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authorYing Xue <ying.xue@windriver.com>2014-02-13 17:29:17 -0500
committerDavid S. Miller <davem@davemloft.net>2014-02-13 17:57:07 -0500
commita83045292daf9f07d0b103e5715ef527123d2fcc (patch)
treeea983884e77ae82b1f099713a7d11834b95e84a9
parent7d33939f475d403e79124e3143d7951dcfe8629f (diff)
downloadop-kernel-dev-a83045292daf9f07d0b103e5715ef527123d2fcc.zip
op-kernel-dev-a83045292daf9f07d0b103e5715ef527123d2fcc.tar.gz
tipc: remove bearer_lock from tipc_bearer struct
After the earlier commits ("tipc: remove 'links' list from tipc_bearer struct") and ("tipc: introduce new spinlock to protect struct link_req"), there is no longer any need to protect struct link_req or or any link list by use of bearer_lock. Furthermore, we have eliminated the need for using bearer_lock during downcalls (send) from the link to the bearer, since we have ensured that bearers always have a longer life cycle that their associated links, and always contain valid data. So, the only need now for a lock protecting bearers is for guaranteeing consistency of the bearer list itself. For this, it is sufficient, at least for the time being, to continue applying 'net_lockĀ“ in write mode. By removing bearer_lock we also pre-empt introduction of issue b) descibed in the previous commit "tipc: remove 'links' list from tipc_bearer struct": "b) When the outer protection from net_lock is gone, taking bearer_lock and node_lock in opposite order of method 1) and 2) will become an obvious deadlock hazard". Therefore, we now eliminate the bearer_lock spinlock. Signed-off-by: Ying Xue <ying.xue@windriver.com> Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/tipc/bcast.c1
-rw-r--r--net/tipc/bearer.c16
-rw-r--r--net/tipc/bearer.h5
3 files changed, 4 insertions, 18 deletions
diff --git a/net/tipc/bcast.c b/net/tipc/bcast.c
index af35f76..06a639c 100644
--- a/net/tipc/bcast.c
+++ b/net/tipc/bcast.c
@@ -785,7 +785,6 @@ void tipc_bclink_init(void)
bcl->owner = &bclink->node;
bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
- spin_lock_init(&bcbearer->bearer.lock);
bcl->b_ptr = &bcbearer->bearer;
bcl->state = WORKING_WORKING;
strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
diff --git a/net/tipc/bearer.c b/net/tipc/bearer.c
index 60caa45..242cddd 100644
--- a/net/tipc/bearer.c
+++ b/net/tipc/bearer.c
@@ -327,7 +327,6 @@ restart:
b_ptr->net_plane = bearer_id + 'A';
b_ptr->active = 1;
b_ptr->priority = priority;
- spin_lock_init(&b_ptr->lock);
res = tipc_disc_create(b_ptr, &b_ptr->bcast_addr, disc_domain);
if (res) {
@@ -351,9 +350,7 @@ static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
{
read_lock_bh(&tipc_net_lock);
pr_info("Resetting bearer <%s>\n", b_ptr->name);
- spin_lock_bh(&b_ptr->lock);
tipc_link_reset_list(b_ptr->identity);
- spin_unlock_bh(&b_ptr->lock);
read_unlock_bh(&tipc_net_lock);
return 0;
}
@@ -365,19 +362,12 @@ static int tipc_reset_bearer(struct tipc_bearer *b_ptr)
*/
static void bearer_disable(struct tipc_bearer *b_ptr, bool shutting_down)
{
- struct tipc_link_req *temp_req;
-
pr_info("Disabling bearer <%s>\n", b_ptr->name);
- spin_lock_bh(&b_ptr->lock);
b_ptr->media->disable_media(b_ptr);
- tipc_link_delete_list(b_ptr->identity, shutting_down);
- temp_req = b_ptr->link_req;
- b_ptr->link_req = NULL;
- spin_unlock_bh(&b_ptr->lock);
-
- if (temp_req)
- tipc_disc_delete(temp_req);
+ tipc_link_delete_list(b_ptr->identity, shutting_down);
+ if (b_ptr->link_req)
+ tipc_disc_delete(b_ptr->link_req);
memset(b_ptr, 0, sizeof(struct tipc_bearer));
}
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h
index 647cb1d..425dd81 100644
--- a/net/tipc/bearer.h
+++ b/net/tipc/bearer.h
@@ -107,10 +107,8 @@ struct tipc_media {
/**
* struct tipc_bearer - Generic TIPC bearer structure
- * @dev: ptr to associated network device
- * @usr_handle: pointer to additional media-specific information about bearer
+ * @media_ptr: pointer to additional media-specific information about bearer
* @mtu: max packet size bearer can support
- * @lock: spinlock for controlling access to bearer
* @addr: media-specific address associated with bearer
* @name: bearer name (format = media:interface)
* @media: ptr to media structure associated with bearer
@@ -133,7 +131,6 @@ struct tipc_bearer {
u32 mtu; /* initalized by media */
struct tipc_media_addr addr; /* initalized by media */
char name[TIPC_MAX_BEARER_NAME];
- spinlock_t lock;
struct tipc_media *media;
struct tipc_media_addr bcast_addr;
u32 priority;
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