[PATCH v2 08/11] hugetlb: make hugetlb_add_to_page_cache() to take PAGE_SIZE granularity index

[Jane Chu <jane.chu@oracle.com>]

hugetlb_add_to_page_cache() is partly a wrapper of the generic
__filemap_add_folio() that takes in PAGE_SIZE granularity index,
hence make it consistent by taking PAGE_SIZE granularity index
as well.

Signed-off-by: Jane Chu <jane.chu@oracle.com>
---
 fs/hugetlbfs/inode.c | 13 ++++++++-----
 mm/hugetlb.c         | 18 +++++++++---------
 mm/memfd.c           |  2 +-
 3 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index 6c883478f7e7..0b49a79efb08 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -599,7 +599,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 	struct mm_struct *mm = current->mm;
 	loff_t hpage_size = huge_page_size(h);
 	unsigned long hpage_shift = huge_page_shift(h);
-	pgoff_t start, index, end;
+	pgoff_t start, idx, end;
 	int error;
 	u32 hash;
 
@@ -639,7 +639,9 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 	vm_flags_init(&pseudo_vma, VM_HUGETLB | VM_MAYSHARE | VM_SHARED);
 	pseudo_vma.vm_file = file;
 
-	for (index = start; index < end; index++) {
+	for (idx = start; idx < end; idx++) {
+		pgoff_t index = idx << huge_page_order(h);
+
 		/*
 		 * This is supposed to be the vaddr where the page is being
 		 * faulted in, but we have no vaddr here.
@@ -659,14 +661,14 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 		}
 
 		/* addr is the offset within the file (zero based) */
-		addr = index * hpage_size;
+		addr = idx * hpage_size;
 
 		/* mutex taken here, fault path and hole punch */
-		hash = hugetlb_fault_mutex_hash(mapping, index << huge_page_order(h));
+		hash = hugetlb_fault_mutex_hash(mapping, index);
 		mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
 		/* See if already present in mapping to avoid alloc/free */
-		folio = filemap_get_folio(mapping, index << huge_page_order(h));
+		folio = filemap_get_folio(mapping, index);
 		if (!IS_ERR(folio)) {
 			folio_put(folio);
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
@@ -690,6 +692,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 		folio_zero_user(folio, addr);
 		__folio_mark_uptodate(folio);
 		error = hugetlb_add_to_page_cache(folio, mapping, index);
+
 		if (unlikely(error)) {
 			restore_reserve_on_error(h, &pseudo_vma, addr, folio);
 			folio_put(folio);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5484e78fe72e..b41e7b8df094 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5621,15 +5621,14 @@ bool hugetlbfs_pagecache_present(struct hstate *h,
 }
 
 int hugetlb_add_to_page_cache(struct folio *folio, struct address_space *mapping,
-			   pgoff_t idx)
+			   pgoff_t index)
 {
 	struct inode *inode = mapping->host;
 	struct hstate *h = hstate_inode(inode);
 	int err;
 
-	idx <<= huge_page_order(h);
 	__folio_set_locked(folio);
-	err = __filemap_add_folio(mapping, folio, idx, GFP_KERNEL, NULL);
+	err = __filemap_add_folio(mapping, folio, index, GFP_KERNEL, NULL);
 
 	if (unlikely(err)) {
 		__folio_clear_locked(folio);
@@ -5696,7 +5695,6 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 	struct folio *folio;
 	unsigned long size;
 	pte_t new_pte;
-	pgoff_t idx = vmf->pgoff >> huge_page_order(h);
 
 	/*
 	 * Currently, we are forced to kill the process in the event the
@@ -5779,7 +5777,8 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 		new_folio = true;
 
 		if (vma->vm_flags & VM_MAYSHARE) {
-			int err = hugetlb_add_to_page_cache(folio, mapping, idx);
+			int err = hugetlb_add_to_page_cache(folio, mapping, vmf->pgoff);
+
 			if (err) {
 				/*
 				 * err can't be -EEXIST which implies someone
@@ -6170,7 +6169,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
 	bool wp_enabled = (flags & MFILL_ATOMIC_WP);
 	struct hstate *h = hstate_vma(dst_vma);
 	struct address_space *mapping = dst_vma->vm_file->f_mapping;
-	pgoff_t idx = vma_hugecache_offset(h, dst_vma, dst_addr);
+	pgoff_t index = linear_page_index(dst_vma, dst_addr);
+
 	unsigned long size = huge_page_size(h);
 	int vm_shared = dst_vma->vm_flags & VM_SHARED;
 	pte_t _dst_pte;
@@ -6201,7 +6201,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
 
 	if (is_continue) {
 		ret = -EFAULT;
-		folio = filemap_lock_folio(mapping, idx << huge_page_order(h));
+		folio = filemap_lock_folio(mapping, index);
 		if (IS_ERR(folio))
 			goto out;
 		folio_in_pagecache = true;
@@ -6297,7 +6297,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
 	/* Add shared, newly allocated pages to the page cache. */
 	if (vm_shared && !is_continue) {
 		ret = -EFAULT;
-		if (idx >= (i_size_read(mapping->host) >> huge_page_shift(h)))
+		if (index >= (i_size_read(mapping->host) >> PAGE_SHIFT))
 			goto out_release_nounlock;
 
 		/*
@@ -6306,7 +6306,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
 		 * hugetlb_fault_mutex_table that here must be hold by
 		 * the caller.
 		 */
-		ret = hugetlb_add_to_page_cache(folio, mapping, idx);
+		ret = hugetlb_add_to_page_cache(folio, mapping, index);
 		if (ret)
 			goto out_release_nounlock;
 		folio_in_pagecache = true;
diff --git a/mm/memfd.c b/mm/memfd.c
index b0ec0b12b98d..0b5e8f111b39 100644
--- a/mm/memfd.c
+++ b/mm/memfd.c
@@ -122,7 +122,7 @@ struct folio *memfd_alloc_folio(struct file *memfd, pgoff_t index)
 
 			err = hugetlb_add_to_page_cache(folio,
 							memfd->f_mapping,
-							idx);
+							index);
 
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 
-- 
2.43.5