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nfs_bio.c revision 1.45.4.5
      1 /*	$NetBSD: nfs_bio.c,v 1.45.4.5 1999/08/31 21:03:44 perseant Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1989, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Rick Macklem at The University of Guelph.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  *	@(#)nfs_bio.c	8.9 (Berkeley) 3/30/95
     39  */
     40 
     41 #include <sys/param.h>
     42 #include <sys/systm.h>
     43 #include <sys/resourcevar.h>
     44 #include <sys/signalvar.h>
     45 #include <sys/proc.h>
     46 #include <sys/buf.h>
     47 #include <sys/vnode.h>
     48 #include <sys/trace.h>
     49 #include <sys/mount.h>
     50 #include <sys/kernel.h>
     51 #include <sys/namei.h>
     52 #include <sys/dirent.h>
     53 #include <sys/malloc.h>
     54 
     55 #include <vm/vm.h>
     56 #include <uvm/uvm_extern.h>
     57 #include <uvm/uvm.h>
     58 
     59 #include <nfs/rpcv2.h>
     60 #include <nfs/nfsproto.h>
     61 #include <nfs/nfs.h>
     62 #include <nfs/nfsmount.h>
     63 #include <nfs/nqnfs.h>
     64 #include <nfs/nfsnode.h>
     65 #include <nfs/nfs_var.h>
     66 
     67 extern int nfs_numasync;
     68 extern struct nfsstats nfsstats;
     69 
     70 /*
     71  * Vnode op for read using bio
     72  * Any similarity to readip() is purely coincidental
     73  */
     74 int
     75 nfs_bioread(vp, uio, ioflag, cred, cflag)
     76 	register struct vnode *vp;
     77 	register struct uio *uio;
     78 	int ioflag, cflag;
     79 	struct ucred *cred;
     80 {
     81 	register struct nfsnode *np = VTONFS(vp);
     82 	register int biosize, diff;
     83 	struct buf *bp = NULL, *rabp;
     84 	struct vattr vattr;
     85 	struct proc *p;
     86 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
     87 	struct nfsdircache *ndp = NULL, *nndp = NULL;
     88 	daddr_t lbn, bn, rabn;
     89 	caddr_t baddr, ep, edp;
     90 	int got_buf = 0, nra, error = 0, n = 0, on = 0, not_readin, en, enn;
     91 	int enough = 0;
     92 	struct dirent *dp, *pdp;
     93 	off_t curoff = 0, offdiff;
     94 
     95 #ifdef DIAGNOSTIC
     96 	if (uio->uio_rw != UIO_READ)
     97 		panic("nfs_read mode");
     98 #endif
     99 	if (uio->uio_resid == 0)
    100 		return (0);
    101 	if (vp->v_type != VDIR && uio->uio_offset < 0)
    102 		return (EINVAL);
    103 	p = uio->uio_procp;
    104 	if ((nmp->nm_flag & NFSMNT_NFSV3) &&
    105 	    !(nmp->nm_iflag & NFSMNT_GOTFSINFO))
    106 		(void)nfs_fsinfo(nmp, vp, cred, p);
    107 	if (vp->v_type != VDIR &&
    108 	    (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
    109 		return (EFBIG);
    110 	biosize = nmp->nm_rsize;
    111 	/*
    112 	 * For nfs, cache consistency can only be maintained approximately.
    113 	 * Although RFC1094 does not specify the criteria, the following is
    114 	 * believed to be compatible with the reference port.
    115 	 * For nqnfs, full cache consistency is maintained within the loop.
    116 	 * For nfs:
    117 	 * If the file's modify time on the server has changed since the
    118 	 * last read rpc or you have written to the file,
    119 	 * you may have lost data cache consistency with the
    120 	 * server, so flush all of the file's data out of the cache.
    121 	 * Then force a getattr rpc to ensure that you have up to date
    122 	 * attributes.
    123 	 * NB: This implies that cache data can be read when up to
    124 	 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
    125 	 * attributes this could be forced by setting n_attrstamp to 0 before
    126 	 * the VOP_GETATTR() call.
    127 	 */
    128 	if ((nmp->nm_flag & NFSMNT_NQNFS) == 0 && vp->v_type != VLNK) {
    129 		if (np->n_flag & NMODIFIED) {
    130 			if (vp->v_type != VREG) {
    131 				if (vp->v_type != VDIR)
    132 					panic("nfs: bioread, not dir");
    133 				nfs_invaldircache(vp, 0);
    134 				np->n_direofoffset = 0;
    135 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    136 				if (error)
    137 					return (error);
    138 			}
    139 			np->n_attrstamp = 0;
    140 			error = VOP_GETATTR(vp, &vattr, cred, p);
    141 			if (error)
    142 				return (error);
    143 			np->n_mtime = vattr.va_mtime.tv_sec;
    144 		} else {
    145 			error = VOP_GETATTR(vp, &vattr, cred, p);
    146 			if (error)
    147 				return (error);
    148 			if (np->n_mtime != vattr.va_mtime.tv_sec) {
    149 				if (vp->v_type == VDIR) {
    150 					nfs_invaldircache(vp, 0);
    151 					np->n_direofoffset = 0;
    152 				}
    153 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    154 				if (error)
    155 					return (error);
    156 				np->n_mtime = vattr.va_mtime.tv_sec;
    157 			}
    158 		}
    159 	}
    160 	do {
    161 
    162 	    /*
    163 	     * Get a valid lease. If cached data is stale, flush it.
    164 	     */
    165 	    if (nmp->nm_flag & NFSMNT_NQNFS) {
    166 		if (NQNFS_CKINVALID(vp, np, ND_READ)) {
    167 		    do {
    168 			error = nqnfs_getlease(vp, ND_READ, cred, p);
    169 		    } while (error == NQNFS_EXPIRED);
    170 		    if (error)
    171 			return (error);
    172 		    if (np->n_lrev != np->n_brev ||
    173 			(np->n_flag & NQNFSNONCACHE) ||
    174 			((np->n_flag & NMODIFIED) && vp->v_type == VDIR)) {
    175 			if (vp->v_type == VDIR) {
    176 				nfs_invaldircache(vp, 0);
    177 				np->n_direofoffset = 0;
    178 			}
    179 			error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    180 			if (error)
    181 			    return (error);
    182 			np->n_brev = np->n_lrev;
    183 		    }
    184 		} else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) {
    185 		    nfs_invaldircache(vp, 0);
    186 		    error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    187 		    np->n_direofoffset = 0;
    188 		    if (error)
    189 			return (error);
    190 		}
    191 	    }
    192 	    /*
    193 	     * Don't cache symlinks.
    194 	     */
    195 	    if (np->n_flag & NQNFSNONCACHE
    196 		|| ((vp->v_flag & VROOT) && vp->v_type == VLNK)) {
    197 		switch (vp->v_type) {
    198 		case VREG:
    199 			return (nfs_readrpc(vp, uio, cred));
    200 		case VLNK:
    201 			return (nfs_readlinkrpc(vp, uio, cred));
    202 		case VDIR:
    203 			break;
    204 		default:
    205 			printf(" NQNFSNONCACHE: type %x unexpected\n",
    206 			    vp->v_type);
    207 		};
    208 	    }
    209 	    baddr = (caddr_t)0;
    210 	    switch (vp->v_type) {
    211 	    case VREG:
    212 		nfsstats.biocache_reads++;
    213 		lbn = uio->uio_offset / biosize;
    214 		on = uio->uio_offset & (biosize - 1);
    215 		bn = lbn * (biosize / DEV_BSIZE);
    216 		not_readin = 1;
    217 
    218 #if 1
    219 		offdiff = nra = rabn = diff = 0;
    220 		error = 0;
    221 		while (uio->uio_resid > 0) {
    222 			void *win;
    223 			vsize_t bytelen = min(np->n_size - uio->uio_offset,
    224 					      uio->uio_resid);
    225 
    226 			if (bytelen == 0)
    227 				break;
    228 			win = ubc_alloc(&vp->v_uvm.u_obj, uio->uio_offset,
    229 					&bytelen, UBC_READ);
    230 #ifdef DIAGNOSTIC
    231 			if (win == NULL)
    232 				panic("nfs_bioread: ubc_alloc -> NULL");
    233 #endif
    234 
    235 			error = uiomove(win, bytelen, uio);
    236 			ubc_release(win, 0);
    237 			if (error)
    238 				break;
    239 		}
    240 #else
    241 		/*
    242 		 * Start the read ahead(s), as required.
    243 		 */
    244 		if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
    245 		    lbn - 1 == vp->v_lastr) {
    246 		    for (nra = 0; nra < nmp->nm_readahead &&
    247 			(lbn + 1 + nra) * biosize < np->n_size; nra++) {
    248 			rabn = (lbn + 1 + nra) * (biosize / DEV_BSIZE);
    249 			if (!incore(vp, rabn)) {
    250 			    rabp = nfs_getcacheblk(vp, rabn, biosize, p);
    251 			    if (!rabp)
    252 				return (EINTR);
    253 			    if ((rabp->b_flags & (B_DELWRI | B_DONE)) == 0) {
    254 				rabp->b_flags |= (B_READ | B_ASYNC);
    255 				if (nfs_asyncio(rabp, cred)) {
    256 				    rabp->b_flags |= B_INVAL;
    257 				    brelse(rabp);
    258 				}
    259 			    } else
    260 				brelse(rabp);
    261 			}
    262 		    }
    263 		}
    264 
    265 		/*
    266 		 * If the block is in the cache and has the required data
    267 		 * in a valid region, just copy it out.
    268 		 * Otherwise, get the block and write back/read in,
    269 		 * as required.
    270 		 */
    271 		if ((bp = incore(vp, bn)) &&
    272 		    (bp->b_flags & (B_BUSY | B_WRITEINPROG)) ==
    273 		    (B_BUSY | B_WRITEINPROG))
    274 			got_buf = 0;
    275 		else {
    276 again:
    277 			bp = nfs_getcacheblk(vp, bn, biosize, p);
    278 			if (!bp)
    279 				return (EINTR);
    280 			got_buf = 1;
    281 			if ((bp->b_flags & (B_DONE | B_DELWRI)) == 0) {
    282 				bp->b_flags |= B_READ;
    283 				not_readin = 0;
    284 				error = nfs_doio(bp, cred, p);
    285 				if (error) {
    286 				    brelse(bp);
    287 				    return (error);
    288 				}
    289 			}
    290 		}
    291 		n = min((unsigned)(biosize - on), uio->uio_resid);
    292 		offdiff = np->n_size - uio->uio_offset;
    293 		if (offdiff < (off_t)n)
    294 			n = (int)offdiff;
    295 		if (not_readin && n > 0) {
    296 			if (on < bp->b_validoff || (on + n) > bp->b_validend) {
    297 				if (!got_buf) {
    298 				    bp = nfs_getcacheblk(vp, bn, biosize, p);
    299 				    if (!bp)
    300 					return (EINTR);
    301 				    got_buf = 1;
    302 				}
    303 				bp->b_flags |= B_INVAFTERWRITE;
    304 				if (bp->b_dirtyend > 0) {
    305 				    if ((bp->b_flags & B_DELWRI) == 0)
    306 					panic("nfsbioread");
    307 				    if (VOP_BWRITE(bp) == EINTR)
    308 					return (EINTR);
    309 				} else
    310 				    brelse(bp);
    311 				goto again;
    312 			}
    313 		}
    314 		vp->v_lastr = lbn;
    315 		diff = (on >= bp->b_validend) ? 0 : (bp->b_validend - on);
    316 		if (diff < n)
    317 			n = diff;
    318 #endif
    319 		break;
    320 	    case VLNK:
    321 		nfsstats.biocache_readlinks++;
    322 		bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, p);
    323 		if (!bp)
    324 			return (EINTR);
    325 		if ((bp->b_flags & B_DONE) == 0) {
    326 			bp->b_flags |= B_READ;
    327 			error = nfs_doio(bp, cred, p);
    328 			if (error) {
    329 				brelse(bp);
    330 				return (error);
    331 			}
    332 		}
    333 		n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
    334 		got_buf = 1;
    335 		on = 0;
    336 		break;
    337 	    case VDIR:
    338 diragain:
    339 		nfsstats.biocache_readdirs++;
    340 		ndp = nfs_searchdircache(vp, uio->uio_offset,
    341 			(nmp->nm_flag & NFSMNT_XLATECOOKIE), 0);
    342 		if (!ndp) {
    343 			/*
    344 			 * We've been handed a cookie that is not
    345 			 * in the cache. If we're not translating
    346 			 * 32 <-> 64, it may be a value that was
    347 			 * flushed out of the cache because it grew
    348 			 * too big. Let the server judge if it's
    349 			 * valid or not. In the translation case,
    350 			 * we have no way of validating this value,
    351 			 * so punt.
    352 			 */
    353 			if (nmp->nm_flag & NFSMNT_XLATECOOKIE)
    354 				return (EINVAL);
    355 			ndp = nfs_enterdircache(vp, uio->uio_offset,
    356 				uio->uio_offset, 0, 0);
    357 		}
    358 
    359 		if (uio->uio_offset != 0 &&
    360 		    ndp->dc_cookie == np->n_direofoffset) {
    361 			nfsstats.direofcache_hits++;
    362 			return (0);
    363 		}
    364 
    365 		bp = nfs_getcacheblk(vp, ndp->dc_blkno, NFS_DIRBLKSIZ, p);
    366 		if (!bp)
    367 		    return (EINTR);
    368 		if ((bp->b_flags & B_DONE) == 0) {
    369 		    bp->b_flags |= B_READ;
    370 		    bp->b_dcookie = ndp->dc_blkcookie;
    371 		    error = nfs_doio(bp, cred, p);
    372 		    if (error) {
    373 			/*
    374 			 * Yuck! The directory has been modified on the
    375 			 * server. Punt and let the userland code
    376 			 * deal with it.
    377 			 */
    378 			brelse(bp);
    379 			if (error == NFSERR_BAD_COOKIE) {
    380 			    nfs_invaldircache(vp, 0);
    381 			    nfs_vinvalbuf(vp, 0, cred, p, 1);
    382 			    error = EINVAL;
    383 			}
    384 			return (error);
    385 		    }
    386 		}
    387 
    388 		/*
    389 		 * Just return if we hit EOF right away with this
    390 		 * block. Always check here, because direofoffset
    391 		 * may have been set by an nfsiod since the last
    392 		 * check.
    393 		 */
    394 		if (np->n_direofoffset != 0 &&
    395 			ndp->dc_blkcookie == np->n_direofoffset) {
    396 			brelse(bp);
    397 			return (0);
    398 		}
    399 
    400 		/*
    401 		 * Find the entry we were looking for in the block.
    402 		 */
    403 
    404 		en = ndp->dc_entry;
    405 
    406 		pdp = dp = (struct dirent *)bp->b_data;
    407 		edp = bp->b_data + bp->b_validend;
    408 		enn = 0;
    409 		while (enn < en && (caddr_t)dp < edp) {
    410 			pdp = dp;
    411 			dp = (struct dirent *)((caddr_t)dp + dp->d_reclen);
    412 			enn++;
    413 		}
    414 
    415 		/*
    416 		 * If the entry number was bigger than the number of
    417 		 * entries in the block, or the cookie of the previous
    418 		 * entry doesn't match, the directory cache is
    419 		 * stale. Flush it and try again (i.e. go to
    420 		 * the server).
    421 		 */
    422 		if ((caddr_t)dp >= edp || (caddr_t)dp + dp->d_reclen > edp ||
    423 		    (en > 0 && NFS_GETCOOKIE(pdp) != ndp->dc_cookie)) {
    424 #ifdef DEBUG
    425 		    	printf("invalid cache: %p %p %p off %lx %lx\n",
    426 				pdp, dp, edp,
    427 				(unsigned long)uio->uio_offset,
    428 				(unsigned long)NFS_GETCOOKIE(pdp));
    429 #endif
    430 			brelse(bp);
    431 			nfs_invaldircache(vp, 0);
    432 			nfs_vinvalbuf(vp, 0, cred, p, 0);
    433 			goto diragain;
    434 		}
    435 
    436 		on = (caddr_t)dp - bp->b_data;
    437 
    438 		/*
    439 		 * Cache all entries that may be exported to the
    440 		 * user, as they may be thrown back at us. The
    441 		 * NFSBIO_CACHECOOKIES flag indicates that all
    442 		 * entries are being 'exported', so cache them all.
    443 		 */
    444 
    445 		if (en == 0 && pdp == dp) {
    446 			dp = (struct dirent *)
    447 			    ((caddr_t)dp + dp->d_reclen);
    448 			enn++;
    449 		}
    450 
    451 		if (uio->uio_resid < (bp->b_validend - on)) {
    452 			n = uio->uio_resid;
    453 			enough = 1;
    454 		} else
    455 			n = bp->b_validend - on;
    456 
    457 		ep = bp->b_data + on + n;
    458 
    459 		/*
    460 		 * Find last complete entry to copy, caching entries
    461 		 * (if requested) as we go.
    462 		 */
    463 
    464 		while ((caddr_t)dp < ep && (caddr_t)dp + dp->d_reclen <= ep) {
    465 			if (cflag & NFSBIO_CACHECOOKIES) {
    466 				nndp = nfs_enterdircache(vp, NFS_GETCOOKIE(pdp),
    467 				    ndp->dc_blkcookie, enn, bp->b_lblkno);
    468 				if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
    469 					NFS_STASHCOOKIE32(pdp,
    470 					    nndp->dc_cookie32);
    471 				}
    472 			}
    473 			pdp = dp;
    474 			dp = (struct dirent *)((caddr_t)dp + dp->d_reclen);
    475 			enn++;
    476 		}
    477 
    478 		/*
    479 		 * If the last requested entry was not the last in the
    480 		 * buffer (happens if NFS_DIRFRAGSIZ < NFS_DIRBLKSIZ),
    481 		 * cache the cookie of the last requested one, and
    482 		 * set of the offset to it.
    483 		 */
    484 
    485 		if ((on + n) < bp->b_validend) {
    486 			curoff = NFS_GETCOOKIE(pdp);
    487 			nndp = nfs_enterdircache(vp, curoff, ndp->dc_blkcookie,
    488 			    enn, bp->b_lblkno);
    489 			if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
    490 				NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32);
    491 				curoff = nndp->dc_cookie32;
    492 			}
    493 		} else
    494 			curoff = bp->b_dcookie;
    495 
    496 		/*
    497 		 * Always cache the entry for the next block,
    498 		 * so that readaheads can use it.
    499 		 */
    500 		nndp = nfs_enterdircache(vp, bp->b_dcookie, bp->b_dcookie, 0,0);
    501 		if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
    502 			if (curoff == bp->b_dcookie) {
    503 				NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32);
    504 				curoff = nndp->dc_cookie32;
    505 			}
    506 		}
    507 
    508 		n = ((caddr_t)pdp + pdp->d_reclen) - (bp->b_data + on);
    509 
    510 		/*
    511 		 * If not eof and read aheads are enabled, start one.
    512 		 * (You need the current block first, so that you have the
    513 		 *  directory offset cookie of the next block.)
    514 		 */
    515 		if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
    516 		    np->n_direofoffset == 0 && !(np->n_flag & NQNFSNONCACHE)) {
    517 			rabp = nfs_getcacheblk(vp, nndp->dc_blkno,
    518 						NFS_DIRBLKSIZ, p);
    519 			if (rabp) {
    520 			    if ((rabp->b_flags & (B_DONE | B_DELWRI)) == 0) {
    521 				rabp->b_dcookie = nndp->dc_cookie;
    522 				rabp->b_flags |= (B_READ | B_ASYNC);
    523 				if (nfs_asyncio(rabp, cred)) {
    524 				    rabp->b_flags |= B_INVAL;
    525 				    brelse(rabp);
    526 				}
    527 			    } else
    528 				brelse(rabp);
    529 			}
    530 		}
    531 		got_buf = 1;
    532 		break;
    533 	    default:
    534 		printf(" nfsbioread: type %x unexpected\n",vp->v_type);
    535 		break;
    536 	    }
    537 
    538 	    if (n > 0) {
    539 		if (!baddr)
    540 			baddr = bp->b_data;
    541 		error = uiomove(baddr + on, (int)n, uio);
    542 	    }
    543 	    switch (vp->v_type) {
    544 	    case VREG:
    545 		break;
    546 	    case VLNK:
    547 		n = 0;
    548 		break;
    549 	    case VDIR:
    550 		if (np->n_flag & NQNFSNONCACHE)
    551 			bp->b_flags |= B_INVAL;
    552 		uio->uio_offset = curoff;
    553 		if (enough)
    554 			n = 0;
    555 		break;
    556 	    default:
    557 		printf(" nfsbioread: type %x unexpected\n",vp->v_type);
    558 	    }
    559 	    if (got_buf)
    560 		brelse(bp);
    561 	} while (error == 0 && uio->uio_resid > 0 && n > 0);
    562 	return (error);
    563 }
    564 
    565 /*
    566  * Vnode op for write using bio
    567  */
    568 int
    569 nfs_write(v)
    570 	void *v;
    571 {
    572 	struct vop_write_args /* {
    573 		struct vnode *a_vp;
    574 		struct uio *a_uio;
    575 		int  a_ioflag;
    576 		struct ucred *a_cred;
    577 	} */ *ap = v;
    578 	register int biosize;
    579 	register struct uio *uio = ap->a_uio;
    580 	struct proc *p = uio->uio_procp;
    581 	register struct vnode *vp = ap->a_vp;
    582 	struct nfsnode *np = VTONFS(vp);
    583 	register struct ucred *cred = ap->a_cred;
    584 	int ioflag = ap->a_ioflag;
    585 	struct buf *bp;
    586 	struct vattr vattr;
    587 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
    588 	daddr_t lbn, bn;
    589 	int n, on, error = 0, iomode, must_commit;
    590 
    591 #ifdef DIAGNOSTIC
    592 	if (uio->uio_rw != UIO_WRITE)
    593 		panic("nfs_write mode");
    594 	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
    595 		panic("nfs_write proc");
    596 #endif
    597 	if (vp->v_type != VREG)
    598 		return (EIO);
    599 	if (np->n_flag & NWRITEERR) {
    600 		np->n_flag &= ~NWRITEERR;
    601 		return (np->n_error);
    602 	}
    603 	if ((nmp->nm_flag & NFSMNT_NFSV3) &&
    604 	    !(nmp->nm_iflag & NFSMNT_GOTFSINFO))
    605 		(void)nfs_fsinfo(nmp, vp, cred, p);
    606 	if (ioflag & (IO_APPEND | IO_SYNC)) {
    607 		if (np->n_flag & NMODIFIED) {
    608 			np->n_attrstamp = 0;
    609 			error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    610 			if (error)
    611 				return (error);
    612 		}
    613 		if (ioflag & IO_APPEND) {
    614 			np->n_attrstamp = 0;
    615 			error = VOP_GETATTR(vp, &vattr, cred, p);
    616 			if (error)
    617 				return (error);
    618 			uio->uio_offset = np->n_size;
    619 		}
    620 	}
    621 	if (uio->uio_offset < 0)
    622 		return (EINVAL);
    623 	if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
    624 		return (EFBIG);
    625 	if (uio->uio_resid == 0)
    626 		return (0);
    627 	/*
    628 	 * Maybe this should be above the vnode op call, but so long as
    629 	 * file servers have no limits, i don't think it matters
    630 	 */
    631 	if (p && uio->uio_offset + uio->uio_resid >
    632 	      p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
    633 		psignal(p, SIGXFSZ);
    634 		return (EFBIG);
    635 	}
    636 	/*
    637 	 * I use nm_rsize, not nm_wsize so that all buffer cache blocks
    638 	 * will be the same size within a filesystem. nfs_writerpc will
    639 	 * still use nm_wsize when sizing the rpc's.
    640 	 */
    641 	biosize = nmp->nm_rsize;
    642 	do {
    643 #if 1
    644 		void *win;
    645 		vaddr_t oldoff = uio->uio_offset;
    646 		vsize_t bytelen = uio->uio_resid;
    647 
    648 		/*
    649 		 * XXX only do one page at a time for now.
    650 		 * otherwise when we're extending the file,
    651 		 * the flush for a given page will invalidate
    652 		 * all the pages after that in the file.
    653 		 * we should probably just defer looking at the attrs
    654 		 * returned with write rpcs until the
    655 		 * the entire write operation has finished.
    656 		 */
    657 		bytelen = min(uio->uio_resid,
    658 			      PAGE_SIZE - (uio->uio_offset & (PAGE_SIZE - 1)));
    659 
    660 		/* XXX */
    661 		on = bn = lbn = 0;
    662 		bp = 0;
    663 		n = bytelen;
    664 #endif
    665 
    666 		/*
    667 		 * Check for a valid write lease.
    668 		 */
    669 		if ((nmp->nm_flag & NFSMNT_NQNFS) &&
    670 		    NQNFS_CKINVALID(vp, np, ND_WRITE)) {
    671 			do {
    672 				error = nqnfs_getlease(vp, ND_WRITE, cred, p);
    673 			} while (error == NQNFS_EXPIRED);
    674 			if (error)
    675 				return (error);
    676 			if (np->n_lrev != np->n_brev ||
    677 			    (np->n_flag & NQNFSNONCACHE)) {
    678 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    679 				if (error)
    680 					return (error);
    681 				np->n_brev = np->n_lrev;
    682 			}
    683 		}
    684 		if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) {
    685 		    iomode = NFSV3WRITE_FILESYNC;
    686 		    error = nfs_writerpc(vp, uio, cred, &iomode, &must_commit);
    687 		    if (must_commit)
    688 			nfs_clearcommit(vp->v_mount);
    689 		    return (error);
    690 		}
    691 		nfsstats.biocache_writes++;
    692 
    693 #if 1
    694 		np->n_flag |= NMODIFIED;
    695 		if (np->n_size < uio->uio_offset + n) {
    696 			np->n_size = uio->uio_offset + n;
    697 			uvm_vnp_setsize(vp, np->n_size);
    698 		}
    699 
    700 		/* XXX check dirty region stuff */
    701 
    702 		win = ubc_alloc(&vp->v_uvm.u_obj, uio->uio_offset, &bytelen,
    703 				UBC_WRITE);
    704 #ifdef DIAGNOSTIC
    705 		if (win == NULL) {
    706 			panic("nfs_bioread: ubc_alloc -> NULL");
    707 		}
    708 #endif
    709 		error = uiomove(win, bytelen, uio);
    710 		ubc_release(win, 0);
    711 
    712 		/* XXX abstract this somehow */
    713 		simple_lock(&vp->v_uvm.u_obj.vmobjlock);
    714 		vp->v_uvm.u_obj.pgops->pgo_flush(&vp->v_uvm.u_obj,
    715 						 trunc_page(oldoff),
    716 						 oldoff + bytelen,
    717 						 PGO_CLEANIT | PGO_SYNCIO);
    718 		simple_unlock(&vp->v_uvm.u_obj.vmobjlock);
    719 
    720 		if (error) {
    721 			/*
    722 			 * XXX zero out any part of the current window
    723 			 * that we might have failed to copyin.
    724 			 */
    725 			break;
    726 		}
    727 
    728 		/* XXX set dirty region stuff */
    729 		/* XXX set page NEEDCOMMIT flag */
    730 		/* XXX handle IO_SYNC and NQNFSNONCACHE */
    731 
    732 #else
    733 		lbn = uio->uio_offset / biosize;
    734 		on = uio->uio_offset & (biosize-1);
    735 		n = min((unsigned)(biosize - on), uio->uio_resid);
    736 		bn = lbn * (biosize / DEV_BSIZE);
    737 again:
    738 		bp = nfs_getcacheblk(vp, bn, biosize, p);
    739 		if (!bp)
    740 			return (EINTR);
    741 		if (bp->b_wcred == NOCRED) {
    742 			crhold(cred);
    743 			bp->b_wcred = cred;
    744 		}
    745 		np->n_flag |= NMODIFIED;
    746 		if (uio->uio_offset + n > np->n_size) {
    747 			np->n_size = uio->uio_offset + n;
    748 			uvm_vnp_setsize(vp, np->n_size);
    749 		}
    750 
    751 		/*
    752 		 * If the new write will leave a contiguous dirty
    753 		 * area, just update the b_dirtyoff and b_dirtyend,
    754 		 * otherwise force a write rpc of the old dirty area.
    755 		 */
    756 		if (bp->b_dirtyend > 0 &&
    757 		    (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
    758 			bp->b_proc = p;
    759 			if (VOP_BWRITE(bp) == EINTR)
    760 				return (EINTR);
    761 			goto again;
    762 		}
    763 
    764 		/*
    765 		 * Check for valid write lease and get one as required.
    766 		 * In case getblk() and/or bwrite() delayed us.
    767 		 */
    768 		if ((nmp->nm_flag & NFSMNT_NQNFS) &&
    769 		    NQNFS_CKINVALID(vp, np, ND_WRITE)) {
    770 			do {
    771 				error = nqnfs_getlease(vp, ND_WRITE, cred, p);
    772 			} while (error == NQNFS_EXPIRED);
    773 			if (error) {
    774 				brelse(bp);
    775 				return (error);
    776 			}
    777 			if (np->n_lrev != np->n_brev ||
    778 			    (np->n_flag & NQNFSNONCACHE)) {
    779 				brelse(bp);
    780 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    781 				if (error)
    782 					return (error);
    783 				np->n_brev = np->n_lrev;
    784 				goto again;
    785 			}
    786 		}
    787 		error = uiomove((char *)bp->b_data + on, n, uio);
    788 		if (error) {
    789 			bp->b_flags |= B_ERROR;
    790 			brelse(bp);
    791 			return (error);
    792 		}
    793 		if (bp->b_dirtyend > 0) {
    794 			bp->b_dirtyoff = min(on, bp->b_dirtyoff);
    795 			bp->b_dirtyend = max((on + n), bp->b_dirtyend);
    796 		} else {
    797 			bp->b_dirtyoff = on;
    798 			bp->b_dirtyend = on + n;
    799 		}
    800 		if (bp->b_validend == 0 || bp->b_validend < bp->b_dirtyoff ||
    801 		    bp->b_validoff > bp->b_dirtyend) {
    802 			bp->b_validoff = bp->b_dirtyoff;
    803 			bp->b_validend = bp->b_dirtyend;
    804 		} else {
    805 			bp->b_validoff = min(bp->b_validoff, bp->b_dirtyoff);
    806 			bp->b_validend = max(bp->b_validend, bp->b_dirtyend);
    807 		}
    808 
    809 		/*
    810 		 * Since this block is being modified, it must be written
    811 		 * again and not just committed.
    812 		 */
    813 		bp->b_flags &= ~B_NEEDCOMMIT;
    814 
    815 		/*
    816 		 * If the lease is non-cachable or IO_SYNC do bwrite().
    817 		 */
    818 		if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) {
    819 			bp->b_proc = p;
    820 			error = VOP_BWRITE(bp);
    821 			if (error)
    822 				return (error);
    823 			if (np->n_flag & NQNFSNONCACHE) {
    824 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    825 				if (error)
    826 					return (error);
    827 			}
    828 		} else if ((n + on) == biosize &&
    829 			(nmp->nm_flag & NFSMNT_NQNFS) == 0) {
    830 			bp->b_proc = (struct proc *)0;
    831 			bp->b_flags |= B_ASYNC;
    832 			(void)nfs_writebp(bp, 0);
    833 		} else {
    834 			bdwrite(bp);
    835 		}
    836 #endif
    837 	} while (uio->uio_resid > 0 && n > 0);
    838 	return (0);
    839 }
    840 
    841 /*
    842  * Get an nfs cache block.
    843  * Allocate a new one if the block isn't currently in the cache
    844  * and return the block marked busy. If the calling process is
    845  * interrupted by a signal for an interruptible mount point, return
    846  * NULL.
    847  */
    848 struct buf *
    849 nfs_getcacheblk(vp, bn, size, p)
    850 	struct vnode *vp;
    851 	daddr_t bn;
    852 	int size;
    853 	struct proc *p;
    854 {
    855 	register struct buf *bp;
    856 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
    857 
    858 	if (nmp->nm_flag & NFSMNT_INT) {
    859 		bp = getblk(vp, bn, size, PCATCH, 0);
    860 		while (bp == (struct buf *)0) {
    861 			if (nfs_sigintr(nmp, (struct nfsreq *)0, p))
    862 				return ((struct buf *)0);
    863 			bp = getblk(vp, bn, size, 0, 2 * hz);
    864 		}
    865 	} else
    866 		bp = getblk(vp, bn, size, 0, 0);
    867 	return (bp);
    868 }
    869 
    870 /*
    871  * Flush and invalidate all dirty buffers. If another process is already
    872  * doing the flush, just wait for completion.
    873  */
    874 int
    875 nfs_vinvalbuf(vp, flags, cred, p, intrflg)
    876 	struct vnode *vp;
    877 	int flags;
    878 	struct ucred *cred;
    879 	struct proc *p;
    880 	int intrflg;
    881 {
    882 	register struct nfsnode *np = VTONFS(vp);
    883 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
    884 	int error = 0, slpflag, slptimeo;
    885 
    886 	if ((nmp->nm_flag & NFSMNT_INT) == 0)
    887 		intrflg = 0;
    888 	if (intrflg) {
    889 		slpflag = PCATCH;
    890 		slptimeo = 2 * hz;
    891 	} else {
    892 		slpflag = 0;
    893 		slptimeo = 0;
    894 	}
    895 	/*
    896 	 * First wait for any other process doing a flush to complete.
    897 	 */
    898 	while (np->n_flag & NFLUSHINPROG) {
    899 		np->n_flag |= NFLUSHWANT;
    900 		error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval",
    901 			slptimeo);
    902 		if (error && intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p))
    903 			return (EINTR);
    904 	}
    905 
    906 	/*
    907 	 * Now, flush as required.
    908 	 */
    909 	np->n_flag |= NFLUSHINPROG;
    910 	error = vinvalbuf(vp, flags, cred, p, slpflag, 0);
    911 	while (error) {
    912 		if (intrflg && nfs_sigintr(nmp, (struct nfsreq *)0, p)) {
    913 			np->n_flag &= ~NFLUSHINPROG;
    914 			if (np->n_flag & NFLUSHWANT) {
    915 				np->n_flag &= ~NFLUSHWANT;
    916 				wakeup((caddr_t)&np->n_flag);
    917 			}
    918 			return (EINTR);
    919 		}
    920 		error = vinvalbuf(vp, flags, cred, p, 0, slptimeo);
    921 	}
    922 	np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
    923 	if (np->n_flag & NFLUSHWANT) {
    924 		np->n_flag &= ~NFLUSHWANT;
    925 		wakeup((caddr_t)&np->n_flag);
    926 	}
    927 	return (0);
    928 }
    929 
    930 /*
    931  * Initiate asynchronous I/O. Return an error if no nfsiods are available.
    932  * This is mainly to avoid queueing async I/O requests when the nfsiods
    933  * are all hung on a dead server.
    934  */
    935 int
    936 nfs_asyncio(bp, cred)
    937 	register struct buf *bp;
    938 	struct ucred *cred;
    939 {
    940 	register int i;
    941 	register struct nfsmount *nmp;
    942 	int gotiod, slpflag = 0, slptimeo = 0, error;
    943 
    944 	if (nfs_numasync == 0)
    945 		return (EIO);
    946 
    947 
    948 	nmp = VFSTONFS(bp->b_vp->v_mount);
    949 again:
    950 	if (nmp->nm_flag & NFSMNT_INT)
    951 		slpflag = PCATCH;
    952 	gotiod = FALSE;
    953 
    954 	/*
    955 	 * Find a free iod to process this request.
    956 	 */
    957 
    958 	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
    959 		if (nfs_iodwant[i]) {
    960 			/*
    961 			 * Found one, so wake it up and tell it which
    962 			 * mount to process.
    963 			 */
    964 			nfs_iodwant[i] = (struct proc *)0;
    965 			nfs_iodmount[i] = nmp;
    966 			nmp->nm_bufqiods++;
    967 			wakeup((caddr_t)&nfs_iodwant[i]);
    968 			gotiod = TRUE;
    969 			break;
    970 		}
    971 	/*
    972 	 * If none are free, we may already have an iod working on this mount
    973 	 * point.  If so, it will process our request.
    974 	 */
    975 	if (!gotiod && nmp->nm_bufqiods > 0)
    976 		gotiod = TRUE;
    977 
    978 	/*
    979 	 * If we have an iod which can process the request, then queue
    980 	 * the buffer.
    981 	 */
    982 	if (gotiod) {
    983 		/*
    984 		 * Ensure that the queue never grows too large.
    985 		 */
    986 		while (nmp->nm_bufqlen >= 2*nfs_numasync) {
    987 			nmp->nm_bufqwant = TRUE;
    988 			error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO,
    989 				"nfsaio", slptimeo);
    990 			if (error) {
    991 				if (nfs_sigintr(nmp, NULL, bp->b_proc))
    992 					return (EINTR);
    993 				if (slpflag == PCATCH) {
    994 					slpflag = 0;
    995 					slptimeo = 2 * hz;
    996 				}
    997 			}
    998 			/*
    999 			 * We might have lost our iod while sleeping,
   1000 			 * so check and loop if nescessary.
   1001 			 */
   1002 			if (nmp->nm_bufqiods == 0)
   1003 				goto again;
   1004 		}
   1005 
   1006 		if (bp->b_flags & B_READ) {
   1007 			if (bp->b_rcred == NOCRED && cred != NOCRED) {
   1008 				crhold(cred);
   1009 				bp->b_rcred = cred;
   1010 			}
   1011 		} else {
   1012 			bp->b_flags |= B_WRITEINPROG;
   1013 			if (bp->b_wcred == NOCRED && cred != NOCRED) {
   1014 				crhold(cred);
   1015 				bp->b_wcred = cred;
   1016 			}
   1017 		}
   1018 
   1019 		TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
   1020 		nmp->nm_bufqlen++;
   1021 		return (0);
   1022 	    }
   1023 
   1024 	/*
   1025 	 * All the iods are busy on other mounts, so return EIO to
   1026 	 * force the caller to process the i/o synchronously.
   1027 	 */
   1028 	return (EIO);
   1029 }
   1030 
   1031 /*
   1032  * Do an I/O operation to/from a cache block. This may be called
   1033  * synchronously or from an nfsiod.
   1034  */
   1035 int
   1036 nfs_doio(bp, cr, p)
   1037 	register struct buf *bp;
   1038 	struct ucred *cr;
   1039 	struct proc *p;
   1040 {
   1041 	register struct uio *uiop;
   1042 	register struct vnode *vp;
   1043 	struct nfsnode *np;
   1044 	struct nfsmount *nmp;
   1045 	int error = 0, diff, len, iomode, must_commit = 0;
   1046 	struct uio uio;
   1047 	struct iovec io;
   1048 
   1049 	vp = bp->b_vp;
   1050 	np = VTONFS(vp);
   1051 	nmp = VFSTONFS(vp->v_mount);
   1052 	uiop = &uio;
   1053 	uiop->uio_iov = &io;
   1054 	uiop->uio_iovcnt = 1;
   1055 	uiop->uio_segflg = UIO_SYSSPACE;
   1056 	uiop->uio_procp = p;
   1057 
   1058 	/*
   1059 	 * Historically, paging was done with physio, but no more...
   1060 	 */
   1061 	if (bp->b_flags & B_PHYS) {
   1062 	    /*
   1063 	     * ...though reading /dev/drum still gets us here.
   1064 	     */
   1065 	    io.iov_len = uiop->uio_resid = bp->b_bcount;
   1066 	    /* mapping was done by vmapbuf() */
   1067 	    io.iov_base = bp->b_data;
   1068 	    uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
   1069 	    if (bp->b_flags & B_READ) {
   1070 		uiop->uio_rw = UIO_READ;
   1071 		nfsstats.read_physios++;
   1072 		error = nfs_readrpc(vp, uiop, cr);
   1073 	    } else {
   1074 		iomode = NFSV3WRITE_DATASYNC;
   1075 		uiop->uio_rw = UIO_WRITE;
   1076 		nfsstats.write_physios++;
   1077 		error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit);
   1078 	    }
   1079 	    if (error) {
   1080 		bp->b_flags |= B_ERROR;
   1081 		bp->b_error = error;
   1082 	    }
   1083 	} else if (bp->b_flags & B_READ) {
   1084 	    io.iov_len = uiop->uio_resid = bp->b_bcount;
   1085 	    io.iov_base = bp->b_data;
   1086 	    uiop->uio_rw = UIO_READ;
   1087 	    switch (vp->v_type) {
   1088 	    case VREG:
   1089 		uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
   1090 		nfsstats.read_bios++;
   1091 		error = nfs_readrpc(vp, uiop, cr);
   1092 		if (!error) {
   1093 		    bp->b_validoff = 0;
   1094 		    if (uiop->uio_resid) {
   1095 			/*
   1096 			 * If len > 0, there is a hole in the file and
   1097 			 * no writes after the hole have been pushed to
   1098 			 * the server yet.
   1099 			 * Just zero fill the rest of the valid area.
   1100 			 */
   1101 			diff = bp->b_bcount - uiop->uio_resid;
   1102 			len = np->n_size - (((u_quad_t)bp->b_blkno) * DEV_BSIZE
   1103 				+ diff);
   1104 			if (len > 0) {
   1105 			    len = min(len, uiop->uio_resid);
   1106 			    memset((char *)bp->b_data + diff, 0, len);
   1107 			    bp->b_validend = diff + len;
   1108 			} else
   1109 			    bp->b_validend = diff;
   1110 		    } else
   1111 			bp->b_validend = bp->b_bcount;
   1112 		}
   1113 		if (p && (vp->v_flag & VTEXT) &&
   1114 			(((nmp->nm_flag & NFSMNT_NQNFS) &&
   1115 			  NQNFS_CKINVALID(vp, np, ND_READ) &&
   1116 			  np->n_lrev != np->n_brev) ||
   1117 			 (!(nmp->nm_flag & NFSMNT_NQNFS) &&
   1118 			  np->n_mtime != np->n_vattr->va_mtime.tv_sec))) {
   1119 			uprintf("Process killed due to text file modification\n");
   1120 			psignal(p, SIGKILL);
   1121 			p->p_holdcnt++;
   1122 		}
   1123 		break;
   1124 	    case VLNK:
   1125 		uiop->uio_offset = (off_t)0;
   1126 		nfsstats.readlink_bios++;
   1127 		error = nfs_readlinkrpc(vp, uiop, cr);
   1128 		break;
   1129 	    case VDIR:
   1130 		nfsstats.readdir_bios++;
   1131 		uiop->uio_offset = bp->b_dcookie;
   1132 		if (nmp->nm_flag & NFSMNT_RDIRPLUS) {
   1133 			error = nfs_readdirplusrpc(vp, uiop, cr);
   1134 			if (error == NFSERR_NOTSUPP)
   1135 				nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
   1136 		}
   1137 		if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
   1138 			error = nfs_readdirrpc(vp, uiop, cr);
   1139 		if (!error) {
   1140 			bp->b_dcookie = uiop->uio_offset;
   1141 			bp->b_validoff = 0;
   1142 			bp->b_validend = bp->b_bcount - uiop->uio_resid;
   1143 		}
   1144 		break;
   1145 	    default:
   1146 		printf("nfs_doio:  type %x unexpected\n",vp->v_type);
   1147 		break;
   1148 	    };
   1149 	    if (error) {
   1150 		bp->b_flags |= B_ERROR;
   1151 		bp->b_error = error;
   1152 	    }
   1153 	} else {
   1154 	    io.iov_len = uiop->uio_resid = bp->b_dirtyend
   1155 		- bp->b_dirtyoff;
   1156 	    uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE
   1157 		+ bp->b_dirtyoff;
   1158 	    io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
   1159 	    uiop->uio_rw = UIO_WRITE;
   1160 	    nfsstats.write_bios++;
   1161 	    if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE)) == B_ASYNC)
   1162 		iomode = NFSV3WRITE_UNSTABLE;
   1163 	    else
   1164 		iomode = NFSV3WRITE_FILESYNC;
   1165 	    bp->b_flags |= B_WRITEINPROG;
   1166 #ifdef fvdl_debug
   1167 	    printf("nfs_doio(%x): bp %x doff %d dend %d\n",
   1168 		vp, bp, bp->b_dirtyoff, bp->b_dirtyend);
   1169 #endif
   1170 	    error = nfs_writerpc(vp, uiop, cr, &iomode, &must_commit);
   1171 	    if (!error && iomode == NFSV3WRITE_UNSTABLE)
   1172 		bp->b_flags |= B_NEEDCOMMIT;
   1173 	    else
   1174 		bp->b_flags &= ~B_NEEDCOMMIT;
   1175 	    bp->b_flags &= ~B_WRITEINPROG;
   1176 
   1177 	    /*
   1178 	     * For an interrupted write, the buffer is still valid and the
   1179 	     * write hasn't been pushed to the server yet, so we can't set
   1180 	     * B_ERROR and report the interruption by setting B_EINTR. For
   1181 	     * the B_ASYNC case, B_EINTR is not relevant, so the rpc attempt
   1182 	     * is essentially a noop.
   1183 	     * For the case of a V3 write rpc not being committed to stable
   1184 	     * storage, the block is still dirty and requires either a commit
   1185 	     * rpc or another write rpc with iomode == NFSV3WRITE_FILESYNC
   1186 	     * before the block is reused. This is indicated by setting the
   1187 	     * B_DELWRI and B_NEEDCOMMIT flags.
   1188 	     */
   1189 	    if (error == EINTR || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
   1190 		bp->b_flags |= B_DELWRI;
   1191 
   1192 		/*
   1193 		 * Since for the B_ASYNC case, nfs_bwrite() has reassigned the
   1194 		 * buffer to the clean list, we have to reassign it back to the
   1195 		 * dirty one. Ugh.
   1196 		 */
   1197 		if (bp->b_flags & B_ASYNC)
   1198 		    reassignbuf(bp, vp);
   1199 		else if (error)
   1200 		    bp->b_flags |= B_EINTR;
   1201 	    } else {
   1202 		if (error) {
   1203 		    bp->b_flags |= B_ERROR;
   1204 		    bp->b_error = np->n_error = error;
   1205 		    np->n_flag |= NWRITEERR;
   1206 		}
   1207 		bp->b_dirtyoff = bp->b_dirtyend = 0;
   1208 	    }
   1209 	}
   1210 	bp->b_resid = uiop->uio_resid;
   1211 	if (must_commit)
   1212 		nfs_clearcommit(vp->v_mount);
   1213 	biodone(bp);
   1214 	return (error);
   1215 }
   1216 
   1217 /*
   1218  * Vnode op for VM getpages.
   1219  */
   1220 int
   1221 nfs_getpages(v)
   1222 	void *v;
   1223 {
   1224 	struct vop_getpages_args /* {
   1225 		struct vnode *a_vp;
   1226 		vaddr_t a_offset;
   1227 		vm_page_t *a_m;
   1228 		int *a_count;
   1229 		int a_centeridx;
   1230 		vm_prot_t a_access_type;
   1231 		int a_advice;
   1232 		int a_flags;
   1233 	} */ *ap = v;
   1234 
   1235 	int i, error, npages;
   1236 	struct uio uio;
   1237 	struct iovec iov;
   1238 	vaddr_t kva;
   1239 	struct buf tmpbuf, *bp;
   1240 	struct vnode *vp = ap->a_vp;
   1241 	struct uvm_object *uobj = &vp->v_uvm.u_obj;
   1242 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
   1243 	vaddr_t offset = ap->a_offset;
   1244 	off_t eof;
   1245 	vm_page_t pgs[2]; /* XXX tmp hack: 4k page 8k rsize */
   1246 	int cidx, vidx;
   1247 
   1248 	UVMHIST_FUNC("nfs_getpages"); UVMHIST_CALLED(ubchist);
   1249 	UVMHIST_LOG(ubchist, "vp %p off 0x%x", vp, (int)offset, 0,0);
   1250 
   1251 #ifdef DIAGNOSTIC
   1252 	if (ap->a_centeridx < 0 || ap->a_centeridx >= *ap->a_count) {
   1253 		panic("nfs_getpages: centeridx %d out of range",
   1254 		      ap->a_centeridx);
   1255 	}
   1256 #endif
   1257 
   1258 	eof = vp->v_uvm.u_size;
   1259 	if (offset >= eof) {
   1260 		if ((ap->a_flags & PGO_LOCKED) == 0) {
   1261 			simple_unlock(&uobj->vmobjlock);
   1262 		}
   1263 		UVMHIST_LOG(ubchist, "off 0x%x past EOF 0x%x",
   1264 			    offset, eof,0,0);
   1265 		return EINVAL;
   1266 	}
   1267 
   1268 
   1269 	if (ap->a_flags & PGO_LOCKED) {
   1270 		uvn_findpages(uobj, offset, ap->a_count, ap->a_m,
   1271 			      UFP_NOWAIT|UFP_NOALLOC);
   1272 
   1273 		/* XXX PGO_ALLPAGES? */
   1274 		return 0;
   1275 	}
   1276 
   1277 	/* vnode is VOP_LOCKed, uobj is locked */
   1278 
   1279 	/*
   1280 	 * first see if center page already exists.
   1281 	 * if it does, return the page.
   1282 	 * XXX
   1283 	 * this is needed because ubc_fault() doesn't
   1284 	 * do a PGO_LOCKED call first.
   1285 	 * XXX change ubc_fault() to do the PGO_LOCKED call.
   1286 	 */
   1287 
   1288 	npages = 1;
   1289 	uvn_findpages(uobj, offset + (ap->a_centeridx << PAGE_SHIFT),
   1290 		      &npages, &ap->a_m[ap->a_centeridx], UFP_NOALLOC);
   1291 	if (npages == 1) {
   1292 		simple_unlock(&uobj->vmobjlock);
   1293 		return 0;
   1294 	}
   1295 
   1296 	npages = nmp->nm_rsize >> PAGE_SHIFT;
   1297 	offset &= ~(nmp->nm_rsize - 1);
   1298 	cidx = ap->a_centeridx + ((ap->a_offset - offset) >> PAGE_SHIFT);
   1299 	UVMHIST_LOG(ubchist, "npages %d offset 0x%lx cidx %d",
   1300 		    npages, offset, cidx,0);
   1301 	memset(pgs, 0, sizeof(pgs));
   1302 	uvn_findpages(uobj, offset, &npages, pgs, UFP_NOCACHE);
   1303 	vidx = (npages == 2) ? 0 : cidx;
   1304 
   1305 	simple_unlock(&uobj->vmobjlock);
   1306 
   1307 #ifdef DIAGNOSTIC
   1308 	if (npages == 0) {
   1309 		panic("nfs_getpages: nothing to read, vp %p", vp);
   1310 	}
   1311 #endif
   1312 
   1313 	/*
   1314 	 * read at last part of the page.
   1315 	 */
   1316 
   1317 	kva = uvm_pagermapin(&pgs[vidx], npages, M_WAITOK);
   1318 
   1319 	uio.uio_iov = &iov;
   1320 	iov.iov_len = 0;
   1321 
   1322 	bp = &tmpbuf;
   1323 	bzero(bp, sizeof *bp);
   1324 
   1325 	bp->b_bufsize = npages << PAGE_SHIFT;
   1326 	bp->b_bcount = min(bp->b_bufsize, vp->v_uvm.u_size -
   1327 			   (offset + (vidx << PAGE_SHIFT)));
   1328 	bp->b_data = (void *)kva;
   1329 	bp->b_blkno = bp->b_lblkno =
   1330 		(offset + (vidx << PAGE_SHIFT)) >> DEV_BSHIFT;
   1331 	bp->b_vp = vp;
   1332 	bp->b_rcred = 0;
   1333 	bp->b_flags = B_BUSY|B_READ;
   1334 
   1335 	UVMHIST_LOG(ubchist, "reading blkno 0x%x bcount 0x%x",
   1336 		    bp->b_blkno, bp->b_bcount,0,0);
   1337 	error = nfs_doio(bp, curproc->p_ucred, curproc);
   1338 
   1339 	uvm_pagermapout(kva, npages);
   1340 
   1341 	simple_lock(&uobj->vmobjlock);
   1342 	uvm_lock_pageq();
   1343 	if (error) {
   1344 		for (i = vidx; i < vidx + npages; i++) {
   1345 			if (pgs[i]->flags & PG_WANTED) {
   1346 				wakeup(pgs[i]);
   1347 			}
   1348 			pgs[i]->flags &= ~(PG_WANTED|PG_BUSY);
   1349 			UVM_PAGE_OWN(pgs[i], NULL);
   1350 			uvm_pagefree(pgs[i]);
   1351 		}
   1352 	} else {
   1353 		for (i = vidx; i < vidx + npages; i++) {
   1354 			if (i != cidx) {
   1355 				if (pgs[i]->flags & PG_WANTED) {
   1356 					wakeup(pgs[i]);
   1357 				}
   1358 				pgs[i]->flags &= ~(PG_WANTED|PG_BUSY);
   1359 				UVM_PAGE_OWN(pgs[i], NULL);
   1360 
   1361 			}
   1362 			pgs[i]->flags &= ~PG_FAKE;
   1363 			pmap_clear_modify(PMAP_PGARG(pgs[i]));
   1364 			uvm_pageactivate(pgs[i]);
   1365 		}
   1366 	}
   1367 	uvm_unlock_pageq();
   1368 	simple_unlock(&uobj->vmobjlock);
   1369 
   1370 	ap->a_m[ap->a_centeridx] = pgs[cidx];
   1371 	UVMHIST_LOG(ubchist, "a_m[%d] = pgs[%d] = %p", ap->a_centeridx,
   1372 		    cidx, pgs[cidx],0);
   1373 #ifdef DIAGNOSTIC
   1374 	if (ap->a_m[ap->a_centeridx] == NULL) {
   1375 		panic("nfs_getpages: returning null page?");
   1376 	}
   1377 #endif
   1378 	return error;
   1379 }
   1380 
   1381 /*
   1382  * Vnode op for VM putpages.
   1383  */
   1384 int
   1385 nfs_putpages(v)
   1386 	void *v;
   1387 {
   1388 	struct vop_putpages_args /* {
   1389 		struct vnode *a_vp;
   1390 		vm_page_t *a_m;
   1391 		int a_count;
   1392 		int a_flags;
   1393 		int *a_rtvals;
   1394 	} */ *ap = v;
   1395 
   1396 	struct vnode *vp = ap->a_vp;
   1397 	int mode, commit;
   1398 	int error;
   1399 	struct uio uio;
   1400 	struct iovec iov;
   1401 	vm_page_t m;
   1402 	vaddr_t kva;
   1403 	int iosize;
   1404 
   1405 	/* XXX for now, just do one page at a time */
   1406 	if (ap->a_count != 1) {
   1407 		panic("nfs_putpages: one at a time, please\n");
   1408 	}
   1409 
   1410 	m = ap->a_m[0];
   1411 	kva = uvm_pagermapin(ap->a_m, ap->a_count, M_WAITOK);
   1412 
   1413 	iosize = min(PAGE_SIZE, vp->v_uvm.u_size - m->offset);
   1414 
   1415 	iov.iov_base = (caddr_t)kva;
   1416 	iov.iov_len = iosize;
   1417 	uio.uio_iov = &iov;
   1418 	uio.uio_iovcnt = 1;
   1419 	uio.uio_offset = m->offset;
   1420 	uio.uio_resid = iosize;
   1421 	uio.uio_segflg = UIO_SYSSPACE;
   1422 	uio.uio_rw = UIO_WRITE;
   1423 	uio.uio_procp = NULL;
   1424 
   1425 	/* XXX */
   1426 	mode = NFSV3WRITE_FILESYNC;
   1427 
   1428 	error = nfs_writerpc(vp, &uio, curproc->p_ucred, &mode, &commit);
   1429 
   1430 	uvm_pagermapout(kva, ap->a_count);
   1431 
   1432 	return error;
   1433 }
   1434