[PATCH v2 05/11] hugetlb: Convert the vmf->pgoff to PAGE_SIZE granularity

[Jane Chu]

Everywhere else in MM, the page fault vmf->pgoff is in PAGE_SIZE
granularity, except in hugetlbfs, it's in hugepagesize granularity.
This is really unnecessary.

Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Jane Chu <jane.chu@xxxxxxxxxx>
---
 mm/hugetlb.c | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 4b80b167cc9c..3255f6b762c9 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5654,6 +5654,8 @@ static inline vm_fault_t hugetlb_handle_userfault(struct vm_fault *vmf,
 						  unsigned long reason)
 {
 	u32 hash;
+	struct hstate *h = hstate_vma(vmf->vma);
+	pgoff_t idx = vmf->pgoff >> huge_page_order(h);
 
 	/*
 	 * vma_lock and hugetlb_fault_mutex must be dropped before handling
@@ -5661,7 +5663,7 @@ static inline vm_fault_t hugetlb_handle_userfault(struct vm_fault *vmf,
 	 * userfault, any vma operation should be careful from here.
 	 */
 	hugetlb_vma_unlock_read(vmf->vma);
-	hash = hugetlb_fault_mutex_hash(mapping, vmf->pgoff);
+	hash = hugetlb_fault_mutex_hash(mapping, idx);
 	mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 	return handle_userfault(vmf, reason);
 }
@@ -5686,7 +5688,7 @@ static bool hugetlb_pte_stable(struct hstate *h, struct mm_struct *mm, unsigned
 static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 			struct vm_fault *vmf)
 {
-	u32 hash = hugetlb_fault_mutex_hash(mapping, vmf->pgoff);
+	u32 hash;
 	bool new_folio, new_anon_folio = false;
 	struct vm_area_struct *vma = vmf->vma;
 	struct mm_struct *mm = vma->vm_mm;
@@ -5696,6 +5698,7 @@ 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
@@ -5714,9 +5717,9 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 	 * before we get page_table_lock.
 	 */
 	new_folio = false;
-	folio = filemap_lock_hugetlb_folio(h, mapping, vmf->pgoff);
+	folio = filemap_lock_hugetlb_folio(h, mapping, idx);
 	if (IS_ERR(folio)) {
-		size = i_size_read(mapping->host) >> huge_page_shift(h);
+		size = i_size_read(mapping->host) >> PAGE_SHIFT;
 		if (vmf->pgoff >= size)
 			goto out;
 		/* Check for page in userfault range */
@@ -5778,8 +5781,7 @@ 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,
-							vmf->pgoff);
+			int err = hugetlb_add_to_page_cache(folio, mapping, idx);
 			if (err) {
 				/*
 				 * err can't be -EEXIST which implies someone
@@ -5894,6 +5896,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 	if (unlikely(ret & VM_FAULT_RETRY))
 		vma_end_read(vma);
 
+	hash = hugetlb_fault_mutex_hash(mapping, idx);
 	mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 	return ret;
 
@@ -5947,8 +5950,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		.address = address & huge_page_mask(h),
 		.real_address = address,
 		.flags = flags,
-		.pgoff = vma_hugecache_offset(h, vma,
-				address & huge_page_mask(h)),
+		.pgoff = linear_page_index(vma, address),
 		/* TODO: Track hugetlb faults using vm_fault */
 
 		/*
@@ -5963,7 +5965,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	 * the same page in the page cache.
 	 */
 	mapping = vma->vm_file->f_mapping;
-	hash = hugetlb_fault_mutex_hash(mapping, vmf.pgoff);
+	hash = hugetlb_fault_mutex_hash(mapping, vmf.pgoff >> huge_page_order(h));
 	mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
 	/*
-- 
2.43.5