MFV: r362513

[FreeBSD/FreeBSD.git] / sys / fs / nfsclient / nfs_clport.c

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * 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.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS 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>
__FBSDID("$FreeBSD$");

#include "opt_inet.h"
#include "opt_inet6.h"

#include <sys/capsicum.h>

/*
 * generally, I don't like #includes inside .h files, but it seems to
 * be the easiest way to handle the port.
 */
#include <sys/fail.h>
#include <sys/hash.h>
#include <sys/sysctl.h>
#include <fs/nfs/nfsport.h>
#include <netinet/in_fib.h>
#include <netinet/if_ether.h>
#include <netinet6/ip6_var.h>
#include <net/if_types.h>
#include <net/route/nhop.h>

#include <fs/nfsclient/nfs_kdtrace.h>

#ifdef KDTRACE_HOOKS
dtrace_nfsclient_attrcache_flush_probe_func_t
                dtrace_nfscl_attrcache_flush_done_probe;
uint32_t        nfscl_attrcache_flush_done_id;

dtrace_nfsclient_attrcache_get_hit_probe_func_t
                dtrace_nfscl_attrcache_get_hit_probe;
uint32_t        nfscl_attrcache_get_hit_id;

dtrace_nfsclient_attrcache_get_miss_probe_func_t
                dtrace_nfscl_attrcache_get_miss_probe;
uint32_t        nfscl_attrcache_get_miss_id;

dtrace_nfsclient_attrcache_load_probe_func_t
                dtrace_nfscl_attrcache_load_done_probe;
uint32_t        nfscl_attrcache_load_done_id;
#endif /* !KDTRACE_HOOKS */

extern u_int32_t newnfs_true, newnfs_false, newnfs_xdrneg1;
extern struct vop_vector newnfs_vnodeops;
extern struct vop_vector newnfs_fifoops;
extern uma_zone_t newnfsnode_zone;
extern struct buf_ops buf_ops_newnfs;
extern uma_zone_t ncl_pbuf_zone;
extern short nfsv4_cbport;
extern int nfscl_enablecallb;
extern int nfs_numnfscbd;
extern int nfscl_inited;
struct mtx ncl_iod_mutex;
NFSDLOCKMUTEX;
extern struct mtx nfsrv_dslock_mtx;

extern void (*ncl_call_invalcaches)(struct vnode *);

SYSCTL_DECL(_vfs_nfs);
static int ncl_fileid_maxwarnings = 10;
SYSCTL_INT(_vfs_nfs, OID_AUTO, fileid_maxwarnings, CTLFLAG_RWTUN,
    &ncl_fileid_maxwarnings, 0,
    "Limit fileid corruption warnings; 0 is off; -1 is unlimited");
static volatile int ncl_fileid_nwarnings;

static void nfscl_warn_fileid(struct nfsmount *, struct nfsvattr *,
    struct nfsvattr *);

/*
 * Comparison function for vfs_hash functions.
 */
int
newnfs_vncmpf(struct vnode *vp, void *arg)
{
        struct nfsfh *nfhp = (struct nfsfh *)arg;
        struct nfsnode *np = VTONFS(vp);

        if (np->n_fhp->nfh_len != nfhp->nfh_len ||
            NFSBCMP(np->n_fhp->nfh_fh, nfhp->nfh_fh, nfhp->nfh_len))
                return (1);
        return (0);
}

/*
 * Look up a vnode/nfsnode by file handle.
 * Callers must check for mount points!!
 * In all cases, a pointer to a
 * nfsnode structure is returned.
 * This variant takes a "struct nfsfh *" as second argument and uses
 * that structure up, either by hanging off the nfsnode or FREEing it.
 */
int
nfscl_nget(struct mount *mntp, struct vnode *dvp, struct nfsfh *nfhp,
    struct componentname *cnp, struct thread *td, struct nfsnode **npp,
    void *stuff, int lkflags)
{
        struct nfsnode *np, *dnp;
        struct vnode *vp, *nvp;
        struct nfsv4node *newd, *oldd;
        int error;
        u_int hash;
        struct nfsmount *nmp;

        nmp = VFSTONFS(mntp);
        dnp = VTONFS(dvp);
        *npp = NULL;

        hash = fnv_32_buf(nfhp->nfh_fh, nfhp->nfh_len, FNV1_32_INIT);

        error = vfs_hash_get(mntp, hash, lkflags,
            td, &nvp, newnfs_vncmpf, nfhp);
        if (error == 0 && nvp != NULL) {
                /*
                 * I believe there is a slight chance that vgonel() could
                 * get called on this vnode between when NFSVOPLOCK() drops
                 * the VI_LOCK() and vget() acquires it again, so that it
                 * hasn't yet had v_usecount incremented. If this were to
                 * happen, the VIRF_DOOMED flag would be set, so check for
                 * that here. Since we now have the v_usecount incremented,
                 * we should be ok until we vrele() it, if the VIRF_DOOMED
                 * flag isn't set now.
                 */
                VI_LOCK(nvp);
                if (VN_IS_DOOMED(nvp)) {
                        VI_UNLOCK(nvp);
                        vrele(nvp);
                        error = ENOENT;
                } else {
                        VI_UNLOCK(nvp);
                }
        }
        if (error) {
                free(nfhp, M_NFSFH);
                return (error);
        }
        if (nvp != NULL) {
                np = VTONFS(nvp);
                /*
                 * For NFSv4, check to see if it is the same name and
                 * replace the name, if it is different.
                 */
                oldd = newd = NULL;
                if ((nmp->nm_flag & NFSMNT_NFSV4) && np->n_v4 != NULL &&
                    nvp->v_type == VREG &&
                    (np->n_v4->n4_namelen != cnp->cn_namelen ||
                     NFSBCMP(cnp->cn_nameptr, NFS4NODENAME(np->n_v4),
                     cnp->cn_namelen) ||
                     dnp->n_fhp->nfh_len != np->n_v4->n4_fhlen ||
                     NFSBCMP(dnp->n_fhp->nfh_fh, np->n_v4->n4_data,
                     dnp->n_fhp->nfh_len))) {
                    newd = malloc(
                        sizeof (struct nfsv4node) + dnp->n_fhp->nfh_len +
                        + cnp->cn_namelen - 1, M_NFSV4NODE, M_WAITOK);
                    NFSLOCKNODE(np);
                    if (newd != NULL && np->n_v4 != NULL && nvp->v_type == VREG
                        && (np->n_v4->n4_namelen != cnp->cn_namelen ||
                         NFSBCMP(cnp->cn_nameptr, NFS4NODENAME(np->n_v4),
                         cnp->cn_namelen) ||
                         dnp->n_fhp->nfh_len != np->n_v4->n4_fhlen ||
                         NFSBCMP(dnp->n_fhp->nfh_fh, np->n_v4->n4_data,
                         dnp->n_fhp->nfh_len))) {
                        oldd = np->n_v4;
                        np->n_v4 = newd;
                        newd = NULL;
                        np->n_v4->n4_fhlen = dnp->n_fhp->nfh_len;
                        np->n_v4->n4_namelen = cnp->cn_namelen;
                        NFSBCOPY(dnp->n_fhp->nfh_fh, np->n_v4->n4_data,
                            dnp->n_fhp->nfh_len);
                        NFSBCOPY(cnp->cn_nameptr, NFS4NODENAME(np->n_v4),
                            cnp->cn_namelen);
                    }
                    NFSUNLOCKNODE(np);
                }
                if (newd != NULL)
                        free(newd, M_NFSV4NODE);
                if (oldd != NULL)
                        free(oldd, M_NFSV4NODE);
                *npp = np;
                free(nfhp, M_NFSFH);
                return (0);
        }
        np = uma_zalloc(newnfsnode_zone, M_WAITOK | M_ZERO);

        error = getnewvnode(nfs_vnode_tag, mntp, &newnfs_vnodeops, &nvp);
        if (error) {
                uma_zfree(newnfsnode_zone, np);
                free(nfhp, M_NFSFH);
                return (error);
        }
        vp = nvp;
        KASSERT(vp->v_bufobj.bo_bsize != 0, ("nfscl_nget: bo_bsize == 0"));
        vp->v_bufobj.bo_ops = &buf_ops_newnfs;
        vp->v_data = np;
        np->n_vnode = vp;
        /* 
         * Initialize the mutex even if the vnode is going to be a loser.
         * This simplifies the logic in reclaim, which can then unconditionally
         * destroy the mutex (in the case of the loser, or if hash_insert
         * happened to return an error no special casing is needed).
         */
        mtx_init(&np->n_mtx, "NEWNFSnode lock", NULL, MTX_DEF | MTX_DUPOK);
        lockinit(&np->n_excl, PVFS, "nfsupg", VLKTIMEOUT, LK_NOSHARE |
            LK_CANRECURSE);

        /* 
         * Are we getting the root? If so, make sure the vnode flags
         * are correct 
         */
        if ((nfhp->nfh_len == nmp->nm_fhsize) &&
            !bcmp(nfhp->nfh_fh, nmp->nm_fh, nfhp->nfh_len)) {
                if (vp->v_type == VNON)
                        vp->v_type = VDIR;
                vp->v_vflag |= VV_ROOT;
        }

        vp->v_vflag |= VV_VMSIZEVNLOCK;
        
        np->n_fhp = nfhp;
        /*
         * For NFSv4, we have to attach the directory file handle and
         * file name, so that Open Ops can be done later.
         */
        if (nmp->nm_flag & NFSMNT_NFSV4) {
                np->n_v4 = malloc(sizeof (struct nfsv4node)
                    + dnp->n_fhp->nfh_len + cnp->cn_namelen - 1, M_NFSV4NODE,
                    M_WAITOK);
                np->n_v4->n4_fhlen = dnp->n_fhp->nfh_len;
                np->n_v4->n4_namelen = cnp->cn_namelen;
                NFSBCOPY(dnp->n_fhp->nfh_fh, np->n_v4->n4_data,
                    dnp->n_fhp->nfh_len);
                NFSBCOPY(cnp->cn_nameptr, NFS4NODENAME(np->n_v4),
                    cnp->cn_namelen);
        } else {
                np->n_v4 = NULL;
        }

        /*
         * NFS supports recursive and shared locking.
         */
        lockmgr(vp->v_vnlock, LK_EXCLUSIVE | LK_NOWITNESS, NULL);
        VN_LOCK_AREC(vp);
        VN_LOCK_ASHARE(vp);
        error = insmntque(vp, mntp);
        if (error != 0) {
                *npp = NULL;
                mtx_destroy(&np->n_mtx);
                lockdestroy(&np->n_excl);
                free(nfhp, M_NFSFH);
                if (np->n_v4 != NULL)
                        free(np->n_v4, M_NFSV4NODE);
                uma_zfree(newnfsnode_zone, np);
                return (error);
        }
        error = vfs_hash_insert(vp, hash, lkflags, 
            td, &nvp, newnfs_vncmpf, nfhp);
        if (error)
                return (error);
        if (nvp != NULL) {
                *npp = VTONFS(nvp);
                /* vfs_hash_insert() vput()'s the losing vnode */
                return (0);
        }
        *npp = np;

        return (0);
}

/*
 * Another variant of nfs_nget(). This one is only used by reopen. It
 * takes almost the same args as nfs_nget(), but only succeeds if an entry
 * exists in the cache. (Since files should already be "open" with a
 * vnode ref cnt on the node when reopen calls this, it should always
 * succeed.)
 * Also, don't get a vnode lock, since it may already be locked by some
 * other process that is handling it. This is ok, since all other threads
 * on the client are blocked by the nfsc_lock being exclusively held by the
 * caller of this function.
 */
int
nfscl_ngetreopen(struct mount *mntp, u_int8_t *fhp, int fhsize,
    struct thread *td, struct nfsnode **npp)
{
        struct vnode *nvp;
        u_int hash;
        struct nfsfh *nfhp;
        int error;

        *npp = NULL;
        /* For forced dismounts, just return error. */
        if (NFSCL_FORCEDISM(mntp))
                return (EINTR);
        nfhp = malloc(sizeof (struct nfsfh) + fhsize,
            M_NFSFH, M_WAITOK);
        bcopy(fhp, &nfhp->nfh_fh[0], fhsize);
        nfhp->nfh_len = fhsize;

        hash = fnv_32_buf(fhp, fhsize, FNV1_32_INIT);

        /*
         * First, try to get the vnode locked, but don't block for the lock.
         */
        error = vfs_hash_get(mntp, hash, (LK_EXCLUSIVE | LK_NOWAIT), td, &nvp,
            newnfs_vncmpf, nfhp);
        if (error == 0 && nvp != NULL) {
                NFSVOPUNLOCK(nvp);
        } else if (error == EBUSY) {
                /*
                 * It is safe so long as a vflush() with
                 * FORCECLOSE has not been done. Since the Renew thread is
                 * stopped and the MNTK_UNMOUNTF flag is set before doing
                 * a vflush() with FORCECLOSE, we should be ok here.
                 */
                if (NFSCL_FORCEDISM(mntp))
                        error = EINTR;
                else {
                        vfs_hash_ref(mntp, hash, td, &nvp, newnfs_vncmpf, nfhp);
                        if (nvp == NULL) {
                                error = ENOENT;
                        } else if (VN_IS_DOOMED(nvp)) {
                                error = ENOENT;
                                vrele(nvp);
                        } else {
                                error = 0;
                        }
                }
        }
        free(nfhp, M_NFSFH);
        if (error)
                return (error);
        if (nvp != NULL) {
                *npp = VTONFS(nvp);
                return (0);
        }
        return (EINVAL);
}

static void
nfscl_warn_fileid(struct nfsmount *nmp, struct nfsvattr *oldnap,
    struct nfsvattr *newnap)
{
        int off;

        if (ncl_fileid_maxwarnings >= 0 &&
            ncl_fileid_nwarnings >= ncl_fileid_maxwarnings)
                return;
        off = 0;
        if (ncl_fileid_maxwarnings >= 0) {
                if (++ncl_fileid_nwarnings >= ncl_fileid_maxwarnings)
                        off = 1;
        }

        printf("newnfs: server '%s' error: fileid changed. "
            "fsid %jx:%jx: expected fileid %#jx, got %#jx. "
            "(BROKEN NFS SERVER OR MIDDLEWARE)\n",
            nmp->nm_com.nmcom_hostname,
            (uintmax_t)nmp->nm_fsid[0],
            (uintmax_t)nmp->nm_fsid[1],
            (uintmax_t)oldnap->na_fileid,
            (uintmax_t)newnap->na_fileid);

        if (off)
                printf("newnfs: Logged %d times about fileid corruption; "
                    "going quiet to avoid spamming logs excessively. (Limit "
                    "is: %d).\n", ncl_fileid_nwarnings,
                    ncl_fileid_maxwarnings);
}

/*
 * Load the attribute cache (that lives in the nfsnode entry) with
 * the attributes of the second argument and
 * Iff vaper not NULL
 *    copy the attributes to *vaper
 * Similar to nfs_loadattrcache(), except the attributes are passed in
 * instead of being parsed out of the mbuf list.
 */
int
nfscl_loadattrcache(struct vnode **vpp, struct nfsvattr *nap, void *nvaper,
    void *stuff, int writeattr, int dontshrink)
{
        struct vnode *vp = *vpp;
        struct vattr *vap, *nvap = &nap->na_vattr, *vaper = nvaper;
        struct nfsnode *np;
        struct nfsmount *nmp;
        struct timespec mtime_save;
        int error, force_fid_err;

        error = 0;

        /*
         * If v_type == VNON it is a new node, so fill in the v_type,
         * n_mtime fields. Check to see if it represents a special 
         * device, and if so, check for a possible alias. Once the
         * correct vnode has been obtained, fill in the rest of the
         * information.
         */
        np = VTONFS(vp);
        NFSLOCKNODE(np);
        if (vp->v_type != nvap->va_type) {
                vp->v_type = nvap->va_type;
                if (vp->v_type == VFIFO)
                        vp->v_op = &newnfs_fifoops;
                np->n_mtime = nvap->va_mtime;
        }
        nmp = VFSTONFS(vp->v_mount);
        vap = &np->n_vattr.na_vattr;
        mtime_save = vap->va_mtime;
        if (writeattr) {
                np->n_vattr.na_filerev = nap->na_filerev;
                np->n_vattr.na_size = nap->na_size;
                np->n_vattr.na_mtime = nap->na_mtime;
                np->n_vattr.na_ctime = nap->na_ctime;
                np->n_vattr.na_fsid = nap->na_fsid;
                np->n_vattr.na_mode = nap->na_mode;
        } else {
                force_fid_err = 0;
                KFAIL_POINT_ERROR(DEBUG_FP, nfscl_force_fileid_warning,
                    force_fid_err);
                /*
                 * BROKEN NFS SERVER OR MIDDLEWARE
                 *
                 * Certain NFS servers (certain old proprietary filers ca.
                 * 2006) or broken middleboxes (e.g. WAN accelerator products)
                 * will respond to GETATTR requests with results for a
                 * different fileid.
                 *
                 * The WAN accelerator we've observed not only serves stale
                 * cache results for a given file, it also occasionally serves
                 * results for wholly different files.  This causes surprising
                 * problems; for example the cached size attribute of a file
                 * may truncate down and then back up, resulting in zero
                 * regions in file contents read by applications.  We observed
                 * this reliably with Clang and .c files during parallel build.
                 * A pcap revealed packet fragmentation and GETATTR RPC
                 * responses with wholly wrong fileids.
                 */
                if ((np->n_vattr.na_fileid != 0 &&
                     np->n_vattr.na_fileid != nap->na_fileid) ||
                    force_fid_err) {
                        nfscl_warn_fileid(nmp, &np->n_vattr, nap);
                        error = EIDRM;
                        goto out;
                }
                NFSBCOPY((caddr_t)nap, (caddr_t)&np->n_vattr,
                    sizeof (struct nfsvattr));
        }

        /*
         * For NFSv4, if the node's fsid is not equal to the mount point's
         * fsid, return the low order 32bits of the node's fsid. This
         * allows getcwd(3) to work. There is a chance that the fsid might
         * be the same as a local fs, but since this is in an NFS mount
         * point, I don't think that will cause any problems?
         */
        if (NFSHASNFSV4(nmp) && NFSHASHASSETFSID(nmp) &&
            (nmp->nm_fsid[0] != np->n_vattr.na_filesid[0] ||
             nmp->nm_fsid[1] != np->n_vattr.na_filesid[1])) {
                /*
                 * va_fsid needs to be set to some value derived from
                 * np->n_vattr.na_filesid that is not equal
                 * vp->v_mount->mnt_stat.f_fsid[0], so that it changes
                 * from the value used for the top level server volume
                 * in the mounted subtree.
                 */
                vn_fsid(vp, vap);
                if ((uint32_t)vap->va_fsid == np->n_vattr.na_filesid[0])
                        vap->va_fsid = hash32_buf(
                            np->n_vattr.na_filesid, 2 * sizeof(uint64_t), 0);
        } else
                vn_fsid(vp, vap);
        np->n_attrstamp = time_second;
        if (vap->va_size != np->n_size) {
                if (vap->va_type == VREG) {
                        if (dontshrink && vap->va_size < np->n_size) {
                                /*
                                 * We've been told not to shrink the file;
                                 * zero np->n_attrstamp to indicate that
                                 * the attributes are stale.
                                 */
                                vap->va_size = np->n_size;
                                np->n_attrstamp = 0;
                                KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
                        } else if (np->n_flag & NMODIFIED) {
                                /*
                                 * We've modified the file: Use the larger
                                 * of our size, and the server's size.
                                 */
                                if (vap->va_size < np->n_size) {
                                        vap->va_size = np->n_size;
                                } else {
                                        np->n_size = vap->va_size;
                                        np->n_flag |= NSIZECHANGED;
                                }
                        } else {
                                np->n_size = vap->va_size;
                                np->n_flag |= NSIZECHANGED;
                        }
                } else {
                        np->n_size = vap->va_size;
                }
        }
        /*
         * The following checks are added to prevent a race between (say)
         * a READDIR+ and a WRITE. 
         * READDIR+, WRITE requests sent out.
         * READDIR+ resp, WRITE resp received on client.
         * However, the WRITE resp was handled before the READDIR+ resp
         * causing the post op attrs from the write to be loaded first
         * and the attrs from the READDIR+ to be loaded later. If this 
         * happens, we have stale attrs loaded into the attrcache.
         * We detect this by for the mtime moving back. We invalidate the 
         * attrcache when this happens.
         */
        if (timespeccmp(&mtime_save, &vap->va_mtime, >)) {
                /* Size changed or mtime went backwards */
                np->n_attrstamp = 0;
                KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
        }
        if (vaper != NULL) {
                NFSBCOPY((caddr_t)vap, (caddr_t)vaper, sizeof(*vap));
                if (np->n_flag & NCHG) {
                        if (np->n_flag & NACC)
                                vaper->va_atime = np->n_atim;
                        if (np->n_flag & NUPD)
                                vaper->va_mtime = np->n_mtim;
                }
        }

out:
#ifdef KDTRACE_HOOKS
        if (np->n_attrstamp != 0)
                KDTRACE_NFS_ATTRCACHE_LOAD_DONE(vp, vap, error);
#endif
        (void)ncl_pager_setsize(vp, NULL);
        return (error);
}

/*
 * Call vnode_pager_setsize() if the size of the node changed, as
 * recorded in nfsnode vs. v_object, or delay the call if notifying
 * the pager is not possible at the moment.
 *
 * If nsizep is non-NULL, the call is delayed and the new node size is
 * provided.  Caller should itself call vnode_pager_setsize() if
 * function returned true.  If nsizep is NULL, function tries to call
 * vnode_pager_setsize() itself if needed and possible, and the nfs
 * node is unlocked unconditionally, the return value is not useful.
 */
bool
ncl_pager_setsize(struct vnode *vp, u_quad_t *nsizep)
{
        struct nfsnode *np;
        vm_object_t object;
        struct vattr *vap;
        u_quad_t nsize;
        bool setnsize;

        np = VTONFS(vp);
        NFSASSERTNODE(np);

        vap = &np->n_vattr.na_vattr;
        nsize = vap->va_size;
        object = vp->v_object;
        setnsize = false;

        if (object != NULL && nsize != object->un_pager.vnp.vnp_size) {
                if (VOP_ISLOCKED(vp) == LK_EXCLUSIVE &&
                    (curthread->td_pflags2 & TDP2_SBPAGES) == 0)
                        setnsize = true;
                else
                        np->n_flag |= NVNSETSZSKIP;
        }
        if (nsizep == NULL) {
                NFSUNLOCKNODE(np);
                if (setnsize)
                        vnode_pager_setsize(vp, nsize);
                setnsize = false;
        } else {
                *nsizep = nsize;
        }
        return (setnsize);
}

/*
 * Fill in the client id name. For these bytes:
 * 1 - they must be unique
 * 2 - they should be persistent across client reboots
 * 1 is more critical than 2
 * Use the mount point's unique id plus either the uuid or, if that
 * isn't set, random junk.
 */
void
nfscl_fillclid(u_int64_t clval, char *uuid, u_int8_t *cp, u_int16_t idlen)
{
        int uuidlen;

        /*
         * First, put in the 64bit mount point identifier.
         */
        if (idlen >= sizeof (u_int64_t)) {
                NFSBCOPY((caddr_t)&clval, cp, sizeof (u_int64_t));
                cp += sizeof (u_int64_t);
                idlen -= sizeof (u_int64_t);
        }

        /*
         * If uuid is non-zero length, use it.
         */
        uuidlen = strlen(uuid);
        if (uuidlen > 0 && idlen >= uuidlen) {
                NFSBCOPY(uuid, cp, uuidlen);
                cp += uuidlen;
                idlen -= uuidlen;
        }

        /*
         * This only normally happens if the uuid isn't set.
         */
        while (idlen > 0) {
                *cp++ = (u_int8_t)(arc4random() % 256);
                idlen--;
        }
}

/*
 * Fill in a lock owner name. For now, pid + the process's creation time.
 */
void
nfscl_filllockowner(void *id, u_int8_t *cp, int flags)
{
        union {
                u_int32_t       lval;
                u_int8_t        cval[4];
        } tl;
        struct proc *p;

        if (id == NULL) {
                /* Return the single open_owner of all 0 bytes. */
                bzero(cp, NFSV4CL_LOCKNAMELEN);
                return;
        }
        if ((flags & F_POSIX) != 0) {
                p = (struct proc *)id;
                tl.lval = p->p_pid;
                *cp++ = tl.cval[0];
                *cp++ = tl.cval[1];
                *cp++ = tl.cval[2];
                *cp++ = tl.cval[3];
                tl.lval = p->p_stats->p_start.tv_sec;
                *cp++ = tl.cval[0];
                *cp++ = tl.cval[1];
                *cp++ = tl.cval[2];
                *cp++ = tl.cval[3];
                tl.lval = p->p_stats->p_start.tv_usec;
                *cp++ = tl.cval[0];
                *cp++ = tl.cval[1];
                *cp++ = tl.cval[2];
                *cp = tl.cval[3];
        } else if ((flags & F_FLOCK) != 0) {
                bcopy(&id, cp, sizeof(id));
                bzero(&cp[sizeof(id)], NFSV4CL_LOCKNAMELEN - sizeof(id));
        } else {
                printf("nfscl_filllockowner: not F_POSIX or F_FLOCK\n");
                bzero(cp, NFSV4CL_LOCKNAMELEN);
        }
}

/*
 * Find the parent process for the thread passed in as an argument.
 * If none exists, return NULL, otherwise return a thread for the parent.
 * (Can be any of the threads, since it is only used for td->td_proc.)
 */
NFSPROC_T *
nfscl_getparent(struct thread *td)
{
        struct proc *p;
        struct thread *ptd;

        if (td == NULL)
                return (NULL);
        p = td->td_proc;
        if (p->p_pid == 0)
                return (NULL);
        p = p->p_pptr;
        if (p == NULL)
                return (NULL);
        ptd = TAILQ_FIRST(&p->p_threads);
        return (ptd);
}

/*
 * Start up the renew kernel thread.
 */
static void
start_nfscl(void *arg)
{
        struct nfsclclient *clp;
        struct thread *td;

        clp = (struct nfsclclient *)arg;
        td = TAILQ_FIRST(&clp->nfsc_renewthread->p_threads);
        nfscl_renewthread(clp, td);
        kproc_exit(0);
}

void
nfscl_start_renewthread(struct nfsclclient *clp)
{

        kproc_create(start_nfscl, (void *)clp, &clp->nfsc_renewthread, 0, 0,
            "nfscl");
}

/*
 * Handle wcc_data.
 * For NFSv4, it assumes that nfsv4_wccattr() was used to set up the getattr
 * as the first Op after PutFH.
 * (For NFSv4, the postop attributes are after the Op, so they can't be
 *  parsed here. A separate call to nfscl_postop_attr() is required.)
 */
int
nfscl_wcc_data(struct nfsrv_descript *nd, struct vnode *vp,
    struct nfsvattr *nap, int *flagp, int *wccflagp, void *stuff)
{
        u_int32_t *tl;
        struct nfsnode *np = VTONFS(vp);
        struct nfsvattr nfsva;
        int error = 0;

        if (wccflagp != NULL)
                *wccflagp = 0;
        if (nd->nd_flag & ND_NFSV3) {
                *flagp = 0;
                NFSM_DISSECT(tl, u_int32_t *, NFSX_UNSIGNED);
                if (*tl == newnfs_true) {
                        NFSM_DISSECT(tl, u_int32_t *, 6 * NFSX_UNSIGNED);
                        if (wccflagp != NULL) {
                                NFSLOCKNODE(np);
                                *wccflagp = (np->n_mtime.tv_sec ==
                                    fxdr_unsigned(u_int32_t, *(tl + 2)) &&
                                    np->n_mtime.tv_nsec ==
                                    fxdr_unsigned(u_int32_t, *(tl + 3)));
                                NFSUNLOCKNODE(np);
                        }
                }
                error = nfscl_postop_attr(nd, nap, flagp, stuff);
                if (wccflagp != NULL && *flagp == 0)
                        *wccflagp = 0;
        } else if ((nd->nd_flag & (ND_NOMOREDATA | ND_NFSV4 | ND_V4WCCATTR))
            == (ND_NFSV4 | ND_V4WCCATTR)) {
                error = nfsv4_loadattr(nd, NULL, &nfsva, NULL,
                    NULL, 0, NULL, NULL, NULL, NULL, NULL, 0,
                    NULL, NULL, NULL, NULL, NULL);
                if (error)
                        return (error);
                /*
                 * Get rid of Op# and status for next op.
                 */
                NFSM_DISSECT(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                if (*++tl)
                        nd->nd_flag |= ND_NOMOREDATA;
                if (wccflagp != NULL &&
                    nfsva.na_vattr.va_mtime.tv_sec != 0) {
                        NFSLOCKNODE(np);
                        *wccflagp = (np->n_mtime.tv_sec ==
                            nfsva.na_vattr.va_mtime.tv_sec &&
                            np->n_mtime.tv_nsec ==
                            nfsva.na_vattr.va_mtime.tv_sec);
                        NFSUNLOCKNODE(np);
                }
        }
nfsmout:
        return (error);
}

/*
 * Get postop attributes.
 */
int
nfscl_postop_attr(struct nfsrv_descript *nd, struct nfsvattr *nap, int *retp,
    void *stuff)
{
        u_int32_t *tl;
        int error = 0;

        *retp = 0;
        if (nd->nd_flag & ND_NOMOREDATA)
                return (error);
        if (nd->nd_flag & ND_NFSV3) {
                NFSM_DISSECT(tl, u_int32_t *, NFSX_UNSIGNED);
                *retp = fxdr_unsigned(int, *tl);
        } else if (nd->nd_flag & ND_NFSV4) {
                /*
                 * For NFSv4, the postop attr are at the end, so no point
                 * in looking if nd_repstat != 0.
                 */
                if (!nd->nd_repstat) {
                        NFSM_DISSECT(tl, u_int32_t *, 2 * NFSX_UNSIGNED);
                        if (*(tl + 1))
                                /* should never happen since nd_repstat != 0 */
                                nd->nd_flag |= ND_NOMOREDATA;
                        else
                                *retp = 1;
                }
        } else if (!nd->nd_repstat) {
                /* For NFSv2, the attributes are here iff nd_repstat == 0 */
                *retp = 1;
        }
        if (*retp) {
                error = nfsm_loadattr(nd, nap);
                if (error)
                        *retp = 0;
        }
nfsmout:
        return (error);
}

/*
 * nfscl_request() - mostly a wrapper for newnfs_request().
 */
int
nfscl_request(struct nfsrv_descript *nd, struct vnode *vp, NFSPROC_T *p,
    struct ucred *cred, void *stuff)
{
        int ret, vers;
        struct nfsmount *nmp;

        nmp = VFSTONFS(vp->v_mount);
        if (nd->nd_flag & ND_NFSV4)
                vers = NFS_VER4;
        else if (nd->nd_flag & ND_NFSV3)
                vers = NFS_VER3;
        else
                vers = NFS_VER2;
        ret = newnfs_request(nd, nmp, NULL, &nmp->nm_sockreq, vp, p, cred,
                NFS_PROG, vers, NULL, 1, NULL, NULL);
        return (ret);
}

/*
 * fill in this bsden's variant of statfs using nfsstatfs.
 */
void
nfscl_loadsbinfo(struct nfsmount *nmp, struct nfsstatfs *sfp, void *statfs)
{
        struct statfs *sbp = (struct statfs *)statfs;

        if (nmp->nm_flag & (NFSMNT_NFSV3 | NFSMNT_NFSV4)) {
                sbp->f_bsize = NFS_FABLKSIZE;
                sbp->f_blocks = sfp->sf_tbytes / NFS_FABLKSIZE;
                sbp->f_bfree = sfp->sf_fbytes / NFS_FABLKSIZE;
                /*
                 * Although sf_abytes is uint64_t and f_bavail is int64_t,
                 * the value after dividing by NFS_FABLKSIZE is small
                 * enough that it will fit in 63bits, so it is ok to
                 * assign it to f_bavail without fear that it will become
                 * negative.
                 */
                sbp->f_bavail = sfp->sf_abytes / NFS_FABLKSIZE;
                sbp->f_files = sfp->sf_tfiles;
                /* Since f_ffree is int64_t, clip it to 63bits. */
                if (sfp->sf_ffiles > INT64_MAX)
                        sbp->f_ffree = INT64_MAX;
                else
                        sbp->f_ffree = sfp->sf_ffiles;
        } else if ((nmp->nm_flag & NFSMNT_NFSV4) == 0) {
                /*
                 * The type casts to (int32_t) ensure that this code is
                 * compatible with the old NFS client, in that it will
                 * propagate bit31 to the high order bits. This may or may
                 * not be correct for NFSv2, but since it is a legacy
                 * environment, I'd rather retain backwards compatibility.
                 */
                sbp->f_bsize = (int32_t)sfp->sf_bsize;
                sbp->f_blocks = (int32_t)sfp->sf_blocks;
                sbp->f_bfree = (int32_t)sfp->sf_bfree;
                sbp->f_bavail = (int32_t)sfp->sf_bavail;
                sbp->f_files = 0;
                sbp->f_ffree = 0;
        }
}

/*
 * Use the fsinfo stuff to update the mount point.
 */
void
nfscl_loadfsinfo(struct nfsmount *nmp, struct nfsfsinfo *fsp)
{

        if ((nmp->nm_wsize == 0 || fsp->fs_wtpref < nmp->nm_wsize) &&
            fsp->fs_wtpref >= NFS_FABLKSIZE)
                nmp->nm_wsize = (fsp->fs_wtpref + NFS_FABLKSIZE - 1) &
                    ~(NFS_FABLKSIZE - 1);
        if (fsp->fs_wtmax < nmp->nm_wsize && fsp->fs_wtmax > 0) {
                nmp->nm_wsize = fsp->fs_wtmax & ~(NFS_FABLKSIZE - 1);
                if (nmp->nm_wsize == 0)
                        nmp->nm_wsize = fsp->fs_wtmax;
        }
        if (nmp->nm_wsize < NFS_FABLKSIZE)
                nmp->nm_wsize = NFS_FABLKSIZE;
        if ((nmp->nm_rsize == 0 || fsp->fs_rtpref < nmp->nm_rsize) &&
            fsp->fs_rtpref >= NFS_FABLKSIZE)
                nmp->nm_rsize = (fsp->fs_rtpref + NFS_FABLKSIZE - 1) &
                    ~(NFS_FABLKSIZE - 1);
        if (fsp->fs_rtmax < nmp->nm_rsize && fsp->fs_rtmax > 0) {
                nmp->nm_rsize = fsp->fs_rtmax & ~(NFS_FABLKSIZE - 1);
                if (nmp->nm_rsize == 0)
                        nmp->nm_rsize = fsp->fs_rtmax;
        }
        if (nmp->nm_rsize < NFS_FABLKSIZE)
                nmp->nm_rsize = NFS_FABLKSIZE;
        if ((nmp->nm_readdirsize == 0 || fsp->fs_dtpref < nmp->nm_readdirsize)
            && fsp->fs_dtpref >= NFS_DIRBLKSIZ)
                nmp->nm_readdirsize = (fsp->fs_dtpref + NFS_DIRBLKSIZ - 1) &
                    ~(NFS_DIRBLKSIZ - 1);
        if (fsp->fs_rtmax < nmp->nm_readdirsize && fsp->fs_rtmax > 0) {
                nmp->nm_readdirsize = fsp->fs_rtmax & ~(NFS_DIRBLKSIZ - 1);
                if (nmp->nm_readdirsize == 0)
                        nmp->nm_readdirsize = fsp->fs_rtmax;
        }
        if (nmp->nm_readdirsize < NFS_DIRBLKSIZ)
                nmp->nm_readdirsize = NFS_DIRBLKSIZ;
        if (fsp->fs_maxfilesize > 0 &&
            fsp->fs_maxfilesize < nmp->nm_maxfilesize)
                nmp->nm_maxfilesize = fsp->fs_maxfilesize;
        nmp->nm_mountp->mnt_stat.f_iosize = newnfs_iosize(nmp);
        nmp->nm_state |= NFSSTA_GOTFSINFO;
}

/*
 * Lookups source address which should be used to communicate with
 * @nmp and stores it inside @pdst.
 *
 * Returns 0 on success.
 */
u_int8_t *
nfscl_getmyip(struct nfsmount *nmp, struct in6_addr *paddr, int *isinet6p)
{
#if defined(INET6) || defined(INET)
        int fibnum;

        fibnum = curthread->td_proc->p_fibnum;
#endif
#ifdef INET
        if (nmp->nm_nam->sa_family == AF_INET) {
                struct epoch_tracker et;
                struct nhop_object *nh;
                struct sockaddr_in *sin;
                struct in_addr addr = {};

                sin = (struct sockaddr_in *)nmp->nm_nam;
                NET_EPOCH_ENTER(et);
                CURVNET_SET(CRED_TO_VNET(nmp->nm_sockreq.nr_cred));
                nh = fib4_lookup(fibnum, sin->sin_addr, 0, NHR_NONE, 0);
                CURVNET_RESTORE();
                if (nh != NULL)
                        addr = IA_SIN(ifatoia(nh->nh_ifa))->sin_addr;
                NET_EPOCH_EXIT(et);
                if (nh == NULL)
                        return (NULL);

                if (IN_LOOPBACK(ntohl(addr.s_addr))) {
                        /* Ignore loopback addresses */
                        return (NULL);
                }

                *isinet6p = 0;
                *((struct in_addr *)paddr) = addr;

                return (u_int8_t *)paddr;
        }
#endif
#ifdef INET6
        if (nmp->nm_nam->sa_family == AF_INET6) {
                struct sockaddr_in6 *sin6;
                int error;

                sin6 = (struct sockaddr_in6 *)nmp->nm_nam;

                CURVNET_SET(CRED_TO_VNET(nmp->nm_sockreq.nr_cred));
                error = in6_selectsrc_addr(fibnum, &sin6->sin6_addr,
                    sin6->sin6_scope_id, NULL, paddr, NULL);
                CURVNET_RESTORE();
                if (error != 0)
                        return (NULL);

                if (IN6_IS_ADDR_LOOPBACK(paddr))
                        return (NULL);

                /* Scope is embedded in */
                *isinet6p = 1;

                return (u_int8_t *)paddr;
        }
#endif
        return (NULL);
}

/*
 * Copy NFS uid, gids from the cred structure.
 */
void
newnfs_copyincred(struct ucred *cr, struct nfscred *nfscr)
{
        int i;

        KASSERT(cr->cr_ngroups >= 0,
            ("newnfs_copyincred: negative cr_ngroups"));
        nfscr->nfsc_uid = cr->cr_uid;
        nfscr->nfsc_ngroups = MIN(cr->cr_ngroups, NFS_MAXGRPS + 1);
        for (i = 0; i < nfscr->nfsc_ngroups; i++)
                nfscr->nfsc_groups[i] = cr->cr_groups[i];
}


/*
 * Do any client specific initialization.
 */
void
nfscl_init(void)
{
        static int inited = 0;

        if (inited)
                return;
        inited = 1;
        nfscl_inited = 1;
        ncl_pbuf_zone = pbuf_zsecond_create("nfspbuf", nswbuf / 2);
}

/*
 * Check each of the attributes to be set, to ensure they aren't already
 * the correct value. Disable setting ones already correct.
 */
int
nfscl_checksattr(struct vattr *vap, struct nfsvattr *nvap)
{

        if (vap->va_mode != (mode_t)VNOVAL) {
                if (vap->va_mode == nvap->na_mode)
                        vap->va_mode = (mode_t)VNOVAL;
        }
        if (vap->va_uid != (uid_t)VNOVAL) {
                if (vap->va_uid == nvap->na_uid)
                        vap->va_uid = (uid_t)VNOVAL;
        }
        if (vap->va_gid != (gid_t)VNOVAL) {
                if (vap->va_gid == nvap->na_gid)
                        vap->va_gid = (gid_t)VNOVAL;
        }
        if (vap->va_size != VNOVAL) {
                if (vap->va_size == nvap->na_size)
                        vap->va_size = VNOVAL;
        }

        /*
         * We are normally called with only a partially initialized
         * VAP.  Since the NFSv3 spec says that server may use the
         * file attributes to store the verifier, the spec requires
         * us to do a SETATTR RPC. FreeBSD servers store the verifier
         * in atime, but we can't really assume that all servers will
         * so we ensure that our SETATTR sets both atime and mtime.
         * Set the VA_UTIMES_NULL flag for this case, so that
         * the server's time will be used.  This is needed to
         * work around a bug in some Solaris servers, where
         * setting the time TOCLIENT causes the Setattr RPC
         * to return NFS_OK, but not set va_mode.
         */
        if (vap->va_mtime.tv_sec == VNOVAL) {
                vfs_timestamp(&vap->va_mtime);
                vap->va_vaflags |= VA_UTIMES_NULL;
        }
        if (vap->va_atime.tv_sec == VNOVAL)
                vap->va_atime = vap->va_mtime;
        return (1);
}

/*
 * Map nfsv4 errors to errno.h errors.
 * The uid and gid arguments are only used for NFSERR_BADOWNER and that
 * error should only be returned for the Open, Create and Setattr Ops.
 * As such, most calls can just pass in 0 for those arguments.
 */
int
nfscl_maperr(struct thread *td, int error, uid_t uid, gid_t gid)
{
        struct proc *p;

        if (error < 10000 || error >= NFSERR_STALEWRITEVERF)
                return (error);
        if (td != NULL)
                p = td->td_proc;
        else
                p = NULL;
        switch (error) {
        case NFSERR_BADOWNER:
                tprintf(p, LOG_INFO,
                    "No name and/or group mapping for uid,gid:(%d,%d)\n",
                    uid, gid);
                return (EPERM);
        case NFSERR_BADNAME:
        case NFSERR_BADCHAR:
                printf("nfsv4 char/name not handled by server\n");
                return (ENOENT);
        case NFSERR_STALECLIENTID:
        case NFSERR_STALESTATEID:
        case NFSERR_EXPIRED:
        case NFSERR_BADSTATEID:
        case NFSERR_BADSESSION:
                printf("nfsv4 recover err returned %d\n", error);
                return (EIO);
        case NFSERR_BADHANDLE:
        case NFSERR_SERVERFAULT:
        case NFSERR_BADTYPE:
        case NFSERR_FHEXPIRED:
        case NFSERR_RESOURCE:
        case NFSERR_MOVED:
        case NFSERR_NOFILEHANDLE:
        case NFSERR_MINORVERMISMATCH:
        case NFSERR_OLDSTATEID:
        case NFSERR_BADSEQID:
        case NFSERR_LEASEMOVED:
        case NFSERR_RECLAIMBAD:
        case NFSERR_BADXDR:
        case NFSERR_OPILLEGAL:
                printf("nfsv4 client/server protocol prob err=%d\n",
                    error);
                return (EIO);
        default:
                tprintf(p, LOG_INFO, "nfsv4 err=%d\n", error);
                return (EIO);
        };
}

/*
 * Check to see if the process for this owner exists. Return 1 if it doesn't
 * and 0 otherwise.
 */
int
nfscl_procdoesntexist(u_int8_t *own)
{
        union {
                u_int32_t       lval;
                u_int8_t        cval[4];
        } tl;
        struct proc *p;
        pid_t pid;
        int i, ret = 0;

        /* For the single open_owner of all 0 bytes, just return 0. */
        for (i = 0; i < NFSV4CL_LOCKNAMELEN; i++)
                if (own[i] != 0)
                        break;
        if (i == NFSV4CL_LOCKNAMELEN)
                return (0);

        tl.cval[0] = *own++;
        tl.cval[1] = *own++;
        tl.cval[2] = *own++;
        tl.cval[3] = *own++;
        pid = tl.lval;
        p = pfind_any_locked(pid);
        if (p == NULL)
                return (1);
        if (p->p_stats == NULL) {
                PROC_UNLOCK(p);
                return (0);
        }
        tl.cval[0] = *own++;
        tl.cval[1] = *own++;
        tl.cval[2] = *own++;
        tl.cval[3] = *own++;
        if (tl.lval != p->p_stats->p_start.tv_sec) {
                ret = 1;
        } else {
                tl.cval[0] = *own++;
                tl.cval[1] = *own++;
                tl.cval[2] = *own++;
                tl.cval[3] = *own;
                if (tl.lval != p->p_stats->p_start.tv_usec)
                        ret = 1;
        }
        PROC_UNLOCK(p);
        return (ret);
}

/*
 * - nfs pseudo system call for the client
 */
/*
 * MPSAFE
 */
static int
nfssvc_nfscl(struct thread *td, struct nfssvc_args *uap)
{
        struct file *fp;
        struct nfscbd_args nfscbdarg;
        struct nfsd_nfscbd_args nfscbdarg2;
        struct nameidata nd;
        struct nfscl_dumpmntopts dumpmntopts;
        cap_rights_t rights;
        char *buf;
        int error;
        struct mount *mp;
        struct nfsmount *nmp;

        if (uap->flag & NFSSVC_CBADDSOCK) {
                error = copyin(uap->argp, (caddr_t)&nfscbdarg, sizeof(nfscbdarg));
                if (error)
                        return (error);
                /*
                 * Since we don't know what rights might be required,
                 * pretend that we need them all. It is better to be too
                 * careful than too reckless.
                 */
                error = fget(td, nfscbdarg.sock,
                    cap_rights_init(&rights, CAP_SOCK_CLIENT), &fp);
                if (error)
                        return (error);
                if (fp->f_type != DTYPE_SOCKET) {
                        fdrop(fp, td);
                        return (EPERM);
                }
                error = nfscbd_addsock(fp);
                fdrop(fp, td);
                if (!error && nfscl_enablecallb == 0) {
                        nfsv4_cbport = nfscbdarg.port;
                        nfscl_enablecallb = 1;
                }
        } else if (uap->flag & NFSSVC_NFSCBD) {
                if (uap->argp == NULL) 
                        return (EINVAL);
                error = copyin(uap->argp, (caddr_t)&nfscbdarg2,
                    sizeof(nfscbdarg2));
                if (error)
                        return (error);
                error = nfscbd_nfsd(td, &nfscbdarg2);
        } else if (uap->flag & NFSSVC_DUMPMNTOPTS) {
                error = copyin(uap->argp, &dumpmntopts, sizeof(dumpmntopts));
                if (error == 0 && (dumpmntopts.ndmnt_blen < 256 ||
                    dumpmntopts.ndmnt_blen > 1024))
                        error = EINVAL;
                if (error == 0)
                        error = nfsrv_lookupfilename(&nd,
                            dumpmntopts.ndmnt_fname, td);
                if (error == 0 && strcmp(nd.ni_vp->v_mount->mnt_vfc->vfc_name,
                    "nfs") != 0) {
                        vput(nd.ni_vp);
                        error = EINVAL;
                }
                if (error == 0) {
                        buf = malloc(dumpmntopts.ndmnt_blen, M_TEMP, M_WAITOK);
                        nfscl_retopts(VFSTONFS(nd.ni_vp->v_mount), buf,
                            dumpmntopts.ndmnt_blen);
                        vput(nd.ni_vp);
                        error = copyout(buf, dumpmntopts.ndmnt_buf,
                            dumpmntopts.ndmnt_blen);
                        free(buf, M_TEMP);
                }
        } else if (uap->flag & NFSSVC_FORCEDISM) {
                buf = malloc(MNAMELEN + 1, M_TEMP, M_WAITOK);
                error = copyinstr(uap->argp, buf, MNAMELEN + 1, NULL);
                if (error == 0) {
                        nmp = NULL;
                        mtx_lock(&mountlist_mtx);
                        TAILQ_FOREACH(mp, &mountlist, mnt_list) {
                                if (strcmp(mp->mnt_stat.f_mntonname, buf) ==
                                    0 && strcmp(mp->mnt_stat.f_fstypename,
                                    "nfs") == 0 && mp->mnt_data != NULL) {
                                        nmp = VFSTONFS(mp);
                                        NFSDDSLOCK();
                                        if (nfsv4_findmirror(nmp) != NULL) {
                                                NFSDDSUNLOCK();
                                                error = ENXIO;
                                                nmp = NULL;
                                                break;
                                        }
                                        mtx_lock(&nmp->nm_mtx);
                                        if ((nmp->nm_privflag &
                                            NFSMNTP_FORCEDISM) == 0) {
                                                nmp->nm_privflag |= 
                                                   (NFSMNTP_FORCEDISM |
                                                    NFSMNTP_CANCELRPCS);
                                                mtx_unlock(&nmp->nm_mtx);
                                        } else {
                                                mtx_unlock(&nmp->nm_mtx);
                                                nmp = NULL;
                                        }
                                        NFSDDSUNLOCK();
                                        break;
                                }
                        }
                        mtx_unlock(&mountlist_mtx);

                        if (nmp != NULL) {
                                /*
                                 * Call newnfs_nmcancelreqs() to cause
                                 * any RPCs in progress on the mount point to
                                 * fail.
                                 * This will cause any process waiting for an
                                 * RPC to complete while holding a vnode lock
                                 * on the mounted-on vnode (such as "df" or
                                 * a non-forced "umount") to fail.
                                 * This will unlock the mounted-on vnode so
                                 * a forced dismount can succeed.
                                 * Then clear NFSMNTP_CANCELRPCS and wakeup(),
                                 * so that nfs_unmount() can complete.
                                 */
                                newnfs_nmcancelreqs(nmp);
                                mtx_lock(&nmp->nm_mtx);
                                nmp->nm_privflag &= ~NFSMNTP_CANCELRPCS;
                                wakeup(nmp);
                                mtx_unlock(&nmp->nm_mtx);
                        } else if (error == 0)
                                error = EINVAL;
                }
                free(buf, M_TEMP);
        } else {
                error = EINVAL;
        }
        return (error);
}

extern int (*nfsd_call_nfscl)(struct thread *, struct nfssvc_args *);

/*
 * Called once to initialize data structures...
 */
static int
nfscl_modevent(module_t mod, int type, void *data)
{
        int error = 0;
        static int loaded = 0;

        switch (type) {
        case MOD_LOAD:
                if (loaded)
                        return (0);
                newnfs_portinit();
                mtx_init(&ncl_iod_mutex, "ncl_iod_mutex", NULL, MTX_DEF);
                nfscl_init();
                NFSD_LOCK();
                nfsrvd_cbinit(0);
                NFSD_UNLOCK();
                ncl_call_invalcaches = ncl_invalcaches;
                nfsd_call_nfscl = nfssvc_nfscl;
                loaded = 1;
                break;

        case MOD_UNLOAD:
                if (nfs_numnfscbd != 0) {
                        error = EBUSY;
                        break;
                }

                /*
                 * XXX: Unloading of nfscl module is unsupported.
                 */
#if 0
                ncl_call_invalcaches = NULL;
                nfsd_call_nfscl = NULL;
                uma_zdestroy(ncl_pbuf_zone);
                /* and get rid of the mutexes */
                mtx_destroy(&ncl_iod_mutex);
                loaded = 0;
                break;
#else
                /* FALLTHROUGH */
#endif
        default:
                error = EOPNOTSUPP;
                break;
        }
        return error;
}
static moduledata_t nfscl_mod = {
        "nfscl",
        nfscl_modevent,
        NULL,
};
DECLARE_MODULE(nfscl, nfscl_mod, SI_SUB_VFS, SI_ORDER_FIRST);

/* So that loader and kldload(2) can find us, wherever we are.. */
MODULE_VERSION(nfscl, 1);
MODULE_DEPEND(nfscl, nfscommon, 1, 1, 1);
MODULE_DEPEND(nfscl, krpc, 1, 1, 1);
MODULE_DEPEND(nfscl, nfssvc, 1, 1, 1);