1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Rick Macklem at The University of Guelph. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * from nfs_syscalls.c 8.5 (Berkeley) 3/30/95 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include <sys/param.h> 41 #include <sys/systm.h> 42 #include <sys/sysproto.h> 43 #include <sys/kernel.h> 44 #include <sys/sysctl.h> 45 #include <sys/file.h> 46 #include <sys/vnode.h> 47 #include <sys/malloc.h> 48 #include <sys/mount.h> 49 #include <sys/proc.h> 50 #include <sys/bio.h> 51 #include <sys/buf.h> 52 #include <sys/mbuf.h> 53 #include <sys/socket.h> 54 #include <sys/socketvar.h> 55 #include <sys/domain.h> 56 #include <sys/protosw.h> 57 #include <sys/namei.h> 58 #include <sys/unistd.h> 59 #include <sys/kthread.h> 60 #include <sys/fcntl.h> 61 #include <sys/lockf.h> 62 #include <sys/mutex.h> 63 #include <sys/taskqueue.h> 64 65 #include <netinet/in.h> 66 #include <netinet/tcp.h> 67 68 #include <fs/nfs/nfsport.h> 69 #include <fs/nfsclient/nfsmount.h> 70 #include <fs/nfsclient/nfs.h> 71 #include <fs/nfsclient/nfsnode.h> 72 73 extern struct mtx ncl_iod_mutex; 74 extern struct task ncl_nfsiodnew_task; 75 76 int ncl_numasync; 77 enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON]; 78 struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON]; 79 80 static void nfssvc_iod(void *); 81 82 static int nfs_asyncdaemon[NFS_MAXASYNCDAEMON]; 83 84 SYSCTL_DECL(_vfs_nfs); 85 86 /* Maximum number of seconds a nfsiod kthread will sleep before exiting */ 87 static unsigned int nfs_iodmaxidle = 120; 88 SYSCTL_UINT(_vfs_nfs, OID_AUTO, iodmaxidle, CTLFLAG_RW, &nfs_iodmaxidle, 0, 89 "Max number of seconds an nfsiod kthread will sleep before exiting"); 90 91 /* Maximum number of nfsiod kthreads */ 92 unsigned int ncl_iodmax = 20; 93 94 /* Minimum number of nfsiod kthreads to keep as spares */ 95 static unsigned int nfs_iodmin = 0; 96 97 static int nfs_nfsiodnew_sync(void); 98 99 static int 100 sysctl_iodmin(SYSCTL_HANDLER_ARGS) 101 { 102 int error, i; 103 int newmin; 104 105 newmin = nfs_iodmin; 106 error = sysctl_handle_int(oidp, &newmin, 0, req); 107 if (error || (req->newptr == NULL)) 108 return (error); 109 NFSLOCKIOD(); 110 if (newmin > ncl_iodmax) { 111 error = EINVAL; 112 goto out; 113 } 114 nfs_iodmin = newmin; 115 if (ncl_numasync >= nfs_iodmin) 116 goto out; 117 /* 118 * If the current number of nfsiod is lower 119 * than the new minimum, create some more. 120 */ 121 for (i = nfs_iodmin - ncl_numasync; i > 0; i--) 122 nfs_nfsiodnew_sync(); 123 out: 124 NFSUNLOCKIOD(); 125 return (0); 126 } 127 SYSCTL_PROC(_vfs_nfs, OID_AUTO, iodmin, 128 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof (nfs_iodmin), 129 sysctl_iodmin, "IU", 130 "Min number of nfsiod kthreads to keep as spares"); 131 132 static int 133 sysctl_iodmax(SYSCTL_HANDLER_ARGS) 134 { 135 int error, i; 136 int iod, newmax; 137 138 newmax = ncl_iodmax; 139 error = sysctl_handle_int(oidp, &newmax, 0, req); 140 if (error || (req->newptr == NULL)) 141 return (error); 142 if (newmax > NFS_MAXASYNCDAEMON) 143 return (EINVAL); 144 NFSLOCKIOD(); 145 ncl_iodmax = newmax; 146 if (ncl_numasync <= ncl_iodmax) 147 goto out; 148 /* 149 * If there are some asleep nfsiods that should 150 * exit, wakeup() them so that they check ncl_iodmax 151 * and exit. Those who are active will exit as 152 * soon as they finish I/O. 153 */ 154 iod = ncl_numasync - 1; 155 for (i = 0; i < ncl_numasync - ncl_iodmax; i++) { 156 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) 157 wakeup(&ncl_iodwant[iod]); 158 iod--; 159 } 160 out: 161 NFSUNLOCKIOD(); 162 return (0); 163 } 164 SYSCTL_PROC(_vfs_nfs, OID_AUTO, iodmax, 165 CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, sizeof (ncl_iodmax), 166 sysctl_iodmax, "IU", 167 "Max number of nfsiod kthreads"); 168 169 static int 170 nfs_nfsiodnew_sync(void) 171 { 172 int error, i; 173 174 NFSASSERTIOD(); 175 for (i = 0; i < ncl_iodmax; i++) { 176 if (nfs_asyncdaemon[i] == 0) { 177 nfs_asyncdaemon[i] = 1; 178 break; 179 } 180 } 181 if (i == ncl_iodmax) 182 return (0); 183 NFSUNLOCKIOD(); 184 error = kproc_create(nfssvc_iod, nfs_asyncdaemon + i, NULL, 185 RFHIGHPID, 0, "newnfs %d", i); 186 NFSLOCKIOD(); 187 if (error == 0) { 188 ncl_numasync++; 189 ncl_iodwant[i] = NFSIOD_AVAILABLE; 190 } else 191 nfs_asyncdaemon[i] = 0; 192 return (error); 193 } 194 195 void 196 ncl_nfsiodnew_tq(__unused void *arg, int pending) 197 { 198 199 NFSLOCKIOD(); 200 while (pending > 0) { 201 pending--; 202 nfs_nfsiodnew_sync(); 203 } 204 NFSUNLOCKIOD(); 205 } 206 207 void 208 ncl_nfsiodnew(void) 209 { 210 211 NFSASSERTIOD(); 212 taskqueue_enqueue(taskqueue_thread, &ncl_nfsiodnew_task); 213 } 214 215 static void 216 nfsiod_setup(void *dummy) 217 { 218 int error; 219 220 TUNABLE_INT_FETCH("vfs.nfs.iodmin", &nfs_iodmin); 221 nfscl_init(); 222 NFSLOCKIOD(); 223 /* Silently limit the start number of nfsiod's */ 224 if (nfs_iodmin > NFS_MAXASYNCDAEMON) 225 nfs_iodmin = NFS_MAXASYNCDAEMON; 226 227 while (ncl_numasync < nfs_iodmin) { 228 error = nfs_nfsiodnew_sync(); 229 if (error == -1) 230 panic("nfsiod_setup: nfs_nfsiodnew failed"); 231 } 232 NFSUNLOCKIOD(); 233 } 234 SYSINIT(newnfsiod, SI_SUB_KTHREAD_IDLE, SI_ORDER_ANY, nfsiod_setup, NULL); 235 236 static int nfs_defect = 0; 237 SYSCTL_INT(_vfs_nfs, OID_AUTO, defect, CTLFLAG_RW, &nfs_defect, 0, 238 "Allow nfsiods to migrate serving different mounts"); 239 240 /* 241 * Asynchronous I/O daemons for client nfs. 242 * They do read-ahead and write-behind operations on the block I/O cache. 243 * Returns if we hit the timeout defined by the iodmaxidle sysctl. 244 */ 245 static void 246 nfssvc_iod(void *instance) 247 { 248 struct buf *bp; 249 struct nfsmount *nmp; 250 int myiod, timo; 251 int error = 0; 252 253 NFSLOCKIOD(); 254 myiod = (int *)instance - nfs_asyncdaemon; 255 /* 256 * Main loop 257 */ 258 for (;;) { 259 while (((nmp = ncl_iodmount[myiod]) == NULL) 260 || !TAILQ_FIRST(&nmp->nm_bufq)) { 261 if (myiod >= ncl_iodmax) 262 goto finish; 263 if (nmp) 264 nmp->nm_bufqiods--; 265 if (ncl_iodwant[myiod] == NFSIOD_NOT_AVAILABLE) 266 ncl_iodwant[myiod] = NFSIOD_AVAILABLE; 267 ncl_iodmount[myiod] = NULL; 268 /* 269 * Always keep at least nfs_iodmin kthreads. 270 */ 271 timo = (myiod < nfs_iodmin) ? 0 : nfs_iodmaxidle * hz; 272 error = msleep(&ncl_iodwant[myiod], &ncl_iod_mutex, PWAIT | PCATCH, 273 "-", timo); 274 if (error) { 275 nmp = ncl_iodmount[myiod]; 276 /* 277 * Rechecking the nm_bufq closes a rare race where the 278 * nfsiod is woken up at the exact time the idle timeout 279 * fires 280 */ 281 if (nmp && TAILQ_FIRST(&nmp->nm_bufq)) 282 error = 0; 283 break; 284 } 285 } 286 if (error) 287 break; 288 while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) { 289 /* Take one off the front of the list */ 290 TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist); 291 nmp->nm_bufqlen--; 292 if (nmp->nm_bufqwant && nmp->nm_bufqlen <= ncl_numasync) { 293 nmp->nm_bufqwant = 0; 294 wakeup(&nmp->nm_bufq); 295 } 296 NFSUNLOCKIOD(); 297 if (bp->b_flags & B_DIRECT) { 298 KASSERT((bp->b_iocmd == BIO_WRITE), ("nfscvs_iod: BIO_WRITE not set")); 299 (void)ncl_doio_directwrite(bp); 300 } else { 301 if (bp->b_iocmd == BIO_READ) 302 (void) ncl_doio(bp->b_vp, bp, bp->b_rcred, 303 NULL, 0); 304 else 305 (void) ncl_doio(bp->b_vp, bp, bp->b_wcred, 306 NULL, 0); 307 } 308 NFSLOCKIOD(); 309 /* 310 * Make sure the nmp hasn't been dismounted as soon as 311 * ncl_doio() completes for the last buffer. 312 */ 313 nmp = ncl_iodmount[myiod]; 314 if (nmp == NULL) 315 break; 316 317 /* 318 * If there are more than one iod on this mount, then defect 319 * so that the iods can be shared out fairly between the mounts 320 */ 321 if (nfs_defect && nmp->nm_bufqiods > 1) { 322 NFS_DPF(ASYNCIO, 323 ("nfssvc_iod: iod %d defecting from mount %p\n", 324 myiod, nmp)); 325 ncl_iodmount[myiod] = NULL; 326 nmp->nm_bufqiods--; 327 break; 328 } 329 } 330 } 331 finish: 332 nfs_asyncdaemon[myiod] = 0; 333 if (nmp) 334 nmp->nm_bufqiods--; 335 ncl_iodwant[myiod] = NFSIOD_NOT_AVAILABLE; 336 ncl_iodmount[myiod] = NULL; 337 /* Someone may be waiting for the last nfsiod to terminate. */ 338 if (--ncl_numasync == 0) 339 wakeup(&ncl_numasync); 340 NFSUNLOCKIOD(); 341 if ((error == 0) || (error == EWOULDBLOCK)) 342 kproc_exit(0); 343 /* Abnormal termination */ 344 kproc_exit(1); 345 } 346