libceph: new pi->last_force_request_resend

The old (v15) pi->last_force_request_resend has been repurposed to
make pre-RESEND_ON_SPLIT clients that don't check for PG splits but do
obey pi->last_force_request_resend resend on splits.  See ceph.git
commit 189ca7ec6420 ("mon/OSDMonitor: make pre-luminous clients resend
ops on split").
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/osdmap.c

@@ -682,11 +682,48 @@ static int decode_pool(void **p, void *end, struct ceph_pg_pool_info *pi)
 		*p += len;
 	}
 
+	/*
+	 * last_force_op_resend_preluminous, will be overridden if the
+	 * map was encoded with RESEND_ON_SPLIT
+	 */
 	if (ev >= 15)
 		pi->last_force_request_resend = ceph_decode_32(p);
 	else
 		pi->last_force_request_resend = 0;
 
+	if (ev >= 16)
+		*p += 4; /* skip min_read_recency_for_promote */
+
+	if (ev >= 17)
+		*p += 8; /* skip expected_num_objects */
+
+	if (ev >= 19)
+		*p += 4; /* skip cache_target_dirty_high_ratio_micro */
+
+	if (ev >= 20)
+		*p += 4; /* skip min_write_recency_for_promote */
+
+	if (ev >= 21)
+		*p += 1; /* skip use_gmt_hitset */
+
+	if (ev >= 22)
+		*p += 1; /* skip fast_read */
+
+	if (ev >= 23) {
+		*p += 4; /* skip hit_set_grade_decay_rate */
+		*p += 4; /* skip hit_set_search_last_n */
+	}
+
+	if (ev >= 24) {
+		/* skip opts */
+		*p += 1 + 1; /* versions */
+		len = ceph_decode_32(p);
+		*p += len;
+	}
+
+	if (ev >= 25)
+		pi->last_force_request_resend = ceph_decode_32(p);
+
 	/* ignore the rest */
 
 	*p = pool_end;