Pull more block updates from Jens Axboe:

 - MD pull request via Song:
      - Improve raid5 sequential IO performance on spinning disks, which
        fixes a regression since v6.0 (Jan Kara)
      - Fix bitmap offset types, which fixes an issue introduced in this
        merge window (Jonathan Derrick)

 - Cleanup of hweight type used for cgroup writeback (Maxim)

 - Fix a regression with the "has_submit_bio" changes across partitions
   (Ming)

 - Cleanup of QUEUE_FLAG_ADD_RANDOM clearing.

   We used to set this flag on queues non blk-mq queues, and hence some
   drivers clear it unconditionally. Since all of these have since been
   converted to true blk-mq drivers, drop the useless clear as the bit
   is not set (Chaitanya)

 - Fix the flags being set in a bio for a flush for drbd (Christoph)

 - Cleanup and deduplication of the code handling setting block device
   capacity (Damien)

 - Fix for ublk handling IO timeouts (Ming)

 - Fix for a regression in blk-cgroup teardown (Tao)

 - NBD documentation and code fixes (Eric)

 - Convert blk-integrity to using device_attributes rather than a second
   kobject to manage lifetimes (Thomas)

* tag 'for-6.4/block-2023-05-06' of git://git.kernel.dk/linux:
  ublk: add timeout handler
  drbd: correctly submit flush bio on barrier
  mailmap: add mailmap entries for Jens Axboe
  block: Skip destroyed blkg when restart in blkg_destroy_all()
  writeback: fix call of incorrect macro
  md: Fix bitmap offset type in sb writer
  md/raid5: Improve performance for sequential IO
  docs nbd: userspace NBD now favors github over sourceforge
  block nbd: use req.cookie instead of req.handle
  uapi nbd: add cookie alias to handle
  uapi nbd: improve doc links to userspace spec
  blk-integrity: register sysfs attributes on struct device
  blk-integrity: convert to struct device_attribute
  blk-integrity: use sysfs_emit
  block/drivers: remove dead clear of random flag
  block: sync part's ->bd_has_submit_bio with disk's
  block: Cleanup set_capacity()/bdev_set_nr_sectors()

Pull dmaengine updates from Vinod Koul:
 "New support:

   - Apple admac t8112 device support

   - StarFive JH7110 DMA controller

  Updates:

   - Big pile of idxd updates to support IAA 2.0 device capabilities,
     DSA 2.0 Event Log and completion record faulting features and
     new DSA operations

   - at_xdmac supend & resume updates and driver code cleanup

   - k3-udma supend & resume support

   - k3-psil thread support for J784s4"

* tag 'dmaengine-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vkoul/dmaengine: (57 commits)
  dmaengine: idxd: add per wq PRS disable
  dmaengine: idxd: add pid to exported sysfs attribute for opened file
  dmaengine: idxd: expose fault counters to sysfs
  dmaengine: idxd: add a device to represent the file opened
  dmaengine: idxd: add per file user counters for completion record faults
  dmaengine: idxd: process batch descriptor completion record faults
  dmaengine: idxd: add descs_completed field for completion record
  dmaengine: idxd: process user page faults for completion record
  dmaengine: idxd: add idxd_copy_cr() to copy user completion record during page fault handling
  dmaengine: idxd: create kmem cache for event log fault items
  dmaengine: idxd: add per DSA wq workqueue for processing cr faults
  dmanegine: idxd: add debugfs for event log dump
  dmaengine: idxd: add interrupt handling for event log
  dmaengine: idxd: setup event log configuration
  dmaengine: idxd: add event log size sysfs attribute
  dmaengine: idxd: make misc interrupt one shot
  dt-bindings: dma: snps,dw-axi-dmac: constrain the items of resets for JH7110 dma
  dt-bindings: dma: Drop unneeded quotes
  dmaengine: at_xdmac: align declaration of ret with the rest of variables
  dmaengine: at_xdmac: add a warning message regarding for unpaused channels
  ...

Pull kvm updates from Paolo Bonzini:
 "s390:

   - More phys_to_virt conversions

   - Improvement of AP management for VSIE (nested virtualization)

  ARM64:

   - Numerous fixes for the pathological lock inversion issue that
     plagued KVM/arm64 since... forever.

   - New framework allowing SMCCC-compliant hypercalls to be forwarded
     to userspace, hopefully paving the way for some more features being
     moved to VMMs rather than be implemented in the kernel.

   - Large rework of the timer code to allow a VM-wide offset to be
     applied to both virtual and physical counters as well as a
     per-timer, per-vcpu offset that complements the global one. This
     last part allows the NV timer code to be implemented on top.

   - A small set of fixes to make sure that we don't change anything
     affecting the EL1&0 translation regime just after having having
     taken an exception to EL2 until we have executed a DSB. This
     ensures that speculative walks started in EL1&0 have completed.

   - The usual selftest fixes and improvements.

  x86:

   - Optimize CR0.WP toggling by avoiding an MMU reload when TDP is
     enabled, and by giving the guest control of CR0.WP when EPT is
     enabled on VMX (VMX-only because SVM doesn't support per-bit
     controls)

   - Add CR0/CR4 helpers to query single bits, and clean up related code
     where KVM was interpreting kvm_read_cr4_bits()'s "unsigned long"
     return as a bool

   - Move AMD_PSFD to cpufeatures.h and purge KVM's definition

   - Avoid unnecessary writes+flushes when the guest is only adding new
     PTEs

   - Overhaul .sync_page() and .invlpg() to utilize .sync_page()'s
     optimizations when emulating invalidations

   - Clean up the range-based flushing APIs

   - Revamp the TDP MMU's reaping of Accessed/Dirty bits to clear a
     single A/D bit using a LOCK AND instead of XCHG, and skip all of
     the "handle changed SPTE" overhead associated with writing the
     entire entry

   - Track the number of "tail" entries in a pte_list_desc to avoid
     having to walk (potentially) all descriptors during insertion and
     deletion, which gets quite expensive if the guest is spamming
     fork()

   - Disallow virtualizing legacy LBRs if architectural LBRs are
     available, the two are mutually exclusive in hardware

   - Disallow writes to immutable feature MSRs (notably
     PERF_CAPABILITIES) after KVM_RUN, similar to CPUID features

   - Overhaul the vmx_pmu_caps selftest to better validate
     PERF_CAPABILITIES

   - Apply PMU filters to emulated events and add test coverage to the
     pmu_event_filter selftest

   - AMD SVM:
       - Add support for virtual NMIs
       - Fixes for edge cases related to virtual interrupts

   - Intel AMX:
       - Don't advertise XTILE_CFG in KVM_GET_SUPPORTED_CPUID if
         XTILE_DATA is not being reported due to userspace not opting in
         via prctl()
       - Fix a bug in emulation of ENCLS in compatibility mode
       - Allow emulation of NOP and PAUSE for L2
       - AMX selftests improvements
       - Misc cleanups

  MIPS:

   - Constify MIPS's internal callbacks (a leftover from the hardware
     enabling rework that landed in 6.3)

  Generic:

   - Drop unnecessary casts from "void *" throughout kvm_main.c

   - Tweak the layout of "struct kvm_mmu_memory_cache" to shrink the
     struct size by 8 bytes on 64-bit kernels by utilizing a padding
     hole

  Documentation:

   - Fix goof introduced by the conversion to rST"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (211 commits)
  KVM: s390: pci: fix virtual-physical confusion on module unload/load
  KVM: s390: vsie: clarifications on setting the APCB
  KVM: s390: interrupt: fix virtual-physical confusion for next alert GISA
  KVM: arm64: Have kvm_psci_vcpu_on() use WRITE_ONCE() to update mp_state
  KVM: arm64: Acquire mp_state_lock in kvm_arch_vcpu_ioctl_vcpu_init()
  KVM: selftests: Test the PMU event "Instructions retired"
  KVM: selftests: Copy full counter values from guest in PMU event filter test
  KVM: selftests: Use error codes to signal errors in PMU event filter test
  KVM: selftests: Print detailed info in PMU event filter asserts
  KVM: selftests: Add helpers for PMC asserts in PMU event filter test
  KVM: selftests: Add a common helper for the PMU event filter guest code
  KVM: selftests: Fix spelling mistake "perrmited" -> "permitted"
  KVM: arm64: vhe: Drop extra isb() on guest exit
  KVM: arm64: vhe: Synchronise with page table walker on MMU update
  KVM: arm64: pkvm: Document the side effects of kvm_flush_dcache_to_poc()
  KVM: arm64: nvhe: Synchronise with page table walker on TLBI
  KVM: arm64: Handle 32bit CNTPCTSS traps
  KVM: arm64: nvhe: Synchronise with page table walker on vcpu run
  KVM: arm64: vgic: Don't acquire its_lock before config_lock
  KVM: selftests: Add test to verify KVM's supported XCR0
  ...

Pull compute express link updates from Dan Williams:
 "DOE support is promoted from drivers/cxl/ to drivers/pci/ with Bjorn's
  blessing, and the CXL core continues to mature its media management
  capabilities with support for listing and injecting media errors. Some
  late fixes that missed v6.3-final are also included:

   - Refactor the DOE infrastructure (Data Object Exchange
     PCI-config-cycle mailbox) to be a facility of the PCI core rather
     than the CXL core.

     This is foundational for upcoming support for PCI
     device-attestation and PCIe / CXL link encryption.

   - Add support for retrieving and injecting poison for CXL memory
     expanders.

     This enabling uses trace-events to convey CXL media error records
     to user tooling. It includes translation of device-local addresses
     (DPA) to system physical addresses (SPA) and their corresponding
     CXL region.

   - Fixes for decoder enumeration that missed v6.3-final

   - Miscellaneous fixups"

* tag 'cxl-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (38 commits)
  cxl/test: Add mock test for set_timestamp
  cxl/mbox: Update CMD_RC_TABLE
  tools/testing/cxl: Require CONFIG_DEBUG_FS
  tools/testing/cxl: Add a sysfs attr to test poison inject limits
  tools/testing/cxl: Use injected poison for get poison list
  tools/testing/cxl: Mock the Clear Poison mailbox command
  tools/testing/cxl: Mock the Inject Poison mailbox command
  cxl/mem: Add debugfs attributes for poison inject and clear
  cxl/memdev: Trace inject and clear poison as cxl_poison events
  cxl/memdev: Warn of poison inject or clear to a mapped region
  cxl/memdev: Add support for the Clear Poison mailbox command
  cxl/memdev: Add support for the Inject Poison mailbox command
  tools/testing/cxl: Mock support for Get Poison List
  cxl/trace: Add an HPA to cxl_poison trace events
  cxl/region: Provide region info to the cxl_poison trace event
  cxl/memdev: Add trigger_poison_list sysfs attribute
  cxl/trace: Add TRACE support for CXL media-error records
  cxl/mbox: Add GET_POISON_LIST mailbox command
  cxl/mbox: Initialize the poison state
  cxl/mbox: Restrict poison cmds to debugfs cxl_raw_allow_all
  ...

Pull rdma updates from Jason Gunthorpe:
 "Usual wide collection of unrelated items in drivers:

   - Driver bug fixes and treewide cleanups in hfi1, siw, qib, mlx5,
     rxe, usnic, usnic, bnxt_re, ocrdma, iser:
       - remove unnecessary NULL checks
       - kmap obsolescence
       - pci_enable_pcie_error_reporting() obsolescence
       - unused variables and macros
       - trace event related warnings
       - casting warnings

   - Code cleanups for irdm and erdma

   - EFA reporting of 128 byte PCIe TLP support

   - mlx5 more agressively uses the out of order HW feature

   - Big rework of how state machines and tasks work in rxe

   - Fix a syzkaller found crash netdev refcount leak in siw

   - bnxt_re revises their HW description header

   - Congestion control for bnxt_re

   - Use mmu_notifiers more safely in hfi1

   - mlx5 gets better support for PCIe relaxed ordering inside VMs"

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (81 commits)
  RDMA/efa: Add rdma write capability to device caps
  RDMA/mlx5: Use correct device num_ports when modify DC
  RDMA/irdma: Drop spurious WQ_UNBOUND from alloc_ordered_workqueue() call
  RDMA/rxe: Fix spinlock recursion deadlock on requester
  RDMA/mlx5: Fix flow counter query via DEVX
  RDMA/rxe: Protect QP state with qp->state_lock
  RDMA/rxe: Move code to check if drained to subroutine
  RDMA/rxe: Remove qp->req.state
  RDMA/rxe: Remove qp->comp.state
  RDMA/rxe: Remove qp->resp.state
  RDMA/mlx5: Allow relaxed ordering read in VFs and VMs
  net/mlx5: Update relaxed ordering read HCA capabilities
  RDMA/mlx5: Check pcie_relaxed_ordering_enabled() in UMR
  RDMA/mlx5: Remove pcie_relaxed_ordering_enabled() check for RO write
  RDMA: Add ib_virt_dma_to_page()
  RDMA/rxe: Fix the error "trying to register non-static key in rxe_cleanup_task"
  RDMA/irdma: Slightly optimize irdma_form_ah_cm_frame()
  RDMA/rxe: Fix incorrect TASKLET_STATE_SCHED check in rxe_task.c
  IB/hfi1: Place struct mmu_rb_handler on cache line start
  IB/hfi1: Fix bugs with non-PAGE_SIZE-end multi-iovec user SDMA requests
  ...

Pull nfsd updates from Chuck Lever:
 "The big ticket item for this release is that support for RPC-with-TLS
  [RFC 9289] has been added to the Linux NFS server.

  The goal is to provide a simple-to-deploy, low-overhead in-transit
  confidentiality and peer authentication mechanism. It can supplement
  NFS Kerberos and it can protect the use of legacy non-cryptographic
  user authentication flavors such as AUTH_SYS. The TLS Record protocol
  is handled entirely by kTLS, meaning it can use either software
  encryption or offload encryption to smart NICs.

  Aside from that, work continues on improving NFSD's open file cache.
  Among the many clean-ups in that area is a patch to convert the
  rhashtable to use the list-hashing version of that data structure"

* tag 'nfsd-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux: (31 commits)
  NFSD: Handle new xprtsec= export option
  SUNRPC: Support TLS handshake in the server-side TCP socket code
  NFSD: Clean up xattr memory allocation flags
  NFSD: Fix problem of COMMIT and NFS4ERR_DELAY in infinite loop
  SUNRPC: Clear rq_xid when receiving a new RPC Call
  SUNRPC: Recognize control messages in server-side TCP socket code
  SUNRPC: Be even lazier about releasing pages
  SUNRPC: Convert svc_xprt_release() to the release_pages() API
  SUNRPC: Relocate svc_free_res_pages()
  nfsd: simplify the delayed disposal list code
  SUNRPC: Ignore return value of ->xpo_sendto
  SUNRPC: Ensure server-side sockets have a sock->file
  NFSD: Watch for rq_pages bounds checking errors in nfsd_splice_actor()
  sunrpc: simplify two-level sysctl registration for svcrdma_parm_table
  SUNRPC: return proper error from get_expiry()
  lockd: add some client-side tracepoints
  nfs: move nfs_fhandle_hash to common include file
  lockd: server should unlock lock if client rejects the grant
  lockd: fix races in client GRANTED_MSG wait logic
  lockd: move struct nlm_wait to lockd.h
  ...

Pull tracing updates from Steven Rostedt:

 - User events are finally ready!

   After lots of collaboration between various parties, we finally
   locked down on a stable interface for user events that can also work
   with user space only tracing.

   This is implemented by telling the kernel (or user space library, but
   that part is user space only and not part of this patch set), where
   the variable is that the application uses to know if something is
   listening to the trace.

   There's also an interface to tell the kernel about these events,
   which will show up in the /sys/kernel/tracing/events/user_events/
   directory, where it can be enabled.

   When it's enabled, the kernel will update the variable, to tell the
   application to start writing to the kernel.

   See https://lwn.net/Articles/927595/

 - Cleaned up the direct trampolines code to simplify arm64 addition of
   direct trampolines.

   Direct trampolines use the ftrace interface but instead of jumping to
   the ftrace trampoline, applications (mostly BPF) can register their
   own trampoline for performance reasons.

 - Some updates to the fprobe infrastructure. fprobes are more efficient
   than kprobes, as it does not need to save all the registers that
   kprobes on ftrace do. More work needs to be done before the fprobes
   will be exposed as dynamic events.

 - More updates to references to the obsolete path of
   /sys/kernel/debug/tracing for the new /sys/kernel/tracing path.

 - Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer
   line by line instead of all at once.

   There are users in production kernels that have a large data dump
   that originally used printk() directly, but the data dump was larger
   than what printk() allowed as a single print.

   Using seq_buf() to do the printing fixes that.

 - Add /sys/kernel/tracing/touched_functions that shows all functions
   that was every traced by ftrace or a direct trampoline. This is used
   for debugging issues where a traced function could have caused a
   crash by a bpf program or live patching.

 - Add a "fields" option that is similar to "raw" but outputs the fields
   of the events. It's easier to read by humans.

 - Some minor fixes and clean ups.

* tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (41 commits)
  ring-buffer: Sync IRQ works before buffer destruction
  tracing: Add missing spaces in trace_print_hex_seq()
  ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus
  recordmcount: Fix memory leaks in the uwrite function
  tracing/user_events: Limit max fault-in attempts
  tracing/user_events: Prevent same address and bit per process
  tracing/user_events: Ensure bit is cleared on unregister
  tracing/user_events: Ensure write index cannot be negative
  seq_buf: Add seq_buf_do_printk() helper
  tracing: Fix print_fields() for __dyn_loc/__rel_loc
  tracing/user_events: Set event filter_type from type
  ring-buffer: Clearly check null ptr returned by rb_set_head_page()
  tracing: Unbreak user events
  tracing/user_events: Use print_format_fields() for trace output
  tracing/user_events: Align structs with tabs for readability
  tracing/user_events: Limit global user_event count
  tracing/user_events: Charge event allocs to cgroups
  tracing/user_events: Update documentation for ABI
  tracing/user_events: Use write ABI in example
  tracing/user_events: Add ABI self-test
  ...

Pull non-MM updates from Andrew Morton:
 "Mainly singleton patches all over the place.

  Series of note are:

   - updates to scripts/gdb from Glenn Washburn

   - kexec cleanups from Bjorn Helgaas"

* tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (50 commits)
  mailmap: add entries for Paul Mackerras
  libgcc: add forward declarations for generic library routines
  mailmap: add entry for Oleksandr
  ocfs2: reduce ioctl stack usage
  fs/proc: add Kthread flag to /proc/$pid/status
  ia64: fix an addr to taddr in huge_pte_offset()
  checkpatch: introduce proper bindings license check
  epoll: rename global epmutex
  scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry()
  scripts/gdb: create linux/vfs.py for VFS related GDB helpers
  uapi/linux/const.h: prefer ISO-friendly __typeof__
  delayacct: track delays from IRQ/SOFTIRQ
  scripts/gdb: timerlist: convert int chunks to str
  scripts/gdb: print interrupts
  scripts/gdb: raise error with reduced debugging information
  scripts/gdb: add a Radix Tree Parser
  lib/rbtree: use '+' instead of '|' for setting color.
  proc/stat: remove arch_idle_time()
  checkpatch: check for misuse of the link tags
  checkpatch: allow Closes tags with links
  ...

Pull MM updates from Andrew Morton:

 - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
   switching from a user process to a kernel thread.

 - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
   Raghav.

 - zsmalloc performance improvements from Sergey Senozhatsky.

 - Yue Zhao has found and fixed some data race issues around the
   alteration of memcg userspace tunables.

 - VFS rationalizations from Christoph Hellwig:
     - removal of most of the callers of write_one_page()
     - make __filemap_get_folio()'s return value more useful

 - Luis Chamberlain has changed tmpfs so it no longer requires swap
   backing. Use `mount -o noswap'.

 - Qi Zheng has made the slab shrinkers operate locklessly, providing
   some scalability benefits.

 - Keith Busch has improved dmapool's performance, making part of its
   operations O(1) rather than O(n).

 - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
   permitting userspace to wr-protect anon memory unpopulated ptes.

 - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
   rather than exclusive, and has fixed a bunch of errors which were
   caused by its unintuitive meaning.

 - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
   which causes minor faults to install a write-protected pte.

 - Vlastimil Babka has done some maintenance work on vma_merge():
   cleanups to the kernel code and improvements to our userspace test
   harness.

 - Cleanups to do_fault_around() by Lorenzo Stoakes.

 - Mike Rapoport has moved a lot of initialization code out of various
   mm/ files and into mm/mm_init.c.

 - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
   DRM, but DRM doesn't use it any more.

 - Lorenzo has also coverted read_kcore() and vread() to use iterators
   and has thereby removed the use of bounce buffers in some cases.

 - Lorenzo has also contributed further cleanups of vma_merge().

 - Chaitanya Prakash provides some fixes to the mmap selftesting code.

 - Matthew Wilcox changes xfs and afs so they no longer take sleeping
   locks in ->map_page(), a step towards RCUification of pagefaults.

 - Suren Baghdasaryan has improved mmap_lock scalability by switching to
   per-VMA locking.

 - Frederic Weisbecker has reworked the percpu cache draining so that it
   no longer causes latency glitches on cpu isolated workloads.

 - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
   logic.

 - Liu Shixin has changed zswap's initialization so we no longer waste a
   chunk of memory if zswap is not being used.

 - Yosry Ahmed has improved the performance of memcg statistics
   flushing.

 - David Stevens has fixed several issues involving khugepaged,
   userfaultfd and shmem.

 - Christoph Hellwig has provided some cleanup work to zram's IO-related
   code paths.

 - David Hildenbrand has fixed up some issues in the selftest code's
   testing of our pte state changing.

 - Pankaj Raghav has made page_endio() unneeded and has removed it.

 - Peter Xu contributed some rationalizations of the userfaultfd
   selftests.

 - Yosry Ahmed has fixed an issue around memcg's page recalim
   accounting.

 - Chaitanya Prakash has fixed some arm-related issues in the
   selftests/mm code.

 - Longlong Xia has improved the way in which KSM handles hwpoisoned
   pages.

 - Peter Xu fixes a few issues with uffd-wp at fork() time.

 - Stefan Roesch has changed KSM so that it may now be used on a
   per-process and per-cgroup basis.

* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
  mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
  shmem: restrict noswap option to initial user namespace
  mm/khugepaged: fix conflicting mods to collapse_file()
  sparse: remove unnecessary 0 values from rc
  mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
  hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
  maple_tree: fix allocation in mas_sparse_area()
  mm: do not increment pgfault stats when page fault handler retries
  zsmalloc: allow only one active pool compaction context
  selftests/mm: add new selftests for KSM
  mm: add new KSM process and sysfs knobs
  mm: add new api to enable ksm per process
  mm: shrinkers: fix debugfs file permissions
  mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
  migrate_pages_batch: fix statistics for longterm pin retry
  userfaultfd: use helper function range_in_vma()
  lib/show_mem.c: use for_each_populated_zone() simplify code
  mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
  fs/buffer: convert create_page_buffers to folio_create_buffers
  fs/buffer: add folio_create_empty_buffers helper
  ...

The uapi <linux/nbd.h> header declares a 'char handle[8]' per request;
which is overloaded in English (are you referring to "handle" the
verb, such as handling a signal or writing a callback handler, or
"handle" the noun, the value used in a lookup table to correlate a
response back to the request).  Many user-space NBD implementations
(both servers and clients) have instead used 'uint64_t cookie' or
similar, as it is easier to directly assign an integer than to futz
around with memcpy.  In fact, upstream documentation is now
encouraging this shift in terminology:
https://github.com/NetworkBlockDevice/nbd/commit/ca4392eb2b

Accomplish this by use of an anonymous union to provide the alias for
anyone getting the definition from the uapi; this does not break
existing clients, while exposing the nicer name for those who prefer
it.  Note that block/nbd.c still uses the term handle (in fact, it
actually combines a 32-bit cookie and a 32-bit tag into the 64-bit
handle), but that internal usage is not changed by the public uapi,
since no compliant NBD server has any reason to inspect or alter the
64 bits sent over the socket.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20230410180611.1051618-3-eblake@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>