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. 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 #include <sys/taskqueue.h> 63 64 #include <netinet/in.h> 65 #include <netinet/tcp.h> 66 67 #include <fs/nfs/nfsport.h> 68 #include <fs/nfsclient/nfsmount.h> 69 #include <fs/nfsclient/nfs.h> 70 #include <fs/nfsclient/nfsnode.h> 71 72 extern struct mtx ncl_iod_mutex; 73 extern struct task ncl_nfsiodnew_task; 74 75 int ncl_numasync; 76 enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON]; 77 struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON]; 78 79 static void nfssvc_iod(void *); 80 81 static int nfs_asyncdaemon[NFS_MAXASYNCDAEMON]; 82 83 SYSCTL_DECL(_vfs_nfs); 84 85 /* Maximum number of seconds a nfsiod kthread will sleep before exiting */ 86 static unsigned int nfs_iodmaxidle = 120; 87 SYSCTL_UINT(_vfs_nfs, OID_AUTO, iodmaxidle, CTLFLAG_RW, &nfs_iodmaxidle, 0, 88 "Max number of seconds an nfsiod kthread will sleep before exiting"); 89 90 /* Maximum number of nfsiod kthreads */ 91 unsigned int ncl_iodmax = 20; 92 93 /* Minimum number of nfsiod kthreads to keep as spares */ 94 static unsigned int nfs_iodmin = 0; 95 96 static int nfs_nfsiodnew_sync(void); 97 98 static int 99 sysctl_iodmin(SYSCTL_HANDLER_ARGS) 100 { 101 int error, i; 102 int newmin; 103 104 newmin = nfs_iodmin; 105 error = sysctl_handle_int(oidp, &newmin, 0, req); 106 if (error || (req->newptr == NULL)) 107 return (error); 108 mtx_lock(&ncl_iod_mutex); 109 if (newmin > ncl_iodmax) { 110 error = EINVAL; 111 goto out; 112 } 113 nfs_iodmin = newmin; 114 if (ncl_numasync >= nfs_iodmin) 115 goto out; 116 /* 117 * If the current number of nfsiod is lower 118 * than the new minimum, create some more. 119 */ 120 for (i = nfs_iodmin - ncl_numasync; i > 0; i--) 121 nfs_nfsiodnew_sync(); 122 out: 123 mtx_unlock(&ncl_iod_mutex); 124 return (0); 125 } 126 SYSCTL_PROC(_vfs_nfs, OID_AUTO, iodmin, CTLTYPE_UINT | CTLFLAG_RW, 0, 127 sizeof (nfs_iodmin), sysctl_iodmin, "IU", 128 "Min number of nfsiod kthreads to keep as spares"); 129 130 static int 131 sysctl_iodmax(SYSCTL_HANDLER_ARGS) 132 { 133 int error, i; 134 int iod, newmax; 135 136 newmax = ncl_iodmax; 137 error = sysctl_handle_int(oidp, &newmax, 0, req); 138 if (error || (req->newptr == NULL)) 139 return (error); 140 if (newmax > NFS_MAXASYNCDAEMON) 141 return (EINVAL); 142 mtx_lock(&ncl_iod_mutex); 143 ncl_iodmax = newmax; 144 if (ncl_numasync <= ncl_iodmax) 145 goto out; 146 /* 147 * If there are some asleep nfsiods that should 148 * exit, wakeup() them so that they check ncl_iodmax 149 * and exit. Those who are active will exit as 150 * soon as they finish I/O. 151 */ 152 iod = ncl_numasync - 1; 153 for (i = 0; i < ncl_numasync - ncl_iodmax; i++) { 154 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) 155 wakeup(&ncl_iodwant[iod]); 156 iod--; 157 } 158 out: 159 mtx_unlock(&ncl_iod_mutex); 160 return (0); 161 } 162 SYSCTL_PROC(_vfs_nfs, OID_AUTO, iodmax, CTLTYPE_UINT | CTLFLAG_RW, 0, 163 sizeof (ncl_iodmax), sysctl_iodmax, "IU", 164 "Max number of nfsiod kthreads"); 165 166 static int 167 nfs_nfsiodnew_sync(void) 168 { 169 int error, i; 170 171 mtx_assert(&ncl_iod_mutex, MA_OWNED); 172 for (i = 0; i < ncl_iodmax; i++) { 173 if (nfs_asyncdaemon[i] == 0) { 174 nfs_asyncdaemon[i] = 1; 175 break; 176 } 177 } 178 if (i == ncl_iodmax) 179 return (0); 180 mtx_unlock(&ncl_iod_mutex); 181 error = kproc_create(nfssvc_iod, nfs_asyncdaemon + i, NULL, 182 RFHIGHPID, 0, "newnfs %d", i); 183 mtx_lock(&ncl_iod_mutex); 184 if (error == 0) { 185 ncl_numasync++; 186 ncl_iodwant[i] = NFSIOD_AVAILABLE; 187 } else 188 nfs_asyncdaemon[i] = 0; 189 return (error); 190 } 191 192 void 193 ncl_nfsiodnew_tq(__unused void *arg, int pending) 194 { 195 196 mtx_lock(&ncl_iod_mutex); 197 while (pending > 0) { 198 pending--; 199 nfs_nfsiodnew_sync(); 200 } 201 mtx_unlock(&ncl_iod_mutex); 202 } 203 204 void 205 ncl_nfsiodnew(void) 206 { 207 208 mtx_assert(&ncl_iod_mutex, MA_OWNED); 209 taskqueue_enqueue(taskqueue_thread, &ncl_nfsiodnew_task); 210 } 211 212 static void 213 nfsiod_setup(void *dummy) 214 { 215 int error; 216 217 TUNABLE_INT_FETCH("vfs.nfs.iodmin", &nfs_iodmin); 218 nfscl_init(); 219 mtx_lock(&ncl_iod_mutex); 220 /* Silently limit the start number of nfsiod's */ 221 if (nfs_iodmin > NFS_MAXASYNCDAEMON) 222 nfs_iodmin = NFS_MAXASYNCDAEMON; 223 224 while (ncl_numasync < nfs_iodmin) { 225 error = nfs_nfsiodnew_sync(); 226 if (error == -1) 227 panic("nfsiod_setup: nfs_nfsiodnew failed"); 228 } 229 mtx_unlock(&ncl_iod_mutex); 230 } 231 SYSINIT(newnfsiod, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, nfsiod_setup, NULL); 232 233 static int nfs_defect = 0; 234 SYSCTL_INT(_vfs_nfs, OID_AUTO, defect, CTLFLAG_RW, &nfs_defect, 0, 235 "Allow nfsiods to migrate serving different mounts"); 236 237 /* 238 * Asynchronous I/O daemons for client nfs. 239 * They do read-ahead and write-behind operations on the block I/O cache. 240 * Returns if we hit the timeout defined by the iodmaxidle sysctl. 241 */ 242 static void 243 nfssvc_iod(void *instance) 244 { 245 struct buf *bp; 246 struct nfsmount *nmp; 247 int myiod, timo; 248 int error = 0; 249 250 mtx_lock(&ncl_iod_mutex); 251 myiod = (int *)instance - nfs_asyncdaemon; 252 /* 253 * Main loop 254 */ 255 for (;;) { 256 while (((nmp = ncl_iodmount[myiod]) == NULL) 257 || !TAILQ_FIRST(&nmp->nm_bufq)) { 258 if (myiod >= ncl_iodmax) 259 goto finish; 260 if (nmp) 261 nmp->nm_bufqiods--; 262 if (ncl_iodwant[myiod] == NFSIOD_NOT_AVAILABLE) 263 ncl_iodwant[myiod] = NFSIOD_AVAILABLE; 264 ncl_iodmount[myiod] = NULL; 265 /* 266 * Always keep at least nfs_iodmin kthreads. 267 */ 268 timo = (myiod < nfs_iodmin) ? 0 : nfs_iodmaxidle * hz; 269 error = msleep(&ncl_iodwant[myiod], &ncl_iod_mutex, PWAIT | PCATCH, 270 "-", timo); 271 if (error) { 272 nmp = ncl_iodmount[myiod]; 273 /* 274 * Rechecking the nm_bufq closes a rare race where the 275 * nfsiod is woken up at the exact time the idle timeout 276 * fires 277 */ 278 if (nmp && TAILQ_FIRST(&nmp->nm_bufq)) 279 error = 0; 280 break; 281 } 282 } 283 if (error) 284 break; 285 while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) { 286 /* Take one off the front of the list */ 287 TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist); 288 nmp->nm_bufqlen--; 289 if (nmp->nm_bufqwant && nmp->nm_bufqlen <= ncl_numasync) { 290 nmp->nm_bufqwant = 0; 291 wakeup(&nmp->nm_bufq); 292 } 293 mtx_unlock(&ncl_iod_mutex); 294 if (bp->b_flags & B_DIRECT) { 295 KASSERT((bp->b_iocmd == BIO_WRITE), ("nfscvs_iod: BIO_WRITE not set")); 296 (void)ncl_doio_directwrite(bp); 297 } else { 298 if (bp->b_iocmd == BIO_READ) 299 (void) ncl_doio(bp->b_vp, bp, bp->b_rcred, 300 NULL, 0); 301 else 302 (void) ncl_doio(bp->b_vp, bp, bp->b_wcred, 303 NULL, 0); 304 } 305 mtx_lock(&ncl_iod_mutex); 306 /* 307 * Make sure the nmp hasn't been dismounted as soon as 308 * ncl_doio() completes for the last buffer. 309 */ 310 nmp = ncl_iodmount[myiod]; 311 if (nmp == NULL) 312 break; 313 314 /* 315 * If there are more than one iod on this mount, then defect 316 * so that the iods can be shared out fairly between the mounts 317 */ 318 if (nfs_defect && nmp->nm_bufqiods > 1) { 319 NFS_DPF(ASYNCIO, 320 ("nfssvc_iod: iod %d defecting from mount %p\n", 321 myiod, nmp)); 322 ncl_iodmount[myiod] = NULL; 323 nmp->nm_bufqiods--; 324 break; 325 } 326 } 327 } 328 finish: 329 nfs_asyncdaemon[myiod] = 0; 330 if (nmp) 331 nmp->nm_bufqiods--; 332 ncl_iodwant[myiod] = NFSIOD_NOT_AVAILABLE; 333 ncl_iodmount[myiod] = NULL; 334 /* Someone may be waiting for the last nfsiod to terminate. */ 335 if (--ncl_numasync == 0) 336 wakeup(&ncl_numasync); 337 mtx_unlock(&ncl_iod_mutex); 338 if ((error == 0) || (error == EWOULDBLOCK)) 339 kproc_exit(0); 340 /* Abnormal termination */ 341 kproc_exit(1); 342 } 343