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Don't hold the node lock over the iterator.

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The "find node" function call will increase the node reference anyway;
so there's no reason to hold the node table lock during the MLME change.

The only reason I could think of is to stop overlapping mlme ioctls
from causing issues, but this should be fixed a different way.

This fixes a whole class of LORs that creep up when nodes are being
timed out or removed by hostapd.

Tested:

* AR5416, hostap, with nodes coming and going.  No LORs or stability
  issues were observed.
This commit is contained in:
Adrian Chadd 2013-06-07 09:03:56 +00:00
parent b70f530bc7
commit 9984c9baf3
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=251488
1 changed files with 24 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
sys/net80211/ieee80211_ioctl.c
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@ -1340,12 +1340,17 @@ setmlme_dropsta(struct ieee80211vap *vap,
if (!IEEE80211_ADDR_EQ(mac, ic->ic_ifp->if_broadcastaddr)) {
IEEE80211_NODE_LOCK(nt);
ni = ieee80211_find_node_locked(nt, mac);
IEEE80211_NODE_UNLOCK(nt);
/*
* Don't do the node update inside the node
* table lock. This unfortunately causes LORs
* with drivers and their TX paths.
*/
if (ni != NULL) {
domlme(mlmeop, ni);
ieee80211_free_node(ni);
} else
error = ENOENT;
IEEE80211_NODE_UNLOCK(nt);
} else {
ieee80211_iterate_nodes(nt, domlme, mlmeop);
}
@ -1400,13 +1405,18 @@ setmlme_common(struct ieee80211vap *vap, int op,
case IEEE80211_M_MBSS:
IEEE80211_NODE_LOCK(nt);
ni = ieee80211_find_node_locked(nt, mac);
/*
* Don't do the node update inside the node
* table lock. This unfortunately causes LORs
* with drivers and their TX paths.
*/
IEEE80211_NODE_UNLOCK(nt);
if (ni != NULL) {
ieee80211_node_leave(ni);
ieee80211_free_node(ni);
} else {
error = ENOENT;
}
IEEE80211_NODE_UNLOCK(nt);
break;
default:
error = EINVAL;
@ -1422,6 +1432,12 @@ setmlme_common(struct ieee80211vap *vap, int op,
}
IEEE80211_NODE_LOCK(nt);
ni = ieee80211_find_vap_node_locked(nt, vap, mac);
/*
* Don't do the node update inside the node
* table lock. This unfortunately causes LORs
* with drivers and their TX paths.
*/
IEEE80211_NODE_UNLOCK(nt);
if (ni != NULL) {
mlmedebug(vap, mac, op, reason);
if (op == IEEE80211_MLME_AUTHORIZE)
@ -1431,7 +1447,6 @@ setmlme_common(struct ieee80211vap *vap, int op,
ieee80211_free_node(ni);
} else
error = ENOENT;
IEEE80211_NODE_UNLOCK(nt);
break;
case IEEE80211_MLME_AUTH:
if (vap->iv_opmode != IEEE80211_M_HOSTAP) {
@ -1440,6 +1455,12 @@ setmlme_common(struct ieee80211vap *vap, int op,
}
IEEE80211_NODE_LOCK(nt);
ni = ieee80211_find_vap_node_locked(nt, vap, mac);
/*
* Don't do the node update inside the node
* table lock. This unfortunately causes LORs
* with drivers and their TX paths.
*/
IEEE80211_NODE_UNLOCK(nt);
if (ni != NULL) {
mlmedebug(vap, mac, op, reason);
if (reason == IEEE80211_STATUS_SUCCESS) {
@ -1463,7 +1484,6 @@ setmlme_common(struct ieee80211vap *vap, int op,
ieee80211_free_node(ni);
} else
error = ENOENT;
IEEE80211_NODE_UNLOCK(nt);
break;
default:
error = EINVAL;