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 <liwang@ubuntukylin.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 3e68ac1..5da06f0 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -213,9 +213,13 @@
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);