Commit 22b3c8d6 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

fs/writeback: Convert inode_switch_wbs_work_fn to folios 



This gets the statistics correct for large folios by modifying the
counters by the number of pages in the folio instead of by 1.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarWilliam Kucharski <william.kucharski@oracle.com>
parent 9144785b

fs/fs-writeback.c

+13 −11
Original line number Diff line number Diff line
@@ -372,7 +372,7 @@ static bool inode_do_switch_wbs(struct inode *inode, 
{

	struct address_space *mapping = inode->i_mapping;

	XA_STATE(xas, &mapping->i_pages, 0);

	struct page *page;

	struct folio *folio;

	bool switched = false;



	spin_lock(&inode->i_lock);
@@ -389,21 +389,23 @@ static bool inode_do_switch_wbs(struct inode *inode, 


	/*

	 * Count and transfer stats.  Note that PAGECACHE_TAG_DIRTY points

	 * to possibly dirty pages while PAGECACHE_TAG_WRITEBACK points to

	 * pages actually under writeback.

	 * to possibly dirty folios while PAGECACHE_TAG_WRITEBACK points to

	 * folios actually under writeback.

	 */

	xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_DIRTY) {

		if (PageDirty(page)) {

			dec_wb_stat(old_wb, WB_RECLAIMABLE);

			inc_wb_stat(new_wb, WB_RECLAIMABLE);

	xas_for_each_marked(&xas, folio, ULONG_MAX, PAGECACHE_TAG_DIRTY) {

		if (folio_test_dirty(folio)) {

			long nr = folio_nr_pages(folio);

			wb_stat_mod(old_wb, WB_RECLAIMABLE, -nr);

			wb_stat_mod(new_wb, WB_RECLAIMABLE, nr);

		}

	}



	xas_set(&xas, 0);

	xas_for_each_marked(&xas, page, ULONG_MAX, PAGECACHE_TAG_WRITEBACK) {

		WARN_ON_ONCE(!PageWriteback(page));

		dec_wb_stat(old_wb, WB_WRITEBACK);

		inc_wb_stat(new_wb, WB_WRITEBACK);

	xas_for_each_marked(&xas, folio, ULONG_MAX, PAGECACHE_TAG_WRITEBACK) {

		long nr = folio_nr_pages(folio);

		WARN_ON_ONCE(!folio_test_writeback(folio));

		wb_stat_mod(old_wb, WB_WRITEBACK, -nr);

		wb_stat_mod(new_wb, WB_WRITEBACK, nr);

	}



	if (mapping_tagged(mapping, PAGECACHE_TAG_WRITEBACK)) {