The patch titled
Subject: mm: abstract vma_expand() to use vma_merge_struct
has been added to the -mm mm-unstable branch. Its filename is
mm-abstract-vma_expand-to-use-vma_merge_struct.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-abstract-vma_expand-to-use-vma_merge_struct.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Subject: mm: abstract vma_expand() to use vma_merge_struct
Date: Fri, 23 Aug 2024 21:07:00 +0100
The purpose of the vmg is to thread merge state through functions and avoid
egregious parameter lists. We expand this to vma_expand(), which is used
for a number of merge cases.
Accordingly, adjust its callers, mmap_region() and relocate_vma_down(), to
use a vmg.
An added purpose of this change is the ability in a future commit to
perform all new VMA range merging using vma_expand().
Link: https://lkml.kernel.org/r/0cc0e4d1af6722b3b0d121647089659bd8060087.1724441678.git.lorenzo.stoakes@xxxxxxxxxx
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Bert Karwatzki <spasswolf@xxxxxx>
Cc: Jiri Olsa <olsajiri@xxxxxxxxx>
Cc: Kees Cook <kees@xxxxxxxxxx>
Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
Cc: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mmap.c | 16 ++++++++-------
mm/vma.c | 39 ++++++++++++++++----------------------
mm/vma.h | 5 ----
tools/testing/vma/vma.c | 3 --
4 files changed, 28 insertions(+), 35 deletions(-)
--- a/mm/mmap.c~mm-abstract-vma_expand-to-use-vma_merge_struct
+++ a/mm/mmap.c
@@ -1371,7 +1371,6 @@ unsigned long mmap_region(struct file *f
struct ma_state mas_detach;
struct maple_tree mt_detach;
unsigned long end = addr + len;
- unsigned long merge_start = addr, merge_end = end;
bool writable_file_mapping = false;
int error = -ENOMEM;
VMA_ITERATOR(vmi, mm, addr);
@@ -1424,8 +1423,8 @@ unsigned long mmap_region(struct file *f
/* Attempt to expand an old mapping */
/* Check next */
if (next && next->vm_start == end && can_vma_merge_before(&vmg)) {
- merge_end = next->vm_end;
- vma = next;
+ vmg.end = next->vm_end;
+ vma = vmg.vma = next;
vmg.pgoff = next->vm_pgoff - pglen;
/*
* We set this here so if we will merge with the previous VMA in
@@ -1438,15 +1437,15 @@ unsigned long mmap_region(struct file *f
/* Check prev */
if (prev && prev->vm_end == addr && can_vma_merge_after(&vmg)) {
- merge_start = prev->vm_start;
- vma = prev;
+ vmg.start = prev->vm_start;
+ vma = vmg.vma = prev;
vmg.pgoff = prev->vm_pgoff;
vma_prev(&vmi); /* Equivalent to going to the previous range */
}
if (vma) {
/* Actually expand, if possible */
- if (!vma_expand(&vmi, vma, merge_start, merge_end, vmg.pgoff, next)) {
+ if (!vma_expand(&vmg)) {
khugepaged_enter_vma(vma, vm_flags);
goto expanded;
}
@@ -2319,6 +2318,7 @@ int relocate_vma_down(struct vm_area_str
unsigned long new_start = old_start - shift;
unsigned long new_end = old_end - shift;
VMA_ITERATOR(vmi, mm, new_start);
+ VMG_STATE(vmg, mm, &vmi, new_start, old_end, 0, vma->vm_pgoff);
struct vm_area_struct *next;
struct mmu_gather tlb;
@@ -2335,7 +2335,8 @@ int relocate_vma_down(struct vm_area_str
/*
* cover the whole range: [new_start, old_end)
*/
- if (vma_expand(&vmi, vma, new_start, old_end, vma->vm_pgoff, NULL))
+ vmg.vma = vma;
+ if (vma_expand(&vmg))
return -ENOMEM;
/*
@@ -2368,6 +2369,7 @@ int relocate_vma_down(struct vm_area_str
tlb_finish_mmu(&tlb);
vma_prev(&vmi);
+
/* Shrink the vma to just the new range */
return vma_shrink(&vmi, vma, new_start, new_end, vma->vm_pgoff);
}
--- a/mm/vma.c~mm-abstract-vma_expand-to-use-vma_merge_struct
+++ a/mm/vma.c
@@ -467,30 +467,25 @@ void validate_mm(struct mm_struct *mm)
/*
* vma_expand - Expand an existing VMA
*
- * @vmi: The vma iterator
- * @vma: The vma to expand
- * @start: The start of the vma
- * @end: The exclusive end of the vma
- * @pgoff: The page offset of vma
- * @next: The current of next vma.
+ * @vmg: Describes a VMA expansion operation.
*
- * Expand @vma to @start and @end. Can expand off the start and end. Will
- * expand over @next if it's different from @vma and @end == @next->vm_end.
- * Checking if the @vma can expand and merge with @next needs to be handled by
- * the caller.
+ * Expand @vma to vmg->start and vmg->end. Can expand off the start and end.
+ * Will expand over vmg->next if it's different from vmg->vma and vmg->end ==
+ * vmg->next->vm_end. Checking if the vmg->vma can expand and merge with
+ * vmg->next needs to be handled by the caller.
*
* Returns: 0 on success
*/
-int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
- unsigned long start, unsigned long end, pgoff_t pgoff,
- struct vm_area_struct *next)
+int vma_expand(struct vma_merge_struct *vmg)
{
struct vm_area_struct *anon_dup = NULL;
bool remove_next = false;
+ struct vm_area_struct *vma = vmg->vma;
+ struct vm_area_struct *next = vmg->next;
struct vma_prepare vp;
vma_start_write(vma);
- if (next && (vma != next) && (end == next->vm_end)) {
+ if (next && (vma != next) && (vmg->end == next->vm_end)) {
int ret;
remove_next = true;
@@ -503,21 +498,21 @@ int vma_expand(struct vma_iterator *vmi,
init_multi_vma_prep(&vp, vma, NULL, remove_next ? next : NULL, NULL);
/* Not merging but overwriting any part of next is not handled. */
VM_WARN_ON(next && !vp.remove &&
- next != vma && end > next->vm_start);
+ next != vma && vmg->end > next->vm_start);
/* Only handles expanding */
- VM_WARN_ON(vma->vm_start < start || vma->vm_end > end);
+ VM_WARN_ON(vma->vm_start < vmg->start || vma->vm_end > vmg->end);
/* Note: vma iterator must be pointing to 'start' */
- vma_iter_config(vmi, start, end);
- if (vma_iter_prealloc(vmi, vma))
+ vma_iter_config(vmg->vmi, vmg->start, vmg->end);
+ if (vma_iter_prealloc(vmg->vmi, vma))
goto nomem;
vma_prepare(&vp);
- vma_adjust_trans_huge(vma, start, end, 0);
- vma_set_range(vma, start, end, pgoff);
- vma_iter_store(vmi, vma);
+ vma_adjust_trans_huge(vma, vmg->start, vmg->end, 0);
+ vma_set_range(vma, vmg->start, vmg->end, vmg->pgoff);
+ vma_iter_store(vmg->vmi, vma);
- vma_complete(&vp, vmi, vma->vm_mm);
+ vma_complete(&vp, vmg->vmi, vma->vm_mm);
return 0;
nomem:
--- a/mm/vma.h~mm-abstract-vma_expand-to-use-vma_merge_struct
+++ a/mm/vma.h
@@ -128,10 +128,7 @@ void init_vma_prep(struct vma_prepare *v
void vma_complete(struct vma_prepare *vp,
struct vma_iterator *vmi, struct mm_struct *mm);
-int vma_expand(struct vma_iterator *vmi, struct vm_area_struct *vma,
- unsigned long start, unsigned long end, pgoff_t pgoff,
- struct vm_area_struct *next);
-
+int vma_expand(struct vma_merge_struct *vmg);
int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long start, unsigned long end, pgoff_t pgoff);
--- a/tools/testing/vma/vma.c~mm-abstract-vma_expand-to-use-vma_merge_struct
+++ a/tools/testing/vma/vma.c
@@ -121,8 +121,7 @@ static struct vm_area_struct *merge_exis
*/
static int expand_existing(struct vma_merge_struct *vmg)
{
- return vma_expand(vmg->vmi, vmg->vma, vmg->start, vmg->end, vmg->pgoff,
- vmg->next);
+ return vma_expand(vmg);
}
/*
_
Patches currently in -mm which might be from lorenzo.stoakes@xxxxxxxxxx are
userfaultfd-move-core-vma-manipulation-logic-to-mm-userfaultfdc.patch
userfaultfd-move-core-vma-manipulation-logic-to-mm-userfaultfdc-fix.patch
mm-move-vma_modify-and-helpers-to-internal-header.patch
mm-move-vma_shrink-vma_expand-to-internal-header.patch
mm-move-internal-core-vma-manipulation-functions-to-own-file.patch
maintainers-add-entry-for-new-vma-files.patch
tools-separate-out-shared-radix-tree-components.patch
tools-add-skeleton-code-for-userland-testing-of-vma-logic.patch
tools-improve-vma-test-makefile.patch
tools-add-vma-merge-tests.patch
mm-introduce-vma_merge_struct-and-abstract-vma_mergevma_modify.patch
mm-remove-duplicated-open-coded-vma-policy-check.patch
mm-abstract-vma_expand-to-use-vma_merge_struct.patch
mm-avoid-using-vma_merge-for-new-vmas.patch
mm-make-vma_prepare-and-friends-static-and-internal-to-vmac.patch
mm-introduce-commit_merge-abstracting-final-commit-of-merge.patch
mm-refactor-vma_merge-into-modify-only-vma_merge_existing_range.patch
mm-rework-vm_ops-close-handling-on-vma-merge.patch
