[PATCH 3/3] userfaultfd: convert __mcopy_atomic() to use a folio
From: Peng Zhang
Date: Mon Mar 13 2023 - 23:38:48 EST
From: ZhangPeng <zhangpeng362@xxxxxxxxxx>
Convert mcopy_atomic_pte(), shmem_mfill_atomic_pte() and
mfill_atomic_pte() to pass in a folio pointer.
Convert __mcopy_atomic() to use a folio.
Signed-off-by: ZhangPeng <zhangpeng362@xxxxxxxxxx>
---
include/linux/shmem_fs.h | 2 +-
mm/shmem.c | 17 ++++++++---------
mm/userfaultfd.c | 35 +++++++++++++++++------------------
3 files changed, 26 insertions(+), 28 deletions(-)
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 103d1000a5a2..580af0e3bf02 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -156,7 +156,7 @@ extern int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, pmd_t *dst_pmd,
unsigned long dst_addr,
unsigned long src_addr,
bool zeropage, bool wp_copy,
- struct page **pagep);
+ struct folio **foliop);
#else /* !CONFIG_SHMEM */
#define shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr, \
src_addr, zeropage, wp_copy, pagep) ({ BUG(); 0; })
diff --git a/mm/shmem.c b/mm/shmem.c
index 448f393d8ab2..986267bf34ef 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2421,7 +2421,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
unsigned long dst_addr,
unsigned long src_addr,
bool zeropage, bool wp_copy,
- struct page **pagep)
+ struct folio **foliop)
{
struct inode *inode = file_inode(dst_vma->vm_file);
struct shmem_inode_info *info = SHMEM_I(inode);
@@ -2439,14 +2439,14 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
* and now we find ourselves with -ENOMEM. Release the page, to
* avoid a BUG_ON in our caller.
*/
- if (unlikely(*pagep)) {
- put_page(*pagep);
- *pagep = NULL;
+ if (unlikely(*foliop)) {
+ folio_put(*foliop);
+ *foliop = NULL;
}
return -ENOMEM;
}
- if (!*pagep) {
+ if (!*foliop) {
ret = -ENOMEM;
folio = shmem_alloc_folio(gfp, info, pgoff);
if (!folio)
@@ -2478,7 +2478,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
- *pagep = &folio->page;
+ *foliop = folio;
ret = -ENOENT;
/* don't free the page */
goto out_unacct_blocks;
@@ -2489,9 +2489,8 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm,
clear_user_highpage(&folio->page, dst_addr);
}
} else {
- folio = page_folio(*pagep);
- VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
- *pagep = NULL;
+ VM_BUG_ON_FOLIO(folio_test_large(*foliop), folio);
+ *foliop = NULL;
}
VM_BUG_ON(folio_test_locked(folio));
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index d7435a1a9d4b..3d08a1e3cbe7 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -132,14 +132,14 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
- struct page **pagep,
+ struct folio **foliop,
bool wp_copy)
{
void *page_kaddr;
int ret;
struct folio *folio;
- if (!*pagep) {
+ if (!*foliop) {
ret = -ENOMEM;
folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, dst_vma, dst_addr, false);
if (!folio)
@@ -171,16 +171,15 @@ static int mcopy_atomic_pte(struct mm_struct *dst_mm,
/* fallback to copy_from_user outside mmap_lock */
if (unlikely(ret)) {
ret = -ENOENT;
- *pagep = &folio->page;
+ *foliop = folio;
/* don't free the page */
goto out;
}
flush_dcache_folio(folio);
} else {
- folio = page_folio(*pagep);
- VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
- *pagep = NULL;
+ VM_BUG_ON_FOLIO(folio_test_large(*foliop), folio);
+ *foliop = NULL;
}
/*
@@ -476,7 +475,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
struct vm_area_struct *dst_vma,
unsigned long dst_addr,
unsigned long src_addr,
- struct page **page,
+ struct folio **foliop,
enum mcopy_atomic_mode mode,
bool wp_copy)
{
@@ -500,7 +499,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
if (!(dst_vma->vm_flags & VM_SHARED)) {
if (mode == MCOPY_ATOMIC_NORMAL)
err = mcopy_atomic_pte(dst_mm, dst_pmd, dst_vma,
- dst_addr, src_addr, page,
+ dst_addr, src_addr, foliop,
wp_copy);
else
err = mfill_zeropage_pte(dst_mm, dst_pmd,
@@ -509,7 +508,7 @@ static __always_inline ssize_t mfill_atomic_pte(struct mm_struct *dst_mm,
err = shmem_mfill_atomic_pte(dst_mm, dst_pmd, dst_vma,
dst_addr, src_addr,
mode != MCOPY_ATOMIC_NORMAL,
- wp_copy, page);
+ wp_copy, foliop);
}
return err;
@@ -528,7 +527,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
pmd_t *dst_pmd;
unsigned long src_addr, dst_addr;
long copied;
- struct page *page;
+ struct folio *folio;
bool wp_copy;
/*
@@ -544,7 +543,7 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
src_addr = src_start;
dst_addr = dst_start;
copied = 0;
- page = NULL;
+ folio = NULL;
retry:
mmap_read_lock(dst_mm);
@@ -641,16 +640,16 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
BUG_ON(pmd_trans_huge(*dst_pmd));
err = mfill_atomic_pte(dst_mm, dst_pmd, dst_vma, dst_addr,
- src_addr, &page, mcopy_mode, wp_copy);
+ src_addr, &folio, mcopy_mode, wp_copy);
cond_resched();
if (unlikely(err == -ENOENT)) {
void *page_kaddr;
mmap_read_unlock(dst_mm);
- BUG_ON(!page);
+ BUG_ON(!folio);
- page_kaddr = kmap_local_page(page);
+ page_kaddr = kmap_local_folio(folio, 0);
err = copy_from_user(page_kaddr,
(const void __user *) src_addr,
PAGE_SIZE);
@@ -659,10 +658,10 @@ static __always_inline ssize_t __mcopy_atomic(struct mm_struct *dst_mm,
err = -EFAULT;
goto out;
}
- flush_dcache_page(page);
+ flush_dcache_folio(folio);
goto retry;
} else
- BUG_ON(page);
+ BUG_ON(folio);
if (!err) {
dst_addr += PAGE_SIZE;
@@ -679,8 +678,8 @@ static __always_inline ssize_t __mcopy_atomic(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