mm/mmap: don't use __vma_adjust() in shift_arg_pages()

Introduce shrink_vma() which uses the vma_prepare() and vma_complete()
functions to reduce the vma coverage.

Convert shift_arg_pages() to use expand_vma() and the new shrink_vma()
function.  Remove support from __vma_adjust() to reduce a vma size since
shift_arg_pages() is the only user that shrinks a VMA in this way.

Link: https://lkml.kernel.org/r/20230120162650.984577-46-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Liam R. Howlett
2023-01-20 11:26:46 -05:00
committed by Andrew Morton
parent 7c9813e886
commit cf51e86dfb
3 changed files with 47 additions and 19 deletions

View File

@@ -2831,17 +2831,11 @@ void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
/* mmap.c */
extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
extern int __vma_adjust(struct vma_iterator *vmi, struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgoff_t pgoff, struct vm_area_struct *expand);
static inline int vma_adjust(struct vma_iterator *vmi,
struct vm_area_struct *vma, unsigned long start, unsigned long end,
pgoff_t pgoff)
{
return __vma_adjust(vmi, vma, start, end, pgoff, NULL);
}
extern 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);
extern int vma_shrink(struct vma_iterator *vmi, struct vm_area_struct *vma,
unsigned long start, unsigned long end, pgoff_t pgoff);
extern struct vm_area_struct *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 *,