diff options
| -rw-r--r-- | fs/dlm/Kconfig | 1 | ||||
| -rw-r--r-- | fs/dlm/lowcomms.c | 86 |
2 files changed, 37 insertions, 50 deletions
diff --git a/fs/dlm/Kconfig b/fs/dlm/Kconfig index f82a4952769d..ee92634196a8 100644 --- a/fs/dlm/Kconfig +++ b/fs/dlm/Kconfig @@ -4,6 +4,7 @@ menuconfig DLM depends on INET depends on SYSFS && CONFIGFS_FS && (IPV6 || IPV6=n) select IP_SCTP + select SRCU help A general purpose distributed lock manager for kernel or userspace applications. diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c index ed098870ba0d..9db7126de793 100644 --- a/fs/dlm/lowcomms.c +++ b/fs/dlm/lowcomms.c @@ -126,6 +126,7 @@ struct connection { struct work_struct rwork; /* Receive workqueue */ struct work_struct swork; /* Send workqueue */ wait_queue_head_t shutdown_wait; /* wait for graceful shutdown */ + struct rcu_head rcu; }; #define sock2con(x) ((struct connection *)(x)->sk_user_data) @@ -167,8 +168,8 @@ static struct workqueue_struct *recv_workqueue; static struct workqueue_struct *send_workqueue; static struct hlist_head connection_hash[CONN_HASH_SIZE]; -static DEFINE_MUTEX(connections_lock); -static struct kmem_cache *con_cache; +static DEFINE_SPINLOCK(connections_lock); +DEFINE_STATIC_SRCU(connections_srcu); static void process_recv_sockets(struct work_struct *work); static void process_send_sockets(struct work_struct *work); @@ -184,15 +185,20 @@ static inline int nodeid_hash(int nodeid) static struct connection *__find_con(int nodeid) { - int r; + int r, idx; struct connection *con; r = nodeid_hash(nodeid); - hlist_for_each_entry(con, &connection_hash[r], list) { - if (con->nodeid == 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); return con; + } } + srcu_read_unlock(&connections_srcu, idx); + return NULL; } @@ -200,7 +206,7 @@ static struct connection *__find_con(int nodeid) * If 'allocation' is zero then we don't attempt to create a new * connection structure for this node. */ -static struct connection *__nodeid2con(int nodeid, gfp_t alloc) +static struct connection *nodeid2con(int nodeid, gfp_t alloc) { struct connection *con = NULL; int r; @@ -209,13 +215,10 @@ static struct connection *__nodeid2con(int nodeid, gfp_t alloc) if (con || !alloc) return con; - con = kmem_cache_zalloc(con_cache, alloc); + con = kzalloc(sizeof(*con), alloc); if (!con) return NULL; - r = nodeid_hash(nodeid); - hlist_add_head(&con->list, &connection_hash[r]); - con->nodeid = nodeid; mutex_init(&con->sock_mutex); INIT_LIST_HEAD(&con->writequeue); @@ -233,31 +236,27 @@ static struct connection *__nodeid2con(int nodeid, gfp_t alloc) con->rx_action = zerocon->rx_action; } + r = nodeid_hash(nodeid); + + spin_lock(&connections_lock); + hlist_add_head_rcu(&con->list, &connection_hash[r]); + spin_unlock(&connections_lock); + return con; } /* Loop round all connections */ static void foreach_conn(void (*conn_func)(struct connection *c)) { - int i; - struct hlist_node *n; + int i, idx; struct connection *con; + idx = srcu_read_lock(&connections_srcu); for (i = 0; i < CONN_HASH_SIZE; i++) { - hlist_for_each_entry_safe(con, n, &connection_hash[i], list) + hlist_for_each_entry_rcu(con, &connection_hash[i], list) conn_func(con); } -} - -static struct connection *nodeid2con(int nodeid, gfp_t allocation) -{ - struct connection *con; - - mutex_lock(&connections_lock); - con = __nodeid2con(nodeid, allocation); - mutex_unlock(&connections_lock); - - return con; + srcu_read_unlock(&connections_srcu, idx); } static struct dlm_node_addr *find_node_addr(int nodeid) @@ -792,12 +791,9 @@ static int accept_from_sock(struct connection *con) struct connection *newcon; struct connection *addcon; - mutex_lock(&connections_lock); if (!dlm_allow_conn) { - mutex_unlock(&connections_lock); return -1; } - mutex_unlock(&connections_lock); mutex_lock_nested(&con->sock_mutex, 0); @@ -847,7 +843,7 @@ static int accept_from_sock(struct connection *con) struct connection *othercon = newcon->othercon; if (!othercon) { - othercon = kmem_cache_zalloc(con_cache, GFP_NOFS); + othercon = kzalloc(sizeof(*othercon), GFP_NOFS); if (!othercon) { log_print("failed to allocate incoming socket"); mutex_unlock(&newcon->sock_mutex); @@ -1612,16 +1608,17 @@ static void free_conn(struct connection *con) { close_connection(con, true, true, true); if (con->othercon) - kmem_cache_free(con_cache, con->othercon); - hlist_del(&con->list); - kmem_cache_free(con_cache, con); + kfree_rcu(con->othercon, rcu); + spin_lock(&connections_lock); + hlist_del_rcu(&con->list); + spin_unlock(&connections_lock); + kfree_rcu(con, rcu); } static void work_flush(void) { - int ok; + int ok, idx; int i; - struct hlist_node *n; struct connection *con; do { @@ -1631,9 +1628,10 @@ 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_safe(con, n, - &connection_hash[i], list) { + hlist_for_each_entry_rcu(con, &connection_hash[i], + list) { ok &= test_bit(CF_READ_PENDING, &con->flags); ok &= test_bit(CF_WRITE_PENDING, &con->flags); if (con->othercon) { @@ -1644,6 +1642,7 @@ static void work_flush(void) } } } + srcu_read_unlock(&connections_srcu, idx); } while (!ok); } @@ -1652,9 +1651,7 @@ void dlm_lowcomms_stop(void) /* Set all the flags to prevent any socket activity. */ - mutex_lock(&connections_lock); dlm_allow_conn = 0; - mutex_unlock(&connections_lock); if (recv_workqueue) flush_workqueue(recv_workqueue); @@ -1666,8 +1663,6 @@ void dlm_lowcomms_stop(void) clean_writequeues(); foreach_conn(free_conn); work_stop(); - - kmem_cache_destroy(con_cache); } int dlm_lowcomms_start(void) @@ -1686,16 +1681,9 @@ int dlm_lowcomms_start(void) goto fail; } - error = -ENOMEM; - con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection), - __alignof__(struct connection), 0, - NULL); - if (!con_cache) - goto fail; - error = work_start(); if (error) - goto fail_destroy; + goto fail; dlm_allow_conn = 1; @@ -1714,10 +1702,8 @@ fail_unlisten: con = nodeid2con(0,0); if (con) { close_connection(con, false, true, true); - kmem_cache_free(con_cache, con); + kfree_rcu(con, rcu); } -fail_destroy: - kmem_cache_destroy(con_cache); fail: return error; } |