improvements for very large file systems and for
   random write workloads into a preallocated file

 - bug fixes and cleanups.

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  jbd2: cleanup write flags handling from jbd2_write_superblock()
  ext4: mark superblock writes synchronous for nobarrier mounts
  ext4: inherit encryption xattr before other xattrs
  ext4: replace BUG_ON with WARN_ONCE in ext4_end_bio()
  ext4: avoid unnecessary transaction stalls during writeback
  ext4: preload block group descriptors
  ext4: make ext4_shutdown() static
  ext4: support GETFSMAP ioctls
  vfs: add common GETFSMAP ioctl definitions
  ext4: evict inline data when writing to memory map
  ext4: remove ext4_xattr_check_entry()
  ext4: rename ext4_xattr_check_names() to ext4_xattr_check_entries()
  ext4: merge ext4_xattr_list() into ext4_listxattr()
  ext4: constify static data that is never modified
  ext4: trim return value and 'dir' argument from ext4_insert_dentry()
  jbd2: fix dbench4 performance regression for 'nobarrier' mounts
  jbd2: Fix lockdep splat with generic/270 test
  mm: retry writepages() on ENOMEM when doing an data integrity writeback

Commit 37d69ee3 ("docs: bump minimal GNU Make version to 3.81")
changes one entry of GNU make version in the changes.rst, there's still
one more entry saying that one need version 3.80.  Fix that.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull cifs fixes from Steve French:
 "Various fixes for stable for CIFS/SMB3 especially for better
  interoperability for SMB3 to Macs.

  It also includes Pavel's improvements to SMB3 async i/o support
  (which is much faster now)"

* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
  CIFS: add misssing SFM mapping for doublequote
  SMB3: Work around mount failure when using SMB3 dialect to Macs
  cifs: fix CIFS_IOC_GET_MNT_INFO oops
  CIFS: fix mapping of SFM_SPACE and SFM_PERIOD
  CIFS: fix oplock break deadlocks
  cifs: fix CIFS_ENUMERATE_SNAPSHOTS oops
  cifs: fix leak in FSCTL_ENUM_SNAPS response handling
  Set unicode flag on cifs echo request to avoid Mac error
  CIFS: Add asynchronous write support through kernel AIO
  CIFS: Add asynchronous read support through kernel AIO
  CIFS: Add asynchronous context to support kernel AIO
  cifs: fix IPv6 link local, with scope id, address parsing
  cifs: small underflow in cnvrtDosUnixTm()

Pull xfs updates from Darrick Wong:
 "Here are the XFS changes for 4.12. The big new feature for this
  release is the new space mapping ioctl that we've been discussing
  since LSF2016, but other than that most of the patches are larger bug
  fixes, memory corruption prevention, and other cleanups.

  Summary:
   - various code cleanups
   - introduce GETFSMAP ioctl
   - various refactoring
   - avoid dio reads past eof
   - fix memory corruption and other errors with fragmented directory blocks
   - fix accidental userspace memory corruptions
   - publish fs uuid in superblock
   - make fstrim terminatable
   - fix race between quotaoff and in-core inode creation
   - avoid use-after-free when finishing up w/ buffer heads
   - reserve enough space to handle bmap tree resizing during cow remap"

* tag 'xfs-4.12-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (53 commits)
  xfs: fix use-after-free in xfs_finish_page_writeback
  xfs: reserve enough blocks to handle btree splits when remapping
  xfs: wait on new inodes during quotaoff dquot release
  xfs: update ag iterator to support wait on new inodes
  xfs: support ability to wait on new inodes
  xfs: publish UUID in struct super_block
  xfs: Allow user to kill fstrim process
  xfs: better log intent item refcount checking
  xfs: fix up quotacheck buffer list error handling
  xfs: remove xfs_trans_ail_delete_bulk
  xfs: don't use bool values in trace buffers
  xfs: fix getfsmap userspace memory corruption while setting OF_LAST
  xfs: fix __user annotations for xfs_ioc_getfsmap
  xfs: corruption needs to respect endianess too!
  xfs: use NULL instead of 0 to initialize a pointer in xfs_ioc_getfsmap
  xfs: use NULL instead of 0 to initialize a pointer in xfs_getfsmap
  xfs: simplify validation of the unwritten extent bit
  xfs: remove unused values from xfs_exntst_t
  xfs: remove the unused XFS_MAXLINK_1 define
  xfs: more do_div cleanups
  ...

Pull block fixes and updates from Jens Axboe:
 "Some fixes and followup features/changes that should go in, in this
  merge window. This contains:

   - Two fixes for lightnvm from Javier, fixing problems in the new code
     merge previously in this merge window.

   - A fix from Jan for the backing device changes, fixing an issue in
     NFS that causes a failure to mount on certain setups.

   - A change from Christoph, cleaning up the blk-mq init and exit
     request paths.

   - Remove elevator_change(), which is now unused. From Bart.

   - A fix for queue operation invocation on a dead queue, from Bart.

   - A series fixing up mtip32xx for blk-mq scheduling, removing a
     bandaid we previously had in place for this. From me.

   - A regression fix for this series, fixing a case where we wait on
     workqueue flushing from an invalid (non-blocking) context. From me.

   - A fix/optimization from Ming, ensuring that we don't both quiesce
     and freeze a queue at the same time.

   - A fix from Peter on lock ordering for CPU hotplug. Not a real
     problem right now, but will be once the CPU hotplug rework goes in.

   - A series from Omar, cleaning up out blk-mq debugfs support, and
     adding support for exporting info from schedulers in debugfs as
     well. This is really useful in debugging stalls or livelocks. From
     Omar"

* 'for-linus' of git://git.kernel.dk/linux-block: (28 commits)
  mq-deadline: add debugfs attributes
  kyber: add debugfs attributes
  blk-mq-debugfs: allow schedulers to register debugfs attributes
  blk-mq: untangle debugfs and sysfs
  blk-mq: move debugfs declarations to a separate header file
  blk-mq: Do not invoke queue operations on a dead queue
  blk-mq-debugfs: get rid of a bunch of boilerplate
  blk-mq-debugfs: rename hw queue directories from <n> to hctx<n>
  blk-mq-debugfs: don't open code strstrip()
  blk-mq-debugfs: error on long write to queue "state" file
  blk-mq-debugfs: clean up flag definitions
  blk-mq-debugfs: separate flags with |
  nfs: Fix bdi handling for cloned superblocks
  block/mq: Cure cpu hotplug lock inversion
  lightnvm: fix bad back free on error path
  lightnvm: create cmd before allocating request
  blk-mq: don't use sync workqueue flushing from drivers
  mtip32xx: convert internal commands to regular block infrastructure
  mtip32xx: cleanup internal tag assumptions
  block: don't call blk_mq_quiesce_queue() after queue is frozen
  ...

Now that kref is using the refcount apis, the _GPL markings are getting
exported to places that it previously wasn't.  Now kref.h is GPLv2
licensed, so any non-GPL code using it better be talking to some
lawyers, but changing api markings isn't considered "nice", so let's fix
this up.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>