#define FALSE 0
/*
- * Estimate rto for an nfs rpc sent via. an unreliable datagram.
- * Use the mean and mean deviation of rtt for the appropriate type of rpc
- * for the frequent rpcs and a default for the others.
- * The justification for doing "other" this way is that these rpcs
- * happen so infrequently that timer est. would probably be stale.
- * Also, since many of these rpcs are
- * non-idempotent, a conservative timeout is desired.
- * getattr, lookup - A+2D
- * read, write - A+4D
- * other - nm_timeo
+ * RTT calculations are scaled by 256 (8 bits). A proper fractional
+ * RTT will still be calculated even with a slow NFS timer.
*/
-#define NFS_RTO(n, t) \
- ((t) == 0 ? (n)->nm_timeo : \
- ((t) < 3 ? \
- (((((n)->nm_srtt[t-1] + 3) >> 2) + (n)->nm_sdrtt[t-1] + 1) >> 1) : \
- ((((n)->nm_srtt[t-1] + 7) >> 3) + (n)->nm_sdrtt[t-1] + 1)))
-#define NFS_SRTT(r) (r)->r_nmp->nm_srtt[proct[(r)->r_procnum] - 1]
-#define NFS_SDRTT(r) (r)->r_nmp->nm_sdrtt[proct[(r)->r_procnum] - 1]
+#define NFS_SRTT(r) (r)->r_nmp->nm_srtt[proct[(r)->r_procnum]]
+#define NFS_SDRTT(r) (r)->r_nmp->nm_sdrtt[proct[(r)->r_procnum]]
+#define NFS_RTT_SCALE_BITS 8 /* bits */
+#define NFS_RTT_SCALE 256 /* value */
/*
* Defines which timer to use for the procnum.
0, 0, 0,
};
+static int nfs_backoff[8] = { 2, 3, 5, 8, 13, 21, 34, 55 };
static int nfs_realign_test;
static int nfs_realign_count;
static int nfs_bufpackets = 4;
-static int nfs_timer_raced;
+static int nfs_showrtt;
+static int nfs_showrexmit;
SYSCTL_DECL(_vfs_nfs);
SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_test, CTLFLAG_RW, &nfs_realign_test, 0, "");
SYSCTL_INT(_vfs_nfs, OID_AUTO, realign_count, CTLFLAG_RW, &nfs_realign_count, 0, "");
SYSCTL_INT(_vfs_nfs, OID_AUTO, bufpackets, CTLFLAG_RW, &nfs_bufpackets, 0, "");
+SYSCTL_INT(_vfs_nfs, OID_AUTO, showrtt, CTLFLAG_RW, &nfs_showrtt, 0, "");
+SYSCTL_INT(_vfs_nfs, OID_AUTO, showrexmit, CTLFLAG_RW, &nfs_showrexmit, 0, "");
static int nfs_request_setup(nfsm_info_t info);
static int nfs_request_auth(struct nfsreq *rep);
static int nfs_request_try(struct nfsreq *rep);
static int nfs_request_waitreply(struct nfsreq *rep);
static int nfs_request_processreply(nfsm_info_t info, int);
-static void nfs_async_return(struct nfsmount *nmp, struct nfsreq *rep);
-/*
- * There is a congestion window for outstanding rpcs maintained per mount
- * point. The cwnd size is adjusted in roughly the way that:
- * Van Jacobson, Congestion avoidance and Control, In "Proceedings of
- * SIGCOMM '88". ACM, August 1988.
- * describes for TCP. The cwnd size is chopped in half on a retransmit timeout
- * and incremented by 1/cwnd when each rpc reply is received and a full cwnd
- * of rpcs is in progress.
- * (The sent count and cwnd are scaled for integer arith.)
- * Variants of "slow start" were tried and were found to be too much of a
- * performance hit (ave. rtt 3 times larger),
- * I suspect due to the large rtt that nfs rpcs have.
- */
-#define NFS_CWNDSCALE 256
-#define NFS_MAXCWND (NFS_CWNDSCALE * 32)
-static int nfs_backoff[8] = { 2, 4, 8, 16, 32, 64, 128, 256, };
int nfsrtton = 0;
struct nfsrtt nfsrtt;
struct callout nfs_timer_handle;
static void nfs_realign (struct mbuf **pm, int hsiz);
static int nfs_receive (struct nfsmount *nmp, struct nfsreq *rep,
struct sockaddr **aname, struct mbuf **mp);
-static void nfs_softterm (struct nfsreq *rep);
+static void nfs_softterm (struct nfsreq *rep, int islocked);
+static void nfs_hardterm (struct nfsreq *rep, int islocked);
static int nfs_reconnect (struct nfsmount *nmp, struct nfsreq *rep);
#ifndef NFS_NOSERVER
static int nfsrv_getstream (struct nfssvc_sock *, int, int *);
/* Initialize other non-zero congestion variables */
nmp->nm_srtt[0] = nmp->nm_srtt[1] = nmp->nm_srtt[2] =
- nmp->nm_srtt[3] = (NFS_TIMEO << 3);
+ nmp->nm_srtt[3] = (NFS_TIMEO << NFS_RTT_SCALE_BITS);
nmp->nm_sdrtt[0] = nmp->nm_sdrtt[1] = nmp->nm_sdrtt[2] =
nmp->nm_sdrtt[3] = 0;
- nmp->nm_cwnd = NFS_MAXCWND / 2; /* Initial send window */
- nmp->nm_sent = 0;
+ nmp->nm_maxasync_scaled = NFS_MINASYNC_SCALED;
nmp->nm_timeouts = 0;
return (0);
* Called when a connection is broken on a reliable protocol.
* - clean up the old socket
* - nfs_connect() again
- * - set R_MUSTRESEND for all outstanding requests on mount point
+ * - set R_NEEDSXMIT for all outstanding requests on mount point
* If this fails the mount point is DEAD!
* nb: Must be called with the nfs_sndlock() set on the mount point.
*/
crit_enter();
TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
KKASSERT(req->r_nmp == nmp);
- req->r_flags |= R_MUSTRESEND;
+ req->r_flags |= R_NEEDSXMIT;
}
crit_exit();
return (0);
* "rep == NULL" indicates that it has been called from a server.
* For the client side:
* - return EINTR if the RPC is terminated, 0 otherwise
- * - set R_MUSTRESEND if the send fails for any reason
+ * - set R_NEEDSXMIT if the send fails for any reason
* - do any cleanup required by recoverable socket errors (?)
* For the server side:
* - return EINTR or ERESTART if interrupted by a signal
return (EINTR);
}
if ((so = rep->r_nmp->nm_so) == NULL) {
- rep->r_flags |= R_MUSTRESEND;
+ rep->r_flags |= R_NEEDSXMIT;
m_freem(top);
return (0);
}
- rep->r_flags &= ~R_MUSTRESEND;
+ rep->r_flags &= ~R_NEEDSXMIT;
soflags = rep->r_nmp->nm_soflags;
- } else
+ } else {
soflags = so->so_proto->pr_flags;
+ }
if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
sendnam = NULL;
else
*/
if (error == ENOBUFS && so->so_type == SOCK_DGRAM) {
error = 0;
- if (rep) /* do backoff retransmit on client */
- rep->r_flags |= R_MUSTRESEND;
+ /*
+ * do backoff retransmit on client
+ */
+ if (rep)
+ rep->r_flags |= R_NEEDSXMIT;
}
if (error) {
if (rep->r_flags & R_SOFTTERM)
error = EINTR;
else
- rep->r_flags |= R_MUSTRESEND;
- } else
+ rep->r_flags |= R_NEEDSXMIT;
+ } else {
log(LOG_INFO, "nfsd send error %d\n", error);
+ }
/*
* Handle any recoverable (soft) socket errors here. (?)
}
goto tryagain;
}
- while (rep && (rep->r_flags & R_MUSTRESEND)) {
+ while (rep && (rep->r_flags & R_NEEDSXMIT)) {
m = m_copym(rep->r_mreq, 0, M_COPYALL, MB_WAIT);
nfsstats.rpcretries++;
error = nfs_send(so, rep->r_nmp->nm_nam, m, rep);
u_int32_t *tl;
int error;
struct nfsm_info info;
- int t1;
/*
* Loop around until we get our own reply
/*
* Get the next Rpc reply off the socket
+ *
+ * We cannot release the receive lock until we've
+ * filled in rep->r_mrep, otherwise a waiting
+ * thread may deadlock in soreceive with no incoming
+ * packets expected.
*/
error = nfs_receive(nmp, myrep, &nam, &info.mrep);
- nfs_rcvunlock(nmp);
if (error) {
/*
* Ignore routing errors on connectionless protocols??
*/
+ nfs_rcvunlock(nmp);
if (NFSIGNORE_SOERROR(nmp->nm_soflags, error)) {
if (nmp->nm_so == NULL)
return (error);
m_freem(info.mrep);
info.mrep = NULL;
nfsmout:
+ nfs_rcvunlock(nmp);
continue;
}
if (rep->r_mrep == NULL && rxid == rep->r_xid)
break;
}
- crit_exit();
/*
* Fill in the rest of the reply if we found a match.
rt = &nfsrtt.rttl[nfsrtt.pos];
rt->proc = rep->r_procnum;
- rt->rto = NFS_RTO(nmp, proct[rep->r_procnum]);
- rt->sent = nmp->nm_sent;
- rt->cwnd = nmp->nm_cwnd;
+ rt->rto = 0;
+ rt->sent = 0;
+ rt->cwnd = nmp->nm_maxasync_scaled;
rt->srtt = nmp->nm_srtt[proct[rep->r_procnum] - 1];
rt->sdrtt = nmp->nm_sdrtt[proct[rep->r_procnum] - 1];
rt->fsid = nmp->nm_mountp->mnt_stat.f_fsid;
rt->rtt = 1000000;
nfsrtt.pos = (nfsrtt.pos + 1) % NFSRTTLOGSIZ;
}
+
/*
- * Update congestion window.
- * Do the additive increase of
- * one rpc/rtt.
+ * New congestion control is based only on async
+ * requests.
*/
- if (nmp->nm_cwnd <= nmp->nm_sent) {
- nmp->nm_cwnd +=
- (NFS_CWNDSCALE * NFS_CWNDSCALE +
- (nmp->nm_cwnd >> 1)) / nmp->nm_cwnd;
- if (nmp->nm_cwnd > NFS_MAXCWND)
- nmp->nm_cwnd = NFS_MAXCWND;
- }
- crit_enter(); /* nfs_timer interlock for nm_sent */
+ if (nmp->nm_maxasync_scaled < NFS_MAXASYNC_SCALED)
+ ++nmp->nm_maxasync_scaled;
if (rep->r_flags & R_SENT) {
rep->r_flags &= ~R_SENT;
- nmp->nm_sent -= NFS_CWNDSCALE;
}
- crit_exit();
/*
* Update rtt using a gain of 0.125 on the mean
* and a gain of 0.25 on the deviation.
+ *
+ * NOTE SRTT/SDRTT are only good if R_TIMING is set.
*/
if (rep->r_flags & R_TIMING) {
/*
* rtt is between N+dt and N+2-dt ticks,
* add 1.
*/
- t1 = rep->r_rtt + 1;
- t1 -= (NFS_SRTT(rep) >> 3);
- NFS_SRTT(rep) += t1;
- if (t1 < 0)
- t1 = -t1;
- t1 -= (NFS_SDRTT(rep) >> 2);
- NFS_SDRTT(rep) += t1;
- }
- nmp->nm_timeouts = 0;
- rep->r_mrep = info.mrep;
+ int n;
+ int d;
- /*
- * Wakeup anyone waiting explicitly for this reply.
- */
- mtx_abort_ex_link(&rep->r_nmp->nm_rxlock, &rep->r_link);
+#define NFSRSB NFS_RTT_SCALE_BITS
+ n = ((NFS_SRTT(rep) * 7) +
+ (rep->r_rtt << NFSRSB)) >> 3;
+ d = n - NFS_SRTT(rep);
+ NFS_SRTT(rep) = n;
- /*
- * Asynchronous replies are bound-over to the
- * rxthread. Note that nmp->nm_reqqlen is not
- * decremented until the rxthread has finished
- * with the request.
- *
- * async is sometimes temporarily turned off to
- * avoid races.
- */
- if (rep->r_info && rep->r_info->async) {
- KKASSERT(rep->r_info->state ==
- NFSM_STATE_WAITREPLY ||
- rep->r_info->state ==
- NFSM_STATE_TRY);
- nfs_async_return(nmp, rep);
+ /*
+ * Don't let the jitter calculation decay
+ * too quickly, but we want a fast rampup.
+ */
+ if (d < 0)
+ d = -d;
+ d <<= NFSRSB;
+ if (d < NFS_SDRTT(rep))
+ n = ((NFS_SDRTT(rep) * 15) + d) >> 4;
+ else
+ n = ((NFS_SDRTT(rep) * 3) + d) >> 2;
+ NFS_SDRTT(rep) = n;
+#undef NFSRSB
}
+ nmp->nm_timeouts = 0;
+ rep->r_mrep = info.mrep;
+ nfs_hardterm(rep, 0);
}
+ nfs_rcvunlock(nmp);
+ crit_exit();
+
/*
* If not matched to a request, drop it.
* If it's mine, get out.
int
nfs_request(struct nfsm_info *info, nfsm_state_t bstate, nfsm_state_t estate)
{
- struct nfsmount *nmp = info->nmp;
struct nfsreq *req;
while (info->state >= bstate && info->state < estate) {
* next state.
*
* This can trivially race the receiver if the
- * request is asynchronous. Temporarily turn
- * off async mode so the structure doesn't get
- * ripped out from under us, and resolve the
- * race.
+ * request is asynchronous. nfs_request_try()
+ * will thus set the state for us and we
+ * must also return immediately if we are
+ * running an async state machine, because
+ * info can become invalid due to races after
+ * try() returns.
*/
- if (info->async) {
- info->async = 0;
- info->error = nfs_request_try(info->req);
- crit_enter();
- info->async = 1;
- KKASSERT(info->state == NFSM_STATE_TRY);
- if (info->req->r_mrep)
- nfs_async_return(nmp, info->req);
- else
- info->state = NFSM_STATE_WAITREPLY;
- crit_exit();
+ if (info->req->r_flags & R_ASYNC) {
+ nfs_request_try(info->req);
+ if (estate == NFSM_STATE_WAITREPLY)
+ return (EINPROGRESS);
} else {
- info->error = nfs_request_try(info->req);
+ nfs_request_try(info->req);
info->state = NFSM_STATE_WAITREPLY;
}
-
- /*
- * The backend can rip the request out from under
- * is at this point. If we were async the estate
- * will be set to WAITREPLY. Return immediately.
- */
- if (estate == NFSM_STATE_WAITREPLY)
- return (EINPROGRESS);
break;
case NFSM_STATE_WAITREPLY:
/*
req->r_td = info->td;
req->r_procnum = info->procnum;
req->r_mreq = NULL;
+ req->r_cred = info->cred;
+
i = 0;
m = info->mreq;
while (m) {
}
req->r_mrest = info->mreq;
req->r_mrest_len = i;
- req->r_cred = info->cred;
/*
* The presence of a non-NULL r_info in req indicates
* async completion via our helper threads. See the receiver
* code.
*/
- req->r_info = info->async ? info : NULL;
+ if (info->bio) {
+ req->r_info = info;
+ req->r_flags = R_ASYNC;
+ } else {
+ req->r_info = NULL;
+ req->r_flags = 0;
+ }
info->req = req;
return(0);
}
struct mbuf *m2;
int error;
+ /*
+ * Request is not on any queue, only the owner has access to it
+ * so it should not be locked by anyone atm.
+ *
+ * Interlock to prevent races. While locked the only remote
+ * action possible is for r_mrep to be set (once we enqueue it).
+ */
+ if (rep->r_flags == 0xdeadc0de) {
+ print_backtrace();
+ panic("flags nbad\n");
+ }
+ KKASSERT((rep->r_flags & (R_LOCKED | R_ONREQQ)) == 0);
if (nmp->nm_flag & NFSMNT_SOFT)
rep->r_retry = nmp->nm_retry;
else
rep->r_retry = NFS_MAXREXMIT + 1; /* past clip limit */
rep->r_rtt = rep->r_rexmit = 0;
if (proct[rep->r_procnum] > 0)
- rep->r_flags = R_TIMING | R_MASKTIMER;
+ rep->r_flags |= R_TIMING | R_LOCKED;
else
- rep->r_flags = R_MASKTIMER;
+ rep->r_flags |= R_LOCKED;
rep->r_mrep = NULL;
/*
/*
* Chain request into list of outstanding requests. Be sure
* to put it LAST so timer finds oldest requests first. Note
- * that R_MASKTIMER is set at the moment to prevent any timer
- * action on this request while we are still doing processing on
- * it below. splsoftclock() primarily protects nm_sent. Note
- * that we may block in this code so there is no atomicy guarentee.
+ * that our control of R_LOCKED prevents the request from
+ * getting ripped out from under us or transmitted by the
+ * timer code.
+ *
+ * For requests with info structures we must atomically set the
+ * info's state because the structure could become invalid upon
+ * return due to races (i.e., if async)
*/
crit_enter();
mtx_link_init(&rep->r_link);
- TAILQ_INSERT_TAIL(&nmp->nm_reqq, rep, r_chain);/* XXX */
+ TAILQ_INSERT_TAIL(&nmp->nm_reqq, rep, r_chain);
+ rep->r_flags |= R_ONREQQ;
++nmp->nm_reqqlen;
- nfssvc_iod_reader_wakeup(nmp);
+ if (rep->r_flags & R_ASYNC)
+ rep->r_info->state = NFSM_STATE_WAITREPLY;
+ crit_exit();
error = 0;
/*
- * If backing off another request or avoiding congestion, don't
- * send this one now but let timer do it. If not timing a request,
- * do it now.
- *
- * Even though the timer will not mess with our request there is
- * still the possibility that we will race a reply (which clears
- * R_SENT), especially on localhost connections, so be very careful
- * when setting R_SENT. We could set R_SENT prior to calling
- * nfs_send() but why bother if the response occurs that quickly?
+ * Send if we can. Congestion control is not handled here any more
+ * becausing trying to defer the initial send based on the nfs_timer
+ * requires having a very fast nfs_timer, which is silly.
*/
- if (nmp->nm_so && (nmp->nm_sotype != SOCK_DGRAM ||
- (nmp->nm_flag & NFSMNT_DUMBTIMR) ||
- nmp->nm_sent < nmp->nm_cwnd)) {
+ if (nmp->nm_so) {
if (nmp->nm_soflags & PR_CONNREQUIRED)
error = nfs_sndlock(nmp, rep);
- if (!error) {
+ if (error == 0) {
m2 = m_copym(rep->r_mreq, 0, M_COPYALL, MB_WAIT);
error = nfs_send(nmp->nm_so, nmp->nm_nam, m2, rep);
if (nmp->nm_soflags & PR_CONNREQUIRED)
nfs_sndunlock(nmp);
- }
- if (!error && (rep->r_flags & R_MUSTRESEND) == 0 &&
- rep->r_mrep == NULL) {
- KASSERT((rep->r_flags & R_SENT) == 0,
- ("R_SENT ASSERT %p", rep));
- nmp->nm_sent += NFS_CWNDSCALE;
- rep->r_flags |= R_SENT;
+ rep->r_flags &= ~R_NEEDSXMIT;
+ if ((rep->r_flags & R_SENT) == 0) {
+ rep->r_flags |= R_SENT;
+ }
+ } else {
+ rep->r_flags |= R_NEEDSXMIT;
}
} else {
+ rep->r_flags |= R_NEEDSXMIT;
rep->r_rtt = -1;
}
if (error == EPIPE)
error = 0;
+
/*
- * Let the timer do what it will with the request, then
- * wait for the reply from our send or the timer's.
+ * Release the lock. The only remote action that may have occurred
+ * would have been the setting of rep->r_mrep. If this occured
+ * and the request was async we have to move it to the reader
+ * thread's queue for action.
+ *
+ * For async requests also make sure the reader is woken up so
+ * it gets on the socket to read responses.
*/
- if (error == 0)
- rep->r_flags &= ~R_MASKTIMER;
+ crit_enter();
+ if (rep->r_flags & R_ASYNC) {
+ if (rep->r_mrep)
+ nfs_hardterm(rep, 1);
+ rep->r_flags &= ~R_LOCKED;
+ nfssvc_iod_reader_wakeup(nmp);
+ } else {
+ rep->r_flags &= ~R_LOCKED;
+ }
+ if (rep->r_flags & R_WANTED) {
+ rep->r_flags &= ~R_WANTED;
+ wakeup(rep);
+ }
crit_exit();
return (error);
}
+/*
+ * This code is only called for synchronous requests. Completed synchronous
+ * requests are left on reqq and we remove them before moving on to the
+ * processing state.
+ */
static int
nfs_request_waitreply(struct nfsreq *rep)
{
struct nfsmount *nmp = rep->r_nmp;
int error;
+ KKASSERT((rep->r_flags & R_ASYNC) == 0);
+
+ /*
+ * Wait until the request is finished.
+ */
error = nfs_reply(nmp, rep);
- crit_enter();
/*
* RPC done, unlink the request, but don't rip it out from under
* the callout timer.
+ *
+ * Once unlinked no other receiver or the timer will have
+ * visibility, so we do not have to set R_LOCKED.
*/
+ crit_enter();
while (rep->r_flags & R_LOCKED) {
- nfs_timer_raced = 1;
- tsleep(&nfs_timer_raced, 0, "nfstrac", 0);
+ rep->r_flags |= R_WANTED;
+ tsleep(rep, 0, "nfstrac", 0);
}
+ KKASSERT(rep->r_flags & R_ONREQQ);
TAILQ_REMOVE(&nmp->nm_reqq, rep, r_chain);
+ rep->r_flags &= ~R_ONREQQ;
--nmp->nm_reqqlen;
+ crit_exit();
/*
* Decrement the outstanding request count.
*/
if (rep->r_flags & R_SENT) {
rep->r_flags &= ~R_SENT;
- nmp->nm_sent -= NFS_CWNDSCALE;
}
- crit_exit();
-
return (error);
}
{
struct nfsreq *req = info->req;
struct nfsmount *nmp = req->r_nmp;
- time_t waituntil;
u_int32_t *tl;
- int trylater_delay = 15, trylater_cnt = 0;
int verf_type;
int i;
NULLOUT(tl = nfsm_dissect(info, NFSX_UNSIGNED));
if (*tl != 0) {
error = fxdr_unsigned(int, *tl);
+
+ /*
+ * Does anyone even implement this? Just impose
+ * a 1-second delay.
+ */
if ((nmp->nm_flag & NFSMNT_NFSV3) &&
error == NFSERR_TRYLATER) {
m_freem(info->mrep);
info->mrep = NULL;
error = 0;
- waituntil = time_second + trylater_delay;
- while (time_second < waituntil)
- (void) tsleep((caddr_t)&lbolt,
- 0, "nqnfstry", 0);
- trylater_delay *= nfs_backoff[trylater_cnt];
- if (trylater_cnt < 7)
- trylater_cnt++;
- req->r_flags &= ~R_MASKTIMER;
+
+ tsleep((caddr_t)&lbolt, 0, "nqnfstry", 0);
return (EAGAIN); /* goto tryagain */
}
#endif /* NFS_NOSERVER */
+
/*
- * Nfs timer routine
+ * Nfs timer routine.
+ *
* Scan the nfsreq list and retranmit any requests that have timed out
* To avoid retransmission attempts on STREAM sockets (in the future) make
* sure to set the r_retry field to 0 (implies nm_retry == 0).
+ *
+ * Requests with attached responses, terminated requests, and
+ * locked requests are ignored. Locked requests will be picked up
+ * in a later timer call.
*/
void
nfs_timer(void *arg /* never used */)
TAILQ_FOREACH(nmp, &nfs_mountq, nm_entry) {
TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
KKASSERT(nmp == req->r_nmp);
- if (req->r_mrep ||
- (req->r_flags & (R_SOFTTERM|R_MASKTIMER))) {
+ if (req->r_mrep)
+ continue;
+ if (req->r_flags & (R_SOFTTERM | R_LOCKED))
continue;
- }
req->r_flags |= R_LOCKED;
if (nfs_sigintr(nmp, req, req->r_td)) {
- nfs_softterm(req);
+ nfs_softterm(req, 1);
} else {
nfs_timer_req(req);
}
req->r_flags &= ~R_LOCKED;
+ if (req->r_flags & R_WANTED) {
+ req->r_flags &= ~R_WANTED;
+ wakeup(req);
+ }
}
}
#ifndef NFS_NOSERVER
nfsrv_wakenfsd(slp, 1);
}
#endif /* NFS_NOSERVER */
-
- /*
- * Due to possible blocking, a client operation may be waiting for
- * us to finish processing this request so it can remove it.
- */
- if (nfs_timer_raced) {
- nfs_timer_raced = 0;
- wakeup(&nfs_timer_raced);
- }
crit_exit();
callout_reset(&nfs_timer_handle, nfs_ticks, nfs_timer, NULL);
}
int timeo;
int error;
+ /*
+ * rtt ticks and timeout calculation. Return if the timeout
+ * has not been reached yet, unless the packet is flagged
+ * for an immediate send.
+ *
+ * The mean rtt doesn't help when we get random I/Os, we have
+ * to multiply by fairly large numbers.
+ */
if (req->r_rtt >= 0) {
req->r_rtt++;
- if (nmp->nm_flag & NFSMNT_DUMBTIMR)
- timeo = nmp->nm_timeo;
- else
- timeo = NFS_RTO(nmp, proct[req->r_procnum]);
+ if (nmp->nm_flag & NFSMNT_DUMBTIMR) {
+ timeo = nmp->nm_timeo << NFS_RTT_SCALE_BITS;
+ } else if (req->r_flags & R_TIMING) {
+ timeo = NFS_SRTT(req) + NFS_SDRTT(req);
+ } else {
+ timeo = nmp->nm_timeo << NFS_RTT_SCALE_BITS;
+ }
+ /* timeo is still scaled by SCALE_BITS */
+
+#define NFSFS (NFS_RTT_SCALE * NFS_HZ)
+ if (req->r_flags & R_TIMING) {
+ static long last_time;
+ if (nfs_showrtt && last_time != time_second) {
+ kprintf("rpccmd %d NFS SRTT %d SDRTT %d "
+ "timeo %d.%03d\n",
+ proct[req->r_procnum],
+ NFS_SRTT(req), NFS_SDRTT(req),
+ timeo / NFSFS,
+ timeo % NFSFS * 1000 / NFSFS);
+ last_time = time_second;
+ }
+ }
+#undef NFSFS
+
+ /*
+ * deal with nfs_timer jitter.
+ */
+ timeo = (timeo >> NFS_RTT_SCALE_BITS) + 1;
+ if (timeo < 2)
+ timeo = 2;
+
if (nmp->nm_timeouts > 0)
timeo *= nfs_backoff[nmp->nm_timeouts - 1];
- if (req->r_rtt <= timeo)
- return;
- if (nmp->nm_timeouts < 8)
+ if (timeo > NFS_MAXTIMEO)
+ timeo = NFS_MAXTIMEO;
+ if (req->r_rtt <= timeo) {
+ if ((req->r_flags & R_NEEDSXMIT) == 0)
+ return;
+ } else if (nmp->nm_timeouts < 8) {
nmp->nm_timeouts++;
+ }
}
+
/*
* Check for server not responding
*/
if ((req->r_flags & R_TPRINTFMSG) == 0 &&
req->r_rexmit > nmp->nm_deadthresh) {
- nfs_msg(req->r_td,
- nmp->nm_mountp->mnt_stat.f_mntfromname,
- "not responding");
+ nfs_msg(req->r_td, nmp->nm_mountp->mnt_stat.f_mntfromname,
+ "not responding");
req->r_flags |= R_TPRINTFMSG;
}
if (req->r_rexmit >= req->r_retry) { /* too many */
nfsstats.rpctimeouts++;
- nfs_softterm(req);
+ nfs_softterm(req, 1);
return;
}
+
+ /*
+ * Generally disable retransmission on reliable sockets,
+ * unless the request is flagged for immediate send.
+ */
if (nmp->nm_sotype != SOCK_DGRAM) {
if (++req->r_rexmit > NFS_MAXREXMIT)
req->r_rexmit = NFS_MAXREXMIT;
- return;
+ if ((req->r_flags & R_NEEDSXMIT) == 0)
+ return;
}
+
+ /*
+ * Stop here if we do not have a socket!
+ */
if ((so = nmp->nm_so) == NULL)
return;
/*
- * If there is enough space and the window allows..
- * Resend it
+ * If there is enough space and the window allows.. resend it.
+ *
* Set r_rtt to -1 in case we fail to send it now.
*/
req->r_rtt = -1;
if (ssb_space(&so->so_snd) >= req->r_mreq->m_pkthdr.len &&
- ((nmp->nm_flag & NFSMNT_DUMBTIMR) ||
- (req->r_flags & R_SENT) ||
- nmp->nm_sent < nmp->nm_cwnd) &&
+ (req->r_flags & (R_SENT | R_NEEDSXMIT)) &&
(m = m_copym(req->r_mreq, 0, M_COPYALL, MB_DONTWAIT))){
+ req->r_flags &= ~R_NEEDSXMIT;
if ((nmp->nm_flag & NFSMNT_NOCONN) == 0)
error = so_pru_send(so, 0, m, NULL, NULL, td);
else
if (error) {
if (NFSIGNORE_SOERROR(nmp->nm_soflags, error))
so->so_error = 0;
+ req->r_flags |= R_NEEDSXMIT;
} else if (req->r_mrep == NULL) {
/*
* Iff first send, start timing
* us entirely.
*/
if (req->r_flags & R_SENT) {
+ if (nfs_showrexmit)
+ kprintf("X");
req->r_flags &= ~R_TIMING;
if (++req->r_rexmit > NFS_MAXREXMIT)
req->r_rexmit = NFS_MAXREXMIT;
- nmp->nm_cwnd >>= 1;
- if (nmp->nm_cwnd < NFS_CWNDSCALE)
- nmp->nm_cwnd = NFS_CWNDSCALE;
+ nmp->nm_maxasync_scaled >>= 1;
+ if (nmp->nm_maxasync_scaled < NFS_MINASYNC_SCALED)
+ nmp->nm_maxasync_scaled = NFS_MINASYNC_SCALED;
nfsstats.rpcretries++;
} else {
req->r_flags |= R_SENT;
- nmp->nm_sent += NFS_CWNDSCALE;
}
req->r_rtt = 0;
}
* Mark all of an nfs mount's outstanding requests with R_SOFTTERM and
* wait for all requests to complete. This is used by forced unmounts
* to terminate any outstanding RPCs.
+ *
+ * Locked requests cannot be canceled but will be marked for
+ * soft-termination.
*/
int
nfs_nmcancelreqs(struct nfsmount *nmp)
crit_enter();
TAILQ_FOREACH(req, &nmp->nm_reqq, r_chain) {
- if (nmp != req->r_nmp || req->r_mrep != NULL ||
- (req->r_flags & R_SOFTTERM)) {
+ if (req->r_mrep != NULL || (req->r_flags & R_SOFTTERM))
continue;
- }
- nfs_softterm(req);
+ nfs_softterm(req, 0);
}
/* XXX the other two queues as well */
crit_exit();
return (EBUSY);
}
+/*
+ * Soft-terminate a request, effectively marking it as failed.
+ *
+ * Must be called from within a critical section.
+ */
static void
-nfs_async_return(struct nfsmount *nmp, struct nfsreq *rep)
+nfs_softterm(struct nfsreq *rep, int islocked)
{
- KKASSERT(rep->r_info->state == NFSM_STATE_TRY ||
- rep->r_info->state == NFSM_STATE_WAITREPLY);
- rep->r_info->state = NFSM_STATE_PROCESSREPLY;
- TAILQ_REMOVE(&nmp->nm_reqq, rep, r_chain);
- if (rep->r_flags & R_SENT) {
- rep->r_flags &= ~R_SENT;
- nmp->nm_sent -= NFS_CWNDSCALE;
- }
- --nmp->nm_reqqlen;
- TAILQ_INSERT_TAIL(&nmp->nm_reqrxq, rep, r_chain);
- nfssvc_iod_reader_wakeup(nmp);
+ rep->r_flags |= R_SOFTTERM;
+ nfs_hardterm(rep, islocked);
}
/*
- * Flag a request as being about to terminate (due to NFSMNT_INT/NFSMNT_SOFT).
- * The nm_send count is decremented now to avoid deadlocks when the process in
- * soreceive() hasn't yet managed to send its own request.
+ * Hard-terminate a request, typically after getting a response.
*
- * This routine must be called at splsoftclock() to protect r_flags and
- * nm_sent.
+ * The state machine can still decide to re-issue it later if necessary.
+ *
+ * Must be called from within a critical section.
*/
static void
-nfs_softterm(struct nfsreq *rep)
+nfs_hardterm(struct nfsreq *rep, int islocked)
{
struct nfsmount *nmp = rep->r_nmp;
- rep->r_flags |= R_SOFTTERM;
-
+ /*
+ * The nm_send count is decremented now to avoid deadlocks
+ * when the process in soreceive() hasn't yet managed to send
+ * its own request.
+ */
if (rep->r_flags & R_SENT) {
- rep->r_nmp->nm_sent -= NFS_CWNDSCALE;
rep->r_flags &= ~R_SENT;
}
/*
- * Asynchronous replies are bound-over to the
- * rxthread. Note that nmp->nm_reqqlen is not
- * decremented until the rxthread has finished
- * with the request.
+ * If we locked the request or nobody else has locked the request,
+ * and the request is async, we can move it to the reader thread's
+ * queue now and fix up the state.
+ *
+ * If we locked the request or nobody else has locked the request,
+ * we can wake up anyone blocked waiting for a response on the
+ * request.
*/
- if (rep->r_info && rep->r_info->async)
- nfs_async_return(nmp, rep);
+ if (islocked || (rep->r_flags & R_LOCKED) == 0) {
+ if ((rep->r_flags & (R_ONREQQ | R_ASYNC)) ==
+ (R_ONREQQ | R_ASYNC)) {
+ rep->r_flags &= ~R_ONREQQ;
+ TAILQ_REMOVE(&nmp->nm_reqq, rep, r_chain);
+ --nmp->nm_reqqlen;
+ TAILQ_INSERT_TAIL(&nmp->nm_reqrxq, rep, r_chain);
+ KKASSERT(rep->r_info->state == NFSM_STATE_TRY ||
+ rep->r_info->state == NFSM_STATE_WAITREPLY);
+ rep->r_info->state = NFSM_STATE_PROCESSREPLY;
+ nfssvc_iod_reader_wakeup(nmp);
+ }
+ mtx_abort_ex_link(&nmp->nm_rxlock, &rep->r_link);
+ }
}
/*
corecode's projects / dragonfly.git / commitdiff