From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753827Ab2KVSeO (ORCPT ); Thu, 22 Nov 2012 13:34:14 -0500 Received: from mail.kernel.org ([198.145.19.201]:49007 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753752Ab2KVSd7 (ORCPT ); Thu, 22 Nov 2012 13:33:59 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , alan@lxorguk.ukuu.org.uk, Sage Weil Subject: [ 152/171] libceph: replace connection state bits with states Date: Wed, 21 Nov 2012 16:41:38 -0800 Message-Id: <20121122004048.602261914@linuxfoundation.org> X-Mailer: git-send-email 1.8.0.197.g5a90748 In-Reply-To: <20121122004033.298367941@linuxfoundation.org> References: <20121122004033.298367941@linuxfoundation.org> User-Agent: quilt/0.60-2.1.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sage Weil (cherry picked from commit 8dacc7da69a491c515851e68de6036f21b5663ce) Use a simple set of 6 enumerated values for the socket states (CON_STATE_*) and use those instead of the state bits. All of the con->state checks are now under the protection of the con mutex, so this is safe. It also simplifies many of the state checks because we can check for anything other than the expected state instead of various bits for races we can think of. This appears to hold up well to stress testing both with and without socket failure injection on the server side. Signed-off-by: Sage Weil Signed-off-by: Greg Kroah-Hartman --- include/linux/ceph/messenger.h | 12 --- net/ceph/messenger.c | 130 +++++++++++++++++++++-------------------- 2 files changed, 68 insertions(+), 74 deletions(-) --- a/include/linux/ceph/messenger.h +++ b/include/linux/ceph/messenger.h @@ -117,18 +117,6 @@ struct ceph_msg_pos { #define BACKOFF 15 /* - * ceph_connection states - */ -#define CONNECTING 1 -#define NEGOTIATING 2 -#define CONNECTED 5 -#define STANDBY 8 /* no outgoing messages, socket closed. we keep - * the ceph_connection around to maintain shared - * state with the peer. */ -#define CLOSED 10 /* we've closed the connection */ -#define OPENING 13 /* open connection w/ (possibly new) peer */ - -/* * A single connection with another host. * * We maintain a queue of outgoing messages, and some session state to --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -77,6 +77,17 @@ #define CON_SOCK_STATE_CONNECTED 3 /* -> CLOSING or -> CLOSED */ #define CON_SOCK_STATE_CLOSING 4 /* -> CLOSED */ +/* + * connection states + */ +#define CON_STATE_CLOSED 1 /* -> PREOPEN */ +#define CON_STATE_PREOPEN 2 /* -> CONNECTING, CLOSED */ +#define CON_STATE_CONNECTING 3 /* -> NEGOTIATING, CLOSED */ +#define CON_STATE_NEGOTIATING 4 /* -> OPEN, CLOSED */ +#define CON_STATE_OPEN 5 /* -> STANDBY, CLOSED */ +#define CON_STATE_STANDBY 6 /* -> PREOPEN, CLOSED */ + + /* static tag bytes (protocol control messages) */ static char tag_msg = CEPH_MSGR_TAG_MSG; static char tag_ack = CEPH_MSGR_TAG_ACK; @@ -503,11 +514,7 @@ void ceph_con_close(struct ceph_connecti mutex_lock(&con->mutex); dout("con_close %p peer %s\n", con, ceph_pr_addr(&con->peer_addr.in_addr)); - clear_bit(NEGOTIATING, &con->state); - clear_bit(CONNECTING, &con->state); - clear_bit(CONNECTED, &con->state); - clear_bit(STANDBY, &con->state); /* avoid connect_seq bump */ - set_bit(CLOSED, &con->state); + con->state = CON_STATE_CLOSED; clear_bit(LOSSYTX, &con->flags); /* so we retry next connect */ clear_bit(KEEPALIVE_PENDING, &con->flags); @@ -530,8 +537,9 @@ void ceph_con_open(struct ceph_connectio { mutex_lock(&con->mutex); dout("con_open %p %s\n", con, ceph_pr_addr(&addr->in_addr)); - set_bit(OPENING, &con->state); - WARN_ON(!test_and_clear_bit(CLOSED, &con->state)); + + BUG_ON(con->state != CON_STATE_CLOSED); + con->state = CON_STATE_PREOPEN; con->peer_name.type = (__u8) entity_type; con->peer_name.num = cpu_to_le64(entity_num); @@ -571,7 +579,7 @@ void ceph_con_init(struct ceph_connectio INIT_LIST_HEAD(&con->out_sent); INIT_DELAYED_WORK(&con->work, con_work); - set_bit(CLOSED, &con->state); + con->state = CON_STATE_CLOSED; } EXPORT_SYMBOL(ceph_con_init); @@ -809,27 +817,21 @@ static struct ceph_auth_handshake *get_c if (!con->ops->get_authorizer) { con->out_connect.authorizer_protocol = CEPH_AUTH_UNKNOWN; con->out_connect.authorizer_len = 0; - return NULL; } /* Can't hold the mutex while getting authorizer */ - mutex_unlock(&con->mutex); - auth = con->ops->get_authorizer(con, auth_proto, con->auth_retry); - mutex_lock(&con->mutex); if (IS_ERR(auth)) return auth; - if (test_bit(CLOSED, &con->state) || test_bit(OPENING, &con->flags)) + if (con->state != CON_STATE_NEGOTIATING) return ERR_PTR(-EAGAIN); con->auth_reply_buf = auth->authorizer_reply_buf; con->auth_reply_buf_len = auth->authorizer_reply_buf_len; - - return auth; } @@ -1484,7 +1486,8 @@ static int process_banner(struct ceph_co static void fail_protocol(struct ceph_connection *con) { reset_connection(con); - set_bit(CLOSED, &con->state); /* in case there's queued work */ + BUG_ON(con->state != CON_STATE_NEGOTIATING); + con->state = CON_STATE_CLOSED; } static int process_connect(struct ceph_connection *con) @@ -1558,8 +1561,7 @@ static int process_connect(struct ceph_c if (con->ops->peer_reset) con->ops->peer_reset(con); mutex_lock(&con->mutex); - if (test_bit(CLOSED, &con->state) || - test_bit(OPENING, &con->state)) + if (con->state != CON_STATE_NEGOTIATING) return -EAGAIN; break; @@ -1605,8 +1607,10 @@ static int process_connect(struct ceph_c fail_protocol(con); return -1; } - clear_bit(NEGOTIATING, &con->state); - set_bit(CONNECTED, &con->state); + + BUG_ON(con->state != CON_STATE_NEGOTIATING); + con->state = CON_STATE_OPEN; + con->peer_global_seq = le32_to_cpu(con->in_reply.global_seq); con->connect_seq++; con->peer_features = server_feat; @@ -1994,8 +1998,9 @@ more: dout("try_write out_kvec_bytes %d\n", con->out_kvec_bytes); /* open the socket first? */ - if (con->sock == NULL) { - set_bit(CONNECTING, &con->state); + if (con->state == CON_STATE_PREOPEN) { + BUG_ON(con->sock); + con->state = CON_STATE_CONNECTING; con_out_kvec_reset(con); prepare_write_banner(con); @@ -2046,8 +2051,7 @@ more_kvec: } do_next: - if (!test_bit(CONNECTING, &con->state) && - !test_bit(NEGOTIATING, &con->state)) { + if (con->state == CON_STATE_OPEN) { /* is anything else pending? */ if (!list_empty(&con->out_queue)) { prepare_write_message(con); @@ -2081,29 +2085,19 @@ static int try_read(struct ceph_connecti { int ret = -1; - if (!con->sock) - return 0; - - if (test_bit(STANDBY, &con->state)) +more: + dout("try_read start on %p state %lu\n", con, con->state); + if (con->state != CON_STATE_CONNECTING && + con->state != CON_STATE_NEGOTIATING && + con->state != CON_STATE_OPEN) return 0; - dout("try_read start on %p\n", con); + BUG_ON(!con->sock); -more: dout("try_read tag %d in_base_pos %d\n", (int)con->in_tag, con->in_base_pos); - /* - * process_connect and process_message drop and re-take - * con->mutex. make sure we handle a racing close or reopen. - */ - if (test_bit(CLOSED, &con->state) || - test_bit(OPENING, &con->state)) { - ret = -EAGAIN; - goto out; - } - - if (test_bit(CONNECTING, &con->state)) { + if (con->state == CON_STATE_CONNECTING) { dout("try_read connecting\n"); ret = read_partial_banner(con); if (ret <= 0) @@ -2112,8 +2106,8 @@ more: if (ret < 0) goto out; - clear_bit(CONNECTING, &con->state); - set_bit(NEGOTIATING, &con->state); + BUG_ON(con->state != CON_STATE_CONNECTING); + con->state = CON_STATE_NEGOTIATING; /* Banner is good, exchange connection info */ ret = prepare_write_connect(con); @@ -2125,7 +2119,7 @@ more: goto out; } - if (test_bit(NEGOTIATING, &con->state)) { + if (con->state == CON_STATE_NEGOTIATING) { dout("try_read negotiating\n"); ret = read_partial_connect(con); if (ret <= 0) @@ -2136,6 +2130,8 @@ more: goto more; } + BUG_ON(con->state != CON_STATE_OPEN); + if (con->in_base_pos < 0) { /* * skipping + discarding content. @@ -2169,8 +2165,8 @@ more: prepare_read_ack(con); break; case CEPH_MSGR_TAG_CLOSE: - clear_bit(CONNECTED, &con->state); - set_bit(CLOSED, &con->state); /* fixme */ + con_close_socket(con); + con->state = CON_STATE_CLOSED; goto out; default: goto bad_tag; @@ -2246,14 +2242,21 @@ static void con_work(struct work_struct mutex_lock(&con->mutex); restart: if (test_and_clear_bit(SOCK_CLOSED, &con->flags)) { - if (test_and_clear_bit(CONNECTED, &con->state)) - con->error_msg = "socket closed"; - else if (test_and_clear_bit(NEGOTIATING, &con->state)) - con->error_msg = "negotiation failed"; - else if (test_and_clear_bit(CONNECTING, &con->state)) + switch (con->state) { + case CON_STATE_CONNECTING: con->error_msg = "connection failed"; - else + break; + case CON_STATE_NEGOTIATING: + con->error_msg = "negotiation failed"; + break; + case CON_STATE_OPEN: + con->error_msg = "socket closed"; + break; + default: + dout("unrecognized con state %d\n", (int)con->state); con->error_msg = "unrecognized con state"; + BUG(); + } goto fault; } @@ -2271,17 +2274,16 @@ restart: } } - if (test_bit(STANDBY, &con->state)) { + if (con->state == CON_STATE_STANDBY) { dout("con_work %p STANDBY\n", con); goto done; } - if (test_bit(CLOSED, &con->state)) { + if (con->state == CON_STATE_CLOSED) { dout("con_work %p CLOSED\n", con); BUG_ON(con->sock); goto done; } - if (test_and_clear_bit(OPENING, &con->state)) { - /* reopen w/ new peer */ + if (con->state == CON_STATE_PREOPEN) { dout("con_work OPENING\n"); BUG_ON(con->sock); } @@ -2328,13 +2330,15 @@ static void ceph_fault(struct ceph_conne dout("fault %p state %lu to peer %s\n", con, con->state, ceph_pr_addr(&con->peer_addr.in_addr)); - if (test_bit(CLOSED, &con->state)) - goto out_unlock; + BUG_ON(con->state != CON_STATE_CONNECTING && + con->state != CON_STATE_NEGOTIATING && + con->state != CON_STATE_OPEN); con_close_socket(con); if (test_bit(LOSSYTX, &con->flags)) { - dout("fault on LOSSYTX channel\n"); + dout("fault on LOSSYTX channel, marking CLOSED\n"); + con->state = CON_STATE_CLOSED; goto out_unlock; } @@ -2355,9 +2359,10 @@ static void ceph_fault(struct ceph_conne !test_bit(KEEPALIVE_PENDING, &con->flags)) { dout("fault %p setting STANDBY clearing WRITE_PENDING\n", con); clear_bit(WRITE_PENDING, &con->flags); - set_bit(STANDBY, &con->state); + con->state = CON_STATE_STANDBY; } else { /* retry after a delay. */ + con->state = CON_STATE_PREOPEN; if (con->delay == 0) con->delay = BASE_DELAY_INTERVAL; else if (con->delay < MAX_DELAY_INTERVAL) @@ -2431,8 +2436,9 @@ EXPORT_SYMBOL(ceph_messenger_init); static void clear_standby(struct ceph_connection *con) { /* come back from STANDBY? */ - if (test_and_clear_bit(STANDBY, &con->state)) { + if (con->state == CON_STATE_STANDBY) { dout("clear_standby %p and ++connect_seq\n", con); + con->state = CON_STATE_PREOPEN; con->connect_seq++; WARN_ON(test_bit(WRITE_PENDING, &con->flags)); WARN_ON(test_bit(KEEPALIVE_PENDING, &con->flags)); @@ -2451,7 +2457,7 @@ void ceph_con_send(struct ceph_connectio mutex_lock(&con->mutex); - if (test_bit(CLOSED, &con->state)) { + if (con->state == CON_STATE_CLOSED) { dout("con_send %p closed, dropping %p\n", con, msg); ceph_msg_put(msg); mutex_unlock(&con->mutex);