mm/mmap: simplify vma link and unlink
The file parameter in the __remove_shared_vm_struct is no longer used,
remove it.
These functions vma_link() and mmap_region() have some of the same code,
introduce vma_link_file() helper function to simplify the code.
Link: https://lkml.kernel.org/r/20240110084622.2425927-1-yajun.deng@linux.dev
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
diff --git a/mm/mmap.c b/mm/mmap.c
index d89770e..282ed6d 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -105,7 +105,7 @@ void vma_set_page_prot(struct vm_area_struct *vma)
* Requires inode->i_mapping->i_mmap_rwsem
*/
static void __remove_shared_vm_struct(struct vm_area_struct *vma,
- struct file *file, struct address_space *mapping)
+ struct address_space *mapping)
{
if (vma_is_shared_maywrite(vma))
mapping_unmap_writable(mapping);
@@ -126,7 +126,7 @@ void unlink_file_vma(struct vm_area_struct *vma)
if (file) {
struct address_space *mapping = file->f_mapping;
i_mmap_lock_write(mapping);
- __remove_shared_vm_struct(vma, file, mapping);
+ __remove_shared_vm_struct(vma, mapping);
i_mmap_unlock_write(mapping);
}
}
@@ -392,26 +392,30 @@ static void __vma_link_file(struct vm_area_struct *vma,
flush_dcache_mmap_unlock(mapping);
}
+static void vma_link_file(struct vm_area_struct *vma)
+{
+ struct file *file = vma->vm_file;
+ struct address_space *mapping;
+
+ if (file) {
+ mapping = file->f_mapping;
+ i_mmap_lock_write(mapping);
+ __vma_link_file(vma, mapping);
+ i_mmap_unlock_write(mapping);
+ }
+}
+
static int vma_link(struct mm_struct *mm, struct vm_area_struct *vma)
{
VMA_ITERATOR(vmi, mm, 0);
- struct address_space *mapping = NULL;
vma_iter_config(&vmi, vma->vm_start, vma->vm_end);
if (vma_iter_prealloc(&vmi, vma))
return -ENOMEM;
vma_start_write(vma);
-
vma_iter_store(&vmi, vma);
-
- if (vma->vm_file) {
- mapping = vma->vm_file->f_mapping;
- i_mmap_lock_write(mapping);
- __vma_link_file(vma, mapping);
- i_mmap_unlock_write(mapping);
- }
-
+ vma_link_file(vma);
mm->map_count++;
validate_mm(mm);
return 0;
@@ -519,10 +523,9 @@ static inline void vma_complete(struct vma_prepare *vp,
}
if (vp->remove && vp->file) {
- __remove_shared_vm_struct(vp->remove, vp->file, vp->mapping);
+ __remove_shared_vm_struct(vp->remove, vp->mapping);
if (vp->remove2)
- __remove_shared_vm_struct(vp->remove2, vp->file,
- vp->mapping);
+ __remove_shared_vm_struct(vp->remove2, vp->mapping);
} else if (vp->insert) {
/*
* split_vma has split insert from vma, and needs
@@ -2891,16 +2894,7 @@ unsigned long mmap_region(struct file *file, unsigned long addr,
vma_start_write(vma);
vma_iter_store(&vmi, vma);
mm->map_count++;
- if (vma->vm_file) {
- i_mmap_lock_write(vma->vm_file->f_mapping);
- if (vma_is_shared_maywrite(vma))
- mapping_allow_writable(vma->vm_file->f_mapping);
-
- flush_dcache_mmap_lock(vma->vm_file->f_mapping);
- vma_interval_tree_insert(vma, &vma->vm_file->f_mapping->i_mmap);
- flush_dcache_mmap_unlock(vma->vm_file->f_mapping);
- i_mmap_unlock_write(vma->vm_file->f_mapping);
- }
+ vma_link_file(vma);
/*
* vma_merge() calls khugepaged_enter_vma() either, the below
