Make the hash table for services resizable in the bit range of 4-20.
Table is attached only while services are present. Resizing is done
by delayed work based on load (the number of hashed services).
Table grows when load increases 2+ times (above 12.5% with factor=3)
and shrinks 8+ times when load decreases 16+ times (below 0.78%).
Switch to jhash hashing to reduce the collisions for multiple
services.
Add a hash_key field into the service that includes table ID and
bucket ID. This helps the lookup and delete operations.
Signed-off-by: Julian Anastasov <ja@xxxxxx>
---
include/net/ip_vs.h | 49 ++-
net/netfilter/ipvs/ip_vs_ctl.c | 676 +++++++++++++++++++++++++++------
2 files changed, 594 insertions(+), 131 deletions(-)
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 51adba5f1bb9..1fe04b91d4a7 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -35,12 +35,10 @@
#define IP_VS_HDR_INVERSE 1
#define IP_VS_HDR_ICMP 2
-/*
- * Hash table: for virtual service lookups
- */
-#define IP_VS_SVC_TAB_BITS 8
-#define IP_VS_SVC_TAB_SIZE BIT(IP_VS_SVC_TAB_BITS)
-#define IP_VS_SVC_TAB_MASK (IP_VS_SVC_TAB_SIZE - 1)
+
+/* svc_table limits */
+#define IP_VS_SVC_TAB_MIN_BITS 4
+#define IP_VS_SVC_TAB_MAX_BITS 20
/* Generic access of ipvs struct */
static inline struct netns_ipvs *net_ipvs(struct net* net)
@@ -51,8 +49,6 @@ static inline struct netns_ipvs *net_ipvs(struct net* net)
/* Connections' size value needed by ip_vs_ctl.c */
extern int ip_vs_conn_tab_size;
-extern struct mutex __ip_vs_mutex;
-
struct ip_vs_iphdr {
int hdr_flags; /* ipvs flags */
__u32 off; /* Where IP or IPv4 header starts */
@@ -289,6 +285,12 @@ static inline int ip_vs_af_index(int af)
return af == AF_INET6 ? IP_VS_AF_INET6 : IP_VS_AF_INET;
}
+/* work_flags */
+enum {
+ IP_VS_WORK_SVC_RESIZE, /* Schedule svc_resize_work */
+ IP_VS_WORK_SVC_NORESIZE, /* Stopping svc_resize_work */
+};
+
/* The port number of FTP service (in network order). */
#define FTPPORT cpu_to_be16(21)
#define FTPDATA cpu_to_be16(20)
@@ -888,14 +890,15 @@ struct ip_vs_dest_user_kern {
* forwarding entries.
*/
struct ip_vs_service {
- struct hlist_node s_list; /* node in service table */
- atomic_t refcnt; /* reference counter */
-
+ struct hlist_bl_node s_list; /* node in service table */
+ u32 hash_key; /* Key for the hash table */
u16 af; /* address family */
__u16 protocol; /* which protocol (TCP/UDP) */
+
union nf_inet_addr addr; /* IP address for virtual service */
- __be16 port; /* port number for the service */
__u32 fwmark; /* firewall mark of the service */
+ atomic_t refcnt; /* reference counter */
+ __be16 port; /* port number for the service */
unsigned int flags; /* service status flags */
unsigned int timeout; /* persistent timeout in ticks */
__be32 netmask; /* grouping granularity, mask/plen */
@@ -1153,6 +1156,10 @@ struct netns_ipvs {
struct list_head dest_trash;
spinlock_t dest_trash_lock;
struct timer_list dest_trash_timer; /* expiration timer */
+ struct mutex service_mutex; /* service reconfig */
+ struct rw_semaphore svc_resize_sem; /* svc_table resizing */
+ struct delayed_work svc_resize_work; /* resize svc_table */
+ atomic_t svc_table_changes;/* ++ on new table */
/* Service counters */
atomic_t num_services[IP_VS_AF_MAX]; /* Services */
atomic_t fwm_services[IP_VS_AF_MAX]; /* Services */
@@ -1216,6 +1223,7 @@ struct netns_ipvs {
int sysctl_est_nice; /* kthread nice */
int est_stopped; /* stop tasks */
#endif
+ int sysctl_svc_lfactor;
/* ip_vs_lblc */
int sysctl_lblc_expiration;
@@ -1225,6 +1233,7 @@ struct netns_ipvs {
int sysctl_lblcr_expiration;
struct ctl_table_header *lblcr_ctl_header;
struct ctl_table *lblcr_ctl_table;
+ unsigned long work_flags; /* IP_VS_WORK_* flags */
/* ip_vs_est */
struct delayed_work est_reload_work;/* Reload kthread tasks */
struct mutex est_mutex; /* protect kthread tasks */
@@ -1256,9 +1265,7 @@ struct netns_ipvs {
unsigned int mixed_address_family_dests;
unsigned int hooks_afmask; /* &1=AF_INET, &2=AF_INET6 */
- /* the service mutex that protect svc_table and svc_fwm_table */
- struct mutex service_mutex;
- struct hlist_head svc_table[IP_VS_SVC_TAB_SIZE]; /* Services */
+ struct ip_vs_rht __rcu *svc_table; /* Services */
};
#define DEFAULT_SYNC_THRESHOLD 3
@@ -1495,6 +1502,18 @@ static inline int sysctl_est_nice(struct netns_ipvs *ipvs)
#endif
+/* Get load factor to map num_services/u_thresh to t->size
+ * Large value decreases u_thresh to reduce collisions but increases
+ * the table size
+ * Returns factor where:
+ * - non-negative: u_thresh = size >> factor, eg. lfactor 2 = 25% load
+ * - negative: u_thresh = size << factor, eg. lfactor -1 = 200% load
+ */
+static inline int sysctl_svc_lfactor(struct netns_ipvs *ipvs)
+{
+ return READ_ONCE(ipvs->sysctl_svc_lfactor);
+}
+
/* IPVS core functions
* (from ip_vs_core.c)
*/
diff --git a/net/netfilter/ipvs/ip_vs_ctl.c b/net/netfilter/ipvs/ip_vs_ctl.c
index 94123a55e1bd..e2429fcc0bc3 100644
--- a/net/netfilter/ipvs/ip_vs_ctl.c
+++ b/net/netfilter/ipvs/ip_vs_ctl.c
@@ -294,47 +294,59 @@ ip_vs_use_count_dec(void)
}
-
+/* Service hashing:
+ * Operation Locking order
+ * ---------------------------------------------------------------------------
+ * add table service_mutex, svc_resize_sem(W)
+ * del table service_mutex
+ * move between tables svc_resize_sem(W), seqcount_t(W), bit lock
+ * add/del service service_mutex, bit lock
+ * find service RCU, seqcount_t(R)
+ * walk services(blocking) service_mutex, svc_resize_sem(R)
+ * walk services(non-blocking) RCU, seqcount_t(R)
+ *
+ * - new tables are linked/unlinked under service_mutex and svc_resize_sem
+ * - new table is linked on resizing and all operations can run in parallel
+ * in 2 tables until the new table is registered as current one
+ * - two contexts can modify buckets: config and table resize, both in
+ * process context
+ * - only table resizer can move entries, so we do not protect t->seqc[]
+ * items with t->lock[]
+ * - lookups occur under RCU lock and seqcount reader lock to detect if
+ * services are moved to new table
+ * - move operations may disturb readers: find operation will not miss entries
+ * but walkers may see same entry twice if they are forced to retry chains
+ * - walkers using cond_resched_rcu() on !PREEMPT_RCU may need to hold
+ * service_mutex to disallow new tables to be installed or to check
+ * svc_table_changes and repeat the RCU read section if new table is installed
+ */
/*
* Returns hash value for virtual service
*/
-static inline unsigned int
-ip_vs_svc_hashkey(struct netns_ipvs *ipvs, int af, unsigned int proto,
+static inline u32
+ip_vs_svc_hashval(struct ip_vs_rht *t, int af, unsigned int proto,
const union nf_inet_addr *addr, __be16 port)
{
- unsigned int porth = ntohs(port);
- __be32 addr_fold = addr->ip;
- __u32 ahash;
-
-#ifdef CONFIG_IP_VS_IPV6
- if (af == AF_INET6)
- addr_fold = addr->ip6[0]^addr->ip6[1]^
- addr->ip6[2]^addr->ip6[3];
-#endif
- ahash = ntohl(addr_fold);
- ahash ^= ((size_t) ipvs >> 8);
-
- return (proto ^ ahash ^ (porth >> IP_VS_SVC_TAB_BITS) ^ porth) &
- IP_VS_SVC_TAB_MASK;
+ return ip_vs_rht_hash_linfo(t, af, addr, ntohs(port), proto);
}
/*
* Returns hash value of fwmark for virtual service lookup
*/
-static inline unsigned int ip_vs_svc_fwm_hashkey(struct netns_ipvs *ipvs, __u32 fwmark)
+static inline u32 ip_vs_svc_fwm_hashval(struct ip_vs_rht *t, int af,
+ __u32 fwmark)
{
- return (((size_t)ipvs>>8) ^ fwmark) & IP_VS_SVC_TAB_MASK;
+ return jhash_2words(fwmark, af, (u32)t->hash_key.key[0]);
}
-/*
- * Hashes a service in the svc_table by <netns,proto,addr,port>
- * or by fwmark.
- * Should be called with locked tables.
- */
+/* Hashes a service in the svc_table by <proto,addr,port> or by fwmark */
static int ip_vs_svc_hash(struct ip_vs_service *svc)
{
- unsigned int hash;
+ struct netns_ipvs *ipvs = svc->ipvs;
+ struct hlist_bl_head *head;
+ struct ip_vs_rht *t;
+ u32 hash;
if (svc->flags & IP_VS_SVC_F_HASHED) {
pr_err("%s(): request for already hashed, called from %pS\n",
@@ -342,23 +354,32 @@ static int ip_vs_svc_hash(struct ip_vs_service *svc)
return 0;
}
+ /* increase its refcnt because it is referenced by the svc table */
+ atomic_inc(&svc->refcnt);
+
+ /* New entries go into recent table */
+ t = rcu_dereference_protected(ipvs->svc_table, 1);
+ t = rcu_dereference_protected(t->new_tbl, 1);
+
if (svc->fwmark == 0) {
/*
- * Hash it by <netns,protocol,addr,port>
+ * Hash it by <protocol,addr,port>
*/
- hash = ip_vs_svc_hashkey(svc->ipvs, svc->af, svc->protocol,
+ hash = ip_vs_svc_hashval(t, svc->af, svc->protocol,
&svc->addr, svc->port);
} else {
/*
* Hash it by fwmark
*/
- hash = ip_vs_svc_fwm_hashkey(svc->ipvs, svc->fwmark);
+ hash = ip_vs_svc_fwm_hashval(t, svc->af, svc->fwmark);
}
- hlist_add_head_rcu(&svc->s_list, &svc->ipvs->svc_table[hash]);
-
+ head = t->buckets + (hash & t->mask);
+ hlist_bl_lock(head);
+ WRITE_ONCE(svc->hash_key, ip_vs_rht_build_hash_key(t, hash));
svc->flags |= IP_VS_SVC_F_HASHED;
- /* increase its refcnt because it is referenced by the svc table */
- atomic_inc(&svc->refcnt);
+ hlist_bl_add_head_rcu(&svc->s_list, head);
+ hlist_bl_unlock(head);
+
return 1;
}
@@ -369,17 +390,45 @@ static int ip_vs_svc_hash(struct ip_vs_service *svc)
*/
static int ip_vs_svc_unhash(struct ip_vs_service *svc)
{
+ struct netns_ipvs *ipvs = svc->ipvs;
+ struct hlist_bl_head *head;
+ struct ip_vs_rht *t;
+ u32 hash_key2;
+ u32 hash_key;
+
if (!(svc->flags & IP_VS_SVC_F_HASHED)) {
pr_err("%s(): request for unhash flagged, called from %pS\n",
__func__, __builtin_return_address(0));
return 0;
}
+ t = rcu_dereference_protected(ipvs->svc_table, 1);
+ hash_key = READ_ONCE(svc->hash_key);
+ /* We need to lock the bucket in the right table */
+ if (ip_vs_rht_same_table(t, hash_key)) {
+ head = t->buckets + (hash_key & t->mask);
+ hlist_bl_lock(head);
+ /* Ensure hash_key is read under lock */
+ hash_key2 = READ_ONCE(svc->hash_key);
+ /* Moved to new table ? */
+ if (hash_key != hash_key2) {
+ hlist_bl_unlock(head);
+ t = rcu_dereference_protected(t->new_tbl, 1);
+ head = t->buckets + (hash_key2 & t->mask);
+ hlist_bl_lock(head);
+ }
+ } else {
+ /* It is already moved to new table */
+ t = rcu_dereference_protected(t->new_tbl, 1);
+ head = t->buckets + (hash_key & t->mask);
+ hlist_bl_lock(head);
+ }
/* Remove it from svc_table */
- hlist_del_rcu(&svc->s_list);
+ hlist_bl_del_rcu(&svc->s_list);
svc->flags &= ~IP_VS_SVC_F_HASHED;
atomic_dec(&svc->refcnt);
+ hlist_bl_unlock(head);
return 1;
}
@@ -391,18 +440,29 @@ static inline struct ip_vs_service *
__ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u16 protocol,
const union nf_inet_addr *vaddr, __be16 vport)
{
- unsigned int hash;
+ DECLARE_IP_VS_RHT_WALK_BUCKET_RCU();
+ struct hlist_bl_head *head;
struct ip_vs_service *svc;
-
- /* Check for "full" addressed entries */
- hash = ip_vs_svc_hashkey(ipvs, af, protocol, vaddr, vport);
-
- hlist_for_each_entry_rcu(svc, &ipvs->svc_table[hash], s_list) {
- if (svc->af == af && ip_vs_addr_equal(af, &svc->addr, vaddr) &&
- svc->port == vport && svc->protocol == protocol &&
- !svc->fwmark) {
- /* HIT */
- return svc;
+ struct ip_vs_rht *t, *p;
+ struct hlist_bl_node *e;
+ u32 hash, hash_key;
+
+ ip_vs_rht_for_each_table_rcu(ipvs->svc_table, t, p) {
+ /* Check for "full" addressed entries */
+ hash = ip_vs_svc_hashval(t, af, protocol, vaddr, vport);
+
+ hash_key = ip_vs_rht_build_hash_key(t, hash);
+ ip_vs_rht_walk_bucket_rcu(t, hash_key, head) {
+ hlist_bl_for_each_entry_rcu(svc, e, head, s_list) {
+ if (READ_ONCE(svc->hash_key) == hash_key &&
+ svc->af == af &&
+ ip_vs_addr_equal(af, &svc->addr, vaddr) &&
+ svc->port == vport &&
+ svc->protocol == protocol && !svc->fwmark) {
+ /* HIT */
+ return svc;
+ }
+ }
}
}
@@ -416,16 +476,26 @@ __ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u16 protocol,
static inline struct ip_vs_service *
__ip_vs_svc_fwm_find(struct netns_ipvs *ipvs, int af, __u32 fwmark)
{
- unsigned int hash;
+ DECLARE_IP_VS_RHT_WALK_BUCKET_RCU();
+ struct hlist_bl_head *head;
struct ip_vs_service *svc;
-
- /* Check for fwmark addressed entries */
- hash = ip_vs_svc_fwm_hashkey(ipvs, fwmark);
-
- hlist_for_each_entry_rcu(svc, &ipvs->svc_table[hash], s_list) {
- if (svc->fwmark == fwmark && svc->af == af) {
- /* HIT */
- return svc;
+ struct ip_vs_rht *t, *p;
+ struct hlist_bl_node *e;
+ u32 hash, hash_key;
+
+ ip_vs_rht_for_each_table_rcu(ipvs->svc_table, t, p) {
+ /* Check for fwmark addressed entries */
+ hash = ip_vs_svc_fwm_hashval(t, af, fwmark);
+
+ hash_key = ip_vs_rht_build_hash_key(t, hash);
+ ip_vs_rht_walk_bucket_rcu(t, hash_key, head) {
+ hlist_bl_for_each_entry_rcu(svc, e, head, s_list) {
+ if (READ_ONCE(svc->hash_key) == hash_key &&
+ svc->fwmark == fwmark && svc->af == af) {
+ /* HIT */
+ return svc;
+ }
+ }
}
}
@@ -488,6 +558,220 @@ ip_vs_service_find(struct netns_ipvs *ipvs, int af, __u32 fwmark, __u16 protocol
return svc;
}
+/* Return the number of registered services */
+static int ip_vs_get_num_services(struct netns_ipvs *ipvs)
+{
+ int ns = 0, ni = IP_VS_AF_MAX;
+
+ while (--ni >= 0)
+ ns += atomic_read(&ipvs->num_services[ni]);
+ return ns;
+}
+
+/* Get default load factor to map num_services/u_thresh to t->size */
+static int ip_vs_svc_default_load_factor(struct netns_ipvs *ipvs)
+{
+ int factor;
+
+ if (net_eq(ipvs->net, &init_net))
+ factor = 3; /* grow if load is above 12.5% */
+ else
+ factor = 2; /* grow if load is above 25% */
+ return factor;
+}
+
+/* Get the desired svc_table size */
+static int ip_vs_svc_desired_size(struct netns_ipvs *ipvs, struct ip_vs_rht *t,
+ int lfactor)
+{
+ return ip_vs_rht_desired_size(ipvs, t, ip_vs_get_num_services(ipvs),
+ lfactor, IP_VS_SVC_TAB_MIN_BITS,
+ IP_VS_SVC_TAB_MAX_BITS);
+}
+
+/* Allocate svc_table */
+static struct ip_vs_rht *ip_vs_svc_table_alloc(struct netns_ipvs *ipvs,
+ int buckets, int lfactor)
+{
+ struct ip_vs_rht *t;
+ int scounts, locks;
+
+ /* No frequent lookups to race with resizing, so use max of 64
+ * seqcounts. Only resizer moves entries, so use 0 locks.
+ */
+ scounts = clamp(buckets >> 4, 1, 64);
+ locks = 0;
+
+ t = ip_vs_rht_alloc(buckets, scounts, locks);
+ if (!t)
+ return NULL;
+ t->lfactor = lfactor;
+ ip_vs_rht_set_thresholds(t, t->size, lfactor, IP_VS_SVC_TAB_MIN_BITS,
+ IP_VS_SVC_TAB_MAX_BITS);
+ return t;
+}
+
+/* svc_table resizer work */
+static void svc_resize_work_handler(struct work_struct *work)
+{
+ struct hlist_bl_head *head, *head2;
+ struct ip_vs_rht *t_free = NULL;
+ unsigned int resched_score = 0;
+ struct hlist_bl_node *cn, *nn;
+ struct ip_vs_rht *t, *t_new;
+ struct ip_vs_service *svc;
+ struct netns_ipvs *ipvs;
+ bool more_work = true;
+ seqcount_t *sc;
+ int limit = 0;
+ int new_size;
+ int lfactor;
+ u32 bucket;
+
+ ipvs = container_of(work, struct netns_ipvs, svc_resize_work.work);
+
+ if (!down_write_trylock(&ipvs->svc_resize_sem))
+ goto out;
+ if (!mutex_trylock(&ipvs->service_mutex))
+ goto unlock_sem;
+ more_work = false;
+ clear_bit(IP_VS_WORK_SVC_RESIZE, &ipvs->work_flags);
+ if (!ipvs->enable ||
+ test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags))
+ goto unlock_m;
+ t = rcu_dereference_protected(ipvs->svc_table, 1);
+ /* Do nothing if table is removed */
+ if (!t)
+ goto unlock_m;
+ /* New table needs to be registered? BUG! */
+ if (t != rcu_dereference_protected(t->new_tbl, 1))
+ goto unlock_m;
+
+ lfactor = sysctl_svc_lfactor(ipvs);
+ /* Should we resize ? */
+ new_size = ip_vs_svc_desired_size(ipvs, t, lfactor);
+ if (new_size == t->size && lfactor == t->lfactor)
+ goto unlock_m;
+
+ t_new = ip_vs_svc_table_alloc(ipvs, new_size, lfactor);
+ if (!t_new) {
+ more_work = true;
+ goto unlock_m;
+ }
+ /* Flip the table_id */
+ t_new->table_id = t->table_id ^ IP_VS_RHT_TABLE_ID_MASK;
+
+ rcu_assign_pointer(t->new_tbl, t_new);
+ /* Allow add/del to new_tbl while moving from old table */
+ mutex_unlock(&ipvs->service_mutex);
+
+ ip_vs_rht_for_each_bucket(t, bucket, head) {
+same_bucket:
+ if (++limit >= 16) {
+ if (!ipvs->enable ||
+ test_bit(IP_VS_WORK_SVC_NORESIZE,
+ &ipvs->work_flags))
+ goto unlock_sem;
+ if (resched_score >= 100) {
+ resched_score = 0;
+ cond_resched();
+ }
+ limit = 0;
+ }
+ if (hlist_bl_empty(head)) {
+ resched_score++;
+ continue;
+ }
+ /* Preemption calls ahead... */
+ resched_score = 0;
+
+ sc = &t->seqc[bucket & t->seqc_mask];
+ /* seqcount_t usage considering PREEMPT_RT rules:
+ * - we are the only writer => preemption can be allowed
+ * - readers (SoftIRQ) => disable BHs
+ * - readers (processes) => preemption should be disabled
+ */
+ local_bh_disable();
+ preempt_disable_nested();
+ write_seqcount_begin(sc);
+ hlist_bl_lock(head);
+
+ hlist_bl_for_each_entry_safe(svc, cn, nn, head, s_list) {
+ u32 hash;
+
+ /* New hash for the new table */
+ if (svc->fwmark == 0) {
+ /* Hash it by <protocol,addr,port> */
+ hash = ip_vs_svc_hashval(t_new, svc->af,
+ svc->protocol,
+ &svc->addr, svc->port);
+ } else {
+ /* Hash it by fwmark */
+ hash = ip_vs_svc_fwm_hashval(t_new, svc->af,
+ svc->fwmark);
+ }
+ hlist_bl_del_rcu(&svc->s_list);
+ head2 = t_new->buckets + (hash & t_new->mask);
+
+ hlist_bl_lock(head2);
+ WRITE_ONCE(svc->hash_key,
+ ip_vs_rht_build_hash_key(t_new, hash));
+ /* t_new->seqc are not used at this stage, we race
+ * only with add/del, so only lock the bucket.
+ */
+ hlist_bl_add_head_rcu(&svc->s_list, head2);
+ hlist_bl_unlock(head2);
+ /* Too long chain? Do it in steps */
+ if (++limit >= 64)
+ break;
+ }
+
+ hlist_bl_unlock(head);
+ write_seqcount_end(sc);
+ preempt_enable_nested();
+ local_bh_enable();
+ if (limit >= 64)
+ goto same_bucket;
+ }
+
+ /* Tables can be switched only under service_mutex */
+ while (!mutex_trylock(&ipvs->service_mutex)) {
+ cond_resched();
+ if (!ipvs->enable ||
+ test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags))
+ goto unlock_sem;
+ }
+ if (!ipvs->enable ||
+ test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags))
+ goto unlock_sem;
+
+ rcu_assign_pointer(ipvs->svc_table, t_new);
+ /* Inform readers that new table is installed */
+ smp_mb__before_atomic();
+ atomic_inc(&ipvs->svc_table_changes);
+ t_free = t;
+
+unlock_m:
+ mutex_unlock(&ipvs->service_mutex);
+
+unlock_sem:
+ up_write(&ipvs->svc_resize_sem);
+
+ if (t_free) {
+ /* RCU readers should not see more than two tables in chain.
+ * To prevent new table to be attached wait here instead of
+ * freeing the old table in RCU callback.
+ */
+ synchronize_rcu();
+ ip_vs_rht_free(t_free);
+ }
+
+out:
+ if (!ipvs->enable || !more_work ||
+ test_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags))
+ return;
+ queue_delayed_work(system_unbound_wq, &ipvs->svc_resize_work, 1);
+}
static inline void
__ip_vs_bind_svc(struct ip_vs_dest *dest, struct ip_vs_service *svc)
@@ -1357,12 +1641,13 @@ static int
ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
struct ip_vs_service **svc_p)
{
- int ret = 0;
struct ip_vs_scheduler *sched = NULL;
+ struct ip_vs_rht *t, *t_new = NULL;
int af_id = ip_vs_af_index(u->af);
- struct ip_vs_pe *pe = NULL;
struct ip_vs_service *svc = NULL;
+ struct ip_vs_pe *pe = NULL;
int ret_hooks = -1;
+ int ret = 0;
/* increase the module use count */
if (!ip_vs_use_count_inc())
@@ -1404,6 +1689,18 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
}
#endif
+ t = rcu_dereference_protected(ipvs->svc_table, 1);
+ if (!t) {
+ int lfactor = sysctl_svc_lfactor(ipvs);
+ int new_size = ip_vs_svc_desired_size(ipvs, NULL, lfactor);
+
+ t_new = ip_vs_svc_table_alloc(ipvs, new_size, lfactor);
+ if (!t_new) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+ }
+
if (!atomic_read(&ipvs->num_services[af_id])) {
ret = ip_vs_register_hooks(ipvs, u->af);
if (ret < 0)
@@ -1453,6 +1750,15 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
RCU_INIT_POINTER(svc->pe, pe);
pe = NULL;
+ if (t_new) {
+ clear_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags);
+ rcu_assign_pointer(ipvs->svc_table, t_new);
+ t_new = NULL;
+ }
+
+ /* Hash the service into the service table */
+ ip_vs_svc_hash(svc);
+
/* Update the virtual service counters */
if (svc->port == FTPPORT)
atomic_inc(&ipvs->ftpsvc_counter[af_id]);
@@ -1467,8 +1773,11 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
atomic_inc(&ipvs->nonfwm_services[af_id]);
atomic_inc(&ipvs->num_services[af_id]);
- /* Hash the service into the service table */
- ip_vs_svc_hash(svc);
+ /* Schedule resize work */
+ if (t && ip_vs_get_num_services(ipvs) > t->u_thresh &&
+ !test_and_set_bit(IP_VS_WORK_SVC_RESIZE, &ipvs->work_flags))
+ queue_delayed_work(system_unbound_wq, &ipvs->svc_resize_work,
+ 1);
*svc_p = svc;
@@ -1484,6 +1793,8 @@ ip_vs_add_service(struct netns_ipvs *ipvs, struct ip_vs_service_user_kern *u,
out_err:
+ if (t_new)
+ ip_vs_rht_free(t_new);
if (ret_hooks >= 0)
ip_vs_unregister_hooks(ipvs, u->af);
if (svc != NULL) {
@@ -1671,10 +1982,38 @@ static void ip_vs_unlink_service(struct ip_vs_service *svc, bool cleanup)
*/
static int ip_vs_del_service(struct ip_vs_service *svc)
{
+ struct netns_ipvs *ipvs;
+ struct ip_vs_rht *t, *p;
+ int ns;
+
if (svc == NULL)
return -EEXIST;
+ ipvs = svc->ipvs;
ip_vs_unlink_service(svc, false);
-
+ t = rcu_dereference_protected(ipvs->svc_table, 1);
+
+ /* Drop the table if no more services */
+ ns = ip_vs_get_num_services(ipvs);
+ if (!ns) {
+ /* Stop the resizer and drop the tables */
+ set_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags);
+ cancel_delayed_work_sync(&ipvs->svc_resize_work);
+ if (t) {
+ rcu_assign_pointer(ipvs->svc_table, NULL);
+ while (1) {
+ p = rcu_dereference_protected(t->new_tbl, 1);
+ call_rcu(&t->rcu_head, ip_vs_rht_rcu_free);
+ if (p == t)
+ break;
+ t = p;
+ }
+ }
+ } else if (ns <= t->l_thresh &&
+ !test_and_set_bit(IP_VS_WORK_SVC_RESIZE,
+ &ipvs->work_flags)) {
+ queue_delayed_work(system_unbound_wq, &ipvs->svc_resize_work,
+ 1);
+ }
return 0;
}
@@ -1684,14 +2023,36 @@ static int ip_vs_del_service(struct ip_vs_service *svc)
*/
static int ip_vs_flush(struct netns_ipvs *ipvs, bool cleanup)
{
- int idx;
+ DECLARE_IP_VS_RHT_WALK_BUCKETS();
+ struct hlist_bl_head *head;
struct ip_vs_service *svc;
- struct hlist_node *n;
+ struct hlist_bl_node *ne;
+ struct hlist_bl_node *e;
+ struct ip_vs_rht *t, *p;
+
+ /* Stop the resizer and drop the tables */
+ if (!test_and_set_bit(IP_VS_WORK_SVC_NORESIZE, &ipvs->work_flags))
+ cancel_delayed_work_sync(&ipvs->svc_resize_work);
+ /* No resizer, so now we have exclusive write access */
+
+ if (ip_vs_get_num_services(ipvs)) {
+ ip_vs_rht_walk_buckets(ipvs->svc_table, head) {
+ hlist_bl_for_each_entry_safe(svc, e, ne, head, s_list)
+ ip_vs_unlink_service(svc, cleanup);
+ }
+ }
- for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry_safe(svc, n, &ipvs->svc_table[idx],
- s_list)
- ip_vs_unlink_service(svc, cleanup);
+ /* Unregister the hash table and release it after RCU grace period */
+ t = rcu_dereference_protected(ipvs->svc_table, 1);
+ if (t) {
+ rcu_assign_pointer(ipvs->svc_table, NULL);
+ while (1) {
+ p = rcu_dereference_protected(t->new_tbl, 1);
+ call_rcu(&t->rcu_head, ip_vs_rht_rcu_free);
+ if (p == t)
+ break;
+ t = p;
+ }
}
return 0;
}
@@ -1742,19 +2103,44 @@ static int ip_vs_dst_event(struct notifier_block *this, unsigned long event,
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net *net = dev_net(dev);
struct netns_ipvs *ipvs = net_ipvs(net);
+ DECLARE_IP_VS_RHT_WALK_BUCKETS_RCU();
+ unsigned int resched_score = 0;
+ struct hlist_bl_head *head;
struct ip_vs_service *svc;
+ struct hlist_bl_node *e;
struct ip_vs_dest *dest;
- unsigned int idx;
+ int old_gen, new_gen;
if (event != NETDEV_DOWN || !ipvs)
return NOTIFY_DONE;
IP_VS_DBG(3, "%s() dev=%s\n", __func__, dev->name);
+
+ old_gen = atomic_read(&ipvs->svc_table_changes);
+
rcu_read_lock();
- for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry_rcu(svc, &ipvs->svc_table[idx], s_list)
+
+repeat:
+ smp_rmb(); /* ipvs->svc_table and svc_table_changes */
+ ip_vs_rht_walk_buckets_rcu(ipvs->svc_table, head) {
+ hlist_bl_for_each_entry_rcu(svc, e, head, s_list) {
list_for_each_entry_rcu(dest, &svc->destinations,
- n_list)
+ n_list) {
ip_vs_forget_dev(dest, dev);
+ resched_score += 10;
+ }
+ resched_score++;
+ }
+ resched_score++;
+ if (resched_score >= 100) {
+ resched_score = 0;
+ cond_resched_rcu();
+ new_gen = atomic_read(&ipvs->svc_table_changes);
+ /* New table installed ? */
+ if (old_gen != new_gen) {
+ old_gen = new_gen;
+ goto repeat;
+ }
+ }
}
rcu_read_unlock();
@@ -1777,14 +2163,28 @@ static int ip_vs_zero_service(struct ip_vs_service *svc)
static int ip_vs_zero_all(struct netns_ipvs *ipvs)
{
- int idx;
+ DECLARE_IP_VS_RHT_WALK_BUCKETS_RCU();
+ unsigned int resched_score = 0;
+ struct hlist_bl_head *head;
struct ip_vs_service *svc;
+ struct hlist_bl_node *e;
+
+ rcu_read_lock();
- for(idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry(svc, &ipvs->svc_table[idx], s_list)
+ ip_vs_rht_walk_buckets_rcu(ipvs->svc_table, head) {
+ hlist_bl_for_each_entry_rcu(svc, e, head, s_list) {
ip_vs_zero_service(svc);
+ resched_score += 10;
+ }
+ resched_score++;
+ if (resched_score >= 100) {
+ resched_score = 0;
+ cond_resched_rcu();
+ }
}
+ rcu_read_unlock();
+
ip_vs_zero_stats(&ipvs->tot_stats->s);
return 0;
}
@@ -2218,7 +2618,8 @@ static struct ctl_table vs_vars[] = {
struct ip_vs_iter {
struct seq_net_private p; /* Do not move this, netns depends upon it*/
- int bucket;
+ struct ip_vs_rht *t;
+ u32 bucket;
};
/*
@@ -2239,17 +2640,23 @@ static inline const char *ip_vs_fwd_name(unsigned int flags)
}
}
-
+/* Do not expect consistent view during add, del and move(table resize).
+ * We may miss entries and even show duplicates.
+ */
static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)
{
- struct net *net = seq_file_net(seq);
- struct netns_ipvs *ipvs = net_ipvs(net);
struct ip_vs_iter *iter = seq->private;
- int idx;
+ struct ip_vs_rht *t = iter->t;
struct ip_vs_service *svc;
+ struct hlist_bl_node *e;
+ int idx;
- for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry_rcu(svc, &ipvs->svc_table[idx], s_list) {
+ if (!t)
+ return NULL;
+ for (idx = 0; idx < t->size; idx++) {
+ hlist_bl_for_each_entry_rcu(svc, e, &t->buckets[idx], s_list) {
+ if (!ip_vs_rht_same_table(t, READ_ONCE(svc->hash_key)))
+ break;
if (pos-- == 0) {
iter->bucket = idx;
return svc;
@@ -2262,18 +2669,22 @@ static struct ip_vs_service *ip_vs_info_array(struct seq_file *seq, loff_t pos)
static void *ip_vs_info_seq_start(struct seq_file *seq, loff_t *pos)
__acquires(RCU)
{
+ struct ip_vs_iter *iter = seq->private;
+ struct net *net = seq_file_net(seq);
+ struct netns_ipvs *ipvs = net_ipvs(net);
+
rcu_read_lock();
+ iter->t = rcu_dereference(ipvs->svc_table);
return *pos ? ip_vs_info_array(seq, *pos - 1) : SEQ_START_TOKEN;
}
static void *ip_vs_info_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct hlist_node *e;
- struct ip_vs_iter *iter;
struct ip_vs_service *svc;
- struct net *net = seq_file_net(seq);
- struct netns_ipvs *ipvs = net_ipvs(net);
+ struct ip_vs_iter *iter;
+ struct hlist_bl_node *e;
+ struct ip_vs_rht *t;
++*pos;
if (v == SEQ_START_TOKEN)
@@ -2281,15 +2692,22 @@ static void *ip_vs_info_seq_next(struct seq_file *seq, void *v, loff_t *pos)
svc = v;
iter = seq->private;
+ t = iter->t;
+ if (!t)
+ return NULL;
- e = rcu_dereference(hlist_next_rcu(&svc->s_list));
- if (e)
- return hlist_entry(e, struct ip_vs_service, s_list);
+ hlist_bl_for_each_entry_continue_rcu(svc, e, s_list) {
+ /* Our cursor was moved to new table ? */
+ if (!ip_vs_rht_same_table(t, READ_ONCE(svc->hash_key)))
+ break;
+ return svc;
+ }
- while (++iter->bucket < IP_VS_SVC_TAB_SIZE) {
- hlist_for_each_entry_rcu(svc,
- &ipvs->svc_table[iter->bucket],
- s_list) {
+ while (++iter->bucket < t->size) {
+ hlist_bl_for_each_entry_rcu(svc, e, &t->buckets[iter->bucket],
+ s_list) {
+ if (!ip_vs_rht_same_table(t, READ_ONCE(svc->hash_key)))
+ break;
return svc;
}
}
@@ -2770,13 +3188,18 @@ __ip_vs_get_service_entries(struct netns_ipvs *ipvs,
const struct ip_vs_get_services *get,
struct ip_vs_get_services __user *uptr)
{
- int idx, count=0;
- struct ip_vs_service *svc;
struct ip_vs_service_entry entry;
+ DECLARE_IP_VS_RHT_WALK_BUCKETS();
+ struct hlist_bl_head *head;
+ struct ip_vs_service *svc;
+ struct hlist_bl_node *e;
+ int count = 0;
int ret = 0;
- for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++) {
- hlist_for_each_entry(svc, &ipvs->svc_table[idx], s_list) {
+ lockdep_assert_held(&ipvs->svc_resize_sem);
+ /* All service modifications are disabled, go ahead */
+ ip_vs_rht_walk_buckets(ipvs->svc_table, head) {
+ hlist_bl_for_each_entry(svc, e, head, s_list) {
/* Only expose IPv4 entries to old interface */
if (svc->af != AF_INET)
continue;
@@ -2948,6 +3371,35 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
return ret;
}
+ if (cmd == IP_VS_SO_GET_SERVICES) {
+ struct ip_vs_get_services *get;
+ int size;
+
+ get = (struct ip_vs_get_services *)arg;
+ size = struct_size(get, entrytable, get->num_services);
+ if (*len != size) {
+ pr_err("length: %u != %u\n", *len, size);
+ return -EINVAL;
+ }
+ /* Protect against table resizer moving the entries.
+ * Try reverse locking, so that we do not hold the mutex
+ * while waiting for semaphore.
+ */
+ while (1) {
+ ret = down_read_killable(&ipvs->svc_resize_sem);
+ if (ret < 0)
+ return ret;
+ if (mutex_trylock(&ipvs->service_mutex))
+ break;
+ up_read(&ipvs->svc_resize_sem);
+ cond_resched();
+ }
+ ret = __ip_vs_get_service_entries(ipvs, get, user);
+ up_read(&ipvs->svc_resize_sem);
+ mutex_unlock(&ipvs->service_mutex);
+ return ret;
+ }
+
mutex_lock(&ipvs->service_mutex);
switch (cmd) {
case IP_VS_SO_GET_VERSION:
@@ -2976,22 +3428,6 @@ do_ip_vs_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
}
break;
- case IP_VS_SO_GET_SERVICES:
- {
- struct ip_vs_get_services *get;
- int size;
-
- get = (struct ip_vs_get_services *)arg;
- size = struct_size(get, entrytable, get->num_services);
- if (*len != size) {
- pr_err("length: %u != %u\n", *len, size);
- ret = -EINVAL;
- goto out;
- }
- ret = __ip_vs_get_service_entries(ipvs, get, user);
- }
- break;
-
case IP_VS_SO_GET_SERVICE:
{
struct ip_vs_service_entry *entry;
@@ -3277,15 +3713,19 @@ static int ip_vs_genl_dump_service(struct sk_buff *skb,
static int ip_vs_genl_dump_services(struct sk_buff *skb,
struct netlink_callback *cb)
{
- int idx = 0, i;
- int start = cb->args[0];
- struct ip_vs_service *svc;
+ DECLARE_IP_VS_RHT_WALK_BUCKETS_SAFE_RCU();
struct net *net = sock_net(skb->sk);
struct netns_ipvs *ipvs = net_ipvs(net);
+ struct hlist_bl_head *head;
+ struct ip_vs_service *svc;
+ struct hlist_bl_node *e;
+ int start = cb->args[0];
+ int idx = 0;
+ down_read(&ipvs->svc_resize_sem);
rcu_read_lock();
- for (i = 0; i < IP_VS_SVC_TAB_SIZE; i++) {
- hlist_for_each_entry_rcu(svc, &ipvs->svc_table[i], s_list) {
+ ip_vs_rht_walk_buckets_safe_rcu(ipvs->svc_table, head) {
+ hlist_bl_for_each_entry_rcu(svc, e, head, s_list) {
if (++idx <= start)
continue;
if (ip_vs_genl_dump_service(skb, svc, cb) < 0) {
@@ -3297,6 +3737,7 @@ static int ip_vs_genl_dump_services(struct sk_buff *skb,
nla_put_failure:
rcu_read_unlock();
+ up_read(&ipvs->svc_resize_sem);
cb->args[0] = idx;
return skb->len;
@@ -4300,8 +4741,10 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)
/* Initialize service_mutex, svc_table per netns */
__mutex_init(&ipvs->service_mutex, "ipvs->service_mutex", &__ipvs_service_key);
- for (idx = 0; idx < IP_VS_SVC_TAB_SIZE; idx++)
- INIT_HLIST_HEAD(&ipvs->svc_table[idx]);
+ init_rwsem(&ipvs->svc_resize_sem);
+ INIT_DELAYED_WORK(&ipvs->svc_resize_work, svc_resize_work_handler);
+ atomic_set(&ipvs->svc_table_changes, 0);
+ RCU_INIT_POINTER(ipvs->svc_table, NULL);
/* Initialize rs_table */
for (idx = 0; idx < IP_VS_RTAB_SIZE; idx++)
@@ -4320,6 +4763,7 @@ int __net_init ip_vs_control_net_init(struct netns_ipvs *ipvs)
}
INIT_DELAYED_WORK(&ipvs->est_reload_work, est_reload_work_handler);
+ ipvs->sysctl_svc_lfactor = ip_vs_svc_default_load_factor(ipvs);
/* procfs stats */
ipvs->tot_stats = kzalloc(sizeof(*ipvs->tot_stats), GFP_KERNEL);
--
2.43.0
