[PATCH 2/3] userfaultfd: convert __mcopy_atomic_hugetlb() to use a folio
From: Peng Zhang
Date: Mon Mar 13 2023 - 23:38:39 EST
From: ZhangPeng <zhangpeng362@xxxxxxxxxx>
Change copy_huge_page_from_user() to copy_large_folio_from_user().
Convert hugetlb_mcopy_atomic_pte() and __mcopy_atomic_hugetlb() to use a
folio.
Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx>
---
include/linux/hugetlb.h | 4 ++--
include/linux/mm.h | 3 +--
mm/hugetlb.c | 25 ++++++++++++-------------
mm/memory.c | 18 ++++++++++--------
mm/userfaultfd.c | 20 +++++++++-----------
5 files changed, 34 insertions(+), 36 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 7c977d234aba..030252ce51bd 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -163,7 +163,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, pte_t *dst_pte,
unsigned long dst_addr,
unsigned long src_addr,
enum mcopy_atomic_mode mode,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy);
#endif /* CONFIG_USERFAULTFD */
bool hugetlb_reserve_pages(struct inode *inode, long from, long to,
@@ -399,7 +399,7 @@ static inline int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
unsigned long dst_addr,
unsigned long src_addr,
enum mcopy_atomic_mode mode,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy)
{
BUG();
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 1f79667824eb..5eff770adbaa 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3546,9 +3546,8 @@ 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,
+extern long copy_large_folio_from_user(struct folio *dst_folio,
const void __user *usr_src,
- unsigned int pages_per_huge_page,
bool allow_pagefault);
/**
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 07abcb6eb203..20ce2b4e32b1 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6163,7 +6163,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
unsigned long dst_addr,
unsigned long src_addr,
enum mcopy_atomic_mode mode,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy)
{
bool is_continue = (mode == MCOPY_ATOMIC_CONTINUE);
@@ -6185,7 +6185,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
if (!folio)
goto out;
folio_in_pagecache = true;
- } else if (!*pagep) {
+ } else if (!*foliop) {
/* If a page already exists, then it's UFFDIO_COPY for
* a non-missing case. Return -EEXIST.
*/
@@ -6201,9 +6201,8 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
goto out;
}
- ret = copy_huge_page_from_user(&folio->page,
- (const void __user *) src_addr,
- pages_per_huge_page(h), false);
+ ret = copy_large_folio_from_user(folio,
+ (const void __user *) src_addr, false);
/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
@@ -6222,7 +6221,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
ret = -ENOMEM;
goto out;
}
- *pagep = &folio->page;
+ *foliop = folio;
/* Set the outparam pagep and return to the caller to
* copy the contents outside the lock. Don't free the
* page.
@@ -6232,23 +6231,23 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm,
} else {
if (vm_shared &&
hugetlbfs_pagecache_present(h, dst_vma, dst_addr)) {
- put_page(*pagep);
+ folio_put(*foliop);
ret = -EEXIST;
- *pagep = NULL;
+ *foliop = NULL;
goto out;
}
folio = alloc_hugetlb_folio(dst_vma, dst_addr, 0);
if (IS_ERR(folio)) {
- put_page(*pagep);
+ folio_put(*foliop);
ret = -ENOMEM;
- *pagep = NULL;
+ *foliop = NULL;
goto out;
}
- copy_user_huge_page(&folio->page, *pagep, dst_addr, dst_vma,
+ copy_user_huge_page(&folio->page, &((*foliop)->page), dst_addr, dst_vma,
pages_per_huge_page(h));
- put_page(*pagep);
- *pagep = NULL;
+ folio_put(*foliop);
+ *foliop = NULL;
}
/*
diff --git a/mm/memory.c b/mm/memory.c
index f456f3b5049c..737794b7a19f 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5769,26 +5769,28 @@ 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,
+long copy_large_folio_from_user(struct folio *dst_folio,
const void __user *usr_src,
- unsigned int pages_per_huge_page,
bool allow_pagefault)
{
void *page_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;
+ struct folio *inner_folio;
- for (i = 0; i < pages_per_huge_page; i++) {
- subpage = nth_page(dst_page, i);
+ for (i = 0; i < nr_pages; i++) {
+ subpage = folio_page(dst_folio, i);
+ inner_folio = page_folio(subpage);
if (allow_pagefault)
- page_kaddr = kmap(subpage);
+ page_kaddr = kmap_local_folio(inner_folio, 0);
else
page_kaddr = kmap_atomic(subpage);
rc = copy_from_user(page_kaddr,
usr_src + i * PAGE_SIZE, PAGE_SIZE);
if (allow_pagefault)
- kunmap(subpage);
+ kunmap_local(page_kaddr);
else
kunmap_atomic(page_kaddr);
@@ -5796,7 +5798,7 @@ long copy_huge_page_from_user(struct page *dst_page,
if (rc)
break;
- flush_dcache_page(subpage);
+ flush_dcache_folio(inner_folio);
cond_resched();
}
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 263191c37fb5..d7435a1a9d4b 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -324,7 +324,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
pte_t *dst_pte;
unsigned long src_addr, dst_addr;
long copied;
- struct page *page;
+ struct folio *folio;
unsigned long vma_hpagesize;
pgoff_t idx;
u32 hash;
@@ -344,7 +344,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
src_addr = src_start;
dst_addr = dst_start;
copied = 0;
- page = NULL;
+ folio = NULL;
vma_hpagesize = vma_kernel_pagesize(dst_vma);
/*
@@ -413,7 +413,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
}
err = hugetlb_mcopy_atomic_pte(dst_mm, dst_pte, dst_vma,
- dst_addr, src_addr, mode, &page,
+ dst_addr, src_addr, mode, &folio,
wp_copy);
hugetlb_vma_unlock_read(dst_vma);
@@ -423,12 +423,10 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
if (unlikely(err == -ENOENT)) {
mmap_read_unlock(dst_mm);
- BUG_ON(!page);
+ BUG_ON(!folio);
- err = copy_huge_page_from_user(page,
- (const void __user *)src_addr,
- vma_hpagesize / PAGE_SIZE,
- true);
+ err = copy_large_folio_from_user(folio,
+ (const void __user *) src_addr, true);
if (unlikely(err)) {
err = -EFAULT;
goto out;
@@ -438,7 +436,7 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
dst_vma = NULL;
goto retry;
} else
- BUG_ON(page);
+ BUG_ON(folio);
if (!err) {
dst_addr += vma_hpagesize;
@@ -455,8 +453,8 @@ static __always_inline ssize_t __mcopy_atomic_hugetlb(struct mm_struct *dst_mm,
out_unlock:
mmap_read_unlock(dst_mm);
out:
- if (page)
- put_page(page);
+ if (folio)
+ folio_put(folio);
BUG_ON(copied < 0);
BUG_ON(err > 0);
BUG_ON(!copied && !err);
--
2.25.1