| From 56f91aad69444d650237295f68c195b74d888d95 Mon Sep 17 00:00:00 2001 |
| From: Li Wang <liwang@ubuntukylin.com> |
| Date: Wed, 13 Nov 2013 15:22:14 +0800 |
| Subject: ceph: Avoid data inconsistency due to d-cache aliasing in readpage() |
| |
| From: Li Wang <liwang@ubuntukylin.com> |
| |
| 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 <liwang@ubuntukylin.com> |
| Signed-off-by: Sage Weil <sage@inktank.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/ceph/addr.c | 8 ++++++-- |
| 1 file changed, 6 insertions(+), 2 deletions(-) |
| |
| --- a/fs/ceph/addr.c |
| +++ b/fs/ceph/addr.c |
| @@ -213,9 +213,13 @@ static int readpage_nounlock(struct file |
| 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); |
| |