The patch titled
Subject: hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()
has been added to the -mm mm-unstable branch. Its filename is
hugetlb-use-vmf_anon_prepare-instead-of-anon_vma_prepare.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlb-use-vmf_anon_prepare-instead-of-anon_vma_prepare.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: "Vishal Moola (Oracle)" <vishal.moola@xxxxxxxxx>
Subject: hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()
Date: Wed, 21 Feb 2024 15:47:31 -0800
hugetlb_no_page() and hugetlb_wp() call anon_vma_prepare(). In
preparation for hugetlb to safely handle faults under the VMA lock, use
vmf_anon_prepare() here instead.
Additionally, passing hugetlb_wp() the vm_fault struct from
hugetlb_fault() works toward cleaning up the hugetlb code and function
stack.
Link: https://lkml.kernel.org/r/20240221234732.187629-5-vishal.moola@xxxxxxxxx
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Reviewed-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/hugetlb.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
--- a/mm/hugetlb.c~hugetlb-use-vmf_anon_prepare-instead-of-anon_vma_prepare
+++ a/mm/hugetlb.c
@@ -5938,7 +5938,8 @@ static void unmap_ref_private(struct mm_
*/
static vm_fault_t hugetlb_wp(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *ptep, unsigned int flags,
- struct folio *pagecache_folio, spinlock_t *ptl)
+ struct folio *pagecache_folio, spinlock_t *ptl,
+ struct vm_fault *vmf)
{
const bool unshare = flags & FAULT_FLAG_UNSHARE;
pte_t pte = huge_ptep_get(ptep);
@@ -6072,10 +6073,9 @@ retry_avoidcopy:
* When the original hugepage is shared one, it does not have
* anon_vma prepared.
*/
- if (unlikely(anon_vma_prepare(vma))) {
- ret = VM_FAULT_OOM;
+ ret = vmf_anon_prepare(vmf);
+ if (unlikely(ret))
goto out_release_all;
- }
if (copy_user_large_folio(new_folio, old_folio, address, vma)) {
ret = VM_FAULT_HWPOISON_LARGE;
@@ -6315,10 +6315,10 @@ static vm_fault_t hugetlb_no_page(struct
new_pagecache_folio = true;
} else {
folio_lock(folio);
- if (unlikely(anon_vma_prepare(vma))) {
- ret = VM_FAULT_OOM;
+
+ ret = vmf_anon_prepare(vmf);
+ if (unlikely(ret))
goto backout_unlocked;
- }
anon_rmap = 1;
}
} else {
@@ -6385,7 +6385,7 @@ static vm_fault_t hugetlb_no_page(struct
hugetlb_count_add(pages_per_huge_page(h), mm);
if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
/* Optimization, do the COW without a second fault */
- ret = hugetlb_wp(mm, vma, address, ptep, flags, folio, ptl);
+ ret = hugetlb_wp(mm, vma, address, ptep, flags, folio, ptl, vmf);
}
spin_unlock(ptl);
@@ -6608,7 +6608,7 @@ vm_fault_t hugetlb_fault(struct mm_struc
if (flags & (FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE)) {
if (!huge_pte_write(entry)) {
ret = hugetlb_wp(mm, vma, address, ptep, flags,
- pagecache_folio, ptl);
+ pagecache_folio, ptl, &vmf);
goto out_put_page;
} else if (likely(flags & FAULT_FLAG_WRITE)) {
entry = huge_pte_mkdirty(entry);
_
Patches currently in -mm which might be from vishal.moola@xxxxxxxxx are
mm-memory-change-vmf_anon_prepare-to-be-non-static.patch
hugetlb-move-vm_struct-declaration-to-the-top-of-hugetlb_fault.patch
hugetlb-pass-struct-vm_fault-through-to-hugetlb_handle_userfault.patch
hugetlb-use-vmf_anon_prepare-instead-of-anon_vma_prepare.patch
hugetlb-allow-faults-to-be-handled-under-the-vma-lock.patch
