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 2010 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25 
  26 /*
  27  * Copyright (c) 2013, Joyent, Inc. All rights reserved.
  28  */
  29 
  30 /*
  31  * File Events Notification
  32  * ------------------------
  33  *
  34  * The File Events Notification facility provides file and directory change
  35  * notification. It is implemented as an event source(PORT_SOURCE_FILE)
  36  * under the Event Ports framework. Therefore the API is an extension to
  37  * the Event Ports API.
  38  *
  39  * It uses the FEM (File Events Monitoring) framework to intercept
  40  * operations on the files & directories and generate appropriate events.
  41  *
  42  * It provides event notification in accordance with what an application
  43  * can find out by stat`ing the file and comparing time stamps. The various
  44  * system calls that update the file's access, modification, and change
  45  * time stamps are documented in the man page section 2.
  46  *
  47  * It is non intrusive. That is, having an active file event watch on a file
  48  * or directory will not prevent it from being removed or renamed or block an
  49  * unmount operation of the file system where the watched file or directory
  50  * resides.
  51  *
  52  *
  53  * Interface:
  54  * ----------
  55  *
  56  *   The object for this event source is of type 'struct file_obj *'
  57  *
  58  *   The file that needs to be monitored is specified in 'fo_name'.
  59  *   The time stamps collected by a stat(2) call are passed in fo_atime,
  60  *   fo_mtime, fo_ctime. At the time a file events watch is registered, the
  61  *   time stamps passed in are compared with the current time stamps of the
  62  *   file. If it has changed, relevant events are sent immediately. If the time
  63  *   stamps are all '0', they will not be compared.
  64  *
  65  *
  66  * The events are delivered to an event port. A port is created using
  67  * port_create().
  68  *
  69  * To register a file events watch on a file or directory.
  70  *
  71  *   port_associate(int port, PORT_SOURCE_FILE, (uintptr_t)&fobj, events, user)
  72  *
  73  *   'user' is the user pointer to be returned with the event.
  74  *
  75  * To de-register a file events watch,
  76  *
  77  *   port_dissociate(int port, PORT_SOURCE_FILE, (uintptr_t)&fobj)
  78  *
  79  * The events are collected using the port_get()/port_getn() interface. The
  80  * event source will be PORT_SOURCE_FILE.
  81  *
  82  * After an event is delivered, the file events watch gets de-activated. To
  83  * receive the next event, the process will have to re-register the watch and
  84  * activate it by calling port_associate() again. This behavior is intentional
  85  * and supports proper multi threaded programming when using file events
  86  * notification API.
  87  *
  88  *
  89  * Implementation overview:
  90  * ------------------------
  91  *
  92  * Each file events watch is represented by 'portfop_t' in the kernel. A
  93  * cache(in portfop_cache_t) of these portfop_t's are maintained per event
  94  * port by this source. The object here is the pointer to the file_obj
  95  * structure. The portfop_t's are hashed in using the object pointer. Therefore
  96  * it is possible to have multiple file events watches on a file by the same
  97  * process by using different object structure(file_obj_t) and hence can
  98  * receive multiple event notification for a file. These watches can be for
  99  * different event types.
 100  *
 101  * The cached entries of these file objects are retained, even after delivering
 102  * an event, marking them inactive for performance reasons. The assumption
 103  * is that the process would come back and re-register the file to receive
 104  * further events. When there are more then 'port_fop_maxpfps' watches per file
 105  * it will attempt to free the oldest inactive watches.
 106  *
 107  * In case the event that is being delivered is an exception event, the cached
 108  * entries get removed. An exception event on a file or directory means its
 109  * identity got changed(rename to/from, delete, mounted over, file system
 110  * unmount).
 111  *
 112  * If the event port gets closed, all the associated file event watches will be
 113  * removed and discarded.
 114  *
 115  *
 116  * Data structures:
 117  * ----------------
 118  *
 119  * The list of file event watches per file are managed by the data structure
 120  * portfop_vp_t. The first time a file events watch is registered for a file,
 121  * a portfop_vp_t is installed on the vnode_t's member v_fopdata. This gets
 122  * removed and freed only when the vnode becomes inactive. The FEM hooks are
 123  * also installed when the first watch is registered on a file. The FEM hooks
 124  * get un-installed when all the watches are removed.
 125  *
 126  * Each file events watch is represented by the structure portfop_t. They
 127  * get added to a list of portfop_t's on the vnode(portfop_vp_t). After
 128  * delivering an event, the portfop_t is marked inactive but retained. It is
 129  * moved to the end of the list. All the active portfop_t's are maintained at
 130  * the beginning. In case of exception events, the portfop_t will be removed
 131  * and discarded.
 132  *
 133  * To intercept unmount operations, FSEM hooks are added to the file system
 134  * under which files are being watched. A hash table('portfop_vfs_hash_t') of
 135  * active file systems is maintained. Each file system that has active watches
 136  * is represented by 'portfop_vfs_t' and is added to the hash table.
 137  * The vnode's 'portfop_vp_t' structure is added to the list of files(vnodes)
 138  * being watched on the portfop_vfs_t structure.
 139  *
 140  *
 141  * File system support:
 142  * -------------------
 143  *
 144  * The file system implementation has to provide vnode event notifications
 145  * (vnevents) in order to support watching any files on that file system.
 146  * The vnode events(vnevents) are notifications provided by the file system
 147  * for name based file operations like rename, remove etc, which do not go
 148  * thru the VOP_** interfaces. If the file system does not implement vnode
 149  * notifications, watching for file events on such file systems is not
 150  * supported. The vnode event notifications support is determined by the call
 151  * vnevent_support(vp) (VOP_VNEVENT(vp, VE_SUPPORT)), which the file system
 152  * has to implement.
 153  *
 154  *
 155  * Locking order:
 156  * --------------
 157  *
 158  * A file(vnode) can have file event watches registered by different processes.
 159  * There is one portfop_t per watch registered. These are on the vnode's list
 160  * protected by the mutex 'pvp_mutex' in 'portfop_vp_t'. The portfop_t's are
 161  * also on the per port cache. The cache is protected by the pfc_lock of
 162  * portfop_cache_t. The lock order here is 'pfc_lock' -> 'pvp_mutex'.
 163  *
 164  */
 165 
 166 #include <sys/types.h>
 167 #include <sys/systm.h>
 168 #include <sys/stat.h>
 169 #include <sys/errno.h>
 170 #include <sys/kmem.h>
 171 #include <sys/sysmacros.h>
 172 #include <sys/debug.h>
 173 #include <sys/vnode.h>
 174 #include <sys/poll_impl.h>
 175 #include <sys/port_impl.h>
 176 #include <sys/fem.h>
 177 #include <sys/vfs_opreg.h>
 178 #include <sys/atomic.h>
 179 #include <sys/mount.h>
 180 #include <sys/mntent.h>
 181 
 182 /*
 183  * For special case support of mnttab (/etc/mnttab).
 184  */
 185 extern struct vnode *vfs_mntdummyvp;
 186 extern int mntfstype;
 187 
 188 #define PORTFOP_PVFSH(vfsp)     (&portvfs_hash[PORTFOP_PVFSHASH(vfsp)])
 189 portfop_vfs_hash_t       portvfs_hash[PORTFOP_PVFSHASH_SZ];
 190 
 191 #define PORTFOP_NVP     20
 192 /*
 193  * Inactive file event watches(portfop_t) are retained on the vnode's list
 194  * for performance reason. If the applications re-registers the file, the
 195  * inactive entry is made active and moved up the list.
 196  *
 197  * If there are greater then the following number of watches on a vnode,
 198  * it will attempt to discard an oldest inactive watch(pfp) at the time
 199  * a new watch is being registered and when events get delivered. We
 200  * do this to avoid accumulating inactive watches on a file.
 201  */
 202 int     port_fop_maxpfps = 20;
 203 
 204 /* local functions */
 205 static int      port_fop_callback(void *, int *, pid_t, int, void *);
 206 
 207 static void     port_pcache_insert(portfop_cache_t *, portfop_t *);
 208 static void     port_pcache_delete(portfop_cache_t *, portfop_t *);
 209 static void     port_close_fop(void *arg, int port, pid_t pid, int lastclose);
 210 
 211 /*
 212  * port fop functions that will be the fem hooks.
 213  */
 214 static int port_fop_open(femarg_t *vf, int mode, cred_t *cr,
 215     caller_context_t *);
 216 static int port_fop_read(femarg_t *vf, uio_t *uiop, int ioflag, cred_t *cr,
 217     struct caller_context *ct);
 218 static int port_fop_write(femarg_t *vf, uio_t *uiop, int ioflag, cred_t *cr,
 219     caller_context_t *ct);
 220 static int port_fop_map(femarg_t *vf, offset_t off, struct as *as,
 221     caddr_t *addrp, size_t len, uchar_t prot, uchar_t maxport,
 222     uint_t flags, cred_t *cr, caller_context_t *ct);
 223 static int port_fop_setattr(femarg_t *vf, vattr_t *vap, int flags, cred_t *cr,
 224     caller_context_t *ct);
 225 static int port_fop_create(femarg_t *vf, char *name, vattr_t *vap,
 226     vcexcl_t excl, int mode, vnode_t **vpp, cred_t *cr, int flag,
 227     caller_context_t *ct, vsecattr_t *vsecp);
 228 static int port_fop_remove(femarg_t *vf, char *nm, cred_t *cr,
 229     caller_context_t *ct, int flags);
 230 static int port_fop_link(femarg_t *vf, vnode_t *svp, char *tnm, cred_t *cr,
 231     caller_context_t *ct, int flags);
 232 static int port_fop_rename(femarg_t *vf, char *snm, vnode_t *tdvp, char *tnm,
 233     cred_t *cr, caller_context_t *ct, int flags);
 234 static int port_fop_mkdir(femarg_t *vf, char *dirname, vattr_t *vap,
 235     vnode_t **vpp, cred_t *cr, caller_context_t *ct, int flags,
 236     vsecattr_t *vsecp);
 237 static int port_fop_rmdir(femarg_t *vf, char *nm, vnode_t *cdir, cred_t *cr,
 238     caller_context_t *ct, int flags);
 239 static int port_fop_readdir(femarg_t *vf, uio_t *uiop, cred_t *cr, int *eofp,
 240     caller_context_t *ct, int flags);
 241 static int port_fop_symlink(femarg_t *vf, char *linkname, vattr_t *vap,
 242     char *target, cred_t *cr, caller_context_t *ct, int flags);
 243 static int port_fop_setsecattr(femarg_t *vf, vsecattr_t *vsap, int flag,
 244     cred_t *cr, caller_context_t *ct);
 245 
 246 static int port_fop_vnevent(femarg_t *vf, vnevent_t vnevent, vnode_t *dvp,
 247     char *cname, caller_context_t *ct);
 248 
 249 static int port_fop_unmount(fsemarg_t *vf, int flag, cred_t *cr);
 250 
 251 
 252 /*
 253  * Fem hooks.
 254  */
 255 const fs_operation_def_t        port_vnodesrc_template[] = {
 256         VOPNAME_OPEN,           { .femop_open = port_fop_open },
 257         VOPNAME_READ,           { .femop_read = port_fop_read },
 258         VOPNAME_WRITE,          { .femop_write = port_fop_write },
 259         VOPNAME_MAP,            { .femop_map = port_fop_map },
 260         VOPNAME_SETATTR,        { .femop_setattr = port_fop_setattr },
 261         VOPNAME_CREATE,         { .femop_create = port_fop_create },
 262         VOPNAME_REMOVE,         { .femop_remove = port_fop_remove },
 263         VOPNAME_LINK,           { .femop_link = port_fop_link },
 264         VOPNAME_RENAME,         { .femop_rename = port_fop_rename },
 265         VOPNAME_MKDIR,          { .femop_mkdir = port_fop_mkdir },
 266         VOPNAME_RMDIR,          { .femop_rmdir = port_fop_rmdir },
 267         VOPNAME_READDIR,        { .femop_readdir = port_fop_readdir },
 268         VOPNAME_SYMLINK,        { .femop_symlink = port_fop_symlink },
 269         VOPNAME_SETSECATTR,     { .femop_setsecattr = port_fop_setsecattr },
 270         VOPNAME_VNEVENT,        { .femop_vnevent = port_fop_vnevent },
 271         NULL,   NULL
 272 };
 273 
 274 /*
 275  * Fsem - vfs ops hooks
 276  */
 277 const fs_operation_def_t        port_vfssrc_template[] = {
 278         VFSNAME_UNMOUNT,        { .fsemop_unmount = port_fop_unmount },
 279         NULL,   NULL
 280 };
 281 
 282 fem_t *fop_femop;
 283 fsem_t *fop_fsemop;
 284 
 285 static fem_t *
 286 port_fop_femop()
 287 {
 288         fem_t *femp;
 289         if (fop_femop != NULL)
 290                 return (fop_femop);
 291         if (fem_create("portfop_fem",
 292             (const struct fs_operation_def *)port_vnodesrc_template,
 293             (fem_t **)&femp)) {
 294                 return (NULL);
 295         }
 296         if (casptr(&fop_femop, NULL, femp) != NULL) {
 297                 /*
 298                  * some other thread beat us to it.
 299                  */
 300                 fem_free(femp);
 301         }
 302         return (fop_femop);
 303 }
 304 
 305 static fsem_t *
 306 port_fop_fsemop()
 307 {
 308         fsem_t *fsemp;
 309         if (fop_fsemop != NULL)
 310                 return (fop_fsemop);
 311         if (fsem_create("portfop_fsem", port_vfssrc_template, &fsemp)) {
 312                 return (NULL);
 313         }
 314         if (casptr(&fop_fsemop, NULL, fsemp) != NULL) {
 315                 /*
 316                  * some other thread beat us to it.
 317                  */
 318                 fsem_free(fsemp);
 319         }
 320         return (fop_fsemop);
 321 }
 322 
 323 /*
 324  * port_fop_callback()
 325  * - PORT_CALLBACK_DEFAULT
 326  *      The file event will be delivered to the application.
 327  * - PORT_CALLBACK_DISSOCIATE
 328  *      The object will be dissociated from  the port.
 329  * - PORT_CALLBACK_CLOSE
 330  *      The object will be dissociated from the port because the port
 331  *      is being closed.
 332  */
 333 /* ARGSUSED */
 334 static int
 335 port_fop_callback(void *arg, int *events, pid_t pid, int flag, void *evp)
 336 {
 337         portfop_t       *pfp = (portfop_t *)arg;
 338         port_kevent_t   *pkevp = (port_kevent_t *)evp;
 339         int             error = 0;
 340 
 341         ASSERT((events != NULL));
 342         if (flag == PORT_CALLBACK_DEFAULT) {
 343                 if (curproc->p_pid != pid) {
 344                                 return (EACCES); /* deny delivery of events */
 345                 }
 346 
 347                 *events = pkevp->portkev_events;
 348                 pkevp->portkev_events = 0;
 349                 if (pfp != NULL) {
 350                         pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
 351                 }
 352         }
 353         return (error);
 354 }
 355 
 356 /*
 357  * Inserts a portfop_t into the port sources cache's.
 358  */
 359 static void
 360 port_pcache_insert(portfop_cache_t *pfcp, portfop_t *pfp)
 361 {
 362         portfop_t       **bucket;
 363 
 364         ASSERT(MUTEX_HELD(&pfcp->pfc_lock));
 365         bucket = PORT_FOP_BUCKET(pfcp, pfp->pfop_object);
 366         pfp->pfop_hashnext = *bucket;
 367         *bucket = pfp;
 368         pfcp->pfc_objcount++;
 369 }
 370 
 371 /*
 372  * Remove the pfp from the port source cache.
 373  */
 374 static void
 375 port_pcache_delete(portfop_cache_t *pfcp, portfop_t *pfp)
 376 {
 377         portfop_t       *lpdp;
 378         portfop_t       *cpdp;
 379         portfop_t       **bucket;
 380 
 381         bucket = PORT_FOP_BUCKET(pfcp, pfp->pfop_object);
 382         cpdp = *bucket;
 383         if (pfp == cpdp) {
 384                 *bucket = pfp->pfop_hashnext;
 385         } else {
 386                 while (cpdp != NULL) {
 387                         lpdp = cpdp;
 388                         cpdp = cpdp->pfop_hashnext;
 389                         if (cpdp == pfp) {
 390                                 /* portfop struct found */
 391                                 lpdp->pfop_hashnext = pfp->pfop_hashnext;
 392                                 break;
 393                         }
 394                 }
 395         }
 396         pfcp->pfc_objcount--;
 397 }
 398 
 399 /*
 400  * The vnode's(portfop_vp_t) pfp list management. The 'pvp_mutex' is held
 401  * when these routines are called.
 402  *
 403  * The 'pvp_lpfop' member points to the oldest inactive entry on the list.
 404  * It is used to discard the oldtest inactive pfp if the number of entries
 405  * exceed the limit.
 406  */
 407 static void
 408 port_fop_listinsert(portfop_vp_t *pvp, portfop_t *pfp, int where)
 409 {
 410         if (where == 1) {
 411                 list_insert_head(&pvp->pvp_pfoplist, (void *)pfp);
 412         } else {
 413                 list_insert_tail(&pvp->pvp_pfoplist, (void *)pfp);
 414         }
 415         if (pvp->pvp_lpfop == NULL) {
 416                 pvp->pvp_lpfop = pfp;
 417         }
 418         pvp->pvp_cnt++;
 419 }
 420 
 421 static void
 422 port_fop_listinsert_head(portfop_vp_t *pvp, portfop_t *pfp)
 423 {
 424         port_fop_listinsert(pvp, pfp, 1);
 425 }
 426 
 427 static void
 428 port_fop_listinsert_tail(portfop_vp_t *pvp, portfop_t *pfp)
 429 {
 430         /*
 431          * We point lpfop to an inactive one, if it was initially pointing
 432          * to an active one. Insert to the tail is done only when a pfp goes
 433          * inactive.
 434          */
 435         if (pvp->pvp_lpfop && pvp->pvp_lpfop->pfop_flags & PORT_FOP_ACTIVE) {
 436                 pvp->pvp_lpfop = pfp;
 437         }
 438         port_fop_listinsert(pvp, pfp, 0);
 439 }
 440 
 441 static void
 442 port_fop_listremove(portfop_vp_t *pvp, portfop_t *pfp)
 443 {
 444         if (pvp->pvp_lpfop == pfp) {
 445                 pvp->pvp_lpfop = list_next(&pvp->pvp_pfoplist, (void *)pfp);
 446         }
 447 
 448         list_remove(&pvp->pvp_pfoplist, (void *)pfp);
 449 
 450         pvp->pvp_cnt--;
 451         if (pvp->pvp_cnt && pvp->pvp_lpfop == NULL) {
 452                 pvp->pvp_lpfop = list_head(&pvp->pvp_pfoplist);
 453         }
 454 }
 455 
 456 static void
 457 port_fop_listmove(portfop_vp_t *pvp, list_t *tlist)
 458 {
 459         list_move_tail(tlist, &pvp->pvp_pfoplist);
 460         pvp->pvp_lpfop = NULL;
 461         pvp->pvp_cnt = 0;
 462 }
 463 
 464 /*
 465  * Remove a portfop_t from the port cache hash table and discard it.
 466  * It is called only when pfp is not on the vnode's list. Otherwise,
 467  * port_remove_fop() is called.
 468  */
 469 void
 470 port_pcache_remove_fop(portfop_cache_t *pfcp, portfop_t *pfp)
 471 {
 472         port_kevent_t   *pkevp;
 473 
 474 
 475         ASSERT(MUTEX_HELD(&pfcp->pfc_lock));
 476 
 477         pkevp = pfp->pfop_pev;
 478         pfp->pfop_pev = NULL;
 479 
 480         if (pkevp != NULL) {
 481                 (void) port_remove_done_event(pkevp);
 482                 port_free_event_local(pkevp, 0);
 483         }
 484 
 485         port_pcache_delete(pfcp, pfp);
 486 
 487         if (pfp->pfop_cname != NULL)
 488                 kmem_free(pfp->pfop_cname, pfp->pfop_clen + 1);
 489         kmem_free(pfp, sizeof (portfop_t));
 490         if (pfcp->pfc_objcount == 0)
 491                 cv_signal(&pfcp->pfc_lclosecv);
 492 }
 493 
 494 /*
 495  * if we have too many watches on the vnode, attempt to discard an
 496  * inactive one.
 497  */
 498 static void
 499 port_fop_trimpfplist(vnode_t *vp)
 500 {
 501         portfop_vp_t *pvp;
 502         portfop_t *pfp = NULL;
 503         portfop_cache_t *pfcp;
 504         vnode_t *tdvp;
 505 
 506         /*
 507          * Due to a reference the vnode cannot disappear, v_fopdata should
 508          * not change.
 509          */
 510         if ((pvp = vp->v_fopdata) != NULL &&
 511             pvp->pvp_cnt > port_fop_maxpfps) {
 512                 mutex_enter(&pvp->pvp_mutex);
 513                 pfp = pvp->pvp_lpfop;
 514                 pfcp = pfp->pfop_pcache;
 515                 /*
 516                  * only if we can get the cache lock, we need to
 517                  * do this due to reverse lock order and some thread
 518                  * that may be trying to reactivate this entry.
 519                  */
 520                 if (mutex_tryenter(&pfcp->pfc_lock)) {
 521                         if (pfp && !(pfp->pfop_flags & PORT_FOP_ACTIVE) &&
 522                             !(pfp->pfop_flags & PORT_FOP_KEV_ONQ)) {
 523                                 port_fop_listremove(pvp, pfp);
 524                                 pfp->pfop_flags |= PORT_FOP_REMOVING;
 525                         } else {
 526                                 mutex_exit(&pfcp->pfc_lock);
 527                                 pfp = NULL;
 528                         }
 529                 } else {
 530                         pfp = NULL;
 531                 }
 532                 mutex_exit(&pvp->pvp_mutex);
 533 
 534                 /*
 535                  * discard pfp if any.
 536                  */
 537                 if (pfp != NULL) {
 538                         tdvp = pfp->pfop_dvp;
 539                         port_pcache_remove_fop(pfcp, pfp);
 540                         mutex_exit(&pfcp->pfc_lock);
 541                         if (tdvp != NULL)
 542                                 VN_RELE(tdvp);
 543                 }
 544         }
 545 }
 546 
 547 /*
 548  * This routine returns 1, if the vnode can be rele'ed by the caller.
 549  * The caller has to VN_RELE the vnode with out holding any
 550  * locks.
 551  */
 552 int
 553 port_fop_femuninstall(vnode_t *vp)
 554 {
 555         portfop_vp_t    *pvp;
 556         vfs_t           *vfsp;
 557         portfop_vfs_t *pvfsp;
 558         portfop_vfs_hash_t      *pvfsh;
 559         kmutex_t        *mtx;
 560         int     ret = 0;
 561 
 562         /*
 563          * if list is empty, uninstall fem.
 564          */
 565         pvp = vp->v_fopdata;
 566         ASSERT(MUTEX_HELD(&pvp->pvp_mutex));
 567 
 568         /*
 569          * make sure the list is empty.
 570          */
 571         if (!list_head(&pvp->pvp_pfoplist)) {
 572 
 573                 /*
 574                  * we could possibly uninstall the fem hooks when
 575                  * the vnode becomes inactive and the v_fopdata is
 576                  * free. But the hooks get triggered unnecessarily
 577                  * even though there are no active watches. So, we
 578                  * uninstall it here.
 579                  */
 580                 (void) fem_uninstall(vp, (fem_t *)pvp->pvp_femp, vp);
 581                 pvp->pvp_femp = NULL;
 582                 mutex_exit(&pvp->pvp_mutex);
 583 
 584 
 585                 /*
 586                  * If we successfully uninstalled fem, no process is watching
 587                  * this vnode, Remove it from the vfs's list of watched vnodes.
 588                  */
 589                 pvfsp = pvp->pvp_pvfsp;
 590                 vfsp = vp->v_vfsp;
 591                 pvfsh = PORTFOP_PVFSH(vfsp);
 592                 mtx = &pvfsh->pvfshash_mutex;
 593                 mutex_enter(mtx);
 594                 /*
 595                  * If unmount is in progress, that thread will remove and
 596                  * release the vnode from the vfs's list, just leave.
 597                  */
 598                 if (!pvfsp->pvfs_unmount) {
 599                         list_remove(&pvfsp->pvfs_pvplist, pvp);
 600                         mutex_exit(mtx);
 601                         ret = 1;
 602                 } else {
 603                         mutex_exit(mtx);
 604                 }
 605         } else {
 606                 mutex_exit(&pvp->pvp_mutex);
 607         }
 608         return (ret);
 609 }
 610 
 611 /*
 612  * Remove pfp from the vnode's watch list and the cache and discard it.
 613  * If it is the last pfp on the vnode's list, the fem hooks get uninstalled.
 614  * Returns 1 if pfp removed successfully.
 615  *
 616  * The *active is set to indicate if the pfp was still active(no events had
 617  * been posted, or the posted event had not been collected yet and it was
 618  * able to remove it from the port's queue).
 619  *
 620  * vpp and dvpp will point to the vnode and directory vnode which the caller
 621  * is required to VN_RELE without holding any locks.
 622  */
 623 int
 624 port_remove_fop(portfop_t *pfp, portfop_cache_t *pfcp, int cleanup,
 625     int *active, vnode_t **vpp, vnode_t **dvpp)
 626 {
 627         vnode_t         *vp;
 628         portfop_vp_t    *pvp;
 629         int     tactive = 0;
 630 
 631         ASSERT(MUTEX_HELD(&pfcp->pfc_lock));
 632         vp = pfp->pfop_vp;
 633         pvp = vp->v_fopdata;
 634         mutex_enter(&pvp->pvp_mutex);
 635 
 636         /*
 637          * if not cleanup, remove it only if the pfp is still active and
 638          * is not being removed by some other thread.
 639          */
 640         if (!cleanup && (!(pfp->pfop_flags & PORT_FOP_ACTIVE) ||
 641             pfp->pfop_flags & PORT_FOP_REMOVING)) {
 642                 mutex_exit(&pvp->pvp_mutex);
 643                 return (0);
 644         }
 645 
 646         /*
 647          * mark it inactive.
 648          */
 649         if (pfp->pfop_flags & PORT_FOP_ACTIVE) {
 650                 pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
 651                 tactive = 1;
 652         }
 653 
 654         /*
 655          * Check if the pfp is still on the vnode's list. This can
 656          * happen if port_fop_excep() is in the process of removing it.
 657          * In case of cleanup, just mark this pfp as inactive so that no
 658          * new events (VNEVENT) will be delivered, and remove it from the
 659          * event queue if it was already queued. Since the cache lock is
 660          * held, the pfp will not disappear, even though it is being
 661          * removed.
 662          */
 663         if (pfp->pfop_flags & PORT_FOP_REMOVING) {
 664                 mutex_exit(&pvp->pvp_mutex);
 665                 if (!tactive && port_remove_done_event(pfp->pfop_pev)) {
 666                         pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
 667                         tactive = 1;
 668                 }
 669                 if (active) {
 670                         *active = tactive;
 671                 }
 672                 return (1);
 673         }
 674 
 675         /*
 676          * if we find an event on the queue and removed it, then this
 677          * association is considered active.
 678          */
 679         if (!tactive && port_remove_done_event(pfp->pfop_pev)) {
 680                 pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
 681                 tactive = 1;
 682         }
 683 
 684         if (active) {
 685                 *active = tactive;
 686         }
 687         pvp = (portfop_vp_t *)vp->v_fopdata;
 688 
 689         /*
 690          * remove pfp from the vnode's list
 691          */
 692         port_fop_listremove(pvp, pfp);
 693 
 694         /*
 695          * If no more associations on the vnode, uninstall fem hooks.
 696          * The pvp mutex will be released in this routine.
 697          */
 698         if (port_fop_femuninstall(vp))
 699                 *vpp = vp;
 700         *dvpp = pfp->pfop_dvp;
 701         port_pcache_remove_fop(pfcp, pfp);
 702         return (1);
 703 }
 704 
 705 /*
 706  * This routine returns a pointer to a cached portfop entry, or NULL if it
 707  * does not find it in the hash table. The object pointer is used as index.
 708  * The entries are hashed by the object's address. We need to match the pid
 709  * as the evet port can be shared between processes. The file events
 710  * watches are per process only.
 711  */
 712 portfop_t *
 713 port_cache_lookup_fop(portfop_cache_t *pfcp, pid_t pid, uintptr_t obj)
 714 {
 715         portfop_t       *pfp = NULL;
 716         portfop_t       **bucket;
 717 
 718         ASSERT(MUTEX_HELD(&pfcp->pfc_lock));
 719         bucket = PORT_FOP_BUCKET(pfcp, obj);
 720         pfp = *bucket;
 721         while (pfp != NULL) {
 722                 if (pfp->pfop_object == obj && pfp->pfop_pid == pid)
 723                         break;
 724                 pfp = pfp->pfop_hashnext;
 725         }
 726         return (pfp);
 727 }
 728 
 729 /*
 730  * Given the file name, get the vnode and also the directory vnode
 731  * On return, the vnodes are held (VN_HOLD). The caller has to VN_RELE
 732  * the vnode(s).
 733  */
 734 int
 735 port_fop_getdvp(void *objptr, vnode_t **vp, vnode_t **dvp,
 736         char **cname, int *len, int follow)
 737 {
 738         int error = 0;
 739         struct pathname pn;
 740         char *fname;
 741 
 742         if (get_udatamodel() == DATAMODEL_NATIVE) {
 743                 fname = ((file_obj_t *)objptr)->fo_name;
 744 #ifdef  _SYSCALL32_IMPL
 745         } else {
 746                 fname = (caddr_t)(uintptr_t)((file_obj32_t *)objptr)->fo_name;
 747 #endif  /* _SYSCALL32_IMPL */
 748         }
 749 
 750         /*
 751          * lookuppn may fail with EINVAL, if dvp is  non-null(like when
 752          * looking for "."). So call again with dvp = NULL.
 753          */
 754         if ((error = pn_get(fname, UIO_USERSPACE, &pn)) != 0) {
 755                 return (error);
 756         }
 757 
 758         error = lookuppn(&pn, NULL, follow, dvp, vp);
 759         if (error == EINVAL) {
 760                 pn_free(&pn);
 761                 if ((error = pn_get(fname, UIO_USERSPACE, &pn)) != 0) {
 762                         return (error);
 763                 }
 764                 error = lookuppn(&pn, NULL, follow, NULL, vp);
 765                 if (dvp != NULL) {
 766                         *dvp = NULL;
 767                 }
 768         }
 769 
 770         if (error == 0 && cname != NULL && len != NULL) {
 771                 pn_setlast(&pn);
 772                 *len = pn.pn_pathlen;
 773                 *cname = kmem_alloc(*len + 1, KM_SLEEP);
 774                 (void) strcpy(*cname, pn.pn_path);
 775         } else {
 776                 if (cname != NULL && len != NULL) {
 777                         *cname = NULL;
 778                         *len = 0;
 779                 }
 780         }
 781 
 782         pn_free(&pn);
 783         return (error);
 784 }
 785 
 786 port_source_t *
 787 port_getsrc(port_t *pp, int source)
 788 {
 789         port_source_t *pse;
 790         int     lock = 0;
 791         /*
 792          * get the port source structure.
 793          */
 794         if (!MUTEX_HELD(&pp->port_queue.portq_source_mutex)) {
 795                 mutex_enter(&pp->port_queue.portq_source_mutex);
 796                 lock = 1;
 797         }
 798 
 799         pse = pp->port_queue.portq_scache[PORT_SHASH(source)];
 800         for (; pse != NULL; pse = pse->portsrc_next) {
 801                 if (pse->portsrc_source == source)
 802                         break;
 803         }
 804 
 805         if (lock) {
 806                 mutex_exit(&pp->port_queue.portq_source_mutex);
 807         }
 808         return (pse);
 809 }
 810 
 811 
 812 /*
 813  * Compare time stamps and generate an event if it has changed.
 814  * Note that the port cache pointer will be valid due to a reference
 815  * to the port. We need to grab the port cache lock and verify that
 816  * the pfp is still the same before proceeding to deliver an event.
 817  */
 818 static void
 819 port_check_timestamp(portfop_cache_t *pfcp, vnode_t *vp, vnode_t *dvp,
 820         portfop_t *pfp, void *objptr, uintptr_t object)
 821 {
 822         vattr_t         vatt;
 823         portfop_vp_t    *pvp = vp->v_fopdata;
 824         int             events = 0;
 825         port_kevent_t   *pkevp;
 826         file_obj_t      *fobj;
 827         portfop_t       *tpfp;
 828 
 829         /*
 830          * If time stamps are specified, get attributes and compare.
 831          */
 832         vatt.va_mask = AT_ATIME|AT_MTIME|AT_CTIME;
 833         if (get_udatamodel() == DATAMODEL_NATIVE) {
 834                 fobj = (file_obj_t *)objptr;
 835                 if (fobj->fo_atime.tv_sec || fobj->fo_atime.tv_nsec ||
 836                     fobj->fo_mtime.tv_sec || fobj->fo_mtime.tv_nsec ||
 837                     fobj->fo_ctime.tv_sec || fobj->fo_ctime.tv_nsec) {
 838                         if (VOP_GETATTR(vp, &vatt, 0, CRED(), NULL)) {
 839                                 return;
 840                         }
 841                 } else {
 842                         /*
 843                          * timestamp not specified, all 0's,
 844                          */
 845                         return;
 846                 }
 847 #ifdef  _SYSCALL32_IMPL
 848         } else {
 849                 file_obj32_t    *fobj32;
 850                 fobj32 = (file_obj32_t *)objptr;
 851                 if (fobj32->fo_atime.tv_sec || fobj32->fo_atime.tv_nsec ||
 852                     fobj32->fo_mtime.tv_sec || fobj32->fo_mtime.tv_nsec ||
 853                     fobj32->fo_ctime.tv_sec || fobj32->fo_ctime.tv_nsec) {
 854                         if (VOP_GETATTR(vp, &vatt, 0, CRED(), NULL)) {
 855                                 return;
 856                         }
 857                 } else {
 858                         /*
 859                          * timestamp not specified, all 0.
 860                          */
 861                         return;
 862                 }
 863 #endif /* _SYSCALL32_IMPL */
 864         }
 865 
 866         /*
 867          * Now grab the cache lock and verify that we are still
 868          * dealing with the same pfp and curthread is the one
 869          * which registered it. We need to do this to avoid
 870          * delivering redundant events.
 871          */
 872         mutex_enter(&pfcp->pfc_lock);
 873         tpfp = port_cache_lookup_fop(pfcp, curproc->p_pid, object);
 874 
 875         if (tpfp == NULL || tpfp != pfp ||
 876             pfp->pfop_vp != vp || pfp->pfop_dvp != dvp ||
 877             pfp->pfop_callrid != curthread ||
 878             !(pfp->pfop_flags & PORT_FOP_ACTIVE)) {
 879                 /*
 880                  * Some other event was delivered, the file
 881                  * watch was removed or reassociated. Just
 882                  * ignore it and leave
 883                  */
 884                 mutex_exit(&pfcp->pfc_lock);
 885                 return;
 886         }
 887 
 888         mutex_enter(&pvp->pvp_mutex);
 889         /*
 890          * The pfp cannot disappear as the port cache lock is held.
 891          * While the pvp_mutex is held, no events will get delivered.
 892          */
 893         if (pfp->pfop_flags & PORT_FOP_ACTIVE &&
 894             !(pfp->pfop_flags & PORT_FOP_REMOVING)) {
 895                 if (get_udatamodel() == DATAMODEL_NATIVE) {
 896                         fobj = (file_obj_t *)objptr;
 897                         if (pfp->pfop_events & FILE_ACCESS &&
 898                             (fobj->fo_atime.tv_sec || fobj->fo_atime.tv_nsec) &&
 899                             (vatt.va_atime.tv_sec != fobj->fo_atime.tv_sec ||
 900                             vatt.va_atime.tv_nsec != fobj->fo_atime.tv_nsec))
 901                                 events |= FILE_ACCESS;
 902 
 903                         if (pfp->pfop_events & FILE_MODIFIED &&
 904                             (fobj->fo_mtime.tv_sec || fobj->fo_mtime.tv_nsec) &&
 905                             (vatt.va_mtime.tv_sec != fobj->fo_mtime.tv_sec ||
 906                             vatt.va_mtime.tv_nsec != fobj->fo_mtime.tv_nsec))
 907                                 events |= FILE_MODIFIED;
 908 
 909                         if (pfp->pfop_events & FILE_ATTRIB &&
 910                             (fobj->fo_ctime.tv_sec || fobj->fo_ctime.tv_nsec) &&
 911                             (vatt.va_ctime.tv_sec != fobj->fo_ctime.tv_sec ||
 912                             vatt.va_ctime.tv_nsec != fobj->fo_ctime.tv_nsec))
 913                                 events |= FILE_ATTRIB;
 914 #ifdef  _SYSCALL32_IMPL
 915                 } else {
 916                         file_obj32_t    *fobj32;
 917                         fobj32 = (file_obj32_t *)objptr;
 918                         if (pfp->pfop_events & FILE_ACCESS &&
 919                             (fobj32->fo_atime.tv_sec ||
 920                             fobj32->fo_atime.tv_nsec) &&
 921                             (vatt.va_atime.tv_sec != fobj32->fo_atime.tv_sec ||
 922                             vatt.va_atime.tv_nsec != fobj32->fo_atime.tv_nsec))
 923                                 events |= FILE_ACCESS;
 924 
 925                         if (pfp->pfop_events & FILE_MODIFIED &&
 926                             (fobj32->fo_mtime.tv_sec ||
 927                             fobj32->fo_mtime.tv_nsec) &&
 928                             (vatt.va_mtime.tv_sec != fobj32->fo_mtime.tv_sec ||
 929                             vatt.va_mtime.tv_nsec != fobj32->fo_mtime.tv_nsec))
 930                                 events |= FILE_MODIFIED;
 931 
 932                         if (pfp->pfop_events & FILE_ATTRIB &&
 933                             (fobj32->fo_ctime.tv_sec ||
 934                             fobj32->fo_ctime.tv_nsec) &&
 935                             (vatt.va_ctime.tv_sec != fobj32->fo_ctime.tv_sec ||
 936                             vatt.va_ctime.tv_nsec != fobj32->fo_ctime.tv_nsec))
 937                                 events |= FILE_ATTRIB;
 938 #endif /* _SYSCALL32_IMPL */
 939                 }
 940 
 941                 /*
 942                  * No events to deliver
 943                  */
 944                 if (events == 0) {
 945                         mutex_exit(&pvp->pvp_mutex);
 946                         mutex_exit(&pfcp->pfc_lock);
 947                         return;
 948                 }
 949 
 950                 /*
 951                  * Deliver the event now.
 952                  */
 953                 pkevp = pfp->pfop_pev;
 954                 pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
 955                 pkevp->portkev_events |= events;
 956                 /*
 957                  * Move it to the tail as active once are in the
 958                  * beginning of the list.
 959                  */
 960                 port_fop_listremove(pvp, pfp);
 961                 port_fop_listinsert_tail(pvp, pfp);
 962                 port_send_event(pkevp);
 963                 pfp->pfop_flags |= PORT_FOP_KEV_ONQ;
 964         }
 965         mutex_exit(&pvp->pvp_mutex);
 966         mutex_exit(&pfcp->pfc_lock);
 967 }
 968 
 969 /*
 970  * Add the event source to the port and return the port source cache pointer.
 971  */
 972 int
 973 port_fop_associate_source(portfop_cache_t **pfcpp, port_t *pp, int source)
 974 {
 975         portfop_cache_t *pfcp;
 976         port_source_t   *pse;
 977         int             error;
 978 
 979         /*
 980          * associate PORT_SOURCE_FILE source with the port, if it is
 981          * not associated yet. Note the PORT_SOURCE_FILE source is
 982          * associated once and will not be dissociated.
 983          */
 984         if ((pse = port_getsrc(pp, PORT_SOURCE_FILE)) == NULL) {
 985                 if (error = port_associate_ksource(pp->port_fd, source,
 986                     &pse, port_close_fop, pp, NULL)) {
 987                         *pfcpp = NULL;
 988                         return (error);
 989                 }
 990         }
 991 
 992         /*
 993          * Get the portfop cache pointer.
 994          */
 995         if ((pfcp = pse->portsrc_data) == NULL) {
 996                 /*
 997                  * This is the first time that a file is being associated,
 998                  * create the portfop cache.
 999                  */
1000                 pfcp = kmem_zalloc(sizeof (portfop_cache_t), KM_SLEEP);
1001                 mutex_enter(&pp->port_queue.portq_source_mutex);
1002                 if (pse->portsrc_data == NULL) {
1003                         pse->portsrc_data = pfcp;
1004                         mutex_exit(&pp->port_queue.portq_source_mutex);
1005                 } else {
1006                         /*
1007                          * someone else created the port cache, free
1008                          * what we just now allocated.
1009                          */
1010                         mutex_exit(&pp->port_queue.portq_source_mutex);
1011                         kmem_free(pfcp, sizeof (portfop_cache_t));
1012                         pfcp = pse->portsrc_data;
1013                 }
1014         }
1015         *pfcpp = pfcp;
1016         return (0);
1017 }
1018 
1019 /*
1020  * Add the given pvp on the file system's list of vnodes watched.
1021  */
1022 int
1023 port_fop_pvfsadd(portfop_vp_t *pvp)
1024 {
1025         int error = 0;
1026         vnode_t *vp = pvp->pvp_vp;
1027         portfop_vfs_hash_t *pvfsh;
1028         portfop_vfs_t    *pvfsp;
1029         fsem_t          *fsemp;
1030 
1031         pvfsh = PORTFOP_PVFSH(vp->v_vfsp);
1032         mutex_enter(&pvfsh->pvfshash_mutex);
1033         for (pvfsp = pvfsh->pvfshash_pvfsp; pvfsp &&
1034             pvfsp->pvfs != vp->v_vfsp; pvfsp = pvfsp->pvfs_next)
1035                 ;
1036 
1037         if (!pvfsp) {
1038                 if ((fsemp = port_fop_fsemop()) != NULL) {
1039                         if ((error = fsem_install(vp->v_vfsp, fsemp,
1040                             vp->v_vfsp, OPUNIQ, NULL, NULL))) {
1041                                 mutex_exit(&pvfsh->pvfshash_mutex);
1042                                 return (error);
1043                         }
1044                 } else {
1045                         mutex_exit(&pvfsh->pvfshash_mutex);
1046                         return (EINVAL);
1047                 }
1048                 pvfsp = kmem_zalloc(sizeof (portfop_vfs_t), KM_SLEEP);
1049                 pvfsp->pvfs = vp->v_vfsp;
1050                 list_create(&(pvfsp->pvfs_pvplist), sizeof (portfop_vp_t),
1051                     offsetof(portfop_vp_t, pvp_pvfsnode));
1052                 pvfsp->pvfs_fsemp = fsemp;
1053                 pvfsp->pvfs_next = pvfsh->pvfshash_pvfsp;
1054                 pvfsh->pvfshash_pvfsp = pvfsp;
1055         }
1056 
1057         /*
1058          * check if an unmount is in progress.
1059          */
1060         if (!pvfsp->pvfs_unmount) {
1061                 /*
1062                  * insert the pvp on list.
1063                  */
1064                 pvp->pvp_pvfsp = pvfsp;
1065                 list_insert_head(&pvfsp->pvfs_pvplist, (void *)pvp);
1066         } else {
1067                 error = EINVAL;
1068         }
1069         mutex_exit(&pvfsh->pvfshash_mutex);
1070         return (error);
1071 }
1072 
1073 /*
1074  * Installs the portfop_vp_t data structure on the
1075  * vnode. The 'pvp_femp == NULL' indicates it is not
1076  * active. The fem hooks have to be installed.
1077  * The portfop_vp_t is only freed when the vnode gets freed.
1078  */
1079 void
1080 port_install_fopdata(vnode_t *vp)
1081 {
1082         portfop_vp_t *npvp;
1083 
1084         npvp = kmem_zalloc(sizeof (*npvp), KM_SLEEP);
1085         mutex_init(&npvp->pvp_mutex, NULL, MUTEX_DEFAULT, NULL);
1086         list_create(&npvp->pvp_pfoplist, sizeof (portfop_t),
1087             offsetof(portfop_t, pfop_node));
1088         npvp->pvp_vp = vp;
1089         /*
1090          * If v_fopdata is not null, some other thread beat us to it.
1091          */
1092         if (casptr(&vp->v_fopdata, NULL, npvp) != NULL) {
1093                 mutex_destroy(&npvp->pvp_mutex);
1094                 list_destroy(&npvp->pvp_pfoplist);
1095                 kmem_free(npvp, sizeof (*npvp));
1096         }
1097 }
1098 
1099 
1100 /*
1101  * Allocate and add a portfop_t to the per port cache. Also add the portfop_t
1102  * to the vnode's list. The association is identified by the object pointer
1103  * address and pid.
1104  */
1105 int
1106 port_pfp_setup(portfop_t **pfpp, port_t *pp, vnode_t *vp, portfop_cache_t *pfcp,
1107         uintptr_t object, int events, void *user, char *cname, int clen,
1108         vnode_t *dvp)
1109 {
1110         portfop_t       *pfp = NULL;
1111         port_kevent_t   *pkevp;
1112         fem_t           *femp;
1113         int             error = 0;
1114         portfop_vp_t    *pvp;
1115 
1116 
1117         /*
1118          * The port cache mutex is held.
1119          */
1120         *pfpp  = NULL;
1121 
1122 
1123         /*
1124          * At this point the fem monitor is installed.
1125          * Allocate a port event structure per vnode association.
1126          */
1127         if (pfp == NULL) {
1128                 if (error = port_alloc_event_local(pp, PORT_SOURCE_FILE,
1129                     PORT_ALLOC_CACHED, &pkevp)) {
1130                         return (error);
1131                 }
1132                 pfp = kmem_zalloc(sizeof (portfop_t), KM_SLEEP);
1133                 pfp->pfop_pev = pkevp;
1134         }
1135 
1136         pfp->pfop_vp = vp;
1137         pfp->pfop_pid = curproc->p_pid;
1138         pfp->pfop_pcache = pfcp;
1139         pfp->pfop_pp = pp;
1140         pfp->pfop_flags |= PORT_FOP_ACTIVE;
1141         pfp->pfop_cname = cname;
1142         pfp->pfop_clen = clen;
1143         pfp->pfop_dvp = dvp;
1144         pfp->pfop_object = object;
1145 
1146         pkevp->portkev_callback = port_fop_callback;
1147         pkevp->portkev_arg = pfp;
1148         pkevp->portkev_object = object;
1149         pkevp->portkev_user = user;
1150         pkevp->portkev_events = 0;
1151 
1152         port_pcache_insert(pfcp, pfp);
1153 
1154         /*
1155          * Register a new file events monitor for this file(vnode), if not
1156          * done already.
1157          */
1158         if ((pvp = vp->v_fopdata) == NULL) {
1159                 port_install_fopdata(vp);
1160                 pvp = vp->v_fopdata;
1161         }
1162 
1163         mutex_enter(&pvp->pvp_mutex);
1164         /*
1165          * if the vnode does not have the file events hooks, install it.
1166          */
1167         if (pvp->pvp_femp == NULL) {
1168                 if ((femp = port_fop_femop()) != NULL) {
1169                         if (!(error = fem_install(pfp->pfop_vp, femp,
1170                             (void *)vp, OPUNIQ, NULL, NULL))) {
1171                                 pvp->pvp_femp = femp;
1172                                 /*
1173                                  * add fsem_t hooks to the vfsp and add pvp to
1174                                  * the list of vnodes for this vfs.
1175                                  */
1176                                 if (!(error = port_fop_pvfsadd(pvp))) {
1177                                         /*
1178                                          * Hold a reference to the vnode since
1179                                          * we successfully installed the hooks.
1180                                          */
1181                                         VN_HOLD(vp);
1182                                 } else {
1183                                         (void) fem_uninstall(vp, femp, vp);
1184                                         pvp->pvp_femp = NULL;
1185                                 }
1186                         }
1187                 } else {
1188                         error = EINVAL;
1189                 }
1190         }
1191 
1192         if (error) {
1193                 /*
1194                  * pkevp will get freed here.
1195                  */
1196                 pfp->pfop_cname = NULL;
1197                 port_pcache_remove_fop(pfcp, pfp);
1198                 mutex_exit(&pvp->pvp_mutex);
1199                 return (error);
1200         }
1201 
1202         /*
1203          * insert the pfp on the vnode's list. After this
1204          * events can get delivered.
1205          */
1206         pfp->pfop_events = events;
1207         port_fop_listinsert_head(pvp, pfp);
1208 
1209         mutex_exit(&pvp->pvp_mutex);
1210         /*
1211          * Hold the directory vnode since we have a reference now.
1212          */
1213         if (dvp != NULL)
1214                 VN_HOLD(dvp);
1215         *pfpp = pfp;
1216         return (0);
1217 }
1218 
1219 vnode_t *
1220 port_resolve_vp(vnode_t *vp)
1221 {
1222         vnode_t *rvp;
1223         /*
1224          * special case /etc/mnttab(mntfs type). The mntfstype != 0
1225          * if mntfs got mounted.
1226          */
1227         if (vfs_mntdummyvp && mntfstype != 0 &&
1228             vp->v_vfsp->vfs_fstype == mntfstype) {
1229                 VN_RELE(vp);
1230                 vp = vfs_mntdummyvp;
1231                 VN_HOLD(vfs_mntdummyvp);
1232         }
1233 
1234         /*
1235          * This should take care of lofs mounted fs systems and nfs4
1236          * hardlinks.
1237          */
1238         if ((VOP_REALVP(vp, &rvp, NULL) == 0) && vp != rvp) {
1239                 VN_HOLD(rvp);
1240                 VN_RELE(vp);
1241                 vp = rvp;
1242         }
1243         return (vp);
1244 }
1245 
1246 /*
1247  * Register a file events watch on the given file associated to the port *pp.
1248  *
1249  * The association is identified by the object pointer and the pid.
1250  * The events argument contains the events to be monitored for.
1251  *
1252  * The vnode will have a VN_HOLD once the fem hooks are installed.
1253  *
1254  * Every reference(pfp) to the directory vnode will have a VN_HOLD to ensure
1255  * that the directory vnode pointer does not change.
1256  */
1257 int
1258 port_associate_fop(port_t *pp, int source, uintptr_t object, int events,
1259     void *user)
1260 {
1261         portfop_cache_t *pfcp;
1262         vnode_t         *vp, *dvp, *oldvp = NULL, *olddvp = NULL;
1263         portfop_t       *pfp;
1264         int             error = 0;
1265         file_obj_t      fobj;
1266         void            *objptr;
1267         char            *cname;
1268         int             clen;
1269         int             follow;
1270 
1271         /*
1272          * check that events specified are valid.
1273          */
1274         if ((events & ~FILE_EVENTS_MASK) != 0)
1275                 return (EINVAL);
1276 
1277         if (get_udatamodel() == DATAMODEL_NATIVE) {
1278                 if (copyin((void *)object, &fobj, sizeof (file_obj_t)))
1279                         return (EFAULT);
1280                 objptr = (void *)&fobj;
1281 #ifdef  _SYSCALL32_IMPL
1282         } else {
1283                 file_obj32_t    fobj32;
1284                 if (copyin((void *)object, &fobj32, sizeof (file_obj32_t)))
1285                         return (EFAULT);
1286                 objptr = (void *)&fobj32;
1287 #endif  /* _SYSCALL32_IMPL */
1288         }
1289 
1290         vp = dvp = NULL;
1291 
1292         /*
1293          * find out if we need to follow symbolic links.
1294          */
1295         follow = !(events & FILE_NOFOLLOW);
1296         events = events & ~FILE_NOFOLLOW;
1297 
1298         /*
1299          * lookup and find the vnode and its directory vnode of the given
1300          * file.
1301          */
1302         if ((error = port_fop_getdvp(objptr, &vp, &dvp, &cname, &clen,
1303             follow)) != 0) {
1304                 return (error);
1305         }
1306 
1307         if (dvp != NULL) {
1308                 dvp = port_resolve_vp(dvp);
1309         }
1310 
1311         /*
1312          * Not found
1313          */
1314         if (vp == NULL) {
1315                 error = ENOENT;
1316                 goto errout;
1317         }
1318 
1319         vp = port_resolve_vp(vp);
1320 
1321 
1322         if (vp != NULL && vnevent_support(vp, NULL)) {
1323                 error = ENOTSUP;
1324                 goto errout;
1325         }
1326 
1327         /*
1328          * If dvp belongs to a different filesystem just ignore it.
1329          * Hardlinks cannot exist across filesystems.
1330          */
1331         if (dvp != NULL && dvp->v_vfsp != vp->v_vfsp) {
1332                 VN_RELE(dvp);
1333                 dvp = NULL;
1334         }
1335 
1336         /*
1337          * Associate this source to the port and get the per port
1338          * fop cache pointer. If the source is already associated, it
1339          * will just return the cache pointer.
1340          */
1341         if (error = port_fop_associate_source(&pfcp, pp, source)) {
1342                 goto errout;
1343         }
1344 
1345         /*
1346          * Check if there is an existing association of this file.
1347          */
1348         mutex_enter(&pfcp->pfc_lock);
1349         pfp = port_cache_lookup_fop(pfcp, curproc->p_pid, object);
1350 
1351         /*
1352          * If it is not the same vnode, just discard it. VN_RELE needs to be
1353          * called with no locks held, therefore save vnode pointers and
1354          * vn_rele them later.
1355          */
1356         if (pfp != NULL && (pfp->pfop_vp != vp || pfp->pfop_dvp != dvp)) {
1357                 (void) port_remove_fop(pfp, pfcp, 1, NULL, &oldvp, &olddvp);
1358                 pfp = NULL;
1359         }
1360 
1361         if (pfp == NULL) {
1362                 vnode_t *tvp, *tdvp;
1363                 portfop_t       *tpfp;
1364                 int error;
1365 
1366                 /*
1367                  * Add a new association, save the file name and the
1368                  * directory vnode pointer.
1369                  */
1370                 if (error = port_pfp_setup(&pfp, pp, vp, pfcp, object,
1371                     events, user, cname, clen, dvp)) {
1372                         mutex_exit(&pfcp->pfc_lock);
1373                         goto errout;
1374                 }
1375 
1376                 pfp->pfop_callrid = curthread;
1377                 /*
1378                  * File name used, so make sure we don't free it.
1379                  */
1380                 cname = NULL;
1381 
1382                 /*
1383                  * We need to check if the file was removed after the
1384                  * the lookup and before the fem hooks where added. If
1385                  * so, return error. The vnode will still exist as we have
1386                  * a hold on it.
1387                  *
1388                  * Drop the cache lock before calling port_fop_getdvp().
1389                  * port_fop_getdvp() may block either in the vfs layer
1390                  * or some filesystem.  Therefore there is potential
1391                  * for deadlock if cache lock is held and if some other
1392                  * thread is attempting to deliver file events which would
1393                  * require getting the cache lock, while it may be holding
1394                  * the filesystem or vfs layer locks.
1395                  */
1396                 mutex_exit(&pfcp->pfc_lock);
1397                 tvp = NULL;
1398                 if ((error = port_fop_getdvp(objptr, &tvp, NULL,
1399                     NULL, NULL, follow)) == 0) {
1400                         if (tvp != NULL) {
1401                                 tvp = port_resolve_vp(tvp);
1402                                 /*
1403                                  * This vnode pointer is just used
1404                                  * for comparison, so rele it
1405                                  */
1406                                 VN_RELE(tvp);
1407                         }
1408                 }
1409 
1410                 if (error || tvp == NULL || tvp != vp) {
1411                         /*
1412                          * Since we dropped the cache lock, make sure
1413                          * we are still dealing with the same pfp and this
1414                          * is the thread which registered it.
1415                          */
1416                         mutex_enter(&pfcp->pfc_lock);
1417                         tpfp = port_cache_lookup_fop(pfcp,
1418                             curproc->p_pid, object);
1419 
1420                         error = 0;
1421                         if (tpfp == NULL || tpfp != pfp ||
1422                             pfp->pfop_vp != vp ||
1423                             pfp->pfop_dvp != dvp ||
1424                             pfp->pfop_callrid != curthread) {
1425                                 /*
1426                                  * Some other event was delivered, the file
1427                                  * watch was removed or reassociated, just
1428                                  * ignore it and leave
1429                                  */
1430                                 mutex_exit(&pfcp->pfc_lock);
1431                                 goto errout;
1432                         }
1433 
1434                         /*
1435                          * remove the pfp and fem hooks, if pfp still
1436                          * active and it is not being removed from
1437                          * the vnode list. This is checked in
1438                          * port_remove_fop with the vnode lock held.
1439                          * The vnode returned is VN_RELE'ed after dropping
1440                          * the locks.
1441                          */
1442                         tdvp = tvp = NULL;
1443                         if (port_remove_fop(pfp, pfcp, 0, NULL, &tvp, &tdvp)) {
1444                                 /*
1445                                  * The pfp was removed, means no
1446                                  * events where queued. Report the
1447                                  * error now.
1448                                  */
1449                                 error = EINVAL;
1450                         }
1451                         mutex_exit(&pfcp->pfc_lock);
1452                         if (tvp != NULL)
1453                                 VN_RELE(tvp);
1454                         if (tdvp != NULL)
1455                                 VN_RELE(tdvp);
1456                         goto errout;
1457                 }
1458         } else {
1459                 portfop_vp_t    *pvp = vp->v_fopdata;
1460 
1461                 /*
1462                  * Re-association of the object.
1463                  */
1464                 mutex_enter(&pvp->pvp_mutex);
1465 
1466                 /*
1467                  * remove any queued up event.
1468                  */
1469                 if (port_remove_done_event(pfp->pfop_pev)) {
1470                         pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
1471                 }
1472 
1473                 /*
1474                  * set new events to watch.
1475                  */
1476                 pfp->pfop_events = events;
1477 
1478                 /*
1479                  * If not active, mark it active even if it is being
1480                  * removed. Then it can send an exception event.
1481                  *
1482                  * Move it to the head, as the active ones are only
1483                  * in the beginning. If removing, the pfp will be on
1484                  * a temporary list, no need to move it to the front
1485                  * all the entries will be processed. Some exception
1486                  * events will be delivered in port_fop_excep();
1487                  */
1488                 if (!(pfp->pfop_flags & PORT_FOP_ACTIVE)) {
1489                         pfp->pfop_flags |= PORT_FOP_ACTIVE;
1490                         if (!(pfp->pfop_flags & PORT_FOP_REMOVING)) {
1491                                 pvp = (portfop_vp_t *)vp->v_fopdata;
1492                                 port_fop_listremove(pvp, pfp);
1493                                 port_fop_listinsert_head(pvp, pfp);
1494                         }
1495                 }
1496                 pfp->pfop_callrid = curthread;
1497                 mutex_exit(&pvp->pvp_mutex);
1498                 mutex_exit(&pfcp->pfc_lock);
1499         }
1500 
1501         /*
1502          * Compare time stamps and deliver events.
1503          */
1504         if (vp->v_type != VFIFO) {
1505                 port_check_timestamp(pfcp, vp, dvp, pfp, objptr, object);
1506         }
1507 
1508         error = 0;
1509 
1510         /*
1511          *  If we have too many watches on the vnode, discard an
1512          *  inactive watch.
1513          */
1514         port_fop_trimpfplist(vp);
1515 
1516 errout:
1517         /*
1518          * Release the hold acquired due to the lookup operation.
1519          */
1520         if (vp != NULL)
1521                 VN_RELE(vp);
1522         if (dvp != NULL)
1523                 VN_RELE(dvp);
1524 
1525         if (oldvp != NULL)
1526                 VN_RELE(oldvp);
1527         if (olddvp != NULL)
1528                 VN_RELE(olddvp);
1529 
1530         /*
1531          * copied file name not used, free it.
1532          */
1533         if (cname != NULL) {
1534                 kmem_free(cname, clen + 1);
1535         }
1536         return (error);
1537 }
1538 
1539 
1540 /*
1541  * The port_dissociate_fop() function dissociates the file object
1542  * from the event port and removes any events that are already on the queue.
1543  * Only the owner of the association is allowed to dissociate the file from
1544  * the port. Returns  success (0) if it was found and removed. Otherwise
1545  * ENOENT.
1546  */
1547 int
1548 port_dissociate_fop(port_t *pp, uintptr_t object)
1549 {
1550         portfop_cache_t *pfcp;
1551         portfop_t       *pfp;
1552         port_source_t   *pse;
1553         int             active = 0;
1554         vnode_t         *tvp = NULL, *tdvp = NULL;
1555 
1556         pse = port_getsrc(pp, PORT_SOURCE_FILE);
1557 
1558         /*
1559          * if this source is not associated or if there is no
1560          * cache, nothing to do just return.
1561          */
1562         if (pse == NULL ||
1563             (pfcp = (portfop_cache_t *)pse->portsrc_data) == NULL)
1564                 return (EINVAL);
1565 
1566         /*
1567          * Check if this object is on the cache. Only the owner pid
1568          * is allowed to dissociate.
1569          */
1570         mutex_enter(&pfcp->pfc_lock);
1571         pfp = port_cache_lookup_fop(pfcp, curproc->p_pid, object);
1572         if (pfp == NULL) {
1573                 mutex_exit(&pfcp->pfc_lock);
1574                 return (ENOENT);
1575         }
1576 
1577         /*
1578          * If this was the last association, it will release
1579          * the hold on the vnode. There is a race condition where
1580          * the the pfp is being removed due to an exception event
1581          * in port_fop_sendevent()->port_fop_excep() and port_remove_fop().
1582          * Since port source cache lock is held, port_fop_excep() cannot
1583          * complete. The vnode itself will not disappear as long its pfps
1584          * have a reference.
1585          */
1586         (void) port_remove_fop(pfp, pfcp, 1, &active, &tvp, &tdvp);
1587         mutex_exit(&pfcp->pfc_lock);
1588         if (tvp != NULL)
1589                 VN_RELE(tvp);
1590         if (tdvp != NULL)
1591                 VN_RELE(tdvp);
1592         return (active ? 0 : ENOENT);
1593 }
1594 
1595 
1596 /*
1597  * port_close() calls this function to request the PORT_SOURCE_FILE source
1598  * to remove/free all resources allocated and associated with the port.
1599  */
1600 
1601 /* ARGSUSED */
1602 static void
1603 port_close_fop(void *arg, int port, pid_t pid, int lastclose)
1604 {
1605         port_t          *pp = arg;
1606         portfop_cache_t *pfcp;
1607         portfop_t       **hashtbl;
1608         portfop_t       *pfp;
1609         portfop_t       *pfpnext;
1610         int             index, i;
1611         port_source_t   *pse;
1612         vnode_t         *tdvp = NULL;
1613         vnode_t         *vpl[PORTFOP_NVP];
1614 
1615         pse = port_getsrc(pp, PORT_SOURCE_FILE);
1616 
1617         /*
1618          * No source or no cache, nothing to do.
1619          */
1620         if (pse == NULL ||
1621             (pfcp = (portfop_cache_t *)pse->portsrc_data) == NULL)
1622                 return;
1623         /*
1624          * Scan the cache and free all allocated portfop_t and port_kevent_t
1625          * structures of this pid. Note, no new association for this pid will
1626          * be possible as the port is being closed.
1627          *
1628          * The common case is that the port is not shared and all the entries
1629          * are of this pid and have to be freed. Since VN_RELE has to be
1630          * called outside the lock, we do it in batches.
1631          */
1632         hashtbl = (portfop_t **)pfcp->pfc_hash;
1633         index = i = 0;
1634         bzero(vpl, sizeof (vpl));
1635         mutex_enter(&pfcp->pfc_lock);
1636         while (index < PORTFOP_HASHSIZE) {
1637                 pfp = hashtbl[index];
1638                 while (pfp != NULL && i < (PORTFOP_NVP - 1)) {
1639                         pfpnext = pfp->pfop_hashnext;
1640                         if (pid == pfp->pfop_pid) {
1641                                 (void) port_remove_fop(pfp, pfcp, 1, NULL,
1642                                     &vpl[i], &tdvp);
1643                                 if (vpl[i] != NULL) {
1644                                         i++;
1645                                 }
1646                                 if (tdvp != NULL) {
1647                                         vpl[i++] = tdvp;
1648                                         tdvp = NULL;
1649                                 }
1650                         }
1651                         pfp = pfpnext;
1652                 }
1653                 if (pfp == NULL)
1654                         index++;
1655                 /*
1656                  * Now call VN_RELE if we have collected enough vnodes or
1657                  * we have reached the end of the hash table.
1658                  */
1659                 if (i >= (PORTFOP_NVP - 1) ||
1660                     (i > 0 && index == PORTFOP_HASHSIZE)) {
1661                         mutex_exit(&pfcp->pfc_lock);
1662                         while (i > 0) {
1663                                 VN_RELE(vpl[--i]);
1664                                 vpl[i] = NULL;
1665                         }
1666                         mutex_enter(&pfcp->pfc_lock);
1667                 }
1668         }
1669 
1670         /*
1671          * Due to a race between port_close_fop() and port_fop()
1672          * trying to remove the pfp's from the port's cache, it is
1673          * possible that some pfp's are still in the process of being
1674          * freed so we wait.
1675          */
1676         while (lastclose && pfcp->pfc_objcount) {
1677                 (void) cv_wait_sig(&pfcp->pfc_lclosecv, &pfcp->pfc_lock);
1678         }
1679         mutex_exit(&pfcp->pfc_lock);
1680         /*
1681          * last close, free the cache.
1682          */
1683         if (lastclose) {
1684                 ASSERT(pfcp->pfc_objcount == 0);
1685                 pse->portsrc_data = NULL;
1686                 kmem_free(pfcp, sizeof (portfop_cache_t));
1687         }
1688 }
1689 
1690 /*
1691  * Given the list of associations(watches), it will send exception events,
1692  * if still active, and discard them. The exception events are handled
1693  * separately because, the pfp needs to be removed from the port cache and
1694  * freed as the vnode's identity is changing or being removed. To remove
1695  * the pfp from the port's cache, we need to hold the cache lock (pfc_lock).
1696  * The lock order is pfc_lock -> pvp_mutex(vnode's) mutex and that is why
1697  * the cache's lock cannot be acquired in port_fop_sendevent().
1698  */
1699 static void
1700 port_fop_excep(list_t *tlist, int op)
1701 {
1702         portfop_t       *pfp;
1703         portfop_cache_t *pfcp;
1704         port_t  *pp;
1705         port_kevent_t   *pkevp;
1706         vnode_t         *tdvp;
1707         int             error = 0;
1708 
1709         while (pfp = (portfop_t *)list_head(tlist)) {
1710                 int removed = 0;
1711                 /*
1712                  * remove from the temp list. Since PORT_FOP_REMOVING is
1713                  * set, no other thread should attempt to perform a
1714                  * list_remove on this pfp.
1715                  */
1716                 list_remove(tlist, pfp);
1717 
1718                 pfcp = pfp->pfop_pcache;
1719                 mutex_enter(&pfcp->pfc_lock);
1720 
1721                 /*
1722                  * Remove the event from the port queue if it was queued up.
1723                  * No need to clear the PORT_FOP_KEV_ONQ flag as this pfp is
1724                  * no longer on the vnode's list.
1725                  */
1726                 if ((pfp->pfop_flags & PORT_FOP_KEV_ONQ)) {
1727                         removed = port_remove_done_event(pfp->pfop_pev);
1728                 }
1729 
1730                 /*
1731                  * If still active or the event was queued up and
1732                  * had not been collected yet, send an EXCEPTION event.
1733                  */
1734                 if (pfp->pfop_flags & (PORT_FOP_ACTIVE) || removed) {
1735                         pp = pfp->pfop_pp;
1736                         /*
1737                          * Allocate a port_kevent_t non cached to send this
1738                          * event since we will be de-registering.
1739                          * The port_kevent_t cannot be pointing back to the
1740                          * pfp anymore.
1741                          */
1742                         pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
1743                         error = port_alloc_event_local(pp, PORT_SOURCE_FILE,
1744                             PORT_ALLOC_DEFAULT, &pkevp);
1745                         if (!error) {
1746 
1747                                 pkevp->portkev_callback = port_fop_callback;
1748                                 pkevp->portkev_arg = NULL;
1749                                 pkevp->portkev_object =
1750                                     pfp->pfop_pev->portkev_object;
1751                                 pkevp->portkev_user =
1752                                     pfp->pfop_pev->portkev_user;
1753                                 /*
1754                                  * Copy the pid of the watching process.
1755                                  */
1756                                 pkevp->portkev_pid =
1757                                     pfp->pfop_pev->portkev_pid;
1758                                 pkevp->portkev_events = op;
1759                                 port_send_event(pkevp);
1760                         }
1761                 }
1762                 /*
1763                  * At this point the pfp has been removed from the vnode's
1764                  * list its cached port_kevent_t is not on the done queue.
1765                  * Remove the pfp and free it from the cache.
1766                  */
1767                 tdvp = pfp->pfop_dvp;
1768                 port_pcache_remove_fop(pfcp, pfp);
1769                 mutex_exit(&pfcp->pfc_lock);
1770                 if (tdvp != NULL)
1771                         VN_RELE(tdvp);
1772         }
1773 }
1774 
1775 /*
1776  * Send the file events to all of the processes watching this
1777  * vnode. In case of hard links, the directory vnode pointer and
1778  * the file name are compared. If the names match, then the specified
1779  * event is sent or else, the FILE_ATTRIB event is sent, This is the
1780  * documented behavior.
1781  */
1782 void
1783 port_fop_sendevent(vnode_t *vp, int events, vnode_t *dvp, char *cname)
1784 {
1785         port_kevent_t   *pkevp;
1786         portfop_t       *pfp, *npfp;
1787         portfop_vp_t    *pvp;
1788         list_t          tmplist;
1789         int             removeall = 0;
1790 
1791         pvp = (portfop_vp_t *)vp->v_fopdata;
1792         mutex_enter(&pvp->pvp_mutex);
1793 
1794         /*
1795          * Check if the list is empty.
1796          *
1797          * All entries have been removed by some other thread.
1798          * The vnode may be still active and we got called,
1799          * but some other thread is in the process of removing the hooks.
1800          */
1801         if (!list_head(&pvp->pvp_pfoplist)) {
1802                 mutex_exit(&pvp->pvp_mutex);
1803                 return;
1804         }
1805 
1806         if ((events & (FILE_EXCEPTION))) {
1807                 /*
1808                  * If it is an event for which we are going to remove
1809                  * the watches so just move it a temporary list and
1810                  * release this vnode.
1811                  */
1812                 list_create(&tmplist, sizeof (portfop_t),
1813                     offsetof(portfop_t, pfop_node));
1814 
1815                 /*
1816                  * If it is an UNMOUNT, MOUNTEDOVER or no file name has been
1817                  * passed for an exception event, all associations need to be
1818                  * removed.
1819                  */
1820                 if (dvp == NULL || cname == NULL) {
1821                         removeall = 1;
1822                 }
1823         }
1824 
1825         if (!removeall) {
1826                 /*
1827                  * All the active ones are in the beginning of the list.
1828                  */
1829                 for (pfp = (portfop_t *)list_head(&pvp->pvp_pfoplist);
1830                     pfp && pfp->pfop_flags & PORT_FOP_ACTIVE; pfp = npfp) {
1831                         int levents = events;
1832 
1833                         npfp = list_next(&pvp->pvp_pfoplist, pfp);
1834                         /*
1835                          * Hard links case - If the file is being
1836                          * removed/renamed, and the name matches
1837                          * the watched file, then it is an EXCEPTION
1838                          * event or else it will be just a FILE_ATTRIB.
1839                          */
1840                         if ((events & (FILE_EXCEPTION))) {
1841                                 ASSERT(dvp != NULL && cname != NULL);
1842                                 if (pfp->pfop_dvp == NULL ||
1843                                     (pfp->pfop_dvp == dvp &&
1844                                     (strcmp(cname, pfp->pfop_cname) == 0))) {
1845                                         /*
1846                                          * It is an exception event, move it
1847                                          * to temp list and process it later.
1848                                          * Note we don't set the pfp->pfop_vp
1849                                          * to NULL even thought it has been
1850                                          * removed from the vnode's list. This
1851                                          * pointer is referenced in
1852                                          * port_remove_fop(). The vnode it
1853                                          * self cannot disappear until this
1854                                          * pfp gets removed and freed.
1855                                          */
1856                                         port_fop_listremove(pvp, pfp);
1857                                         list_insert_tail(&tmplist, (void *)pfp);
1858                                         pfp->pfop_flags  |= PORT_FOP_REMOVING;
1859                                         continue;
1860                                 } else {
1861                                         levents = FILE_ATTRIB;
1862                                 }
1863 
1864                         }
1865 
1866                         if (pfp->pfop_events & levents) {
1867                                 /*
1868                                  * deactivate and move it to the tail.
1869                                  * If the pfp was active, it cannot be
1870                                  * on the port's done queue.
1871                                  */
1872                                 pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
1873                                 port_fop_listremove(pvp, pfp);
1874                                 port_fop_listinsert_tail(pvp, pfp);
1875 
1876                                 pkevp = pfp->pfop_pev;
1877                                 pkevp->portkev_events |=
1878                                     (levents & pfp->pfop_events);
1879                                 port_send_event(pkevp);
1880                                 pfp->pfop_flags |= PORT_FOP_KEV_ONQ;
1881                         }
1882                 }
1883         }
1884 
1885 
1886         if ((events & (FILE_EXCEPTION))) {
1887                 if (!removeall) {
1888                         /*
1889                          * Check the inactive associations and remove them if
1890                          * the file name matches.
1891                          */
1892                         for (; pfp; pfp = npfp) {
1893                                 npfp = list_next(&pvp->pvp_pfoplist, pfp);
1894                                 if (dvp == NULL || cname == NULL ||
1895                                     pfp->pfop_dvp == NULL ||
1896                                     (pfp->pfop_dvp == dvp &&
1897                                     (strcmp(cname, pfp->pfop_cname) == 0))) {
1898                                         port_fop_listremove(pvp, pfp);
1899                                         list_insert_tail(&tmplist, (void *)pfp);
1900                                         pfp->pfop_flags  |= PORT_FOP_REMOVING;
1901                                 }
1902                         }
1903                 } else {
1904                         /*
1905                          * Can be optimized to avoid two pass over this list
1906                          * by having a flag in the vnode's portfop_vp_t
1907                          * structure to indicate that it is going away,
1908                          * Or keep the list short by reusing inactive watches.
1909                          */
1910                         port_fop_listmove(pvp, &tmplist);
1911                         for (pfp = (portfop_t *)list_head(&tmplist);
1912                             pfp; pfp = list_next(&tmplist, pfp)) {
1913                                 pfp->pfop_flags |= PORT_FOP_REMOVING;
1914                         }
1915                 }
1916 
1917                 /*
1918                  * Uninstall the fem hooks if there are no more associations.
1919                  * This will release the pvp mutex.
1920                  *
1921                  * Even thought all entries may have been removed,
1922                  * the vnode itself cannot disappear as there will be a
1923                  * hold on it due to this call to port_fop_sendevent. This is
1924                  * important to syncronize with a port_dissociate_fop() call
1925                  * that may be attempting to remove an object from the vnode's.
1926                  */
1927                 if (port_fop_femuninstall(vp))
1928                         VN_RELE(vp);
1929 
1930                 /*
1931                  * Send exception events and discard the watch entries.
1932                  */
1933                 port_fop_excep(&tmplist, events);
1934                 list_destroy(&tmplist);
1935 
1936         } else {
1937                 mutex_exit(&pvp->pvp_mutex);
1938 
1939                 /*
1940                  * trim the list.
1941                  */
1942                 port_fop_trimpfplist(vp);
1943         }
1944 }
1945 
1946 /*
1947  * Given the file operation, map it to the event types and send.
1948  */
1949 void
1950 port_fop(vnode_t *vp, int op, int retval)
1951 {
1952         int event = 0;
1953         /*
1954          * deliver events only if the operation was successful.
1955          */
1956         if (retval)
1957                 return;
1958 
1959         /*
1960          * These events occurring on the watched file.
1961          */
1962         if (op & FOP_MODIFIED_MASK) {
1963                 event  = FILE_MODIFIED;
1964         }
1965         if (op & FOP_ACCESS_MASK) {
1966                 event  |= FILE_ACCESS;
1967         }
1968         if (op & FOP_ATTRIB_MASK) {
1969                 event  |= FILE_ATTRIB;
1970         }
1971         if (op & FOP_TRUNC_MASK) {
1972                 event  |= FILE_TRUNC;
1973         }
1974         if (event) {
1975                 port_fop_sendevent(vp,  event, NULL, NULL);
1976         }
1977 }
1978 
1979 static int port_forceunmount(vfs_t *vfsp)
1980 {
1981         char *fsname = vfssw[vfsp->vfs_fstype].vsw_name;
1982 
1983         if (fsname == NULL) {
1984                 return (0);
1985         }
1986 
1987         if (strcmp(fsname, MNTTYPE_NFS) == 0) {
1988                 return (1);
1989         }
1990 
1991         if (strcmp(fsname, MNTTYPE_NFS3) == 0) {
1992                 return (1);
1993         }
1994 
1995         if (strcmp(fsname, MNTTYPE_NFS4) == 0) {
1996                 return (1);
1997         }
1998         return (0);
1999 }
2000 /*
2001  * ----- the unmount filesystem op(fsem) hook.
2002  */
2003 int
2004 port_fop_unmount(fsemarg_t *vf, int flag, cred_t *cr)
2005 {
2006         vfs_t   *vfsp = (vfs_t *)vf->fa_fnode->fn_available;
2007         kmutex_t        *mtx;
2008         portfop_vfs_t   *pvfsp, **ppvfsp;
2009         portfop_vp_t    *pvp;
2010         int error;
2011         int fmfs;
2012 
2013         fmfs = port_forceunmount(vfsp);
2014 
2015         mtx = &(portvfs_hash[PORTFOP_PVFSHASH(vfsp)].pvfshash_mutex);
2016         ppvfsp = &(portvfs_hash[PORTFOP_PVFSHASH(vfsp)].pvfshash_pvfsp);
2017         pvfsp = NULL;
2018         mutex_enter(mtx);
2019         /*
2020          * since this fsem hook is triggered, the vfsp has to be on
2021          * the hash list.
2022          */
2023         for (pvfsp = *ppvfsp; pvfsp->pvfs != vfsp; pvfsp = pvfsp->pvfs_next)
2024         ;
2025 
2026         /*
2027          * For some of the filesystems, allow unmounts to proceed only if
2028          * there are no files being watched or it is a forced unmount.
2029          */
2030         if (fmfs && !(flag & MS_FORCE) &&
2031             !list_is_empty(&pvfsp->pvfs_pvplist)) {
2032                 mutex_exit(mtx);
2033                 return (EBUSY);
2034         }
2035 
2036         /*
2037          * Indicate that the unmount is in process. Don't remove it yet.
2038          * The underlying filesystem unmount routine sets the VFS_UNMOUNTED
2039          * flag on the vfs_t structure. But we call the filesystem unmount
2040          * routine after removing all the file watches for this filesystem,
2041          * otherwise the unmount will fail due to active vnodes.
2042          * Meanwhile setting pvfsp->unmount = 1 will prevent any thread
2043          * attempting to add a file watch.
2044          */
2045         pvfsp->pvfs_unmount = 1;
2046         mutex_exit(mtx);
2047 
2048         /*
2049          * uninstall the fsem hooks.
2050          */
2051         (void) fsem_uninstall(vfsp, (fsem_t *)pvfsp->pvfs_fsemp, vfsp);
2052 
2053         while (pvp = list_head(&pvfsp->pvfs_pvplist)) {
2054                 list_remove(&pvfsp->pvfs_pvplist, pvp);
2055                 /*
2056                  * This should send an UNMOUNTED event to all the
2057                  * watched vnode of this filesystem and uninstall
2058                  * the fem hooks. We release the hold on the vnode here
2059                  * because port_fop_femuninstall() will not do it if
2060                  * unmount is in process.
2061                  */
2062                 port_fop_sendevent(pvp->pvp_vp, UNMOUNTED, NULL, NULL);
2063                 VN_RELE(pvp->pvp_vp);
2064         }
2065 
2066         error = vfsnext_unmount(vf, flag, cr);
2067 
2068         /*
2069          * we free the pvfsp after the unmount has been completed.
2070          */
2071         mutex_enter(mtx);
2072         for (; *ppvfsp && (*ppvfsp)->pvfs != vfsp;
2073             ppvfsp = &(*ppvfsp)->pvfs_next)
2074         ;
2075 
2076         /*
2077          * remove and free it.
2078          */
2079         ASSERT(list_head(&pvfsp->pvfs_pvplist) == NULL);
2080         if (*ppvfsp) {
2081                 pvfsp = *ppvfsp;
2082                 *ppvfsp = pvfsp->pvfs_next;
2083         }
2084         mutex_exit(mtx);
2085         kmem_free(pvfsp, sizeof (portfop_vfs_t));
2086         return (error);
2087 }
2088 
2089 /*
2090  * ------------------------------file op hooks--------------------------
2091  * The O_TRUNC operation is caught with the VOP_SETATTR(AT_SIZE) call.
2092  */
2093 static int
2094 port_fop_open(femarg_t *vf, int mode, cred_t *cr, caller_context_t *ct)
2095 {
2096         int             retval;
2097         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2098 
2099         retval = vnext_open(vf, mode, cr, ct);
2100         port_fop(vp, FOP_FILE_OPEN, retval);
2101         return (retval);
2102 }
2103 
2104 static int
2105 port_fop_write(femarg_t *vf, struct uio *uiop, int ioflag, struct cred *cr,
2106     caller_context_t *ct)
2107 {
2108         int             retval;
2109         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2110 
2111         retval =  vnext_write(vf, uiop, ioflag, cr, ct);
2112         port_fop(vp, FOP_FILE_WRITE, retval);
2113         return (retval);
2114 }
2115 
2116 static int
2117 port_fop_map(femarg_t *vf, offset_t off, struct as *as, caddr_t *addrp,
2118     size_t len, uchar_t prot, uchar_t maxport, uint_t flags, cred_t *cr,
2119     caller_context_t *ct)
2120 {
2121         int             retval;
2122         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2123 
2124         retval =  vnext_map(vf, off, as, addrp, len, prot, maxport,
2125             flags, cr, ct);
2126         port_fop(vp, FOP_FILE_MAP, retval);
2127         return (retval);
2128 }
2129 
2130 static int
2131 port_fop_read(femarg_t *vf, struct uio *uiop, int ioflag, struct cred *cr,
2132     caller_context_t *ct)
2133 {
2134         int             retval;
2135         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2136 
2137         retval =  vnext_read(vf, uiop, ioflag, cr, ct);
2138         port_fop(vp, FOP_FILE_READ, retval);
2139         return (retval);
2140 }
2141 
2142 
2143 /*
2144  * AT_SIZE - is for the open(O_TRUNC) case.
2145  */
2146 int
2147 port_fop_setattr(femarg_t *vf, vattr_t *vap, int flags, cred_t *cr,
2148     caller_context_t *ct)
2149 {
2150         int             retval;
2151         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2152         int             events = 0;
2153 
2154         retval = vnext_setattr(vf, vap, flags, cr, ct);
2155         if (vap->va_mask & AT_SIZE) {
2156                 events |= FOP_FILE_TRUNC;
2157         }
2158         if (vap->va_mask & (AT_SIZE|AT_MTIME)) {
2159                 events |= FOP_FILE_SETATTR_MTIME;
2160         }
2161         if (vap->va_mask & AT_ATIME) {
2162                 events |= FOP_FILE_SETATTR_ATIME;
2163         }
2164         events |= FOP_FILE_SETATTR_CTIME;
2165 
2166         port_fop(vp, events, retval);
2167         return (retval);
2168 }
2169 
2170 int
2171 port_fop_create(femarg_t *vf, char *name, vattr_t *vap, vcexcl_t excl,
2172     int mode, vnode_t **vpp, cred_t *cr, int flag,
2173     caller_context_t *ct, vsecattr_t *vsecp)
2174 {
2175         int             retval, got = 1;
2176         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2177         vattr_t         vatt, vatt1;
2178 
2179         /*
2180          * If the file already exists, then there will be no change
2181          * to the directory. Therefore, we need to compare the
2182          * modification time of the directory to determine if the
2183          * file was actually created.
2184          */
2185         vatt.va_mask = AT_ATIME|AT_MTIME|AT_CTIME;
2186         if (VOP_GETATTR(vp, &vatt, 0, CRED(), ct)) {
2187                 got = 0;
2188         }
2189         retval = vnext_create(vf, name, vap, excl, mode, vpp, cr,
2190             flag, ct, vsecp);
2191 
2192         vatt1.va_mask = AT_ATIME|AT_MTIME|AT_CTIME;
2193         if (got && !VOP_GETATTR(vp, &vatt1, 0, CRED(), ct)) {
2194                 if ((vatt1.va_mtime.tv_sec > vatt.va_mtime.tv_sec ||
2195                     (vatt1.va_mtime.tv_sec = vatt.va_mtime.tv_sec &&
2196                     vatt1.va_mtime.tv_nsec > vatt.va_mtime.tv_nsec))) {
2197                         /*
2198                          * File was created.
2199                          */
2200                         port_fop(vp, FOP_FILE_CREATE, retval);
2201                 }
2202         }
2203         return (retval);
2204 }
2205 
2206 int
2207 port_fop_remove(femarg_t *vf, char *nm, cred_t *cr, caller_context_t *ct,
2208     int flags)
2209 {
2210         int             retval;
2211         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2212 
2213         retval = vnext_remove(vf, nm, cr, ct, flags);
2214         port_fop(vp, FOP_FILE_REMOVE, retval);
2215         return (retval);
2216 }
2217 
2218 int
2219 port_fop_link(femarg_t *vf, vnode_t *svp, char *tnm, cred_t *cr,
2220     caller_context_t *ct, int flags)
2221 {
2222         int             retval;
2223         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2224 
2225         retval = vnext_link(vf, svp, tnm, cr, ct, flags);
2226         port_fop(vp, FOP_FILE_LINK, retval);
2227         return (retval);
2228 }
2229 
2230 /*
2231  * Rename operation is allowed only when from and to directories are
2232  * on the same filesystem. This is checked in vn_rename().
2233  * The target directory is notified thru a VNEVENT by the filesystem
2234  * if the source dir != target dir.
2235  */
2236 int
2237 port_fop_rename(femarg_t *vf, char *snm, vnode_t *tdvp, char *tnm, cred_t *cr,
2238     caller_context_t *ct, int flags)
2239 {
2240         int             retval;
2241         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2242 
2243         retval = vnext_rename(vf, snm, tdvp, tnm, cr, ct, flags);
2244         port_fop(vp, FOP_FILE_RENAMESRC, retval);
2245         return (retval);
2246 }
2247 
2248 int
2249 port_fop_mkdir(femarg_t *vf, char *dirname, vattr_t *vap, vnode_t **vpp,
2250     cred_t *cr, caller_context_t *ct, int flags, vsecattr_t *vsecp)
2251 {
2252         int             retval;
2253         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2254 
2255         retval = vnext_mkdir(vf, dirname, vap, vpp, cr, ct, flags, vsecp);
2256         port_fop(vp, FOP_FILE_MKDIR, retval);
2257         return (retval);
2258 }
2259 
2260 int
2261 port_fop_rmdir(femarg_t *vf, char *nm, vnode_t *cdir, cred_t *cr,
2262     caller_context_t *ct, int flags)
2263 {
2264         int             retval;
2265         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2266 
2267         retval = vnext_rmdir(vf, nm, cdir, cr, ct, flags);
2268         port_fop(vp, FOP_FILE_RMDIR, retval);
2269         return (retval);
2270 }
2271 
2272 int
2273 port_fop_readdir(femarg_t *vf, uio_t *uiop, cred_t *cr, int *eofp,
2274     caller_context_t *ct, int flags)
2275 {
2276         int             retval;
2277         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2278 
2279         retval = vnext_readdir(vf, uiop, cr, eofp, ct, flags);
2280         port_fop(vp, FOP_FILE_READDIR, retval);
2281         return (retval);
2282 }
2283 
2284 int
2285 port_fop_symlink(femarg_t *vf, char *linkname, vattr_t *vap, char *target,
2286     cred_t *cr, caller_context_t *ct, int flags)
2287 {
2288         int             retval;
2289         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2290 
2291         retval = vnext_symlink(vf, linkname, vap, target, cr, ct, flags);
2292         port_fop(vp, FOP_FILE_SYMLINK, retval);
2293         return (retval);
2294 }
2295 
2296 /*
2297  * acl, facl call this.
2298  */
2299 int
2300 port_fop_setsecattr(femarg_t *vf, vsecattr_t *vsap, int flags, cred_t *cr,
2301     caller_context_t *ct)
2302 {
2303         int     retval;
2304         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2305         retval = vnext_setsecattr(vf, vsap, flags, cr, ct);
2306         port_fop(vp, FOP_FILE_SETSECATTR, retval);
2307         return (retval);
2308 }
2309 
2310 /*
2311  * these are events on the watched file/directory
2312  */
2313 int
2314 port_fop_vnevent(femarg_t *vf, vnevent_t vnevent, vnode_t *dvp, char *name,
2315     caller_context_t *ct)
2316 {
2317         vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
2318 
2319         switch (vnevent) {
2320         case    VE_RENAME_SRC:
2321                         port_fop_sendevent(vp, FILE_RENAME_FROM, dvp, name);
2322                 break;
2323         case    VE_RENAME_DEST:
2324                         port_fop_sendevent(vp, FILE_RENAME_TO, dvp, name);
2325                 break;
2326         case    VE_REMOVE:
2327                         port_fop_sendevent(vp, FILE_DELETE, dvp, name);
2328                 break;
2329         case    VE_RMDIR:
2330                         port_fop_sendevent(vp, FILE_DELETE, dvp, name);
2331                 break;
2332         case    VE_CREATE:
2333                         port_fop_sendevent(vp,
2334                             FILE_MODIFIED|FILE_ATTRIB|FILE_TRUNC, NULL, NULL);
2335                 break;
2336         case    VE_LINK:
2337                         port_fop_sendevent(vp, FILE_ATTRIB, NULL, NULL);
2338                 break;
2339 
2340         case    VE_RENAME_DEST_DIR:
2341                         port_fop_sendevent(vp, FILE_MODIFIED|FILE_ATTRIB,
2342                             NULL, NULL);
2343                 break;
2344 
2345         case    VE_MOUNTEDOVER:
2346                         port_fop_sendevent(vp, MOUNTEDOVER, NULL, NULL);
2347                 break;
2348         default:
2349                 break;
2350         }
2351         return (vnext_vnevent(vf, vnevent, dvp, name, ct));
2352 }