[PATCH v4 3/6] userfaultfd: convert copy_huge_page_from_user() to copy_folio_from_user()

Peng Zhang
2023-03-30T13:41:47Z

From: ZhangPeng <zhangpeng362@huawei.com>

Replace copy_huge_page_from_user() with copy_folio_from_user().
copy_folio_from_user() does the same as copy_huge_page_from_user(), but
takes in a folio instead of a page. Convert page_kaddr to kaddr in
copy_folio_from_user() to do indenting cleanup.

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
include/linux/mm.h | 7 +++----
mm/hugetlb.c | 5 ++---
mm/memory.c | 26 ++++++++++++--------------
mm/userfaultfd.c | 6 ++----
4 files changed, 19 insertions(+), 25 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index e249208f8fbe..cf4d773ca506 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3682,10 +3682,9 @@ extern void copy_user_huge_page(struct page *dst, struct page *src,
unsigned long addr_hint,
struct vm_area_struct *vma,
unsigned int pages_per_huge_page);
-extern long copy_huge_page_from_user(struct page *dst_page,
- const void __user *usr_src,
- unsigned int pages_per_huge_page,
- bool allow_pagefault);
+long copy_folio_from_user(struct folio *dst_folio,
+ const void __user *usr_src,
+ bool allow_pagefault);

/**
* vma_is_special_huge - Are transhuge page-table entries considered special?
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7e4a80769c9e..aade1b513474 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6217,9 +6217,8 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
goto out;
}

- ret = copy_huge_page_from_user(&folio->page,
- (const void __user *) src_addr,
- pages_per_huge_page(h), false);
+ ret = copy_folio_from_user(folio, (const void __user *) src_addr,
+ false);

/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
diff --git a/mm/memory.c b/mm/memory.c
index c47b8991410a..9d59dad319b3 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5854,35 +5854,33 @@ void copy_user_huge_page(struct page *dst, struct page *src,
process_huge_page(addr_hint, pages_per_huge_page, copy_subpage, &arg);
}

-long copy_huge_page_from_user(struct page *dst_page,
- const void __user *usr_src,
- unsigned int pages_per_huge_page,
- bool allow_pagefault)
+long copy_folio_from_user(struct folio *dst_folio,
+ const void __user *usr_src,
+ bool allow_pagefault)
{
- void *page_kaddr;
+ void *kaddr;
unsigned long i, rc = 0;
- unsigned long ret_val = pages_per_huge_page * PAGE_SIZE;
+ unsigned int nr_pages = folio_nr_pages(dst_folio);
+ unsigned long ret_val = nr_pages * PAGE_SIZE;
struct page *subpage;

- for (i = 0; i < pages_per_huge_page; i++) {
- subpage = nth_page(dst_page, i);
- page_kaddr = kmap_local_page(subpage);
+ for (i = 0; i < nr_pages; i++) {
+ subpage = folio_page(dst_folio, i);
+ kaddr = kmap_local_page(subpage);
if (!allow_pagefault)
pagefault_disable();
- rc = copy_from_user(page_kaddr,
- usr_src + i * PAGE_SIZE, PAGE_SIZE);
+ rc = copy_from_user(kaddr, usr_src + i * PAGE_SIZE, PAGE_SIZE);
if (!allow_pagefault)
pagefault_enable();
- kunmap_local(page_kaddr);
+ kunmap_local(kaddr);

ret_val -= (PAGE_SIZE - rc);
if (rc)
break;

- flush_dcache_page(subpage);
-
cond_resched();
}
+ flush_dcache_folio(dst_folio);
return ret_val;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index efa9e1d681ee..b453a4d2a0d3 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -422,10 +422,8 @@ static __always_inline ssize_t mfill_atomic_hugetlb(
mmap_read_unlock(dst_mm);
BUG_ON(!page);

- err = copy_huge_page_from_user(page,
- (const void __user *)src_addr,
- vma_hpagesize / PAGE_SIZE,
- true);
+ err = copy_folio_from_user(page_folio(page),
+ (const void __user *)src_addr, true);
if (unlikely(err)) {
err = -EFAULT;
goto out;
--
2.25.1