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nfs_bio.c revision 1.45.8.3
      1 /*	$NetBSD: nfs_bio.c,v 1.45.8.3 2000/12/13 15:50:37 bouyer 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 "opt_nfs.h"
     42 #include "opt_ddb.h"
     43 
     44 #include <sys/param.h>
     45 #include <sys/systm.h>
     46 #include <sys/resourcevar.h>
     47 #include <sys/signalvar.h>
     48 #include <sys/proc.h>
     49 #include <sys/buf.h>
     50 #include <sys/vnode.h>
     51 #include <sys/trace.h>
     52 #include <sys/mount.h>
     53 #include <sys/kernel.h>
     54 #include <sys/namei.h>
     55 #include <sys/dirent.h>
     56 #include <sys/malloc.h>
     57 
     58 #include <uvm/uvm_extern.h>
     59 #include <uvm/uvm.h>
     60 
     61 #include <nfs/rpcv2.h>
     62 #include <nfs/nfsproto.h>
     63 #include <nfs/nfs.h>
     64 #include <nfs/nfsmount.h>
     65 #include <nfs/nqnfs.h>
     66 #include <nfs/nfsnode.h>
     67 #include <nfs/nfs_var.h>
     68 
     69 extern int nfs_numasync;
     70 extern struct nfsstats nfsstats;
     71 
     72 /*
     73  * Vnode op for read using bio
     74  * Any similarity to readip() is purely coincidental
     75  */
     76 int
     77 nfs_bioread(vp, uio, ioflag, cred, cflag)
     78 	struct vnode *vp;
     79 	struct uio *uio;
     80 	int ioflag, cflag;
     81 	struct ucred *cred;
     82 {
     83 	struct nfsnode *np = VTONFS(vp);
     84 	int biosize;
     85 	struct buf *bp = NULL, *rabp;
     86 	struct vattr vattr;
     87 	struct proc *p;
     88 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
     89 	struct nfsdircache *ndp = NULL, *nndp = NULL;
     90 	caddr_t baddr, ep, edp;
     91 	int got_buf = 0, error = 0, n = 0, on = 0, en, enn;
     92 	int enough = 0;
     93 	struct dirent *dp, *pdp;
     94 	off_t curoff = 0;
     95 
     96 #ifdef DIAGNOSTIC
     97 	if (uio->uio_rw != UIO_READ)
     98 		panic("nfs_read mode");
     99 #endif
    100 	if (uio->uio_resid == 0)
    101 		return (0);
    102 	if (vp->v_type != VDIR && uio->uio_offset < 0)
    103 		return (EINVAL);
    104 	p = uio->uio_procp;
    105 #ifndef NFS_V2_ONLY
    106 	if ((nmp->nm_flag & NFSMNT_NFSV3) &&
    107 	    !(nmp->nm_iflag & NFSMNT_GOTFSINFO))
    108 		(void)nfs_fsinfo(nmp, vp, cred, p);
    109 #endif
    110 	if (vp->v_type != VDIR &&
    111 	    (uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
    112 		return (EFBIG);
    113 	biosize = nmp->nm_rsize;
    114 
    115 	/*
    116 	 * For nfs, cache consistency can only be maintained approximately.
    117 	 * Although RFC1094 does not specify the criteria, the following is
    118 	 * believed to be compatible with the reference port.
    119 	 * For nqnfs, full cache consistency is maintained within the loop.
    120 	 * For nfs:
    121 	 * If the file's modify time on the server has changed since the
    122 	 * last read rpc or you have written to the file,
    123 	 * you may have lost data cache consistency with the
    124 	 * server, so flush all of the file's data out of the cache.
    125 	 * Then force a getattr rpc to ensure that you have up to date
    126 	 * attributes.
    127 	 * NB: This implies that cache data can be read when up to
    128 	 * NFS_ATTRTIMEO seconds out of date. If you find that you need current
    129 	 * attributes this could be forced by setting n_attrstamp to 0 before
    130 	 * the VOP_GETATTR() call.
    131 	 */
    132 
    133 	if ((nmp->nm_flag & NFSMNT_NQNFS) == 0 && vp->v_type != VLNK) {
    134 		if (np->n_flag & NMODIFIED) {
    135 			if (vp->v_type != VREG) {
    136 				if (vp->v_type != VDIR)
    137 					panic("nfs: bioread, not dir");
    138 				nfs_invaldircache(vp, 0);
    139 				np->n_direofoffset = 0;
    140 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    141 				if (error)
    142 					return (error);
    143 			}
    144 			np->n_attrstamp = 0;
    145 			error = VOP_GETATTR(vp, &vattr, cred, p);
    146 			if (error)
    147 				return (error);
    148 			np->n_mtime = vattr.va_mtime.tv_sec;
    149 		} else {
    150 			error = VOP_GETATTR(vp, &vattr, cred, p);
    151 			if (error)
    152 				return (error);
    153 			if (np->n_mtime != vattr.va_mtime.tv_sec) {
    154 				if (vp->v_type == VDIR) {
    155 					nfs_invaldircache(vp, 0);
    156 					np->n_direofoffset = 0;
    157 				}
    158 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    159 				if (error)
    160 					return (error);
    161 				np->n_mtime = vattr.va_mtime.tv_sec;
    162 			}
    163 		}
    164 	}
    165 
    166 	/*
    167 	 * update the cached read creds for this node.
    168 	 */
    169 
    170 	if (np->n_rcred) {
    171 		crfree(np->n_rcred);
    172 	}
    173 	np->n_rcred = cred;
    174 	crhold(cred);
    175 
    176 	do {
    177 #ifndef NFS_V2_ONLY
    178 	    /*
    179 	     * Get a valid lease. If cached data is stale, flush it.
    180 	     */
    181 	    if (nmp->nm_flag & NFSMNT_NQNFS) {
    182 		if (NQNFS_CKINVALID(vp, np, ND_READ)) {
    183 		    do {
    184 			error = nqnfs_getlease(vp, ND_READ, cred, p);
    185 		    } while (error == NQNFS_EXPIRED);
    186 		    if (error)
    187 			return (error);
    188 		    if (np->n_lrev != np->n_brev ||
    189 			(np->n_flag & NQNFSNONCACHE) ||
    190 			((np->n_flag & NMODIFIED) && vp->v_type == VDIR)) {
    191 			if (vp->v_type == VDIR) {
    192 				nfs_invaldircache(vp, 0);
    193 				np->n_direofoffset = 0;
    194 			}
    195 			error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    196 			if (error)
    197 			    return (error);
    198 			np->n_brev = np->n_lrev;
    199 		    }
    200 		} else if (vp->v_type == VDIR && (np->n_flag & NMODIFIED)) {
    201 		    nfs_invaldircache(vp, 0);
    202 		    error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    203 		    np->n_direofoffset = 0;
    204 		    if (error)
    205 			return (error);
    206 		}
    207 	    }
    208 #endif
    209 	    /*
    210 	     * Don't cache symlinks.
    211 	     */
    212 	    if (np->n_flag & NQNFSNONCACHE
    213 		|| ((vp->v_flag & VROOT) && vp->v_type == VLNK)) {
    214 		switch (vp->v_type) {
    215 		case VREG:
    216 			return (nfs_readrpc(vp, uio));
    217 		case VLNK:
    218 			return (nfs_readlinkrpc(vp, uio, cred));
    219 		case VDIR:
    220 			break;
    221 		default:
    222 			printf(" NQNFSNONCACHE: type %x unexpected\n",
    223 			    vp->v_type);
    224 		};
    225 	    }
    226 	    baddr = (caddr_t)0;
    227 	    switch (vp->v_type) {
    228 	    case VREG:
    229 		nfsstats.biocache_reads++;
    230 
    231 		error = 0;
    232 		while (uio->uio_resid > 0) {
    233 			void *win;
    234 			vsize_t bytelen = min(np->n_size - uio->uio_offset,
    235 					      uio->uio_resid);
    236 
    237 			if (bytelen == 0)
    238 				break;
    239 			win = ubc_alloc(&vp->v_uvm.u_obj, uio->uio_offset,
    240 					&bytelen, UBC_READ);
    241 			error = uiomove(win, bytelen, uio);
    242 			ubc_release(win, 0);
    243 			if (error) {
    244 				break;
    245 			}
    246 		}
    247 		n = 0;
    248 		break;
    249 
    250 	    case VLNK:
    251 		nfsstats.biocache_readlinks++;
    252 		bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, p);
    253 		if (!bp)
    254 			return (EINTR);
    255 		if ((bp->b_flags & B_DONE) == 0) {
    256 			bp->b_flags |= B_READ;
    257 			error = nfs_doio(bp, p);
    258 			if (error) {
    259 				brelse(bp);
    260 				return (error);
    261 			}
    262 		}
    263 		n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
    264 		got_buf = 1;
    265 		on = 0;
    266 		break;
    267 	    case VDIR:
    268 diragain:
    269 		nfsstats.biocache_readdirs++;
    270 		ndp = nfs_searchdircache(vp, uio->uio_offset,
    271 			(nmp->nm_flag & NFSMNT_XLATECOOKIE), 0);
    272 		if (!ndp) {
    273 			/*
    274 			 * We've been handed a cookie that is not
    275 			 * in the cache. If we're not translating
    276 			 * 32 <-> 64, it may be a value that was
    277 			 * flushed out of the cache because it grew
    278 			 * too big. Let the server judge if it's
    279 			 * valid or not. In the translation case,
    280 			 * we have no way of validating this value,
    281 			 * so punt.
    282 			 */
    283 			if (nmp->nm_flag & NFSMNT_XLATECOOKIE)
    284 				return (EINVAL);
    285 			ndp = nfs_enterdircache(vp, uio->uio_offset,
    286 				uio->uio_offset, 0, 0);
    287 		}
    288 
    289 		if (uio->uio_offset != 0 &&
    290 		    ndp->dc_cookie == np->n_direofoffset) {
    291 			nfsstats.direofcache_hits++;
    292 			return (0);
    293 		}
    294 
    295 		bp = nfs_getcacheblk(vp, ndp->dc_blkno, NFS_DIRBLKSIZ, p);
    296 		if (!bp)
    297 		    return (EINTR);
    298 		if ((bp->b_flags & B_DONE) == 0) {
    299 		    bp->b_flags |= B_READ;
    300 		    bp->b_dcookie = ndp->dc_blkcookie;
    301 		    error = nfs_doio(bp, p);
    302 		    if (error) {
    303 			/*
    304 			 * Yuck! The directory has been modified on the
    305 			 * server. Punt and let the userland code
    306 			 * deal with it.
    307 			 */
    308 			brelse(bp);
    309 			if (error == NFSERR_BAD_COOKIE) {
    310 			    nfs_invaldircache(vp, 0);
    311 			    nfs_vinvalbuf(vp, 0, cred, p, 1);
    312 			    error = EINVAL;
    313 			}
    314 			return (error);
    315 		    }
    316 		}
    317 
    318 		/*
    319 		 * Just return if we hit EOF right away with this
    320 		 * block. Always check here, because direofoffset
    321 		 * may have been set by an nfsiod since the last
    322 		 * check.
    323 		 */
    324 		if (np->n_direofoffset != 0 &&
    325 			ndp->dc_blkcookie == np->n_direofoffset) {
    326 			brelse(bp);
    327 			return (0);
    328 		}
    329 
    330 		/*
    331 		 * Find the entry we were looking for in the block.
    332 		 */
    333 
    334 		en = ndp->dc_entry;
    335 
    336 		pdp = dp = (struct dirent *)bp->b_data;
    337 		edp = bp->b_data + bp->b_bcount;
    338 		enn = 0;
    339 		while (enn < en && (caddr_t)dp < edp) {
    340 			pdp = dp;
    341 			dp = (struct dirent *)((caddr_t)dp + dp->d_reclen);
    342 			enn++;
    343 		}
    344 
    345 		/*
    346 		 * If the entry number was bigger than the number of
    347 		 * entries in the block, or the cookie of the previous
    348 		 * entry doesn't match, the directory cache is
    349 		 * stale. Flush it and try again (i.e. go to
    350 		 * the server).
    351 		 */
    352 		if ((caddr_t)dp >= edp || (caddr_t)dp + dp->d_reclen > edp ||
    353 		    (en > 0 && NFS_GETCOOKIE(pdp) != ndp->dc_cookie)) {
    354 #ifdef DEBUG
    355 		    	printf("invalid cache: %p %p %p off %lx %lx\n",
    356 				pdp, dp, edp,
    357 				(unsigned long)uio->uio_offset,
    358 				(unsigned long)NFS_GETCOOKIE(pdp));
    359 #endif
    360 			brelse(bp);
    361 			nfs_invaldircache(vp, 0);
    362 			nfs_vinvalbuf(vp, 0, cred, p, 0);
    363 			goto diragain;
    364 		}
    365 
    366 		on = (caddr_t)dp - bp->b_data;
    367 
    368 		/*
    369 		 * Cache all entries that may be exported to the
    370 		 * user, as they may be thrown back at us. The
    371 		 * NFSBIO_CACHECOOKIES flag indicates that all
    372 		 * entries are being 'exported', so cache them all.
    373 		 */
    374 
    375 		if (en == 0 && pdp == dp) {
    376 			dp = (struct dirent *)
    377 			    ((caddr_t)dp + dp->d_reclen);
    378 			enn++;
    379 		}
    380 
    381 		if (uio->uio_resid < (bp->b_bcount - on)) {
    382 			n = uio->uio_resid;
    383 			enough = 1;
    384 		} else
    385 			n = bp->b_bcount - on;
    386 
    387 		ep = bp->b_data + on + n;
    388 
    389 		/*
    390 		 * Find last complete entry to copy, caching entries
    391 		 * (if requested) as we go.
    392 		 */
    393 
    394 		while ((caddr_t)dp < ep && (caddr_t)dp + dp->d_reclen <= ep) {
    395 			if (cflag & NFSBIO_CACHECOOKIES) {
    396 				nndp = nfs_enterdircache(vp, NFS_GETCOOKIE(pdp),
    397 				    ndp->dc_blkcookie, enn, bp->b_lblkno);
    398 				if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
    399 					NFS_STASHCOOKIE32(pdp,
    400 					    nndp->dc_cookie32);
    401 				}
    402 			}
    403 			pdp = dp;
    404 			dp = (struct dirent *)((caddr_t)dp + dp->d_reclen);
    405 			enn++;
    406 		}
    407 
    408 		/*
    409 		 * If the last requested entry was not the last in the
    410 		 * buffer (happens if NFS_DIRFRAGSIZ < NFS_DIRBLKSIZ),
    411 		 * cache the cookie of the last requested one, and
    412 		 * set of the offset to it.
    413 		 */
    414 
    415 		if ((on + n) < bp->b_bcount) {
    416 			curoff = NFS_GETCOOKIE(pdp);
    417 			nndp = nfs_enterdircache(vp, curoff, ndp->dc_blkcookie,
    418 			    enn, bp->b_lblkno);
    419 			if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
    420 				NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32);
    421 				curoff = nndp->dc_cookie32;
    422 			}
    423 		} else
    424 			curoff = bp->b_dcookie;
    425 
    426 		/*
    427 		 * Always cache the entry for the next block,
    428 		 * so that readaheads can use it.
    429 		 */
    430 		nndp = nfs_enterdircache(vp, bp->b_dcookie, bp->b_dcookie, 0,0);
    431 		if (nmp->nm_flag & NFSMNT_XLATECOOKIE) {
    432 			if (curoff == bp->b_dcookie) {
    433 				NFS_STASHCOOKIE32(pdp, nndp->dc_cookie32);
    434 				curoff = nndp->dc_cookie32;
    435 			}
    436 		}
    437 
    438 		n = ((caddr_t)pdp + pdp->d_reclen) - (bp->b_data + on);
    439 
    440 		/*
    441 		 * If not eof and read aheads are enabled, start one.
    442 		 * (You need the current block first, so that you have the
    443 		 *  directory offset cookie of the next block.)
    444 		 */
    445 		if (nfs_numasync > 0 && nmp->nm_readahead > 0 &&
    446 		    np->n_direofoffset == 0 && !(np->n_flag & NQNFSNONCACHE)) {
    447 			rabp = nfs_getcacheblk(vp, nndp->dc_blkno,
    448 						NFS_DIRBLKSIZ, p);
    449 			if (rabp) {
    450 			    if ((rabp->b_flags & (B_DONE | B_DELWRI)) == 0) {
    451 				rabp->b_dcookie = nndp->dc_cookie;
    452 				rabp->b_flags |= (B_READ | B_ASYNC);
    453 				if (nfs_asyncio(rabp)) {
    454 				    rabp->b_flags |= B_INVAL;
    455 				    brelse(rabp);
    456 				}
    457 			    } else
    458 				brelse(rabp);
    459 			}
    460 		}
    461 		got_buf = 1;
    462 		break;
    463 	    default:
    464 		printf(" nfsbioread: type %x unexpected\n",vp->v_type);
    465 		break;
    466 	    }
    467 
    468 	    if (n > 0) {
    469 		if (!baddr)
    470 			baddr = bp->b_data;
    471 		error = uiomove(baddr + on, (int)n, uio);
    472 	    }
    473 	    switch (vp->v_type) {
    474 	    case VREG:
    475 		break;
    476 	    case VLNK:
    477 		n = 0;
    478 		break;
    479 	    case VDIR:
    480 		if (np->n_flag & NQNFSNONCACHE)
    481 			bp->b_flags |= B_INVAL;
    482 		uio->uio_offset = curoff;
    483 		if (enough)
    484 			n = 0;
    485 		break;
    486 	    default:
    487 		printf(" nfsbioread: type %x unexpected\n",vp->v_type);
    488 	    }
    489 	    if (got_buf)
    490 		brelse(bp);
    491 	} while (error == 0 && uio->uio_resid > 0 && n > 0);
    492 	return (error);
    493 }
    494 
    495 /*
    496  * Vnode op for write using bio
    497  */
    498 int
    499 nfs_write(v)
    500 	void *v;
    501 {
    502 	struct vop_write_args /* {
    503 		struct vnode *a_vp;
    504 		struct uio *a_uio;
    505 		int  a_ioflag;
    506 		struct ucred *a_cred;
    507 	} */ *ap = v;
    508 	struct uio *uio = ap->a_uio;
    509 	struct proc *p = uio->uio_procp;
    510 	struct vnode *vp = ap->a_vp;
    511 	struct nfsnode *np = VTONFS(vp);
    512 	struct ucred *cred = ap->a_cred;
    513 	int ioflag = ap->a_ioflag;
    514 	struct vattr vattr;
    515 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
    516 	int error = 0, iomode, must_commit;
    517 	int rv;
    518 
    519 #ifdef DIAGNOSTIC
    520 	if (uio->uio_rw != UIO_WRITE)
    521 		panic("nfs_write mode");
    522 	if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
    523 		panic("nfs_write proc");
    524 #endif
    525 	if (vp->v_type != VREG)
    526 		return (EIO);
    527 	if (np->n_flag & NWRITEERR) {
    528 		np->n_flag &= ~NWRITEERR;
    529 		return (np->n_error);
    530 	}
    531 #ifndef NFS_V2_ONLY
    532 	if ((nmp->nm_flag & NFSMNT_NFSV3) &&
    533 	    !(nmp->nm_iflag & NFSMNT_GOTFSINFO))
    534 		(void)nfs_fsinfo(nmp, vp, cred, p);
    535 #endif
    536 	if (ioflag & (IO_APPEND | IO_SYNC)) {
    537 		if (np->n_flag & NMODIFIED) {
    538 			np->n_attrstamp = 0;
    539 			error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    540 			if (error)
    541 				return (error);
    542 		}
    543 		if (ioflag & IO_APPEND) {
    544 			np->n_attrstamp = 0;
    545 			error = VOP_GETATTR(vp, &vattr, cred, p);
    546 			if (error)
    547 				return (error);
    548 			uio->uio_offset = np->n_size;
    549 		}
    550 	}
    551 	if (uio->uio_offset < 0)
    552 		return (EINVAL);
    553 	if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
    554 		return (EFBIG);
    555 	if (uio->uio_resid == 0)
    556 		return (0);
    557 	/*
    558 	 * Maybe this should be above the vnode op call, but so long as
    559 	 * file servers have no limits, i don't think it matters
    560 	 */
    561 	if (p && uio->uio_offset + uio->uio_resid >
    562 	      p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
    563 		psignal(p, SIGXFSZ);
    564 		return (EFBIG);
    565 	}
    566 
    567 	/*
    568 	 * update the cached write creds for this node.
    569 	 */
    570 
    571 	if (np->n_wcred) {
    572 		crfree(np->n_wcred);
    573 	}
    574 	np->n_wcred = cred;
    575 	crhold(cred);
    576 
    577 	if ((np->n_flag & NQNFSNONCACHE) && uio->uio_iovcnt == 1) {
    578 		iomode = NFSV3WRITE_FILESYNC;
    579 		error = nfs_writerpc(vp, uio, &iomode, &must_commit);
    580 		if (must_commit)
    581 			nfs_clearcommit(vp->v_mount);
    582 		return (error);
    583 	}
    584 
    585 	do {
    586 		void *win;
    587 		voff_t oldoff = uio->uio_offset;
    588 		vsize_t bytelen = uio->uio_resid;
    589 
    590 #ifndef NFS_V2_ONLY
    591 		/*
    592 		 * Check for a valid write lease.
    593 		 */
    594 		if ((nmp->nm_flag & NFSMNT_NQNFS) &&
    595 		    NQNFS_CKINVALID(vp, np, ND_WRITE)) {
    596 			do {
    597 				error = nqnfs_getlease(vp, ND_WRITE, cred, p);
    598 			} while (error == NQNFS_EXPIRED);
    599 			if (error)
    600 				return (error);
    601 			if (np->n_lrev != np->n_brev ||
    602 			    (np->n_flag & NQNFSNONCACHE)) {
    603 				error = nfs_vinvalbuf(vp, V_SAVE, cred, p, 1);
    604 				if (error)
    605 					return (error);
    606 				np->n_brev = np->n_lrev;
    607 			}
    608 		}
    609 #endif
    610 		nfsstats.biocache_writes++;
    611 
    612 		np->n_flag |= NMODIFIED;
    613 		if (np->n_size < uio->uio_offset + bytelen) {
    614 			np->n_size = uio->uio_offset + bytelen;
    615 			uvm_vnp_setsize(vp, np->n_size);
    616 		}
    617 		win = ubc_alloc(&vp->v_uvm.u_obj, uio->uio_offset, &bytelen,
    618 				UBC_WRITE);
    619 		error = uiomove(win, bytelen, uio);
    620 		if (error) {
    621 			memset((void *)trunc_page((vaddr_t)win), 0,
    622 			       round_page((vaddr_t)win + bytelen) -
    623 			       trunc_page((vaddr_t)win));
    624 		}
    625 		ubc_release(win, 0);
    626 		rv = 1;
    627 		if ((np->n_flag & NQNFSNONCACHE) || (ioflag & IO_SYNC)) {
    628 			simple_lock(&vp->v_uvm.u_obj.vmobjlock);
    629 			rv = vp->v_uvm.u_obj.pgops->pgo_flush(
    630 			    &vp->v_uvm.u_obj,
    631 			    oldoff & ~(nmp->nm_wsize - 1),
    632 			    uio->uio_offset & ~(nmp->nm_wsize - 1),
    633 			    PGO_CLEANIT|PGO_SYNCIO);
    634 			simple_unlock(&vp->v_uvm.u_obj.vmobjlock);
    635 		} else if ((oldoff & ~(nmp->nm_wsize - 1)) !=
    636 		    (uio->uio_offset & ~(nmp->nm_wsize - 1))) {
    637 			simple_lock(&vp->v_uvm.u_obj.vmobjlock);
    638 			rv = vp->v_uvm.u_obj.pgops->pgo_flush(
    639 			    &vp->v_uvm.u_obj,
    640 			    oldoff & ~(nmp->nm_wsize - 1),
    641 			    uio->uio_offset & ~(nmp->nm_wsize - 1),
    642 			    PGO_CLEANIT|PGO_WEAK);
    643 			simple_unlock(&vp->v_uvm.u_obj.vmobjlock);
    644 		}
    645 		if (!rv) {
    646 			error = EIO;
    647 			break;
    648 		}
    649 	} while (uio->uio_resid > 0);
    650 	return error;
    651 }
    652 
    653 /*
    654  * Get an nfs cache block.
    655  * Allocate a new one if the block isn't currently in the cache
    656  * and return the block marked busy. If the calling process is
    657  * interrupted by a signal for an interruptible mount point, return
    658  * NULL.
    659  */
    660 struct buf *
    661 nfs_getcacheblk(vp, bn, size, p)
    662 	struct vnode *vp;
    663 	daddr_t bn;
    664 	int size;
    665 	struct proc *p;
    666 {
    667 	struct buf *bp;
    668 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
    669 
    670 	if (nmp->nm_flag & NFSMNT_INT) {
    671 		bp = getblk(vp, bn, size, PCATCH, 0);
    672 		while (bp == NULL) {
    673 			if (nfs_sigintr(nmp, NULL, p))
    674 				return (NULL);
    675 			bp = getblk(vp, bn, size, 0, 2 * hz);
    676 		}
    677 	} else
    678 		bp = getblk(vp, bn, size, 0, 0);
    679 	return (bp);
    680 }
    681 
    682 /*
    683  * Flush and invalidate all dirty buffers. If another process is already
    684  * doing the flush, just wait for completion.
    685  */
    686 int
    687 nfs_vinvalbuf(vp, flags, cred, p, intrflg)
    688 	struct vnode *vp;
    689 	int flags;
    690 	struct ucred *cred;
    691 	struct proc *p;
    692 	int intrflg;
    693 {
    694 	struct nfsnode *np = VTONFS(vp);
    695 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
    696 	int error = 0, slpflag, slptimeo;
    697 
    698 	if ((nmp->nm_flag & NFSMNT_INT) == 0)
    699 		intrflg = 0;
    700 	if (intrflg) {
    701 		slpflag = PCATCH;
    702 		slptimeo = 2 * hz;
    703 	} else {
    704 		slpflag = 0;
    705 		slptimeo = 0;
    706 	}
    707 	/*
    708 	 * First wait for any other process doing a flush to complete.
    709 	 */
    710 	while (np->n_flag & NFLUSHINPROG) {
    711 		np->n_flag |= NFLUSHWANT;
    712 		error = tsleep((caddr_t)&np->n_flag, PRIBIO + 2, "nfsvinval",
    713 			slptimeo);
    714 		if (error && intrflg && nfs_sigintr(nmp, NULL, p))
    715 			return (EINTR);
    716 	}
    717 
    718 	/*
    719 	 * Now, flush as required.
    720 	 */
    721 	np->n_flag |= NFLUSHINPROG;
    722 	error = vinvalbuf(vp, flags, cred, p, slpflag, 0);
    723 	while (error) {
    724 		if (intrflg && nfs_sigintr(nmp, NULL, p)) {
    725 			np->n_flag &= ~NFLUSHINPROG;
    726 			if (np->n_flag & NFLUSHWANT) {
    727 				np->n_flag &= ~NFLUSHWANT;
    728 				wakeup((caddr_t)&np->n_flag);
    729 			}
    730 			return (EINTR);
    731 		}
    732 		error = vinvalbuf(vp, flags, cred, p, 0, slptimeo);
    733 	}
    734 	np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
    735 	if (np->n_flag & NFLUSHWANT) {
    736 		np->n_flag &= ~NFLUSHWANT;
    737 		wakeup((caddr_t)&np->n_flag);
    738 	}
    739 	return (0);
    740 }
    741 
    742 /*
    743  * Initiate asynchronous I/O. Return an error if no nfsiods are available.
    744  * This is mainly to avoid queueing async I/O requests when the nfsiods
    745  * are all hung on a dead server.
    746  */
    747 int
    748 nfs_asyncio(bp)
    749 	struct buf *bp;
    750 {
    751 	int i;
    752 	struct nfsmount *nmp;
    753 	int gotiod, slpflag = 0, slptimeo = 0, error;
    754 
    755 	if (nfs_numasync == 0)
    756 		return (EIO);
    757 
    758 
    759 	nmp = VFSTONFS(bp->b_vp->v_mount);
    760 again:
    761 	if (nmp->nm_flag & NFSMNT_INT)
    762 		slpflag = PCATCH;
    763 	gotiod = FALSE;
    764 
    765 	/*
    766 	 * Find a free iod to process this request.
    767 	 */
    768 
    769 	for (i = 0; i < NFS_MAXASYNCDAEMON; i++)
    770 		if (nfs_iodwant[i]) {
    771 			/*
    772 			 * Found one, so wake it up and tell it which
    773 			 * mount to process.
    774 			 */
    775 			nfs_iodwant[i] = NULL;
    776 			nfs_iodmount[i] = nmp;
    777 			nmp->nm_bufqiods++;
    778 			wakeup((caddr_t)&nfs_iodwant[i]);
    779 			gotiod = TRUE;
    780 			break;
    781 		}
    782 	/*
    783 	 * If none are free, we may already have an iod working on this mount
    784 	 * point.  If so, it will process our request.
    785 	 */
    786 	if (!gotiod && nmp->nm_bufqiods > 0)
    787 		gotiod = TRUE;
    788 
    789 	/*
    790 	 * If we have an iod which can process the request, then queue
    791 	 * the buffer.
    792 	 */
    793 	if (gotiod) {
    794 		/*
    795 		 * Ensure that the queue never grows too large.
    796 		 */
    797 		while (nmp->nm_bufqlen >= 2*nfs_numasync) {
    798 			nmp->nm_bufqwant = TRUE;
    799 			error = tsleep(&nmp->nm_bufq, slpflag | PRIBIO,
    800 				"nfsaio", slptimeo);
    801 			if (error) {
    802 				if (nfs_sigintr(nmp, NULL, bp->b_proc))
    803 					return (EINTR);
    804 				if (slpflag == PCATCH) {
    805 					slpflag = 0;
    806 					slptimeo = 2 * hz;
    807 				}
    808 			}
    809 			/*
    810 			 * We might have lost our iod while sleeping,
    811 			 * so check and loop if nescessary.
    812 			 */
    813 			if (nmp->nm_bufqiods == 0)
    814 				goto again;
    815 		}
    816 		TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
    817 		nmp->nm_bufqlen++;
    818 		return (0);
    819 	    }
    820 
    821 	/*
    822 	 * All the iods are busy on other mounts, so return EIO to
    823 	 * force the caller to process the i/o synchronously.
    824 	 */
    825 	return (EIO);
    826 }
    827 
    828 /*
    829  * Do an I/O operation to/from a cache block. This may be called
    830  * synchronously or from an nfsiod.
    831  */
    832 int
    833 nfs_doio(bp, p)
    834 	struct buf *bp;
    835 	struct proc *p;
    836 {
    837 	struct uio *uiop;
    838 	struct vnode *vp;
    839 	struct nfsnode *np;
    840 	struct nfsmount *nmp;
    841 	int error = 0, diff, len, iomode, must_commit = 0;
    842 	struct uio uio;
    843 	struct iovec io;
    844 
    845 	vp = bp->b_vp;
    846 	np = VTONFS(vp);
    847 	nmp = VFSTONFS(vp->v_mount);
    848 	uiop = &uio;
    849 	uiop->uio_iov = &io;
    850 	uiop->uio_iovcnt = 1;
    851 	uiop->uio_segflg = UIO_SYSSPACE;
    852 	uiop->uio_procp = p;
    853 
    854 	/*
    855 	 * Historically, paging was done with physio, but no more...
    856 	 */
    857 	if (bp->b_flags & B_PHYS) {
    858 	    /*
    859 	     * ...though reading /dev/drum still gets us here.
    860 	     */
    861 	    io.iov_len = uiop->uio_resid = bp->b_bcount;
    862 	    /* mapping was done by vmapbuf() */
    863 	    io.iov_base = bp->b_data;
    864 	    uiop->uio_offset = ((off_t)bp->b_blkno) << DEV_BSHIFT;
    865 	    if (bp->b_flags & B_READ) {
    866 		uiop->uio_rw = UIO_READ;
    867 		nfsstats.read_physios++;
    868 		error = nfs_readrpc(vp, uiop);
    869 	    } else {
    870 		iomode = NFSV3WRITE_DATASYNC;
    871 		uiop->uio_rw = UIO_WRITE;
    872 		nfsstats.write_physios++;
    873 		error = nfs_writerpc(vp, uiop, &iomode, &must_commit);
    874 	    }
    875 	    if (error) {
    876 		bp->b_flags |= B_ERROR;
    877 		bp->b_error = error;
    878 	    }
    879 	} else if (bp->b_flags & B_READ) {
    880 	    io.iov_len = uiop->uio_resid = bp->b_bcount;
    881 	    io.iov_base = bp->b_data;
    882 	    uiop->uio_rw = UIO_READ;
    883 	    switch (vp->v_type) {
    884 	    case VREG:
    885 		uiop->uio_offset = ((off_t)bp->b_blkno) << DEV_BSHIFT;
    886 		nfsstats.read_bios++;
    887 		error = nfs_readrpc(vp, uiop);
    888 		if (!error && uiop->uio_resid) {
    889 
    890 			/*
    891 			 * If len > 0, there is a hole in the file and
    892 			 * no writes after the hole have been pushed to
    893 			 * the server yet.
    894 			 * Just zero fill the rest of the valid area.
    895 			 */
    896 
    897 			diff = bp->b_bcount - uiop->uio_resid;
    898 			len = np->n_size - ((((off_t)bp->b_blkno) << DEV_BSHIFT)
    899 				+ diff);
    900 			if (len > 0) {
    901 				len = min(len, uiop->uio_resid);
    902 				memset((char *)bp->b_data + diff, 0, len);
    903 			}
    904 		}
    905 		if (p && (vp->v_flag & VTEXT) &&
    906 			(((nmp->nm_flag & NFSMNT_NQNFS) &&
    907 			  NQNFS_CKINVALID(vp, np, ND_READ) &&
    908 			  np->n_lrev != np->n_brev) ||
    909 			 (!(nmp->nm_flag & NFSMNT_NQNFS) &&
    910 			  np->n_mtime != np->n_vattr->va_mtime.tv_sec))) {
    911 			uprintf("Process killed due to "
    912 				"text file modification\n");
    913 			psignal(p, SIGKILL);
    914 			p->p_holdcnt++;
    915 		}
    916 		break;
    917 	    case VLNK:
    918 		uiop->uio_offset = (off_t)0;
    919 		nfsstats.readlink_bios++;
    920 		error = nfs_readlinkrpc(vp, uiop, curproc->p_ucred);
    921 		break;
    922 	    case VDIR:
    923 		nfsstats.readdir_bios++;
    924 		uiop->uio_offset = bp->b_dcookie;
    925 		if (nmp->nm_flag & NFSMNT_RDIRPLUS) {
    926 			error = nfs_readdirplusrpc(vp, uiop, curproc->p_ucred);
    927 			if (error == NFSERR_NOTSUPP)
    928 				nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
    929 		}
    930 		if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
    931 			error = nfs_readdirrpc(vp, uiop, curproc->p_ucred);
    932 		if (!error) {
    933 			bp->b_dcookie = uiop->uio_offset;
    934 		}
    935 		break;
    936 	    default:
    937 		printf("nfs_doio:  type %x unexpected\n",vp->v_type);
    938 		break;
    939 	    }
    940 	    if (error) {
    941 		bp->b_flags |= B_ERROR;
    942 		bp->b_error = error;
    943 	    }
    944 	} else {
    945 	    /*
    946 	     * If B_NEEDCOMMIT is set, a commit rpc may do the trick. If not
    947 	     * an actual write will have to be scheduled.
    948 	     */
    949 
    950 	    io.iov_base = bp->b_data;
    951 	    io.iov_len = uiop->uio_resid = bp->b_bcount;
    952 	    uiop->uio_offset = (((off_t)bp->b_blkno) << DEV_BSHIFT);
    953 	    uiop->uio_rw = UIO_WRITE;
    954 	    nfsstats.write_bios++;
    955 	    iomode = NFSV3WRITE_UNSTABLE;
    956 	    error = nfs_writerpc(vp, uiop, &iomode, &must_commit);
    957 	}
    958 	bp->b_resid = uiop->uio_resid;
    959 	if (must_commit)
    960 		nfs_clearcommit(vp->v_mount);
    961 	biodone(bp);
    962 	return (error);
    963 }
    964 
    965 /*
    966  * Vnode op for VM getpages.
    967  */
    968 int
    969 nfs_getpages(v)
    970 	void *v;
    971 {
    972 	struct vop_getpages_args /* {
    973 		struct vnode *a_vp;
    974 		voff_t a_offset;
    975 		vm_page_t *a_m;
    976 		int *a_count;
    977 		int a_centeridx;
    978 		vm_prot_t a_access_type;
    979 		int a_advice;
    980 		int a_flags;
    981 	} */ *ap = v;
    982 
    983 	off_t eof, offset, origoffset, startoffset, endoffset;
    984 	int s, i, error, npages, orignpages, npgs, ridx, pidx, pcount;
    985 	vaddr_t kva;
    986 	struct buf *bp, *mbp;
    987 	struct vnode *vp = ap->a_vp;
    988 	struct nfsnode *np = VTONFS(vp);
    989 	struct uvm_object *uobj = &vp->v_uvm.u_obj;
    990 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
    991 	size_t bytes, iobytes, tailbytes, totalbytes, skipbytes;
    992 	int flags = ap->a_flags;
    993 	int bsize;
    994 	struct vm_page *pgs[16];			/* XXXUBC 16 */
    995 	boolean_t v3 = NFS_ISV3(vp);
    996 	boolean_t async = (flags & PGO_SYNCIO) == 0;
    997 	boolean_t write = (ap->a_access_type & VM_PROT_WRITE) != 0;
    998 
    999 	UVMHIST_FUNC("nfs_getpages"); UVMHIST_CALLED(ubchist);
   1000 	UVMHIST_LOG(ubchist, "vp %p off 0x%x count %d", vp, (int)ap->a_offset,
   1001 		    *ap->a_count,0);
   1002 
   1003 #ifdef DIAGNOSTIC
   1004 	if (ap->a_centeridx < 0 || ap->a_centeridx >= *ap->a_count) {
   1005 		panic("nfs_getpages: centeridx %d out of range",
   1006 		      ap->a_centeridx);
   1007 	}
   1008 #endif
   1009 
   1010 	error = 0;
   1011 	origoffset = ap->a_offset;
   1012 	eof = vp->v_uvm.u_size;
   1013 	if (origoffset >= eof) {
   1014 		if ((flags & PGO_LOCKED) == 0) {
   1015 			simple_unlock(&uobj->vmobjlock);
   1016 		}
   1017 		UVMHIST_LOG(ubchist, "off 0x%x past EOF 0x%x",
   1018 			    (int)origoffset, (int)eof,0,0);
   1019 		return EINVAL;
   1020 	}
   1021 
   1022 	if (flags & PGO_LOCKED) {
   1023 		uvn_findpages(uobj, origoffset, ap->a_count, ap->a_m,
   1024 			      UFP_NOWAIT|UFP_NOALLOC);
   1025 		return 0;
   1026 	}
   1027 
   1028 	/* vnode is VOP_LOCKed, uobj is locked */
   1029 
   1030 	bsize = nmp->nm_rsize;
   1031 	orignpages = min(*ap->a_count,
   1032 			 round_page(eof - origoffset) >> PAGE_SHIFT);
   1033 	npages = orignpages;
   1034 	startoffset = origoffset & ~(bsize - 1);
   1035 	endoffset = round_page((origoffset + (npages << PAGE_SHIFT)
   1036 				+ bsize - 1) & ~(bsize - 1));
   1037 	endoffset = min(endoffset, round_page(eof));
   1038 	ridx = (origoffset - startoffset) >> PAGE_SHIFT;
   1039 
   1040 	if (!async && !write) {
   1041 		int rapages = max(PAGE_SIZE, nmp->nm_rsize) >> PAGE_SHIFT;
   1042 
   1043 		(void) VOP_GETPAGES(vp, endoffset, NULL, &rapages, 0,
   1044 				    VM_PROT_READ, 0, 0);
   1045 		simple_lock(&uobj->vmobjlock);
   1046 	}
   1047 
   1048 	UVMHIST_LOG(ubchist, "npages %d offset 0x%x", npages,
   1049 		    (int)origoffset, 0,0);
   1050 	memset(pgs, 0, sizeof(pgs));
   1051 	uvn_findpages(uobj, origoffset, &npages, &pgs[ridx], UFP_ALL);
   1052 
   1053 	if (flags & PGO_OVERWRITE) {
   1054 		UVMHIST_LOG(ubchist, "PGO_OVERWRITE",0,0,0,0);
   1055 
   1056 		/* XXXUBC for now, zero the page if we allocated it */
   1057 		for (i = 0; i < npages; i++) {
   1058 			struct vm_page *pg = pgs[ridx + i];
   1059 
   1060 			if (pg->flags & PG_FAKE) {
   1061 				uvm_pagezero(pg);
   1062 				pg->flags &= ~(PG_FAKE);
   1063 			}
   1064 		}
   1065 		goto out;
   1066 	}
   1067 
   1068 	/*
   1069 	 * if the pages are already resident, just return them.
   1070 	 */
   1071 
   1072 	for (i = 0; i < npages; i++) {
   1073 		struct vm_page *pg = pgs[ridx + i];
   1074 
   1075 		if ((pg->flags & PG_FAKE) != 0 ||
   1076 		    ((ap->a_access_type & VM_PROT_WRITE) &&
   1077 		      (pg->flags & PG_RDONLY))) {
   1078 			break;
   1079 		}
   1080 	}
   1081 	if (i == npages) {
   1082 		UVMHIST_LOG(ubchist, "returning cached pages", 0,0,0,0);
   1083 		goto out;
   1084 	}
   1085 
   1086 	/*
   1087 	 * the page wasn't resident and we're not overwriting,
   1088 	 * so we're going to have to do some i/o.
   1089 	 * find any additional pages needed to cover the expanded range.
   1090 	 */
   1091 
   1092 	if (startoffset != origoffset ||
   1093 	    startoffset + (npages << PAGE_SHIFT) != endoffset) {
   1094 		UVMHIST_LOG(ubchist, "reset npages start 0x%x end 0x%x",
   1095 			    (int)startoffset, (int)endoffset, 0,0);
   1096 		npages = (endoffset - startoffset) >> PAGE_SHIFT;
   1097 		KASSERT(npages != 0);
   1098 		npgs = npages;
   1099 		uvn_findpages(uobj, startoffset, &npgs, pgs, UFP_ALL);
   1100 	}
   1101 	simple_unlock(&uobj->vmobjlock);
   1102 
   1103 	/*
   1104 	 * update the cached read creds for this node.
   1105 	 */
   1106 
   1107 	if (np->n_rcred) {
   1108 		crfree(np->n_rcred);
   1109 	}
   1110 	np->n_rcred = curproc->p_ucred;
   1111 	crhold(np->n_rcred);
   1112 
   1113 	/*
   1114 	 * read the desired page(s).
   1115 	 */
   1116 
   1117 	totalbytes = npages << PAGE_SHIFT;
   1118 	bytes = min(totalbytes, vp->v_uvm.u_size - startoffset);
   1119 	tailbytes = totalbytes - bytes;
   1120 	skipbytes = 0;
   1121 
   1122 	kva = uvm_pagermapin(pgs, npages, UVMPAGER_MAPIN_WAITOK |
   1123 			     UVMPAGER_MAPIN_READ);
   1124 
   1125 	s = splbio();
   1126 	mbp = pool_get(&bufpool, PR_WAITOK);
   1127 	splx(s);
   1128 	mbp->b_bufsize = totalbytes;
   1129 	mbp->b_data = (void *)kva;
   1130 	mbp->b_resid = mbp->b_bcount = bytes;
   1131 	mbp->b_flags = B_BUSY|B_READ| (async ? B_CALL|B_ASYNC : 0);
   1132 	mbp->b_iodone = uvm_aio_biodone;
   1133 	mbp->b_vp = vp;
   1134 	LIST_INIT(&mbp->b_dep);
   1135 
   1136 	/*
   1137 	 * if EOF is in the middle of the last page, zero the part past EOF.
   1138 	 */
   1139 
   1140 	if (tailbytes > 0 && (pgs[bytes >> PAGE_SHIFT]->flags & PG_FAKE)) {
   1141 		memset((char *)kva + bytes, 0, tailbytes);
   1142 	}
   1143 
   1144 	/*
   1145 	 * now loop over the pages, reading as needed.
   1146 	 */
   1147 
   1148 	bp = NULL;
   1149 	for (offset = startoffset;
   1150 	     bytes > 0;
   1151 	     offset += iobytes, bytes -= iobytes) {
   1152 
   1153 		/*
   1154 		 * skip pages which don't need to be read.
   1155 		 */
   1156 
   1157 		pidx = (offset - startoffset) >> PAGE_SHIFT;
   1158 		UVMHIST_LOG(ubchist, "pidx %d offset 0x%x startoffset 0x%x",
   1159 			    pidx, (int)offset, (int)startoffset,0);
   1160 		while ((pgs[pidx]->flags & PG_FAKE) == 0) {
   1161 			size_t b;
   1162 
   1163 #ifdef DEBUG
   1164 			if (offset & (PAGE_SIZE - 1)) {
   1165 				panic("nfs_getpages: skipping from middle "
   1166 				      "of page");
   1167 			}
   1168 #endif
   1169 
   1170 			b = min(PAGE_SIZE, bytes);
   1171 			offset += b;
   1172 			bytes -= b;
   1173 			skipbytes += b;
   1174 			pidx++;
   1175 			UVMHIST_LOG(ubchist, "skipping, new offset 0x%x",
   1176 				    (int)offset, 0,0,0);
   1177 			if (bytes == 0) {
   1178 				goto loopdone;
   1179 			}
   1180 		}
   1181 
   1182 		/*
   1183 		 * see how many pages can be read with this i/o.
   1184 		 * reduce the i/o size if necessary.
   1185 		 */
   1186 
   1187 		iobytes = bytes;
   1188 		if (offset + iobytes > round_page(offset)) {
   1189 			pcount = 1;
   1190 			while (pidx + pcount < npages &&
   1191 			       pgs[pidx + pcount]->flags & PG_FAKE) {
   1192 				pcount++;
   1193 			}
   1194 			iobytes = min(iobytes, (pcount << PAGE_SHIFT) -
   1195 				      (offset - trunc_page(offset)));
   1196 		}
   1197 		iobytes = min(iobytes, nmp->nm_rsize);
   1198 
   1199 		/*
   1200 		 * allocate a sub-buf for this piece of the i/o
   1201 		 * (or just use mbp if there's only 1 piece),
   1202 		 * and start it going.
   1203 		 */
   1204 
   1205 		if (offset == startoffset && iobytes == bytes) {
   1206 			bp = mbp;
   1207 		} else {
   1208 			s = splbio();
   1209 			bp = pool_get(&bufpool, PR_WAITOK);
   1210 			splx(s);
   1211 			bp->b_data = (char *)kva + offset - startoffset;
   1212 			bp->b_resid = bp->b_bcount = iobytes;
   1213 			bp->b_flags = B_BUSY|B_READ|B_CALL|B_ASYNC;
   1214 			bp->b_iodone = uvm_aio_biodone1;
   1215 			bp->b_vp = vp;
   1216 			LIST_INIT(&bp->b_dep);
   1217 		}
   1218 		bp->b_private = mbp;
   1219 		bp->b_lblkno = bp->b_blkno = offset >> DEV_BSHIFT;
   1220 
   1221 		UVMHIST_LOG(ubchist, "bp %p offset 0x%x bcount 0x%x blkno 0x%x",
   1222 			    bp, offset, iobytes, bp->b_blkno);
   1223 
   1224 		VOP_STRATEGY(bp);
   1225 	}
   1226 
   1227 loopdone:
   1228 	if (skipbytes) {
   1229 		s = splbio();
   1230 		mbp->b_resid -= skipbytes;
   1231 		if (mbp->b_resid == 0) {
   1232 			biodone(mbp);
   1233 		}
   1234 		splx(s);
   1235 	}
   1236 	if (async) {
   1237 		UVMHIST_LOG(ubchist, "returning PEND",0,0,0,0);
   1238 		return EINPROGRESS;
   1239 	}
   1240 	if (bp != NULL) {
   1241 		error = biowait(mbp);
   1242 	}
   1243 	s = splbio();
   1244 	pool_put(&bufpool, mbp);
   1245 	splx(s);
   1246 	uvm_pagermapout(kva, npages);
   1247 
   1248 	if (write && v3) {
   1249 		lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL);
   1250 		nfs_del_committed_range(vp, origoffset, npages);
   1251 		nfs_del_tobecommitted_range(vp, origoffset, npages);
   1252 		for (i = 0; i < npages; i++) {
   1253 			if (pgs[i] == NULL) {
   1254 				continue;
   1255 			}
   1256 			pgs[i]->flags &= ~(PG_NEEDCOMMIT|PG_RDONLY);
   1257 		}
   1258 		lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
   1259 	}
   1260 
   1261 	simple_lock(&uobj->vmobjlock);
   1262 
   1263 out:
   1264 	uvm_lock_pageq();
   1265 	if (error) {
   1266 		for (i = 0; i < npages; i++) {
   1267 			if (pgs[i] == NULL) {
   1268 				continue;
   1269 			}
   1270 			UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x",
   1271 				    pgs[i], pgs[i]->flags, 0,0);
   1272 			if ((pgs[i]->flags & PG_FAKE) == 0) {
   1273 				continue;
   1274 			}
   1275 			if (pgs[i]->flags & PG_WANTED) {
   1276 				wakeup(pgs[i]);
   1277 			}
   1278 			uvm_pagefree(pgs[i]);
   1279 		}
   1280 		goto done;
   1281 	}
   1282 
   1283 	UVMHIST_LOG(ubchist, "ridx %d count %d", ridx, npages, 0,0);
   1284 	for (i = 0; i < npages; i++) {
   1285 		if (pgs[i] == NULL) {
   1286 			continue;
   1287 		}
   1288 		UVMHIST_LOG(ubchist, "examining pg %p flags 0x%x",
   1289 			    pgs[i], pgs[i]->flags, 0,0);
   1290 		if (pgs[i]->flags & PG_FAKE) {
   1291 			UVMHIST_LOG(ubchist, "unfaking pg %p offset 0x%x",
   1292 				    pgs[i], (int)pgs[i]->offset,0,0);
   1293 			pgs[i]->flags &= ~(PG_FAKE);
   1294 			pmap_clear_modify(pgs[i]);
   1295 			pmap_clear_reference(pgs[i]);
   1296 		}
   1297 		if (i < ridx || i >= ridx + orignpages || async) {
   1298 			UVMHIST_LOG(ubchist, "unbusy pg %p offset 0x%x",
   1299 				    pgs[i], (int)pgs[i]->offset,0,0);
   1300 			KASSERT((pgs[i]->flags & PG_RELEASED) == 0);
   1301 			if (pgs[i]->flags & PG_WANTED) {
   1302 				wakeup(pgs[i]);
   1303 			}
   1304 			if (pgs[i]->wire_count == 0) {
   1305 				uvm_pageactivate(pgs[i]);
   1306 			}
   1307 			pgs[i]->flags &= ~(PG_WANTED|PG_BUSY);
   1308 			UVM_PAGE_OWN(pgs[i], NULL);
   1309 		}
   1310 	}
   1311 
   1312 done:
   1313 	uvm_unlock_pageq();
   1314 	simple_unlock(&uobj->vmobjlock);
   1315 	if (ap->a_m != NULL) {
   1316 		memcpy(ap->a_m, &pgs[ridx],
   1317 		       *ap->a_count * sizeof(struct vm_page *));
   1318 	}
   1319 
   1320 	UVMHIST_LOG(ubchist, "done -> %d", error, 0,0,0);
   1321 	return error;
   1322 }
   1323 
   1324 /*
   1325  * Vnode op for VM putpages.
   1326  */
   1327 int
   1328 nfs_putpages(v)
   1329 	void *v;
   1330 {
   1331 	struct vop_putpages_args /* {
   1332 		struct vnode *a_vp;
   1333 		struct vm_page **a_m;
   1334 		int a_count;
   1335 		int a_flags;
   1336 		int *a_rtvals;
   1337 	} */ *ap = v;
   1338 
   1339 	struct vnode *vp = ap->a_vp;
   1340 	struct nfsnode *np = VTONFS(vp);
   1341 	struct nfsmount *nmp = VFSTONFS(vp->v_mount);
   1342 	struct buf *bp, *mbp;
   1343 	struct vm_page **pgs = ap->a_m;
   1344 	int flags = ap->a_flags;
   1345 	int npages = ap->a_count;
   1346 	int s, error = 0, i;
   1347 	size_t bytes, iobytes, skipbytes;
   1348 	vaddr_t kva;
   1349 	off_t offset, origoffset, commitoff;
   1350 	uint32_t commitbytes;
   1351 	boolean_t v3 = NFS_ISV3(vp);
   1352 	boolean_t async = (flags & PGO_SYNCIO) == 0;
   1353 	boolean_t weak = (flags & PGO_WEAK) && v3;
   1354 	UVMHIST_FUNC("nfs_putpages"); UVMHIST_CALLED(ubchist);
   1355 
   1356 	UVMHIST_LOG(ubchist, "vp %p pgp %p count %d",
   1357 		    vp, ap->a_m, ap->a_count,0);
   1358 
   1359 	simple_unlock(&vp->v_uvm.u_obj.vmobjlock);
   1360 
   1361 	origoffset = pgs[0]->offset;
   1362 	bytes = min(ap->a_count << PAGE_SHIFT, vp->v_uvm.u_size - origoffset);
   1363 	skipbytes = 0;
   1364 
   1365 	/*
   1366 	 * if the range has been committed already, mark the pages thus.
   1367 	 * if the range just needs to be committed, we're done
   1368 	 * if it's a weak putpage, otherwise commit the range.
   1369 	 */
   1370 
   1371 	if (v3) {
   1372 		lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL);
   1373 		if (nfs_in_committed_range(vp, origoffset, bytes)) {
   1374 			goto committed;
   1375 		}
   1376 		if (nfs_in_tobecommitted_range(vp, origoffset, bytes)) {
   1377 			if (weak) {
   1378 				lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
   1379 				return 0;
   1380 			} else {
   1381 				commitoff = np->n_pushlo;
   1382 				commitbytes = (uint32_t)(np->n_pushhi -
   1383 							 np->n_pushlo);
   1384 				goto commit;
   1385 			}
   1386 		}
   1387 		lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
   1388 	}
   1389 
   1390 	/*
   1391 	 * otherwise write or commit all the pages.
   1392 	 */
   1393 
   1394 	kva = uvm_pagermapin(pgs, ap->a_count, UVMPAGER_MAPIN_WAITOK|
   1395 			     UVMPAGER_MAPIN_WRITE);
   1396 
   1397 	s = splbio();
   1398 	vp->v_numoutput += 2;
   1399 	mbp = pool_get(&bufpool, PR_WAITOK);
   1400 	UVMHIST_LOG(ubchist, "vp %p mbp %p num now %d bytes 0x%x",
   1401 		    vp, mbp, vp->v_numoutput, bytes);
   1402 	splx(s);
   1403 	mbp->b_bufsize = npages << PAGE_SHIFT;
   1404 	mbp->b_data = (void *)kva;
   1405 	mbp->b_resid = mbp->b_bcount = bytes;
   1406 	mbp->b_flags = B_BUSY|B_WRITE|B_AGE |
   1407 		(async ? B_CALL|B_ASYNC : 0) |
   1408 		(curproc == uvm.pagedaemon_proc ? B_PDAEMON : 0);
   1409 	mbp->b_iodone = uvm_aio_aiodone;
   1410 	mbp->b_vp = vp;
   1411 	LIST_INIT(&mbp->b_dep);
   1412 
   1413 	for (offset = origoffset;
   1414 	     bytes > 0;
   1415 	     offset += iobytes, bytes -= iobytes) {
   1416 		iobytes = min(nmp->nm_wsize, bytes);
   1417 
   1418 		/*
   1419 		 * skip writing any pages which only need a commit.
   1420 		 */
   1421 
   1422 		if ((pgs[(offset - origoffset) >> PAGE_SHIFT]->flags &
   1423 		     PG_NEEDCOMMIT) != 0) {
   1424 			iobytes = PAGE_SIZE;
   1425 			skipbytes += min(iobytes, vp->v_uvm.u_size - offset);
   1426 			continue;
   1427 		}
   1428 
   1429 		/* if it's really one i/o, don't make a second buf */
   1430 		if (offset == origoffset && iobytes == bytes) {
   1431 			bp = mbp;
   1432 		} else {
   1433 			s = splbio();
   1434 			vp->v_numoutput++;
   1435 			bp = pool_get(&bufpool, PR_WAITOK);
   1436 			UVMHIST_LOG(ubchist, "vp %p bp %p num now %d",
   1437 				    vp, bp, vp->v_numoutput, 0);
   1438 			splx(s);
   1439 			bp->b_data = (char *)kva + (offset - origoffset);
   1440 			bp->b_resid = bp->b_bcount = iobytes;
   1441 			bp->b_flags = B_BUSY|B_WRITE|B_CALL|B_ASYNC;
   1442 			bp->b_iodone = uvm_aio_biodone1;
   1443 			bp->b_vp = vp;
   1444 			LIST_INIT(&bp->b_dep);
   1445 		}
   1446 		bp->b_private = mbp;
   1447 		bp->b_lblkno = bp->b_blkno = (daddr_t)(offset >> DEV_BSHIFT);
   1448 		UVMHIST_LOG(ubchist, "bp %p numout %d",
   1449 			    bp, vp->v_numoutput,0,0);
   1450 		VOP_STRATEGY(bp);
   1451 	}
   1452 	if (skipbytes) {
   1453 		UVMHIST_LOG(ubchist, "skipbytes %d", bytes, 0,0,0);
   1454 		s = splbio();
   1455 		mbp->b_resid -= skipbytes;
   1456 		if (mbp->b_resid == 0) {
   1457 			biodone(mbp);
   1458 		}
   1459 		splx(s);
   1460 	}
   1461 	if (async) {
   1462 		return EINPROGRESS;
   1463 	}
   1464 	error = biowait(mbp);
   1465 
   1466 	s = splbio();
   1467 	vwakeup(mbp);
   1468 	pool_put(&bufpool, mbp);
   1469 	splx(s);
   1470 
   1471 	uvm_pagermapout(kva, ap->a_count);
   1472 	if (error || !v3) {
   1473 		UVMHIST_LOG(ubchist, "returning error %d", error, 0,0,0);
   1474 		return error;
   1475 	}
   1476 
   1477 	/*
   1478 	 * for a weak put, mark the range as "to be committed"
   1479 	 * and mark the pages read-only so that we will be notified
   1480 	 * to remove the pages from the "to be committed" range
   1481 	 * if they are made dirty again.
   1482 	 * for a strong put, commit the pages and remove them from the
   1483 	 * "to be committed" range.  also, mark them as writable
   1484 	 * and not cleanable with just a commit.
   1485 	 */
   1486 
   1487 	lockmgr(&np->n_commitlock, LK_EXCLUSIVE, NULL);
   1488 	if (weak) {
   1489 		nfs_add_tobecommitted_range(vp, origoffset,
   1490 					    npages << PAGE_SHIFT);
   1491 		for (i = 0; i < npages; i++) {
   1492 			pgs[i]->flags |= PG_NEEDCOMMIT|PG_RDONLY;
   1493 		}
   1494 	} else {
   1495 		commitoff = origoffset;
   1496 		commitbytes = npages << PAGE_SHIFT;
   1497 commit:
   1498 		error = nfs_commit(vp, commitoff, commitbytes, curproc);
   1499 		nfs_del_tobecommitted_range(vp, commitoff, commitbytes);
   1500 committed:
   1501 		for (i = 0; i < npages; i++) {
   1502 			pgs[i]->flags &= ~(PG_NEEDCOMMIT|PG_RDONLY);
   1503 		}
   1504 	}
   1505 	lockmgr(&np->n_commitlock, LK_RELEASE, NULL);
   1506 	return error;
   1507 }
   1508