[PATCH 7.1 076/228] ceph: fix MDS random selection readiness predicate

7.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Yiming Zhu <[email protected]>

commit 2c11c4bfdb7bd2808b3b3ac228e1f2d9bcf25457 upstream.

CEPH_MDS_IS_READY() is parsed so that the ternary expression can
return true for an MDS entry with state 0 when it is not laggy. This
allows the random selector to choose a down/DNE rank.

Group the ternary expression under the state check so zero-state ranks
are not treated as ready.

Cc: [email protected]
Fixes: b38c9eb4757d ("ceph: add possible_max_rank and make the code more readable")
Link: https://tracker.ceph.com/issues/78648
Signed-off-by: Yiming Zhu <[email protected]>
Reviewed-by: Viacheslav Dubeyko <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 fs/ceph/mdsmap.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/ceph/mdsmap.c
+++ b/fs/ceph/mdsmap.c
@@ -15,7 +15,7 @@
 #include "super.h"
 
 #define CEPH_MDS_IS_READY(i, ignore_laggy) \
-	(m->m_info[i].state > 0 && ignore_laggy ? true : !m->m_info[i].laggy)
+	(m->m_info[i].state > 0 && (ignore_laggy ? true : !m->m_info[i].laggy))
 
 static int __mdsmap_get_random_mds(struct ceph_mdsmap *m, bool ignore_laggy)
 {