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-rw-r--r--include/linux/rtnetlink.h7
-rw-r--r--include/net/pkt_sched.h1
-rw-r--r--include/net/sch_generic.h20
-rw-r--r--net/core/rtnetlink.c6
-rw-r--r--net/sched/cls_api.c242
-rw-r--r--net/sched/sch_api.c24
-rw-r--r--net/sched/sch_atm.c2
-rw-r--r--net/sched/sch_cbq.c2
-rw-r--r--net/sched/sch_cbs.c2
-rw-r--r--net/sched/sch_drr.c4
-rw-r--r--net/sched/sch_dsmark.c2
-rw-r--r--net/sched/sch_fifo.c2
-rw-r--r--net/sched/sch_generic.c48
-rw-r--r--net/sched/sch_hfsc.c2
-rw-r--r--net/sched/sch_htb.c4
-rw-r--r--net/sched/sch_mq.c4
-rw-r--r--net/sched/sch_mqprio.c4
-rw-r--r--net/sched/sch_multiq.c6
-rw-r--r--net/sched/sch_netem.c2
-rw-r--r--net/sched/sch_prio.c6
-rw-r--r--net/sched/sch_qfq.c4
-rw-r--r--net/sched/sch_red.c4
-rw-r--r--net/sched/sch_sfb.c4
-rw-r--r--net/sched/sch_tbf.c4
24 files changed, 294 insertions, 112 deletions
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 5225832bd6ff..bb9cb84114c1 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -6,6 +6,7 @@
#include <linux/mutex.h>
#include <linux/netdevice.h>
#include <linux/wait.h>
+#include <linux/refcount.h>
#include <uapi/linux/rtnetlink.h>
extern int rtnetlink_send(struct sk_buff *skb, struct net *net, u32 pid, u32 group, int echo);
@@ -34,6 +35,7 @@ extern void rtnl_unlock(void);
extern int rtnl_trylock(void);
extern int rtnl_is_locked(void);
extern int rtnl_lock_killable(void);
+extern bool refcount_dec_and_rtnl_lock(refcount_t *r);
extern wait_queue_head_t netdev_unregistering_wq;
extern struct rw_semaphore pernet_ops_rwsem;
@@ -83,6 +85,11 @@ static inline struct netdev_queue *dev_ingress_queue(struct net_device *dev)
return rtnl_dereference(dev->ingress_queue);
}
+static inline struct netdev_queue *dev_ingress_queue_rcu(struct net_device *dev)
+{
+ return rcu_dereference(dev->ingress_queue);
+}
+
struct netdev_queue *dev_ingress_queue_create(struct net_device *dev);
#ifdef CONFIG_NET_INGRESS
diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 7dc769e5452b..a16fbe9a2a67 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -102,6 +102,7 @@ int qdisc_set_default(const char *id);
void qdisc_hash_add(struct Qdisc *q, bool invisible);
void qdisc_hash_del(struct Qdisc *q);
struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
+struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle);
struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
struct nlattr *tab,
struct netlink_ext_ack *extack);
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index d326fd553b58..7a6b71ee5433 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -105,6 +105,7 @@ struct Qdisc {
spinlock_t busylock ____cacheline_aligned_in_smp;
spinlock_t seqlock;
+ struct rcu_head rcu;
};
static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
@@ -114,6 +115,19 @@ static inline void qdisc_refcount_inc(struct Qdisc *qdisc)
refcount_inc(&qdisc->refcnt);
}
+/* Intended to be used by unlocked users, when concurrent qdisc release is
+ * possible.
+ */
+
+static inline struct Qdisc *qdisc_refcount_inc_nz(struct Qdisc *qdisc)
+{
+ if (qdisc->flags & TCQ_F_BUILTIN)
+ return qdisc;
+ if (refcount_inc_not_zero(&qdisc->refcnt))
+ return qdisc;
+ return NULL;
+}
+
static inline bool qdisc_is_running(struct Qdisc *qdisc)
{
if (qdisc->flags & TCQ_F_NOLOCK)
@@ -331,7 +345,7 @@ struct tcf_chain {
struct tcf_block {
struct list_head chain_list;
u32 index; /* block index for shared blocks */
- unsigned int refcnt;
+ refcount_t refcnt;
struct net *net;
struct Qdisc *q;
struct list_head cb_list;
@@ -343,6 +357,7 @@ struct tcf_block {
struct tcf_chain *chain;
struct list_head filter_chain_list;
} chain0;
+ struct rcu_head rcu;
};
static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)
@@ -554,7 +569,8 @@ void dev_deactivate_many(struct list_head *head);
struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
struct Qdisc *qdisc);
void qdisc_reset(struct Qdisc *qdisc);
-void qdisc_destroy(struct Qdisc *qdisc);
+void qdisc_put(struct Qdisc *qdisc);
+void qdisc_put_unlocked(struct Qdisc *qdisc);
void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
unsigned int len);
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 80a7e18c65fb..35162e1b06ad 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -130,6 +130,12 @@ int rtnl_is_locked(void)
}
EXPORT_SYMBOL(rtnl_is_locked);
+bool refcount_dec_and_rtnl_lock(refcount_t *r)
+{
+ return refcount_dec_and_mutex_lock(r, &rtnl_mutex);
+}
+EXPORT_SYMBOL(refcount_dec_and_rtnl_lock);
+
#ifdef CONFIG_PROVE_LOCKING
bool lockdep_rtnl_is_held(void)
{
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 0a75cb2e5e7b..3de47e99b788 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -240,8 +240,8 @@ static void tcf_chain_destroy(struct tcf_chain *chain)
if (!chain->index)
block->chain0.chain = NULL;
kfree(chain);
- if (list_empty(&block->chain_list) && block->refcnt == 0)
- kfree(block);
+ if (list_empty(&block->chain_list) && !refcount_read(&block->refcnt))
+ kfree_rcu(block, rcu);
}
static void tcf_chain_hold(struct tcf_chain *chain)
@@ -473,6 +473,7 @@ tcf_chain0_head_change_cb_del(struct tcf_block *block,
}
struct tcf_net {
+ spinlock_t idr_lock; /* Protects idr */
struct idr idr;
};
@@ -482,16 +483,25 @@ static int tcf_block_insert(struct tcf_block *block, struct net *net,
struct netlink_ext_ack *extack)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
+ int err;
+
+ idr_preload(GFP_KERNEL);
+ spin_lock(&tn->idr_lock);
+ err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
+ GFP_NOWAIT);
+ spin_unlock(&tn->idr_lock);
+ idr_preload_end();
- return idr_alloc_u32(&tn->idr, block, &block->index, block->index,
- GFP_KERNEL);
+ return err;
}
static void tcf_block_remove(struct tcf_block *block, struct net *net)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
+ spin_lock(&tn->idr_lock);
idr_remove(&tn->idr, block->index);
+ spin_unlock(&tn->idr_lock);
}
static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
@@ -510,7 +520,7 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
INIT_LIST_HEAD(&block->owner_list);
INIT_LIST_HEAD(&block->chain0.filter_chain_list);
- block->refcnt = 1;
+ refcount_set(&block->refcnt, 1);
block->net = net;
block->index = block_index;
@@ -527,6 +537,78 @@ static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
return idr_find(&tn->idr, block_index);
}
+static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
+{
+ struct tcf_block *block;
+
+ rcu_read_lock();
+ block = tcf_block_lookup(net, block_index);
+ if (block && !refcount_inc_not_zero(&block->refcnt))
+ block = NULL;
+ rcu_read_unlock();
+
+ return block;
+}
+
+static void tcf_block_flush_all_chains(struct tcf_block *block)
+{
+ struct tcf_chain *chain;
+
+ /* Hold a refcnt for all chains, so that they don't disappear
+ * while we are iterating.
+ */
+ list_for_each_entry(chain, &block->chain_list, list)
+ tcf_chain_hold(chain);
+
+ list_for_each_entry(chain, &block->chain_list, list)
+ tcf_chain_flush(chain);
+}
+
+static void tcf_block_put_all_chains(struct tcf_block *block)
+{
+ struct tcf_chain *chain, *tmp;
+
+ /* At this point, all the chains should have refcnt >= 1. */
+ list_for_each_entry_safe(chain, tmp, &block->chain_list, list) {
+ tcf_chain_put_explicitly_created(chain);
+ tcf_chain_put(chain);
+ }
+}
+
+static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
+ struct tcf_block_ext_info *ei)
+{
+ if (refcount_dec_and_test(&block->refcnt)) {
+ /* Flushing/putting all chains will cause the block to be
+ * deallocated when last chain is freed. However, if chain_list
+ * is empty, block has to be manually deallocated. After block
+ * reference counter reached 0, it is no longer possible to
+ * increment it or add new chains to block.
+ */
+ bool free_block = list_empty(&block->chain_list);
+
+ if (tcf_block_shared(block))
+ tcf_block_remove(block, block->net);
+ if (!free_block)
+ tcf_block_flush_all_chains(block);
+
+ if (q)
+ tcf_block_offload_unbind(block, q, ei);
+
+ if (free_block)
+ kfree_rcu(block, rcu);
+ else
+ tcf_block_put_all_chains(block);
+ } else if (q) {
+ tcf_block_offload_unbind(block, q, ei);
+ }
+}
+
+static void tcf_block_refcnt_put(struct tcf_block *block)
+{
+ __tcf_block_put(block, NULL, NULL);
+}
+
/* Find tcf block.
* Set q, parent, cl when appropriate.
*/
@@ -537,9 +619,10 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
struct netlink_ext_ack *extack)
{
struct tcf_block *block;
+ int err = 0;
if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
- block = tcf_block_lookup(net, block_index);
+ block = tcf_block_refcnt_get(net, block_index);
if (!block) {
NL_SET_ERR_MSG(extack, "Block of given index was not found");
return ERR_PTR(-EINVAL);
@@ -548,55 +631,104 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
const struct Qdisc_class_ops *cops;
struct net_device *dev;
+ rcu_read_lock();
+
/* Find link */
- dev = __dev_get_by_index(net, ifindex);
- if (!dev)
+ dev = dev_get_by_index_rcu(net, ifindex);
+ if (!dev) {
+ rcu_read_unlock();
return ERR_PTR(-ENODEV);
+ }
/* Find qdisc */
if (!*parent) {
*q = dev->qdisc;
*parent = (*q)->handle;
} else {
- *q = qdisc_lookup(dev, TC_H_MAJ(*parent));
+ *q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
if (!*q) {
NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
- return ERR_PTR(-EINVAL);
+ err = -EINVAL;
+ goto errout_rcu;
}
}
+ *q = qdisc_refcount_inc_nz(*q);
+ if (!*q) {
+ NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
+ err = -EINVAL;
+ goto errout_rcu;
+ }
+
/* Is it classful? */
cops = (*q)->ops->cl_ops;
if (!cops) {
NL_SET_ERR_MSG(extack, "Qdisc not classful");
- return ERR_PTR(-EINVAL);
+ err = -EINVAL;
+ goto errout_rcu;
}
if (!cops->tcf_block) {
NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
- return ERR_PTR(-EOPNOTSUPP);
+ err = -EOPNOTSUPP;
+ goto errout_rcu;
}
+ /* At this point we know that qdisc is not noop_qdisc,
+ * which means that qdisc holds a reference to net_device
+ * and we hold a reference to qdisc, so it is safe to release
+ * rcu read lock.
+ */
+ rcu_read_unlock();
+
/* Do we search for filter, attached to class? */
if (TC_H_MIN(*parent)) {
*cl = cops->find(*q, *parent);
if (*cl == 0) {
NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
- return ERR_PTR(-ENOENT);
+ err = -ENOENT;
+ goto errout_qdisc;
}
}
/* And the last stroke */
block = cops->tcf_block(*q, *cl, extack);
- if (!block)
- return ERR_PTR(-EINVAL);
+ if (!block) {
+ err = -EINVAL;
+ goto errout_qdisc;
+ }
if (tcf_block_shared(block)) {
NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
- return ERR_PTR(-EOPNOTSUPP);
+ err = -EOPNOTSUPP;
+ goto errout_qdisc;
}
+
+ /* Always take reference to block in order to support execution
+ * of rules update path of cls API without rtnl lock. Caller
+ * must release block when it is finished using it. 'if' block
+ * of this conditional obtain reference to block by calling
+ * tcf_block_refcnt_get().
+ */
+ refcount_inc(&block->refcnt);
}
return block;
+
+errout_rcu:
+ rcu_read_unlock();
+errout_qdisc:
+ if (*q)
+ qdisc_put(*q);
+ return ERR_PTR(err);
+}
+
+static void tcf_block_release(struct Qdisc *q, struct tcf_block *block)
+{
+ if (!IS_ERR_OR_NULL(block))
+ tcf_block_refcnt_put(block);
+
+ if (q)
+ qdisc_put(q);
}
struct tcf_block_owner_item {
@@ -664,21 +796,16 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
{
struct net *net = qdisc_net(q);
struct tcf_block *block = NULL;
- bool created = false;
int err;
- if (ei->block_index) {
+ if (ei->block_index)
/* block_index not 0 means the shared block is requested */
- block = tcf_block_lookup(net, ei->block_index);
- if (block)
- block->refcnt++;
- }
+ block = tcf_block_refcnt_get(net, ei->block_index);
if (!block) {
block = tcf_block_create(net, q, ei->block_index, extack);
if (IS_ERR(block))
return PTR_ERR(block);
- created = true;
if (tcf_block_shared(block)) {
err = tcf_block_insert(block, net, extack);
if (err)
@@ -708,14 +835,8 @@ err_block_offload_bind:
err_chain0_head_change_cb_add:
tcf_block_owner_del(block, q, ei->binder_type);
err_block_owner_add:
- if (created) {
- if (tcf_block_shared(block))
- tcf_block_remove(block, net);
err_block_insert:
- kfree(block);
- } else {
- block->refcnt--;
- }
+ tcf_block_refcnt_put(block);
return err;
}
EXPORT_SYMBOL(tcf_block_get_ext);
@@ -747,42 +868,12 @@ EXPORT_SYMBOL(tcf_block_get);
void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
struct tcf_block_ext_info *ei)
{
- struct tcf_chain *chain, *tmp;
-
if (!block)
return;
tcf_chain0_head_change_cb_del(block, ei);
tcf_block_owner_del(block, q, ei->binder_type);
- if (block->refcnt == 1) {
- if (tcf_block_shared(block))
- tcf_block_remove(block, block->net);
-
- /* Hold a refcnt for all chains, so that they don't disappear
- * while we are iterating.
- */
- list_for_each_entry(chain, &block->chain_list, list)
- tcf_chain_hold(chain);
-
- list_for_each_entry(chain, &block->chain_list, list)
- tcf_chain_flush(chain);
- }
-
- tcf_block_offload_unbind(block, q, ei);
-
- if (block->refcnt == 1) {
- /* At this point, all the chains should have refcnt >= 1. */
- list_for_each_entry_safe(chain, tmp, &block->chain_list, list) {
- tcf_chain_put_explicitly_created(chain);
- tcf_chain_put(chain);
- }
-
- block->refcnt--;
- if (list_empty(&block->chain_list))
- kfree(block);
- } else {
- block->refcnt--;
- }
+ __tcf_block_put(block, q, ei);
}
EXPORT_SYMBOL(tcf_block_put_ext);
@@ -1332,6 +1423,7 @@ replay:
errout:
if (chain)
tcf_chain_put(chain);
+ tcf_block_release(q, block);
if (err == -EAGAIN)
/* Replay the request. */
goto replay;
@@ -1453,6 +1545,7 @@ static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
errout:
if (chain)
tcf_chain_put(chain);
+ tcf_block_release(q, block);
return err;
}
@@ -1538,6 +1631,7 @@ static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
errout:
if (chain)
tcf_chain_put(chain);
+ tcf_block_release(q, block);
return err;
}
@@ -1636,7 +1730,7 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
return err;
if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
- block = tcf_block_lookup(net, tcm->tcm_block_index);
+ block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
if (!block)
goto out;
/* If we work with block index, q is NULL and parent value
@@ -1695,6 +1789,8 @@ static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
}
}
+ if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
+ tcf_block_refcnt_put(block);
cb->args[0] = index;
out:
@@ -1854,7 +1950,8 @@ replay:
chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
if (chain_index > TC_ACT_EXT_VAL_MASK) {
NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
- return -EINVAL;
+ err = -EINVAL;
+ goto errout_block;
}
chain = tcf_chain_lookup(block, chain_index);
if (n->nlmsg_type == RTM_NEWCHAIN) {
@@ -1866,23 +1963,27 @@ replay:
tcf_chain_hold(chain);
} else {
NL_SET_ERR_MSG(extack, "Filter chain already exists");
- return -EEXIST;
+ err = -EEXIST;
+ goto errout_block;
}
} else {
if (!(n->nlmsg_flags & NLM_F_CREATE)) {
NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
- return -ENOENT;
+ err = -ENOENT;
+ goto errout_block;
}
chain = tcf_chain_create(block, chain_index);
if (!chain) {
NL_SET_ERR_MSG(extack, "Failed to create filter chain");
- return -ENOMEM;
+ err = -ENOMEM;
+ goto errout_block;
}
}
} else {
if (!chain || tcf_chain_held_by_acts_only(chain)) {
NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
- return -EINVAL;
+ err = -EINVAL;
+ goto errout_block;
}
tcf_chain_hold(chain);
}
@@ -1926,6 +2027,8 @@ replay:
errout:
tcf_chain_put(chain);
+errout_block:
+ tcf_block_release(q, block);
if (err == -EAGAIN)
/* Replay the request. */
goto replay;
@@ -1954,7 +2057,7 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
return err;
if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
- block = tcf_block_lookup(net, tcm->tcm_block_index);
+ block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
if (!block)
goto out;
/* If we work with block index, q is NULL and parent value
@@ -2021,6 +2124,8 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
index++;
}
+ if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
+ tcf_block_refcnt_put(block);
cb->args[0] = index;
out:
@@ -2213,6 +2318,7 @@ static __net_init int tcf_net_init(struct net *net)
{
struct tcf_net *tn = net_generic(net, tcf_net_id);
+ spin_lock_init(&tn->idr_lock);
idr_init(&tn->idr);
return 0;
}
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 411c40344b77..22e9799e5b69 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -314,6 +314,24 @@ out:
return q;
}
+struct Qdisc *qdisc_lookup_rcu(struct net_device *dev, u32 handle)
+{
+ struct netdev_queue *nq;
+ struct Qdisc *q;
+
+ if (!handle)
+ return NULL;
+ q = qdisc_match_from_root(dev->qdisc, handle);
+ if (q)
+ goto out;
+
+ nq = dev_ingress_queue_rcu(dev);
+ if (nq)
+ q = qdisc_match_from_root(nq->qdisc_sleeping, handle);
+out:
+ return q;
+}
+
static struct Qdisc *qdisc_leaf(struct Qdisc *p, u32 classid)
{
unsigned long cl;
@@ -920,7 +938,7 @@ static void notify_and_destroy(struct net *net, struct sk_buff *skb,
qdisc_notify(net, skb, n, clid, old, new);
if (old)
- qdisc_destroy(old);
+ qdisc_put(old);
}
/* Graft qdisc "new" to class "classid" of qdisc "parent" or
@@ -973,7 +991,7 @@ static int qdisc_graft(struct net_device *dev, struct Qdisc *parent,
qdisc_refcount_inc(new);
if (!ingress)
- qdisc_destroy(old);
+ qdisc_put(old);
}
skip:
@@ -1561,7 +1579,7 @@ graft:
err = qdisc_graft(dev, p, skb, n, clid, q, NULL, extack);
if (err) {
if (q)
- qdisc_destroy(q);
+ qdisc_put(q);
return err;
}
diff --git a/net/sched/sch_atm.c b/net/sched/sch_atm.c
index cd49afca9617..d714d3747bcb 100644
--- a/net/sched/sch_atm.c
+++ b/net/sched/sch_atm.c
@@ -150,7 +150,7 @@ static void atm_tc_put(struct Qdisc *sch, unsigned long cl)
pr_debug("atm_tc_put: destroying\n");
list_del_init(&flow->list);
pr_debug("atm_tc_put: qdisc %p\n", flow->q);
- qdisc_destroy(flow->q);
+ qdisc_put(flow->q);
tcf_block_put(flow->block);
if (flow->sock) {
pr_debug("atm_tc_put: f_count %ld\n",
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index f42025d53cfe..4dc05409e3fb 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1418,7 +1418,7 @@ static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl)
WARN_ON(cl->filters);
tcf_block_put(cl->block);
- qdisc_destroy(cl->q);
+ qdisc_put(cl->q);
qdisc_put_rtab(cl->R_tab);
gen_kill_estimator(&cl->rate_est);
if (cl != &q->link)
diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c
index e26a24017faa..e689e11b6d0f 100644
--- a/net/sched/sch_cbs.c
+++ b/net/sched/sch_cbs.c
@@ -379,7 +379,7 @@ static void cbs_destroy(struct Qdisc *sch)
cbs_disable_offload(dev, q);
if (q->qdisc)
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
}
static int cbs_dump(struct Qdisc *sch, struct sk_buff *skb)
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index e0b0cf8a9939..cdebaed0f8cf 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -134,7 +134,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
tca[TCA_RATE]);
if (err) {
NL_SET_ERR_MSG(extack, "Failed to replace estimator");
- qdisc_destroy(cl->qdisc);
+ qdisc_put(cl->qdisc);
kfree(cl);
return err;
}
@@ -153,7 +153,7 @@ static int drr_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
static void drr_destroy_class(struct Qdisc *sch, struct drr_class *cl)
{
gen_kill_estimator(&cl->rate_est);
- qdisc_destroy(cl->qdisc);
+ qdisc_put(cl->qdisc);
kfree(cl);
}
diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
index 049714c57075..f6f480784bc6 100644
--- a/net/sched/sch_dsmark.c
+++ b/net/sched/sch_dsmark.c
@@ -412,7 +412,7 @@ static void dsmark_destroy(struct Qdisc *sch)
pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
tcf_block_put(p->block);
- qdisc_destroy(p->q);
+ qdisc_put(p->q);
if (p->mv != p->embedded)
kfree(p->mv);
}
diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index 24893d3b5d22..3809c9bf8896 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -177,7 +177,7 @@ struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
if (q) {
err = fifo_set_limit(q, limit);
if (err < 0) {
- qdisc_destroy(q);
+ qdisc_put(q);
q = NULL;
}
}
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index a64132a5db36..531fac1d2875 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -901,7 +901,7 @@ struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
if (!ops->init || ops->init(sch, NULL, extack) == 0)
return sch;
- qdisc_destroy(sch);
+ qdisc_put(sch);
return NULL;
}
EXPORT_SYMBOL(qdisc_create_dflt);
@@ -941,15 +941,18 @@ void qdisc_free(struct Qdisc *qdisc)
kfree((char *) qdisc - qdisc->padded);
}
-void qdisc_destroy(struct Qdisc *qdisc)
+void qdisc_free_cb(struct rcu_head *head)
+{
+ struct Qdisc *q = container_of(head, struct Qdisc, rcu);
+
+ qdisc_free(q);
+}
+
+static void qdisc_destroy(struct Qdisc *qdisc)
{
const struct Qdisc_ops *ops = qdisc->ops;
struct sk_buff *skb, *tmp;
- if (qdisc->flags & TCQ_F_BUILTIN ||
- !refcount_dec_and_test(&qdisc->refcnt))
- return;
-
#ifdef CONFIG_NET_SCHED
qdisc_hash_del(qdisc);
@@ -974,9 +977,34 @@ void qdisc_destroy(struct Qdisc *qdisc)
kfree_skb_list(skb);
}
- qdisc_free(qdisc);
+ call_rcu(&qdisc->rcu, qdisc_free_cb);
+}
+
+void qdisc_put(struct Qdisc *qdisc)
+{
+ if (qdisc->flags & TCQ_F_BUILTIN ||
+ !refcount_dec_and_test(&qdisc->refcnt))
+ return;
+
+ qdisc_destroy(qdisc);
+}
+EXPORT_SYMBOL(qdisc_put);
+
+/* Version of qdisc_put() that is called with rtnl mutex unlocked.
+ * Intended to be used as optimization, this function only takes rtnl lock if
+ * qdisc reference counter reached zero.
+ */
+
+void qdisc_put_unlocked(struct Qdisc *qdisc)
+{
+ if (qdisc->flags & TCQ_F_BUILTIN ||
+ !refcount_dec_and_rtnl_lock(&qdisc->refcnt))
+ return;
+
+ qdisc_destroy(qdisc);
+ rtnl_unlock();
}
-EXPORT_SYMBOL(qdisc_destroy);
+EXPORT_SYMBOL(qdisc_put_unlocked);
/* Attach toplevel qdisc to device queue. */
struct Qdisc *dev_graft_qdisc(struct netdev_queue *dev_queue,
@@ -1270,7 +1298,7 @@ static void shutdown_scheduler_queue(struct net_device *dev,
rcu_assign_pointer(dev_queue->qdisc, qdisc_default);
dev_queue->qdisc_sleeping = qdisc_default;
- qdisc_destroy(qdisc);
+ qdisc_put(qdisc);
}
}
@@ -1279,7 +1307,7 @@ void dev_shutdown(struct net_device *dev)
netdev_for_each_tx_queue(dev, shutdown_scheduler_queue, &noop_qdisc);
if (dev_ingress_queue(dev))
shutdown_scheduler_queue(dev, dev_ingress_queue(dev), &noop_qdisc);
- qdisc_destroy(dev->qdisc);
+ qdisc_put(dev->qdisc);
dev->qdisc = &noop_qdisc;
WARN_ON(timer_pending(&dev->watchdog_timer));
diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 3278a76f6861..b18ec1f6de60 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -1092,7 +1092,7 @@ hfsc_destroy_class(struct Qdisc *sch, struct hfsc_class *cl)
struct hfsc_sched *q = qdisc_priv(sch);
tcf_block_put(cl->block);
- qdisc_destroy(cl->qdisc);
+ qdisc_put(cl->qdisc);
gen_kill_estimator(&cl->rate_est);
if (cl != &q->root)
kfree(cl);
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index 18ac2d6ca294..58b449490757 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -1208,7 +1208,7 @@ static void htb_destroy_class(struct Qdisc *sch, struct htb_class *cl)
{
if (!cl->level) {
WARN_ON(!cl->leaf.q);
- qdisc_destroy(cl->leaf.q);
+ qdisc_put(cl->leaf.q);
}
gen_kill_estimator(&cl->rate_est);
tcf_block_put(cl->block);
@@ -1409,7 +1409,7 @@ static int htb_change_class(struct Qdisc *sch, u32 classid,
/* turn parent into inner node */
qdisc_reset(parent->leaf.q);
qdisc_tree_reduce_backlog(parent->leaf.q, qlen, backlog);
- qdisc_destroy(parent->leaf.q);
+ qdisc_put(parent->leaf.q);
if (parent->prio_activity)
htb_deactivate(q, parent);
diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index d6b8ae4ed7a3..f20f3a0f8424 100644
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -65,7 +65,7 @@ static void mq_destroy(struct Qdisc *sch)
if (!priv->qdiscs)
return;
for (ntx = 0; ntx < dev->num_tx_queues && priv->qdiscs[ntx]; ntx++)
- qdisc_destroy(priv->qdiscs[ntx]);
+ qdisc_put(priv->qdiscs[ntx]);
kfree(priv->qdiscs);
}
@@ -119,7 +119,7 @@ static void mq_attach(struct Qdisc *sch)
qdisc = priv->qdiscs[ntx];
old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
if (old)
- qdisc_destroy(old);
+ qdisc_put(old);
#ifdef CONFIG_NET_SCHED
if (ntx < dev->real_num_tx_queues)
qdisc_hash_add(qdisc, false);
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 0e9d761cdd80..d364e63c396d 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -40,7 +40,7 @@ static void mqprio_destroy(struct Qdisc *sch)
for (ntx = 0;
ntx < dev->num_tx_queues && priv->qdiscs[ntx];
ntx++)
- qdisc_destroy(priv->qdiscs[ntx]);
+ qdisc_put(priv->qdiscs[ntx]);
kfree(priv->qdiscs);
}
@@ -300,7 +300,7 @@ static void mqprio_attach(struct Qdisc *sch)
qdisc = priv->qdiscs[ntx];
old = dev_graft_qdisc(qdisc->dev_queue, qdisc);
if (old)
- qdisc_destroy(old);
+ qdisc_put(old);
if (ntx < dev->real_num_tx_queues)
qdisc_hash_add(qdisc, false);
}
diff --git a/net/sched/sch_multiq.c b/net/sched/sch_multiq.c
index 1da7ea8de0ad..7410ce4d0321 100644
--- a/net/sched/sch_multiq.c
+++ b/net/sched/sch_multiq.c
@@ -175,7 +175,7 @@ multiq_destroy(struct Qdisc *sch)
tcf_block_put(q->block);
for (band = 0; band < q->bands; band++)
- qdisc_destroy(q->queues[band]);
+ qdisc_put(q->queues[band]);
kfree(q->queues);
}
@@ -204,7 +204,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt,
q->queues[i] = &noop_qdisc;
qdisc_tree_reduce_backlog(child, child->q.qlen,
child->qstats.backlog);
- qdisc_destroy(child);
+ qdisc_put(child);
}
}
@@ -228,7 +228,7 @@ static int multiq_tune(struct Qdisc *sch, struct nlattr *opt,
qdisc_tree_reduce_backlog(old,
old->q.qlen,
old->qstats.backlog);
- qdisc_destroy(old);
+ qdisc_put(old);
}
sch_tree_unlock(sch);
}
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index 506e1960ed7f..57b3ad9394ad 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -1022,7 +1022,7 @@ static void netem_destroy(struct Qdisc *sch)
qdisc_watchdog_cancel(&q->watchdog);
if (q->qdisc)
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
dist_free(q->delay_dist);
dist_free(q->slot_dist);
}
diff --git a/net/sched/sch_prio.c b/net/sched/sch_prio.c
index 222e53d3d27a..f8af98621179 100644
--- a/net/sched/sch_prio.c
+++ b/net/sched/sch_prio.c
@@ -175,7 +175,7 @@ prio_destroy(struct Qdisc *sch)
tcf_block_put(q->block);
prio_offload(sch, NULL);
for (prio = 0; prio < q->bands; prio++)
- qdisc_destroy(q->queues[prio]);
+ qdisc_put(q->queues[prio]);
}
static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
@@ -205,7 +205,7 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
extack);
if (!queues[i]) {
while (i > oldbands)
- qdisc_destroy(queues[--i]);
+ qdisc_put(queues[--i]);
return -ENOMEM;
}
}
@@ -220,7 +220,7 @@ static int prio_tune(struct Qdisc *sch, struct nlattr *opt,
qdisc_tree_reduce_backlog(child, child->q.qlen,
child->qstats.backlog);
- qdisc_destroy(child);
+ qdisc_put(child);
}
for (i = oldbands; i < q->bands; i++) {
diff --git a/net/sched/sch_qfq.c b/net/sched/sch_qfq.c
index bb1a9c11fc54..dc37c4ead439 100644
--- a/net/sched/sch_qfq.c
+++ b/net/sched/sch_qfq.c
@@ -526,7 +526,7 @@ set_change_agg:
return 0;
destroy_class:
- qdisc_destroy(cl->qdisc);
+ qdisc_put(cl->qdisc);
kfree(cl);
return err;
}
@@ -537,7 +537,7 @@ static void qfq_destroy_class(struct Qdisc *sch, struct qfq_class *cl)
qfq_rm_from_agg(q, cl);
gen_kill_estimator(&cl->rate_est);
- qdisc_destroy(cl->qdisc);
+ qdisc_put(cl->qdisc);
kfree(cl);
}
diff --git a/net/sched/sch_red.c b/net/sched/sch_red.c
index 56c181c3feeb..3ce6c0a2c493 100644
--- a/net/sched/sch_red.c
+++ b/net/sched/sch_red.c
@@ -181,7 +181,7 @@ static void red_destroy(struct Qdisc *sch)
del_timer_sync(&q->adapt_timer);
red_offload(sch, false);
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
}
static const struct nla_policy red_policy[TCA_RED_MAX + 1] = {
@@ -233,7 +233,7 @@ static int red_change(struct Qdisc *sch, struct nlattr *opt,
if (child) {
qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
q->qdisc->qstats.backlog);
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
q->qdisc = child;
}
diff --git a/net/sched/sch_sfb.c b/net/sched/sch_sfb.c
index 7cbdad8419b7..bab506b01a32 100644
--- a/net/sched/sch_sfb.c
+++ b/net/sched/sch_sfb.c
@@ -469,7 +469,7 @@ static void sfb_destroy(struct Qdisc *sch)
struct sfb_sched_data *q = qdisc_priv(sch);
tcf_block_put(q->block);
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
}
static const struct nla_policy sfb_policy[TCA_SFB_MAX + 1] = {
@@ -523,7 +523,7 @@ static int sfb_change(struct Qdisc *sch, struct nlattr *opt,
qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
q->qdisc->qstats.backlog);
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
q->qdisc = child;
q->rehash_interval = msecs_to_jiffies(ctl->rehash_interval);
diff --git a/net/sched/sch_tbf.c b/net/sched/sch_tbf.c
index a4530e85bd02..942dcca09cf2 100644
--- a/net/sched/sch_tbf.c
+++ b/net/sched/sch_tbf.c
@@ -392,7 +392,7 @@ static int tbf_change(struct Qdisc *sch, struct nlattr *opt,
if (child) {
qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
q->qdisc->qstats.backlog);
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
q->qdisc = child;
}
q->limit = qopt->limit;
@@ -438,7 +438,7 @@ static void tbf_destroy(struct Qdisc *sch)
struct tbf_sched_data *q = qdisc_priv(sch);
qdisc_watchdog_cancel(&q->watchdog);
- qdisc_destroy(q->qdisc);
+ qdisc_put(q->qdisc);
}
static int tbf_dump(struct Qdisc *sch, struct sk_buff *skb)