diff options
| -rw-r--r-- | sys/nfsclient/nfs.h | 25 | ||||
| -rw-r--r-- | sys/nfsclient/nfs_socket.c | 191 | ||||
| -rw-r--r-- | sys/nfsclient/nfsmount.h | 4 |
3 files changed, 158 insertions, 62 deletions
diff --git a/sys/nfsclient/nfs.h b/sys/nfsclient/nfs.h index c3c54b2..9dc34a7 100644 --- a/sys/nfsclient/nfs.h +++ b/sys/nfsclient/nfs.h @@ -257,6 +257,31 @@ extern int nfs_debug; #endif +/* + * On fast networks, the estimator will try to reduce the + * timeout lower than the latency of the server's disks, + * which results in too many timeouts, so cap the lower + * bound. + */ +#define NFS_MINRTO (NFS_HZ >> 2) + +/* + * Keep the RTO from increasing to unreasonably large values + * when a server is not responding. + */ +#define NFS_MAXRTO (20 * NFS_HZ) + +enum nfs_rto_timer_t { + NFS_DEFAULT_TIMER, + NFS_GETATTR_TIMER, + NFS_LOOKUP_TIMER, + NFS_READ_TIMER, + NFS_WRITE_TIMER, +}; +#define NFS_MAX_TIMER (NFS_WRITE_TIMER) + +#define NFS_INITRTT (NFS_HZ << 3) + vfs_init_t nfs_init; vfs_uninit_t nfs_uninit; int nfs_mountroot(struct mount *mp, struct thread *td); diff --git a/sys/nfsclient/nfs_socket.c b/sys/nfsclient/nfs_socket.c index d2fd025..5e12939 100644 --- a/sys/nfsclient/nfs_socket.c +++ b/sys/nfsclient/nfs_socket.c @@ -79,38 +79,6 @@ __FBSDID("$FreeBSD$"); extern u_int32_t nfs_xid; -/* - * 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 - */ -#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] - -/* - * Defines which timer to use for the procnum. - * 0 - default - * 1 - getattr - * 2 - lookup - * 3 - read - * 4 - write - */ -static int proct[NFS_NPROCS] = { - 0, 1, 0, 2, 1, 3, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0, 3, 3, 0, 0, 0, 0, 0, -}; - static int nfs_realign_test; static int nfs_realign_count; static int nfs_bufpackets = 4; @@ -157,6 +125,132 @@ static void nfs_clnt_udp_soupcall(struct socket *so, void *arg, int waitflag); extern struct mtx nfs_reqq_mtx; /* + * RTT estimator + */ + +static enum nfs_rto_timer_t nfs_proct[NFS_NPROCS] = { + NFS_DEFAULT_TIMER, /* NULL */ + NFS_GETATTR_TIMER, /* GETATTR */ + NFS_DEFAULT_TIMER, /* SETATTR */ + NFS_LOOKUP_TIMER, /* LOOKUP */ + NFS_GETATTR_TIMER, /* ACCESS */ + NFS_READ_TIMER, /* READLINK */ + NFS_READ_TIMER, /* READ */ + NFS_WRITE_TIMER, /* WRITE */ + NFS_DEFAULT_TIMER, /* CREATE */ + NFS_DEFAULT_TIMER, /* MKDIR */ + NFS_DEFAULT_TIMER, /* SYMLINK */ + NFS_DEFAULT_TIMER, /* MKNOD */ + NFS_DEFAULT_TIMER, /* REMOVE */ + NFS_DEFAULT_TIMER, /* RMDIR */ + NFS_DEFAULT_TIMER, /* RENAME */ + NFS_DEFAULT_TIMER, /* LINK */ + NFS_READ_TIMER, /* READDIR */ + NFS_READ_TIMER, /* READDIRPLUS */ + NFS_DEFAULT_TIMER, /* FSSTAT */ + NFS_DEFAULT_TIMER, /* FSINFO */ + NFS_DEFAULT_TIMER, /* PATHCONF */ + NFS_DEFAULT_TIMER, /* COMMIT */ + NFS_DEFAULT_TIMER, /* NOOP */ +}; + +/* + * Choose the correct RTT timer for this NFS procedure. + */ +static inline enum nfs_rto_timer_t +nfs_rto_timer(u_int32_t procnum) +{ + return nfs_proct[procnum]; +} + +/* + * Initialize the RTT estimator state for a new mount point. + */ +static void +nfs_init_rtt(struct nfsmount *nmp) +{ + int i; + + for (i = 0; i < NFS_MAX_TIMER; i++) + nmp->nm_srtt[i] = NFS_INITRTT; + for (i = 0; i < NFS_MAX_TIMER; i++) + nmp->nm_sdrtt[i] = 0; +} + +/* + * Update a mount point's RTT estimator state using data from the + * passed-in request. + * + * Use a gain of 0.125 on the mean and a gain of 0.25 on the deviation. + * + * NB: Since the timer resolution of NFS_HZ is so course, it can often + * result in r_rtt == 0. Since r_rtt == N means that the actual RTT is + * between N + dt and N + 2 - dt ticks, add 1 before calculating the + * update values. + */ +static void +nfs_update_rtt(struct nfsreq *rep) +{ + int t1 = rep->r_rtt + 1; + int index = nfs_rto_timer(rep->r_procnum) - 1; + int *srtt = &rep->r_nmp->nm_srtt[index]; + int *sdrtt = &rep->r_nmp->nm_sdrtt[index]; + + t1 -= *srtt >> 3; + *srtt += t1; + if (t1 < 0) + t1 = -t1; + t1 -= *sdrtt >> 2; + *sdrtt += t1; +} + +/* + * 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 + */ +static int +nfs_estimate_rto(struct nfsmount *nmp, u_int32_t procnum) +{ + enum nfs_rto_timer_t timer = nfs_rto_timer(procnum); + int index = timer - 1; + int rto; + + switch (timer) { + case NFS_GETATTR_TIMER: + case NFS_LOOKUP_TIMER: + rto = ((nmp->nm_srtt[index] + 3) >> 2) + + ((nmp->nm_sdrtt[index] + 1) >> 1); + break; + case NFS_READ_TIMER: + case NFS_WRITE_TIMER: + rto = ((nmp->nm_srtt[index] + 7) >> 3) + + (nmp->nm_sdrtt[index] + 1); + break; + default: + rto = nmp->nm_timeo; + return (rto); + } + + if (rto < NFS_MINRTO) + rto = NFS_MINRTO; + else if (rto > NFS_MAXRTO) + rto = NFS_MAXRTO; + + return (rto); +} + + +/* * Initialize sockets and congestion for a new NFS connection. * We do not free the sockaddr if error. */ @@ -357,10 +451,7 @@ nfs_connect(struct nfsmount *nmp, struct nfsreq *rep) mtx_lock(&nmp->nm_mtx); /* 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_sdrtt[0] = nmp->nm_sdrtt[1] = nmp->nm_sdrtt[2] = - nmp->nm_sdrtt[3] = 0; + nfs_init_rtt(nmp); nmp->nm_cwnd = NFS_MAXCWND / 2; /* Initial send window */ nmp->nm_sent = 0; nmp->nm_timeouts = 0; @@ -685,7 +776,6 @@ nfs_clnt_match_xid(struct socket *so, caddr_t dpos; u_int32_t rxid, *tl; struct nfsreq *rep; - register int32_t t1; int error; /* @@ -743,27 +833,8 @@ nfsmout: rep->r_flags &= ~R_SENT; nmp->nm_sent -= NFS_CWNDSCALE; } - /* - * Update rtt using a gain of 0.125 on the mean - * and a gain of 0.25 on the deviation. - */ - if (rep->r_flags & R_TIMING) { - /* - * Since the timer resolution of - * NFS_HZ is so course, it can often - * result in r_rtt == 0. Since - * r_rtt == N means that the actual - * 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; - } + if (rep->r_flags & R_TIMING) + nfs_update_rtt(rep); nmp->nm_timeouts = 0; wakeup((caddr_t)rep); mtx_unlock(&rep->r_mtx); @@ -1073,7 +1144,7 @@ tryagain: else rep->r_retry = NFS_MAXREXMIT + 1; /* past clip limit */ rep->r_rtt = rep->r_rexmit = 0; - if (proct[procnum] > 0) + if (nfs_rto_timer(procnum) != NFS_DEFAULT_TIMER) rep->r_flags = R_TIMING; else rep->r_flags = 0; @@ -1328,7 +1399,7 @@ nfs_timer(void *arg) if (nmp->nm_flag & NFSMNT_DUMBTIMR) timeo = nmp->nm_timeo; else - timeo = NFS_RTO(nmp, proct[rep->r_procnum]); + timeo = nfs_estimate_rto(nmp, rep->r_procnum); if (nmp->nm_timeouts > 0) timeo *= nfs_backoff[nmp->nm_timeouts - 1]; if (rep->r_rtt <= timeo) { diff --git a/sys/nfsclient/nfsmount.h b/sys/nfsclient/nfsmount.h index e7b9d0f..4fd2afe 100644 --- a/sys/nfsclient/nfsmount.h +++ b/sys/nfsclient/nfsmount.h @@ -64,8 +64,8 @@ struct nfsmount { struct sockaddr *nm_nam; /* Addr of server */ int nm_timeo; /* Init timer for NFSMNT_DUMBTIMR */ int nm_retry; /* Max retries */ - int nm_srtt[4]; /* Timers for rpcs */ - int nm_sdrtt[4]; + int nm_srtt[NFS_MAX_TIMER], /* RTT Timers for rpcs */ + nm_sdrtt[NFS_MAX_TIMER]; int nm_sent; /* Request send count */ int nm_cwnd; /* Request send window */ int nm_timeouts; /* Request timeouts */ |
