[PATCH v4 3/5] mm,hugetlb: rename anon_rmap to new_anon_folio and make it boolean

[Oscar Salvador]

anon_rmap is used to determine whether the new allocated folio is
anonymous.  Rename it to something more meaningul like new_anon_folio and
make it boolean, as we use it like that.

While we are at it, drop 'new_pagecache_folio' as 'new_anon_folio' is
enough to check whether we need to restore the consumed reservation.

Link: https://lkml.kernel.org/r/20250627102904.107202-4-osalvador@xxxxxxx
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: Gavin Guo <gavinguo@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
 mm/hugetlb.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 31d39e2a0879..67f3c9c16348 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6424,17 +6424,16 @@ static bool hugetlb_pte_stable(struct hstate *h, struct mm_struct *mm, unsigned
 static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 			struct vm_fault *vmf)
 {
+	u32 hash = hugetlb_fault_mutex_hash(mapping, vmf->pgoff);
+	bool new_folio, new_anon_folio = false;
 	struct vm_area_struct *vma = vmf->vma;
 	struct mm_struct *mm = vma->vm_mm;
 	struct hstate *h = hstate_vma(vma);
 	vm_fault_t ret = VM_FAULT_SIGBUS;
-	int anon_rmap = 0;
-	unsigned long size;
+	bool folio_locked = true;
 	struct folio *folio;
+	unsigned long size;
 	pte_t new_pte;
-	bool new_folio, new_pagecache_folio = false;
-	u32 hash = hugetlb_fault_mutex_hash(mapping, vmf->pgoff);
-	bool folio_locked = true;
 
 	/*
 	 * Currently, we are forced to kill the process in the event the
@@ -6533,10 +6532,9 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 				ret = VM_FAULT_SIGBUS;
 				goto out;
 			}
-			new_pagecache_folio = true;
 		} else {
+			new_anon_folio = true;
 			folio_lock(folio);
-			anon_rmap = 1;
 		}
 	} else {
 		/*
@@ -6585,7 +6583,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 	if (!pte_same(huge_ptep_get(mm, vmf->address, vmf->pte), vmf->orig_pte))
 		goto backout;
 
-	if (anon_rmap)
+	if (new_anon_folio)
 		hugetlb_add_new_anon_rmap(folio, vma, vmf->address);
 	else
 		hugetlb_add_file_rmap(folio);
@@ -6604,7 +6602,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 		 * No need to keep file folios locked. See comment in
 		 * hugetlb_fault().
 		 */
-		if (!anon_rmap) {
+		if (!new_anon_folio) {
 			folio_locked = false;
 			folio_unlock(folio);
 		}
@@ -6640,7 +6638,8 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 backout:
 	spin_unlock(vmf->ptl);
 backout_unlocked:
-	if (new_folio && !new_pagecache_folio)
+	/* We only need to restore reservations for private mappings */
+	if (new_anon_folio)
 		restore_reserve_on_error(h, vma, vmf->address, folio);
 
 	folio_unlock(folio);
-- 
2.50.0