From 266cf658efcf6ac33541a46740f74f50c79d2b6b Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 3 Apr 2009 16:42:36 +0100 Subject: FS-Cache: Recruit a page flags for cache management Recruit a page flag to aid in cache management. The following extra flag is defined: (1) PG_fscache (PG_private_2) The marked page is backed by a local cache and is pinning resources in the cache driver. If PG_fscache is set, then things that checked for PG_private will now also check for that. This includes things like truncation and page invalidation. The function page_has_private() had been added to make the checks for both PG_private and PG_private_2 at the same time. Signed-off-by: David Howells Acked-by: Steve Dickson Acked-by: Trond Myklebust Acked-by: Rik van Riel Acked-by: Al Viro Tested-by: Daire Byrne --- mm/migrate.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'mm/migrate.c') diff --git a/mm/migrate.c b/mm/migrate.c index a9eff3f092f..068655d8f88 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -250,7 +250,7 @@ out: * The number of remaining references must be: * 1 for anonymous pages without a mapping * 2 for pages with a mapping - * 3 for pages with a mapping and PagePrivate set. + * 3 for pages with a mapping and PagePrivate/PagePrivate2 set. */ static int migrate_page_move_mapping(struct address_space *mapping, struct page *newpage, struct page *page) @@ -270,7 +270,7 @@ static int migrate_page_move_mapping(struct address_space *mapping, pslot = radix_tree_lookup_slot(&mapping->page_tree, page_index(page)); - expected_count = 2 + !!PagePrivate(page); + expected_count = 2 + !!page_has_private(page); if (page_count(page) != expected_count || (struct page *)radix_tree_deref_slot(pslot) != page) { spin_unlock_irq(&mapping->tree_lock); @@ -386,7 +386,7 @@ EXPORT_SYMBOL(fail_migrate_page); /* * Common logic to directly migrate a single page suitable for - * pages that do not use PagePrivate. + * pages that do not use PagePrivate/PagePrivate2. * * Pages are locked upon entry and exit. */ @@ -522,7 +522,7 @@ static int fallback_migrate_page(struct address_space *mapping, * Buffers may be managed in a filesystem specific way. * We must have no buffers or drop them. */ - if (PagePrivate(page) && + if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return -EAGAIN; @@ -655,7 +655,7 @@ static int unmap_and_move(new_page_t get_new_page, unsigned long private, * free the metadata, so the page can be freed. */ if (!page->mapping) { - if (!PageAnon(page) && PagePrivate(page)) { + if (!PageAnon(page) && page_has_private(page)) { /* * Go direct to try_to_free_buffers() here because * a) that's what try_to_release_page() would do anyway -- cgit v1.2.3-18-g5258