/**
* @brief Check for expired TCP DRCs.
*/
static inline void drc_free_expired(void)
{
drc_t *drc;
time_t now = time(NULL);
struct rbtree_x_part *t;
struct opr_rbtree_node *odrc = NULL;
DRC_ST_LOCK();
if ((drc_st->tcp_drc_recycle_qlen < 1) ||
(now - drc_st->last_expire_check) < 600) /* 10m */
goto unlock;
do {
drc = TAILQ_FIRST(&drc_st->tcp_drc_recycle_q);
if (drc && (drc->d_u.tcp.recycle_time > 0)
&& ((now - drc->d_u.tcp.recycle_time) >
drc_st->expire_delta) && (drc->refcnt == 0)) {
LogFullDebug(COMPONENT_DUPREQ,
"remove expired drc %p from recycle queue",
drc);
t = rbtx_partition_of_scalar(&drc_st->tcp_drc_recycle_t,
drc->d_u.tcp.hk);
odrc =
opr_rbtree_lookup(&t->t, &drc->d_u.tcp.recycle_k);
if (!odrc) {
LogCrit(COMPONENT_DUPREQ,
"BUG: asked to dequeue DRC not on queue");
} else {
(void)opr_rbtree_remove(&t->t,
&drc->d_u.tcp.
recycle_k);
}
TAILQ_REMOVE(&drc_st->tcp_drc_recycle_q, drc,
d_u.tcp.recycle_q);
--(drc_st->tcp_drc_recycle_qlen);
/* expect DRC to be reachable from some xprt(s) */
PTHREAD_MUTEX_lock(&drc->mtx);
drc->flags &= ~DRC_FLAG_RECYCLE;
/* but if not, dispose it */
if (drc->refcnt == 0) {
PTHREAD_MUTEX_unlock(&drc->mtx);
free_tcp_drc(drc);
continue;
}
PTHREAD_MUTEX_unlock(&drc->mtx);
} else {
LogFullDebug(COMPONENT_DUPREQ,
"unexpired drc %p in recycle queue expire check (nothing happens)",
drc);
drc_st->last_expire_check = now;
break;
}
} while (1);
unlock:
DRC_ST_UNLOCK();
}
/**
* @brief Release previously-ref'd DRC.
*
* Release previously-ref'd DRC. If its refcnt drops to 0, the DRC
* is queued for later recycling.
*
* @param[in] xprt The SVCXPRT associated with DRC, if applicable
* @param[in] drc The DRC
* @param[in] flags Control flags
*/
void nfs_dupreq_put_drc(SVCXPRT *xprt, drc_t *drc, uint32_t flags)
{
if (!(flags & DRC_FLAG_LOCKED))
pthread_mutex_lock(&drc->mtx);
/* drc LOCKED */
if (drc->refcnt == 0) {
LogCrit(COMPONENT_DUPREQ,
"drc %p refcnt will underrun " "refcnt=%u", drc,
drc->refcnt);
}
nfs_dupreq_unref_drc(drc);
LogFullDebug(COMPONENT_DUPREQ, "drc %p refcnt==%u", drc, drc->refcnt);
switch (drc->type) {
case DRC_UDP_V234:
/* do nothing */
break;
case DRC_TCP_V4:
case DRC_TCP_V3:
if (drc->refcnt == 0) {
if (!(drc->flags & DRC_FLAG_RECYCLE)) {
/* note t's lock order wrt drc->mtx is
* the opposite of drc->xt[*].lock */
drc->d_u.tcp.recycle_time = time(NULL);
drc->flags |= DRC_FLAG_RECYCLE;
pthread_mutex_unlock(&drc->mtx); /* !LOCKED */
DRC_ST_LOCK();
TAILQ_INSERT_TAIL(&drc_st->tcp_drc_recycle_q,
drc, d_u.tcp.recycle_q);
++(drc_st->tcp_drc_recycle_qlen);
LogFullDebug(COMPONENT_DUPREQ,
"enqueue drc %p for recycle", drc);
DRC_ST_UNLOCK();
goto out;
}
}
default:
break;
};
pthread_mutex_unlock(&drc->mtx); /* !LOCKED */
out:
return;
}
/**
* @brief Find and reference a DRC to process the supplied svc_req.
*
* @param[in] req The svc_req being processed.
*
* @return The ref'd DRC if sucessfully located, else NULL.
*/
static /* inline */ drc_t *
nfs_dupreq_get_drc(struct svc_req *req)
{
enum drc_type dtype = get_drc_type(req);
drc_t *drc = NULL;
bool drc_check_expired = false;
switch (dtype) {
case DRC_UDP_V234:
LogFullDebug(COMPONENT_DUPREQ, "ref shared UDP DRC");
drc = &(drc_st->udp_drc);
DRC_ST_LOCK();
(void)nfs_dupreq_ref_drc(drc);
DRC_ST_UNLOCK();
goto out;
case DRC_TCP_V4:
case DRC_TCP_V3:
/* Idempotent address, no need for lock;
* xprt will be valid as long as svc_req.
*/
drc = (drc_t *)req->rq_xprt->xp_u2;
if (drc) {
/* found, no danger of removal */
LogFullDebug(COMPONENT_DUPREQ, "ref DRC=%p for xprt=%p",
drc, req->rq_xprt);
PTHREAD_MUTEX_lock(&drc->mtx); /* LOCKED */
} else {
drc_t drc_k;
struct rbtree_x_part *t = NULL;
struct opr_rbtree_node *ndrc = NULL;
drc_t *tdrc = NULL;
memset(&drc_k, 0, sizeof(drc_k));
drc_k.type = dtype;
/* Since the drc can last longer than the xprt,
* copy the address. Read operation of constant data,
* no xprt lock required.
*/
(void)copy_xprt_addr(&drc_k.d_u.tcp.addr, req->rq_xprt);
drc_k.d_u.tcp.hk =
CityHash64WithSeed((char *)&drc_k.d_u.tcp.addr,
sizeof(sockaddr_t), 911);
{
char str[SOCK_NAME_MAX];
sprint_sockaddr(&drc_k.d_u.tcp.addr,
str, sizeof(str));
LogFullDebug(COMPONENT_DUPREQ,
"get drc for addr: %s", str);
}
t = rbtx_partition_of_scalar(&drc_st->tcp_drc_recycle_t,
drc_k.d_u.tcp.hk);
DRC_ST_LOCK();
ndrc =
opr_rbtree_lookup(&t->t, &drc_k.d_u.tcp.recycle_k);
if (ndrc) {
/* reuse old DRC */
tdrc =
opr_containerof(ndrc, drc_t,
d_u.tcp.recycle_k);
PTHREAD_MUTEX_lock(&tdrc->mtx); /* LOCKED */
if (tdrc->flags & DRC_FLAG_RECYCLE) {
TAILQ_REMOVE(&drc_st->tcp_drc_recycle_q,
tdrc, d_u.tcp.recycle_q);
--(drc_st->tcp_drc_recycle_qlen);
tdrc->flags &= ~DRC_FLAG_RECYCLE;
}
drc = tdrc;
LogFullDebug(COMPONENT_DUPREQ,
"recycle TCP DRC=%p for xprt=%p",
tdrc, req->rq_xprt);
}
if (!drc) {
drc = alloc_tcp_drc(dtype);
LogFullDebug(COMPONENT_DUPREQ,
"alloc new TCP DRC=%p for xprt=%p",
drc, req->rq_xprt);
/* assign addr */
memcpy(&drc->d_u.tcp.addr, &drc_k.d_u.tcp.addr,
sizeof(sockaddr_t));
/* assign already-computed hash */
drc->d_u.tcp.hk = drc_k.d_u.tcp.hk;
PTHREAD_MUTEX_lock(&drc->mtx); /* LOCKED */
/* xprt ref */
drc->refcnt = 1;
/* insert dict */
opr_rbtree_insert(&t->t,
&drc->d_u.tcp.recycle_k);
}
DRC_ST_UNLOCK();
drc->d_u.tcp.recycle_time = 0;
(void)nfs_dupreq_ref_drc(drc); /* xprt ref */
/* try to expire unused DRCs somewhat in proportion to
* new connection arrivals */
drc_check_expired = true;
LogFullDebug(COMPONENT_DUPREQ,
"after ref drc %p refcnt==%u ", drc,
drc->refcnt);
/* Idempotent address, no need for lock;
* set once here, never changes.
* No other fields are modified.
* Assumes address stores are atomic.
*/
req->rq_xprt->xp_u2 = (void *)drc;
}
break;
default:
/* XXX error */
break;
}
/* call path ref */
(void)nfs_dupreq_ref_drc(drc);
PTHREAD_MUTEX_unlock(&drc->mtx);
if (drc_check_expired)
drc_free_expired();
out:
return drc;
}
/**
* @brief Find and reference a DRC to process the supplied svc_req.
*
* @param[in] req The svc_req being processed.
*
* @return The ref'd DRC if sucessfully located, else NULL.
*/
static /* inline */ drc_t *
nfs_dupreq_get_drc(struct svc_req *req)
{
enum drc_type dtype = get_drc_type(req);
gsh_xprt_private_t *xu = (gsh_xprt_private_t *) req->rq_xprt->xp_u1;
drc_t *drc = NULL;
bool drc_check_expired = false;
switch (dtype) {
case DRC_UDP_V234:
LogFullDebug(COMPONENT_DUPREQ, "ref shared UDP DRC");
drc = &(drc_st->udp_drc);
DRC_ST_LOCK();
(void)nfs_dupreq_ref_drc(drc);
DRC_ST_UNLOCK();
goto out;
break;
case DRC_TCP_V4:
case DRC_TCP_V3:
pthread_mutex_lock(&req->rq_xprt->xp_lock);
if (xu->drc) {
drc = xu->drc;
LogFullDebug(COMPONENT_DUPREQ, "ref DRC=%p for xprt=%p",
drc, req->rq_xprt);
pthread_mutex_lock(&drc->mtx); /* LOCKED */
} else {
drc_t drc_k;
struct rbtree_x_part *t = NULL;
struct opr_rbtree_node *ndrc = NULL;
drc_t *tdrc = NULL;
memset(&drc_k, 0, sizeof(drc_k));
drc_k.type = dtype;
(void)copy_xprt_addr(&drc_k.d_u.tcp.addr, req->rq_xprt);
drc_k.d_u.tcp.hk =
CityHash64WithSeed((char *)&drc_k.d_u.tcp.addr,
sizeof(sockaddr_t), 911);
{
char str[512];
sprint_sockaddr(&drc_k.d_u.tcp.addr, str, 512);
LogFullDebug(COMPONENT_DUPREQ,
"get drc for addr: %s", str);
}
t = rbtx_partition_of_scalar(&drc_st->tcp_drc_recycle_t,
drc_k.d_u.tcp.hk);
DRC_ST_LOCK();
ndrc =
opr_rbtree_lookup(&t->t, &drc_k.d_u.tcp.recycle_k);
if (ndrc) {
/* reuse old DRC */
tdrc =
opr_containerof(ndrc, drc_t,
d_u.tcp.recycle_k);
pthread_mutex_lock(&tdrc->mtx); /* LOCKED */
if (tdrc->flags & DRC_FLAG_RECYCLE) {
TAILQ_REMOVE(&drc_st->tcp_drc_recycle_q,
tdrc, d_u.tcp.recycle_q);
--(drc_st->tcp_drc_recycle_qlen);
tdrc->flags &= ~DRC_FLAG_RECYCLE;
}
drc = tdrc;
LogFullDebug(COMPONENT_DUPREQ,
"recycle TCP DRC=%p for xprt=%p",
tdrc, req->rq_xprt);
}
if (!drc) {
drc = alloc_tcp_drc(dtype);
LogFullDebug(COMPONENT_DUPREQ,
"alloc new TCP DRC=%p for xprt=%p",
drc, req->rq_xprt);
/* assign addr */
memcpy(&drc->d_u.tcp.addr, &drc_k.d_u.tcp.addr,
sizeof(sockaddr_t));
/* assign already-computed hash */
drc->d_u.tcp.hk = drc_k.d_u.tcp.hk;
pthread_mutex_lock(&drc->mtx); /* LOCKED */
/* xprt ref */
drc->refcnt = 1;
/* insert dict */
opr_rbtree_insert(&t->t,
&drc->d_u.tcp.recycle_k);
}
DRC_ST_UNLOCK();
drc->d_u.tcp.recycle_time = 0;
/* xprt drc */
(void)nfs_dupreq_ref_drc(drc); /* xu ref */
/* try to expire unused DRCs somewhat in proportion to
* new connection arrivals */
drc_check_expired = true;
LogFullDebug(COMPONENT_DUPREQ,
"after ref drc %p refcnt==%u ", drc,
drc->refcnt);
xu->drc = drc;
}
pthread_mutex_unlock(&req->rq_xprt->xp_lock);
break;
default:
/* XXX error */
break;
}
/* call path ref */
(void)nfs_dupreq_ref_drc(drc);
pthread_mutex_unlock(&drc->mtx);
if (drc_check_expired)
drc_free_expired();
out:
return drc;
}
