ceph: using hash value to compose dentry offset
If MDS sorts dentries in dirfrag in hash order, we use hash value to
compose dentry offset. dentry offset is:
(0xff << 52) | ((24 bits hash) << 28) |
(the nth entry hash hash collision)
This offset is stable across directory fragmentation. This alos means
there is no need to reset readdir offset if directory get fragmented
in the middle of readdir.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 48def22..7ad3128 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -185,6 +185,7 @@
u16 flags = ceph_decode_16(p);
info->dir_end = !!(flags & CEPH_READDIR_FRAG_END);
info->dir_complete = !!(flags & CEPH_READDIR_FRAG_COMPLETE);
+ info->hash_order = !!(flags & CEPH_READDIR_HASH_ORDER);
}
if (num == 0)
goto done;