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From:   Mike Kravetz <mike.kravetz@oracle.com>
To:     linux-mm@kvack.org, linux-kernel@vger.kernel.org,
        clang-built-linux@googlegroups.com
Cc:     Nathan Chancellor <natechancellor@gmail.com>,
        Davidlohr Bueso <dave@stgolabs.net>,
        Andrew Morton <akpm@linux-foundation.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Ilie Halip <ilie.halip@gmail.com>,
        David Bolvansky <david.bolvansky@gmail.com>,
        Mike Kravetz <mike.kravetz@oracle.com>
Subject: [PATCH] hugetlbfs: hugetlb_fault_mutex_hash cleanup
Date:   Wed, 18 Sep 2019 18:18:47 -0700
Message-Id: <20190919011847.18400-1-mike.kravetz@oracle.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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.

Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
---
 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 edfca4278319..5bf11fffbbd4 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 6d7296dd11b8..3705d3c69e32 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3847,7 +3847,7 @@ 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]);
@@ -3975,7 +3975,7 @@ 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;
@@ -3983,7 +3983,7 @@ 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);
 }
@@ -3993,7 +3993,7 @@ 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;
 }
@@ -4037,7 +4037,7 @@ 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;
-- 
2.20.1