1ee624b31d
mechanism so that early processing on mbufs can be performed before a context switch to the NFS server threads. Because of this, if the socket code is running without Giant, the NFS server also needs to be able to run the upcall code without relying on the presence on Giant. This change modifies the NFS server to run using a "giant code lock" covering operation of the whole subsystem. Work is in progress to move to data-based locking as part of the NFSv4 server changes. Introduce an NFS server subsystem lock, 'nfsd_mtx', and a set of macros to operate on the lock: NFSD_LOCK_ASSERT() Assert nfsd_mtx owned by current thread NFSD_UNLOCK_ASSERT() Assert nfsd_mtx not owned by current thread NFSD_LOCK_DONTCARE() Advisory: this function doesn't care NFSD_LOCK() Lock nfsd_mtx NFSD_UNLOCK() Unlock nfsd_mtx Constify a number of global variables/structures in the NFS server code, as they are not modified and contain constants only: nfsrvv2_procid nfsrv_nfsv3_procid nonidempotent nfsv2_repstat nfsv2_type nfsrv_nfsv3_procid nfsrvv2_procid nfsrv_v2errmap nfsv3err_null nfsv3err_getattr nfsv3err_setattr nfsv3err_lookup nfsv3err_access nfsv3err_readlink nfsv3err_read nfsv3err_write nfsv3err_create nfsv3err_mkdir nfsv3err_symlink nfsv3err_mknod nfsv3err_remove nfsv3err_rmdir nfsv3err_rename nfsv3err_link nfsv3err_readdir nfsv3err_readdirplus nfsv3err_fsstat nfsv3err_fsinfo nfsv3err_pathconf nfsv3err_commit nfsrv_v3errmap There are additional structures that should be constified but due to their being passed into general purpose functions without const arguments, I have not yet converted. In general, acquire nfsd_mtx when accessing any of the global NFS structures, including struct nfssvc_sock, struct nfsd, struct nfsrv_descript. Release nfsd_mtx whenever calling into VFS, and acquire Giant for calls into VFS. Giant is not required for any part of the operation of the NFS server with the exception of calls into VFS. Giant will never by acquired in the upcall code path. However, it may operate entirely covered by Giant, or not. If debug.mpsafenet is set to 0, the system calls will acquire Giant across all operations, and the upcall will assert Giant. As such, by default, this enables locking and allows us to test assertions, but should not cause any substantial new amount of code to be run without Giant. Bugs should manifest in the form of lock assertion failures for now. This approach is similar (but not identical) to modifications to the BSD/OS NFS server code snapshot provided by BSDi as part of their SMPng snapshot. The strategy is almost the same (single lock over the NFS server), but differs in the following ways: - Our NFS client and server code bases don't overlap, which means both fewer bugs and easier locking (thanks Peter!). Also means NFSD_*() as opposed to NFS_*(). - We make broad use of assertions, whereas the BSD/OS code does not. - Made slightly different choices about how to handle macros building packets but operating with side effects. - We acquire Giant only when entering VFS from the NFS server daemon threads. - Serious bugs in BSD/OS implementation corrected -- the snapshot we received was clearly a work in progress. Based on ideas from: BSDi SMPng Snapshot Reviewed by: rick@snowhite.cis.uoguelph.ca Extensive testing by: kris
353 lines
9.0 KiB
C
353 lines
9.0 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* @(#)nfs_srvcache.c 8.3 (Berkeley) 3/30/95
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
/*
|
|
* Reference: Chet Juszczak, "Improving the Performance and Correctness
|
|
* of an NFS Server", in Proc. Winter 1989 USENIX Conference,
|
|
* pages 53-63. San Diego, February 1989.
|
|
*/
|
|
#include <sys/param.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mount.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/lock.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/mutex.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h> /* for sodupsockaddr */
|
|
|
|
#include <netinet/in.h>
|
|
#include <nfs/rpcv2.h>
|
|
#include <nfs/nfsproto.h>
|
|
#include <nfsserver/nfs.h>
|
|
#include <nfsserver/nfsrvcache.h>
|
|
|
|
static long numnfsrvcache;
|
|
static long desirednfsrvcache = NFSRVCACHESIZ;
|
|
|
|
#define NFSRCHASH(xid) \
|
|
(&nfsrvhashtbl[((xid) + ((xid) >> 24)) & nfsrvhash])
|
|
static LIST_HEAD(nfsrvhash, nfsrvcache) *nfsrvhashtbl;
|
|
static TAILQ_HEAD(nfsrvlru, nfsrvcache) nfsrvlruhead;
|
|
static u_long nfsrvhash;
|
|
|
|
#define TRUE 1
|
|
#define FALSE 0
|
|
|
|
#define NETFAMILY(rp) \
|
|
(((rp)->rc_flag & RC_NAM) ? (rp)->rc_nam->sa_family : AF_INET)
|
|
|
|
/*
|
|
* Static array that defines which nfs rpc's are nonidempotent
|
|
*/
|
|
static const int nonidempotent[NFS_NPROCS] = {
|
|
FALSE,
|
|
FALSE,
|
|
TRUE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
};
|
|
|
|
/* True iff the rpc reply is an nfs status ONLY! */
|
|
static const int nfsv2_repstat[NFS_NPROCS] = {
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
FALSE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
TRUE,
|
|
FALSE,
|
|
TRUE,
|
|
FALSE,
|
|
FALSE,
|
|
};
|
|
|
|
/*
|
|
* Initialize the server request cache list
|
|
*/
|
|
void
|
|
nfsrv_initcache(void)
|
|
{
|
|
|
|
nfsrvhashtbl = hashinit(desirednfsrvcache, M_NFSD, &nfsrvhash);
|
|
TAILQ_INIT(&nfsrvlruhead);
|
|
}
|
|
|
|
/*
|
|
* Look for the request in the cache
|
|
* If found then
|
|
* return action and optionally reply
|
|
* else
|
|
* insert it in the cache
|
|
*
|
|
* The rules are as follows:
|
|
* - if in progress, return DROP request
|
|
* - if completed within DELAY of the current time, return DROP it
|
|
* - if completed a longer time ago return REPLY if the reply was cached or
|
|
* return DOIT
|
|
* Update/add new request at end of lru list
|
|
*/
|
|
int
|
|
nfsrv_getcache(struct nfsrv_descript *nd, struct mbuf **repp)
|
|
{
|
|
struct nfsrvcache *rp;
|
|
struct mbuf *mb;
|
|
struct sockaddr_in *saddr;
|
|
caddr_t bpos;
|
|
int ret;
|
|
|
|
NFSD_LOCK_ASSERT();
|
|
|
|
/*
|
|
* Don't cache recent requests for reliable transport protocols.
|
|
* (Maybe we should for the case of a reconnect, but..)
|
|
*/
|
|
if (!nd->nd_nam2)
|
|
return (RC_DOIT);
|
|
loop:
|
|
LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
|
|
if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
|
|
netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
|
|
NFS_DPF(RC, ("H%03x", rp->rc_xid & 0xfff));
|
|
if ((rp->rc_flag & RC_LOCKED) != 0) {
|
|
rp->rc_flag |= RC_WANTED;
|
|
(void) msleep(rp, &nfsd_mtx, PZERO-1,
|
|
"nfsrc", 0);
|
|
goto loop;
|
|
}
|
|
rp->rc_flag |= RC_LOCKED;
|
|
/* If not at end of LRU chain, move it there */
|
|
if (TAILQ_NEXT(rp, rc_lru)) {
|
|
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
|
|
TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
|
|
}
|
|
if (rp->rc_state == RC_UNUSED)
|
|
panic("nfsrv cache");
|
|
if (rp->rc_state == RC_INPROG) {
|
|
nfsrvstats.srvcache_inproghits++;
|
|
ret = RC_DROPIT;
|
|
} else if (rp->rc_flag & RC_REPSTATUS) {
|
|
nfsrvstats.srvcache_nonidemdonehits++;
|
|
*repp = nfs_rephead(0, nd, rp->rc_status,
|
|
&mb, &bpos);
|
|
ret = RC_REPLY;
|
|
} else if (rp->rc_flag & RC_REPMBUF) {
|
|
nfsrvstats.srvcache_nonidemdonehits++;
|
|
NFSD_UNLOCK();
|
|
*repp = m_copym(rp->rc_reply, 0, M_COPYALL,
|
|
M_TRYWAIT);
|
|
NFSD_LOCK();
|
|
ret = RC_REPLY;
|
|
} else {
|
|
nfsrvstats.srvcache_idemdonehits++;
|
|
rp->rc_state = RC_INPROG;
|
|
ret = RC_DOIT;
|
|
}
|
|
rp->rc_flag &= ~RC_LOCKED;
|
|
if (rp->rc_flag & RC_WANTED) {
|
|
rp->rc_flag &= ~RC_WANTED;
|
|
wakeup(rp);
|
|
}
|
|
return (ret);
|
|
}
|
|
}
|
|
nfsrvstats.srvcache_misses++;
|
|
NFS_DPF(RC, ("M%03x", nd->nd_retxid & 0xfff));
|
|
if (numnfsrvcache < desirednfsrvcache) {
|
|
NFSD_UNLOCK();
|
|
rp = (struct nfsrvcache *)malloc((u_long)sizeof *rp,
|
|
M_NFSD, M_WAITOK | M_ZERO);
|
|
NFSD_LOCK();
|
|
numnfsrvcache++;
|
|
rp->rc_flag = RC_LOCKED;
|
|
} else {
|
|
rp = TAILQ_FIRST(&nfsrvlruhead);
|
|
while ((rp->rc_flag & RC_LOCKED) != 0) {
|
|
rp->rc_flag |= RC_WANTED;
|
|
(void) msleep(rp, &nfsd_mtx, PZERO-1, "nfsrc", 0);
|
|
rp = TAILQ_FIRST(&nfsrvlruhead);
|
|
}
|
|
rp->rc_flag |= RC_LOCKED;
|
|
LIST_REMOVE(rp, rc_hash);
|
|
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
|
|
if (rp->rc_flag & RC_REPMBUF)
|
|
m_freem(rp->rc_reply);
|
|
if (rp->rc_flag & RC_NAM)
|
|
FREE(rp->rc_nam, M_SONAME);
|
|
rp->rc_flag &= (RC_LOCKED | RC_WANTED);
|
|
}
|
|
TAILQ_INSERT_TAIL(&nfsrvlruhead, rp, rc_lru);
|
|
rp->rc_state = RC_INPROG;
|
|
rp->rc_xid = nd->nd_retxid;
|
|
saddr = (struct sockaddr_in *)nd->nd_nam;
|
|
switch (saddr->sin_family) {
|
|
case AF_INET:
|
|
rp->rc_flag |= RC_INETADDR;
|
|
rp->rc_inetaddr = saddr->sin_addr.s_addr;
|
|
break;
|
|
/* case AF_INET6: */
|
|
/* case AF_ISO: */
|
|
default:
|
|
rp->rc_flag |= RC_NAM;
|
|
rp->rc_nam = sodupsockaddr(nd->nd_nam, M_WAITOK);
|
|
break;
|
|
};
|
|
rp->rc_proc = nd->nd_procnum;
|
|
LIST_INSERT_HEAD(NFSRCHASH(nd->nd_retxid), rp, rc_hash);
|
|
rp->rc_flag &= ~RC_LOCKED;
|
|
if (rp->rc_flag & RC_WANTED) {
|
|
rp->rc_flag &= ~RC_WANTED;
|
|
wakeup(rp);
|
|
}
|
|
return (RC_DOIT);
|
|
}
|
|
|
|
/*
|
|
* Update a request cache entry after the rpc has been done
|
|
*/
|
|
void
|
|
nfsrv_updatecache(struct nfsrv_descript *nd, int repvalid, struct mbuf *repmbuf)
|
|
{
|
|
struct nfsrvcache *rp;
|
|
|
|
NFSD_LOCK_ASSERT();
|
|
|
|
if (!nd->nd_nam2)
|
|
return;
|
|
loop:
|
|
LIST_FOREACH(rp, NFSRCHASH(nd->nd_retxid), rc_hash) {
|
|
if (nd->nd_retxid == rp->rc_xid && nd->nd_procnum == rp->rc_proc &&
|
|
netaddr_match(NETFAMILY(rp), &rp->rc_haddr, nd->nd_nam)) {
|
|
NFS_DPF(RC, ("U%03x", rp->rc_xid & 0xfff));
|
|
if ((rp->rc_flag & RC_LOCKED) != 0) {
|
|
rp->rc_flag |= RC_WANTED;
|
|
(void) msleep(rp, &nfsd_mtx, PZERO-1,
|
|
"nfsrc", 0);
|
|
goto loop;
|
|
}
|
|
rp->rc_flag |= RC_LOCKED;
|
|
if (rp->rc_state == RC_DONE) {
|
|
/*
|
|
* This can occur if the cache is too small.
|
|
* Retransmits of the same request aren't
|
|
* dropped so we may see the operation
|
|
* complete more then once.
|
|
*/
|
|
if (rp->rc_flag & RC_REPMBUF) {
|
|
m_freem(rp->rc_reply);
|
|
rp->rc_flag &= ~RC_REPMBUF;
|
|
}
|
|
}
|
|
rp->rc_state = RC_DONE;
|
|
/*
|
|
* If we have a valid reply update status and save
|
|
* the reply for non-idempotent rpc's.
|
|
*/
|
|
if (repvalid && nonidempotent[nd->nd_procnum]) {
|
|
if ((nd->nd_flag & ND_NFSV3) == 0 &&
|
|
nfsv2_repstat[
|
|
nfsrvv2_procid[nd->nd_procnum]]) {
|
|
rp->rc_status = nd->nd_repstat;
|
|
rp->rc_flag |= RC_REPSTATUS;
|
|
} else {
|
|
NFSD_UNLOCK();
|
|
rp->rc_reply = m_copym(repmbuf,
|
|
0, M_COPYALL, M_TRYWAIT);
|
|
NFSD_LOCK();
|
|
rp->rc_flag |= RC_REPMBUF;
|
|
}
|
|
}
|
|
rp->rc_flag &= ~RC_LOCKED;
|
|
if (rp->rc_flag & RC_WANTED) {
|
|
rp->rc_flag &= ~RC_WANTED;
|
|
wakeup(rp);
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
NFS_DPF(RC, ("L%03x", nd->nd_retxid & 0xfff));
|
|
}
|
|
|
|
/*
|
|
* Clean out the cache. Called when the last nfsd terminates.
|
|
*/
|
|
void
|
|
nfsrv_cleancache(void)
|
|
{
|
|
struct nfsrvcache *rp, *nextrp;
|
|
|
|
NFSD_LOCK_ASSERT();
|
|
|
|
for (rp = TAILQ_FIRST(&nfsrvlruhead); rp != 0; rp = nextrp) {
|
|
nextrp = TAILQ_NEXT(rp, rc_lru);
|
|
LIST_REMOVE(rp, rc_hash);
|
|
TAILQ_REMOVE(&nfsrvlruhead, rp, rc_lru);
|
|
if (rp->rc_flag & RC_REPMBUF)
|
|
m_freem(rp->rc_reply);
|
|
if (rp->rc_flag & RC_NAM)
|
|
free(rp->rc_nam, M_SONAME);
|
|
free(rp, M_NFSD);
|
|
}
|
|
numnfsrvcache = 0;
|
|
}
|