Example #1
0
/*
 * Asynchronous I/O daemons for client nfs.
 * They do read-ahead and write-behind operations on the block I/O cache.
 * Returns if we hit the timeout defined by the iodmaxidle sysctl.
 */
static void
nfssvc_iod(void *instance)
{
	struct buf *bp;
	struct nfsmount *nmp;
	int myiod, timo;
	int error = 0;

	mtx_lock(&nfs_iod_mtx);
	myiod = (int *)instance - nfs_asyncdaemon;
	/*
	 * Main loop
	 */
	for (;;) {
	    while (((nmp = nfs_iodmount[myiod]) == NULL)
		   || !TAILQ_FIRST(&nmp->nm_bufq)) {
		if (myiod >= nfs_iodmax)
			goto finish;
		if (nmp)
			nmp->nm_bufqiods--;
		if (nfs_iodwant[myiod] == NFSIOD_NOT_AVAILABLE)
			nfs_iodwant[myiod] = NFSIOD_AVAILABLE;
		nfs_iodmount[myiod] = NULL;
		/*
		 * Always keep at least nfs_iodmin kthreads.
		 */
		timo = (myiod < nfs_iodmin) ? 0 : nfs_iodmaxidle * hz;
		error = msleep(&nfs_iodwant[myiod], &nfs_iod_mtx, PWAIT | PCATCH,
		    "-", timo);
		if (error) {
			nmp = nfs_iodmount[myiod];
			/*
			 * Rechecking the nm_bufq closes a rare race where the 
			 * nfsiod is woken up at the exact time the idle timeout
			 * fires
			 */
			if (nmp && TAILQ_FIRST(&nmp->nm_bufq))
				error = 0;
			break;
		}
	    }
	    if (error)
		    break;
	    while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) {
	        int giant_locked = 0;
		    
		/* Take one off the front of the list */
		TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist);
		nmp->nm_bufqlen--;
		if (nmp->nm_bufqwant && nmp->nm_bufqlen <= nfs_numasync) {
		    nmp->nm_bufqwant = 0;
		    wakeup(&nmp->nm_bufq);
		}
		mtx_unlock(&nfs_iod_mtx);
		if (NFS_ISV4(bp->b_vp)) {
			giant_locked = 1;
			mtx_lock(&Giant);
		}
		if (bp->b_flags & B_DIRECT) {
			KASSERT((bp->b_iocmd == BIO_WRITE), ("nfscvs_iod: BIO_WRITE not set"));
			(void)nfs_doio_directwrite(bp);
		} else {
			if (bp->b_iocmd == BIO_READ)
				(void) nfs_doio(bp->b_vp, bp, bp->b_rcred, NULL);
			else
				(void) nfs_doio(bp->b_vp, bp, bp->b_wcred, NULL);
		}
		if (giant_locked)
			mtx_unlock(&Giant);
		mtx_lock(&nfs_iod_mtx);
		/*
		 * If there are more than one iod on this mount, then defect
		 * so that the iods can be shared out fairly between the mounts
		 */
		if (nfs_defect && nmp->nm_bufqiods > 1) {
		    NFS_DPF(ASYNCIO,
			    ("nfssvc_iod: iod %d defecting from mount %p\n",
			     myiod, nmp));
		    nfs_iodmount[myiod] = NULL;
		    nmp->nm_bufqiods--;
		    break;
		}
	    }
	}
finish:
	nfs_asyncdaemon[myiod] = 0;
	if (nmp)
	    nmp->nm_bufqiods--;
	nfs_iodwant[myiod] = NFSIOD_NOT_AVAILABLE;
	nfs_iodmount[myiod] = NULL;
	/* Someone may be waiting for the last nfsiod to terminate. */
	if (--nfs_numasync == 0)
		wakeup(&nfs_numasync);
	mtx_unlock(&nfs_iod_mtx);
	if ((error == 0) || (error == EWOULDBLOCK))
		kproc_exit(0);
	/* Abnormal termination */
	kproc_exit(1);
}
Example #2
0
/*
 * 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 nfssvc_sock *slp,
	       struct mbuf **repp)
{
	struct nfsrvcache *rp;
	struct mbuf *mb;
	struct sockaddr_in *saddr;
	caddr_t bpos;
	int ret;

	/*
	 * 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);

	lwkt_gettoken(&srvcache_token);
loop:
	for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != NULL;
	    rp = rp->rc_hash.le_next) {
	    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;
				tsleep((caddr_t)rp, 0, "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) != NULL) {
				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) {
				nfsstats.srvcache_inproghits++;
				ret = RC_DROPIT;
			} else if (rp->rc_flag & RC_REPSTATUS) {
				nfsstats.srvcache_nonidemdonehits++;
				nfs_rephead(0, nd, slp, rp->rc_status,
					    repp, &mb, &bpos);
				ret = RC_REPLY;
			} else if (rp->rc_flag & RC_REPMBUF) {
				nfsstats.srvcache_nonidemdonehits++;
				*repp = m_copym(rp->rc_reply, 0, M_COPYALL,
						MB_WAIT);
				ret = RC_REPLY;
			} else {
				nfsstats.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((caddr_t)rp);
			}
			lwkt_reltoken(&srvcache_token);
			return (ret);
		}
	}

	nfsstats.srvcache_misses++;
	NFS_DPF(RC, ("M%03x", nd->nd_retxid & 0xfff));
	if (numnfsrvcache < desirednfsrvcache) {
		rp = kmalloc((u_long)sizeof *rp, M_NFSD, M_WAITOK | M_ZERO);
		numnfsrvcache++;
		rp->rc_flag = RC_LOCKED;
	} else {
		rp = TAILQ_FIRST(&nfsrvlruhead);
		while ((rp->rc_flag & RC_LOCKED) != 0) {
			rp->rc_flag |= RC_WANTED;
			tsleep((caddr_t)rp, 0, "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);
			rp->rc_reply = NULL;
			rp->rc_flag &= ~RC_REPMBUF;
		}
		if (rp->rc_flag & RC_NAM) {
			kfree(rp->rc_nam, M_SONAME);
			rp->rc_nam = NULL;
			rp->rc_flag &= ~RC_NAM;
		}
	}
	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_ISO:
	default:
		rp->rc_flag |= RC_NAM;
		rp->rc_nam = dup_sockaddr(nd->nd_nam);
		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((caddr_t)rp);
	}
	lwkt_reltoken(&srvcache_token);

	return (RC_DOIT);
}
Example #3
0
/*
 * 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;

	if (!nd->nd_nam2)
		return;

	lwkt_gettoken(&srvcache_token);
loop:
	for (rp = NFSRCHASH(nd->nd_retxid)->lh_first; rp != NULL;
	    rp = rp->rc_hash.le_next) {
	    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;
				tsleep((caddr_t)rp, 0, "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_reply = NULL;
					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[nfsv2_procid[nd->nd_procnum]]) {
					rp->rc_status = nd->nd_repstat;
					rp->rc_flag |= RC_REPSTATUS;
				} else {
					if (rp->rc_flag & RC_REPMBUF) {
						m_freem(rp->rc_reply);
						rp->rc_reply = NULL;
						rp->rc_flag &= ~RC_REPMBUF;
					}
					rp->rc_reply = m_copym(repmbuf, 0,
							M_COPYALL, MB_WAIT);
					rp->rc_flag |= RC_REPMBUF;
				}
			}
			rp->rc_flag &= ~RC_LOCKED;
			if (rp->rc_flag & RC_WANTED) {
				rp->rc_flag &= ~RC_WANTED;
				wakeup((caddr_t)rp);
			}
			break;
		}
	}
	lwkt_reltoken(&srvcache_token);
	NFS_DPF(RC, ("L%03x", nd->nd_retxid & 0xfff));
}
Example #4
0
/*
 * Asynchronous I/O daemons for client nfs.
 * They do read-ahead and write-behind operations on the block I/O cache.
 * Returns if we hit the timeout defined by the iodmaxidle sysctl.
 */
static void
nfssvc_iod(void *instance)
{
	struct buf *bp;
	struct nfsmount *nmp;
	int myiod, timo;
	int error = 0;

	mtx_lock(&Giant);
	myiod = (int *)instance - nfs_asyncdaemon;
	/*
	 * Main loop
	 */
	for (;;) {
	    while (((nmp = nfs_iodmount[myiod]) == NULL
		   || !TAILQ_FIRST(&nmp->nm_bufq))
		   && error == 0) {
		if (myiod >= nfs_iodmax)
			goto finish;
		if (nmp)
			nmp->nm_bufqiods--;
		nfs_iodwant[myiod] = curthread->td_proc;
		nfs_iodmount[myiod] = NULL;
		/*
		 * Always keep at least nfs_iodmin kthreads.
		 */
		timo = (myiod < nfs_iodmin) ? 0 : nfs_iodmaxidle * hz;
		error = tsleep((caddr_t)&nfs_iodwant[myiod], PWAIT | PCATCH,
		    "nfsidl", timo);
	    }
	    if (error)
		    break;
	    while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) {
		/* Take one off the front of the list */
		TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist);
		nmp->nm_bufqlen--;
		if (nmp->nm_bufqwant && nmp->nm_bufqlen <= nfs_numasync) {
		    nmp->nm_bufqwant = 0;
		    wakeup(&nmp->nm_bufq);
		}
		if (bp->b_iocmd == BIO_READ)
		    (void) nfs_doio(bp, bp->b_rcred, NULL);
		else
		    (void) nfs_doio(bp, bp->b_wcred, NULL);
		/*
		 * If there are more than one iod on this mount, then defect
		 * so that the iods can be shared out fairly between the mounts
		 */
		if (nfs_defect && nmp->nm_bufqiods > 1) {
		    NFS_DPF(ASYNCIO,
			    ("nfssvc_iod: iod %d defecting from mount %p\n",
			     myiod, nmp));
		    nfs_iodmount[myiod] = NULL;
		    nmp->nm_bufqiods--;
		    break;
		}
	    }
	}
finish:
	nfs_asyncdaemon[myiod] = 0;
	if (nmp)
	    nmp->nm_bufqiods--;
	nfs_iodwant[myiod] = NULL;
	nfs_iodmount[myiod] = NULL;
	nfs_numasync--;
	if ((error == 0) || (error == EWOULDBLOCK))
		kthread_exit(0);
	/* Abnormal termination */
	kthread_exit(1);
}