[PATCH 4.14 77/79] hugetlbfs: hugetlb_fault_mutex_hash() cleanup

From: Greg Kroah-Hartman
Date: Mon May 31 2021 - 10:11:38 EST


From: Mike Kravetz <mike.kravetz@xxxxxxxxxx>

commit 552546366a30d88bd1d6f5efe848b2ab50fd57e5 upstream.

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@xxxxxxxxxx
Signed-off-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Reviewed-by: Davidlohr Bueso <dbueso@xxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Ilie Halip <ilie.halip@xxxxxxxxx>
Cc: David Bolvansky <david.bolvansky@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/hugetlbfs/inode.c | 4 ++--
include/linux/hugetlb.h | 2 +-
mm/hugetlb.c | 11 +++++------
mm/userfaultfd.c | 2 +-
4 files changed, 9 insertions(+), 10 deletions(-)

--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -436,7 +436,7 @@ static void remove_inode_hugepages(struc
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]);

/*
@@ -618,7 +618,7 @@ static long hugetlbfs_fallocate(struct f
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 */
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -123,7 +123,7 @@ 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);

--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3802,8 +3802,7 @@ retry:
* handling userfault. Reacquire after handling
* fault to make calling code simpler.
*/
- hash = hugetlb_fault_mutex_hash(h, mapping, idx,
- address);
+ 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]);
@@ -3916,7 +3915,7 @@ backout_unlocked:

#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;
@@ -3924,7 +3923,7 @@ u32 hugetlb_fault_mutex_hash(struct hsta
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);
}
@@ -3934,7 +3933,7 @@ u32 hugetlb_fault_mutex_hash(struct hsta
* 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;
}
@@ -3979,7 +3978,7 @@ int hugetlb_fault(struct mm_struct *mm,
* 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, address);
+ hash = hugetlb_fault_mutex_hash(h, mapping, idx);
mutex_lock(&hugetlb_fault_mutex_table[hash]);

entry = huge_ptep_get(ptep);
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -272,7 +272,7 @@ retry:
*/
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;