From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Horman Subject: Re: [PATCH net-next 4/5] tipc: Rework data structures that track neighboring nodes and links Date: Wed, 13 Oct 2010 12:24:58 -0400 Message-ID: <20101013162458.GE31379@hmsreliant.think-freely.org> References: <1286929558-2954-1-git-send-email-paul.gortmaker@windriver.com> <1286929558-2954-4-git-send-email-paul.gortmaker@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, netdev@vger.kernel.org, allan.stephens@windriver.com To: Paul Gortmaker Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:54857 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751876Ab0JMQZS (ORCPT ); Wed, 13 Oct 2010 12:25:18 -0400 Content-Disposition: inline In-Reply-To: <1286929558-2954-4-git-send-email-paul.gortmaker@windriver.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, Oct 12, 2010 at 08:25:57PM -0400, Paul Gortmaker wrote: > From: Allan Stephens > > Convert existing linked list of neighboring nodes to a standard > doubly-linked list. Add counters that track total number of nodes > in list and total number of links to these nodes, thereby allowing > configuration message replies to allocate only space based on > the actual number of nodes and links rather than the worst case. > > Signed-off-by: Allan Stephens > Signed-off-by: Paul Gortmaker > --- > net/tipc/bcast.c | 5 ++- > net/tipc/link.c | 3 +- > net/tipc/node.c | 60 ++++++++++++++++++++++++++--------------------------- > net/tipc/node.h | 5 +-- > 4 files changed, 36 insertions(+), 37 deletions(-) > NAK, this is completely broken. You're casting tipc_node structure as struct list_heads. That basically makes the first 64 (or 128 bits on 64 bit arches) act like a list_heads prev and next pointers. So if you use node like a list head, you're corrupting those first 64 or 128 bits. If you modify node->addr, node->lock, etc, you're corrupting your list pointers. What you want is an empty list head pointer defined somewhere to serve as the head of your list, and to use the node_list member that you added to tipc_node to serve as your list member in the use of list_add, list_del and list_for_each_entry calls. Neil > diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c > index ba6dcb2..e006678 100644 > --- a/net/tipc/bcast.c > +++ b/net/tipc/bcast.c > @@ -454,10 +454,11 @@ void tipc_bclink_recv_pkt(struct sk_buff *buf) > tipc_node_unlock(node); > spin_lock_bh(&bc_lock); > bcl->stats.recv_nacks++; > - bcl->owner->next = node; /* remember requestor */ > + /* remember retransmit requester */ > + bcl->owner->node_list.next = > + (struct list_head *)node; > bclink_retransmit_pkt(msg_bcgap_after(msg), > msg_bcgap_to(msg)); > - bcl->owner->next = NULL; > spin_unlock_bh(&bc_lock); > } else { > tipc_bclink_peek_nack(msg_destnode(msg), > diff --git a/net/tipc/link.c b/net/tipc/link.c > index 54bd99d..13bc0b6 100644 > --- a/net/tipc/link.c > +++ b/net/tipc/link.c > @@ -1652,7 +1652,8 @@ static void link_retransmit_failure(struct link *l_ptr, struct sk_buff *buf) > tipc_printf(TIPC_OUTPUT, "Outstanding acks: %lu\n", > (unsigned long) TIPC_SKB_CB(buf)->handle); > > - n_ptr = l_ptr->owner->next; > + /* recover retransmit requester */ > + n_ptr = (struct tipc_node *)l_ptr->owner->node_list.next; > tipc_node_lock(n_ptr); > > tipc_addr_string_fill(addr_string, n_ptr->addr); > diff --git a/net/tipc/node.c b/net/tipc/node.c > index 7c49cd0..944b480 100644 > --- a/net/tipc/node.c > +++ b/net/tipc/node.c > @@ -50,7 +50,9 @@ void node_print(struct print_buf *buf, struct tipc_node *n_ptr, char *str); > static void node_lost_contact(struct tipc_node *n_ptr); > static void node_established_contact(struct tipc_node *n_ptr); > > -struct tipc_node *tipc_nodes = NULL; /* sorted list of nodes within cluster */ > +static LIST_HEAD(nodes_list); /* sorted list of neighboring nodes */ > +static int node_count; /* number of neighboring nodes that exist */ > +static int link_count; /* number of unicast links node currently has */ > > static DEFINE_SPINLOCK(node_create_lock); > > @@ -70,11 +72,11 @@ struct tipc_node *tipc_node_create(u32 addr) > { > struct cluster *c_ptr; > struct tipc_node *n_ptr; > - struct tipc_node **curr_node; > + struct tipc_node *new_n_ptr; > > spin_lock_bh(&node_create_lock); > > - for (n_ptr = tipc_nodes; n_ptr; n_ptr = n_ptr->next) { > + list_for_each_entry(n_ptr, &nodes_list, node_list) { > if (addr < n_ptr->addr) > break; > if (addr == n_ptr->addr) { > @@ -83,8 +85,8 @@ struct tipc_node *tipc_node_create(u32 addr) > } > } > > - n_ptr = kzalloc(sizeof(*n_ptr),GFP_ATOMIC); > - if (!n_ptr) { > + new_n_ptr = kzalloc(sizeof(*new_n_ptr), GFP_ATOMIC); > + if (!new_n_ptr) { > spin_unlock_bh(&node_create_lock); > warn("Node creation failed, no memory\n"); > return NULL; > @@ -96,28 +98,22 @@ struct tipc_node *tipc_node_create(u32 addr) > } > if (!c_ptr) { > spin_unlock_bh(&node_create_lock); > - kfree(n_ptr); > + kfree(new_n_ptr); > return NULL; > } > > - n_ptr->addr = addr; > - spin_lock_init(&n_ptr->lock); > - INIT_LIST_HEAD(&n_ptr->nsub); > - n_ptr->owner = c_ptr; > - tipc_cltr_attach_node(c_ptr, n_ptr); > - n_ptr->last_router = -1; > + new_n_ptr->addr = addr; > + spin_lock_init(&new_n_ptr->lock); > + INIT_LIST_HEAD(&new_n_ptr->nsub); > + new_n_ptr->owner = c_ptr; > + tipc_cltr_attach_node(c_ptr, new_n_ptr); > + new_n_ptr->last_router = -1; > + > + list_add_tail(&new_n_ptr->node_list, &n_ptr->node_list); > + node_count++; > > - /* Insert node into ordered list */ > - for (curr_node = &tipc_nodes; *curr_node; > - curr_node = &(*curr_node)->next) { > - if (addr < (*curr_node)->addr) { > - n_ptr->next = *curr_node; > - break; > - } > - } > - (*curr_node) = n_ptr; > spin_unlock_bh(&node_create_lock); > - return n_ptr; > + return new_n_ptr; > } > > void tipc_node_delete(struct tipc_node *n_ptr) > @@ -136,6 +132,8 @@ void tipc_node_delete(struct tipc_node *n_ptr) > #endif > > dbg("node %x deleted\n", n_ptr->addr); > + node_count--; > + list_del(&n_ptr->node_list); > kfree(n_ptr); > } > > @@ -275,6 +273,7 @@ struct tipc_node *tipc_node_attach_link(struct link *l_ptr) > n_ptr->links[bearer_id] = l_ptr; > tipc_net.zones[tipc_zone(l_ptr->addr)]->links++; > n_ptr->link_cnt++; > + link_count++; > return n_ptr; > } > err("Attempt to establish second link on <%s> to %s\n", > @@ -289,6 +288,7 @@ void tipc_node_detach_link(struct tipc_node *n_ptr, struct link *l_ptr) > n_ptr->links[l_ptr->b_ptr->identity] = NULL; > tipc_net.zones[tipc_zone(l_ptr->addr)]->links--; > n_ptr->link_cnt--; > + link_count--; > } > > /* > @@ -619,7 +619,7 @@ u32 tipc_available_nodes(const u32 domain) > u32 cnt = 0; > > read_lock_bh(&tipc_net_lock); > - for (n_ptr = tipc_nodes; n_ptr; n_ptr = n_ptr->next) { > + list_for_each_entry(n_ptr, &nodes_list, node_list) { > if (!tipc_in_scope(domain, n_ptr->addr)) > continue; > if (tipc_node_is_up(n_ptr)) > @@ -646,15 +646,14 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) > " (network address)"); > > read_lock_bh(&tipc_net_lock); > - if (!tipc_nodes) { > + if (!node_count) { > read_unlock_bh(&tipc_net_lock); > return tipc_cfg_reply_none(); > } > > - /* For now, get space for all other nodes > - (will need to modify this when slave nodes are supported */ > + /* Get space for all neighboring nodes */ > > - payload_size = TLV_SPACE(sizeof(node_info)) * (tipc_max_nodes - 1); > + payload_size = TLV_SPACE(sizeof(node_info)) * node_count; > if (payload_size > 32768u) { > read_unlock_bh(&tipc_net_lock); > return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED > @@ -668,7 +667,7 @@ struct sk_buff *tipc_node_get_nodes(const void *req_tlv_area, int req_tlv_space) > > /* Add TLVs for all nodes in scope */ > > - for (n_ptr = tipc_nodes; n_ptr; n_ptr = n_ptr->next) { > + list_for_each_entry(n_ptr, &nodes_list, node_list) { > if (!tipc_in_scope(domain, n_ptr->addr)) > continue; > node_info.addr = htonl(n_ptr->addr); > @@ -704,8 +703,7 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) > > /* Get space for all unicast links + multicast link */ > > - payload_size = TLV_SPACE(sizeof(link_info)) * > - (tipc_net.zones[tipc_zone(tipc_own_addr)]->links + 1); > + payload_size = TLV_SPACE(sizeof(link_info)) * (link_count + 1); > if (payload_size > 32768u) { > read_unlock_bh(&tipc_net_lock); > return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED > @@ -726,7 +724,7 @@ struct sk_buff *tipc_node_get_links(const void *req_tlv_area, int req_tlv_space) > > /* Add TLVs for any other links in scope */ > > - for (n_ptr = tipc_nodes; n_ptr; n_ptr = n_ptr->next) { > + list_for_each_entry(n_ptr, &nodes_list, node_list) { > u32 i; > > if (!tipc_in_scope(domain, n_ptr->addr)) > diff --git a/net/tipc/node.h b/net/tipc/node.h > index 45f3db3..26715dc 100644 > --- a/net/tipc/node.h > +++ b/net/tipc/node.h > @@ -47,7 +47,7 @@ > * @addr: network address of node > * @lock: spinlock governing access to structure > * @owner: pointer to cluster that node belongs to > - * @next: pointer to next node in sorted list of cluster's nodes > + * @node_list: adjacent entries in sorted list of nodes > * @nsub: list of "node down" subscriptions monitoring node > * @active_links: pointers to active links to node > * @links: pointers to all links to node > @@ -73,7 +73,7 @@ struct tipc_node { > u32 addr; > spinlock_t lock; > struct cluster *owner; > - struct tipc_node *next; > + struct list_head node_list; > struct list_head nsub; > struct link *active_links[2]; > struct link *links[MAX_BEARERS]; > @@ -96,7 +96,6 @@ struct tipc_node { > } bclink; > }; > > -extern struct tipc_node *tipc_nodes; > extern u32 tipc_own_tag; > > struct tipc_node *tipc_node_create(u32 addr); > -- > 1.7.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >