From 36bbba06712195d38c027655bc4b9c0c2ac2b006 Mon Sep 17 00:00:00 2001 From: Li Wang Date: Wed, 13 Nov 2013 15:22:14 +0800 Subject: [PATCH] ceph: Avoid data inconsistency due to d-cache aliasing in readpage() commit 56f91aad69444d650237295f68c195b74d888d95 upstream. If the length of data to be read in readpage() is exactly PAGE_CACHE_SIZE, the original code does not flush d-cache for data consistency after finishing reading. This patches fixes this. Signed-off-by: Li Wang Signed-off-by: Sage Weil Signed-off-by: Greg Kroah-Hartman --- fs/ceph/addr.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 1e561c0..ec3ba43 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -210,9 +210,13 @@ static int readpage_nounlock(struct file *filp, struct page *page) if (err < 0) { SetPageError(page); goto out; - } else if (err < PAGE_CACHE_SIZE) { + } else { + if (err < PAGE_CACHE_SIZE) { /* zero fill remainder of page */ - zero_user_segment(page, err, PAGE_CACHE_SIZE); + zero_user_segment(page, err, PAGE_CACHE_SIZE); + } else { + flush_dcache_page(page); + } } SetPageUptodate(page); -- 2.7.4