[PATCH 2/3] mm/khugepaged: use enum scan_result for result variables

[Shivank Garg <shivankg@amd.com>]

Use enum scan_result for local variables and the result pointer in
khugepaged_scan_mm_slot(), instead of plain int. This improves code
readability and clarifies intent,

No functional change.

Signed-off-by: Shivank Garg <shivankg@amd.com>
---
 mm/khugepaged.c | 29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 107146f012b1..65b1b778378a 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -547,7 +547,8 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
 	struct folio *folio = NULL;
 	unsigned long addr = start_addr;
 	pte_t *_pte;
-	int none_or_zero = 0, shared = 0, result = SCAN_FAIL, referenced = 0;
+	int none_or_zero = 0, shared = 0, referenced = 0;
+	enum scan_result result = SCAN_FAIL;
 
 	for (_pte = pte; _pte < pte + HPAGE_PMD_NR;
 	     _pte++, addr += PAGE_SIZE) {
@@ -786,7 +787,7 @@ static int __collapse_huge_page_copy(pte_t *pte, struct folio *folio,
 		struct list_head *compound_pagelist)
 {
 	unsigned int i;
-	int result = SCAN_SUCCEED;
+	enum scan_result result = SCAN_SUCCEED;
 
 	/*
 	 * Copying pages' contents is subject to memory poison at any iteration.
@@ -969,7 +970,7 @@ static int check_pmd_still_valid(struct mm_struct *mm,
 				 pmd_t *pmd)
 {
 	pmd_t *new_pmd;
-	int result = find_pmd_or_thp_or_none(mm, address, &new_pmd);
+	enum scan_result result = find_pmd_or_thp_or_none(mm, address, &new_pmd);
 
 	if (result != SCAN_SUCCEED)
 		return result;
@@ -993,7 +994,7 @@ static int __collapse_huge_page_swapin(struct mm_struct *mm,
 	int swapped_in = 0;
 	vm_fault_t ret = 0;
 	unsigned long addr, end = start_addr + (HPAGE_PMD_NR * PAGE_SIZE);
-	int result;
+	enum scan_result result;
 	pte_t *pte = NULL;
 	spinlock_t *ptl;
 
@@ -1100,7 +1101,7 @@ static int collapse_huge_page(struct mm_struct *mm, unsigned long address,
 	pgtable_t pgtable;
 	struct folio *folio;
 	spinlock_t *pmd_ptl, *pte_ptl;
-	int result = SCAN_FAIL;
+	enum scan_result result = SCAN_FAIL;
 	struct vm_area_struct *vma;
 	struct mmu_notifier_range range;
 
@@ -1253,8 +1254,8 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm,
 {
 	pmd_t *pmd;
 	pte_t *pte, *_pte;
-	int result = SCAN_FAIL, referenced = 0;
-	int none_or_zero = 0, shared = 0;
+	int none_or_zero = 0, shared = 0, referenced = 0;
+	enum scan_result result = SCAN_FAIL;
 	struct page *page = NULL;
 	struct folio *folio = NULL;
 	unsigned long addr;
@@ -1492,7 +1493,8 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,
 int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
 			    bool install_pmd)
 {
-	int nr_mapped_ptes = 0, result = SCAN_FAIL;
+	enum scan_result result = SCAN_FAIL;
+	int nr_mapped_ptes = 0;
 	unsigned int nr_batch_ptes;
 	struct mmu_notifier_range range;
 	bool notified = false;
@@ -1866,7 +1868,8 @@ static int collapse_file(struct mm_struct *mm, unsigned long addr,
 	pgoff_t index = 0, end = start + HPAGE_PMD_NR;
 	LIST_HEAD(pagelist);
 	XA_STATE_ORDER(xas, &mapping->i_pages, start, HPAGE_PMD_ORDER);
-	int nr_none = 0, result = SCAN_SUCCEED;
+	enum scan_result result = SCAN_SUCCEED;
+	int nr_none = 0;
 	bool is_shmem = shmem_file(file);
 
 	VM_BUG_ON(!IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && !is_shmem);
@@ -2296,7 +2299,7 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr,
 	XA_STATE(xas, &mapping->i_pages, start);
 	int present, swap;
 	int node = NUMA_NO_NODE;
-	int result = SCAN_SUCCEED;
+	enum scan_result result = SCAN_SUCCEED;
 
 	present = 0;
 	swap = 0;
@@ -2394,7 +2397,7 @@ static int hpage_collapse_scan_file(struct mm_struct *mm, unsigned long addr,
 	return result;
 }
 
-static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result,
+static unsigned int khugepaged_scan_mm_slot(unsigned int pages, enum scan_result *result,
 					    struct collapse_control *cc)
 	__releases(&khugepaged_mm_lock)
 	__acquires(&khugepaged_mm_lock)
@@ -2555,7 +2558,7 @@ static void khugepaged_do_scan(struct collapse_control *cc)
 	unsigned int progress = 0, pass_through_head = 0;
 	unsigned int pages = READ_ONCE(khugepaged_pages_to_scan);
 	bool wait = true;
-	int result = SCAN_SUCCEED;
+	enum scan_result result = SCAN_SUCCEED;
 
 	lru_add_drain_all();
 
@@ -2790,7 +2793,7 @@ int madvise_collapse(struct vm_area_struct *vma, unsigned long start,
 
 	for (addr = hstart; addr < hend; addr += HPAGE_PMD_SIZE) {
 		bool retried = false;
-		int result = SCAN_FAIL;
+		enum scan_result result = SCAN_FAIL;
 
 		if (!mmap_locked) {
 retry:
-- 
2.43.0