Commit b7dd44a1 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

mm/shmem: convert shmem_add_to_page_cache to take a folio 

Shrinks shmem_add_to_page_cache() by 16 bytes.  All the callers grow,
but this is temporary as they will all be converted to folios soon.

Link: https://lkml.kernel.org/r/20220504182857.4013401-19-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 039bc124

mm/shmem.c

+31 −26
Original line number Diff line number Diff line
@@ -696,36 +696,35 @@ static unsigned long shmem_unused_huge_shrink(struct shmem_sb_info *sbinfo, 
/*

 * Like add_to_page_cache_locked, but error if expected item has gone.

 */

static int shmem_add_to_page_cache(struct page *page,

static int shmem_add_to_page_cache(struct folio *folio,

				   struct address_space *mapping,

				   pgoff_t index, void *expected, gfp_t gfp,

				   struct mm_struct *charge_mm)

{

	XA_STATE_ORDER(xas, &mapping->i_pages, index, compound_order(page));

	unsigned long nr = compound_nr(page);

	XA_STATE_ORDER(xas, &mapping->i_pages, index, folio_order(folio));

	long nr = folio_nr_pages(folio);

	int error;



	VM_BUG_ON_PAGE(PageTail(page), page);

	VM_BUG_ON_PAGE(index != round_down(index, nr), page);

	VM_BUG_ON_PAGE(!PageLocked(page), page);

	VM_BUG_ON_PAGE(!PageSwapBacked(page), page);

	VM_BUG_ON(expected && PageTransHuge(page));

	VM_BUG_ON_FOLIO(index != round_down(index, nr), folio);

	VM_BUG_ON_FOLIO(!folio_test_locked(folio), folio);

	VM_BUG_ON_FOLIO(!folio_test_swapbacked(folio), folio);

	VM_BUG_ON(expected && folio_test_large(folio));



	page_ref_add(page, nr);

	page->mapping = mapping;

	page->index = index;

	folio_ref_add(folio, nr);

	folio->mapping = mapping;

	folio->index = index;



	if (!PageSwapCache(page)) {

		error = mem_cgroup_charge(page_folio(page), charge_mm, gfp);

	if (!folio_test_swapcache(folio)) {

		error = mem_cgroup_charge(folio, charge_mm, gfp);

		if (error) {

			if (PageTransHuge(page)) {

			if (folio_test_pmd_mappable(folio)) {

				count_vm_event(THP_FILE_FALLBACK);

				count_vm_event(THP_FILE_FALLBACK_CHARGE);

			}

			goto error;

		}

	}

	cgroup_throttle_swaprate(page, gfp);

	folio_throttle_swaprate(folio, gfp);



	do {

		xas_lock_irq(&xas);
@@ -737,16 +736,16 @@ static int shmem_add_to_page_cache(struct page *page, 
			xas_set_err(&xas, -EEXIST);

			goto unlock;

		}

		xas_store(&xas, page);

		xas_store(&xas, folio);

		if (xas_error(&xas))

			goto unlock;

		if (PageTransHuge(page)) {

		if (folio_test_pmd_mappable(folio)) {

			count_vm_event(THP_FILE_ALLOC);

			__mod_lruvec_page_state(page, NR_SHMEM_THPS, nr);

			__lruvec_stat_mod_folio(folio, NR_SHMEM_THPS, nr);

		}

		mapping->nrpages += nr;

		__mod_lruvec_page_state(page, NR_FILE_PAGES, nr);

		__mod_lruvec_page_state(page, NR_SHMEM, nr);

		__lruvec_stat_mod_folio(folio, NR_FILE_PAGES, nr);

		__lruvec_stat_mod_folio(folio, NR_SHMEM, nr);

unlock:

		xas_unlock_irq(&xas);

	} while (xas_nomem(&xas, gfp));
@@ -758,8 +757,8 @@ static int shmem_add_to_page_cache(struct page *page, 


	return 0;

error:

	page->mapping = NULL;

	page_ref_sub(page, nr);

	folio->mapping = NULL;

	folio_ref_sub(folio, nr);

	return error;

}
@@ -1691,7 +1690,8 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, 
	struct address_space *mapping = inode->i_mapping;

	struct shmem_inode_info *info = SHMEM_I(inode);

	struct mm_struct *charge_mm = vma ? vma->vm_mm : NULL;

	struct page *page;

	struct page *page = NULL;

	struct folio *folio;

	swp_entry_t swap;

	int error;
@@ -1741,7 +1741,8 @@ static int shmem_swapin_page(struct inode *inode, pgoff_t index, 
			goto failed;

	}



	error = shmem_add_to_page_cache(page, mapping, index,

	folio = page_folio(page);

	error = shmem_add_to_page_cache(folio, mapping, index,

					swp_to_radix_entry(swap), gfp,

					charge_mm);

	if (error)
@@ -1792,6 +1793,7 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, 
	struct shmem_inode_info *info = SHMEM_I(inode);

	struct shmem_sb_info *sbinfo;

	struct mm_struct *charge_mm;

	struct folio *folio;

	struct page *page;

	pgoff_t hindex = index;

	gfp_t huge_gfp;
@@ -1906,7 +1908,8 @@ static int shmem_getpage_gfp(struct inode *inode, pgoff_t index, 
	if (sgp == SGP_WRITE)

		__SetPageReferenced(page);



	error = shmem_add_to_page_cache(page, mapping, hindex,

	folio = page_folio(page);

	error = shmem_add_to_page_cache(folio, mapping, hindex,

					NULL, gfp & GFP_RECLAIM_MASK,

					charge_mm);

	if (error)
@@ -2328,6 +2331,7 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, 
	gfp_t gfp = mapping_gfp_mask(mapping);

	pgoff_t pgoff = linear_page_index(dst_vma, dst_addr);

	void *page_kaddr;

	struct folio *folio;

	struct page *page;

	int ret;

	pgoff_t max_off;
@@ -2386,7 +2390,8 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_mm, 
	if (unlikely(pgoff >= max_off))

		goto out_release;



	ret = shmem_add_to_page_cache(page, mapping, pgoff, NULL,

	folio = page_folio(page);

	ret = shmem_add_to_page_cache(folio, mapping, pgoff, NULL,

				      gfp & GFP_RECLAIM_MASK, dst_mm);

	if (ret)

		goto out_release;