[PATCH -next 3/7] mm: memory: convert do_cow_fault to use folios

From: Kefeng Wang
Date: Thu Jan 12 2023 - 03:18:16 EST


The page functions are converted to corresponding folio functions in
do_cow_fault().

Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
mm/memory.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 1cfdb0fd8d79..f29bca499e0d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4507,22 +4507,24 @@ static vm_fault_t do_read_fault(struct vm_fault *vmf)
static vm_fault_t do_cow_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
+ struct folio *cow_folio, *folio;
vm_fault_t ret;

if (unlikely(anon_vma_prepare(vma)))
return VM_FAULT_OOM;

- vmf->cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address);
- if (!vmf->cow_page)
+ cow_folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma, vmf->address,
+ false);
+ if (!cow_folio)
return VM_FAULT_OOM;

- if (mem_cgroup_charge(page_folio(vmf->cow_page), vma->vm_mm,
- GFP_KERNEL)) {
- put_page(vmf->cow_page);
+ if (mem_cgroup_charge(cow_folio, vma->vm_mm, GFP_KERNEL)) {
+ folio_put(cow_folio);
return VM_FAULT_OOM;
}
- cgroup_throttle_swaprate(vmf->cow_page, GFP_KERNEL);
+ folio_throttle_swaprate(cow_folio, GFP_KERNEL);

+ vmf->cow_page = &cow_folio->page;
ret = __do_fault(vmf);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
goto uncharge_out;
@@ -4530,16 +4532,17 @@ static vm_fault_t do_cow_fault(struct vm_fault *vmf)
return ret;

copy_user_highpage(vmf->cow_page, vmf->page, vmf->address, vma);
- __SetPageUptodate(vmf->cow_page);
+ __folio_mark_uptodate(cow_folio);

ret |= finish_fault(vmf);
- unlock_page(vmf->page);
- put_page(vmf->page);
+ folio = page_folio(vmf->page);
+ folio_unlock(folio);
+ folio_put(folio);
if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))
goto uncharge_out;
return ret;
uncharge_out:
- put_page(vmf->cow_page);
+ folio_put(cow_folio);
return ret;
}

--
2.35.3