mm,hugetlb: rename anon_rmap to new_anon_folio and make it boolean

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@suse.de
Link: https://lkml.kernel.org/r/20250630144212.156938-4-osalvador@suse.de
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Gavin Guo <gavinguo@igalia.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 68a260e4f4c77d7dd0c264a8468e4fb1bd58077d..3e5cefd5e1d9073eec78c2c18555d74f1c5473bf 100644 (file)
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6406,17 +6406,16 @@ 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
@@ -6515,10 +6514,9 @@ 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 {
                /*
@@ -6567,7 +6565,7 @@ 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);
@@ -6586,7 +6584,7 @@ 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);
                }
@@ -6622,7 +6620,8 @@ out:
 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);