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freebsd-skq/sys/fs/nfsserver/nfs_nfsdkrpc.c
kib ff588ae9b0 Currently, softupdate code detects overstepping on the workitems 
limits in the code which is deep in the call stack, and owns several
critical system resources, like vnode locks.  Attempt to wait while
the per-mount softupdate thread cleans up the backlog may deadlock,
because the thread might need to lock the same vnode which is owned by
the waiting thread.

Instead of synchronously waiting for the worker, perform the worker'
tickle and pause until the backlog is cleaned, at the safe point
during return from kernel to usermode.  A new ast request to call
softdep_ast_cleanup() is created, the SU code now only checks the size
of queue and schedules ast.

There is no ast delivery for the kernel threads, so they are exempted
from the mechanism, except NFS daemon threads.  NFS server loop
explicitely checks for the request, and informs the schedule_cleanup()
that it is capable of handling the requests by the process P2_AST_SU
flag.  This is needed because nfsd may be the sole cause of the SU
workqueue overflow.  But, to not cause nsfd to spawn additional
threads just because we slow down existing workers, only tickle su
threads, without waiting for the backlog cleanup.

Reviewed by:	jhb, mckusick
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
MFC after:	2 weeks
2015-05-27 09:20:42 +00:00

562 lines
14 KiB
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/*-
* Copyright (c) 1989, 1993
* 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet6.h"
#include "opt_kgssapi.h"
#include <fs/nfs/nfsport.h>
#include <rpc/rpc.h>
#include <rpc/rpcsec_gss.h>
#include <nfs/nfs_fha.h>
#include <fs/nfsserver/nfs_fha_new.h>
#include <security/mac/mac_framework.h>
NFSDLOCKMUTEX;
NFSV4ROOTLOCKMUTEX;
struct nfsv4lock nfsd_suspend_lock;
/*
* Mapping of old NFS Version 2 RPC numbers to generic numbers.
*/
int newnfs_nfsv3_procid[NFS_V3NPROCS] = {
NFSPROC_NULL,
NFSPROC_GETATTR,
NFSPROC_SETATTR,
NFSPROC_NOOP,
NFSPROC_LOOKUP,
NFSPROC_READLINK,
NFSPROC_READ,
NFSPROC_NOOP,
NFSPROC_WRITE,
NFSPROC_CREATE,
NFSPROC_REMOVE,
NFSPROC_RENAME,
NFSPROC_LINK,
NFSPROC_SYMLINK,
NFSPROC_MKDIR,
NFSPROC_RMDIR,
NFSPROC_READDIR,
NFSPROC_FSSTAT,
NFSPROC_NOOP,
NFSPROC_NOOP,
NFSPROC_NOOP,
NFSPROC_NOOP,
};
SYSCTL_DECL(_vfs_nfsd);
SVCPOOL *nfsrvd_pool;
static int nfs_privport = 0;
SYSCTL_INT(_vfs_nfsd, OID_AUTO, nfs_privport, CTLFLAG_RWTUN,
&nfs_privport, 0,
"Only allow clients using a privileged port for NFSv2 and 3");
static int nfs_minvers = NFS_VER2;
SYSCTL_INT(_vfs_nfsd, OID_AUTO, server_min_nfsvers, CTLFLAG_RWTUN,
&nfs_minvers, 0, "The lowest version of NFS handled by the server");
static int nfs_maxvers = NFS_VER4;
SYSCTL_INT(_vfs_nfsd, OID_AUTO, server_max_nfsvers, CTLFLAG_RWTUN,
&nfs_maxvers, 0, "The highest version of NFS handled by the server");
static int nfs_proc(struct nfsrv_descript *, u_int32_t, SVCXPRT *xprt,
struct nfsrvcache **);
extern u_long sb_max_adj;
extern int newnfs_numnfsd;
extern struct proc *nfsd_master_proc;
/*
* NFS server system calls
*/
static void
nfssvc_program(struct svc_req *rqst, SVCXPRT *xprt)
{
struct nfsrv_descript nd;
struct nfsrvcache *rp = NULL;
int cacherep, credflavor;
memset(&nd, 0, sizeof(nd));
if (rqst->rq_vers == NFS_VER2) {
if (rqst->rq_proc > NFSV2PROC_STATFS ||
newnfs_nfsv3_procid[rqst->rq_proc] == NFSPROC_NOOP) {
svcerr_noproc(rqst);
svc_freereq(rqst);
goto out;
}
nd.nd_procnum = newnfs_nfsv3_procid[rqst->rq_proc];
nd.nd_flag = ND_NFSV2;
} else if (rqst->rq_vers == NFS_VER3) {
if (rqst->rq_proc >= NFS_V3NPROCS) {
svcerr_noproc(rqst);
svc_freereq(rqst);
goto out;
}
nd.nd_procnum = rqst->rq_proc;
nd.nd_flag = ND_NFSV3;
} else {
if (rqst->rq_proc != NFSPROC_NULL &&
rqst->rq_proc != NFSV4PROC_COMPOUND) {
svcerr_noproc(rqst);
svc_freereq(rqst);
goto out;
}
nd.nd_procnum = rqst->rq_proc;
nd.nd_flag = ND_NFSV4;
}
/*
* Note: we want rq_addr, not svc_getrpccaller for nd_nam2 -
* NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP
* mounts.
*/
nd.nd_mrep = rqst->rq_args;
rqst->rq_args = NULL;
newnfs_realign(&nd.nd_mrep, M_WAITOK);
nd.nd_md = nd.nd_mrep;
nd.nd_dpos = mtod(nd.nd_md, caddr_t);
nd.nd_nam = svc_getrpccaller(rqst);
nd.nd_nam2 = rqst->rq_addr;
nd.nd_mreq = NULL;
nd.nd_cred = NULL;
if (nfs_privport && (nd.nd_flag & ND_NFSV4) == 0) {
/* Check if source port is privileged */
u_short port;
struct sockaddr *nam = nd.nd_nam;
struct sockaddr_in *sin;
sin = (struct sockaddr_in *)nam;
/*
* INET/INET6 - same code:
* sin_port and sin6_port are at same offset
*/
port = ntohs(sin->sin_port);
if (port >= IPPORT_RESERVED &&
nd.nd_procnum != NFSPROC_NULL) {
#ifdef INET6
char b6[INET6_ADDRSTRLEN];
#if defined(KLD_MODULE)
/* Do not use ip6_sprintf: the nfs module should work without INET6. */
#define ip6_sprintf(buf, a) \
(sprintf((buf), "%x:%x:%x:%x:%x:%x:%x:%x", \
(a)->s6_addr16[0], (a)->s6_addr16[1], \
(a)->s6_addr16[2], (a)->s6_addr16[3], \
(a)->s6_addr16[4], (a)->s6_addr16[5], \
(a)->s6_addr16[6], (a)->s6_addr16[7]), \
(buf))
#endif
#endif
printf("NFS request from unprivileged port (%s:%d)\n",
#ifdef INET6
sin->sin_family == AF_INET6 ?
ip6_sprintf(b6, &satosin6(sin)->sin6_addr) :
#if defined(KLD_MODULE)
#undef ip6_sprintf
#endif
#endif
inet_ntoa(sin->sin_addr), port);
svcerr_weakauth(rqst);
svc_freereq(rqst);
m_freem(nd.nd_mrep);
goto out;
}
}
if (nd.nd_procnum != NFSPROC_NULL) {
if (!svc_getcred(rqst, &nd.nd_cred, &credflavor)) {
svcerr_weakauth(rqst);
svc_freereq(rqst);
m_freem(nd.nd_mrep);
goto out;
}
/* Set the flag based on credflavor */
if (credflavor == RPCSEC_GSS_KRB5) {
nd.nd_flag |= ND_GSS;
} else if (credflavor == RPCSEC_GSS_KRB5I) {
nd.nd_flag |= (ND_GSS | ND_GSSINTEGRITY);
} else if (credflavor == RPCSEC_GSS_KRB5P) {
nd.nd_flag |= (ND_GSS | ND_GSSPRIVACY);
} else if (credflavor != AUTH_SYS) {
svcerr_weakauth(rqst);
svc_freereq(rqst);
m_freem(nd.nd_mrep);
goto out;
}
#ifdef MAC
mac_cred_associate_nfsd(nd.nd_cred);
#endif
/*
* Get a refcnt (shared lock) on nfsd_suspend_lock.
* NFSSVC_SUSPENDNFSD will take an exclusive lock on
* nfsd_suspend_lock to suspend these threads.
* This must be done here, before the check of
* nfsv4root exports by nfsvno_v4rootexport().
*/
NFSLOCKV4ROOTMUTEX();
nfsv4_getref(&nfsd_suspend_lock, NULL, NFSV4ROOTLOCKMUTEXPTR,
NULL);
NFSUNLOCKV4ROOTMUTEX();
if ((nd.nd_flag & ND_NFSV4) != 0) {
nd.nd_repstat = nfsvno_v4rootexport(&nd);
if (nd.nd_repstat != 0) {
NFSLOCKV4ROOTMUTEX();
nfsv4_relref(&nfsd_suspend_lock);
NFSUNLOCKV4ROOTMUTEX();
svcerr_weakauth(rqst);
svc_freereq(rqst);
m_freem(nd.nd_mrep);
goto out;
}
}
cacherep = nfs_proc(&nd, rqst->rq_xid, xprt, &rp);
NFSLOCKV4ROOTMUTEX();
nfsv4_relref(&nfsd_suspend_lock);
NFSUNLOCKV4ROOTMUTEX();
} else {
NFSMGET(nd.nd_mreq);
nd.nd_mreq->m_len = 0;
cacherep = RC_REPLY;
}
if (nd.nd_mrep != NULL)
m_freem(nd.nd_mrep);
if (nd.nd_cred != NULL)
crfree(nd.nd_cred);
if (cacherep == RC_DROPIT) {
if (nd.nd_mreq != NULL)
m_freem(nd.nd_mreq);
svc_freereq(rqst);
goto out;
}
if (nd.nd_mreq == NULL) {
svcerr_decode(rqst);
svc_freereq(rqst);
goto out;
}
if (nd.nd_repstat & NFSERR_AUTHERR) {
svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR);
if (nd.nd_mreq != NULL)
m_freem(nd.nd_mreq);
} else if (!svc_sendreply_mbuf(rqst, nd.nd_mreq)) {
svcerr_systemerr(rqst);
}
if (rp != NULL) {
nfsrvd_sentcache(rp, (rqst->rq_reply_seq != 0 ||
SVC_ACK(xprt, NULL)), rqst->rq_reply_seq);
}
svc_freereq(rqst);
out:
if (softdep_ast_cleanup != NULL)
softdep_ast_cleanup();
NFSEXITCODE(0);
}
/*
* Check the cache and, optionally, do the RPC.
* Return the appropriate cache response.
*/
static int
nfs_proc(struct nfsrv_descript *nd, u_int32_t xid, SVCXPRT *xprt,
struct nfsrvcache **rpp)
{
struct thread *td = curthread;
int cacherep = RC_DOIT, isdgram, taglen = -1;
struct mbuf *m;
u_char tag[NFSV4_SMALLSTR + 1], *tagstr = NULL;
u_int32_t minorvers = 0;
uint32_t ack;
*rpp = NULL;
if (nd->nd_nam2 == NULL) {
nd->nd_flag |= ND_STREAMSOCK;
isdgram = 0;
} else {
isdgram = 1;
}
/*
* Two cases:
* 1 - For NFSv2 over UDP, if we are near our malloc/mget
* limit, just drop the request. There is no
* NFSERR_RESOURCE or NFSERR_DELAY for NFSv2 and the
* client will timeout/retry over UDP in a little while.
* 2 - nd_repstat == 0 && nd_mreq == NULL, which
* means a normal nfs rpc, so check the cache
*/
if ((nd->nd_flag & ND_NFSV2) && nd->nd_nam2 != NULL &&
nfsrv_mallocmget_limit()) {
cacherep = RC_DROPIT;
} else {
/*
* For NFSv3, play it safe and assume that the client is
* doing retries on the same TCP connection.
*/
if ((nd->nd_flag & (ND_NFSV4 | ND_STREAMSOCK)) ==
ND_STREAMSOCK)
nd->nd_flag |= ND_SAMETCPCONN;
nd->nd_retxid = xid;
nd->nd_tcpconntime = NFSD_MONOSEC;
nd->nd_sockref = xprt->xp_sockref;
if ((nd->nd_flag & ND_NFSV4) != 0)
nfsd_getminorvers(nd, tag, &tagstr, &taglen,
&minorvers);
if ((nd->nd_flag & ND_NFSV41) != 0)
/* NFSv4.1 caches replies in the session slots. */
cacherep = RC_DOIT;
else {
cacherep = nfsrvd_getcache(nd);
ack = 0;
SVC_ACK(xprt, &ack);
nfsrc_trimcache(xprt->xp_sockref, ack, 0);
}
}
/*
* Handle the request. There are three cases.
* RC_DOIT - do the RPC
* RC_REPLY - return the reply already created
* RC_DROPIT - just throw the request away
*/
if (cacherep == RC_DOIT) {
if ((nd->nd_flag & ND_NFSV41) != 0)
nd->nd_xprt = xprt;
nfsrvd_dorpc(nd, isdgram, tagstr, taglen, minorvers, td);
if ((nd->nd_flag & ND_NFSV41) != 0) {
if (nd->nd_repstat != NFSERR_REPLYFROMCACHE &&
(nd->nd_flag & ND_SAVEREPLY) != 0) {
/* Cache a copy of the reply. */
m = m_copym(nd->nd_mreq, 0, M_COPYALL,
M_WAITOK);
} else
m = NULL;
if ((nd->nd_flag & ND_HASSEQUENCE) != 0)
nfsrv_cache_session(nd->nd_sessionid,
nd->nd_slotid, nd->nd_repstat, &m);
if (nd->nd_repstat == NFSERR_REPLYFROMCACHE)
nd->nd_repstat = 0;
cacherep = RC_REPLY;
} else {
if (nd->nd_repstat == NFSERR_DONTREPLY)
cacherep = RC_DROPIT;
else
cacherep = RC_REPLY;
*rpp = nfsrvd_updatecache(nd);
}
}
if (tagstr != NULL && taglen > NFSV4_SMALLSTR)
free(tagstr, M_TEMP);
NFSEXITCODE2(0, nd);
return (cacherep);
}
static void
nfssvc_loss(SVCXPRT *xprt)
{
uint32_t ack;
ack = 0;
SVC_ACK(xprt, &ack);
nfsrc_trimcache(xprt->xp_sockref, ack, 1);
}
/*
* Adds a socket to the list for servicing by nfsds.
*/
int
nfsrvd_addsock(struct file *fp)
{
int siz;
struct socket *so;
int error = 0;
SVCXPRT *xprt;
static u_int64_t sockref = 0;
so = fp->f_data;
siz = sb_max_adj;
error = soreserve(so, siz, siz);
if (error)
goto out;
/*
* Steal the socket from userland so that it doesn't close
* unexpectedly.
*/
if (so->so_type == SOCK_DGRAM)
xprt = svc_dg_create(nfsrvd_pool, so, 0, 0);
else
xprt = svc_vc_create(nfsrvd_pool, so, 0, 0);
if (xprt) {
fp->f_ops = &badfileops;
fp->f_data = NULL;
xprt->xp_sockref = ++sockref;
if (nfs_minvers == NFS_VER2)
svc_reg(xprt, NFS_PROG, NFS_VER2, nfssvc_program,
NULL);
if (nfs_minvers <= NFS_VER3 && nfs_maxvers >= NFS_VER3)
svc_reg(xprt, NFS_PROG, NFS_VER3, nfssvc_program,
NULL);
if (nfs_maxvers >= NFS_VER4)
svc_reg(xprt, NFS_PROG, NFS_VER4, nfssvc_program,
NULL);
if (so->so_type == SOCK_STREAM)
svc_loss_reg(xprt, nfssvc_loss);
SVC_RELEASE(xprt);
}
out:
NFSEXITCODE(error);
return (error);
}
/*
* Called by nfssvc() for nfsds. Just loops around servicing rpc requests
* until it is killed by a signal.
*/
int
nfsrvd_nfsd(struct thread *td, struct nfsd_nfsd_args *args)
{
char principal[MAXHOSTNAMELEN + 5];
struct proc *p;
int error = 0;
bool_t ret2, ret3, ret4;
error = copyinstr(args->principal, principal, sizeof (principal),
NULL);
if (error)
goto out;
/*
* Only the first nfsd actually does any work. The RPC code
* adds threads to it as needed. Any extra processes offered
* by nfsd just exit. If nfsd is new enough, it will call us
* once with a structure that specifies how many threads to
* use.
*/
NFSD_LOCK();
if (newnfs_numnfsd == 0) {
p = td->td_proc;
PROC_LOCK(p);
p->p_flag2 |= P2_AST_SU;
PROC_UNLOCK(p);
newnfs_numnfsd++;
NFSD_UNLOCK();
/* An empty string implies AUTH_SYS only. */
if (principal[0] != '\0') {
ret2 = rpc_gss_set_svc_name_call(principal,
"kerberosv5", GSS_C_INDEFINITE, NFS_PROG, NFS_VER2);
ret3 = rpc_gss_set_svc_name_call(principal,
"kerberosv5", GSS_C_INDEFINITE, NFS_PROG, NFS_VER3);
ret4 = rpc_gss_set_svc_name_call(principal,
"kerberosv5", GSS_C_INDEFINITE, NFS_PROG, NFS_VER4);
if (!ret2 || !ret3 || !ret4)
printf("nfsd: can't register svc name\n");
}
nfsrvd_pool->sp_minthreads = args->minthreads;
nfsrvd_pool->sp_maxthreads = args->maxthreads;
svc_run(nfsrvd_pool);
if (principal[0] != '\0') {
rpc_gss_clear_svc_name_call(NFS_PROG, NFS_VER2);
rpc_gss_clear_svc_name_call(NFS_PROG, NFS_VER3);
rpc_gss_clear_svc_name_call(NFS_PROG, NFS_VER4);
}
NFSD_LOCK();
newnfs_numnfsd--;
nfsrvd_init(1);
PROC_LOCK(p);
p->p_flag2 &= ~P2_AST_SU;
PROC_UNLOCK(p);
}
NFSD_UNLOCK();
out:
NFSEXITCODE(error);
return (error);
}
/*
* Initialize the data structures for the server.
* Handshake with any new nfsds starting up to avoid any chance of
* corruption.
*/
void
nfsrvd_init(int terminating)
{
NFSD_LOCK_ASSERT();
if (terminating) {
nfsd_master_proc = NULL;
NFSD_UNLOCK();
svcpool_destroy(nfsrvd_pool);
nfsrvd_pool = NULL;
NFSD_LOCK();
}
NFSD_UNLOCK();
nfsrvd_pool = svcpool_create("nfsd", SYSCTL_STATIC_CHILDREN(_vfs_nfsd));
nfsrvd_pool->sp_rcache = NULL;
nfsrvd_pool->sp_assign = fhanew_assign;
nfsrvd_pool->sp_done = fha_nd_complete;
NFSD_LOCK();
}
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