ceph: use page_offset() in ceph_writepages_start()
There's one spot in ceph_writepages_start() that open-codes what
page_offset() does safely. Use the macro so we don't have to worry
about wrapping.
This resolves:
http://tracker.ceph.com/issues/4648
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 45745aa..ae438d0 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -900,7 +900,7 @@
}
/* submit the write */
- offset = req->r_data_out.pages[0]->index << PAGE_CACHE_SHIFT;
+ offset = page_offset(req->r_data_out.pages[0]);
len = min((snap_size ? snap_size : i_size_read(inode)) - offset,
(u64)locked_pages << PAGE_CACHE_SHIFT);
dout("writepages got %d pages at %llu~%llu\n",