libceph: ignore pool overlay and cache logic on redirects

OSD client should ignore cache/overlay flag if got redirect reply.
Otherwise, the client hangs when the cache tier is in forward mode.

[ idryomov: Redirects are effectively deprecated and no longer
  used or tested.  The original tiering modes based on redirects
  are inherently flawed because redirects can race and reorder,
  potentially resulting in data corruption.  The new proxy and
  readproxy tiering modes should be used instead of forward and
  readforward.  Still marking for stable as obviously correct,
  though. ]

Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/23296
URL: https://tracker.ceph.com/issues/36406
Signed-off-by: Jerry Lee <leisurelysw24@gmail.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

net/ceph/osd_client.c

@@ -3649,7 +3649,9 @@ static void handle_reply(struct ceph_osd *osd, struct ceph_msg *msg)
 		 * supported.
 		 */
 		req->r_t.target_oloc.pool = m.redirect.oloc.pool;
-		req->r_flags |= CEPH_OSD_FLAG_REDIRECTED;
+		req->r_flags |= CEPH_OSD_FLAG_REDIRECTED |
+				CEPH_OSD_FLAG_IGNORE_OVERLAY |
+				CEPH_OSD_FLAG_IGNORE_CACHE;
 		req->r_tid = 0;
 		__submit_request(req, false);
 		goto out_unlock_osdc;