[mirror_zfs.git] / module / os / freebsd / zfs / zfs_vnops_os.c

/*
 * 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 https://opensource.org/licenses/CDDL-1.0.
 * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2012, 2015 by Delphix. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 * Copyright 2017 Nexenta Systems, Inc.
 */

/* Portions Copyright 2007 Jeremy Teo */
/* Portions Copyright 2010 Robert Milkowski */


#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/resource.h>
#include <sys/vfs.h>
#include <sys/endian.h>
#include <sys/vm.h>
#include <sys/vnode.h>
#if __FreeBSD_version >= 1300102
#include <sys/smr.h>
#endif
#include <sys/dirent.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/kmem.h>
#include <sys/taskq.h>
#include <sys/uio.h>
#include <sys/atomic.h>
#include <sys/namei.h>
#include <sys/mman.h>
#include <sys/cmn_err.h>
#include <sys/kdb.h>
#include <sys/sysproto.h>
#include <sys/errno.h>
#include <sys/unistd.h>
#include <sys/zfs_dir.h>
#include <sys/zfs_ioctl.h>
#include <sys/fs/zfs.h>
#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/spa.h>
#include <sys/txg.h>
#include <sys/dbuf.h>
#include <sys/zap.h>
#include <sys/sa.h>
#include <sys/policy.h>
#include <sys/sunddi.h>
#include <sys/filio.h>
#include <sys/sid.h>
#include <sys/zfs_ctldir.h>
#include <sys/zfs_fuid.h>
#include <sys/zfs_quota.h>
#include <sys/zfs_sa.h>
#include <sys/zfs_rlock.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/sched.h>
#include <sys/acl.h>
#include <sys/vmmeter.h>
#include <vm/vm_param.h>
#include <sys/zil.h>
#include <sys/zfs_vnops.h>

#include <vm/vm_object.h>

#include <sys/extattr.h>
#include <sys/priv.h>

#ifndef VN_OPEN_INVFS
#define VN_OPEN_INVFS   0x0
#endif

VFS_SMR_DECLARE;

#if __FreeBSD_version < 1300103
#define NDFREE_PNBUF(ndp)       NDFREE((ndp), NDF_ONLY_PNBUF)
#endif

#if __FreeBSD_version >= 1300047
#define vm_page_wire_lock(pp)
#define vm_page_wire_unlock(pp)
#else
#define vm_page_wire_lock(pp) vm_page_lock(pp)
#define vm_page_wire_unlock(pp) vm_page_unlock(pp)
#endif

#ifdef DEBUG_VFS_LOCKS
#define VNCHECKREF(vp)                            \
        VNASSERT((vp)->v_holdcnt > 0 && (vp)->v_usecount > 0, vp,       \
            ("%s: wrong ref counts", __func__));
#else
#define VNCHECKREF(vp)
#endif

#if __FreeBSD_version >= 1400045
typedef uint64_t cookie_t;
#else
typedef ulong_t cookie_t;
#endif

/*
 * Programming rules.
 *
 * Each vnode op performs some logical unit of work.  To do this, the ZPL must
 * properly lock its in-core state, create a DMU transaction, do the work,
 * record this work in the intent log (ZIL), commit the DMU transaction,
 * and wait for the intent log to commit if it is a synchronous operation.
 * Moreover, the vnode ops must work in both normal and log replay context.
 * The ordering of events is important to avoid deadlocks and references
 * to freed memory.  The example below illustrates the following Big Rules:
 *
 *  (1) A check must be made in each zfs thread for a mounted file system.
 *      This is done avoiding races using zfs_enter(zfsvfs).
 *      A zfs_exit(zfsvfs) is needed before all returns.  Any znodes
 *      must be checked with zfs_verify_zp(zp).  Both of these macros
 *      can return EIO from the calling function.
 *
 *  (2) VN_RELE() should always be the last thing except for zil_commit()
 *      (if necessary) and zfs_exit(). This is for 3 reasons:
 *      First, if it's the last reference, the vnode/znode
 *      can be freed, so the zp may point to freed memory.  Second, the last
 *      reference will call zfs_zinactive(), which may induce a lot of work --
 *      pushing cached pages (which acquires range locks) and syncing out
 *      cached atime changes.  Third, zfs_zinactive() may require a new tx,
 *      which could deadlock the system if you were already holding one.
 *      If you must call VN_RELE() within a tx then use VN_RELE_ASYNC().
 *
 *  (3) All range locks must be grabbed before calling dmu_tx_assign(),
 *      as they can span dmu_tx_assign() calls.
 *
 *  (4) If ZPL locks are held, pass TXG_NOWAIT as the second argument to
 *      dmu_tx_assign().  This is critical because we don't want to block
 *      while holding locks.
 *
 *      If no ZPL locks are held (aside from zfs_enter()), use TXG_WAIT.  This
 *      reduces lock contention and CPU usage when we must wait (note that if
 *      throughput is constrained by the storage, nearly every transaction
 *      must wait).
 *
 *      Note, in particular, that if a lock is sometimes acquired before
 *      the tx assigns, and sometimes after (e.g. z_lock), then failing
 *      to use a non-blocking assign can deadlock the system.  The scenario:
 *
 *      Thread A has grabbed a lock before calling dmu_tx_assign().
 *      Thread B is in an already-assigned tx, and blocks for this lock.
 *      Thread A calls dmu_tx_assign(TXG_WAIT) and blocks in txg_wait_open()
 *      forever, because the previous txg can't quiesce until B's tx commits.
 *
 *      If dmu_tx_assign() returns ERESTART and zfsvfs->z_assign is TXG_NOWAIT,
 *      then drop all locks, call dmu_tx_wait(), and try again.  On subsequent
 *      calls to dmu_tx_assign(), pass TXG_NOTHROTTLE in addition to TXG_NOWAIT,
 *      to indicate that this operation has already called dmu_tx_wait().
 *      This will ensure that we don't retry forever, waiting a short bit
 *      each time.
 *
 *  (5) If the operation succeeded, generate the intent log entry for it
 *      before dropping locks.  This ensures that the ordering of events
 *      in the intent log matches the order in which they actually occurred.
 *      During ZIL replay the zfs_log_* functions will update the sequence
 *      number to indicate the zil transaction has replayed.
 *
 *  (6) At the end of each vnode op, the DMU tx must always commit,
 *      regardless of whether there were any errors.
 *
 *  (7) After dropping all locks, invoke zil_commit(zilog, foid)
 *      to ensure that synchronous semantics are provided when necessary.
 *
 * In general, this is how things should be ordered in each vnode op:
 *
 *      zfs_enter(zfsvfs);              // exit if unmounted
 * top:
 *      zfs_dirent_lookup(&dl, ...)     // lock directory entry (may VN_HOLD())
 *      rw_enter(...);                  // grab any other locks you need
 *      tx = dmu_tx_create(...);        // get DMU tx
 *      dmu_tx_hold_*();                // hold each object you might modify
 *      error = dmu_tx_assign(tx, (waited ? TXG_NOTHROTTLE : 0) | TXG_NOWAIT);
 *      if (error) {
 *              rw_exit(...);           // drop locks
 *              zfs_dirent_unlock(dl);  // unlock directory entry
 *              VN_RELE(...);           // release held vnodes
 *              if (error == ERESTART) {
 *                      waited = B_TRUE;
 *                      dmu_tx_wait(tx);
 *                      dmu_tx_abort(tx);
 *                      goto top;
 *              }
 *              dmu_tx_abort(tx);       // abort DMU tx
 *              zfs_exit(zfsvfs);       // finished in zfs
 *              return (error);         // really out of space
 *      }
 *      error = do_real_work();         // do whatever this VOP does
 *      if (error == 0)
 *              zfs_log_*(...);         // on success, make ZIL entry
 *      dmu_tx_commit(tx);              // commit DMU tx -- error or not
 *      rw_exit(...);                   // drop locks
 *      zfs_dirent_unlock(dl);          // unlock directory entry
 *      VN_RELE(...);                   // release held vnodes
 *      zil_commit(zilog, foid);        // synchronous when necessary
 *      zfs_exit(zfsvfs);               // finished in zfs
 *      return (error);                 // done, report error
 */
static int
zfs_open(vnode_t **vpp, int flag, cred_t *cr)
{
        (void) cr;
        znode_t *zp = VTOZ(*vpp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        int error;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        if ((flag & FWRITE) && (zp->z_pflags & ZFS_APPENDONLY) &&
            ((flag & FAPPEND) == 0)) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EPERM));
        }

        /* Keep a count of the synchronous opens in the znode */
        if (flag & O_SYNC)
                atomic_inc_32(&zp->z_sync_cnt);

        zfs_exit(zfsvfs, FTAG);
        return (0);
}

static int
zfs_close(vnode_t *vp, int flag, int count, offset_t offset, cred_t *cr)
{
        (void) offset, (void) cr;
        znode_t *zp = VTOZ(vp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        int error;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        /* Decrement the synchronous opens in the znode */
        if ((flag & O_SYNC) && (count == 1))
                atomic_dec_32(&zp->z_sync_cnt);

        zfs_exit(zfsvfs, FTAG);
        return (0);
}

static int
zfs_ioctl(vnode_t *vp, ulong_t com, intptr_t data, int flag, cred_t *cred,
    int *rvalp)
{
        (void) flag, (void) cred, (void) rvalp;
        loff_t off;
        int error;

        switch (com) {
        case _FIOFFS:
        {
                return (0);

                /*
                 * The following two ioctls are used by bfu.  Faking out,
                 * necessary to avoid bfu errors.
                 */
        }
        case _FIOGDIO:
        case _FIOSDIO:
        {
                return (0);
        }

        case F_SEEK_DATA:
        case F_SEEK_HOLE:
        {
                off = *(offset_t *)data;
                /* offset parameter is in/out */
                error = zfs_holey(VTOZ(vp), com, &off);
                if (error)
                        return (error);
                *(offset_t *)data = off;
                return (0);
        }
        }
        return (SET_ERROR(ENOTTY));
}

static vm_page_t
page_busy(vnode_t *vp, int64_t start, int64_t off, int64_t nbytes)
{
        vm_object_t obj;
        vm_page_t pp;
        int64_t end;

        /*
         * At present vm_page_clear_dirty extends the cleared range to DEV_BSIZE
         * aligned boundaries, if the range is not aligned.  As a result a
         * DEV_BSIZE subrange with partially dirty data may get marked as clean.
         * It may happen that all DEV_BSIZE subranges are marked clean and thus
         * the whole page would be considered clean despite have some
         * dirty data.
         * For this reason we should shrink the range to DEV_BSIZE aligned
         * boundaries before calling vm_page_clear_dirty.
         */
        end = rounddown2(off + nbytes, DEV_BSIZE);
        off = roundup2(off, DEV_BSIZE);
        nbytes = end - off;

        obj = vp->v_object;
        zfs_vmobject_assert_wlocked_12(obj);
#if __FreeBSD_version < 1300050
        for (;;) {
                if ((pp = vm_page_lookup(obj, OFF_TO_IDX(start))) != NULL &&
                    pp->valid) {
                        if (vm_page_xbusied(pp)) {
                                /*
                                 * Reference the page before unlocking and
                                 * sleeping so that the page daemon is less
                                 * likely to reclaim it.
                                 */
                                vm_page_reference(pp);
                                vm_page_lock(pp);
                                zfs_vmobject_wunlock(obj);
                                vm_page_busy_sleep(pp, "zfsmwb", true);
                                zfs_vmobject_wlock(obj);
                                continue;
                        }
                        vm_page_sbusy(pp);
                } else if (pp != NULL) {
                        ASSERT(!pp->valid);
                        pp = NULL;
                }
                if (pp != NULL) {
                        ASSERT3U(pp->valid, ==, VM_PAGE_BITS_ALL);
                        vm_object_pip_add(obj, 1);
                        pmap_remove_write(pp);
                        if (nbytes != 0)
                                vm_page_clear_dirty(pp, off, nbytes);
                }
                break;
        }
#else
        vm_page_grab_valid_unlocked(&pp, obj, OFF_TO_IDX(start),
            VM_ALLOC_NOCREAT | VM_ALLOC_SBUSY | VM_ALLOC_NORMAL |
            VM_ALLOC_IGN_SBUSY);
        if (pp != NULL) {
                ASSERT3U(pp->valid, ==, VM_PAGE_BITS_ALL);
                vm_object_pip_add(obj, 1);
                pmap_remove_write(pp);
                if (nbytes != 0)
                        vm_page_clear_dirty(pp, off, nbytes);
        }
#endif
        return (pp);
}

static void
page_unbusy(vm_page_t pp)
{

        vm_page_sunbusy(pp);
#if __FreeBSD_version >= 1300041
        vm_object_pip_wakeup(pp->object);
#else
        vm_object_pip_subtract(pp->object, 1);
#endif
}

#if __FreeBSD_version > 1300051
static vm_page_t
page_hold(vnode_t *vp, int64_t start)
{
        vm_object_t obj;
        vm_page_t m;

        obj = vp->v_object;
        vm_page_grab_valid_unlocked(&m, obj, OFF_TO_IDX(start),
            VM_ALLOC_NOCREAT | VM_ALLOC_WIRED | VM_ALLOC_IGN_SBUSY |
            VM_ALLOC_NOBUSY);
        return (m);
}
#else
static vm_page_t
page_hold(vnode_t *vp, int64_t start)
{
        vm_object_t obj;
        vm_page_t pp;

        obj = vp->v_object;
        zfs_vmobject_assert_wlocked(obj);

        for (;;) {
                if ((pp = vm_page_lookup(obj, OFF_TO_IDX(start))) != NULL &&
                    pp->valid) {
                        if (vm_page_xbusied(pp)) {
                                /*
                                 * Reference the page before unlocking and
                                 * sleeping so that the page daemon is less
                                 * likely to reclaim it.
                                 */
                                vm_page_reference(pp);
                                vm_page_lock(pp);
                                zfs_vmobject_wunlock(obj);
                                vm_page_busy_sleep(pp, "zfsmwb", true);
                                zfs_vmobject_wlock(obj);
                                continue;
                        }

                        ASSERT3U(pp->valid, ==, VM_PAGE_BITS_ALL);
                        vm_page_wire_lock(pp);
                        vm_page_hold(pp);
                        vm_page_wire_unlock(pp);

                } else
                        pp = NULL;
                break;
        }
        return (pp);
}
#endif

static void
page_unhold(vm_page_t pp)
{

        vm_page_wire_lock(pp);
#if __FreeBSD_version >= 1300035
        vm_page_unwire(pp, PQ_ACTIVE);
#else
        vm_page_unhold(pp);
#endif
        vm_page_wire_unlock(pp);
}

/*
 * When a file is memory mapped, we must keep the IO data synchronized
 * between the DMU cache and the memory mapped pages.  What this means:
 *
 * On Write:    If we find a memory mapped page, we write to *both*
 *              the page and the dmu buffer.
 */
void
update_pages(znode_t *zp, int64_t start, int len, objset_t *os)
{
        vm_object_t obj;
        struct sf_buf *sf;
        vnode_t *vp = ZTOV(zp);
        caddr_t va;
        int off;

        ASSERT3P(vp->v_mount, !=, NULL);
        obj = vp->v_object;
        ASSERT3P(obj, !=, NULL);

        off = start & PAGEOFFSET;
        zfs_vmobject_wlock_12(obj);
#if __FreeBSD_version >= 1300041
        vm_object_pip_add(obj, 1);
#endif
        for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
                vm_page_t pp;
                int nbytes = imin(PAGESIZE - off, len);

                if ((pp = page_busy(vp, start, off, nbytes)) != NULL) {
                        zfs_vmobject_wunlock_12(obj);

                        va = zfs_map_page(pp, &sf);
                        (void) dmu_read(os, zp->z_id, start + off, nbytes,
                            va + off, DMU_READ_PREFETCH);
                        zfs_unmap_page(sf);

                        zfs_vmobject_wlock_12(obj);
                        page_unbusy(pp);
                }
                len -= nbytes;
                off = 0;
        }
#if __FreeBSD_version >= 1300041
        vm_object_pip_wakeup(obj);
#else
        vm_object_pip_wakeupn(obj, 0);
#endif
        zfs_vmobject_wunlock_12(obj);
}

/*
 * Read with UIO_NOCOPY flag means that sendfile(2) requests
 * ZFS to populate a range of page cache pages with data.
 *
 * NOTE: this function could be optimized to pre-allocate
 * all pages in advance, drain exclusive busy on all of them,
 * map them into contiguous KVA region and populate them
 * in one single dmu_read() call.
 */
int
mappedread_sf(znode_t *zp, int nbytes, zfs_uio_t *uio)
{
        vnode_t *vp = ZTOV(zp);
        objset_t *os = zp->z_zfsvfs->z_os;
        struct sf_buf *sf;
        vm_object_t obj;
        vm_page_t pp;
        int64_t start;
        caddr_t va;
        int len = nbytes;
        int error = 0;

        ASSERT3U(zfs_uio_segflg(uio), ==, UIO_NOCOPY);
        ASSERT3P(vp->v_mount, !=, NULL);
        obj = vp->v_object;
        ASSERT3P(obj, !=, NULL);
        ASSERT0(zfs_uio_offset(uio) & PAGEOFFSET);

        zfs_vmobject_wlock_12(obj);
        for (start = zfs_uio_offset(uio); len > 0; start += PAGESIZE) {
                int bytes = MIN(PAGESIZE, len);

                pp = vm_page_grab_unlocked(obj, OFF_TO_IDX(start),
                    VM_ALLOC_SBUSY | VM_ALLOC_NORMAL | VM_ALLOC_IGN_SBUSY);
                if (vm_page_none_valid(pp)) {
                        zfs_vmobject_wunlock_12(obj);
                        va = zfs_map_page(pp, &sf);
                        error = dmu_read(os, zp->z_id, start, bytes, va,
                            DMU_READ_PREFETCH);
                        if (bytes != PAGESIZE && error == 0)
                                memset(va + bytes, 0, PAGESIZE - bytes);
                        zfs_unmap_page(sf);
                        zfs_vmobject_wlock_12(obj);
#if  __FreeBSD_version >= 1300081
                        if (error == 0) {
                                vm_page_valid(pp);
                                vm_page_activate(pp);
                                vm_page_do_sunbusy(pp);
                        } else {
                                zfs_vmobject_wlock(obj);
                                if (!vm_page_wired(pp) && pp->valid == 0 &&
                                    vm_page_busy_tryupgrade(pp))
                                        vm_page_free(pp);
                                else
                                        vm_page_sunbusy(pp);
                                zfs_vmobject_wunlock(obj);
                        }
#else
                        vm_page_do_sunbusy(pp);
                        vm_page_lock(pp);
                        if (error) {
                                if (pp->wire_count == 0 && pp->valid == 0 &&
                                    !vm_page_busied(pp))
                                        vm_page_free(pp);
                        } else {
                                pp->valid = VM_PAGE_BITS_ALL;
                                vm_page_activate(pp);
                        }
                        vm_page_unlock(pp);
#endif
                } else {
                        ASSERT3U(pp->valid, ==, VM_PAGE_BITS_ALL);
                        vm_page_do_sunbusy(pp);
                }
                if (error)
                        break;
                zfs_uio_advance(uio, bytes);
                len -= bytes;
        }
        zfs_vmobject_wunlock_12(obj);
        return (error);
}

/*
 * When a file is memory mapped, we must keep the IO data synchronized
 * between the DMU cache and the memory mapped pages.  What this means:
 *
 * On Read:     We "read" preferentially from memory mapped pages,
 *              else we default from the dmu buffer.
 *
 * NOTE: We will always "break up" the IO into PAGESIZE uiomoves when
 *       the file is memory mapped.
 */
int
mappedread(znode_t *zp, int nbytes, zfs_uio_t *uio)
{
        vnode_t *vp = ZTOV(zp);
        vm_object_t obj;
        int64_t start;
        int len = nbytes;
        int off;
        int error = 0;

        ASSERT3P(vp->v_mount, !=, NULL);
        obj = vp->v_object;
        ASSERT3P(obj, !=, NULL);

        start = zfs_uio_offset(uio);
        off = start & PAGEOFFSET;
        zfs_vmobject_wlock_12(obj);
        for (start &= PAGEMASK; len > 0; start += PAGESIZE) {
                vm_page_t pp;
                uint64_t bytes = MIN(PAGESIZE - off, len);

                if ((pp = page_hold(vp, start))) {
                        struct sf_buf *sf;
                        caddr_t va;

                        zfs_vmobject_wunlock_12(obj);
                        va = zfs_map_page(pp, &sf);
                        error = vn_io_fault_uiomove(va + off, bytes,
                            GET_UIO_STRUCT(uio));
                        zfs_unmap_page(sf);
                        zfs_vmobject_wlock_12(obj);
                        page_unhold(pp);
                } else {
                        zfs_vmobject_wunlock_12(obj);
                        error = dmu_read_uio_dbuf(sa_get_db(zp->z_sa_hdl),
                            uio, bytes);
                        zfs_vmobject_wlock_12(obj);
                }
                len -= bytes;
                off = 0;
                if (error)
                        break;
        }
        zfs_vmobject_wunlock_12(obj);
        return (error);
}

int
zfs_write_simple(znode_t *zp, const void *data, size_t len,
    loff_t pos, size_t *presid)
{
        int error = 0;
        ssize_t resid;

        error = vn_rdwr(UIO_WRITE, ZTOV(zp), __DECONST(void *, data), len, pos,
            UIO_SYSSPACE, IO_SYNC, kcred, NOCRED, &resid, curthread);

        if (error) {
                return (SET_ERROR(error));
        } else if (presid == NULL) {
                if (resid != 0) {
                        error = SET_ERROR(EIO);
                }
        } else {
                *presid = resid;
        }
        return (error);
}

void
zfs_zrele_async(znode_t *zp)
{
        vnode_t *vp = ZTOV(zp);
        objset_t *os = ITOZSB(vp)->z_os;

        VN_RELE_ASYNC(vp, dsl_pool_zrele_taskq(dmu_objset_pool(os)));
}

static int
zfs_dd_callback(struct mount *mp, void *arg, int lkflags, struct vnode **vpp)
{
        int error;

        *vpp = arg;
        error = vn_lock(*vpp, lkflags);
        if (error != 0)
                vrele(*vpp);
        return (error);
}

static int
zfs_lookup_lock(vnode_t *dvp, vnode_t *vp, const char *name, int lkflags)
{
        znode_t *zdp = VTOZ(dvp);
        zfsvfs_t *zfsvfs __unused = zdp->z_zfsvfs;
        int error;
        int ltype;

        if (zfsvfs->z_replay == B_FALSE)
                ASSERT_VOP_LOCKED(dvp, __func__);

        if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
                ASSERT3P(dvp, ==, vp);
                vref(dvp);
                ltype = lkflags & LK_TYPE_MASK;
                if (ltype != VOP_ISLOCKED(dvp)) {
                        if (ltype == LK_EXCLUSIVE)
                                vn_lock(dvp, LK_UPGRADE | LK_RETRY);
                        else /* if (ltype == LK_SHARED) */
                                vn_lock(dvp, LK_DOWNGRADE | LK_RETRY);

                        /*
                         * Relock for the "." case could leave us with
                         * reclaimed vnode.
                         */
                        if (VN_IS_DOOMED(dvp)) {
                                vrele(dvp);
                                return (SET_ERROR(ENOENT));
                        }
                }
                return (0);
        } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
                /*
                 * Note that in this case, dvp is the child vnode, and we
                 * are looking up the parent vnode - exactly reverse from
                 * normal operation.  Unlocking dvp requires some rather
                 * tricky unlock/relock dance to prevent mp from being freed;
                 * use vn_vget_ino_gen() which takes care of all that.
                 *
                 * XXX Note that there is a time window when both vnodes are
                 * unlocked.  It is possible, although highly unlikely, that
                 * during that window the parent-child relationship between
                 * the vnodes may change, for example, get reversed.
                 * In that case we would have a wrong lock order for the vnodes.
                 * All other filesystems seem to ignore this problem, so we
                 * do the same here.
                 * A potential solution could be implemented as follows:
                 * - using LK_NOWAIT when locking the second vnode and retrying
                 *   if necessary
                 * - checking that the parent-child relationship still holds
                 *   after locking both vnodes and retrying if it doesn't
                 */
                error = vn_vget_ino_gen(dvp, zfs_dd_callback, vp, lkflags, &vp);
                return (error);
        } else {
                error = vn_lock(vp, lkflags);
                if (error != 0)
                        vrele(vp);
                return (error);
        }
}

/*
 * Lookup an entry in a directory, or an extended attribute directory.
 * If it exists, return a held vnode reference for it.
 *
 *      IN:     dvp     - vnode of directory to search.
 *              nm      - name of entry to lookup.
 *              pnp     - full pathname to lookup [UNUSED].
 *              flags   - LOOKUP_XATTR set if looking for an attribute.
 *              rdir    - root directory vnode [UNUSED].
 *              cr      - credentials of caller.
 *              ct      - caller context
 *
 *      OUT:    vpp     - vnode of located entry, NULL if not found.
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      NA
 */
static int
zfs_lookup(vnode_t *dvp, const char *nm, vnode_t **vpp,
    struct componentname *cnp, int nameiop, cred_t *cr, int flags,
    boolean_t cached)
{
        znode_t *zdp = VTOZ(dvp);
        znode_t *zp;
        zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
#if     __FreeBSD_version > 1300124
        seqc_t dvp_seqc;
#endif
        int     error = 0;

        /*
         * Fast path lookup, however we must skip DNLC lookup
         * for case folding or normalizing lookups because the
         * DNLC code only stores the passed in name.  This means
         * creating 'a' and removing 'A' on a case insensitive
         * file system would work, but DNLC still thinks 'a'
         * exists and won't let you create it again on the next
         * pass through fast path.
         */
        if (!(flags & LOOKUP_XATTR)) {
                if (dvp->v_type != VDIR) {
                        return (SET_ERROR(ENOTDIR));
                } else if (zdp->z_sa_hdl == NULL) {
                        return (SET_ERROR(EIO));
                }
        }

        DTRACE_PROBE2(zfs__fastpath__lookup__miss, vnode_t *, dvp,
            const char *, nm);

        if ((error = zfs_enter_verify_zp(zfsvfs, zdp, FTAG)) != 0)
                return (error);

#if     __FreeBSD_version > 1300124
        dvp_seqc = vn_seqc_read_notmodify(dvp);
#endif

        *vpp = NULL;

        if (flags & LOOKUP_XATTR) {
                /*
                 * If the xattr property is off, refuse the lookup request.
                 */
                if (!(zfsvfs->z_flags & ZSB_XATTR)) {
                        zfs_exit(zfsvfs, FTAG);
                        return (SET_ERROR(EOPNOTSUPP));
                }

                /*
                 * We don't allow recursive attributes..
                 * Maybe someday we will.
                 */
                if (zdp->z_pflags & ZFS_XATTR) {
                        zfs_exit(zfsvfs, FTAG);
                        return (SET_ERROR(EINVAL));
                }

                if ((error = zfs_get_xattrdir(VTOZ(dvp), &zp, cr, flags))) {
                        zfs_exit(zfsvfs, FTAG);
                        return (error);
                }
                *vpp = ZTOV(zp);

                /*
                 * Do we have permission to get into attribute directory?
                 */
                error = zfs_zaccess(zp, ACE_EXECUTE, 0, B_FALSE, cr, NULL);
                if (error) {
                        vrele(ZTOV(zp));
                }

                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * Check accessibility of directory if we're not coming in via
         * VOP_CACHEDLOOKUP.
         */
        if (!cached) {
#ifdef NOEXECCHECK
                if ((cnp->cn_flags & NOEXECCHECK) != 0) {
                        cnp->cn_flags &= ~NOEXECCHECK;
                } else
#endif
                if ((error = zfs_zaccess(zdp, ACE_EXECUTE, 0, B_FALSE, cr,
                    NULL))) {
                        zfs_exit(zfsvfs, FTAG);
                        return (error);
                }
        }

        if (zfsvfs->z_utf8 && u8_validate(nm, strlen(nm),
            NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EILSEQ));
        }


        /*
         * First handle the special cases.
         */
        if ((cnp->cn_flags & ISDOTDOT) != 0) {
                /*
                 * If we are a snapshot mounted under .zfs, return
                 * the vp for the snapshot directory.
                 */
                if (zdp->z_id == zfsvfs->z_root && zfsvfs->z_parent != zfsvfs) {
                        struct componentname cn;
                        vnode_t *zfsctl_vp;
                        int ltype;

                        zfs_exit(zfsvfs, FTAG);
                        ltype = VOP_ISLOCKED(dvp);
                        VOP_UNLOCK1(dvp);
                        error = zfsctl_root(zfsvfs->z_parent, LK_SHARED,
                            &zfsctl_vp);
                        if (error == 0) {
                                cn.cn_nameptr = "snapshot";
                                cn.cn_namelen = strlen(cn.cn_nameptr);
                                cn.cn_nameiop = cnp->cn_nameiop;
                                cn.cn_flags = cnp->cn_flags & ~ISDOTDOT;
                                cn.cn_lkflags = cnp->cn_lkflags;
                                error = VOP_LOOKUP(zfsctl_vp, vpp, &cn);
                                vput(zfsctl_vp);
                        }
                        vn_lock(dvp, ltype | LK_RETRY);
                        return (error);
                }
        }
        if (zfs_has_ctldir(zdp) && strcmp(nm, ZFS_CTLDIR_NAME) == 0) {
                zfs_exit(zfsvfs, FTAG);
                if ((cnp->cn_flags & ISLASTCN) != 0 && nameiop != LOOKUP)
                        return (SET_ERROR(ENOTSUP));
                error = zfsctl_root(zfsvfs, cnp->cn_lkflags, vpp);
                return (error);
        }

        /*
         * The loop is retry the lookup if the parent-child relationship
         * changes during the dot-dot locking complexities.
         */
        for (;;) {
                uint64_t parent;

                error = zfs_dirlook(zdp, nm, &zp);
                if (error == 0)
                        *vpp = ZTOV(zp);

                zfs_exit(zfsvfs, FTAG);
                if (error != 0)
                        break;

                error = zfs_lookup_lock(dvp, *vpp, nm, cnp->cn_lkflags);
                if (error != 0) {
                        /*
                         * If we've got a locking error, then the vnode
                         * got reclaimed because of a force unmount.
                         * We never enter doomed vnodes into the name cache.
                         */
                        *vpp = NULL;
                        return (error);
                }

                if ((cnp->cn_flags & ISDOTDOT) == 0)
                        break;

                if ((error = zfs_enter(zfsvfs, FTAG)) != 0) {
                        vput(ZTOV(zp));
                        *vpp = NULL;
                        return (error);
                }
                if (zdp->z_sa_hdl == NULL) {
                        error = SET_ERROR(EIO);
                } else {
                        error = sa_lookup(zdp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
                            &parent, sizeof (parent));
                }
                if (error != 0) {
                        zfs_exit(zfsvfs, FTAG);
                        vput(ZTOV(zp));
                        break;
                }
                if (zp->z_id == parent) {
                        zfs_exit(zfsvfs, FTAG);
                        break;
                }
                vput(ZTOV(zp));
        }

        if (error != 0)
                *vpp = NULL;

        /* Translate errors and add SAVENAME when needed. */
        if (cnp->cn_flags & ISLASTCN) {
                switch (nameiop) {
                case CREATE:
                case RENAME:
                        if (error == ENOENT) {
                                error = EJUSTRETURN;
#if __FreeBSD_version < 1400068
                                cnp->cn_flags |= SAVENAME;
#endif
                                break;
                        }
                        zfs_fallthrough;
                case DELETE:
#if __FreeBSD_version < 1400068
                        if (error == 0)
                                cnp->cn_flags |= SAVENAME;
#endif
                        break;
                }
        }

#if     __FreeBSD_version > 1300124
        if ((cnp->cn_flags & ISDOTDOT) != 0) {
                /*
                 * FIXME: zfs_lookup_lock relocks vnodes and does nothing to
                 * handle races. In particular different callers may end up
                 * with different vnodes and will try to add conflicting
                 * entries to the namecache.
                 *
                 * While finding different result may be acceptable in face
                 * of concurrent modification, adding conflicting entries
                 * trips over an assert in the namecache.
                 *
                 * Ultimately let an entry through once everything settles.
                 */
                if (!vn_seqc_consistent(dvp, dvp_seqc)) {
                        cnp->cn_flags &= ~MAKEENTRY;
                }
        }
#endif

        /* Insert name into cache (as non-existent) if appropriate. */
        if (zfsvfs->z_use_namecache && !zfsvfs->z_replay &&
            error == ENOENT && (cnp->cn_flags & MAKEENTRY) != 0)
                cache_enter(dvp, NULL, cnp);

        /* Insert name into cache if appropriate. */
        if (zfsvfs->z_use_namecache && !zfsvfs->z_replay &&
            error == 0 && (cnp->cn_flags & MAKEENTRY)) {
                if (!(cnp->cn_flags & ISLASTCN) ||
                    (nameiop != DELETE && nameiop != RENAME)) {
                        cache_enter(dvp, *vpp, cnp);
                }
        }

        return (error);
}

/*
 * Attempt to create a new entry in a directory.  If the entry
 * already exists, truncate the file if permissible, else return
 * an error.  Return the vp of the created or trunc'd file.
 *
 *      IN:     dvp     - vnode of directory to put new file entry in.
 *              name    - name of new file entry.
 *              vap     - attributes of new file.
 *              excl    - flag indicating exclusive or non-exclusive mode.
 *              mode    - mode to open file with.
 *              cr      - credentials of caller.
 *              flag    - large file flag [UNUSED].
 *              ct      - caller context
 *              vsecp   - ACL to be set
 *              mnt_ns  - Unused on FreeBSD
 *
 *      OUT:    vpp     - vnode of created or trunc'd entry.
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      dvp - ctime|mtime updated if new entry created
 *       vp - ctime|mtime always, atime if new
 */
int
zfs_create(znode_t *dzp, const char *name, vattr_t *vap, int excl, int mode,
    znode_t **zpp, cred_t *cr, int flag, vsecattr_t *vsecp, zuserns_t *mnt_ns)
{
        (void) excl, (void) mode, (void) flag;
        znode_t         *zp;
        zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
        zilog_t         *zilog;
        objset_t        *os;
        dmu_tx_t        *tx;
        int             error;
        uid_t           uid = crgetuid(cr);
        gid_t           gid = crgetgid(cr);
        uint64_t        projid = ZFS_DEFAULT_PROJID;
        zfs_acl_ids_t   acl_ids;
        boolean_t       fuid_dirtied;
        uint64_t        txtype;
#ifdef DEBUG_VFS_LOCKS
        vnode_t *dvp = ZTOV(dzp);
#endif

        /*
         * If we have an ephemeral id, ACL, or XVATTR then
         * make sure file system is at proper version
         */
        if (zfsvfs->z_use_fuids == B_FALSE &&
            (vsecp || (vap->va_mask & AT_XVATTR) ||
            IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
                return (SET_ERROR(EINVAL));

        if ((error = zfs_enter_verify_zp(zfsvfs, dzp, FTAG)) != 0)
                return (error);
        os = zfsvfs->z_os;
        zilog = zfsvfs->z_log;

        if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
            NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EILSEQ));
        }

        if (vap->va_mask & AT_XVATTR) {
                if ((error = secpolicy_xvattr(ZTOV(dzp), (xvattr_t *)vap,
                    crgetuid(cr), cr, vap->va_type)) != 0) {
                        zfs_exit(zfsvfs, FTAG);
                        return (error);
                }
        }

        *zpp = NULL;

        if ((vap->va_mode & S_ISVTX) && secpolicy_vnode_stky_modify(cr))
                vap->va_mode &= ~S_ISVTX;

        error = zfs_dirent_lookup(dzp, name, &zp, ZNEW);
        if (error) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        ASSERT3P(zp, ==, NULL);

        /*
         * Create a new file object and update the directory
         * to reference it.
         */
        if ((error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr, mnt_ns))) {
                goto out;
        }

        /*
         * We only support the creation of regular files in
         * extended attribute directories.
         */

        if ((dzp->z_pflags & ZFS_XATTR) &&
            (vap->va_type != VREG)) {
                error = SET_ERROR(EINVAL);
                goto out;
        }

        if ((error = zfs_acl_ids_create(dzp, 0, vap,
            cr, vsecp, &acl_ids, NULL)) != 0)
                goto out;

        if (S_ISREG(vap->va_mode) || S_ISDIR(vap->va_mode))
                projid = zfs_inherit_projid(dzp);
        if (zfs_acl_ids_overquota(zfsvfs, &acl_ids, projid)) {
                zfs_acl_ids_free(&acl_ids);
                error = SET_ERROR(EDQUOT);
                goto out;
        }

        getnewvnode_reserve_();

        tx = dmu_tx_create(os);

        dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
            ZFS_SA_BASE_ATTR_SIZE);

        fuid_dirtied = zfsvfs->z_fuid_dirty;
        if (fuid_dirtied)
                zfs_fuid_txhold(zfsvfs, tx);
        dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
        dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
        if (!zfsvfs->z_use_sa &&
            acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
                dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
                    0, acl_ids.z_aclp->z_acl_bytes);
        }
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                zfs_acl_ids_free(&acl_ids);
                dmu_tx_abort(tx);
                getnewvnode_drop_reserve();
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);
        if (fuid_dirtied)
                zfs_fuid_sync(zfsvfs, tx);

        (void) zfs_link_create(dzp, name, zp, tx, ZNEW);
        txtype = zfs_log_create_txtype(Z_FILE, vsecp, vap);
        zfs_log_create(zilog, tx, txtype, dzp, zp, name,
            vsecp, acl_ids.z_fuidp, vap);
        zfs_acl_ids_free(&acl_ids);
        dmu_tx_commit(tx);

        getnewvnode_drop_reserve();

out:
        VNCHECKREF(dvp);
        if (error == 0) {
                *zpp = zp;
        }

        if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);

        zfs_exit(zfsvfs, FTAG);
        return (error);
}

/*
 * Remove an entry from a directory.
 *
 *      IN:     dvp     - vnode of directory to remove entry from.
 *              name    - name of entry to remove.
 *              cr      - credentials of caller.
 *              ct      - caller context
 *              flags   - case flags
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      dvp - ctime|mtime
 *       vp - ctime (if nlink > 0)
 */
static int
zfs_remove_(vnode_t *dvp, vnode_t *vp, const char *name, cred_t *cr)
{
        znode_t         *dzp = VTOZ(dvp);
        znode_t         *zp;
        znode_t         *xzp;
        zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
        zilog_t         *zilog;
        uint64_t        xattr_obj;
        uint64_t        obj = 0;
        dmu_tx_t        *tx;
        boolean_t       unlinked;
        uint64_t        txtype;
        int             error;


        if ((error = zfs_enter_verify_zp(zfsvfs, dzp, FTAG)) != 0)
                return (error);
        zp = VTOZ(vp);
        if ((error = zfs_verify_zp(zp)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        zilog = zfsvfs->z_log;

        xattr_obj = 0;
        xzp = NULL;

        if ((error = zfs_zaccess_delete(dzp, zp, cr, NULL))) {
                goto out;
        }

        /*
         * Need to use rmdir for removing directories.
         */
        if (vp->v_type == VDIR) {
                error = SET_ERROR(EPERM);
                goto out;
        }

        vnevent_remove(vp, dvp, name, ct);

        obj = zp->z_id;

        /* are there any extended attributes? */
        error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
            &xattr_obj, sizeof (xattr_obj));
        if (error == 0 && xattr_obj) {
                error = zfs_zget(zfsvfs, xattr_obj, &xzp);
                ASSERT0(error);
        }

        /*
         * We may delete the znode now, or we may put it in the unlinked set;
         * it depends on whether we're the last link, and on whether there are
         * other holds on the vnode.  So we dmu_tx_hold() the right things to
         * allow for either case.
         */
        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
        zfs_sa_upgrade_txholds(tx, zp);
        zfs_sa_upgrade_txholds(tx, dzp);

        if (xzp) {
                dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
                dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
        }

        /* charge as an update -- would be nice not to charge at all */
        dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);

        /*
         * Mark this transaction as typically resulting in a net free of space
         */
        dmu_tx_mark_netfree(tx);

        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * Remove the directory entry.
         */
        error = zfs_link_destroy(dzp, name, zp, tx, ZEXISTS, &unlinked);

        if (error) {
                dmu_tx_commit(tx);
                goto out;
        }

        if (unlinked) {
                zfs_unlinked_add(zp, tx);
                vp->v_vflag |= VV_NOSYNC;
        }
        /* XXX check changes to linux vnops */
        txtype = TX_REMOVE;
        zfs_log_remove(zilog, tx, txtype, dzp, name, obj, unlinked);

        dmu_tx_commit(tx);
out:

        if (xzp)
                vrele(ZTOV(xzp));

        if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);


        zfs_exit(zfsvfs, FTAG);
        return (error);
}


static int
zfs_lookup_internal(znode_t *dzp, const char *name, vnode_t **vpp,
    struct componentname *cnp, int nameiop)
{
        zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
        int error;

        cnp->cn_nameptr = __DECONST(char *, name);
        cnp->cn_namelen = strlen(name);
        cnp->cn_nameiop = nameiop;
        cnp->cn_flags = ISLASTCN;
#if __FreeBSD_version < 1400068
        cnp->cn_flags |= SAVENAME;
#endif
        cnp->cn_lkflags = LK_EXCLUSIVE | LK_RETRY;
        cnp->cn_cred = kcred;
#if __FreeBSD_version < 1400037
        cnp->cn_thread = curthread;
#endif

        if (zfsvfs->z_use_namecache && !zfsvfs->z_replay) {
                struct vop_lookup_args a;

                a.a_gen.a_desc = &vop_lookup_desc;
                a.a_dvp = ZTOV(dzp);
                a.a_vpp = vpp;
                a.a_cnp = cnp;
                error = vfs_cache_lookup(&a);
        } else {
                error = zfs_lookup(ZTOV(dzp), name, vpp, cnp, nameiop, kcred, 0,
                    B_FALSE);
        }
#ifdef ZFS_DEBUG
        if (error) {
                printf("got error %d on name %s on op %d\n", error, name,
                    nameiop);
                kdb_backtrace();
        }
#endif
        return (error);
}

int
zfs_remove(znode_t *dzp, const char *name, cred_t *cr, int flags)
{
        vnode_t *vp;
        int error;
        struct componentname cn;

        if ((error = zfs_lookup_internal(dzp, name, &vp, &cn, DELETE)))
                return (error);

        error = zfs_remove_(ZTOV(dzp), vp, name, cr);
        vput(vp);
        return (error);
}
/*
 * Create a new directory and insert it into dvp using the name
 * provided.  Return a pointer to the inserted directory.
 *
 *      IN:     dvp     - vnode of directory to add subdir to.
 *              dirname - name of new directory.
 *              vap     - attributes of new directory.
 *              cr      - credentials of caller.
 *              ct      - caller context
 *              flags   - case flags
 *              vsecp   - ACL to be set
 *              mnt_ns  - Unused on FreeBSD
 *
 *      OUT:    vpp     - vnode of created directory.
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      dvp - ctime|mtime updated
 *       vp - ctime|mtime|atime updated
 */
int
zfs_mkdir(znode_t *dzp, const char *dirname, vattr_t *vap, znode_t **zpp,
    cred_t *cr, int flags, vsecattr_t *vsecp, zuserns_t *mnt_ns)
{
        (void) flags, (void) vsecp;
        znode_t         *zp;
        zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
        zilog_t         *zilog;
        uint64_t        txtype;
        dmu_tx_t        *tx;
        int             error;
        uid_t           uid = crgetuid(cr);
        gid_t           gid = crgetgid(cr);
        zfs_acl_ids_t   acl_ids;
        boolean_t       fuid_dirtied;

        ASSERT3U(vap->va_type, ==, VDIR);

        /*
         * If we have an ephemeral id, ACL, or XVATTR then
         * make sure file system is at proper version
         */
        if (zfsvfs->z_use_fuids == B_FALSE &&
            ((vap->va_mask & AT_XVATTR) ||
            IS_EPHEMERAL(uid) || IS_EPHEMERAL(gid)))
                return (SET_ERROR(EINVAL));

        if ((error = zfs_enter_verify_zp(zfsvfs, dzp, FTAG)) != 0)
                return (error);
        zilog = zfsvfs->z_log;

        if (dzp->z_pflags & ZFS_XATTR) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EINVAL));
        }

        if (zfsvfs->z_utf8 && u8_validate(dirname,
            strlen(dirname), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EILSEQ));
        }

        if (vap->va_mask & AT_XVATTR) {
                if ((error = secpolicy_xvattr(ZTOV(dzp), (xvattr_t *)vap,
                    crgetuid(cr), cr, vap->va_type)) != 0) {
                        zfs_exit(zfsvfs, FTAG);
                        return (error);
                }
        }

        if ((error = zfs_acl_ids_create(dzp, 0, vap, cr,
            NULL, &acl_ids, NULL)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * First make sure the new directory doesn't exist.
         *
         * Existence is checked first to make sure we don't return
         * EACCES instead of EEXIST which can cause some applications
         * to fail.
         */
        *zpp = NULL;

        if ((error = zfs_dirent_lookup(dzp, dirname, &zp, ZNEW))) {
                zfs_acl_ids_free(&acl_ids);
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        ASSERT3P(zp, ==, NULL);

        if ((error = zfs_zaccess(dzp, ACE_ADD_SUBDIRECTORY, 0, B_FALSE, cr,
            mnt_ns))) {
                zfs_acl_ids_free(&acl_ids);
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        if (zfs_acl_ids_overquota(zfsvfs, &acl_ids, zfs_inherit_projid(dzp))) {
                zfs_acl_ids_free(&acl_ids);
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EDQUOT));
        }

        /*
         * Add a new entry to the directory.
         */
        getnewvnode_reserve_();
        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_zap(tx, dzp->z_id, TRUE, dirname);
        dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
        fuid_dirtied = zfsvfs->z_fuid_dirty;
        if (fuid_dirtied)
                zfs_fuid_txhold(zfsvfs, tx);
        if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
                dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
                    acl_ids.z_aclp->z_acl_bytes);
        }

        dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
            ZFS_SA_BASE_ATTR_SIZE);

        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                zfs_acl_ids_free(&acl_ids);
                dmu_tx_abort(tx);
                getnewvnode_drop_reserve();
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * Create new node.
         */
        zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);

        if (fuid_dirtied)
                zfs_fuid_sync(zfsvfs, tx);

        /*
         * Now put new name in parent dir.
         */
        (void) zfs_link_create(dzp, dirname, zp, tx, ZNEW);

        *zpp = zp;

        txtype = zfs_log_create_txtype(Z_DIR, NULL, vap);
        zfs_log_create(zilog, tx, txtype, dzp, zp, dirname, NULL,
            acl_ids.z_fuidp, vap);

        zfs_acl_ids_free(&acl_ids);

        dmu_tx_commit(tx);

        getnewvnode_drop_reserve();

        if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);

        zfs_exit(zfsvfs, FTAG);
        return (0);
}

#if     __FreeBSD_version < 1300124
static void
cache_vop_rmdir(struct vnode *dvp, struct vnode *vp)
{

        cache_purge(dvp);
        cache_purge(vp);
}
#endif

/*
 * Remove a directory subdir entry.  If the current working
 * directory is the same as the subdir to be removed, the
 * remove will fail.
 *
 *      IN:     dvp     - vnode of directory to remove from.
 *              name    - name of directory to be removed.
 *              cwd     - vnode of current working directory.
 *              cr      - credentials of caller.
 *              ct      - caller context
 *              flags   - case flags
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      dvp - ctime|mtime updated
 */
static int
zfs_rmdir_(vnode_t *dvp, vnode_t *vp, const char *name, cred_t *cr)
{
        znode_t         *dzp = VTOZ(dvp);
        znode_t         *zp = VTOZ(vp);
        zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
        zilog_t         *zilog;
        dmu_tx_t        *tx;
        int             error;

        if ((error = zfs_enter_verify_zp(zfsvfs, dzp, FTAG)) != 0)
                return (error);
        if ((error = zfs_verify_zp(zp)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        zilog = zfsvfs->z_log;


        if ((error = zfs_zaccess_delete(dzp, zp, cr, NULL))) {
                goto out;
        }

        if (vp->v_type != VDIR) {
                error = SET_ERROR(ENOTDIR);
                goto out;
        }

        vnevent_rmdir(vp, dvp, name, ct);

        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_zap(tx, dzp->z_id, FALSE, name);
        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
        dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
        zfs_sa_upgrade_txholds(tx, zp);
        zfs_sa_upgrade_txholds(tx, dzp);
        dmu_tx_mark_netfree(tx);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        error = zfs_link_destroy(dzp, name, zp, tx, ZEXISTS, NULL);

        if (error == 0) {
                uint64_t txtype = TX_RMDIR;
                zfs_log_remove(zilog, tx, txtype, dzp, name,
                    ZFS_NO_OBJECT, B_FALSE);
        }

        dmu_tx_commit(tx);

        cache_vop_rmdir(dvp, vp);
out:
        if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);

        zfs_exit(zfsvfs, FTAG);
        return (error);
}

int
zfs_rmdir(znode_t *dzp, const char *name, znode_t *cwd, cred_t *cr, int flags)
{
        struct componentname cn;
        vnode_t *vp;
        int error;

        if ((error = zfs_lookup_internal(dzp, name, &vp, &cn, DELETE)))
                return (error);

        error = zfs_rmdir_(ZTOV(dzp), vp, name, cr);
        vput(vp);
        return (error);
}

/*
 * Read as many directory entries as will fit into the provided
 * buffer from the given directory cursor position (specified in
 * the uio structure).
 *
 *      IN:     vp      - vnode of directory to read.
 *              uio     - structure supplying read location, range info,
 *                        and return buffer.
 *              cr      - credentials of caller.
 *              ct      - caller context
 *
 *      OUT:    uio     - updated offset and range, buffer filled.
 *              eofp    - set to true if end-of-file detected.
 *              ncookies- number of entries in cookies
 *              cookies - offsets to directory entries
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      vp - atime updated
 *
 * Note that the low 4 bits of the cookie returned by zap is always zero.
 * This allows us to use the low range for "special" directory entries:
 * We use 0 for '.', and 1 for '..'.  If this is the root of the filesystem,
 * we use the offset 2 for the '.zfs' directory.
 */
static int
zfs_readdir(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, int *eofp,
    int *ncookies, cookie_t **cookies)
{
        znode_t         *zp = VTOZ(vp);
        iovec_t         *iovp;
        dirent64_t      *odp;
        zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
        objset_t        *os;
        caddr_t         outbuf;
        size_t          bufsize;
        zap_cursor_t    zc;
        zap_attribute_t zap;
        uint_t          bytes_wanted;
        uint64_t        offset; /* must be unsigned; checks for < 1 */
        uint64_t        parent;
        int             local_eof;
        int             outcount;
        int             error;
        uint8_t         prefetch;
        uint8_t         type;
        int             ncooks;
        cookie_t        *cooks = NULL;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
            &parent, sizeof (parent))) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * If we are not given an eof variable,
         * use a local one.
         */
        if (eofp == NULL)
                eofp = &local_eof;

        /*
         * Check for valid iov_len.
         */
        if (GET_UIO_STRUCT(uio)->uio_iov->iov_len <= 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EINVAL));
        }

        /*
         * Quit if directory has been removed (posix)
         */
        if ((*eofp = zp->z_unlinked) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (0);
        }

        error = 0;
        os = zfsvfs->z_os;
        offset = zfs_uio_offset(uio);
        prefetch = zp->z_zn_prefetch;

        /*
         * Initialize the iterator cursor.
         */
        if (offset <= 3) {
                /*
                 * Start iteration from the beginning of the directory.
                 */
                zap_cursor_init(&zc, os, zp->z_id);
        } else {
                /*
                 * The offset is a serialized cursor.
                 */
                zap_cursor_init_serialized(&zc, os, zp->z_id, offset);
        }

        /*
         * Get space to change directory entries into fs independent format.
         */
        iovp = GET_UIO_STRUCT(uio)->uio_iov;
        bytes_wanted = iovp->iov_len;
        if (zfs_uio_segflg(uio) != UIO_SYSSPACE || zfs_uio_iovcnt(uio) != 1) {
                bufsize = bytes_wanted;
                outbuf = kmem_alloc(bufsize, KM_SLEEP);
                odp = (struct dirent64 *)outbuf;
        } else {
                bufsize = bytes_wanted;
                outbuf = NULL;
                odp = (struct dirent64 *)iovp->iov_base;
        }

        if (ncookies != NULL) {
                /*
                 * Minimum entry size is dirent size and 1 byte for a file name.
                 */
                ncooks = zfs_uio_resid(uio) / (sizeof (struct dirent) -
                    sizeof (((struct dirent *)NULL)->d_name) + 1);
                cooks = malloc(ncooks * sizeof (*cooks), M_TEMP, M_WAITOK);
                *cookies = cooks;
                *ncookies = ncooks;
        }

        /*
         * Transform to file-system independent format
         */
        outcount = 0;
        while (outcount < bytes_wanted) {
                ino64_t objnum;
                ushort_t reclen;
                off64_t *next = NULL;

                /*
                 * Special case `.', `..', and `.zfs'.
                 */
                if (offset == 0) {
                        (void) strcpy(zap.za_name, ".");
                        zap.za_normalization_conflict = 0;
                        objnum = zp->z_id;
                        type = DT_DIR;
                } else if (offset == 1) {
                        (void) strcpy(zap.za_name, "..");
                        zap.za_normalization_conflict = 0;
                        objnum = parent;
                        type = DT_DIR;
                } else if (offset == 2 && zfs_show_ctldir(zp)) {
                        (void) strcpy(zap.za_name, ZFS_CTLDIR_NAME);
                        zap.za_normalization_conflict = 0;
                        objnum = ZFSCTL_INO_ROOT;
                        type = DT_DIR;
                } else {
                        /*
                         * Grab next entry.
                         */
                        if ((error = zap_cursor_retrieve(&zc, &zap))) {
                                if ((*eofp = (error == ENOENT)) != 0)
                                        break;
                                else
                                        goto update;
                        }

                        if (zap.za_integer_length != 8 ||
                            zap.za_num_integers != 1) {
                                cmn_err(CE_WARN, "zap_readdir: bad directory "
                                    "entry, obj = %lld, offset = %lld\n",
                                    (u_longlong_t)zp->z_id,
                                    (u_longlong_t)offset);
                                error = SET_ERROR(ENXIO);
                                goto update;
                        }

                        objnum = ZFS_DIRENT_OBJ(zap.za_first_integer);
                        /*
                         * MacOS X can extract the object type here such as:
                         * uint8_t type = ZFS_DIRENT_TYPE(zap.za_first_integer);
                         */
                        type = ZFS_DIRENT_TYPE(zap.za_first_integer);
                }

                reclen = DIRENT64_RECLEN(strlen(zap.za_name));

                /*
                 * Will this entry fit in the buffer?
                 */
                if (outcount + reclen > bufsize) {
                        /*
                         * Did we manage to fit anything in the buffer?
                         */
                        if (!outcount) {
                                error = SET_ERROR(EINVAL);
                                goto update;
                        }
                        break;
                }
                /*
                 * Add normal entry:
                 */
                odp->d_ino = objnum;
                odp->d_reclen = reclen;
                odp->d_namlen = strlen(zap.za_name);
                /* NOTE: d_off is the offset for the *next* entry. */
                next = &odp->d_off;
                strlcpy(odp->d_name, zap.za_name, odp->d_namlen + 1);
                odp->d_type = type;
                dirent_terminate(odp);
                odp = (dirent64_t *)((intptr_t)odp + reclen);

                outcount += reclen;

                ASSERT3S(outcount, <=, bufsize);

                /* Prefetch znode */
                if (prefetch)
                        dmu_prefetch(os, objnum, 0, 0, 0,
                            ZIO_PRIORITY_SYNC_READ);

                /*
                 * Move to the next entry, fill in the previous offset.
                 */
                if (offset > 2 || (offset == 2 && !zfs_show_ctldir(zp))) {
                        zap_cursor_advance(&zc);
                        offset = zap_cursor_serialize(&zc);
                } else {
                        offset += 1;
                }

                /* Fill the offset right after advancing the cursor. */
                if (next != NULL)
                        *next = offset;
                if (cooks != NULL) {
                        *cooks++ = offset;
                        ncooks--;
                        KASSERT(ncooks >= 0, ("ncookies=%d", ncooks));
                }
        }
        zp->z_zn_prefetch = B_FALSE; /* a lookup will re-enable pre-fetching */

        /* Subtract unused cookies */
        if (ncookies != NULL)
                *ncookies -= ncooks;

        if (zfs_uio_segflg(uio) == UIO_SYSSPACE && zfs_uio_iovcnt(uio) == 1) {
                iovp->iov_base += outcount;
                iovp->iov_len -= outcount;
                zfs_uio_resid(uio) -= outcount;
        } else if ((error =
            zfs_uiomove(outbuf, (long)outcount, UIO_READ, uio))) {
                /*
                 * Reset the pointer.
                 */
                offset = zfs_uio_offset(uio);
        }

update:
        zap_cursor_fini(&zc);
        if (zfs_uio_segflg(uio) != UIO_SYSSPACE || zfs_uio_iovcnt(uio) != 1)
                kmem_free(outbuf, bufsize);

        if (error == ENOENT)
                error = 0;

        ZFS_ACCESSTIME_STAMP(zfsvfs, zp);

        zfs_uio_setoffset(uio, offset);
        zfs_exit(zfsvfs, FTAG);
        if (error != 0 && cookies != NULL) {
                free(*cookies, M_TEMP);
                *cookies = NULL;
                *ncookies = 0;
        }
        return (error);
}

/*
 * Get the requested file attributes and place them in the provided
 * vattr structure.
 *
 *      IN:     vp      - vnode of file.
 *              vap     - va_mask identifies requested attributes.
 *                        If AT_XVATTR set, then optional attrs are requested
 *              flags   - ATTR_NOACLCHECK (CIFS server context)
 *              cr      - credentials of caller.
 *
 *      OUT:    vap     - attribute values.
 *
 *      RETURN: 0 (always succeeds).
 */
static int
zfs_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr)
{
        znode_t *zp = VTOZ(vp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        int     error = 0;
        uint32_t blksize;
        u_longlong_t nblocks;
        uint64_t mtime[2], ctime[2], crtime[2], rdev;
        xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
        xoptattr_t *xoap = NULL;
        boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
        sa_bulk_attr_t bulk[4];
        int count = 0;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        zfs_fuid_map_ids(zp, cr, &vap->va_uid, &vap->va_gid);

        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, &mtime, 16);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, &ctime, 16);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CRTIME(zfsvfs), NULL, &crtime, 16);
        if (vp->v_type == VBLK || vp->v_type == VCHR)
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_RDEV(zfsvfs), NULL,
                    &rdev, 8);

        if ((error = sa_bulk_lookup(zp->z_sa_hdl, bulk, count)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * If ACL is trivial don't bother looking for ACE_READ_ATTRIBUTES.
         * Also, if we are the owner don't bother, since owner should
         * always be allowed to read basic attributes of file.
         */
        if (!(zp->z_pflags & ZFS_ACL_TRIVIAL) &&
            (vap->va_uid != crgetuid(cr))) {
                if ((error = zfs_zaccess(zp, ACE_READ_ATTRIBUTES, 0,
                    skipaclchk, cr, NULL))) {
                        zfs_exit(zfsvfs, FTAG);
                        return (error);
                }
        }

        /*
         * Return all attributes.  It's cheaper to provide the answer
         * than to determine whether we were asked the question.
         */

        vap->va_type = IFTOVT(zp->z_mode);
        vap->va_mode = zp->z_mode & ~S_IFMT;
        vn_fsid(vp, vap);
        vap->va_nodeid = zp->z_id;
        vap->va_nlink = zp->z_links;
        if ((vp->v_flag & VROOT) && zfs_show_ctldir(zp) &&
            zp->z_links < ZFS_LINK_MAX)
                vap->va_nlink++;
        vap->va_size = zp->z_size;
        if (vp->v_type == VBLK || vp->v_type == VCHR)
                vap->va_rdev = zfs_cmpldev(rdev);
        vap->va_gen = zp->z_gen;
        vap->va_flags = 0;      /* FreeBSD: Reset chflags(2) flags. */
        vap->va_filerev = zp->z_seq;

        /*
         * Add in any requested optional attributes and the create time.
         * Also set the corresponding bits in the returned attribute bitmap.
         */
        if ((xoap = xva_getxoptattr(xvap)) != NULL && zfsvfs->z_use_fuids) {
                if (XVA_ISSET_REQ(xvap, XAT_ARCHIVE)) {
                        xoap->xoa_archive =
                            ((zp->z_pflags & ZFS_ARCHIVE) != 0);
                        XVA_SET_RTN(xvap, XAT_ARCHIVE);
                }

                if (XVA_ISSET_REQ(xvap, XAT_READONLY)) {
                        xoap->xoa_readonly =
                            ((zp->z_pflags & ZFS_READONLY) != 0);
                        XVA_SET_RTN(xvap, XAT_READONLY);
                }

                if (XVA_ISSET_REQ(xvap, XAT_SYSTEM)) {
                        xoap->xoa_system =
                            ((zp->z_pflags & ZFS_SYSTEM) != 0);
                        XVA_SET_RTN(xvap, XAT_SYSTEM);
                }

                if (XVA_ISSET_REQ(xvap, XAT_HIDDEN)) {
                        xoap->xoa_hidden =
                            ((zp->z_pflags & ZFS_HIDDEN) != 0);
                        XVA_SET_RTN(xvap, XAT_HIDDEN);
                }

                if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
                        xoap->xoa_nounlink =
                            ((zp->z_pflags & ZFS_NOUNLINK) != 0);
                        XVA_SET_RTN(xvap, XAT_NOUNLINK);
                }

                if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
                        xoap->xoa_immutable =
                            ((zp->z_pflags & ZFS_IMMUTABLE) != 0);
                        XVA_SET_RTN(xvap, XAT_IMMUTABLE);
                }

                if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
                        xoap->xoa_appendonly =
                            ((zp->z_pflags & ZFS_APPENDONLY) != 0);
                        XVA_SET_RTN(xvap, XAT_APPENDONLY);
                }

                if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
                        xoap->xoa_nodump =
                            ((zp->z_pflags & ZFS_NODUMP) != 0);
                        XVA_SET_RTN(xvap, XAT_NODUMP);
                }

                if (XVA_ISSET_REQ(xvap, XAT_OPAQUE)) {
                        xoap->xoa_opaque =
                            ((zp->z_pflags & ZFS_OPAQUE) != 0);
                        XVA_SET_RTN(xvap, XAT_OPAQUE);
                }

                if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
                        xoap->xoa_av_quarantined =
                            ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0);
                        XVA_SET_RTN(xvap, XAT_AV_QUARANTINED);
                }

                if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
                        xoap->xoa_av_modified =
                            ((zp->z_pflags & ZFS_AV_MODIFIED) != 0);
                        XVA_SET_RTN(xvap, XAT_AV_MODIFIED);
                }

                if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) &&
                    vp->v_type == VREG) {
                        zfs_sa_get_scanstamp(zp, xvap);
                }

                if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
                        xoap->xoa_reparse = ((zp->z_pflags & ZFS_REPARSE) != 0);
                        XVA_SET_RTN(xvap, XAT_REPARSE);
                }
                if (XVA_ISSET_REQ(xvap, XAT_GEN)) {
                        xoap->xoa_generation = zp->z_gen;
                        XVA_SET_RTN(xvap, XAT_GEN);
                }

                if (XVA_ISSET_REQ(xvap, XAT_OFFLINE)) {
                        xoap->xoa_offline =
                            ((zp->z_pflags & ZFS_OFFLINE) != 0);
                        XVA_SET_RTN(xvap, XAT_OFFLINE);
                }

                if (XVA_ISSET_REQ(xvap, XAT_SPARSE)) {
                        xoap->xoa_sparse =
                            ((zp->z_pflags & ZFS_SPARSE) != 0);
                        XVA_SET_RTN(xvap, XAT_SPARSE);
                }

                if (XVA_ISSET_REQ(xvap, XAT_PROJINHERIT)) {
                        xoap->xoa_projinherit =
                            ((zp->z_pflags & ZFS_PROJINHERIT) != 0);
                        XVA_SET_RTN(xvap, XAT_PROJINHERIT);
                }

                if (XVA_ISSET_REQ(xvap, XAT_PROJID)) {
                        xoap->xoa_projid = zp->z_projid;
                        XVA_SET_RTN(xvap, XAT_PROJID);
                }
        }

        ZFS_TIME_DECODE(&vap->va_atime, zp->z_atime);
        ZFS_TIME_DECODE(&vap->va_mtime, mtime);
        ZFS_TIME_DECODE(&vap->va_ctime, ctime);
        ZFS_TIME_DECODE(&vap->va_birthtime, crtime);


        sa_object_size(zp->z_sa_hdl, &blksize, &nblocks);
        vap->va_blksize = blksize;
        vap->va_bytes = nblocks << 9;   /* nblocks * 512 */

        if (zp->z_blksz == 0) {
                /*
                 * Block size hasn't been set; suggest maximal I/O transfers.
                 */
                vap->va_blksize = zfsvfs->z_max_blksz;
        }

        zfs_exit(zfsvfs, FTAG);
        return (0);
}

/*
 * Set the file attributes to the values contained in the
 * vattr structure.
 *
 *      IN:     zp      - znode of file to be modified.
 *              vap     - new attribute values.
 *                        If AT_XVATTR set, then optional attrs are being set
 *              flags   - ATTR_UTIME set if non-default time values provided.
 *                      - ATTR_NOACLCHECK (CIFS context only).
 *              cr      - credentials of caller.
 *              mnt_ns  - Unused on FreeBSD
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      vp - ctime updated, mtime updated if size changed.
 */
int
zfs_setattr(znode_t *zp, vattr_t *vap, int flags, cred_t *cr, zuserns_t *mnt_ns)
{
        vnode_t         *vp = ZTOV(zp);
        zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
        objset_t        *os;
        zilog_t         *zilog;
        dmu_tx_t        *tx;
        vattr_t         oldva;
        xvattr_t        tmpxvattr;
        uint_t          mask = vap->va_mask;
        uint_t          saved_mask = 0;
        uint64_t        saved_mode;
        int             trim_mask = 0;
        uint64_t        new_mode;
        uint64_t        new_uid, new_gid;
        uint64_t        xattr_obj;
        uint64_t        mtime[2], ctime[2];
        uint64_t        projid = ZFS_INVALID_PROJID;
        znode_t         *attrzp;
        int             need_policy = FALSE;
        int             err, err2;
        zfs_fuid_info_t *fuidp = NULL;
        xvattr_t *xvap = (xvattr_t *)vap;       /* vap may be an xvattr_t * */
        xoptattr_t      *xoap;
        zfs_acl_t       *aclp;
        boolean_t skipaclchk = (flags & ATTR_NOACLCHECK) ? B_TRUE : B_FALSE;
        boolean_t       fuid_dirtied = B_FALSE;
        sa_bulk_attr_t  bulk[7], xattr_bulk[7];
        int             count = 0, xattr_count = 0;

        if (mask == 0)
                return (0);

        if (mask & AT_NOSET)
                return (SET_ERROR(EINVAL));

        if ((err = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (err);

        os = zfsvfs->z_os;
        zilog = zfsvfs->z_log;

        /*
         * Make sure that if we have ephemeral uid/gid or xvattr specified
         * that file system is at proper version level
         */

        if (zfsvfs->z_use_fuids == B_FALSE &&
            (((mask & AT_UID) && IS_EPHEMERAL(vap->va_uid)) ||
            ((mask & AT_GID) && IS_EPHEMERAL(vap->va_gid)) ||
            (mask & AT_XVATTR))) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EINVAL));
        }

        if (mask & AT_SIZE && vp->v_type == VDIR) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EISDIR));
        }

        if (mask & AT_SIZE && vp->v_type != VREG && vp->v_type != VFIFO) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EINVAL));
        }

        /*
         * If this is an xvattr_t, then get a pointer to the structure of
         * optional attributes.  If this is NULL, then we have a vattr_t.
         */
        xoap = xva_getxoptattr(xvap);

        xva_init(&tmpxvattr);

        /*
         * Immutable files can only alter immutable bit and atime
         */
        if ((zp->z_pflags & ZFS_IMMUTABLE) &&
            ((mask & (AT_SIZE|AT_UID|AT_GID|AT_MTIME|AT_MODE)) ||
            ((mask & AT_XVATTR) && XVA_ISSET_REQ(xvap, XAT_CREATETIME)))) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EPERM));
        }

        /*
         * Note: ZFS_READONLY is handled in zfs_zaccess_common.
         */

        /*
         * Verify timestamps doesn't overflow 32 bits.
         * ZFS can handle large timestamps, but 32bit syscalls can't
         * handle times greater than 2039.  This check should be removed
         * once large timestamps are fully supported.
         */
        if (mask & (AT_ATIME | AT_MTIME)) {
                if (((mask & AT_ATIME) && TIMESPEC_OVERFLOW(&vap->va_atime)) ||
                    ((mask & AT_MTIME) && TIMESPEC_OVERFLOW(&vap->va_mtime))) {
                        zfs_exit(zfsvfs, FTAG);
                        return (SET_ERROR(EOVERFLOW));
                }
        }
        if (xoap != NULL && (mask & AT_XVATTR)) {
                if (XVA_ISSET_REQ(xvap, XAT_CREATETIME) &&
                    TIMESPEC_OVERFLOW(&vap->va_birthtime)) {
                        zfs_exit(zfsvfs, FTAG);
                        return (SET_ERROR(EOVERFLOW));
                }

                if (XVA_ISSET_REQ(xvap, XAT_PROJID)) {
                        if (!dmu_objset_projectquota_enabled(os) ||
                            (!S_ISREG(zp->z_mode) && !S_ISDIR(zp->z_mode))) {
                                zfs_exit(zfsvfs, FTAG);
                                return (SET_ERROR(EOPNOTSUPP));
                        }

                        projid = xoap->xoa_projid;
                        if (unlikely(projid == ZFS_INVALID_PROJID)) {
                                zfs_exit(zfsvfs, FTAG);
                                return (SET_ERROR(EINVAL));
                        }

                        if (projid == zp->z_projid && zp->z_pflags & ZFS_PROJID)
                                projid = ZFS_INVALID_PROJID;
                        else
                                need_policy = TRUE;
                }

                if (XVA_ISSET_REQ(xvap, XAT_PROJINHERIT) &&
                    (xoap->xoa_projinherit !=
                    ((zp->z_pflags & ZFS_PROJINHERIT) != 0)) &&
                    (!dmu_objset_projectquota_enabled(os) ||
                    (!S_ISREG(zp->z_mode) && !S_ISDIR(zp->z_mode)))) {
                        zfs_exit(zfsvfs, FTAG);
                        return (SET_ERROR(EOPNOTSUPP));
                }
        }

        attrzp = NULL;
        aclp = NULL;

        if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EROFS));
        }

        /*
         * First validate permissions
         */

        if (mask & AT_SIZE) {
                /*
                 * XXX - Note, we are not providing any open
                 * mode flags here (like FNDELAY), so we may
                 * block if there are locks present... this
                 * should be addressed in openat().
                 */
                /* XXX - would it be OK to generate a log record here? */
                err = zfs_freesp(zp, vap->va_size, 0, 0, FALSE);
                if (err) {
                        zfs_exit(zfsvfs, FTAG);
                        return (err);
                }
        }

        if (mask & (AT_ATIME|AT_MTIME) ||
            ((mask & AT_XVATTR) && (XVA_ISSET_REQ(xvap, XAT_HIDDEN) ||
            XVA_ISSET_REQ(xvap, XAT_READONLY) ||
            XVA_ISSET_REQ(xvap, XAT_ARCHIVE) ||
            XVA_ISSET_REQ(xvap, XAT_OFFLINE) ||
            XVA_ISSET_REQ(xvap, XAT_SPARSE) ||
            XVA_ISSET_REQ(xvap, XAT_CREATETIME) ||
            XVA_ISSET_REQ(xvap, XAT_SYSTEM)))) {
                need_policy = zfs_zaccess(zp, ACE_WRITE_ATTRIBUTES, 0,
                    skipaclchk, cr, mnt_ns);
        }

        if (mask & (AT_UID|AT_GID)) {
                int     idmask = (mask & (AT_UID|AT_GID));
                int     take_owner;
                int     take_group;

                /*
                 * NOTE: even if a new mode is being set,
                 * we may clear S_ISUID/S_ISGID bits.
                 */

                if (!(mask & AT_MODE))
                        vap->va_mode = zp->z_mode;

                /*
                 * Take ownership or chgrp to group we are a member of
                 */

                take_owner = (mask & AT_UID) && (vap->va_uid == crgetuid(cr));
                take_group = (mask & AT_GID) &&
                    zfs_groupmember(zfsvfs, vap->va_gid, cr);

                /*
                 * If both AT_UID and AT_GID are set then take_owner and
                 * take_group must both be set in order to allow taking
                 * ownership.
                 *
                 * Otherwise, send the check through secpolicy_vnode_setattr()
                 *
                 */

                if (((idmask == (AT_UID|AT_GID)) && take_owner && take_group) ||
                    ((idmask == AT_UID) && take_owner) ||
                    ((idmask == AT_GID) && take_group)) {
                        if (zfs_zaccess(zp, ACE_WRITE_OWNER, 0,
                            skipaclchk, cr, mnt_ns) == 0) {
                                /*
                                 * Remove setuid/setgid for non-privileged users
                                 */
                                secpolicy_setid_clear(vap, vp, cr);
                                trim_mask = (mask & (AT_UID|AT_GID));
                        } else {
                                need_policy =  TRUE;
                        }
                } else {
                        need_policy =  TRUE;
                }
        }

        oldva.va_mode = zp->z_mode;
        zfs_fuid_map_ids(zp, cr, &oldva.va_uid, &oldva.va_gid);
        if (mask & AT_XVATTR) {
                /*
                 * Update xvattr mask to include only those attributes
                 * that are actually changing.
                 *
                 * the bits will be restored prior to actually setting
                 * the attributes so the caller thinks they were set.
                 */
                if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
                        if (xoap->xoa_appendonly !=
                            ((zp->z_pflags & ZFS_APPENDONLY) != 0)) {
                                need_policy = TRUE;
                        } else {
                                XVA_CLR_REQ(xvap, XAT_APPENDONLY);
                                XVA_SET_REQ(&tmpxvattr, XAT_APPENDONLY);
                        }
                }

                if (XVA_ISSET_REQ(xvap, XAT_PROJINHERIT)) {
                        if (xoap->xoa_projinherit !=
                            ((zp->z_pflags & ZFS_PROJINHERIT) != 0)) {
                                need_policy = TRUE;
                        } else {
                                XVA_CLR_REQ(xvap, XAT_PROJINHERIT);
                                XVA_SET_REQ(&tmpxvattr, XAT_PROJINHERIT);
                        }
                }

                if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
                        if (xoap->xoa_nounlink !=
                            ((zp->z_pflags & ZFS_NOUNLINK) != 0)) {
                                need_policy = TRUE;
                        } else {
                                XVA_CLR_REQ(xvap, XAT_NOUNLINK);
                                XVA_SET_REQ(&tmpxvattr, XAT_NOUNLINK);
                        }
                }

                if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
                        if (xoap->xoa_immutable !=
                            ((zp->z_pflags & ZFS_IMMUTABLE) != 0)) {
                                need_policy = TRUE;
                        } else {
                                XVA_CLR_REQ(xvap, XAT_IMMUTABLE);
                                XVA_SET_REQ(&tmpxvattr, XAT_IMMUTABLE);
                        }
                }

                if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
                        if (xoap->xoa_nodump !=
                            ((zp->z_pflags & ZFS_NODUMP) != 0)) {
                                need_policy = TRUE;
                        } else {
                                XVA_CLR_REQ(xvap, XAT_NODUMP);
                                XVA_SET_REQ(&tmpxvattr, XAT_NODUMP);
                        }
                }

                if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
                        if (xoap->xoa_av_modified !=
                            ((zp->z_pflags & ZFS_AV_MODIFIED) != 0)) {
                                need_policy = TRUE;
                        } else {
                                XVA_CLR_REQ(xvap, XAT_AV_MODIFIED);
                                XVA_SET_REQ(&tmpxvattr, XAT_AV_MODIFIED);
                        }
                }

                if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
                        if ((vp->v_type != VREG &&
                            xoap->xoa_av_quarantined) ||
                            xoap->xoa_av_quarantined !=
                            ((zp->z_pflags & ZFS_AV_QUARANTINED) != 0)) {
                                need_policy = TRUE;
                        } else {
                                XVA_CLR_REQ(xvap, XAT_AV_QUARANTINED);
                                XVA_SET_REQ(&tmpxvattr, XAT_AV_QUARANTINED);
                        }
                }

                if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
                        zfs_exit(zfsvfs, FTAG);
                        return (SET_ERROR(EPERM));
                }

                if (need_policy == FALSE &&
                    (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP) ||
                    XVA_ISSET_REQ(xvap, XAT_OPAQUE))) {
                        need_policy = TRUE;
                }
        }

        if (mask & AT_MODE) {
                if (zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr,
                    mnt_ns) == 0) {
                        err = secpolicy_setid_setsticky_clear(vp, vap,
                            &oldva, cr);
                        if (err) {
                                zfs_exit(zfsvfs, FTAG);
                                return (err);
                        }
                        trim_mask |= AT_MODE;
                } else {
                        need_policy = TRUE;
                }
        }

        if (need_policy) {
                /*
                 * If trim_mask is set then take ownership
                 * has been granted or write_acl is present and user
                 * has the ability to modify mode.  In that case remove
                 * UID|GID and or MODE from mask so that
                 * secpolicy_vnode_setattr() doesn't revoke it.
                 */

                if (trim_mask) {
                        saved_mask = vap->va_mask;
                        vap->va_mask &= ~trim_mask;
                        if (trim_mask & AT_MODE) {
                                /*
                                 * Save the mode, as secpolicy_vnode_setattr()
                                 * will overwrite it with ova.va_mode.
                                 */
                                saved_mode = vap->va_mode;
                        }
                }
                err = secpolicy_vnode_setattr(cr, vp, vap, &oldva, flags,
                    (int (*)(void *, int, cred_t *))zfs_zaccess_unix, zp);
                if (err) {
                        zfs_exit(zfsvfs, FTAG);
                        return (err);
                }

                if (trim_mask) {
                        vap->va_mask |= saved_mask;
                        if (trim_mask & AT_MODE) {
                                /*
                                 * Recover the mode after
                                 * secpolicy_vnode_setattr().
                                 */
                                vap->va_mode = saved_mode;
                        }
                }
        }

        /*
         * secpolicy_vnode_setattr, or take ownership may have
         * changed va_mask
         */
        mask = vap->va_mask;

        if ((mask & (AT_UID | AT_GID)) || projid != ZFS_INVALID_PROJID) {
                err = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
                    &xattr_obj, sizeof (xattr_obj));

                if (err == 0 && xattr_obj) {
                        err = zfs_zget(zp->z_zfsvfs, xattr_obj, &attrzp);
                        if (err == 0) {
                                err = vn_lock(ZTOV(attrzp), LK_EXCLUSIVE);
                                if (err != 0)
                                        vrele(ZTOV(attrzp));
                        }
                        if (err)
                                goto out2;
                }
                if (mask & AT_UID) {
                        new_uid = zfs_fuid_create(zfsvfs,
                            (uint64_t)vap->va_uid, cr, ZFS_OWNER, &fuidp);
                        if (new_uid != zp->z_uid &&
                            zfs_id_overquota(zfsvfs, DMU_USERUSED_OBJECT,
                            new_uid)) {
                                if (attrzp)
                                        vput(ZTOV(attrzp));
                                err = SET_ERROR(EDQUOT);
                                goto out2;
                        }
                }

                if (mask & AT_GID) {
                        new_gid = zfs_fuid_create(zfsvfs, (uint64_t)vap->va_gid,
                            cr, ZFS_GROUP, &fuidp);
                        if (new_gid != zp->z_gid &&
                            zfs_id_overquota(zfsvfs, DMU_GROUPUSED_OBJECT,
                            new_gid)) {
                                if (attrzp)
                                        vput(ZTOV(attrzp));
                                err = SET_ERROR(EDQUOT);
                                goto out2;
                        }
                }

                if (projid != ZFS_INVALID_PROJID &&
                    zfs_id_overquota(zfsvfs, DMU_PROJECTUSED_OBJECT, projid)) {
                        if (attrzp)
                                vput(ZTOV(attrzp));
                        err = SET_ERROR(EDQUOT);
                        goto out2;
                }
        }
        tx = dmu_tx_create(os);

        if (mask & AT_MODE) {
                uint64_t pmode = zp->z_mode;
                uint64_t acl_obj;
                new_mode = (pmode & S_IFMT) | (vap->va_mode & ~S_IFMT);

                if (zp->z_zfsvfs->z_acl_mode == ZFS_ACL_RESTRICTED &&
                    !(zp->z_pflags & ZFS_ACL_TRIVIAL)) {
                        err = SET_ERROR(EPERM);
                        goto out;
                }

                if ((err = zfs_acl_chmod_setattr(zp, &aclp, new_mode)))
                        goto out;

                if (!zp->z_is_sa && ((acl_obj = zfs_external_acl(zp)) != 0)) {
                        /*
                         * Are we upgrading ACL from old V0 format
                         * to V1 format?
                         */
                        if (zfsvfs->z_version >= ZPL_VERSION_FUID &&
                            zfs_znode_acl_version(zp) ==
                            ZFS_ACL_VERSION_INITIAL) {
                                dmu_tx_hold_free(tx, acl_obj, 0,
                                    DMU_OBJECT_END);
                                dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
                                    0, aclp->z_acl_bytes);
                        } else {
                                dmu_tx_hold_write(tx, acl_obj, 0,
                                    aclp->z_acl_bytes);
                        }
                } else if (!zp->z_is_sa && aclp->z_acl_bytes > ZFS_ACE_SPACE) {
                        dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
                            0, aclp->z_acl_bytes);
                }
                dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
        } else {
                if (((mask & AT_XVATTR) &&
                    XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP)) ||
                    (projid != ZFS_INVALID_PROJID &&
                    !(zp->z_pflags & ZFS_PROJID)))
                        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
                else
                        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
        }

        if (attrzp) {
                dmu_tx_hold_sa(tx, attrzp->z_sa_hdl, B_FALSE);
        }

        fuid_dirtied = zfsvfs->z_fuid_dirty;
        if (fuid_dirtied)
                zfs_fuid_txhold(zfsvfs, tx);

        zfs_sa_upgrade_txholds(tx, zp);

        err = dmu_tx_assign(tx, TXG_WAIT);
        if (err)
                goto out;

        count = 0;
        /*
         * Set each attribute requested.
         * We group settings according to the locks they need to acquire.
         *
         * Note: you cannot set ctime directly, although it will be
         * updated as a side-effect of calling this function.
         */

        if (projid != ZFS_INVALID_PROJID && !(zp->z_pflags & ZFS_PROJID)) {
                /*
                 * For the existed object that is upgraded from old system,
                 * its on-disk layout has no slot for the project ID attribute.
                 * But quota accounting logic needs to access related slots by
                 * offset directly. So we need to adjust old objects' layout
                 * to make the project ID to some unified and fixed offset.
                 */
                if (attrzp)
                        err = sa_add_projid(attrzp->z_sa_hdl, tx, projid);
                if (err == 0)
                        err = sa_add_projid(zp->z_sa_hdl, tx, projid);

                if (unlikely(err == EEXIST))
                        err = 0;
                else if (err != 0)
                        goto out;
                else
                        projid = ZFS_INVALID_PROJID;
        }

        if (mask & (AT_UID|AT_GID|AT_MODE))
                mutex_enter(&zp->z_acl_lock);

        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
            &zp->z_pflags, sizeof (zp->z_pflags));

        if (attrzp) {
                if (mask & (AT_UID|AT_GID|AT_MODE))
                        mutex_enter(&attrzp->z_acl_lock);
                SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
                    SA_ZPL_FLAGS(zfsvfs), NULL, &attrzp->z_pflags,
                    sizeof (attrzp->z_pflags));
                if (projid != ZFS_INVALID_PROJID) {
                        attrzp->z_projid = projid;
                        SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
                            SA_ZPL_PROJID(zfsvfs), NULL, &attrzp->z_projid,
                            sizeof (attrzp->z_projid));
                }
        }

        if (mask & (AT_UID|AT_GID)) {

                if (mask & AT_UID) {
                        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_UID(zfsvfs), NULL,
                            &new_uid, sizeof (new_uid));
                        zp->z_uid = new_uid;
                        if (attrzp) {
                                SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
                                    SA_ZPL_UID(zfsvfs), NULL, &new_uid,
                                    sizeof (new_uid));
                                attrzp->z_uid = new_uid;
                        }
                }

                if (mask & AT_GID) {
                        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GID(zfsvfs),
                            NULL, &new_gid, sizeof (new_gid));
                        zp->z_gid = new_gid;
                        if (attrzp) {
                                SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
                                    SA_ZPL_GID(zfsvfs), NULL, &new_gid,
                                    sizeof (new_gid));
                                attrzp->z_gid = new_gid;
                        }
                }
                if (!(mask & AT_MODE)) {
                        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs),
                            NULL, &new_mode, sizeof (new_mode));
                        new_mode = zp->z_mode;
                }
                err = zfs_acl_chown_setattr(zp);
                ASSERT0(err);
                if (attrzp) {
                        vn_seqc_write_begin(ZTOV(attrzp));
                        err = zfs_acl_chown_setattr(attrzp);
                        vn_seqc_write_end(ZTOV(attrzp));
                        ASSERT0(err);
                }
        }

        if (mask & AT_MODE) {
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs), NULL,
                    &new_mode, sizeof (new_mode));
                zp->z_mode = new_mode;
                ASSERT3P(aclp, !=, NULL);
                err = zfs_aclset_common(zp, aclp, cr, tx);
                ASSERT0(err);
                if (zp->z_acl_cached)
                        zfs_acl_free(zp->z_acl_cached);
                zp->z_acl_cached = aclp;
                aclp = NULL;
        }


        if (mask & AT_ATIME) {
                ZFS_TIME_ENCODE(&vap->va_atime, zp->z_atime);
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_ATIME(zfsvfs), NULL,
                    &zp->z_atime, sizeof (zp->z_atime));
        }

        if (mask & AT_MTIME) {
                ZFS_TIME_ENCODE(&vap->va_mtime, mtime);
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
                    mtime, sizeof (mtime));
        }

        if (projid != ZFS_INVALID_PROJID) {
                zp->z_projid = projid;
                SA_ADD_BULK_ATTR(bulk, count,
                    SA_ZPL_PROJID(zfsvfs), NULL, &zp->z_projid,
                    sizeof (zp->z_projid));
        }

        /* XXX - shouldn't this be done *before* the ATIME/MTIME checks? */
        if (mask & AT_SIZE && !(mask & AT_MTIME)) {
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
                    NULL, mtime, sizeof (mtime));
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
                    &ctime, sizeof (ctime));
                zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime);
        } else if (mask != 0) {
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
                    &ctime, sizeof (ctime));
                zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime);
                if (attrzp) {
                        SA_ADD_BULK_ATTR(xattr_bulk, xattr_count,
                            SA_ZPL_CTIME(zfsvfs), NULL,
                            &ctime, sizeof (ctime));
                        zfs_tstamp_update_setup(attrzp, STATE_CHANGED,
                            mtime, ctime);
                }
        }

        /*
         * Do this after setting timestamps to prevent timestamp
         * update from toggling bit
         */

        if (xoap && (mask & AT_XVATTR)) {

                if (XVA_ISSET_REQ(xvap, XAT_CREATETIME))
                        xoap->xoa_createtime = vap->va_birthtime;
                /*
                 * restore trimmed off masks
                 * so that return masks can be set for caller.
                 */

                if (XVA_ISSET_REQ(&tmpxvattr, XAT_APPENDONLY)) {
                        XVA_SET_REQ(xvap, XAT_APPENDONLY);
                }
                if (XVA_ISSET_REQ(&tmpxvattr, XAT_NOUNLINK)) {
                        XVA_SET_REQ(xvap, XAT_NOUNLINK);
                }
                if (XVA_ISSET_REQ(&tmpxvattr, XAT_IMMUTABLE)) {
                        XVA_SET_REQ(xvap, XAT_IMMUTABLE);
                }
                if (XVA_ISSET_REQ(&tmpxvattr, XAT_NODUMP)) {
                        XVA_SET_REQ(xvap, XAT_NODUMP);
                }
                if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_MODIFIED)) {
                        XVA_SET_REQ(xvap, XAT_AV_MODIFIED);
                }
                if (XVA_ISSET_REQ(&tmpxvattr, XAT_AV_QUARANTINED)) {
                        XVA_SET_REQ(xvap, XAT_AV_QUARANTINED);
                }
                if (XVA_ISSET_REQ(&tmpxvattr, XAT_PROJINHERIT)) {
                        XVA_SET_REQ(xvap, XAT_PROJINHERIT);
                }

                if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP))
                        ASSERT3S(vp->v_type, ==, VREG);

                zfs_xvattr_set(zp, xvap, tx);
        }

        if (fuid_dirtied)
                zfs_fuid_sync(zfsvfs, tx);

        if (mask != 0)
                zfs_log_setattr(zilog, tx, TX_SETATTR, zp, vap, mask, fuidp);

        if (mask & (AT_UID|AT_GID|AT_MODE))
                mutex_exit(&zp->z_acl_lock);

        if (attrzp) {
                if (mask & (AT_UID|AT_GID|AT_MODE))
                        mutex_exit(&attrzp->z_acl_lock);
        }
out:
        if (err == 0 && attrzp) {
                err2 = sa_bulk_update(attrzp->z_sa_hdl, xattr_bulk,
                    xattr_count, tx);
                ASSERT0(err2);
        }

        if (attrzp)
                vput(ZTOV(attrzp));

        if (aclp)
                zfs_acl_free(aclp);

        if (fuidp) {
                zfs_fuid_info_free(fuidp);
                fuidp = NULL;
        }

        if (err) {
                dmu_tx_abort(tx);
        } else {
                err2 = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
                dmu_tx_commit(tx);
        }

out2:
        if (os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);

        zfs_exit(zfsvfs, FTAG);
        return (err);
}

/*
 * Look up the directory entries corresponding to the source and target
 * directory/name pairs.
 */
static int
zfs_rename_relock_lookup(znode_t *sdzp, const struct componentname *scnp,
    znode_t **szpp, znode_t *tdzp, const struct componentname *tcnp,
    znode_t **tzpp)
{
        zfsvfs_t *zfsvfs;
        znode_t *szp, *tzp;
        int error;

        /*
         * Before using sdzp and tdzp we must ensure that they are live.
         * As a porting legacy from illumos we have two things to worry
         * about.  One is typical for FreeBSD and it is that the vnode is
         * not reclaimed (doomed).  The other is that the znode is live.
         * The current code can invalidate the znode without acquiring the
         * corresponding vnode lock if the object represented by the znode
         * and vnode is no longer valid after a rollback or receive operation.
         * z_teardown_lock hidden behind zfs_enter and zfs_exit is the lock
         * that protects the znodes from the invalidation.
         */
        zfsvfs = sdzp->z_zfsvfs;
        ASSERT3P(zfsvfs, ==, tdzp->z_zfsvfs);
        if ((error = zfs_enter_verify_zp(zfsvfs, sdzp, FTAG)) != 0)
                return (error);
        if ((error = zfs_verify_zp(tdzp)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * Re-resolve svp to be certain it still exists and fetch the
         * correct vnode.
         */
        error = zfs_dirent_lookup(sdzp, scnp->cn_nameptr, &szp, ZEXISTS);
        if (error != 0) {
                /* Source entry invalid or not there. */
                if ((scnp->cn_flags & ISDOTDOT) != 0 ||
                    (scnp->cn_namelen == 1 && scnp->cn_nameptr[0] == '.'))
                        error = SET_ERROR(EINVAL);
                goto out;
        }
        *szpp = szp;

        /*
         * Re-resolve tvp, if it disappeared we just carry on.
         */
        error = zfs_dirent_lookup(tdzp, tcnp->cn_nameptr, &tzp, 0);
        if (error != 0) {
                vrele(ZTOV(szp));
                if ((tcnp->cn_flags & ISDOTDOT) != 0)
                        error = SET_ERROR(EINVAL);
                goto out;
        }
        *tzpp = tzp;
out:
        zfs_exit(zfsvfs, FTAG);
        return (error);
}

/*
 * We acquire all but fdvp locks using non-blocking acquisitions.  If we
 * fail to acquire any lock in the path we will drop all held locks,
 * acquire the new lock in a blocking fashion, and then release it and
 * restart the rename.  This acquire/release step ensures that we do not
 * spin on a lock waiting for release.  On error release all vnode locks
 * and decrement references the way tmpfs_rename() would do.
 */
static int
zfs_rename_relock(struct vnode *sdvp, struct vnode **svpp,
    struct vnode *tdvp, struct vnode **tvpp,
    const struct componentname *scnp, const struct componentname *tcnp)
{
        struct vnode    *nvp, *svp, *tvp;
        znode_t         *sdzp, *tdzp, *szp, *tzp;
        int             error;

        VOP_UNLOCK1(tdvp);
        if (*tvpp != NULL && *tvpp != tdvp)
                VOP_UNLOCK1(*tvpp);

relock:
        error = vn_lock(sdvp, LK_EXCLUSIVE);
        if (error)
                goto out;
        error = vn_lock(tdvp, LK_EXCLUSIVE | LK_NOWAIT);
        if (error != 0) {
                VOP_UNLOCK1(sdvp);
                if (error != EBUSY)
                        goto out;
                error = vn_lock(tdvp, LK_EXCLUSIVE);
                if (error)
                        goto out;
                VOP_UNLOCK1(tdvp);
                goto relock;
        }
        tdzp = VTOZ(tdvp);
        sdzp = VTOZ(sdvp);

        error = zfs_rename_relock_lookup(sdzp, scnp, &szp, tdzp, tcnp, &tzp);
        if (error != 0) {
                VOP_UNLOCK1(sdvp);
                VOP_UNLOCK1(tdvp);
                goto out;
        }
        svp = ZTOV(szp);
        tvp = tzp != NULL ? ZTOV(tzp) : NULL;

        /*
         * Now try acquire locks on svp and tvp.
         */
        nvp = svp;
        error = vn_lock(nvp, LK_EXCLUSIVE | LK_NOWAIT);
        if (error != 0) {
                VOP_UNLOCK1(sdvp);
                VOP_UNLOCK1(tdvp);
                if (tvp != NULL)
                        vrele(tvp);
                if (error != EBUSY) {
                        vrele(nvp);
                        goto out;
                }
                error = vn_lock(nvp, LK_EXCLUSIVE);
                if (error != 0) {
                        vrele(nvp);
                        goto out;
                }
                VOP_UNLOCK1(nvp);
                /*
                 * Concurrent rename race.
                 * XXX ?
                 */
                if (nvp == tdvp) {
                        vrele(nvp);
                        error = SET_ERROR(EINVAL);
                        goto out;
                }
                vrele(*svpp);
                *svpp = nvp;
                goto relock;
        }
        vrele(*svpp);
        *svpp = nvp;

        if (*tvpp != NULL)
                vrele(*tvpp);
        *tvpp = NULL;
        if (tvp != NULL) {
                nvp = tvp;
                error = vn_lock(nvp, LK_EXCLUSIVE | LK_NOWAIT);
                if (error != 0) {
                        VOP_UNLOCK1(sdvp);
                        VOP_UNLOCK1(tdvp);
                        VOP_UNLOCK1(*svpp);
                        if (error != EBUSY) {
                                vrele(nvp);
                                goto out;
                        }
                        error = vn_lock(nvp, LK_EXCLUSIVE);
                        if (error != 0) {
                                vrele(nvp);
                                goto out;
                        }
                        vput(nvp);
                        goto relock;
                }
                *tvpp = nvp;
        }

        return (0);

out:
        return (error);
}

/*
 * Note that we must use VRELE_ASYNC in this function as it walks
 * up the directory tree and vrele may need to acquire an exclusive
 * lock if a last reference to a vnode is dropped.
 */
static int
zfs_rename_check(znode_t *szp, znode_t *sdzp, znode_t *tdzp)
{
        zfsvfs_t        *zfsvfs;
        znode_t         *zp, *zp1;
        uint64_t        parent;
        int             error;

        zfsvfs = tdzp->z_zfsvfs;
        if (tdzp == szp)
                return (SET_ERROR(EINVAL));
        if (tdzp == sdzp)
                return (0);
        if (tdzp->z_id == zfsvfs->z_root)
                return (0);
        zp = tdzp;
        for (;;) {
                ASSERT(!zp->z_unlinked);
                if ((error = sa_lookup(zp->z_sa_hdl,
                    SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
                        break;

                if (parent == szp->z_id) {
                        error = SET_ERROR(EINVAL);
                        break;
                }
                if (parent == zfsvfs->z_root)
                        break;
                if (parent == sdzp->z_id)
                        break;

                error = zfs_zget(zfsvfs, parent, &zp1);
                if (error != 0)
                        break;

                if (zp != tdzp)
                        VN_RELE_ASYNC(ZTOV(zp),
                            dsl_pool_zrele_taskq(
                            dmu_objset_pool(zfsvfs->z_os)));
                zp = zp1;
        }

        if (error == ENOTDIR)
                panic("checkpath: .. not a directory\n");
        if (zp != tdzp)
                VN_RELE_ASYNC(ZTOV(zp),
                    dsl_pool_zrele_taskq(dmu_objset_pool(zfsvfs->z_os)));
        return (error);
}

#if     __FreeBSD_version < 1300124
static void
cache_vop_rename(struct vnode *fdvp, struct vnode *fvp, struct vnode *tdvp,
    struct vnode *tvp, struct componentname *fcnp, struct componentname *tcnp)
{

        cache_purge(fvp);
        if (tvp != NULL)
                cache_purge(tvp);
        cache_purge_negative(tdvp);
}
#endif

static int
zfs_do_rename_impl(vnode_t *sdvp, vnode_t **svpp, struct componentname *scnp,
    vnode_t *tdvp, vnode_t **tvpp, struct componentname *tcnp,
    cred_t *cr);

/*
 * Move an entry from the provided source directory to the target
 * directory.  Change the entry name as indicated.
 *
 *      IN:     sdvp    - Source directory containing the "old entry".
 *              scnp    - Old entry name.
 *              tdvp    - Target directory to contain the "new entry".
 *              tcnp    - New entry name.
 *              cr      - credentials of caller.
 *      INOUT:  svpp    - Source file
 *              tvpp    - Target file, may point to NULL initially
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      sdvp,tdvp - ctime|mtime updated
 */
static int
zfs_do_rename(vnode_t *sdvp, vnode_t **svpp, struct componentname *scnp,
    vnode_t *tdvp, vnode_t **tvpp, struct componentname *tcnp,
    cred_t *cr)
{
        int     error;

        ASSERT_VOP_ELOCKED(tdvp, __func__);
        if (*tvpp != NULL)
                ASSERT_VOP_ELOCKED(*tvpp, __func__);

        /* Reject renames across filesystems. */
        if ((*svpp)->v_mount != tdvp->v_mount ||
            ((*tvpp) != NULL && (*svpp)->v_mount != (*tvpp)->v_mount)) {
                error = SET_ERROR(EXDEV);
                goto out;
        }

        if (zfsctl_is_node(tdvp)) {
                error = SET_ERROR(EXDEV);
                goto out;
        }

        /*
         * Lock all four vnodes to ensure safety and semantics of renaming.
         */
        error = zfs_rename_relock(sdvp, svpp, tdvp, tvpp, scnp, tcnp);
        if (error != 0) {
                /* no vnodes are locked in the case of error here */
                return (error);
        }

        error = zfs_do_rename_impl(sdvp, svpp, scnp, tdvp, tvpp, tcnp, cr);
        VOP_UNLOCK1(sdvp);
        VOP_UNLOCK1(*svpp);
out:
        if (*tvpp != NULL)
                VOP_UNLOCK1(*tvpp);
        if (tdvp != *tvpp)
                VOP_UNLOCK1(tdvp);

        return (error);
}

static int
zfs_do_rename_impl(vnode_t *sdvp, vnode_t **svpp, struct componentname *scnp,
    vnode_t *tdvp, vnode_t **tvpp, struct componentname *tcnp,
    cred_t *cr)
{
        dmu_tx_t        *tx;
        zfsvfs_t        *zfsvfs;
        zilog_t         *zilog;
        znode_t         *tdzp, *sdzp, *tzp, *szp;
        const char      *snm = scnp->cn_nameptr;
        const char      *tnm = tcnp->cn_nameptr;
        int             error;

        tdzp = VTOZ(tdvp);
        sdzp = VTOZ(sdvp);
        zfsvfs = tdzp->z_zfsvfs;

        if ((error = zfs_enter_verify_zp(zfsvfs, tdzp, FTAG)) != 0)
                return (error);
        if ((error = zfs_verify_zp(sdzp)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        zilog = zfsvfs->z_log;

        if (zfsvfs->z_utf8 && u8_validate(tnm,
            strlen(tnm), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
                error = SET_ERROR(EILSEQ);
                goto out;
        }

        /* If source and target are the same file, there is nothing to do. */
        if ((*svpp) == (*tvpp)) {
                error = 0;
                goto out;
        }

        if (((*svpp)->v_type == VDIR && (*svpp)->v_mountedhere != NULL) ||
            ((*tvpp) != NULL && (*tvpp)->v_type == VDIR &&
            (*tvpp)->v_mountedhere != NULL)) {
                error = SET_ERROR(EXDEV);
                goto out;
        }

        szp = VTOZ(*svpp);
        if ((error = zfs_verify_zp(szp)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        tzp = *tvpp == NULL ? NULL : VTOZ(*tvpp);
        if (tzp != NULL) {
                if ((error = zfs_verify_zp(tzp)) != 0) {
                        zfs_exit(zfsvfs, FTAG);
                        return (error);
                }
        }

        /*
         * This is to prevent the creation of links into attribute space
         * by renaming a linked file into/outof an attribute directory.
         * See the comment in zfs_link() for why this is considered bad.
         */
        if ((tdzp->z_pflags & ZFS_XATTR) != (sdzp->z_pflags & ZFS_XATTR)) {
                error = SET_ERROR(EINVAL);
                goto out;
        }

        /*
         * If we are using project inheritance, means if the directory has
         * ZFS_PROJINHERIT set, then its descendant directories will inherit
         * not only the project ID, but also the ZFS_PROJINHERIT flag. Under
         * such case, we only allow renames into our tree when the project
         * IDs are the same.
         */
        if (tdzp->z_pflags & ZFS_PROJINHERIT &&
            tdzp->z_projid != szp->z_projid) {
                error = SET_ERROR(EXDEV);
                goto out;
        }

        /*
         * Must have write access at the source to remove the old entry
         * and write access at the target to create the new entry.
         * Note that if target and source are the same, this can be
         * done in a single check.
         */
        if ((error = zfs_zaccess_rename(sdzp, szp, tdzp, tzp, cr, NULL)))
                goto out;

        if ((*svpp)->v_type == VDIR) {
                /*
                 * Avoid ".", "..", and aliases of "." for obvious reasons.
                 */
                if ((scnp->cn_namelen == 1 && scnp->cn_nameptr[0] == '.') ||
                    sdzp == szp ||
                    (scnp->cn_flags | tcnp->cn_flags) & ISDOTDOT) {
                        error = EINVAL;
                        goto out;
                }

                /*
                 * Check to make sure rename is valid.
                 * Can't do a move like this: /usr/a/b to /usr/a/b/c/d
                 */
                if ((error = zfs_rename_check(szp, sdzp, tdzp)))
                        goto out;
        }

        /*
         * Does target exist?
         */
        if (tzp) {
                /*
                 * Source and target must be the same type.
                 */
                if ((*svpp)->v_type == VDIR) {
                        if ((*tvpp)->v_type != VDIR) {
                                error = SET_ERROR(ENOTDIR);
                                goto out;
                        } else {
                                cache_purge(tdvp);
                                if (sdvp != tdvp)
                                        cache_purge(sdvp);
                        }
                } else {
                        if ((*tvpp)->v_type == VDIR) {
                                error = SET_ERROR(EISDIR);
                                goto out;
                        }
                }
        }

        vn_seqc_write_begin(*svpp);
        vn_seqc_write_begin(sdvp);
        if (*tvpp != NULL)
                vn_seqc_write_begin(*tvpp);
        if (tdvp != *tvpp)
                vn_seqc_write_begin(tdvp);

        vnevent_rename_src(*svpp, sdvp, scnp->cn_nameptr, ct);
        if (tzp)
                vnevent_rename_dest(*tvpp, tdvp, tnm, ct);

        /*
         * notify the target directory if it is not the same
         * as source directory.
         */
        if (tdvp != sdvp) {
                vnevent_rename_dest_dir(tdvp, ct);
        }

        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
        dmu_tx_hold_sa(tx, sdzp->z_sa_hdl, B_FALSE);
        dmu_tx_hold_zap(tx, sdzp->z_id, FALSE, snm);
        dmu_tx_hold_zap(tx, tdzp->z_id, TRUE, tnm);
        if (sdzp != tdzp) {
                dmu_tx_hold_sa(tx, tdzp->z_sa_hdl, B_FALSE);
                zfs_sa_upgrade_txholds(tx, tdzp);
        }
        if (tzp) {
                dmu_tx_hold_sa(tx, tzp->z_sa_hdl, B_FALSE);
                zfs_sa_upgrade_txholds(tx, tzp);
        }

        zfs_sa_upgrade_txholds(tx, szp);
        dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                goto out_seq;
        }

        if (tzp)        /* Attempt to remove the existing target */
                error = zfs_link_destroy(tdzp, tnm, tzp, tx, 0, NULL);

        if (error == 0) {
                error = zfs_link_create(tdzp, tnm, szp, tx, ZRENAMING);
                if (error == 0) {
                        szp->z_pflags |= ZFS_AV_MODIFIED;

                        error = sa_update(szp->z_sa_hdl, SA_ZPL_FLAGS(zfsvfs),
                            (void *)&szp->z_pflags, sizeof (uint64_t), tx);
                        ASSERT0(error);

                        error = zfs_link_destroy(sdzp, snm, szp, tx, ZRENAMING,
                            NULL);
                        if (error == 0) {
                                zfs_log_rename(zilog, tx, TX_RENAME, sdzp,
                                    snm, tdzp, tnm, szp);

                                /*
                                 * Update path information for the target vnode
                                 */
                                vn_renamepath(tdvp, *svpp, tnm, strlen(tnm));
                        } else {
                                /*
                                 * At this point, we have successfully created
                                 * the target name, but have failed to remove
                                 * the source name.  Since the create was done
                                 * with the ZRENAMING flag, there are
                                 * complications; for one, the link count is
                                 * wrong.  The easiest way to deal with this
                                 * is to remove the newly created target, and
                                 * return the original error.  This must
                                 * succeed; fortunately, it is very unlikely to
                                 * fail, since we just created it.
                                 */
                                VERIFY0(zfs_link_destroy(tdzp, tnm, szp, tx,
                                    ZRENAMING, NULL));
                        }
                }
                if (error == 0) {
                        cache_vop_rename(sdvp, *svpp, tdvp, *tvpp, scnp, tcnp);
                }
        }

        dmu_tx_commit(tx);

out_seq:
        vn_seqc_write_end(*svpp);
        vn_seqc_write_end(sdvp);
        if (*tvpp != NULL)
                vn_seqc_write_end(*tvpp);
        if (tdvp != *tvpp)
                vn_seqc_write_end(tdvp);

out:
        if (error == 0 && zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);
        zfs_exit(zfsvfs, FTAG);

        return (error);
}

int
zfs_rename(znode_t *sdzp, const char *sname, znode_t *tdzp, const char *tname,
    cred_t *cr, int flags, zuserns_t *mnt_ns)
{
        struct componentname scn, tcn;
        vnode_t *sdvp, *tdvp;
        vnode_t *svp, *tvp;
        int error;
        svp = tvp = NULL;

        sdvp = ZTOV(sdzp);
        tdvp = ZTOV(tdzp);
        error = zfs_lookup_internal(sdzp, sname, &svp, &scn, DELETE);
        if (sdzp->z_zfsvfs->z_replay == B_FALSE)
                VOP_UNLOCK1(sdvp);
        if (error != 0)
                goto fail;
        VOP_UNLOCK1(svp);

        vn_lock(tdvp, LK_EXCLUSIVE | LK_RETRY);
        error = zfs_lookup_internal(tdzp, tname, &tvp, &tcn, RENAME);
        if (error == EJUSTRETURN)
                tvp = NULL;
        else if (error != 0) {
                VOP_UNLOCK1(tdvp);
                goto fail;
        }

        error = zfs_do_rename(sdvp, &svp, &scn, tdvp, &tvp, &tcn, cr);
fail:
        if (svp != NULL)
                vrele(svp);
        if (tvp != NULL)
                vrele(tvp);

        return (error);
}

/*
 * Insert the indicated symbolic reference entry into the directory.
 *
 *      IN:     dvp     - Directory to contain new symbolic link.
 *              link    - Name for new symlink entry.
 *              vap     - Attributes of new entry.
 *              cr      - credentials of caller.
 *              ct      - caller context
 *              flags   - case flags
 *              mnt_ns  - Unused on FreeBSD
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      dvp - ctime|mtime updated
 */
int
zfs_symlink(znode_t *dzp, const char *name, vattr_t *vap,
    const char *link, znode_t **zpp, cred_t *cr, int flags, zuserns_t *mnt_ns)
{
        (void) flags;
        znode_t         *zp;
        dmu_tx_t        *tx;
        zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
        zilog_t         *zilog;
        uint64_t        len = strlen(link);
        int             error;
        zfs_acl_ids_t   acl_ids;
        boolean_t       fuid_dirtied;
        uint64_t        txtype = TX_SYMLINK;

        ASSERT3S(vap->va_type, ==, VLNK);

        if ((error = zfs_enter_verify_zp(zfsvfs, dzp, FTAG)) != 0)
                return (error);
        zilog = zfsvfs->z_log;

        if (zfsvfs->z_utf8 && u8_validate(name, strlen(name),
            NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EILSEQ));
        }

        if (len > MAXPATHLEN) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(ENAMETOOLONG));
        }

        if ((error = zfs_acl_ids_create(dzp, 0,
            vap, cr, NULL, &acl_ids, NULL)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * Attempt to lock directory; fail if entry already exists.
         */
        error = zfs_dirent_lookup(dzp, name, &zp, ZNEW);
        if (error) {
                zfs_acl_ids_free(&acl_ids);
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        if ((error = zfs_zaccess(dzp, ACE_ADD_FILE, 0, B_FALSE, cr, mnt_ns))) {
                zfs_acl_ids_free(&acl_ids);
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        if (zfs_acl_ids_overquota(zfsvfs, &acl_ids,
            0 /* projid */)) {
                zfs_acl_ids_free(&acl_ids);
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EDQUOT));
        }

        getnewvnode_reserve_();
        tx = dmu_tx_create(zfsvfs->z_os);
        fuid_dirtied = zfsvfs->z_fuid_dirty;
        dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, MAX(1, len));
        dmu_tx_hold_zap(tx, dzp->z_id, TRUE, name);
        dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
            ZFS_SA_BASE_ATTR_SIZE + len);
        dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
        if (!zfsvfs->z_use_sa && acl_ids.z_aclp->z_acl_bytes > ZFS_ACE_SPACE) {
                dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
                    acl_ids.z_aclp->z_acl_bytes);
        }
        if (fuid_dirtied)
                zfs_fuid_txhold(zfsvfs, tx);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                zfs_acl_ids_free(&acl_ids);
                dmu_tx_abort(tx);
                getnewvnode_drop_reserve();
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * Create a new object for the symlink.
         * for version 4 ZPL datasets the symlink will be an SA attribute
         */
        zfs_mknode(dzp, vap, tx, cr, 0, &zp, &acl_ids);

        if (fuid_dirtied)
                zfs_fuid_sync(zfsvfs, tx);

        if (zp->z_is_sa)
                error = sa_update(zp->z_sa_hdl, SA_ZPL_SYMLINK(zfsvfs),
                    __DECONST(void *, link), len, tx);
        else
                zfs_sa_symlink(zp, __DECONST(char *, link), len, tx);

        zp->z_size = len;
        (void) sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zfsvfs),
            &zp->z_size, sizeof (zp->z_size), tx);
        /*
         * Insert the new object into the directory.
         */
        (void) zfs_link_create(dzp, name, zp, tx, ZNEW);

        zfs_log_symlink(zilog, tx, txtype, dzp, zp, name, link);
        *zpp = zp;

        zfs_acl_ids_free(&acl_ids);

        dmu_tx_commit(tx);

        getnewvnode_drop_reserve();

        if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);

        zfs_exit(zfsvfs, FTAG);
        return (error);
}

/*
 * Return, in the buffer contained in the provided uio structure,
 * the symbolic path referred to by vp.
 *
 *      IN:     vp      - vnode of symbolic link.
 *              uio     - structure to contain the link path.
 *              cr      - credentials of caller.
 *              ct      - caller context
 *
 *      OUT:    uio     - structure containing the link path.
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      vp - atime updated
 */
static int
zfs_readlink(vnode_t *vp, zfs_uio_t *uio, cred_t *cr, caller_context_t *ct)
{
        (void) cr, (void) ct;
        znode_t         *zp = VTOZ(vp);
        zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
        int             error;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        if (zp->z_is_sa)
                error = sa_lookup_uio(zp->z_sa_hdl,
                    SA_ZPL_SYMLINK(zfsvfs), uio);
        else
                error = zfs_sa_readlink(zp, uio);

        ZFS_ACCESSTIME_STAMP(zfsvfs, zp);

        zfs_exit(zfsvfs, FTAG);
        return (error);
}

/*
 * Insert a new entry into directory tdvp referencing svp.
 *
 *      IN:     tdvp    - Directory to contain new entry.
 *              svp     - vnode of new entry.
 *              name    - name of new entry.
 *              cr      - credentials of caller.
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      tdvp - ctime|mtime updated
 *       svp - ctime updated
 */
int
zfs_link(znode_t *tdzp, znode_t *szp, const char *name, cred_t *cr,
    int flags)
{
        (void) flags;
        znode_t         *tzp;
        zfsvfs_t        *zfsvfs = tdzp->z_zfsvfs;
        zilog_t         *zilog;
        dmu_tx_t        *tx;
        int             error;
        uint64_t        parent;
        uid_t           owner;

        ASSERT3S(ZTOV(tdzp)->v_type, ==, VDIR);

        if ((error = zfs_enter_verify_zp(zfsvfs, tdzp, FTAG)) != 0)
                return (error);
        zilog = zfsvfs->z_log;

        /*
         * POSIX dictates that we return EPERM here.
         * Better choices include ENOTSUP or EISDIR.
         */
        if (ZTOV(szp)->v_type == VDIR) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EPERM));
        }

        if ((error = zfs_verify_zp(szp)) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * If we are using project inheritance, means if the directory has
         * ZFS_PROJINHERIT set, then its descendant directories will inherit
         * not only the project ID, but also the ZFS_PROJINHERIT flag. Under
         * such case, we only allow hard link creation in our tree when the
         * project IDs are the same.
         */
        if (tdzp->z_pflags & ZFS_PROJINHERIT &&
            tdzp->z_projid != szp->z_projid) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EXDEV));
        }

        if (szp->z_pflags & (ZFS_APPENDONLY |
            ZFS_IMMUTABLE | ZFS_READONLY)) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EPERM));
        }

        /* Prevent links to .zfs/shares files */

        if ((error = sa_lookup(szp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
            &parent, sizeof (uint64_t))) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        if (parent == zfsvfs->z_shares_dir) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EPERM));
        }

        if (zfsvfs->z_utf8 && u8_validate(name,
            strlen(name), NULL, U8_VALIDATE_ENTIRE, &error) < 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EILSEQ));
        }

        /*
         * We do not support links between attributes and non-attributes
         * because of the potential security risk of creating links
         * into "normal" file space in order to circumvent restrictions
         * imposed in attribute space.
         */
        if ((szp->z_pflags & ZFS_XATTR) != (tdzp->z_pflags & ZFS_XATTR)) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EINVAL));
        }


        owner = zfs_fuid_map_id(zfsvfs, szp->z_uid, cr, ZFS_OWNER);
        if (owner != crgetuid(cr) && secpolicy_basic_link(ZTOV(szp), cr) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EPERM));
        }

        if ((error = zfs_zaccess(tdzp, ACE_ADD_FILE, 0, B_FALSE, cr, NULL))) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        /*
         * Attempt to lock directory; fail if entry already exists.
         */
        error = zfs_dirent_lookup(tdzp, name, &tzp, ZNEW);
        if (error) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_sa(tx, szp->z_sa_hdl, B_FALSE);
        dmu_tx_hold_zap(tx, tdzp->z_id, TRUE, name);
        zfs_sa_upgrade_txholds(tx, szp);
        zfs_sa_upgrade_txholds(tx, tdzp);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        error = zfs_link_create(tdzp, name, szp, tx, 0);

        if (error == 0) {
                uint64_t txtype = TX_LINK;
                zfs_log_link(zilog, tx, txtype, tdzp, szp, name);
        }

        dmu_tx_commit(tx);

        if (error == 0) {
                vnevent_link(ZTOV(szp), ct);
        }

        if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zilog, 0);

        zfs_exit(zfsvfs, FTAG);
        return (error);
}

/*
 * Free or allocate space in a file.  Currently, this function only
 * supports the `F_FREESP' command.  However, this command is somewhat
 * misnamed, as its functionality includes the ability to allocate as
 * well as free space.
 *
 *      IN:     ip      - inode of file to free data in.
 *              cmd     - action to take (only F_FREESP supported).
 *              bfp     - section of file to free/alloc.
 *              flag    - current file open mode flags.
 *              offset  - current file offset.
 *              cr      - credentials of caller.
 *
 *      RETURN: 0 on success, error code on failure.
 *
 * Timestamps:
 *      ip - ctime|mtime updated
 */
int
zfs_space(znode_t *zp, int cmd, flock64_t *bfp, int flag,
    offset_t offset, cred_t *cr)
{
        (void) offset;
        zfsvfs_t        *zfsvfs = ZTOZSB(zp);
        uint64_t        off, len;
        int             error;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        if (cmd != F_FREESP) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EINVAL));
        }

        /*
         * Callers might not be able to detect properly that we are read-only,
         * so check it explicitly here.
         */
        if (zfs_is_readonly(zfsvfs)) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EROFS));
        }

        if (bfp->l_len < 0) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EINVAL));
        }

        /*
         * Permissions aren't checked on Solaris because on this OS
         * zfs_space() can only be called with an opened file handle.
         * On Linux we can get here through truncate_range() which
         * operates directly on inodes, so we need to check access rights.
         */
        if ((error = zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr, NULL))) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        off = bfp->l_start;
        len = bfp->l_len; /* 0 means from off to end of file */

        error = zfs_freesp(zp, off, len, flag, TRUE);

        zfs_exit(zfsvfs, FTAG);
        return (error);
}

static void
zfs_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
{
        (void) cr, (void) ct;
        znode_t *zp = VTOZ(vp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        int error;

        ZFS_TEARDOWN_INACTIVE_ENTER_READ(zfsvfs);
        if (zp->z_sa_hdl == NULL) {
                /*
                 * The fs has been unmounted, or we did a
                 * suspend/resume and this file no longer exists.
                 */
                ZFS_TEARDOWN_INACTIVE_EXIT_READ(zfsvfs);
                vrecycle(vp);
                return;
        }

        if (zp->z_unlinked) {
                /*
                 * Fast path to recycle a vnode of a removed file.
                 */
                ZFS_TEARDOWN_INACTIVE_EXIT_READ(zfsvfs);
                vrecycle(vp);
                return;
        }

        if (zp->z_atime_dirty && zp->z_unlinked == 0) {
                dmu_tx_t *tx = dmu_tx_create(zfsvfs->z_os);

                dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
                zfs_sa_upgrade_txholds(tx, zp);
                error = dmu_tx_assign(tx, TXG_WAIT);
                if (error) {
                        dmu_tx_abort(tx);
                } else {
                        (void) sa_update(zp->z_sa_hdl, SA_ZPL_ATIME(zfsvfs),
                            (void *)&zp->z_atime, sizeof (zp->z_atime), tx);
                        zp->z_atime_dirty = 0;
                        dmu_tx_commit(tx);
                }
        }
        ZFS_TEARDOWN_INACTIVE_EXIT_READ(zfsvfs);
}


_Static_assert(sizeof (struct zfid_short) <= sizeof (struct fid),
        "struct zfid_short bigger than struct fid");
_Static_assert(sizeof (struct zfid_long) <= sizeof (struct fid),
        "struct zfid_long bigger than struct fid");

static int
zfs_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
{
        (void) ct;
        znode_t         *zp = VTOZ(vp);
        zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
        uint32_t        gen;
        uint64_t        gen64;
        uint64_t        object = zp->z_id;
        zfid_short_t    *zfid;
        int             size, i, error;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_GEN(zfsvfs),
            &gen64, sizeof (uint64_t))) != 0) {
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }

        gen = (uint32_t)gen64;

        size = (zfsvfs->z_parent != zfsvfs) ? LONG_FID_LEN : SHORT_FID_LEN;
        fidp->fid_len = size;

        zfid = (zfid_short_t *)fidp;

        zfid->zf_len = size;

        for (i = 0; i < sizeof (zfid->zf_object); i++)
                zfid->zf_object[i] = (uint8_t)(object >> (8 * i));

        /* Must have a non-zero generation number to distinguish from .zfs */
        if (gen == 0)
                gen = 1;
        for (i = 0; i < sizeof (zfid->zf_gen); i++)
                zfid->zf_gen[i] = (uint8_t)(gen >> (8 * i));

        if (size == LONG_FID_LEN) {
                uint64_t        objsetid = dmu_objset_id(zfsvfs->z_os);
                zfid_long_t     *zlfid;

                zlfid = (zfid_long_t *)fidp;

                for (i = 0; i < sizeof (zlfid->zf_setid); i++)
                        zlfid->zf_setid[i] = (uint8_t)(objsetid >> (8 * i));

                /* XXX - this should be the generation number for the objset */
                for (i = 0; i < sizeof (zlfid->zf_setgen); i++)
                        zlfid->zf_setgen[i] = 0;
        }

        zfs_exit(zfsvfs, FTAG);
        return (0);
}

static int
zfs_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr,
    caller_context_t *ct)
{
        znode_t *zp;
        zfsvfs_t *zfsvfs;
        int error;

        switch (cmd) {
        case _PC_LINK_MAX:
                *valp = MIN(LONG_MAX, ZFS_LINK_MAX);
                return (0);

        case _PC_FILESIZEBITS:
                *valp = 64;
                return (0);
        case _PC_MIN_HOLE_SIZE:
                *valp = (int)SPA_MINBLOCKSIZE;
                return (0);
        case _PC_ACL_EXTENDED:
#if 0           /* POSIX ACLs are not implemented for ZFS on FreeBSD yet. */
                zp = VTOZ(vp);
                zfsvfs = zp->z_zfsvfs;
                if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                        return (error);
                *valp = zfsvfs->z_acl_type == ZFSACLTYPE_POSIX ? 1 : 0;
                zfs_exit(zfsvfs, FTAG);
#else
                *valp = 0;
#endif
                return (0);

        case _PC_ACL_NFS4:
                zp = VTOZ(vp);
                zfsvfs = zp->z_zfsvfs;
                if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                        return (error);
                *valp = zfsvfs->z_acl_type == ZFS_ACLTYPE_NFSV4 ? 1 : 0;
                zfs_exit(zfsvfs, FTAG);
                return (0);

        case _PC_ACL_PATH_MAX:
                *valp = ACL_MAX_ENTRIES;
                return (0);

        default:
                return (EOPNOTSUPP);
        }
}

static int
zfs_getpages(struct vnode *vp, vm_page_t *ma, int count, int *rbehind,
    int *rahead)
{
        znode_t *zp = VTOZ(vp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        zfs_locked_range_t *lr;
        vm_object_t object;
        off_t start, end, obj_size;
        uint_t blksz;
        int pgsin_b, pgsin_a;
        int error;

        if (zfs_enter_verify_zp(zfsvfs, zp, FTAG) != 0)
                return (zfs_vm_pagerret_error);

        start = IDX_TO_OFF(ma[0]->pindex);
        end = IDX_TO_OFF(ma[count - 1]->pindex + 1);

        /*
         * Lock a range covering all required and optional pages.
         * Note that we need to handle the case of the block size growing.
         */
        for (;;) {
                blksz = zp->z_blksz;
                lr = zfs_rangelock_tryenter(&zp->z_rangelock,
                    rounddown(start, blksz),
                    roundup(end, blksz) - rounddown(start, blksz), RL_READER);
                if (lr == NULL) {
                        if (rahead != NULL) {
                                *rahead = 0;
                                rahead = NULL;
                        }
                        if (rbehind != NULL) {
                                *rbehind = 0;
                                rbehind = NULL;
                        }
                        break;
                }
                if (blksz == zp->z_blksz)
                        break;
                zfs_rangelock_exit(lr);
        }

        object = ma[0]->object;
        zfs_vmobject_wlock(object);
        obj_size = object->un_pager.vnp.vnp_size;
        zfs_vmobject_wunlock(object);
        if (IDX_TO_OFF(ma[count - 1]->pindex) >= obj_size) {
                if (lr != NULL)
                        zfs_rangelock_exit(lr);
                zfs_exit(zfsvfs, FTAG);
                return (zfs_vm_pagerret_bad);
        }

        pgsin_b = 0;
        if (rbehind != NULL) {
                pgsin_b = OFF_TO_IDX(start - rounddown(start, blksz));
                pgsin_b = MIN(*rbehind, pgsin_b);
        }

        pgsin_a = 0;
        if (rahead != NULL) {
                pgsin_a = OFF_TO_IDX(roundup(end, blksz) - end);
                if (end + IDX_TO_OFF(pgsin_a) >= obj_size)
                        pgsin_a = OFF_TO_IDX(round_page(obj_size) - end);
                pgsin_a = MIN(*rahead, pgsin_a);
        }

        /*
         * NB: we need to pass the exact byte size of the data that we expect
         * to read after accounting for the file size.  This is required because
         * ZFS will panic if we request DMU to read beyond the end of the last
         * allocated block.
         */
        error = dmu_read_pages(zfsvfs->z_os, zp->z_id, ma, count, &pgsin_b,
            &pgsin_a, MIN(end, obj_size) - (end - PAGE_SIZE));

        if (lr != NULL)
                zfs_rangelock_exit(lr);
        ZFS_ACCESSTIME_STAMP(zfsvfs, zp);

        dataset_kstats_update_read_kstats(&zfsvfs->z_kstat, count*PAGE_SIZE);

        zfs_exit(zfsvfs, FTAG);

        if (error != 0)
                return (zfs_vm_pagerret_error);

        VM_CNT_INC(v_vnodein);
        VM_CNT_ADD(v_vnodepgsin, count + pgsin_b + pgsin_a);
        if (rbehind != NULL)
                *rbehind = pgsin_b;
        if (rahead != NULL)
                *rahead = pgsin_a;
        return (zfs_vm_pagerret_ok);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_getpages_args {
        struct vnode *a_vp;
        vm_page_t *a_m;
        int a_count;
        int *a_rbehind;
        int *a_rahead;
};
#endif

static int
zfs_freebsd_getpages(struct vop_getpages_args *ap)
{

        return (zfs_getpages(ap->a_vp, ap->a_m, ap->a_count, ap->a_rbehind,
            ap->a_rahead));
}

static int
zfs_putpages(struct vnode *vp, vm_page_t *ma, size_t len, int flags,
    int *rtvals)
{
        znode_t         *zp = VTOZ(vp);
        zfsvfs_t        *zfsvfs = zp->z_zfsvfs;
        zfs_locked_range_t              *lr;
        dmu_tx_t        *tx;
        struct sf_buf   *sf;
        vm_object_t     object;
        vm_page_t       m;
        caddr_t         va;
        size_t          tocopy;
        size_t          lo_len;
        vm_ooffset_t    lo_off;
        vm_ooffset_t    off;
        uint_t          blksz;
        int             ncount;
        int             pcount;
        int             err;
        int             i;

        object = vp->v_object;
        KASSERT(ma[0]->object == object, ("mismatching object"));
        KASSERT(len > 0 && (len & PAGE_MASK) == 0, ("unexpected length"));

        pcount = btoc(len);
        ncount = pcount;
        for (i = 0; i < pcount; i++)
                rtvals[i] = zfs_vm_pagerret_error;

        if (zfs_enter_verify_zp(zfsvfs, zp, FTAG) != 0)
                return (zfs_vm_pagerret_error);

        off = IDX_TO_OFF(ma[0]->pindex);
        blksz = zp->z_blksz;
        lo_off = rounddown(off, blksz);
        lo_len = roundup(len + (off - lo_off), blksz);
        lr = zfs_rangelock_enter(&zp->z_rangelock, lo_off, lo_len, RL_WRITER);

        zfs_vmobject_wlock(object);
        if (len + off > object->un_pager.vnp.vnp_size) {
                if (object->un_pager.vnp.vnp_size > off) {
                        int pgoff;

                        len = object->un_pager.vnp.vnp_size - off;
                        ncount = btoc(len);
                        if ((pgoff = (int)len & PAGE_MASK) != 0) {
                                /*
                                 * If the object is locked and the following
                                 * conditions hold, then the page's dirty
                                 * field cannot be concurrently changed by a
                                 * pmap operation.
                                 */
                                m = ma[ncount - 1];
                                vm_page_assert_sbusied(m);
                                KASSERT(!pmap_page_is_write_mapped(m),
                                    ("zfs_putpages: page %p is not read-only",
                                    m));
                                vm_page_clear_dirty(m, pgoff, PAGE_SIZE -
                                    pgoff);
                        }
                } else {
                        len = 0;
                        ncount = 0;
                }
                if (ncount < pcount) {
                        for (i = ncount; i < pcount; i++) {
                                rtvals[i] = zfs_vm_pagerret_bad;
                        }
                }
        }
        zfs_vmobject_wunlock(object);

        if (ncount == 0)
                goto out;

        if (zfs_id_overblockquota(zfsvfs, DMU_USERUSED_OBJECT, zp->z_uid) ||
            zfs_id_overblockquota(zfsvfs, DMU_GROUPUSED_OBJECT, zp->z_gid) ||
            (zp->z_projid != ZFS_DEFAULT_PROJID &&
            zfs_id_overblockquota(zfsvfs, DMU_PROJECTUSED_OBJECT,
            zp->z_projid))) {
                goto out;
        }

        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_write(tx, zp->z_id, off, len);

        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
        zfs_sa_upgrade_txholds(tx, zp);
        err = dmu_tx_assign(tx, TXG_WAIT);
        if (err != 0) {
                dmu_tx_abort(tx);
                goto out;
        }

        if (zp->z_blksz < PAGE_SIZE) {
                for (i = 0; len > 0; off += tocopy, len -= tocopy, i++) {
                        tocopy = len > PAGE_SIZE ? PAGE_SIZE : len;
                        va = zfs_map_page(ma[i], &sf);
                        dmu_write(zfsvfs->z_os, zp->z_id, off, tocopy, va, tx);
                        zfs_unmap_page(sf);
                }
        } else {
                err = dmu_write_pages(zfsvfs->z_os, zp->z_id, off, len, ma, tx);
        }

        if (err == 0) {
                uint64_t mtime[2], ctime[2];
                sa_bulk_attr_t bulk[3];
                int count = 0;

                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
                    &mtime, 16);
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
                    &ctime, 16);
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
                    &zp->z_pflags, 8);
                zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime);
                err = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
                ASSERT0(err);
                /*
                 * XXX we should be passing a callback to undirty
                 * but that would make the locking messier
                 */
                zfs_log_write(zfsvfs->z_log, tx, TX_WRITE, zp, off,
                    len, 0, NULL, NULL);

                zfs_vmobject_wlock(object);
                for (i = 0; i < ncount; i++) {
                        rtvals[i] = zfs_vm_pagerret_ok;
                        vm_page_undirty(ma[i]);
                }
                zfs_vmobject_wunlock(object);
                VM_CNT_INC(v_vnodeout);
                VM_CNT_ADD(v_vnodepgsout, ncount);
        }
        dmu_tx_commit(tx);

out:
        zfs_rangelock_exit(lr);
        if ((flags & (zfs_vm_pagerput_sync | zfs_vm_pagerput_inval)) != 0 ||
            zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS)
                zil_commit(zfsvfs->z_log, zp->z_id);

        dataset_kstats_update_write_kstats(&zfsvfs->z_kstat, len);

        zfs_exit(zfsvfs, FTAG);
        return (rtvals[0]);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_putpages_args {
        struct vnode *a_vp;
        vm_page_t *a_m;
        int a_count;
        int a_sync;
        int *a_rtvals;
};
#endif

static int
zfs_freebsd_putpages(struct vop_putpages_args *ap)
{

        return (zfs_putpages(ap->a_vp, ap->a_m, ap->a_count, ap->a_sync,
            ap->a_rtvals));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_bmap_args {
        struct vnode *a_vp;
        daddr_t  a_bn;
        struct bufobj **a_bop;
        daddr_t *a_bnp;
        int *a_runp;
        int *a_runb;
};
#endif

static int
zfs_freebsd_bmap(struct vop_bmap_args *ap)
{

        if (ap->a_bop != NULL)
                *ap->a_bop = &ap->a_vp->v_bufobj;
        if (ap->a_bnp != NULL)
                *ap->a_bnp = ap->a_bn;
        if (ap->a_runp != NULL)
                *ap->a_runp = 0;
        if (ap->a_runb != NULL)
                *ap->a_runb = 0;

        return (0);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_open_args {
        struct vnode *a_vp;
        int a_mode;
        struct ucred *a_cred;
        struct thread *a_td;
};
#endif

static int
zfs_freebsd_open(struct vop_open_args *ap)
{
        vnode_t *vp = ap->a_vp;
        znode_t *zp = VTOZ(vp);
        int error;

        error = zfs_open(&vp, ap->a_mode, ap->a_cred);
        if (error == 0)
                vnode_create_vobject(vp, zp->z_size, ap->a_td);
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_close_args {
        struct vnode *a_vp;
        int  a_fflag;
        struct ucred *a_cred;
        struct thread *a_td;
};
#endif

static int
zfs_freebsd_close(struct vop_close_args *ap)
{

        return (zfs_close(ap->a_vp, ap->a_fflag, 1, 0, ap->a_cred));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_ioctl_args {
        struct vnode *a_vp;
        ulong_t a_command;
        caddr_t a_data;
        int a_fflag;
        struct ucred *cred;
        struct thread *td;
};
#endif

static int
zfs_freebsd_ioctl(struct vop_ioctl_args *ap)
{

        return (zfs_ioctl(ap->a_vp, ap->a_command, (intptr_t)ap->a_data,
            ap->a_fflag, ap->a_cred, NULL));
}

static int
ioflags(int ioflags)
{
        int flags = 0;

        if (ioflags & IO_APPEND)
                flags |= O_APPEND;
        if (ioflags & IO_NDELAY)
                flags |= O_NONBLOCK;
        if (ioflags & IO_SYNC)
                flags |= O_SYNC;

        return (flags);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_read_args {
        struct vnode *a_vp;
        struct uio *a_uio;
        int a_ioflag;
        struct ucred *a_cred;
};
#endif

static int
zfs_freebsd_read(struct vop_read_args *ap)
{
        zfs_uio_t uio;
        zfs_uio_init(&uio, ap->a_uio);
        return (zfs_read(VTOZ(ap->a_vp), &uio, ioflags(ap->a_ioflag),
            ap->a_cred));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_write_args {
        struct vnode *a_vp;
        struct uio *a_uio;
        int a_ioflag;
        struct ucred *a_cred;
};
#endif

static int
zfs_freebsd_write(struct vop_write_args *ap)
{
        zfs_uio_t uio;
        zfs_uio_init(&uio, ap->a_uio);
        return (zfs_write(VTOZ(ap->a_vp), &uio, ioflags(ap->a_ioflag),
            ap->a_cred));
}

#if __FreeBSD_version >= 1300102
/*
 * VOP_FPLOOKUP_VEXEC routines are subject to special circumstances, see
 * the comment above cache_fplookup for details.
 */
static int
zfs_freebsd_fplookup_vexec(struct vop_fplookup_vexec_args *v)
{
        vnode_t *vp;
        znode_t *zp;
        uint64_t pflags;

        vp = v->a_vp;
        zp = VTOZ_SMR(vp);
        if (__predict_false(zp == NULL))
                return (EAGAIN);
        pflags = atomic_load_64(&zp->z_pflags);
        if (pflags & ZFS_AV_QUARANTINED)
                return (EAGAIN);
        if (pflags & ZFS_XATTR)
                return (EAGAIN);
        if ((pflags & ZFS_NO_EXECS_DENIED) == 0)
                return (EAGAIN);
        return (0);
}
#endif

#if __FreeBSD_version >= 1300139
static int
zfs_freebsd_fplookup_symlink(struct vop_fplookup_symlink_args *v)
{
        vnode_t *vp;
        znode_t *zp;
        char *target;

        vp = v->a_vp;
        zp = VTOZ_SMR(vp);
        if (__predict_false(zp == NULL)) {
                return (EAGAIN);
        }

        target = atomic_load_consume_ptr(&zp->z_cached_symlink);
        if (target == NULL) {
                return (EAGAIN);
        }
        return (cache_symlink_resolve(v->a_fpl, target, strlen(target)));
}
#endif

#ifndef _SYS_SYSPROTO_H_
struct vop_access_args {
        struct vnode *a_vp;
        accmode_t a_accmode;
        struct ucred *a_cred;
        struct thread *a_td;
};
#endif

static int
zfs_freebsd_access(struct vop_access_args *ap)
{
        vnode_t *vp = ap->a_vp;
        znode_t *zp = VTOZ(vp);
        accmode_t accmode;
        int error = 0;


        if (ap->a_accmode == VEXEC) {
                if (zfs_fastaccesschk_execute(zp, ap->a_cred) == 0)
                        return (0);
        }

        /*
         * ZFS itself only knowns about VREAD, VWRITE, VEXEC and VAPPEND,
         */
        accmode = ap->a_accmode & (VREAD|VWRITE|VEXEC|VAPPEND);
        if (accmode != 0)
                error = zfs_access(zp, accmode, 0, ap->a_cred);

        /*
         * VADMIN has to be handled by vaccess().
         */
        if (error == 0) {
                accmode = ap->a_accmode & ~(VREAD|VWRITE|VEXEC|VAPPEND);
                if (accmode != 0) {
#if __FreeBSD_version >= 1300105
                        error = vaccess(vp->v_type, zp->z_mode, zp->z_uid,
                            zp->z_gid, accmode, ap->a_cred);
#else
                        error = vaccess(vp->v_type, zp->z_mode, zp->z_uid,
                            zp->z_gid, accmode, ap->a_cred, NULL);
#endif
                }
        }

        /*
         * For VEXEC, ensure that at least one execute bit is set for
         * non-directories.
         */
        if (error == 0 && (ap->a_accmode & VEXEC) != 0 && vp->v_type != VDIR &&
            (zp->z_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0) {
                error = EACCES;
        }

        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_lookup_args {
        struct vnode *a_dvp;
        struct vnode **a_vpp;
        struct componentname *a_cnp;
};
#endif

static int
zfs_freebsd_lookup(struct vop_lookup_args *ap, boolean_t cached)
{
        struct componentname *cnp = ap->a_cnp;
        char nm[NAME_MAX + 1];

        ASSERT3U(cnp->cn_namelen, <, sizeof (nm));
        strlcpy(nm, cnp->cn_nameptr, MIN(cnp->cn_namelen + 1, sizeof (nm)));

        return (zfs_lookup(ap->a_dvp, nm, ap->a_vpp, cnp, cnp->cn_nameiop,
            cnp->cn_cred, 0, cached));
}

static int
zfs_freebsd_cachedlookup(struct vop_cachedlookup_args *ap)
{

        return (zfs_freebsd_lookup((struct vop_lookup_args *)ap, B_TRUE));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_lookup_args {
        struct vnode *a_dvp;
        struct vnode **a_vpp;
        struct componentname *a_cnp;
};
#endif

static int
zfs_cache_lookup(struct vop_lookup_args *ap)
{
        zfsvfs_t *zfsvfs;

        zfsvfs = ap->a_dvp->v_mount->mnt_data;
        if (zfsvfs->z_use_namecache)
                return (vfs_cache_lookup(ap));
        else
                return (zfs_freebsd_lookup(ap, B_FALSE));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_create_args {
        struct vnode *a_dvp;
        struct vnode **a_vpp;
        struct componentname *a_cnp;
        struct vattr *a_vap;
};
#endif

static int
zfs_freebsd_create(struct vop_create_args *ap)
{
        zfsvfs_t *zfsvfs;
        struct componentname *cnp = ap->a_cnp;
        vattr_t *vap = ap->a_vap;
        znode_t *zp = NULL;
        int rc, mode;

#if __FreeBSD_version < 1400068
        ASSERT(cnp->cn_flags & SAVENAME);
#endif

        vattr_init_mask(vap);
        mode = vap->va_mode & ALLPERMS;
        zfsvfs = ap->a_dvp->v_mount->mnt_data;
        *ap->a_vpp = NULL;

        rc = zfs_create(VTOZ(ap->a_dvp), cnp->cn_nameptr, vap, 0, mode,
            &zp, cnp->cn_cred, 0 /* flag */, NULL /* vsecattr */, NULL);
        if (rc == 0)
                *ap->a_vpp = ZTOV(zp);
        if (zfsvfs->z_use_namecache &&
            rc == 0 && (cnp->cn_flags & MAKEENTRY) != 0)
                cache_enter(ap->a_dvp, *ap->a_vpp, cnp);

        return (rc);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_remove_args {
        struct vnode *a_dvp;
        struct vnode *a_vp;
        struct componentname *a_cnp;
};
#endif

static int
zfs_freebsd_remove(struct vop_remove_args *ap)
{

#if __FreeBSD_version < 1400068
        ASSERT(ap->a_cnp->cn_flags & SAVENAME);
#endif

        return (zfs_remove_(ap->a_dvp, ap->a_vp, ap->a_cnp->cn_nameptr,
            ap->a_cnp->cn_cred));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_mkdir_args {
        struct vnode *a_dvp;
        struct vnode **a_vpp;
        struct componentname *a_cnp;
        struct vattr *a_vap;
};
#endif

static int
zfs_freebsd_mkdir(struct vop_mkdir_args *ap)
{
        vattr_t *vap = ap->a_vap;
        znode_t *zp = NULL;
        int rc;

#if __FreeBSD_version < 1400068
        ASSERT(ap->a_cnp->cn_flags & SAVENAME);
#endif

        vattr_init_mask(vap);
        *ap->a_vpp = NULL;

        rc = zfs_mkdir(VTOZ(ap->a_dvp), ap->a_cnp->cn_nameptr, vap, &zp,
            ap->a_cnp->cn_cred, 0, NULL, NULL);

        if (rc == 0)
                *ap->a_vpp = ZTOV(zp);
        return (rc);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_rmdir_args {
        struct vnode *a_dvp;
        struct vnode *a_vp;
        struct componentname *a_cnp;
};
#endif

static int
zfs_freebsd_rmdir(struct vop_rmdir_args *ap)
{
        struct componentname *cnp = ap->a_cnp;

#if __FreeBSD_version < 1400068
        ASSERT(cnp->cn_flags & SAVENAME);
#endif

        return (zfs_rmdir_(ap->a_dvp, ap->a_vp, cnp->cn_nameptr, cnp->cn_cred));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_readdir_args {
        struct vnode *a_vp;
        struct uio *a_uio;
        struct ucred *a_cred;
        int *a_eofflag;
        int *a_ncookies;
        cookie_t **a_cookies;
};
#endif

static int
zfs_freebsd_readdir(struct vop_readdir_args *ap)
{
        zfs_uio_t uio;
        zfs_uio_init(&uio, ap->a_uio);
        return (zfs_readdir(ap->a_vp, &uio, ap->a_cred, ap->a_eofflag,
            ap->a_ncookies, ap->a_cookies));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_fsync_args {
        struct vnode *a_vp;
        int a_waitfor;
        struct thread *a_td;
};
#endif

static int
zfs_freebsd_fsync(struct vop_fsync_args *ap)
{

        vop_stdfsync(ap);
        return (zfs_fsync(VTOZ(ap->a_vp), 0, ap->a_td->td_ucred));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_getattr_args {
        struct vnode *a_vp;
        struct vattr *a_vap;
        struct ucred *a_cred;
};
#endif

static int
zfs_freebsd_getattr(struct vop_getattr_args *ap)
{
        vattr_t *vap = ap->a_vap;
        xvattr_t xvap;
        ulong_t fflags = 0;
        int error;

        xva_init(&xvap);
        xvap.xva_vattr = *vap;
        xvap.xva_vattr.va_mask |= AT_XVATTR;

        /* Convert chflags into ZFS-type flags. */
        /* XXX: what about SF_SETTABLE?. */
        XVA_SET_REQ(&xvap, XAT_IMMUTABLE);
        XVA_SET_REQ(&xvap, XAT_APPENDONLY);
        XVA_SET_REQ(&xvap, XAT_NOUNLINK);
        XVA_SET_REQ(&xvap, XAT_NODUMP);
        XVA_SET_REQ(&xvap, XAT_READONLY);
        XVA_SET_REQ(&xvap, XAT_ARCHIVE);
        XVA_SET_REQ(&xvap, XAT_SYSTEM);
        XVA_SET_REQ(&xvap, XAT_HIDDEN);
        XVA_SET_REQ(&xvap, XAT_REPARSE);
        XVA_SET_REQ(&xvap, XAT_OFFLINE);
        XVA_SET_REQ(&xvap, XAT_SPARSE);

        error = zfs_getattr(ap->a_vp, (vattr_t *)&xvap, 0, ap->a_cred);
        if (error != 0)
                return (error);

        /* Convert ZFS xattr into chflags. */
#define FLAG_CHECK(fflag, xflag, xfield)        do {                    \
        if (XVA_ISSET_RTN(&xvap, (xflag)) && (xfield) != 0)             \
                fflags |= (fflag);                                      \
} while (0)
        FLAG_CHECK(SF_IMMUTABLE, XAT_IMMUTABLE,
            xvap.xva_xoptattrs.xoa_immutable);
        FLAG_CHECK(SF_APPEND, XAT_APPENDONLY,
            xvap.xva_xoptattrs.xoa_appendonly);
        FLAG_CHECK(SF_NOUNLINK, XAT_NOUNLINK,
            xvap.xva_xoptattrs.xoa_nounlink);
        FLAG_CHECK(UF_ARCHIVE, XAT_ARCHIVE,
            xvap.xva_xoptattrs.xoa_archive);
        FLAG_CHECK(UF_NODUMP, XAT_NODUMP,
            xvap.xva_xoptattrs.xoa_nodump);
        FLAG_CHECK(UF_READONLY, XAT_READONLY,
            xvap.xva_xoptattrs.xoa_readonly);
        FLAG_CHECK(UF_SYSTEM, XAT_SYSTEM,
            xvap.xva_xoptattrs.xoa_system);
        FLAG_CHECK(UF_HIDDEN, XAT_HIDDEN,
            xvap.xva_xoptattrs.xoa_hidden);
        FLAG_CHECK(UF_REPARSE, XAT_REPARSE,
            xvap.xva_xoptattrs.xoa_reparse);
        FLAG_CHECK(UF_OFFLINE, XAT_OFFLINE,
            xvap.xva_xoptattrs.xoa_offline);
        FLAG_CHECK(UF_SPARSE, XAT_SPARSE,
            xvap.xva_xoptattrs.xoa_sparse);

#undef  FLAG_CHECK
        *vap = xvap.xva_vattr;
        vap->va_flags = fflags;
        return (0);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_setattr_args {
        struct vnode *a_vp;
        struct vattr *a_vap;
        struct ucred *a_cred;
};
#endif

static int
zfs_freebsd_setattr(struct vop_setattr_args *ap)
{
        vnode_t *vp = ap->a_vp;
        vattr_t *vap = ap->a_vap;
        cred_t *cred = ap->a_cred;
        xvattr_t xvap;
        ulong_t fflags;
        uint64_t zflags;

        vattr_init_mask(vap);
        vap->va_mask &= ~AT_NOSET;

        xva_init(&xvap);
        xvap.xva_vattr = *vap;

        zflags = VTOZ(vp)->z_pflags;

        if (vap->va_flags != VNOVAL) {
                zfsvfs_t *zfsvfs = VTOZ(vp)->z_zfsvfs;
                int error;

                if (zfsvfs->z_use_fuids == B_FALSE)
                        return (EOPNOTSUPP);

                fflags = vap->va_flags;
                /*
                 * XXX KDM
                 * We need to figure out whether it makes sense to allow
                 * UF_REPARSE through, since we don't really have other
                 * facilities to handle reparse points and zfs_setattr()
                 * doesn't currently allow setting that attribute anyway.
                 */
                if ((fflags & ~(SF_IMMUTABLE|SF_APPEND|SF_NOUNLINK|UF_ARCHIVE|
                    UF_NODUMP|UF_SYSTEM|UF_HIDDEN|UF_READONLY|UF_REPARSE|
                    UF_OFFLINE|UF_SPARSE)) != 0)
                        return (EOPNOTSUPP);
                /*
                 * Unprivileged processes are not permitted to unset system
                 * flags, or modify flags if any system flags are set.
                 * Privileged non-jail processes may not modify system flags
                 * if securelevel > 0 and any existing system flags are set.
                 * Privileged jail processes behave like privileged non-jail
                 * processes if the PR_ALLOW_CHFLAGS permission bit is set;
                 * otherwise, they behave like unprivileged processes.
                 */
                if (secpolicy_fs_owner(vp->v_mount, cred) == 0 ||
                    spl_priv_check_cred(cred, PRIV_VFS_SYSFLAGS) == 0) {
                        if (zflags &
                            (ZFS_IMMUTABLE | ZFS_APPENDONLY | ZFS_NOUNLINK)) {
                                error = securelevel_gt(cred, 0);
                                if (error != 0)
                                        return (error);
                        }
                } else {
                        /*
                         * Callers may only modify the file flags on
                         * objects they have VADMIN rights for.
                         */
                        if ((error = VOP_ACCESS(vp, VADMIN, cred,
                            curthread)) != 0)
                                return (error);
                        if (zflags &
                            (ZFS_IMMUTABLE | ZFS_APPENDONLY |
                            ZFS_NOUNLINK)) {
                                return (EPERM);
                        }
                        if (fflags &
                            (SF_IMMUTABLE | SF_APPEND | SF_NOUNLINK)) {
                                return (EPERM);
                        }
                }

#define FLAG_CHANGE(fflag, zflag, xflag, xfield)        do {            \
        if (((fflags & (fflag)) && !(zflags & (zflag))) ||              \
            ((zflags & (zflag)) && !(fflags & (fflag)))) {              \
                XVA_SET_REQ(&xvap, (xflag));                            \
                (xfield) = ((fflags & (fflag)) != 0);                   \
        }                                                               \
} while (0)
                /* Convert chflags into ZFS-type flags. */
                /* XXX: what about SF_SETTABLE?. */
                FLAG_CHANGE(SF_IMMUTABLE, ZFS_IMMUTABLE, XAT_IMMUTABLE,
                    xvap.xva_xoptattrs.xoa_immutable);
                FLAG_CHANGE(SF_APPEND, ZFS_APPENDONLY, XAT_APPENDONLY,
                    xvap.xva_xoptattrs.xoa_appendonly);
                FLAG_CHANGE(SF_NOUNLINK, ZFS_NOUNLINK, XAT_NOUNLINK,
                    xvap.xva_xoptattrs.xoa_nounlink);
                FLAG_CHANGE(UF_ARCHIVE, ZFS_ARCHIVE, XAT_ARCHIVE,
                    xvap.xva_xoptattrs.xoa_archive);
                FLAG_CHANGE(UF_NODUMP, ZFS_NODUMP, XAT_NODUMP,
                    xvap.xva_xoptattrs.xoa_nodump);
                FLAG_CHANGE(UF_READONLY, ZFS_READONLY, XAT_READONLY,
                    xvap.xva_xoptattrs.xoa_readonly);
                FLAG_CHANGE(UF_SYSTEM, ZFS_SYSTEM, XAT_SYSTEM,
                    xvap.xva_xoptattrs.xoa_system);
                FLAG_CHANGE(UF_HIDDEN, ZFS_HIDDEN, XAT_HIDDEN,
                    xvap.xva_xoptattrs.xoa_hidden);
                FLAG_CHANGE(UF_REPARSE, ZFS_REPARSE, XAT_REPARSE,
                    xvap.xva_xoptattrs.xoa_reparse);
                FLAG_CHANGE(UF_OFFLINE, ZFS_OFFLINE, XAT_OFFLINE,
                    xvap.xva_xoptattrs.xoa_offline);
                FLAG_CHANGE(UF_SPARSE, ZFS_SPARSE, XAT_SPARSE,
                    xvap.xva_xoptattrs.xoa_sparse);
#undef  FLAG_CHANGE
        }
        if (vap->va_birthtime.tv_sec != VNOVAL) {
                xvap.xva_vattr.va_mask |= AT_XVATTR;
                XVA_SET_REQ(&xvap, XAT_CREATETIME);
        }
        return (zfs_setattr(VTOZ(vp), (vattr_t *)&xvap, 0, cred, NULL));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_rename_args {
        struct vnode *a_fdvp;
        struct vnode *a_fvp;
        struct componentname *a_fcnp;
        struct vnode *a_tdvp;
        struct vnode *a_tvp;
        struct componentname *a_tcnp;
};
#endif

static int
zfs_freebsd_rename(struct vop_rename_args *ap)
{
        vnode_t *fdvp = ap->a_fdvp;
        vnode_t *fvp = ap->a_fvp;
        vnode_t *tdvp = ap->a_tdvp;
        vnode_t *tvp = ap->a_tvp;
        int error;

#if __FreeBSD_version < 1400068
        ASSERT(ap->a_fcnp->cn_flags & (SAVENAME|SAVESTART));
        ASSERT(ap->a_tcnp->cn_flags & (SAVENAME|SAVESTART));
#endif

        error = zfs_do_rename(fdvp, &fvp, ap->a_fcnp, tdvp, &tvp,
            ap->a_tcnp, ap->a_fcnp->cn_cred);

        vrele(fdvp);
        vrele(fvp);
        vrele(tdvp);
        if (tvp != NULL)
                vrele(tvp);

        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_symlink_args {
        struct vnode *a_dvp;
        struct vnode **a_vpp;
        struct componentname *a_cnp;
        struct vattr *a_vap;
        char *a_target;
};
#endif

static int
zfs_freebsd_symlink(struct vop_symlink_args *ap)
{
        struct componentname *cnp = ap->a_cnp;
        vattr_t *vap = ap->a_vap;
        znode_t *zp = NULL;
#if __FreeBSD_version >= 1300139
        char *symlink;
        size_t symlink_len;
#endif
        int rc;

#if __FreeBSD_version < 1400068
        ASSERT(cnp->cn_flags & SAVENAME);
#endif

        vap->va_type = VLNK;    /* FreeBSD: Syscall only sets va_mode. */
        vattr_init_mask(vap);
        *ap->a_vpp = NULL;

        rc = zfs_symlink(VTOZ(ap->a_dvp), cnp->cn_nameptr, vap,
            ap->a_target, &zp, cnp->cn_cred, 0 /* flags */, NULL);
        if (rc == 0) {
                *ap->a_vpp = ZTOV(zp);
                ASSERT_VOP_ELOCKED(ZTOV(zp), __func__);
#if __FreeBSD_version >= 1300139
                MPASS(zp->z_cached_symlink == NULL);
                symlink_len = strlen(ap->a_target);
                symlink = cache_symlink_alloc(symlink_len + 1, M_WAITOK);
                if (symlink != NULL) {
                        memcpy(symlink, ap->a_target, symlink_len);
                        symlink[symlink_len] = '\0';
                        atomic_store_rel_ptr((uintptr_t *)&zp->z_cached_symlink,
                            (uintptr_t)symlink);
                }
#endif
        }
        return (rc);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_readlink_args {
        struct vnode *a_vp;
        struct uio *a_uio;
        struct ucred *a_cred;
};
#endif

static int
zfs_freebsd_readlink(struct vop_readlink_args *ap)
{
        zfs_uio_t uio;
        int error;
#if __FreeBSD_version >= 1300139
        znode_t *zp = VTOZ(ap->a_vp);
        char *symlink, *base;
        size_t symlink_len;
        bool trycache;
#endif

        zfs_uio_init(&uio, ap->a_uio);
#if __FreeBSD_version >= 1300139
        trycache = false;
        if (zfs_uio_segflg(&uio) == UIO_SYSSPACE &&
            zfs_uio_iovcnt(&uio) == 1) {
                base = zfs_uio_iovbase(&uio, 0);
                symlink_len = zfs_uio_iovlen(&uio, 0);
                trycache = true;
        }
#endif
        error = zfs_readlink(ap->a_vp, &uio, ap->a_cred, NULL);
#if __FreeBSD_version >= 1300139
        if (atomic_load_ptr(&zp->z_cached_symlink) != NULL ||
            error != 0 || !trycache) {
                return (error);
        }
        symlink_len -= zfs_uio_resid(&uio);
        symlink = cache_symlink_alloc(symlink_len + 1, M_WAITOK);
        if (symlink != NULL) {
                memcpy(symlink, base, symlink_len);
                symlink[symlink_len] = '\0';
                if (!atomic_cmpset_rel_ptr((uintptr_t *)&zp->z_cached_symlink,
                    (uintptr_t)NULL, (uintptr_t)symlink)) {
                        cache_symlink_free(symlink, symlink_len + 1);
                }
        }
#endif
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_link_args {
        struct vnode *a_tdvp;
        struct vnode *a_vp;
        struct componentname *a_cnp;
};
#endif

static int
zfs_freebsd_link(struct vop_link_args *ap)
{
        struct componentname *cnp = ap->a_cnp;
        vnode_t *vp = ap->a_vp;
        vnode_t *tdvp = ap->a_tdvp;

        if (tdvp->v_mount != vp->v_mount)
                return (EXDEV);

#if __FreeBSD_version < 1400068
        ASSERT(cnp->cn_flags & SAVENAME);
#endif

        return (zfs_link(VTOZ(tdvp), VTOZ(vp),
            cnp->cn_nameptr, cnp->cn_cred, 0));
}

#ifndef _SYS_SYSPROTO_H_
struct vop_inactive_args {
        struct vnode *a_vp;
        struct thread *a_td;
};
#endif

static int
zfs_freebsd_inactive(struct vop_inactive_args *ap)
{
        vnode_t *vp = ap->a_vp;

#if __FreeBSD_version >= 1300123
        zfs_inactive(vp, curthread->td_ucred, NULL);
#else
        zfs_inactive(vp, ap->a_td->td_ucred, NULL);
#endif
        return (0);
}

#if __FreeBSD_version >= 1300042
#ifndef _SYS_SYSPROTO_H_
struct vop_need_inactive_args {
        struct vnode *a_vp;
        struct thread *a_td;
};
#endif

static int
zfs_freebsd_need_inactive(struct vop_need_inactive_args *ap)
{
        vnode_t *vp = ap->a_vp;
        znode_t *zp = VTOZ(vp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        int need;

        if (vn_need_pageq_flush(vp))
                return (1);

        if (!ZFS_TEARDOWN_INACTIVE_TRY_ENTER_READ(zfsvfs))
                return (1);
        need = (zp->z_sa_hdl == NULL || zp->z_unlinked || zp->z_atime_dirty);
        ZFS_TEARDOWN_INACTIVE_EXIT_READ(zfsvfs);

        return (need);
}
#endif

#ifndef _SYS_SYSPROTO_H_
struct vop_reclaim_args {
        struct vnode *a_vp;
        struct thread *a_td;
};
#endif

static int
zfs_freebsd_reclaim(struct vop_reclaim_args *ap)
{
        vnode_t *vp = ap->a_vp;
        znode_t *zp = VTOZ(vp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;

        ASSERT3P(zp, !=, NULL);

#if __FreeBSD_version < 1300042
        /* Destroy the vm object and flush associated pages. */
        vnode_destroy_vobject(vp);
#endif
        /*
         * z_teardown_inactive_lock protects from a race with
         * zfs_znode_dmu_fini in zfsvfs_teardown during
         * force unmount.
         */
        ZFS_TEARDOWN_INACTIVE_ENTER_READ(zfsvfs);
        if (zp->z_sa_hdl == NULL)
                zfs_znode_free(zp);
        else
                zfs_zinactive(zp);
        ZFS_TEARDOWN_INACTIVE_EXIT_READ(zfsvfs);

        vp->v_data = NULL;
        return (0);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_fid_args {
        struct vnode *a_vp;
        struct fid *a_fid;
};
#endif

static int
zfs_freebsd_fid(struct vop_fid_args *ap)
{

        return (zfs_fid(ap->a_vp, (void *)ap->a_fid, NULL));
}


#ifndef _SYS_SYSPROTO_H_
struct vop_pathconf_args {
        struct vnode *a_vp;
        int a_name;
        register_t *a_retval;
} *ap;
#endif

static int
zfs_freebsd_pathconf(struct vop_pathconf_args *ap)
{
        ulong_t val;
        int error;

        error = zfs_pathconf(ap->a_vp, ap->a_name, &val,
            curthread->td_ucred, NULL);
        if (error == 0) {
                *ap->a_retval = val;
                return (error);
        }
        if (error != EOPNOTSUPP)
                return (error);

        switch (ap->a_name) {
        case _PC_NAME_MAX:
                *ap->a_retval = NAME_MAX;
                return (0);
#if __FreeBSD_version >= 1400032
        case _PC_DEALLOC_PRESENT:
                *ap->a_retval = 1;
                return (0);
#endif
        case _PC_PIPE_BUF:
                if (ap->a_vp->v_type == VDIR || ap->a_vp->v_type == VFIFO) {
                        *ap->a_retval = PIPE_BUF;
                        return (0);
                }
                return (EINVAL);
        default:
                return (vop_stdpathconf(ap));
        }
}

static int zfs_xattr_compat = 1;

static int
zfs_check_attrname(const char *name)
{
        /* We don't allow '/' character in attribute name. */
        if (strchr(name, '/') != NULL)
                return (SET_ERROR(EINVAL));
        /* We don't allow attribute names that start with a namespace prefix. */
        if (ZFS_XA_NS_PREFIX_FORBIDDEN(name))
                return (SET_ERROR(EINVAL));
        return (0);
}

/*
 * FreeBSD's extended attributes namespace defines file name prefix for ZFS'
 * extended attribute name:
 *
 *      NAMESPACE       XATTR_COMPAT    PREFIX
 *      system          *               freebsd:system:
 *      user            1               (none, can be used to access ZFS
 *                                      fsattr(5) attributes created on Solaris)
 *      user            0               user.
 */
static int
zfs_create_attrname(int attrnamespace, const char *name, char *attrname,
    size_t size, boolean_t compat)
{
        const char *namespace, *prefix, *suffix;

        memset(attrname, 0, size);

        switch (attrnamespace) {
        case EXTATTR_NAMESPACE_USER:
                if (compat) {
                        /*
                         * This is the default namespace by which we can access
                         * all attributes created on Solaris.
                         */
                        prefix = namespace = suffix = "";
                } else {
                        /*
                         * This is compatible with the user namespace encoding
                         * on Linux prior to xattr_compat, but nothing
                         * else.
                         */
                        prefix = "";
                        namespace = "user";
                        suffix = ".";
                }
                break;
        case EXTATTR_NAMESPACE_SYSTEM:
                prefix = "freebsd:";
                namespace = EXTATTR_NAMESPACE_SYSTEM_STRING;
                suffix = ":";
                break;
        case EXTATTR_NAMESPACE_EMPTY:
        default:
                return (SET_ERROR(EINVAL));
        }
        if (snprintf(attrname, size, "%s%s%s%s", prefix, namespace, suffix,
            name) >= size) {
                return (SET_ERROR(ENAMETOOLONG));
        }
        return (0);
}

static int
zfs_ensure_xattr_cached(znode_t *zp)
{
        int error = 0;

        ASSERT(RW_LOCK_HELD(&zp->z_xattr_lock));

        if (zp->z_xattr_cached != NULL)
                return (0);

        if (rw_write_held(&zp->z_xattr_lock))
                return (zfs_sa_get_xattr(zp));

        if (!rw_tryupgrade(&zp->z_xattr_lock)) {
                rw_exit(&zp->z_xattr_lock);
                rw_enter(&zp->z_xattr_lock, RW_WRITER);
        }
        if (zp->z_xattr_cached == NULL)
                error = zfs_sa_get_xattr(zp);
        rw_downgrade(&zp->z_xattr_lock);
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_getextattr {
        IN struct vnode *a_vp;
        IN int a_attrnamespace;
        IN const char *a_name;
        INOUT struct uio *a_uio;
        OUT size_t *a_size;
        IN struct ucred *a_cred;
        IN struct thread *a_td;
};
#endif

static int
zfs_getextattr_dir(struct vop_getextattr_args *ap, const char *attrname)
{
        struct thread *td = ap->a_td;
        struct nameidata nd;
        struct vattr va;
        vnode_t *xvp = NULL, *vp;
        int error, flags;

        error = zfs_lookup(ap->a_vp, NULL, &xvp, NULL, 0, ap->a_cred,
            LOOKUP_XATTR, B_FALSE);
        if (error != 0)
                return (error);

        flags = FREAD;
#if __FreeBSD_version < 1400043
        NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, attrname,
            xvp, td);
#else
        NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, attrname, xvp);
#endif
        error = vn_open_cred(&nd, &flags, 0, VN_OPEN_INVFS, ap->a_cred, NULL);
        if (error != 0)
                return (SET_ERROR(error));
        vp = nd.ni_vp;
        NDFREE_PNBUF(&nd);

        if (ap->a_size != NULL) {
                error = VOP_GETATTR(vp, &va, ap->a_cred);
                if (error == 0)
                        *ap->a_size = (size_t)va.va_size;
        } else if (ap->a_uio != NULL)
                error = VOP_READ(vp, ap->a_uio, IO_UNIT, ap->a_cred);

        VOP_UNLOCK1(vp);
        vn_close(vp, flags, ap->a_cred, td);
        return (error);
}

static int
zfs_getextattr_sa(struct vop_getextattr_args *ap, const char *attrname)
{
        znode_t *zp = VTOZ(ap->a_vp);
        uchar_t *nv_value;
        uint_t nv_size;
        int error;

        error = zfs_ensure_xattr_cached(zp);
        if (error != 0)
                return (error);

        ASSERT(RW_LOCK_HELD(&zp->z_xattr_lock));
        ASSERT3P(zp->z_xattr_cached, !=, NULL);

        error = nvlist_lookup_byte_array(zp->z_xattr_cached, attrname,
            &nv_value, &nv_size);
        if (error != 0)
                return (SET_ERROR(error));

        if (ap->a_size != NULL)
                *ap->a_size = nv_size;
        else if (ap->a_uio != NULL)
                error = uiomove(nv_value, nv_size, ap->a_uio);
        if (error != 0)
                return (SET_ERROR(error));

        return (0);
}

static int
zfs_getextattr_impl(struct vop_getextattr_args *ap, boolean_t compat)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        char attrname[EXTATTR_MAXNAMELEN+1];
        int error;

        error = zfs_create_attrname(ap->a_attrnamespace, ap->a_name, attrname,
            sizeof (attrname), compat);
        if (error != 0)
                return (error);

        error = ENOENT;
        if (zfsvfs->z_use_sa && zp->z_is_sa)
                error = zfs_getextattr_sa(ap, attrname);
        if (error == ENOENT)
                error = zfs_getextattr_dir(ap, attrname);
        return (error);
}

/*
 * Vnode operation to retrieve a named extended attribute.
 */
static int
zfs_getextattr(struct vop_getextattr_args *ap)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        int error;

        /*
         * If the xattr property is off, refuse the request.
         */
        if (!(zfsvfs->z_flags & ZSB_XATTR))
                return (SET_ERROR(EOPNOTSUPP));

        error = extattr_check_cred(ap->a_vp, ap->a_attrnamespace,
            ap->a_cred, ap->a_td, VREAD);
        if (error != 0)
                return (SET_ERROR(error));

        error = zfs_check_attrname(ap->a_name);
        if (error != 0)
                return (error);

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);
        error = ENOENT;
        rw_enter(&zp->z_xattr_lock, RW_READER);

        error = zfs_getextattr_impl(ap, zfs_xattr_compat);
        if ((error == ENOENT || error == ENOATTR) &&
            ap->a_attrnamespace == EXTATTR_NAMESPACE_USER) {
                /*
                 * Fall back to the alternate namespace format if we failed to
                 * find a user xattr.
                 */
                error = zfs_getextattr_impl(ap, !zfs_xattr_compat);
        }

        rw_exit(&zp->z_xattr_lock);
        zfs_exit(zfsvfs, FTAG);
        if (error == ENOENT)
                error = SET_ERROR(ENOATTR);
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_deleteextattr {
        IN struct vnode *a_vp;
        IN int a_attrnamespace;
        IN const char *a_name;
        IN struct ucred *a_cred;
        IN struct thread *a_td;
};
#endif

static int
zfs_deleteextattr_dir(struct vop_deleteextattr_args *ap, const char *attrname)
{
        struct nameidata nd;
        vnode_t *xvp = NULL, *vp;
        int error;

        error = zfs_lookup(ap->a_vp, NULL, &xvp, NULL, 0, ap->a_cred,
            LOOKUP_XATTR, B_FALSE);
        if (error != 0)
                return (error);

#if __FreeBSD_version < 1400043
        NDINIT_ATVP(&nd, DELETE, NOFOLLOW | LOCKPARENT | LOCKLEAF,
            UIO_SYSSPACE, attrname, xvp, ap->a_td);
#else
        NDINIT_ATVP(&nd, DELETE, NOFOLLOW | LOCKPARENT | LOCKLEAF,
            UIO_SYSSPACE, attrname, xvp);
#endif
        error = namei(&nd);
        if (error != 0)
                return (SET_ERROR(error));

        vp = nd.ni_vp;
        error = VOP_REMOVE(nd.ni_dvp, vp, &nd.ni_cnd);
        NDFREE_PNBUF(&nd);

        vput(nd.ni_dvp);
        if (vp == nd.ni_dvp)
                vrele(vp);
        else
                vput(vp);

        return (error);
}

static int
zfs_deleteextattr_sa(struct vop_deleteextattr_args *ap, const char *attrname)
{
        znode_t *zp = VTOZ(ap->a_vp);
        nvlist_t *nvl;
        int error;

        error = zfs_ensure_xattr_cached(zp);
        if (error != 0)
                return (error);

        ASSERT(RW_WRITE_HELD(&zp->z_xattr_lock));
        ASSERT3P(zp->z_xattr_cached, !=, NULL);

        nvl = zp->z_xattr_cached;
        error = nvlist_remove(nvl, attrname, DATA_TYPE_BYTE_ARRAY);
        if (error != 0)
                error = SET_ERROR(error);
        else
                error = zfs_sa_set_xattr(zp, attrname, NULL, 0);
        if (error != 0) {
                zp->z_xattr_cached = NULL;
                nvlist_free(nvl);
        }
        return (error);
}

static int
zfs_deleteextattr_impl(struct vop_deleteextattr_args *ap, boolean_t compat)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        char attrname[EXTATTR_MAXNAMELEN+1];
        int error;

        error = zfs_create_attrname(ap->a_attrnamespace, ap->a_name, attrname,
            sizeof (attrname), compat);
        if (error != 0)
                return (error);

        error = ENOENT;
        if (zfsvfs->z_use_sa && zp->z_is_sa)
                error = zfs_deleteextattr_sa(ap, attrname);
        if (error == ENOENT)
                error = zfs_deleteextattr_dir(ap, attrname);
        return (error);
}

/*
 * Vnode operation to remove a named attribute.
 */
static int
zfs_deleteextattr(struct vop_deleteextattr_args *ap)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        int error;

        /*
         * If the xattr property is off, refuse the request.
         */
        if (!(zfsvfs->z_flags & ZSB_XATTR))
                return (SET_ERROR(EOPNOTSUPP));

        error = extattr_check_cred(ap->a_vp, ap->a_attrnamespace,
            ap->a_cred, ap->a_td, VWRITE);
        if (error != 0)
                return (SET_ERROR(error));

        error = zfs_check_attrname(ap->a_name);
        if (error != 0)
                return (error);

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);
        rw_enter(&zp->z_xattr_lock, RW_WRITER);

        error = zfs_deleteextattr_impl(ap, zfs_xattr_compat);
        if ((error == ENOENT || error == ENOATTR) &&
            ap->a_attrnamespace == EXTATTR_NAMESPACE_USER) {
                /*
                 * Fall back to the alternate namespace format if we failed to
                 * find a user xattr.
                 */
                error = zfs_deleteextattr_impl(ap, !zfs_xattr_compat);
        }

        rw_exit(&zp->z_xattr_lock);
        zfs_exit(zfsvfs, FTAG);
        if (error == ENOENT)
                error = SET_ERROR(ENOATTR);
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_setextattr {
        IN struct vnode *a_vp;
        IN int a_attrnamespace;
        IN const char *a_name;
        INOUT struct uio *a_uio;
        IN struct ucred *a_cred;
        IN struct thread *a_td;
};
#endif

static int
zfs_setextattr_dir(struct vop_setextattr_args *ap, const char *attrname)
{
        struct thread *td = ap->a_td;
        struct nameidata nd;
        struct vattr va;
        vnode_t *xvp = NULL, *vp;
        int error, flags;

        error = zfs_lookup(ap->a_vp, NULL, &xvp, NULL, 0, ap->a_cred,
            LOOKUP_XATTR | CREATE_XATTR_DIR, B_FALSE);
        if (error != 0)
                return (error);

        flags = FFLAGS(O_WRONLY | O_CREAT);
#if __FreeBSD_version < 1400043
        NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, attrname, xvp, td);
#else
        NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW, UIO_SYSSPACE, attrname, xvp);
#endif
        error = vn_open_cred(&nd, &flags, 0600, VN_OPEN_INVFS, ap->a_cred,
            NULL);
        if (error != 0)
                return (SET_ERROR(error));
        vp = nd.ni_vp;
        NDFREE_PNBUF(&nd);

        VATTR_NULL(&va);
        va.va_size = 0;
        error = VOP_SETATTR(vp, &va, ap->a_cred);
        if (error == 0)
                VOP_WRITE(vp, ap->a_uio, IO_UNIT, ap->a_cred);

        VOP_UNLOCK1(vp);
        vn_close(vp, flags, ap->a_cred, td);
        return (error);
}

static int
zfs_setextattr_sa(struct vop_setextattr_args *ap, const char *attrname)
{
        znode_t *zp = VTOZ(ap->a_vp);
        nvlist_t *nvl;
        size_t sa_size;
        int error;

        error = zfs_ensure_xattr_cached(zp);
        if (error != 0)
                return (error);

        ASSERT(RW_WRITE_HELD(&zp->z_xattr_lock));
        ASSERT3P(zp->z_xattr_cached, !=, NULL);

        nvl = zp->z_xattr_cached;
        size_t entry_size = ap->a_uio->uio_resid;
        if (entry_size > DXATTR_MAX_ENTRY_SIZE)
                return (SET_ERROR(EFBIG));
        error = nvlist_size(nvl, &sa_size, NV_ENCODE_XDR);
        if (error != 0)
                return (SET_ERROR(error));
        if (sa_size > DXATTR_MAX_SA_SIZE)
                return (SET_ERROR(EFBIG));
        uchar_t *buf = kmem_alloc(entry_size, KM_SLEEP);
        error = uiomove(buf, entry_size, ap->a_uio);
        if (error != 0) {
                error = SET_ERROR(error);
        } else {
                error = nvlist_add_byte_array(nvl, attrname, buf, entry_size);
                if (error != 0)
                        error = SET_ERROR(error);
        }
        if (error == 0)
                error = zfs_sa_set_xattr(zp, attrname, buf, entry_size);
        kmem_free(buf, entry_size);
        if (error != 0) {
                zp->z_xattr_cached = NULL;
                nvlist_free(nvl);
        }
        return (error);
}

static int
zfs_setextattr_impl(struct vop_setextattr_args *ap, boolean_t compat)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        char attrname[EXTATTR_MAXNAMELEN+1];
        int error;

        error = zfs_create_attrname(ap->a_attrnamespace, ap->a_name, attrname,
            sizeof (attrname), compat);
        if (error != 0)
                return (error);

        struct vop_deleteextattr_args vda = {
                .a_vp = ap->a_vp,
                .a_attrnamespace = ap->a_attrnamespace,
                .a_name = ap->a_name,
                .a_cred = ap->a_cred,
                .a_td = ap->a_td,
        };
        error = ENOENT;
        if (zfsvfs->z_use_sa && zp->z_is_sa && zfsvfs->z_xattr_sa) {
                error = zfs_setextattr_sa(ap, attrname);
                if (error == 0) {
                        /*
                         * Successfully put into SA, we need to clear the one
                         * in dir if present.
                         */
                        zfs_deleteextattr_dir(&vda, attrname);
                }
        }
        if (error != 0) {
                error = zfs_setextattr_dir(ap, attrname);
                if (error == 0 && zp->z_is_sa) {
                        /*
                         * Successfully put into dir, we need to clear the one
                         * in SA if present.
                         */
                        zfs_deleteextattr_sa(&vda, attrname);
                }
        }
        if (error == 0 && ap->a_attrnamespace == EXTATTR_NAMESPACE_USER) {
                /*
                 * Also clear all versions of the alternate compat name.
                 */
                zfs_deleteextattr_impl(&vda, !compat);
        }
        return (error);
}

/*
 * Vnode operation to set a named attribute.
 */
static int
zfs_setextattr(struct vop_setextattr_args *ap)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        int error;

        /*
         * If the xattr property is off, refuse the request.
         */
        if (!(zfsvfs->z_flags & ZSB_XATTR))
                return (SET_ERROR(EOPNOTSUPP));

        error = extattr_check_cred(ap->a_vp, ap->a_attrnamespace,
            ap->a_cred, ap->a_td, VWRITE);
        if (error != 0)
                return (SET_ERROR(error));

        error = zfs_check_attrname(ap->a_name);
        if (error != 0)
                return (error);

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);
        rw_enter(&zp->z_xattr_lock, RW_WRITER);

        error = zfs_setextattr_impl(ap, zfs_xattr_compat);

        rw_exit(&zp->z_xattr_lock);
        zfs_exit(zfsvfs, FTAG);
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_listextattr {
        IN struct vnode *a_vp;
        IN int a_attrnamespace;
        INOUT struct uio *a_uio;
        OUT size_t *a_size;
        IN struct ucred *a_cred;
        IN struct thread *a_td;
};
#endif

static int
zfs_listextattr_dir(struct vop_listextattr_args *ap, const char *attrprefix)
{
        struct thread *td = ap->a_td;
        struct nameidata nd;
        uint8_t dirbuf[sizeof (struct dirent)];
        struct iovec aiov;
        struct uio auio;
        vnode_t *xvp = NULL, *vp;
        int error, eof;

        error = zfs_lookup(ap->a_vp, NULL, &xvp, NULL, 0, ap->a_cred,
            LOOKUP_XATTR, B_FALSE);
        if (error != 0) {
                /*
                 * ENOATTR means that the EA directory does not yet exist,
                 * i.e. there are no extended attributes there.
                 */
                if (error == ENOATTR)
                        error = 0;
                return (error);
        }

#if __FreeBSD_version < 1400043
        NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | LOCKSHARED,
            UIO_SYSSPACE, ".", xvp, td);
#else
        NDINIT_ATVP(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | LOCKSHARED,
            UIO_SYSSPACE, ".", xvp);
#endif
        error = namei(&nd);
        if (error != 0)
                return (SET_ERROR(error));
        vp = nd.ni_vp;
        NDFREE_PNBUF(&nd);

        auio.uio_iov = &aiov;
        auio.uio_iovcnt = 1;
        auio.uio_segflg = UIO_SYSSPACE;
        auio.uio_td = td;
        auio.uio_rw = UIO_READ;
        auio.uio_offset = 0;

        size_t plen = strlen(attrprefix);

        do {
                aiov.iov_base = (void *)dirbuf;
                aiov.iov_len = sizeof (dirbuf);
                auio.uio_resid = sizeof (dirbuf);
                error = VOP_READDIR(vp, &auio, ap->a_cred, &eof, NULL, NULL);
                if (error != 0)
                        break;
                int done = sizeof (dirbuf) - auio.uio_resid;
                for (int pos = 0; pos < done; ) {
                        struct dirent *dp = (struct dirent *)(dirbuf + pos);
                        pos += dp->d_reclen;
                        /*
                         * XXX: Temporarily we also accept DT_UNKNOWN, as this
                         * is what we get when attribute was created on Solaris.
                         */
                        if (dp->d_type != DT_REG && dp->d_type != DT_UNKNOWN)
                                continue;
                        else if (plen == 0 &&
                            ZFS_XA_NS_PREFIX_FORBIDDEN(dp->d_name))
                                continue;
                        else if (strncmp(dp->d_name, attrprefix, plen) != 0)
                                continue;
                        uint8_t nlen = dp->d_namlen - plen;
                        if (ap->a_size != NULL) {
                                *ap->a_size += 1 + nlen;
                        } else if (ap->a_uio != NULL) {
                                /*
                                 * Format of extattr name entry is one byte for
                                 * length and the rest for name.
                                 */
                                error = uiomove(&nlen, 1, ap->a_uio);
                                if (error == 0) {
                                        char *namep = dp->d_name + plen;
                                        error = uiomove(namep, nlen, ap->a_uio);
                                }
                                if (error != 0) {
                                        error = SET_ERROR(error);
                                        break;
                                }
                        }
                }
        } while (!eof && error == 0);

        vput(vp);
        return (error);
}

static int
zfs_listextattr_sa(struct vop_listextattr_args *ap, const char *attrprefix)
{
        znode_t *zp = VTOZ(ap->a_vp);
        int error;

        error = zfs_ensure_xattr_cached(zp);
        if (error != 0)
                return (error);

        ASSERT(RW_LOCK_HELD(&zp->z_xattr_lock));
        ASSERT3P(zp->z_xattr_cached, !=, NULL);

        size_t plen = strlen(attrprefix);
        nvpair_t *nvp = NULL;
        while ((nvp = nvlist_next_nvpair(zp->z_xattr_cached, nvp)) != NULL) {
                ASSERT3U(nvpair_type(nvp), ==, DATA_TYPE_BYTE_ARRAY);

                const char *name = nvpair_name(nvp);
                if (plen == 0 && ZFS_XA_NS_PREFIX_FORBIDDEN(name))
                        continue;
                else if (strncmp(name, attrprefix, plen) != 0)
                        continue;
                uint8_t nlen = strlen(name) - plen;
                if (ap->a_size != NULL) {
                        *ap->a_size += 1 + nlen;
                } else if (ap->a_uio != NULL) {
                        /*
                         * Format of extattr name entry is one byte for
                         * length and the rest for name.
                         */
                        error = uiomove(&nlen, 1, ap->a_uio);
                        if (error == 0) {
                                char *namep = __DECONST(char *, name) + plen;
                                error = uiomove(namep, nlen, ap->a_uio);
                        }
                        if (error != 0) {
                                error = SET_ERROR(error);
                                break;
                        }
                }
        }

        return (error);
}

static int
zfs_listextattr_impl(struct vop_listextattr_args *ap, boolean_t compat)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        char attrprefix[16];
        int error;

        error = zfs_create_attrname(ap->a_attrnamespace, "", attrprefix,
            sizeof (attrprefix), compat);
        if (error != 0)
                return (error);

        if (zfsvfs->z_use_sa && zp->z_is_sa)
                error = zfs_listextattr_sa(ap, attrprefix);
        if (error == 0)
                error = zfs_listextattr_dir(ap, attrprefix);
        return (error);
}

/*
 * Vnode operation to retrieve extended attributes on a vnode.
 */
static int
zfs_listextattr(struct vop_listextattr_args *ap)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = ZTOZSB(zp);
        int error;

        if (ap->a_size != NULL)
                *ap->a_size = 0;

        /*
         * If the xattr property is off, refuse the request.
         */
        if (!(zfsvfs->z_flags & ZSB_XATTR))
                return (SET_ERROR(EOPNOTSUPP));

        error = extattr_check_cred(ap->a_vp, ap->a_attrnamespace,
            ap->a_cred, ap->a_td, VREAD);
        if (error != 0)
                return (SET_ERROR(error));

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);
        rw_enter(&zp->z_xattr_lock, RW_READER);

        error = zfs_listextattr_impl(ap, zfs_xattr_compat);
        if (error == 0 && ap->a_attrnamespace == EXTATTR_NAMESPACE_USER) {
                /* Also list user xattrs with the alternate format. */
                error = zfs_listextattr_impl(ap, !zfs_xattr_compat);
        }

        rw_exit(&zp->z_xattr_lock);
        zfs_exit(zfsvfs, FTAG);
        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_getacl_args {
        struct vnode *vp;
        acl_type_t type;
        struct acl *aclp;
        struct ucred *cred;
        struct thread *td;
};
#endif

static int
zfs_freebsd_getacl(struct vop_getacl_args *ap)
{
        int             error;
        vsecattr_t      vsecattr;

        if (ap->a_type != ACL_TYPE_NFS4)
                return (EINVAL);

        vsecattr.vsa_mask = VSA_ACE | VSA_ACECNT;
        if ((error = zfs_getsecattr(VTOZ(ap->a_vp),
            &vsecattr, 0, ap->a_cred)))
                return (error);

        error = acl_from_aces(ap->a_aclp, vsecattr.vsa_aclentp,
            vsecattr.vsa_aclcnt);
        if (vsecattr.vsa_aclentp != NULL)
                kmem_free(vsecattr.vsa_aclentp, vsecattr.vsa_aclentsz);

        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_setacl_args {
        struct vnode *vp;
        acl_type_t type;
        struct acl *aclp;
        struct ucred *cred;
        struct thread *td;
};
#endif

static int
zfs_freebsd_setacl(struct vop_setacl_args *ap)
{
        int             error;
        vsecattr_t vsecattr;
        int             aclbsize;       /* size of acl list in bytes */
        aclent_t        *aaclp;

        if (ap->a_type != ACL_TYPE_NFS4)
                return (EINVAL);

        if (ap->a_aclp == NULL)
                return (EINVAL);

        if (ap->a_aclp->acl_cnt < 1 || ap->a_aclp->acl_cnt > MAX_ACL_ENTRIES)
                return (EINVAL);

        /*
         * With NFSv4 ACLs, chmod(2) may need to add additional entries,
         * splitting every entry into two and appending "canonical six"
         * entries at the end.  Don't allow for setting an ACL that would
         * cause chmod(2) to run out of ACL entries.
         */
        if (ap->a_aclp->acl_cnt * 2 + 6 > ACL_MAX_ENTRIES)
                return (ENOSPC);

        error = acl_nfs4_check(ap->a_aclp, ap->a_vp->v_type == VDIR);
        if (error != 0)
                return (error);

        vsecattr.vsa_mask = VSA_ACE;
        aclbsize = ap->a_aclp->acl_cnt * sizeof (ace_t);
        vsecattr.vsa_aclentp = kmem_alloc(aclbsize, KM_SLEEP);
        aaclp = vsecattr.vsa_aclentp;
        vsecattr.vsa_aclentsz = aclbsize;

        aces_from_acl(vsecattr.vsa_aclentp, &vsecattr.vsa_aclcnt, ap->a_aclp);
        error = zfs_setsecattr(VTOZ(ap->a_vp), &vsecattr, 0, ap->a_cred);
        kmem_free(aaclp, aclbsize);

        return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct vop_aclcheck_args {
        struct vnode *vp;
        acl_type_t type;
        struct acl *aclp;
        struct ucred *cred;
        struct thread *td;
};
#endif

static int
zfs_freebsd_aclcheck(struct vop_aclcheck_args *ap)
{

        return (EOPNOTSUPP);
}

static int
zfs_vptocnp(struct vop_vptocnp_args *ap)
{
        vnode_t *covered_vp;
        vnode_t *vp = ap->a_vp;
        zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
        znode_t *zp = VTOZ(vp);
        int ltype;
        int error;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        /*
         * If we are a snapshot mounted under .zfs, run the operation
         * on the covered vnode.
         */
        if (zp->z_id != zfsvfs->z_root || zfsvfs->z_parent == zfsvfs) {
                char name[MAXNAMLEN + 1];
                znode_t *dzp;
                size_t len;

                error = zfs_znode_parent_and_name(zp, &dzp, name);
                if (error == 0) {
                        len = strlen(name);
                        if (*ap->a_buflen < len)
                                error = SET_ERROR(ENOMEM);
                }
                if (error == 0) {
                        *ap->a_buflen -= len;
                        memcpy(ap->a_buf + *ap->a_buflen, name, len);
                        *ap->a_vpp = ZTOV(dzp);
                }
                zfs_exit(zfsvfs, FTAG);
                return (error);
        }
        zfs_exit(zfsvfs, FTAG);

        covered_vp = vp->v_mount->mnt_vnodecovered;
#if __FreeBSD_version >= 1300045
        enum vgetstate vs = vget_prep(covered_vp);
#else
        vhold(covered_vp);
#endif
        ltype = VOP_ISLOCKED(vp);
        VOP_UNLOCK1(vp);
#if __FreeBSD_version >= 1300045
        error = vget_finish(covered_vp, LK_SHARED, vs);
#else
        error = vget(covered_vp, LK_SHARED | LK_VNHELD, curthread);
#endif
        if (error == 0) {
#if __FreeBSD_version >= 1300123
                error = VOP_VPTOCNP(covered_vp, ap->a_vpp, ap->a_buf,
                    ap->a_buflen);
#else
                error = VOP_VPTOCNP(covered_vp, ap->a_vpp, ap->a_cred,
                    ap->a_buf, ap->a_buflen);
#endif
                vput(covered_vp);
        }
        vn_lock(vp, ltype | LK_RETRY);
        if (VN_IS_DOOMED(vp))
                error = SET_ERROR(ENOENT);
        return (error);
}

#if __FreeBSD_version >= 1400032
static int
zfs_deallocate(struct vop_deallocate_args *ap)
{
        znode_t *zp = VTOZ(ap->a_vp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        zilog_t *zilog;
        off_t off, len, file_sz;
        int error;

        if ((error = zfs_enter_verify_zp(zfsvfs, zp, FTAG)) != 0)
                return (error);

        /*
         * Callers might not be able to detect properly that we are read-only,
         * so check it explicitly here.
         */
        if (zfs_is_readonly(zfsvfs)) {
                zfs_exit(zfsvfs, FTAG);
                return (SET_ERROR(EROFS));
        }

        zilog = zfsvfs->z_log;
        off = *ap->a_offset;
        len = *ap->a_len;
        file_sz = zp->z_size;
        if (off + len > file_sz)
                len = file_sz - off;
        /* Fast path for out-of-range request. */
        if (len <= 0) {
                *ap->a_len = 0;
                zfs_exit(zfsvfs, FTAG);
                return (0);
        }

        error = zfs_freesp(zp, off, len, O_RDWR, TRUE);
        if (error == 0) {
                if (zfsvfs->z_os->os_sync == ZFS_SYNC_ALWAYS ||
                    (ap->a_ioflag & IO_SYNC) != 0)
                        zil_commit(zilog, zp->z_id);
                *ap->a_offset = off + len;
                *ap->a_len = 0;
        }

        zfs_exit(zfsvfs, FTAG);
        return (error);
}
#endif

struct vop_vector zfs_vnodeops;
struct vop_vector zfs_fifoops;
struct vop_vector zfs_shareops;

struct vop_vector zfs_vnodeops = {
        .vop_default =          &default_vnodeops,
        .vop_inactive =         zfs_freebsd_inactive,
#if __FreeBSD_version >= 1300042
        .vop_need_inactive =    zfs_freebsd_need_inactive,
#endif
        .vop_reclaim =          zfs_freebsd_reclaim,
#if __FreeBSD_version >= 1300102
        .vop_fplookup_vexec = zfs_freebsd_fplookup_vexec,
#endif
#if __FreeBSD_version >= 1300139
        .vop_fplookup_symlink = zfs_freebsd_fplookup_symlink,
#endif
        .vop_access =           zfs_freebsd_access,
        .vop_allocate =         VOP_EINVAL,
#if __FreeBSD_version >= 1400032
        .vop_deallocate =       zfs_deallocate,
#endif
        .vop_lookup =           zfs_cache_lookup,
        .vop_cachedlookup =     zfs_freebsd_cachedlookup,
        .vop_getattr =          zfs_freebsd_getattr,
        .vop_setattr =          zfs_freebsd_setattr,
        .vop_create =           zfs_freebsd_create,
        .vop_mknod =            (vop_mknod_t *)zfs_freebsd_create,
        .vop_mkdir =            zfs_freebsd_mkdir,
        .vop_readdir =          zfs_freebsd_readdir,
        .vop_fsync =            zfs_freebsd_fsync,
        .vop_open =             zfs_freebsd_open,
        .vop_close =            zfs_freebsd_close,
        .vop_rmdir =            zfs_freebsd_rmdir,
        .vop_ioctl =            zfs_freebsd_ioctl,
        .vop_link =             zfs_freebsd_link,
        .vop_symlink =          zfs_freebsd_symlink,
        .vop_readlink =         zfs_freebsd_readlink,
        .vop_read =             zfs_freebsd_read,
        .vop_write =            zfs_freebsd_write,
        .vop_remove =           zfs_freebsd_remove,
        .vop_rename =           zfs_freebsd_rename,
        .vop_pathconf =         zfs_freebsd_pathconf,
        .vop_bmap =             zfs_freebsd_bmap,
        .vop_fid =              zfs_freebsd_fid,
        .vop_getextattr =       zfs_getextattr,
        .vop_deleteextattr =    zfs_deleteextattr,
        .vop_setextattr =       zfs_setextattr,
        .vop_listextattr =      zfs_listextattr,
        .vop_getacl =           zfs_freebsd_getacl,
        .vop_setacl =           zfs_freebsd_setacl,
        .vop_aclcheck =         zfs_freebsd_aclcheck,
        .vop_getpages =         zfs_freebsd_getpages,
        .vop_putpages =         zfs_freebsd_putpages,
        .vop_vptocnp =          zfs_vptocnp,
#if __FreeBSD_version >= 1300064
        .vop_lock1 =            vop_lock,
        .vop_unlock =           vop_unlock,
        .vop_islocked =         vop_islocked,
#endif
#if __FreeBSD_version >= 1400043
        .vop_add_writecount =   vop_stdadd_writecount_nomsync,
#endif
};
VFS_VOP_VECTOR_REGISTER(zfs_vnodeops);

struct vop_vector zfs_fifoops = {
        .vop_default =          &fifo_specops,
        .vop_fsync =            zfs_freebsd_fsync,
#if __FreeBSD_version >= 1300102
        .vop_fplookup_vexec = zfs_freebsd_fplookup_vexec,
#endif
#if __FreeBSD_version >= 1300139
        .vop_fplookup_symlink = zfs_freebsd_fplookup_symlink,
#endif
        .vop_access =           zfs_freebsd_access,
        .vop_getattr =          zfs_freebsd_getattr,
        .vop_inactive =         zfs_freebsd_inactive,
        .vop_read =             VOP_PANIC,
        .vop_reclaim =          zfs_freebsd_reclaim,
        .vop_setattr =          zfs_freebsd_setattr,
        .vop_write =            VOP_PANIC,
        .vop_pathconf =         zfs_freebsd_pathconf,
        .vop_fid =              zfs_freebsd_fid,
        .vop_getacl =           zfs_freebsd_getacl,
        .vop_setacl =           zfs_freebsd_setacl,
        .vop_aclcheck =         zfs_freebsd_aclcheck,
#if __FreeBSD_version >= 1400043
        .vop_add_writecount =   vop_stdadd_writecount_nomsync,
#endif
};
VFS_VOP_VECTOR_REGISTER(zfs_fifoops);

/*
 * special share hidden files vnode operations template
 */
struct vop_vector zfs_shareops = {
        .vop_default =          &default_vnodeops,
#if __FreeBSD_version >= 1300121
        .vop_fplookup_vexec =   VOP_EAGAIN,
#endif
#if __FreeBSD_version >= 1300139
        .vop_fplookup_symlink = VOP_EAGAIN,
#endif
        .vop_access =           zfs_freebsd_access,
        .vop_inactive =         zfs_freebsd_inactive,
        .vop_reclaim =          zfs_freebsd_reclaim,
        .vop_fid =              zfs_freebsd_fid,
        .vop_pathconf =         zfs_freebsd_pathconf,
#if __FreeBSD_version >= 1400043
        .vop_add_writecount =   vop_stdadd_writecount_nomsync,
#endif
};
VFS_VOP_VECTOR_REGISTER(zfs_shareops);

ZFS_MODULE_PARAM(zfs, zfs_, xattr_compat, INT, ZMOD_RW,
        "Use legacy ZFS xattr naming for writing new user namespace xattrs");