From 48c935ad88f5be20eb5445a77c171351b1eb5111 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 15 Jan 2016 16:51:24 -0800 Subject: page-flags: define PG_locked behavior on compound pages MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit lock_page() must operate on the whole compound page. It doesn't make much sense to lock part of compound page. Change code to use head page's PG_locked, if tail page is passed. This patch also gets rid of custom helper functions -- __set_page_locked() and __clear_page_locked(). They are replaced with helpers generated by __SETPAGEFLAG/__CLEARPAGEFLAG. Tail pages to these helper would trigger VM_BUG_ON(). SLUB uses PG_locked as a bit spin locked. IIUC, tail pages should never appear there. VM_BUG_ON() is added to make sure that this assumption is correct. [akpm@linux-foundation.org: fix fs/cifs/file.c] Signed-off-by: Kirill A. Shutemov Cc: Andrea Arcangeli Cc: Hugh Dickins Cc: Dave Hansen Cc: Mel Gorman Cc: Rik van Riel Cc: Vlastimil Babka Cc: Christoph Lameter Cc: Naoya Horiguchi Cc: Steve Capper Cc: "Aneesh Kumar K.V" Cc: Johannes Weiner Cc: Michal Hocko Cc: Jerome Marchand Cc: Jérôme Glisse Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/cifs/file.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'fs') diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 0068e82217c3..0a2752b79e72 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -3391,13 +3391,13 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list, * should have access to this page, we're safe to simply set * PG_locked without checking it first. */ - __set_page_locked(page); + __SetPageLocked(page); rc = add_to_page_cache_locked(page, mapping, page->index, gfp); /* give up if we can't stick it in the cache */ if (rc) { - __clear_page_locked(page); + __ClearPageLocked(page); return rc; } @@ -3418,9 +3418,9 @@ readpages_get_pages(struct address_space *mapping, struct list_head *page_list, if (*bytes + PAGE_CACHE_SIZE > rsize) break; - __set_page_locked(page); + __SetPageLocked(page); if (add_to_page_cache_locked(page, mapping, page->index, gfp)) { - __clear_page_locked(page); + __ClearPageLocked(page); break; } list_move_tail(&page->lru, tmplist); -- cgit v1.2.3