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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 * 32 * from nfs_syscalls.c 8.5 (Berkeley) 3/30/95 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/sysproto.h> 41 #include <sys/kernel.h> 42 #include <sys/sysctl.h> 43 #include <sys/file.h> 44 #include <sys/filedesc.h> 45 #include <sys/vnode.h> 46 #include <sys/malloc.h> 47 #include <sys/mount.h> 48 #include <sys/proc.h> 49 #include <sys/bio.h> 50 #include <sys/buf.h> 51 #include <sys/mbuf.h> 52 #include <sys/socket.h> 53 #include <sys/socketvar.h> 54 #include <sys/domain.h> 55 #include <sys/protosw.h> 56 #include <sys/namei.h> 57 #include <sys/unistd.h> 58 #include <sys/kthread.h> 59 #include <sys/fcntl.h> 60 #include <sys/lockf.h> 61 #include <sys/mutex.h> 62 63 #include <netinet/in.h> 64 #include <netinet/tcp.h> 65 66 #include <fs/nfs/nfsport.h> 67 #include <fs/nfsclient/nfsmount.h> 68 #include <fs/nfsclient/nfs.h> 69 #include <fs/nfsclient/nfsnode.h> 70 71 extern struct mtx ncl_iod_mutex; 72 73 int ncl_numasync; 74 enum nfsiod_state ncl_iodwant[NFS_MAXRAHEAD]; 75 struct nfsmount *ncl_iodmount[NFS_MAXRAHEAD]; 76 77 static void nfssvc_iod(void *); 78 79 static int nfs_asyncdaemon[NFS_MAXRAHEAD]; 80 81 SYSCTL_DECL(_vfs_newnfs); 82 83 /* Maximum number of seconds a nfsiod kthread will sleep before exiting */ 84 static unsigned int ncl_iodmaxidle = 120; 85 SYSCTL_UINT(_vfs_newnfs, OID_AUTO, iodmaxidle, CTLFLAG_RW, &ncl_iodmaxidle, 0, ""); 86 87 /* Maximum number of nfsiod kthreads */ 88 unsigned int ncl_iodmax = NFS_MAXRAHEAD; 89 90 /* Minimum number of nfsiod kthreads to keep as spares */ 91 static unsigned int nfs_iodmin = 0; 92 93 static int 94 sysctl_iodmin(SYSCTL_HANDLER_ARGS) 95 { 96 int error, i; 97 int newmin; 98 99 newmin = nfs_iodmin; 100 error = sysctl_handle_int(oidp, &newmin, 0, req); 101 if (error || (req->newptr == NULL)) 102 return (error); 103 mtx_lock(&ncl_iod_mutex); 104 if (newmin > ncl_iodmax) { 105 error = EINVAL; 106 goto out; 107 } 108 nfs_iodmin = newmin; 109 if (ncl_numasync >= nfs_iodmin) 110 goto out; 111 /* 112 * If the current number of nfsiod is lower 113 * than the new minimum, create some more. 114 */ 115 for (i = nfs_iodmin - ncl_numasync; i > 0; i--) 116 ncl_nfsiodnew(0); 117 out: 118 mtx_unlock(&ncl_iod_mutex); 119 return (0); 120 } 121 SYSCTL_PROC(_vfs_newnfs, OID_AUTO, iodmin, CTLTYPE_UINT | CTLFLAG_RW, 0, 122 sizeof (nfs_iodmin), sysctl_iodmin, "IU", ""); 123 124 125 static int 126 sysctl_iodmax(SYSCTL_HANDLER_ARGS) 127 { 128 int error, i; 129 int iod, newmax; 130 131 newmax = ncl_iodmax; 132 error = sysctl_handle_int(oidp, &newmax, 0, req); 133 if (error || (req->newptr == NULL)) 134 return (error); 135 if (newmax > NFS_MAXRAHEAD) 136 return (EINVAL); 137 mtx_lock(&ncl_iod_mutex); 138 ncl_iodmax = newmax; 139 if (ncl_numasync <= ncl_iodmax) 140 goto out; 141 /* 142 * If there are some asleep nfsiods that should 143 * exit, wakeup() them so that they check ncl_iodmax 144 * and exit. Those who are active will exit as 145 * soon as they finish I/O. 146 */ 147 iod = ncl_numasync - 1; 148 for (i = 0; i < ncl_numasync - ncl_iodmax; i++) { 149 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) 150 wakeup(&ncl_iodwant[iod]); 151 iod--; 152 } 153 out: 154 mtx_unlock(&ncl_iod_mutex); 155 return (0); 156 } 157 SYSCTL_PROC(_vfs_newnfs, OID_AUTO, iodmax, CTLTYPE_UINT | CTLFLAG_RW, 0, 158 sizeof (ncl_iodmax), sysctl_iodmax, "IU", ""); 159 160 int 161 ncl_nfsiodnew(int set_iodwant) 162 { 163 int error, i; 164 int newiod; 165 166 if (ncl_numasync >= ncl_iodmax) 167 return (-1); 168 newiod = -1; 169 for (i = 0; i < ncl_iodmax; i++) 170 if (nfs_asyncdaemon[i] == 0) { 171 nfs_asyncdaemon[i]++; 172 newiod = i; 173 break; 174 } 175 if (newiod == -1) 176 return (-1); 177 if (set_iodwant > 0) 178 ncl_iodwant[i] = NFSIOD_CREATED_FOR_NFS_ASYNCIO; 179 mtx_unlock(&ncl_iod_mutex); 180 error = kproc_create(nfssvc_iod, nfs_asyncdaemon + i, NULL, RFHIGHPID, 181 0, "nfsiod %d", newiod); 182 mtx_lock(&ncl_iod_mutex); 183 if (error) { 184 if (set_iodwant > 0) 185 ncl_iodwant[i] = NFSIOD_NOT_AVAILABLE; 186 return (-1); 187 } 188 ncl_numasync++; 189 return (newiod); 190 } 191 192 static void 193 nfsiod_setup(void *dummy) 194 { 195 int i; 196 int error; 197 198 TUNABLE_INT_FETCH("vfs.newnfs.iodmin", &nfs_iodmin); 199 nfscl_init(); 200 mtx_lock(&ncl_iod_mutex); 201 /* Silently limit the start number of nfsiod's */ 202 if (nfs_iodmin > NFS_MAXRAHEAD) 203 nfs_iodmin = NFS_MAXRAHEAD; 204 205 for (i = 0; i < nfs_iodmin; i++) { 206 error = ncl_nfsiodnew(0); 207 if (error == -1) 208 panic("newnfsiod_setup: ncl_nfsiodnew failed"); 209 } 210 mtx_unlock(&ncl_iod_mutex); 211 } 212 SYSINIT(newnfsiod, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, nfsiod_setup, NULL); 213 214 static int nfs_defect = 0; 215 SYSCTL_INT(_vfs_newnfs, OID_AUTO, defect, CTLFLAG_RW, &nfs_defect, 0, ""); 216 217 /* 218 * Asynchronous I/O daemons for client nfs. 219 * They do read-ahead and write-behind operations on the block I/O cache. 220 * Returns if we hit the timeout defined by the iodmaxidle sysctl. 221 */ 222 static void 223 nfssvc_iod(void *instance) 224 { 225 struct buf *bp; 226 struct nfsmount *nmp; 227 int myiod, timo; 228 int error = 0; 229 230 mtx_lock(&ncl_iod_mutex); 231 myiod = (int *)instance - nfs_asyncdaemon; 232 /* 233 * Main loop 234 */ 235 for (;;) { 236 while (((nmp = ncl_iodmount[myiod]) == NULL) 237 || !TAILQ_FIRST(&nmp->nm_bufq)) { 238 if (myiod >= ncl_iodmax) 239 goto finish; 240 if (nmp) 241 nmp->nm_bufqiods--; 242 if (ncl_iodwant[myiod] == NFSIOD_NOT_AVAILABLE) 243 ncl_iodwant[myiod] = NFSIOD_AVAILABLE; 244 ncl_iodmount[myiod] = NULL; 245 /* 246 * Always keep at least nfs_iodmin kthreads. 247 */ 248 timo = (myiod < nfs_iodmin) ? 0 : ncl_iodmaxidle * hz; 249 error = msleep(&ncl_iodwant[myiod], &ncl_iod_mutex, PWAIT | PCATCH, 250 "-", timo); 251 if (error) { 252 nmp = ncl_iodmount[myiod]; 253 /* 254 * Rechecking the nm_bufq closes a rare race where the 255 * nfsiod is woken up at the exact time the idle timeout 256 * fires 257 */ 258 if (nmp && TAILQ_FIRST(&nmp->nm_bufq)) 259 error = 0; 260 break; 261 } 262 } 263 if (error) 264 break; 265 while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) { 266 267 /* Take one off the front of the list */ 268 TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist); 269 nmp->nm_bufqlen--; 270 if (nmp->nm_bufqwant && nmp->nm_bufqlen <= ncl_numasync) { 271 nmp->nm_bufqwant = 0; 272 wakeup(&nmp->nm_bufq); 273 } 274 mtx_unlock(&ncl_iod_mutex); 275 if (bp->b_flags & B_DIRECT) { 276 KASSERT((bp->b_iocmd == BIO_WRITE), ("nfscvs_iod: BIO_WRITE not set")); 277 (void)ncl_doio_directwrite(bp); 278 } else { 279 if (bp->b_iocmd == BIO_READ) 280 (void) ncl_doio(bp->b_vp, bp, bp->b_rcred, 281 NULL, 0); 282 else 283 (void) ncl_doio(bp->b_vp, bp, bp->b_wcred, 284 NULL, 0); 285 } 286 mtx_lock(&ncl_iod_mutex); 287 /* 288 * If there are more than one iod on this mount, then defect 289 * so that the iods can be shared out fairly between the mounts 290 */ 291 if (nfs_defect && nmp->nm_bufqiods > 1) { 292 NFS_DPF(ASYNCIO, 293 ("nfssvc_iod: iod %d defecting from mount %p\n", 294 myiod, nmp)); 295 ncl_iodmount[myiod] = NULL; 296 nmp->nm_bufqiods--; 297 break; 298 } 299 } 300 } 301 finish: 302 nfs_asyncdaemon[myiod] = 0; 303 if (nmp) 304 nmp->nm_bufqiods--; 305 ncl_iodwant[myiod] = NFSIOD_NOT_AVAILABLE; 306 ncl_iodmount[myiod] = NULL; 307 /* Someone may be waiting for the last nfsiod to terminate. */ 308 if (--ncl_numasync == 0) 309 wakeup(&ncl_numasync); 310 mtx_unlock(&ncl_iod_mutex); 311 if ((error == 0) || (error == EWOULDBLOCK)) 312 kproc_exit(0); 313 /* Abnormal termination */ 314 kproc_exit(1); 315 } 316