mm: memory: use folio_prealloc() in wp_page_copy()

Use folio_prealloc() helper to simplify code a bit.

Link: https://lkml.kernel.org/r/20231118023232.1409103-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory.c b/mm/memory.c
index 3d92b4a7b6e43bb56fc13ed7dbcc644a8ffad78f..99582b188ed21c8d64bf178ec5b8b678312c3c66 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -3117,6 +3117,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
        int page_copied = 0;
        struct mmu_notifier_range range;
        vm_fault_t ret;
+       bool pfn_is_zero;
 
        delayacct_wpcopy_start();
 
@@ -3126,16 +3127,13 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
        if (unlikely(ret))
                goto out;
 
-       if (is_zero_pfn(pte_pfn(vmf->orig_pte))) {
-               new_folio = vma_alloc_zeroed_movable_folio(vma, vmf->address);
-               if (!new_folio)
-                       goto oom;
-       } else {
+       pfn_is_zero = is_zero_pfn(pte_pfn(vmf->orig_pte));
+       new_folio = folio_prealloc(mm, vma, vmf->address, pfn_is_zero);
+       if (!new_folio)
+               goto oom;
+
+       if (!pfn_is_zero) {
                int err;
-               new_folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma,
-                               vmf->address, false);
-               if (!new_folio)
-                       goto oom;
 
                err = __wp_page_copy_user(&new_folio->page, vmf->page, vmf);
                if (err) {
@@ -3156,10 +3154,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
                kmsan_copy_page_meta(&new_folio->page, vmf->page);
        }
 
-       if (mem_cgroup_charge(new_folio, mm, GFP_KERNEL))
-               goto oom_free_new;
-       folio_throttle_swaprate(new_folio, GFP_KERNEL);
-
        __folio_mark_uptodate(new_folio);
 
        mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, mm,
@@ -3258,8 +3252,6 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf)
 
        delayacct_wpcopy_end();
        return 0;
-oom_free_new:
-       folio_put(new_folio);
 oom:
        ret = VM_FAULT_OOM;
 out: