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Commit 936ca80d authored by Jan Kara's avatar Jan Kara Committed by Linus Torvalds
Browse files

mm: trim __do_fault() arguments 

Use vm_fault structure to pass cow_page, page, and entry in and out of
the function.

That reduces number of __do_fault() arguments from 4 to 1.

Link: http://lkml.kernel.org/r/1479460644-25076-6-git-send-email-jack@suse.cz


Signed-off-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 667240e0

mm/memory.c

+29 −38
Original line number Diff line number Diff line
@@ -2844,26 +2844,22 @@ static int do_anonymous_page(struct vm_fault *vmf) 
 * released depending on flags and vma->vm_ops->fault() return value.

 * See filemap_fault() and __lock_page_retry().

 */

static int __do_fault(struct vm_fault *vmf, struct page *cow_page,

		      struct page **page, void **entry)

static int __do_fault(struct vm_fault *vmf)

{

	struct vm_area_struct *vma = vmf->vma;

	int ret;



	vmf->cow_page = cow_page;



	ret = vma->vm_ops->fault(vma, vmf);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))

		return ret;

	if (ret & VM_FAULT_DAX_LOCKED) {

		*entry = vmf->entry;

	if (ret & VM_FAULT_DAX_LOCKED)

		return ret;

	}



	if (unlikely(PageHWPoison(vmf->page))) {

		if (ret & VM_FAULT_LOCKED)

			unlock_page(vmf->page);

		put_page(vmf->page);

		vmf->page = NULL;

		return VM_FAULT_HWPOISON;

	}
@@ -2872,7 +2868,6 @@ static int __do_fault(struct vm_fault *vmf, struct page *cow_page, 
	else

		VM_BUG_ON_PAGE(!PageLocked(vmf->page), vmf->page);



	*page = vmf->page;

	return ret;

}
@@ -3208,7 +3203,6 @@ static int do_fault_around(struct vm_fault *vmf) 
static int do_read_fault(struct vm_fault *vmf)

{

	struct vm_area_struct *vma = vmf->vma;

	struct page *fault_page;

	int ret = 0;



	/*
@@ -3222,54 +3216,52 @@ static int do_read_fault(struct vm_fault *vmf) 
			return ret;

	}



	ret = __do_fault(vmf, NULL, &fault_page, NULL);

	ret = __do_fault(vmf);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))

		return ret;



	ret |= alloc_set_pte(vmf, NULL, fault_page);

	ret |= alloc_set_pte(vmf, NULL, vmf->page);

	if (vmf->pte)

		pte_unmap_unlock(vmf->pte, vmf->ptl);

	unlock_page(fault_page);

	unlock_page(vmf->page);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))

		put_page(fault_page);

		put_page(vmf->page);

	return ret;

}



static int do_cow_fault(struct vm_fault *vmf)

{

	struct vm_area_struct *vma = vmf->vma;

	struct page *fault_page, *new_page;

	void *fault_entry;

	struct mem_cgroup *memcg;

	int ret;



	if (unlikely(anon_vma_prepare(vma)))

		return VM_FAULT_OOM;



	new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address);

	if (!new_page)

	vmf->cow_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vmf->address);

	if (!vmf->cow_page)

		return VM_FAULT_OOM;



	if (mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL,

	if (mem_cgroup_try_charge(vmf->cow_page, vma->vm_mm, GFP_KERNEL,

				&memcg, false)) {

		put_page(new_page);

		put_page(vmf->cow_page);

		return VM_FAULT_OOM;

	}



	ret = __do_fault(vmf, new_page, &fault_page, &fault_entry);

	ret = __do_fault(vmf);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))

		goto uncharge_out;



	if (!(ret & VM_FAULT_DAX_LOCKED))

		copy_user_highpage(new_page, fault_page, vmf->address, vma);

	__SetPageUptodate(new_page);

		copy_user_highpage(vmf->cow_page, vmf->page, vmf->address, vma);

	__SetPageUptodate(vmf->cow_page);



	ret |= alloc_set_pte(vmf, memcg, new_page);

	ret |= alloc_set_pte(vmf, memcg, vmf->cow_page);

	if (vmf->pte)

		pte_unmap_unlock(vmf->pte, vmf->ptl);

	if (!(ret & VM_FAULT_DAX_LOCKED)) {

		unlock_page(fault_page);

		put_page(fault_page);

		unlock_page(vmf->page);

		put_page(vmf->page);

	} else {

		dax_unlock_mapping_entry(vma->vm_file->f_mapping, vmf->pgoff);

	}
@@ -3277,20 +3269,19 @@ static int do_cow_fault(struct vm_fault *vmf) 
		goto uncharge_out;

	return ret;

uncharge_out:

	mem_cgroup_cancel_charge(new_page, memcg, false);

	put_page(new_page);

	mem_cgroup_cancel_charge(vmf->cow_page, memcg, false);

	put_page(vmf->cow_page);

	return ret;

}



static int do_shared_fault(struct vm_fault *vmf)

{

	struct vm_area_struct *vma = vmf->vma;

	struct page *fault_page;

	struct address_space *mapping;

	int dirtied = 0;

	int ret, tmp;



	ret = __do_fault(vmf, NULL, &fault_page, NULL);

	ret = __do_fault(vmf);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))

		return ret;
@@ -3299,26 +3290,26 @@ static int do_shared_fault(struct vm_fault *vmf) 
	 * about to become writable

	 */

	if (vma->vm_ops->page_mkwrite) {

		unlock_page(fault_page);

		tmp = do_page_mkwrite(vma, fault_page, vmf->address);

		unlock_page(vmf->page);

		tmp = do_page_mkwrite(vma, vmf->page, vmf->address);

		if (unlikely(!tmp ||

				(tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {

			put_page(fault_page);

			put_page(vmf->page);

			return tmp;

		}

	}



	ret |= alloc_set_pte(vmf, NULL, fault_page);

	ret |= alloc_set_pte(vmf, NULL, vmf->page);

	if (vmf->pte)

		pte_unmap_unlock(vmf->pte, vmf->ptl);

	if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE |

					VM_FAULT_RETRY))) {

		unlock_page(fault_page);

		put_page(fault_page);

		unlock_page(vmf->page);

		put_page(vmf->page);

		return ret;

	}



	if (set_page_dirty(fault_page))

	if (set_page_dirty(vmf->page))

		dirtied = 1;

	/*

	 * Take a local copy of the address_space - page.mapping may be zeroed
@@ -3326,8 +3317,8 @@ static int do_shared_fault(struct vm_fault *vmf) 
	 * pinned by vma->vm_file's reference.  We rely on unlock_page()'s

	 * release semantics to prevent the compiler from undoing this copying.

	 */

	mapping = page_rmapping(fault_page);

	unlock_page(fault_page);

	mapping = page_rmapping(vmf->page);

	unlock_page(vmf->page);

	if ((dirtied || vma->vm_ops->page_mkwrite) && mapping) {

		/*

		 * Some device drivers do not set page.mapping but still