[PATCH RFC 05/14] mm/huge_memory: move more common code into insert_pud()

From: David Hildenbrand
Date: Tue Jun 17 2025 - 11:47:32 EST


Let's clean it all further up.

Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
mm/huge_memory.c | 36 +++++++++++++-----------------------
1 file changed, 13 insertions(+), 23 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index a85e0cd455109..1ea23900b5adb 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1507,25 +1507,30 @@ static pud_t maybe_pud_mkwrite(pud_t pud, struct vm_area_struct *vma)
return pud;
}

-static void insert_pud(struct vm_area_struct *vma, unsigned long addr,
+static vm_fault_t insert_pud(struct vm_area_struct *vma, unsigned long addr,
pud_t *pud, struct folio_or_pfn fop, pgprot_t prot, bool write)
{
struct mm_struct *mm = vma->vm_mm;
+ spinlock_t *ptl;
pud_t entry;

+ if (addr < vma->vm_start || addr >= vma->vm_end)
+ return VM_FAULT_SIGBUS;
+
+ ptl = pud_lock(mm, pud);
if (!pud_none(*pud)) {
const unsigned long pfn = fop.is_folio ? folio_pfn(fop.folio) :
fop.pfn;

if (write && pud_present(*pud)) {
if (WARN_ON_ONCE(pud_pfn(*pud) != pfn))
- return;
+ goto out_unlock;
entry = pud_mkyoung(*pud);
entry = maybe_pud_mkwrite(pud_mkdirty(entry), vma);
if (pudp_set_access_flags(vma, addr, pud, entry, 1))
update_mmu_cache_pud(vma, addr, pud);
}
- return;
+ goto out_unlock;
}

if (fop.is_folio) {
@@ -1544,6 +1549,9 @@ static void insert_pud(struct vm_area_struct *vma, unsigned long addr,
}
set_pud_at(mm, addr, pud, entry);
update_mmu_cache_pud(vma, addr, pud);
+out_unlock:
+ spin_unlock(ptl);
+ return VM_FAULT_NOPAGE;
}

/**
@@ -1565,7 +1573,6 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, unsigned long pfn,
struct folio_or_pfn fop = {
.pfn = pfn,
};
- spinlock_t *ptl;

/*
* If we had pud_special, we could avoid all these restrictions,
@@ -1577,16 +1584,9 @@ vm_fault_t vmf_insert_pfn_pud(struct vm_fault *vmf, unsigned long pfn,
(VM_PFNMAP|VM_MIXEDMAP));
BUG_ON((vma->vm_flags & VM_PFNMAP) && is_cow_mapping(vma->vm_flags));

- if (addr < vma->vm_start || addr >= vma->vm_end)
- return VM_FAULT_SIGBUS;
-
pfnmap_setup_cachemode_pfn(pfn, &pgprot);

- ptl = pud_lock(vma->vm_mm, vmf->pud);
- insert_pud(vma, addr, vmf->pud, fop, pgprot, write);
- spin_unlock(ptl);
-
- return VM_FAULT_NOPAGE;
+ return insert_pud(vma, addr, vmf->pud, fop, pgprot, write);
}
EXPORT_SYMBOL_GPL(vmf_insert_pfn_pud);

@@ -1603,25 +1603,15 @@ vm_fault_t vmf_insert_folio_pud(struct vm_fault *vmf, struct folio *folio,
{
struct vm_area_struct *vma = vmf->vma;
unsigned long addr = vmf->address & PUD_MASK;
- pud_t *pud = vmf->pud;
- struct mm_struct *mm = vma->vm_mm;
struct folio_or_pfn fop = {
.folio = folio,
.is_folio = true,
};
- spinlock_t *ptl;
-
- if (addr < vma->vm_start || addr >= vma->vm_end)
- return VM_FAULT_SIGBUS;

if (WARN_ON_ONCE(folio_order(folio) != PUD_ORDER))
return VM_FAULT_SIGBUS;

- ptl = pud_lock(mm, pud);
- insert_pud(vma, addr, vmf->pud, fop, vma->vm_page_prot, write);
- spin_unlock(ptl);
-
- return VM_FAULT_NOPAGE;
+ return insert_pud(vma, addr, vmf->pud, fop, vma->vm_page_prot, write);
}
EXPORT_SYMBOL_GPL(vmf_insert_folio_pud);
#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
--
2.49.0