[PATCH v4 6/6] userfaultfd: convert mfill_atomic() to use a folio

Peng Zhang
2023-03-30T13:41:57Z

From: ZhangPeng <zhangpeng362@huawei.com>

Convert mfill_atomic_pte_copy(), shmem_mfill_atomic_pte() and
mfill_atomic_pte() to take in a folio pointer.
Convert mfill_atomic() to use a folio.

Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
---
include/linux/shmem_fs.h | 4 ++--
mm/shmem.c | 16 ++++++++--------
mm/userfaultfd.c | 34 +++++++++++++++++-----------------
3 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h
index 3bb8d21edbb3..9e151ba45068 100644
--- a/include/linux/shmem_fs.h
+++ b/include/linux/shmem_fs.h
@@ -158,10 +158,10 @@ extern int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
unsigned long dst_addr,
unsigned long src_addr,
uffd_flags_t flags,
- struct page **pagep);
+ struct folio **foliop);
#else /* !CONFIG_SHMEM */
#define shmem_mfill_atomic_pte(dst_pmd, dst_vma, dst_addr, \
- src_addr, flags, pagep) ({ BUG(); 0; })
+ src_addr, flags, foliop) ({ BUG(); 0; })
#endif /* CONFIG_SHMEM */
#endif /* CONFIG_USERFAULTFD */

diff --git a/mm/shmem.c b/mm/shmem.c
index 6c08f5a75d3a..9218c955f482 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2548,7 +2548,7 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
unsigned long dst_addr,
unsigned long src_addr,
uffd_flags_t flags,
- struct page **pagep)
+ struct folio **foliop)
{
struct inode *inode = file_inode(dst_vma->vm_file);
struct shmem_inode_info *info = SHMEM_I(inode);
@@ -2566,14 +2566,14 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
* 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)
@@ -2605,7 +2605,7 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd,

/* 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;
@@ -2616,9 +2616,9 @@ int shmem_mfill_atomic_pte(pmd_t *dst_pmd,
clear_user_highpage(&folio->page, dst_addr);
}
} else {
- folio = page_folio(*pagep);
+ folio = *foliop;
VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
- *pagep = NULL;
+ *foliop = NULL;
}

VM_BUG_ON(folio_test_locked(folio));
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 9e95af5ce2dd..74b122887901 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -133,13 +133,13 @@ static int mfill_atomic_pte_copy(pmd_t *dst_pmd,
unsigned long dst_addr,
unsigned long src_addr,
uffd_flags_t flags,
- struct page **pagep)
+ struct folio **foliop)
{
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 +171,16 @@ static int mfill_atomic_pte_copy(pmd_t *dst_pmd,
/* 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);
+ folio = *foliop;
VM_BUG_ON_FOLIO(folio_test_large(folio), folio);
- *pagep = NULL;
+ *foliop = NULL;
}

/*
@@ -471,7 +471,7 @@ static __always_inline ssize_t mfill_atomic_pte(pmd_t *dst_pmd,
unsigned long dst_addr,
unsigned long src_addr,
uffd_flags_t flags,
- struct page **pagep)
+ struct folio **foliop)
{
ssize_t err;

@@ -494,14 +494,14 @@ static __always_inline ssize_t mfill_atomic_pte(pmd_t *dst_pmd,
if (uffd_flags_mode_is(flags, MFILL_ATOMIC_COPY))
err = mfill_atomic_pte_copy(dst_pmd, dst_vma,
dst_addr, src_addr,
- flags, pagep);
+ flags, foliop);
else
err = mfill_atomic_pte_zeropage(dst_pmd,
dst_vma, dst_addr);
} else {
err = shmem_mfill_atomic_pte(dst_pmd, dst_vma,
dst_addr, src_addr,
- flags, pagep);
+ flags, foliop);
}

return err;
@@ -519,7 +519,7 @@ static __always_inline ssize_t mfill_atomic(struct mm_struct *dst_mm,
pmd_t *dst_pmd;
unsigned long src_addr, dst_addr;
long copied;
- struct page *page;
+ struct folio *folio;

/*
* Sanitize the command parameters:
@@ -534,7 +534,7 @@ static __always_inline ssize_t mfill_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);

@@ -630,16 +630,16 @@ static __always_inline ssize_t mfill_atomic(struct mm_struct *dst_mm,
BUG_ON(pmd_trans_huge(*dst_pmd));

err = mfill_atomic_pte(dst_pmd, dst_vma, dst_addr,
- src_addr, flags, &page);
+ src_addr, flags, &folio);
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);
@@ -648,10 +648,10 @@ static __always_inline ssize_t mfill_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;
@@ -668,8 +668,8 @@ static __always_inline ssize_t mfill_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