1 files changed, 33 insertions, 24 deletions

diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 07d3befc80e4..e24e8a47ce8a 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -243,20 +243,22 @@ static int mcontinue_atomic_pte(struct mm_struct *dst_mm,
 {
 	struct inode *inode = file_inode(dst_vma->vm_file);
 	pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);
+	struct folio *folio;
 	struct page *page;
 	int ret;
 
-	ret = shmem_getpage(inode, pgoff, &page, SGP_NOALLOC);
-	/* Our caller expects us to return -EFAULT if we failed to find page. */
+	ret = shmem_get_folio(inode, pgoff, &folio, SGP_NOALLOC);
+	/* Our caller expects us to return -EFAULT if we failed to find folio */
 	if (ret == -ENOENT)
 		ret = -EFAULT;
 	if (ret)
 		goto out;
-	if (!page) {
+	if (!folio) {
 		ret = -EFAULT;
 		goto out;
 	}
 
+	page = folio_file_page(folio, pgoff);
 	if (PageHWPoison(page)) {
 		ret = -EIO;
 		goto out_release;
@@ -267,13 +269,13 @@ static int mcontinue_atomic_pte(struct mm_struct *dst_mm,
 	if (ret)
 		goto out_release;
 
-	unlock_page(page);
+	folio_unlock(folio);
 	ret = 0;
 out:
 	return ret;
 out_release:
-	unlock_page(page);
-	put_page(page);
+	folio_unlock(folio);
+	folio_put(folio);
 	goto out;
 }
 
@@ -377,30 +379,30 @@ retry:
 		BUG_ON(dst_addr >= dst_start + len);
 
 		/*
-		 * Serialize via i_mmap_rwsem and hugetlb_fault_mutex.
-		 * i_mmap_rwsem ensures the dst_pte remains valid even
+		 * Serialize via vma_lock and hugetlb_fault_mutex.
+		 * vma_lock ensures the dst_pte remains valid even
 		 * in the case of shared pmds.  fault mutex prevents
 		 * races with other faulting threads.
 		 */
-		mapping = dst_vma->vm_file->f_mapping;
-		i_mmap_lock_read(mapping);
 		idx = linear_page_index(dst_vma, dst_addr);
+		mapping = dst_vma->vm_file->f_mapping;
 		hash = hugetlb_fault_mutex_hash(mapping, idx);
 		mutex_lock(&hugetlb_fault_mutex_table[hash]);
+		hugetlb_vma_lock_read(dst_vma);
 
 		err = -ENOMEM;
 		dst_pte = huge_pte_alloc(dst_mm, dst_vma, dst_addr, vma_hpagesize);
 		if (!dst_pte) {
+			hugetlb_vma_unlock_read(dst_vma);
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
-			i_mmap_unlock_read(mapping);
 			goto out_unlock;
 		}
 
 		if (mode != MCOPY_ATOMIC_CONTINUE &&
 		    !huge_pte_none_mostly(huge_ptep_get(dst_pte))) {
 			err = -EEXIST;
+			hugetlb_vma_unlock_read(dst_vma);
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
-			i_mmap_unlock_read(mapping);
 			goto out_unlock;
 		}
 
@@ -408,8 +410,8 @@ retry:
 					       dst_addr, src_addr, mode, &page,
 					       wp_copy);
 
+		hugetlb_vma_unlock_read(dst_vma);
 		mutex_unlock(&hugetlb_fault_mutex_table[hash]);
-		i_mmap_unlock_read(mapping);
 
 		cond_resched();
 
@@ -703,14 +705,29 @@ ssize_t mcopy_continue(struct mm_struct *dst_mm, unsigned long start,
 			      mmap_changing, 0);
 }
 
+void uffd_wp_range(struct mm_struct *dst_mm, struct vm_area_struct *dst_vma,
+		   unsigned long start, unsigned long len, bool enable_wp)
+{
+	struct mmu_gather tlb;
+	pgprot_t newprot;
+
+	if (enable_wp)
+		newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE));
+	else
+		newprot = vm_get_page_prot(dst_vma->vm_flags);
+
+	tlb_gather_mmu(&tlb, dst_mm);
+	change_protection(&tlb, dst_vma, start, start + len, newprot,
+			  enable_wp ? MM_CP_UFFD_WP : MM_CP_UFFD_WP_RESOLVE);
+	tlb_finish_mmu(&tlb);
+}
+
 int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
 			unsigned long len, bool enable_wp,
 			atomic_t *mmap_changing)
 {
 	struct vm_area_struct *dst_vma;
 	unsigned long page_mask;
-	struct mmu_gather tlb;
-	pgprot_t newprot;
 	int err;
 
 	/*
@@ -750,15 +767,7 @@ int mwriteprotect_range(struct mm_struct *dst_mm, unsigned long start,
 			goto out_unlock;
 	}
 
-	if (enable_wp)
-		newprot = vm_get_page_prot(dst_vma->vm_flags & ~(VM_WRITE));
-	else
-		newprot = vm_get_page_prot(dst_vma->vm_flags);
-
-	tlb_gather_mmu(&tlb, dst_mm);
-	change_protection(&tlb, dst_vma, start, start + len, newprot,
-			  enable_wp ? MM_CP_UFFD_WP : MM_CP_UFFD_WP_RESOLVE);
-	tlb_finish_mmu(&tlb);
+	uffd_wp_range(dst_mm, dst_vma, start, len, enable_wp);
 
 	err = 0;
 out_unlock: