[PATCH v3 4/6] userfaultfd: convert __mcopy_atomic_hugetlb() to use a folio

[Peng Zhang]

From: ZhangPeng <zhangpeng362@xxxxxxxxxx>

Convert hugetlb_mcopy_atomic_pte() to take in a folio pointer instead of
a page pointer. Convert __mcopy_atomic_hugetlb() to use a folio.

Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx>
---
 include/linux/hugetlb.h |  4 ++--
 mm/hugetlb.c            | 26 +++++++++++++-------------
 mm/userfaultfd.c        | 16 ++++++++--------
 3 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 7c977d234aba..030252ce51bd 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -163,7 +163,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
 				unsigned long dst_addr,
 				unsigned long src_addr,
 				enum mcopy_atomic_mode mode,
-				struct page **pagep,
+				struct folio **foliop,
 				bool wp_copy);
 #endif /* CONFIG_USERFAULTFD */
 bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
@@ -399,7 +399,7 @@ static inline int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 						unsigned long dst_addr,
 						unsigned long src_addr,
 						enum mcopy_atomic_mode mode,
-						struct page **pagep,
+						struct folio **foliop,
 						bool wp_copy)
 {
 	BUG();
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 29ac064f69d6..1cfd20e5fe8b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6163,7 +6163,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			    unsigned long dst_addr,
 			    unsigned long src_addr,
 			    enum mcopy_atomic_mode mode,
-			    struct page **pagep,
+			    struct folio **foliop,
 			    bool wp_copy)
 {
 	bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE);
@@ -6185,8 +6185,8 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 		if (!folio)
 			goto out;
 		folio_in_pagecache = true;
-	} else if (!*pagep) {
-		/* If a page already exists, then it's UFFDIO_COPY for
+	} else if (!*foliop) {
+		/* If a folio already exists, then it's UFFDIO_COPY for
 		 * a non-missing case. Return -EEXIST.
 		 */
 		if (vm_shared &&
@@ -6221,33 +6221,33 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 				ret = -ENOMEM;
 				goto out;
 			}
-			*pagep = &folio->page;
-			/* Set the outparam pagep and return to the caller to
+			*foliop = folio;
+			/* Set the outparam foliop and return to the caller to
 			 * copy the contents outside the lock. Don't free the
-			 * page.
+			 * folio.
 			 */
 			goto out;
 		}
 	} else {
 		if (vm_shared &&
 		    hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) {
-			put_page(*pagep);
+			folio_put(*foliop);
 			ret = -EEXIST;
-			*pagep = NULL;
+			*foliop = NULL;
 			goto out;
 		}
 
 		folio = alloc_hugetlb_folio(dst_vma, dst_addr, 0);
 		if (IS_ERR(folio)) {
-			put_page(*pagep);
+			folio_put(*foliop);
 			ret = -ENOMEM;
-			*pagep = NULL;
+			*foliop = NULL;
 			goto out;
 		}
-		copy_user_huge_page(&folio->page, *pagep, dst_addr, dst_vma,
+		copy_user_huge_page(&folio->page, &(*foliop)->page, dst_addr, dst_vma,
 				    pages_per_huge_page(h));
-		put_page(*pagep);
-		*pagep = NULL;
+		folio_put(*foliop);
+		*foliop = NULL;
 	}
 
 	/*
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 7b660bc07d71..cbcc7eb1d36e 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -324,7 +324,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 	pte_t *dst_pte;
 	unsigned long src_addr, dst_addr;
 	long copied;
-	struct page *page;
+	struct folio *folio;
 	unsigned long vma_hpagesize;
 	pgoff_t idx;
 	u32 hash;
@@ -344,7 +344,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 	src_addr = src_start;
 	dst_addr = dst_start;
 	copied = 0;
-	page = NULL;
+	folio = NULL;
 	vma_hpagesize = vma_kernel_pagesize(dst_vma);
 
 	/*
@@ -413,7 +413,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 		}
 
 		err = hugetlb_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma,
-					       dst_addr, src_addr, mode, &page,
+					       dst_addr, src_addr, mode, &folio,
 					       wp_copy);
 
 		hugetlb_vma_unlock_read(dst_vma);
@@ -423,9 +423,9 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 
 		if (unlikely(err == -ENOENT)) {
 			mmap_read_unlock(dst_mm);
-			BUG_ON(!page);
+			BUG_ON(!folio);
 
-			err = copy_folio_from_user(page_folio(page),
+			err = copy_folio_from_user(folio,
 						   (const void __user *)src_addr, true);
 			if (unlikely(err)) {
 				err = -EFAULT;
@@ -436,7 +436,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 			dst_vma = NULL;
 			goto retry;
 		} else
-			BUG_ON(page);
+			BUG_ON(folio);
 
 		if (!err) {
 			dst_addr += vma_hpagesize;
@@ -453,8 +453,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 out_unlock:
 	mmap_read_unlock(dst_mm);
 out:
-	if (page)
-		put_page(page);
+	if (folio)
+		folio_put(folio);
 	BUG_ON(copied < 0);
 	BUG_ON(err > 0);
 	BUG_ON(!copied && !err);
-- 
2.25.1