From 132fc0c2a19a00a69cab91910e4d0a4f5eee40f8 Mon Sep 17 00:00:00 2001
From: Mike Kravetz <mike.kravetz@oracle.com>
Date: Sat, 30 Nov 2019 17:56:30 -0800
Subject: [PATCH] hugetlbfs: hugetlb_fault_mutex_hash() cleanup

References: bnc#1155780 (VM/FS functional and performance backports)
Patch-mainline: v5.5-rc1
Git-commit: 552546366a30d88bd1d6f5efe848b2ab50fd57e5

A new clang diagnostic (-Wsizeof-array-div) warns about the calculation
to determine the number of u32's in an array of unsigned longs.
Suppress warning by adding parentheses.

While looking at the above issue, noticed that the 'address' parameter
to hugetlb_fault_mutex_hash is no longer used.  So, remove it from the
definition and all callers.

No functional change.

Link: http://lkml.kernel.org/r/20190919011847.18400-1-mike.kravetz@oracle.com
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Ilie Halip <ilie.halip@gmail.com>
Cc: David Bolvansky <david.bolvansky@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Mel Gorman <mgorman@suse.de>
---
 fs/hugetlbfs/inode.c    |  4 ++--
 include/linux/hugetlb.h |  2 +-
 mm/hugetlb.c            | 10 +++++-----
 mm/userfaultfd.c        |  2 +-
 4 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index a478df035651..6e5eadee6b0d 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -440,7 +440,7 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart,
 			u32 hash;
 
 			index = page->index;
-			hash = hugetlb_fault_mutex_hash(h, mapping, index, 0);
+			hash = hugetlb_fault_mutex_hash(h, mapping, index);
 			mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
 			/*
@@ -644,7 +644,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 		addr = index * hpage_size;
 
 		/* mutex taken here, fault path and hole punch */
-		hash = hugetlb_fault_mutex_hash(h, mapping, index, addr);
+		hash = hugetlb_fault_mutex_hash(h, mapping, index);
 		mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
 		/* See if already present in mapping to avoid alloc/free */
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 53fc34f930d0..d3814bd686ba 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -106,7 +106,7 @@ void free_huge_page(struct page *page);
 void hugetlb_fix_reserve_counts(struct inode *inode);
 extern struct mutex *hugetlb_fault_mutex_table;
 u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
-				pgoff_t idx, unsigned long address);
+				pgoff_t idx);
 
 pte_t *huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud);
 
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index b45a95363a84..f8656a4a7f7d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3915,7 +3915,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 			 * handling userfault.  Reacquire after handling
 			 * fault to make calling code simpler.
 			 */
-			hash = hugetlb_fault_mutex_hash(h, mapping, idx, haddr);
+			hash = hugetlb_fault_mutex_hash(h, mapping, idx);
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 			ret = handle_userfault(&vmf, VM_UFFD_MISSING);
 			mutex_lock(&hugetlb_fault_mutex_table[hash]);
@@ -4043,7 +4043,7 @@ static vm_fault_t hugetlb_no_page(struct mm_struct *mm,
 
 #ifdef CONFIG_SMP
 u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
-			    pgoff_t idx, unsigned long address)
+			    pgoff_t idx)
 {
 	unsigned long key[2];
 	u32 hash;
@@ -4051,7 +4051,7 @@ u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
 	key[0] = (unsigned long) mapping;
 	key[1] = idx;
 
-	hash = jhash2((u32 *)&key, sizeof(key)/sizeof(u32), 0);
+	hash = jhash2((u32 *)&key, sizeof(key)/(sizeof(u32)), 0);
 
 	return hash & (num_fault_mutexes - 1);
 }
@@ -4061,7 +4061,7 @@ u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
  * return 0 and avoid the hashing overhead.
  */
 u32 hugetlb_fault_mutex_hash(struct hstate *h, struct address_space *mapping,
-			    pgoff_t idx, unsigned long address)
+			    pgoff_t idx)
 {
 	return 0;
 }
@@ -4105,7 +4105,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	 * get spurious allocation failures if two CPUs race to instantiate
 	 * the same page in the page cache.
 	 */
-	hash = hugetlb_fault_mutex_hash(h, mapping, idx, haddr);
+	hash = hugetlb_fault_mutex_hash(h, mapping, idx);
 	mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
 	entry = huge_ptep_get(ptep);
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index c7ae74ce5ff3..640ff2bd9a69 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -269,7 +269,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
 		 */
 		idx = linear_page_index(dst_vma, dst_addr);
 		mapping = dst_vma->vm_file->f_mapping;
-		hash = hugetlb_fault_mutex_hash(h, mapping, idx, dst_addr);
+		hash = hugetlb_fault_mutex_hash(h, mapping, idx);
 		mutex_lock(&hugetlb_fault_mutex_table[hash]);
 
 		err = -ENOMEM;