lib min_heap: add type safe interface

Implement a type-safe interface for min_heap using strong type pointers
instead of void * in the data field.  This change includes adding small
macro wrappers around functions, enabling the use of __minheap_cast and
__minheap_obj_size macros for type casting and obtaining element size. 
This implementation removes the necessity of passing element size in
min_heap_callbacks.  Additionally, introduce the MIN_HEAP_PREALLOCATED
macro for preallocating some elements.

Link: https://lkml.kernel.org/ioyfizrzq7w7mjrqcadtzsfgpuntowtjdw5pgn4qhvsdp4mqqg@nrlek5vmisbu
Link: https://lkml.kernel.org/r/20240524152958.919343-5-visitorckw@gmail.com
Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Ching-Chun (Jim) Huang <jserv@ccns.ncku.edu.tw>
Cc: Coly Li <colyli@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Sakai <msakai@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

2 files changed, 7 insertions, 7 deletions

diff --git a/drivers/md/dm-vdo/repair.c b/drivers/md/dm-vdo/repair.c
index defc9359f10e..e8ad611fe7c1 100644
--- a/drivers/md/dm-vdo/repair.c
+++ b/drivers/md/dm-vdo/repair.c
@@ -51,6 +51,8 @@ struct recovery_point {
 	bool increment_applied;
 };
 
+DEFINE_MIN_HEAP(struct numbered_block_mapping, replay_heap);
+
 struct repair_completion {
 	/* The completion header */
 	struct vdo_completion completion;
@@ -97,7 +99,7 @@ struct repair_completion {
 	 * order, then original journal order. This permits efficient iteration over the journal
 	 * entries in order.
 	 */
-	struct min_heap replay_heap;
+	struct replay_heap replay_heap;
 	/* Fields tracking progress through the journal entries. */
 	struct numbered_block_mapping *current_entry;
 	struct numbered_block_mapping *current_unfetched_entry;
@@ -163,14 +165,13 @@ static void swap_mappings(void *item1, void *item2)
 }
 
 static const struct min_heap_callbacks repair_min_heap = {
-	.elem_size = sizeof(struct numbered_block_mapping),
 	.less = mapping_is_less_than,
 	.swp = swap_mappings,
 };
 
 static struct numbered_block_mapping *sort_next_heap_element(struct repair_completion *repair)
 {
-	struct min_heap *heap = &repair->replay_heap;
+	struct replay_heap *heap = &repair->replay_heap;
 	struct numbered_block_mapping *last;
 
 	if (heap->nr == 0)
@@ -1117,7 +1118,7 @@ static void recover_block_map(struct vdo_completion *completion)
 	 * Organize the journal entries into a binary heap so we can iterate over them in sorted
 	 * order incrementally, avoiding an expensive sort call.
 	 */
-	repair->replay_heap = (struct min_heap) {
+	repair->replay_heap = (struct replay_heap) {
 		.data = repair->entries,
 		.nr = repair->block_map_entry_count,
 		.size = repair->block_map_entry_count,
diff --git a/drivers/md/dm-vdo/slab-depot.c b/drivers/md/dm-vdo/slab-depot.c
index 46e4721e5b4f..ef9a6e53109c 100644
--- a/drivers/md/dm-vdo/slab-depot.c
+++ b/drivers/md/dm-vdo/slab-depot.c
@@ -3309,7 +3309,6 @@ static void swap_slab_statuses(void *item1, void *item2)
 }
 
 static const struct min_heap_callbacks slab_status_min_heap = {
-	.elem_size = sizeof(struct slab_status),
 	.less = slab_status_is_less_than,
 	.swp = swap_slab_statuses,
 };
@@ -3509,7 +3508,7 @@ static int get_slab_statuses(struct block_allocator *allocator,
 static int __must_check vdo_prepare_slabs_for_allocation(struct block_allocator *allocator)
 {
 	struct slab_status current_slab_status;
-	struct min_heap heap;
+	DEFINE_MIN_HEAP(struct slab_status, heap) heap;
 	int result;
 	struct slab_status *slab_statuses;
 	struct slab_depot *depot = allocator->depot;
@@ -3521,7 +3520,7 @@ static int __must_check vdo_prepare_slabs_for_allocation(struct block_allocator
 		return result;
 
 	/* Sort the slabs by cleanliness, then by emptiness hint. */
-	heap = (struct min_heap) {
+	heap = (struct heap) {
 		.data = slab_statuses,
 		.nr = allocator->slab_count,
 		.size = allocator->slab_count,