freebsd-dev/sys/nfsserver/nfs_srvsock.c
ps f02e58b811 Now that we have a non blocking version of nfsm_dissect(), change all the
nfsm_dissect() calls (done under the NFSD lock) to nfsm_dissect_nonblock().

Submitted by:	Mohan Srinivasan
2005-01-19 22:53:40 +00:00

825 lines
20 KiB
C

/*-
* Copyright (c) 1989, 1991, 1993, 1995
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Rick Macklem at The University of Guelph.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)nfs_socket.c 8.5 (Berkeley) 3/30/95
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Socket operations for use by nfs
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mount.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/protosw.h>
#include <sys/signalvar.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/vnode.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <nfs/rpcv2.h>
#include <nfs/nfsproto.h>
#include <nfsserver/nfs.h>
#include <nfs/xdr_subs.h>
#include <nfsserver/nfsm_subs.h>
#define TRUE 1
#define FALSE 0
static int nfs_realign_test;
static int nfs_realign_count;
SYSCTL_DECL(_vfs_nfsrv);
SYSCTL_INT(_vfs_nfsrv, OID_AUTO, realign_test, CTLFLAG_RW, &nfs_realign_test, 0, "");
SYSCTL_INT(_vfs_nfsrv, OID_AUTO, realign_count, CTLFLAG_RW, &nfs_realign_count, 0, "");
/*
* 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)
struct callout nfsrv_callout;
static void nfs_realign(struct mbuf **pm, int hsiz); /* XXX SHARED */
static int nfsrv_getstream(struct nfssvc_sock *, int);
int32_t (*nfsrv3_procs[NFS_NPROCS])(struct nfsrv_descript *nd,
struct nfssvc_sock *slp,
struct thread *td,
struct mbuf **mreqp) = {
nfsrv_null,
nfsrv_getattr,
nfsrv_setattr,
nfsrv_lookup,
nfsrv3_access,
nfsrv_readlink,
nfsrv_read,
nfsrv_write,
nfsrv_create,
nfsrv_mkdir,
nfsrv_symlink,
nfsrv_mknod,
nfsrv_remove,
nfsrv_rmdir,
nfsrv_rename,
nfsrv_link,
nfsrv_readdir,
nfsrv_readdirplus,
nfsrv_statfs,
nfsrv_fsinfo,
nfsrv_pathconf,
nfsrv_commit,
nfsrv_noop
};
/*
* Generate the rpc reply header
* siz arg. is used to decide if adding a cluster is worthwhile
*/
struct mbuf *
nfs_rephead(int siz, struct nfsrv_descript *nd, int err,
struct mbuf **mbp, caddr_t *bposp)
{
u_int32_t *tl;
struct mbuf *mreq;
caddr_t bpos;
struct mbuf *mb;
/* XXXRW: not 100% clear the lock is needed here. */
NFSD_LOCK_ASSERT();
nd->nd_repstat = err;
if (err && (nd->nd_flag & ND_NFSV3) == 0) /* XXX recheck */
siz = 0;
NFSD_UNLOCK();
MGETHDR(mreq, M_TRYWAIT, MT_DATA);
mb = mreq;
/*
* If this is a big reply, use a cluster else
* try and leave leading space for the lower level headers.
*/
mreq->m_len = 6 * NFSX_UNSIGNED;
siz += RPC_REPLYSIZ;
if ((max_hdr + siz) >= MINCLSIZE) {
MCLGET(mreq, M_TRYWAIT);
} else
mreq->m_data += min(max_hdr, M_TRAILINGSPACE(mreq));
NFSD_LOCK();
tl = mtod(mreq, u_int32_t *);
bpos = ((caddr_t)tl) + mreq->m_len;
*tl++ = txdr_unsigned(nd->nd_retxid);
*tl++ = nfsrv_rpc_reply;
if (err == ERPCMISMATCH || (err & NFSERR_AUTHERR)) {
*tl++ = nfsrv_rpc_msgdenied;
if (err & NFSERR_AUTHERR) {
*tl++ = nfsrv_rpc_autherr;
*tl = txdr_unsigned(err & ~NFSERR_AUTHERR);
mreq->m_len -= NFSX_UNSIGNED;
bpos -= NFSX_UNSIGNED;
} else {
*tl++ = nfsrv_rpc_mismatch;
*tl++ = txdr_unsigned(RPC_VER2);
*tl = txdr_unsigned(RPC_VER2);
}
} else {
*tl++ = nfsrv_rpc_msgaccepted;
/*
* Send a RPCAUTH_NULL verifier - no Kerberos.
*/
*tl++ = 0;
*tl++ = 0;
switch (err) {
case EPROGUNAVAIL:
*tl = txdr_unsigned(RPC_PROGUNAVAIL);
break;
case EPROGMISMATCH:
*tl = txdr_unsigned(RPC_PROGMISMATCH);
tl = nfsm_build(u_int32_t *, 2 * NFSX_UNSIGNED);
*tl++ = txdr_unsigned(2);
*tl = txdr_unsigned(3);
break;
case EPROCUNAVAIL:
*tl = txdr_unsigned(RPC_PROCUNAVAIL);
break;
case EBADRPC:
*tl = txdr_unsigned(RPC_GARBAGE);
break;
default:
*tl = 0;
if (err != NFSERR_RETVOID) {
tl = nfsm_build(u_int32_t *, NFSX_UNSIGNED);
if (err)
*tl = txdr_unsigned(nfsrv_errmap(nd, err));
else
*tl = 0;
}
break;
}
}
*mbp = mb;
*bposp = bpos;
if (err != 0 && err != NFSERR_RETVOID)
nfsrvstats.srvrpc_errs++;
return mreq;
}
/*
* nfs_realign:
*
* Check for badly aligned mbuf data and realign by copying the unaligned
* portion of the data into a new mbuf chain and freeing the portions
* of the old chain that were replaced.
*
* We cannot simply realign the data within the existing mbuf chain
* because the underlying buffers may contain other rpc commands and
* we cannot afford to overwrite them.
*
* We would prefer to avoid this situation entirely. The situation does
* not occur with NFS/UDP and is supposed to only occassionally occur
* with TCP. Use vfs.nfs.realign_count and realign_test to check this.
*/
static void
nfs_realign(struct mbuf **pm, int hsiz) /* XXX COMMON */
{
struct mbuf *m;
struct mbuf *n = NULL;
int off = 0;
/* XXXRW: may not need lock? */
NFSD_LOCK_ASSERT();
++nfs_realign_test;
while ((m = *pm) != NULL) {
if ((m->m_len & 0x3) || (mtod(m, intptr_t) & 0x3)) {
NFSD_UNLOCK();
MGET(n, M_TRYWAIT, MT_DATA);
if (m->m_len >= MINCLSIZE) {
MCLGET(n, M_TRYWAIT);
}
NFSD_LOCK();
n->m_len = 0;
break;
}
pm = &m->m_next;
}
/*
* If n is non-NULL, loop on m copying data, then replace the
* portion of the chain that had to be realigned.
*/
if (n != NULL) {
++nfs_realign_count;
while (m) {
m_copyback(n, off, m->m_len, mtod(m, caddr_t));
off += m->m_len;
m = m->m_next;
}
m_freem(*pm);
*pm = n;
}
}
/*
* Parse an RPC request
* - verify it
* - fill in the cred struct.
*/
int
nfs_getreq(struct nfsrv_descript *nd, struct nfsd *nfsd, int has_header)
{
int len, i;
u_int32_t *tl;
caddr_t dpos;
u_int32_t nfsvers, auth_type;
int error = 0;
struct mbuf *mrep, *md;
NFSD_LOCK_ASSERT();
mrep = nd->nd_mrep;
md = nd->nd_md;
dpos = nd->nd_dpos;
if (has_header) {
tl = nfsm_dissect_nonblock(u_int32_t *, 10 * NFSX_UNSIGNED);
nd->nd_retxid = fxdr_unsigned(u_int32_t, *tl++);
if (*tl++ != nfsrv_rpc_call) {
m_freem(mrep);
return (EBADRPC);
}
} else
tl = nfsm_dissect_nonblock(u_int32_t *, 8 * NFSX_UNSIGNED);
nd->nd_repstat = 0;
nd->nd_flag = 0;
if (*tl++ != nfsrv_rpc_vers) {
nd->nd_repstat = ERPCMISMATCH;
nd->nd_procnum = NFSPROC_NOOP;
return (0);
}
if (*tl != nfsrv_nfs_prog) {
nd->nd_repstat = EPROGUNAVAIL;
nd->nd_procnum = NFSPROC_NOOP;
return (0);
}
tl++;
nfsvers = fxdr_unsigned(u_int32_t, *tl++);
if (nfsvers < NFS_VER2 || nfsvers > NFS_VER3) {
nd->nd_repstat = EPROGMISMATCH;
nd->nd_procnum = NFSPROC_NOOP;
return (0);
}
nd->nd_procnum = fxdr_unsigned(u_int32_t, *tl++);
if (nd->nd_procnum == NFSPROC_NULL)
return (0);
if (nfsvers == NFS_VER3) {
nd->nd_flag = ND_NFSV3;
if (nd->nd_procnum >= NFS_NPROCS) {
nd->nd_repstat = EPROCUNAVAIL;
nd->nd_procnum = NFSPROC_NOOP;
return (0);
}
} else {
if (nd->nd_procnum > NFSV2PROC_STATFS) {
nd->nd_repstat = EPROCUNAVAIL;
nd->nd_procnum = NFSPROC_NOOP;
return (0);
}
/* Map the v2 procedure numbers into v3 ones */
nd->nd_procnum = nfsrv_nfsv3_procid[nd->nd_procnum];
}
auth_type = *tl++;
len = fxdr_unsigned(int, *tl++);
if (len < 0 || len > RPCAUTH_MAXSIZ) {
m_freem(mrep);
return (EBADRPC);
}
/*
* Handle auth_unix;
*/
if (auth_type == nfsrv_rpc_auth_unix) {
len = fxdr_unsigned(int, *++tl);
if (len < 0 || len > NFS_MAXNAMLEN) {
m_freem(mrep);
return (EBADRPC);
}
nfsm_adv(nfsm_rndup(len));
tl = nfsm_dissect_nonblock(u_int32_t *, 3 * NFSX_UNSIGNED);
/*
* XXX: This credential should be managed using crget(9)
* and related calls. Right now, this tramples on any
* extensible data in the ucred, fails to initialize the
* mutex, and worse. This must be fixed before FreeBSD
* 5.3-RELEASE.
*/
bzero((caddr_t)&nd->nd_cr, sizeof (struct ucred));
nd->nd_cr.cr_ref = 1;
nd->nd_cr.cr_uid = fxdr_unsigned(uid_t, *tl++);
nd->nd_cr.cr_gid = fxdr_unsigned(gid_t, *tl++);
len = fxdr_unsigned(int, *tl);
if (len < 0 || len > RPCAUTH_UNIXGIDS) {
m_freem(mrep);
return (EBADRPC);
}
tl = nfsm_dissect_nonblock(u_int32_t *, (len + 2) * NFSX_UNSIGNED);
for (i = 1; i <= len; i++)
if (i < NGROUPS)
nd->nd_cr.cr_groups[i] = fxdr_unsigned(gid_t, *tl++);
else
tl++;
nd->nd_cr.cr_ngroups = (len >= NGROUPS) ? NGROUPS : (len + 1);
if (nd->nd_cr.cr_ngroups > 1)
nfsrvw_sort(nd->nd_cr.cr_groups, nd->nd_cr.cr_ngroups);
len = fxdr_unsigned(int, *++tl);
if (len < 0 || len > RPCAUTH_MAXSIZ) {
m_freem(mrep);
return (EBADRPC);
}
if (len > 0)
nfsm_adv(nfsm_rndup(len));
} else {
nd->nd_repstat = (NFSERR_AUTHERR | AUTH_REJECTCRED);
nd->nd_procnum = NFSPROC_NOOP;
return (0);
}
nd->nd_md = md;
nd->nd_dpos = dpos;
return (0);
nfsmout:
return (error);
}
/*
* Socket upcall routine for the nfsd sockets.
* The caddr_t arg is a pointer to the "struct nfssvc_sock".
* Essentially do as much as possible non-blocking, else punt and it will
* be called with M_TRYWAIT from an nfsd.
*/
void
nfsrv_rcv(struct socket *so, void *arg, int waitflag)
{
struct nfssvc_sock *slp = (struct nfssvc_sock *)arg;
struct mbuf *m;
struct mbuf *mp;
struct sockaddr *nam;
struct uio auio;
int flags, error;
/*
* XXXRW: For now, assert Giant here since the NFS server upcall
* will perform socket operations requiring Giant in a non-mpsafe
* kernel.
*/
NET_ASSERT_GIANT();
NFSD_UNLOCK_ASSERT();
/* XXXRW: Unlocked read. */
if ((slp->ns_flag & SLP_VALID) == 0)
return;
/*
* We can't do this in the context of a socket callback
* because we're called with locks held.
* XXX: SMP
*/
if (waitflag == M_DONTWAIT) {
NFSD_LOCK();
slp->ns_flag |= SLP_NEEDQ;
goto dorecs;
}
NFSD_LOCK();
auio.uio_td = NULL;
if (so->so_type == SOCK_STREAM) {
/*
* If there are already records on the queue, defer soreceive()
* to an nfsd so that there is feedback to the TCP layer that
* the nfs servers are heavily loaded.
*/
if (STAILQ_FIRST(&slp->ns_rec) != NULL &&
waitflag == M_DONTWAIT) {
slp->ns_flag |= SLP_NEEDQ;
goto dorecs;
}
/*
* Do soreceive().
*/
auio.uio_resid = 1000000000;
flags = MSG_DONTWAIT;
NFSD_UNLOCK();
error = so->so_proto->pr_usrreqs->pru_soreceive
(so, &nam, &auio, &mp, NULL, &flags);
NFSD_LOCK();
if (error || mp == NULL) {
if (error == EWOULDBLOCK)
slp->ns_flag |= SLP_NEEDQ;
else
slp->ns_flag |= SLP_DISCONN;
goto dorecs;
}
m = mp;
if (slp->ns_rawend) {
slp->ns_rawend->m_next = m;
slp->ns_cc += 1000000000 - auio.uio_resid;
} else {
slp->ns_raw = m;
slp->ns_cc = 1000000000 - auio.uio_resid;
}
while (m->m_next)
m = m->m_next;
slp->ns_rawend = m;
/*
* Now try and parse record(s) out of the raw stream data.
*/
error = nfsrv_getstream(slp, waitflag);
if (error) {
if (error == EPERM)
slp->ns_flag |= SLP_DISCONN;
else
slp->ns_flag |= SLP_NEEDQ;
}
} else {
do {
auio.uio_resid = 1000000000;
flags = MSG_DONTWAIT;
NFSD_UNLOCK();
error = so->so_proto->pr_usrreqs->pru_soreceive
(so, &nam, &auio, &mp, NULL, &flags);
if (mp) {
struct nfsrv_rec *rec;
rec = malloc(sizeof(struct nfsrv_rec),
M_NFSRVDESC,
waitflag == M_DONTWAIT ? M_NOWAIT : M_WAITOK);
if (!rec) {
if (nam)
FREE(nam, M_SONAME);
m_freem(mp);
NFSD_LOCK();
continue;
}
NFSD_LOCK();
nfs_realign(&mp, 10 * NFSX_UNSIGNED);
rec->nr_address = nam;
rec->nr_packet = mp;
STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
} else
NFSD_LOCK();
if (error) {
if ((so->so_proto->pr_flags & PR_CONNREQUIRED)
&& error != EWOULDBLOCK) {
slp->ns_flag |= SLP_DISCONN;
goto dorecs;
}
}
} while (mp);
}
/*
* Now try and process the request records, non-blocking.
*/
dorecs:
if (waitflag == M_DONTWAIT &&
(STAILQ_FIRST(&slp->ns_rec) != NULL ||
(slp->ns_flag & (SLP_NEEDQ | SLP_DISCONN))))
nfsrv_wakenfsd(slp);
NFSD_UNLOCK();
}
/*
* Try and extract an RPC request from the mbuf data list received on a
* stream socket. The "waitflag" argument indicates whether or not it
* can sleep.
*/
static int
nfsrv_getstream(struct nfssvc_sock *slp, int waitflag)
{
struct mbuf *m, **mpp;
char *cp1, *cp2;
int len;
struct mbuf *om, *m2, *recm;
u_int32_t recmark;
NFSD_LOCK_ASSERT();
if (slp->ns_flag & SLP_GETSTREAM)
panic("nfs getstream");
slp->ns_flag |= SLP_GETSTREAM;
for (;;) {
if (slp->ns_reclen == 0) {
if (slp->ns_cc < NFSX_UNSIGNED) {
slp->ns_flag &= ~SLP_GETSTREAM;
return (0);
}
m = slp->ns_raw;
if (m->m_len >= NFSX_UNSIGNED) {
bcopy(mtod(m, caddr_t), (caddr_t)&recmark, NFSX_UNSIGNED);
m->m_data += NFSX_UNSIGNED;
m->m_len -= NFSX_UNSIGNED;
} else {
cp1 = (caddr_t)&recmark;
cp2 = mtod(m, caddr_t);
while (cp1 < ((caddr_t)&recmark) + NFSX_UNSIGNED) {
while (m->m_len == 0) {
m = m->m_next;
cp2 = mtod(m, caddr_t);
}
*cp1++ = *cp2++;
m->m_data++;
m->m_len--;
}
}
slp->ns_cc -= NFSX_UNSIGNED;
recmark = ntohl(recmark);
slp->ns_reclen = recmark & ~0x80000000;
if (recmark & 0x80000000)
slp->ns_flag |= SLP_LASTFRAG;
else
slp->ns_flag &= ~SLP_LASTFRAG;
if (slp->ns_reclen > NFS_MAXPACKET) {
slp->ns_flag &= ~SLP_GETSTREAM;
return (EPERM);
}
}
/*
* Now get the record part.
*
* Note that slp->ns_reclen may be 0. Linux sometimes
* generates 0-length RPCs.
*/
recm = NULL;
if (slp->ns_cc == slp->ns_reclen) {
recm = slp->ns_raw;
slp->ns_raw = slp->ns_rawend = NULL;
slp->ns_cc = slp->ns_reclen = 0;
} else if (slp->ns_cc > slp->ns_reclen) {
len = 0;
m = slp->ns_raw;
om = NULL;
while (len < slp->ns_reclen) {
if ((len + m->m_len) > slp->ns_reclen) {
NFSD_UNLOCK();
m2 = m_copym(m, 0, slp->ns_reclen - len,
waitflag);
NFSD_LOCK();
if (m2) {
if (om) {
om->m_next = m2;
recm = slp->ns_raw;
} else
recm = m2;
m->m_data += slp->ns_reclen - len;
m->m_len -= slp->ns_reclen - len;
len = slp->ns_reclen;
} else {
slp->ns_flag &= ~SLP_GETSTREAM;
return (EWOULDBLOCK);
}
} else if ((len + m->m_len) == slp->ns_reclen) {
om = m;
len += m->m_len;
m = m->m_next;
recm = slp->ns_raw;
om->m_next = NULL;
} else {
om = m;
len += m->m_len;
m = m->m_next;
}
}
slp->ns_raw = m;
slp->ns_cc -= len;
slp->ns_reclen = 0;
} else {
slp->ns_flag &= ~SLP_GETSTREAM;
return (0);
}
/*
* Accumulate the fragments into a record.
*/
mpp = &slp->ns_frag;
while (*mpp)
mpp = &((*mpp)->m_next);
*mpp = recm;
if (slp->ns_flag & SLP_LASTFRAG) {
struct nfsrv_rec *rec;
NFSD_UNLOCK();
rec = malloc(sizeof(struct nfsrv_rec), M_NFSRVDESC,
waitflag == M_DONTWAIT ? M_NOWAIT : M_WAITOK);
NFSD_LOCK();
if (!rec) {
m_freem(slp->ns_frag);
} else {
nfs_realign(&slp->ns_frag, 10 * NFSX_UNSIGNED);
rec->nr_address = NULL;
rec->nr_packet = slp->ns_frag;
STAILQ_INSERT_TAIL(&slp->ns_rec, rec, nr_link);
}
slp->ns_frag = NULL;
}
}
}
/*
* Parse an RPC header.
*/
int
nfsrv_dorec(struct nfssvc_sock *slp, struct nfsd *nfsd,
struct nfsrv_descript **ndp)
{
struct nfsrv_rec *rec;
struct mbuf *m;
struct sockaddr *nam;
struct nfsrv_descript *nd;
int error;
NFSD_LOCK_ASSERT();
*ndp = NULL;
if ((slp->ns_flag & SLP_VALID) == 0 ||
STAILQ_FIRST(&slp->ns_rec) == NULL)
return (ENOBUFS);
rec = STAILQ_FIRST(&slp->ns_rec);
STAILQ_REMOVE_HEAD(&slp->ns_rec, nr_link);
nam = rec->nr_address;
m = rec->nr_packet;
free(rec, M_NFSRVDESC);
NFSD_UNLOCK();
MALLOC(nd, struct nfsrv_descript *, sizeof (struct nfsrv_descript),
M_NFSRVDESC, M_WAITOK);
NFSD_LOCK();
nd->nd_md = nd->nd_mrep = m;
nd->nd_nam2 = nam;
nd->nd_dpos = mtod(m, caddr_t);
error = nfs_getreq(nd, nfsd, TRUE);
if (error) {
if (nam) {
FREE(nam, M_SONAME);
}
free((caddr_t)nd, M_NFSRVDESC);
return (error);
}
*ndp = nd;
nfsd->nfsd_nd = nd;
return (0);
}
/*
* Search for a sleeping nfsd and wake it up.
* SIDE EFFECT: If none found, set NFSD_CHECKSLP flag, so that one of the
* running nfsds will go look for the work in the nfssvc_sock list.
*/
void
nfsrv_wakenfsd(struct nfssvc_sock *slp)
{
struct nfsd *nd;
NFSD_LOCK_ASSERT();
if ((slp->ns_flag & SLP_VALID) == 0)
return;
TAILQ_FOREACH(nd, &nfsd_head, nfsd_chain) {
if (nd->nfsd_flag & NFSD_WAITING) {
nd->nfsd_flag &= ~NFSD_WAITING;
if (nd->nfsd_slp)
panic("nfsd wakeup");
slp->ns_sref++;
nd->nfsd_slp = slp;
wakeup(nd);
return;
}
}
slp->ns_flag |= SLP_DOREC;
nfsd_head_flag |= NFSD_CHECKSLP;
}
/*
* This is the nfs send routine.
* For the server side:
* - return EINTR or ERESTART if interrupted by a signal
* - return EPIPE if a connection is lost for connection based sockets (TCP...)
* - do any cleanup required by recoverable socket errors (?)
*/
int
nfsrv_send(struct socket *so, struct sockaddr *nam, struct mbuf *top)
{
struct sockaddr *sendnam;
int error, soflags, flags;
NET_ASSERT_GIANT();
NFSD_UNLOCK_ASSERT();
soflags = so->so_proto->pr_flags;
if ((soflags & PR_CONNREQUIRED) || (so->so_state & SS_ISCONNECTED))
sendnam = NULL;
else
sendnam = nam;
if (so->so_type == SOCK_SEQPACKET)
flags = MSG_EOR;
else
flags = 0;
error = so->so_proto->pr_usrreqs->pru_sosend(so, sendnam, 0, top, 0,
flags, curthread/*XXX*/);
if (error == ENOBUFS && so->so_type == SOCK_DGRAM)
error = 0;
if (error) {
log(LOG_INFO, "nfsd send error %d\n", error);
/*
* Handle any recoverable (soft) socket errors here. (?)
*/
if (error != EINTR && error != ERESTART &&
error != EWOULDBLOCK && error != EPIPE)
error = 0;
}
return (error);
}
/*
* NFS server timer routine.
*/
void
nfsrv_timer(void *arg)
{
struct nfssvc_sock *slp;
u_quad_t cur_usec;
NFSD_LOCK();
/*
* Scan the write gathering queues for writes that need to be
* completed now.
*/
cur_usec = nfs_curusec();
TAILQ_FOREACH(slp, &nfssvc_sockhead, ns_chain) {
if (LIST_FIRST(&slp->ns_tq) &&
LIST_FIRST(&slp->ns_tq)->nd_time <= cur_usec)
nfsrv_wakenfsd(slp);
}
NFSD_UNLOCK();
callout_reset(&nfsrv_callout, nfsrv_ticks, nfsrv_timer, NULL);
}