Merge tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - The series "resource: A couple of cleanups" from Andy Shevchenko
   performs some cleanups in the resource management code

 - The series "Improve the copy of task comm" from Yafang Shao addresses
   possible race-induced overflows in the management of
   task_struct.comm[]

 - The series "Remove unnecessary header includes from
   {tools/}lib/list_sort.c" from Kuan-Wei Chiu adds some cleanups and a
   small fix to the list_sort library code and to its selftest

 - The series "Enhance min heap API with non-inline functions and
   optimizations" also from Kuan-Wei Chiu optimizes and cleans up the
   min_heap library code

 - The series "nilfs2: Finish folio conversion" from Ryusuke Konishi
   finishes off nilfs2's folioification

 - The series "add detect count for hung tasks" from Lance Yang adds
   more userspace visibility into the hung-task detector's activity

 - Apart from that, singelton patches in many places - please see the
   individual changelogs for details

* tag 'mm-nonmm-stable-2024-11-24-02-05' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  gdb: lx-symbols: do not error out on monolithic build
  kernel/reboot: replace sprintf() with sysfs_emit()
  lib: util_macros_kunit: add kunit test for util_macros.h
  util_macros.h: fix/rework find_closest() macros
  Improve consistency of '#error' directive messages
  ocfs2: fix uninitialized value in ocfs2_file_read_iter()
  hung_task: add docs for hung_task_detect_count
  hung_task: add detect count for hung tasks
  dma-buf: use atomic64_inc_return() in dma_buf_getfile()
  fs/proc/kcore.c: fix coccinelle reported ERROR instances
  resource: avoid unnecessary resource tree walking in __region_intersects()
  ocfs2: remove unused errmsg function and table
  ocfs2: cluster: fix a typo
  lib/scatterlist: use sg_phys() helper
  checkpatch: always parse orig_commit in fixes tag
  nilfs2: convert metadata aops from writepage to writepages
  nilfs2: convert nilfs_recovery_copy_block() to take a folio
  nilfs2: convert nilfs_page_count_clean_buffers() to take a folio
  nilfs2: remove nilfs_writepage
  nilfs2: convert checkpoint file to be folio-based
  ...

Documentation/admin-guide/sysctl/kernel.rst

@@ -401,6 +401,15 @@ The upper bound on the number of tasks that are checked.
 This file shows up if ``CONFIG_DETECT_HUNG_TASK`` is enabled.
 
 
+hung_task_detect_count
+======================
+
+Indicates the total number of tasks that have been detected as hung since
+the system boot.
+
+This file shows up if ``CONFIG_DETECT_HUNG_TASK`` is enabled.
+
+
 hung_task_timeout_secs
 ======================
 

Documentation/core-api/index.rst

@@ -52,6 +52,7 @@ Library functionality that is used throughout the kernel.
    wrappers/atomic_bitops
    floating-point
    union_find
+   min_heap
 
 Low level entry and exit
 ========================

Documentation/core-api/min_heap.rst

@@ -0,0 +1,300 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============
+Min Heap API
+============
+
+Introduction
+============
+
+The Min Heap API provides a set of functions and macros for managing min-heaps
+in the Linux kernel. A min-heap is a binary tree structure where the value of
+each node is less than or equal to the values of its children, ensuring that
+the smallest element is always at the root.
+
+This document provides a guide to the Min Heap API, detailing how to define and
+use min-heaps. Users should not directly call functions with **__min_heap_*()**
+prefixes, but should instead use the provided macro wrappers.
+
+In addition to the standard version of the functions, the API also includes a
+set of inline versions for performance-critical scenarios. These inline
+functions have the same names as their non-inline counterparts but include an
+**_inline** suffix. For example, **__min_heap_init_inline** and its
+corresponding macro wrapper **min_heap_init_inline**. The inline versions allow
+custom comparison and swap functions to be called directly, rather than through
+indirect function calls. This can significantly reduce overhead, especially
+when CONFIG_MITIGATION_RETPOLINE is enabled, as indirect function calls become
+more expensive. As with the non-inline versions, it is important to use the
+macro wrappers for inline functions instead of directly calling the functions
+themselves.
+
+Data Structures
+===============
+
+Min-Heap Definition
+-------------------
+
+The core data structure for representing a min-heap is defined using the
+**MIN_HEAP_PREALLOCATED** and **DEFINE_MIN_HEAP** macros. These macros allow
+you to define a min-heap with a preallocated buffer or dynamically allocated
+memory.
+
+Example:
+
+.. code-block:: c
+
+    #define MIN_HEAP_PREALLOCATED(_type, _name, _nr)
+    struct _name {
+        int nr;         /* Number of elements in the heap */
+        int size;       /* Maximum number of elements that can be held */
+        _type *data;    /* Pointer to the heap data */
+        _type preallocated[_nr];  /* Static preallocated array */
+    }
+
+    #define DEFINE_MIN_HEAP(_type, _name) MIN_HEAP_PREALLOCATED(_type, _name, 0)
+
+A typical heap structure will include a counter for the number of elements
+(`nr`), the maximum capacity of the heap (`size`), and a pointer to an array of
+elements (`data`). Optionally, you can specify a static array for preallocated
+heap storage using **MIN_HEAP_PREALLOCATED**.
+
+Min Heap Callbacks
+------------------
+
+The **struct min_heap_callbacks** provides customization options for ordering
+elements in the heap and swapping them. It contains two function pointers:
+
+.. code-block:: c
+
+    struct min_heap_callbacks {
+        bool (*less)(const void *lhs, const void *rhs, void *args);
+        void (*swp)(void *lhs, void *rhs, void *args);
+    };
+
+- **less** is the comparison function used to establish the order of elements.
+- **swp** is a function for swapping elements in the heap. If swp is set to
+  NULL, the default swap function will be used, which swaps the elements based on their size
+
+Macro Wrappers
+==============
+
+The following macro wrappers are provided for interacting with the heap in a
+user-friendly manner. Each macro corresponds to a function that operates on the
+heap, and they abstract away direct calls to internal functions.
+
+Each macro accepts various parameters that are detailed below.
+
+Heap Initialization
+--------------------
+
+.. code-block:: c
+
+    min_heap_init(heap, data, size);
+
+- **heap**: A pointer to the min-heap structure to be initialized.
+- **data**: A pointer to the buffer where the heap elements will be stored. If
+  `NULL`, the preallocated buffer within the heap structure will be used.
+- **size**: The maximum number of elements the heap can hold.
+
+This macro initializes the heap, setting its initial state. If `data` is
+`NULL`, the preallocated memory inside the heap structure will be used for
+storage. Otherwise, the user-provided buffer is used. The operation is **O(1)**.
+
+**Inline Version:** min_heap_init_inline(heap, data, size)
+
+Accessing the Top Element
+-------------------------
+
+.. code-block:: c
+
+    element = min_heap_peek(heap);
+
+- **heap**: A pointer to the min-heap from which to retrieve the smallest
+  element.
+
+This macro returns a pointer to the smallest element (the root) of the heap, or
+`NULL` if the heap is empty. The operation is **O(1)**.
+
+**Inline Version:** min_heap_peek_inline(heap)
+
+Heap Insertion
+--------------
+
+.. code-block:: c
+
+    success = min_heap_push(heap, element, callbacks, args);
+
+- **heap**: A pointer to the min-heap into which the element should be inserted.
+- **element**: A pointer to the element to be inserted into the heap.
+- **callbacks**: A pointer to a `struct min_heap_callbacks` providing the
+  `less` and `swp` functions.
+- **args**: Optional arguments passed to the `less` and `swp` functions.
+
+This macro inserts an element into the heap. It returns `true` if the insertion
+was successful and `false` if the heap is full. The operation is **O(log n)**.
+
+**Inline Version:** min_heap_push_inline(heap, element, callbacks, args)
+
+Heap Removal
+------------
+
+.. code-block:: c
+
+    success = min_heap_pop(heap, callbacks, args);
+
+- **heap**: A pointer to the min-heap from which to remove the smallest element.
+- **callbacks**: A pointer to a `struct min_heap_callbacks` providing the
+  `less` and `swp` functions.
+- **args**: Optional arguments passed to the `less` and `swp` functions.
+
+This macro removes the smallest element (the root) from the heap. It returns
+`true` if the element was successfully removed, or `false` if the heap is
+empty. The operation is **O(log n)**.
+
+**Inline Version:** min_heap_pop_inline(heap, callbacks, args)
+
+Heap Maintenance
+----------------
+
+You can use the following macros to maintain the heap's structure:
+
+.. code-block:: c
+
+    min_heap_sift_down(heap, pos, callbacks, args);
+
+- **heap**: A pointer to the min-heap.
+- **pos**: The index from which to start sifting down.
+- **callbacks**: A pointer to a `struct min_heap_callbacks` providing the
+  `less` and `swp` functions.
+- **args**: Optional arguments passed to the `less` and `swp` functions.
+
+This macro restores the heap property by moving the element at the specified
+index (`pos`) down the heap until it is in the correct position. The operation
+is **O(log n)**.
+
+**Inline Version:** min_heap_sift_down_inline(heap, pos, callbacks, args)
+
+.. code-block:: c
+
+    min_heap_sift_up(heap, idx, callbacks, args);
+
+- **heap**: A pointer to the min-heap.
+- **idx**: The index of the element to sift up.
+- **callbacks**: A pointer to a `struct min_heap_callbacks` providing the
+  `less` and `swp` functions.
+- **args**: Optional arguments passed to the `less` and `swp` functions.
+
+This macro restores the heap property by moving the element at the specified
+index (`idx`) up the heap. The operation is **O(log n)**.
+
+**Inline Version:** min_heap_sift_up_inline(heap, idx, callbacks, args)
+
+.. code-block:: c
+
+    min_heapify_all(heap, callbacks, args);
+
+- **heap**: A pointer to the min-heap.
+- **callbacks**: A pointer to a `struct min_heap_callbacks` providing the
+  `less` and `swp` functions.
+- **args**: Optional arguments passed to the `less` and `swp` functions.
+
+This macro ensures that the entire heap satisfies the heap property. It is
+called when the heap is built from scratch or after many modifications. The
+operation is **O(n)**.
+
+**Inline Version:** min_heapify_all_inline(heap, callbacks, args)
+
+Removing Specific Elements
+--------------------------
+
+.. code-block:: c
+
+    success = min_heap_del(heap, idx, callbacks, args);
+
+- **heap**: A pointer to the min-heap.
+- **idx**: The index of the element to delete.
+- **callbacks**: A pointer to a `struct min_heap_callbacks` providing the
+  `less` and `swp` functions.
+- **args**: Optional arguments passed to the `less` and `swp` functions.
+
+This macro removes an element at the specified index (`idx`) from the heap and
+restores the heap property. The operation is **O(log n)**.
+
+**Inline Version:** min_heap_del_inline(heap, idx, callbacks, args)
+
+Other Utilities
+===============
+
+- **min_heap_full(heap)**: Checks whether the heap is full.
+  Complexity: **O(1)**.
+
+.. code-block:: c
+
+    bool full = min_heap_full(heap);
+
+- `heap`: A pointer to the min-heap to check.
+
+This macro returns `true` if the heap is full, otherwise `false`.
+
+**Inline Version:** min_heap_full_inline(heap)
+
+- **min_heap_empty(heap)**: Checks whether the heap is empty.
+  Complexity: **O(1)**.
+
+.. code-block:: c
+
+    bool empty = min_heap_empty(heap);
+
+- `heap`: A pointer to the min-heap to check.
+
+This macro returns `true` if the heap is empty, otherwise `false`.
+
+**Inline Version:** min_heap_empty_inline(heap)
+
+Example Usage
+=============
+
+An example usage of the min-heap API would involve defining a heap structure,
+initializing it, and inserting and removing elements as needed.
+
+.. code-block:: c
+
+    #include <linux/min_heap.h>
+
+    int my_less_function(const void *lhs, const void *rhs, void *args) {
+        return (*(int *)lhs < *(int *)rhs);
+    }
+
+    struct min_heap_callbacks heap_cb = {
+        .less = my_less_function,    /* Comparison function for heap order */
+        .swp  = NULL,                /* Use default swap function */
+    };
+
+    void example_usage(void) {
+        /* Pre-populate the buffer with elements */
+        int buffer[5] = {5, 2, 8, 1, 3};
+        /* Declare a min-heap */
+        DEFINE_MIN_HEAP(int, my_heap);
+
+        /* Initialize the heap with preallocated buffer and size */
+        min_heap_init(&my_heap, buffer, 5);
+
+        /* Build the heap using min_heapify_all */
+        my_heap.nr = 5;  /* Set the number of elements in the heap */
+        min_heapify_all(&my_heap, &heap_cb, NULL);
+
+        /* Peek at the top element (should be 1 in this case) */
+        int *top = min_heap_peek(&my_heap);
+        pr_info("Top element: %d\n", *top);
+
+        /* Pop the top element (1) and get the new top (2) */
+        min_heap_pop(&my_heap, &heap_cb, NULL);
+        top = min_heap_peek(&my_heap);
+        pr_info("New top element: %d\n", *top);
+
+        /* Insert a new element (0) and recheck the top */
+        int new_element = 0;
+        min_heap_push(&my_heap, &new_element, &heap_cb, NULL);
+        top = min_heap_peek(&my_heap);
+        pr_info("Top element after insertion: %d\n", *top);
+    }

MAINTAINERS

@@ -15585,6 +15585,15 @@ F:	arch/arm/boot/dts/marvell/armada-xp-crs326-24g-2s.dts
 F:	arch/arm/boot/dts/marvell/armada-xp-crs328-4c-20s-4s-bit.dts
 F:	arch/arm/boot/dts/marvell/armada-xp-crs328-4c-20s-4s.dts
 
+MIN HEAP
+M:	Kuan-Wei Chiu <visitorckw@gmail.com>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	Documentation/core-api/min_heap.rst
+F:	include/linux/min_heap.h
+F:	lib/min_heap.c
+F:	lib/test_min_heap.c
+
 MIPI CCS, SMIA AND SMIA++ IMAGE SENSOR DRIVER
 M:	Sakari Ailus <sakari.ailus@linux.intel.com>
 L:	linux-media@vger.kernel.org

arch/alpha/include/asm/spinlock_types.h

@@ -3,7 +3,7 @@
 #define _ALPHA_SPINLOCK_TYPES_H
 
 #ifndef __LINUX_SPINLOCK_TYPES_RAW_H
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 typedef struct {

arch/arm/include/asm/spinlock_types.h

@@ -3,7 +3,7 @@
 #define __ASM_SPINLOCK_TYPES_H
 
 #ifndef __LINUX_SPINLOCK_TYPES_RAW_H
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 #define TICKET_SHIFT	16

arch/arm64/include/asm/spinlock_types.h

@@ -6,7 +6,7 @@
 #define __ASM_SPINLOCK_TYPES_H
 
 #if !defined(__LINUX_SPINLOCK_TYPES_RAW_H) && !defined(__ASM_SPINLOCK_H)
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 #include <asm-generic/qspinlock_types.h>

arch/hexagon/include/asm/spinlock_types.h

@@ -9,7 +9,7 @@
 #define _ASM_SPINLOCK_TYPES_H
 
 #ifndef __LINUX_SPINLOCK_TYPES_RAW_H
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 typedef struct {

arch/powerpc/include/asm/simple_spinlock_types.h

@@ -3,7 +3,7 @@
 #define _ASM_POWERPC_SIMPLE_SPINLOCK_TYPES_H
 
 #ifndef __LINUX_SPINLOCK_TYPES_RAW_H
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 typedef struct {

arch/powerpc/include/asm/spinlock_types.h

@@ -3,7 +3,7 @@
 #define _ASM_POWERPC_SPINLOCK_TYPES_H
 
 #ifndef __LINUX_SPINLOCK_TYPES_RAW_H
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 #ifdef CONFIG_PPC_QUEUED_SPINLOCKS

arch/s390/include/asm/spinlock_types.h

@@ -3,7 +3,7 @@
 #define __ASM_SPINLOCK_TYPES_H
 
 #ifndef __LINUX_SPINLOCK_TYPES_RAW_H
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 typedef struct {

arch/sh/include/asm/spinlock_types.h

@@ -3,7 +3,7 @@
 #define __ASM_SH_SPINLOCK_TYPES_H
 
 #ifndef __LINUX_SPINLOCK_TYPES_RAW_H
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 typedef struct {

arch/xtensa/include/asm/spinlock_types.h

@@ -3,7 +3,7 @@
 #define __ASM_SPINLOCK_TYPES_H
 
 #if !defined(__LINUX_SPINLOCK_TYPES_RAW_H) && !defined(__ASM_SPINLOCK_H)
-# error "please don't include this file directly"
+# error "Please do not include this file directly."
 #endif
 
 #include <asm-generic/qspinlock_types.h>

drivers/gpu/drm/drm_framebuffer.c

@@ -870,7 +870,7 @@ int drm_framebuffer_init(struct drm_device *dev, struct drm_framebuffer *fb,
 	INIT_LIST_HEAD(&fb->filp_head);
 
 	fb->funcs = funcs;
-	strcpy(fb->comm, current->comm);
+	strscpy(fb->comm, current->comm);
 
 	ret = __drm_mode_object_add(dev, &fb->base, DRM_MODE_OBJECT_FB,
 				    false, drm_framebuffer_free);

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -1104,7 +1104,7 @@ i915_vma_coredump_create(const struct intel_gt *gt,
 	}
 
 	INIT_LIST_HEAD(&dst->page_list);
-	strcpy(dst->name, name);
+	strscpy(dst->name, name);
 	dst->next = NULL;
 
 	dst->gtt_offset = vma_res->start;
@@ -1404,7 +1404,7 @@ static bool record_context(struct i915_gem_context_coredump *e,
 	rcu_read_lock();
 	task = pid_task(ctx->pid, PIDTYPE_PID);
 	if (task) {
-		strcpy(e->comm, task->comm);
+		strscpy(e->comm, task->comm);
 		e->pid = task->pid;
 	}
 	rcu_read_unlock();
@@ -1450,7 +1450,7 @@ capture_vma_snapshot(struct intel_engine_capture_vma *next,
 		return next;
 	}
 
-	strcpy(c->name, name);
+	strscpy(c->name, name);
 	c->vma_res = i915_vma_resource_get(vma_res);
 
 	c->next = next;

drivers/md/bcache/Kconfig

@@ -5,6 +5,7 @@ config BCACHE
 	select BLOCK_HOLDER_DEPRECATED if SYSFS
 	select CRC64
 	select CLOSURES
+	select MIN_HEAP
 	help
 	Allows a block device to be used as cache for other devices; uses
 	a btree for indexing and the layout is optimized for SSDs.

drivers/md/bcache/alloc.c

@@ -189,23 +189,16 @@ static inline bool new_bucket_min_cmp(const void *l, const void *r, void *args)
 	return new_bucket_prio(ca, *lhs) < new_bucket_prio(ca, *rhs);
 }
 
-static inline void new_bucket_swap(void *l, void *r, void __always_unused *args)
-{
-	struct bucket **lhs = l, **rhs = r;
-
-	swap(*lhs, *rhs);
-}
-
 static void invalidate_buckets_lru(struct cache *ca)
 {
 	struct bucket *b;
 	const struct min_heap_callbacks bucket_max_cmp_callback = {
 		.less = new_bucket_max_cmp,
-		.swp = new_bucket_swap,
+		.swp = NULL,
 	};
 	const struct min_heap_callbacks bucket_min_cmp_callback = {
 		.less = new_bucket_min_cmp,
-		.swp = new_bucket_swap,
+		.swp = NULL,
 	};
 
 	ca->heap.nr = 0;

drivers/md/bcache/bset.c

@@ -1093,14 +1093,6 @@ static inline bool new_btree_iter_cmp(const void *l, const void *r, void __alway
 	return bkey_cmp(_l->k, _r->k) <= 0;
 }
 
-static inline void new_btree_iter_swap(void *iter1, void *iter2, void __always_unused *args)
-{
-	struct btree_iter_set *_iter1 = iter1;
-	struct btree_iter_set *_iter2 = iter2;
-
-	swap(*_iter1, *_iter2);
-}
-
 static inline bool btree_iter_end(struct btree_iter *iter)
 {
 	return !iter->heap.nr;
@@ -1111,7 +1103,7 @@ void bch_btree_iter_push(struct btree_iter *iter, struct bkey *k,
 {
 	const struct min_heap_callbacks callbacks = {
 		.less = new_btree_iter_cmp,
-		.swp = new_btree_iter_swap,
+		.swp = NULL,
 	};
 
 	if (k != end)
@@ -1157,7 +1149,7 @@ static inline struct bkey *__bch_btree_iter_next(struct btree_iter *iter,
 	struct bkey *ret = NULL;
 	const struct min_heap_callbacks callbacks = {
 		.less = cmp,
-		.swp = new_btree_iter_swap,
+		.swp = NULL,
 	};
 
 	if (!btree_iter_end(iter)) {
@@ -1231,7 +1223,7 @@ static void btree_mergesort(struct btree_keys *b, struct bset *out,
 		: bch_ptr_invalid;
 	const struct min_heap_callbacks callbacks = {
 		.less = b->ops->sort_cmp,
-		.swp = new_btree_iter_swap,
+		.swp = NULL,
 	};
 
 	/* Heapify the iterator, using our comparison function */

drivers/md/bcache/extents.c

@@ -266,20 +266,12 @@ static bool new_bch_extent_sort_cmp(const void *l, const void *r, void __always_
 	return !(c ? c > 0 : _l->k < _r->k);
 }
 
-static inline void new_btree_iter_swap(void *iter1, void *iter2, void __always_unused *args)
-{
-	struct btree_iter_set *_iter1 = iter1;
-	struct btree_iter_set *_iter2 = iter2;
-
-	swap(*_iter1, *_iter2);
-}
-
 static struct bkey *bch_extent_sort_fixup(struct btree_iter *iter,
 					  struct bkey *tmp)
 {
 	const struct min_heap_callbacks callbacks = {
 		.less = new_bch_extent_sort_cmp,
-		.swp = new_btree_iter_swap,
+		.swp = NULL,
 	};
 	while (iter->heap.nr > 1) {
 		struct btree_iter_set *top = iter->heap.data, *i = top + 1;

drivers/md/bcache/movinggc.c

@@ -190,14 +190,6 @@ static bool new_bucket_cmp(const void *l, const void *r, void __always_unused *a
 	return GC_SECTORS_USED(*_l) >= GC_SECTORS_USED(*_r);
 }
 
-static void new_bucket_swap(void *l, void *r, void __always_unused *args)
-{
-	struct bucket **_l = l;
-	struct bucket **_r = r;
-
-	swap(*_l, *_r);
-}
-
 static unsigned int bucket_heap_top(struct cache *ca)
 {
 	struct bucket *b;
@@ -212,7 +204,7 @@ void bch_moving_gc(struct cache_set *c)
 	unsigned long sectors_to_move, reserve_sectors;
 	const struct min_heap_callbacks callbacks = {
 		.less = new_bucket_cmp,
-		.swp = new_bucket_swap,
+		.swp = NULL,
 	};
 
 	if (!c->copy_gc_enabled)