diff --git a/sys/fs/nfsclient/nfs_clbio.c b/sys/fs/nfsclient/nfs_clbio.c
index 10a76f0a4b83..250d01d88948 100644
--- a/sys/fs/nfsclient/nfs_clbio.c
+++ b/sys/fs/nfsclient/nfs_clbio.c
@@ -1,1908 +1,1920 @@
 /*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Rick Macklem at The University of Guelph.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  *	@(#)nfs_bio.c	8.9 (Berkeley) 3/30/95
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/bio.h>
 #include <sys/buf.h>
 #include <sys/kernel.h>
 #include <sys/mount.h>
 #include <sys/rwlock.h>
 #include <sys/vmmeter.h>
 #include <sys/vnode.h>
 
 #include <vm/vm.h>
 #include <vm/vm_param.h>
 #include <vm/vm_extern.h>
 #include <vm/vm_page.h>
 #include <vm/vm_object.h>
 #include <vm/vm_pager.h>
 #include <vm/vnode_pager.h>
 
 #include <fs/nfs/nfsport.h>
 #include <fs/nfsclient/nfsmount.h>
 #include <fs/nfsclient/nfs.h>
 #include <fs/nfsclient/nfsnode.h>
 #include <fs/nfsclient/nfs_kdtrace.h>
 
 extern int newnfs_directio_allow_mmap;
 extern struct nfsstatsv1 nfsstatsv1;
 extern struct mtx ncl_iod_mutex;
 extern int ncl_numasync;
 extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON];
 extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON];
 extern int newnfs_directio_enable;
 extern int nfs_keep_dirty_on_error;
 
 uma_zone_t ncl_pbuf_zone;
 
 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
     struct thread *td);
 static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
     struct ucred *cred, int ioflag);
 
 /*
  * Vnode op for VM getpages.
  */
 SYSCTL_DECL(_vfs_nfs);
 static int use_buf_pager = 1;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN,
     &use_buf_pager, 0,
     "Use buffer pager instead of direct readrpc call");
 
 static daddr_t
 ncl_gbp_getblkno(struct vnode *vp, vm_ooffset_t off)
 {
 
 	return (off / vp->v_bufobj.bo_bsize);
 }
 
 static int
 ncl_gbp_getblksz(struct vnode *vp, daddr_t lbn, long *sz)
 {
 	struct nfsnode *np;
 	u_quad_t nsize;
 	int biosize, bcount;
 
 	np = VTONFS(vp);
 	NFSLOCKNODE(np);
 	nsize = np->n_size;
 	NFSUNLOCKNODE(np);
 
 	biosize = vp->v_bufobj.bo_bsize;
 	bcount = biosize;
 	if ((off_t)lbn * biosize >= nsize)
 		bcount = 0;
 	else if ((off_t)(lbn + 1) * biosize > nsize)
 		bcount = nsize - (off_t)lbn * biosize;
 	*sz = bcount;
 	return (0);
 }
 
 int
 ncl_getpages(struct vop_getpages_args *ap)
 {
 	int i, error, nextoff, size, toff, count, npages;
 	struct uio uio;
 	struct iovec iov;
 	vm_offset_t kva;
 	struct buf *bp;
 	struct vnode *vp;
 	struct thread *td;
 	struct ucred *cred;
 	struct nfsmount *nmp;
 	vm_object_t object;
 	vm_page_t *pages;
 	struct nfsnode *np;
 
 	vp = ap->a_vp;
 	np = VTONFS(vp);
 	td = curthread;
 	cred = curthread->td_ucred;
 	nmp = VFSTONFS(vp->v_mount);
 	pages = ap->a_m;
 	npages = ap->a_count;
 
 	if ((object = vp->v_object) == NULL) {
 		printf("ncl_getpages: called with non-merged cache vnode\n");
 		return (VM_PAGER_ERROR);
 	}
 
 	if (newnfs_directio_enable && !newnfs_directio_allow_mmap) {
 		NFSLOCKNODE(np);
 		if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
 			NFSUNLOCKNODE(np);
 			printf("ncl_getpages: called on non-cacheable vnode\n");
 			return (VM_PAGER_ERROR);
 		} else
 			NFSUNLOCKNODE(np);
 	}
 
 	mtx_lock(&nmp->nm_mtx);
 	if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
 	    (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
 		mtx_unlock(&nmp->nm_mtx);
 		/* We'll never get here for v4, because we always have fsinfo */
 		(void)ncl_fsinfo(nmp, vp, cred, td);
 	} else
 		mtx_unlock(&nmp->nm_mtx);
 
 	if (use_buf_pager)
 		return (vfs_bio_getpages(vp, pages, npages, ap->a_rbehind,
 		    ap->a_rahead, ncl_gbp_getblkno, ncl_gbp_getblksz));
 
 	/*
 	 * If the requested page is partially valid, just return it and
 	 * allow the pager to zero-out the blanks.  Partially valid pages
 	 * can only occur at the file EOF.
 	 *
 	 * XXXGL: is that true for NFS, where short read can occur???
 	 */
 	VM_OBJECT_WLOCK(object);
 	if (!vm_page_none_valid(pages[npages - 1]) && --npages == 0)
 		goto out;
 	VM_OBJECT_WUNLOCK(object);
 
 	/*
 	 * We use only the kva address for the buffer, but this is extremely
 	 * convenient and fast.
 	 */
 	bp = uma_zalloc(ncl_pbuf_zone, M_WAITOK);
 
 	kva = (vm_offset_t) bp->b_data;
 	pmap_qenter(kva, pages, npages);
 	VM_CNT_INC(v_vnodein);
 	VM_CNT_ADD(v_vnodepgsin, npages);
 
 	count = npages << PAGE_SHIFT;
 	iov.iov_base = (caddr_t) kva;
 	iov.iov_len = count;
 	uio.uio_iov = &iov;
 	uio.uio_iovcnt = 1;
 	uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
 	uio.uio_resid = count;
 	uio.uio_segflg = UIO_SYSSPACE;
 	uio.uio_rw = UIO_READ;
 	uio.uio_td = td;
 
 	error = ncl_readrpc(vp, &uio, cred);
 	pmap_qremove(kva, npages);
 
 	uma_zfree(ncl_pbuf_zone, bp);
 
 	if (error && (uio.uio_resid == count)) {
 		printf("ncl_getpages: error %d\n", error);
 		return (VM_PAGER_ERROR);
 	}
 
 	/*
 	 * Calculate the number of bytes read and validate only that number
 	 * of bytes.  Note that due to pending writes, size may be 0.  This
 	 * does not mean that the remaining data is invalid!
 	 */
 
 	size = count - uio.uio_resid;
 	VM_OBJECT_WLOCK(object);
 	for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
 		vm_page_t m;
 		nextoff = toff + PAGE_SIZE;
 		m = pages[i];
 
 		if (nextoff <= size) {
 			/*
 			 * Read operation filled an entire page
 			 */
 			vm_page_valid(m);
 			KASSERT(m->dirty == 0,
 			    ("nfs_getpages: page %p is dirty", m));
 		} else if (size > toff) {
 			/*
 			 * Read operation filled a partial page.
 			 */
 			vm_page_invalid(m);
 			vm_page_set_valid_range(m, 0, size - toff);
 			KASSERT(m->dirty == 0,
 			    ("nfs_getpages: page %p is dirty", m));
 		} else {
 			/*
 			 * Read operation was short.  If no error
 			 * occurred we may have hit a zero-fill
 			 * section.  We leave valid set to 0, and page
 			 * is freed by vm_page_readahead_finish() if
 			 * its index is not equal to requested, or
 			 * page is zeroed and set valid by
 			 * vm_pager_get_pages() for requested page.
 			 */
 			;
 		}
 	}
 out:
 	VM_OBJECT_WUNLOCK(object);
 	if (ap->a_rbehind)
 		*ap->a_rbehind = 0;
 	if (ap->a_rahead)
 		*ap->a_rahead = 0;
 	return (VM_PAGER_OK);
 }
 
 /*
  * Vnode op for VM putpages.
  */
 int
 ncl_putpages(struct vop_putpages_args *ap)
 {
 	struct uio uio;
 	struct iovec iov;
 	int i, error, npages, count;
 	off_t offset;
 	int *rtvals;
 	struct vnode *vp;
 	struct thread *td;
 	struct ucred *cred;
 	struct nfsmount *nmp;
 	struct nfsnode *np;
 	vm_page_t *pages;
 
 	vp = ap->a_vp;
 	np = VTONFS(vp);
 	td = curthread;				/* XXX */
 	/* Set the cred to n_writecred for the write rpcs. */
 	if (np->n_writecred != NULL)
 		cred = crhold(np->n_writecred);
 	else
 		cred = crhold(curthread->td_ucred);	/* XXX */
 	nmp = VFSTONFS(vp->v_mount);
 	pages = ap->a_m;
 	count = ap->a_count;
 	rtvals = ap->a_rtvals;
 	npages = btoc(count);
 	offset = IDX_TO_OFF(pages[0]->pindex);
 
 	mtx_lock(&nmp->nm_mtx);
 	if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
 	    (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
 		mtx_unlock(&nmp->nm_mtx);
 		(void)ncl_fsinfo(nmp, vp, cred, td);
 	} else
 		mtx_unlock(&nmp->nm_mtx);
 
 	NFSLOCKNODE(np);
 	if (newnfs_directio_enable && !newnfs_directio_allow_mmap &&
 	    (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
 		NFSUNLOCKNODE(np);
 		printf("ncl_putpages: called on noncache-able vnode\n");
 		NFSLOCKNODE(np);
 	}
 	/*
 	 * When putting pages, do not extend file past EOF.
 	 */
 	if (offset + count > np->n_size) {
 		count = np->n_size - offset;
 		if (count < 0)
 			count = 0;
 	}
 	NFSUNLOCKNODE(np);
 
 	for (i = 0; i < npages; i++)
 		rtvals[i] = VM_PAGER_ERROR;
 
 	VM_CNT_INC(v_vnodeout);
 	VM_CNT_ADD(v_vnodepgsout, count);
 
 	iov.iov_base = unmapped_buf;
 	iov.iov_len = count;
 	uio.uio_iov = &iov;
 	uio.uio_iovcnt = 1;
 	uio.uio_offset = offset;
 	uio.uio_resid = count;
 	uio.uio_segflg = UIO_NOCOPY;
 	uio.uio_rw = UIO_WRITE;
 	uio.uio_td = td;
 
 	error = VOP_WRITE(vp, &uio, vnode_pager_putpages_ioflags(ap->a_sync),
 	    cred);
 	crfree(cred);
 
 	if (error == 0 || !nfs_keep_dirty_on_error) {
 		vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid,
 		    np->n_size - offset, npages * PAGE_SIZE);
 	}
 	return (rtvals[0]);
 }
 
 /*
  * For nfs, cache consistency can only be maintained approximately.
  * Although RFC1094 does not specify the criteria, the following is
  * believed to be compatible with the reference port.
  * For nfs:
  * If the file's modify time on the server has changed since the
  * last read rpc or you have written to the file,
  * you may have lost data cache consistency with the
  * server, so flush all of the file's data out of the cache.
  * Then force a getattr rpc to ensure that you have up to date
  * attributes.
  * NB: This implies that cache data can be read when up to
  * NFS_ATTRTIMEO seconds out of date. If you find that you need current
  * attributes this could be forced by setting n_attrstamp to 0 before
  * the VOP_GETATTR() call.
  */
 static inline int
 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
 {
 	int error = 0;
 	struct vattr vattr;
 	struct nfsnode *np = VTONFS(vp);
 	bool old_lock;
 
 	/*
 	 * Ensure the exclusove access to the node before checking
 	 * whether the cache is consistent.
 	 */
 	old_lock = ncl_excl_start(vp);
 	NFSLOCKNODE(np);
 	if (np->n_flag & NMODIFIED) {
 		NFSUNLOCKNODE(np);
 		if (vp->v_type != VREG) {
 			if (vp->v_type != VDIR)
 				panic("nfs: bioread, not dir");
 			ncl_invaldir(vp);
 			error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1);
 			if (error != 0)
 				goto out;
 		}
 		np->n_attrstamp = 0;
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 		error = VOP_GETATTR(vp, &vattr, cred);
 		if (error)
 			goto out;
 		NFSLOCKNODE(np);
 		np->n_mtime = vattr.va_mtime;
 		NFSUNLOCKNODE(np);
 	} else {
 		NFSUNLOCKNODE(np);
 		error = VOP_GETATTR(vp, &vattr, cred);
 		if (error)
 			goto out;
 		NFSLOCKNODE(np);
 		if ((np->n_flag & NSIZECHANGED)
 		    || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
 			NFSUNLOCKNODE(np);
 			if (vp->v_type == VDIR)
 				ncl_invaldir(vp);
 			error = ncl_vinvalbuf(vp, V_SAVE | V_ALLOWCLEAN, td, 1);
 			if (error != 0)
 				goto out;
 			NFSLOCKNODE(np);
 			np->n_mtime = vattr.va_mtime;
 			np->n_flag &= ~NSIZECHANGED;
 		}
 		NFSUNLOCKNODE(np);
 	}
 out:
 	ncl_excl_finish(vp, old_lock);
 	return (error);
 }
 
 /*
  * Vnode op for read using bio
  */
 int
 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
 {
 	struct nfsnode *np = VTONFS(vp);
 	struct buf *bp, *rabp;
 	struct thread *td;
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	daddr_t lbn, rabn;
 	int biosize, bcount, error, i, n, nra, on, save2, seqcount;
 	off_t tmp_off;
 
 	KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode"));
 	if (uio->uio_resid == 0)
 		return (0);
 	if (uio->uio_offset < 0)	/* XXX VDIR cookies can be negative */
 		return (EINVAL);
 	td = uio->uio_td;
 
 	mtx_lock(&nmp->nm_mtx);
 	if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
 	    (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
 		mtx_unlock(&nmp->nm_mtx);
 		(void)ncl_fsinfo(nmp, vp, cred, td);
 		mtx_lock(&nmp->nm_mtx);
 	}
 	if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0)
 		(void) newnfs_iosize(nmp);
 
 	tmp_off = uio->uio_offset + uio->uio_resid;
 	if (vp->v_type != VDIR &&
 	    (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) {
 		mtx_unlock(&nmp->nm_mtx);
 		return (EFBIG);
 	}
 	mtx_unlock(&nmp->nm_mtx);
 
 	if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
 		/* No caching/ no readaheads. Just read data into the user buffer */
 		return ncl_readrpc(vp, uio, cred);
 
 	n = 0;
 	on = 0;
 	biosize = vp->v_bufobj.bo_bsize;
 	seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
 
 	error = nfs_bioread_check_cons(vp, td, cred);
 	if (error)
 		return error;
 
 	save2 = curthread_pflags2_set(TDP2_SBPAGES);
 	do {
 	    u_quad_t nsize;
 
 	    NFSLOCKNODE(np);
 	    nsize = np->n_size;
 	    NFSUNLOCKNODE(np);
 
 	    switch (vp->v_type) {
 	    case VREG:
 		NFSINCRGLOBAL(nfsstatsv1.biocache_reads);
 		lbn = uio->uio_offset / biosize;
 		on = uio->uio_offset - (lbn * biosize);
 
 		/*
 		 * Start the read ahead(s), as required.
 		 */
 		if (nmp->nm_readahead > 0) {
 		    for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
 			(off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
 			rabn = lbn + 1 + nra;
 			if (incore(&vp->v_bufobj, rabn) == NULL) {
 			    rabp = nfs_getcacheblk(vp, rabn, biosize, td);
 			    if (!rabp) {
 				error = newnfs_sigintr(nmp, td);
 				if (error == 0)
 					error = EINTR;
 				goto out;
 			    }
 			    if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
 				rabp->b_flags |= B_ASYNC;
 				rabp->b_iocmd = BIO_READ;
 				vfs_busy_pages(rabp, 0);
 				if (ncl_asyncio(nmp, rabp, cred, td)) {
 				    rabp->b_flags |= B_INVAL;
 				    rabp->b_ioflags |= BIO_ERROR;
 				    vfs_unbusy_pages(rabp);
 				    brelse(rabp);
 				    break;
 				}
 			    } else {
 				brelse(rabp);
 			    }
 			}
 		    }
 		}
 
 		/* Note that bcount is *not* DEV_BSIZE aligned. */
 		bcount = biosize;
 		if ((off_t)lbn * biosize >= nsize) {
 			bcount = 0;
 		} else if ((off_t)(lbn + 1) * biosize > nsize) {
 			bcount = nsize - (off_t)lbn * biosize;
 		}
 		bp = nfs_getcacheblk(vp, lbn, bcount, td);
 
 		if (!bp) {
 			error = newnfs_sigintr(nmp, td);
 			if (error == 0)
 				error = EINTR;
 			goto out;
 		}
 
 		/*
 		 * If B_CACHE is not set, we must issue the read.  If this
 		 * fails, we return an error.
 		 */
 
 		if ((bp->b_flags & B_CACHE) == 0) {
 		    bp->b_iocmd = BIO_READ;
 		    vfs_busy_pages(bp, 0);
 		    error = ncl_doio(vp, bp, cred, td, 0);
 		    if (error) {
 			brelse(bp);
 			goto out;
 		    }
 		}
 
 		/*
 		 * on is the offset into the current bp.  Figure out how many
 		 * bytes we can copy out of the bp.  Note that bcount is
 		 * NOT DEV_BSIZE aligned.
 		 *
 		 * Then figure out how many bytes we can copy into the uio.
 		 */
 
 		n = 0;
 		if (on < bcount)
 			n = MIN((unsigned)(bcount - on), uio->uio_resid);
 		break;
 	    case VLNK:
 		NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks);
 		bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
 		if (!bp) {
 			error = newnfs_sigintr(nmp, td);
 			if (error == 0)
 				error = EINTR;
 			goto out;
 		}
 		if ((bp->b_flags & B_CACHE) == 0) {
 		    bp->b_iocmd = BIO_READ;
 		    vfs_busy_pages(bp, 0);
 		    error = ncl_doio(vp, bp, cred, td, 0);
 		    if (error) {
 			bp->b_ioflags |= BIO_ERROR;
 			brelse(bp);
 			goto out;
 		    }
 		}
 		n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
 		on = 0;
 		break;
 	    case VDIR:
 		NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs);
 		NFSLOCKNODE(np);
 		if (np->n_direofoffset
 		    && uio->uio_offset >= np->n_direofoffset) {
 			NFSUNLOCKNODE(np);
 			error = 0;
 			goto out;
 		}
 		NFSUNLOCKNODE(np);
 		lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
 		on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
 		bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
 		if (!bp) {
 			error = newnfs_sigintr(nmp, td);
 			if (error == 0)
 				error = EINTR;
 			goto out;
 		}
 		if ((bp->b_flags & B_CACHE) == 0) {
 		    bp->b_iocmd = BIO_READ;
 		    vfs_busy_pages(bp, 0);
 		    error = ncl_doio(vp, bp, cred, td, 0);
 		    if (error) {
 			    brelse(bp);
 		    }
 		    while (error == NFSERR_BAD_COOKIE) {
 			ncl_invaldir(vp);
 			error = ncl_vinvalbuf(vp, 0, td, 1);
 
 			/*
 			 * Yuck! The directory has been modified on the
 			 * server. The only way to get the block is by
 			 * reading from the beginning to get all the
 			 * offset cookies.
 			 *
 			 * Leave the last bp intact unless there is an error.
 			 * Loop back up to the while if the error is another
 			 * NFSERR_BAD_COOKIE (double yuch!).
 			 */
 			for (i = 0; i <= lbn && !error; i++) {
 			    NFSLOCKNODE(np);
 			    if (np->n_direofoffset
 				&& (i * NFS_DIRBLKSIZ) >= np->n_direofoffset) {
 				    NFSUNLOCKNODE(np);
 				    error = 0;
 				    goto out;
 			    }
 			    NFSUNLOCKNODE(np);
 			    bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
 			    if (!bp) {
 				error = newnfs_sigintr(nmp, td);
 				if (error == 0)
 					error = EINTR;
 				goto out;
 			    }
 			    if ((bp->b_flags & B_CACHE) == 0) {
 				    bp->b_iocmd = BIO_READ;
 				    vfs_busy_pages(bp, 0);
 				    error = ncl_doio(vp, bp, cred, td, 0);
 				    /*
 				     * no error + B_INVAL == directory EOF,
 				     * use the block.
 				     */
 				    if (error == 0 && (bp->b_flags & B_INVAL))
 					    break;
 			    }
 			    /*
 			     * An error will throw away the block and the
 			     * for loop will break out.  If no error and this
 			     * is not the block we want, we throw away the
 			     * block and go for the next one via the for loop.
 			     */
 			    if (error || i < lbn)
 				    brelse(bp);
 			}
 		    }
 		    /*
 		     * The above while is repeated if we hit another cookie
 		     * error.  If we hit an error and it wasn't a cookie error,
 		     * we give up.
 		     */
 		    if (error)
 			    goto out;
 		}
 
 		/*
 		 * If not eof and read aheads are enabled, start one.
 		 * (You need the current block first, so that you have the
 		 *  directory offset cookie of the next block.)
 		 */
 		NFSLOCKNODE(np);
 		if (nmp->nm_readahead > 0 &&
 		    (bp->b_flags & B_INVAL) == 0 &&
 		    (np->n_direofoffset == 0 ||
 		    (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
 		    incore(&vp->v_bufobj, lbn + 1) == NULL) {
 			NFSUNLOCKNODE(np);
 			rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
 			if (rabp) {
 			    if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
 				rabp->b_flags |= B_ASYNC;
 				rabp->b_iocmd = BIO_READ;
 				vfs_busy_pages(rabp, 0);
 				if (ncl_asyncio(nmp, rabp, cred, td)) {
 				    rabp->b_flags |= B_INVAL;
 				    rabp->b_ioflags |= BIO_ERROR;
 				    vfs_unbusy_pages(rabp);
 				    brelse(rabp);
 				}
 			    } else {
 				brelse(rabp);
 			    }
 			}
 			NFSLOCKNODE(np);
 		}
 		/*
 		 * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
 		 * chopped for the EOF condition, we cannot tell how large
 		 * NFS directories are going to be until we hit EOF.  So
 		 * an NFS directory buffer is *not* chopped to its EOF.  Now,
 		 * it just so happens that b_resid will effectively chop it
 		 * to EOF.  *BUT* this information is lost if the buffer goes
 		 * away and is reconstituted into a B_CACHE state ( due to
 		 * being VMIO ) later.  So we keep track of the directory eof
 		 * in np->n_direofoffset and chop it off as an extra step
 		 * right here.
 		 */
 		n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
 		if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
 			n = np->n_direofoffset - uio->uio_offset;
 		NFSUNLOCKNODE(np);
 		break;
 	    default:
 		printf(" ncl_bioread: type %x unexpected\n", vp->v_type);
 		bp = NULL;
 		break;
 	    }
 
 	    if (n > 0) {
 		    error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio);
 	    }
 	    if (vp->v_type == VLNK)
 		n = 0;
 	    if (bp != NULL)
 		brelse(bp);
 	} while (error == 0 && uio->uio_resid > 0 && n > 0);
 out:
 	curthread_pflags2_restore(save2);
 	if ((curthread->td_pflags2 & TDP2_SBPAGES) == 0) {
 		NFSLOCKNODE(np);
 		ncl_pager_setsize(vp, NULL);
 	}
 	return (error);
 }
 
 /*
  * The NFS write path cannot handle iovecs with len > 1. So we need to
  * break up iovecs accordingly (restricting them to wsize).
  * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
  * For the ASYNC case, 2 copies are needed. The first a copy from the
  * user buffer to a staging buffer and then a second copy from the staging
  * buffer to mbufs. This can be optimized by copying from the user buffer
  * directly into mbufs and passing the chain down, but that requires a
  * fair amount of re-working of the relevant codepaths (and can be done
  * later).
  */
 static int
 nfs_directio_write(vp, uiop, cred, ioflag)
 	struct vnode *vp;
 	struct uio *uiop;
 	struct ucred *cred;
 	int ioflag;
 {
 	int error;
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	struct thread *td = uiop->uio_td;
 	int size;
 	int wsize;
 
 	mtx_lock(&nmp->nm_mtx);
 	wsize = nmp->nm_wsize;
 	mtx_unlock(&nmp->nm_mtx);
 	if (ioflag & IO_SYNC) {
 		int iomode, must_commit;
 		struct uio uio;
 		struct iovec iov;
 do_sync:
 		while (uiop->uio_resid > 0) {
 			size = MIN(uiop->uio_resid, wsize);
 			size = MIN(uiop->uio_iov->iov_len, size);
 			iov.iov_base = uiop->uio_iov->iov_base;
 			iov.iov_len = size;
 			uio.uio_iov = &iov;
 			uio.uio_iovcnt = 1;
 			uio.uio_offset = uiop->uio_offset;
 			uio.uio_resid = size;
 			uio.uio_segflg = UIO_USERSPACE;
 			uio.uio_rw = UIO_WRITE;
 			uio.uio_td = td;
 			iomode = NFSWRITE_FILESYNC;
 			error = ncl_writerpc(vp, &uio, cred, &iomode,
 			    &must_commit, 0);
 			KASSERT((must_commit == 0),
 				("ncl_directio_write: Did not commit write"));
 			if (error)
 				return (error);
 			uiop->uio_offset += size;
 			uiop->uio_resid -= size;
 			if (uiop->uio_iov->iov_len <= size) {
 				uiop->uio_iovcnt--;
 				uiop->uio_iov++;
 			} else {
 				uiop->uio_iov->iov_base =
 					(char *)uiop->uio_iov->iov_base + size;
 				uiop->uio_iov->iov_len -= size;
 			}
 		}
 	} else {
 		struct uio *t_uio;
 		struct iovec *t_iov;
 		struct buf *bp;
 
 		/*
 		 * Break up the write into blocksize chunks and hand these
 		 * over to nfsiod's for write back.
 		 * Unfortunately, this incurs a copy of the data. Since
 		 * the user could modify the buffer before the write is
 		 * initiated.
 		 *
 		 * The obvious optimization here is that one of the 2 copies
 		 * in the async write path can be eliminated by copying the
 		 * data here directly into mbufs and passing the mbuf chain
 		 * down. But that will require a fair amount of re-working
 		 * of the code and can be done if there's enough interest
 		 * in NFS directio access.
 		 */
 		while (uiop->uio_resid > 0) {
 			size = MIN(uiop->uio_resid, wsize);
 			size = MIN(uiop->uio_iov->iov_len, size);
 			bp = uma_zalloc(ncl_pbuf_zone, M_WAITOK);
 			t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
 			t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
 			t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
 			t_iov->iov_len = size;
 			t_uio->uio_iov = t_iov;
 			t_uio->uio_iovcnt = 1;
 			t_uio->uio_offset = uiop->uio_offset;
 			t_uio->uio_resid = size;
 			t_uio->uio_segflg = UIO_SYSSPACE;
 			t_uio->uio_rw = UIO_WRITE;
 			t_uio->uio_td = td;
 			KASSERT(uiop->uio_segflg == UIO_USERSPACE ||
 			    uiop->uio_segflg == UIO_SYSSPACE,
 			    ("nfs_directio_write: Bad uio_segflg"));
 			if (uiop->uio_segflg == UIO_USERSPACE) {
 				error = copyin(uiop->uio_iov->iov_base,
 				    t_iov->iov_base, size);
 				if (error != 0)
 					goto err_free;
 			} else
 				/*
 				 * UIO_SYSSPACE may never happen, but handle
 				 * it just in case it does.
 				 */
 				bcopy(uiop->uio_iov->iov_base, t_iov->iov_base,
 				    size);
 			bp->b_flags |= B_DIRECT;
 			bp->b_iocmd = BIO_WRITE;
 			if (cred != NOCRED) {
 				crhold(cred);
 				bp->b_wcred = cred;
 			} else
 				bp->b_wcred = NOCRED;
 			bp->b_caller1 = (void *)t_uio;
 			bp->b_vp = vp;
 			error = ncl_asyncio(nmp, bp, NOCRED, td);
 err_free:
 			if (error) {
 				free(t_iov->iov_base, M_NFSDIRECTIO);
 				free(t_iov, M_NFSDIRECTIO);
 				free(t_uio, M_NFSDIRECTIO);
 				bp->b_vp = NULL;
 				uma_zfree(ncl_pbuf_zone, bp);
 				if (error == EINTR)
 					return (error);
 				goto do_sync;
 			}
 			uiop->uio_offset += size;
 			uiop->uio_resid -= size;
 			if (uiop->uio_iov->iov_len <= size) {
 				uiop->uio_iovcnt--;
 				uiop->uio_iov++;
 			} else {
 				uiop->uio_iov->iov_base =
 					(char *)uiop->uio_iov->iov_base + size;
 				uiop->uio_iov->iov_len -= size;
 			}
 		}
 	}
 	return (0);
 }
 
 /*
  * Vnode op for write using bio
  */
 int
 ncl_write(struct vop_write_args *ap)
 {
 	int biosize;
 	struct uio *uio = ap->a_uio;
 	struct thread *td = uio->uio_td;
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 	struct ucred *cred = ap->a_cred;
 	int ioflag = ap->a_ioflag;
 	struct buf *bp;
 	struct vattr vattr;
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	daddr_t lbn;
 	int bcount, noncontig_write, obcount;
 	int bp_cached, n, on, error = 0, error1, save2, wouldcommit;
 	size_t orig_resid, local_resid;
 	off_t orig_size, tmp_off;
+	struct timespec ts;
 
 	KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
 	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
 	    ("ncl_write proc"));
 	if (vp->v_type != VREG)
 		return (EIO);
 	NFSLOCKNODE(np);
 	if (np->n_flag & NWRITEERR) {
 		np->n_flag &= ~NWRITEERR;
 		NFSUNLOCKNODE(np);
 		return (np->n_error);
 	} else
 		NFSUNLOCKNODE(np);
 	mtx_lock(&nmp->nm_mtx);
 	if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
 	    (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
 		mtx_unlock(&nmp->nm_mtx);
 		(void)ncl_fsinfo(nmp, vp, cred, td);
 		mtx_lock(&nmp->nm_mtx);
 	}
 	if (nmp->nm_wsize == 0)
 		(void) newnfs_iosize(nmp);
 	mtx_unlock(&nmp->nm_mtx);
 
 	/*
 	 * Synchronously flush pending buffers if we are in synchronous
 	 * mode or if we are appending.
 	 */
 	if (ioflag & (IO_APPEND | IO_SYNC)) {
 		NFSLOCKNODE(np);
 		if (np->n_flag & NMODIFIED) {
 			NFSUNLOCKNODE(np);
 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
 			/*
 			 * Require non-blocking, synchronous writes to
 			 * dirty files to inform the program it needs
 			 * to fsync(2) explicitly.
 			 */
 			if (ioflag & IO_NDELAY)
 				return (EAGAIN);
 #endif
 			np->n_attrstamp = 0;
 			KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 			error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
 			    IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
 			if (error != 0)
 				return (error);
 		} else
 			NFSUNLOCKNODE(np);
 	}
 
 	orig_resid = uio->uio_resid;
 	NFSLOCKNODE(np);
 	orig_size = np->n_size;
 	NFSUNLOCKNODE(np);
 
 	/*
 	 * If IO_APPEND then load uio_offset.  We restart here if we cannot
 	 * get the append lock.
 	 */
 	if (ioflag & IO_APPEND) {
 		np->n_attrstamp = 0;
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 		error = VOP_GETATTR(vp, &vattr, cred);
 		if (error)
 			return (error);
 		NFSLOCKNODE(np);
 		uio->uio_offset = np->n_size;
 		NFSUNLOCKNODE(np);
 	}
 
 	if (uio->uio_offset < 0)
 		return (EINVAL);
 	tmp_off = uio->uio_offset + uio->uio_resid;
 	if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)
 		return (EFBIG);
 	if (uio->uio_resid == 0)
 		return (0);
 
 	if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
 		return nfs_directio_write(vp, uio, cred, ioflag);
 
 	/*
 	 * Maybe this should be above the vnode op call, but so long as
 	 * file servers have no limits, i don't think it matters
 	 */
 	if (vn_rlimit_fsize(vp, uio, td))
 		return (EFBIG);
 
 	save2 = curthread_pflags2_set(TDP2_SBPAGES);
 	biosize = vp->v_bufobj.bo_bsize;
 	/*
 	 * Find all of this file's B_NEEDCOMMIT buffers.  If our writes
 	 * would exceed the local maximum per-file write commit size when
 	 * combined with those, we must decide whether to flush,
 	 * go synchronous, or return error.  We don't bother checking
 	 * IO_UNIT -- we just make all writes atomic anyway, as there's
 	 * no point optimizing for something that really won't ever happen.
 	 */
 	wouldcommit = 0;
 	if (!(ioflag & IO_SYNC)) {
 		int nflag;
 
 		NFSLOCKNODE(np);
 		nflag = np->n_flag;
 		NFSUNLOCKNODE(np);
 		if (nflag & NMODIFIED) {
 			BO_LOCK(&vp->v_bufobj);
 			if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
 				TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
 				    b_bobufs) {
 					if (bp->b_flags & B_NEEDCOMMIT)
 						wouldcommit += bp->b_bcount;
 				}
 			}
 			BO_UNLOCK(&vp->v_bufobj);
 		}
 	}
 
 	do {
 		if (!(ioflag & IO_SYNC)) {
 			wouldcommit += biosize;
 			if (wouldcommit > nmp->nm_wcommitsize) {
 				np->n_attrstamp = 0;
 				KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 				error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
 				    IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
 				if (error != 0)
 					goto out;
 				wouldcommit = biosize;
 			}
 		}
 
 		NFSINCRGLOBAL(nfsstatsv1.biocache_writes);
 		lbn = uio->uio_offset / biosize;
 		on = uio->uio_offset - (lbn * biosize);
 		n = MIN((unsigned)(biosize - on), uio->uio_resid);
 again:
 		/*
 		 * Handle direct append and file extension cases, calculate
 		 * unaligned buffer size.
 		 */
 		NFSLOCKNODE(np);
 		if ((np->n_flag & NHASBEENLOCKED) == 0 &&
 		    (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0)
 			noncontig_write = 1;
 		else
 			noncontig_write = 0;
 		if ((uio->uio_offset == np->n_size ||
 		    (noncontig_write != 0 &&
 		    lbn == (np->n_size / biosize) &&
 		    uio->uio_offset + n > np->n_size)) && n) {
 			NFSUNLOCKNODE(np);
 			/*
 			 * Get the buffer (in its pre-append state to maintain
 			 * B_CACHE if it was previously set).  Resize the
 			 * nfsnode after we have locked the buffer to prevent
 			 * readers from reading garbage.
 			 */
 			obcount = np->n_size - (lbn * biosize);
 			bp = nfs_getcacheblk(vp, lbn, obcount, td);
 
 			if (bp != NULL) {
 				long save;
 
 				NFSLOCKNODE(np);
 				np->n_size = uio->uio_offset + n;
 				np->n_flag |= NMODIFIED;
 				np->n_flag &= ~NVNSETSZSKIP;
 				vnode_pager_setsize(vp, np->n_size);
 				NFSUNLOCKNODE(np);
 
 				save = bp->b_flags & B_CACHE;
 				bcount = on + n;
 				allocbuf(bp, bcount);
 				bp->b_flags |= save;
 				if (noncontig_write != 0 && on > obcount)
 					vfs_bio_bzero_buf(bp, obcount, on -
 					    obcount);
 			}
 		} else {
 			/*
 			 * Obtain the locked cache block first, and then
 			 * adjust the file's size as appropriate.
 			 */
 			bcount = on + n;
 			if ((off_t)lbn * biosize + bcount < np->n_size) {
 				if ((off_t)(lbn + 1) * biosize < np->n_size)
 					bcount = biosize;
 				else
 					bcount = np->n_size - (off_t)lbn * biosize;
 			}
 			NFSUNLOCKNODE(np);
 			bp = nfs_getcacheblk(vp, lbn, bcount, td);
 			NFSLOCKNODE(np);
 			if (uio->uio_offset + n > np->n_size) {
 				np->n_size = uio->uio_offset + n;
 				np->n_flag |= NMODIFIED;
 				np->n_flag &= ~NVNSETSZSKIP;
 				vnode_pager_setsize(vp, np->n_size);
 			}
 			NFSUNLOCKNODE(np);
 		}
 
 		if (!bp) {
 			error = newnfs_sigintr(nmp, td);
 			if (!error)
 				error = EINTR;
 			break;
 		}
 
 		/*
 		 * Issue a READ if B_CACHE is not set.  In special-append
 		 * mode, B_CACHE is based on the buffer prior to the write
 		 * op and is typically set, avoiding the read.  If a read
 		 * is required in special append mode, the server will
 		 * probably send us a short-read since we extended the file
 		 * on our end, resulting in b_resid == 0 and, thusly,
 		 * B_CACHE getting set.
 		 *
 		 * We can also avoid issuing the read if the write covers
 		 * the entire buffer.  We have to make sure the buffer state
 		 * is reasonable in this case since we will not be initiating
 		 * I/O.  See the comments in kern/vfs_bio.c's getblk() for
 		 * more information.
 		 *
 		 * B_CACHE may also be set due to the buffer being cached
 		 * normally.
 		 */
 
 		bp_cached = 1;
 		if (on == 0 && n == bcount) {
 			if ((bp->b_flags & B_CACHE) == 0)
 				bp_cached = 0;
 			bp->b_flags |= B_CACHE;
 			bp->b_flags &= ~B_INVAL;
 			bp->b_ioflags &= ~BIO_ERROR;
 		}
 
 		if ((bp->b_flags & B_CACHE) == 0) {
 			bp->b_iocmd = BIO_READ;
 			vfs_busy_pages(bp, 0);
 			error = ncl_doio(vp, bp, cred, td, 0);
 			if (error) {
 				brelse(bp);
 				break;
 			}
 		}
 		if (bp->b_wcred == NOCRED)
 			bp->b_wcred = crhold(cred);
 		NFSLOCKNODE(np);
 		np->n_flag |= NMODIFIED;
 		NFSUNLOCKNODE(np);
 
 		/*
 		 * If dirtyend exceeds file size, chop it down.  This should
 		 * not normally occur but there is an append race where it
 		 * might occur XXX, so we log it.
 		 *
 		 * If the chopping creates a reverse-indexed or degenerate
 		 * situation with dirtyoff/end, we 0 both of them.
 		 */
 
 		if (bp->b_dirtyend > bcount) {
 			printf("NFS append race @%lx:%d\n",
 			    (long)bp->b_blkno * DEV_BSIZE,
 			    bp->b_dirtyend - bcount);
 			bp->b_dirtyend = bcount;
 		}
 
 		if (bp->b_dirtyoff >= bp->b_dirtyend)
 			bp->b_dirtyoff = bp->b_dirtyend = 0;
 
 		/*
 		 * If the new write will leave a contiguous dirty
 		 * area, just update the b_dirtyoff and b_dirtyend,
 		 * otherwise force a write rpc of the old dirty area.
 		 *
 		 * If there has been a file lock applied to this file
 		 * or vfs.nfs.old_noncontig_writing is set, do the following:
 		 * While it is possible to merge discontiguous writes due to
 		 * our having a B_CACHE buffer ( and thus valid read data
 		 * for the hole), we don't because it could lead to
 		 * significant cache coherency problems with multiple clients,
 		 * especially if locking is implemented later on.
 		 *
 		 * If vfs.nfs.old_noncontig_writing is not set and there has
 		 * not been file locking done on this file:
 		 * Relax coherency a bit for the sake of performance and
 		 * expand the current dirty region to contain the new
 		 * write even if it means we mark some non-dirty data as
 		 * dirty.
 		 */
 
 		if (noncontig_write == 0 && bp->b_dirtyend > 0 &&
 		    (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
 			if (bwrite(bp) == EINTR) {
 				error = EINTR;
 				break;
 			}
 			goto again;
 		}
 
 		local_resid = uio->uio_resid;
 		error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio);
 
 		if (error != 0 && !bp_cached) {
 			/*
 			 * This block has no other content then what
 			 * possibly was written by the faulty uiomove.
 			 * Release it, forgetting the data pages, to
 			 * prevent the leak of uninitialized data to
 			 * usermode.
 			 */
 			bp->b_ioflags |= BIO_ERROR;
 			brelse(bp);
 			uio->uio_offset -= local_resid - uio->uio_resid;
 			uio->uio_resid = local_resid;
 			break;
 		}
 
 		/*
 		 * Since this block is being modified, it must be written
 		 * again and not just committed.  Since write clustering does
 		 * not work for the stage 1 data write, only the stage 2
 		 * commit rpc, we have to clear B_CLUSTEROK as well.
 		 */
 		bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 
 		/*
 		 * Get the partial update on the progress made from
 		 * uiomove, if an error occurred.
 		 */
 		if (error != 0)
 			n = local_resid - uio->uio_resid;
 
 		/*
 		 * Only update dirtyoff/dirtyend if not a degenerate
 		 * condition.
 		 */
 		if (n > 0) {
 			if (bp->b_dirtyend > 0) {
 				bp->b_dirtyoff = min(on, bp->b_dirtyoff);
 				bp->b_dirtyend = max((on + n), bp->b_dirtyend);
 			} else {
 				bp->b_dirtyoff = on;
 				bp->b_dirtyend = on + n;
 			}
 			vfs_bio_set_valid(bp, on, n);
 		}
 
 		/*
 		 * If IO_SYNC do bwrite().
 		 *
 		 * IO_INVAL appears to be unused.  The idea appears to be
 		 * to turn off caching in this case.  Very odd.  XXX
 		 */
 		if ((ioflag & IO_SYNC)) {
 			if (ioflag & IO_INVAL)
 				bp->b_flags |= B_NOCACHE;
 			error1 = bwrite(bp);
 			if (error1 != 0) {
 				if (error == 0)
 					error = error1;
 				break;
 			}
 		} else if ((n + on) == biosize || (ioflag & IO_ASYNC) != 0) {
 			bp->b_flags |= B_ASYNC;
 			(void) ncl_writebp(bp, 0, NULL);
 		} else {
 			bdwrite(bp);
 		}
 
 		if (error != 0)
 			break;
 	} while (uio->uio_resid > 0 && n > 0);
 
-	if (error != 0) {
+	if (error == 0) {
+		nanouptime(&ts);
+		NFSLOCKNODE(np);
+		np->n_localmodtime = ts;
+		NFSUNLOCKNODE(np);
+	} else {
 		if (ioflag & IO_UNIT) {
 			VATTR_NULL(&vattr);
 			vattr.va_size = orig_size;
 			/* IO_SYNC is handled implicitely */
 			(void)VOP_SETATTR(vp, &vattr, cred);
 			uio->uio_offset -= orig_resid - uio->uio_resid;
 			uio->uio_resid = orig_resid;
 		}
 	}
 
 out:
 	curthread_pflags2_restore(save2);
 	return (error);
 }
 
 /*
  * Get an nfs cache block.
  *
  * Allocate a new one if the block isn't currently in the cache
  * and return the block marked busy. If the calling process is
  * interrupted by a signal for an interruptible mount point, return
  * NULL.
  *
  * The caller must carefully deal with the possible B_INVAL state of
  * the buffer.  ncl_doio() clears B_INVAL (and ncl_asyncio() clears it
  * indirectly), so synchronous reads can be issued without worrying about
  * the B_INVAL state.  We have to be a little more careful when dealing
  * with writes (see comments in nfs_write()) when extending a file past
  * its EOF.
  */
 static struct buf *
 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
 {
 	struct buf *bp;
 	struct mount *mp;
 	struct nfsmount *nmp;
 
 	mp = vp->v_mount;
 	nmp = VFSTONFS(mp);
 
 	if (nmp->nm_flag & NFSMNT_INT) {
 		sigset_t oldset;
 
 		newnfs_set_sigmask(td, &oldset);
 		bp = getblk(vp, bn, size, PCATCH, 0, 0);
 		newnfs_restore_sigmask(td, &oldset);
 		while (bp == NULL) {
 			if (newnfs_sigintr(nmp, td))
 				return (NULL);
 			bp = getblk(vp, bn, size, 0, 2 * hz, 0);
 		}
 	} else {
 		bp = getblk(vp, bn, size, 0, 0, 0);
 	}
 
 	if (vp->v_type == VREG)
 		bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE);
 	return (bp);
 }
 
 /*
  * Flush and invalidate all dirty buffers. If another process is already
  * doing the flush, just wait for completion.
  */
 int
 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
 {
 	struct nfsnode *np = VTONFS(vp);
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	int error = 0, slpflag, slptimeo;
 	bool old_lock;
+	struct timespec ts;
 
 	ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf");
 
 	if ((nmp->nm_flag & NFSMNT_INT) == 0)
 		intrflg = 0;
 	if (NFSCL_FORCEDISM(nmp->nm_mountp))
 		intrflg = 1;
 	if (intrflg) {
 		slpflag = PCATCH;
 		slptimeo = 2 * hz;
 	} else {
 		slpflag = 0;
 		slptimeo = 0;
 	}
 
 	old_lock = ncl_excl_start(vp);
 	if (old_lock)
 		flags |= V_ALLOWCLEAN;
 
 	/*
 	 * Now, flush as required.
 	 */
 	if ((flags & (V_SAVE | V_VMIO)) == V_SAVE &&
 	     vp->v_bufobj.bo_object != NULL) {
 		VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
 		vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
 		VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
 		/*
 		 * If the page clean was interrupted, fail the invalidation.
 		 * Not doing so, we run the risk of losing dirty pages in the
 		 * vinvalbuf() call below.
 		 */
 		if (intrflg && (error = newnfs_sigintr(nmp, td)))
 			goto out;
 	}
 
 	error = vinvalbuf(vp, flags, slpflag, 0);
 	while (error) {
 		if (intrflg && (error = newnfs_sigintr(nmp, td)))
 			goto out;
 		error = vinvalbuf(vp, flags, 0, slptimeo);
 	}
 	if (NFSHASPNFS(nmp)) {
 		nfscl_layoutcommit(vp, td);
+		nanouptime(&ts);
 		/*
 		 * Invalidate the attribute cache, since writes to a DS
 		 * won't update the size attribute.
 		 */
 		NFSLOCKNODE(np);
 		np->n_attrstamp = 0;
-	} else
+	} else {
+		nanouptime(&ts);
 		NFSLOCKNODE(np);
-	if (np->n_directio_asyncwr == 0)
+	}
+	if (np->n_directio_asyncwr == 0 && (np->n_flag & NMODIFIED) != 0) {
+		np->n_localmodtime = ts;
 		np->n_flag &= ~NMODIFIED;
+	}
 	NFSUNLOCKNODE(np);
 out:
 	ncl_excl_finish(vp, old_lock);
 	return error;
 }
 
 /*
  * Initiate asynchronous I/O. Return an error if no nfsiods are available.
  * This is mainly to avoid queueing async I/O requests when the nfsiods
  * are all hung on a dead server.
  *
  * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
  * is eventually dequeued by the async daemon, ncl_doio() *will*.
  */
 int
 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
 {
 	int iod;
 	int gotiod;
 	int slpflag = 0;
 	int slptimeo = 0;
 	int error, error2;
 
 	/*
 	 * Commits are usually short and sweet so lets save some cpu and
 	 * leave the async daemons for more important rpc's (such as reads
 	 * and writes).
 	 *
 	 * Readdirplus RPCs do vget()s to acquire the vnodes for entries
 	 * in the directory in order to update attributes. This can deadlock
 	 * with another thread that is waiting for async I/O to be done by
 	 * an nfsiod thread while holding a lock on one of these vnodes.
 	 * To avoid this deadlock, don't allow the async nfsiod threads to
 	 * perform Readdirplus RPCs.
 	 */
 	NFSLOCKIOD();
 	if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
 	     (nmp->nm_bufqiods > ncl_numasync / 2)) ||
 	    (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) {
 		NFSUNLOCKIOD();
 		return(EIO);
 	}
 again:
 	if (nmp->nm_flag & NFSMNT_INT)
 		slpflag = PCATCH;
 	gotiod = FALSE;
 
 	/*
 	 * Find a free iod to process this request.
 	 */
 	for (iod = 0; iod < ncl_numasync; iod++)
 		if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) {
 			gotiod = TRUE;
 			break;
 		}
 
 	/*
 	 * Try to create one if none are free.
 	 */
 	if (!gotiod)
 		ncl_nfsiodnew();
 	else {
 		/*
 		 * Found one, so wake it up and tell it which
 		 * mount to process.
 		 */
 		NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n",
 		    iod, nmp));
 		ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
 		ncl_iodmount[iod] = nmp;
 		nmp->nm_bufqiods++;
 		wakeup(&ncl_iodwant[iod]);
 	}
 
 	/*
 	 * If none are free, we may already have an iod working on this mount
 	 * point.  If so, it will process our request.
 	 */
 	if (!gotiod) {
 		if (nmp->nm_bufqiods > 0) {
 			NFS_DPF(ASYNCIO,
 				("ncl_asyncio: %d iods are already processing mount %p\n",
 				 nmp->nm_bufqiods, nmp));
 			gotiod = TRUE;
 		}
 	}
 
 	/*
 	 * If we have an iod which can process the request, then queue
 	 * the buffer.
 	 */
 	if (gotiod) {
 		/*
 		 * Ensure that the queue never grows too large.  We still want
 		 * to asynchronize so we block rather then return EIO.
 		 */
 		while (nmp->nm_bufqlen >= 2*ncl_numasync) {
 			NFS_DPF(ASYNCIO,
 				("ncl_asyncio: waiting for mount %p queue to drain\n", nmp));
 			nmp->nm_bufqwant = TRUE;
 			error = newnfs_msleep(td, &nmp->nm_bufq,
 			    &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio",
 			   slptimeo);
 			if (error) {
 				error2 = newnfs_sigintr(nmp, td);
 				if (error2) {
 					NFSUNLOCKIOD();
 					return (error2);
 				}
 				if (slpflag == PCATCH) {
 					slpflag = 0;
 					slptimeo = 2 * hz;
 				}
 			}
 			/*
 			 * We might have lost our iod while sleeping,
 			 * so check and loop if necessary.
 			 */
 			goto again;
 		}
 
 		/* We might have lost our nfsiod */
 		if (nmp->nm_bufqiods == 0) {
 			NFS_DPF(ASYNCIO,
 				("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
 			goto again;
 		}
 
 		if (bp->b_iocmd == BIO_READ) {
 			if (bp->b_rcred == NOCRED && cred != NOCRED)
 				bp->b_rcred = crhold(cred);
 		} else {
 			if (bp->b_wcred == NOCRED && cred != NOCRED)
 				bp->b_wcred = crhold(cred);
 		}
 
 		if (bp->b_flags & B_REMFREE)
 			bremfreef(bp);
 		BUF_KERNPROC(bp);
 		TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
 		nmp->nm_bufqlen++;
 		if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
 			NFSLOCKNODE(VTONFS(bp->b_vp));
 			VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
 			VTONFS(bp->b_vp)->n_directio_asyncwr++;
 			NFSUNLOCKNODE(VTONFS(bp->b_vp));
 		}
 		NFSUNLOCKIOD();
 		return (0);
 	}
 
 	NFSUNLOCKIOD();
 
 	/*
 	 * All the iods are busy on other mounts, so return EIO to
 	 * force the caller to process the i/o synchronously.
 	 */
 	NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n"));
 	return (EIO);
 }
 
 void
 ncl_doio_directwrite(struct buf *bp)
 {
 	int iomode, must_commit;
 	struct uio *uiop = (struct uio *)bp->b_caller1;
 	char *iov_base = uiop->uio_iov->iov_base;
 
 	iomode = NFSWRITE_FILESYNC;
 	uiop->uio_td = NULL; /* NULL since we're in nfsiod */
 	ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0);
 	KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write"));
 	free(iov_base, M_NFSDIRECTIO);
 	free(uiop->uio_iov, M_NFSDIRECTIO);
 	free(uiop, M_NFSDIRECTIO);
 	if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
 		struct nfsnode *np = VTONFS(bp->b_vp);
 		NFSLOCKNODE(np);
 		if (NFSHASPNFS(VFSTONFS(bp->b_vp->v_mount))) {
 			/*
 			 * Invalidate the attribute cache, since writes to a DS
 			 * won't update the size attribute.
 			 */
 			np->n_attrstamp = 0;
 		}
 		np->n_directio_asyncwr--;
 		if (np->n_directio_asyncwr == 0) {
 			np->n_flag &= ~NMODIFIED;
 			if ((np->n_flag & NFSYNCWAIT)) {
 				np->n_flag &= ~NFSYNCWAIT;
 				wakeup((caddr_t)&np->n_directio_asyncwr);
 			}
 		}
 		NFSUNLOCKNODE(np);
 	}
 	bp->b_vp = NULL;
 	uma_zfree(ncl_pbuf_zone, bp);
 }
 
 /*
  * Do an I/O operation to/from a cache block. This may be called
  * synchronously or from an nfsiod.
  */
 int
 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
     int called_from_strategy)
 {
 	struct uio *uiop;
 	struct nfsnode *np;
 	struct nfsmount *nmp;
 	int error = 0, iomode, must_commit = 0;
 	struct uio uio;
 	struct iovec io;
 	struct proc *p = td ? td->td_proc : NULL;
 	uint8_t	iocmd;
 
 	np = VTONFS(vp);
 	nmp = VFSTONFS(vp->v_mount);
 	uiop = &uio;
 	uiop->uio_iov = &io;
 	uiop->uio_iovcnt = 1;
 	uiop->uio_segflg = UIO_SYSSPACE;
 	uiop->uio_td = td;
 
 	/*
 	 * clear BIO_ERROR and B_INVAL state prior to initiating the I/O.  We
 	 * do this here so we do not have to do it in all the code that
 	 * calls us.
 	 */
 	bp->b_flags &= ~B_INVAL;
 	bp->b_ioflags &= ~BIO_ERROR;
 
 	KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp));
 	iocmd = bp->b_iocmd;
 	if (iocmd == BIO_READ) {
 	    io.iov_len = uiop->uio_resid = bp->b_bcount;
 	    io.iov_base = bp->b_data;
 	    uiop->uio_rw = UIO_READ;
 
 	    switch (vp->v_type) {
 	    case VREG:
 		uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
 		NFSINCRGLOBAL(nfsstatsv1.read_bios);
 		error = ncl_readrpc(vp, uiop, cr);
 
 		if (!error) {
 		    if (uiop->uio_resid) {
 			/*
 			 * If we had a short read with no error, we must have
 			 * hit a file hole.  We should zero-fill the remainder.
 			 * This can also occur if the server hits the file EOF.
 			 *
 			 * Holes used to be able to occur due to pending
 			 * writes, but that is not possible any longer.
 			 */
 			int nread = bp->b_bcount - uiop->uio_resid;
 			ssize_t left = uiop->uio_resid;
 
 			if (left > 0)
 				bzero((char *)bp->b_data + nread, left);
 			uiop->uio_resid = 0;
 		    }
 		}
 		/* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */
 		if (p && vp->v_writecount <= -1) {
 			NFSLOCKNODE(np);
 			if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) {
 				NFSUNLOCKNODE(np);
 				PROC_LOCK(p);
 				killproc(p, "text file modification");
 				PROC_UNLOCK(p);
 			} else
 				NFSUNLOCKNODE(np);
 		}
 		break;
 	    case VLNK:
 		uiop->uio_offset = (off_t)0;
 		NFSINCRGLOBAL(nfsstatsv1.readlink_bios);
 		error = ncl_readlinkrpc(vp, uiop, cr);
 		break;
 	    case VDIR:
 		NFSINCRGLOBAL(nfsstatsv1.readdir_bios);
 		uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
 		if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
 			error = ncl_readdirplusrpc(vp, uiop, cr, td);
 			if (error == NFSERR_NOTSUPP)
 				nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
 		}
 		if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
 			error = ncl_readdirrpc(vp, uiop, cr, td);
 		/*
 		 * end-of-directory sets B_INVAL but does not generate an
 		 * error.
 		 */
 		if (error == 0 && uiop->uio_resid == bp->b_bcount)
 			bp->b_flags |= B_INVAL;
 		break;
 	    default:
 		printf("ncl_doio:  type %x unexpected\n", vp->v_type);
 		break;
 	    }
 	    if (error) {
 		bp->b_ioflags |= BIO_ERROR;
 		bp->b_error = error;
 	    }
 	} else {
 	    /*
 	     * If we only need to commit, try to commit
 	     */
 	    if (bp->b_flags & B_NEEDCOMMIT) {
 		    int retv;
 		    off_t off;
 
 		    off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
 		    retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff,
 			bp->b_wcred, td);
 		    if (retv == 0) {
 			    bp->b_dirtyoff = bp->b_dirtyend = 0;
 			    bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 			    bp->b_resid = 0;
 			    bufdone(bp);
 			    return (0);
 		    }
 		    if (retv == NFSERR_STALEWRITEVERF) {
 			    ncl_clearcommit(vp->v_mount);
 		    }
 	    }
 
 	    /*
 	     * Setup for actual write
 	     */
 	    NFSLOCKNODE(np);
 	    if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
 		bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
 	    NFSUNLOCKNODE(np);
 
 	    if (bp->b_dirtyend > bp->b_dirtyoff) {
 		io.iov_len = uiop->uio_resid = bp->b_dirtyend
 		    - bp->b_dirtyoff;
 		uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
 		    + bp->b_dirtyoff;
 		io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
 		uiop->uio_rw = UIO_WRITE;
 		NFSINCRGLOBAL(nfsstatsv1.write_bios);
 
 		if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
 		    iomode = NFSWRITE_UNSTABLE;
 		else
 		    iomode = NFSWRITE_FILESYNC;
 
 		error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit,
 		    called_from_strategy);
 
 		/*
 		 * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
 		 * to cluster the buffers needing commit.  This will allow
 		 * the system to submit a single commit rpc for the whole
 		 * cluster.  We can do this even if the buffer is not 100%
 		 * dirty (relative to the NFS blocksize), so we optimize the
 		 * append-to-file-case.
 		 *
 		 * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
 		 * cleared because write clustering only works for commit
 		 * rpc's, not for the data portion of the write).
 		 */
 
 		if (!error && iomode == NFSWRITE_UNSTABLE) {
 		    bp->b_flags |= B_NEEDCOMMIT;
 		    if (bp->b_dirtyoff == 0
 			&& bp->b_dirtyend == bp->b_bcount)
 			bp->b_flags |= B_CLUSTEROK;
 		} else {
 		    bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 		}
 
 		/*
 		 * For an interrupted write, the buffer is still valid
 		 * and the write hasn't been pushed to the server yet,
 		 * so we can't set BIO_ERROR and report the interruption
 		 * by setting B_EINTR. For the B_ASYNC case, B_EINTR
 		 * is not relevant, so the rpc attempt is essentially
 		 * a noop.  For the case of a V3 write rpc not being
 		 * committed to stable storage, the block is still
 		 * dirty and requires either a commit rpc or another
 		 * write rpc with iomode == NFSV3WRITE_FILESYNC before
 		 * the block is reused. This is indicated by setting
 		 * the B_DELWRI and B_NEEDCOMMIT flags.
 		 *
 		 * EIO is returned by ncl_writerpc() to indicate a recoverable
 		 * write error and is handled as above, except that
 		 * B_EINTR isn't set. One cause of this is a stale stateid
 		 * error for the RPC that indicates recovery is required,
 		 * when called with called_from_strategy != 0.
 		 *
 		 * If the buffer is marked B_PAGING, it does not reside on
 		 * the vp's paging queues so we cannot call bdirty().  The
 		 * bp in this case is not an NFS cache block so we should
 		 * be safe. XXX
 		 *
 		 * The logic below breaks up errors into recoverable and
 		 * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
 		 * and keep the buffer around for potential write retries.
 		 * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
 		 * and save the error in the nfsnode. This is less than ideal
 		 * but necessary. Keeping such buffers around could potentially
 		 * cause buffer exhaustion eventually (they can never be written
 		 * out, so will get constantly be re-dirtied). It also causes
 		 * all sorts of vfs panics. For non-recoverable write errors,
 		 * also invalidate the attrcache, so we'll be forced to go over
 		 * the wire for this object, returning an error to user on next
 		 * call (most of the time).
 		 */
 		if (error == EINTR || error == EIO || error == ETIMEDOUT
 		    || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
 			bp->b_flags &= ~(B_INVAL|B_NOCACHE);
 			if ((bp->b_flags & B_PAGING) == 0) {
 			    bdirty(bp);
 			    bp->b_flags &= ~B_DONE;
 			}
 			if ((error == EINTR || error == ETIMEDOUT) &&
 			    (bp->b_flags & B_ASYNC) == 0)
 			    bp->b_flags |= B_EINTR;
 		} else {
 		    if (error) {
 			bp->b_ioflags |= BIO_ERROR;
 			bp->b_flags |= B_INVAL;
 			bp->b_error = np->n_error = error;
 			NFSLOCKNODE(np);
 			np->n_flag |= NWRITEERR;
 			np->n_attrstamp = 0;
 			KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 			NFSUNLOCKNODE(np);
 		    }
 		    bp->b_dirtyoff = bp->b_dirtyend = 0;
 		}
 	    } else {
 		bp->b_resid = 0;
 		bufdone(bp);
 		return (0);
 	    }
 	}
 	bp->b_resid = uiop->uio_resid;
 	if (must_commit)
 	    ncl_clearcommit(vp->v_mount);
 	bufdone(bp);
 	return (error);
 }
 
 /*
  * Used to aid in handling ftruncate() operations on the NFS client side.
  * Truncation creates a number of special problems for NFS.  We have to
  * throw away VM pages and buffer cache buffers that are beyond EOF, and
  * we have to properly handle VM pages or (potentially dirty) buffers
  * that straddle the truncation point.
  */
 
 int
 ncl_meta_setsize(struct vnode *vp, struct thread *td, u_quad_t nsize)
 {
 	struct nfsnode *np = VTONFS(vp);
 	u_quad_t tsize;
 	int biosize = vp->v_bufobj.bo_bsize;
 	int error = 0;
 
 	NFSLOCKNODE(np);
 	tsize = np->n_size;
 	np->n_size = nsize;
 	NFSUNLOCKNODE(np);
 
 	if (nsize < tsize) {
 		struct buf *bp;
 		daddr_t lbn;
 		int bufsize;
 
 		/*
 		 * vtruncbuf() doesn't get the buffer overlapping the
 		 * truncation point.  We may have a B_DELWRI and/or B_CACHE
 		 * buffer that now needs to be truncated.
 		 */
 		error = vtruncbuf(vp, nsize, biosize);
 		lbn = nsize / biosize;
 		bufsize = nsize - (lbn * biosize);
 		bp = nfs_getcacheblk(vp, lbn, bufsize, td);
 		if (!bp)
 			return EINTR;
 		if (bp->b_dirtyoff > bp->b_bcount)
 			bp->b_dirtyoff = bp->b_bcount;
 		if (bp->b_dirtyend > bp->b_bcount)
 			bp->b_dirtyend = bp->b_bcount;
 		bp->b_flags |= B_RELBUF;  /* don't leave garbage around */
 		brelse(bp);
 	} else {
 		vnode_pager_setsize(vp, nsize);
 	}
 	return(error);
 }
diff --git a/sys/fs/nfsclient/nfs_clvnops.c b/sys/fs/nfsclient/nfs_clvnops.c
index f63eadf26a91..1685edf5b2de 100644
--- a/sys/fs/nfsclient/nfs_clvnops.c
+++ b/sys/fs/nfsclient/nfs_clvnops.c
@@ -1,4517 +1,4524 @@
 /*-
  * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Rick Macklem at The University of Guelph.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
  *	from nfs_vnops.c	8.16 (Berkeley) 5/27/95
  */
 
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD$");
 
 /*
  * vnode op calls for Sun NFS version 2, 3 and 4
  */
 
 #include "opt_inet.h"
 
 #include <sys/param.h>
 #include <sys/kernel.h>
 #include <sys/systm.h>
 #include <sys/resourcevar.h>
 #include <sys/proc.h>
 #include <sys/mount.h>
 #include <sys/bio.h>
 #include <sys/buf.h>
 #include <sys/extattr.h>
 #include <sys/filio.h>
 #include <sys/jail.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/namei.h>
 #include <sys/socket.h>
 #include <sys/vnode.h>
 #include <sys/dirent.h>
 #include <sys/fcntl.h>
 #include <sys/lockf.h>
 #include <sys/stat.h>
 #include <sys/sysctl.h>
 #include <sys/signalvar.h>
 
 #include <vm/vm.h>
 #include <vm/vm_extern.h>
 #include <vm/vm_object.h>
 
 #include <fs/nfs/nfsport.h>
 #include <fs/nfsclient/nfsnode.h>
 #include <fs/nfsclient/nfsmount.h>
 #include <fs/nfsclient/nfs.h>
 #include <fs/nfsclient/nfs_kdtrace.h>
 
 #include <net/if.h>
 #include <netinet/in.h>
 #include <netinet/in_var.h>
 
 #include <nfs/nfs_lock.h>
 
 #ifdef KDTRACE_HOOKS
 #include <sys/dtrace_bsd.h>
 
 dtrace_nfsclient_accesscache_flush_probe_func_t
 		dtrace_nfscl_accesscache_flush_done_probe;
 uint32_t	nfscl_accesscache_flush_done_id;
 
 dtrace_nfsclient_accesscache_get_probe_func_t
 		dtrace_nfscl_accesscache_get_hit_probe,
 		dtrace_nfscl_accesscache_get_miss_probe;
 uint32_t	nfscl_accesscache_get_hit_id;
 uint32_t	nfscl_accesscache_get_miss_id;
 
 dtrace_nfsclient_accesscache_load_probe_func_t
 		dtrace_nfscl_accesscache_load_done_probe;
 uint32_t	nfscl_accesscache_load_done_id;
 #endif /* !KDTRACE_HOOKS */
 
 /* Defs */
 #define	TRUE	1
 #define	FALSE	0
 
 extern struct nfsstatsv1 nfsstatsv1;
 extern int nfsrv_useacl;
 extern int nfscl_debuglevel;
 MALLOC_DECLARE(M_NEWNFSREQ);
 
 static vop_read_t	nfsfifo_read;
 static vop_write_t	nfsfifo_write;
 static vop_close_t	nfsfifo_close;
 static int	nfs_setattrrpc(struct vnode *, struct vattr *, struct ucred *,
 		    struct thread *);
 static vop_lookup_t	nfs_lookup;
 static vop_create_t	nfs_create;
 static vop_mknod_t	nfs_mknod;
 static vop_open_t	nfs_open;
 static vop_pathconf_t	nfs_pathconf;
 static vop_close_t	nfs_close;
 static vop_access_t	nfs_access;
 static vop_getattr_t	nfs_getattr;
 static vop_setattr_t	nfs_setattr;
 static vop_read_t	nfs_read;
 static vop_fsync_t	nfs_fsync;
 static vop_remove_t	nfs_remove;
 static vop_link_t	nfs_link;
 static vop_rename_t	nfs_rename;
 static vop_mkdir_t	nfs_mkdir;
 static vop_rmdir_t	nfs_rmdir;
 static vop_symlink_t	nfs_symlink;
 static vop_readdir_t	nfs_readdir;
 static vop_strategy_t	nfs_strategy;
 static	int	nfs_lookitup(struct vnode *, char *, int,
 		    struct ucred *, struct thread *, struct nfsnode **);
 static	int	nfs_sillyrename(struct vnode *, struct vnode *,
 		    struct componentname *);
 static vop_access_t	nfsspec_access;
 static vop_readlink_t	nfs_readlink;
 static vop_print_t	nfs_print;
 static vop_advlock_t	nfs_advlock;
 static vop_advlockasync_t nfs_advlockasync;
 static vop_getacl_t nfs_getacl;
 static vop_setacl_t nfs_setacl;
 static vop_advise_t nfs_advise;
 static vop_allocate_t nfs_allocate;
 static vop_deallocate_t nfs_deallocate;
 static vop_copy_file_range_t nfs_copy_file_range;
 static vop_ioctl_t nfs_ioctl;
 static vop_getextattr_t nfs_getextattr;
 static vop_setextattr_t nfs_setextattr;
 static vop_listextattr_t nfs_listextattr;
 static vop_deleteextattr_t nfs_deleteextattr;
 static vop_lock1_t	nfs_lock;
 
 /*
  * Global vfs data structures for nfs
  */
 
 static struct vop_vector newnfs_vnodeops_nosig = {
 	.vop_default =		&default_vnodeops,
 	.vop_access =		nfs_access,
 	.vop_advlock =		nfs_advlock,
 	.vop_advlockasync =	nfs_advlockasync,
 	.vop_close =		nfs_close,
 	.vop_create =		nfs_create,
 	.vop_fsync =		nfs_fsync,
 	.vop_getattr =		nfs_getattr,
 	.vop_getpages =		ncl_getpages,
 	.vop_putpages =		ncl_putpages,
 	.vop_inactive =		ncl_inactive,
 	.vop_link =		nfs_link,
 	.vop_lock1 =		nfs_lock,
 	.vop_lookup =		nfs_lookup,
 	.vop_mkdir =		nfs_mkdir,
 	.vop_mknod =		nfs_mknod,
 	.vop_open =		nfs_open,
 	.vop_pathconf =		nfs_pathconf,
 	.vop_print =		nfs_print,
 	.vop_read =		nfs_read,
 	.vop_readdir =		nfs_readdir,
 	.vop_readlink =		nfs_readlink,
 	.vop_reclaim =		ncl_reclaim,
 	.vop_remove =		nfs_remove,
 	.vop_rename =		nfs_rename,
 	.vop_rmdir =		nfs_rmdir,
 	.vop_setattr =		nfs_setattr,
 	.vop_strategy =		nfs_strategy,
 	.vop_symlink =		nfs_symlink,
 	.vop_write =		ncl_write,
 	.vop_getacl =		nfs_getacl,
 	.vop_setacl =		nfs_setacl,
 	.vop_advise =		nfs_advise,
 	.vop_allocate =		nfs_allocate,
 	.vop_deallocate =	nfs_deallocate,
 	.vop_copy_file_range =	nfs_copy_file_range,
 	.vop_ioctl =		nfs_ioctl,
 	.vop_getextattr =	nfs_getextattr,
 	.vop_setextattr =	nfs_setextattr,
 	.vop_listextattr =	nfs_listextattr,
 	.vop_deleteextattr =	nfs_deleteextattr,
 };
 VFS_VOP_VECTOR_REGISTER(newnfs_vnodeops_nosig);
 
 static int
 nfs_vnodeops_bypass(struct vop_generic_args *a)
 {
 
 	return (vop_sigdefer(&newnfs_vnodeops_nosig, a));
 }
 
 struct vop_vector newnfs_vnodeops = {
 	.vop_default =		&default_vnodeops,
 	.vop_bypass =		nfs_vnodeops_bypass,
 };
 VFS_VOP_VECTOR_REGISTER(newnfs_vnodeops);
 
 static struct vop_vector newnfs_fifoops_nosig = {
 	.vop_default =		&fifo_specops,
 	.vop_access =		nfsspec_access,
 	.vop_close =		nfsfifo_close,
 	.vop_fsync =		nfs_fsync,
 	.vop_getattr =		nfs_getattr,
 	.vop_inactive =		ncl_inactive,
 	.vop_pathconf =		nfs_pathconf,
 	.vop_print =		nfs_print,
 	.vop_read =		nfsfifo_read,
 	.vop_reclaim =		ncl_reclaim,
 	.vop_setattr =		nfs_setattr,
 	.vop_write =		nfsfifo_write,
 };
 VFS_VOP_VECTOR_REGISTER(newnfs_fifoops_nosig);
 
 static int
 nfs_fifoops_bypass(struct vop_generic_args *a)
 {
 
 	return (vop_sigdefer(&newnfs_fifoops_nosig, a));
 }
 
 struct vop_vector newnfs_fifoops = {
 	.vop_default =		&default_vnodeops,
 	.vop_bypass =		nfs_fifoops_bypass,
 };
 VFS_VOP_VECTOR_REGISTER(newnfs_fifoops);
 
 static int nfs_mknodrpc(struct vnode *dvp, struct vnode **vpp,
     struct componentname *cnp, struct vattr *vap);
 static int nfs_removerpc(struct vnode *dvp, struct vnode *vp, char *name,
     int namelen, struct ucred *cred, struct thread *td);
 static int nfs_renamerpc(struct vnode *fdvp, struct vnode *fvp,
     char *fnameptr, int fnamelen, struct vnode *tdvp, struct vnode *tvp,
     char *tnameptr, int tnamelen, struct ucred *cred, struct thread *td);
 static int nfs_renameit(struct vnode *sdvp, struct vnode *svp,
     struct componentname *scnp, struct sillyrename *sp);
 
 /*
  * Global variables
  */
 SYSCTL_DECL(_vfs_nfs);
 
 static int	nfsaccess_cache_timeout = NFS_MAXATTRTIMO;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, access_cache_timeout, CTLFLAG_RW,
 	   &nfsaccess_cache_timeout, 0, "NFS ACCESS cache timeout");
 
 static int	nfs_prime_access_cache = 0;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, prime_access_cache, CTLFLAG_RW,
 	   &nfs_prime_access_cache, 0,
 	   "Prime NFS ACCESS cache when fetching attributes");
 
 static int	newnfs_commit_on_close = 0;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, commit_on_close, CTLFLAG_RW,
     &newnfs_commit_on_close, 0, "write+commit on close, else only write");
 
 static int	nfs_clean_pages_on_close = 1;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, clean_pages_on_close, CTLFLAG_RW,
 	   &nfs_clean_pages_on_close, 0, "NFS clean dirty pages on close");
 
 int newnfs_directio_enable = 0;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_directio_enable, CTLFLAG_RW,
 	   &newnfs_directio_enable, 0, "Enable NFS directio");
 
 int nfs_keep_dirty_on_error;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_keep_dirty_on_error, CTLFLAG_RW,
     &nfs_keep_dirty_on_error, 0, "Retry pageout if error returned");
 
 /*
  * This sysctl allows other processes to mmap a file that has been opened
  * O_DIRECT by a process.  In general, having processes mmap the file while
  * Direct IO is in progress can lead to Data Inconsistencies.  But, we allow
  * this by default to prevent DoS attacks - to prevent a malicious user from
  * opening up files O_DIRECT preventing other users from mmap'ing these
  * files.  "Protected" environments where stricter consistency guarantees are
  * required can disable this knob.  The process that opened the file O_DIRECT
  * cannot mmap() the file, because mmap'ed IO on an O_DIRECT open() is not
  * meaningful.
  */
 int newnfs_directio_allow_mmap = 1;
 SYSCTL_INT(_vfs_nfs, OID_AUTO, nfs_directio_allow_mmap, CTLFLAG_RW,
 	   &newnfs_directio_allow_mmap, 0, "Enable mmaped IO on file with O_DIRECT opens");
 
 static uint64_t	nfs_maxalloclen = 64 * 1024 * 1024;
 SYSCTL_U64(_vfs_nfs, OID_AUTO, maxalloclen, CTLFLAG_RW,
 	   &nfs_maxalloclen, 0, "NFS max allocate/deallocate length");
 
 #define	NFSACCESS_ALL (NFSACCESS_READ | NFSACCESS_MODIFY		\
 			 | NFSACCESS_EXTEND | NFSACCESS_EXECUTE	\
 			 | NFSACCESS_DELETE | NFSACCESS_LOOKUP)
 
 /*
  * SMP Locking Note :
  * The list of locks after the description of the lock is the ordering
  * of other locks acquired with the lock held.
  * np->n_mtx : Protects the fields in the nfsnode.
        VM Object Lock
        VI_MTX (acquired indirectly)
  * nmp->nm_mtx : Protects the fields in the nfsmount.
        rep->r_mtx
  * ncl_iod_mutex : Global lock, protects shared nfsiod state.
  * nfs_reqq_mtx : Global lock, protects the nfs_reqq list.
        nmp->nm_mtx
        rep->r_mtx
  * rep->r_mtx : Protects the fields in an nfsreq.
  */
 
 static int
 nfs_lock(struct vop_lock1_args *ap)
 {
 	struct vnode *vp;
 	struct nfsnode *np;
 	u_quad_t nsize;
 	int error, lktype;
 	bool onfault;
 
 	vp = ap->a_vp;
 	lktype = ap->a_flags & LK_TYPE_MASK;
 	error = VOP_LOCK1_APV(&default_vnodeops, ap);
 	if (error != 0 || vp->v_op != &newnfs_vnodeops)
 		return (error);
 	np = VTONFS(vp);
 	if (np == NULL)
 		return (0);
 	NFSLOCKNODE(np);
 	if ((np->n_flag & NVNSETSZSKIP) == 0 || (lktype != LK_SHARED &&
 	    lktype != LK_EXCLUSIVE && lktype != LK_UPGRADE &&
 	    lktype != LK_TRYUPGRADE)) {
 		NFSUNLOCKNODE(np);
 		return (0);
 	}
 	onfault = (ap->a_flags & LK_EATTR_MASK) == LK_NOWAIT &&
 	    (ap->a_flags & LK_INIT_MASK) == LK_CANRECURSE &&
 	    (lktype == LK_SHARED || lktype == LK_EXCLUSIVE);
 	if (onfault && vp->v_vnlock->lk_recurse == 0) {
 		/*
 		 * Force retry in vm_fault(), to make the lock request
 		 * sleepable, which allows us to piggy-back the
 		 * sleepable call to vnode_pager_setsize().
 		 */
 		NFSUNLOCKNODE(np);
 		VOP_UNLOCK(vp);
 		return (EBUSY);
 	}
 	if ((ap->a_flags & LK_NOWAIT) != 0 ||
 	    (lktype == LK_SHARED && vp->v_vnlock->lk_recurse > 0)) {
 		NFSUNLOCKNODE(np);
 		return (0);
 	}
 	if (lktype == LK_SHARED) {
 		NFSUNLOCKNODE(np);
 		VOP_UNLOCK(vp);
 		ap->a_flags &= ~(LK_TYPE_MASK | LK_INTERLOCK);
 		ap->a_flags |= LK_EXCLUSIVE;
 		error = VOP_LOCK1_APV(&default_vnodeops, ap);
 		if (error != 0 || vp->v_op != &newnfs_vnodeops)
 			return (error);
 		if (vp->v_data == NULL)
 			goto downgrade;
 		MPASS(vp->v_data == np);
 		NFSLOCKNODE(np);
 		if ((np->n_flag & NVNSETSZSKIP) == 0) {
 			NFSUNLOCKNODE(np);
 			goto downgrade;
 		}
 	}
 	np->n_flag &= ~NVNSETSZSKIP;
 	nsize = np->n_size;
 	NFSUNLOCKNODE(np);
 	vnode_pager_setsize(vp, nsize);
 downgrade:
 	if (lktype == LK_SHARED) {
 		ap->a_flags &= ~(LK_TYPE_MASK | LK_INTERLOCK);
 		ap->a_flags |= LK_DOWNGRADE;
 		(void)VOP_LOCK1_APV(&default_vnodeops, ap);
 	}
 	return (0);
 }
 
 static int
 nfs34_access_otw(struct vnode *vp, int wmode, struct thread *td,
     struct ucred *cred, u_int32_t *retmode)
 {
 	int error = 0, attrflag, i, lrupos;
 	u_int32_t rmode;
 	struct nfsnode *np = VTONFS(vp);
 	struct nfsvattr nfsva;
 
 	error = nfsrpc_accessrpc(vp, wmode, cred, td, &nfsva, &attrflag,
 	    &rmode, NULL);
 	if (attrflag)
 		(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 	if (!error) {
 		lrupos = 0;
 		NFSLOCKNODE(np);
 		for (i = 0; i < NFS_ACCESSCACHESIZE; i++) {
 			if (np->n_accesscache[i].uid == cred->cr_uid) {
 				np->n_accesscache[i].mode = rmode;
 				np->n_accesscache[i].stamp = time_second;
 				break;
 			}
 			if (i > 0 && np->n_accesscache[i].stamp <
 			    np->n_accesscache[lrupos].stamp)
 				lrupos = i;
 		}
 		if (i == NFS_ACCESSCACHESIZE) {
 			np->n_accesscache[lrupos].uid = cred->cr_uid;
 			np->n_accesscache[lrupos].mode = rmode;
 			np->n_accesscache[lrupos].stamp = time_second;
 		}
 		NFSUNLOCKNODE(np);
 		if (retmode != NULL)
 			*retmode = rmode;
 		KDTRACE_NFS_ACCESSCACHE_LOAD_DONE(vp, cred->cr_uid, rmode, 0);
 	} else if (NFS_ISV4(vp)) {
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	}
 #ifdef KDTRACE_HOOKS
 	if (error != 0)
 		KDTRACE_NFS_ACCESSCACHE_LOAD_DONE(vp, cred->cr_uid, 0,
 		    error);
 #endif
 	return (error);
 }
 
 /*
  * nfs access vnode op.
  * For nfs version 2, just return ok. File accesses may fail later.
  * For nfs version 3, use the access rpc to check accessibility. If file modes
  * are changed on the server, accesses might still fail later.
  */
 static int
 nfs_access(struct vop_access_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	int error = 0, i, gotahit;
 	u_int32_t mode, wmode, rmode;
 	int v34 = NFS_ISV34(vp);
 	struct nfsnode *np = VTONFS(vp);
 
 	/*
 	 * Disallow write attempts on filesystems mounted read-only;
 	 * unless the file is a socket, fifo, or a block or character
 	 * device resident on the filesystem.
 	 */
 	if ((ap->a_accmode & (VWRITE | VAPPEND | VWRITE_NAMED_ATTRS |
 	    VDELETE_CHILD | VWRITE_ATTRIBUTES | VDELETE | VWRITE_ACL |
 	    VWRITE_OWNER)) != 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) != 0) {
 		switch (vp->v_type) {
 		case VREG:
 		case VDIR:
 		case VLNK:
 			return (EROFS);
 		default:
 			break;
 		}
 	}
 	/*
 	 * For nfs v3 or v4, check to see if we have done this recently, and if
 	 * so return our cached result instead of making an ACCESS call.
 	 * If not, do an access rpc, otherwise you are stuck emulating
 	 * ufs_access() locally using the vattr. This may not be correct,
 	 * since the server may apply other access criteria such as
 	 * client uid-->server uid mapping that we do not know about.
 	 */
 	if (v34) {
 		if (ap->a_accmode & VREAD)
 			mode = NFSACCESS_READ;
 		else
 			mode = 0;
 		if (vp->v_type != VDIR) {
 			if (ap->a_accmode & VWRITE)
 				mode |= (NFSACCESS_MODIFY | NFSACCESS_EXTEND);
 			if (ap->a_accmode & VAPPEND)
 				mode |= NFSACCESS_EXTEND;
 			if (ap->a_accmode & VEXEC)
 				mode |= NFSACCESS_EXECUTE;
 			if (ap->a_accmode & VDELETE)
 				mode |= NFSACCESS_DELETE;
 		} else {
 			if (ap->a_accmode & VWRITE)
 				mode |= (NFSACCESS_MODIFY | NFSACCESS_EXTEND);
 			if (ap->a_accmode & VAPPEND)
 				mode |= NFSACCESS_EXTEND;
 			if (ap->a_accmode & VEXEC)
 				mode |= NFSACCESS_LOOKUP;
 			if (ap->a_accmode & VDELETE)
 				mode |= NFSACCESS_DELETE;
 			if (ap->a_accmode & VDELETE_CHILD)
 				mode |= NFSACCESS_MODIFY;
 		}
 		/* XXX safety belt, only make blanket request if caching */
 		if (nfsaccess_cache_timeout > 0) {
 			wmode = NFSACCESS_READ | NFSACCESS_MODIFY |
 				NFSACCESS_EXTEND | NFSACCESS_EXECUTE |
 				NFSACCESS_DELETE | NFSACCESS_LOOKUP;
 		} else {
 			wmode = mode;
 		}
 
 		/*
 		 * Does our cached result allow us to give a definite yes to
 		 * this request?
 		 */
 		gotahit = 0;
 		NFSLOCKNODE(np);
 		for (i = 0; i < NFS_ACCESSCACHESIZE; i++) {
 			if (ap->a_cred->cr_uid == np->n_accesscache[i].uid) {
 			    if (time_second < (np->n_accesscache[i].stamp
 				+ nfsaccess_cache_timeout) &&
 				(np->n_accesscache[i].mode & mode) == mode) {
 				NFSINCRGLOBAL(nfsstatsv1.accesscache_hits);
 				gotahit = 1;
 			    }
 			    break;
 			}
 		}
 		NFSUNLOCKNODE(np);
 #ifdef KDTRACE_HOOKS
 		if (gotahit != 0)
 			KDTRACE_NFS_ACCESSCACHE_GET_HIT(vp,
 			    ap->a_cred->cr_uid, mode);
 		else
 			KDTRACE_NFS_ACCESSCACHE_GET_MISS(vp,
 			    ap->a_cred->cr_uid, mode);
 #endif
 		if (gotahit == 0) {
 			/*
 			 * Either a no, or a don't know.  Go to the wire.
 			 */
 			NFSINCRGLOBAL(nfsstatsv1.accesscache_misses);
 		        error = nfs34_access_otw(vp, wmode, ap->a_td,
 			    ap->a_cred, &rmode);
 			if (!error &&
 			    (rmode & mode) != mode)
 				error = EACCES;
 		}
 		return (error);
 	} else {
 		if ((error = nfsspec_access(ap)) != 0) {
 			return (error);
 		}
 		/*
 		 * Attempt to prevent a mapped root from accessing a file
 		 * which it shouldn't.  We try to read a byte from the file
 		 * if the user is root and the file is not zero length.
 		 * After calling nfsspec_access, we should have the correct
 		 * file size cached.
 		 */
 		NFSLOCKNODE(np);
 		if (ap->a_cred->cr_uid == 0 && (ap->a_accmode & VREAD)
 		    && VTONFS(vp)->n_size > 0) {
 			struct iovec aiov;
 			struct uio auio;
 			char buf[1];
 
 			NFSUNLOCKNODE(np);
 			aiov.iov_base = buf;
 			aiov.iov_len = 1;
 			auio.uio_iov = &aiov;
 			auio.uio_iovcnt = 1;
 			auio.uio_offset = 0;
 			auio.uio_resid = 1;
 			auio.uio_segflg = UIO_SYSSPACE;
 			auio.uio_rw = UIO_READ;
 			auio.uio_td = ap->a_td;
 
 			if (vp->v_type == VREG)
 				error = ncl_readrpc(vp, &auio, ap->a_cred);
 			else if (vp->v_type == VDIR) {
 				char* bp;
 				bp = malloc(NFS_DIRBLKSIZ, M_TEMP, M_WAITOK);
 				aiov.iov_base = bp;
 				aiov.iov_len = auio.uio_resid = NFS_DIRBLKSIZ;
 				error = ncl_readdirrpc(vp, &auio, ap->a_cred,
 				    ap->a_td);
 				free(bp, M_TEMP);
 			} else if (vp->v_type == VLNK)
 				error = ncl_readlinkrpc(vp, &auio, ap->a_cred);
 			else
 				error = EACCES;
 		} else
 			NFSUNLOCKNODE(np);
 		return (error);
 	}
 }
 
 /*
  * nfs open vnode op
  * Check to see if the type is ok
  * and that deletion is not in progress.
  * For paged in text files, you will need to flush the page cache
  * if consistency is lost.
  */
 /* ARGSUSED */
 static int
 nfs_open(struct vop_open_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 	struct vattr vattr;
 	int error;
 	int fmode = ap->a_mode;
 	struct ucred *cred;
 	vm_object_t obj;
 
 	if (vp->v_type != VREG && vp->v_type != VDIR && vp->v_type != VLNK)
 		return (EOPNOTSUPP);
 
 	/*
 	 * For NFSv4, we need to do the Open Op before cache validation,
 	 * so that we conform to RFC3530 Sec. 9.3.1.
 	 */
 	if (NFS_ISV4(vp)) {
 		error = nfsrpc_open(vp, fmode, ap->a_cred, ap->a_td);
 		if (error) {
 			error = nfscl_maperr(ap->a_td, error, (uid_t)0,
 			    (gid_t)0);
 			return (error);
 		}
 	}
 
 	/*
 	 * Now, if this Open will be doing reading, re-validate/flush the
 	 * cache, so that Close/Open coherency is maintained.
 	 */
 	NFSLOCKNODE(np);
 	if (np->n_flag & NMODIFIED) {
 		NFSUNLOCKNODE(np);
 		error = ncl_vinvalbuf(vp, V_SAVE, ap->a_td, 1);
 		if (error == EINTR || error == EIO) {
 			if (NFS_ISV4(vp))
 				(void) nfsrpc_close(vp, 0, ap->a_td);
 			return (error);
 		}
 		NFSLOCKNODE(np);
 		np->n_attrstamp = 0;
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 		if (vp->v_type == VDIR)
 			np->n_direofoffset = 0;
 		NFSUNLOCKNODE(np);
 		error = VOP_GETATTR(vp, &vattr, ap->a_cred);
 		if (error) {
 			if (NFS_ISV4(vp))
 				(void) nfsrpc_close(vp, 0, ap->a_td);
 			return (error);
 		}
 		NFSLOCKNODE(np);
 		np->n_mtime = vattr.va_mtime;
 		if (NFS_ISV4(vp))
 			np->n_change = vattr.va_filerev;
 	} else {
 		NFSUNLOCKNODE(np);
 		error = VOP_GETATTR(vp, &vattr, ap->a_cred);
 		if (error) {
 			if (NFS_ISV4(vp))
 				(void) nfsrpc_close(vp, 0, ap->a_td);
 			return (error);
 		}
 		NFSLOCKNODE(np);
 		if ((NFS_ISV4(vp) && np->n_change != vattr.va_filerev) ||
 		    NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime)) {
 			if (vp->v_type == VDIR)
 				np->n_direofoffset = 0;
 			NFSUNLOCKNODE(np);
 			error = ncl_vinvalbuf(vp, V_SAVE, ap->a_td, 1);
 			if (error == EINTR || error == EIO) {
 				if (NFS_ISV4(vp))
 					(void) nfsrpc_close(vp, 0, ap->a_td);
 				return (error);
 			}
 			NFSLOCKNODE(np);
 			np->n_mtime = vattr.va_mtime;
 			if (NFS_ISV4(vp))
 				np->n_change = vattr.va_filerev;
 		}
 	}
 
 	/*
 	 * If the object has >= 1 O_DIRECT active opens, we disable caching.
 	 */
 	if (newnfs_directio_enable && (fmode & O_DIRECT) &&
 	    (vp->v_type == VREG)) {
 		if (np->n_directio_opens == 0) {
 			NFSUNLOCKNODE(np);
 			error = ncl_vinvalbuf(vp, V_SAVE, ap->a_td, 1);
 			if (error) {
 				if (NFS_ISV4(vp))
 					(void) nfsrpc_close(vp, 0, ap->a_td);
 				return (error);
 			}
 			NFSLOCKNODE(np);
 			np->n_flag |= NNONCACHE;
 		}
 		np->n_directio_opens++;
 	}
 
 	/* If opened for writing via NFSv4.1 or later, mark that for pNFS. */
 	if (NFSHASPNFS(VFSTONFS(vp->v_mount)) && (fmode & FWRITE) != 0)
 		np->n_flag |= NWRITEOPENED;
 
 	/*
 	 * If this is an open for writing, capture a reference to the
 	 * credentials, so they can be used by ncl_putpages(). Using
 	 * these write credentials is preferable to the credentials of
 	 * whatever thread happens to be doing the VOP_PUTPAGES() since
 	 * the write RPCs are less likely to fail with EACCES.
 	 */
 	if ((fmode & FWRITE) != 0) {
 		cred = np->n_writecred;
 		np->n_writecred = crhold(ap->a_cred);
 	} else
 		cred = NULL;
 	NFSUNLOCKNODE(np);
 
 	if (cred != NULL)
 		crfree(cred);
 	vnode_create_vobject(vp, vattr.va_size, ap->a_td);
 
 	/*
 	 * If the text file has been mmap'd, flush any dirty pages to the
 	 * buffer cache and then...
 	 * Make sure all writes are pushed to the NFS server.  If this is not
 	 * done, the modify time of the file can change while the text
 	 * file is being executed.  This will cause the process that is
 	 * executing the text file to be terminated.
 	 */
 	if (vp->v_writecount <= -1) {
 		if ((obj = vp->v_object) != NULL &&
 		    vm_object_mightbedirty(obj)) {
 			VM_OBJECT_WLOCK(obj);
 			vm_object_page_clean(obj, 0, 0, OBJPC_SYNC);
 			VM_OBJECT_WUNLOCK(obj);
 		}
 
 		/* Now, flush the buffer cache. */
 		ncl_flush(vp, MNT_WAIT, curthread, 0, 0);
 
 		/* And, finally, make sure that n_mtime is up to date. */
 		np = VTONFS(vp);
 		NFSLOCKNODE(np);
 		np->n_mtime = np->n_vattr.na_mtime;
 		NFSUNLOCKNODE(np);
 	}
 	return (0);
 }
 
 /*
  * nfs close vnode op
  * What an NFS client should do upon close after writing is a debatable issue.
  * Most NFS clients push delayed writes to the server upon close, basically for
  * two reasons:
  * 1 - So that any write errors may be reported back to the client process
  *     doing the close system call. By far the two most likely errors are
  *     NFSERR_NOSPC and NFSERR_DQUOT to indicate space allocation failure.
  * 2 - To put a worst case upper bound on cache inconsistency between
  *     multiple clients for the file.
  * There is also a consistency problem for Version 2 of the protocol w.r.t.
  * not being able to tell if other clients are writing a file concurrently,
  * since there is no way of knowing if the changed modify time in the reply
  * is only due to the write for this client.
  * (NFS Version 3 provides weak cache consistency data in the reply that
  *  should be sufficient to detect and handle this case.)
  *
  * The current code does the following:
  * for NFS Version 2 - play it safe and flush/invalidate all dirty buffers
  * for NFS Version 3 - flush dirty buffers to the server but don't invalidate
  *                     or commit them (this satisfies 1 and 2 except for the
  *                     case where the server crashes after this close but
  *                     before the commit RPC, which is felt to be "good
  *                     enough". Changing the last argument to ncl_flush() to
  *                     a 1 would force a commit operation, if it is felt a
  *                     commit is necessary now.
  * for NFS Version 4 - flush the dirty buffers and commit them, if
  *		       nfscl_mustflush() says this is necessary.
  *                     It is necessary if there is no write delegation held,
  *                     in order to satisfy open/close coherency.
  *                     If the file isn't cached on local stable storage,
  *                     it may be necessary in order to detect "out of space"
  *                     errors from the server, if the write delegation
  *                     issued by the server doesn't allow the file to grow.
  */
 /* ARGSUSED */
 static int
 nfs_close(struct vop_close_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 	struct nfsvattr nfsva;
 	struct ucred *cred;
 	int error = 0, ret, localcred = 0;
 	int fmode = ap->a_fflag;
 
 	if (NFSCL_FORCEDISM(vp->v_mount))
 		return (0);
 	/*
 	 * During shutdown, a_cred isn't valid, so just use root.
 	 */
 	if (ap->a_cred == NOCRED) {
 		cred = newnfs_getcred();
 		localcred = 1;
 	} else {
 		cred = ap->a_cred;
 	}
 	if (vp->v_type == VREG) {
 	    /*
 	     * Examine and clean dirty pages, regardless of NMODIFIED.
 	     * This closes a major hole in close-to-open consistency.
 	     * We want to push out all dirty pages (and buffers) on
 	     * close, regardless of whether they were dirtied by
 	     * mmap'ed writes or via write().
 	     */
 	    if (nfs_clean_pages_on_close && vp->v_object) {
 		VM_OBJECT_WLOCK(vp->v_object);
 		vm_object_page_clean(vp->v_object, 0, 0, 0);
 		VM_OBJECT_WUNLOCK(vp->v_object);
 	    }
 	    NFSLOCKNODE(np);
 	    if (np->n_flag & NMODIFIED) {
 		NFSUNLOCKNODE(np);
 		if (NFS_ISV3(vp)) {
 		    /*
 		     * Under NFSv3 we have dirty buffers to dispose of.  We
 		     * must flush them to the NFS server.  We have the option
 		     * of waiting all the way through the commit rpc or just
 		     * waiting for the initial write.  The default is to only
 		     * wait through the initial write so the data is in the
 		     * server's cache, which is roughly similar to the state
 		     * a standard disk subsystem leaves the file in on close().
 		     *
 		     * We cannot clear the NMODIFIED bit in np->n_flag due to
 		     * potential races with other processes, and certainly
 		     * cannot clear it if we don't commit.
 		     * These races occur when there is no longer the old
 		     * traditional vnode locking implemented for Vnode Ops.
 		     */
 		    int cm = newnfs_commit_on_close ? 1 : 0;
 		    error = ncl_flush(vp, MNT_WAIT, ap->a_td, cm, 0);
 		    /* np->n_flag &= ~NMODIFIED; */
 		} else if (NFS_ISV4(vp)) { 
 			if (nfscl_mustflush(vp) != 0) {
 				int cm = newnfs_commit_on_close ? 1 : 0;
 				error = ncl_flush(vp, MNT_WAIT, ap->a_td,
 				    cm, 0);
 				/*
 				 * as above w.r.t races when clearing
 				 * NMODIFIED.
 				 * np->n_flag &= ~NMODIFIED;
 				 */
 			}
 		} else {
 			error = ncl_vinvalbuf(vp, V_SAVE, ap->a_td, 1);
 		}
 		NFSLOCKNODE(np);
 	    }
  	    /* 
  	     * Invalidate the attribute cache in all cases.
  	     * An open is going to fetch fresh attrs any way, other procs
  	     * on this node that have file open will be forced to do an 
  	     * otw attr fetch, but this is safe.
 	     * --> A user found that their RPC count dropped by 20% when
 	     *     this was commented out and I can't see any requirement
 	     *     for it, so I've disabled it when negative lookups are
 	     *     enabled. (What does this have to do with negative lookup
 	     *     caching? Well nothing, except it was reported by the
 	     *     same user that needed negative lookup caching and I wanted
 	     *     there to be a way to disable it to see if it
 	     *     is the cause of some caching/coherency issue that might
 	     *     crop up.)
  	     */
 	    if (VFSTONFS(vp->v_mount)->nm_negnametimeo == 0) {
 		    np->n_attrstamp = 0;
 		    KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 	    }
 	    if (np->n_flag & NWRITEERR) {
 		np->n_flag &= ~NWRITEERR;
 		error = np->n_error;
 	    }
 	    NFSUNLOCKNODE(np);
 	}
 
 	if (NFS_ISV4(vp)) {
 		/*
 		 * Get attributes so "change" is up to date.
 		 */
 		if (error == 0 && nfscl_mustflush(vp) != 0 &&
 		    vp->v_type == VREG &&
 		    (VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_NOCTO) == 0) {
 			ret = nfsrpc_getattr(vp, cred, ap->a_td, &nfsva,
 			    NULL);
 			if (!ret) {
 				np->n_change = nfsva.na_filerev;
 				(void) nfscl_loadattrcache(&vp, &nfsva, NULL,
 				    NULL, 0, 0);
 			}
 		}
 
 		/*
 		 * and do the close.
 		 */
 		ret = nfsrpc_close(vp, 0, ap->a_td);
 		if (!error && ret)
 			error = ret;
 		if (error)
 			error = nfscl_maperr(ap->a_td, error, (uid_t)0,
 			    (gid_t)0);
 	}
 	if (newnfs_directio_enable)
 		KASSERT((np->n_directio_asyncwr == 0),
 			("nfs_close: dirty unflushed (%d) directio buffers\n",
 			 np->n_directio_asyncwr));
 	if (newnfs_directio_enable && (fmode & O_DIRECT) && (vp->v_type == VREG)) {
 		NFSLOCKNODE(np);
 		KASSERT((np->n_directio_opens > 0), 
 			("nfs_close: unexpectedly value (0) of n_directio_opens\n"));
 		np->n_directio_opens--;
 		if (np->n_directio_opens == 0)
 			np->n_flag &= ~NNONCACHE;
 		NFSUNLOCKNODE(np);
 	}
 	if (localcred)
 		NFSFREECRED(cred);
 	return (error);
 }
 
 /*
  * nfs getattr call from vfs.
  */
 static int
 nfs_getattr(struct vop_getattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct thread *td = curthread;	/* XXX */
 	struct nfsnode *np = VTONFS(vp);
 	int error = 0;
 	struct nfsvattr nfsva;
 	struct vattr *vap = ap->a_vap;
 	struct vattr vattr;
 
 	/*
 	 * Update local times for special files.
 	 */
 	NFSLOCKNODE(np);
 	if (np->n_flag & (NACC | NUPD))
 		np->n_flag |= NCHG;
 	NFSUNLOCKNODE(np);
 	/*
 	 * First look in the cache.
 	 */
 	if (ncl_getattrcache(vp, &vattr) == 0) {
 		ncl_copy_vattr(vap, &vattr);
 
 		/*
 		 * Get the local modify time for the case of a write
 		 * delegation.
 		 */
 		nfscl_deleggetmodtime(vp, &vap->va_mtime);
 		return (0);
 	}
 
 	if (NFS_ISV34(vp) && nfs_prime_access_cache &&
 	    nfsaccess_cache_timeout > 0) {
 		NFSINCRGLOBAL(nfsstatsv1.accesscache_misses);
 		nfs34_access_otw(vp, NFSACCESS_ALL, td, ap->a_cred, NULL);
 		if (ncl_getattrcache(vp, ap->a_vap) == 0) {
 			nfscl_deleggetmodtime(vp, &ap->a_vap->va_mtime);
 			return (0);
 		}
 	}
 	error = nfsrpc_getattr(vp, ap->a_cred, td, &nfsva, NULL);
 	if (!error)
 		error = nfscl_loadattrcache(&vp, &nfsva, vap, NULL, 0, 0);
 	if (!error) {
 		/*
 		 * Get the local modify time for the case of a write
 		 * delegation.
 		 */
 		nfscl_deleggetmodtime(vp, &vap->va_mtime);
 	} else if (NFS_ISV4(vp)) {
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	}
 	return (error);
 }
 
 /*
  * nfs setattr call.
  */
 static int
 nfs_setattr(struct vop_setattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 	struct thread *td = curthread;	/* XXX */
 	struct vattr *vap = ap->a_vap;
 	int error = 0;
 	u_quad_t tsize;
 	struct timespec ts;
 
 #ifndef nolint
 	tsize = (u_quad_t)0;
 #endif
 
 	/*
 	 * Setting of flags and marking of atimes are not supported.
 	 */
 	if (vap->va_flags != VNOVAL)
 		return (EOPNOTSUPP);
 
 	/*
 	 * Disallow write attempts if the filesystem is mounted read-only.
 	 */
   	if ((vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
 	    vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
 	    vap->va_mtime.tv_sec != VNOVAL ||
 	    vap->va_birthtime.tv_sec != VNOVAL ||
 	    vap->va_mode != (mode_t)VNOVAL) &&
 	    (vp->v_mount->mnt_flag & MNT_RDONLY))
 		return (EROFS);
 	if (vap->va_size != VNOVAL) {
  		switch (vp->v_type) {
  		case VDIR:
  			return (EISDIR);
  		case VCHR:
  		case VBLK:
  		case VSOCK:
  		case VFIFO:
 			if (vap->va_mtime.tv_sec == VNOVAL &&
 			    vap->va_atime.tv_sec == VNOVAL &&
 			    vap->va_birthtime.tv_sec == VNOVAL &&
 			    vap->va_mode == (mode_t)VNOVAL &&
 			    vap->va_uid == (uid_t)VNOVAL &&
 			    vap->va_gid == (gid_t)VNOVAL)
 				return (0);		
  			vap->va_size = VNOVAL;
  			break;
  		default:
 			/*
 			 * Disallow write attempts if the filesystem is
 			 * mounted read-only.
 			 */
 			if (vp->v_mount->mnt_flag & MNT_RDONLY)
 				return (EROFS);
 			/*
 			 *  We run vnode_pager_setsize() early (why?),
 			 * we must set np->n_size now to avoid vinvalbuf
 			 * V_SAVE races that might setsize a lower
 			 * value.
 			 */
 			NFSLOCKNODE(np);
 			tsize = np->n_size;
 			NFSUNLOCKNODE(np);
 			error = ncl_meta_setsize(vp, td, vap->va_size);
 			NFSLOCKNODE(np);
  			if (np->n_flag & NMODIFIED) {
 			    tsize = np->n_size;
 			    NFSUNLOCKNODE(np);
 			    error = ncl_vinvalbuf(vp, vap->va_size == 0 ?
 			        0 : V_SAVE, td, 1);
 			    if (error != 0) {
 				    vnode_pager_setsize(vp, tsize);
 				    return (error);
 			    }
 			    /*
 			     * Call nfscl_delegmodtime() to set the modify time
 			     * locally, as required.
 			     */
 			    nfscl_delegmodtime(vp);
  			} else
 			    NFSUNLOCKNODE(np);
 			/*
 			 * np->n_size has already been set to vap->va_size
 			 * in ncl_meta_setsize(). We must set it again since
 			 * nfs_loadattrcache() could be called through
 			 * ncl_meta_setsize() and could modify np->n_size.
 			 */
 			NFSLOCKNODE(np);
  			np->n_vattr.na_size = np->n_size = vap->va_size;
 			NFSUNLOCKNODE(np);
   		}
   	} else {
 		NFSLOCKNODE(np);
 		if ((vap->va_mtime.tv_sec != VNOVAL || vap->va_atime.tv_sec != VNOVAL) && 
 		    (np->n_flag & NMODIFIED) && vp->v_type == VREG) {
 			NFSUNLOCKNODE(np);
 			error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
 			if (error == EINTR || error == EIO)
 				return (error);
 		} else
 			NFSUNLOCKNODE(np);
 	}
 	error = nfs_setattrrpc(vp, vap, ap->a_cred, td);
 	if (vap->va_size != VNOVAL) {
 		if (error == 0) {
 			nanouptime(&ts);
 			NFSLOCKNODE(np);
 			np->n_localmodtime = ts;
 			NFSUNLOCKNODE(np);
 		} else {
 			NFSLOCKNODE(np);
 			np->n_size = np->n_vattr.na_size = tsize;
 			vnode_pager_setsize(vp, tsize);
 			NFSUNLOCKNODE(np);
 		}
 	}
 	return (error);
 }
 
 /*
  * Do an nfs setattr rpc.
  */
 static int
 nfs_setattrrpc(struct vnode *vp, struct vattr *vap, struct ucred *cred,
     struct thread *td)
 {
 	struct nfsnode *np = VTONFS(vp);
 	int error, ret, attrflag, i;
 	struct nfsvattr nfsva;
 
 	if (NFS_ISV34(vp)) {
 		NFSLOCKNODE(np);
 		for (i = 0; i < NFS_ACCESSCACHESIZE; i++)
 			np->n_accesscache[i].stamp = 0;
 		np->n_flag |= NDELEGMOD;
 		NFSUNLOCKNODE(np);
 		KDTRACE_NFS_ACCESSCACHE_FLUSH_DONE(vp);
 	}
 	error = nfsrpc_setattr(vp, vap, NULL, cred, td, &nfsva, &attrflag,
 	    NULL);
 	if (attrflag) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (ret && !error)
 			error = ret;
 	}
 	if (error && NFS_ISV4(vp))
 		error = nfscl_maperr(td, error, vap->va_uid, vap->va_gid);
 	return (error);
 }
 
 /*
  * nfs lookup call, one step at a time...
  * First look in cache
  * If not found, unlock the directory nfsnode and do the rpc
  */
 static int
 nfs_lookup(struct vop_lookup_args *ap)
 {
 	struct componentname *cnp = ap->a_cnp;
 	struct vnode *dvp = ap->a_dvp;
 	struct vnode **vpp = ap->a_vpp;
 	struct mount *mp = dvp->v_mount;
 	int flags = cnp->cn_flags;
 	struct vnode *newvp;
 	struct nfsmount *nmp;
 	struct nfsnode *np, *newnp;
 	int error = 0, attrflag, dattrflag, ltype, ncticks;
 	struct thread *td = curthread;
 	struct nfsfh *nfhp;
 	struct nfsvattr dnfsva, nfsva;
 	struct vattr vattr;
 	struct timespec nctime, ts;
 	uint32_t openmode;
 
 	*vpp = NULLVP;
 	if ((flags & ISLASTCN) && (mp->mnt_flag & MNT_RDONLY) &&
 	    (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
 		return (EROFS);
 	if (dvp->v_type != VDIR)
 		return (ENOTDIR);
 	nmp = VFSTONFS(mp);
 	np = VTONFS(dvp);
 
 	/* For NFSv4, wait until any remove is done. */
 	NFSLOCKNODE(np);
 	while (NFSHASNFSV4(nmp) && (np->n_flag & NREMOVEINPROG)) {
 		np->n_flag |= NREMOVEWANT;
 		(void) msleep((caddr_t)np, &np->n_mtx, PZERO, "nfslkup", 0);
 	}
 	NFSUNLOCKNODE(np);
 
 	error = vn_dir_check_exec(dvp, cnp);
 	if (error != 0)
 		return (error);
 	error = cache_lookup(dvp, vpp, cnp, &nctime, &ncticks);
 	if (error > 0 && error != ENOENT)
 		return (error);
 	if (error == -1) {
 		/*
 		 * Lookups of "." are special and always return the
 		 * current directory.  cache_lookup() already handles
 		 * associated locking bookkeeping, etc.
 		 */
 		if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') {
 			/* XXX: Is this really correct? */
 			if (cnp->cn_nameiop != LOOKUP &&
 			    (flags & ISLASTCN))
 				cnp->cn_flags |= SAVENAME;
 			return (0);
 		}
 
 		/*
 		 * We only accept a positive hit in the cache if the
 		 * change time of the file matches our cached copy.
 		 * Otherwise, we discard the cache entry and fallback
 		 * to doing a lookup RPC.  We also only trust cache
 		 * entries for less than nm_nametimeo seconds.
 		 *
 		 * To better handle stale file handles and attributes,
 		 * clear the attribute cache of this node if it is a
 		 * leaf component, part of an open() call, and not
 		 * locally modified before fetching the attributes.
 		 * This should allow stale file handles to be detected
 		 * here where we can fall back to a LOOKUP RPC to
 		 * recover rather than having nfs_open() detect the
 		 * stale file handle and failing open(2) with ESTALE.
 		 */
 		newvp = *vpp;
 		newnp = VTONFS(newvp);
 		if (!(nmp->nm_flag & NFSMNT_NOCTO) &&
 		    (flags & (ISLASTCN | ISOPEN)) == (ISLASTCN | ISOPEN) &&
 		    !(newnp->n_flag & NMODIFIED)) {
 			NFSLOCKNODE(newnp);
 			newnp->n_attrstamp = 0;
 			KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(newvp);
 			NFSUNLOCKNODE(newnp);
 		}
 		if (nfscl_nodeleg(newvp, 0) == 0 ||
 		    ((u_int)(ticks - ncticks) < (nmp->nm_nametimeo * hz) &&
 		    VOP_GETATTR(newvp, &vattr, cnp->cn_cred) == 0 &&
 		    timespeccmp(&vattr.va_ctime, &nctime, ==))) {
 			NFSINCRGLOBAL(nfsstatsv1.lookupcache_hits);
 			if (cnp->cn_nameiop != LOOKUP &&
 			    (flags & ISLASTCN))
 				cnp->cn_flags |= SAVENAME;
 			return (0);
 		}
 		cache_purge(newvp);
 		if (dvp != newvp)
 			vput(newvp);
 		else 
 			vrele(newvp);
 		*vpp = NULLVP;
 	} else if (error == ENOENT) {
 		if (VN_IS_DOOMED(dvp))
 			return (ENOENT);
 		/*
 		 * We only accept a negative hit in the cache if the
 		 * modification time of the parent directory matches
 		 * the cached copy in the name cache entry.
 		 * Otherwise, we discard all of the negative cache
 		 * entries for this directory.  We also only trust
 		 * negative cache entries for up to nm_negnametimeo
 		 * seconds.
 		 */
 		if ((u_int)(ticks - ncticks) < (nmp->nm_negnametimeo * hz) &&
 		    VOP_GETATTR(dvp, &vattr, cnp->cn_cred) == 0 &&
 		    timespeccmp(&vattr.va_mtime, &nctime, ==)) {
 			NFSINCRGLOBAL(nfsstatsv1.lookupcache_hits);
 			return (ENOENT);
 		}
 		cache_purge_negative(dvp);
 	}
 
 	/*
 	 * If this an NFSv4.1/4.2 mount using the "oneopenown" mount
 	 * option, it is possible to do the Open operation in the same
 	 * compound as Lookup, so long as delegations are not being
 	 * issued.  This saves doing a separate RPC for Open.
 	 */
 	openmode = 0;
 	NFSLOCKMNT(nmp);
 	if (NFSHASNFSV4N(nmp) && NFSHASONEOPENOWN(nmp) &&
 	    (nmp->nm_privflag & NFSMNTP_DELEGISSUED) == 0 &&
 	    (!NFSMNT_RDONLY(mp) || (flags & OPENWRITE) == 0) &&
 	    (flags & (ISLASTCN | ISOPEN)) == (ISLASTCN | ISOPEN)) {
 		if ((flags & OPENREAD) != 0)
 			openmode |= NFSV4OPEN_ACCESSREAD;
 		if ((flags & OPENWRITE) != 0)
 			openmode |= NFSV4OPEN_ACCESSWRITE;
 	}
 	NFSUNLOCKMNT(nmp);
 
 	newvp = NULLVP;
 	NFSINCRGLOBAL(nfsstatsv1.lookupcache_misses);
 	nanouptime(&ts);
 	error = nfsrpc_lookup(dvp, cnp->cn_nameptr, cnp->cn_namelen,
 	    cnp->cn_cred, td, &dnfsva, &nfsva, &nfhp, &attrflag, &dattrflag,
 	    NULL, openmode);
 	if (dattrflag)
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	if (error) {
 		if (newvp != NULLVP) {
 			vput(newvp);
 			*vpp = NULLVP;
 		}
 
 		if (error != ENOENT) {
 			if (NFS_ISV4(dvp))
 				error = nfscl_maperr(td, error, (uid_t)0,
 				    (gid_t)0);
 			return (error);
 		}
 
 		/* The requested file was not found. */
 		if ((cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME) &&
 		    (flags & ISLASTCN)) {
 			/*
 			 * XXX: UFS does a full VOP_ACCESS(dvp,
 			 * VWRITE) here instead of just checking
 			 * MNT_RDONLY.
 			 */
 			if (mp->mnt_flag & MNT_RDONLY)
 				return (EROFS);
 			cnp->cn_flags |= SAVENAME;
 			return (EJUSTRETURN);
 		}
 
 		if ((cnp->cn_flags & MAKEENTRY) != 0 && dattrflag) {
 			/*
 			 * Cache the modification time of the parent
 			 * directory from the post-op attributes in
 			 * the name cache entry.  The negative cache
 			 * entry will be ignored once the directory
 			 * has changed.  Don't bother adding the entry
 			 * if the directory has already changed.
 			 */
 			NFSLOCKNODE(np);
 			if (timespeccmp(&np->n_vattr.na_mtime,
 			    &dnfsva.na_mtime, ==)) {
 				NFSUNLOCKNODE(np);
 				cache_enter_time(dvp, NULL, cnp,
 				    &dnfsva.na_mtime, NULL);
 			} else
 				NFSUNLOCKNODE(np);
 		}
 		return (ENOENT);
 	}
 
 	/*
 	 * Handle RENAME case...
 	 */
 	if (cnp->cn_nameiop == RENAME && (flags & ISLASTCN)) {
 		if (NFS_CMPFH(np, nfhp->nfh_fh, nfhp->nfh_len)) {
 			free(nfhp, M_NFSFH);
 			return (EISDIR);
 		}
 		error = nfscl_nget(mp, dvp, nfhp, cnp, td, &np, NULL,
 		    LK_EXCLUSIVE);
 		if (error)
 			return (error);
 		newvp = NFSTOV(np);
 		/*
 		 * If n_localmodtime >= time before RPC, then
 		 * a file modification operation, such as
 		 * VOP_SETATTR() of size, has occurred while
 		 * the Lookup RPC and acquisition of the vnode
 		 * happened.  As such, the attributes might
 		 * be stale, with possibly an incorrect size.
 		 */
 		NFSLOCKNODE(np);
 		if (timespecisset(&np->n_localmodtime) &&
 		    timespeccmp(&np->n_localmodtime, &ts, >=)) {
 			NFSCL_DEBUG(4, "nfs_lookup: rename localmod "
 			    "stale attributes\n");
 			attrflag = 0;
 		}
 		NFSUNLOCKNODE(np);
 		if (attrflag)
 			(void) nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 		*vpp = newvp;
 		cnp->cn_flags |= SAVENAME;
 		return (0);
 	}
 
 	if (flags & ISDOTDOT) {
 		ltype = NFSVOPISLOCKED(dvp);
 		error = vfs_busy(mp, MBF_NOWAIT);
 		if (error != 0) {
 			vfs_ref(mp);
 			NFSVOPUNLOCK(dvp);
 			error = vfs_busy(mp, 0);
 			NFSVOPLOCK(dvp, ltype | LK_RETRY);
 			vfs_rel(mp);
 			if (error == 0 && VN_IS_DOOMED(dvp)) {
 				vfs_unbusy(mp);
 				error = ENOENT;
 			}
 			if (error != 0)
 				return (error);
 		}
 		NFSVOPUNLOCK(dvp);
 		error = nfscl_nget(mp, dvp, nfhp, cnp, td, &np, NULL,
 		    cnp->cn_lkflags);
 		if (error == 0)
 			newvp = NFSTOV(np);
 		vfs_unbusy(mp);
 		if (newvp != dvp)
 			NFSVOPLOCK(dvp, ltype | LK_RETRY);
 		if (VN_IS_DOOMED(dvp)) {
 			if (error == 0) {
 				if (newvp == dvp)
 					vrele(newvp);
 				else
 					vput(newvp);
 			}
 			error = ENOENT;
 		}
 		if (error != 0)
 			return (error);
 		if (attrflag)
 			(void) nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 	} else if (NFS_CMPFH(np, nfhp->nfh_fh, nfhp->nfh_len)) {
 		free(nfhp, M_NFSFH);
 		VREF(dvp);
 		newvp = dvp;
 		if (attrflag)
 			(void) nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 	} else {
 		error = nfscl_nget(mp, dvp, nfhp, cnp, td, &np, NULL,
 		    cnp->cn_lkflags);
 		if (error)
 			return (error);
 		newvp = NFSTOV(np);
 		/*
 		 * If n_localmodtime >= time before RPC, then
 		 * a file modification operation, such as
 		 * VOP_SETATTR() of size, has occurred while
 		 * the Lookup RPC and acquisition of the vnode
 		 * happened.  As such, the attributes might
 		 * be stale, with possibly an incorrect size.
 		 */
 		NFSLOCKNODE(np);
 		if (timespecisset(&np->n_localmodtime) &&
 		    timespeccmp(&np->n_localmodtime, &ts, >=)) {
 			NFSCL_DEBUG(4, "nfs_lookup: localmod "
 			    "stale attributes\n");
 			attrflag = 0;
 		}
 		NFSUNLOCKNODE(np);
 		if (attrflag)
 			(void) nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 		else if ((flags & (ISLASTCN | ISOPEN)) == (ISLASTCN | ISOPEN) &&
 		    !(np->n_flag & NMODIFIED)) {			
 			/*
 			 * Flush the attribute cache when opening a
 			 * leaf node to ensure that fresh attributes
 			 * are fetched in nfs_open() since we did not
 			 * fetch attributes from the LOOKUP reply.
 			 */
 			NFSLOCKNODE(np);
 			np->n_attrstamp = 0;
 			KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(newvp);
 			NFSUNLOCKNODE(np);
 		}
 	}
 	if (cnp->cn_nameiop != LOOKUP && (flags & ISLASTCN))
 		cnp->cn_flags |= SAVENAME;
 	if ((cnp->cn_flags & MAKEENTRY) && dvp != newvp &&
 	    (cnp->cn_nameiop != DELETE || !(flags & ISLASTCN)) &&
 	    attrflag != 0 && (newvp->v_type != VDIR || dattrflag != 0))
 		cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime,
 		    newvp->v_type != VDIR ? NULL : &dnfsva.na_ctime);
 	*vpp = newvp;
 	return (0);
 }
 
 /*
  * nfs read call.
  * Just call ncl_bioread() to do the work.
  */
 static int
 nfs_read(struct vop_read_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 
 	switch (vp->v_type) {
 	case VREG:
 		return (ncl_bioread(vp, ap->a_uio, ap->a_ioflag, ap->a_cred));
 	case VDIR:
 		return (EISDIR);
 	default:
 		return (EOPNOTSUPP);
 	}
 }
 
 /*
  * nfs readlink call
  */
 static int
 nfs_readlink(struct vop_readlink_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 
 	if (vp->v_type != VLNK)
 		return (EINVAL);
 	return (ncl_bioread(vp, ap->a_uio, 0, ap->a_cred));
 }
 
 /*
  * Do a readlink rpc.
  * Called by ncl_doio() from below the buffer cache.
  */
 int
 ncl_readlinkrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred)
 {
 	int error, ret, attrflag;
 	struct nfsvattr nfsva;
 
 	error = nfsrpc_readlink(vp, uiop, cred, uiop->uio_td, &nfsva,
 	    &attrflag, NULL);
 	if (attrflag) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (ret && !error)
 			error = ret;
 	}
 	if (error && NFS_ISV4(vp))
 		error = nfscl_maperr(uiop->uio_td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs read rpc call
  * Ditto above
  */
 int
 ncl_readrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred)
 {
 	int error, ret, attrflag;
 	struct nfsvattr nfsva;
 	struct nfsmount *nmp;
 
 	nmp = VFSTONFS(vp->v_mount);
 	error = EIO;
 	attrflag = 0;
 	if (NFSHASPNFS(nmp))
 		error = nfscl_doiods(vp, uiop, NULL, NULL,
 		    NFSV4OPEN_ACCESSREAD, 0, cred, uiop->uio_td);
 	NFSCL_DEBUG(4, "readrpc: aft doiods=%d\n", error);
 	if (error != 0)
 		error = nfsrpc_read(vp, uiop, cred, uiop->uio_td, &nfsva,
 		    &attrflag, NULL);
 	if (attrflag) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (ret && !error)
 			error = ret;
 	}
 	if (error && NFS_ISV4(vp))
 		error = nfscl_maperr(uiop->uio_td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs write call
  */
 int
 ncl_writerpc(struct vnode *vp, struct uio *uiop, struct ucred *cred,
     int *iomode, int *must_commit, int called_from_strategy)
 {
 	struct nfsvattr nfsva;
 	int error, attrflag, ret;
 	struct nfsmount *nmp;
 
 	nmp = VFSTONFS(vp->v_mount);
 	error = EIO;
 	attrflag = 0;
 	if (NFSHASPNFS(nmp))
 		error = nfscl_doiods(vp, uiop, iomode, must_commit,
 		    NFSV4OPEN_ACCESSWRITE, 0, cred, uiop->uio_td);
 	NFSCL_DEBUG(4, "writerpc: aft doiods=%d\n", error);
 	if (error != 0)
 		error = nfsrpc_write(vp, uiop, iomode, must_commit, cred,
 		    uiop->uio_td, &nfsva, &attrflag, NULL,
 		    called_from_strategy);
 	if (attrflag) {
 		if (VTONFS(vp)->n_flag & ND_NFSV4)
 			ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 1,
 			    1);
 		else
 			ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0,
 			    1);
 		if (ret && !error)
 			error = ret;
 	}
 	if (DOINGASYNC(vp))
 		*iomode = NFSWRITE_FILESYNC;
 	if (error && NFS_ISV4(vp))
 		error = nfscl_maperr(uiop->uio_td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs mknod rpc
  * For NFS v2 this is a kludge. Use a create rpc but with the IFMT bits of the
  * mode set to specify the file type and the size field for rdev.
  */
 static int
 nfs_mknodrpc(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp,
     struct vattr *vap)
 {
 	struct nfsvattr nfsva, dnfsva;
 	struct vnode *newvp = NULL;
 	struct nfsnode *np = NULL, *dnp;
 	struct nfsfh *nfhp;
 	struct vattr vattr;
 	int error = 0, attrflag, dattrflag;
 	u_int32_t rdev;
 
 	if (vap->va_type == VCHR || vap->va_type == VBLK)
 		rdev = vap->va_rdev;
 	else if (vap->va_type == VFIFO || vap->va_type == VSOCK)
 		rdev = 0xffffffff;
 	else
 		return (EOPNOTSUPP);
 	if ((error = VOP_GETATTR(dvp, &vattr, cnp->cn_cred)))
 		return (error);
 	error = nfsrpc_mknod(dvp, cnp->cn_nameptr, cnp->cn_namelen, vap,
 	    rdev, vap->va_type, cnp->cn_cred, curthread, &dnfsva,
 	    &nfsva, &nfhp, &attrflag, &dattrflag, NULL);
 	if (!error) {
 		if (!nfhp)
 			(void) nfsrpc_lookup(dvp, cnp->cn_nameptr,
 			    cnp->cn_namelen, cnp->cn_cred, curthread,
 			    &dnfsva, &nfsva, &nfhp, &attrflag, &dattrflag,
 			    NULL, 0);
 		if (nfhp)
 			error = nfscl_nget(dvp->v_mount, dvp, nfhp, cnp,
 			    curthread, &np, NULL, LK_EXCLUSIVE);
 	}
 	if (dattrflag)
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	if (!error) {
 		newvp = NFSTOV(np);
 		if (attrflag != 0) {
 			error = nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 			if (error != 0)
 				vput(newvp);
 		}
 	}
 	if (!error) {
 		*vpp = newvp;
 	} else if (NFS_ISV4(dvp)) {
 		error = nfscl_maperr(curthread, error, vap->va_uid,
 		    vap->va_gid);
 	}
 	dnp = VTONFS(dvp);
 	NFSLOCKNODE(dnp);
 	dnp->n_flag |= NMODIFIED;
 	if (!dattrflag) {
 		dnp->n_attrstamp = 0;
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(dvp);
 	}
 	NFSUNLOCKNODE(dnp);
 	return (error);
 }
 
 /*
  * nfs mknod vop
  * just call nfs_mknodrpc() to do the work.
  */
 /* ARGSUSED */
 static int
 nfs_mknod(struct vop_mknod_args *ap)
 {
 	return (nfs_mknodrpc(ap->a_dvp, ap->a_vpp, ap->a_cnp, ap->a_vap));
 }
 
 static struct mtx nfs_cverf_mtx;
 MTX_SYSINIT(nfs_cverf_mtx, &nfs_cverf_mtx, "NFS create verifier mutex",
     MTX_DEF);
 
 static nfsquad_t
 nfs_get_cverf(void)
 {
 	static nfsquad_t cverf;
 	nfsquad_t ret;
 	static int cverf_initialized = 0;
 
 	mtx_lock(&nfs_cverf_mtx);
 	if (cverf_initialized == 0) {
 		cverf.lval[0] = arc4random();
 		cverf.lval[1] = arc4random();
 		cverf_initialized = 1;
 	} else
 		cverf.qval++;
 	ret = cverf;
 	mtx_unlock(&nfs_cverf_mtx);
 
 	return (ret);
 }
 
 /*
  * nfs file create call
  */
 static int
 nfs_create(struct vop_create_args *ap)
 {
 	struct vnode *dvp = ap->a_dvp;
 	struct vattr *vap = ap->a_vap;
 	struct componentname *cnp = ap->a_cnp;
 	struct nfsnode *np = NULL, *dnp;
 	struct vnode *newvp = NULL;
 	struct nfsmount *nmp;
 	struct nfsvattr dnfsva, nfsva;
 	struct nfsfh *nfhp;
 	nfsquad_t cverf;
 	int error = 0, attrflag, dattrflag, fmode = 0;
 	struct vattr vattr;
 
 	/*
 	 * Oops, not for me..
 	 */
 	if (vap->va_type == VSOCK)
 		return (nfs_mknodrpc(dvp, ap->a_vpp, cnp, vap));
 
 	if ((error = VOP_GETATTR(dvp, &vattr, cnp->cn_cred)))
 		return (error);
 	if (vap->va_vaflags & VA_EXCLUSIVE)
 		fmode |= O_EXCL;
 	dnp = VTONFS(dvp);
 	nmp = VFSTONFS(dvp->v_mount);
 again:
 	/* For NFSv4, wait until any remove is done. */
 	NFSLOCKNODE(dnp);
 	while (NFSHASNFSV4(nmp) && (dnp->n_flag & NREMOVEINPROG)) {
 		dnp->n_flag |= NREMOVEWANT;
 		(void) msleep((caddr_t)dnp, &dnp->n_mtx, PZERO, "nfscrt", 0);
 	}
 	NFSUNLOCKNODE(dnp);
 
 	cverf = nfs_get_cverf();
 	error = nfsrpc_create(dvp, cnp->cn_nameptr, cnp->cn_namelen,
 	    vap, cverf, fmode, cnp->cn_cred, curthread, &dnfsva, &nfsva,
 	    &nfhp, &attrflag, &dattrflag, NULL);
 	if (!error) {
 		if (nfhp == NULL)
 			(void) nfsrpc_lookup(dvp, cnp->cn_nameptr,
 			    cnp->cn_namelen, cnp->cn_cred, curthread,
 			    &dnfsva, &nfsva, &nfhp, &attrflag, &dattrflag,
 			    NULL, 0);
 		if (nfhp != NULL)
 			error = nfscl_nget(dvp->v_mount, dvp, nfhp, cnp,
 			    curthread, &np, NULL, LK_EXCLUSIVE);
 	}
 	if (dattrflag)
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	if (!error) {
 		newvp = NFSTOV(np);
 		if (attrflag == 0)
 			error = nfsrpc_getattr(newvp, cnp->cn_cred,
 			    curthread, &nfsva, NULL);
 		if (error == 0)
 			error = nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 	}
 	if (error) {
 		if (newvp != NULL) {
 			vput(newvp);
 			newvp = NULL;
 		}
 		if (NFS_ISV34(dvp) && (fmode & O_EXCL) &&
 		    error == NFSERR_NOTSUPP) {
 			fmode &= ~O_EXCL;
 			goto again;
 		}
 	} else if (NFS_ISV34(dvp) && (fmode & O_EXCL)) {
 		if (nfscl_checksattr(vap, &nfsva)) {
 			error = nfsrpc_setattr(newvp, vap, NULL, cnp->cn_cred,
 			    curthread, &nfsva, &attrflag, NULL);
 			if (error && (vap->va_uid != (uid_t)VNOVAL ||
 			    vap->va_gid != (gid_t)VNOVAL)) {
 				/* try again without setting uid/gid */
 				vap->va_uid = (uid_t)VNOVAL;
 				vap->va_gid = (uid_t)VNOVAL;
 				error = nfsrpc_setattr(newvp, vap, NULL, 
 				    cnp->cn_cred, curthread, &nfsva,
 				    &attrflag, NULL);
 			}
 			if (attrflag)
 				(void) nfscl_loadattrcache(&newvp, &nfsva, NULL,
 				    NULL, 0, 1);
 			if (error != 0)
 				vput(newvp);
 		}
 	}
 	if (!error) {
 		if ((cnp->cn_flags & MAKEENTRY) && attrflag) {
 			if (dvp != newvp)
 				cache_enter_time(dvp, newvp, cnp,
 				    &nfsva.na_ctime, NULL);
 			else
 				printf("nfs_create: bogus NFS server returned "
 				    "the directory as the new file object\n");
 		}
 		*ap->a_vpp = newvp;
 	} else if (NFS_ISV4(dvp)) {
 		error = nfscl_maperr(curthread, error, vap->va_uid,
 		    vap->va_gid);
 	}
 	NFSLOCKNODE(dnp);
 	dnp->n_flag |= NMODIFIED;
 	if (!dattrflag) {
 		dnp->n_attrstamp = 0;
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(dvp);
 	}
 	NFSUNLOCKNODE(dnp);
 	return (error);
 }
 
 /*
  * nfs file remove call
  * To try and make nfs semantics closer to ufs semantics, a file that has
  * other processes using the vnode is renamed instead of removed and then
  * removed later on the last close.
  * - If v_usecount > 1
  *	  If a rename is not already in the works
  *	     call nfs_sillyrename() to set it up
  *     else
  *	  do the remove rpc
  */
 static int
 nfs_remove(struct vop_remove_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct vnode *dvp = ap->a_dvp;
 	struct componentname *cnp = ap->a_cnp;
 	struct nfsnode *np = VTONFS(vp);
 	int error = 0;
 	struct vattr vattr;
 
 	KASSERT((cnp->cn_flags & HASBUF) != 0, ("nfs_remove: no name"));
 	KASSERT(vrefcnt(vp) > 0, ("nfs_remove: bad v_usecount"));
 	if (vp->v_type == VDIR)
 		error = EPERM;
 	else if (vrefcnt(vp) == 1 || (np->n_sillyrename &&
 	    VOP_GETATTR(vp, &vattr, cnp->cn_cred) == 0 &&
 	    vattr.va_nlink > 1)) {
 		/*
 		 * Purge the name cache so that the chance of a lookup for
 		 * the name succeeding while the remove is in progress is
 		 * minimized. Without node locking it can still happen, such
 		 * that an I/O op returns ESTALE, but since you get this if
 		 * another host removes the file..
 		 */
 		cache_purge(vp);
 		/*
 		 * throw away biocache buffers, mainly to avoid
 		 * unnecessary delayed writes later.
 		 */
 		error = ncl_vinvalbuf(vp, 0, curthread, 1);
 		if (error != EINTR && error != EIO)
 			/* Do the rpc */
 			error = nfs_removerpc(dvp, vp, cnp->cn_nameptr,
 			    cnp->cn_namelen, cnp->cn_cred, curthread);
 		/*
 		 * Kludge City: If the first reply to the remove rpc is lost..
 		 *   the reply to the retransmitted request will be ENOENT
 		 *   since the file was in fact removed
 		 *   Therefore, we cheat and return success.
 		 */
 		if (error == ENOENT)
 			error = 0;
 	} else if (!np->n_sillyrename)
 		error = nfs_sillyrename(dvp, vp, cnp);
 	NFSLOCKNODE(np);
 	np->n_attrstamp = 0;
 	NFSUNLOCKNODE(np);
 	KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 	return (error);
 }
 
 /*
  * nfs file remove rpc called from nfs_inactive
  */
 int
 ncl_removeit(struct sillyrename *sp, struct vnode *vp)
 {
 	/*
 	 * Make sure that the directory vnode is still valid.
 	 * XXX we should lock sp->s_dvp here.
 	 */
 	if (sp->s_dvp->v_type == VBAD)
 		return (0);
 	return (nfs_removerpc(sp->s_dvp, vp, sp->s_name, sp->s_namlen,
 	    sp->s_cred, NULL));
 }
 
 /*
  * Nfs remove rpc, called from nfs_remove() and ncl_removeit().
  */
 static int
 nfs_removerpc(struct vnode *dvp, struct vnode *vp, char *name,
     int namelen, struct ucred *cred, struct thread *td)
 {
 	struct nfsvattr dnfsva;
 	struct nfsnode *dnp = VTONFS(dvp);
 	int error = 0, dattrflag;
 
 	NFSLOCKNODE(dnp);
 	dnp->n_flag |= NREMOVEINPROG;
 	NFSUNLOCKNODE(dnp);
 	error = nfsrpc_remove(dvp, name, namelen, vp, cred, td, &dnfsva,
 	    &dattrflag, NULL);
 	NFSLOCKNODE(dnp);
 	if ((dnp->n_flag & NREMOVEWANT)) {
 		dnp->n_flag &= ~(NREMOVEWANT | NREMOVEINPROG);
 		NFSUNLOCKNODE(dnp);
 		wakeup((caddr_t)dnp);
 	} else {
 		dnp->n_flag &= ~NREMOVEINPROG;
 		NFSUNLOCKNODE(dnp);
 	}
 	if (dattrflag)
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	NFSLOCKNODE(dnp);
 	dnp->n_flag |= NMODIFIED;
 	if (!dattrflag) {
 		dnp->n_attrstamp = 0;
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(dvp);
 	}
 	NFSUNLOCKNODE(dnp);
 	if (error && NFS_ISV4(dvp))
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs file rename call
  */
 static int
 nfs_rename(struct vop_rename_args *ap)
 {
 	struct vnode *fvp = ap->a_fvp;
 	struct vnode *tvp = ap->a_tvp;
 	struct vnode *fdvp = ap->a_fdvp;
 	struct vnode *tdvp = ap->a_tdvp;
 	struct componentname *tcnp = ap->a_tcnp;
 	struct componentname *fcnp = ap->a_fcnp;
 	struct nfsnode *fnp = VTONFS(ap->a_fvp);
 	struct nfsnode *tdnp = VTONFS(ap->a_tdvp);
 	struct nfsv4node *newv4 = NULL;
 	int error;
 
 	KASSERT((tcnp->cn_flags & HASBUF) != 0 &&
 	    (fcnp->cn_flags & HASBUF) != 0, ("nfs_rename: no name"));
 	/* Check for cross-device rename */
 	if ((fvp->v_mount != tdvp->v_mount) ||
 	    (tvp && (fvp->v_mount != tvp->v_mount))) {
 		error = EXDEV;
 		goto out;
 	}
 
 	if (fvp == tvp) {
 		printf("nfs_rename: fvp == tvp (can't happen)\n");
 		error = 0;
 		goto out;
 	}
 	if ((error = NFSVOPLOCK(fvp, LK_EXCLUSIVE)) != 0)
 		goto out;
 
 	/*
 	 * We have to flush B_DELWRI data prior to renaming
 	 * the file.  If we don't, the delayed-write buffers
 	 * can be flushed out later after the file has gone stale
 	 * under NFSV3.  NFSV2 does not have this problem because
 	 * ( as far as I can tell ) it flushes dirty buffers more
 	 * often.
 	 * 
 	 * Skip the rename operation if the fsync fails, this can happen
 	 * due to the server's volume being full, when we pushed out data
 	 * that was written back to our cache earlier. Not checking for
 	 * this condition can result in potential (silent) data loss.
 	 */
 	error = VOP_FSYNC(fvp, MNT_WAIT, curthread);
 	NFSVOPUNLOCK(fvp);
 	if (!error && tvp)
 		error = VOP_FSYNC(tvp, MNT_WAIT, curthread);
 	if (error)
 		goto out;
 
 	/*
 	 * If the tvp exists and is in use, sillyrename it before doing the
 	 * rename of the new file over it.
 	 * XXX Can't sillyrename a directory.
 	 */
 	if (tvp && vrefcnt(tvp) > 1 && !VTONFS(tvp)->n_sillyrename &&
 		tvp->v_type != VDIR && !nfs_sillyrename(tdvp, tvp, tcnp)) {
 		vput(tvp);
 		tvp = NULL;
 	}
 
 	error = nfs_renamerpc(fdvp, fvp, fcnp->cn_nameptr, fcnp->cn_namelen,
 	    tdvp, tvp, tcnp->cn_nameptr, tcnp->cn_namelen, tcnp->cn_cred,
 	    curthread);
 
 	if (error == 0 && NFS_ISV4(tdvp)) {
 		/*
 		 * For NFSv4, check to see if it is the same name and
 		 * replace the name, if it is different.
 		 */
 		newv4 = malloc(
 		    sizeof (struct nfsv4node) +
 		    tdnp->n_fhp->nfh_len + tcnp->cn_namelen - 1,
 		    M_NFSV4NODE, M_WAITOK);
 		NFSLOCKNODE(tdnp);
 		NFSLOCKNODE(fnp);
 		if (fnp->n_v4 != NULL && fvp->v_type == VREG &&
 		    (fnp->n_v4->n4_namelen != tcnp->cn_namelen ||
 		      NFSBCMP(tcnp->cn_nameptr, NFS4NODENAME(fnp->n_v4),
 		      tcnp->cn_namelen) ||
 		      tdnp->n_fhp->nfh_len != fnp->n_v4->n4_fhlen ||
 		      NFSBCMP(tdnp->n_fhp->nfh_fh, fnp->n_v4->n4_data,
 			tdnp->n_fhp->nfh_len))) {
 #ifdef notdef
 { char nnn[100]; int nnnl;
 nnnl = (tcnp->cn_namelen < 100) ? tcnp->cn_namelen : 99;
 bcopy(tcnp->cn_nameptr, nnn, nnnl);
 nnn[nnnl] = '\0';
 printf("ren replace=%s\n",nnn);
 }
 #endif
 			free(fnp->n_v4, M_NFSV4NODE);
 			fnp->n_v4 = newv4;
 			newv4 = NULL;
 			fnp->n_v4->n4_fhlen = tdnp->n_fhp->nfh_len;
 			fnp->n_v4->n4_namelen = tcnp->cn_namelen;
 			NFSBCOPY(tdnp->n_fhp->nfh_fh, fnp->n_v4->n4_data,
 			    tdnp->n_fhp->nfh_len);
 			NFSBCOPY(tcnp->cn_nameptr,
 			    NFS4NODENAME(fnp->n_v4), tcnp->cn_namelen);
 		}
 		NFSUNLOCKNODE(tdnp);
 		NFSUNLOCKNODE(fnp);
 		if (newv4 != NULL)
 			free(newv4, M_NFSV4NODE);
 	}
 
 	if (fvp->v_type == VDIR) {
 		if (tvp != NULL && tvp->v_type == VDIR)
 			cache_purge(tdvp);
 		cache_purge(fdvp);
 	}
 
 out:
 	if (tdvp == tvp)
 		vrele(tdvp);
 	else
 		vput(tdvp);
 	if (tvp)
 		vput(tvp);
 	vrele(fdvp);
 	vrele(fvp);
 	/*
 	 * Kludge: Map ENOENT => 0 assuming that it is a reply to a retry.
 	 */
 	if (error == ENOENT)
 		error = 0;
 	return (error);
 }
 
 /*
  * nfs file rename rpc called from nfs_remove() above
  */
 static int
 nfs_renameit(struct vnode *sdvp, struct vnode *svp, struct componentname *scnp,
     struct sillyrename *sp)
 {
 
 	return (nfs_renamerpc(sdvp, svp, scnp->cn_nameptr, scnp->cn_namelen,
 	    sdvp, NULL, sp->s_name, sp->s_namlen, scnp->cn_cred,
 	    curthread));
 }
 
 /*
  * Do an nfs rename rpc. Called from nfs_rename() and nfs_renameit().
  */
 static int
 nfs_renamerpc(struct vnode *fdvp, struct vnode *fvp, char *fnameptr,
     int fnamelen, struct vnode *tdvp, struct vnode *tvp, char *tnameptr,
     int tnamelen, struct ucred *cred, struct thread *td)
 {
 	struct nfsvattr fnfsva, tnfsva;
 	struct nfsnode *fdnp = VTONFS(fdvp);
 	struct nfsnode *tdnp = VTONFS(tdvp);
 	int error = 0, fattrflag, tattrflag;
 
 	error = nfsrpc_rename(fdvp, fvp, fnameptr, fnamelen, tdvp, tvp,
 	    tnameptr, tnamelen, cred, td, &fnfsva, &tnfsva, &fattrflag,
 	    &tattrflag, NULL, NULL);
 	NFSLOCKNODE(fdnp);
 	fdnp->n_flag |= NMODIFIED;
 	if (fattrflag != 0) {
 		NFSUNLOCKNODE(fdnp);
 		(void) nfscl_loadattrcache(&fdvp, &fnfsva, NULL, NULL, 0, 1);
 	} else {
 		fdnp->n_attrstamp = 0;
 		NFSUNLOCKNODE(fdnp);
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(fdvp);
 	}
 	NFSLOCKNODE(tdnp);
 	tdnp->n_flag |= NMODIFIED;
 	if (tattrflag != 0) {
 		NFSUNLOCKNODE(tdnp);
 		(void) nfscl_loadattrcache(&tdvp, &tnfsva, NULL, NULL, 0, 1);
 	} else {
 		tdnp->n_attrstamp = 0;
 		NFSUNLOCKNODE(tdnp);
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(tdvp);
 	}
 	if (error && NFS_ISV4(fdvp))
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs hard link create call
  */
 static int
 nfs_link(struct vop_link_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct vnode *tdvp = ap->a_tdvp;
 	struct componentname *cnp = ap->a_cnp;
 	struct nfsnode *np, *tdnp;
 	struct nfsvattr nfsva, dnfsva;
 	int error = 0, attrflag, dattrflag;
 
 	/*
 	 * Push all writes to the server, so that the attribute cache
 	 * doesn't get "out of sync" with the server.
 	 * XXX There should be a better way!
 	 */
 	VOP_FSYNC(vp, MNT_WAIT, curthread);
 
 	error = nfsrpc_link(tdvp, vp, cnp->cn_nameptr, cnp->cn_namelen,
 	    cnp->cn_cred, curthread, &dnfsva, &nfsva, &attrflag,
 	    &dattrflag, NULL);
 	tdnp = VTONFS(tdvp);
 	NFSLOCKNODE(tdnp);
 	tdnp->n_flag |= NMODIFIED;
 	if (dattrflag != 0) {
 		NFSUNLOCKNODE(tdnp);
 		(void) nfscl_loadattrcache(&tdvp, &dnfsva, NULL, NULL, 0, 1);
 	} else {
 		tdnp->n_attrstamp = 0;
 		NFSUNLOCKNODE(tdnp);
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(tdvp);
 	}
 	if (attrflag)
 		(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 	else {
 		np = VTONFS(vp);
 		NFSLOCKNODE(np);
 		np->n_attrstamp = 0;
 		NFSUNLOCKNODE(np);
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 	}
 	/*
 	 * If negative lookup caching is enabled, I might as well
 	 * add an entry for this node. Not necessary for correctness,
 	 * but if negative caching is enabled, then the system
 	 * must care about lookup caching hit rate, so...
 	 */
 	if (VFSTONFS(vp->v_mount)->nm_negnametimeo != 0 &&
 	    (cnp->cn_flags & MAKEENTRY) && attrflag != 0 && error == 0) {
 		if (tdvp != vp)
 			cache_enter_time(tdvp, vp, cnp, &nfsva.na_ctime, NULL);
 		else
 			printf("nfs_link: bogus NFS server returned "
 			    "the directory as the new link\n");
 	}
 	if (error && NFS_ISV4(vp))
 		error = nfscl_maperr(curthread, error, (uid_t)0,
 		    (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs symbolic link create call
  */
 static int
 nfs_symlink(struct vop_symlink_args *ap)
 {
 	struct vnode *dvp = ap->a_dvp;
 	struct vattr *vap = ap->a_vap;
 	struct componentname *cnp = ap->a_cnp;
 	struct nfsvattr nfsva, dnfsva;
 	struct nfsfh *nfhp;
 	struct nfsnode *np = NULL, *dnp;
 	struct vnode *newvp = NULL;
 	int error = 0, attrflag, dattrflag, ret;
 
 	vap->va_type = VLNK;
 	error = nfsrpc_symlink(dvp, cnp->cn_nameptr, cnp->cn_namelen,
 	    ap->a_target, vap, cnp->cn_cred, curthread, &dnfsva,
 	    &nfsva, &nfhp, &attrflag, &dattrflag, NULL);
 	if (nfhp) {
 		ret = nfscl_nget(dvp->v_mount, dvp, nfhp, cnp, curthread,
 		    &np, NULL, LK_EXCLUSIVE);
 		if (!ret)
 			newvp = NFSTOV(np);
 		else if (!error)
 			error = ret;
 	}
 	if (newvp != NULL) {
 		if (attrflag)
 			(void) nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 	} else if (!error) {
 		/*
 		 * If we do not have an error and we could not extract the
 		 * newvp from the response due to the request being NFSv2, we
 		 * have to do a lookup in order to obtain a newvp to return.
 		 */
 		error = nfs_lookitup(dvp, cnp->cn_nameptr, cnp->cn_namelen,
 		    cnp->cn_cred, curthread, &np);
 		if (!error)
 			newvp = NFSTOV(np);
 	}
 	if (error) {
 		if (newvp)
 			vput(newvp);
 		if (NFS_ISV4(dvp))
 			error = nfscl_maperr(curthread, error,
 			    vap->va_uid, vap->va_gid);
 	} else {
 		*ap->a_vpp = newvp;
 	}
 
 	dnp = VTONFS(dvp);
 	NFSLOCKNODE(dnp);
 	dnp->n_flag |= NMODIFIED;
 	if (dattrflag != 0) {
 		NFSUNLOCKNODE(dnp);
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	} else {
 		dnp->n_attrstamp = 0;
 		NFSUNLOCKNODE(dnp);
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(dvp);
 	}
 	/*
 	 * If negative lookup caching is enabled, I might as well
 	 * add an entry for this node. Not necessary for correctness,
 	 * but if negative caching is enabled, then the system
 	 * must care about lookup caching hit rate, so...
 	 */
 	if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 &&
 	    (cnp->cn_flags & MAKEENTRY) && attrflag != 0 && error == 0) {
 		if (dvp != newvp)
 			cache_enter_time(dvp, newvp, cnp, &nfsva.na_ctime,
 			    NULL);
 		else
 			printf("nfs_symlink: bogus NFS server returned "
 			    "the directory as the new file object\n");
 	}
 	return (error);
 }
 
 /*
  * nfs make dir call
  */
 static int
 nfs_mkdir(struct vop_mkdir_args *ap)
 {
 	struct vnode *dvp = ap->a_dvp;
 	struct vattr *vap = ap->a_vap;
 	struct componentname *cnp = ap->a_cnp;
 	struct nfsnode *np = NULL, *dnp;
 	struct vnode *newvp = NULL;
 	struct vattr vattr;
 	struct nfsfh *nfhp;
 	struct nfsvattr nfsva, dnfsva;
 	int error = 0, attrflag, dattrflag, ret;
 
 	if ((error = VOP_GETATTR(dvp, &vattr, cnp->cn_cred)) != 0)
 		return (error);
 	vap->va_type = VDIR;
 	error = nfsrpc_mkdir(dvp, cnp->cn_nameptr, cnp->cn_namelen,
 	    vap, cnp->cn_cred, curthread, &dnfsva, &nfsva, &nfhp,
 	    &attrflag, &dattrflag, NULL);
 	dnp = VTONFS(dvp);
 	NFSLOCKNODE(dnp);
 	dnp->n_flag |= NMODIFIED;
 	if (dattrflag != 0) {
 		NFSUNLOCKNODE(dnp);
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	} else {
 		dnp->n_attrstamp = 0;
 		NFSUNLOCKNODE(dnp);
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(dvp);
 	}
 	if (nfhp) {
 		ret = nfscl_nget(dvp->v_mount, dvp, nfhp, cnp, curthread,
 		    &np, NULL, LK_EXCLUSIVE);
 		if (!ret) {
 			newvp = NFSTOV(np);
 			if (attrflag)
 			   (void) nfscl_loadattrcache(&newvp, &nfsva, NULL,
 				NULL, 0, 1);
 		} else if (!error)
 			error = ret;
 	}
 	if (!error && newvp == NULL) {
 		error = nfs_lookitup(dvp, cnp->cn_nameptr, cnp->cn_namelen,
 		    cnp->cn_cred, curthread, &np);
 		if (!error) {
 			newvp = NFSTOV(np);
 			if (newvp->v_type != VDIR)
 				error = EEXIST;
 		}
 	}
 	if (error) {
 		if (newvp)
 			vput(newvp);
 		if (NFS_ISV4(dvp))
 			error = nfscl_maperr(curthread, error,
 			    vap->va_uid, vap->va_gid);
 	} else {
 		/*
 		 * If negative lookup caching is enabled, I might as well
 		 * add an entry for this node. Not necessary for correctness,
 		 * but if negative caching is enabled, then the system
 		 * must care about lookup caching hit rate, so...
 		 */
 		if (VFSTONFS(dvp->v_mount)->nm_negnametimeo != 0 &&
 		    (cnp->cn_flags & MAKEENTRY) &&
 		    attrflag != 0 && dattrflag != 0) {
 			if (dvp != newvp)
 				cache_enter_time(dvp, newvp, cnp,
 				    &nfsva.na_ctime, &dnfsva.na_ctime);
 			else
 				printf("nfs_mkdir: bogus NFS server returned "
 				    "the directory that the directory was "
 				    "created in as the new file object\n");
 		}
 		*ap->a_vpp = newvp;
 	}
 	return (error);
 }
 
 /*
  * nfs remove directory call
  */
 static int
 nfs_rmdir(struct vop_rmdir_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct vnode *dvp = ap->a_dvp;
 	struct componentname *cnp = ap->a_cnp;
 	struct nfsnode *dnp;
 	struct nfsvattr dnfsva;
 	int error, dattrflag;
 
 	if (dvp == vp)
 		return (EINVAL);
 	error = nfsrpc_rmdir(dvp, cnp->cn_nameptr, cnp->cn_namelen,
 	    cnp->cn_cred, curthread, &dnfsva, &dattrflag, NULL);
 	dnp = VTONFS(dvp);
 	NFSLOCKNODE(dnp);
 	dnp->n_flag |= NMODIFIED;
 	if (dattrflag != 0) {
 		NFSUNLOCKNODE(dnp);
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	} else {
 		dnp->n_attrstamp = 0;
 		NFSUNLOCKNODE(dnp);
 		KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(dvp);
 	}
 
 	cache_purge(dvp);
 	cache_purge(vp);
 	if (error && NFS_ISV4(dvp))
 		error = nfscl_maperr(curthread, error, (uid_t)0,
 		    (gid_t)0);
 	/*
 	 * Kludge: Map ENOENT => 0 assuming that you have a reply to a retry.
 	 */
 	if (error == ENOENT)
 		error = 0;
 	return (error);
 }
 
 /*
  * nfs readdir call
  */
 static int
 nfs_readdir(struct vop_readdir_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 	struct uio *uio = ap->a_uio;
 	ssize_t tresid, left;
 	int error = 0;
 	struct vattr vattr;
 
 	if (ap->a_eofflag != NULL)
 		*ap->a_eofflag = 0;
 	if (vp->v_type != VDIR) 
 		return(EPERM);
 
 	/*
 	 * First, check for hit on the EOF offset cache
 	 */
 	NFSLOCKNODE(np);
 	if (np->n_direofoffset > 0 && uio->uio_offset >= np->n_direofoffset &&
 	    (np->n_flag & NMODIFIED) == 0) {
 		NFSUNLOCKNODE(np);
 		if (VOP_GETATTR(vp, &vattr, ap->a_cred) == 0) {
 			NFSLOCKNODE(np);
 			if ((NFS_ISV4(vp) && np->n_change == vattr.va_filerev) ||
 			    !NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime)) {
 				NFSUNLOCKNODE(np);
 				NFSINCRGLOBAL(nfsstatsv1.direofcache_hits);
 				if (ap->a_eofflag != NULL)
 					*ap->a_eofflag = 1;
 				return (0);
 			} else
 				NFSUNLOCKNODE(np);
 		}
 	} else
 		NFSUNLOCKNODE(np);
 
 	/*
 	 * NFS always guarantees that directory entries don't straddle
 	 * DIRBLKSIZ boundaries.  As such, we need to limit the size
 	 * to an exact multiple of DIRBLKSIZ, to avoid copying a partial
 	 * directory entry.
 	 */
 	left = uio->uio_resid % DIRBLKSIZ;
 	if (left == uio->uio_resid)
 		return (EINVAL);
 	uio->uio_resid -= left;
 
 	/*
 	 * Call ncl_bioread() to do the real work.
 	 */
 	tresid = uio->uio_resid;
 	error = ncl_bioread(vp, uio, 0, ap->a_cred);
 
 	if (!error && uio->uio_resid == tresid) {
 		NFSINCRGLOBAL(nfsstatsv1.direofcache_misses);
 		if (ap->a_eofflag != NULL)
 			*ap->a_eofflag = 1;
 	}
 
 	/* Add the partial DIRBLKSIZ (left) back in. */
 	uio->uio_resid += left;
 	return (error);
 }
 
 /*
  * Readdir rpc call.
  * Called from below the buffer cache by ncl_doio().
  */
 int
 ncl_readdirrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred,
     struct thread *td)
 {
 	struct nfsvattr nfsva;
 	nfsuint64 *cookiep, cookie;
 	struct nfsnode *dnp = VTONFS(vp);
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	int error = 0, eof, attrflag;
 
 	KASSERT(uiop->uio_iovcnt == 1 &&
 	    (uiop->uio_offset & (DIRBLKSIZ - 1)) == 0 &&
 	    (uiop->uio_resid & (DIRBLKSIZ - 1)) == 0,
 	    ("nfs readdirrpc bad uio"));
 
 	/*
 	 * If there is no cookie, assume directory was stale.
 	 */
 	ncl_dircookie_lock(dnp);
 	NFSUNLOCKNODE(dnp);
 	cookiep = ncl_getcookie(dnp, uiop->uio_offset, 0);
 	if (cookiep) {
 		cookie = *cookiep;
 		ncl_dircookie_unlock(dnp);
 	} else {
 		ncl_dircookie_unlock(dnp);		
 		return (NFSERR_BAD_COOKIE);
 	}
 
 	if (NFSHASNFSV3(nmp) && !NFSHASGOTFSINFO(nmp))
 		(void)ncl_fsinfo(nmp, vp, cred, td);
 
 	error = nfsrpc_readdir(vp, uiop, &cookie, cred, td, &nfsva,
 	    &attrflag, &eof, NULL);
 	if (attrflag)
 		(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 
 	if (!error) {
 		/*
 		 * We are now either at the end of the directory or have filled
 		 * the block.
 		 */
 		if (eof) {
 			NFSLOCKNODE(dnp);
 			dnp->n_direofoffset = uiop->uio_offset;
 			NFSUNLOCKNODE(dnp);
 		} else {
 			if (uiop->uio_resid > 0)
 				printf("EEK! readdirrpc resid > 0\n");
 			ncl_dircookie_lock(dnp);
 			NFSUNLOCKNODE(dnp);
 			cookiep = ncl_getcookie(dnp, uiop->uio_offset, 1);
 			*cookiep = cookie;
 			ncl_dircookie_unlock(dnp);
 		}
 	} else if (NFS_ISV4(vp)) {
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	}
 	return (error);
 }
 
 /*
  * NFS V3 readdir plus RPC. Used in place of ncl_readdirrpc().
  */
 int
 ncl_readdirplusrpc(struct vnode *vp, struct uio *uiop, struct ucred *cred,
     struct thread *td)
 {
 	struct nfsvattr nfsva;
 	nfsuint64 *cookiep, cookie;
 	struct nfsnode *dnp = VTONFS(vp);
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	int error = 0, attrflag, eof;
 
 	KASSERT(uiop->uio_iovcnt == 1 &&
 	    (uiop->uio_offset & (DIRBLKSIZ - 1)) == 0 &&
 	    (uiop->uio_resid & (DIRBLKSIZ - 1)) == 0,
 	    ("nfs readdirplusrpc bad uio"));
 
 	/*
 	 * If there is no cookie, assume directory was stale.
 	 */
 	ncl_dircookie_lock(dnp);
 	NFSUNLOCKNODE(dnp);
 	cookiep = ncl_getcookie(dnp, uiop->uio_offset, 0);
 	if (cookiep) {
 		cookie = *cookiep;
 		ncl_dircookie_unlock(dnp);
 	} else {
 		ncl_dircookie_unlock(dnp);
 		return (NFSERR_BAD_COOKIE);
 	}
 
 	if (NFSHASNFSV3(nmp) && !NFSHASGOTFSINFO(nmp))
 		(void)ncl_fsinfo(nmp, vp, cred, td);
 	error = nfsrpc_readdirplus(vp, uiop, &cookie, cred, td, &nfsva,
 	    &attrflag, &eof, NULL);
 	if (attrflag)
 		(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 
 	if (!error) {
 		/*
 		 * We are now either at end of the directory or have filled the
 		 * the block.
 		 */
 		if (eof) {
 			NFSLOCKNODE(dnp);
 			dnp->n_direofoffset = uiop->uio_offset;
 			NFSUNLOCKNODE(dnp);
 		} else {
 			if (uiop->uio_resid > 0)
 				printf("EEK! readdirplusrpc resid > 0\n");
 			ncl_dircookie_lock(dnp);
 			NFSUNLOCKNODE(dnp);
 			cookiep = ncl_getcookie(dnp, uiop->uio_offset, 1);
 			*cookiep = cookie;
 			ncl_dircookie_unlock(dnp);
 		}
 	} else if (NFS_ISV4(vp)) {
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	}
 	return (error);
 }
 
 /*
  * Silly rename. To make the NFS filesystem that is stateless look a little
  * more like the "ufs" a remove of an active vnode is translated to a rename
  * to a funny looking filename that is removed by nfs_inactive on the
  * nfsnode. There is the potential for another process on a different client
  * to create the same funny name between the nfs_lookitup() fails and the
  * nfs_rename() completes, but...
  */
 static int
 nfs_sillyrename(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
 {
 	struct sillyrename *sp;
 	struct nfsnode *np;
 	int error;
 	short pid;
 	unsigned int lticks;
 
 	cache_purge(dvp);
 	np = VTONFS(vp);
 	KASSERT(vp->v_type != VDIR, ("nfs: sillyrename dir"));
 	sp = malloc(sizeof (struct sillyrename),
 	    M_NEWNFSREQ, M_WAITOK);
 	sp->s_cred = crhold(cnp->cn_cred);
 	sp->s_dvp = dvp;
 	VREF(dvp);
 
 	/* 
 	 * Fudge together a funny name.
 	 * Changing the format of the funny name to accommodate more 
 	 * sillynames per directory.
 	 * The name is now changed to .nfs.<ticks>.<pid>.4, where ticks is 
 	 * CPU ticks since boot.
 	 */
 	pid = curthread->td_proc->p_pid;
 	lticks = (unsigned int)ticks;
 	for ( ; ; ) {
 		sp->s_namlen = sprintf(sp->s_name, 
 				       ".nfs.%08x.%04x4.4", lticks, 
 				       pid);
 		if (nfs_lookitup(dvp, sp->s_name, sp->s_namlen, sp->s_cred,
 				 curthread, NULL))
 			break;
 		lticks++;
 	}
 	error = nfs_renameit(dvp, vp, cnp, sp);
 	if (error)
 		goto bad;
 	error = nfs_lookitup(dvp, sp->s_name, sp->s_namlen, sp->s_cred,
 		curthread, &np);
 	np->n_sillyrename = sp;
 	return (0);
 bad:
 	vrele(sp->s_dvp);
 	crfree(sp->s_cred);
 	free(sp, M_NEWNFSREQ);
 	return (error);
 }
 
 /*
  * Look up a file name and optionally either update the file handle or
  * allocate an nfsnode, depending on the value of npp.
  * npp == NULL	--> just do the lookup
  * *npp == NULL --> allocate a new nfsnode and make sure attributes are
  *			handled too
  * *npp != NULL --> update the file handle in the vnode
  */
 static int
 nfs_lookitup(struct vnode *dvp, char *name, int len, struct ucred *cred,
     struct thread *td, struct nfsnode **npp)
 {
 	struct vnode *newvp = NULL, *vp;
 	struct nfsnode *np, *dnp = VTONFS(dvp);
 	struct nfsfh *nfhp, *onfhp;
 	struct nfsvattr nfsva, dnfsva;
 	struct componentname cn;
 	int error = 0, attrflag, dattrflag;
 	u_int hash;
 	struct timespec ts;
 
 	nanouptime(&ts);
 	error = nfsrpc_lookup(dvp, name, len, cred, td, &dnfsva, &nfsva,
 	    &nfhp, &attrflag, &dattrflag, NULL, 0);
 	if (dattrflag)
 		(void) nfscl_loadattrcache(&dvp, &dnfsva, NULL, NULL, 0, 1);
 	if (npp && !error) {
 		if (*npp != NULL) {
 		    np = *npp;
 		    vp = NFSTOV(np);
 		    /*
 		     * For NFSv4, check to see if it is the same name and
 		     * replace the name, if it is different.
 		     */
 		    if (np->n_v4 != NULL && nfsva.na_type == VREG &&
 			(np->n_v4->n4_namelen != len ||
 			 NFSBCMP(name, NFS4NODENAME(np->n_v4), len) ||
 			 dnp->n_fhp->nfh_len != np->n_v4->n4_fhlen ||
 			 NFSBCMP(dnp->n_fhp->nfh_fh, np->n_v4->n4_data,
 			 dnp->n_fhp->nfh_len))) {
 #ifdef notdef
 { char nnn[100]; int nnnl;
 nnnl = (len < 100) ? len : 99;
 bcopy(name, nnn, nnnl);
 nnn[nnnl] = '\0';
 printf("replace=%s\n",nnn);
 }
 #endif
 			    free(np->n_v4, M_NFSV4NODE);
 			    np->n_v4 = malloc(
 				sizeof (struct nfsv4node) +
 				dnp->n_fhp->nfh_len + len - 1,
 				M_NFSV4NODE, M_WAITOK);
 			    np->n_v4->n4_fhlen = dnp->n_fhp->nfh_len;
 			    np->n_v4->n4_namelen = len;
 			    NFSBCOPY(dnp->n_fhp->nfh_fh, np->n_v4->n4_data,
 				dnp->n_fhp->nfh_len);
 			    NFSBCOPY(name, NFS4NODENAME(np->n_v4), len);
 		    }
 		    hash = fnv_32_buf(nfhp->nfh_fh, nfhp->nfh_len,
 			FNV1_32_INIT);
 		    onfhp = np->n_fhp;
 		    /*
 		     * Rehash node for new file handle.
 		     */
 		    vfs_hash_rehash(vp, hash);
 		    np->n_fhp = nfhp;
 		    if (onfhp != NULL)
 			free(onfhp, M_NFSFH);
 		    newvp = NFSTOV(np);
 		} else if (NFS_CMPFH(dnp, nfhp->nfh_fh, nfhp->nfh_len)) {
 		    free(nfhp, M_NFSFH);
 		    VREF(dvp);
 		    newvp = dvp;
 		} else {
 		    cn.cn_nameptr = name;
 		    cn.cn_namelen = len;
 		    error = nfscl_nget(dvp->v_mount, dvp, nfhp, &cn, td,
 			&np, NULL, LK_EXCLUSIVE);
 		    if (error)
 			return (error);
 		    newvp = NFSTOV(np);
 		    /*
 		     * If n_localmodtime >= time before RPC, then
 		     * a file modification operation, such as
 		     * VOP_SETATTR() of size, has occurred while
 		     * the Lookup RPC and acquisition of the vnode
 		     * happened.  As such, the attributes might
 		     * be stale, with possibly an incorrect size.
 		     */
 		    NFSLOCKNODE(np);
 		    if (timespecisset(&np->n_localmodtime) &&
 			timespeccmp(&np->n_localmodtime, &ts, >=)) {
 			NFSCL_DEBUG(4, "nfs_lookitup: localmod "
 			    "stale attributes\n");
 			attrflag = 0;
 		    }
 		    NFSUNLOCKNODE(np);
 		}
 		if (!attrflag && *npp == NULL) {
 			if (newvp == dvp)
 				vrele(newvp);
 			else
 				vput(newvp);
 			return (ENOENT);
 		}
 		if (attrflag)
 			(void) nfscl_loadattrcache(&newvp, &nfsva, NULL, NULL,
 			    0, 1);
 	}
 	if (npp && *npp == NULL) {
 		if (error) {
 			if (newvp) {
 				if (newvp == dvp)
 					vrele(newvp);
 				else
 					vput(newvp);
 			}
 		} else
 			*npp = np;
 	}
 	if (error && NFS_ISV4(dvp))
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * Nfs Version 3 and 4 commit rpc
  */
 int
 ncl_commit(struct vnode *vp, u_quad_t offset, int cnt, struct ucred *cred,
    struct thread *td)
 {
 	struct nfsvattr nfsva;
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	struct nfsnode *np;
 	struct uio uio;
 	int error, attrflag;
 
 	np = VTONFS(vp);
 	error = EIO;
 	attrflag = 0;
 	if (NFSHASPNFS(nmp) && (np->n_flag & NDSCOMMIT) != 0) {
 		uio.uio_offset = offset;
 		uio.uio_resid = cnt;
 		error = nfscl_doiods(vp, &uio, NULL, NULL,
 		    NFSV4OPEN_ACCESSWRITE, 1, cred, td);
 		if (error != 0) {
 			NFSLOCKNODE(np);
 			np->n_flag &= ~NDSCOMMIT;
 			NFSUNLOCKNODE(np);
 		}
 	}
 	if (error != 0) {
 		mtx_lock(&nmp->nm_mtx);
 		if ((nmp->nm_state & NFSSTA_HASWRITEVERF) == 0) {
 			mtx_unlock(&nmp->nm_mtx);
 			return (0);
 		}
 		mtx_unlock(&nmp->nm_mtx);
 		error = nfsrpc_commit(vp, offset, cnt, cred, td, &nfsva,
 		    &attrflag, NULL);
 	}
 	if (attrflag != 0)
 		(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL,
 		    0, 1);
 	if (error != 0 && NFS_ISV4(vp))
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * Strategy routine.
  * For async requests when nfsiod(s) are running, queue the request by
  * calling ncl_asyncio(), otherwise just all ncl_doio() to do the
  * request.
  */
 static int
 nfs_strategy(struct vop_strategy_args *ap)
 {
 	struct buf *bp;
 	struct vnode *vp;
 	struct ucred *cr;
 
 	bp = ap->a_bp;
 	vp = ap->a_vp;
 	KASSERT(bp->b_vp == vp, ("missing b_getvp"));
 	KASSERT(!(bp->b_flags & B_DONE),
 	    ("nfs_strategy: buffer %p unexpectedly marked B_DONE", bp));
 
 	if (vp->v_type == VREG && bp->b_blkno == bp->b_lblkno)
 		bp->b_blkno = bp->b_lblkno * (vp->v_bufobj.bo_bsize /
 		    DEV_BSIZE);
 	if (bp->b_iocmd == BIO_READ)
 		cr = bp->b_rcred;
 	else
 		cr = bp->b_wcred;
 
 	/*
 	 * If the op is asynchronous and an i/o daemon is waiting
 	 * queue the request, wake it up and wait for completion
 	 * otherwise just do it ourselves.
 	 */
 	if ((bp->b_flags & B_ASYNC) == 0 ||
 	    ncl_asyncio(VFSTONFS(vp->v_mount), bp, NOCRED, curthread))
 		(void) ncl_doio(vp, bp, cr, curthread, 1);
 	return (0);
 }
 
 /*
  * fsync vnode op. Just call ncl_flush() with commit == 1.
  */
 /* ARGSUSED */
 static int
 nfs_fsync(struct vop_fsync_args *ap)
 {
 
 	if (ap->a_vp->v_type != VREG) {
 		/*
 		 * For NFS, metadata is changed synchronously on the server,
 		 * so there is nothing to flush. Also, ncl_flush() clears
 		 * the NMODIFIED flag and that shouldn't be done here for
 		 * directories.
 		 */
 		return (0);
 	}
 	return (ncl_flush(ap->a_vp, ap->a_waitfor, ap->a_td, 1, 0));
 }
 
 /*
  * Flush all the blocks associated with a vnode.
  * 	Walk through the buffer pool and push any dirty pages
  *	associated with the vnode.
  * If the called_from_renewthread argument is TRUE, it has been called
  * from the NFSv4 renew thread and, as such, cannot block indefinitely
  * waiting for a buffer write to complete.
  */
 int
 ncl_flush(struct vnode *vp, int waitfor, struct thread *td,
     int commit, int called_from_renewthread)
 {
 	struct nfsnode *np = VTONFS(vp);
 	struct buf *bp;
 	int i;
 	struct buf *nbp;
 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 	int error = 0, slptimeo = 0, slpflag = 0, retv, bvecpos;
 	int passone = 1, trycnt = 0;
 	u_quad_t off, endoff, toff;
 	struct ucred* wcred = NULL;
 	struct buf **bvec = NULL;
 	struct bufobj *bo;
 #ifndef NFS_COMMITBVECSIZ
 #define	NFS_COMMITBVECSIZ	20
 #endif
 	struct buf *bvec_on_stack[NFS_COMMITBVECSIZ];
 	u_int bvecsize = 0, bveccount;
+	struct timespec ts;
 
 	if (called_from_renewthread != 0)
 		slptimeo = hz;
 	if (nmp->nm_flag & NFSMNT_INT)
 		slpflag = PCATCH;
 	if (!commit)
 		passone = 0;
 	bo = &vp->v_bufobj;
 	/*
 	 * A b_flags == (B_DELWRI | B_NEEDCOMMIT) block has been written to the
 	 * server, but has not been committed to stable storage on the server
 	 * yet. On the first pass, the byte range is worked out and the commit
 	 * rpc is done. On the second pass, ncl_writebp() is called to do the
 	 * job.
 	 */
 again:
 	off = (u_quad_t)-1;
 	endoff = 0;
 	bvecpos = 0;
 	if (NFS_ISV34(vp) && commit) {
 		if (bvec != NULL && bvec != bvec_on_stack)
 			free(bvec, M_TEMP);
 		/*
 		 * Count up how many buffers waiting for a commit.
 		 */
 		bveccount = 0;
 		BO_LOCK(bo);
 		TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
 			if (!BUF_ISLOCKED(bp) &&
 			    (bp->b_flags & (B_DELWRI | B_NEEDCOMMIT))
 				== (B_DELWRI | B_NEEDCOMMIT))
 				bveccount++;
 		}
 		/*
 		 * Allocate space to remember the list of bufs to commit.  It is
 		 * important to use M_NOWAIT here to avoid a race with nfs_write.
 		 * If we can't get memory (for whatever reason), we will end up
 		 * committing the buffers one-by-one in the loop below.
 		 */
 		if (bveccount > NFS_COMMITBVECSIZ) {
 			/*
 			 * Release the vnode interlock to avoid a lock
 			 * order reversal.
 			 */
 			BO_UNLOCK(bo);
 			bvec = (struct buf **)
 				malloc(bveccount * sizeof(struct buf *),
 				       M_TEMP, M_NOWAIT);
 			BO_LOCK(bo);
 			if (bvec == NULL) {
 				bvec = bvec_on_stack;
 				bvecsize = NFS_COMMITBVECSIZ;
 			} else
 				bvecsize = bveccount;
 		} else {
 			bvec = bvec_on_stack;
 			bvecsize = NFS_COMMITBVECSIZ;
 		}
 		TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
 			if (bvecpos >= bvecsize)
 				break;
 			if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
 				nbp = TAILQ_NEXT(bp, b_bobufs);
 				continue;
 			}
 			if ((bp->b_flags & (B_DELWRI | B_NEEDCOMMIT)) !=
 			    (B_DELWRI | B_NEEDCOMMIT)) {
 				BUF_UNLOCK(bp);
 				nbp = TAILQ_NEXT(bp, b_bobufs);
 				continue;
 			}
 			BO_UNLOCK(bo);
 			bremfree(bp);
 			/*
 			 * Work out if all buffers are using the same cred
 			 * so we can deal with them all with one commit.
 			 *
 			 * NOTE: we are not clearing B_DONE here, so we have
 			 * to do it later on in this routine if we intend to
 			 * initiate I/O on the bp.
 			 *
 			 * Note: to avoid loopback deadlocks, we do not
 			 * assign b_runningbufspace.
 			 */
 			if (wcred == NULL)
 				wcred = bp->b_wcred;
 			else if (wcred != bp->b_wcred)
 				wcred = NOCRED;
 			vfs_busy_pages(bp, 1);
 
 			BO_LOCK(bo);
 			/*
 			 * bp is protected by being locked, but nbp is not
 			 * and vfs_busy_pages() may sleep.  We have to
 			 * recalculate nbp.
 			 */
 			nbp = TAILQ_NEXT(bp, b_bobufs);
 
 			/*
 			 * A list of these buffers is kept so that the
 			 * second loop knows which buffers have actually
 			 * been committed. This is necessary, since there
 			 * may be a race between the commit rpc and new
 			 * uncommitted writes on the file.
 			 */
 			bvec[bvecpos++] = bp;
 			toff = ((u_quad_t)bp->b_blkno) * DEV_BSIZE +
 				bp->b_dirtyoff;
 			if (toff < off)
 				off = toff;
 			toff += (u_quad_t)(bp->b_dirtyend - bp->b_dirtyoff);
 			if (toff > endoff)
 				endoff = toff;
 		}
 		BO_UNLOCK(bo);
 	}
 	if (bvecpos > 0) {
 		/*
 		 * Commit data on the server, as required.
 		 * If all bufs are using the same wcred, then use that with
 		 * one call for all of them, otherwise commit each one
 		 * separately.
 		 */
 		if (wcred != NOCRED)
 			retv = ncl_commit(vp, off, (int)(endoff - off),
 					  wcred, td);
 		else {
 			retv = 0;
 			for (i = 0; i < bvecpos; i++) {
 				off_t off, size;
 				bp = bvec[i];
 				off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE +
 					bp->b_dirtyoff;
 				size = (u_quad_t)(bp->b_dirtyend
 						  - bp->b_dirtyoff);
 				retv = ncl_commit(vp, off, (int)size,
 						  bp->b_wcred, td);
 				if (retv) break;
 			}
 		}
 
 		if (retv == NFSERR_STALEWRITEVERF)
 			ncl_clearcommit(vp->v_mount);
 
 		/*
 		 * Now, either mark the blocks I/O done or mark the
 		 * blocks dirty, depending on whether the commit
 		 * succeeded.
 		 */
 		for (i = 0; i < bvecpos; i++) {
 			bp = bvec[i];
 			bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 			if (retv) {
 				/*
 				 * Error, leave B_DELWRI intact
 				 */
 				vfs_unbusy_pages(bp);
 				brelse(bp);
 			} else {
 				/*
 				 * Success, remove B_DELWRI ( bundirty() ).
 				 *
 				 * b_dirtyoff/b_dirtyend seem to be NFS
 				 * specific.  We should probably move that
 				 * into bundirty(). XXX
 				 */
 				bufobj_wref(bo);
 				bp->b_flags |= B_ASYNC;
 				bundirty(bp);
 				bp->b_flags &= ~B_DONE;
 				bp->b_ioflags &= ~BIO_ERROR;
 				bp->b_dirtyoff = bp->b_dirtyend = 0;
 				bufdone(bp);
 			}
 		}
 	}
 
 	/*
 	 * Start/do any write(s) that are required.
 	 */
 loop:
 	BO_LOCK(bo);
 	TAILQ_FOREACH_SAFE(bp, &bo->bo_dirty.bv_hd, b_bobufs, nbp) {
 		if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT, NULL)) {
 			if (waitfor != MNT_WAIT || passone)
 				continue;
 
 			error = BUF_TIMELOCK(bp,
 			    LK_EXCLUSIVE | LK_SLEEPFAIL | LK_INTERLOCK,
 			    BO_LOCKPTR(bo), "nfsfsync", slpflag, slptimeo);
 			if (error == 0) {
 				BUF_UNLOCK(bp);
 				goto loop;
 			}
 			if (error == ENOLCK) {
 				error = 0;
 				goto loop;
 			}
 			if (called_from_renewthread != 0) {
 				/*
 				 * Return EIO so the flush will be retried
 				 * later.
 				 */
 				error = EIO;
 				goto done;
 			}
 			if (newnfs_sigintr(nmp, td)) {
 				error = EINTR;
 				goto done;
 			}
 			if (slpflag == PCATCH) {
 				slpflag = 0;
 				slptimeo = 2 * hz;
 			}
 			goto loop;
 		}
 		if ((bp->b_flags & B_DELWRI) == 0)
 			panic("nfs_fsync: not dirty");
 		if ((passone || !commit) && (bp->b_flags & B_NEEDCOMMIT)) {
 			BUF_UNLOCK(bp);
 			continue;
 		}
 		BO_UNLOCK(bo);
 		bremfree(bp);
 		bp->b_flags |= B_ASYNC;
 		bwrite(bp);
 		if (newnfs_sigintr(nmp, td)) {
 			error = EINTR;
 			goto done;
 		}
 		goto loop;
 	}
 	if (passone) {
 		passone = 0;
 		BO_UNLOCK(bo);
 		goto again;
 	}
 	if (waitfor == MNT_WAIT) {
 		while (bo->bo_numoutput) {
 			error = bufobj_wwait(bo, slpflag, slptimeo);
 			if (error) {
 			    BO_UNLOCK(bo);
 			    if (called_from_renewthread != 0) {
 				/*
 				 * Return EIO so that the flush will be
 				 * retried later.
 				 */
 				error = EIO;
 				goto done;
 			    }
 			    error = newnfs_sigintr(nmp, td);
 			    if (error)
 				goto done;
 			    if (slpflag == PCATCH) {
 				slpflag = 0;
 				slptimeo = 2 * hz;
 			    }
 			    BO_LOCK(bo);
 			}
 		}
 		if (bo->bo_dirty.bv_cnt != 0 && commit) {
 			BO_UNLOCK(bo);
 			goto loop;
 		}
 		/*
 		 * Wait for all the async IO requests to drain
 		 */
 		BO_UNLOCK(bo);
 		NFSLOCKNODE(np);
 		while (np->n_directio_asyncwr > 0) {
 			np->n_flag |= NFSYNCWAIT;
 			error = newnfs_msleep(td, &np->n_directio_asyncwr,
 			    &np->n_mtx, slpflag | (PRIBIO + 1), 
 			    "nfsfsync", 0);
 			if (error) {
 				if (newnfs_sigintr(nmp, td)) {
 					NFSUNLOCKNODE(np);
 					error = EINTR;	
 					goto done;
 				}
 			}
 		}
 		NFSUNLOCKNODE(np);
 	} else
 		BO_UNLOCK(bo);
 	if (NFSHASPNFS(nmp)) {
 		nfscl_layoutcommit(vp, td);
 		/*
 		 * Invalidate the attribute cache, since writes to a DS
 		 * won't update the size attribute.
 		 */
 		NFSLOCKNODE(np);
 		np->n_attrstamp = 0;
 	} else
 		NFSLOCKNODE(np);
 	if (np->n_flag & NWRITEERR) {
 		error = np->n_error;
 		np->n_flag &= ~NWRITEERR;
 	}
   	if (commit && bo->bo_dirty.bv_cnt == 0 &&
 	    bo->bo_numoutput == 0 && np->n_directio_asyncwr == 0)
   		np->n_flag &= ~NMODIFIED;
 	NFSUNLOCKNODE(np);
 done:
 	if (bvec != NULL && bvec != bvec_on_stack)
 		free(bvec, M_TEMP);
 	if (error == 0 && commit != 0 && waitfor == MNT_WAIT &&
 	    (bo->bo_dirty.bv_cnt != 0 || bo->bo_numoutput != 0 ||
 	    np->n_directio_asyncwr != 0)) {
 		if (trycnt++ < 5) {
 			/* try, try again... */
 			passone = 1;
 			wcred = NULL;
 			bvec = NULL;
 			bvecsize = 0;
 			goto again;
 		}
 		vn_printf(vp, "ncl_flush failed");
 		error = called_from_renewthread != 0 ? EIO : EBUSY;
 	}
+	if (error == 0) {
+		nanouptime(&ts);
+		NFSLOCKNODE(np);
+		np->n_localmodtime = ts;
+		NFSUNLOCKNODE(np);
+	}
 	return (error);
 }
 
 /*
  * NFS advisory byte-level locks.
  */
 static int
 nfs_advlock(struct vop_advlock_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct ucred *cred;
 	struct nfsnode *np = VTONFS(ap->a_vp);
 	struct proc *p = (struct proc *)ap->a_id;
 	struct thread *td = curthread;	/* XXX */
 	struct vattr va;
 	int ret, error;
 	u_quad_t size;
 	struct nfsmount *nmp;
 
 	error = NFSVOPLOCK(vp, LK_SHARED);
 	if (error != 0)
 		return (EBADF);
 	if (NFS_ISV4(vp) && (ap->a_flags & (F_POSIX | F_FLOCK)) != 0) {
 		if (vp->v_type != VREG) {
 			error = EINVAL;
 			goto out;
 		}
 		if ((ap->a_flags & F_POSIX) != 0)
 			cred = p->p_ucred;
 		else
 			cred = td->td_ucred;
 		NFSVOPLOCK(vp, LK_UPGRADE | LK_RETRY);
 		if (VN_IS_DOOMED(vp)) {
 			error = EBADF;
 			goto out;
 		}
 
 		/*
 		 * If this is unlocking a write locked region, flush and
 		 * commit them before unlocking. This is required by
 		 * RFC3530 Sec. 9.3.2.
 		 */
 		if (ap->a_op == F_UNLCK &&
 		    nfscl_checkwritelocked(vp, ap->a_fl, cred, td, ap->a_id,
 		    ap->a_flags))
 			(void) ncl_flush(vp, MNT_WAIT, td, 1, 0);
 
 		/*
 		 * Mark NFS node as might have acquired a lock.
 		 * This is separate from NHASBEENLOCKED, because it must
 		 * be done before the nfsrpc_advlock() call, which might
 		 * add a nfscllock structure to the client state.
 		 * It is used to check for the case where a nfscllock
 		 * state structure cannot exist for the file.
 		 * Only done for "oneopenown" NFSv4.1/4.2 mounts.
 		 */
 		nmp = VFSTONFS(vp->v_mount);
 		if (NFSHASNFSV4N(nmp) && NFSHASONEOPENOWN(nmp)) {
 			NFSLOCKNODE(np);
 			np->n_flag |= NMIGHTBELOCKED;
 			NFSUNLOCKNODE(np);
 		}
 
 		/*
 		 * Loop around doing the lock op, while a blocking lock
 		 * must wait for the lock op to succeed.
 		 */
 		do {
 			ret = nfsrpc_advlock(vp, np->n_size, ap->a_op,
 			    ap->a_fl, 0, cred, td, ap->a_id, ap->a_flags);
 			if (ret == NFSERR_DENIED && (ap->a_flags & F_WAIT) &&
 			    ap->a_op == F_SETLK) {
 				NFSVOPUNLOCK(vp);
 				error = nfs_catnap(PZERO | PCATCH, ret,
 				    "ncladvl");
 				if (error)
 					return (EINTR);
 				NFSVOPLOCK(vp, LK_EXCLUSIVE | LK_RETRY);
 				if (VN_IS_DOOMED(vp)) {
 					error = EBADF;
 					goto out;
 				}
 			}
 		} while (ret == NFSERR_DENIED && (ap->a_flags & F_WAIT) &&
 		     ap->a_op == F_SETLK);
 		if (ret == NFSERR_DENIED) {
 			error = EAGAIN;
 			goto out;
 		} else if (ret == EINVAL || ret == EBADF || ret == EINTR) {
 			error = ret;
 			goto out;
 		} else if (ret != 0) {
 			error = EACCES;
 			goto out;
 		}
 
 		/*
 		 * Now, if we just got a lock, invalidate data in the buffer
 		 * cache, as required, so that the coherency conforms with
 		 * RFC3530 Sec. 9.3.2.
 		 */
 		if (ap->a_op == F_SETLK) {
 			if ((np->n_flag & NMODIFIED) == 0) {
 				np->n_attrstamp = 0;
 				KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 				ret = VOP_GETATTR(vp, &va, cred);
 			}
 			if ((np->n_flag & NMODIFIED) || ret ||
 			    np->n_change != va.va_filerev) {
 				(void) ncl_vinvalbuf(vp, V_SAVE, td, 1);
 				np->n_attrstamp = 0;
 				KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 				ret = VOP_GETATTR(vp, &va, cred);
 				if (!ret) {
 					np->n_mtime = va.va_mtime;
 					np->n_change = va.va_filerev;
 				}
 			}
 			/* Mark that a file lock has been acquired. */
 			NFSLOCKNODE(np);
 			np->n_flag |= NHASBEENLOCKED;
 			NFSUNLOCKNODE(np);
 		}
 	} else if (!NFS_ISV4(vp)) {
 		if ((VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_NOLOCKD) != 0) {
 			size = VTONFS(vp)->n_size;
 			NFSVOPUNLOCK(vp);
 			error = lf_advlock(ap, &(vp->v_lockf), size);
 		} else {
 			if (nfs_advlock_p != NULL)
 				error = nfs_advlock_p(ap);
 			else {
 				NFSVOPUNLOCK(vp);
 				error = ENOLCK;
 			}
 		}
 		if (error == 0 && ap->a_op == F_SETLK) {
 			error = NFSVOPLOCK(vp, LK_SHARED);
 			if (error == 0) {
 				/* Mark that a file lock has been acquired. */
 				NFSLOCKNODE(np);
 				np->n_flag |= NHASBEENLOCKED;
 				NFSUNLOCKNODE(np);
 				NFSVOPUNLOCK(vp);
 			}
 		}
 		return (error);
 	} else
 		error = EOPNOTSUPP;
 out:
 	NFSVOPUNLOCK(vp);
 	return (error);
 }
 
 /*
  * NFS advisory byte-level locks.
  */
 static int
 nfs_advlockasync(struct vop_advlockasync_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	u_quad_t size;
 	int error;
 
 	if (NFS_ISV4(vp))
 		return (EOPNOTSUPP);
 	error = NFSVOPLOCK(vp, LK_SHARED);
 	if (error)
 		return (error);
 	if ((VFSTONFS(vp->v_mount)->nm_flag & NFSMNT_NOLOCKD) != 0) {
 		size = VTONFS(vp)->n_size;
 		NFSVOPUNLOCK(vp);
 		error = lf_advlockasync(ap, &(vp->v_lockf), size);
 	} else {
 		NFSVOPUNLOCK(vp);
 		error = EOPNOTSUPP;
 	}
 	return (error);
 }
 
 /*
  * Print out the contents of an nfsnode.
  */
 static int
 nfs_print(struct vop_print_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 
 	printf("\tfileid %jd fsid 0x%jx", (uintmax_t)np->n_vattr.na_fileid,
 	    (uintmax_t)np->n_vattr.na_fsid);
 	if (vp->v_type == VFIFO)
 		fifo_printinfo(vp);
 	printf("\n");
 	return (0);
 }
 
 /*
  * This is the "real" nfs::bwrite(struct buf*).
  * We set B_CACHE if this is a VMIO buffer.
  */
 int
 ncl_writebp(struct buf *bp, int force __unused, struct thread *td)
 {
 	int oldflags, rtval;
 
 	if (bp->b_flags & B_INVAL) {
 		brelse(bp);
 		return (0);
 	}
 
 	oldflags = bp->b_flags;
 	bp->b_flags |= B_CACHE;
 
 	/*
 	 * Undirty the bp.  We will redirty it later if the I/O fails.
 	 */
 	bundirty(bp);
 	bp->b_flags &= ~B_DONE;
 	bp->b_ioflags &= ~BIO_ERROR;
 	bp->b_iocmd = BIO_WRITE;
 
 	bufobj_wref(bp->b_bufobj);
 	curthread->td_ru.ru_oublock++;
 
 	/*
 	 * Note: to avoid loopback deadlocks, we do not
 	 * assign b_runningbufspace.
 	 */
 	vfs_busy_pages(bp, 1);
 
 	BUF_KERNPROC(bp);
 	bp->b_iooffset = dbtob(bp->b_blkno);
 	bstrategy(bp);
 
 	if ((oldflags & B_ASYNC) != 0)
 		return (0);
 
 	rtval = bufwait(bp);
 	if (oldflags & B_DELWRI)
 		reassignbuf(bp);
 	brelse(bp);
 	return (rtval);
 }
 
 /*
  * nfs special file access vnode op.
  * Essentially just get vattr and then imitate iaccess() since the device is
  * local to the client.
  */
 static int
 nfsspec_access(struct vop_access_args *ap)
 {
 	struct vattr *vap;
 	struct ucred *cred = ap->a_cred;
 	struct vnode *vp = ap->a_vp;
 	accmode_t accmode = ap->a_accmode;
 	struct vattr vattr;
 	int error;
 
 	/*
 	 * Disallow write attempts on filesystems mounted read-only;
 	 * unless the file is a socket, fifo, or a block or character
 	 * device resident on the filesystem.
 	 */
 	if ((accmode & VWRITE) && (vp->v_mount->mnt_flag & MNT_RDONLY)) {
 		switch (vp->v_type) {
 		case VREG:
 		case VDIR:
 		case VLNK:
 			return (EROFS);
 		default:
 			break;
 		}
 	}
 	vap = &vattr;
 	error = VOP_GETATTR(vp, vap, cred);
 	if (error)
 		goto out;
 	error = vaccess(vp->v_type, vap->va_mode, vap->va_uid, vap->va_gid,
 	    accmode, cred);
 out:
 	return error;
 }
 
 /*
  * Read wrapper for fifos.
  */
 static int
 nfsfifo_read(struct vop_read_args *ap)
 {
 	struct nfsnode *np = VTONFS(ap->a_vp);
 	int error;
 
 	/*
 	 * Set access flag.
 	 */
 	NFSLOCKNODE(np);
 	np->n_flag |= NACC;
 	vfs_timestamp(&np->n_atim);
 	NFSUNLOCKNODE(np);
 	error = fifo_specops.vop_read(ap);
 	return error;	
 }
 
 /*
  * Write wrapper for fifos.
  */
 static int
 nfsfifo_write(struct vop_write_args *ap)
 {
 	struct nfsnode *np = VTONFS(ap->a_vp);
 
 	/*
 	 * Set update flag.
 	 */
 	NFSLOCKNODE(np);
 	np->n_flag |= NUPD;
 	vfs_timestamp(&np->n_mtim);
 	NFSUNLOCKNODE(np);
 	return(fifo_specops.vop_write(ap));
 }
 
 /*
  * Close wrapper for fifos.
  *
  * Update the times on the nfsnode then do fifo close.
  */
 static int
 nfsfifo_close(struct vop_close_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsnode *np = VTONFS(vp);
 	struct vattr vattr;
 	struct timespec ts;
 
 	NFSLOCKNODE(np);
 	if (np->n_flag & (NACC | NUPD)) {
 		vfs_timestamp(&ts);
 		if (np->n_flag & NACC)
 			np->n_atim = ts;
 		if (np->n_flag & NUPD)
 			np->n_mtim = ts;
 		np->n_flag |= NCHG;
 		if (vrefcnt(vp) == 1 &&
 		    (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
 			VATTR_NULL(&vattr);
 			if (np->n_flag & NACC)
 				vattr.va_atime = np->n_atim;
 			if (np->n_flag & NUPD)
 				vattr.va_mtime = np->n_mtim;
 			NFSUNLOCKNODE(np);
 			(void)VOP_SETATTR(vp, &vattr, ap->a_cred);
 			goto out;
 		}
 	}
 	NFSUNLOCKNODE(np);
 out:
 	return (fifo_specops.vop_close(ap));
 }
 
 /*
  * Just call ncl_writebp() with the force argument set to 1.
  *
  * NOTE: B_DONE may or may not be set in a_bp on call.
  */
 static int
 nfs_bwrite(struct buf *bp)
 {
 
 	return (ncl_writebp(bp, 1, curthread));
 }
 
 struct buf_ops buf_ops_newnfs = {
 	.bop_name	=	"buf_ops_nfs",
 	.bop_write	=	nfs_bwrite,
 	.bop_strategy	=	bufstrategy,
 	.bop_sync	=	bufsync,
 	.bop_bdflush	=	bufbdflush,
 };
 
 static int
 nfs_getacl(struct vop_getacl_args *ap)
 {
 	int error;
 
 	if (ap->a_type != ACL_TYPE_NFS4)
 		return (EOPNOTSUPP);
 	error = nfsrpc_getacl(ap->a_vp, ap->a_cred, ap->a_td, ap->a_aclp,
 	    NULL);
 	if (error > NFSERR_STALE) {
 		(void) nfscl_maperr(ap->a_td, error, (uid_t)0, (gid_t)0);
 		error = EPERM;
 	}
 	return (error);
 }
 
 static int
 nfs_setacl(struct vop_setacl_args *ap)
 {
 	int error;
 
 	if (ap->a_type != ACL_TYPE_NFS4)
 		return (EOPNOTSUPP);
 	error = nfsrpc_setacl(ap->a_vp, ap->a_cred, ap->a_td, ap->a_aclp,
 	    NULL);
 	if (error > NFSERR_STALE) {
 		(void) nfscl_maperr(ap->a_td, error, (uid_t)0, (gid_t)0);
 		error = EPERM;
 	}
 	return (error);
 }
 
 /*
  * VOP_ADVISE for NFS.
  * Just return 0 for any errors, since it is just a hint.
  */
 static int
 nfs_advise(struct vop_advise_args *ap)
 {
 	struct thread *td = curthread;
 	struct nfsmount *nmp;
 	uint64_t len;
 	int error;
 
 	/*
 	 * First do vop_stdadvise() to handle the buffer cache.
 	 */
 	error = vop_stdadvise(ap);
 	if (error != 0)
 		return (error);
 	if (ap->a_start < 0 || ap->a_end < 0)
 		return (0);
 	if (ap->a_end == OFF_MAX)
 		len = 0;
 	else if (ap->a_end < ap->a_start)
 		return (0);
 	else
 		len = ap->a_end - ap->a_start + 1;
 	nmp = VFSTONFS(ap->a_vp->v_mount);
 	mtx_lock(&nmp->nm_mtx);
 	if (!NFSHASNFSV4(nmp) || nmp->nm_minorvers < NFSV42_MINORVERSION ||
 	    (NFSHASPNFS(nmp) && (nmp->nm_privflag & NFSMNTP_IOADVISETHRUMDS) ==
 	    0) || (nmp->nm_privflag & NFSMNTP_NOADVISE) != 0) {
 		mtx_unlock(&nmp->nm_mtx);
 		return (0);
 	}
 	mtx_unlock(&nmp->nm_mtx);
 	error = nfsrpc_advise(ap->a_vp, ap->a_start, len, ap->a_advice,
 	    td->td_ucred, td);
 	if (error == NFSERR_NOTSUPP) {
 		mtx_lock(&nmp->nm_mtx);
 		nmp->nm_privflag |= NFSMNTP_NOADVISE;
 		mtx_unlock(&nmp->nm_mtx);
 	}
 	return (0);
 }
 
 /*
  * nfs allocate call
  */
 static int
 nfs_allocate(struct vop_allocate_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct thread *td = curthread;
 	struct nfsvattr nfsva;
 	struct nfsmount *nmp;
 	struct nfsnode *np;
 	off_t alen;
 	int attrflag, error, ret;
 	struct timespec ts;
 
 	attrflag = 0;
 	nmp = VFSTONFS(vp->v_mount);
 	np = VTONFS(vp);
 	mtx_lock(&nmp->nm_mtx);
 	if (NFSHASNFSV4(nmp) && nmp->nm_minorvers >= NFSV42_MINORVERSION &&
 	    (nmp->nm_privflag & NFSMNTP_NOALLOCATE) == 0) {
 		mtx_unlock(&nmp->nm_mtx);
 		/*
 		 * Flush first to ensure that the allocate adds to the
 		 * file's allocation on the server.
 		 */
 		error = ncl_flush(vp, MNT_WAIT, td, 1, 0);
 		if (error == 0) {
 			alen = *ap->a_len;
 			if ((uint64_t)alen > nfs_maxalloclen)
 				alen = nfs_maxalloclen;
 			error = nfsrpc_allocate(vp, *ap->a_offset, alen,
 			    &nfsva, &attrflag, td->td_ucred, td, NULL);
 		}
 		if (error == 0) {
 			*ap->a_offset += alen;
 			*ap->a_len -= alen;
 			nanouptime(&ts);
 			NFSLOCKNODE(np);
 			np->n_localmodtime = ts;
 			NFSUNLOCKNODE(np);
 		} else if (error == NFSERR_NOTSUPP) {
 			mtx_lock(&nmp->nm_mtx);
 			nmp->nm_privflag |= NFSMNTP_NOALLOCATE;
 			mtx_unlock(&nmp->nm_mtx);
 			error = EINVAL;
 		}
 	} else {
 		mtx_unlock(&nmp->nm_mtx);
 		error = EINVAL;
 	}
 	if (attrflag != 0) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (error == 0 && ret != 0)
 			error = ret;
 	}
 	if (error != 0)
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs deallocate call
  */
 static int
 nfs_deallocate(struct vop_deallocate_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct thread *td = curthread;
 	struct nfsvattr nfsva;
 	struct nfsmount *nmp;
 	struct nfsnode *np;
 	off_t tlen, mlen;
 	int attrflag, error, ret;
 	bool clipped;
 	struct timespec ts;
 
 	error = 0;
 	attrflag = 0;
 	nmp = VFSTONFS(vp->v_mount);
 	np = VTONFS(vp);
 	mtx_lock(&nmp->nm_mtx);
 	if (NFSHASNFSV4(nmp) && nmp->nm_minorvers >= NFSV42_MINORVERSION &&
 	    (nmp->nm_privflag & NFSMNTP_NODEALLOCATE) == 0) {
 		mtx_unlock(&nmp->nm_mtx);
 		tlen = omin(OFF_MAX - *ap->a_offset, *ap->a_len);
 		NFSCL_DEBUG(4, "dealloc: off=%jd len=%jd maxfilesize=%ju\n",
 		    (intmax_t)*ap->a_offset, (intmax_t)tlen,
 		    (uintmax_t)nmp->nm_maxfilesize);
 		if ((uint64_t)*ap->a_offset >= nmp->nm_maxfilesize) {
 			/* Avoid EFBIG error return from the NFSv4.2 server. */
 			*ap->a_len = 0;
 			return (0);
 		}
 		clipped = false;
 		if ((uint64_t)*ap->a_offset + tlen > nmp->nm_maxfilesize)
 			tlen = nmp->nm_maxfilesize - *ap->a_offset;
 		if ((uint64_t)*ap->a_offset < np->n_size) {
 			/* Limit the len to nfs_maxalloclen before EOF. */
 			mlen = omin((off_t)np->n_size - *ap->a_offset, tlen);
 			if ((uint64_t)mlen > nfs_maxalloclen) {
 				NFSCL_DEBUG(4, "dealloc: tlen maxalloclen\n");
 				tlen = nfs_maxalloclen;
 				clipped = true;
 			}
 		}
 		if (error == 0)
 			error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
 		if (error == 0) {
 			vnode_pager_purge_range(vp, *ap->a_offset,
 			    *ap->a_offset + tlen);
 			error = nfsrpc_deallocate(vp, *ap->a_offset, tlen,
 			    &nfsva, &attrflag, ap->a_cred, td, NULL);
 			NFSCL_DEBUG(4, "dealloc: rpc=%d\n", error);
 		}
 		if (error == 0) {
 			NFSCL_DEBUG(4, "dealloc: attrflag=%d na_size=%ju\n",
 			    attrflag, (uintmax_t)nfsva.na_size);
 			nanouptime(&ts);
 			NFSLOCKNODE(np);
 			np->n_localmodtime = ts;
 			NFSUNLOCKNODE(np);
 			if (attrflag != 0) {
 				if ((uint64_t)*ap->a_offset < nfsva.na_size)
 					*ap->a_offset += omin((off_t)
 					    nfsva.na_size - *ap->a_offset,
 					    tlen);
 			}
 			if (clipped && tlen < *ap->a_len)
 				*ap->a_len -= tlen;
 			else
 				*ap->a_len = 0;
 		} else if (error == NFSERR_NOTSUPP) {
 			mtx_lock(&nmp->nm_mtx);
 			nmp->nm_privflag |= NFSMNTP_NODEALLOCATE;
 			mtx_unlock(&nmp->nm_mtx);
 		}
 	} else {
 		mtx_unlock(&nmp->nm_mtx);
 		error = EIO;
 	}
 	/*
 	 * If the NFS server cannot perform the Deallocate operation, just call
 	 * vop_stddeallocate() to perform it.
 	 */
 	if (error != 0 && error != NFSERR_FBIG && error != NFSERR_INVAL) {
 		error = vop_stddeallocate(ap);
 		NFSCL_DEBUG(4, "dealloc: stddeallocate=%d\n", error);
 	}
 	if (attrflag != 0) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (error == 0 && ret != 0)
 			error = ret;
 	}
 	if (error != 0)
 		error = nfscl_maperr(td, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs copy_file_range call
  */
 static int
 nfs_copy_file_range(struct vop_copy_file_range_args *ap)
 {
 	struct vnode *invp = ap->a_invp;
 	struct vnode *outvp = ap->a_outvp;
 	struct mount *mp;
 	struct nfsvattr innfsva, outnfsva;
 	struct vattr *vap;
 	struct uio io;
 	struct nfsmount *nmp;
 	size_t len, len2;
 	int error, inattrflag, outattrflag, ret, ret2;
 	off_t inoff, outoff;
 	bool consecutive, must_commit, tryoutcred;
 
 	ret = ret2 = 0;
 	nmp = VFSTONFS(invp->v_mount);
 	mtx_lock(&nmp->nm_mtx);
 	/* NFSv4.2 Copy is not permitted for infile == outfile. */
 	if (!NFSHASNFSV4(nmp) || nmp->nm_minorvers < NFSV42_MINORVERSION ||
 	    (nmp->nm_privflag & NFSMNTP_NOCOPY) != 0 || invp == outvp) {
 		mtx_unlock(&nmp->nm_mtx);
 		error = vn_generic_copy_file_range(ap->a_invp, ap->a_inoffp,
 		    ap->a_outvp, ap->a_outoffp, ap->a_lenp, ap->a_flags,
 		    ap->a_incred, ap->a_outcred, ap->a_fsizetd);
 		return (error);
 	}
 	mtx_unlock(&nmp->nm_mtx);
 
 	/* Lock both vnodes, avoiding risk of deadlock. */
 	do {
 		mp = NULL;
 		error = vn_start_write(outvp, &mp, V_WAIT);
 		if (error == 0) {
 			error = vn_lock(outvp, LK_EXCLUSIVE);
 			if (error == 0) {
 				error = vn_lock(invp, LK_SHARED | LK_NOWAIT);
 				if (error == 0)
 					break;
 				VOP_UNLOCK(outvp);
 				if (mp != NULL)
 					vn_finished_write(mp);
 				mp = NULL;
 				error = vn_lock(invp, LK_SHARED);
 				if (error == 0)
 					VOP_UNLOCK(invp);
 			}
 		}
 		if (mp != NULL)
 			vn_finished_write(mp);
 	} while (error == 0);
 	if (error != 0)
 		return (error);
 
 	/*
 	 * Do the vn_rlimit_fsize() check.  Should this be above the VOP layer?
 	 */
 	io.uio_offset = *ap->a_outoffp;
 	io.uio_resid = *ap->a_lenp;
 	error = vn_rlimit_fsize(outvp, &io, ap->a_fsizetd);
 
 	/*
 	 * Flush the input file so that the data is up to date before
 	 * the copy.  Flush writes for the output file so that they
 	 * do not overwrite the data copied to the output file by the Copy.
 	 * Set the commit argument for both flushes so that the data is on
 	 * stable storage before the Copy RPC.  This is done in case the
 	 * server reboots during the Copy and needs to be redone.
 	 */
 	if (error == 0)
 		error = ncl_flush(invp, MNT_WAIT, curthread, 1, 0);
 	if (error == 0)
 		error = ncl_flush(outvp, MNT_WAIT, curthread, 1, 0);
 
 	/* Do the actual NFSv4.2 RPC. */
 	len = *ap->a_lenp;
 	mtx_lock(&nmp->nm_mtx);
 	if ((nmp->nm_privflag & NFSMNTP_NOCONSECUTIVE) == 0)
 		consecutive = true;
 	else
 		consecutive = false;
 	mtx_unlock(&nmp->nm_mtx);
 	inoff = *ap->a_inoffp;
 	outoff = *ap->a_outoffp;
 	tryoutcred = true;
 	must_commit = false;
 	if (error == 0) {
 		vap = &VTONFS(invp)->n_vattr.na_vattr;
 		error = VOP_GETATTR(invp, vap, ap->a_incred);
 		if (error == 0) {
 			/*
 			 * Clip "len" at va_size so that RFC compliant servers
 			 * will not reply NFSERR_INVAL.
 			 * Setting "len == 0" for the RPC would be preferred,
 			 * but some Linux servers do not support that.
 			 */
 			if (inoff >= vap->va_size)
 				*ap->a_lenp = len = 0;
 			else if (inoff + len > vap->va_size)
 				*ap->a_lenp = len = vap->va_size - inoff;
 		} else
 			error = 0;
 	}
 
 	/*
 	 * len will be set to 0 upon a successful Copy RPC.
 	 * As such, this only loops when the Copy RPC needs to be retried.
 	 */
 	while (len > 0 && error == 0) {
 		inattrflag = outattrflag = 0;
 		len2 = len;
 		if (tryoutcred)
 			error = nfsrpc_copy_file_range(invp, ap->a_inoffp,
 			    outvp, ap->a_outoffp, &len2, ap->a_flags,
 			    &inattrflag, &innfsva, &outattrflag, &outnfsva,
 			    ap->a_outcred, consecutive, &must_commit);
 		else
 			error = nfsrpc_copy_file_range(invp, ap->a_inoffp,
 			    outvp, ap->a_outoffp, &len2, ap->a_flags,
 			    &inattrflag, &innfsva, &outattrflag, &outnfsva,
 			    ap->a_incred, consecutive, &must_commit);
 		if (inattrflag != 0)
 			ret = nfscl_loadattrcache(&invp, &innfsva, NULL, NULL,
 			    0, 1);
 		if (outattrflag != 0)
 			ret2 = nfscl_loadattrcache(&outvp, &outnfsva, NULL,
 			    NULL, 1, 1);
 		if (error == 0) {
 			if (consecutive == false) {
 				if (len2 == len) {
 					mtx_lock(&nmp->nm_mtx);
 					nmp->nm_privflag |=
 					    NFSMNTP_NOCONSECUTIVE;
 					mtx_unlock(&nmp->nm_mtx);
 				} else
 					error = NFSERR_OFFLOADNOREQS;
 			}
 			*ap->a_lenp = len2;
 			len = 0;
 			if (len2 > 0 && must_commit && error == 0)
 				error = ncl_commit(outvp, outoff, *ap->a_lenp,
 				    ap->a_outcred, curthread);
 			if (error == 0 && ret != 0)
 				error = ret;
 			if (error == 0 && ret2 != 0)
 				error = ret2;
 		} else if (error == NFSERR_OFFLOADNOREQS && consecutive) {
 			/*
 			 * Try consecutive == false, which is ok only if all
 			 * bytes are copied.
 			 * If only some bytes were copied when consecutive
 			 * is false, there is no way to know which bytes
 			 * still need to be written.
 			 */
 			consecutive = false;
 			error = 0;
 		} else if (error == NFSERR_ACCES && tryoutcred) {
 			/* Try again with incred. */
 			tryoutcred = false;
 			error = 0;
 		}
 		if (error == NFSERR_STALEWRITEVERF) {
 			/*
 			 * Server rebooted, so do it all again.
 			 */
 			*ap->a_inoffp = inoff;
 			*ap->a_outoffp = outoff;
 			len = *ap->a_lenp;
 			must_commit = false;
 			error = 0;
 		}
 	}
 	VOP_UNLOCK(invp);
 	VOP_UNLOCK(outvp);
 	if (mp != NULL)
 		vn_finished_write(mp);
 	if (error == NFSERR_NOTSUPP || error == NFSERR_OFFLOADNOREQS ||
 	    error == NFSERR_ACCES) {
 		/*
 		 * Unlike the NFSv4.2 Copy, vn_generic_copy_file_range() can
 		 * use a_incred for the read and a_outcred for the write, so
 		 * try this for NFSERR_ACCES failures for the Copy.
 		 * For NFSERR_NOTSUPP and NFSERR_OFFLOADNOREQS, the Copy can
 		 * never succeed, so disable it.
 		 */
 		if (error != NFSERR_ACCES) {
 			/* Can never do Copy on this mount. */
 			mtx_lock(&nmp->nm_mtx);
 			nmp->nm_privflag |= NFSMNTP_NOCOPY;
 			mtx_unlock(&nmp->nm_mtx);
 		}
 		*ap->a_inoffp = inoff;
 		*ap->a_outoffp = outoff;
 		error = vn_generic_copy_file_range(ap->a_invp, ap->a_inoffp,
 		    ap->a_outvp, ap->a_outoffp, ap->a_lenp, ap->a_flags,
 		    ap->a_incred, ap->a_outcred, ap->a_fsizetd);
 	} else if (error != 0)
 		*ap->a_lenp = 0;
 
 	if (error != 0)
 		error = nfscl_maperr(curthread, error, (uid_t)0, (gid_t)0);
 	return (error);
 }
 
 /*
  * nfs ioctl call
  */
 static int
 nfs_ioctl(struct vop_ioctl_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsvattr nfsva;
 	struct nfsmount *nmp;
 	int attrflag, content, error, ret;
 	bool eof = false;			/* shut up compiler. */
 
 	if (vp->v_type != VREG)
 		return (ENOTTY);
 	nmp = VFSTONFS(vp->v_mount);
 	if (!NFSHASNFSV4(nmp) || nmp->nm_minorvers < NFSV42_MINORVERSION) {
 		error = vop_stdioctl(ap);
 		return (error);
 	}
 
 	/* Do the actual NFSv4.2 RPC. */
 	switch (ap->a_command) {
 	case FIOSEEKDATA:
 		content = NFSV4CONTENT_DATA;
 		break;
 	case FIOSEEKHOLE:
 		content = NFSV4CONTENT_HOLE;
 		break;
 	default:
 		return (ENOTTY);
 	}
 
 	error = vn_lock(vp, LK_SHARED);
 	if (error != 0)
 		return (EBADF);
 	attrflag = 0;
 	if (*((off_t *)ap->a_data) >= VTONFS(vp)->n_size)
 		error = ENXIO;
 	else {
 		/*
 		 * Flush all writes, so that the server is up to date.
 		 * Although a Commit is not required, the commit argument
 		 * is set so that, for a pNFS File/Flexible File Layout
 		 * server, the LayoutCommit will be done to ensure the file
 		 * size is up to date on the Metadata Server.
 		 */
 		error = ncl_flush(vp, MNT_WAIT, ap->a_td, 1, 0);
 		if (error == 0)
 			error = nfsrpc_seek(vp, (off_t *)ap->a_data, &eof,
 			    content, ap->a_cred, &nfsva, &attrflag);
 		/* If at eof for FIOSEEKDATA, return ENXIO. */
 		if (eof && error == 0 && content == NFSV4CONTENT_DATA)
 			error = ENXIO;
 	}
 	if (attrflag != 0) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (error == 0 && ret != 0)
 			error = ret;
 	}
 	NFSVOPUNLOCK(vp);
 
 	if (error != 0)
 		error = ENXIO;
 	return (error);
 }
 
 /*
  * nfs getextattr call
  */
 static int
 nfs_getextattr(struct vop_getextattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsmount *nmp;
 	struct ucred *cred;
 	struct thread *td = ap->a_td;
 	struct nfsvattr nfsva;
 	ssize_t len;
 	int attrflag, error, ret;
 
 	nmp = VFSTONFS(vp->v_mount);
 	mtx_lock(&nmp->nm_mtx);
 	if (!NFSHASNFSV4(nmp) || nmp->nm_minorvers < NFSV42_MINORVERSION ||
 	    (nmp->nm_privflag & NFSMNTP_NOXATTR) != 0 ||
 	    ap->a_attrnamespace != EXTATTR_NAMESPACE_USER) {
 		mtx_unlock(&nmp->nm_mtx);
 		return (EOPNOTSUPP);
 	}
 	mtx_unlock(&nmp->nm_mtx);
 
 	cred = ap->a_cred;
 	if (cred == NULL)
 		cred = td->td_ucred;
 	/* Do the actual NFSv4.2 Optional Extended Attribute (RFC-8276) RPC. */
 	attrflag = 0;
 	error = nfsrpc_getextattr(vp, ap->a_name, ap->a_uio, &len, &nfsva,
 	    &attrflag, cred, td);
 	if (attrflag != 0) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (error == 0 && ret != 0)
 			error = ret;
 	}
 	if (error == 0 && ap->a_size != NULL)
 		*ap->a_size = len;
 
 	switch (error) {
 	case NFSERR_NOTSUPP:
 	case NFSERR_OPILLEGAL:
 		mtx_lock(&nmp->nm_mtx);
 		nmp->nm_privflag |= NFSMNTP_NOXATTR;
 		mtx_unlock(&nmp->nm_mtx);
 		error = EOPNOTSUPP;
 		break;
 	case NFSERR_NOXATTR:
 	case NFSERR_XATTR2BIG:
 		error = ENOATTR;
 		break;
 	default:
 		error = nfscl_maperr(td, error, 0, 0);
 		break;
 	}
 	return (error);
 }
 
 /*
  * nfs setextattr call
  */
 static int
 nfs_setextattr(struct vop_setextattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsmount *nmp;
 	struct ucred *cred;
 	struct thread *td = ap->a_td;
 	struct nfsvattr nfsva;
 	int attrflag, error, ret;
 
 	nmp = VFSTONFS(vp->v_mount);
 	mtx_lock(&nmp->nm_mtx);
 	if (!NFSHASNFSV4(nmp) || nmp->nm_minorvers < NFSV42_MINORVERSION ||
 	    (nmp->nm_privflag & NFSMNTP_NOXATTR) != 0 ||
 	    ap->a_attrnamespace != EXTATTR_NAMESPACE_USER) {
 		mtx_unlock(&nmp->nm_mtx);
 		return (EOPNOTSUPP);
 	}
 	mtx_unlock(&nmp->nm_mtx);
 
 	if (ap->a_uio->uio_resid < 0)
 		return (EINVAL);
 	cred = ap->a_cred;
 	if (cred == NULL)
 		cred = td->td_ucred;
 	/* Do the actual NFSv4.2 Optional Extended Attribute (RFC-8276) RPC. */
 	attrflag = 0;
 	error = nfsrpc_setextattr(vp, ap->a_name, ap->a_uio, &nfsva,
 	    &attrflag, cred, td);
 	if (attrflag != 0) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (error == 0 && ret != 0)
 			error = ret;
 	}
 
 	switch (error) {
 	case NFSERR_NOTSUPP:
 	case NFSERR_OPILLEGAL:
 		mtx_lock(&nmp->nm_mtx);
 		nmp->nm_privflag |= NFSMNTP_NOXATTR;
 		mtx_unlock(&nmp->nm_mtx);
 		error = EOPNOTSUPP;
 		break;
 	case NFSERR_NOXATTR:
 	case NFSERR_XATTR2BIG:
 		error = ENOATTR;
 		break;
 	default:
 		error = nfscl_maperr(td, error, 0, 0);
 		break;
 	}
 	return (error);
 }
 
 /*
  * nfs listextattr call
  */
 static int
 nfs_listextattr(struct vop_listextattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsmount *nmp;
 	struct ucred *cred;
 	struct thread *td = ap->a_td;
 	struct nfsvattr nfsva;
 	size_t len, len2;
 	uint64_t cookie;
 	int attrflag, error, ret;
 	bool eof;
 
 	nmp = VFSTONFS(vp->v_mount);
 	mtx_lock(&nmp->nm_mtx);
 	if (!NFSHASNFSV4(nmp) || nmp->nm_minorvers < NFSV42_MINORVERSION ||
 	    (nmp->nm_privflag & NFSMNTP_NOXATTR) != 0 ||
 	    ap->a_attrnamespace != EXTATTR_NAMESPACE_USER) {
 		mtx_unlock(&nmp->nm_mtx);
 		return (EOPNOTSUPP);
 	}
 	mtx_unlock(&nmp->nm_mtx);
 
 	cred = ap->a_cred;
 	if (cred == NULL)
 		cred = td->td_ucred;
 
 	/* Loop around doing List Extended Attribute RPCs. */
 	eof = false;
 	cookie = 0;
 	len2 = 0;
 	error = 0;
 	while (!eof && error == 0) {
 		len = nmp->nm_rsize;
 		attrflag = 0;
 		error = nfsrpc_listextattr(vp, &cookie, ap->a_uio, &len, &eof,
 		    &nfsva, &attrflag, cred, td);
 		if (attrflag != 0) {
 			ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0,
 			    1);
 			if (error == 0 && ret != 0)
 				error = ret;
 		}
 		if (error == 0) {
 			len2 += len;
 			if (len2 > SSIZE_MAX)
 				error = ENOATTR;
 		}
 	}
 	if (error == 0 && ap->a_size != NULL)
 		*ap->a_size = len2;
 
 	switch (error) {
 	case NFSERR_NOTSUPP:
 	case NFSERR_OPILLEGAL:
 		mtx_lock(&nmp->nm_mtx);
 		nmp->nm_privflag |= NFSMNTP_NOXATTR;
 		mtx_unlock(&nmp->nm_mtx);
 		error = EOPNOTSUPP;
 		break;
 	case NFSERR_NOXATTR:
 	case NFSERR_XATTR2BIG:
 		error = ENOATTR;
 		break;
 	default:
 		error = nfscl_maperr(td, error, 0, 0);
 		break;
 	}
 	return (error);
 }
 
 /*
  * nfs setextattr call
  */
 static int
 nfs_deleteextattr(struct vop_deleteextattr_args *ap)
 {
 	struct vnode *vp = ap->a_vp;
 	struct nfsmount *nmp;
 	struct nfsvattr nfsva;
 	int attrflag, error, ret;
 
 	nmp = VFSTONFS(vp->v_mount);
 	mtx_lock(&nmp->nm_mtx);
 	if (!NFSHASNFSV4(nmp) || nmp->nm_minorvers < NFSV42_MINORVERSION ||
 	    (nmp->nm_privflag & NFSMNTP_NOXATTR) != 0 ||
 	    ap->a_attrnamespace != EXTATTR_NAMESPACE_USER) {
 		mtx_unlock(&nmp->nm_mtx);
 		return (EOPNOTSUPP);
 	}
 	mtx_unlock(&nmp->nm_mtx);
 
 	/* Do the actual NFSv4.2 Optional Extended Attribute (RFC-8276) RPC. */
 	attrflag = 0;
 	error = nfsrpc_rmextattr(vp, ap->a_name, &nfsva, &attrflag, ap->a_cred,
 	    ap->a_td);
 	if (attrflag != 0) {
 		ret = nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0, 1);
 		if (error == 0 && ret != 0)
 			error = ret;
 	}
 
 	switch (error) {
 	case NFSERR_NOTSUPP:
 	case NFSERR_OPILLEGAL:
 		mtx_lock(&nmp->nm_mtx);
 		nmp->nm_privflag |= NFSMNTP_NOXATTR;
 		mtx_unlock(&nmp->nm_mtx);
 		error = EOPNOTSUPP;
 		break;
 	case NFSERR_NOXATTR:
 	case NFSERR_XATTR2BIG:
 		error = ENOATTR;
 		break;
 	default:
 		error = nfscl_maperr(ap->a_td, error, 0, 0);
 		break;
 	}
 	return (error);
 }
 
 /*
  * Return POSIX pathconf information applicable to nfs filesystems.
  */
 static int
 nfs_pathconf(struct vop_pathconf_args *ap)
 {
 	struct nfsv3_pathconf pc;
 	struct nfsvattr nfsva;
 	struct vnode *vp = ap->a_vp;
 	struct nfsmount *nmp;
 	struct thread *td = curthread;
 	off_t off;
 	bool eof;
 	int attrflag, error;
 
 	if ((NFS_ISV34(vp) && (ap->a_name == _PC_LINK_MAX ||
 	    ap->a_name == _PC_NAME_MAX || ap->a_name == _PC_CHOWN_RESTRICTED ||
 	    ap->a_name == _PC_NO_TRUNC)) ||
 	    (NFS_ISV4(vp) && ap->a_name == _PC_ACL_NFS4)) {
 		/*
 		 * Since only the above 4 a_names are returned by the NFSv3
 		 * Pathconf RPC, there is no point in doing it for others.
 		 * For NFSv4, the Pathconf RPC (actually a Getattr Op.) can
 		 * be used for _PC_NFS4_ACL as well.
 		 */
 		error = nfsrpc_pathconf(vp, &pc, td->td_ucred, td, &nfsva,
 		    &attrflag, NULL);
 		if (attrflag != 0)
 			(void) nfscl_loadattrcache(&vp, &nfsva, NULL, NULL, 0,
 			    1);
 		if (error != 0)
 			return (error);
 	} else {
 		/*
 		 * For NFSv2 (or NFSv3 when not one of the above 4 a_names),
 		 * just fake them.
 		 */
 		pc.pc_linkmax = NFS_LINK_MAX;
 		pc.pc_namemax = NFS_MAXNAMLEN;
 		pc.pc_notrunc = 1;
 		pc.pc_chownrestricted = 1;
 		pc.pc_caseinsensitive = 0;
 		pc.pc_casepreserving = 1;
 		error = 0;
 	}
 	switch (ap->a_name) {
 	case _PC_LINK_MAX:
 #ifdef _LP64
 		*ap->a_retval = pc.pc_linkmax;
 #else
 		*ap->a_retval = MIN(LONG_MAX, pc.pc_linkmax);
 #endif
 		break;
 	case _PC_NAME_MAX:
 		*ap->a_retval = pc.pc_namemax;
 		break;
 	case _PC_PIPE_BUF:
 		if (ap->a_vp->v_type == VDIR || ap->a_vp->v_type == VFIFO)
 			*ap->a_retval = PIPE_BUF;
 		else
 			error = EINVAL;
 		break;
 	case _PC_CHOWN_RESTRICTED:
 		*ap->a_retval = pc.pc_chownrestricted;
 		break;
 	case _PC_NO_TRUNC:
 		*ap->a_retval = pc.pc_notrunc;
 		break;
 	case _PC_ACL_NFS4:
 		if (NFS_ISV4(vp) && nfsrv_useacl != 0 && attrflag != 0 &&
 		    NFSISSET_ATTRBIT(&nfsva.na_suppattr, NFSATTRBIT_ACL))
 			*ap->a_retval = 1;
 		else
 			*ap->a_retval = 0;
 		break;
 	case _PC_ACL_PATH_MAX:
 		if (NFS_ISV4(vp))
 			*ap->a_retval = ACL_MAX_ENTRIES;
 		else
 			*ap->a_retval = 3;
 		break;
 	case _PC_PRIO_IO:
 		*ap->a_retval = 0;
 		break;
 	case _PC_SYNC_IO:
 		*ap->a_retval = 0;
 		break;
 	case _PC_ALLOC_SIZE_MIN:
 		*ap->a_retval = vp->v_mount->mnt_stat.f_bsize;
 		break;
 	case _PC_FILESIZEBITS:
 		if (NFS_ISV34(vp))
 			*ap->a_retval = 64;
 		else
 			*ap->a_retval = 32;
 		break;
 	case _PC_REC_INCR_XFER_SIZE:
 		*ap->a_retval = vp->v_mount->mnt_stat.f_iosize;
 		break;
 	case _PC_REC_MAX_XFER_SIZE:
 		*ap->a_retval = -1; /* means ``unlimited'' */
 		break;
 	case _PC_REC_MIN_XFER_SIZE:
 		*ap->a_retval = vp->v_mount->mnt_stat.f_iosize;
 		break;
 	case _PC_REC_XFER_ALIGN:
 		*ap->a_retval = PAGE_SIZE;
 		break;
 	case _PC_SYMLINK_MAX:
 		*ap->a_retval = NFS_MAXPATHLEN;
 		break;
 	case _PC_MIN_HOLE_SIZE:
 		/* Only some NFSv4.2 servers support Seek for Holes. */
 		*ap->a_retval = 0;
 		nmp = VFSTONFS(vp->v_mount);
 		if (NFS_ISV4(vp) && nmp->nm_minorvers == NFSV42_MINORVERSION) {
 			/*
 			 * NFSv4.2 doesn't have an attribute for hole size,
 			 * so all we can do is see if the Seek operation is
 			 * supported and then use f_iosize as a "best guess".
 			 */
 			mtx_lock(&nmp->nm_mtx);
 			if ((nmp->nm_privflag & NFSMNTP_SEEKTESTED) == 0) {
 				mtx_unlock(&nmp->nm_mtx);
 				off = 0;
 				attrflag = 0;
 				error = nfsrpc_seek(vp, &off, &eof,
 				    NFSV4CONTENT_HOLE, td->td_ucred, &nfsva,
 				    &attrflag);
 				if (attrflag != 0)
 					nfscl_loadattrcache(&vp, &nfsva,
 					    NULL, NULL, 0, 1);
 				mtx_lock(&nmp->nm_mtx);
 				if (error == NFSERR_NOTSUPP)
 					nmp->nm_privflag |= NFSMNTP_SEEKTESTED;
 				else
 					nmp->nm_privflag |= NFSMNTP_SEEKTESTED |
 					    NFSMNTP_SEEK;
 				error = 0;
 			}
 			if ((nmp->nm_privflag & NFSMNTP_SEEK) != 0)
 				*ap->a_retval = vp->v_mount->mnt_stat.f_iosize;
 			mtx_unlock(&nmp->nm_mtx);
 		}
 		break;
 
 	default:
 		error = vop_stdpathconf(ap);
 		break;
 	}
 	return (error);
 }