Pull locking updates from Ingo Molnar:
 "Futexes:

   - Use runtime constants for futex_hash computation (K Prateek Nayak,
     Peter Zijlstra)

   - Optimise the size check get_futex_key() (Sebastian Andrzej Siewior)

   - Avoid private hash use-after-free on final put (Felix Hoffmann)

   - Tell kmemleak we're not leaking __futex_queues (Peter Zijlstra)

  Rust integration updates:

   - Implement refcounted interrupt disable and SpinLockIrq for Rust
     (Boqun Feng, Heiko Carstens, Joel Fernandes, Lyude Paul)

   - Rust sync: add helpers for mb, dma_mb and friends; add generic
     memory barriers and use LKMM atomics instead of Rust atomics in the
     revocable code (Gary Guo)

   - Add abstraction and integrate synchronize_rcu() (Philipp Stanner)

  Lock debugging:

   - Add qspinlock contended_release tracepoint (Dmitry Ilvokhin, Peter
     Zijlstra)

   - Enable the printing of held locks of remote running tasks and print
     task CPU (Ingo Molnar)

   - percpu-rwsem: Annotate intentional data race in readers_active_check()
     (Sun Shaojie)

  Misc fixes and updates by Boqun Feng, Peter Zijlstra, Fangrui Song,
  Naveen Kumar Chaudhary and Thomas Huth"

* tag 'locking-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
  rust: sync: Introduce SpinLockIrq::lock_with() and friends
  rust: sync: Add SpinLockIrq
  rust: sync: Use super::* in spinlock.rs
  rust: helper: Add spin_{un,}lock_irq_{enable,disable}() helpers
  rust: Introduce interrupt module
  s390/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS
  arm64: sched/preempt: Enable HAS_SEPARATE_PREEMPT_RESCHED_BITS
  preempt: Introduce HAS_SEPARATE_PREEMPT_RESCHED_BITS
  sched: Avoid signed comparison of preempt_count() in __cant_migrate()
  sched: Remove the unused preempt_offset parameter of __cant_sleep()
  locking: Switch to _irq_{disable,enable}() variants in cleanup guards
  irq: Add KUnit test for refcounted interrupt enable/disable
  irq,spin_lock: Add counted interrupt disabling/enabling
  openrisc: Include <linux/cpumask.h> in smp.h
  preempt: Introduce __preempt_count_{sub,add}_return()
  preempt: Introduce HARDIRQ_DISABLE_BITS
  preempt: Track NMI nesting to separate per-CPU counter
  futex: Tell kmemleak we're not leaking __futex_queues
  x86/paravirt: Trace contended_release on unlock
  tracing/lock: Use TRACE_EVENT_FN() for contended_release
  ...

It was an effort to enhance fscache as a kernel cache for lazy
pulling (at least according to previous Incremental FS discussion [1])
and EROFS over fscache was the in-tree user of this mode.

fscache has since evolved to be netfslib-oriented, serving network
filesystem inodes via the netfs library, but EROFS never acts as a
network filesystem and we need to cache golden filesystem images rather
than individual EROFS inodes.

Since EROFS over fscache is now removed, clean up netfs/fscache/
cachefiles upstream too.

[1] https://lore.kernel.org/r/CAOQ4uxi4dzxArY24YO=+kBCK2gGoq3Ptb8WkzCqSogPgU_R3dQ@mail.gmail.com

[dh] Fixed up comments on:
https://sashiko.dev/#/patchset/20260716103030.3065561-1-dhowells%40redhat.com
https://sashiko.dev/#/patchset/20260722130218.78958-1-dhowells%40redhat.com

Signed-off-by: Gao Xiang <xiang@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/1046393.1786544127@warthog.procyon.org.uk
cc: Paulo Alcantara <pc@manguebit.org>
cc: netfs@lists.linux.dev
cc: linux-erofs@lists.ozlabs.org
cc: bpf@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

queued_spin_unlock() gates its contended_release trace call behind a
static branch, so a NOP sits on the unlock path even while the
tracepoint is disabled. Removing that requires replacing the unlock
implementation only while contended_release is enabled, which needs a
callback when the tracepoint is toggled.

Convert contended_release to TRACE_EVENT_FN() and add weak no-op
arch_contended_release_trace_reg()/arch_contended_release_trace_unreg()
hooks.

The default hooks are empty, so this is a no-op until an architecture
overrides them.

No functional change intended.

Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Juergen Gross <jgross@suse.com>
Link: https://patch.msgid.link/1c2fcccfb584c075c02890c484f22c76a1948bf1.1785778551.git.d@ilvokhin.com

Pull Btrfs Fixes 2: Electric Boogaloo from David Sterba:
 "This brings back the fixup worker infrastructure.

  It's a mechanism to detect pages/folios that are marked dirty without
  filesystem knowledge and require COW fixup. The consequence of not
  doing so is silent data loss.

  The first patch covers the scenarios in detail, also reflecting folio
  API port and subpage block size support added in recent years. The
  original fixup worker was only for pages.

  The patch is relatively big, half of the code is debugging and support
  code, the rest is the core design around the detection and fix.

  The second patch handles an unlikely case when there's work left
  during unmount"

* tag 'for-7.2-rc6-fixup-worker-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: flush the fixup workers during close_ctree
  btrfs: trigger cow fixup via dirty_folio()

The problem scenario:
If we have a folio mmapped shared and then somebody does a dio read with
that folio as the read destination, then it is possible that the dio
will see a dirty destination page when it starts (and thus skip
dirtying and just GUP pin it) but then while it is doing the read, btrfs
finishes writing it back and by the endio, the folio is clean. In that
case, the dio read must re-dirty the folio with aops->dirty_folio():

btrfs_check_read_bio()
|- __iomap_dio_bio_end_io() from btrfs_bio_end_io()
   |- bio_check_pages_dirty()
      |- bio_dirty_fn()
         |- bio_release_pages(bio, true)
            |- __bio_release_pages(bio, mark_dirty == true)
               |- folio_lock()
               |- folio_mark_dirty()
                  |- aops->dirty_folio()
               |- folio_unlock()

A data block normally moves through writeback as follows:

  TASK
    folio_lock
    write              clean -> dirty bit + delalloc
    folio_unlock
  WRITEBACK
    for-each-dirty-folio:
      folio_lock
      run_delalloc     delalloc consumed  -> dirty bit + OE
      submission       dirty bit consumed -> writeback bit + OE
      folio_unlock
  ENDIO
    endio              OE bytes accounted
    OE finish          writeback -> clean; destroy OE

Three critical invariants that this path maintains are:

  I1. Any dirty block is covered by delalloc xor an ordered extent
  I2. Any dirty block covered by an OE will be submitted into that OE
  I3. Any dirty block already submitted into an OE will not be submitted
      again into the same OE.

These ensure that the block will be written exactly once. It is clear
that not reserving delalloc for the re-dirty case violates I1.

This situation, even without bs < folio_size, has long required btrfs to
fixup such dirty pages during writeback with an asynchronous worker that
is allowed to do this expensive work and writeback does not proceed for
a folio while it is doing this work.

Commit 247e743cbe6e ("Btrfs: Use async helpers to deal with pages that
have been improperly dirtied") introduced the COW fixup to catch exactly
this class at writeback, way back in 2008.

Since then, there have been many advances to prevent most of the causes
of such re-dirtying and we thought we could get away with removing the
annoying cow-fixup in the hope of simplifying writeback for large folio
support.

  Commit b2a9f217ad3f ("btrfs: remove the COW fixup mechanism")
  Commit 4927b141877c ("btrfs: remove folio ordered flag and subpage bitmap")

Since it turns out this assumption was incorrect, as evidenced by the
report and attendant reproducers, we must reintroduce the fixup concept.

This is of course critically further complicated by bs < folio_size. In
that case, rather than just a folio dirty bit, we have a bitmap for the
dirty blocks in the folio. And the (also broken) invariant is:

  I4. folio dirty IFF at least one block bitmap dirty.

The original report of a stall on a misinterpreted empty bitmap is
exactly evidence of a violation of I4.

It is exactly because of bs < folio_size we don't want to simply revert the
removal patches. The original fixup was not properly bs < folio_size
aware, which motivated removal in the first place. So we wish to build a
bs < folio_size aware fixup.

One other important detail from the old design, any normal write that
happens after a re-dirty but before a fixup is racing with the cow fixup
to do the delalloc reservation, therefore it must cancel the fixup state.
If it arrives after the reservation exists, it will be a normal dirty
overwrite. This critically informs the design in a pretty clear way.
fixup requiring re-dirty has folio granularity, while cancellation has
delalloc (block) granularity so while we only ever produce fixup in
chunks of folios, we must be able to clear it in blocks. Therefore we
must track the blocks needing fixup at block granularity.

The obvious way to do this is with a new bitmap in btrfs_folio_state,
but it is desirable to avoid that if possible. Unfortunately, I don't
think it is possible and the reason is subtle and leans on a sort of
extreme reproducer, but I think can be explained relatively succinctly.

Consider a folio whose two halves will land in different ordered extents
(can be accomplished with tricks using nodatasum) and a dio read is
running with it as the shared mmap destination.

1. The front half:
   a. folio comes clean on a normal write
   b. dio read completes into the folio marking it fixup.
   c. a write comes for the previous folio for a range extending into
      this folio, this is a cancellation of the fixup which reserves
      space.
   d. writeback runs on the range *not* overlapping the folio. This half
      remains dirty but is now covered by an OE and is awaiting
      writeback running on its range to be submitted and finish the OE.

2. The back half:
   a. the folio is part of an OE that gets far enough along to clear
      writeback.
   b. dio read completes into the folio marking it fixup.

After this, the folio's front half is dirty in the "normal" sense, it
needs to be submitted to the OE waiting for it. It's a cancelled fixup.
Meanwhile, the second half is a true fresh fixup. So at this point if we
run writeback on this folio, we genuinely can't know what to do without
block level information. If we submit it, we submit unreserved dirty
from the back half. If we don't, we will never finish the OE waiting for
it. So it's either a corruption or a deadlock.

Thus, the full high level design picture:

- btrfs_data_dirty_folio(): For out of band non-reserving dirties,
  mark still-clean blocks inside EOF dirty and set their fixup bits
  (the event carries no range, so every clean block is suspect).
  Already-dirty blocks are covered or pending and are left alone.

- Writeback: skip fixup blocks and enqueue work for them

- writepage_fixup(): for each fixup block do the fixup reservation in a
  worker, after which the blocks can be written back normally.

- Typical reserving write paths cancel fixup state for the ranges they
  cover with btrfs_folio_cancel_fixup()

Link: https://lore.kernel.org/linux-btrfs/20260721191152.101118-1-borntraeger@linux.ibm.com/
Assisted-by: LLM
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>

Commit 97f0b1345219 ("tracing: add trace event for memory-failure")
introduced memory_failure_event in ras subsystem.  commit 31807483d395
("mm/memory-failure: remove the selection of RAS") changed
memory_failure_event to memory_failure subsystem.  This breaks the
backward compatibility, some user programs rely on it.

Change memory_failure_event to ras subsystem to keep backward
compatibility.

Link: https://lore.kernel.org/20260605081213.154660-1-xieyuanbin1@huawei.com
Fixes: 31807483d395 ("mm/memory-failure: remove the selection of RAS")
Signed-off-by: Xie Yuanbin <xieyuanbin1@huawei.com>
Reported-by: Yi Lai <yi1.lai@intel.com>
Reported-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Closes: https://lore.kernel.org/linux-mm/CY8PR11MB7134346A3E4BB28ECA28D6E989132@CY8PR11MB7134.namprd11.prod.outlook.com
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull ceph updates from Ilya Dryomov:
 "This adds support for manual client session reset in CephFS, allowing
  operators to get out of tricky livelock situations involving caps and
  file locks without evicting the problematic client instance on the MDS
  side or rebooting the client node both of which can be disruptive"

* tag 'ceph-for-7.2-rc1' of https://github.com/ceph/ceph-client:
  ceph: add manual reset debugfs control and tracepoints
  ceph: add client reset state machine and session teardown
  ceph: add diagnostic timeout loop to wait_caps_flush()
  ceph: harden send_mds_reconnect and handle active-MDS peer reset
  ceph: use proper endian conversion for flock_len in reconnect
  ceph: convert inode flags to named bit positions and atomic bitops
  rbd: switch to dynamic root device

Pull f2fs updates from Jaegeuk Kim:
 "The changes primarily focus on filesystem error reporting, reducing
  memory footprint by reverting in-memory data structures used for
  runtime validation, honoring FDP hints, and adding trace and debug
  logs. In addition, there are critical bug fixes resolving
  out-of-bounds read vulnerabilities in inline directory and ACL
  handling, potential deadlocks in balance_fs, use-after-free issues in
  atomic writes, and false data/node type assignments in large sections.

  Enhancements:
   - Revert  in-memory sit version and block bitmaps
   - support to report fserror
   - add trace_f2fs_fault_report
   - add iostat latency tracking for direct IO
   - add logs in f2fs_disable_checkpoint()
   - honor per-I/O write streams for direct writes
   - map data writes to FDP streams
   - skip inode folio lookup for cached overwrite
   - skip direct I/O iostat context when disabled
   - revert "check in-memory block bitmap"
   - revert "check in-memory sit version bitmap"

  Fixes:
   - optimize representative type determination in GC
   - fix incorrect FI_NO_EXTENT handling in __destroy_extent_node()
   - fix potential deadlock in f2fs_balance_fs()
   - fix potential deadlock in gc_merge path of f2fs_balance_fs()
   - atomic: fix UAF issue on f2fs_inode_info.atomic_inode
   - fix missing read bio submission on large folio error
   - pass correct iostat type for single node writes
   - fix to do sanity check on f2fs_get_node_folio_ra()
   - validate orphan inode entry count
   - keep atomic write retry from zeroing original data
   - read COW data with the original inode during atomic write
   - validate inline dentry name lengths before conversion
   - validate dentry name length before lookup compares it
   - reject setattr size changes on large folio files
   - revert "remove non-uptodate folio from the page cache in move_data_block"
   - validate ACL entry sizes in f2fs_acl_from_disk()
   - bound i_inline_xattr_size for non-inline-xattr inodes
   - fix listxattr handling of corrupted xattr entries
   - fix to round down start offset of fallocate for pin file"

* tag 'f2fs-for-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (42 commits)
  f2fs: fix to round down start offset of fallocate for pin file
  f2fs: fix listxattr handling of corrupted xattr entries
  f2fs: skip direct I/O iostat context when disabled
  f2fs: remove unneeded f2fs_is_compressed_page()
  f2fs: avoid unnecessary fscrypt_finalize_bounce_page()
  f2fs: avoid unnecessary sanity check on ckpt_valid_blocks
  f2fs: misc cleanup in f2fs_record_stop_reason()
  f2fs: fix wrong description in printed log
  f2fs: bound i_inline_xattr_size for non-inline-xattr inodes
  f2fs: validate ACL entry sizes in f2fs_acl_from_disk()
  Revert "f2fs: remove non-uptodate folio from the page cache in move_data_block"
  f2fs: Split f2fs_write_end_io()
  f2fs: Rename f2fs_post_read_wq into f2fs_wq
  f2fs: Prepare for supporting delayed bio completion
  f2fs: reject setattr size changes on large folio files
  f2fs: validate dentry name length before lookup compares it
  f2fs: validate inline dentry name lengths before conversion
  f2fs: read COW data with the original inode during atomic write
  f2fs: skip inode folio lookup for cached overwrite
  f2fs: keep atomic write retry from zeroing original data
  ...

Pull more MM updates from Andrew Morton:

 - "khugepaged: add mTHP collapse support" (Nico Pache)

   Provide khugepaged with the capability to collapse anonymous memory
   regions to mTHPs

 - "Remove CONFIG_READ_ONLY_THP_FOR_FS and enable file THP for writable
   files" (Zi Yan)

   Remove the READ_ONLY_THP_FOR_FS check in file_thp_enabled(), so that
   khugepaged and MADV_COLLAPSE can run on filesystems with PMD THP
   pagecache support even without READ_ONLY_THP_FOR_FS enabled

 - "make MM selftests more CI friendly" (Mike Rapoport)

   General fixes and cleanups to the MM selftests. Also move more MM
   selftests under the kselftest framework, making them more amenable to
   ongoing CI testing

 - "selftests/mm: fix failures and robustness improvements" and
   "selftests/mm: assorted fixes for hmm-tests" (Sayali Patil)

   Fix several issues in MM selftests which were revealed by powerpc 64k
   pagesize

* tag 'mm-stable-2026-06-23-08-55' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (118 commits)
  Revert "mm: limit filemap_fault readahead to VMA boundaries"
  mm/vmscan: pass NULL to trace vmscan node reclaim
  mm: use mapping_mapped to simplify the code
  selftests/mm: fix exclusive_cow test fork() handling
  selftests/mm: remove hardcoded THP sizing assumptions in hmm tests
  selftests/mm: allow PUD-level entries in compound testcase of hmm tests
  mm/gup_test: reject wrapped user ranges
  mm/page_frag: reject invalid CPUs in page_frag_test
  mm/damon/core: always put unsuccessfully committed target pids
  mm: page_isolation: avoid unsafe folio reads while scanning compound pages
  mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show()
  selftests: mm: fix and speedup "droppable" test
  mm: merge writeout into pageout
  MAINTAINERS: add Hao Ge as reviewer for codetag and alloc_tag
  selftests/mm: clarify alternate unmapping in compaction_test
  selftests/mm: move hwpoison setup into run_test() and silence modprobe output for memory-failure category
  selftests/mm: skip uffd-stress test when nr_pages_per_cpu is zero
  selftests/mm: skip uffd-wp-mremap if UFFD write-protect is unsupported
  selftests/mm: ensure destination is hugetlb-backed in hugetlb-mremap
  selftest/mm: register existing mapping with userfaultfd in hugetlb-mremap
  ...

Pull erofs updates from Gao Xiang:
 "The most notable change is the removal of the fscache backend: it has
  been deprecated for almost two years, mainly because EROFS file-backed
  mounts and fanotify pre-content hooks (together with erofs-utils) now
  provide better functionality and simpler codebase. In addition,
  fscache has depended on netfslib for years, which is undesirable for
  EROFS since it is a local filesystem. More details in [1].

  In addition, sparse support has been added to the pcluster layout,
  which is helpful for large sparse AI datasets, and map requests for
  chunk-based inodes have been optimized to be more efficient as well.
  There are also the usual fixes and cleanups.

  Summary:

   - Report more consecutive chunks of the same type for
     each iomap request

   - Add sparse support for the pcluster layout

   - Update the EROFS documentation overview

   - Remove the deprecated fscache backend

   - Various fixes and cleanups"

Link: https://lore.kernel.org/r/20260622013622.934174-1-hsiangkao@linux.alibaba.com [1]

* tag 'erofs-for-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: handle 48-bit blocks_hi for compressed inodes
  erofs: remove fscache backend entirely
  erofs: simplify RCU read critical sections
  erofs: add sparse support to pcluster layout
  erofs: add folio order to trace_erofs_read_folio
  erofs: introduce erofs_map_chunks()
  erofs: call erofs_exit_ishare() before rcu_barrier()
  erofs: update the overview of the documentation
  erofs: clean up erofs_ishare_fill_inode()