1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2006, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2013, 2016 Joyent, Inc. All rights reserved.
  24  */
  25 
  26 /*
  27  * utility routines for the /dev fs
  28  */
  29 
  30 #include <sys/types.h>
  31 #include <sys/param.h>
  32 #include <sys/t_lock.h>
  33 #include <sys/systm.h>
  34 #include <sys/sysmacros.h>
  35 #include <sys/user.h>
  36 #include <sys/time.h>
  37 #include <sys/vfs.h>
  38 #include <sys/vnode.h>
  39 #include <sys/file.h>
  40 #include <sys/fcntl.h>
  41 #include <sys/flock.h>
  42 #include <sys/kmem.h>
  43 #include <sys/uio.h>
  44 #include <sys/errno.h>
  45 #include <sys/stat.h>
  46 #include <sys/cred.h>
  47 #include <sys/dirent.h>
  48 #include <sys/pathname.h>
  49 #include <sys/cmn_err.h>
  50 #include <sys/debug.h>
  51 #include <sys/mode.h>
  52 #include <sys/policy.h>
  53 #include <fs/fs_subr.h>
  54 #include <sys/mount.h>
  55 #include <sys/fs/snode.h>
  56 #include <sys/fs/dv_node.h>
  57 #include <sys/fs/sdev_impl.h>
  58 #include <sys/sunndi.h>
  59 #include <sys/sunmdi.h>
  60 #include <sys/conf.h>
  61 #include <sys/proc.h>
  62 #include <sys/user.h>
  63 #include <sys/modctl.h>
  64 
  65 #ifdef DEBUG
  66 int sdev_debug = 0x00000001;
  67 int sdev_debug_cache_flags = 0;
  68 #endif
  69 
  70 /*
  71  * globals
  72  */
  73 /* prototype memory vattrs */
  74 vattr_t sdev_vattr_dir = {
  75         AT_TYPE|AT_MODE|AT_UID|AT_GID,          /* va_mask */
  76         VDIR,                                   /* va_type */
  77         SDEV_DIRMODE_DEFAULT,                   /* va_mode */
  78         SDEV_UID_DEFAULT,                       /* va_uid */
  79         SDEV_GID_DEFAULT,                       /* va_gid */
  80         0,                                      /* va_fsid */
  81         0,                                      /* va_nodeid */
  82         0,                                      /* va_nlink */
  83         0,                                      /* va_size */
  84         0,                                      /* va_atime */
  85         0,                                      /* va_mtime */
  86         0,                                      /* va_ctime */
  87         0,                                      /* va_rdev */
  88         0,                                      /* va_blksize */
  89         0,                                      /* va_nblocks */
  90         0                                       /* va_vcode */
  91 };
  92 
  93 vattr_t sdev_vattr_lnk = {
  94         AT_TYPE|AT_MODE,                        /* va_mask */
  95         VLNK,                                   /* va_type */
  96         SDEV_LNKMODE_DEFAULT,                   /* va_mode */
  97         SDEV_UID_DEFAULT,                       /* va_uid */
  98         SDEV_GID_DEFAULT,                       /* va_gid */
  99         0,                                      /* va_fsid */
 100         0,                                      /* va_nodeid */
 101         0,                                      /* va_nlink */
 102         0,                                      /* va_size */
 103         0,                                      /* va_atime */
 104         0,                                      /* va_mtime */
 105         0,                                      /* va_ctime */
 106         0,                                      /* va_rdev */
 107         0,                                      /* va_blksize */
 108         0,                                      /* va_nblocks */
 109         0                                       /* va_vcode */
 110 };
 111 
 112 vattr_t sdev_vattr_blk = {
 113         AT_TYPE|AT_MODE|AT_UID|AT_GID,          /* va_mask */
 114         VBLK,                                   /* va_type */
 115         S_IFBLK | SDEV_DEVMODE_DEFAULT,         /* va_mode */
 116         SDEV_UID_DEFAULT,                       /* va_uid */
 117         SDEV_GID_DEFAULT,                       /* va_gid */
 118         0,                                      /* va_fsid */
 119         0,                                      /* va_nodeid */
 120         0,                                      /* va_nlink */
 121         0,                                      /* va_size */
 122         0,                                      /* va_atime */
 123         0,                                      /* va_mtime */
 124         0,                                      /* va_ctime */
 125         0,                                      /* va_rdev */
 126         0,                                      /* va_blksize */
 127         0,                                      /* va_nblocks */
 128         0                                       /* va_vcode */
 129 };
 130 
 131 vattr_t sdev_vattr_chr = {
 132         AT_TYPE|AT_MODE|AT_UID|AT_GID,          /* va_mask */
 133         VCHR,                                   /* va_type */
 134         S_IFCHR | SDEV_DEVMODE_DEFAULT,         /* va_mode */
 135         SDEV_UID_DEFAULT,                       /* va_uid */
 136         SDEV_GID_DEFAULT,                       /* va_gid */
 137         0,                                      /* va_fsid */
 138         0,                                      /* va_nodeid */
 139         0,                                      /* va_nlink */
 140         0,                                      /* va_size */
 141         0,                                      /* va_atime */
 142         0,                                      /* va_mtime */
 143         0,                                      /* va_ctime */
 144         0,                                      /* va_rdev */
 145         0,                                      /* va_blksize */
 146         0,                                      /* va_nblocks */
 147         0                                       /* va_vcode */
 148 };
 149 
 150 kmem_cache_t    *sdev_node_cache;       /* sdev_node cache */
 151 int             devtype;                /* fstype */
 152 
 153 /* static */
 154 static struct vnodeops *sdev_get_vop(struct sdev_node *);
 155 static void sdev_set_no_negcache(struct sdev_node *);
 156 static fs_operation_def_t *sdev_merge_vtab(const fs_operation_def_t []);
 157 static void sdev_free_vtab(fs_operation_def_t *);
 158 
 159 static void
 160 sdev_prof_free(struct sdev_node *dv)
 161 {
 162         ASSERT(!SDEV_IS_GLOBAL(dv));
 163         nvlist_free(dv->sdev_prof.dev_name);
 164         nvlist_free(dv->sdev_prof.dev_map);
 165         nvlist_free(dv->sdev_prof.dev_symlink);
 166         nvlist_free(dv->sdev_prof.dev_glob_incdir);
 167         nvlist_free(dv->sdev_prof.dev_glob_excdir);
 168         bzero(&dv->sdev_prof, sizeof (dv->sdev_prof));
 169 }
 170 
 171 /* sdev_node cache constructor */
 172 /*ARGSUSED1*/
 173 static int
 174 i_sdev_node_ctor(void *buf, void *cfarg, int flag)
 175 {
 176         struct sdev_node *dv = (struct sdev_node *)buf;
 177         struct vnode *vp;
 178 
 179         bzero(buf, sizeof (struct sdev_node));
 180         vp = dv->sdev_vnode = vn_alloc(flag);
 181         if (vp == NULL) {
 182                 return (-1);
 183         }
 184         vp->v_data = dv;
 185         rw_init(&dv->sdev_contents, NULL, RW_DEFAULT, NULL);
 186         return (0);
 187 }
 188 
 189 /* sdev_node cache destructor */
 190 /*ARGSUSED1*/
 191 static void
 192 i_sdev_node_dtor(void *buf, void *arg)
 193 {
 194         struct sdev_node *dv = (struct sdev_node *)buf;
 195         struct vnode *vp = SDEVTOV(dv);
 196 
 197         rw_destroy(&dv->sdev_contents);
 198         vn_free(vp);
 199 }
 200 
 201 /* initialize sdev_node cache */
 202 void
 203 sdev_node_cache_init()
 204 {
 205         int flags = 0;
 206 
 207 #ifdef  DEBUG
 208         flags = sdev_debug_cache_flags;
 209         if (flags)
 210                 sdcmn_err(("cache debug flags 0x%x\n", flags));
 211 #endif  /* DEBUG */
 212 
 213         ASSERT(sdev_node_cache == NULL);
 214         sdev_node_cache = kmem_cache_create("sdev_node_cache",
 215             sizeof (struct sdev_node), 0, i_sdev_node_ctor, i_sdev_node_dtor,
 216             NULL, NULL, NULL, flags);
 217 }
 218 
 219 /* destroy sdev_node cache */
 220 void
 221 sdev_node_cache_fini()
 222 {
 223         ASSERT(sdev_node_cache != NULL);
 224         kmem_cache_destroy(sdev_node_cache);
 225         sdev_node_cache = NULL;
 226 }
 227 
 228 /*
 229  * Compare two nodes lexographically to balance avl tree
 230  */
 231 static int
 232 sdev_compare_nodes(const struct sdev_node *dv1, const struct sdev_node *dv2)
 233 {
 234         int rv;
 235         if ((rv = strcmp(dv1->sdev_name, dv2->sdev_name)) == 0)
 236                 return (0);
 237         return ((rv < 0) ? -1 : 1);
 238 }
 239 
 240 void
 241 sdev_set_nodestate(struct sdev_node *dv, sdev_node_state_t state)
 242 {
 243         ASSERT(dv);
 244         ASSERT(RW_WRITE_HELD(&dv->sdev_contents));
 245         dv->sdev_state = state;
 246 }
 247 
 248 static void
 249 sdev_attr_update(struct sdev_node *dv, vattr_t *vap)
 250 {
 251         timestruc_t     now;
 252         struct vattr    *attrp;
 253         uint_t          mask;
 254 
 255         ASSERT(dv->sdev_attr);
 256         ASSERT(vap);
 257 
 258         attrp = dv->sdev_attr;
 259         mask = vap->va_mask;
 260         if (mask & AT_TYPE)
 261                 attrp->va_type = vap->va_type;
 262         if (mask & AT_MODE)
 263                 attrp->va_mode = vap->va_mode;
 264         if (mask & AT_UID)
 265                 attrp->va_uid = vap->va_uid;
 266         if (mask & AT_GID)
 267                 attrp->va_gid = vap->va_gid;
 268         if (mask & AT_RDEV)
 269                 attrp->va_rdev = vap->va_rdev;
 270 
 271         gethrestime(&now);
 272         attrp->va_atime = (mask & AT_ATIME) ? vap->va_atime : now;
 273         attrp->va_mtime = (mask & AT_MTIME) ? vap->va_mtime : now;
 274         attrp->va_ctime = (mask & AT_CTIME) ? vap->va_ctime : now;
 275 }
 276 
 277 static void
 278 sdev_attr_alloc(struct sdev_node *dv, vattr_t *vap)
 279 {
 280         ASSERT(dv->sdev_attr == NULL);
 281         ASSERT(vap->va_mask & AT_TYPE);
 282         ASSERT(vap->va_mask & AT_MODE);
 283 
 284         dv->sdev_attr = kmem_zalloc(sizeof (struct vattr), KM_SLEEP);
 285         sdev_attr_update(dv, vap);
 286 }
 287 
 288 /* alloc and initialize a sdev_node */
 289 int
 290 sdev_nodeinit(struct sdev_node *ddv, char *nm, struct sdev_node **newdv,
 291     vattr_t *vap)
 292 {
 293         struct sdev_node *dv = NULL;
 294         struct vnode *vp;
 295         size_t nmlen, len;
 296         devname_handle_t  *dhl;
 297 
 298         nmlen = strlen(nm) + 1;
 299         if (nmlen > MAXNAMELEN) {
 300                 sdcmn_err9(("sdev_nodeinit: node name %s"
 301                     " too long\n", nm));
 302                 *newdv = NULL;
 303                 return (ENAMETOOLONG);
 304         }
 305 
 306         dv = kmem_cache_alloc(sdev_node_cache, KM_SLEEP);
 307 
 308         dv->sdev_name = kmem_alloc(nmlen, KM_SLEEP);
 309         bcopy(nm, dv->sdev_name, nmlen);
 310         dv->sdev_namelen = nmlen - 1;        /* '\0' not included */
 311         len = strlen(ddv->sdev_path) + strlen(nm) + 2;
 312         dv->sdev_path = kmem_alloc(len, KM_SLEEP);
 313         (void) snprintf(dv->sdev_path, len, "%s/%s", ddv->sdev_path, nm);
 314         /* overwritten for VLNK nodes */
 315         dv->sdev_symlink = NULL;
 316 
 317         vp = SDEVTOV(dv);
 318         vn_reinit(vp);
 319         vp->v_vfsp = SDEVTOV(ddv)->v_vfsp;
 320         if (vap)
 321                 vp->v_type = vap->va_type;
 322 
 323         /*
 324          * initialized to the parent's vnodeops.
 325          * maybe overwriten for a VDIR
 326          */
 327         vn_setops(vp, vn_getops(SDEVTOV(ddv)));
 328         vn_exists(vp);
 329 
 330         dv->sdev_dotdot = NULL;
 331         dv->sdev_attrvp = NULL;
 332         if (vap) {
 333                 sdev_attr_alloc(dv, vap);
 334         } else {
 335                 dv->sdev_attr = NULL;
 336         }
 337 
 338         dv->sdev_ino = sdev_mkino(dv);
 339         dv->sdev_nlink = 0;          /* updated on insert */
 340         dv->sdev_flags = ddv->sdev_flags; /* inherit from the parent first */
 341         dv->sdev_flags |= SDEV_BUILD;
 342         mutex_init(&dv->sdev_lookup_lock, NULL, MUTEX_DEFAULT, NULL);
 343         cv_init(&dv->sdev_lookup_cv, NULL, CV_DEFAULT, NULL);
 344         if (SDEV_IS_GLOBAL(ddv)) {
 345                 dv->sdev_flags |= SDEV_GLOBAL;
 346                 dhl = &(dv->sdev_handle);
 347                 dhl->dh_data = dv;
 348                 dhl->dh_args = NULL;
 349                 sdev_set_no_negcache(dv);
 350                 dv->sdev_gdir_gen = 0;
 351         } else {
 352                 dv->sdev_flags &= ~SDEV_GLOBAL;
 353                 dv->sdev_origin = NULL; /* set later */
 354                 bzero(&dv->sdev_prof, sizeof (dv->sdev_prof));
 355                 dv->sdev_ldir_gen = 0;
 356                 dv->sdev_devtree_gen = 0;
 357         }
 358 
 359         rw_enter(&dv->sdev_contents, RW_WRITER);
 360         sdev_set_nodestate(dv, SDEV_INIT);
 361         rw_exit(&dv->sdev_contents);
 362         *newdv = dv;
 363 
 364         return (0);
 365 }
 366 
 367 /*
 368  * Transition a sdev_node into SDEV_READY state. If this fails, it is up to the
 369  * caller to transition the node to the SDEV_ZOMBIE state.
 370  */
 371 int
 372 sdev_nodeready(struct sdev_node *dv, struct vattr *vap, struct vnode *avp,
 373     void *args, struct cred *cred)
 374 {
 375         int error = 0;
 376         struct vnode *vp = SDEVTOV(dv);
 377         vtype_t type;
 378 
 379         ASSERT(dv && (dv->sdev_state != SDEV_READY) && vap);
 380 
 381         type = vap->va_type;
 382         vp->v_type = type;
 383         vp->v_rdev = vap->va_rdev;
 384         rw_enter(&dv->sdev_contents, RW_WRITER);
 385         if (type == VDIR) {
 386                 dv->sdev_nlink = 2;
 387                 dv->sdev_flags &= ~SDEV_PERSIST;
 388                 dv->sdev_flags &= ~SDEV_DYNAMIC;
 389                 vn_setops(vp, sdev_get_vop(dv)); /* from internal vtab */
 390                 ASSERT(dv->sdev_dotdot);
 391                 ASSERT(SDEVTOV(dv->sdev_dotdot)->v_type == VDIR);
 392                 vp->v_rdev = SDEVTOV(dv->sdev_dotdot)->v_rdev;
 393                 avl_create(&dv->sdev_entries,
 394                     (int (*)(const void *, const void *))sdev_compare_nodes,
 395                     sizeof (struct sdev_node),
 396                     offsetof(struct sdev_node, sdev_avllink));
 397         } else if (type == VLNK) {
 398                 ASSERT(args);
 399                 dv->sdev_nlink = 1;
 400                 dv->sdev_symlink = i_ddi_strdup((char *)args, KM_SLEEP);
 401         } else {
 402                 dv->sdev_nlink = 1;
 403         }
 404 
 405         if (!(SDEV_IS_GLOBAL(dv))) {
 406                 dv->sdev_origin = (struct sdev_node *)args;
 407                 dv->sdev_flags &= ~SDEV_PERSIST;
 408         }
 409 
 410         /*
 411          * shadow node is created here OR
 412          * if failed (indicated by dv->sdev_attrvp == NULL),
 413          * created later in sdev_setattr
 414          */
 415         if (avp) {
 416                 dv->sdev_attrvp = avp;
 417         } else {
 418                 if (dv->sdev_attr == NULL) {
 419                         sdev_attr_alloc(dv, vap);
 420                 } else {
 421                         sdev_attr_update(dv, vap);
 422                 }
 423 
 424                 if ((dv->sdev_attrvp == NULL) && SDEV_IS_PERSIST(dv))
 425                         error = sdev_shadow_node(dv, cred);
 426         }
 427 
 428         if (error == 0) {
 429                 /* transition to READY state */
 430                 sdev_set_nodestate(dv, SDEV_READY);
 431                 sdev_nc_node_exists(dv);
 432         }
 433         rw_exit(&dv->sdev_contents);
 434         return (error);
 435 }
 436 
 437 /*
 438  * Build the VROOT sdev_node.
 439  */
 440 /*ARGSUSED*/
 441 struct sdev_node *
 442 sdev_mkroot(struct vfs *vfsp, dev_t devdev, struct vnode *mvp,
 443     struct vnode *avp, struct cred *cred)
 444 {
 445         struct sdev_node *dv;
 446         struct vnode *vp;
 447         char devdir[] = "/dev";
 448 
 449         ASSERT(sdev_node_cache != NULL);
 450         ASSERT(avp);
 451         dv = kmem_cache_alloc(sdev_node_cache, KM_SLEEP);
 452         vp = SDEVTOV(dv);
 453         vn_reinit(vp);
 454         vp->v_flag |= VROOT;
 455         vp->v_vfsp = vfsp;
 456         vp->v_type = VDIR;
 457         vp->v_rdev = devdev;
 458         vn_setops(vp, sdev_vnodeops); /* apply the default vnodeops at /dev */
 459         vn_exists(vp);
 460 
 461         if (vfsp->vfs_mntpt)
 462                 dv->sdev_name = i_ddi_strdup(
 463                     (char *)refstr_value(vfsp->vfs_mntpt), KM_SLEEP);
 464         else
 465                 /* vfs_mountdev1 set mount point later */
 466                 dv->sdev_name = i_ddi_strdup("/dev", KM_SLEEP);
 467         dv->sdev_namelen = strlen(dv->sdev_name); /* '\0' not included */
 468         dv->sdev_path = i_ddi_strdup(devdir, KM_SLEEP);
 469         dv->sdev_ino = SDEV_ROOTINO;
 470         dv->sdev_nlink = 2;          /* name + . (no sdev_insert) */
 471         dv->sdev_dotdot = dv;                /* .. == self */
 472         dv->sdev_attrvp = avp;
 473         dv->sdev_attr = NULL;
 474         mutex_init(&dv->sdev_lookup_lock, NULL, MUTEX_DEFAULT, NULL);
 475         cv_init(&dv->sdev_lookup_cv, NULL, CV_DEFAULT, NULL);
 476         if (strcmp(dv->sdev_name, "/dev") == 0) {
 477                 dv->sdev_flags = SDEV_BUILD|SDEV_GLOBAL|SDEV_PERSIST;
 478                 bzero(&dv->sdev_handle, sizeof (dv->sdev_handle));
 479                 dv->sdev_gdir_gen = 0;
 480         } else {
 481                 dv->sdev_flags = SDEV_BUILD;
 482                 dv->sdev_flags &= ~SDEV_PERSIST;
 483                 bzero(&dv->sdev_prof, sizeof (dv->sdev_prof));
 484                 dv->sdev_ldir_gen = 0;
 485                 dv->sdev_devtree_gen = 0;
 486         }
 487 
 488         avl_create(&dv->sdev_entries,
 489             (int (*)(const void *, const void *))sdev_compare_nodes,
 490             sizeof (struct sdev_node),
 491             offsetof(struct sdev_node, sdev_avllink));
 492 
 493         rw_enter(&dv->sdev_contents, RW_WRITER);
 494         sdev_set_nodestate(dv, SDEV_READY);
 495         rw_exit(&dv->sdev_contents);
 496         sdev_nc_node_exists(dv);
 497         return (dv);
 498 }
 499 
 500 /* directory dependent vop table */
 501 struct sdev_vop_table {
 502         char *vt_name;                          /* subdirectory name */
 503         const fs_operation_def_t *vt_service;   /* vnodeops table */
 504         struct vnodeops *vt_vops;               /* constructed vop */
 505         struct vnodeops **vt_global_vops;       /* global container for vop */
 506         int (*vt_vtor)(struct sdev_node *);     /* validate sdev_node */
 507         int vt_flags;
 508 };
 509 
 510 /*
 511  * A nice improvement would be to provide a plug-in mechanism
 512  * for this table instead of a const table.
 513  */
 514 static struct sdev_vop_table vtab[] =
 515 {
 516         { "pts", devpts_vnodeops_tbl, NULL, &devpts_vnodeops, devpts_validate,
 517         SDEV_DYNAMIC | SDEV_VTOR },
 518 
 519         { "vt", devvt_vnodeops_tbl, NULL, &devvt_vnodeops, devvt_validate,
 520         SDEV_DYNAMIC | SDEV_VTOR },
 521 
 522         { "zvol", devzvol_vnodeops_tbl, NULL, &devzvol_vnodeops,
 523         devzvol_validate, SDEV_ZONED | SDEV_DYNAMIC | SDEV_VTOR | SDEV_SUBDIR },
 524 
 525         { "zcons", NULL, NULL, NULL, NULL, SDEV_NO_NCACHE },
 526 
 527         { "net", devnet_vnodeops_tbl, NULL, &devnet_vnodeops, devnet_validate,
 528         SDEV_DYNAMIC | SDEV_VTOR },
 529 
 530         { "ipnet", devipnet_vnodeops_tbl, NULL, &devipnet_vnodeops,
 531         devipnet_validate, SDEV_DYNAMIC | SDEV_VTOR | SDEV_NO_NCACHE },
 532 
 533         /*
 534          * SDEV_DYNAMIC: prevent calling out to devfsadm, since only the
 535          * lofi driver controls child nodes.
 536          *
 537          * SDEV_PERSIST: ensure devfsadm knows to clean up any persisted
 538          * stale nodes (e.g. from devfsadm -R).
 539          *
 540          * In addition, devfsadm knows not to attempt a rmdir: a zone
 541          * may hold a reference, which would zombify the node,
 542          * preventing a mkdir.
 543          */
 544 
 545         { "lofi", NULL, NULL, NULL, NULL,
 546             SDEV_ZONED | SDEV_DYNAMIC | SDEV_PERSIST },
 547         { "rlofi", NULL, NULL, NULL, NULL,
 548             SDEV_ZONED | SDEV_DYNAMIC | SDEV_PERSIST },
 549 
 550         { NULL, NULL, NULL, NULL, NULL, 0}
 551 };
 552 
 553 /*
 554  * We need to match off of the sdev_path, not the sdev_name. We are only allowed
 555  * to exist directly under /dev.
 556  */
 557 struct sdev_vop_table *
 558 sdev_match(struct sdev_node *dv)
 559 {
 560         int vlen;
 561         int i;
 562         const char *path;
 563 
 564         if (strlen(dv->sdev_path) <= 5)
 565                 return (NULL);
 566 
 567         if (strncmp(dv->sdev_path, "/dev/", 5) != 0)
 568                 return (NULL);
 569         path = dv->sdev_path + 5;
 570 
 571         for (i = 0; vtab[i].vt_name; i++) {
 572                 if (strcmp(vtab[i].vt_name, path) == 0)
 573                         return (&vtab[i]);
 574                 if (vtab[i].vt_flags & SDEV_SUBDIR) {
 575                         vlen = strlen(vtab[i].vt_name);
 576                         if ((strncmp(vtab[i].vt_name, path,
 577                             vlen - 1) == 0) && path[vlen] == '/')
 578                                 return (&vtab[i]);
 579                 }
 580 
 581         }
 582         return (NULL);
 583 }
 584 
 585 /*
 586  *  sets a directory's vnodeops if the directory is in the vtab;
 587  */
 588 static struct vnodeops *
 589 sdev_get_vop(struct sdev_node *dv)
 590 {
 591         struct sdev_vop_table *vtp;
 592         char *path;
 593 
 594         path = dv->sdev_path;
 595         ASSERT(path);
 596 
 597         /* gets the relative path to /dev/ */
 598         path += 5;
 599 
 600         /* gets the vtab entry it matches */
 601         if ((vtp = sdev_match(dv)) != NULL) {
 602                 dv->sdev_flags |= vtp->vt_flags;
 603                 if (SDEV_IS_PERSIST(dv->sdev_dotdot) &&
 604                     (SDEV_IS_PERSIST(dv) || !SDEV_IS_DYNAMIC(dv)))
 605                         dv->sdev_flags |= SDEV_PERSIST;
 606 
 607                 if (vtp->vt_vops) {
 608                         if (vtp->vt_global_vops)
 609                                 *(vtp->vt_global_vops) = vtp->vt_vops;
 610 
 611                         return (vtp->vt_vops);
 612                 }
 613 
 614                 if (vtp->vt_service) {
 615                         fs_operation_def_t *templ;
 616                         templ = sdev_merge_vtab(vtp->vt_service);
 617                         if (vn_make_ops(vtp->vt_name,
 618                             (const fs_operation_def_t *)templ,
 619                             &vtp->vt_vops) != 0) {
 620                                 cmn_err(CE_PANIC, "%s: malformed vnode ops\n",
 621                                     vtp->vt_name);
 622                                 /*NOTREACHED*/
 623                         }
 624                         if (vtp->vt_global_vops) {
 625                                 *(vtp->vt_global_vops) = vtp->vt_vops;
 626                         }
 627                         sdev_free_vtab(templ);
 628 
 629                         return (vtp->vt_vops);
 630                 }
 631 
 632                 return (sdev_vnodeops);
 633         }
 634 
 635         /* child inherits the persistence of the parent */
 636         if (SDEV_IS_PERSIST(dv->sdev_dotdot))
 637                 dv->sdev_flags |= SDEV_PERSIST;
 638 
 639         return (sdev_vnodeops);
 640 }
 641 
 642 static void
 643 sdev_set_no_negcache(struct sdev_node *dv)
 644 {
 645         int i;
 646         char *path;
 647 
 648         ASSERT(dv->sdev_path);
 649         path = dv->sdev_path + strlen("/dev/");
 650 
 651         for (i = 0; vtab[i].vt_name; i++) {
 652                 if (strcmp(vtab[i].vt_name, path) == 0) {
 653                         if (vtab[i].vt_flags & SDEV_NO_NCACHE)
 654                                 dv->sdev_flags |= SDEV_NO_NCACHE;
 655                         break;
 656                 }
 657         }
 658 }
 659 
 660 void *
 661 sdev_get_vtor(struct sdev_node *dv)
 662 {
 663         struct sdev_vop_table *vtp;
 664 
 665         vtp = sdev_match(dv);
 666         if (vtp)
 667                 return ((void *)vtp->vt_vtor);
 668         else
 669                 return (NULL);
 670 }
 671 
 672 /*
 673  * Build the base root inode
 674  */
 675 ino_t
 676 sdev_mkino(struct sdev_node *dv)
 677 {
 678         ino_t   ino;
 679 
 680         /*
 681          * for now, follow the lead of tmpfs here
 682          * need to someday understand the requirements here
 683          */
 684         ino = (ino_t)(uint32_t)((uintptr_t)dv >> 3);
 685         ino += SDEV_ROOTINO + 1;
 686 
 687         return (ino);
 688 }
 689 
 690 int
 691 sdev_getlink(struct vnode *linkvp, char **link)
 692 {
 693         int err;
 694         char *buf;
 695         struct uio uio = {0};
 696         struct iovec iov = {0};
 697 
 698         if (linkvp == NULL)
 699                 return (ENOENT);
 700         ASSERT(linkvp->v_type == VLNK);
 701 
 702         buf = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
 703         iov.iov_base = buf;
 704         iov.iov_len = MAXPATHLEN;
 705         uio.uio_iov = &iov;
 706         uio.uio_iovcnt = 1;
 707         uio.uio_resid = MAXPATHLEN;
 708         uio.uio_segflg = UIO_SYSSPACE;
 709         uio.uio_llimit = MAXOFFSET_T;
 710 
 711         err = VOP_READLINK(linkvp, &uio, kcred, NULL);
 712         if (err) {
 713                 cmn_err(CE_WARN, "readlink %s failed in dev\n", buf);
 714                 kmem_free(buf, MAXPATHLEN);
 715                 return (ENOENT);
 716         }
 717 
 718         /* mission complete */
 719         *link = i_ddi_strdup(buf, KM_SLEEP);
 720         kmem_free(buf, MAXPATHLEN);
 721         return (0);
 722 }
 723 
 724 /*
 725  * A convenient wrapper to get the devfs node vnode for a device
 726  * minor functionality: readlink() of a /dev symlink
 727  * Place the link into dv->sdev_symlink
 728  */
 729 static int
 730 sdev_follow_link(struct sdev_node *dv)
 731 {
 732         int err;
 733         struct vnode *linkvp;
 734         char *link = NULL;
 735 
 736         linkvp = SDEVTOV(dv);
 737         if (linkvp == NULL)
 738                 return (ENOENT);
 739         ASSERT(linkvp->v_type == VLNK);
 740         err = sdev_getlink(linkvp, &link);
 741         if (err) {
 742                 dv->sdev_symlink = NULL;
 743                 return (ENOENT);
 744         }
 745 
 746         ASSERT(link != NULL);
 747         dv->sdev_symlink = link;
 748         return (0);
 749 }
 750 
 751 static int
 752 sdev_node_check(struct sdev_node *dv, struct vattr *nvap, void *nargs)
 753 {
 754         vtype_t otype = SDEVTOV(dv)->v_type;
 755 
 756         /*
 757          * existing sdev_node has a different type.
 758          */
 759         if (otype != nvap->va_type) {
 760                 sdcmn_err9(("sdev_node_check: existing node "
 761                     "  %s type %d does not match new node type %d\n",
 762                     dv->sdev_name, otype, nvap->va_type));
 763                 return (EEXIST);
 764         }
 765 
 766         /*
 767          * For a symlink, the target should be the same.
 768          */
 769         if (otype == VLNK) {
 770                 ASSERT(nargs != NULL);
 771                 ASSERT(dv->sdev_symlink != NULL);
 772                 if (strcmp(dv->sdev_symlink, (char *)nargs) != 0) {
 773                         sdcmn_err9(("sdev_node_check: existing node "
 774                             " %s has different symlink %s as new node "
 775                             " %s\n", dv->sdev_name, dv->sdev_symlink,
 776                             (char *)nargs));
 777                         return (EEXIST);
 778                 }
 779         }
 780 
 781         return (0);
 782 }
 783 
 784 /*
 785  * sdev_mknode - a wrapper for sdev_nodeinit(), sdev_nodeready()
 786  *
 787  * arguments:
 788  *      - ddv (parent)
 789  *      - nm (child name)
 790  *      - newdv (sdev_node for nm is returned here)
 791  *      - vap (vattr for the node to be created, va_type should be set.
 792  *      - avp (attribute vnode)
 793  *        the defaults should be used if unknown)
 794  *      - cred
 795  *      - args
 796  *          . tnm (for VLNK)
 797  *          . global sdev_node (for !SDEV_GLOBAL)
 798  *      - state: SDEV_INIT, SDEV_READY
 799  *
 800  * only ddv, nm, newddv, vap, cred are required for sdev_mknode(SDEV_INIT)
 801  *
 802  * NOTE:  directory contents writers lock needs to be held before
 803  *        calling this routine.
 804  */
 805 int
 806 sdev_mknode(struct sdev_node *ddv, char *nm, struct sdev_node **newdv,
 807     struct vattr *vap, struct vnode *avp, void *args, struct cred *cred,
 808     sdev_node_state_t state)
 809 {
 810         int error = 0;
 811         sdev_node_state_t node_state;
 812         struct sdev_node *dv = NULL;
 813 
 814         ASSERT(state != SDEV_ZOMBIE);
 815         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
 816 
 817         if (*newdv) {
 818                 dv = *newdv;
 819         } else {
 820                 /* allocate and initialize a sdev_node */
 821                 if (ddv->sdev_state == SDEV_ZOMBIE) {
 822                         sdcmn_err9(("sdev_mknode: parent %s ZOMBIEd\n",
 823                             ddv->sdev_path));
 824                         return (ENOENT);
 825                 }
 826 
 827                 error = sdev_nodeinit(ddv, nm, &dv, vap);
 828                 if (error != 0) {
 829                         sdcmn_err9(("sdev_mknode: error %d,"
 830                             " name %s can not be initialized\n",
 831                             error, nm));
 832                         return (error);
 833                 }
 834                 ASSERT(dv);
 835 
 836                 /* insert into the directory cache */
 837                 sdev_cache_update(ddv, &dv, nm, SDEV_CACHE_ADD);
 838         }
 839 
 840         ASSERT(dv);
 841         node_state = dv->sdev_state;
 842         ASSERT(node_state != SDEV_ZOMBIE);
 843 
 844         if (state == SDEV_READY) {
 845                 switch (node_state) {
 846                 case SDEV_INIT:
 847                         error = sdev_nodeready(dv, vap, avp, args, cred);
 848                         if (error) {
 849                                 sdcmn_err9(("sdev_mknode: node %s can NOT"
 850                                     " be transitioned into READY state, "
 851                                     "error %d\n", nm, error));
 852                         }
 853                         break;
 854                 case SDEV_READY:
 855                         /*
 856                          * Do some sanity checking to make sure
 857                          * the existing sdev_node is what has been
 858                          * asked for.
 859                          */
 860                         error = sdev_node_check(dv, vap, args);
 861                         break;
 862                 default:
 863                         break;
 864                 }
 865         }
 866 
 867         if (!error) {
 868                 *newdv = dv;
 869                 ASSERT((*newdv)->sdev_state != SDEV_ZOMBIE);
 870         } else {
 871                 sdev_cache_update(ddv, &dv, nm, SDEV_CACHE_DELETE);
 872                 /*
 873                  * We created this node, it wasn't passed into us. Therefore it
 874                  * is up to us to delete it.
 875                  */
 876                 if (*newdv == NULL)
 877                         SDEV_SIMPLE_RELE(dv);
 878                 *newdv = NULL;
 879         }
 880 
 881         return (error);
 882 }
 883 
 884 /*
 885  * convenient wrapper to change vp's ATIME, CTIME and MTIME
 886  */
 887 void
 888 sdev_update_timestamps(struct vnode *vp, cred_t *cred, uint_t mask)
 889 {
 890         struct vattr attr;
 891         timestruc_t now;
 892         int err;
 893 
 894         ASSERT(vp);
 895         gethrestime(&now);
 896         if (mask & AT_CTIME)
 897                 attr.va_ctime = now;
 898         if (mask & AT_MTIME)
 899                 attr.va_mtime = now;
 900         if (mask & AT_ATIME)
 901                 attr.va_atime = now;
 902 
 903         attr.va_mask = (mask & AT_TIMES);
 904         err = VOP_SETATTR(vp, &attr, 0, cred, NULL);
 905         if (err && (err != EROFS)) {
 906                 sdcmn_err(("update timestamps error %d\n", err));
 907         }
 908 }
 909 
 910 /*
 911  * the backing store vnode is released here
 912  */
 913 /*ARGSUSED1*/
 914 void
 915 sdev_nodedestroy(struct sdev_node *dv, uint_t flags)
 916 {
 917         /* no references */
 918         ASSERT(dv->sdev_nlink == 0);
 919 
 920         if (dv->sdev_attrvp != NULLVP) {
 921                 VN_RELE(dv->sdev_attrvp);
 922                 /*
 923                  * reset the attrvp so that no more
 924                  * references can be made on this already
 925                  * vn_rele() vnode
 926                  */
 927                 dv->sdev_attrvp = NULLVP;
 928         }
 929 
 930         if (dv->sdev_attr != NULL) {
 931                 kmem_free(dv->sdev_attr, sizeof (struct vattr));
 932                 dv->sdev_attr = NULL;
 933         }
 934 
 935         if (dv->sdev_name != NULL) {
 936                 kmem_free(dv->sdev_name, dv->sdev_namelen + 1);
 937                 dv->sdev_name = NULL;
 938         }
 939 
 940         if (dv->sdev_symlink != NULL) {
 941                 kmem_free(dv->sdev_symlink, strlen(dv->sdev_symlink) + 1);
 942                 dv->sdev_symlink = NULL;
 943         }
 944 
 945         if (dv->sdev_path) {
 946                 kmem_free(dv->sdev_path, strlen(dv->sdev_path) + 1);
 947                 dv->sdev_path = NULL;
 948         }
 949 
 950         if (!SDEV_IS_GLOBAL(dv))
 951                 sdev_prof_free(dv);
 952 
 953         if (SDEVTOV(dv)->v_type == VDIR) {
 954                 ASSERT(SDEV_FIRST_ENTRY(dv) == NULL);
 955                 avl_destroy(&dv->sdev_entries);
 956         }
 957 
 958         mutex_destroy(&dv->sdev_lookup_lock);
 959         cv_destroy(&dv->sdev_lookup_cv);
 960 
 961         /* return node to initial state as per constructor */
 962         (void) memset((void *)&dv->sdev_instance_data, 0,
 963             sizeof (dv->sdev_instance_data));
 964         vn_invalid(SDEVTOV(dv));
 965         dv->sdev_private = NULL;
 966         kmem_cache_free(sdev_node_cache, dv);
 967 }
 968 
 969 /*
 970  * DIRECTORY CACHE lookup
 971  */
 972 struct sdev_node *
 973 sdev_findbyname(struct sdev_node *ddv, char *nm)
 974 {
 975         struct sdev_node *dv;
 976         struct sdev_node dvtmp;
 977         avl_index_t     where;
 978 
 979         ASSERT(RW_LOCK_HELD(&ddv->sdev_contents));
 980 
 981         dvtmp.sdev_name = nm;
 982         dv = avl_find(&ddv->sdev_entries, &dvtmp, &where);
 983         if (dv) {
 984                 ASSERT(dv->sdev_dotdot == ddv);
 985                 ASSERT(strcmp(dv->sdev_name, nm) == 0);
 986                 ASSERT(dv->sdev_state != SDEV_ZOMBIE);
 987                 SDEV_HOLD(dv);
 988                 return (dv);
 989         }
 990         return (NULL);
 991 }
 992 
 993 /*
 994  * Inserts a new sdev_node in a parent directory
 995  */
 996 void
 997 sdev_direnter(struct sdev_node *ddv, struct sdev_node *dv)
 998 {
 999         avl_index_t where;
1000 
1001         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1002         ASSERT(SDEVTOV(ddv)->v_type == VDIR);
1003         ASSERT(ddv->sdev_nlink >= 2);
1004         ASSERT(dv->sdev_nlink == 0);
1005         ASSERT(dv->sdev_state != SDEV_ZOMBIE);
1006 
1007         dv->sdev_dotdot = ddv;
1008         VERIFY(avl_find(&ddv->sdev_entries, dv, &where) == NULL);
1009         avl_insert(&ddv->sdev_entries, dv, where);
1010         ddv->sdev_nlink++;
1011 }
1012 
1013 /*
1014  * The following check is needed because while sdev_nodes are linked
1015  * in SDEV_INIT state, they have their link counts incremented only
1016  * in SDEV_READY state.
1017  */
1018 static void
1019 decr_link(struct sdev_node *dv)
1020 {
1021         VERIFY(RW_WRITE_HELD(&dv->sdev_contents));
1022         if (dv->sdev_state != SDEV_INIT) {
1023                 VERIFY(dv->sdev_nlink >= 1);
1024                 dv->sdev_nlink--;
1025         } else {
1026                 VERIFY(dv->sdev_nlink == 0);
1027         }
1028 }
1029 
1030 /*
1031  * Delete an existing dv from directory cache
1032  *
1033  * In the case of a node is still held by non-zero reference count, the node is
1034  * put into ZOMBIE state. The node is always unlinked from its parent, but it is
1035  * not destroyed via sdev_inactive until its reference count reaches "0".
1036  */
1037 static void
1038 sdev_dirdelete(struct sdev_node *ddv, struct sdev_node *dv)
1039 {
1040         struct vnode *vp;
1041         sdev_node_state_t os;
1042 
1043         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1044 
1045         vp = SDEVTOV(dv);
1046         mutex_enter(&vp->v_lock);
1047         rw_enter(&dv->sdev_contents, RW_WRITER);
1048         os = dv->sdev_state;
1049         ASSERT(os != SDEV_ZOMBIE);
1050         dv->sdev_state = SDEV_ZOMBIE;
1051 
1052         /*
1053          * unlink ourselves from the parent directory now to take care of the ..
1054          * link. However, if we're a directory, we don't remove our reference to
1055          * ourself eg. '.' until we are torn down in the inactive callback.
1056          */
1057         decr_link(ddv);
1058         avl_remove(&ddv->sdev_entries, dv);
1059         /*
1060          * sdev_inactive expects nodes to have a link to themselves when we're
1061          * tearing them down. If we're transitioning from the initial state to
1062          * zombie and not via ready, then we're not going to have this link that
1063          * comes from the node being ready. As a result, we need to increment
1064          * our link count by one to account for this.
1065          */
1066         if (os == SDEV_INIT && dv->sdev_nlink == 0)
1067                 dv->sdev_nlink++;
1068         rw_exit(&dv->sdev_contents);
1069         mutex_exit(&vp->v_lock);
1070 }
1071 
1072 /*
1073  * check if the source is in the path of the target
1074  *
1075  * source and target are different
1076  */
1077 /*ARGSUSED2*/
1078 static int
1079 sdev_checkpath(struct sdev_node *sdv, struct sdev_node *tdv, struct cred *cred)
1080 {
1081         int error = 0;
1082         struct sdev_node *dotdot, *dir;
1083 
1084         dotdot = tdv->sdev_dotdot;
1085         ASSERT(dotdot);
1086 
1087         /* fs root */
1088         if (dotdot == tdv) {
1089                 return (0);
1090         }
1091 
1092         for (;;) {
1093                 /*
1094                  * avoid error cases like
1095                  *      mv a a/b
1096                  *      mv a a/b/c
1097                  *      etc.
1098                  */
1099                 if (dotdot == sdv) {
1100                         error = EINVAL;
1101                         break;
1102                 }
1103 
1104                 dir = dotdot;
1105                 dotdot = dir->sdev_dotdot;
1106 
1107                 /* done checking because root is reached */
1108                 if (dir == dotdot) {
1109                         break;
1110                 }
1111         }
1112         return (error);
1113 }
1114 
1115 int
1116 sdev_rnmnode(struct sdev_node *oddv, struct sdev_node *odv,
1117     struct sdev_node *nddv, struct sdev_node **ndvp, char *nnm,
1118     struct cred *cred)
1119 {
1120         int error = 0;
1121         struct vnode *ovp = SDEVTOV(odv);
1122         struct vnode *nvp;
1123         struct vattr vattr;
1124         int doingdir = (ovp->v_type == VDIR);
1125         char *link = NULL;
1126         int samedir = (oddv == nddv) ? 1 : 0;
1127         int bkstore = 0;
1128         struct sdev_node *idv = NULL;
1129         struct sdev_node *ndv = NULL;
1130         timestruc_t now;
1131 
1132         vattr.va_mask = AT_TYPE|AT_MODE|AT_UID|AT_GID;
1133         error = VOP_GETATTR(ovp, &vattr, 0, cred, NULL);
1134         if (error)
1135                 return (error);
1136 
1137         if (!samedir)
1138                 rw_enter(&oddv->sdev_contents, RW_WRITER);
1139         rw_enter(&nddv->sdev_contents, RW_WRITER);
1140 
1141         /*
1142          * the source may have been deleted by another thread before
1143          * we gets here.
1144          */
1145         if (odv->sdev_state != SDEV_READY) {
1146                 error = ENOENT;
1147                 goto err_out;
1148         }
1149 
1150         if (doingdir && (odv == nddv)) {
1151                 error = EINVAL;
1152                 goto err_out;
1153         }
1154 
1155         /*
1156          * If renaming a directory, and the parents are different (".." must be
1157          * changed) then the source dir must not be in the dir hierarchy above
1158          * the target since it would orphan everything below the source dir.
1159          */
1160         if (doingdir && (oddv != nddv)) {
1161                 error = sdev_checkpath(odv, nddv, cred);
1162                 if (error)
1163                         goto err_out;
1164         }
1165 
1166         /* fix the source for a symlink */
1167         if (vattr.va_type == VLNK) {
1168                 if (odv->sdev_symlink == NULL) {
1169                         error = sdev_follow_link(odv);
1170                         if (error) {
1171                                 /*
1172                                  * The underlying symlink doesn't exist. This
1173                                  * node probably shouldn't even exist. While
1174                                  * it's a bit jarring to consumers, we're going
1175                                  * to remove the node from /dev.
1176                                  */
1177                                 if (SDEV_IS_PERSIST((*ndvp)))
1178                                         bkstore = 1;
1179                                 sdev_dirdelete(oddv, odv);
1180                                 if (bkstore) {
1181                                         ASSERT(nddv->sdev_attrvp);
1182                                         error = VOP_REMOVE(nddv->sdev_attrvp,
1183                                             nnm, cred, NULL, 0);
1184                                         if (error)
1185                                                 goto err_out;
1186                                 }
1187                                 error = ENOENT;
1188                                 goto err_out;
1189                         }
1190                 }
1191                 ASSERT(odv->sdev_symlink);
1192                 link = i_ddi_strdup(odv->sdev_symlink, KM_SLEEP);
1193         }
1194 
1195         /* destination existing */
1196         if (*ndvp) {
1197                 nvp = SDEVTOV(*ndvp);
1198                 ASSERT(nvp);
1199 
1200                 /* handling renaming to itself */
1201                 if (odv == *ndvp) {
1202                         error = 0;
1203                         goto err_out;
1204                 }
1205 
1206                 if (nvp->v_type == VDIR) {
1207                         if (!doingdir) {
1208                                 error = EISDIR;
1209                                 goto err_out;
1210                         }
1211 
1212                         if (vn_vfswlock(nvp)) {
1213                                 error = EBUSY;
1214                                 goto err_out;
1215                         }
1216 
1217                         if (vn_mountedvfs(nvp) != NULL) {
1218                                 vn_vfsunlock(nvp);
1219                                 error = EBUSY;
1220                                 goto err_out;
1221                         }
1222 
1223                         /* in case dir1 exists in dir2 and "mv dir1 dir2" */
1224                         if ((*ndvp)->sdev_nlink > 2) {
1225                                 vn_vfsunlock(nvp);
1226                                 error = EEXIST;
1227                                 goto err_out;
1228                         }
1229                         vn_vfsunlock(nvp);
1230 
1231                         /*
1232                          * We did not place the hold on *ndvp, so even though
1233                          * we're deleting the node, we should not get rid of our
1234                          * reference.
1235                          */
1236                         sdev_dirdelete(nddv, *ndvp);
1237                         *ndvp = NULL;
1238                         ASSERT(nddv->sdev_attrvp);
1239                         error = VOP_RMDIR(nddv->sdev_attrvp, nnm,
1240                             nddv->sdev_attrvp, cred, NULL, 0);
1241                         if (error)
1242                                 goto err_out;
1243                 } else {
1244                         if (doingdir) {
1245                                 error = ENOTDIR;
1246                                 goto err_out;
1247                         }
1248 
1249                         if (SDEV_IS_PERSIST((*ndvp))) {
1250                                 bkstore = 1;
1251                         }
1252 
1253                         /*
1254                          * Get rid of the node from the directory cache note.
1255                          * Don't forget that it's not up to us to remove the vn
1256                          * ref on the sdev node, as we did not place it.
1257                          */
1258                         sdev_dirdelete(nddv, *ndvp);
1259                         *ndvp = NULL;
1260                         if (bkstore) {
1261                                 ASSERT(nddv->sdev_attrvp);
1262                                 error = VOP_REMOVE(nddv->sdev_attrvp,
1263                                     nnm, cred, NULL, 0);
1264                                 if (error)
1265                                         goto err_out;
1266                         }
1267                 }
1268         }
1269 
1270         /*
1271          * make a fresh node from the source attrs
1272          */
1273         ASSERT(RW_WRITE_HELD(&nddv->sdev_contents));
1274         error = sdev_mknode(nddv, nnm, ndvp, &vattr,
1275             NULL, (void *)link, cred, SDEV_READY);
1276 
1277         if (link != NULL) {
1278                 kmem_free(link, strlen(link) + 1);
1279                 link = NULL;
1280         }
1281 
1282         if (error)
1283                 goto err_out;
1284         ASSERT(*ndvp);
1285         ASSERT((*ndvp)->sdev_state == SDEV_READY);
1286 
1287         /* move dir contents */
1288         if (doingdir) {
1289                 for (idv = SDEV_FIRST_ENTRY(odv); idv;
1290                     idv = SDEV_NEXT_ENTRY(odv, idv)) {
1291                         SDEV_HOLD(idv);
1292                         error = sdev_rnmnode(odv, idv,
1293                             (struct sdev_node *)(*ndvp), &ndv,
1294                             idv->sdev_name, cred);
1295                         SDEV_RELE(idv);
1296                         if (error)
1297                                 goto err_out;
1298                         ndv = NULL;
1299                 }
1300         }
1301 
1302         if ((*ndvp)->sdev_attrvp) {
1303                 sdev_update_timestamps((*ndvp)->sdev_attrvp, kcred,
1304                     AT_CTIME|AT_ATIME);
1305         } else {
1306                 ASSERT((*ndvp)->sdev_attr);
1307                 gethrestime(&now);
1308                 (*ndvp)->sdev_attr->va_ctime = now;
1309                 (*ndvp)->sdev_attr->va_atime = now;
1310         }
1311 
1312         if (nddv->sdev_attrvp) {
1313                 sdev_update_timestamps(nddv->sdev_attrvp, kcred,
1314                     AT_MTIME|AT_ATIME);
1315         } else {
1316                 ASSERT(nddv->sdev_attr);
1317                 gethrestime(&now);
1318                 nddv->sdev_attr->va_mtime = now;
1319                 nddv->sdev_attr->va_atime = now;
1320         }
1321         rw_exit(&nddv->sdev_contents);
1322         if (!samedir)
1323                 rw_exit(&oddv->sdev_contents);
1324 
1325         SDEV_RELE(*ndvp);
1326         return (error);
1327 
1328 err_out:
1329         if (link != NULL) {
1330                 kmem_free(link, strlen(link) + 1);
1331                 link = NULL;
1332         }
1333 
1334         rw_exit(&nddv->sdev_contents);
1335         if (!samedir)
1336                 rw_exit(&oddv->sdev_contents);
1337         return (error);
1338 }
1339 
1340 /*
1341  * Merge sdev_node specific information into an attribute structure.
1342  *
1343  * note: sdev_node is not locked here
1344  */
1345 void
1346 sdev_vattr_merge(struct sdev_node *dv, struct vattr *vap)
1347 {
1348         struct vnode *vp = SDEVTOV(dv);
1349 
1350         vap->va_nlink = dv->sdev_nlink;
1351         vap->va_nodeid = dv->sdev_ino;
1352         vap->va_fsid = SDEVTOV(dv->sdev_dotdot)->v_rdev;
1353         vap->va_type = vp->v_type;
1354 
1355         if (vp->v_type == VDIR) {
1356                 vap->va_rdev = 0;
1357                 vap->va_fsid = vp->v_rdev;
1358         } else if (vp->v_type == VLNK) {
1359                 vap->va_rdev = 0;
1360                 vap->va_mode  &= ~S_IFMT;
1361                 vap->va_mode |= S_IFLNK;
1362         } else if ((vp->v_type == VCHR) || (vp->v_type == VBLK)) {
1363                 vap->va_rdev = vp->v_rdev;
1364                 vap->va_mode &= ~S_IFMT;
1365                 if (vap->va_type == VCHR)
1366                         vap->va_mode |= S_IFCHR;
1367                 else
1368                         vap->va_mode |= S_IFBLK;
1369         } else {
1370                 vap->va_rdev = 0;
1371         }
1372 }
1373 
1374 struct vattr *
1375 sdev_getdefault_attr(enum vtype type)
1376 {
1377         if (type == VDIR)
1378                 return (&sdev_vattr_dir);
1379         else if (type == VCHR)
1380                 return (&sdev_vattr_chr);
1381         else if (type == VBLK)
1382                 return (&sdev_vattr_blk);
1383         else if (type == VLNK)
1384                 return (&sdev_vattr_lnk);
1385         else
1386                 return (NULL);
1387 }
1388 int
1389 sdev_to_vp(struct sdev_node *dv, struct vnode **vpp)
1390 {
1391         int rv = 0;
1392         struct vnode *vp = SDEVTOV(dv);
1393 
1394         switch (vp->v_type) {
1395         case VCHR:
1396         case VBLK:
1397                 /*
1398                  * If vnode is a device, return special vnode instead
1399                  * (though it knows all about -us- via sp->s_realvp)
1400                  */
1401                 *vpp = specvp(vp, vp->v_rdev, vp->v_type, kcred);
1402                 VN_RELE(vp);
1403                 if (*vpp == NULLVP)
1404                         rv = ENOSYS;
1405                 break;
1406         default:        /* most types are returned as is */
1407                 *vpp = vp;
1408                 break;
1409         }
1410         return (rv);
1411 }
1412 
1413 /*
1414  * junction between devname and root file system, e.g. ufs
1415  */
1416 int
1417 devname_backstore_lookup(struct sdev_node *ddv, char *nm, struct vnode **rvp)
1418 {
1419         struct vnode *rdvp = ddv->sdev_attrvp;
1420         int rval = 0;
1421 
1422         ASSERT(rdvp);
1423 
1424         rval = VOP_LOOKUP(rdvp, nm, rvp, NULL, 0, NULL, kcred, NULL, NULL,
1425             NULL);
1426         return (rval);
1427 }
1428 
1429 static int
1430 sdev_filldir_from_store(struct sdev_node *ddv, int dlen, struct cred *cred)
1431 {
1432         struct sdev_node *dv = NULL;
1433         char    *nm;
1434         struct vnode *dirvp;
1435         int     error;
1436         vnode_t *vp;
1437         int eof;
1438         struct iovec iov;
1439         struct uio uio;
1440         struct dirent64 *dp;
1441         dirent64_t *dbuf;
1442         size_t dbuflen;
1443         struct vattr vattr;
1444         char *link = NULL;
1445 
1446         if (ddv->sdev_attrvp == NULL)
1447                 return (0);
1448         if (!(ddv->sdev_flags & SDEV_BUILD))
1449                 return (0);
1450 
1451         dirvp = ddv->sdev_attrvp;
1452         VN_HOLD(dirvp);
1453         dbuf = kmem_zalloc(dlen, KM_SLEEP);
1454 
1455         uio.uio_iov = &iov;
1456         uio.uio_iovcnt = 1;
1457         uio.uio_segflg = UIO_SYSSPACE;
1458         uio.uio_fmode = 0;
1459         uio.uio_extflg = UIO_COPY_CACHED;
1460         uio.uio_loffset = 0;
1461         uio.uio_llimit = MAXOFFSET_T;
1462 
1463         eof = 0;
1464         error = 0;
1465         while (!error && !eof) {
1466                 uio.uio_resid = dlen;
1467                 iov.iov_base = (char *)dbuf;
1468                 iov.iov_len = dlen;
1469                 (void) VOP_RWLOCK(dirvp, V_WRITELOCK_FALSE, NULL);
1470                 error = VOP_READDIR(dirvp, &uio, kcred, &eof, NULL, 0);
1471                 VOP_RWUNLOCK(dirvp, V_WRITELOCK_FALSE, NULL);
1472 
1473                 dbuflen = dlen - uio.uio_resid;
1474                 if (error || dbuflen == 0)
1475                         break;
1476 
1477                 if (!(ddv->sdev_flags & SDEV_BUILD))
1478                         break;
1479 
1480                 for (dp = dbuf; ((intptr_t)dp <
1481                     (intptr_t)dbuf + dbuflen);
1482                     dp = (dirent64_t *)((intptr_t)dp + dp->d_reclen)) {
1483                         nm = dp->d_name;
1484 
1485                         if (strcmp(nm, ".") == 0 ||
1486                             strcmp(nm, "..") == 0)
1487                                 continue;
1488 
1489                         vp = NULLVP;
1490                         dv = sdev_cache_lookup(ddv, nm);
1491                         if (dv) {
1492                                 VERIFY(dv->sdev_state != SDEV_ZOMBIE);
1493                                 SDEV_SIMPLE_RELE(dv);
1494                                 continue;
1495                         }
1496 
1497                         /* refill the cache if not already */
1498                         error = devname_backstore_lookup(ddv, nm, &vp);
1499                         if (error)
1500                                 continue;
1501 
1502                         vattr.va_mask = AT_TYPE|AT_MODE|AT_UID|AT_GID;
1503                         error = VOP_GETATTR(vp, &vattr, 0, cred, NULL);
1504                         if (error)
1505                                 continue;
1506 
1507                         if (vattr.va_type == VLNK) {
1508                                 error = sdev_getlink(vp, &link);
1509                                 if (error) {
1510                                         continue;
1511                                 }
1512                                 ASSERT(link != NULL);
1513                         }
1514 
1515                         if (!rw_tryupgrade(&ddv->sdev_contents)) {
1516                                 rw_exit(&ddv->sdev_contents);
1517                                 rw_enter(&ddv->sdev_contents, RW_WRITER);
1518                         }
1519                         error = sdev_mknode(ddv, nm, &dv, &vattr, vp, link,
1520                             cred, SDEV_READY);
1521                         rw_downgrade(&ddv->sdev_contents);
1522 
1523                         if (link != NULL) {
1524                                 kmem_free(link, strlen(link) + 1);
1525                                 link = NULL;
1526                         }
1527 
1528                         if (!error) {
1529                                 ASSERT(dv);
1530                                 ASSERT(dv->sdev_state != SDEV_ZOMBIE);
1531                                 SDEV_SIMPLE_RELE(dv);
1532                         }
1533                         vp = NULL;
1534                         dv = NULL;
1535                 }
1536         }
1537 
1538 done:
1539         VN_RELE(dirvp);
1540         kmem_free(dbuf, dlen);
1541 
1542         return (error);
1543 }
1544 
1545 void
1546 sdev_filldir_dynamic(struct sdev_node *ddv)
1547 {
1548         int error;
1549         int i;
1550         struct vattr vattr;
1551         struct vattr *vap = &vattr;
1552         char *nm = NULL;
1553         struct sdev_node *dv = NULL;
1554 
1555         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1556         ASSERT((ddv->sdev_flags & SDEV_BUILD));
1557 
1558         *vap = *sdev_getdefault_attr(VDIR);     /* note structure copy here */
1559         gethrestime(&vap->va_atime);
1560         vap->va_mtime = vap->va_atime;
1561         vap->va_ctime = vap->va_atime;
1562         for (i = 0; vtab[i].vt_name != NULL; i++) {
1563                 /*
1564                  * This early, we may be in a read-only /dev environment: leave
1565                  * the creation of any nodes we'd attempt to persist to
1566                  * devfsadm. Because /dev itself is normally persistent, any
1567                  * node which is not marked dynamic will end up being marked
1568                  * persistent. However, some nodes are both dynamic and
1569                  * persistent, mostly lofi and rlofi, so we need to be careful
1570                  * in our check.
1571                  */
1572                 if ((vtab[i].vt_flags & SDEV_PERSIST) ||
1573                     !(vtab[i].vt_flags & SDEV_DYNAMIC))
1574                         continue;
1575                 nm = vtab[i].vt_name;
1576                 ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1577                 dv = NULL;
1578                 error = sdev_mknode(ddv, nm, &dv, vap, NULL,
1579                     NULL, kcred, SDEV_READY);
1580                 if (error) {
1581                         cmn_err(CE_WARN, "%s/%s: error %d\n",
1582                             ddv->sdev_name, nm, error);
1583                 } else {
1584                         ASSERT(dv);
1585                         ASSERT(dv->sdev_state != SDEV_ZOMBIE);
1586                         SDEV_SIMPLE_RELE(dv);
1587                 }
1588         }
1589 }
1590 
1591 /*
1592  * Creating a backing store entry based on sdev_attr.
1593  * This is called either as part of node creation in a persistent directory
1594  * or from setattr/setsecattr to persist access attributes across reboot.
1595  */
1596 int
1597 sdev_shadow_node(struct sdev_node *dv, struct cred *cred)
1598 {
1599         int error = 0;
1600         struct vnode *dvp = SDEVTOV(dv->sdev_dotdot);
1601         struct vnode *rdvp = VTOSDEV(dvp)->sdev_attrvp;
1602         struct vattr *vap = dv->sdev_attr;
1603         char *nm = dv->sdev_name;
1604         struct vnode *tmpvp, **rvp = &tmpvp, *rrvp = NULL;
1605 
1606         ASSERT(dv && dv->sdev_name && rdvp);
1607         ASSERT(RW_WRITE_HELD(&dv->sdev_contents) && dv->sdev_attrvp == NULL);
1608 
1609 lookup:
1610         /* try to find it in the backing store */
1611         error = VOP_LOOKUP(rdvp, nm, rvp, NULL, 0, NULL, cred, NULL, NULL,
1612             NULL);
1613         if (error == 0) {
1614                 if (VOP_REALVP(*rvp, &rrvp, NULL) == 0) {
1615                         VN_HOLD(rrvp);
1616                         VN_RELE(*rvp);
1617                         *rvp = rrvp;
1618                 }
1619 
1620                 kmem_free(dv->sdev_attr, sizeof (vattr_t));
1621                 dv->sdev_attr = NULL;
1622                 dv->sdev_attrvp = *rvp;
1623                 return (0);
1624         }
1625 
1626         /* let's try to persist the node */
1627         gethrestime(&vap->va_atime);
1628         vap->va_mtime = vap->va_atime;
1629         vap->va_ctime = vap->va_atime;
1630         vap->va_mask |= AT_TYPE|AT_MODE;
1631         switch (vap->va_type) {
1632         case VDIR:
1633                 error = VOP_MKDIR(rdvp, nm, vap, rvp, cred, NULL, 0, NULL);
1634                 sdcmn_err9(("sdev_shadow_node: mkdir vp %p error %d\n",
1635                     (void *)(*rvp), error));
1636                 if (!error)
1637                         VN_RELE(*rvp);
1638                 break;
1639         case VCHR:
1640         case VBLK:
1641         case VREG:
1642         case VDOOR:
1643                 error = VOP_CREATE(rdvp, nm, vap, NONEXCL, VREAD|VWRITE,
1644                     rvp, cred, 0, NULL, NULL);
1645                 sdcmn_err9(("sdev_shadow_node: create vp %p, error %d\n",
1646                     (void *)(*rvp), error));
1647                 if (!error)
1648                         VN_RELE(*rvp);
1649                 break;
1650         case VLNK:
1651                 ASSERT(dv->sdev_symlink);
1652                 error = VOP_SYMLINK(rdvp, nm, vap, dv->sdev_symlink, cred,
1653                     NULL, 0);
1654                 sdcmn_err9(("sdev_shadow_node: create symlink error %d\n",
1655                     error));
1656                 break;
1657         default:
1658                 cmn_err(CE_PANIC, "dev: %s: sdev_shadow_node "
1659                     "create\n", nm);
1660                 /*NOTREACHED*/
1661         }
1662 
1663         /* go back to lookup to factor out spec node and set attrvp */
1664         if (error == 0)
1665                 goto lookup;
1666 
1667         sdcmn_err(("cannot persist %s - error %d\n", dv->sdev_path, error));
1668         return (error);
1669 }
1670 
1671 static void
1672 sdev_cache_add(struct sdev_node *ddv, struct sdev_node **dv, char *nm)
1673 {
1674         struct sdev_node *dup = NULL;
1675 
1676         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1677         if ((dup = sdev_findbyname(ddv, nm)) == NULL) {
1678                 sdev_direnter(ddv, *dv);
1679         } else {
1680                 VERIFY(dup->sdev_state != SDEV_ZOMBIE);
1681                 SDEV_SIMPLE_RELE(*dv);
1682                 sdev_nodedestroy(*dv, 0);
1683                 *dv = dup;
1684         }
1685 }
1686 
1687 static void
1688 sdev_cache_delete(struct sdev_node *ddv, struct sdev_node **dv)
1689 {
1690         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1691         sdev_dirdelete(ddv, *dv);
1692 }
1693 
1694 /*
1695  * update the in-core directory cache
1696  */
1697 void
1698 sdev_cache_update(struct sdev_node *ddv, struct sdev_node **dv, char *nm,
1699     sdev_cache_ops_t ops)
1700 {
1701         ASSERT((SDEV_HELD(*dv)));
1702 
1703         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1704         switch (ops) {
1705         case SDEV_CACHE_ADD:
1706                 sdev_cache_add(ddv, dv, nm);
1707                 break;
1708         case SDEV_CACHE_DELETE:
1709                 sdev_cache_delete(ddv, dv);
1710                 break;
1711         default:
1712                 break;
1713         }
1714 }
1715 
1716 /*
1717  * retrieve the named entry from the directory cache
1718  */
1719 struct sdev_node *
1720 sdev_cache_lookup(struct sdev_node *ddv, char *nm)
1721 {
1722         struct sdev_node *dv = NULL;
1723 
1724         ASSERT(RW_LOCK_HELD(&ddv->sdev_contents));
1725         dv = sdev_findbyname(ddv, nm);
1726 
1727         return (dv);
1728 }
1729 
1730 /*
1731  * Implicit reconfig for nodes constructed by a link generator
1732  * Start devfsadm if needed, or if devfsadm is in progress,
1733  * prepare to block on devfsadm either completing or
1734  * constructing the desired node.  As devfsadmd is global
1735  * in scope, constructing all necessary nodes, we only
1736  * need to initiate it once.
1737  */
1738 static int
1739 sdev_call_devfsadmd(struct sdev_node *ddv, struct sdev_node *dv, char *nm)
1740 {
1741         int error = 0;
1742 
1743         if (DEVNAME_DEVFSADM_IS_RUNNING(devfsadm_state)) {
1744                 sdcmn_err6(("lookup: waiting for %s/%s, 0x%x\n",
1745                     ddv->sdev_name, nm, devfsadm_state));
1746                 mutex_enter(&dv->sdev_lookup_lock);
1747                 SDEV_BLOCK_OTHERS(dv, (SDEV_LOOKUP | SDEV_LGWAITING));
1748                 mutex_exit(&dv->sdev_lookup_lock);
1749                 error = 0;
1750         } else if (!DEVNAME_DEVFSADM_HAS_RUN(devfsadm_state)) {
1751                 sdcmn_err6(("lookup %s/%s starting devfsadm, 0x%x\n",
1752                     ddv->sdev_name, nm, devfsadm_state));
1753 
1754                 sdev_devfsadmd_thread(ddv, dv, kcred);
1755                 mutex_enter(&dv->sdev_lookup_lock);
1756                 SDEV_BLOCK_OTHERS(dv,
1757                     (SDEV_LOOKUP | SDEV_LGWAITING));
1758                 mutex_exit(&dv->sdev_lookup_lock);
1759                 error = 0;
1760         } else {
1761                 error = -1;
1762         }
1763 
1764         return (error);
1765 }
1766 
1767 /*
1768  *  Support for specialized device naming construction mechanisms
1769  */
1770 static int
1771 sdev_call_dircallback(struct sdev_node *ddv, struct sdev_node **dvp, char *nm,
1772     int (*callback)(struct sdev_node *, char *, void **, struct cred *,
1773     void *, char *), int flags, struct cred *cred)
1774 {
1775         int rv = 0;
1776         char *physpath = NULL;
1777         struct vattr vattr;
1778         struct vattr *vap = &vattr;
1779         struct sdev_node *dv = NULL;
1780 
1781         ASSERT(RW_WRITE_HELD(&ddv->sdev_contents));
1782         if (flags & SDEV_VLINK) {
1783                 physpath = kmem_zalloc(MAXPATHLEN, KM_SLEEP);
1784                 rv = callback(ddv, nm, (void *)&physpath, kcred, NULL,
1785                     NULL);
1786                 if (rv) {
1787                         kmem_free(physpath, MAXPATHLEN);
1788                         return (-1);
1789                 }
1790 
1791                 *vap = *sdev_getdefault_attr(VLNK);     /* structure copy */
1792                 vap->va_size = strlen(physpath);
1793                 gethrestime(&vap->va_atime);
1794                 vap->va_mtime = vap->va_atime;
1795                 vap->va_ctime = vap->va_atime;
1796 
1797                 rv = sdev_mknode(ddv, nm, &dv, vap, NULL,
1798                     (void *)physpath, cred, SDEV_READY);
1799                 kmem_free(physpath, MAXPATHLEN);
1800                 if (rv)
1801                         return (rv);
1802         } else if (flags & SDEV_VATTR) {
1803                 /*
1804                  * /dev/pts
1805                  *
1806                  * callback is responsible to set the basic attributes,
1807                  * e.g. va_type/va_uid/va_gid/
1808                  *    dev_t if VCHR or VBLK/
1809                  */
1810                 ASSERT(callback);
1811                 rv = callback(ddv, nm, (void *)&vattr, kcred, NULL, NULL);
1812                 if (rv) {
1813                         sdcmn_err3(("devname_lookup_func: SDEV_NONE "
1814                             "callback failed \n"));
1815                         return (-1);
1816                 }
1817 
1818                 rv = sdev_mknode(ddv, nm, &dv, &vattr, NULL, NULL,
1819                     cred, SDEV_READY);
1820 
1821                 if (rv)
1822                         return (rv);
1823 
1824         } else {
1825                 impossible(("lookup: %s/%s by %s not supported (%d)\n",
1826                     SDEVTOV(ddv)->v_path, nm, curproc->p_user.u_comm,
1827                     __LINE__));
1828                 rv = -1;
1829         }
1830 
1831         *dvp = dv;
1832         return (rv);
1833 }
1834 
1835 static int
1836 is_devfsadm_thread(char *exec_name)
1837 {
1838         /*
1839          * note: because devfsadmd -> /usr/sbin/devfsadm
1840          * it is safe to use "devfsadm" to capture the lookups
1841          * from devfsadm and its daemon version.
1842          */
1843         if (strcmp(exec_name, "devfsadm") == 0)
1844                 return (1);
1845         return (0);
1846 }
1847 
1848 /*
1849  * Lookup Order:
1850  *      sdev_node cache;
1851  *      backing store (SDEV_PERSIST);
1852  *      DBNR: a. dir_ops implemented in the loadable modules;
1853  *            b. vnode ops in vtab.
1854  */
1855 int
1856 devname_lookup_func(struct sdev_node *ddv, char *nm, struct vnode **vpp,
1857     struct cred *cred, int (*callback)(struct sdev_node *, char *, void **,
1858     struct cred *, void *, char *), int flags)
1859 {
1860         int rv = 0, nmlen;
1861         struct vnode *rvp = NULL;
1862         struct sdev_node *dv = NULL;
1863         int     retried = 0;
1864         int     error = 0;
1865         struct vattr vattr;
1866         char *lookup_thread = curproc->p_user.u_comm;
1867         int failed_flags = 0;
1868         int (*vtor)(struct sdev_node *) = NULL;
1869         int state;
1870         int parent_state;
1871         char *link = NULL;
1872 
1873         if (SDEVTOV(ddv)->v_type != VDIR)
1874                 return (ENOTDIR);
1875 
1876         /*
1877          * Empty name or ., return node itself.
1878          */
1879         nmlen = strlen(nm);
1880         if ((nmlen == 0) || ((nmlen == 1) && (nm[0] == '.'))) {
1881                 *vpp = SDEVTOV(ddv);
1882                 VN_HOLD(*vpp);
1883                 return (0);
1884         }
1885 
1886         /*
1887          * .., return the parent directory
1888          */
1889         if ((nmlen == 2) && (strcmp(nm, "..") == 0)) {
1890                 *vpp = SDEVTOV(ddv->sdev_dotdot);
1891                 VN_HOLD(*vpp);
1892                 return (0);
1893         }
1894 
1895         rw_enter(&ddv->sdev_contents, RW_READER);
1896         if (ddv->sdev_flags & SDEV_VTOR) {
1897                 vtor = (int (*)(struct sdev_node *))sdev_get_vtor(ddv);
1898                 ASSERT(vtor);
1899         }
1900 
1901 tryagain:
1902         /*
1903          * (a) directory cache lookup:
1904          */
1905         ASSERT(RW_READ_HELD(&ddv->sdev_contents));
1906         parent_state = ddv->sdev_state;
1907         dv = sdev_cache_lookup(ddv, nm);
1908         if (dv) {
1909                 state = dv->sdev_state;
1910                 switch (state) {
1911                 case SDEV_INIT:
1912                         if (is_devfsadm_thread(lookup_thread))
1913                                 break;
1914 
1915                         /* ZOMBIED parent won't allow node creation */
1916                         if (parent_state == SDEV_ZOMBIE) {
1917                                 SD_TRACE_FAILED_LOOKUP(ddv, nm,
1918                                     retried);
1919                                 goto nolock_notfound;
1920                         }
1921 
1922                         mutex_enter(&dv->sdev_lookup_lock);
1923                         /* compensate the threads started after devfsadm */
1924                         if (DEVNAME_DEVFSADM_IS_RUNNING(devfsadm_state) &&
1925                             !(SDEV_IS_LOOKUP(dv)))
1926                                 SDEV_BLOCK_OTHERS(dv,
1927                                     (SDEV_LOOKUP | SDEV_LGWAITING));
1928 
1929                         if (SDEV_IS_LOOKUP(dv)) {
1930                                 failed_flags |= SLF_REBUILT;
1931                                 rw_exit(&ddv->sdev_contents);
1932                                 error = sdev_wait4lookup(dv, SDEV_LOOKUP);
1933                                 mutex_exit(&dv->sdev_lookup_lock);
1934                                 rw_enter(&ddv->sdev_contents, RW_READER);
1935 
1936                                 if (error != 0) {
1937                                         SD_TRACE_FAILED_LOOKUP(ddv, nm,
1938                                             retried);
1939                                         goto nolock_notfound;
1940                                 }
1941 
1942                                 state = dv->sdev_state;
1943                                 if (state == SDEV_INIT) {
1944                                         SD_TRACE_FAILED_LOOKUP(ddv, nm,
1945                                             retried);
1946                                         goto nolock_notfound;
1947                                 } else if (state == SDEV_READY) {
1948                                         goto found;
1949                                 } else if (state == SDEV_ZOMBIE) {
1950                                         rw_exit(&ddv->sdev_contents);
1951                                         SD_TRACE_FAILED_LOOKUP(ddv, nm,
1952                                             retried);
1953                                         SDEV_RELE(dv);
1954                                         goto lookup_failed;
1955                                 }
1956                         } else {
1957                                 mutex_exit(&dv->sdev_lookup_lock);
1958                         }
1959                         break;
1960                 case SDEV_READY:
1961                         goto found;
1962                 case SDEV_ZOMBIE:
1963                         rw_exit(&ddv->sdev_contents);
1964                         SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
1965                         SDEV_RELE(dv);
1966                         goto lookup_failed;
1967                 default:
1968                         rw_exit(&ddv->sdev_contents);
1969                         SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
1970                         sdev_lookup_failed(ddv, nm, failed_flags);
1971                         *vpp = NULLVP;
1972                         return (ENOENT);
1973                 }
1974         }
1975         ASSERT(RW_READ_HELD(&ddv->sdev_contents));
1976 
1977         /*
1978          * ZOMBIED parent does not allow new node creation.
1979          * bail out early
1980          */
1981         if (parent_state == SDEV_ZOMBIE) {
1982                 rw_exit(&ddv->sdev_contents);
1983                 *vpp = NULLVP;
1984                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
1985                 return (ENOENT);
1986         }
1987 
1988         /*
1989          * (b0): backing store lookup
1990          *      SDEV_PERSIST is default except:
1991          *              1) pts nodes
1992          *              2) non-chmod'ed local nodes
1993          *              3) zvol nodes
1994          */
1995         if (SDEV_IS_PERSIST(ddv)) {
1996                 error = devname_backstore_lookup(ddv, nm, &rvp);
1997 
1998                 if (!error) {
1999 
2000                         vattr.va_mask = AT_TYPE|AT_MODE|AT_UID|AT_GID;
2001                         error = VOP_GETATTR(rvp, &vattr, 0, cred, NULL);
2002                         if (error) {
2003                                 rw_exit(&ddv->sdev_contents);
2004                                 if (dv)
2005                                         SDEV_RELE(dv);
2006                                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2007                                 sdev_lookup_failed(ddv, nm, failed_flags);
2008                                 *vpp = NULLVP;
2009                                 return (ENOENT);
2010                         }
2011 
2012                         if (vattr.va_type == VLNK) {
2013                                 error = sdev_getlink(rvp, &link);
2014                                 if (error) {
2015                                         rw_exit(&ddv->sdev_contents);
2016                                         if (dv)
2017                                                 SDEV_RELE(dv);
2018                                         SD_TRACE_FAILED_LOOKUP(ddv, nm,
2019                                             retried);
2020                                         sdev_lookup_failed(ddv, nm,
2021                                             failed_flags);
2022                                         *vpp = NULLVP;
2023                                         return (ENOENT);
2024                                 }
2025                                 ASSERT(link != NULL);
2026                         }
2027 
2028                         if (!rw_tryupgrade(&ddv->sdev_contents)) {
2029                                 rw_exit(&ddv->sdev_contents);
2030                                 rw_enter(&ddv->sdev_contents, RW_WRITER);
2031                         }
2032                         error = sdev_mknode(ddv, nm, &dv, &vattr,
2033                             rvp, link, cred, SDEV_READY);
2034                         rw_downgrade(&ddv->sdev_contents);
2035 
2036                         if (link != NULL) {
2037                                 kmem_free(link, strlen(link) + 1);
2038                                 link = NULL;
2039                         }
2040 
2041                         if (error) {
2042                                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2043                                 rw_exit(&ddv->sdev_contents);
2044                                 if (dv)
2045                                         SDEV_RELE(dv);
2046                                 goto lookup_failed;
2047                         } else {
2048                                 goto found;
2049                         }
2050                 } else if (retried) {
2051                         rw_exit(&ddv->sdev_contents);
2052                         sdcmn_err3(("retry of lookup of %s/%s: failed\n",
2053                             ddv->sdev_name, nm));
2054                         if (dv)
2055                                 SDEV_RELE(dv);
2056                         SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2057                         sdev_lookup_failed(ddv, nm, failed_flags);
2058                         *vpp = NULLVP;
2059                         return (ENOENT);
2060                 }
2061         }
2062 
2063 lookup_create_node:
2064         /* first thread that is doing the lookup on this node */
2065         if (callback) {
2066                 ASSERT(dv == NULL);
2067                 if (!rw_tryupgrade(&ddv->sdev_contents)) {
2068                         rw_exit(&ddv->sdev_contents);
2069                         rw_enter(&ddv->sdev_contents, RW_WRITER);
2070                 }
2071                 error = sdev_call_dircallback(ddv, &dv, nm, callback,
2072                     flags, cred);
2073                 rw_downgrade(&ddv->sdev_contents);
2074                 if (error == 0) {
2075                         goto found;
2076                 } else {
2077                         SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2078                         rw_exit(&ddv->sdev_contents);
2079                         goto lookup_failed;
2080                 }
2081         }
2082         if (!dv) {
2083                 if (!rw_tryupgrade(&ddv->sdev_contents)) {
2084                         rw_exit(&ddv->sdev_contents);
2085                         rw_enter(&ddv->sdev_contents, RW_WRITER);
2086                 }
2087                 error = sdev_mknode(ddv, nm, &dv, NULL, NULL, NULL,
2088                     cred, SDEV_INIT);
2089                 if (!dv) {
2090                         rw_exit(&ddv->sdev_contents);
2091                         SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2092                         sdev_lookup_failed(ddv, nm, failed_flags);
2093                         *vpp = NULLVP;
2094                         return (ENOENT);
2095                 }
2096                 rw_downgrade(&ddv->sdev_contents);
2097         }
2098 
2099         /*
2100          * (b1) invoking devfsadm once per life time for devfsadm nodes
2101          */
2102         ASSERT(SDEV_HELD(dv));
2103 
2104         if (SDEV_IS_NO_NCACHE(dv))
2105                 failed_flags |= SLF_NO_NCACHE;
2106         if (sdev_reconfig_boot || !i_ddi_io_initialized() ||
2107             SDEV_IS_DYNAMIC(ddv) || SDEV_IS_NO_NCACHE(dv) ||
2108             ((moddebug & MODDEBUG_FINI_EBUSY) != 0)) {
2109                 ASSERT(SDEV_HELD(dv));
2110                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2111                 goto nolock_notfound;
2112         }
2113 
2114         /*
2115          * filter out known non-existent devices recorded
2116          * during initial reconfiguration boot for which
2117          * reconfig should not be done and lookup may
2118          * be short-circuited now.
2119          */
2120         if (sdev_lookup_filter(ddv, nm)) {
2121                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2122                 goto nolock_notfound;
2123         }
2124 
2125         /* bypassing devfsadm internal nodes */
2126         if (is_devfsadm_thread(lookup_thread)) {
2127                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2128                 goto nolock_notfound;
2129         }
2130 
2131         if (sdev_reconfig_disable) {
2132                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2133                 goto nolock_notfound;
2134         }
2135 
2136         error = sdev_call_devfsadmd(ddv, dv, nm);
2137         if (error == 0) {
2138                 sdcmn_err8(("lookup of %s/%s by %s: reconfig\n",
2139                     ddv->sdev_name, nm, curproc->p_user.u_comm));
2140                 if (sdev_reconfig_verbose) {
2141                         cmn_err(CE_CONT,
2142                             "?lookup of %s/%s by %s: reconfig\n",
2143                             ddv->sdev_name, nm, curproc->p_user.u_comm);
2144                 }
2145                 retried = 1;
2146                 failed_flags |= SLF_REBUILT;
2147                 ASSERT(dv->sdev_state != SDEV_ZOMBIE);
2148                 SDEV_SIMPLE_RELE(dv);
2149                 goto tryagain;
2150         } else {
2151                 SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2152                 goto nolock_notfound;
2153         }
2154 
2155 found:
2156         ASSERT(dv->sdev_state == SDEV_READY);
2157         if (vtor) {
2158                 /*
2159                  * Check validity of returned node
2160                  */
2161                 switch (vtor(dv)) {
2162                 case SDEV_VTOR_VALID:
2163                         break;
2164                 case SDEV_VTOR_STALE:
2165                         /*
2166                          * The name exists, but the cache entry is
2167                          * stale and needs to be re-created.
2168                          */
2169                         ASSERT(RW_READ_HELD(&ddv->sdev_contents));
2170                         if (rw_tryupgrade(&ddv->sdev_contents) == 0) {
2171                                 rw_exit(&ddv->sdev_contents);
2172                                 rw_enter(&ddv->sdev_contents, RW_WRITER);
2173                         }
2174                         sdev_cache_update(ddv, &dv, nm, SDEV_CACHE_DELETE);
2175                         rw_downgrade(&ddv->sdev_contents);
2176                         SDEV_RELE(dv);
2177                         dv = NULL;
2178                         goto lookup_create_node;
2179                         /* FALLTHRU */
2180                 case SDEV_VTOR_INVALID:
2181                         SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2182                         sdcmn_err7(("lookup: destroy invalid "
2183                             "node: %s(%p)\n", dv->sdev_name, (void *)dv));
2184                         goto nolock_notfound;
2185                 case SDEV_VTOR_SKIP:
2186                         sdcmn_err7(("lookup: node not applicable - "
2187                             "skipping: %s(%p)\n", dv->sdev_name, (void *)dv));
2188                         rw_exit(&ddv->sdev_contents);
2189                         SD_TRACE_FAILED_LOOKUP(ddv, nm, retried);
2190                         SDEV_RELE(dv);
2191                         goto lookup_failed;
2192                 default:
2193                         cmn_err(CE_PANIC,
2194                             "dev fs: validator failed: %s(%p)\n",
2195                             dv->sdev_name, (void *)dv);
2196                         break;
2197                 }
2198         }
2199 
2200         rw_exit(&ddv->sdev_contents);
2201         rv = sdev_to_vp(dv, vpp);
2202         sdcmn_err3(("devname_lookup_func: returning vp %p v_count %d state %d "
2203             "for nm %s, error %d\n", (void *)*vpp, (*vpp)->v_count,
2204             dv->sdev_state, nm, rv));
2205         return (rv);
2206 
2207 nolock_notfound:
2208         /*
2209          * Destroy the node that is created for synchronization purposes.
2210          */
2211         sdcmn_err3(("devname_lookup_func: %s with state %d\n",
2212             nm, dv->sdev_state));
2213         ASSERT(RW_READ_HELD(&ddv->sdev_contents));
2214         if (dv->sdev_state == SDEV_INIT) {
2215                 if (!rw_tryupgrade(&ddv->sdev_contents)) {
2216                         rw_exit(&ddv->sdev_contents);
2217                         rw_enter(&ddv->sdev_contents, RW_WRITER);
2218                 }
2219 
2220                 /*
2221                  * Node state may have changed during the lock
2222                  * changes. Re-check.
2223                  */
2224                 if (dv->sdev_state == SDEV_INIT) {
2225                         sdev_dirdelete(ddv, dv);
2226                         rw_exit(&ddv->sdev_contents);
2227                         sdev_lookup_failed(ddv, nm, failed_flags);
2228                         SDEV_RELE(dv);
2229                         *vpp = NULL;
2230                         return (ENOENT);
2231                 }
2232         }
2233 
2234         rw_exit(&ddv->sdev_contents);
2235         SDEV_RELE(dv);
2236 
2237 lookup_failed:
2238         sdev_lookup_failed(ddv, nm, failed_flags);
2239         *vpp = NULL;
2240         return (ENOENT);
2241 }
2242 
2243 /*
2244  * Given a directory node, mark all nodes beneath as
2245  * STALE, i.e. nodes that don't exist as far as new
2246  * consumers are concerned.  Remove them from the
2247  * list of directory entries so that no lookup or
2248  * directory traversal will find them.  The node
2249  * not deallocated so existing holds are not affected.
2250  */
2251 void
2252 sdev_stale(struct sdev_node *ddv)
2253 {
2254         struct sdev_node *dv;
2255         struct vnode *vp;
2256 
2257         ASSERT(SDEVTOV(ddv)->v_type == VDIR);
2258 
2259         rw_enter(&ddv->sdev_contents, RW_WRITER);
2260         while ((dv = SDEV_FIRST_ENTRY(ddv)) != NULL) {
2261                 vp = SDEVTOV(dv);
2262                 SDEV_HOLD(dv);
2263                 if (vp->v_type == VDIR)
2264                         sdev_stale(dv);
2265 
2266                 sdev_dirdelete(ddv, dv);
2267                 SDEV_RELE(dv);
2268         }
2269         ddv->sdev_flags |= SDEV_BUILD;
2270         rw_exit(&ddv->sdev_contents);
2271 }
2272 
2273 /*
2274  * Given a directory node, clean out all the nodes beneath.
2275  * If expr is specified, clean node with names matching expr.
2276  * If SDEV_ENFORCE is specified in flags, busy nodes are made stale,
2277  *      so they are excluded from future lookups.
2278  */
2279 int
2280 sdev_cleandir(struct sdev_node *ddv, char *expr, uint_t flags)
2281 {
2282         int error = 0;
2283         int busy = 0;
2284         struct vnode *vp;
2285         struct sdev_node *dv, *next;
2286         int bkstore = 0;
2287         int len = 0;
2288         char *bks_name = NULL;
2289 
2290         ASSERT(SDEVTOV(ddv)->v_type == VDIR);
2291 
2292         /*
2293          * We try our best to destroy all unused sdev_node's
2294          */
2295         rw_enter(&ddv->sdev_contents, RW_WRITER);
2296         for (dv = SDEV_FIRST_ENTRY(ddv); dv != NULL; dv = next) {
2297                 next = SDEV_NEXT_ENTRY(ddv, dv);
2298                 vp = SDEVTOV(dv);
2299 
2300                 if (expr && gmatch(dv->sdev_name, expr) == 0)
2301                         continue;
2302 
2303                 if (vp->v_type == VDIR &&
2304                     sdev_cleandir(dv, NULL, flags) != 0) {
2305                         sdcmn_err9(("sdev_cleandir: dir %s busy\n",
2306                             dv->sdev_name));
2307                         busy++;
2308                         continue;
2309                 }
2310 
2311                 if (vp->v_count > 0 && (flags & SDEV_ENFORCE) == 0) {
2312                         sdcmn_err9(("sdev_cleandir: dir %s busy\n",
2313                             dv->sdev_name));
2314                         busy++;
2315                         continue;
2316                 }
2317 
2318                 /*
2319                  * at this point, either dv is not held or SDEV_ENFORCE
2320                  * is specified. In either case, dv needs to be deleted
2321                  */
2322                 SDEV_HOLD(dv);
2323 
2324                 bkstore = SDEV_IS_PERSIST(dv) ? 1 : 0;
2325                 if (bkstore && (vp->v_type == VDIR))
2326                         bkstore += 1;
2327 
2328                 if (bkstore) {
2329                         len = strlen(dv->sdev_name) + 1;
2330                         bks_name = kmem_alloc(len, KM_SLEEP);
2331                         bcopy(dv->sdev_name, bks_name, len);
2332                 }
2333 
2334                 sdev_dirdelete(ddv, dv);
2335 
2336                 /* take care the backing store clean up */
2337                 if (bkstore) {
2338                         ASSERT(bks_name);
2339                         ASSERT(ddv->sdev_attrvp);
2340 
2341                         if (bkstore == 1) {
2342                                 error = VOP_REMOVE(ddv->sdev_attrvp,
2343                                     bks_name, kcred, NULL, 0);
2344                         } else if (bkstore == 2) {
2345                                 error = VOP_RMDIR(ddv->sdev_attrvp,
2346                                     bks_name, ddv->sdev_attrvp, kcred, NULL, 0);
2347                         }
2348 
2349                         /* do not propagate the backing store errors */
2350                         if (error) {
2351                                 sdcmn_err9(("sdev_cleandir: backing store"
2352                                     "not cleaned\n"));
2353                                 error = 0;
2354                         }
2355 
2356                         bkstore = 0;
2357                         kmem_free(bks_name, len);
2358                         bks_name = NULL;
2359                         len = 0;
2360                 }
2361 
2362                 ddv->sdev_flags |= SDEV_BUILD;
2363                 SDEV_RELE(dv);
2364         }
2365 
2366         ddv->sdev_flags |= SDEV_BUILD;
2367         rw_exit(&ddv->sdev_contents);
2368 
2369         if (busy) {
2370                 error = EBUSY;
2371         }
2372 
2373         return (error);
2374 }
2375 
2376 /*
2377  * a convenient wrapper for readdir() funcs
2378  */
2379 size_t
2380 add_dir_entry(dirent64_t *de, char *nm, size_t size, ino_t ino, offset_t off)
2381 {
2382         size_t reclen = DIRENT64_RECLEN(strlen(nm));
2383         if (reclen > size)
2384                 return (0);
2385 
2386         de->d_ino = (ino64_t)ino;
2387         de->d_off = (off64_t)off + 1;
2388         de->d_reclen = (ushort_t)reclen;
2389         (void) strncpy(de->d_name, nm, DIRENT64_NAMELEN(reclen));
2390         return (reclen);
2391 }
2392 
2393 /*
2394  * sdev_mount service routines
2395  */
2396 int
2397 sdev_copyin_mountargs(struct mounta *uap, struct sdev_mountargs *args)
2398 {
2399         int     error;
2400 
2401         if (uap->datalen != sizeof (*args))
2402                 return (EINVAL);
2403 
2404         if (error = copyin(uap->dataptr, args, sizeof (*args))) {
2405                 cmn_err(CE_WARN, "sdev_copyin_mountargs: can not"
2406                     "get user data. error %d\n", error);
2407                 return (EFAULT);
2408         }
2409 
2410         return (0);
2411 }
2412 
2413 #ifdef nextdp
2414 #undef nextdp
2415 #endif
2416 #define nextdp(dp)      ((struct dirent64 *) \
2417                             (intptr_t)((char *)(dp) + (dp)->d_reclen))
2418 
2419 /*
2420  * readdir helper func
2421  */
2422 int
2423 devname_readdir_func(vnode_t *vp, uio_t *uiop, cred_t *cred, int *eofp,
2424     int flags)
2425 {
2426         struct sdev_node *ddv = VTOSDEV(vp);
2427         struct sdev_node *dv;
2428         dirent64_t      *dp;
2429         ulong_t         outcount = 0;
2430         size_t          namelen;
2431         ulong_t         alloc_count;
2432         void            *outbuf;
2433         struct iovec    *iovp;
2434         int             error = 0;
2435         size_t          reclen;
2436         offset_t        diroff;
2437         offset_t        soff;
2438         int             this_reclen;
2439         int (*vtor)(struct sdev_node *) = NULL;
2440         struct vattr attr;
2441         timestruc_t now;
2442 
2443         ASSERT(ddv->sdev_attr || ddv->sdev_attrvp);
2444         ASSERT(RW_READ_HELD(&ddv->sdev_contents));
2445 
2446         if (uiop->uio_loffset >= MAXOFF_T) {
2447                 if (eofp)
2448                         *eofp = 1;
2449                 return (0);
2450         }
2451 
2452         if (uiop->uio_iovcnt != 1)
2453                 return (EINVAL);
2454 
2455         if (vp->v_type != VDIR)
2456                 return (ENOTDIR);
2457 
2458         if (ddv->sdev_flags & SDEV_VTOR) {
2459                 vtor = (int (*)(struct sdev_node *))sdev_get_vtor(ddv);
2460                 ASSERT(vtor);
2461         }
2462 
2463         if (eofp != NULL)
2464                 *eofp = 0;
2465 
2466         soff = uiop->uio_loffset;
2467         iovp = uiop->uio_iov;
2468         alloc_count = iovp->iov_len;
2469         dp = outbuf = kmem_alloc(alloc_count, KM_SLEEP);
2470         outcount = 0;
2471 
2472         if (ddv->sdev_state == SDEV_ZOMBIE)
2473                 goto get_cache;
2474 
2475         if (SDEV_IS_GLOBAL(ddv)) {
2476 
2477                 if ((sdev_boot_state == SDEV_BOOT_STATE_COMPLETE) &&
2478                     !sdev_reconfig_boot && (flags & SDEV_BROWSE) &&
2479                     !SDEV_IS_DYNAMIC(ddv) && !SDEV_IS_NO_NCACHE(ddv) &&
2480                     ((moddebug & MODDEBUG_FINI_EBUSY) == 0) &&
2481                     !DEVNAME_DEVFSADM_HAS_RUN(devfsadm_state) &&
2482                     !DEVNAME_DEVFSADM_IS_RUNNING(devfsadm_state) &&
2483                     !sdev_reconfig_disable) {
2484                         /*
2485                          * invoking "devfsadm" to do system device reconfig
2486                          */
2487                         mutex_enter(&ddv->sdev_lookup_lock);
2488                         SDEV_BLOCK_OTHERS(ddv,
2489                             (SDEV_READDIR|SDEV_LGWAITING));
2490                         mutex_exit(&ddv->sdev_lookup_lock);
2491 
2492                         sdcmn_err8(("readdir of %s by %s: reconfig\n",
2493                             ddv->sdev_path, curproc->p_user.u_comm));
2494                         if (sdev_reconfig_verbose) {
2495                                 cmn_err(CE_CONT,
2496                                     "?readdir of %s by %s: reconfig\n",
2497                                     ddv->sdev_path, curproc->p_user.u_comm);
2498                         }
2499 
2500                         sdev_devfsadmd_thread(ddv, NULL, kcred);
2501                 } else if (DEVNAME_DEVFSADM_IS_RUNNING(devfsadm_state)) {
2502                         /*
2503                          * compensate the "ls" started later than "devfsadm"
2504                          */
2505                         mutex_enter(&ddv->sdev_lookup_lock);
2506                         SDEV_BLOCK_OTHERS(ddv, (SDEV_READDIR|SDEV_LGWAITING));
2507                         mutex_exit(&ddv->sdev_lookup_lock);
2508                 }
2509 
2510                 /*
2511                  * release the contents lock so that
2512                  * the cache may be updated by devfsadmd
2513                  */
2514                 rw_exit(&ddv->sdev_contents);
2515                 mutex_enter(&ddv->sdev_lookup_lock);
2516                 if (SDEV_IS_READDIR(ddv))
2517                         (void) sdev_wait4lookup(ddv, SDEV_READDIR);
2518                 mutex_exit(&ddv->sdev_lookup_lock);
2519                 rw_enter(&ddv->sdev_contents, RW_READER);
2520 
2521                 sdcmn_err4(("readdir of directory %s by %s\n",
2522                     ddv->sdev_name, curproc->p_user.u_comm));
2523                 if (ddv->sdev_flags & SDEV_BUILD) {
2524                         if (SDEV_IS_PERSIST(ddv)) {
2525                                 error = sdev_filldir_from_store(ddv,
2526                                     alloc_count, cred);
2527                         }
2528                         ddv->sdev_flags &= ~SDEV_BUILD;
2529                 }
2530         }
2531 
2532 get_cache:
2533         /* handle "." and ".." */
2534         diroff = 0;
2535         if (soff == 0) {
2536                 /* first time */
2537                 this_reclen = DIRENT64_RECLEN(1);
2538                 if (alloc_count < this_reclen) {
2539                         error = EINVAL;
2540                         goto done;
2541                 }
2542 
2543                 dp->d_ino = (ino64_t)ddv->sdev_ino;
2544                 dp->d_off = (off64_t)1;
2545                 dp->d_reclen = (ushort_t)this_reclen;
2546 
2547                 (void) strncpy(dp->d_name, ".",
2548                     DIRENT64_NAMELEN(this_reclen));
2549                 outcount += dp->d_reclen;
2550                 dp = nextdp(dp);
2551         }
2552 
2553         diroff++;
2554         if (soff <= 1) {
2555                 this_reclen = DIRENT64_RECLEN(2);
2556                 if (alloc_count < outcount + this_reclen) {
2557                         error = EINVAL;
2558                         goto done;
2559                 }
2560 
2561                 dp->d_reclen = (ushort_t)this_reclen;
2562                 dp->d_ino = (ino64_t)ddv->sdev_dotdot->sdev_ino;
2563                 dp->d_off = (off64_t)2;
2564 
2565                 (void) strncpy(dp->d_name, "..",
2566                     DIRENT64_NAMELEN(this_reclen));
2567                 outcount += dp->d_reclen;
2568 
2569                 dp = nextdp(dp);
2570         }
2571 
2572 
2573         /* gets the cache */
2574         diroff++;
2575         for (dv = SDEV_FIRST_ENTRY(ddv); dv;
2576             dv = SDEV_NEXT_ENTRY(ddv, dv), diroff++) {
2577                 sdcmn_err3(("sdev_readdir: diroff %lld soff %lld for '%s' \n",
2578                     diroff, soff, dv->sdev_name));
2579 
2580                 /* bypassing pre-matured nodes */
2581                 if (diroff < soff || (dv->sdev_state != SDEV_READY)) {
2582                         sdcmn_err3(("sdev_readdir: pre-mature node  "
2583                             "%s %d\n", dv->sdev_name, dv->sdev_state));
2584                         continue;
2585                 }
2586 
2587                 /*
2588                  * Check validity of node
2589                  * Drop invalid and nodes to be skipped.
2590                  * A node the validator indicates as stale needs
2591                  * to be returned as presumably the node name itself
2592                  * is valid and the node data itself will be refreshed
2593                  * on lookup.  An application performing a readdir then
2594                  * stat on each entry should thus always see consistent
2595                  * data.  In any case, it is not possible to synchronize
2596                  * with dynamic kernel state, and any view we return can
2597                  * never be anything more than a snapshot at a point in time.
2598                  */
2599                 if (vtor) {
2600                         switch (vtor(dv)) {
2601                         case SDEV_VTOR_VALID:
2602                                 break;
2603                         case SDEV_VTOR_INVALID:
2604                         case SDEV_VTOR_SKIP:
2605                                 continue;
2606                         case SDEV_VTOR_STALE:
2607                                 sdcmn_err3(("sdev_readir: %s stale\n",
2608                                     dv->sdev_name));
2609                                 break;
2610                         default:
2611                                 cmn_err(CE_PANIC,
2612                                     "dev fs: validator failed: %s(%p)\n",
2613                                     dv->sdev_name, (void *)dv);
2614                                 break;
2615                         /*NOTREACHED*/
2616                         }
2617                 }
2618 
2619                 namelen = strlen(dv->sdev_name);
2620                 reclen = DIRENT64_RECLEN(namelen);
2621                 if (outcount + reclen > alloc_count) {
2622                         goto full;
2623                 }
2624                 dp->d_reclen = (ushort_t)reclen;
2625                 dp->d_ino = (ino64_t)dv->sdev_ino;
2626                 dp->d_off = (off64_t)diroff + 1;
2627                 (void) strncpy(dp->d_name, dv->sdev_name,
2628                     DIRENT64_NAMELEN(reclen));
2629                 outcount += reclen;
2630                 dp = nextdp(dp);
2631         }
2632 
2633 full:
2634         sdcmn_err4(("sdev_readdir: moving %lu bytes: "
2635             "diroff %lld, soff %lld, dv %p\n", outcount, diroff, soff,
2636             (void *)dv));
2637 
2638         if (outcount)
2639                 error = uiomove(outbuf, outcount, UIO_READ, uiop);
2640 
2641         if (!error) {
2642                 uiop->uio_loffset = diroff;
2643                 if (eofp)
2644                         *eofp = dv ? 0 : 1;
2645         }
2646 
2647 
2648         if (ddv->sdev_attrvp) {
2649                 gethrestime(&now);
2650                 attr.va_ctime = now;
2651                 attr.va_atime = now;
2652                 attr.va_mask = AT_CTIME|AT_ATIME;
2653 
2654                 (void) VOP_SETATTR(ddv->sdev_attrvp, &attr, 0, kcred, NULL);
2655         }
2656 done:
2657         kmem_free(outbuf, alloc_count);
2658         return (error);
2659 }
2660 
2661 static int
2662 sdev_modctl_lookup(const char *path, vnode_t **r_vp)
2663 {
2664         vnode_t *vp;
2665         vnode_t *cvp;
2666         struct sdev_node *svp;
2667         char *nm;
2668         struct pathname pn;
2669         int error;
2670         int persisted = 0;
2671 
2672         ASSERT(INGLOBALZONE(curproc));
2673 
2674         if (error = pn_get((char *)path, UIO_SYSSPACE, &pn))
2675                 return (error);
2676         nm = kmem_alloc(MAXNAMELEN, KM_SLEEP);
2677 
2678         vp = rootdir;
2679         VN_HOLD(vp);
2680 
2681         while (pn_pathleft(&pn)) {
2682                 ASSERT(vp->v_type == VDIR || vp->v_type == VLNK);
2683                 (void) pn_getcomponent(&pn, nm);
2684 
2685                 /*
2686                  * Deal with the .. special case where we may be
2687                  * traversing up across a mount point, to the
2688                  * root of this filesystem or global root.
2689                  */
2690                 if (nm[0] == '.' && nm[1] == '.' && nm[2] == 0) {
2691 checkforroot:
2692                         if (VN_CMP(vp, rootdir)) {
2693                                 nm[1] = 0;
2694                         } else if (vp->v_flag & VROOT) {
2695                                 vfs_t *vfsp;
2696                                 cvp = vp;
2697                                 vfsp = cvp->v_vfsp;
2698                                 vfs_rlock_wait(vfsp);
2699                                 vp = cvp->v_vfsp->vfs_vnodecovered;
2700                                 if (vp == NULL ||
2701                                     (cvp->v_vfsp->vfs_flag & VFS_UNMOUNTED)) {
2702                                         vfs_unlock(vfsp);
2703                                         VN_RELE(cvp);
2704                                         error = EIO;
2705                                         break;
2706                                 }
2707                                 VN_HOLD(vp);
2708                                 vfs_unlock(vfsp);
2709                                 VN_RELE(cvp);
2710                                 cvp = NULL;
2711                                 goto checkforroot;
2712                         }
2713                 }
2714 
2715                 error = VOP_LOOKUP(vp, nm, &cvp, NULL, 0, NULL, kcred, NULL,
2716                     NULL, NULL);
2717                 if (error) {
2718                         VN_RELE(vp);
2719                         break;
2720                 }
2721 
2722                 /* traverse mount points encountered on our journey */
2723                 if (vn_ismntpt(cvp) && (error = traverse(&cvp)) != 0) {
2724                         VN_RELE(vp);
2725                         VN_RELE(cvp);
2726                         break;
2727                 }
2728 
2729                 /*
2730                  * symbolic link, can be either relative and absolute
2731                  */
2732                 if ((cvp->v_type == VLNK) && pn_pathleft(&pn)) {
2733                         struct pathname linkpath;
2734                         pn_alloc(&linkpath);
2735                         if (error = pn_getsymlink(cvp, &linkpath, kcred)) {
2736                                 pn_free(&linkpath);
2737                                 break;
2738                         }
2739                         if (pn_pathleft(&linkpath) == 0)
2740                                 (void) pn_set(&linkpath, ".");
2741                         error = pn_insert(&pn, &linkpath, strlen(nm));
2742                         pn_free(&linkpath);
2743                         if (pn.pn_pathlen == 0) {
2744                                 VN_RELE(vp);
2745                                 return (ENOENT);
2746                         }
2747                         if (pn.pn_path[0] == '/') {
2748                                 pn_skipslash(&pn);
2749                                 VN_RELE(vp);
2750                                 VN_RELE(cvp);
2751                                 vp = rootdir;
2752                                 VN_HOLD(vp);
2753                         } else {
2754                                 VN_RELE(cvp);
2755                         }
2756                         continue;
2757                 }
2758 
2759                 VN_RELE(vp);
2760 
2761                 /*
2762                  * Direct the operation to the persisting filesystem
2763                  * underlying /dev.  Bail if we encounter a
2764                  * non-persistent dev entity here.
2765                  */
2766                 if (cvp->v_vfsp->vfs_fstype == devtype) {
2767 
2768                         if ((VTOSDEV(cvp)->sdev_flags & SDEV_PERSIST) == 0) {
2769                                 error = ENOENT;
2770                                 VN_RELE(cvp);
2771                                 break;
2772                         }
2773 
2774                         if (VTOSDEV(cvp) == NULL) {
2775                                 error = ENOENT;
2776                                 VN_RELE(cvp);
2777                                 break;
2778                         }
2779                         svp = VTOSDEV(cvp);
2780                         if ((vp = svp->sdev_attrvp) == NULL) {
2781                                 error = ENOENT;
2782                                 VN_RELE(cvp);
2783                                 break;
2784                         }
2785                         persisted = 1;
2786                         VN_HOLD(vp);
2787                         VN_RELE(cvp);
2788                         cvp = vp;
2789                 }
2790 
2791                 vp = cvp;
2792                 pn_skipslash(&pn);
2793         }
2794 
2795         kmem_free(nm, MAXNAMELEN);
2796         pn_free(&pn);
2797 
2798         if (error)
2799                 return (error);
2800 
2801         /*
2802          * Only return persisted nodes in the filesystem underlying /dev.
2803          */
2804         if (!persisted) {
2805                 VN_RELE(vp);
2806                 return (ENOENT);
2807         }
2808 
2809         *r_vp = vp;
2810         return (0);
2811 }
2812 
2813 int
2814 sdev_modctl_readdir(const char *dir, char ***dirlistp,
2815         int *npathsp, int *npathsp_alloc, int checking_empty)
2816 {
2817         char    **pathlist = NULL;
2818         char    **newlist = NULL;
2819         int     npaths = 0;
2820         int     npaths_alloc = 0;
2821         dirent64_t *dbuf = NULL;
2822         int     n;
2823         char    *s;
2824         int error;
2825         vnode_t *vp;
2826         int eof;
2827         struct iovec iov;
2828         struct uio uio;
2829         struct dirent64 *dp;
2830         size_t dlen;
2831         size_t dbuflen;
2832         int ndirents = 64;
2833         char *nm;
2834 
2835         error = sdev_modctl_lookup(dir, &vp);
2836         sdcmn_err11(("modctl readdir: %s by %s: %s\n",
2837             dir, curproc->p_user.u_comm,
2838             (error == 0) ? "ok" : "failed"));
2839         if (error)
2840                 return (error);
2841 
2842         dlen = ndirents * (sizeof (*dbuf));
2843         dbuf = kmem_alloc(dlen, KM_SLEEP);
2844 
2845         uio.uio_iov = &iov;
2846         uio.uio_iovcnt = 1;
2847         uio.uio_segflg = UIO_SYSSPACE;
2848         uio.uio_fmode = 0;
2849         uio.uio_extflg = UIO_COPY_CACHED;
2850         uio.uio_loffset = 0;
2851         uio.uio_llimit = MAXOFFSET_T;
2852 
2853         eof = 0;
2854         error = 0;
2855         while (!error && !eof) {
2856                 uio.uio_resid = dlen;
2857                 iov.iov_base = (char *)dbuf;
2858                 iov.iov_len = dlen;
2859 
2860                 (void) VOP_RWLOCK(vp, V_WRITELOCK_FALSE, NULL);
2861                 error = VOP_READDIR(vp, &uio, kcred, &eof, NULL, 0);
2862                 VOP_RWUNLOCK(vp, V_WRITELOCK_FALSE, NULL);
2863 
2864                 dbuflen = dlen - uio.uio_resid;
2865 
2866                 if (error || dbuflen == 0)
2867                         break;
2868 
2869                 for (dp = dbuf; ((intptr_t)dp < (intptr_t)dbuf + dbuflen);
2870                     dp = (dirent64_t *)((intptr_t)dp + dp->d_reclen)) {
2871 
2872                         nm = dp->d_name;
2873 
2874                         if (strcmp(nm, ".") == 0 || strcmp(nm, "..") == 0)
2875                                 continue;
2876                         if (npaths == npaths_alloc) {
2877                                 npaths_alloc += 64;
2878                                 newlist = (char **)
2879                                     kmem_zalloc((npaths_alloc + 1) *
2880                                     sizeof (char *), KM_SLEEP);
2881                                 if (pathlist) {
2882                                         bcopy(pathlist, newlist,
2883                                             npaths * sizeof (char *));
2884                                         kmem_free(pathlist,
2885                                             (npaths + 1) * sizeof (char *));
2886                                 }
2887                                 pathlist = newlist;
2888                         }
2889                         n = strlen(nm) + 1;
2890                         s = kmem_alloc(n, KM_SLEEP);
2891                         bcopy(nm, s, n);
2892                         pathlist[npaths++] = s;
2893                         sdcmn_err11(("  %s/%s\n", dir, s));
2894 
2895                         /* if checking empty, one entry is as good as many */
2896                         if (checking_empty) {
2897                                 eof = 1;
2898                                 break;
2899                         }
2900                 }
2901         }
2902 
2903 exit:
2904         VN_RELE(vp);
2905 
2906         if (dbuf)
2907                 kmem_free(dbuf, dlen);
2908 
2909         if (error)
2910                 return (error);
2911 
2912         *dirlistp = pathlist;
2913         *npathsp = npaths;
2914         *npathsp_alloc = npaths_alloc;
2915 
2916         return (0);
2917 }
2918 
2919 void
2920 sdev_modctl_readdir_free(char **pathlist, int npaths, int npaths_alloc)
2921 {
2922         int     i, n;
2923 
2924         for (i = 0; i < npaths; i++) {
2925                 n = strlen(pathlist[i]) + 1;
2926                 kmem_free(pathlist[i], n);
2927         }
2928 
2929         kmem_free(pathlist, (npaths_alloc + 1) * sizeof (char *));
2930 }
2931 
2932 int
2933 sdev_modctl_devexists(const char *path)
2934 {
2935         vnode_t *vp;
2936         int error;
2937 
2938         error = sdev_modctl_lookup(path, &vp);
2939         sdcmn_err11(("modctl dev exists: %s by %s: %s\n",
2940             path, curproc->p_user.u_comm,
2941             (error == 0) ? "ok" : "failed"));
2942         if (error == 0)
2943                 VN_RELE(vp);
2944 
2945         return (error);
2946 }
2947 
2948 extern int sdev_vnodeops_tbl_size;
2949 
2950 /*
2951  * construct a new template with overrides from vtab
2952  */
2953 static fs_operation_def_t *
2954 sdev_merge_vtab(const fs_operation_def_t tab[])
2955 {
2956         fs_operation_def_t *new;
2957         const fs_operation_def_t *tab_entry;
2958 
2959         /* make a copy of standard vnode ops table */
2960         new = kmem_alloc(sdev_vnodeops_tbl_size, KM_SLEEP);
2961         bcopy((void *)sdev_vnodeops_tbl, new, sdev_vnodeops_tbl_size);
2962 
2963         /* replace the overrides from tab */
2964         for (tab_entry = tab; tab_entry->name != NULL; tab_entry++) {
2965                 fs_operation_def_t *std_entry = new;
2966                 while (std_entry->name) {
2967                         if (strcmp(tab_entry->name, std_entry->name) == 0) {
2968                                 std_entry->func = tab_entry->func;
2969                                 break;
2970                         }
2971                         std_entry++;
2972                 }
2973                 if (std_entry->name == NULL)
2974                         cmn_err(CE_NOTE, "sdev_merge_vtab: entry %s unused.",
2975                             tab_entry->name);
2976         }
2977 
2978         return (new);
2979 }
2980 
2981 /* free memory allocated by sdev_merge_vtab */
2982 static void
2983 sdev_free_vtab(fs_operation_def_t *new)
2984 {
2985         kmem_free(new, sdev_vnodeops_tbl_size);
2986 }
2987 
2988 /*
2989  * a generic setattr() function
2990  *
2991  * note: flags only supports AT_UID and AT_GID.
2992  *       Future enhancements can be done for other types, e.g. AT_MODE
2993  */
2994 int
2995 devname_setattr_func(struct vnode *vp, struct vattr *vap, int flags,
2996     struct cred *cred, int (*callback)(struct sdev_node *, struct vattr *,
2997     int), int protocol)
2998 {
2999         struct sdev_node        *dv = VTOSDEV(vp);
3000         struct sdev_node        *parent = dv->sdev_dotdot;
3001         struct vattr            *get;
3002         uint_t                  mask = vap->va_mask;
3003         int                     error;
3004 
3005         /* some sanity checks */
3006         if (vap->va_mask & AT_NOSET)
3007                 return (EINVAL);
3008 
3009         if (vap->va_mask & AT_SIZE) {
3010                 if (vp->v_type == VDIR) {
3011                         return (EISDIR);
3012                 }
3013         }
3014 
3015         /* no need to set attribute, but do not fail either */
3016         ASSERT(parent);
3017         rw_enter(&parent->sdev_contents, RW_READER);
3018         if (dv->sdev_state == SDEV_ZOMBIE) {
3019                 rw_exit(&parent->sdev_contents);
3020                 return (0);
3021         }
3022 
3023         /* If backing store exists, just set it. */
3024         if (dv->sdev_attrvp) {
3025                 rw_exit(&parent->sdev_contents);
3026                 return (VOP_SETATTR(dv->sdev_attrvp, vap, flags, cred, NULL));
3027         }
3028 
3029         /*
3030          * Otherwise, for nodes with the persistence attribute, create it.
3031          */
3032         ASSERT(dv->sdev_attr);
3033         if (SDEV_IS_PERSIST(dv) ||
3034             ((vap->va_mask & ~AT_TIMES) != 0 && !SDEV_IS_DYNAMIC(dv))) {
3035                 sdev_vattr_merge(dv, vap);
3036                 rw_enter(&dv->sdev_contents, RW_WRITER);
3037                 error = sdev_shadow_node(dv, cred);
3038                 rw_exit(&dv->sdev_contents);
3039                 rw_exit(&parent->sdev_contents);
3040 
3041                 if (error)
3042                         return (error);
3043                 return (VOP_SETATTR(dv->sdev_attrvp, vap, flags, cred, NULL));
3044         }
3045 
3046 
3047         /*
3048          * sdev_attr was allocated in sdev_mknode
3049          */
3050         rw_enter(&dv->sdev_contents, RW_WRITER);
3051         error = secpolicy_vnode_setattr(cred, vp, vap,
3052             dv->sdev_attr, flags, sdev_unlocked_access, dv);
3053         if (error) {
3054                 rw_exit(&dv->sdev_contents);
3055                 rw_exit(&parent->sdev_contents);
3056                 return (error);
3057         }
3058 
3059         get = dv->sdev_attr;
3060         if (mask & AT_MODE) {
3061                 get->va_mode &= S_IFMT;
3062                 get->va_mode |= vap->va_mode & ~S_IFMT;
3063         }
3064 
3065         if ((mask & AT_UID) || (mask & AT_GID)) {
3066                 if (mask & AT_UID)
3067                         get->va_uid = vap->va_uid;
3068                 if (mask & AT_GID)
3069                         get->va_gid = vap->va_gid;
3070                 /*
3071                  * a callback must be provided if the protocol is set
3072                  */
3073                 if ((protocol & AT_UID) || (protocol & AT_GID)) {
3074                         ASSERT(callback);
3075                         error = callback(dv, get, protocol);
3076                         if (error) {
3077                                 rw_exit(&dv->sdev_contents);
3078                                 rw_exit(&parent->sdev_contents);
3079                                 return (error);
3080                         }
3081                 }
3082         }
3083 
3084         if (mask & AT_ATIME)
3085                 get->va_atime = vap->va_atime;
3086         if (mask & AT_MTIME)
3087                 get->va_mtime = vap->va_mtime;
3088         if (mask & (AT_MODE | AT_UID | AT_GID | AT_CTIME)) {
3089                 gethrestime(&get->va_ctime);
3090         }
3091 
3092         sdev_vattr_merge(dv, get);
3093         rw_exit(&dv->sdev_contents);
3094         rw_exit(&parent->sdev_contents);
3095         return (0);
3096 }
3097 
3098 /*
3099  * a generic inactive() function
3100  */
3101 /*ARGSUSED*/
3102 void
3103 devname_inactive_func(struct vnode *vp, struct cred *cred,
3104     void (*callback)(struct vnode *))
3105 {
3106         int clean;
3107         struct sdev_node *dv = VTOSDEV(vp);
3108         int state;
3109 
3110         mutex_enter(&vp->v_lock);
3111         ASSERT(vp->v_count >= 1);
3112 
3113 
3114         if (vp->v_count == 1 && callback != NULL)
3115                 callback(vp);
3116 
3117         rw_enter(&dv->sdev_contents, RW_WRITER);
3118         state = dv->sdev_state;
3119 
3120         clean = (vp->v_count == 1) && (state == SDEV_ZOMBIE);
3121 
3122         /*
3123          * sdev is a rather bad public citizen. It violates the general
3124          * agreement that in memory nodes should always have a valid reference
3125          * count on their vnode. But that's not the case here. This means that
3126          * we do actually have to distinguish between getting inactive callbacks
3127          * for zombies and otherwise. This should probably be fixed.
3128          */
3129         if (clean) {
3130                 /* Remove the . entry to ourselves */
3131                 if (vp->v_type == VDIR) {
3132                         decr_link(dv);
3133                 }
3134                 VERIFY(dv->sdev_nlink == 1);
3135                 decr_link(dv);
3136                 --vp->v_count;
3137                 rw_exit(&dv->sdev_contents);
3138                 mutex_exit(&vp->v_lock);
3139                 sdev_nodedestroy(dv, 0);
3140         } else {
3141                 --vp->v_count;
3142                 rw_exit(&dv->sdev_contents);
3143                 mutex_exit(&vp->v_lock);
3144         }
3145 }