[PATCH v3 0/6] userfaultfd: convert userfaultfd functions to use folios

[PATCH v3 0/6] userfaultfd: convert userfaultfd functions to use folios

[Peng Zhang]

From: ZhangPeng <zhangpeng362@huawei.com>

This patch series converts several userfaultfd functions to use folios.

Change log:

v2->v3:
- Split patch 2 into three patches, suggested by Mike Kravetz. (patch
  2-4)
- Add a new patch to convert copy_user_huge_page to copy_user_folio,
  suggested by Mike Kravetz. (patch 5)
- Fix two uninitialized bugs, thanks to Dan Carpenter. (patch 6)
- Do some indenting cleanups.

v1->v2:
In patch 2:
- Rename copy_large_folio_from_user() to copy_folio_from_user().
- Delete the inner_folio.
- kmap() and kmap_atomic() are converted to kmap_local_page(). Use
  pagefault_disable() to ensure that a deadlock will not occur.
- flush_dcache_folio() is placed outside the loop.

ZhangPeng (6):
  userfaultfd: convert mcopy_atomic_pte() to use a folio
  userfaultfd: use kmap_local_page() in copy_huge_page_from_user()
  userfaultfd: convert copy_huge_page_from_user() to
    copy_folio_from_user()
  userfaultfd: convert __mcopy_atomic_hugetlb() to use a folio
  mm: convert copy_user_huge_page() to copy_user_folio()
  userfaultfd: convert __mcopy_atomic() to use a folio

 include/linux/hugetlb.h  |  4 +--
 include/linux/mm.h       | 15 ++++----
 include/linux/shmem_fs.h |  2 +-
 mm/hugetlb.c             | 41 +++++++++++-----------
 mm/memory.c              | 64 ++++++++++++++++------------------
 mm/shmem.c               | 16 ++++-----
 mm/userfaultfd.c         | 75 ++++++++++++++++++++--------------------
 7 files changed, 105 insertions(+), 112 deletions(-)

-- 
2.25.1

[PATCH v3 1/6] userfaultfd: convert mcopy_atomic_pte() to use a folio

[Peng Zhang]

From: ZhangPeng <zhangpeng362@huawei.com>

Call vma_alloc_folio() directly instead of alloc_page_vma(). Add an
assertion that this is a single-page folio and removes several calls to
compound_head().

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
 mm/userfaultfd.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 53c3d916ff66..263191c37fb5 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -137,15 +137,15 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 {
 	void *page_kaddr;
 	int ret;
-	struct page *page;
+	struct folio *folio;
 
 	if (!*pagep) {
 		ret = -ENOMEM;
-		page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, dst_vma, dst_addr);
-		if (!page)
+		folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, dst_addr, false);
+		if (!folio)
 			goto out;
 
-		page_kaddr = kmap_local_page(page);
+		page_kaddr = kmap_local_folio(folio, 0);
 		/*
 		 * The read mmap_lock is held here.  Despite the
 		 * mmap_lock being read recursive a deadlock is still
@@ -171,36 +171,37 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 		/* fallback to copy_from_user outside mmap_lock */
 		if (unlikely(ret)) {
 			ret = -ENOENT;
-			*pagep = page;
+			*pagep = &folio->page;
 			/* don't free the page */
 			goto out;
 		}
 
-		flush_dcache_page(page);
+		flush_dcache_folio(folio);
 	} else {
-		page = *pagep;
+		folio = page_folio(*pagep);
+		VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
 		*pagep = NULL;
 	}
 
 	/*
-	 * The memory barrier inside __SetPageUptodate makes sure that
+	 * The memory barrier inside __folio_mark_uptodate makes sure that
 	 * preceding stores to the page contents become visible before
 	 * the set_pte_at() write.
 	 */
-	__SetPageUptodate(page);
+	__folio_mark_uptodate(folio);
 
 	ret = -ENOMEM;
-	if (mem_cgroup_charge(page_folio(page), dst_mm, GFP_KERNEL))
+	if (mem_cgroup_charge(folio, dst_mm, GFP_KERNEL))
 		goto out_release;
 
 	ret = mfill_atomic_install_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
-				       page, true, wp_copy);
+				       &folio->page, true, wp_copy);
 	if (ret)
 		goto out_release;
 out:
 	return ret;
 out_release:
-	put_page(page);
+	folio_put(folio);
 	goto out;
 }
 
-- 
2.25.1

[PATCH v3 2/6] userfaultfd: use kmap_local_page() in copy_huge_page_from_user()

[Peng Zhang]

From: ZhangPeng <zhangpeng362@huawei.com>

kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page() which is appropriate for any thread local context.[1]

Let's replace the kmap() and kmap_atomic() with kmap_local_page() in
copy_huge_page_from_user(). When allow_pagefault is false, disable page
faults to prevent potential deadlock.[2]

[1] https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com/
[2] https://lkml.kernel.org/r/20221025220136.2366143-1-ira.weiny@intel.com

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
 mm/memory.c | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index f456f3b5049c..062bd215bea8 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5781,16 +5781,14 @@ long copy_huge_page_from_user(struct page *dst_page,
 
 	for (i = 0; i < pages_per_huge_page; i++) {
 		subpage = nth_page(dst_page, i);
-		if (allow_pagefault)
-			page_kaddr = kmap(subpage);
-		else
-			page_kaddr = kmap_atomic(subpage);
+		page_kaddr = kmap_local_page(subpage);
+		if (!allow_pagefault)
+			pagefault_disable();
 		rc = copy_from_user(page_kaddr,
 				usr_src + i * PAGE_SIZE, PAGE_SIZE);
-		if (allow_pagefault)
-			kunmap(subpage);
-		else
-			kunmap_atomic(page_kaddr);
+		if (!allow_pagefault)
+			pagefault_enable();
+		kunmap_local(page_kaddr);
 
 		ret_val -= (PAGE_SIZE - rc);
 		if (rc)
-- 
2.25.1

[PATCH v3 3/6] userfaultfd: convert copy_huge_page_from_user() to copy_folio_from_user()

[Peng Zhang]

From: ZhangPeng <zhangpeng362@huawei.com>

Replace copy_huge_page_from_user() with copy_folio_from_user().
copy_folio_from_user() does the same as copy_huge_page_from_user(), but
takes in a folio instead of a page. Convert page_kaddr to kaddr in
copy_folio_from_user() to do indenting cleanup.

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
 include/linux/mm.h |  7 +++----
 mm/hugetlb.c       |  5 ++---
 mm/memory.c        | 26 ++++++++++++--------------
 mm/userfaultfd.c   |  6 ++----
 4 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1f79667824eb..69dfadee23e8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3546,10 +3546,9 @@ extern void copy_user_huge_page(struct page *dst, struct page *src,
 				unsigned long addr_hint,
 				struct vm_area_struct *vma,
 				unsigned int pages_per_huge_page);
-extern long copy_huge_page_from_user(struct page *dst_page,
-				const void __user *usr_src,
-				unsigned int pages_per_huge_page,
-				bool allow_pagefault);
+long copy_folio_from_user(struct folio *dst_folio,
+			   const void __user *usr_src,
+			   bool allow_pagefault);
 
 /**
  * vma_is_special_huge - Are transhuge page-table entries considered special?
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 07abcb6eb203..29ac064f69d6 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6201,9 +6201,8 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			goto out;
 		}
 
-		ret = copy_huge_page_from_user(&folio->page,
-						(const void __user *) src_addr,
-						pages_per_huge_page(h), false);
+		ret = copy_folio_from_user(folio, (const void __user *) src_addr,
+					   false);
 
 		/* fallback to copy_from_user outside mmap_lock */
 		if (unlikely(ret)) {
diff --git a/mm/memory.c b/mm/memory.c
index 062bd215bea8..faf79742e0b6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5769,35 +5769,33 @@ void copy_user_huge_page(struct page *dst, struct page *src,
 	process_huge_page(addr_hint, pages_per_huge_page, copy_subpage, &arg);
 }
 
-long copy_huge_page_from_user(struct page *dst_page,
-				const void __user *usr_src,
-				unsigned int pages_per_huge_page,
-				bool allow_pagefault)
+long copy_folio_from_user(struct folio *dst_folio,
+			   const void __user *usr_src,
+			   bool allow_pagefault)
 {
-	void *page_kaddr;
+	void *kaddr;
 	unsigned long i, rc = 0;
-	unsigned long ret_val = pages_per_huge_page * PAGE_SIZE;
+	unsigned int nr_pages = folio_nr_pages(dst_folio);
+	unsigned long ret_val = nr_pages * PAGE_SIZE;
 	struct page *subpage;
 
-	for (i = 0; i < pages_per_huge_page; i++) {
-		subpage = nth_page(dst_page, i);
-		page_kaddr = kmap_local_page(subpage);
+	for (i = 0; i < nr_pages; i++) {
+		subpage = folio_page(dst_folio, i);
+		kaddr = kmap_local_page(subpage);
 		if (!allow_pagefault)
 			pagefault_disable();
-		rc = copy_from_user(page_kaddr,
-				usr_src + i * PAGE_SIZE, PAGE_SIZE);
+		rc = copy_from_user(kaddr, usr_src + i * PAGE_SIZE, PAGE_SIZE);
 		if (!allow_pagefault)
 			pagefault_enable();
-		kunmap_local(page_kaddr);
+		kunmap_local(kaddr);
 
 		ret_val -= (PAGE_SIZE - rc);
 		if (rc)
 			break;
 
-		flush_dcache_page(subpage);
-
 		cond_resched();
 	}
+	flush_dcache_folio(dst_folio);
 	return ret_val;
 }
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 263191c37fb5..7b660bc07d71 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -425,10 +425,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 			mmap_read_unlock(dst_mm);
 			BUG_ON(!page);
 
-			err = copy_huge_page_from_user(page,
-						(const void __user *)src_addr,
-						vma_hpagesize / PAGE_SIZE,
-						true);
+			err = copy_folio_from_user(page_folio(page),
+						   (const void __user *)src_addr, true);
 			if (unlikely(err)) {
 				err = -EFAULT;
 				goto out;
-- 
2.25.1

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

[Peng Zhang]

From: ZhangPeng <zhangpeng362@huawei.com>

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@huawei.com>
---
 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

[PATCH v3 5/6] mm: convert copy_user_huge_page() to copy_user_folio()

[Peng Zhang]

From: ZhangPeng <zhangpeng362@huawei.com>

Replace copy_user_huge_page() with copy_user_folio(). copy_user_folio()
does the same as copy_user_huge_page(), but takes in folios instead of
pages. Convert copy_user_gigantic_page() to take in folios.

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
 include/linux/mm.h |  8 ++++----
 mm/hugetlb.c       | 12 ++++++------
 mm/memory.c        | 28 ++++++++++++++--------------
 3 files changed, 24 insertions(+), 24 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 69dfadee23e8..6a787fe66ea1 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3542,10 +3542,10 @@ extern const struct attribute_group memory_failure_attr_group;
 extern void clear_huge_page(struct page *page,
 			    unsigned long addr_hint,
 			    unsigned int pages_per_huge_page);
-extern void copy_user_huge_page(struct page *dst, struct page *src,
-				unsigned long addr_hint,
-				struct vm_area_struct *vma,
-				unsigned int pages_per_huge_page);
+void copy_user_folio(struct folio *dst, struct folio *src,
+		      unsigned long addr_hint,
+		      struct vm_area_struct *vma,
+		      unsigned int pages_per_huge_page);
 long copy_folio_from_user(struct folio *dst_folio,
 			   const void __user *usr_src,
 			   bool allow_pagefault);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 1cfd20e5fe8b..85657f9007ee 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5093,8 +5093,8 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 					ret = PTR_ERR(new_folio);
 					break;
 				}
-				copy_user_huge_page(&new_folio->page, ptepage, addr, dst_vma,
-						    npages);
+				copy_user_folio(new_folio, page_folio(ptepage), addr, dst_vma,
+						npages);
 				put_page(ptepage);
 
 				/* Install the new hugetlb folio if src pte stable */
@@ -5602,8 +5602,8 @@ static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
 		goto out_release_all;
 	}
 
-	copy_user_huge_page(&new_folio->page, old_page, address, vma,
-			    pages_per_huge_page(h));
+	copy_user_folio(new_folio, page_folio(old_page), address, vma,
+			pages_per_huge_page(h));
 	__folio_mark_uptodate(new_folio);
 
 	mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm, haddr,
@@ -6244,8 +6244,8 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
 			*foliop = NULL;
 			goto out;
 		}
-		copy_user_huge_page(&folio->page, &(*foliop)->page, dst_addr, dst_vma,
-				    pages_per_huge_page(h));
+		copy_user_folio(folio, *foliop, dst_addr, dst_vma,
+				pages_per_huge_page(h));
 		folio_put(*foliop);
 		*foliop = NULL;
 	}
diff --git a/mm/memory.c b/mm/memory.c
index faf79742e0b6..4752f0e829b6 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5716,21 +5716,21 @@ void clear_huge_page(struct page *page,
 	process_huge_page(addr_hint, pages_per_huge_page, clear_subpage, page);
 }
 
-static void copy_user_gigantic_page(struct page *dst, struct page *src,
-				    unsigned long addr,
-				    struct vm_area_struct *vma,
-				    unsigned int pages_per_huge_page)
+static void copy_user_gigantic_page(struct folio *dst, struct folio *src,
+				     unsigned long addr,
+				     struct vm_area_struct *vma,
+				     unsigned int pages_per_huge_page)
 {
 	int i;
-	struct page *dst_base = dst;
-	struct page *src_base = src;
+	struct page *dst_page;
+	struct page *src_page;
 
 	for (i = 0; i < pages_per_huge_page; i++) {
-		dst = nth_page(dst_base, i);
-		src = nth_page(src_base, i);
+		dst_page = folio_page(dst, i);
+		src_page = folio_page(src, i);
 
 		cond_resched();
-		copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
+		copy_user_highpage(dst_page, src_page, addr + i*PAGE_SIZE, vma);
 	}
 }
 
@@ -5748,15 +5748,15 @@ static void copy_subpage(unsigned long addr, int idx, void *arg)
 			   addr, copy_arg->vma);
 }
 
-void copy_user_huge_page(struct page *dst, struct page *src,
-			 unsigned long addr_hint, struct vm_area_struct *vma,
-			 unsigned int pages_per_huge_page)
+void copy_user_folio(struct folio *dst, struct folio *src,
+		      unsigned long addr_hint, struct vm_area_struct *vma,
+		      unsigned int pages_per_huge_page)
 {
 	unsigned long addr = addr_hint &
 		~(((unsigned long)pages_per_huge_page << PAGE_SHIFT) - 1);
 	struct copy_subpage_arg arg = {
-		.dst = dst,
-		.src = src,
+		.dst = &dst->page,
+		.src = &src->page,
 		.vma = vma,
 	};
 
-- 
2.25.1

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

[Peng Zhang]

From: ZhangPeng <zhangpeng362@huawei.com>

Convert mcopy_atomic_pte(), shmem_mfill_atomic_pte() and
mfill_atomic_pte() to take in a folio pointer.
Convert __mcopy_atomic() to use a folio.

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
 include/linux/shmem_fs.h |  2 +-
 mm/shmem.c               | 16 ++++++++--------
 mm/userfaultfd.c         | 34 +++++++++++++++++-----------------
 3 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 103d1000a5a2..580af0e3bf02 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -156,7 +156,7 @@ extern int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
 				  unsigned long dst_addr,
 				  unsigned long src_addr,
 				  bool zeropage, bool wp_copy,
-				  struct page **pagep);
+				  struct folio **foliop);
 #else /* !CONFIG_SHMEM */
 #define shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, \
 			       src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; })
diff --git a/mm/shmem.c b/mm/shmem.c
index 448f393d8ab2..e07e11a5812b 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2421,7 +2421,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 			   unsigned long dst_addr,
 			   unsigned long src_addr,
 			   bool zeropage, bool wp_copy,
-			   struct page **pagep)
+			   struct folio **foliop)
 {
 	struct inode *inode = file_inode(dst_vma->vm_file);
 	struct shmem_inode_info *info = SHMEM_I(inode);
@@ -2439,14 +2439,14 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 		 * and now we find ourselves with -ENOMEM. Release the page, to
 		 * avoid a BUG_ON in our caller.
 		 */
-		if (unlikely(*pagep)) {
-			put_page(*pagep);
-			*pagep = NULL;
+		if (unlikely(*foliop)) {
+			folio_put(*foliop);
+			*foliop = NULL;
 		}
 		return -ENOMEM;
 	}
 
-	if (!*pagep) {
+	if (!*foliop) {
 		ret = -ENOMEM;
 		folio = shmem_alloc_folio(gfp, info, pgoff);
 		if (!folio)
@@ -2478,7 +2478,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 
 			/* fallback to copy_from_user outside mmap_lock */
 			if (unlikely(ret)) {
-				*pagep = &folio->page;
+				*foliop = folio;
 				ret = -ENOENT;
 				/* don't free the page */
 				goto out_unacct_blocks;
@@ -2489,9 +2489,9 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
 			clear_user_highpage(&folio->page, dst_addr);
 		}
 	} else {
-		folio = page_folio(*pagep);
+		folio = *foliop;
 		VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
-		*pagep = NULL;
+		*foliop = NULL;
 	}
 
 	VM_BUG_ON(folio_test_locked(folio));
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index cbcc7eb1d36e..2cecaf507b3f 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -132,14 +132,14 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 			    struct vm_area_struct *dst_vma,
 			    unsigned long dst_addr,
 			    unsigned long src_addr,
-			    struct page **pagep,
+			    struct folio **foliop,
 			    bool wp_copy)
 {
 	void *page_kaddr;
 	int ret;
 	struct folio *folio;
 
-	if (!*pagep) {
+	if (!*foliop) {
 		ret = -ENOMEM;
 		folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, dst_addr, false);
 		if (!folio)
@@ -171,16 +171,16 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
 		/* fallback to copy_from_user outside mmap_lock */
 		if (unlikely(ret)) {
 			ret = -ENOENT;
-			*pagep = &folio->page;
+			*foliop = folio;
 			/* don't free the page */
 			goto out;
 		}
 
 		flush_dcache_folio(folio);
 	} else {
-		folio = page_folio(*pagep);
+		folio = *foliop;
 		VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
-		*pagep = NULL;
+		*foliop = NULL;
 	}
 
 	/*
@@ -476,7 +476,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
 						struct vm_area_struct *dst_vma,
 						unsigned long dst_addr,
 						unsigned long src_addr,
-						struct page **page,
+						struct folio **foliop,
 						enum mcopy_atomic_mode mode,
 						bool wp_copy)
 {
@@ -500,7 +500,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
 	if (!(dst_vma->vm_flags & VM_SHARED)) {
 		if (mode == MCOPY_ATOMIC_NORMAL)
 			err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma,
-					       dst_addr, src_addr, page,
+					       dst_addr, src_addr, foliop,
 					       wp_copy);
 		else
 			err = mfill_zeropage_pte(dst_mm, dst_pmd,
@@ -509,7 +509,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
 		err = shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma,
 					     dst_addr, src_addr,
 					     mode != MCOPY_ATOMIC_NORMAL,
-					     wp_copy, page);
+					     wp_copy, foliop);
 	}
 
 	return err;
@@ -528,7 +528,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
 	pmd_t *dst_pmd;
 	unsigned long src_addr, dst_addr;
 	long copied;
-	struct page *page;
+	struct folio *folio;
 	bool wp_copy;
 
 	/*
@@ -544,7 +544,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
 	src_addr = src_start;
 	dst_addr = dst_start;
 	copied = 0;
-	page = NULL;
+	folio = NULL;
 retry:
 	mmap_read_lock(dst_mm);
 
@@ -641,16 +641,16 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
 		BUG_ON(pmd_trans_huge(*dst_pmd));
 
 		err = mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
-				       src_addr, &page, mcopy_mode, wp_copy);
+				       src_addr, &folio, mcopy_mode, wp_copy);
 		cond_resched();
 
 		if (unlikely(err == -ENOENT)) {
 			void *page_kaddr;
 
 			mmap_read_unlock(dst_mm);
-			BUG_ON(!page);
+			BUG_ON(!folio);
 
-			page_kaddr = kmap_local_page(page);
+			page_kaddr = kmap_local_folio(folio, 0);
 			err = copy_from_user(page_kaddr,
 					     (const void __user *) src_addr,
 					     PAGE_SIZE);
@@ -659,10 +659,10 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
 				err = -EFAULT;
 				goto out;
 			}
-			flush_dcache_page(page);
+			flush_dcache_folio(folio);
 			goto retry;
 		} else
-			BUG_ON(page);
+			BUG_ON(folio);
 
 		if (!err) {
 			dst_addr += PAGE_SIZE;
@@ -679,8 +679,8 @@ static __always_inline ssize_t __mcopy_atomic(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