From f143f1ea5a5380b2682e6836fcd24338a2aa82c7 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Sat, 24 Apr 2021 12:00:48 -0400 Subject: [PATCH] mm/writeback: Add folio_start_writeback() Rename set_page_writeback() to folio_start_writeback() to match folio_end_writeback(). Do not bother with wrappers that return void; callers are perfectly capable of ignoring return values. Add wrappers for set_page_writeback(), set_page_writeback_keepwrite() and test_set_page_writeback() for compatibililty with existing filesystems. The main advantage of this patch is getting the statistics right, although it does eliminate a couple of calls to compound_head(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Reviewed-by: David Howells Acked-by: Vlastimil Babka --- include/linux/page-flags.h | 23 +++++++++++----------- mm/folio-compat.c | 6 ++++++ mm/page-writeback.c | 39 +++++++++++++++++++------------------- 3 files changed, 38 insertions(+), 30 deletions(-) diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 3aebb2060a26..a68af80649a4 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -657,21 +657,22 @@ static __always_inline void SetPageUptodate(struct page *page) CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) -int __test_set_page_writeback(struct page *page, bool keep_write); +bool __folio_start_writeback(struct folio *folio, bool keep_write); +bool set_page_writeback(struct page *page); -#define test_set_page_writeback(page) \ - __test_set_page_writeback(page, false) -#define test_set_page_writeback_keepwrite(page) \ - __test_set_page_writeback(page, true) - -static inline void set_page_writeback(struct page *page) -{ - test_set_page_writeback(page); -} +#define folio_start_writeback(folio) \ + __folio_start_writeback(folio, false) +#define folio_start_writeback_keepwrite(folio) \ + __folio_start_writeback(folio, true) static inline void set_page_writeback_keepwrite(struct page *page) { - test_set_page_writeback_keepwrite(page); + folio_start_writeback_keepwrite(page_folio(page)); +} + +static inline bool test_set_page_writeback(struct page *page) +{ + return set_page_writeback(page); } __PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) diff --git a/mm/folio-compat.c b/mm/folio-compat.c index 2ccd8f213fc4..10ce5582d869 100644 --- a/mm/folio-compat.c +++ b/mm/folio-compat.c @@ -71,3 +71,9 @@ void migrate_page_copy(struct page *newpage, struct page *page) } EXPORT_SYMBOL(migrate_page_copy); #endif + +bool set_page_writeback(struct page *page) +{ + return folio_start_writeback(page_folio(page)); +} +EXPORT_SYMBOL(set_page_writeback); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 9ff9a33bced1..82938b037103 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2811,21 +2811,23 @@ bool __folio_end_writeback(struct folio *folio) return ret; } -int __test_set_page_writeback(struct page *page, bool keep_write) +bool __folio_start_writeback(struct folio *folio, bool keep_write) { - struct address_space *mapping = page_mapping(page); - int ret, access_ret; + long nr = folio_nr_pages(folio); + struct address_space *mapping = folio_mapping(folio); + bool ret; + int access_ret; - lock_page_memcg(page); + folio_memcg_lock(folio); if (mapping && mapping_use_writeback_tags(mapping)) { - XA_STATE(xas, &mapping->i_pages, page_index(page)); + XA_STATE(xas, &mapping->i_pages, folio_index(folio)); struct inode *inode = mapping->host; struct backing_dev_info *bdi = inode_to_bdi(inode); unsigned long flags; xas_lock_irqsave(&xas, flags); xas_load(&xas); - ret = TestSetPageWriteback(page); + ret = folio_test_set_writeback(folio); if (!ret) { bool on_wblist; @@ -2836,43 +2838,42 @@ int __test_set_page_writeback(struct page *page, bool keep_write) if (bdi->capabilities & BDI_CAP_WRITEBACK_ACCT) { struct bdi_writeback *wb = inode_to_wb(inode); - inc_wb_stat(wb, WB_WRITEBACK); + wb_stat_mod(wb, WB_WRITEBACK, nr); if (!on_wblist) wb_inode_writeback_start(wb); } /* - * We can come through here when swapping anonymous - * pages, so we don't necessarily have an inode to track - * for sync. + * We can come through here when swapping + * anonymous folios, so we don't necessarily + * have an inode to track for sync. */ if (mapping->host && !on_wblist) sb_mark_inode_writeback(mapping->host); } - if (!PageDirty(page)) + if (!folio_test_dirty(folio)) xas_clear_mark(&xas, PAGECACHE_TAG_DIRTY); if (!keep_write) xas_clear_mark(&xas, PAGECACHE_TAG_TOWRITE); xas_unlock_irqrestore(&xas, flags); } else { - ret = TestSetPageWriteback(page); + ret = folio_test_set_writeback(folio); } if (!ret) { - inc_lruvec_page_state(page, NR_WRITEBACK); - inc_zone_page_state(page, NR_ZONE_WRITE_PENDING); + lruvec_stat_mod_folio(folio, NR_WRITEBACK, nr); + zone_stat_mod_folio(folio, NR_ZONE_WRITE_PENDING, nr); } - unlock_page_memcg(page); - access_ret = arch_make_page_accessible(page); + folio_memcg_unlock(folio); + access_ret = arch_make_folio_accessible(folio); /* * If writeback has been triggered on a page that cannot be made * accessible, it is too late to recover here. */ - VM_BUG_ON_PAGE(access_ret != 0, page); + VM_BUG_ON_FOLIO(access_ret != 0, folio); return ret; - } -EXPORT_SYMBOL(__test_set_page_writeback); +EXPORT_SYMBOL(__folio_start_writeback); /** * folio_wait_writeback - Wait for a folio to finish writeback.