linux.git/lib/rhashtable.c, branch v7.1-rc4 Linux kernel source tree rhashtable: Add bucket_table_free_atomic() helper 2026-05-05T08:12:07+00:00 Uladzislau Rezki (Sony) urezki@gmail.com 2026-04-28T16:14:19+00:00 d1fa83ecac31093a550534a79a33bc7f4ba8fc10 rhashtable_insert_rehash() allocates a new bucket table with GFP_ATOMIC, as it is called from an RCU read-side critical section. If rhashtable_rehash_attach() then fails, the new table is freed via kvfree(). This is unsafe, since kvfree() may fall back to vfree() for vmalloc-backed allocations, which can sleep and trigger: BUG: sleeping function called from invalid context Add bucket_table_free_atomic(), which uses kvfree_atomic() so the table can be freed safely from non-sleeping context. Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
rhashtable_insert_rehash() allocates a new bucket table
with GFP_ATOMIC, as it is called from an RCU read-side
critical section.

If rhashtable_rehash_attach() then fails, the new table
is freed via kvfree(). This is unsafe, since kvfree() may
fall back to vfree() for vmalloc-backed allocations, which
can sleep and trigger:

  BUG: sleeping function called from invalid context

Add bucket_table_free_atomic(), which uses kvfree_atomic()
so the table can be freed safely from non-sleeping context.

Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
rhashtable: drop ht->mutex in rhashtable_free_and_destroy() 2026-05-05T08:12:06+00:00 Mikhail Gavrilov mikhail.v.gavrilov@gmail.com 2026-04-22T21:33:49+00:00 09ae540e1d5c02210795911bf5459282d7af04e9 rhashtable_free_and_destroy() is a single-shot teardown routine: cancel_work_sync() has already quiesced the deferred rehash worker, and the function's documented contract requires the caller to guarantee no other concurrent access to the rhashtable. Under those conditions ht->mutex is not protecting anything -- taking it is a leftover from the original teardown path. That leftover is actively harmful: it closes a circular lock-class dependency with fs_reclaim. The deferred rehash worker takes ht->mutex and then allocates GFP_KERNEL memory in bucket_table_alloc(), establishing &ht->mutex -> fs_reclaim After commit b32c4a213698 ("xattr: add rhashtable-based simple_xattr infrastructure") introduced simple_xattr_ht_free(), which calls rhashtable_free_and_destroy(), the simple_xattrs teardown became reachable from evict() under the dcache shrinker. The subsequent per-subsystem adaptations made the reverse edge concrete in three independent code paths: * commit 52b364fed6e1 ("shmem: adapt to rhashtable-based simple_xattrs with lazy allocation") * commit 5bd97f5c5f24 ("kernfs: adapt to rhashtable-based simple_xattrs with lazy allocation") * commit 50704c391fbf ("pidfs: adapt to rhashtable-based simple_xattrs") Any of the three closes the cycle fs_reclaim -> &ht->mutex which lockdep reports as follows. This particular splat was observed organically on a workstation kernel built from vfs-7.1-rc1.xattr at ~35h uptime under normal mixed workload, with CONFIG_PROVE_LOCKING=y. The path happens to go through kernfs: WARNING: possible circular locking dependency detected 7.0.0-faeab166167f-with-fixes-v1+ #191 Tainted: G U kswapd0/243 is trying to acquire lock: ffff8882e475c0f8 (&ht->mutex){+.+.}-{4:4}, at: rhashtable_free_and_destroy+0x36/0x740 but task is already holding lock: ffffffffa8ad1d00 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x995/0x1600 the existing dependency chain (in reverse order) is: -> #1 (fs_reclaim){+.+.}-{0:0}: __lock_acquire+0x506/0xbf0 lock_acquire.part.0+0xc7/0x280 fs_reclaim_acquire+0xd9/0x130 __kvmalloc_node_noprof+0xcd/0xb40 bucket_table_alloc.isra.0+0x5a/0x440 rhashtable_rehash_alloc+0x4e/0xd0 rht_deferred_worker+0x14b/0x440 process_one_work+0x8fd/0x16a0 worker_thread+0x601/0xff0 kthread+0x36b/0x470 ret_from_fork+0x5bf/0x910 ret_from_fork_asm+0x1a/0x30 -> #0 (&ht->mutex){+.+.}-{4:4}: check_prev_add+0xdb/0xce0 validate_chain+0x554/0x780 __lock_acquire+0x506/0xbf0 lock_acquire.part.0+0xc7/0x280 __mutex_lock+0x1b2/0x2550 rhashtable_free_and_destroy+0x36/0x740 kernfs_put.part.0+0x119/0x570 evict+0x3b6/0x9c0 __dentry_kill+0x181/0x540 shrink_dentry_list+0x135/0x440 prune_dcache_sb+0xdb/0x150 super_cache_scan+0x2ff/0x520 do_shrink_slab+0x35a/0xee0 shrink_slab_memcg+0x457/0x950 shrink_slab+0x43b/0x550 shrink_one+0x31a/0x6f0 shrink_many+0x31e/0xc80 shrink_node+0xeb3/0x14a0 balance_pgdat+0x8ed/0x1600 kswapd+0x2f3/0x530 kthread+0x36b/0x470 ret_from_fork+0x5bf/0x910 ret_from_fork_asm+0x1a/0x30 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&ht->mutex); lock(fs_reclaim); lock(&ht->mutex); Note that lockdep tracks lock classes, not instances: the two &ht->mutex sites are on different rhashtable objects (the deferred worker was triggered by some unrelated rhashtable growth), but because rhashtable_init() uses a single static lockdep key for all rhashtables, this is a real class-level cycle. Once reported, lockdep disables itself for the remainder of the boot, masking any subsequent locking bugs. Drop the mutex. After cancel_work_sync() the rehash worker is quiesced and, per this function's contract, no other concurrent access is possible; the tables are therefore owned exclusively by this function and can be walked without any lock held. Switch the table walks from rht_dereference() (which requires ht->mutex to be held under CONFIG_PROVE_RCU) to rcu_dereference_raw(), which has no lockdep annotation. rht_ptr_exclusive() already uses rcu_dereference_protected(p, 1) and needs no change. This is the only place in lib/rhashtable.c where &ht->mutex is acquired from a path reachable under fs_reclaim; the deferred worker is the only other site and it is the forward edge. Removing the acquisition here therefore eliminates the class cycle for all three subsystems that use simple_xattrs, not just the one in the splat above. No locking-semantics change is introduced for correct users; incorrect users would already be racing with rehash worker completion regardless of the mutex. Synthetic reproduction of the splat within a few-minute window was unsuccessful across several attempts (tmpfs and kernfs zombies via cgroupfs with open-fd-through-rmdir, with and without swap, up to ~60k reclaim-path executions of simple_xattr_ht_free() in a single run), consistent with the rare coincidence-of-edges profile of the bug: the forward edge is already registered in /proc/lockdep on any idle system via rht_deferred_worker, but the reverse edge requires evict() to complete kernfs_put()'s final release inside the fs_reclaim critical section, which in my attempts was ordered against rather than interleaved with the worker. Fixes: b32c4a213698 ("xattr: add rhashtable-based simple_xattr infrastructure") Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
rhashtable_free_and_destroy() is a single-shot teardown routine:
cancel_work_sync() has already quiesced the deferred rehash worker, and
the function's documented contract requires the caller to guarantee no
other concurrent access to the rhashtable. Under those conditions
ht->mutex is not protecting anything -- taking it is a leftover from
the original teardown path.

That leftover is actively harmful: it closes a circular lock-class
dependency with fs_reclaim. The deferred rehash worker takes ht->mutex
and then allocates GFP_KERNEL memory in bucket_table_alloc(),
establishing

    &ht->mutex  ->  fs_reclaim

After commit b32c4a213698 ("xattr: add rhashtable-based simple_xattr
infrastructure") introduced simple_xattr_ht_free(), which calls
rhashtable_free_and_destroy(), the simple_xattrs teardown became
reachable from evict() under the dcache shrinker. The subsequent
per-subsystem adaptations made the reverse edge concrete in three
independent code paths:

  * commit 52b364fed6e1 ("shmem: adapt to rhashtable-based simple_xattrs with lazy allocation")
  * commit 5bd97f5c5f24 ("kernfs: adapt to rhashtable-based simple_xattrs with lazy allocation")
  * commit 50704c391fbf ("pidfs: adapt to rhashtable-based simple_xattrs")

Any of the three closes the cycle

    fs_reclaim  ->  &ht->mutex

which lockdep reports as follows. This particular splat was observed
organically on a workstation kernel built from vfs-7.1-rc1.xattr at
~35h uptime under normal mixed workload, with CONFIG_PROVE_LOCKING=y.
The path happens to go through kernfs:

  WARNING: possible circular locking dependency detected
  7.0.0-faeab166167f-with-fixes-v1+ #191 Tainted: G     U
  kswapd0/243 is trying to acquire lock:
  ffff8882e475c0f8 (&ht->mutex){+.+.}-{4:4},
    at: rhashtable_free_and_destroy+0x36/0x740
  but task is already holding lock:
  ffffffffa8ad1d00 (fs_reclaim){+.+.}-{0:0},
    at: balance_pgdat+0x995/0x1600

  the existing dependency chain (in reverse order) is:

  -> #1 (fs_reclaim){+.+.}-{0:0}:
         __lock_acquire+0x506/0xbf0
         lock_acquire.part.0+0xc7/0x280
         fs_reclaim_acquire+0xd9/0x130
         __kvmalloc_node_noprof+0xcd/0xb40
         bucket_table_alloc.isra.0+0x5a/0x440
         rhashtable_rehash_alloc+0x4e/0xd0
         rht_deferred_worker+0x14b/0x440
         process_one_work+0x8fd/0x16a0
         worker_thread+0x601/0xff0
         kthread+0x36b/0x470
         ret_from_fork+0x5bf/0x910
         ret_from_fork_asm+0x1a/0x30

  -> #0 (&ht->mutex){+.+.}-{4:4}:
         check_prev_add+0xdb/0xce0
         validate_chain+0x554/0x780
         __lock_acquire+0x506/0xbf0
         lock_acquire.part.0+0xc7/0x280
         __mutex_lock+0x1b2/0x2550
         rhashtable_free_and_destroy+0x36/0x740
         kernfs_put.part.0+0x119/0x570
         evict+0x3b6/0x9c0
         __dentry_kill+0x181/0x540
         shrink_dentry_list+0x135/0x440
         prune_dcache_sb+0xdb/0x150
         super_cache_scan+0x2ff/0x520
         do_shrink_slab+0x35a/0xee0
         shrink_slab_memcg+0x457/0x950
         shrink_slab+0x43b/0x550
         shrink_one+0x31a/0x6f0
         shrink_many+0x31e/0xc80
         shrink_node+0xeb3/0x14a0
         balance_pgdat+0x8ed/0x1600
         kswapd+0x2f3/0x530
         kthread+0x36b/0x470
         ret_from_fork+0x5bf/0x910
         ret_from_fork_asm+0x1a/0x30

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(fs_reclaim);
                                 lock(&ht->mutex);
                                 lock(fs_reclaim);
    lock(&ht->mutex);

Note that lockdep tracks lock classes, not instances: the two
&ht->mutex sites are on different rhashtable objects (the deferred
worker was triggered by some unrelated rhashtable growth), but because
rhashtable_init() uses a single static lockdep key for all rhashtables,
this is a real class-level cycle. Once reported, lockdep disables
itself for the remainder of the boot, masking any subsequent locking
bugs.

Drop the mutex. After cancel_work_sync() the rehash worker is quiesced
and, per this function's contract, no other concurrent access is
possible; the tables are therefore owned exclusively by this function
and can be walked without any lock held.

Switch the table walks from rht_dereference() (which requires
ht->mutex to be held under CONFIG_PROVE_RCU) to rcu_dereference_raw(),
which has no lockdep annotation. rht_ptr_exclusive() already uses
rcu_dereference_protected(p, 1) and needs no change.

This is the only place in lib/rhashtable.c where &ht->mutex is
acquired from a path reachable under fs_reclaim; the deferred worker
is the only other site and it is the forward edge. Removing the
acquisition here therefore eliminates the class cycle for all three
subsystems that use simple_xattrs, not just the one in the splat
above. No locking-semantics change is introduced for correct users;
incorrect users would already be racing with rehash worker completion
regardless of the mutex.

Synthetic reproduction of the splat within a few-minute window was
unsuccessful across several attempts (tmpfs and kernfs zombies via
cgroupfs with open-fd-through-rmdir, with and without swap, up to
~60k reclaim-path executions of simple_xattr_ht_free() in a single
run), consistent with the rare coincidence-of-edges profile of the
bug: the forward edge is already registered in /proc/lockdep on any
idle system via rht_deferred_worker, but the reverse edge requires
evict() to complete kernfs_put()'s final release inside the fs_reclaim
critical section, which in my attempts was ordered against rather than
interleaved with the worker.

Fixes: b32c4a213698 ("xattr: add rhashtable-based simple_xattr infrastructure")
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
rhashtable: Bounce deferred worker kick through irq_work 2026-04-21T06:10:50+00:00 Tejun Heo tj@kernel.org 2026-04-21T06:03:26+00:00 4fe985292709eeb6a4653c71660f893e26c2f2dd Inserts past 75% load call schedule_work(&ht->run_work) to kick an async resize. If a caller holds a raw spinlock (e.g. an insecure_elasticity user), schedule_work() under that lock records caller_lock -> pool->lock -> pi_lock -> rq->__lock A cycle forms if any of these locks is acquired in the reverse direction elsewhere. sched_ext, the only current insecure_elasticity user, hits this: it holds scx_sched_lock across rhashtable inserts of sub-schedulers, while scx_bypass() takes rq->__lock -> scx_sched_lock. Exercising the resize path produces: Chain exists of: &pool->lock --> &rq->__lock --> scx_sched_lock Bounce the kick from the insert paths through irq_work so schedule_work() runs from hard IRQ context with the caller's lock no longer held. rht_deferred_worker()'s self-rearm on error stays on schedule_work(&ht->run_work) - the worker runs in process context with no caller lock held, and keeping the self-requeue on @run_work lets cancel_work_sync() in rhashtable_free_and_destroy() drain it. v3: Keep rht_deferred_worker()'s self-rearm on schedule_work(&run_work). Routing it through irq_work in v2 broke cancel_work_sync()'s self-requeue handling - an irq_work queued after irq_work_sync() returned but while cancel_work_sync() was still waiting could fire post-teardown. v2: Bounce unconditionally instead of gating on insecure_elasticity, as suggested by Herbert. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Herbert Xu <herbert@gondor.apana.org.au> 
Inserts past 75% load call schedule_work(&ht->run_work) to kick an
async resize. If a caller holds a raw spinlock (e.g. an
insecure_elasticity user), schedule_work() under that lock records

  caller_lock -> pool->lock -> pi_lock -> rq->__lock

A cycle forms if any of these locks is acquired in the reverse
direction elsewhere. sched_ext, the only current insecure_elasticity
user, hits this: it holds scx_sched_lock across rhashtable inserts of
sub-schedulers, while scx_bypass() takes rq->__lock -> scx_sched_lock.
Exercising the resize path produces:

  Chain exists of:
    &pool->lock --> &rq->__lock --> scx_sched_lock

Bounce the kick from the insert paths through irq_work so
schedule_work() runs from hard IRQ context with the caller's lock no
longer held. rht_deferred_worker()'s self-rearm on error stays on
schedule_work(&ht->run_work) - the worker runs in process context with
no caller lock held, and keeping the self-requeue on @run_work lets
cancel_work_sync() in rhashtable_free_and_destroy() drain it.

v3: Keep rht_deferred_worker()'s self-rearm on schedule_work(&run_work).
    Routing it through irq_work in v2 broke cancel_work_sync()'s
    self-requeue handling - an irq_work queued after irq_work_sync()
    returned but while cancel_work_sync() was still waiting could fire
    post-teardown.

v2: Bounce unconditionally instead of gating on insecure_elasticity,
    as suggested by Herbert.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
rhashtable: Restore insecure_elasticity toggle 2026-04-19T15:47:21+00:00 Herbert Xu herbert@gondor.apana.org.au 2026-04-18T01:41:21+00:00 73bd1227787bfe73eea3d04c63a89cb55db9c23e Some users of rhashtable cannot handle insertion failures, and are happy to accept the consequences of a hash table that having very long chains. Restore the insecure_elasticity toggle for these users. In addition to disabling the chain length checks, this also removes the emergency resize that would otherwise occur when the hash table occupancy hits 100% (an async resize is still scheduled at 75%). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Tejun Heo <tj@kernel.org> 
Some users of rhashtable cannot handle insertion failures, and
are happy to accept the consequences of a hash table that having
very long chains.

Restore the insecure_elasticity toggle for these users.  In
addition to disabling the chain length checks, this also removes
the emergency resize that would otherwise occur when the hash
table occupancy hits 100% (an async resize is still scheduled
at 75%).

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Tejun Heo <tj@kernel.org>
rhashtable: Enable context analysis 2026-01-05T15:43:35+00:00 Marco Elver elver@google.com 2025-12-19T15:40:21+00:00 322366b8f13a8cafe169dc1dc6f6ec0d82ff8734 Enable context analysis for rhashtable, which was used as an initial test as it contains a combination of RCU, mutex, and bit_spinlock usage. Users of rhashtable now also benefit from annotations on the API, which will now warn if the RCU read lock is not held where required. Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20251219154418.3592607-33-elver@google.com 
Enable context analysis for rhashtable, which was used as an initial
test as it contains a combination of RCU, mutex, and bit_spinlock usage.

Users of rhashtable now also benefit from annotations on the API, which
will now warn if the RCU read lock is not held where required.

Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20251219154418.3592607-33-elver@google.com
mm/slub: allow to set node and align in k[v]realloc 2025-09-13T23:54:45+00:00 Vitaly Wool vitaly.wool@konsulko.se 2025-08-06T12:41:47+00:00 2cd8231796b5e7133b1c3d66ad7d2a3c42c97258 Reimplement k[v]realloc_node() to be able to set node and alignment should a user need to do so. In order to do that while retaining the maximal backward compatibility, add k[v]realloc_node_align() functions and redefine the rest of API using these new ones. While doing that, we also keep the number of _noprof variants to a minimum, which implies some changes to the existing users of older _noprof functions, that basically being bcachefs. With that change we also provide the ability for the Rust part of the kernel to set node and alignment in its K[v]xxx [re]allocations. Link: https://lkml.kernel.org/r/20250806124147.1724658-1-vitaly.wool@konsulko.se Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alice Ryhl <aliceryhl@google.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Jann Horn <jannh@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Reimplement k[v]realloc_node() to be able to set node and alignment should
a user need to do so.  In order to do that while retaining the maximal
backward compatibility, add k[v]realloc_node_align() functions and
redefine the rest of API using these new ones.

While doing that, we also keep the number of _noprof variants to a
minimum, which implies some changes to the existing users of older _noprof
functions, that basically being bcachefs.

With that change we also provide the ability for the Rust part of the
kernel to set node and alignment in its K[v]xxx [re]allocations.

Link: https://lkml.kernel.org/r/20250806124147.1724658-1-vitaly.wool@konsulko.se
Signed-off-by: Vitaly Wool <vitaly.wool@konsulko.se>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jann Horn <jannh@google.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Merge tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2025-01-27T01:50:53+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-01-27T01:50:53+00:00 c159dfbdd4fc62fa08f6715d9d6c34d39cf40446 Pull non-MM updates from Andrew Morton: "Mainly individually changelogged singleton patches. The patch series in this pull are: - "lib min_heap: Improve min_heap safety, testing, and documentation" from Kuan-Wei Chiu provides various tightenings to the min_heap library code - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms some cleanup and Rust preparation in the xarray library code - "Update reference to include/asm-<arch>" from Geert Uytterhoeven fixes pathnames in some code comments - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses the new secs_to_jiffies() in various places where that is appropriate - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen switches two filesystems to the new mount API - "Convert ocfs2 to use folios" from Matthew Wilcox does that - "Remove get_task_comm() and print task comm directly" from Yafang Shao removes now-unneeded calls to get_task_comm() in various places - "squashfs: reduce memory usage and update docs" from Phillip Lougher implements some memory savings in squashfs and performs some maintainability work - "lib: clarify comparison function requirements" from Kuan-Wei Chiu tightens the sort code's behaviour and adds some maintenance work - "nilfs2: protect busy buffer heads from being force-cleared" from Ryusuke Konishi fixes an issues in nlifs when the fs is presented with a corrupted image - "nilfs2: fix kernel-doc comments for function return values" from Ryusuke Konishi fixes some nilfs kerneldoc - "nilfs2: fix issues with rename operations" from Ryusuke Konishi addresses some nilfs BUG_ONs which syzbot was able to trigger - "minmax.h: Cleanups and minor optimisations" from David Laight does some maintenance work on the min/max library code - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance work on the xarray library code" * tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (131 commits) ocfs2: use str_yes_no() and str_no_yes() helper functions include/linux/lz4.h: add some missing macros Xarray: use xa_mark_t in xas_squash_marks() to keep code consistent Xarray: remove repeat check in xas_squash_marks() Xarray: distinguish large entries correctly in xas_split_alloc() Xarray: move forward index correctly in xas_pause() Xarray: do not return sibling entries from xas_find_marked() ipc/util.c: complete the kernel-doc function descriptions gcov: clang: use correct function param names latencytop: use correct kernel-doc format for func params minmax.h: remove some #defines that are only expanded once minmax.h: simplify the variants of clamp() minmax.h: move all the clamp() definitions after the min/max() ones minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp() minmax.h: reduce the #define expansion of min(), max() and clamp() minmax.h: update some comments minmax.h: add whitespace around operators and after commas nilfs2: do not update mtime of renamed directory that is not moved nilfs2: handle errors that nilfs_prepare_chunk() may return CREDITS: fix spelling mistake ... 
Pull non-MM updates from Andrew Morton:
 "Mainly individually changelogged singleton patches. The patch series
  in this pull are:

   - "lib min_heap: Improve min_heap safety, testing, and documentation"
     from Kuan-Wei Chiu provides various tightenings to the min_heap
     library code

   - "xarray: extract __xa_cmpxchg_raw" from Tamir Duberstein preforms
     some cleanup and Rust preparation in the xarray library code

   - "Update reference to include/asm-<arch>" from Geert Uytterhoeven
     fixes pathnames in some code comments

   - "Converge on using secs_to_jiffies()" from Easwar Hariharan uses
     the new secs_to_jiffies() in various places where that is
     appropriate

   - "ocfs2, dlmfs: convert to the new mount API" from Eric Sandeen
     switches two filesystems to the new mount API

   - "Convert ocfs2 to use folios" from Matthew Wilcox does that

   - "Remove get_task_comm() and print task comm directly" from Yafang
     Shao removes now-unneeded calls to get_task_comm() in various
     places

   - "squashfs: reduce memory usage and update docs" from Phillip
     Lougher implements some memory savings in squashfs and performs
     some maintainability work

   - "lib: clarify comparison function requirements" from Kuan-Wei Chiu
     tightens the sort code's behaviour and adds some maintenance work

   - "nilfs2: protect busy buffer heads from being force-cleared" from
     Ryusuke Konishi fixes an issues in nlifs when the fs is presented
     with a corrupted image

   - "nilfs2: fix kernel-doc comments for function return values" from
     Ryusuke Konishi fixes some nilfs kerneldoc

   - "nilfs2: fix issues with rename operations" from Ryusuke Konishi
     addresses some nilfs BUG_ONs which syzbot was able to trigger

   - "minmax.h: Cleanups and minor optimisations" from David Laight does
     some maintenance work on the min/max library code

   - "Fixes and cleanups to xarray" from Kemeng Shi does maintenance
     work on the xarray library code"

* tag 'mm-nonmm-stable-2025-01-24-23-16' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (131 commits)
  ocfs2: use str_yes_no() and str_no_yes() helper functions
  include/linux/lz4.h: add some missing macros
  Xarray: use xa_mark_t in xas_squash_marks() to keep code consistent
  Xarray: remove repeat check in xas_squash_marks()
  Xarray: distinguish large entries correctly in xas_split_alloc()
  Xarray: move forward index correctly in xas_pause()
  Xarray: do not return sibling entries from xas_find_marked()
  ipc/util.c: complete the kernel-doc function descriptions
  gcov: clang: use correct function param names
  latencytop: use correct kernel-doc format for func params
  minmax.h: remove some #defines that are only expanded once
  minmax.h: simplify the variants of clamp()
  minmax.h: move all the clamp() definitions after the min/max() ones
  minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()
  minmax.h: reduce the #define expansion of min(), max() and clamp()
  minmax.h: update some comments
  minmax.h: add whitespace around operators and after commas
  nilfs2: do not update mtime of renamed directory that is not moved
  nilfs2: handle errors that nilfs_prepare_chunk() may return
  CREDITS: fix spelling mistake
  ...
rhashtable: Fix rhashtable_try_insert test 2025-01-19T04:44:28+00:00 Herbert Xu herbert@gondor.apana.org.au 2025-01-14T03:15:19+00:00 9d4f8e54cef2c42e23ef258833dbd06a1eaff89b The test on whether rhashtable_insert_one did an insertion relies on the value returned by rhashtable_lookup_one. Unfortunately that value is overwritten after rhashtable_insert_one returns. Fix this by moving the test before data gets overwritten. Simplify the test as only data == NULL matters. Finally move atomic_inc back within the lock as otherwise it may be reordered with the atomic_dec on the removal side, potentially leading to an underflow. Reported-by: Michael Kelley <mhklinux@outlook.com> Fixes: e1d3422c95f0 ("rhashtable: Fix potential deadlock by moving schedule_work outside lock") Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Tested-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Breno Leitao <leitao@debian.org> Tested-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
The test on whether rhashtable_insert_one did an insertion relies
on the value returned by rhashtable_lookup_one.  Unfortunately that
value is overwritten after rhashtable_insert_one returns.  Fix this
by moving the test before data gets overwritten.

Simplify the test as only data == NULL matters.

Finally move atomic_inc back within the lock as otherwise it may
be reordered with the atomic_dec on the removal side, potentially
leading to an underflow.

Reported-by: Michael Kelley <mhklinux@outlook.com>
Fixes: e1d3422c95f0 ("rhashtable: Fix potential deadlock by moving schedule_work outside lock")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Tested-by: Michael Kelley <mhklinux@outlook.com>
Reviewed-by: Breno Leitao <leitao@debian.org>
Tested-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
lib/rhashtable: fix the typo for preemptible 2025-01-13T04:21:06+00:00 Pratyush Mittal pratyushmittal@gmail.com 2024-11-23T10:29:29+00:00 f3a6101b00ad6426488c80d4fc472aee8df93aaa Fix the spelling of the mis-spelled word Link: https://lkml.kernel.org/r/20241123102929.11660-1-pratyushmittal@gmail.com Signed-off-by: Pratyush Mittal <pratyushmittal@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> 
Fix the spelling of the mis-spelled word

Link: https://lkml.kernel.org/r/20241123102929.11660-1-pratyushmittal@gmail.com
Signed-off-by: Pratyush Mittal <pratyushmittal@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
rhashtable: Fix potential deadlock by moving schedule_work outside lock 2024-12-21T09:05:29+00:00 Breno Leitao leitao@debian.org 2024-11-28T12:16:25+00:00 e1d3422c95f003eba241c176adfe593c33e8a8f6 Move the hash table growth check and work scheduling outside the rht lock to prevent a possible circular locking dependency. The original implementation could trigger a lockdep warning due to a potential deadlock scenario involving nested locks between rhashtable bucket, rq lock, and dsq lock. By relocating the growth check and work scheduling after releasing the rth lock, we break this potential deadlock chain. This change expands the flexibility of rhashtable by removing restrictive locking that previously limited its use in scheduler and workqueue contexts. Import to say that this calls rht_grow_above_75(), which reads from struct rhashtable without holding the lock, if this is a problem, we can move the check to the lock, and schedule the workqueue after the lock. Fixes: f0e1a0643a59 ("sched_ext: Implement BPF extensible scheduler class") Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Breno Leitao <leitao@debian.org> Modified so that atomic_inc is also moved outside of the bucket lock along with the growth above 75% check. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> 
Move the hash table growth check and work scheduling outside the
rht lock to prevent a possible circular locking dependency.

The original implementation could trigger a lockdep warning due to
a potential deadlock scenario involving nested locks between
rhashtable bucket, rq lock, and dsq lock. By relocating the
growth check and work scheduling after releasing the rth lock, we break
this potential deadlock chain.

This change expands the flexibility of rhashtable by removing
restrictive locking that previously limited its use in scheduler
and workqueue contexts.

Import to say that this calls rht_grow_above_75(), which reads from
struct rhashtable without holding the lock, if this is a problem, we can
move the check to the lock, and schedule the workqueue after the lock.

Fixes: f0e1a0643a59 ("sched_ext: Implement BPF extensible scheduler class")
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>

Modified so that atomic_inc is also moved outside of the bucket
lock along with the growth above 75% check.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>