From: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Mon, 12 May 2025 02:57:12 +0000 (+0800)
Subject: mm: convert do_set_pmd() to take a folio
X-Git-Tag: v6.16-rc1~92^2~25
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=698c0089cdf0b27d37f0b24824b682c23de5f72d;p=thirdparty%2Flinux.git

mm: convert do_set_pmd() to take a folio

In do_set_pmd(), we always use the folio->page to build PMD mappings for
the entire folio.  Since all callers of do_set_pmd() already hold a stable
folio, converting do_set_pmd() to take a folio is safe and more
straightforward.

In addition, to ensure the extensibility of do_set_pmd() for supporting
larger folios beyond PMD size, we keep the 'page' parameter to specify
which page within the folio should be mapped.

No functional changes expected.

Link: https://lkml.kernel.org/r/9b488f4ecb4d3fd8634e3d448dd0ed6964482480.1747017104.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a916ea42cfd5c..cd2e513189d60 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1235,7 +1235,7 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
 	return pte;
 }
 
-vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
+vm_fault_t do_set_pmd(struct vm_fault *vmf, struct folio *folio, struct page *page);
 void set_pte_range(struct vm_fault *vmf, struct folio *folio,
 		struct page *page, unsigned int nr, unsigned long addr);
 
diff --git a/mm/filemap.c b/mm/filemap.c
index 7b90cbeb4a1ad..09d005848f0d1 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3533,7 +3533,7 @@ static bool filemap_map_pmd(struct vm_fault *vmf, struct folio *folio,
 
 	if (pmd_none(*vmf->pmd) && folio_test_pmd_mappable(folio)) {
 		struct page *page = folio_file_page(folio, start);
-		vm_fault_t ret = do_set_pmd(vmf, page);
+		vm_fault_t ret = do_set_pmd(vmf, folio, page);
 		if (!ret) {
 			/* The page is mapped successfully, reference consumed. */
 			folio_unlock(folio);
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 33daea8f667e8..ebcd7c8a4b445 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1478,7 +1478,7 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,
 
 	mmap_assert_locked(vma->vm_mm);
 
-	if (do_set_pmd(&vmf, page))
+	if (do_set_pmd(&vmf, folio, page))
 		return SCAN_FAIL;
 
 	folio_get(folio);
diff --git a/mm/memory.c b/mm/memory.c
index 4cf4adb0de266..5cb48f262ab01 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5227,9 +5227,8 @@ static void deposit_prealloc_pte(struct vm_fault *vmf)
 	vmf->prealloc_pte = NULL;
 }
 
-vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
+vm_fault_t do_set_pmd(struct vm_fault *vmf, struct folio *folio, struct page *page)
 {
-	struct folio *folio = page_folio(page);
 	struct vm_area_struct *vma = vmf->vma;
 	bool write = vmf->flags & FAULT_FLAG_WRITE;
 	unsigned long haddr = vmf->address & HPAGE_PMD_MASK;
@@ -5302,7 +5301,7 @@ out:
 	return ret;
 }
 #else
-vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
+vm_fault_t do_set_pmd(struct vm_fault *vmf, struct folio *folio, struct page *page)
 {
 	return VM_FAULT_FALLBACK;
 }
@@ -5396,6 +5395,7 @@ fallback:
 	else
 		page = vmf->page;
 
+	folio = page_folio(page);
 	/*
 	 * check even for read faults because we might have lost our CoWed
 	 * page
@@ -5407,8 +5407,8 @@ fallback:
 	}
 
 	if (pmd_none(*vmf->pmd)) {
-		if (PageTransCompound(page)) {
-			ret = do_set_pmd(vmf, page);
+		if (folio_test_pmd_mappable(folio)) {
+			ret = do_set_pmd(vmf, folio, page);
 			if (ret != VM_FAULT_FALLBACK)
 				return ret;
 		}
@@ -5419,7 +5419,6 @@ fallback:
 			return VM_FAULT_OOM;
 	}
 
-	folio = page_folio(page);
 	nr_pages = folio_nr_pages(folio);
 
 	/*