sys/nfs/nfs_iod.c

   1 /*      $NetBSD: nfs_iod.c,v 1.3 2009/03/14 21:04:25 dsl Exp $  */
   2
   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  *      @(#)nfs_syscalls.c      8.5 (Berkeley) 3/30/95
  35  */
  36
  37 #include <sys/cdefs.h>
  38 __KERNEL_RCSID(0, "$NetBSD: nfs_iod.c,v 1.3 2009/03/14 21:04:25 dsl Exp $");
  39
  40 #include <sys/param.h>
  41 #include <sys/systm.h>
  42 #include <sys/kernel.h>
  43 #include <sys/file.h>
  44 #include <sys/stat.h>
  45 #include <sys/vnode.h>
  46 #include <sys/mount.h>
  47 #include <sys/proc.h>
  48 #include <sys/uio.h>
  49 #include <sys/malloc.h>
  50 #include <sys/kmem.h>
  51 #include <sys/buf.h>
  52 #include <sys/mbuf.h>
  53 #include <sys/socket.h>
  54 #include <sys/socketvar.h>
  55 #include <sys/signalvar.h>
  56 #include <sys/domain.h>
  57 #include <sys/protosw.h>
  58 #include <sys/namei.h>
  59 #include <sys/syslog.h>
  60 #include <sys/filedesc.h>
  61 #include <sys/kthread.h>
  62 #include <sys/kauth.h>
  63 #include <sys/syscallargs.h>
  64
  65 #include <netinet/in.h>
  66 #include <netinet/tcp.h>
  67 #include <nfs/xdr_subs.h>
  68 #include <nfs/rpcv2.h>
  69 #include <nfs/nfsproto.h>
  70 #include <nfs/nfs.h>
  71 #include <nfs/nfsm_subs.h>
  72 #include <nfs/nfsrvcache.h>
  73 #include <nfs/nfsmount.h>
  74 #include <nfs/nfsnode.h>
  75 #include <nfs/nfsrtt.h>
  76 #include <nfs/nfs_var.h>
  77
  78 extern int nuidhash_max;
  79
  80 /*
  81  * locking order:
  82  *      nfs_iodlist_lock -> nid_lock -> nm_lock
  83  */
  84 kmutex_t nfs_iodlist_lock;
  85 struct nfs_iodlist nfs_iodlist_idle;
  86 struct nfs_iodlist nfs_iodlist_all;
  87 int nfs_niothreads = -1; /* == "0, and has never been set" */
  88 int nfs_defect = 0;
  89
  90 /*
  91  * Asynchronous I/O threads for client nfs.
  92  * They do read-ahead and write-behind operations on the block I/O cache.
  93  * Never returns unless it fails or gets killed.
  94  */
  95
  96 static void
  97 nfssvc_iod(void *arg)
  98 {
  99         struct buf *bp;
 100         struct nfs_iod *myiod;
 101         struct nfsmount *nmp;
 102
 103         myiod = kmem_alloc(sizeof(*myiod), KM_SLEEP);
 104         mutex_init(&myiod->nid_lock, MUTEX_DEFAULT, IPL_NONE);
 105         cv_init(&myiod->nid_cv, "nfsiod");
 106         myiod->nid_exiting = false;
 107         myiod->nid_mount = NULL;
 108         mutex_enter(&nfs_iodlist_lock);
 109         LIST_INSERT_HEAD(&nfs_iodlist_all, myiod, nid_all);
 110         mutex_exit(&nfs_iodlist_lock);
 111
 112         for (;;) {
 113                 mutex_enter(&nfs_iodlist_lock);
 114                 LIST_INSERT_HEAD(&nfs_iodlist_idle, myiod, nid_idle);
 115                 mutex_exit(&nfs_iodlist_lock);
 116
 117                 mutex_enter(&myiod->nid_lock);
 118                 while (/*CONSTCOND*/ true) {
 119                         nmp = myiod->nid_mount;
 120                         if (nmp) {
 121                                 myiod->nid_mount = NULL;
 122                                 break;
 123                         }
 124                         if (__predict_false(myiod->nid_exiting)) {
 125                                 /*
 126                                  * drop nid_lock to preserve locking order.
 127                                  */
 128                                 mutex_exit(&myiod->nid_lock);
 129                                 mutex_enter(&nfs_iodlist_lock);
 130                                 mutex_enter(&myiod->nid_lock);
 131                                 /*
 132                                  * recheck nid_mount because nfs_asyncio can
 133                                  * pick us in the meantime as we are still on
 134                                  * nfs_iodlist_lock.
 135                                  */
 136                                 if (myiod->nid_mount != NULL) {
 137                                         mutex_exit(&nfs_iodlist_lock);
 138                                         continue;
 139                                 }
 140                                 LIST_REMOVE(myiod, nid_idle);
 141                                 mutex_exit(&nfs_iodlist_lock);
 142                                 goto quit;
 143                         }
 144                         cv_wait(&myiod->nid_cv, &myiod->nid_lock);
 145                 }
 146                 mutex_exit(&myiod->nid_lock);
 147
 148                 mutex_enter(&nmp->nm_lock);
 149                 while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) {
 150                         /* Take one off the front of the list */
 151                         TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist);
 152                         nmp->nm_bufqlen--;
 153                         if (nmp->nm_bufqlen < 2 * nmp->nm_bufqiods) {
 154                                 cv_broadcast(&nmp->nm_aiocv);
 155                         }
 156                         mutex_exit(&nmp->nm_lock);
 157                         KERNEL_LOCK(1, curlwp);
 158                         (void)nfs_doio(bp);
 159                         KERNEL_UNLOCK_LAST(curlwp);
 160                         mutex_enter(&nmp->nm_lock);
 161                         /*
 162                          * If there are more than one iod on this mount,
 163                          * then defect so that the iods can be shared out
 164                          * fairly between the mounts
 165                          */
 166                         if (nfs_defect && nmp->nm_bufqiods > 1) {
 167                                 break;
 168                         }
 169                 }
 170                 KASSERT(nmp->nm_bufqiods > 0);
 171                 nmp->nm_bufqiods--;
 172                 mutex_exit(&nmp->nm_lock);
 173         }
 174 quit:
 175         KASSERT(myiod->nid_mount == NULL);
 176         mutex_exit(&myiod->nid_lock);
 177
 178         cv_destroy(&myiod->nid_cv);
 179         mutex_destroy(&myiod->nid_lock);
 180         kmem_free(myiod, sizeof(*myiod));
 181
 182         kthread_exit(0);
 183 }
 184
 185 void
 186 nfs_iodinit(void)
 187 {
 188
 189         mutex_init(&nfs_iodlist_lock, MUTEX_DEFAULT, IPL_NONE);
 190         LIST_INIT(&nfs_iodlist_all);
 191         LIST_INIT(&nfs_iodlist_idle);
 192 }
 193
 194 void
 195 nfs_iodfini(void)
 196 {
 197         int error;
 198
 199         error = nfs_set_niothreads(0);
 200         KASSERT(error == 0);
 201         mutex_destroy(&nfs_iodlist_lock);
 202 }
 203
 204 int
 205 nfs_set_niothreads(int newval)
 206 {
 207         struct nfs_iod *nid;
 208         int error = 0;
 209         int hold_count;
 210
 211         KERNEL_UNLOCK_ALL(curlwp, &hold_count);
 212
 213         mutex_enter(&nfs_iodlist_lock);
 214         /* clamp to sane range */
 215         nfs_niothreads = max(0, min(newval, NFS_MAXASYNCDAEMON));
 216
 217         while (nfs_numasync != nfs_niothreads && error == 0) {
 218                 while (nfs_numasync < nfs_niothreads) {
 219
 220                         /*
 221                          * kthread_create can wait for pagedaemon and
 222                          * pagedaemon can wait for nfsiod which needs to acquire
 223                          * nfs_iodlist_lock.
 224                          */
 225
 226                         mutex_exit(&nfs_iodlist_lock);
 227                         error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
 228                             nfssvc_iod, NULL, NULL, "nfsio");
 229                         mutex_enter(&nfs_iodlist_lock);
 230                         if (error) {
 231                                 /* give up */
 232                                 nfs_niothreads = nfs_numasync;
 233                                 break;
 234                         }
 235                         nfs_numasync++;
 236                 }
 237                 while (nfs_numasync > nfs_niothreads) {
 238                         nid = LIST_FIRST(&nfs_iodlist_all);
 239                         if (nid == NULL) {
 240                                 /* iod has not started yet. */
 241                                 kpause("nfsiorm", false, hz, &nfs_iodlist_lock);
 242                                 continue;
 243                         }
 244                         LIST_REMOVE(nid, nid_all);
 245                         mutex_enter(&nid->nid_lock);
 246                         KASSERT(!nid->nid_exiting);
 247                         nid->nid_exiting = true;
 248                         cv_signal(&nid->nid_cv);
 249                         mutex_exit(&nid->nid_lock);
 250                         nfs_numasync--;
 251                 }
 252         }
 253         mutex_exit(&nfs_iodlist_lock);
 254
 255         KERNEL_LOCK(hold_count, curlwp);
 256         return error;
 257 }
 258
 259 /*
 260  * Get an authorization string for the uid by having the mount_nfs sitting
 261  * on this mount point porpous out of the kernel and do it.
 262  */
 263 int
 264 nfs_getauth(struct nfsmount *nmp, struct nfsreq *rep, kauth_cred_t cred, char **auth_str, int *auth_len, char *verf_str, int *verf_len, NFSKERBKEY_T key)
 265         /* key:          return session key */
 266 {
 267         int error = 0;
 268
 269         while ((nmp->nm_iflag & NFSMNT_WAITAUTH) == 0) {
 270                 nmp->nm_iflag |= NFSMNT_WANTAUTH;
 271                 (void) tsleep((void *)&nmp->nm_authtype, PSOCK,
 272                         "nfsauth1", 2 * hz);
 273                 error = nfs_sigintr(nmp, rep, rep->r_lwp);
 274                 if (error) {
 275                         nmp->nm_iflag &= ~NFSMNT_WANTAUTH;
 276                         return (error);
 277                 }
 278         }
 279         nmp->nm_iflag &= ~(NFSMNT_WAITAUTH | NFSMNT_WANTAUTH);
 280         nmp->nm_authstr = *auth_str = (char *)malloc(RPCAUTH_MAXSIZ, M_TEMP, M_WAITOK);
 281         nmp->nm_authlen = RPCAUTH_MAXSIZ;
 282         nmp->nm_verfstr = verf_str;
 283         nmp->nm_verflen = *verf_len;
 284         nmp->nm_authuid = kauth_cred_geteuid(cred);
 285         wakeup((void *)&nmp->nm_authstr);
 286
 287         /*
 288          * And wait for mount_nfs to do its stuff.
 289          */
 290         while ((nmp->nm_iflag & NFSMNT_HASAUTH) == 0 && error == 0) {
 291                 (void) tsleep((void *)&nmp->nm_authlen, PSOCK,
 292                         "nfsauth2", 2 * hz);
 293                 error = nfs_sigintr(nmp, rep, rep->r_lwp);
 294         }
 295         if (nmp->nm_iflag & NFSMNT_AUTHERR) {
 296                 nmp->nm_iflag &= ~NFSMNT_AUTHERR;
 297                 error = EAUTH;
 298         }
 299         if (error)
 300                 free((void *)*auth_str, M_TEMP);
 301         else {
 302                 *auth_len = nmp->nm_authlen;
 303                 *verf_len = nmp->nm_verflen;
 304                 memcpy(key, nmp->nm_key, sizeof (NFSKERBKEY_T));
 305         }
 306         nmp->nm_iflag &= ~NFSMNT_HASAUTH;
 307         nmp->nm_iflag |= NFSMNT_WAITAUTH;
 308         if (nmp->nm_iflag & NFSMNT_WANTAUTH) {
 309                 nmp->nm_iflag &= ~NFSMNT_WANTAUTH;
 310                 wakeup((void *)&nmp->nm_authtype);
 311         }
 312         return (error);
 313 }
 314
 315 /*
 316  * Get a nickname authenticator and verifier.
 317  */
 318 int
 319 nfs_getnickauth(struct nfsmount *nmp, kauth_cred_t cred, char **auth_str,
 320     int *auth_len, char *verf_str, int verf_len)
 321 {
 322         struct timeval ktvin, ktvout, tv;
 323         struct nfsuid *nuidp;
 324         u_int32_t *nickp, *verfp;
 325
 326         memset(&ktvout, 0, sizeof ktvout);      /* XXX gcc */
 327
 328 #ifdef DIAGNOSTIC
 329         if (verf_len < (4 * NFSX_UNSIGNED))
 330                 panic("nfs_getnickauth verf too small");
 331 #endif
 332         LIST_FOREACH(nuidp, NMUIDHASH(nmp, kauth_cred_geteuid(cred)), nu_hash) {
 333                 if (kauth_cred_geteuid(nuidp->nu_cr) == kauth_cred_geteuid(cred))
 334                         break;
 335         }
 336         if (!nuidp || nuidp->nu_expire < time_second)
 337                 return (EACCES);
 338
 339         /*
 340          * Move to the end of the lru list (end of lru == most recently used).
 341          */
 342         TAILQ_REMOVE(&nmp->nm_uidlruhead, nuidp, nu_lru);
 343         TAILQ_INSERT_TAIL(&nmp->nm_uidlruhead, nuidp, nu_lru);
 344
 345         nickp = (u_int32_t *)malloc(2 * NFSX_UNSIGNED, M_TEMP, M_WAITOK);
 346         *nickp++ = txdr_unsigned(RPCAKN_NICKNAME);
 347         *nickp = txdr_unsigned(nuidp->nu_nickname);
 348         *auth_str = (char *)nickp;
 349         *auth_len = 2 * NFSX_UNSIGNED;
 350
 351         /*
 352          * Now we must encrypt the verifier and package it up.
 353          */
 354         verfp = (u_int32_t *)verf_str;
 355         *verfp++ = txdr_unsigned(RPCAKN_NICKNAME);
 356         getmicrotime(&tv);
 357         if (tv.tv_sec > nuidp->nu_timestamp.tv_sec ||
 358             (tv.tv_sec == nuidp->nu_timestamp.tv_sec &&
 359              tv.tv_usec > nuidp->nu_timestamp.tv_usec))
 360                 nuidp->nu_timestamp = tv;
 361         else
 362                 nuidp->nu_timestamp.tv_usec++;
 363         ktvin.tv_sec = txdr_unsigned(nuidp->nu_timestamp.tv_sec);
 364         ktvin.tv_usec = txdr_unsigned(nuidp->nu_timestamp.tv_usec);
 365
 366         /*
 367          * Now encrypt the timestamp verifier in ecb mode using the session
 368          * key.
 369          */
 370 #ifdef NFSKERB
 371         XXX
 372 #endif
 373
 374         *verfp++ = ktvout.tv_sec;
 375         *verfp++ = ktvout.tv_usec;
 376         *verfp = 0;
 377         return (0);
 378 }
 379
 380 /*
 381  * Save the current nickname in a hash list entry on the mount point.
 382  */
 383 int
 384 nfs_savenickauth(struct nfsmount *nmp, kauth_cred_t cred, int len, NFSKERBKEY_T key, struct mbuf **mdp, char **dposp, struct mbuf *mrep)
 385 {
 386         struct nfsuid *nuidp;
 387         u_int32_t *tl;
 388         int32_t t1;
 389         struct mbuf *md = *mdp;
 390         struct timeval ktvin, ktvout;
 391         u_int32_t nick;
 392         char *dpos = *dposp, *cp2;
 393         int deltasec, error = 0;
 394
 395         memset(&ktvout, 0, sizeof ktvout);       /* XXX gcc */
 396
 397         if (len == (3 * NFSX_UNSIGNED)) {
 398                 nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
 399                 ktvin.tv_sec = *tl++;
 400                 ktvin.tv_usec = *tl++;
 401                 nick = fxdr_unsigned(u_int32_t, *tl);
 402
 403                 /*
 404                  * Decrypt the timestamp in ecb mode.
 405                  */
 406 #ifdef NFSKERB
 407                 XXX
 408 #endif
 409                 ktvout.tv_sec = fxdr_unsigned(long, ktvout.tv_sec);
 410                 ktvout.tv_usec = fxdr_unsigned(long, ktvout.tv_usec);
 411                 deltasec = time_second - ktvout.tv_sec;
 412                 if (deltasec < 0)
 413                         deltasec = -deltasec;
 414                 /*
 415                  * If ok, add it to the hash list for the mount point.
 416                  */
 417                 if (deltasec <= NFS_KERBCLOCKSKEW) {
 418                         if (nmp->nm_numuids < nuidhash_max) {
 419                                 nmp->nm_numuids++;
 420                                 nuidp = kmem_alloc(sizeof(*nuidp), KM_SLEEP);
 421                         } else {
 422                                 nuidp = TAILQ_FIRST(&nmp->nm_uidlruhead);
 423                                 LIST_REMOVE(nuidp, nu_hash);
 424                                 TAILQ_REMOVE(&nmp->nm_uidlruhead, nuidp,
 425                                         nu_lru);
 426                         }
 427                         nuidp->nu_flag = 0;
 428                         kauth_cred_seteuid(nuidp->nu_cr, kauth_cred_geteuid(cred));
 429                         nuidp->nu_expire = time_second + NFS_KERBTTL;
 430                         nuidp->nu_timestamp = ktvout;
 431                         nuidp->nu_nickname = nick;
 432                         memcpy(nuidp->nu_key, key, sizeof (NFSKERBKEY_T));
 433                         TAILQ_INSERT_TAIL(&nmp->nm_uidlruhead, nuidp,
 434                                 nu_lru);
 435                         LIST_INSERT_HEAD(NMUIDHASH(nmp, kauth_cred_geteuid(cred)),
 436                                 nuidp, nu_hash);
 437                 }
 438         } else
 439                 nfsm_adv(nfsm_rndup(len));
 440 nfsmout:
 441         *mdp = md;
 442         *dposp = dpos;
 443         return (error);
 444 }