nfs_nfsiod.c revision 86363
1/* 2 * Copyright (c) 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Rick Macklem at The University of Guelph. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)nfs_syscalls.c 8.5 (Berkeley) 3/30/95 37 */ 38 39#include <sys/cdefs.h> 40__FBSDID("$FreeBSD: head/sys/nfsclient/nfs_nfsiod.c 86363 2001-11-14 18:20:45Z rwatson $"); 41 42#include <sys/param.h> 43#include <sys/systm.h> 44#include <sys/sysproto.h> 45#include <sys/kernel.h> 46#include <sys/sysctl.h> 47#include <sys/file.h> 48#include <sys/filedesc.h> 49#include <sys/vnode.h> 50#include <sys/malloc.h> 51#include <sys/mount.h> 52#include <sys/proc.h> 53#include <sys/bio.h> 54#include <sys/buf.h> 55#include <sys/mbuf.h> 56#include <sys/socket.h> 57#include <sys/socketvar.h> 58#include <sys/domain.h> 59#include <sys/protosw.h> 60#include <sys/namei.h> 61#include <sys/unistd.h> 62#include <sys/kthread.h> 63#include <sys/fcntl.h> 64#include <sys/lockf.h> 65#include <sys/mutex.h> 66 67#include <netinet/in.h> 68#include <netinet/tcp.h> 69#include <nfs/xdr_subs.h> 70#include <nfs/rpcv2.h> 71#include <nfs/nfsproto.h> 72#include <nfsclient/nfs.h> 73#include <nfsclient/nfsm_subs.h> 74#include <nfsclient/nfsmount.h> 75#include <nfsclient/nfsnode.h> 76#include <nfsclient/nfs_lock.h> 77 78static MALLOC_DEFINE(M_NFSSVC, "NFS srvsock", "Nfs server structure"); 79 80static void nfssvc_iod(void *); 81 82#define TRUE 1 83#define FALSE 0 84 85static int nfs_asyncdaemon[NFS_MAXASYNCDAEMON]; 86 87SYSCTL_DECL(_vfs_nfs); 88 89static void 90nfsiod_setup(void *dummy) 91{ 92 int i; 93 int error; 94 struct proc *p; 95 96 for (i = 0; i < 4; i++) { 97 error = kthread_create(nfssvc_iod, NULL, &p, RFHIGHPID, 98 "nfsiod %d", i); 99 if (error) 100 panic("nfsiod_setup: kthread_create error %d", error); 101 } 102} 103SYSINIT(nfsiod, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, nfsiod_setup, NULL); 104 105static int nfs_defect = 0; 106SYSCTL_INT(_vfs_nfs, OID_AUTO, defect, CTLFLAG_RW, &nfs_defect, 0, ""); 107 108int 109nfsclnt(struct thread *td, struct nfsclnt_args *uap) 110{ 111 struct lockd_ans la; 112 int error; 113 114 if ((uap->flag & NFSCLNT_LOCKDANS) != 0) { 115 error = copyin(uap->argp, &la, sizeof(la)); 116 return (error != 0 ? error : nfslockdans(td, &la)); 117 } 118 return EINVAL; 119} 120 121/* 122 * Asynchronous I/O daemons for client nfs. 123 * They do read-ahead and write-behind operations on the block I/O cache. 124 * Never returns unless it fails or gets killed. 125 */ 126static void 127nfssvc_iod(void *dummy) 128{ 129 struct buf *bp; 130 int i, myiod; 131 struct nfsmount *nmp; 132 int error = 0; 133 134 mtx_lock(&Giant); 135 /* 136 * Assign my position or return error if too many already running 137 */ 138 myiod = -1; 139 for (i = 0; i < NFS_MAXASYNCDAEMON; i++) 140 if (nfs_asyncdaemon[i] == 0) { 141 nfs_asyncdaemon[i]++; 142 myiod = i; 143 break; 144 } 145 if (myiod == -1) 146 return /* XXX (EBUSY) */; 147 nfs_numasync++; 148 /* 149 * Just loop around doin our stuff until SIGKILL 150 */ 151 for (;;) { 152 while (((nmp = nfs_iodmount[myiod]) == NULL 153 || !TAILQ_FIRST(&nmp->nm_bufq)) 154 && error == 0) { 155 if (nmp) 156 nmp->nm_bufqiods--; 157 nfs_iodwant[myiod] = curthread->td_proc; 158 nfs_iodmount[myiod] = NULL; 159 error = tsleep((caddr_t)&nfs_iodwant[myiod], 160 PWAIT | PCATCH, "nfsidl", 0); 161 } 162 if (error) { 163 nfs_asyncdaemon[myiod] = 0; 164 if (nmp) 165 nmp->nm_bufqiods--; 166 nfs_iodwant[myiod] = NULL; 167 nfs_iodmount[myiod] = NULL; 168 nfs_numasync--; 169 return /* XXX (error) */; 170 } 171 while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) { 172 /* Take one off the front of the list */ 173 TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist); 174 nmp->nm_bufqlen--; 175 if (nmp->nm_bufqwant && nmp->nm_bufqlen <= nfs_numasync) { 176 nmp->nm_bufqwant = FALSE; 177 wakeup(&nmp->nm_bufq); 178 } 179 if (bp->b_iocmd == BIO_READ) 180 (void) nfs_doio(bp, bp->b_rcred, (struct thread *)0); 181 else 182 (void) nfs_doio(bp, bp->b_wcred, (struct thread *)0); 183 /* 184 * If there are more than one iod on this mount, then defect 185 * so that the iods can be shared out fairly between the mounts 186 */ 187 if (nfs_defect && nmp->nm_bufqiods > 1) { 188 NFS_DPF(ASYNCIO, 189 ("nfssvc_iod: iod %d defecting from mount %p\n", 190 myiod, nmp)); 191 nfs_iodmount[myiod] = NULL; 192 nmp->nm_bufqiods--; 193 break; 194 } 195 } 196 } 197} 198