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-rw-r--r--net/sched/cls_route.c226
1 files changed, 132 insertions, 94 deletions
diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index dd9fc2523c76..ba96deacf27c 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -29,25 +29,26 @@
* are mutually exclusive.
* 3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
*/
-
struct route4_fastmap {
- struct route4_filter *filter;
- u32 id;
- int iif;
+ struct route4_filter *filter;
+ u32 id;
+ int iif;
};
struct route4_head {
- struct route4_fastmap fastmap[16];
- struct route4_bucket *table[256 + 1];
+ struct route4_fastmap fastmap[16];
+ struct route4_bucket __rcu *table[256 + 1];
+ struct rcu_head rcu;
};
struct route4_bucket {
/* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
- struct route4_filter *ht[16 + 16 + 1];
+ struct route4_filter __rcu *ht[16 + 16 + 1];
+ struct rcu_head rcu;
};
struct route4_filter {
- struct route4_filter *next;
+ struct route4_filter __rcu *next;
u32 id;
int iif;
@@ -55,6 +56,8 @@ struct route4_filter {
struct tcf_exts exts;
u32 handle;
struct route4_bucket *bkt;
+ struct tcf_proto *tp;
+ struct rcu_head rcu;
};
#define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
@@ -64,14 +67,13 @@ static inline int route4_fastmap_hash(u32 id, int iif)
return id & 0xF;
}
+static DEFINE_SPINLOCK(fastmap_lock);
static void
-route4_reset_fastmap(struct Qdisc *q, struct route4_head *head, u32 id)
+route4_reset_fastmap(struct route4_head *head)
{
- spinlock_t *root_lock = qdisc_root_sleeping_lock(q);
-
- spin_lock_bh(root_lock);
+ spin_lock_bh(&fastmap_lock);
memset(head->fastmap, 0, sizeof(head->fastmap));
- spin_unlock_bh(root_lock);
+ spin_unlock_bh(&fastmap_lock);
}
static void
@@ -80,9 +82,12 @@ route4_set_fastmap(struct route4_head *head, u32 id, int iif,
{
int h = route4_fastmap_hash(id, iif);
+ /* fastmap updates must look atomic to aling id, iff, filter */
+ spin_lock_bh(&fastmap_lock);
head->fastmap[h].id = id;
head->fastmap[h].iif = iif;
head->fastmap[h].filter = f;
+ spin_unlock_bh(&fastmap_lock);
}
static inline int route4_hash_to(u32 id)
@@ -123,7 +128,7 @@ static inline int route4_hash_wild(void)
static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
struct tcf_result *res)
{
- struct route4_head *head = tp->root;
+ struct route4_head *head = rcu_dereference_bh(tp->root);
struct dst_entry *dst;
struct route4_bucket *b;
struct route4_filter *f;
@@ -141,32 +146,43 @@ static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
iif = inet_iif(skb);
h = route4_fastmap_hash(id, iif);
+
+ spin_lock(&fastmap_lock);
if (id == head->fastmap[h].id &&
iif == head->fastmap[h].iif &&
(f = head->fastmap[h].filter) != NULL) {
- if (f == ROUTE4_FAILURE)
+ if (f == ROUTE4_FAILURE) {
+ spin_unlock(&fastmap_lock);
goto failure;
+ }
*res = f->res;
+ spin_unlock(&fastmap_lock);
return 0;
}
+ spin_unlock(&fastmap_lock);
h = route4_hash_to(id);
restart:
- b = head->table[h];
+ b = rcu_dereference_bh(head->table[h]);
if (b) {
- for (f = b->ht[route4_hash_from(id)]; f; f = f->next)
+ for (f = rcu_dereference_bh(b->ht[route4_hash_from(id)]);
+ f;
+ f = rcu_dereference_bh(f->next))
if (f->id == id)
ROUTE4_APPLY_RESULT();
- for (f = b->ht[route4_hash_iif(iif)]; f; f = f->next)
+ for (f = rcu_dereference_bh(b->ht[route4_hash_iif(iif)]);
+ f;
+ f = rcu_dereference_bh(f->next))
if (f->iif == iif)
ROUTE4_APPLY_RESULT();
- for (f = b->ht[route4_hash_wild()]; f; f = f->next)
+ for (f = rcu_dereference_bh(b->ht[route4_hash_wild()]);
+ f;
+ f = rcu_dereference_bh(f->next))
ROUTE4_APPLY_RESULT();
-
}
if (h < 256) {
h = 256;
@@ -213,7 +229,7 @@ static inline u32 from_hash(u32 id)
static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
{
- struct route4_head *head = tp->root;
+ struct route4_head *head = rtnl_dereference(tp->root);
struct route4_bucket *b;
struct route4_filter *f;
unsigned int h1, h2;
@@ -229,9 +245,11 @@ static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
if (h2 > 32)
return 0;
- b = head->table[h1];
+ b = rtnl_dereference(head->table[h1]);
if (b) {
- for (f = b->ht[h2]; f; f = f->next)
+ for (f = rtnl_dereference(b->ht[h2]);
+ f;
+ f = rtnl_dereference(f->next))
if (f->handle == handle)
return (unsigned long)f;
}
@@ -248,8 +266,11 @@ static int route4_init(struct tcf_proto *tp)
}
static void
-route4_delete_filter(struct tcf_proto *tp, struct route4_filter *f)
+route4_delete_filter(struct rcu_head *head)
{
+ struct route4_filter *f = container_of(head, struct route4_filter, rcu);
+ struct tcf_proto *tp = f->tp;
+
tcf_unbind_filter(tp, &f->res);
tcf_exts_destroy(tp, &f->exts);
kfree(f);
@@ -257,7 +278,7 @@ route4_delete_filter(struct tcf_proto *tp, struct route4_filter *f)
static void route4_destroy(struct tcf_proto *tp)
{
- struct route4_head *head = tp->root;
+ struct route4_head *head = rtnl_dereference(tp->root);
int h1, h2;
if (head == NULL)
@@ -266,28 +287,35 @@ static void route4_destroy(struct tcf_proto *tp)
for (h1 = 0; h1 <= 256; h1++) {
struct route4_bucket *b;
- b = head->table[h1];
+ b = rtnl_dereference(head->table[h1]);
if (b) {
for (h2 = 0; h2 <= 32; h2++) {
struct route4_filter *f;
- while ((f = b->ht[h2]) != NULL) {
- b->ht[h2] = f->next;
- route4_delete_filter(tp, f);
+ while ((f = rtnl_dereference(b->ht[h2])) != NULL) {
+ struct route4_filter *next;
+
+ next = rtnl_dereference(f->next);
+ RCU_INIT_POINTER(b->ht[h2], next);
+ call_rcu(&f->rcu, route4_delete_filter);
}
}
- kfree(b);
+ RCU_INIT_POINTER(head->table[h1], NULL);
+ kfree_rcu(b, rcu);
}
}
- kfree(head);
+ RCU_INIT_POINTER(tp->root, NULL);
+ kfree_rcu(head, rcu);
}
static int route4_delete(struct tcf_proto *tp, unsigned long arg)
{
- struct route4_head *head = tp->root;
- struct route4_filter **fp, *f = (struct route4_filter *)arg;
- unsigned int h = 0;
+ struct route4_head *head = rtnl_dereference(tp->root);
+ struct route4_filter *f = (struct route4_filter *)arg;
+ struct route4_filter __rcu **fp;
+ struct route4_filter *nf;
struct route4_bucket *b;
+ unsigned int h = 0;
int i;
if (!head || !f)
@@ -296,27 +324,35 @@ static int route4_delete(struct tcf_proto *tp, unsigned long arg)
h = f->handle;
b = f->bkt;
- for (fp = &b->ht[from_hash(h >> 16)]; *fp; fp = &(*fp)->next) {
- if (*fp == f) {
- tcf_tree_lock(tp);
- *fp = f->next;
- tcf_tree_unlock(tp);
+ fp = &b->ht[from_hash(h >> 16)];
+ for (nf = rtnl_dereference(*fp); nf;
+ fp = &nf->next, nf = rtnl_dereference(*fp)) {
+ if (nf == f) {
+ /* unlink it */
+ RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
- route4_reset_fastmap(tp->q, head, f->id);
- route4_delete_filter(tp, f);
+ /* Remove any fastmap lookups that might ref filter
+ * notice we unlink'd the filter so we can't get it
+ * back in the fastmap.
+ */
+ route4_reset_fastmap(head);
- /* Strip tree */
+ /* Delete it */
+ call_rcu(&f->rcu, route4_delete_filter);
- for (i = 0; i <= 32; i++)
- if (b->ht[i])
+ /* Strip RTNL protected tree */
+ for (i = 0; i <= 32; i++) {
+ struct route4_filter *rt;
+
+ rt = rtnl_dereference(b->ht[i]);
+ if (rt)
return 0;
+ }
/* OK, session has no flows */
- tcf_tree_lock(tp);
- head->table[to_hash(h)] = NULL;
- tcf_tree_unlock(tp);
+ RCU_INIT_POINTER(head->table[to_hash(h)], NULL);
+ kfree_rcu(b, rcu);
- kfree(b);
return 0;
}
}
@@ -380,26 +416,25 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
}
h1 = to_hash(nhandle);
- b = head->table[h1];
+ b = rtnl_dereference(head->table[h1]);
if (!b) {
err = -ENOBUFS;
b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
if (b == NULL)
goto errout;
- tcf_tree_lock(tp);
- head->table[h1] = b;
- tcf_tree_unlock(tp);
+ rcu_assign_pointer(head->table[h1], b);
} else {
unsigned int h2 = from_hash(nhandle >> 16);
err = -EEXIST;
- for (fp = b->ht[h2]; fp; fp = fp->next)
+ for (fp = rtnl_dereference(b->ht[h2]);
+ fp;
+ fp = rtnl_dereference(fp->next))
if (fp->handle == f->handle)
goto errout;
}
- tcf_tree_lock(tp);
if (tb[TCA_ROUTE4_TO])
f->id = to;
@@ -410,7 +445,7 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
f->handle = nhandle;
f->bkt = b;
- tcf_tree_unlock(tp);
+ f->tp = tp;
if (tb[TCA_ROUTE4_CLASSID]) {
f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]);
@@ -431,14 +466,15 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
struct nlattr **tca,
unsigned long *arg, bool ovr)
{
- struct route4_head *head = tp->root;
- struct route4_filter *f, *f1, **fp;
+ struct route4_head *head = rtnl_dereference(tp->root);
+ struct route4_filter __rcu **fp;
+ struct route4_filter *fold, *f1, *pfp, *f = NULL;
struct route4_bucket *b;
struct nlattr *opt = tca[TCA_OPTIONS];
struct nlattr *tb[TCA_ROUTE4_MAX + 1];
unsigned int h, th;
- u32 old_handle = 0;
int err;
+ bool new = true;
if (opt == NULL)
return handle ? -EINVAL : 0;
@@ -447,70 +483,70 @@ static int route4_change(struct net *net, struct sk_buff *in_skb,
if (err < 0)
return err;
- f = (struct route4_filter *)*arg;
- if (f) {
- if (f->handle != handle && handle)
+ fold = (struct route4_filter *)*arg;
+ if (fold && handle && fold->handle != handle)
return -EINVAL;
- if (f->bkt)
- old_handle = f->handle;
-
- err = route4_set_parms(net, tp, base, f, handle, head, tb,
- tca[TCA_RATE], 0, ovr);
- if (err < 0)
- return err;
-
- goto reinsert;
- }
-
err = -ENOBUFS;
if (head == NULL) {
head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
if (head == NULL)
goto errout;
-
- tcf_tree_lock(tp);
- tp->root = head;
- tcf_tree_unlock(tp);
+ rcu_assign_pointer(tp->root, head);
}
f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
- if (f == NULL)
+ if (!f)
goto errout;
tcf_exts_init(&f->exts, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE);
+ if (fold) {
+ f->id = fold->id;
+ f->iif = fold->iif;
+ f->res = fold->res;
+ f->handle = fold->handle;
+
+ f->tp = fold->tp;
+ f->bkt = fold->bkt;
+ new = false;
+ }
+
err = route4_set_parms(net, tp, base, f, handle, head, tb,
- tca[TCA_RATE], 1, ovr);
+ tca[TCA_RATE], new, ovr);
if (err < 0)
goto errout;
-reinsert:
h = from_hash(f->handle >> 16);
- for (fp = &f->bkt->ht[h]; (f1 = *fp) != NULL; fp = &f1->next)
+ fp = &f->bkt->ht[h];
+ for (pfp = rtnl_dereference(*fp);
+ (f1 = rtnl_dereference(*fp)) != NULL;
+ fp = &f1->next)
if (f->handle < f1->handle)
break;
- f->next = f1;
- tcf_tree_lock(tp);
- *fp = f;
+ rcu_assign_pointer(f->next, f1);
+ rcu_assign_pointer(*fp, f);
- if (old_handle && f->handle != old_handle) {
- th = to_hash(old_handle);
- h = from_hash(old_handle >> 16);
- b = head->table[th];
+ if (fold && fold->handle && f->handle != fold->handle) {
+ th = to_hash(fold->handle);
+ h = from_hash(fold->handle >> 16);
+ b = rtnl_dereference(head->table[th]);
if (b) {
- for (fp = &b->ht[h]; *fp; fp = &(*fp)->next) {
- if (*fp == f) {
+ fp = &b->ht[h];
+ for (pfp = rtnl_dereference(*fp); pfp;
+ fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
+ if (pfp == f) {
*fp = f->next;
break;
}
}
}
}
- tcf_tree_unlock(tp);
- route4_reset_fastmap(tp->q, head, f->id);
+ route4_reset_fastmap(head);
*arg = (unsigned long)f;
+ if (fold)
+ call_rcu(&fold->rcu, route4_delete_filter);
return 0;
errout:
@@ -520,7 +556,7 @@ errout:
static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
- struct route4_head *head = tp->root;
+ struct route4_head *head = rtnl_dereference(tp->root);
unsigned int h, h1;
if (head == NULL)
@@ -530,13 +566,15 @@ static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
return;
for (h = 0; h <= 256; h++) {
- struct route4_bucket *b = head->table[h];
+ struct route4_bucket *b = rtnl_dereference(head->table[h]);
if (b) {
for (h1 = 0; h1 <= 32; h1++) {
struct route4_filter *f;
- for (f = b->ht[h1]; f; f = f->next) {
+ for (f = rtnl_dereference(b->ht[h1]);
+ f;
+ f = rtnl_dereference(f->next)) {
if (arg->count < arg->skip) {
arg->count++;
continue;
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