/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 2018, Joyent, Inc.
 * Copyright 2022 Oxide Computer Company
 */

/*
 * File Events Notification
 * ------------------------
 *
 * The File Events Notification facility provides file and directory change
 * notification. It is implemented as an event source(PORT_SOURCE_FILE)
 * under the Event Ports framework. Therefore the API is an extension to
 * the Event Ports API.
 *
 * It uses the FEM (File Events Monitoring) framework to intercept
 * operations on the files & directories and generate appropriate events.
 *
 * It provides event notification in accordance with what an application
 * can find out by stat`ing the file and comparing time stamps. The various
 * system calls that update the file's access, modification, and change
 * time stamps are documented in the man page section 2.
 *
 * It is non intrusive. That is, having an active file event watch on a file
 * or directory will not prevent it from being removed or renamed or block an
 * unmount operation of the file system where the watched file or directory
 * resides.
 *
 *
 * Interface:
 * ----------
 *
 *   The object for this event source is of type 'struct file_obj *'
 *
 *   The file that needs to be monitored is specified in 'fo_name'.
 *   The time stamps collected by a stat(2) call are passed in fo_atime,
 *   fo_mtime, fo_ctime. At the time a file events watch is registered, the
 *   time stamps passed in are compared with the current time stamps of the
 *   file. If it has changed, relevant events are sent immediately. If the time
 *   stamps are all '0', they will not be compared.
 *
 *
 * The events are delivered to an event port. A port is created using
 * port_create().
 *
 * To register a file events watch on a file or directory.
 *
 *   port_associate(int port, PORT_SOURCE_FILE, (uintptr_t)&fobj, events, user)
 *
 *   'user' is the user pointer to be returned with the event.
 *
 * To de-register a file events watch,
 *
 *   port_dissociate(int port, PORT_SOURCE_FILE, (uintptr_t)&fobj)
 *
 * The events are collected using the port_get()/port_getn() interface. The
 * event source will be PORT_SOURCE_FILE.
 *
 * After an event is delivered, the file events watch gets de-activated. To
 * receive the next event, the process will have to re-register the watch and
 * activate it by calling port_associate() again. This behavior is intentional
 * and supports proper multi threaded programming when using file events
 * notification API.
 *
 *
 * Implementation overview:
 * ------------------------
 *
 * Each file events watch is represented by 'portfop_t' in the kernel. A
 * cache(in portfop_cache_t) of these portfop_t's are maintained per event
 * port by this source. The object here is the pointer to the file_obj
 * structure. The portfop_t's are hashed in using the object pointer. Therefore
 * it is possible to have multiple file events watches on a file by the same
 * process by using different object structure(file_obj_t) and hence can
 * receive multiple event notification for a file. These watches can be for
 * different event types.
 *
 * The cached entries of these file objects are retained, even after delivering
 * an event, marking them inactive for performance reasons. The assumption
 * is that the process would come back and re-register the file to receive
 * further events. When there are more then 'port_fop_maxpfps' watches per file
 * it will attempt to free the oldest inactive watches.
 *
 * In case the event that is being delivered is an exception event, the cached
 * entries get removed. An exception event on a file or directory means its
 * identity got changed(rename to/from, delete, mounted over, file system
 * unmount).
 *
 * If the event port gets closed, all the associated file event watches will be
 * removed and discarded.
 *
 *
 * Data structures:
 * ----------------
 *
 * The list of file event watches per file are managed by the data structure
 * portfop_vp_t. The first time a file events watch is registered for a file,
 * a portfop_vp_t is installed on the vnode_t's member v_fopdata. This gets
 * removed and freed only when the vnode becomes inactive. The FEM hooks are
 * also installed when the first watch is registered on a file. The FEM hooks
 * get un-installed when all the watches are removed.
 *
 * Each file events watch is represented by the structure portfop_t. They
 * get added to a list of portfop_t's on the vnode(portfop_vp_t). After
 * delivering an event, the portfop_t is marked inactive but retained. It is
 * moved to the end of the list. All the active portfop_t's are maintained at
 * the beginning. In case of exception events, the portfop_t will be removed
 * and discarded.
 *
 * To intercept unmount operations, FSEM hooks are added to the file system
 * under which files are being watched. A hash table('portfop_vfs_hash_t') of
 * active file systems is maintained. Each file system that has active watches
 * is represented by 'portfop_vfs_t' and is added to the hash table.
 * The vnode's 'portfop_vp_t' structure is added to the list of files(vnodes)
 * being watched on the portfop_vfs_t structure.
 *
 *
 * File system support:
 * -------------------
 *
 * The file system implementation has to provide vnode event notifications
 * (vnevents) in order to support watching any files on that file system.
 * The vnode events(vnevents) are notifications provided by the file system
 * for name based file operations like rename, remove etc, which do not go
 * thru the VOP_** interfaces. If the file system does not implement vnode
 * notifications, watching for file events on such file systems is not
 * supported. The vnode event notifications support is determined by the call
 * vnevent_support(vp) (VOP_VNEVENT(vp, VE_SUPPORT)), which the file system
 * has to implement.
 *
 *
 * Locking order:
 * --------------
 *
 * A file(vnode) can have file event watches registered by different processes.
 * There is one portfop_t per watch registered. These are on the vnode's list
 * protected by the mutex 'pvp_mutex' in 'portfop_vp_t'. The portfop_t's are
 * also on the per port cache. The cache is protected by the pfc_lock of
 * portfop_cache_t. The lock order here is 'pfc_lock' -> 'pvp_mutex'.
 *
 */

#include <sys/types.h>
#include <sys/systm.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <sys/kmem.h>
#include <sys/sysmacros.h>
#include <sys/debug.h>
#include <sys/vnode.h>
#include <sys/poll_impl.h>
#include <sys/port_impl.h>
#include <sys/fem.h>
#include <sys/vfs_opreg.h>
#include <sys/atomic.h>
#include <sys/mount.h>
#include <sys/mntent.h>

/*
 * For special case support of mnttab (/etc/mnttab).
 */
extern struct vnode *vfs_mntdummyvp;
extern int mntfstype;

#define PORTFOP_PVFSH(vfsp)     (&portvfs_hash[PORTFOP_PVFSHASH(vfsp)])
portfop_vfs_hash_t       portvfs_hash[PORTFOP_PVFSHASH_SZ];

#define PORTFOP_NVP     20
/*
 * Inactive file event watches(portfop_t) are retained on the vnode's list
 * for performance reason. If the applications re-registers the file, the
 * inactive entry is made active and moved up the list.
 *
 * If there are greater then the following number of watches on a vnode,
 * it will attempt to discard an oldest inactive watch(pfp) at the time
 * a new watch is being registered and when events get delivered. We
 * do this to avoid accumulating inactive watches on a file.
 */
int     port_fop_maxpfps = 20;

/* local functions */
static int      port_fop_callback(void *, int *, pid_t, int, void *);

static void     port_pcache_insert(portfop_cache_t *, portfop_t *);
static void     port_pcache_delete(portfop_cache_t *, portfop_t *);
static void     port_close_fop(void *arg, int port, pid_t pid, int lastclose);

/*
 * port fop functions that will be the fem hooks.
 */
static int port_fop_open(femarg_t *vf, int mode, cred_t *cr,
    caller_context_t *);
static int port_fop_read(femarg_t *vf, uio_t *uiop, int ioflag, cred_t *cr,
    struct caller_context *ct);
static int port_fop_write(femarg_t *vf, uio_t *uiop, int ioflag, cred_t *cr,
    caller_context_t *ct);
static int port_fop_map(femarg_t *vf, offset_t off, struct as *as,
    caddr_t *addrp, size_t len, uchar_t prot, uchar_t maxport,
    uint_t flags, cred_t *cr, caller_context_t *ct);
static int port_fop_setattr(femarg_t *vf, vattr_t *vap, int flags, cred_t *cr,
    caller_context_t *ct);
static int port_fop_create(femarg_t *vf, char *name, vattr_t *vap,
    vcexcl_t excl, int mode, vnode_t **vpp, cred_t *cr, int flag,
    caller_context_t *ct, vsecattr_t *vsecp);
static int port_fop_remove(femarg_t *vf, char *nm, cred_t *cr,
    caller_context_t *ct, int flags);
static int port_fop_link(femarg_t *vf, vnode_t *svp, char *tnm, cred_t *cr,
    caller_context_t *ct, int flags);
static int port_fop_rename(femarg_t *vf, char *snm, vnode_t *tdvp, char *tnm,
    cred_t *cr, caller_context_t *ct, int flags);
static int port_fop_mkdir(femarg_t *vf, char *dirname, vattr_t *vap,
    vnode_t **vpp, cred_t *cr, caller_context_t *ct, int flags,
    vsecattr_t *vsecp);
static int port_fop_rmdir(femarg_t *vf, char *nm, vnode_t *cdir, cred_t *cr,
    caller_context_t *ct, int flags);
static int port_fop_readdir(femarg_t *vf, uio_t *uiop, cred_t *cr, int *eofp,
    caller_context_t *ct, int flags);
static int port_fop_symlink(femarg_t *vf, char *linkname, vattr_t *vap,
    char *target, cred_t *cr, caller_context_t *ct, int flags);
static int port_fop_setsecattr(femarg_t *vf, vsecattr_t *vsap, int flag,
    cred_t *cr, caller_context_t *ct);

static int port_fop_vnevent(femarg_t *vf, vnevent_t vnevent, vnode_t *dvp,
    char *cname, caller_context_t *ct);

static int port_fop_unmount(fsemarg_t *vf, int flag, cred_t *cr);


/*
 * Fem hooks.
 */
const fs_operation_def_t        port_vnodesrc_template[] = {
        VOPNAME_OPEN,           { .femop_open = port_fop_open },
        VOPNAME_READ,           { .femop_read = port_fop_read },
        VOPNAME_WRITE,          { .femop_write = port_fop_write },
        VOPNAME_MAP,            { .femop_map = port_fop_map },
        VOPNAME_SETATTR,        { .femop_setattr = port_fop_setattr },
        VOPNAME_CREATE,         { .femop_create = port_fop_create },
        VOPNAME_REMOVE,         { .femop_remove = port_fop_remove },
        VOPNAME_LINK,           { .femop_link = port_fop_link },
        VOPNAME_RENAME,         { .femop_rename = port_fop_rename },
        VOPNAME_MKDIR,          { .femop_mkdir = port_fop_mkdir },
        VOPNAME_RMDIR,          { .femop_rmdir = port_fop_rmdir },
        VOPNAME_READDIR,        { .femop_readdir = port_fop_readdir },
        VOPNAME_SYMLINK,        { .femop_symlink = port_fop_symlink },
        VOPNAME_SETSECATTR,     { .femop_setsecattr = port_fop_setsecattr },
        VOPNAME_VNEVENT,        { .femop_vnevent = port_fop_vnevent },
        NULL,   NULL
};

/*
 * Fsem - vfs ops hooks
 */
const fs_operation_def_t        port_vfssrc_template[] = {
        VFSNAME_UNMOUNT,        { .fsemop_unmount = port_fop_unmount },
        NULL,   NULL
};

fem_t *fop_femop;
fsem_t *fop_fsemop;

static fem_t *
port_fop_femop()
{
        fem_t *femp;
        if (fop_femop != NULL)
                return (fop_femop);
        if (fem_create("portfop_fem",
            (const struct fs_operation_def *)port_vnodesrc_template,
            (fem_t **)&femp)) {
                return (NULL);
        }
        if (atomic_cas_ptr(&fop_femop, NULL, femp) != NULL) {
                /*
                 * some other thread beat us to it.
                 */
                fem_free(femp);
        }
        return (fop_femop);
}

static fsem_t *
port_fop_fsemop()
{
        fsem_t *fsemp;
        if (fop_fsemop != NULL)
                return (fop_fsemop);
        if (fsem_create("portfop_fsem", port_vfssrc_template, &fsemp)) {
                return (NULL);
        }
        if (atomic_cas_ptr(&fop_fsemop, NULL, fsemp) != NULL) {
                /*
                 * some other thread beat us to it.
                 */
                fsem_free(fsemp);
        }
        return (fop_fsemop);
}

/*
 * port_fop_callback()
 * - PORT_CALLBACK_DEFAULT
 *      The file event will be delivered to the application.
 * - PORT_CALLBACK_DISSOCIATE
 *      The object will be dissociated from  the port.
 * - PORT_CALLBACK_CLOSE
 *      The object will be dissociated from the port because the port
 *      is being closed.
 */
/* ARGSUSED */
static int
port_fop_callback(void *arg, int *events, pid_t pid, int flag, void *evp)
{
        portfop_t       *pfp = (portfop_t *)arg;
        port_kevent_t   *pkevp = (port_kevent_t *)evp;
        int             error = 0;

        ASSERT((events != NULL));
        if (flag == PORT_CALLBACK_DEFAULT) {
                if (curproc->p_pid != pid) {
                                return (EACCES); /* deny delivery of events */
                }

                *events = pkevp->portkev_events;
                pkevp->portkev_events = 0;
                if (pfp != NULL) {
                        pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
                }
        }
        return (error);
}

/*
 * Inserts a portfop_t into the port sources cache's.
 */
static void
port_pcache_insert(portfop_cache_t *pfcp, portfop_t *pfp)
{
        portfop_t       **bucket;

        ASSERT(MUTEX_HELD(&pfcp->pfc_lock));
        bucket = PORT_FOP_BUCKET(pfcp, pfp->pfop_object);
        pfp->pfop_hashnext = *bucket;
        *bucket = pfp;
        pfcp->pfc_objcount++;
}

/*
 * Remove the pfp from the port source cache.
 */
static void
port_pcache_delete(portfop_cache_t *pfcp, portfop_t *pfp)
{
        portfop_t       *lpdp;
        portfop_t       *cpdp;
        portfop_t       **bucket;

        bucket = PORT_FOP_BUCKET(pfcp, pfp->pfop_object);
        cpdp = *bucket;
        if (pfp == cpdp) {
                *bucket = pfp->pfop_hashnext;
        } else {
                while (cpdp != NULL) {
                        lpdp = cpdp;
                        cpdp = cpdp->pfop_hashnext;
                        if (cpdp == pfp) {
                                /* portfop struct found */
                                lpdp->pfop_hashnext = pfp->pfop_hashnext;
                                break;
                        }
                }
        }
        pfcp->pfc_objcount--;
}

/*
 * The vnode's(portfop_vp_t) pfp list management. The 'pvp_mutex' is held
 * when these routines are called.
 *
 * The 'pvp_lpfop' member points to the oldest inactive entry on the list.
 * It is used to discard the oldtest inactive pfp if the number of entries
 * exceed the limit.
 */
static void
port_fop_listinsert(portfop_vp_t *pvp, portfop_t *pfp, int where)
{
        if (where == 1) {
                list_insert_head(&pvp->pvp_pfoplist, (void *)pfp);
        } else {
                list_insert_tail(&pvp->pvp_pfoplist, (void *)pfp);
        }
        if (pvp->pvp_lpfop == NULL) {
                pvp->pvp_lpfop = pfp;
        }
        pvp->pvp_cnt++;
}

static void
port_fop_listinsert_head(portfop_vp_t *pvp, portfop_t *pfp)
{
        port_fop_listinsert(pvp, pfp, 1);
}

static void
port_fop_listinsert_tail(portfop_vp_t *pvp, portfop_t *pfp)
{
        /*
         * We point lpfop to an inactive one, if it was initially pointing
         * to an active one. Insert to the tail is done only when a pfp goes
         * inactive.
         */
        if (pvp->pvp_lpfop && pvp->pvp_lpfop->pfop_flags & PORT_FOP_ACTIVE) {
                pvp->pvp_lpfop = pfp;
        }
        port_fop_listinsert(pvp, pfp, 0);
}

static void
port_fop_listremove(portfop_vp_t *pvp, portfop_t *pfp)
{
        if (pvp->pvp_lpfop == pfp) {
                pvp->pvp_lpfop = list_next(&pvp->pvp_pfoplist, (void *)pfp);
        }

        list_remove(&pvp->pvp_pfoplist, (void *)pfp);

        pvp->pvp_cnt--;
        if (pvp->pvp_cnt && pvp->pvp_lpfop == NULL) {
                pvp->pvp_lpfop = list_head(&pvp->pvp_pfoplist);
        }
}

static void
port_fop_listmove(portfop_vp_t *pvp, list_t *tlist)
{
        list_move_tail(tlist, &pvp->pvp_pfoplist);
        pvp->pvp_lpfop = NULL;
        pvp->pvp_cnt = 0;
}

/*
 * Remove a portfop_t from the port cache hash table and discard it.
 * It is called only when pfp is not on the vnode's list. Otherwise,
 * port_remove_fop() is called.
 */
void
port_pcache_remove_fop(portfop_cache_t *pfcp, portfop_t *pfp)
{
        port_kevent_t   *pkevp;


        ASSERT(MUTEX_HELD(&pfcp->pfc_lock));

        pkevp = pfp->pfop_pev;
        pfp->pfop_pev = NULL;

        if (pkevp != NULL) {
                (void) port_remove_done_event(pkevp);
                port_free_event_local(pkevp, 0);
        }

        port_pcache_delete(pfcp, pfp);

        if (pfp->pfop_cname != NULL)
                kmem_free(pfp->pfop_cname, pfp->pfop_clen + 1);
        kmem_free(pfp, sizeof (portfop_t));
        if (pfcp->pfc_objcount == 0)
                cv_signal(&pfcp->pfc_lclosecv);
}

/*
 * if we have too many watches on the vnode, attempt to discard an
 * inactive one.
 */
static void
port_fop_trimpfplist(vnode_t *vp)
{
        portfop_vp_t *pvp;
        portfop_t *pfp = NULL;
        portfop_cache_t *pfcp;
        vnode_t *tdvp;

        /*
         * Due to a reference the vnode cannot disappear, v_fopdata should
         * not change.
         */
        if ((pvp = vp->v_fopdata) != NULL &&
            pvp->pvp_cnt > port_fop_maxpfps) {
                mutex_enter(&pvp->pvp_mutex);
                pfp = pvp->pvp_lpfop;
                pfcp = pfp->pfop_pcache;
                /*
                 * only if we can get the cache lock, we need to
                 * do this due to reverse lock order and some thread
                 * that may be trying to reactivate this entry.
                 */
                if (mutex_tryenter(&pfcp->pfc_lock)) {
                        if (pfp && !(pfp->pfop_flags & PORT_FOP_ACTIVE) &&
                            !(pfp->pfop_flags & PORT_FOP_KEV_ONQ)) {
                                port_fop_listremove(pvp, pfp);
                                pfp->pfop_flags |= PORT_FOP_REMOVING;
                        } else {
                                mutex_exit(&pfcp->pfc_lock);
                                pfp = NULL;
                        }
                } else {
                        pfp = NULL;
                }
                mutex_exit(&pvp->pvp_mutex);

                /*
                 * discard pfp if any.
                 */
                if (pfp != NULL) {
                        tdvp = pfp->pfop_dvp;
                        port_pcache_remove_fop(pfcp, pfp);
                        mutex_exit(&pfcp->pfc_lock);
                        if (tdvp != NULL)
                                VN_RELE(tdvp);
                }
        }
}

/*
 * This routine returns 1, if the vnode can be rele'ed by the caller.
 * The caller has to VN_RELE the vnode with out holding any
 * locks.
 */
int
port_fop_femuninstall(vnode_t *vp)
{
        portfop_vp_t    *pvp;
        vfs_t           *vfsp;
        portfop_vfs_t *pvfsp;
        portfop_vfs_hash_t      *pvfsh;
        kmutex_t        *mtx;
        int     ret = 0;

        /*
         * if list is empty, uninstall fem.
         */
        pvp = vp->v_fopdata;
        ASSERT(MUTEX_HELD(&pvp->pvp_mutex));

        /*
         * make sure the list is empty.
         */
        if (!list_head(&pvp->pvp_pfoplist)) {

                /*
                 * we could possibly uninstall the fem hooks when
                 * the vnode becomes inactive and the v_fopdata is
                 * free. But the hooks get triggered unnecessarily
                 * even though there are no active watches. So, we
                 * uninstall it here.
                 */
                (void) fem_uninstall(vp, (fem_t *)pvp->pvp_femp, vp);
                pvp->pvp_femp = NULL;


                /*
                 * If we successfully uninstalled fem, no process is watching
                 * this vnode, Remove it from the vfs's list of watched vnodes.
                 */
                pvfsp = pvp->pvp_pvfsp;
                vfsp = vp->v_vfsp;
                pvfsh = PORTFOP_PVFSH(vfsp);
                mtx = &pvfsh->pvfshash_mutex;
                mutex_enter(mtx);
                /*
                 * If unmount is in progress, that thread will remove and
                 * release the vnode from the vfs's list, just leave.
                 */
                if (!pvfsp->pvfs_unmount) {
                        list_remove(&pvfsp->pvfs_pvplist, pvp);
                        mutex_exit(mtx);
                        ret = 1;
                } else {
                        mutex_exit(mtx);
                }
        }
        mutex_exit(&pvp->pvp_mutex);
        return (ret);
}

/*
 * Remove pfp from the vnode's watch list and the cache and discard it.
 * If it is the last pfp on the vnode's list, the fem hooks get uninstalled.
 * Returns 1 if pfp removed successfully.
 *
 * The *active is set to indicate if the pfp was still active(no events had
 * been posted, or the posted event had not been collected yet and it was
 * able to remove it from the port's queue).
 *
 * vpp and dvpp will point to the vnode and directory vnode which the caller
 * is required to VN_RELE without holding any locks.
 */
int
port_remove_fop(portfop_t *pfp, portfop_cache_t *pfcp, int cleanup,
    int *active, vnode_t **vpp, vnode_t **dvpp)
{
        vnode_t         *vp;
        portfop_vp_t    *pvp;
        int     tactive = 0;

        ASSERT(MUTEX_HELD(&pfcp->pfc_lock));
        vp = pfp->pfop_vp;
        pvp = vp->v_fopdata;
        mutex_enter(&pvp->pvp_mutex);

        /*
         * if not cleanup, remove it only if the pfp is still active and
         * is not being removed by some other thread.
         */
        if (!cleanup && (!(pfp->pfop_flags & PORT_FOP_ACTIVE) ||
            pfp->pfop_flags & PORT_FOP_REMOVING)) {
                mutex_exit(&pvp->pvp_mutex);
                return (0);
        }

        /*
         * mark it inactive.
         */
        if (pfp->pfop_flags & PORT_FOP_ACTIVE) {
                pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
                tactive = 1;
        }

        /*
         * Check if the pfp is still on the vnode's list. This can
         * happen if port_fop_excep() is in the process of removing it.
         * In case of cleanup, just mark this pfp as inactive so that no
         * new events (VNEVENT) will be delivered, and remove it from the
         * event queue if it was already queued. Since the cache lock is
         * held, the pfp will not disappear, even though it is being
         * removed.
         */
        if (pfp->pfop_flags & PORT_FOP_REMOVING) {
                mutex_exit(&pvp->pvp_mutex);
                if (!tactive && port_remove_done_event(pfp->pfop_pev)) {
                        pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
                        tactive = 1;
                }
                if (active) {
                        *active = tactive;
                }
                return (1);
        }

        /*
         * if we find an event on the queue and removed it, then this
         * association is considered active.
         */
        if (!tactive && port_remove_done_event(pfp->pfop_pev)) {
                pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
                tactive = 1;
        }

        if (active) {
                *active = tactive;
        }
        pvp = (portfop_vp_t *)vp->v_fopdata;

        /*
         * remove pfp from the vnode's list
         */
        port_fop_listremove(pvp, pfp);

        /*
         * If no more associations on the vnode, uninstall fem hooks.
         * The pvp mutex will be released in this routine.
         */
        if (port_fop_femuninstall(vp))
                *vpp = vp;
        *dvpp = pfp->pfop_dvp;
        port_pcache_remove_fop(pfcp, pfp);
        return (1);
}

/*
 * This routine returns a pointer to a cached portfop entry, or NULL if it
 * does not find it in the hash table. The object pointer is used as index.
 * The entries are hashed by the object's address. We need to match the pid
 * as the evet port can be shared between processes. The file events
 * watches are per process only.
 */
portfop_t *
port_cache_lookup_fop(portfop_cache_t *pfcp, pid_t pid, uintptr_t obj)
{
        portfop_t       *pfp = NULL;
        portfop_t       **bucket;

        ASSERT(MUTEX_HELD(&pfcp->pfc_lock));
        bucket = PORT_FOP_BUCKET(pfcp, obj);
        pfp = *bucket;
        while (pfp != NULL) {
                if (pfp->pfop_object == obj && pfp->pfop_pid == pid)
                        break;
                pfp = pfp->pfop_hashnext;
        }
        return (pfp);
}

/*
 * Given the file name, get the vnode and also the directory vnode
 * On return, the vnodes are held (VN_HOLD). The caller has to VN_RELE
 * the vnode(s).
 */
int
port_fop_getdvp(void *objptr, vnode_t **vp, vnode_t **dvp, char **cname,
    int *len, int follow)
{
        int error = 0;
        struct pathname pn;
        char *fname;

        if (get_udatamodel() == DATAMODEL_NATIVE) {
                fname = ((file_obj_t *)objptr)->fo_name;
#ifdef  _SYSCALL32_IMPL
        } else {
                fname = (caddr_t)(uintptr_t)((file_obj32_t *)objptr)->fo_name;
#endif  /* _SYSCALL32_IMPL */
        }

        /*
         * lookuppn may fail with EINVAL, if dvp is  non-null(like when
         * looking for "."). So call again with dvp = NULL.
         */
        if ((error = pn_get(fname, UIO_USERSPACE, &pn)) != 0) {
                return (error);
        }

        error = lookuppn(&pn, NULL, follow, dvp, vp);
        if (error == EINVAL) {
                pn_free(&pn);
                if ((error = pn_get(fname, UIO_USERSPACE, &pn)) != 0) {
                        return (error);
                }
                error = lookuppn(&pn, NULL, follow, NULL, vp);
                if (dvp != NULL) {
                        *dvp = NULL;
                }
        }

        if (error == 0 && cname != NULL && len != NULL) {
                pn_setlast(&pn);
                *len = pn.pn_pathlen;
                *cname = kmem_alloc(*len + 1, KM_SLEEP);
                (void) strcpy(*cname, pn.pn_path);
        } else {
                if (cname != NULL && len != NULL) {
                        *cname = NULL;
                        *len = 0;
                }
        }

        pn_free(&pn);
        return (error);
}

port_source_t *
port_getsrc(port_t *pp, int source)
{
        port_source_t *pse;
        int     lock = 0;
        /*
         * get the port source structure.
         */
        if (!MUTEX_HELD(&pp->port_queue.portq_source_mutex)) {
                mutex_enter(&pp->port_queue.portq_source_mutex);
                lock = 1;
        }

        pse = pp->port_queue.portq_scache[PORT_SHASH(source)];
        for (; pse != NULL; pse = pse->portsrc_next) {
                if (pse->portsrc_source == source)
                        break;
        }

        if (lock) {
                mutex_exit(&pp->port_queue.portq_source_mutex);
        }
        return (pse);
}


/*
 * Compare time stamps and generate an event if it has changed.
 * Note that the port cache pointer will be valid due to a reference
 * to the port. We need to grab the port cache lock and verify that
 * the pfp is still the same before proceeding to deliver an event.
 */
static void
port_check_timestamp(portfop_cache_t *pfcp, vnode_t *vp, vnode_t *dvp,
    portfop_t *pfp, void *objptr, uintptr_t object)
{
        vattr_t         vatt;
        portfop_vp_t    *pvp = vp->v_fopdata;
        int             events = 0;
        port_kevent_t   *pkevp;
        file_obj_t      *fobj;
        portfop_t       *tpfp;

        /*
         * If time stamps are specified, get attributes and compare.
         */
        vatt.va_mask = AT_ATIME|AT_MTIME|AT_CTIME;
        if (get_udatamodel() == DATAMODEL_NATIVE) {
                fobj = (file_obj_t *)objptr;
                if (fobj->fo_atime.tv_sec || fobj->fo_atime.tv_nsec ||
                    fobj->fo_mtime.tv_sec || fobj->fo_mtime.tv_nsec ||
                    fobj->fo_ctime.tv_sec || fobj->fo_ctime.tv_nsec) {
                        if (VOP_GETATTR(vp, &vatt, 0, CRED(), NULL)) {
                                return;
                        }
                } else {
                        /*
                         * timestamp not specified, all 0's,
                         */
                        return;
                }
#ifdef  _SYSCALL32_IMPL
        } else {
                file_obj32_t    *fobj32;
                fobj32 = (file_obj32_t *)objptr;
                if (fobj32->fo_atime.tv_sec || fobj32->fo_atime.tv_nsec ||
                    fobj32->fo_mtime.tv_sec || fobj32->fo_mtime.tv_nsec ||
                    fobj32->fo_ctime.tv_sec || fobj32->fo_ctime.tv_nsec) {
                        if (VOP_GETATTR(vp, &vatt, 0, CRED(), NULL)) {
                                return;
                        }
                } else {
                        /*
                         * timestamp not specified, all 0.
                         */
                        return;
                }
#endif /* _SYSCALL32_IMPL */
        }

        /*
         * Now grab the cache lock and verify that we are still
         * dealing with the same pfp and curthread is the one
         * which registered it. We need to do this to avoid
         * delivering redundant events.
         */
        mutex_enter(&pfcp->pfc_lock);
        tpfp = port_cache_lookup_fop(pfcp, curproc->p_pid, object);

        if (tpfp == NULL || tpfp != pfp ||
            pfp->pfop_vp != vp || pfp->pfop_dvp != dvp ||
            pfp->pfop_callrid != curthread ||
            !(pfp->pfop_flags & PORT_FOP_ACTIVE)) {
                /*
                 * Some other event was delivered, the file
                 * watch was removed or reassociated. Just
                 * ignore it and leave
                 */
                mutex_exit(&pfcp->pfc_lock);
                return;
        }

        mutex_enter(&pvp->pvp_mutex);
        /*
         * The pfp cannot disappear as the port cache lock is held.
         * While the pvp_mutex is held, no events will get delivered.
         */
        if (pfp->pfop_flags & PORT_FOP_ACTIVE &&
            !(pfp->pfop_flags & PORT_FOP_REMOVING)) {
                if (get_udatamodel() == DATAMODEL_NATIVE) {
                        fobj = (file_obj_t *)objptr;
                        if (pfp->pfop_events & FILE_ACCESS &&
                            (fobj->fo_atime.tv_sec || fobj->fo_atime.tv_nsec) &&
                            (vatt.va_atime.tv_sec != fobj->fo_atime.tv_sec ||
                            vatt.va_atime.tv_nsec != fobj->fo_atime.tv_nsec))
                                events |= FILE_ACCESS;

                        if (pfp->pfop_events & FILE_MODIFIED &&
                            (fobj->fo_mtime.tv_sec || fobj->fo_mtime.tv_nsec) &&
                            (vatt.va_mtime.tv_sec != fobj->fo_mtime.tv_sec ||
                            vatt.va_mtime.tv_nsec != fobj->fo_mtime.tv_nsec))
                                events |= FILE_MODIFIED;

                        if (pfp->pfop_events & FILE_ATTRIB &&
                            (fobj->fo_ctime.tv_sec || fobj->fo_ctime.tv_nsec) &&
                            (vatt.va_ctime.tv_sec != fobj->fo_ctime.tv_sec ||
                            vatt.va_ctime.tv_nsec != fobj->fo_ctime.tv_nsec))
                                events |= FILE_ATTRIB;
#ifdef  _SYSCALL32_IMPL
                } else {
                        file_obj32_t    *fobj32;
                        fobj32 = (file_obj32_t *)objptr;
                        if (pfp->pfop_events & FILE_ACCESS &&
                            (fobj32->fo_atime.tv_sec ||
                            fobj32->fo_atime.tv_nsec) &&
                            (vatt.va_atime.tv_sec != fobj32->fo_atime.tv_sec ||
                            vatt.va_atime.tv_nsec != fobj32->fo_atime.tv_nsec))
                                events |= FILE_ACCESS;

                        if (pfp->pfop_events & FILE_MODIFIED &&
                            (fobj32->fo_mtime.tv_sec ||
                            fobj32->fo_mtime.tv_nsec) &&
                            (vatt.va_mtime.tv_sec != fobj32->fo_mtime.tv_sec ||
                            vatt.va_mtime.tv_nsec != fobj32->fo_mtime.tv_nsec))
                                events |= FILE_MODIFIED;

                        if (pfp->pfop_events & FILE_ATTRIB &&
                            (fobj32->fo_ctime.tv_sec ||
                            fobj32->fo_ctime.tv_nsec) &&
                            (vatt.va_ctime.tv_sec != fobj32->fo_ctime.tv_sec ||
                            vatt.va_ctime.tv_nsec != fobj32->fo_ctime.tv_nsec))
                                events |= FILE_ATTRIB;
#endif /* _SYSCALL32_IMPL */
                }

                /*
                 * No events to deliver
                 */
                if (events == 0) {
                        mutex_exit(&pvp->pvp_mutex);
                        mutex_exit(&pfcp->pfc_lock);
                        return;
                }

                /*
                 * Deliver the event now.
                 */
                pkevp = pfp->pfop_pev;
                pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
                pkevp->portkev_events |= events;
                /*
                 * Move it to the tail as active once are in the
                 * beginning of the list.
                 */
                port_fop_listremove(pvp, pfp);
                port_fop_listinsert_tail(pvp, pfp);
                port_send_event(pkevp);
                pfp->pfop_flags |= PORT_FOP_KEV_ONQ;
        }
        mutex_exit(&pvp->pvp_mutex);
        mutex_exit(&pfcp->pfc_lock);
}

/*
 * Add the event source to the port and return the port source cache pointer.
 */
int
port_fop_associate_source(portfop_cache_t **pfcpp, port_t *pp, int source)
{
        portfop_cache_t *pfcp;
        port_source_t   *pse;
        int             error;

        /*
         * associate PORT_SOURCE_FILE source with the port, if it is
         * not associated yet. Note the PORT_SOURCE_FILE source is
         * associated once and will not be dissociated.
         */
        if ((pse = port_getsrc(pp, PORT_SOURCE_FILE)) == NULL) {
                if (error = port_associate_ksource(pp->port_fd, source,
                    &pse, port_close_fop, pp, NULL)) {
                        *pfcpp = NULL;
                        return (error);
                }
        }

        /*
         * Get the portfop cache pointer.
         */
        if ((pfcp = pse->portsrc_data) == NULL) {
                /*
                 * This is the first time that a file is being associated,
                 * create the portfop cache.
                 */
                pfcp = kmem_zalloc(sizeof (portfop_cache_t), KM_SLEEP);
                mutex_enter(&pp->port_queue.portq_source_mutex);
                if (pse->portsrc_data == NULL) {
                        pse->portsrc_data = pfcp;
                        mutex_exit(&pp->port_queue.portq_source_mutex);
                } else {
                        /*
                         * someone else created the port cache, free
                         * what we just now allocated.
                         */
                        mutex_exit(&pp->port_queue.portq_source_mutex);
                        kmem_free(pfcp, sizeof (portfop_cache_t));
                        pfcp = pse->portsrc_data;
                }
        }
        *pfcpp = pfcp;
        return (0);
}

/*
 * Add the given pvp on the file system's list of vnodes watched.
 */
int
port_fop_pvfsadd(portfop_vp_t *pvp)
{
        int error = 0;
        vnode_t *vp = pvp->pvp_vp;
        portfop_vfs_hash_t *pvfsh;
        portfop_vfs_t    *pvfsp;
        fsem_t          *fsemp;

        pvfsh = PORTFOP_PVFSH(vp->v_vfsp);
        mutex_enter(&pvfsh->pvfshash_mutex);
        for (pvfsp = pvfsh->pvfshash_pvfsp; pvfsp &&
            pvfsp->pvfs != vp->v_vfsp; pvfsp = pvfsp->pvfs_next)
                ;

        if (!pvfsp) {
                if ((fsemp = port_fop_fsemop()) != NULL) {
                        if ((error = fsem_install(vp->v_vfsp, fsemp,
                            vp->v_vfsp, OPUNIQ, NULL, NULL))) {
                                mutex_exit(&pvfsh->pvfshash_mutex);
                                return (error);
                        }
                } else {
                        mutex_exit(&pvfsh->pvfshash_mutex);
                        return (EINVAL);
                }
                pvfsp = kmem_zalloc(sizeof (portfop_vfs_t), KM_SLEEP);
                pvfsp->pvfs = vp->v_vfsp;
                list_create(&(pvfsp->pvfs_pvplist), sizeof (portfop_vp_t),
                    offsetof(portfop_vp_t, pvp_pvfsnode));
                pvfsp->pvfs_fsemp = fsemp;
                pvfsp->pvfs_next = pvfsh->pvfshash_pvfsp;
                pvfsh->pvfshash_pvfsp = pvfsp;
        }

        /*
         * check if an unmount is in progress.
         */
        if (!pvfsp->pvfs_unmount) {
                /*
                 * insert the pvp on list.
                 */
                pvp->pvp_pvfsp = pvfsp;
                list_insert_head(&pvfsp->pvfs_pvplist, (void *)pvp);
        } else {
                error = EINVAL;
        }
        mutex_exit(&pvfsh->pvfshash_mutex);
        return (error);
}

/*
 * Installs the portfop_vp_t data structure on the
 * vnode. The 'pvp_femp == NULL' indicates it is not
 * active. The fem hooks have to be installed.
 * The portfop_vp_t is only freed when the vnode gets freed.
 */
void
port_install_fopdata(vnode_t *vp)
{
        portfop_vp_t *npvp;

        npvp = kmem_zalloc(sizeof (*npvp), KM_SLEEP);
        mutex_init(&npvp->pvp_mutex, NULL, MUTEX_DEFAULT, NULL);
        list_create(&npvp->pvp_pfoplist, sizeof (portfop_t),
            offsetof(portfop_t, pfop_node));
        npvp->pvp_vp = vp;
        /*
         * If v_fopdata is not null, some other thread beat us to it.
         */
        if (atomic_cas_ptr(&vp->v_fopdata, NULL, npvp) != NULL) {
                mutex_destroy(&npvp->pvp_mutex);
                list_destroy(&npvp->pvp_pfoplist);
                kmem_free(npvp, sizeof (*npvp));
        }
}


/*
 * Allocate and add a portfop_t to the per port cache. Also add the portfop_t
 * to the vnode's list. The association is identified by the object pointer
 * address and pid.
 */
int
port_pfp_setup(portfop_t **pfpp, port_t *pp, vnode_t *vp, portfop_cache_t *pfcp,
    uintptr_t object, int events, void *user, char *cname, int clen,
    vnode_t *dvp)
{
        portfop_t       *pfp = NULL;
        port_kevent_t   *pkevp;
        fem_t           *femp;
        int             error = 0;
        portfop_vp_t    *pvp;


        /*
         * The port cache mutex is held.
         */
        *pfpp  = NULL;


        /*
         * At this point the fem monitor is installed.
         * Allocate a port event structure per vnode association.
         */
        if (pfp == NULL) {
                if (error = port_alloc_event_local(pp, PORT_SOURCE_FILE,
                    PORT_ALLOC_CACHED, &pkevp)) {
                        return (error);
                }
                pfp = kmem_zalloc(sizeof (portfop_t), KM_SLEEP);
                pfp->pfop_pev = pkevp;
        }

        pfp->pfop_vp = vp;
        pfp->pfop_pid = curproc->p_pid;
        pfp->pfop_pcache = pfcp;
        pfp->pfop_pp = pp;
        pfp->pfop_flags |= PORT_FOP_ACTIVE;
        pfp->pfop_cname = cname;
        pfp->pfop_clen = clen;
        pfp->pfop_dvp = dvp;
        pfp->pfop_object = object;

        pkevp->portkev_callback = port_fop_callback;
        pkevp->portkev_arg = pfp;
        pkevp->portkev_object = object;
        pkevp->portkev_user = user;
        pkevp->portkev_events = 0;

        port_pcache_insert(pfcp, pfp);

        /*
         * Register a new file events monitor for this file(vnode), if not
         * done already.
         */
        if ((pvp = vp->v_fopdata) == NULL) {
                port_install_fopdata(vp);
                pvp = vp->v_fopdata;
        }

        mutex_enter(&pvp->pvp_mutex);
        /*
         * if the vnode does not have the file events hooks, install it.
         */
        if (pvp->pvp_femp == NULL) {
                if ((femp = port_fop_femop()) != NULL) {
                        if (!(error = fem_install(pfp->pfop_vp, femp,
                            (void *)vp, OPUNIQ, NULL, NULL))) {
                                pvp->pvp_femp = femp;
                                /*
                                 * add fsem_t hooks to the vfsp and add pvp to
                                 * the list of vnodes for this vfs.
                                 */
                                if (!(error = port_fop_pvfsadd(pvp))) {
                                        /*
                                         * Hold a reference to the vnode since
                                         * we successfully installed the hooks.
                                         */
                                        VN_HOLD(vp);
                                } else {
                                        (void) fem_uninstall(vp, femp, vp);
                                        pvp->pvp_femp = NULL;
                                }
                        }
                } else {
                        error = EINVAL;
                }
        }

        if (error) {
                /*
                 * pkevp will get freed here.
                 */
                pfp->pfop_cname = NULL;
                port_pcache_remove_fop(pfcp, pfp);
                mutex_exit(&pvp->pvp_mutex);
                return (error);
        }

        /*
         * insert the pfp on the vnode's list. After this
         * events can get delivered.
         */
        pfp->pfop_events = events;
        port_fop_listinsert_head(pvp, pfp);

        mutex_exit(&pvp->pvp_mutex);
        /*
         * Hold the directory vnode since we have a reference now.
         */
        if (dvp != NULL)
                VN_HOLD(dvp);
        *pfpp = pfp;
        return (0);
}

vnode_t *
port_resolve_vp(vnode_t *vp)
{
        vnode_t *rvp;
        /*
         * special case /etc/mnttab(mntfs type). The mntfstype != 0
         * if mntfs got mounted.
         */
        if (vfs_mntdummyvp && mntfstype != 0 &&
            vp->v_vfsp->vfs_fstype == mntfstype) {
                VN_RELE(vp);
                vp = vfs_mntdummyvp;
                VN_HOLD(vfs_mntdummyvp);
        }

        /*
         * This should take care of lofs mounted fs systems and nfs4
         * hardlinks.
         */
        if ((VOP_REALVP(vp, &rvp, NULL) == 0) && vp != rvp) {
                VN_HOLD(rvp);
                VN_RELE(vp);
                vp = rvp;
        }
        return (vp);
}

/*
 * Register a file events watch on the given file associated to the port *pp.
 *
 * The association is identified by the object pointer and the pid.
 * The events argument contains the events to be monitored for.
 *
 * The vnode will have a VN_HOLD once the fem hooks are installed.
 *
 * Every reference(pfp) to the directory vnode will have a VN_HOLD to ensure
 * that the directory vnode pointer does not change.
 */
int
port_associate_fop(port_t *pp, int source, uintptr_t object, int events,
    void *user)
{
        portfop_cache_t *pfcp;
        vnode_t         *vp, *dvp, *oldvp = NULL, *olddvp = NULL, *orig;
        portfop_t       *pfp;
        int             error = 0;
        file_obj_t      fobj;
        void            *objptr;
        char            *cname;
        int             clen;
        int             follow;

        /*
         * check that events specified are valid.
         */
        if ((events & ~FILE_EVENTS_MASK) != 0)
                return (EINVAL);

        if (get_udatamodel() == DATAMODEL_NATIVE) {
                if (copyin((void *)object, &fobj, sizeof (file_obj_t)))
                        return (EFAULT);
                objptr = (void *)&fobj;
#ifdef  _SYSCALL32_IMPL
        } else {
                file_obj32_t    fobj32;
                if (copyin((void *)object, &fobj32, sizeof (file_obj32_t)))
                        return (EFAULT);
                objptr = (void *)&fobj32;
#endif  /* _SYSCALL32_IMPL */
        }

        vp = dvp = NULL;

        /*
         * find out if we need to follow symbolic links.
         */
        follow = !(events & FILE_NOFOLLOW);
        events = events & ~FILE_NOFOLLOW;

        /*
         * lookup and find the vnode and its directory vnode of the given
         * file.
         */
        if ((error = port_fop_getdvp(objptr, &vp, &dvp, &cname, &clen,
            follow)) != 0) {
                return (error);
        }

        if (dvp != NULL) {
                dvp = port_resolve_vp(dvp);
        }

        /*
         * Not found
         */
        if (vp == NULL) {
                error = ENOENT;
                goto errout;
        }

        vp = port_resolve_vp(orig = vp);

        if (vp != NULL && vnevent_support(vp, NULL)) {
                error = ENOTSUP;
                goto errout;
        }

        /*
         * If dvp belongs to a different filesystem just ignore it, as hard
         * links cannot exist across filesystems.  We make an exception for
         * procfs, however, the magic of which we treat semantically as a hard
         * link, allowing one to use /proc/[pid]/fd/[fd] for PORT_SOURCE_FILE
         * and avoid spurious FILE_RENAME_FROM/FILE_RENAME_TO events.
         */
        if (dvp != NULL && dvp->v_vfsp != vp->v_vfsp &&
            !(orig->v_type == VPROC && vp != NULL && vp->v_type != VPROC)) {
                VN_RELE(dvp);
                dvp = NULL;
        }

        /*
         * Associate this source to the port and get the per port
         * fop cache pointer. If the source is already associated, it
         * will just return the cache pointer.
         */
        if (error = port_fop_associate_source(&pfcp, pp, source)) {
                goto errout;
        }

        /*
         * Check if there is an existing association of this file.
         */
        mutex_enter(&pfcp->pfc_lock);
        pfp = port_cache_lookup_fop(pfcp, curproc->p_pid, object);

        /*
         * If it is not the same vnode, just discard it. VN_RELE needs to be
         * called with no locks held, therefore save vnode pointers and
         * vn_rele them later.
         */
        if (pfp != NULL && (pfp->pfop_vp != vp || pfp->pfop_dvp != dvp)) {
                (void) port_remove_fop(pfp, pfcp, 1, NULL, &oldvp, &olddvp);
                pfp = NULL;
        }

        if (pfp == NULL) {
                vnode_t *tvp, *tdvp;
                portfop_t       *tpfp;
                int error;

                /*
                 * Add a new association, save the file name and the
                 * directory vnode pointer.
                 */
                if (error = port_pfp_setup(&pfp, pp, vp, pfcp, object,
                    events, user, cname, clen, dvp)) {
                        mutex_exit(&pfcp->pfc_lock);
                        goto errout;
                }

                pfp->pfop_callrid = curthread;
                /*
                 * File name used, so make sure we don't free it.
                 */
                cname = NULL;

                /*
                 * We need to check if the file was removed after the
                 * the lookup and before the fem hooks where added. If
                 * so, return error. The vnode will still exist as we have
                 * a hold on it.
                 *
                 * Drop the cache lock before calling port_fop_getdvp().
                 * port_fop_getdvp() may block either in the vfs layer
                 * or some filesystem.  Therefore there is potential
                 * for deadlock if cache lock is held and if some other
                 * thread is attempting to deliver file events which would
                 * require getting the cache lock, while it may be holding
                 * the filesystem or vfs layer locks.
                 */
                mutex_exit(&pfcp->pfc_lock);
                tvp = NULL;
                if ((error = port_fop_getdvp(objptr, &tvp, NULL,
                    NULL, NULL, follow)) == 0) {
                        if (tvp != NULL) {
                                tvp = port_resolve_vp(tvp);
                                /*
                                 * This vnode pointer is just used
                                 * for comparison, so rele it
                                 */
                                VN_RELE(tvp);
                        }
                }

                if (error || tvp == NULL || tvp != vp) {
                        /*
                         * Since we dropped the cache lock, make sure
                         * we are still dealing with the same pfp and this
                         * is the thread which registered it.
                         */
                        mutex_enter(&pfcp->pfc_lock);
                        tpfp = port_cache_lookup_fop(pfcp,
                            curproc->p_pid, object);

                        error = 0;
                        if (tpfp == NULL || tpfp != pfp ||
                            pfp->pfop_vp != vp ||
                            pfp->pfop_dvp != dvp ||
                            pfp->pfop_callrid != curthread) {
                                /*
                                 * Some other event was delivered, the file
                                 * watch was removed or reassociated, just
                                 * ignore it and leave
                                 */
                                mutex_exit(&pfcp->pfc_lock);
                                goto errout;
                        }

                        /*
                         * remove the pfp and fem hooks, if pfp still
                         * active and it is not being removed from
                         * the vnode list. This is checked in
                         * port_remove_fop with the vnode lock held.
                         * The vnode returned is VN_RELE'ed after dropping
                         * the locks.
                         */
                        tdvp = tvp = NULL;
                        if (port_remove_fop(pfp, pfcp, 0, NULL, &tvp, &tdvp)) {
                                /*
                                 * The pfp was removed, means no
                                 * events where queued. Report the
                                 * error now.
                                 */
                                error = EINVAL;
                        }
                        mutex_exit(&pfcp->pfc_lock);
                        if (tvp != NULL)
                                VN_RELE(tvp);
                        if (tdvp != NULL)
                                VN_RELE(tdvp);
                        goto errout;
                }
        } else {
                portfop_vp_t    *pvp = vp->v_fopdata;

                /*
                 * Re-association of the object.
                 */
                mutex_enter(&pvp->pvp_mutex);

                /*
                 * Remove any queued up event.
                 */
                if (port_remove_done_event(pfp->pfop_pev)) {
                        pfp->pfop_flags &= ~PORT_FOP_KEV_ONQ;
                }

                /*
                 * Set new events to watch and update the user pointer.
                 */
                pfp->pfop_events = events;
                pfp->pfop_pev->portkev_user = user;

                /*
                 * If not active, mark it active even if it is being
                 * removed. Then it can send an exception event.
                 *
                 * Move it to the head, as the active ones are only
                 * in the beginning. If removing, the pfp will be on
                 * a temporary list, no need to move it to the front
                 * all the entries will be processed. Some exception
                 * events will be delivered in port_fop_excep();
                 */
                if (!(pfp->pfop_flags & PORT_FOP_ACTIVE)) {
                        pfp->pfop_flags |= PORT_FOP_ACTIVE;
                        if (!(pfp->pfop_flags & PORT_FOP_REMOVING)) {
                                pvp = (portfop_vp_t *)vp->v_fopdata;
                                port_fop_listremove(pvp, pfp);
                                port_fop_listinsert_head(pvp, pfp);
                        }
                }
                pfp->pfop_callrid = curthread;
                mutex_exit(&pvp->pvp_mutex);
                mutex_exit(&pfcp->pfc_lock);
        }

        /*
         * Compare time stamps and deliver events.
         */
        if (vp->v_type != VFIFO) {
                port_check_timestamp(pfcp, vp, dvp, pfp, objptr, object);
        }

        error = 0;

        /*
         *  If we have too many watches on the vnode, discard an
         *  inactive watch.
         */
        port_fop_trimpfplist(vp);

errout:
        /*
         * Release the hold acquired due to the lookup operation.
         */
        if (vp != NULL)
                VN_RELE(vp);
        if (dvp != NULL)
                VN_RELE(dvp);

        if (oldvp != NULL)
                VN_RELE(oldvp);
        if (olddvp != NULL)
                VN_RELE(olddvp);

        /*
         * copied file name not used, free it.
         */
        if (cname != NULL) {
                kmem_free(cname, clen + 1);
        }
        return (error);
}


/*
 * The port_dissociate_fop() function dissociates the file object
 * from the event port and removes any events that are already on the queue.
 * Only the owner of the association is allowed to dissociate the file from
 * the port. Returns  success (0) if it was found and removed. Otherwise
 * ENOENT.
 */
int
port_dissociate_fop(port_t *pp, uintptr_t object)
{
        portfop_cache_t *pfcp;
        portfop_t       *pfp;
        port_source_t   *pse;
        int             active = 0;
        vnode_t         *tvp = NULL, *tdvp = NULL;

        pse = port_getsrc(pp, PORT_SOURCE_FILE);

        /*
         * if this source is not associated or if there is no
         * cache, nothing to do just return.
         */
        if (pse == NULL ||
            (pfcp = (portfop_cache_t *)pse->portsrc_data) == NULL)
                return (EINVAL);

        /*
         * Check if this object is on the cache. Only the owner pid
         * is allowed to dissociate.
         */
        mutex_enter(&pfcp->pfc_lock);
        pfp = port_cache_lookup_fop(pfcp, curproc->p_pid, object);
        if (pfp == NULL) {
                mutex_exit(&pfcp->pfc_lock);
                return (ENOENT);
        }

        /*
         * If this was the last association, it will release
         * the hold on the vnode. There is a race condition where
         * the the pfp is being removed due to an exception event
         * in port_fop_sendevent()->port_fop_excep() and port_remove_fop().
         * Since port source cache lock is held, port_fop_excep() cannot
         * complete. The vnode itself will not disappear as long its pfps
         * have a reference.
         */
        (void) port_remove_fop(pfp, pfcp, 1, &active, &tvp, &tdvp);
        mutex_exit(&pfcp->pfc_lock);
        if (tvp != NULL)
                VN_RELE(tvp);
        if (tdvp != NULL)
                VN_RELE(tdvp);
        return (active ? 0 : ENOENT);
}


/*
 * port_close() calls this function to request the PORT_SOURCE_FILE source
 * to remove/free all resources allocated and associated with the port.
 */

/* ARGSUSED */
static void
port_close_fop(void *arg, int port, pid_t pid, int lastclose)
{
        port_t          *pp = arg;
        portfop_cache_t *pfcp;
        portfop_t       **hashtbl;
        portfop_t       *pfp;
        portfop_t       *pfpnext;
        int             index, i;
        port_source_t   *pse;
        vnode_t         *tdvp = NULL;
        vnode_t         *vpl[PORTFOP_NVP];

        pse = port_getsrc(pp, PORT_SOURCE_FILE);

        /*
         * No source or no cache, nothing to do.
         */
        if (pse == NULL ||
            (pfcp = (portfop_cache_t *)pse->portsrc_data) == NULL)
                return;
        /*
         * Scan the cache and free all allocated portfop_t and port_kevent_t
         * structures of this pid. Note, no new association for this pid will
         * be possible as the port is being closed.
         *
         * The common case is that the port is not shared and all the entries
         * are of this pid and have to be freed. Since VN_RELE has to be
         * called outside the lock, we do it in batches.
         */
        hashtbl = (portfop_t **)pfcp->pfc_hash;
        index = i = 0;
        bzero(vpl, sizeof (vpl));
        mutex_enter(&pfcp->pfc_lock);
        while (index < PORTFOP_HASHSIZE) {
                pfp = hashtbl[index];
                while (pfp != NULL && i < (PORTFOP_NVP - 1)) {
                        pfpnext = pfp->pfop_hashnext;
                        if (pid == pfp->pfop_pid) {
                                (void) port_remove_fop(pfp, pfcp, 1, NULL,
                                    &vpl[i], &tdvp);
                                if (vpl[i] != NULL) {
                                        i++;
                                }
                                if (tdvp != NULL) {
                                        vpl[i++] = tdvp;
                                        tdvp = NULL;
                                }
                        }
                        pfp = pfpnext;
                }
                if (pfp == NULL)
                        index++;
                /*
                 * Now call VN_RELE if we have collected enough vnodes or
                 * we have reached the end of the hash table.
                 */
                if (i >= (PORTFOP_NVP - 1) ||
                    (i > 0 && index == PORTFOP_HASHSIZE)) {
                        mutex_exit(&pfcp->pfc_lock);
                        while (i > 0) {
                                VN_RELE(vpl[--i]);
                                vpl[i] = NULL;
                        }
                        mutex_enter(&pfcp->pfc_lock);
                }
        }

        /*
         * Due to a race between port_close_fop() and port_fop()
         * trying to remove the pfp's from the port's cache, it is
         * possible that some pfp's are still in the process of being
         * freed so we wait.
         */
        while (lastclose && pfcp->pfc_objcount) {
                (void) cv_wait_sig(&pfcp->pfc_lclosecv, &pfcp->pfc_lock);
        }
        mutex_exit(&pfcp->pfc_lock);
        /*
         * last close, free the cache.
         */
        if (lastclose) {
                ASSERT(pfcp->pfc_objcount == 0);
                pse->portsrc_data = NULL;
                kmem_free(pfcp, sizeof (portfop_cache_t));
        }
}

/*
 * Given the list of associations(watches), it will send exception events,
 * if still active, and discard them. The exception events are handled
 * separately because, the pfp needs to be removed from the port cache and
 * freed as the vnode's identity is changing or being removed. To remove
 * the pfp from the port's cache, we need to hold the cache lock (pfc_lock).
 * The lock order is pfc_lock -> pvp_mutex(vnode's) mutex and that is why
 * the cache's lock cannot be acquired in port_fop_sendevent().
 */
static void
port_fop_excep(list_t *tlist, int op)
{
        portfop_t       *pfp;
        portfop_cache_t *pfcp;
        port_t  *pp;
        port_kevent_t   *pkevp;
        vnode_t         *tdvp;
        int             error = 0;

        while (pfp = (portfop_t *)list_head(tlist)) {
                int removed = 0;
                /*
                 * remove from the temp list. Since PORT_FOP_REMOVING is
                 * set, no other thread should attempt to perform a
                 * list_remove on this pfp.
                 */
                list_remove(tlist, pfp);

                pfcp = pfp->pfop_pcache;
                mutex_enter(&pfcp->pfc_lock);

                /*
                 * Remove the event from the port queue if it was queued up.
                 * No need to clear the PORT_FOP_KEV_ONQ flag as this pfp is
                 * no longer on the vnode's list.
                 */
                if ((pfp->pfop_flags & PORT_FOP_KEV_ONQ)) {
                        removed = port_remove_done_event(pfp->pfop_pev);
                }

                /*
                 * If still active or the event was queued up and
                 * had not been collected yet, send an EXCEPTION event.
                 */
                if (pfp->pfop_flags & (PORT_FOP_ACTIVE) || removed) {
                        pp = pfp->pfop_pp;
                        /*
                         * Allocate a port_kevent_t non cached to send this
                         * event since we will be de-registering.
                         * The port_kevent_t cannot be pointing back to the
                         * pfp anymore.
                         */
                        pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
                        error = port_alloc_event_local(pp, PORT_SOURCE_FILE,
                            PORT_ALLOC_DEFAULT, &pkevp);
                        if (!error) {

                                pkevp->portkev_callback = port_fop_callback;
                                pkevp->portkev_arg = NULL;
                                pkevp->portkev_object =
                                    pfp->pfop_pev->portkev_object;
                                pkevp->portkev_user =
                                    pfp->pfop_pev->portkev_user;
                                /*
                                 * Copy the pid of the watching process.
                                 */
                                pkevp->portkev_pid =
                                    pfp->pfop_pev->portkev_pid;
                                pkevp->portkev_events = op;
                                port_send_event(pkevp);
                        }
                }
                /*
                 * At this point the pfp has been removed from the vnode's
                 * list its cached port_kevent_t is not on the done queue.
                 * Remove the pfp and free it from the cache.
                 */
                tdvp = pfp->pfop_dvp;
                port_pcache_remove_fop(pfcp, pfp);
                mutex_exit(&pfcp->pfc_lock);
                if (tdvp != NULL)
                        VN_RELE(tdvp);
        }
}

/*
 * Send the file events to all of the processes watching this
 * vnode. In case of hard links, the directory vnode pointer and
 * the file name are compared. If the names match, then the specified
 * event is sent or else, the FILE_ATTRIB event is sent, This is the
 * documented behavior.
 */
void
port_fop_sendevent(vnode_t *vp, int events, vnode_t *dvp, char *cname)
{
        port_kevent_t   *pkevp;
        portfop_t       *pfp, *npfp;
        portfop_vp_t    *pvp;
        list_t          tmplist;
        int             removeall = 0;

        pvp = (portfop_vp_t *)vp->v_fopdata;
        mutex_enter(&pvp->pvp_mutex);

        /*
         * Check if the list is empty.
         *
         * All entries have been removed by some other thread.
         * The vnode may be still active and we got called,
         * but some other thread is in the process of removing the hooks.
         */
        if (!list_head(&pvp->pvp_pfoplist)) {
                mutex_exit(&pvp->pvp_mutex);
                return;
        }

        if ((events & (FILE_EXCEPTION))) {
                /*
                 * If it is an event for which we are going to remove
                 * the watches so just move it a temporary list and
                 * release this vnode.
                 */
                list_create(&tmplist, sizeof (portfop_t),
                    offsetof(portfop_t, pfop_node));

                /*
                 * If it is an UNMOUNT, MOUNTEDOVER or no file name has been
                 * passed for an exception event, all associations need to be
                 * removed.
                 */
                if (dvp == NULL || cname == NULL) {
                        removeall = 1;
                }
        }

        if (!removeall) {
                /*
                 * All the active ones are in the beginning of the list.
                 * Note that we process this list in reverse order to assure
                 * that events are delivered in the order that they were
                 * associated.
                 */
                for (pfp = (portfop_t *)list_tail(&pvp->pvp_pfoplist);
                    pfp && !(pfp->pfop_flags & PORT_FOP_ACTIVE); pfp = npfp) {
                        npfp = list_prev(&pvp->pvp_pfoplist, pfp);
                }

                for (; pfp != NULL; pfp = npfp) {
                        int levents = events;

                        npfp = list_prev(&pvp->pvp_pfoplist, pfp);
                        /*
                         * Hard links case - If the file is being
                         * removed/renamed, and the name matches
                         * the watched file, then it is an EXCEPTION
                         * event or else it will be just a FILE_ATTRIB.
                         */
                        if ((events & (FILE_EXCEPTION))) {
                                ASSERT(dvp != NULL && cname != NULL);
                                if (pfp->pfop_dvp == NULL ||
                                    (pfp->pfop_dvp == dvp &&
                                    (strcmp(cname, pfp->pfop_cname) == 0))) {
                                        /*
                                         * It is an exception event, move it
                                         * to temp list and process it later.
                                         * Note we don't set the pfp->pfop_vp
                                         * to NULL even thought it has been
                                         * removed from the vnode's list. This
                                         * pointer is referenced in
                                         * port_remove_fop(). The vnode it
                                         * self cannot disappear until this
                                         * pfp gets removed and freed.
                                         */
                                        port_fop_listremove(pvp, pfp);
                                        list_insert_tail(&tmplist, (void *)pfp);
                                        pfp->pfop_flags  |= PORT_FOP_REMOVING;
                                        continue;
                                } else {
                                        levents = FILE_ATTRIB;
                                }

                        }

                        if (pfp->pfop_events & levents) {
                                /*
                                 * deactivate and move it to the tail.
                                 * If the pfp was active, it cannot be
                                 * on the port's done queue.
                                 */
                                pfp->pfop_flags &= ~PORT_FOP_ACTIVE;
                                port_fop_listremove(pvp, pfp);
                                port_fop_listinsert_tail(pvp, pfp);

                                pkevp = pfp->pfop_pev;
                                pkevp->portkev_events |=
                                    (levents & pfp->pfop_events);
                                port_send_event(pkevp);
                                pfp->pfop_flags |= PORT_FOP_KEV_ONQ;
                        }
                }
        }


        if ((events & (FILE_EXCEPTION))) {
                if (!removeall) {
                        /*
                         * Check the inactive associations and remove them if
                         * the file name matches.
                         */
                        for (; pfp; pfp = npfp) {
                                npfp = list_next(&pvp->pvp_pfoplist, pfp);
                                if (dvp == NULL || cname == NULL ||
                                    pfp->pfop_dvp == NULL ||
                                    (pfp->pfop_dvp == dvp &&
                                    (strcmp(cname, pfp->pfop_cname) == 0))) {
                                        port_fop_listremove(pvp, pfp);
                                        list_insert_tail(&tmplist, (void *)pfp);
                                        pfp->pfop_flags  |= PORT_FOP_REMOVING;
                                }
                        }
                } else {
                        /*
                         * Can be optimized to avoid two pass over this list
                         * by having a flag in the vnode's portfop_vp_t
                         * structure to indicate that it is going away,
                         * Or keep the list short by reusing inactive watches.
                         */
                        port_fop_listmove(pvp, &tmplist);
                        for (pfp = (portfop_t *)list_head(&tmplist);
                            pfp; pfp = list_next(&tmplist, pfp)) {
                                pfp->pfop_flags |= PORT_FOP_REMOVING;
                        }
                }

                /*
                 * Uninstall the fem hooks if there are no more associations.
                 * This will release the pvp mutex.
                 *
                 * Even thought all entries may have been removed,
                 * the vnode itself cannot disappear as there will be a
                 * hold on it due to this call to port_fop_sendevent. This is
                 * important to syncronize with a port_dissociate_fop() call
                 * that may be attempting to remove an object from the vnode's.
                 */
                if (port_fop_femuninstall(vp))
                        VN_RELE(vp);

                /*
                 * Send exception events and discard the watch entries.
                 */
                port_fop_excep(&tmplist, events);
                list_destroy(&tmplist);

        } else {
                mutex_exit(&pvp->pvp_mutex);

                /*
                 * trim the list.
                 */
                port_fop_trimpfplist(vp);
        }
}

/*
 * Given the file operation, map it to the event types and send.
 */
void
port_fop(vnode_t *vp, int op, int retval)
{
        int event = 0;
        /*
         * deliver events only if the operation was successful.
         */
        if (retval)
                return;

        /*
         * These events occurring on the watched file.
         */
        if (op & FOP_MODIFIED_MASK) {
                event  = FILE_MODIFIED;
        }
        if (op & FOP_ACCESS_MASK) {
                event  |= FILE_ACCESS;
        }
        if (op & FOP_ATTRIB_MASK) {
                event  |= FILE_ATTRIB;
        }
        if (op & FOP_TRUNC_MASK) {
                event  |= FILE_TRUNC;
        }
        if (event) {
                port_fop_sendevent(vp, event, NULL, NULL);
        }
}

static int port_forceunmount(vfs_t *vfsp)
{
        char *fsname = vfssw[vfsp->vfs_fstype].vsw_name;

        if (fsname == NULL) {
                return (0);
        }

        if (strcmp(fsname, MNTTYPE_NFS) == 0) {
                return (1);
        }

        if (strcmp(fsname, MNTTYPE_NFS3) == 0) {
                return (1);
        }

        if (strcmp(fsname, MNTTYPE_NFS4) == 0) {
                return (1);
        }
        return (0);
}
/*
 * ----- the unmount filesystem op(fsem) hook.
 */
int
port_fop_unmount(fsemarg_t *vf, int flag, cred_t *cr)
{
        vfs_t   *vfsp = (vfs_t *)vf->fa_fnode->fn_available;
        kmutex_t        *mtx;
        portfop_vfs_t   *pvfsp, **ppvfsp;
        portfop_vp_t    *pvp;
        int error;
        int fmfs;

        fmfs = port_forceunmount(vfsp);

        mtx = &(portvfs_hash[PORTFOP_PVFSHASH(vfsp)].pvfshash_mutex);
        ppvfsp = &(portvfs_hash[PORTFOP_PVFSHASH(vfsp)].pvfshash_pvfsp);
        pvfsp = NULL;
        mutex_enter(mtx);
        /*
         * since this fsem hook is triggered, the vfsp has to be on
         * the hash list.
         */
        for (pvfsp = *ppvfsp; pvfsp->pvfs != vfsp; pvfsp = pvfsp->pvfs_next)
                ;

        /*
         * For some of the filesystems, allow unmounts to proceed only if
         * there are no files being watched or it is a forced unmount.
         */
        if (fmfs && !(flag & MS_FORCE) &&
            !list_is_empty(&pvfsp->pvfs_pvplist)) {
                mutex_exit(mtx);
                return (EBUSY);
        }

        /*
         * Indicate that the unmount is in process. Don't remove it yet.
         * The underlying filesystem unmount routine sets the VFS_UNMOUNTED
         * flag on the vfs_t structure. But we call the filesystem unmount
         * routine after removing all the file watches for this filesystem,
         * otherwise the unmount will fail due to active vnodes.
         * Meanwhile setting pvfsp->unmount = 1 will prevent any thread
         * attempting to add a file watch.
         */
        pvfsp->pvfs_unmount = 1;
        mutex_exit(mtx);

        /*
         * uninstall the fsem hooks.
         */
        (void) fsem_uninstall(vfsp, (fsem_t *)pvfsp->pvfs_fsemp, vfsp);

        while (pvp = list_head(&pvfsp->pvfs_pvplist)) {
                list_remove(&pvfsp->pvfs_pvplist, pvp);
                /*
                 * This should send an UNMOUNTED event to all the
                 * watched vnode of this filesystem and uninstall
                 * the fem hooks. We release the hold on the vnode here
                 * because port_fop_femuninstall() will not do it if
                 * unmount is in process.
                 */
                port_fop_sendevent(pvp->pvp_vp, UNMOUNTED, NULL, NULL);
                VN_RELE(pvp->pvp_vp);
        }

        error = vfsnext_unmount(vf, flag, cr);

        /*
         * we free the pvfsp after the unmount has been completed.
         */
        mutex_enter(mtx);
        for (; *ppvfsp && (*ppvfsp)->pvfs != vfsp;
            ppvfsp = &(*ppvfsp)->pvfs_next)
                ;

        /*
         * remove and free it.
         */
        ASSERT(list_head(&pvfsp->pvfs_pvplist) == NULL);
        if (*ppvfsp) {
                pvfsp = *ppvfsp;
                *ppvfsp = pvfsp->pvfs_next;
        }
        mutex_exit(mtx);
        kmem_free(pvfsp, sizeof (portfop_vfs_t));
        return (error);
}

/*
 * ------------------------------file op hooks--------------------------
 * The O_TRUNC operation is caught with the VOP_SETATTR(AT_SIZE) call.
 */
static int
port_fop_open(femarg_t *vf, int mode, cred_t *cr, caller_context_t *ct)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_open(vf, mode, cr, ct);
        port_fop(vp, FOP_FILE_OPEN, retval);
        return (retval);
}

static int
port_fop_write(femarg_t *vf, struct uio *uiop, int ioflag, struct cred *cr,
    caller_context_t *ct)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval =  vnext_write(vf, uiop, ioflag, cr, ct);
        port_fop(vp, FOP_FILE_WRITE, retval);
        return (retval);
}

static int
port_fop_map(femarg_t *vf, offset_t off, struct as *as, caddr_t *addrp,
    size_t len, uchar_t prot, uchar_t maxport, uint_t flags, cred_t *cr,
    caller_context_t *ct)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval =  vnext_map(vf, off, as, addrp, len, prot, maxport,
            flags, cr, ct);
        port_fop(vp, FOP_FILE_MAP, retval);
        return (retval);
}

static int
port_fop_read(femarg_t *vf, struct uio *uiop, int ioflag, struct cred *cr,
    caller_context_t *ct)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval =  vnext_read(vf, uiop, ioflag, cr, ct);
        port_fop(vp, FOP_FILE_READ, retval);
        return (retval);
}


/*
 * AT_SIZE - is for the open(O_TRUNC) case.
 */
int
port_fop_setattr(femarg_t *vf, vattr_t *vap, int flags, cred_t *cr,
    caller_context_t *ct)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
        int             events = 0;

        retval = vnext_setattr(vf, vap, flags, cr, ct);
        if (vap->va_mask & AT_SIZE) {
                events |= FOP_FILE_TRUNC;
        }
        if (vap->va_mask & (AT_SIZE|AT_MTIME)) {
                events |= FOP_FILE_SETATTR_MTIME;
        }
        if (vap->va_mask & AT_ATIME) {
                events |= FOP_FILE_SETATTR_ATIME;
        }
        events |= FOP_FILE_SETATTR_CTIME;

        port_fop(vp, events, retval);
        return (retval);
}

int
port_fop_create(femarg_t *vf, char *name, vattr_t *vap, vcexcl_t excl,
    int mode, vnode_t **vpp, cred_t *cr, int flag,
    caller_context_t *ct, vsecattr_t *vsecp)
{
        int             retval, got = 1;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
        vattr_t         vatt, vatt1;

        /*
         * If the file already exists, then there will be no change
         * to the directory. Therefore, we need to compare the
         * modification time of the directory to determine if the
         * file was actually created.
         */
        vatt.va_mask = AT_ATIME|AT_MTIME|AT_CTIME;
        if (VOP_GETATTR(vp, &vatt, 0, CRED(), ct)) {
                got = 0;
        }
        retval = vnext_create(vf, name, vap, excl, mode, vpp, cr,
            flag, ct, vsecp);

        vatt1.va_mask = AT_ATIME|AT_MTIME|AT_CTIME;
        if (got && !VOP_GETATTR(vp, &vatt1, 0, CRED(), ct)) {
                if ((vatt1.va_mtime.tv_sec > vatt.va_mtime.tv_sec ||
                    (vatt1.va_mtime.tv_sec = vatt.va_mtime.tv_sec &&
                    vatt1.va_mtime.tv_nsec > vatt.va_mtime.tv_nsec))) {
                        /*
                         * File was created.
                         */
                        port_fop(vp, FOP_FILE_CREATE, retval);
                }
        }
        return (retval);
}

int
port_fop_remove(femarg_t *vf, char *nm, cred_t *cr, caller_context_t *ct,
    int flags)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_remove(vf, nm, cr, ct, flags);
        port_fop(vp, FOP_FILE_REMOVE, retval);
        return (retval);
}

int
port_fop_link(femarg_t *vf, vnode_t *svp, char *tnm, cred_t *cr,
    caller_context_t *ct, int flags)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_link(vf, svp, tnm, cr, ct, flags);
        port_fop(vp, FOP_FILE_LINK, retval);
        return (retval);
}

/*
 * Rename operation is allowed only when from and to directories are
 * on the same filesystem. This is checked in vn_rename().
 * The target directory is notified thru a VNEVENT by the filesystem
 * if the source dir != target dir.
 */
int
port_fop_rename(femarg_t *vf, char *snm, vnode_t *tdvp, char *tnm, cred_t *cr,
    caller_context_t *ct, int flags)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_rename(vf, snm, tdvp, tnm, cr, ct, flags);
        port_fop(vp, FOP_FILE_RENAMESRC, retval);
        return (retval);
}

int
port_fop_mkdir(femarg_t *vf, char *dirname, vattr_t *vap, vnode_t **vpp,
    cred_t *cr, caller_context_t *ct, int flags, vsecattr_t *vsecp)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_mkdir(vf, dirname, vap, vpp, cr, ct, flags, vsecp);
        port_fop(vp, FOP_FILE_MKDIR, retval);
        return (retval);
}

int
port_fop_rmdir(femarg_t *vf, char *nm, vnode_t *cdir, cred_t *cr,
    caller_context_t *ct, int flags)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_rmdir(vf, nm, cdir, cr, ct, flags);
        port_fop(vp, FOP_FILE_RMDIR, retval);
        return (retval);
}

int
port_fop_readdir(femarg_t *vf, uio_t *uiop, cred_t *cr, int *eofp,
    caller_context_t *ct, int flags)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_readdir(vf, uiop, cr, eofp, ct, flags);
        port_fop(vp, FOP_FILE_READDIR, retval);
        return (retval);
}

int
port_fop_symlink(femarg_t *vf, char *linkname, vattr_t *vap, char *target,
    cred_t *cr, caller_context_t *ct, int flags)
{
        int             retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        retval = vnext_symlink(vf, linkname, vap, target, cr, ct, flags);
        port_fop(vp, FOP_FILE_SYMLINK, retval);
        return (retval);
}

/*
 * acl, facl call this.
 */
int
port_fop_setsecattr(femarg_t *vf, vsecattr_t *vsap, int flags, cred_t *cr,
    caller_context_t *ct)
{
        int     retval;
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;
        retval = vnext_setsecattr(vf, vsap, flags, cr, ct);
        port_fop(vp, FOP_FILE_SETSECATTR, retval);
        return (retval);
}

/*
 * these are events on the watched file/directory
 */
int
port_fop_vnevent(femarg_t *vf, vnevent_t vnevent, vnode_t *dvp, char *name,
    caller_context_t *ct)
{
        vnode_t         *vp = (vnode_t *)vf->fa_fnode->fn_available;

        switch (vnevent) {
        case    VE_RENAME_SRC:
                        port_fop_sendevent(vp, FILE_RENAME_FROM, dvp, name);
                break;
        case    VE_RENAME_DEST:
                        port_fop_sendevent(vp, FILE_RENAME_TO, dvp, name);
                break;
        case    VE_REMOVE:
                        port_fop_sendevent(vp, FILE_DELETE, dvp, name);
                break;
        case    VE_RMDIR:
                        port_fop_sendevent(vp, FILE_DELETE, dvp, name);
                break;
        case    VE_CREATE:
                        port_fop_sendevent(vp,
                            FILE_MODIFIED|FILE_ATTRIB|FILE_TRUNC, NULL, NULL);
                break;
        case    VE_LINK:
                        port_fop_sendevent(vp, FILE_ATTRIB, NULL, NULL);
                break;

        case    VE_RENAME_DEST_DIR:
                        port_fop_sendevent(vp, FILE_MODIFIED|FILE_ATTRIB,
                            NULL, NULL);
                break;

        case    VE_MOUNTEDOVER:
                        port_fop_sendevent(vp, MOUNTEDOVER, NULL, NULL);
                break;
        case    VE_TRUNCATE:
                        port_fop_sendevent(vp, FILE_TRUNC, NULL, NULL);
                break;
        default:
                break;
        }
        return (vnext_vnevent(vf, vnevent, dvp, name, ct));
}