ceph: include preferred osd in placement seed

Mix the preferred osd (if any) into the placement seed that is fed into
the CRUSH object placement calculation.  This prevents all the placement
pgs from peering with the same osds.

Rev the osd client protocol with this change.

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

1 files changed, 2 insertions, 0 deletions

diff --git a/fs/ceph/osdmap.c b/fs/ceph/osdmap.c
index 6f0aeff4185a..72d75a239ac2 100644
--- a/fs/ceph/osdmap.c
+++ b/fs/ceph/osdmap.c
@@ -791,6 +791,8 @@ int ceph_calc_object_layout(struct ceph_object_layout *ol,
         pgid.pg64 = 0;   /* start with it zeroed out */
         pgid.pg.ps = ceph_full_name_hash(oid, strlen(oid));
         pgid.pg.preferred = preferred;
+        if (preferred >= 0)
+                pgid.pg.ps += preferred;
         pgid.pg.pool = le32_to_cpu(fl->fl_pg_pool);
         if (preferred >= 0)
                 dout("calc_object_layout '%s' pgid %d.%xp%d (%llx)\n", oid,