Commit 4e5e68c0 authored by Yajun Deng's avatar Yajun Deng Committed by Liu Shixin
Browse files

mm/mmap: simplify vma link and unlink 

mainline inclusion
from mainline-v6.9-rc1
commit 30afc8c34290184c023fa79136ce5f8813fc73da
category: cleanup
bugzilla: https://gitee.com/openeuler/kernel/issues/IAHY3K

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=30afc8c34290184c023fa79136ce5f8813fc73da

--------------------------------

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: default avatarYajun Deng <yajun.deng@linux.dev>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Conflicts:
	mm/mmap.c
[ Context conflicts with commit 4f4042f1 and e8e17ee90eaf ]
Signed-off-by: default avatarLiu Shixin <liushixin2@huawei.com>
parent e4aec577

mm/mmap.c

+19 −25
Original line number Diff line number Diff line
@@ -106,7 +106,7 @@ 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->vm_flags & VM_SHARED)

		mapping_unmap_writable(mapping);
@@ -127,7 +127,7 @@ 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);

	}

}
@@ -394,26 +394,30 @@ 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;
@@ -521,10 +525,9 @@ 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
@@ -2875,16 +2878,7 @@ static unsigned long __mmap_region(struct mm_struct *mm, 
	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->vm_flags & VM_SHARED)

			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