Author: marek Date: 2010-03-04 11:28:10 +0100 (Thu, 04 Mar 2010) New Revision: 1579

Modified: trunk/batman-adv-kernelland/vis.c trunk/batman-adv-kernelland/vis.h Log: batman-adv: don't have interrupts disabled while sending.

send_vis_packets() would disable interrupts before calling dev_queue_xmit() which resulting in a backtrace in local_bh_enable(). Fix this by using kref on the vis_info object so that we can call send_vis_packets() without holding vis_hash_lock. vis_hash_lock also used to protect recv_list, so we now need a new lock to protect that instead of vis_hash_lock.

Also a few checkpatch cleanups.

Reported-by: Linus Luessing linus.luessing@web.de Signed-off-by: Andrew Lunn andrew@lunn.ch Signed-off-by: Marek Lindner lindner_marek@yahoo.de Signed-off-by: Simon Wunderlich siwu@hrz.tu-chemnitz.de

Modified: trunk/batman-adv-kernelland/vis.c =================================================================== --- trunk/batman-adv-kernelland/vis.c 2010-02-27 05:56:18 UTC (rev 1578) +++ trunk/batman-adv-kernelland/vis.c 2010-03-04 10:28:10 UTC (rev 1579) @@ -30,22 +30,26 @@

struct hashtable_t *vis_hash; DEFINE_SPINLOCK(vis_hash_lock); +static DEFINE_SPINLOCK(recv_list_lock); static struct vis_info *my_vis_info; static struct list_head send_list; /* always locked with vis_hash_lock */

static void start_vis_timer(void);

/* free the info */ -static void free_info(void *data) +static void free_info(struct kref *ref) { - struct vis_info *info = data; + struct vis_info *info = container_of(ref, struct vis_info, refcount); struct recvlist_node *entry, *tmp; + unsigned long flags;

list_del_init(&info->send_list); + spin_lock_irqsave(&recv_list_lock, flags); list_for_each_entry_safe(entry, tmp, &info->recv_list, list) { list_del(&entry->list); kfree(entry); } + spin_unlock_irqrestore(&recv_list_lock, flags); kfree(info); }

@@ -143,36 +147,65 @@ } }

+/* add the info packet to the send list, if it was not + * already linked in. */ +static void send_list_add(struct vis_info *info) +{ + if (list_empty(&info->send_list)) { + kref_get(&info->refcount); + list_add_tail(&info->send_list, &send_list); + } +} + +/* delete the info packet from the send list, if it was + * linked in. */ +static void send_list_del(struct vis_info *info) +{ + if (!list_empty(&info->send_list)) { + list_del_init(&info->send_list); + kref_put(&info->refcount, free_info); + } +} + /* tries to add one entry to the receive list. */ static void recv_list_add(struct list_head *recv_list, char *mac) { struct recvlist_node *entry; + unsigned long flags; + entry = kmalloc(sizeof(struct recvlist_node), GFP_ATOMIC); if (!entry) return;

memcpy(entry->mac, mac, ETH_ALEN); + spin_lock_irqsave(&recv_list_lock, flags); list_add_tail(&entry->list, recv_list); + spin_unlock_irqrestore(&recv_list_lock, flags); }

/* returns 1 if this mac is in the recv_list */ static int recv_list_is_in(struct list_head *recv_list, char *mac) { struct recvlist_node *entry; + unsigned long flags;

+ spin_lock_irqsave(&recv_list_lock, flags); list_for_each_entry(entry, recv_list, list) { - if (memcmp(entry->mac, mac, ETH_ALEN) == 0) + if (memcmp(entry->mac, mac, ETH_ALEN) == 0) { + spin_unlock_irqrestore(&recv_list_lock, flags); return 1; + } } - + spin_unlock_irqrestore(&recv_list_lock, flags); return 0; }

/* try to add the packet to the vis_hash. return NULL if invalid (e.g. too old, - * broken.. ). vis hash must be locked outside. is_new is set when the packet + * broken.. ). vis hash must be locked outside. is_new is set when the packet * is newer than old entries in the hash. */ static struct vis_info *add_packet(struct vis_packet *vis_packet, - int vis_info_len, int *is_new) + int vis_info_len, int *is_new, + int make_broadcast) { struct vis_info *info, *old_info; struct vis_info search_elem; @@ -199,13 +232,15 @@ } /* remove old entry */ hash_remove(vis_hash, old_info); - free_info(old_info); + send_list_del(old_info); + kref_put(&old_info->refcount, free_info); }

info = kmalloc(sizeof(struct vis_info) + vis_info_len, GFP_ATOMIC); if (info == NULL) return NULL;

+ kref_init(&info->refcount); INIT_LIST_HEAD(&info->send_list); INIT_LIST_HEAD(&info->recv_list); info->first_seen = jiffies; @@ -215,16 +250,21 @@ /* initialize and add new packet. */ *is_new = 1;

+ /* Make it a broadcast packet, if required */ + if (make_broadcast) + memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN); + /* repair if entries is longer than packet. */ if (info->packet.entries * sizeof(struct vis_info_entry) > vis_info_len) - info->packet.entries = vis_info_len / sizeof(struct vis_info_entry); + info->packet.entries = vis_info_len / + sizeof(struct vis_info_entry);

recv_list_add(&info->recv_list, info->packet.sender_orig);

/* try to add it */ if (hash_add(vis_hash, info) < 0) { /* did not work (for some reason) */ - free_info(info); + kref_put(&old_info->refcount, free_info); info = NULL; }

@@ -235,22 +275,21 @@ void receive_server_sync_packet(struct vis_packet *vis_packet, int vis_info_len) { struct vis_info *info; - int is_new; + int is_new, make_broadcast; unsigned long flags; int vis_server = atomic_read(&vis_mode);

+ make_broadcast = (vis_server == VIS_TYPE_SERVER_SYNC); + spin_lock_irqsave(&vis_hash_lock, flags); - info = add_packet(vis_packet, vis_info_len, &is_new); + info = add_packet(vis_packet, vis_info_len, &is_new, make_broadcast); if (info == NULL) goto end;

/* only if we are server ourselves and packet is newer than the one in * hash.*/ - if (vis_server == VIS_TYPE_SERVER_SYNC && is_new) { - memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN); - if (list_empty(&info->send_list)) - list_add_tail(&info->send_list, &send_list); - } + if (vis_server == VIS_TYPE_SERVER_SYNC && is_new) + send_list_add(info); end: spin_unlock_irqrestore(&vis_hash_lock, flags); } @@ -263,31 +302,32 @@ int is_new; unsigned long flags; int vis_server = atomic_read(&vis_mode); + int are_target = 0;

/* clients shall not broadcast. */ if (is_bcast(vis_packet->target_orig)) return;

+ /* Are we the target for this VIS packet? */ + if (vis_server == VIS_TYPE_SERVER_SYNC && + is_my_mac(vis_packet->target_orig)) + are_target = 1; + spin_lock_irqsave(&vis_hash_lock, flags); - info = add_packet(vis_packet, vis_info_len, &is_new); + info = add_packet(vis_packet, vis_info_len, &is_new, are_target); if (info == NULL) goto end; /* note that outdated packets will be dropped at this point. */

/* send only if we're the target server or ... */ - if (vis_server == VIS_TYPE_SERVER_SYNC && - is_my_mac(info->packet.target_orig) && - is_new) { + if (are_target && is_new) { info->packet.vis_type = VIS_TYPE_SERVER_SYNC; /* upgrade! */ - memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN); - if (list_empty(&info->send_list)) - list_add_tail(&info->send_list, &send_list); + send_list_add(info);

/* ... we're not the recipient (and thus need to forward). */ } else if (!is_my_mac(info->packet.target_orig)) { - if (list_empty(&info->send_list)) - list_add_tail(&info->send_list, &send_list); + send_list_add(info); } end: spin_unlock_irqrestore(&vis_hash_lock, flags); @@ -362,14 +402,17 @@ while (hash_iterate(orig_hash, &hashit_global)) { orig_node = hashit_global.bucket->data; if (orig_node->router != NULL - && compare_orig(orig_node->router->addr, orig_node->orig) + && compare_orig(orig_node->router->addr, + orig_node->orig) && orig_node->batman_if && (orig_node->batman_if->if_active == IF_ACTIVE) && orig_node->router->tq_avg > 0) {

/* fill one entry into buffer. */ entry = &entry_array[info->packet.entries]; - memcpy(entry->src, orig_node->batman_if->net_dev->dev_addr, ETH_ALEN); + memcpy(entry->src, + orig_node->batman_if->net_dev->dev_addr, + ETH_ALEN); memcpy(entry->dest, orig_node->orig, ETH_ALEN); entry->quality = orig_node->router->tq_avg; info->packet.entries++; @@ -401,6 +444,8 @@ return 0; }

+/* free old vis packets. Must be called with this vis_hash_lock + * held */ static void purge_vis_packets(void) { HASHIT(hashit); @@ -413,7 +458,8 @@ if (time_after(jiffies, info->first_seen + (VIS_TIMEOUT*HZ)/1000)) { hash_remove_bucket(vis_hash, &hashit); - free_info(info); + send_list_del(info); + kref_put(&info->refcount, free_info); } } } @@ -423,6 +469,8 @@ HASHIT(hashit); struct orig_node *orig_node; unsigned long flags; + struct batman_if *batman_if; + uint8_t dstaddr[ETH_ALEN];

spin_lock_irqsave(&orig_hash_lock, flags);

@@ -431,46 +479,57 @@ orig_node = hashit.bucket->data;

/* if it's a vis server and reachable, send it. */ - if (orig_node && - (orig_node->flags & VIS_SERVER) && - orig_node->batman_if && - orig_node->router) { + if ((!orig_node) || (!orig_node->batman_if) || + (!orig_node->router)) + continue; + if (!(orig_node->flags & VIS_SERVER)) + continue; + /* don't send it if we already received the packet from + * this node. */ + if (recv_list_is_in(&info->recv_list, orig_node->orig)) + continue;

- /* don't send it if we already received the packet from - * this node. */ - if (recv_list_is_in(&info->recv_list, orig_node->orig)) - continue; + memcpy(info->packet.target_orig, orig_node->orig, ETH_ALEN); + batman_if = orig_node->batman_if; + memcpy(dstaddr, orig_node->router->addr, ETH_ALEN); + spin_unlock_irqrestore(&orig_hash_lock, flags);

- memcpy(info->packet.target_orig, - orig_node->orig, ETH_ALEN); + send_raw_packet((unsigned char *)&info->packet, + packet_length, batman_if, dstaddr);

- send_raw_packet((unsigned char *) &info->packet, - packet_length, - orig_node->batman_if, - orig_node->router->addr); - } + spin_lock_irqsave(&orig_hash_lock, flags); + } + spin_unlock_irqrestore(&orig_hash_lock, flags); memcpy(info->packet.target_orig, broadcastAddr, ETH_ALEN); - spin_unlock_irqrestore(&orig_hash_lock, flags); }

static void unicast_vis_packet(struct vis_info *info, int packet_length) { struct orig_node *orig_node; unsigned long flags; + struct batman_if *batman_if; + uint8_t dstaddr[ETH_ALEN];

spin_lock_irqsave(&orig_hash_lock, flags); orig_node = ((struct orig_node *) hash_find(orig_hash, info->packet.target_orig));

- if ((orig_node != NULL) && - (orig_node->batman_if != NULL) && - (orig_node->router != NULL)) { - send_raw_packet((unsigned char *) &info->packet, packet_length, - orig_node->batman_if, - orig_node->router->addr); - } + if ((!orig_node) || (!orig_node->batman_if) || (!orig_node->router)) + goto out; + + /* don't lock while sending the packets ... we therefore + * copy the required data before sending */ + batman_if = orig_node->batman_if; + memcpy(dstaddr, orig_node->router->addr, ETH_ALEN); spin_unlock_irqrestore(&orig_hash_lock, flags); + + send_raw_packet((unsigned char *)&info->packet, + packet_length, batman_if, dstaddr); + return; + +out: + spin_unlock_irqrestore(&orig_hash_lock, flags); }

/* only send one vis packet. called from send_vis_packets() */ @@ -503,15 +562,24 @@ unsigned long flags;

spin_lock_irqsave(&vis_hash_lock, flags); + purge_vis_packets();

- if (generate_vis_packet() == 0) + if (generate_vis_packet() == 0) { /* schedule if generation was successful */ - list_add_tail(&my_vis_info->send_list, &send_list); + send_list_add(my_vis_info); + }

list_for_each_entry_safe(info, temp, &send_list, send_list) { - list_del_init(&info->send_list); + + kref_get(&info->refcount); + spin_unlock_irqrestore(&vis_hash_lock, flags); + send_vis_packet(info); + + spin_lock_irqsave(&vis_hash_lock, flags); + send_list_del(info); + kref_put(&info->refcount, free_info); } spin_unlock_irqrestore(&vis_hash_lock, flags); start_vis_timer(); @@ -544,6 +612,7 @@ my_vis_info->first_seen = jiffies - atomic_read(&vis_interval); INIT_LIST_HEAD(&my_vis_info->recv_list); INIT_LIST_HEAD(&my_vis_info->send_list); + kref_init(&my_vis_info->refcount); my_vis_info->packet.version = COMPAT_VERSION; my_vis_info->packet.packet_type = BAT_VIS; my_vis_info->packet.ttl = TTL; @@ -557,9 +626,9 @@

if (hash_add(vis_hash, my_vis_info) < 0) { printk(KERN_ERR - "batman-adv:Can't add own vis packet into hash\n"); - free_info(my_vis_info); /* not in hash, need to remove it - * manually. */ + "batman-adv:Can't add own vis packet into hash\n"); + /* not in hash, need to remove it manually. */ + kref_put(&my_vis_info->refcount, free_info); goto err; }

@@ -573,6 +642,15 @@ return 0; }

+/* Decrease the reference count on a hash item info */ +static void free_info_ref(void *data) +{ + struct vis_info *info = data; + + send_list_del(info); + kref_put(&info->refcount, free_info); +} + /* shutdown vis-server */ void vis_quit(void) { @@ -584,7 +662,7 @@

spin_lock_irqsave(&vis_hash_lock, flags); /* properly remove, kill timers ... */ - hash_delete(vis_hash, free_info); + hash_delete(vis_hash, free_info_ref); vis_hash = NULL; my_vis_info = NULL; spin_unlock_irqrestore(&vis_hash_lock, flags); @@ -594,5 +672,5 @@ static void start_vis_timer(void) { queue_delayed_work(bat_event_workqueue, &vis_timer_wq, - (atomic_read(&vis_interval) * HZ ) / 1000); + (atomic_read(&vis_interval) * HZ) / 1000); }

Modified: trunk/batman-adv-kernelland/vis.h =================================================================== --- trunk/batman-adv-kernelland/vis.h 2010-02-27 05:56:18 UTC (rev 1578) +++ trunk/batman-adv-kernelland/vis.h 2010-03-04 10:28:10 UTC (rev 1579) @@ -29,6 +29,7 @@ /* list of server-neighbors we received a vis-packet * from. we should not reply to them. */ struct list_head send_list; + struct kref refcount; /* this packet might be part of the vis send queue. */ struct vis_packet packet; /* vis_info may follow here*/