ceph: fix file offset wrapping at 4GB on 32-bit archs

Cast the value before shifting so that we don't run out of bits with a
32-bit unsigned long.  This fixes wrapping of high file offsets into the
low 4GB of a file on disk, and the subsequent data corruption for large
files.

Signed-off-by: Sage Weil <sage@newdream.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 4cfce1ee31fa..50461b8c23a4 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -766,7 +766,8 @@ get_more_pages:
                         /* ok */
                         if (locked_pages == 0) {
                                 /* prepare async write request */
-                                offset = page->index << PAGE_CACHE_SHIFT;
+                                offset = (unsigned long long)page->index
+                                        << PAGE_CACHE_SHIFT;
                                 len = wsize;
                                 req = ceph_osdc_new_request(&client->osdc,
                                             &ci->i_layout,