diff options
Diffstat (limited to 'fs/ceph/mds_client.c')
| -rw-r--r-- | fs/ceph/mds_client.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 75506ac30307..b5139382cf9b 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -2651,7 +2651,28 @@ static int __prepare_send_request(struct ceph_mds_session *session, struct ceph_mds_client *mdsc = session->s_mdsc; struct ceph_mds_request_head_old *rhead; struct ceph_msg *msg; - int flags = 0; + int flags = 0, max_retry; + + /* + * The type of 'r_attempts' in kernel 'ceph_mds_request' + * is 'int', while in 'ceph_mds_request_head' the type of + * 'num_retry' is '__u8'. So in case the request retries + * exceeding 256 times, the MDS will receive a incorrect + * retry seq. + * + * In this case it's ususally a bug in MDS and continue + * retrying the request makes no sense. + * + * In future this could be fixed in ceph code, so avoid + * using the hardcode here. + */ + max_retry = sizeof_field(struct ceph_mds_request_head, num_retry); + max_retry = 1 << (max_retry * BITS_PER_BYTE); + if (req->r_attempts >= max_retry) { + pr_warn_ratelimited("%s request tid %llu seq overflow\n", + __func__, req->r_tid); + return -EMULTIHOP; + } req->r_attempts++; if (req->r_inode) { @@ -2663,7 +2684,7 @@ static int __prepare_send_request(struct ceph_mds_session *session, else req->r_sent_on_mseq = -1; } - dout("prepare_send_request %p tid %lld %s (attempt %d)\n", req, + dout("%s %p tid %lld %s (attempt %d)\n", __func__, req, req->r_tid, ceph_mds_op_name(req->r_op), req->r_attempts); if (test_bit(CEPH_MDS_R_GOT_UNSAFE, &req->r_req_flags)) { |