diff options
| -rw-r--r-- | fs/dlm/lowcomms.c | 75 |
1 files changed, 52 insertions, 23 deletions
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index 15810701b13e..7c7a31377f27 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -113,6 +113,7 @@ struct writequeue_entry { int len; int end; int users; + int idx; /* get()/commit() idx exchange */ struct connection *con; }; @@ -163,21 +164,14 @@ static inline int nodeid_hash(int nodeid) return nodeid & (CONN_HASH_SIZE-1); } -static struct connection *__find_con(int nodeid) +static struct connection *__find_con(int nodeid, int r) { - int r, idx; struct connection *con; - r = nodeid_hash(nodeid); - - idx = srcu_read_lock(&connections_srcu); hlist_for_each_entry_rcu(con, &connection_hash[r], list) { - if (con->nodeid == nodeid) { - srcu_read_unlock(&connections_srcu, idx); + if (con->nodeid == nodeid) return con; - } } - srcu_read_unlock(&connections_srcu, idx); return NULL; } @@ -216,7 +210,8 @@ static struct connection *nodeid2con(int nodeid, gfp_t alloc) struct connection *con, *tmp; int r, ret; - con = __find_con(nodeid); + r = nodeid_hash(nodeid); + con = __find_con(nodeid, r); if (con || !alloc) return con; @@ -230,8 +225,6 @@ static struct connection *nodeid2con(int nodeid, gfp_t alloc) return NULL; } - r = nodeid_hash(nodeid); - spin_lock(&connections_lock); /* Because multiple workqueues/threads calls this function it can * race on multiple cpu's. Instead of locking hot path __find_con() @@ -239,7 +232,7 @@ static struct connection *nodeid2con(int nodeid, gfp_t alloc) * under protection of connections_lock. If this is the case we * abort our connection creation and return the existing connection. */ - tmp = __find_con(nodeid); + tmp = __find_con(nodeid, r); if (tmp) { spin_unlock(&connections_lock); kfree(con->rx_buf); @@ -256,15 +249,13 @@ static struct connection *nodeid2con(int nodeid, gfp_t alloc) /* Loop round all connections */ static void foreach_conn(void (*conn_func)(struct connection *c)) { - int i, idx; + int i; struct connection *con; - idx = srcu_read_lock(&connections_srcu); for (i = 0; i < CONN_HASH_SIZE; i++) { hlist_for_each_entry_rcu(con, &connection_hash[i], list) conn_func(con); } - srcu_read_unlock(&connections_srcu, idx); } static struct dlm_node_addr *find_node_addr(int nodeid) @@ -518,14 +509,21 @@ static void lowcomms_state_change(struct sock *sk) int dlm_lowcomms_connect_node(int nodeid) { struct connection *con; + int idx; if (nodeid == dlm_our_nodeid()) return 0; + idx = srcu_read_lock(&connections_srcu); con = nodeid2con(nodeid, GFP_NOFS); - if (!con) + if (!con) { + srcu_read_unlock(&connections_srcu, idx); return -ENOMEM; + } + lowcomms_connect_sock(con); + srcu_read_unlock(&connections_srcu, idx); + return 0; } @@ -864,7 +862,7 @@ static int accept_from_sock(struct listen_connection *con) int result; struct sockaddr_storage peeraddr; struct socket *newsock; - int len; + int len, idx; int nodeid; struct connection *newcon; struct connection *addcon; @@ -907,8 +905,10 @@ static int accept_from_sock(struct listen_connection *con) * the same time and the connections cross on the wire. * In this case we store the incoming one in "othercon" */ + idx = srcu_read_lock(&connections_srcu); newcon = nodeid2con(nodeid, GFP_NOFS); if (!newcon) { + srcu_read_unlock(&connections_srcu, idx); result = -ENOMEM; goto accept_err; } @@ -924,6 +924,7 @@ static int accept_from_sock(struct listen_connection *con) if (!othercon) { log_print("failed to allocate incoming socket"); mutex_unlock(&newcon->sock_mutex); + srcu_read_unlock(&connections_srcu, idx); result = -ENOMEM; goto accept_err; } @@ -932,6 +933,7 @@ static int accept_from_sock(struct listen_connection *con) if (result < 0) { kfree(othercon); mutex_unlock(&newcon->sock_mutex); + srcu_read_unlock(&connections_srcu, idx); goto accept_err; } @@ -966,6 +968,8 @@ static int accept_from_sock(struct listen_connection *con) if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) queue_work(recv_workqueue, &addcon->rwork); + srcu_read_unlock(&connections_srcu, idx); + return 0; accept_err: @@ -1403,7 +1407,9 @@ static struct writequeue_entry *new_wq_entry(struct connection *con, int len, void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) { + struct writequeue_entry *e; struct connection *con; + int idx; if (len > DEFAULT_BUFFER_SIZE || len < sizeof(struct dlm_header)) { @@ -1413,11 +1419,23 @@ void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc) return NULL; } + idx = srcu_read_lock(&connections_srcu); con = nodeid2con(nodeid, allocation); - if (!con) + if (!con) { + srcu_read_unlock(&connections_srcu, idx); return NULL; + } + + e = new_wq_entry(con, len, allocation, ppc); + if (!e) { + srcu_read_unlock(&connections_srcu, idx); + return NULL; + } + + /* we assume if successful commit must called */ + e->idx = idx; - return new_wq_entry(con, len, allocation, ppc); + return e; } void dlm_lowcomms_commit_buffer(void *mh) @@ -1435,10 +1453,12 @@ void dlm_lowcomms_commit_buffer(void *mh) spin_unlock(&con->writequeue_lock); queue_work(send_workqueue, &con->swork); + srcu_read_unlock(&connections_srcu, e->idx); return; out: spin_unlock(&con->writequeue_lock); + srcu_read_unlock(&connections_srcu, e->idx); return; } @@ -1532,8 +1552,10 @@ int dlm_lowcomms_close(int nodeid) { struct connection *con; struct dlm_node_addr *na; + int idx; log_print("closing connection to node %d", nodeid); + idx = srcu_read_lock(&connections_srcu); con = nodeid2con(nodeid, 0); if (con) { set_bit(CF_CLOSE, &con->flags); @@ -1542,6 +1564,7 @@ int dlm_lowcomms_close(int nodeid) if (con->othercon) clean_one_writequeue(con->othercon); } + srcu_read_unlock(&connections_srcu, idx); spin_lock(&dlm_node_addrs_spin); na = find_node_addr(nodeid); @@ -1621,6 +1644,8 @@ static void shutdown_conn(struct connection *con) void dlm_lowcomms_shutdown(void) { + int idx; + /* Set all the flags to prevent any * socket activity. */ @@ -1633,7 +1658,9 @@ void dlm_lowcomms_shutdown(void) dlm_close_sock(&listen_con.sock); + idx = srcu_read_lock(&connections_srcu); foreach_conn(shutdown_conn); + srcu_read_unlock(&connections_srcu, idx); } static void _stop_conn(struct connection *con, bool and_other) @@ -1682,7 +1709,7 @@ static void free_conn(struct connection *con) static void work_flush(void) { - int ok, idx; + int ok; int i; struct connection *con; @@ -1693,7 +1720,6 @@ static void work_flush(void) flush_workqueue(recv_workqueue); if (send_workqueue) flush_workqueue(send_workqueue); - idx = srcu_read_lock(&connections_srcu); for (i = 0; i < CONN_HASH_SIZE && ok; i++) { hlist_for_each_entry_rcu(con, &connection_hash[i], list) { @@ -1707,14 +1733,17 @@ static void work_flush(void) } } } - srcu_read_unlock(&connections_srcu, idx); } while (!ok); } void dlm_lowcomms_stop(void) { + int idx; + + idx = srcu_read_lock(&connections_srcu); work_flush(); foreach_conn(free_conn); + srcu_read_unlock(&connections_srcu, idx); work_stop(); deinit_local(); } |