/*      $NetBSD: puffs_vfsops.c,v 1.127 2026/05/03 16:02:35 thorpej Exp $       */

/*
 * Copyright (c) 2005, 2006  Antti Kantee.  All Rights Reserved.
 *
 * Development of this software was supported by the
 * Google Summer of Code program and the Ulla Tuominen Foundation.
 * The Google SoC project was mentored by Bill Studenmund.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: puffs_vfsops.c,v 1.127 2026/05/03 16:02:35 thorpej Exp $");

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/extattr.h>
#include <sys/queue.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#include <sys/kauth.h>
#include <sys/proc.h>
#include <sys/module.h>
#include <sys/kthread.h>

#include <uvm/uvm.h>

#include <dev/putter/putter_sys.h>

#include <miscfs/genfs/genfs.h>

#include <fs/puffs/puffs_msgif.h>
#include <fs/puffs/puffs_sys.h>

#include <lib/libkern/libkern.h>

#include <nfs/nfsproto.h> /* for fh sizes */

MODULE(MODULE_CLASS_VFS, puffs, "putter");

VFS_PROTOS(puffs_vfsop);

static struct putter_ops puffs_putter = {
        .pop_getout     = puffs_msgif_getout,
        .pop_releaseout = puffs_msgif_releaseout,
        .pop_waitcount  = puffs_msgif_waitcount,
        .pop_dispatch   = puffs_msgif_dispatch,
        .pop_close      = puffs_msgif_close,
};

static const struct genfs_ops puffs_genfsops = {
        .gop_size = puffs_gop_size,
        .gop_write = genfs_gop_write,
        .gop_markupdate = puffs_gop_markupdate,
#if 0
        .gop_alloc, should ask userspace
#endif
        .gop_putrange = genfs_gop_putrange,
};

/*
 * Try to ensure data structures used by the puffs protocol
 * do not unexpectedly change.
 */
#if defined(__i386__) && defined(__ELF__)
CTASSERT(sizeof(struct puffs_kargs) == 3928);
CTASSERT(sizeof(struct vattr) == 136);
CTASSERT(sizeof(struct puffs_req) == 44);
#endif

int
puffs_vfsop_mount(struct mount *mp, const char *path, void *data,
        size_t *data_len)
{
        struct puffs_mount *pmp = NULL;
        struct puffs_kargs *args;
        char fstype[_VFS_NAMELEN];
        char *p;
        int error = 0, i;
        pid_t mntpid = curlwp->l_proc->p_pid;

        if (data == NULL)
                return EINVAL;
        if (*data_len < sizeof *args)
                return EINVAL;

        if (mp->mnt_flag & MNT_GETARGS) {
                pmp = MPTOPUFFSMP(mp);
                *(struct puffs_kargs *)data = pmp->pmp_args;
                *data_len = sizeof *args;
                return 0;
        }

        /* update is not supported currently */
        if (mp->mnt_flag & MNT_UPDATE)
                return EOPNOTSUPP;

        args = (struct puffs_kargs *)data;

        if (args->pa_vers != PUFFSVERSION) {
                printf("puffs_mount: development version mismatch: "
                    "kernel %d, lib %d\n", PUFFSVERSION, args->pa_vers);
                error = EINVAL;
                goto out;
        }

        if ((args->pa_flags & ~PUFFS_KFLAG_MASK) != 0) {
                printf("puffs_mount: invalid KFLAGs 0x%x\n", args->pa_flags);
                error = EINVAL;
                goto out;
        }
        if ((args->pa_fhflags & ~PUFFS_FHFLAG_MASK) != 0) {
                printf("puffs_mount: invalid FHFLAGs 0x%x\n", args->pa_fhflags);
                error = EINVAL;
                goto out;
        }

        for (i = 0; i < __arraycount(args->pa_spare); i++) {
                if (args->pa_spare[i] != 0) {
                        printf("puffs_mount: pa_spare[%d] = 0x%x\n",
                            i, args->pa_spare[i]);
                        error = EINVAL;
                        goto out;
                }
        }

        /* use dummy value for passthrough */
        if (args->pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH)
                args->pa_fhsize = sizeof(struct fid);

        /* sanitize file handle length */
        if (PUFFS_TOFHSIZE(args->pa_fhsize) > FHANDLE_SIZE_MAX) {
                printf("puffs_mount: handle size %zu too large\n",
                    args->pa_fhsize);
                error = EINVAL;
                goto out;
        }
        /* sanity check file handle max sizes */
        if (args->pa_fhsize && args->pa_fhflags & PUFFS_FHFLAG_PROTOMASK) {
                size_t kfhsize = PUFFS_TOFHSIZE(args->pa_fhsize);

                if (args->pa_fhflags & PUFFS_FHFLAG_NFSV2) {
                        if (NFSX_FHTOOBIG_P(kfhsize, 0)) {
                                printf("puffs_mount: fhsize larger than "
                                    "NFSv2 max %d\n",
                                    PUFFS_FROMFHSIZE(NFSX_V2FH));
                                error = EINVAL;
                                goto out;
                        }
                }

                if (args->pa_fhflags & PUFFS_FHFLAG_NFSV3) {
                        if (NFSX_FHTOOBIG_P(kfhsize, 1)) {
                                printf("puffs_mount: fhsize larger than "
                                    "NFSv3 max %d\n",
                                    PUFFS_FROMFHSIZE(NFSX_V3FHMAX));
                                error = EINVAL;
                                goto out;
                        }
                }
        }

        /* don't allow non-printing characters (like my sweet umlauts.. snif) */
        args->pa_typename[sizeof(args->pa_typename)-1] = '\0';
        for (p = args->pa_typename; *p; p++)
                if (*p < ' ' || *p > '~')
                        *p = '.';

        args->pa_mntfromname[sizeof(args->pa_mntfromname)-1] = '\0';
        for (p = args->pa_mntfromname; *p; p++)
                if (*p < ' ' || *p > '~')
                        *p = '.';

        /* build real name */
        (void)strlcpy(fstype, PUFFS_TYPEPREFIX, sizeof(fstype));
        (void)strlcat(fstype, args->pa_typename, sizeof(fstype));

        /* inform user server if it got the max request size it wanted */
        if (args->pa_maxmsglen == 0 || args->pa_maxmsglen > PUFFS_MSG_MAXSIZE)
                args->pa_maxmsglen = PUFFS_MSG_MAXSIZE;
        else if (args->pa_maxmsglen < 2*PUFFS_MSGSTRUCT_MAX)
                args->pa_maxmsglen = 2*PUFFS_MSGSTRUCT_MAX;

        (void)strlcpy(args->pa_typename, fstype, sizeof(args->pa_typename));

        error = set_statvfs_info(path, UIO_USERSPACE, args->pa_mntfromname,
            UIO_SYSSPACE, fstype, mp, curlwp);
        if (error)
                goto out;
        mp->mnt_stat.f_iosize = DEV_BSIZE;
        mp->mnt_stat.f_namemax = args->pa_svfsb.f_namemax;

        /*
         * We can't handle the VFS_STATVFS() mount_domount() does
         * after VFS_MOUNT() because we'd deadlock, so handle it
         * here already.
         */
        struct statvfs *sb = STATVFSBUF_GET();
        puffs_statvfs_to_statvfs(&args->pa_svfsb, sb);
        copy_statvfs_info(sb, mp);
        STATVFSBUF_PUT(sb);

        statvfs_to_puffs_statvfs(&mp->mnt_stat, &args->pa_svfsb);

        KASSERT(!uvm_lwp_is_pagedaemon(curlwp));
        pmp = kmem_zalloc(sizeof(struct puffs_mount), KM_SLEEP);

        mp->mnt_fs_bshift = DEV_BSHIFT;
        mp->mnt_dev_bshift = DEV_BSHIFT;
        mp->mnt_flag &= ~MNT_LOCAL; /* we don't really know, so ... */
        mp->mnt_data = pmp;

#if 0
        /*
         * XXX: puffs code is MPSAFE.  However, VFS really isn't.
         * Currently, there is nothing which protects an inode from
         * reclaim while there are threads inside the file system.
         * This means that in the event of a server crash, an MPSAFE
         * mount is likely to end up accessing invalid memory.  For the
         * non-mpsafe case, the kernel lock, general structure of
         * puffs and pmp_refcount protect the threads during escape.
         *
         * Fixing this will require:
         *  a) fixing vfs
         * OR
         *  b) adding a small sleep to puffs_msgif_close() between
         *     userdead() and dounmount().
         *     (well, this isn't really a fix, but would solve
         *     99.999% of the race conditions).
         *
         * Also, in the event of "b", unmount -f should be used,
         * like with any other file system, sparingly and only when
         * it is "known" to be safe.
         */
        mp->mnt_iflags |= IMNT_MPSAFE;
#endif

        pmp->pmp_status = PUFFSTAT_MOUNTING;
        pmp->pmp_mp = mp;
        pmp->pmp_msg_maxsize = args->pa_maxmsglen;
        pmp->pmp_args = *args;

        /*
         * Inform the fileops processing code that we have a mountpoint.
         * If it doesn't know about anyone with our pid/fd having the
         * device open, punt
         */
        if ((pmp->pmp_pi
            = putter_attach(mntpid, args->pa_fd, pmp, &puffs_putter)) == NULL) {
                error = ENOENT;
                goto out;
        }

        /* XXX: check parameters */
        pmp->pmp_root_cookie = args->pa_root_cookie;
        switch (args->pa_root_vtype) {
        case VNON: case VREG: case VDIR: case VBLK:
        case VCHR: case VLNK: case VSOCK: case VFIFO:
                break;
        default:
                error = EINVAL;
                goto out;
        }
        pmp->pmp_root_vtype = args->pa_root_vtype;

        if (args->pa_root_vsize < 0) {
                error = EINVAL;
                goto out;
        }
        pmp->pmp_root_vsize = args->pa_root_vsize;

        pmp->pmp_root_rdev = args->pa_root_rdev;
        pmp->pmp_docompat = args->pa_time32;

        mutex_init(&pmp->pmp_lock, MUTEX_DEFAULT, IPL_NONE);
        mutex_init(&pmp->pmp_sopmtx, MUTEX_DEFAULT, IPL_NONE);
        cv_init(&pmp->pmp_msg_waiter_cv, "puffsget");
        cv_init(&pmp->pmp_refcount_cv, "puffsref");
        cv_init(&pmp->pmp_unmounting_cv, "puffsum");
        cv_init(&pmp->pmp_sopcv, "puffsop");
        TAILQ_INIT(&pmp->pmp_msg_touser);
        TAILQ_INIT(&pmp->pmp_msg_replywait);
        TAILQ_INIT(&pmp->pmp_sopfastreqs);
        TAILQ_INIT(&pmp->pmp_sopnodereqs);

        if ((error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
            puffs_sop_thread, pmp, NULL, "puffsop")) != 0)
                goto out;
        pmp->pmp_sopthrcount = 1;

        DPRINTF(("puffs_mount: mount point at %p, puffs specific at %p\n",
            mp, MPTOPUFFSMP(mp)));

        vfs_getnewfsid(mp);

 out:
        if (error && pmp && pmp->pmp_pi)
                putter_detach(pmp->pmp_pi);
        if (error && pmp)
                kmem_free(pmp, sizeof(struct puffs_mount));
        return error;
}

int
puffs_vfsop_start(struct mount *mp, int flags)
{
        struct puffs_mount *pmp = MPTOPUFFSMP(mp);

        KASSERT(pmp->pmp_status == PUFFSTAT_MOUNTING);
        pmp->pmp_status = PUFFSTAT_RUNNING;

        return 0;
}

int
puffs_vfsop_unmount(struct mount *mp, int mntflags)
{
        PUFFS_MSG_VARS(vfs, unmount);
        struct puffs_mount *pmp;
        int error, force;

        error = 0;
        force = mntflags & MNT_FORCE;
        pmp = MPTOPUFFSMP(mp);

        DPRINTF(("puffs_unmount: detach filesystem from vfs, current "
            "status 0x%x\n", pmp->pmp_status));

        /*
         * flush all the vnodes.  VOP_RECLAIM() takes care that the
         * root vnode does not get flushed until unmount.  The
         * userspace root node cookie is stored in the mount
         * structure, so we can always re-instantiate a root vnode,
         * should userspace unmount decide it doesn't want to
         * cooperate.
         */
        error = vflush(mp, NULLVP, force ? FORCECLOSE : 0);
        if (error)
                goto out;

        /*
         * If we are not DYING, we should ask userspace's opinion
         * about the situation
         */
        mutex_enter(&pmp->pmp_lock);
        if (pmp->pmp_status != PUFFSTAT_DYING) {
                pmp->pmp_unmounting = 1;
                mutex_exit(&pmp->pmp_lock);

                PUFFS_MSG_ALLOC(vfs, unmount);
                puffs_msg_setinfo(park_unmount,
                    PUFFSOP_VFS, PUFFS_VFS_UNMOUNT, NULL);
                unmount_msg->pvfsr_flags = mntflags;

                PUFFS_MSG_ENQUEUEWAIT(pmp, park_unmount, error);
                PUFFS_MSG_RELEASE(unmount);

                error = checkerr(pmp, error, __func__);
                DPRINTF(("puffs_unmount: error %d force %d\n", error, force));

                mutex_enter(&pmp->pmp_lock);
                pmp->pmp_unmounting = 0;
                cv_broadcast(&pmp->pmp_unmounting_cv);
        }

        /*
         * if userspace cooperated or we really need to die,
         * screw what userland thinks and just die.
         */
        if (error == 0 || force) {
                struct puffs_sopreq *psopr;

                /* tell waiters & other resources to go unwait themselves */
                puffs_userdead(pmp);
                putter_detach(pmp->pmp_pi);

                /*
                 * Wait until there are no more users for the mount resource.
                 * Notice that this is hooked against transport_close
                 * and return from touser.  In an ideal world, it would
                 * be hooked against final return from all operations.
                 * But currently it works well enough, since nobody
                 * does weird blocking voodoo after return from touser().
                 */
                while (pmp->pmp_refcount != 0)
                        cv_wait(&pmp->pmp_refcount_cv, &pmp->pmp_lock);
                mutex_exit(&pmp->pmp_lock);

                /*
                 * Release kernel thread now that there is nothing
                 * it would be wanting to lock.
                 */
                KASSERT(!uvm_lwp_is_pagedaemon(curlwp));
                psopr = kmem_alloc(sizeof(*psopr), KM_SLEEP);
                psopr->psopr_sopreq = PUFFS_SOPREQSYS_EXIT;
                mutex_enter(&pmp->pmp_sopmtx);
                if (pmp->pmp_sopthrcount == 0) {
                        mutex_exit(&pmp->pmp_sopmtx);
                        kmem_free(psopr, sizeof(*psopr));
                        mutex_enter(&pmp->pmp_sopmtx);
                        KASSERT(pmp->pmp_sopthrcount == 0);
                } else {
                        TAILQ_INSERT_TAIL(&pmp->pmp_sopfastreqs,
                            psopr, psopr_entries);
                        cv_signal(&pmp->pmp_sopcv);
                }
                while (pmp->pmp_sopthrcount > 0)
                        cv_wait(&pmp->pmp_sopcv, &pmp->pmp_sopmtx);
                mutex_exit(&pmp->pmp_sopmtx);

                /* free resources now that we hopefully have no waiters left */
                cv_destroy(&pmp->pmp_unmounting_cv);
                cv_destroy(&pmp->pmp_refcount_cv);
                cv_destroy(&pmp->pmp_msg_waiter_cv);
                cv_destroy(&pmp->pmp_sopcv);
                mutex_destroy(&pmp->pmp_lock);
                mutex_destroy(&pmp->pmp_sopmtx);

                kmem_free(pmp, sizeof(struct puffs_mount));
                error = 0;
        } else {
                mutex_exit(&pmp->pmp_lock);
        }

 out:
        DPRINTF(("puffs_unmount: return %d\n", error));
        return error;
}

/*
 * This doesn't need to travel to userspace
 */
int
puffs_vfsop_root(struct mount *mp, int lktype, struct vnode **vpp)
{
        struct puffs_mount *pmp = MPTOPUFFSMP(mp);
        int rv;

        rv = puffs_cookie2vnode(pmp, pmp->pmp_root_cookie, vpp);
        KASSERT(rv != PUFFS_NOSUCHCOOKIE);
        if (rv != 0)
                return rv;
        rv = vn_lock(*vpp, lktype);
        if (rv != 0) {
                vrele(*vpp);
                *vpp = NULL;
                return rv;
        }
        return 0;
}

int
puffs_vfsop_statvfs(struct mount *mp, struct statvfs *sbp)
{
        PUFFS_MSG_VARS(vfs, statvfs);
        struct puffs_mount *pmp;
        int error = 0;

        pmp = MPTOPUFFSMP(mp);

        /*
         * If we are mounting, it means that the userspace counterpart
         * is calling mount(2), but mount(2) also calls statvfs.  So
         * requesting statvfs from userspace would mean a deadlock.
         * Compensate.
         */
        if (__predict_false(pmp->pmp_status == PUFFSTAT_MOUNTING))
                return EINPROGRESS;

        PUFFS_MSG_ALLOC(vfs, statvfs);
        puffs_msg_setinfo(park_statvfs, PUFFSOP_VFS, PUFFS_VFS_STATVFS, NULL);

        PUFFS_MSG_ENQUEUEWAIT(pmp, park_statvfs, error);
        error = checkerr(pmp, error, __func__);
        statvfs_msg->pvfsr_sb.f_iosize = DEV_BSIZE;

        /*
         * Try to produce a sensible result even in the event
         * of userspace error.
         *
         * XXX: cache the copy in non-error case
         */
        if (!error) {
                puffs_statvfs_to_statvfs(&statvfs_msg->pvfsr_sb, sbp);
        }
        copy_statvfs_info(sbp, mp);
        if (!error) {
                statvfs_to_puffs_statvfs(sbp, &statvfs_msg->pvfsr_sb);
        }

        PUFFS_MSG_RELEASE(statvfs);
        return error;
}

static bool
pageflush_selector(void *cl, struct vnode *vp)
{

        KASSERT(mutex_owned(vp->v_interlock));

        return vp->v_type == VREG &&
            !(LIST_EMPTY(&vp->v_dirtyblkhd) &&
            (vp->v_iflag & VI_ONWORKLST) == 0);

}

static int
pageflush(struct mount *mp, kauth_cred_t cred, int waitfor)
{
        struct puffs_node *pn;
        struct vnode *vp;
        struct vnode_iterator *marker;
        int error, rv, fsyncwait;

        error = 0;
        fsyncwait = (waitfor == MNT_WAIT) ? FSYNC_WAIT : 0;

        /*
         * Sync all cached data from regular vnodes (which are not
         * currently locked, see below).  After this we call VFS_SYNC
         * for the fs server, which should handle data and metadata for
         * all the nodes it knows to exist.
         */
        vfs_vnode_iterator_init(mp, &marker);
        while ((vp = vfs_vnode_iterator_next(marker, pageflush_selector,
            NULL)))
        {
                /*
                 * Here we try to get a reference to the vnode and to
                 * lock it.  This is mostly cargo-culted, but I will
                 * offer an explanation to why I believe this might
                 * actually do the right thing.
                 *
                 * If the vnode is a goner, we quite obviously don't need
                 * to sync it.
                 *
                 * If the vnode was busy, we don't need to sync it because
                 * this is never called with MNT_WAIT except from
                 * dounmount(), when we are wait-flushing all the dirty
                 * vnodes through other routes in any case.  So there,
                 * sync() doesn't actually sync.  Happy now?
                 */
                error = vn_lock(vp, LK_EXCLUSIVE | LK_NOWAIT);
                if (error) {
                        vrele(vp);
                        continue;
                }
                pn = VPTOPP(vp);
                /* hmm.. is the FAF thing entirely sensible? */
                if (waitfor == MNT_LAZY) {
                        mutex_enter(vp->v_interlock);
                        pn->pn_stat |= PNODE_FAF;
                        mutex_exit(vp->v_interlock);
                }
                rv = VOP_FSYNC(vp, cred, fsyncwait, 0, 0);
                if (waitfor == MNT_LAZY) {
                        mutex_enter(vp->v_interlock);
                        pn->pn_stat &= ~PNODE_FAF;
                        mutex_exit(vp->v_interlock);
                }
                if (rv)
                        error = rv;
                vput(vp);
        }
        vfs_vnode_iterator_destroy(marker);

        return error;
}

int
puffs_vfsop_sync(struct mount *mp, int waitfor, struct kauth_cred *cred)
{
        PUFFS_MSG_VARS(vfs, sync);
        struct puffs_mount *pmp = MPTOPUFFSMP(mp);
        int error, rv;

        error = pageflush(mp, cred, waitfor);

        /* sync fs */
        PUFFS_MSG_ALLOC(vfs, sync);
        sync_msg->pvfsr_waitfor = waitfor;
        puffs_credcvt(&sync_msg->pvfsr_cred, cred);
        puffs_msg_setinfo(park_sync, PUFFSOP_VFS, PUFFS_VFS_SYNC, NULL);

        PUFFS_MSG_ENQUEUEWAIT(pmp, park_sync, rv);
        rv = checkerr(pmp, rv, __func__);
        if (rv)
                error = rv;

        PUFFS_MSG_RELEASE(sync);
        return error;
}

int
puffs_vfsop_fhtovp(struct mount *mp, struct fid *fhp, int lktype,
    struct vnode **vpp)
{
        PUFFS_MSG_VARS(vfs, fhtonode);
        struct puffs_mount *pmp = MPTOPUFFSMP(mp);
        struct vnode *vp;
        void *fhdata;
        size_t argsize, fhlen;
        int error;

        if (pmp->pmp_args.pa_fhsize == 0)
                return EOPNOTSUPP;

        if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH) {
                fhlen = fhp->fid_len;
                fhdata = fhp;
        } else {
                fhlen = PUFFS_FROMFHSIZE(fhp->fid_len);
                fhdata = fhp->fid_data;

                if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_DYNAMIC) {
                        if (pmp->pmp_args.pa_fhsize < fhlen)
                                return EINVAL;
                } else {
                        if (pmp->pmp_args.pa_fhsize != fhlen)
                                return EINVAL;
                }
        }

        argsize = sizeof(struct puffs_vfsmsg_fhtonode) + fhlen;
        puffs_msgmem_alloc(argsize, &park_fhtonode, (void *)&fhtonode_msg, 1);
        fhtonode_msg->pvfsr_dsize = fhlen;
        memcpy(fhtonode_msg->pvfsr_data, fhdata, fhlen);
        puffs_msg_setinfo(park_fhtonode, PUFFSOP_VFS, PUFFS_VFS_FHTOVP, NULL);

        PUFFS_MSG_ENQUEUEWAIT(pmp, park_fhtonode, error);
        error = checkerr(pmp, error, __func__);
        if (error)
                goto out;

        error = puffs_getvnode(mp, fhtonode_msg->pvfsr_fhcookie,
            fhtonode_msg->pvfsr_vtype, fhtonode_msg->pvfsr_size,
            fhtonode_msg->pvfsr_rdev, &vp);
        if (error)
                goto out;
        vn_lock(vp, lktype | LK_RETRY);

        *vpp = vp;
 out:
        puffs_msgmem_release(park_fhtonode);
        return error;
}

int
puffs_vfsop_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size)
{
        PUFFS_MSG_VARS(vfs, nodetofh);
        struct puffs_mount *pmp = MPTOPUFFSMP(vp->v_mount);
        size_t argsize, fhlen;
        int error;

        if (pmp->pmp_args.pa_fhsize == 0)
                return EOPNOTSUPP;

        /* if file handles are static len, we can test len immediately */
        if (((pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_DYNAMIC) == 0)
            && ((pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH) == 0)
            && (PUFFS_FROMFHSIZE(*fh_size) < pmp->pmp_args.pa_fhsize)) {
                *fh_size = PUFFS_TOFHSIZE(pmp->pmp_args.pa_fhsize);
                return E2BIG;
        }

        if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH)
                fhlen = *fh_size;
        else
                fhlen = PUFFS_FROMFHSIZE(*fh_size);

        argsize = sizeof(struct puffs_vfsmsg_nodetofh) + fhlen;
        puffs_msgmem_alloc(argsize, &park_nodetofh, (void *)&nodetofh_msg, 1);
        nodetofh_msg->pvfsr_fhcookie = VPTOPNC(vp);
        nodetofh_msg->pvfsr_dsize = fhlen;
        puffs_msg_setinfo(park_nodetofh, PUFFSOP_VFS, PUFFS_VFS_VPTOFH, NULL);

        PUFFS_MSG_ENQUEUEWAIT(pmp, park_nodetofh, error);
        error = checkerr(pmp, error, __func__);

        if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH)
                fhlen = nodetofh_msg->pvfsr_dsize;
        else if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_DYNAMIC)
                fhlen = PUFFS_TOFHSIZE(nodetofh_msg->pvfsr_dsize);
        else
                fhlen = PUFFS_TOFHSIZE(pmp->pmp_args.pa_fhsize);

        if (error) {
                if (error == E2BIG)
                        *fh_size = fhlen;
                goto out;
        }

        if (fhlen > FHANDLE_SIZE_MAX) {
                puffs_senderr(pmp, PUFFS_ERR_VPTOFH, E2BIG,
                    "file handle too big", VPTOPNC(vp));
                error = EPROTO;
                goto out;
        }

        if (*fh_size < fhlen) {
                *fh_size = fhlen;
                error = E2BIG;
                goto out;
        }
        *fh_size = fhlen;

        if (fhp) {
                if (pmp->pmp_args.pa_fhflags & PUFFS_FHFLAG_PASSTHROUGH) {
                        memcpy(fhp, nodetofh_msg->pvfsr_data, fhlen);
                } else {
                        fhp->fid_len = *fh_size;
                        memcpy(fhp->fid_data, nodetofh_msg->pvfsr_data,
                            nodetofh_msg->pvfsr_dsize);
                }
        }

 out:
        puffs_msgmem_release(park_nodetofh);
        return error;
}

int
puffs_vfsop_loadvnode(struct mount *mp, struct vnode *vp,
    const void *key, size_t key_len, const void **new_key)
{
        struct puffs_mount *pmp;
        struct puffs_node *pnode;

        KASSERT(key_len == sizeof(puffs_cookie_t));

        pmp = MPTOPUFFSMP(mp);

        /* Allocate and initialize the pnode. */
        pnode = pool_get(&puffs_pnpool, PR_WAITOK);
        memset(pnode, 0, sizeof(struct puffs_node));

        pnode->pn_vp = vp;
        memcpy(&pnode->pn_cookie, key, key_len);
        pnode->pn_refcount = 1;
        mutex_init(&pnode->pn_mtx, MUTEX_DEFAULT, IPL_NONE);
        mutex_init(&pnode->pn_sizemtx, MUTEX_DEFAULT, IPL_NONE);
        selinit(&pnode->pn_sel);
        vp->v_tag = VT_PUFFS;
        vp->v_type = VNON;
        vp->v_op = puffs_vnodeop_p;
        if (pnode->pn_cookie == pmp->pmp_root_cookie)
                vp->v_vflag |= VV_ROOT;
        vp->v_data = pnode;

        genfs_node_init(vp, &puffs_genfsops);
        uvm_vnp_setsize(vp, 0);

        *new_key = &pnode->pn_cookie;
        return 0;
}

void
puffs_vfsop_init(void)
{

        /* some checks depend on this */
        KASSERT(VNOVAL == VSIZENOTSET);

        pool_init(&puffs_pnpool, sizeof(struct puffs_node), 0, 0, 0,
            "puffpnpl", &pool_allocator_nointr, IPL_NONE);
        pool_init(&puffs_vapool, sizeof(struct vattr), 0, 0, 0,
            "puffvapl", &pool_allocator_nointr, IPL_NONE);
        puffs_msgif_init();
}

void
puffs_vfsop_done(void)
{

        puffs_msgif_destroy();
        pool_destroy(&puffs_pnpool);
        pool_destroy(&puffs_vapool);
}

int
puffs_vfsop_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ts)
{

        return EOPNOTSUPP;
}

int
puffs_vfsop_extattrctl(struct mount *mp, int cmd, struct vnode *vp,
        int attrnamespace, const char *attrname)
{
        PUFFS_MSG_VARS(vfs, extattrctl);
        struct puffs_mount *pmp = MPTOPUFFSMP(mp);
        struct puffs_node *pnp;
        puffs_cookie_t pnc;
        int error, flags;

        if (vp) {
                /* doesn't make sense for puffs servers */
                if (vp->v_mount != mp)
                        return EXDEV;
                pnp = vp->v_data;
                pnc = pnp->pn_cookie;
                flags = PUFFS_EXTATTRCTL_HASNODE;
        } else {
                pnp = pnc = NULL;
                flags = 0;
        }

        PUFFS_MSG_ALLOC(vfs, extattrctl);
        extattrctl_msg->pvfsr_cmd = cmd;
        extattrctl_msg->pvfsr_attrnamespace = attrnamespace;
        extattrctl_msg->pvfsr_flags = flags;
        if (attrname) {
                strlcpy(extattrctl_msg->pvfsr_attrname, attrname,
                    sizeof(extattrctl_msg->pvfsr_attrname));
                extattrctl_msg->pvfsr_flags |= PUFFS_EXTATTRCTL_HASATTRNAME;
        }
        puffs_msg_setinfo(park_extattrctl,
            PUFFSOP_VFS, PUFFS_VFS_EXTATTRCTL, pnc);

        puffs_msg_enqueue(pmp, park_extattrctl);
        if (vp) {
                mutex_enter(&pnp->pn_mtx);
                puffs_referencenode(pnp);
                mutex_exit(&pnp->pn_mtx);
                VOP_UNLOCK(vp);
        }
        error = puffs_msg_wait2(pmp, park_extattrctl, pnp, NULL);
        PUFFS_MSG_RELEASE(extattrctl);
        if (vp) {
                puffs_releasenode(pnp);
        }

        return checkerr(pmp, error, __func__);
}

const struct vnodeopv_desc * const puffs_vnodeopv_descs[] = {
        &puffs_vnodeop_opv_desc,
        &puffs_specop_opv_desc,
        &puffs_fifoop_opv_desc,
        &puffs_msgop_opv_desc,
        NULL,
};

struct vfsops puffs_vfsops = {
        .vfs_name = MOUNT_PUFFS,
        .vfs_min_mount_data = sizeof (struct puffs_kargs),
        .vfs_mount = puffs_vfsop_mount,
        .vfs_start = puffs_vfsop_start,
        .vfs_unmount = puffs_vfsop_unmount,
        .vfs_root = puffs_vfsop_root,
        .vfs_quotactl = (void *)eopnotsupp,
        .vfs_statvfs = puffs_vfsop_statvfs,
        .vfs_sync = puffs_vfsop_sync,
        .vfs_vget = (void *)eopnotsupp,
        .vfs_loadvnode = puffs_vfsop_loadvnode,
        .vfs_fhtovp = puffs_vfsop_fhtovp,
        .vfs_vptofh = puffs_vfsop_vptofh,
        .vfs_init = puffs_vfsop_init,
        .vfs_done = puffs_vfsop_done,
        .vfs_snapshot = puffs_vfsop_snapshot,
        .vfs_extattrctl = puffs_vfsop_extattrctl,
        .vfs_suspendctl = genfs_suspendctl,
        .vfs_renamelock_enter = genfs_renamelock_enter,
        .vfs_renamelock_exit = genfs_renamelock_exit,
        .vfs_fsync = (void *)eopnotsupp,
        .vfs_opv_descs = puffs_vnodeopv_descs
};

static int
puffs_modcmd(modcmd_t cmd, void *arg)
{

        switch (cmd) {
        case MODULE_CMD_INIT:
                return vfs_attach(&puffs_vfsops);
        case MODULE_CMD_FINI:
                return vfs_detach(&puffs_vfsops);
        default:
                return ENOTTY;
        }
}