From f1f1c1ccf7848a6e25db30ee9216e1a1e7eb6bef Mon Sep 17 00:00:00 2001 From: Patrick Caulfield Date: Wed, 24 Jan 2007 11:17:59 +0000 Subject: [PATCH] [DLM] Make sock_sem into a mutex Now that there can be multiple dlm_recv threads running we need to prevent two recvs running for the same connection - it's unlikely but it can happen and it causes message corruption. Signed-Off-By: Patrick Caulfield Signed-off-by: Steven Whitehouse --- fs/dlm/lowcomms-tcp.c | 44 +++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) diff --git a/fs/dlm/lowcomms-tcp.c b/fs/dlm/lowcomms-tcp.c index 8e6a76cf180..18ade44287e 100644 --- a/fs/dlm/lowcomms-tcp.c +++ b/fs/dlm/lowcomms-tcp.c @@ -96,7 +96,7 @@ static bool cbuf_empty(struct cbuf *cb) struct connection { struct socket *sock; /* NULL if not connected */ uint32_t nodeid; /* So we know who we are in the list */ - struct rw_semaphore sock_sem; /* Stop connect races */ + struct mutex sock_mutex; unsigned long flags; /* bit 1,2 = We are on the read/write lists */ #define CF_READ_PENDING 1 #define CF_WRITE_PENDING 2 @@ -171,7 +171,7 @@ static struct connection *nodeid2con(int nodeid, gfp_t allocation) goto finish; con->nodeid = nodeid; - init_rwsem(&con->sock_sem); + mutex_init(&con->sock_mutex); INIT_LIST_HEAD(&con->writequeue); spin_lock_init(&con->writequeue_lock); INIT_WORK(&con->swork, process_send_sockets); @@ -247,7 +247,7 @@ static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, /* Close a remote connection and tidy up */ static void close_connection(struct connection *con, bool and_other) { - down_write(&con->sock_sem); + mutex_lock(&con->sock_mutex); if (con->sock) { sock_release(con->sock); @@ -262,7 +262,7 @@ static void close_connection(struct connection *con, bool and_other) con->rx_page = NULL; } con->retries = 0; - up_write(&con->sock_sem); + mutex_unlock(&con->sock_mutex); } /* Data received from remote end */ @@ -276,7 +276,7 @@ static int receive_from_sock(struct connection *con) int r; int call_again_soon = 0; - down_read(&con->sock_sem); + mutex_lock(&con->sock_mutex); if (con->sock == NULL) goto out; @@ -355,17 +355,17 @@ static int receive_from_sock(struct connection *con) out: if (call_again_soon) goto out_resched; - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); return 0; out_resched: if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) queue_work(recv_workqueue, &con->rwork); - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); return -EAGAIN; out_close: - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) { close_connection(con, false); /* Reconnect when there is something to send */ @@ -391,7 +391,7 @@ static int accept_from_sock(struct connection *con) if (result < 0) return -ENOMEM; - down_read_nested(&con->sock_sem, 0); + mutex_lock_nested(&con->sock_mutex, 0); result = -ENOTCONN; if (con->sock == NULL) @@ -417,7 +417,7 @@ static int accept_from_sock(struct connection *con) if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) { printk("dlm: connect from non cluster node\n"); sock_release(newsock); - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); return -1; } @@ -434,7 +434,7 @@ static int accept_from_sock(struct connection *con) result = -ENOMEM; goto accept_err; } - down_write_nested(&newcon->sock_sem, 1); + mutex_lock_nested(&newcon->sock_mutex, 1); if (newcon->sock) { struct connection *othercon = newcon->othercon; @@ -442,13 +442,13 @@ static int accept_from_sock(struct connection *con) othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL); if (!othercon) { printk("dlm: failed to allocate incoming socket\n"); - up_write(&newcon->sock_sem); + mutex_unlock(&newcon->sock_mutex); result = -ENOMEM; goto accept_err; } othercon->nodeid = nodeid; othercon->rx_action = receive_from_sock; - init_rwsem(&othercon->sock_sem); + mutex_init(&othercon->sock_mutex); INIT_WORK(&othercon->swork, process_send_sockets); INIT_WORK(&othercon->rwork, process_recv_sockets); set_bit(CF_IS_OTHERCON, &othercon->flags); @@ -466,7 +466,7 @@ static int accept_from_sock(struct connection *con) addcon = newcon; } - up_write(&newcon->sock_sem); + mutex_unlock(&newcon->sock_mutex); /* * Add it to the active queue in case we got data @@ -475,12 +475,12 @@ static int accept_from_sock(struct connection *con) */ if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) queue_work(recv_workqueue, &addcon->rwork); - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); return 0; accept_err: - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); sock_release(newsock); if (result != -EAGAIN) @@ -501,7 +501,7 @@ static void connect_to_sock(struct connection *con) return; } - down_write(&con->sock_sem); + mutex_lock(&con->sock_mutex); if (con->retries++ > MAX_CONNECT_RETRIES) goto out; @@ -553,7 +553,7 @@ out_err: result = 0; } out: - up_write(&con->sock_sem); + mutex_unlock(&con->sock_mutex); return; } @@ -757,7 +757,7 @@ static void send_to_sock(struct connection *con) struct writequeue_entry *e; int len, offset; - down_read(&con->sock_sem); + mutex_lock(&con->sock_mutex); if (con->sock == NULL) goto out_connect; @@ -803,17 +803,17 @@ static void send_to_sock(struct connection *con) } spin_unlock(&con->writequeue_lock); out: - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); return; send_error: - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); close_connection(con, false); lowcomms_connect_sock(con); return; out_connect: - up_read(&con->sock_sem); + mutex_unlock(&con->sock_mutex); connect_to_sock(con); return; } -- 2.41.1