[PATCH v3 14/48] mm: Add temporary vma iterator versions of vma_merge(), split_vma(), and __split_vma()

Liam Howlett
2023-01-17T02:35:42Z

These wrappers are short-lived in this patch set so that each user can
be converted on its own. In the end, these functions are renamed in one
commit.

Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
---
include/linux/mm.h | 11 ++++++++++-
mm/mmap.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 126f94b6f434..14e3698fcbe7 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2834,11 +2834,20 @@ extern struct vm_area_struct *vma_merge(struct mm_struct *,
struct vm_area_struct *prev, unsigned long addr, unsigned long end,
unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
struct mempolicy *, struct vm_userfaultfd_ctx, struct anon_vma_name *);
+extern struct vm_area_struct *vmi_vma_merge(struct vma_iterator *vmi,
+ struct mm_struct *, struct vm_area_struct *prev, unsigned long addr,
+ unsigned long end, unsigned long vm_flags, struct anon_vma *,
+ struct file *, pgoff_t, struct mempolicy *, struct vm_userfaultfd_ctx,
+ struct anon_vma_name *);
extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
extern int __split_vma(struct mm_struct *, struct vm_area_struct *,
- unsigned long addr, int new_below);
+ unsigned long addr, int new_below);
+extern int vmi__split_vma(struct vma_iterator *vmi, struct mm_struct *,
+ struct vm_area_struct *, unsigned long addr, int new_below);
extern int split_vma(struct mm_struct *, struct vm_area_struct *,
unsigned long addr, int new_below);
+extern int vmi_split_vma(struct vma_iterator *vmi, struct mm_struct *,
+ struct vm_area_struct *, unsigned long addr, int new_below);
extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
extern void unlink_file_vma(struct vm_area_struct *);
extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
diff --git a/mm/mmap.c b/mm/mmap.c
index 02083b2cacfa..1fd6962f440a 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1091,6 +1091,25 @@ struct vm_area_struct *vma_merge(struct mm_struct *mm,
return res;
}

+struct vm_area_struct *vmi_vma_merge(struct vma_iterator *vmi,
+ struct mm_struct *mm,
+ struct vm_area_struct *prev, unsigned long addr,
+ unsigned long end, unsigned long vm_flags,
+ struct anon_vma *anon_vma, struct file *file,
+ pgoff_t pgoff, struct mempolicy *policy,
+ struct vm_userfaultfd_ctx vm_userfaultfd_ctx,
+ struct anon_vma_name *anon_name)
+{
+ struct vm_area_struct *tmp;
+
+ tmp = vma_merge(mm, prev, addr, end, vm_flags, anon_vma, file, pgoff,
+ policy, vm_userfaultfd_ctx, anon_name);
+ if (tmp)
+ vma_iter_set(vmi, end);
+
+ return tmp;
+}
+
/*
* Rough compatibility check to quickly see if it's even worth looking
* at sharing an anon_vma.
@@ -2272,6 +2291,18 @@ int __split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
validate_mm_mt(mm);
return err;
}
+int vmi__split_vma(struct vma_iterator *vmi, struct mm_struct *mm,
+ struct vm_area_struct *vma, unsigned long addr, int new_below)
+{
+ int ret;
+ unsigned long end = vma->vm_end;
+
+ ret = __split_vma(mm, vma, addr, new_below);
+ if (!ret)
+ vma_iter_set(vmi, end);
+
+ return ret;
+}

/*
* Split a vma into two pieces at address 'addr', a new vma is allocated
@@ -2286,6 +2317,19 @@ int split_vma(struct mm_struct *mm, struct vm_area_struct *vma,
return __split_vma(mm, vma, addr, new_below);
}

+int vmi_split_vma(struct vma_iterator *vmi, struct mm_struct *mm,
+ struct vm_area_struct *vma, unsigned long addr, int new_below)
+{
+ int ret;
+ unsigned long end = vma->vm_end;
+
+ ret = split_vma(mm, vma, addr, new_below);
+ if (!ret)
+ vma_iter_set(vmi, end);
+
+ return ret;
+}
+
static inline int munmap_sidetree(struct vm_area_struct *vma,
struct ma_state *mas_detach)
{
--
2.35.1