sys/vfs/nwfs/nwfs_io.c

   1 /*
   2  * Copyright (c) 1999, Boris Popov
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *    This product includes software developed by Boris Popov.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  * $FreeBSD: src/sys/nwfs/nwfs_io.c,v 1.6.2.1 2000/10/25 02:11:10 bp Exp $
  33  * $DragonFly: src/sys/vfs/nwfs/nwfs_io.c,v 1.24 2007/02/22 15:50:50 corecode Exp $
  34  *
  35  */
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/resourcevar.h>    /* defines plimit structure in proc struct */
  39 #include <sys/kernel.h>
  40 #include <sys/buf.h>
  41 #include <sys/proc.h>
  42 #include <sys/mount.h>
  43 #include <sys/namei.h>
  44 #include <sys/vnode.h>
  45 #include <sys/dirent.h>
  46 #include <sys/signalvar.h>
  47 #include <sys/sysctl.h>
  48
  49 #include <vm/vm.h>
  50 #include <vm/vm_page.h>
  51 #include <vm/vm_extern.h>
  52 #include <vm/vm_object.h>
  53 #include <vm/vm_pager.h>
  54 #include <vm/vnode_pager.h>
  55
  56 #include <netproto/ncp/ncp.h>
  57 #include <netproto/ncp/ncp_conn.h>
  58 #include <netproto/ncp/ncp_subr.h>
  59
  60 #include <sys/thread2.h>
  61
  62 #include <machine/limits.h>
  63
  64 #include "nwfs.h"
  65 #include "nwfs_node.h"
  66 #include "nwfs_subr.h"
  67
  68 static int nwfs_fastlookup = 1;
  69
  70 SYSCTL_DECL(_vfs_nwfs);
  71 SYSCTL_INT(_vfs_nwfs, OID_AUTO, fastlookup, CTLFLAG_RW, &nwfs_fastlookup, 0, "");
  72
  73
  74 extern int nwfs_pbuf_freecnt;
  75
  76 #define NWFS_RWCACHE
  77
  78 static int
  79 nwfs_readvdir(struct vnode *vp, struct uio *uio, struct ucred *cred)
  80 {
  81         struct nwmount *nmp = VTONWFS(vp);
  82         int error, i;
  83         struct nwnode *np;
  84         struct nw_entry_info fattr;
  85         struct vnode *newvp;
  86         ncpfid fid;
  87         ino_t d_ino;
  88         size_t d_namlen;
  89         const char *d_name;
  90         uint8_t d_type;
  91
  92         np = VTONW(vp);
  93         NCPVNDEBUG("dirname='%s'\n",np->n_name);
  94         if (uio->uio_offset < 0 || uio->uio_offset > INT_MAX)
  95                 return (EINVAL);
  96         error = 0;
  97         i = (int)uio->uio_offset; /* offset in directory */
  98         if (i == 0) {
  99                 error = ncp_initsearch(vp, uio->uio_td, cred);
 100                 if (error) {
 101                         NCPVNDEBUG("cannot initialize search, error=%d",error);
 102                         return( error );
 103                 }
 104         }
 105
 106         for (; !error && uio->uio_resid > 0; i++) {
 107                 switch (i) {
 108                     case 0:             /* `.' */
 109                         d_ino = np->n_fid.f_id;
 110                         if (d_ino == 0)
 111                                 d_ino = NWFS_ROOT_INO;
 112                         d_namlen = 1;
 113                         d_name = ".";
 114                         d_type = DT_DIR;
 115                         break;
 116                     case 1:             /* `..' */
 117                         d_ino = np->n_parent.f_id;
 118                         if (d_ino == 0)
 119                                 d_ino = NWFS_ROOT_INO;
 120                         d_namlen = 2;
 121                         d_name = "..";
 122                         d_type = DT_DIR;
 123                         break;
 124                     default:
 125                         error = ncp_search_for_file_or_subdir(nmp, &np->n_seq, &fattr, uio->uio_td, cred);
 126                         if (error && error < 0x80)
 127                                 goto done;
 128                         d_ino = fattr.dirEntNum;
 129                         d_type = (fattr.attributes & aDIR) ? DT_DIR : DT_REG;
 130                         d_namlen = fattr.nameLen;
 131                         d_name = fattr.entryName;
 132 #if 0
 133                         if (error && eofflag) {
 134                         /*      *eofflag = 1;*/
 135                                 break;
 136                         }
 137 #endif
 138                         break;
 139                 }
 140                 if (nwfs_fastlookup && !error && i > 1) {
 141                         fid.f_id = fattr.dirEntNum;
 142                         fid.f_parent = np->n_fid.f_id;
 143                         error = nwfs_nget(vp->v_mount, fid, &fattr, vp, &newvp);
 144                         if (!error) {
 145                                 VTONW(newvp)->n_ctime = VTONW(newvp)->n_vattr.va_ctime.tv_sec;
 146                                 vput(newvp);
 147                         } else
 148                                 error = 0;
 149                 }
 150                 if (error >= 0x80) {
 151                     error = 0;
 152                     break;
 153                 }
 154                 if (vop_write_dirent(&error, uio, d_ino, d_type, d_namlen, d_name))
 155                         break;
 156         }
 157 done:
 158         uio->uio_offset = i;
 159         return (error);
 160 }
 161
 162 int
 163 nwfs_readvnode(struct vnode *vp, struct uio *uiop, struct ucred *cred)
 164 {
 165         struct nwmount *nmp = VFSTONWFS(vp->v_mount);
 166         struct nwnode *np = VTONW(vp);
 167         struct thread *td;
 168         struct vattr vattr;
 169         int error, biosize;
 170
 171         if (vp->v_type != VREG && vp->v_type != VDIR) {
 172                 kprintf("%s: vn types other than VREG or VDIR are unsupported !\n",__func__);
 173                 return EIO;
 174         }
 175         if (uiop->uio_resid == 0) return 0;
 176         if (uiop->uio_offset < 0) return EINVAL;
 177         td = uiop->uio_td;
 178         if (vp->v_type == VDIR) {
 179                 error = nwfs_readvdir(vp, uiop, cred);
 180                 return error;
 181         }
 182         biosize = NWFSTOCONN(nmp)->buffer_size;
 183         if (np->n_flag & NMODIFIED) {
 184                 nwfs_attr_cacheremove(vp);
 185                 error = VOP_GETATTR(vp, &vattr);
 186                 if (error) return (error);
 187                 np->n_mtime = vattr.va_mtime.tv_sec;
 188         } else {
 189                 error = VOP_GETATTR(vp, &vattr);
 190                 if (error) return (error);
 191                 if (np->n_mtime != vattr.va_mtime.tv_sec) {
 192                         error = nwfs_vinvalbuf(vp, V_SAVE, 1);
 193                         if (error) return (error);
 194                         np->n_mtime = vattr.va_mtime.tv_sec;
 195                 }
 196         }
 197         error = ncp_read(NWFSTOCONN(nmp), &np->n_fh, uiop,cred);
 198         return (error);
 199 }
 200
 201 int
 202 nwfs_writevnode(struct vnode *vp, struct uio *uiop, struct ucred *cred,
 203                 int ioflag)
 204 {
 205         struct nwmount *nmp = VTONWFS(vp);
 206         struct nwnode *np = VTONW(vp);
 207         struct thread *td;
 208 /*      struct vattr vattr;*/
 209         int error = 0;
 210
 211         if (vp->v_type != VREG) {
 212                 kprintf("%s: vn types other than VREG unsupported !\n",__func__);
 213                 return EIO;
 214         }
 215         NCPVNDEBUG("ofs=%d,resid=%d\n",(int)uiop->uio_offset, uiop->uio_resid);
 216         if (uiop->uio_offset < 0) return EINVAL;
 217         td = uiop->uio_td;
 218         if (ioflag & (IO_APPEND | IO_SYNC)) {
 219                 if (np->n_flag & NMODIFIED) {
 220                         nwfs_attr_cacheremove(vp);
 221                         error = nwfs_vinvalbuf(vp, V_SAVE, 1);
 222                         if (error) return (error);
 223                 }
 224                 if (ioflag & IO_APPEND) {
 225                 /* We can relay only on local information about file size,
 226                  * because until file is closed NetWare will not return
 227                  * the correct size. */
 228 #if notyet
 229                         nwfs_attr_cacheremove(vp);
 230                         error = VOP_GETATTR(vp, &vattr);
 231                         if (error) return (error);
 232 #endif
 233                         uiop->uio_offset = np->n_size;
 234                 }
 235         }
 236         if (uiop->uio_resid == 0) return 0;
 237         if (td->td_proc && uiop->uio_offset + uiop->uio_resid >
 238             td->td_proc->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
 239                 lwpsignal(td->td_proc, td->td_lwp, SIGXFSZ);
 240                 return (EFBIG);
 241         }
 242         error = ncp_write(NWFSTOCONN(nmp), &np->n_fh, uiop, cred);
 243         NCPVNDEBUG("after: ofs=%d,resid=%d\n",(int)uiop->uio_offset, uiop->uio_resid);
 244         if (!error) {
 245                 if (uiop->uio_offset > np->n_size) {
 246                         np->n_vattr.va_size = np->n_size = uiop->uio_offset;
 247                         vnode_pager_setsize(vp, np->n_size);
 248                 }
 249         }
 250         return (error);
 251 }
 252
 253 /*
 254  * Do an I/O operation to/from a cache block.
 255  */
 256 int
 257 nwfs_doio(struct vnode *vp, struct bio *bio, struct ucred *cr, struct thread *td)
 258 {
 259         struct buf *bp = bio->bio_buf;
 260         struct uio *uiop;
 261         struct nwnode *np;
 262         struct nwmount *nmp;
 263         int error = 0;
 264         struct uio uio;
 265         struct iovec io;
 266
 267         np = VTONW(vp);
 268         nmp = VFSTONWFS(vp->v_mount);
 269         uiop = &uio;
 270         uiop->uio_iov = &io;
 271         uiop->uio_iovcnt = 1;
 272         uiop->uio_segflg = UIO_SYSSPACE;
 273         uiop->uio_td = td;
 274
 275         if (bp->b_cmd == BUF_CMD_READ) {
 276             io.iov_len = uiop->uio_resid = (size_t)bp->b_bcount;
 277             io.iov_base = bp->b_data;
 278             uiop->uio_rw = UIO_READ;
 279             switch (vp->v_type) {
 280               case VREG:
 281                 uiop->uio_offset = bio->bio_offset;
 282                 error = ncp_read(NWFSTOCONN(nmp), &np->n_fh, uiop, cr);
 283                 if (error)
 284                         break;
 285                 if (uiop->uio_resid) {
 286                         size_t left = uiop->uio_resid;
 287                         size_t nread = bp->b_bcount - left;
 288                         if (left > 0)
 289                                 bzero((char *)bp->b_data + nread, left);
 290                 }
 291                 break;
 292 /*          case VDIR:
 293                 nfsstats.readdir_bios++;
 294                 uiop->uio_offset = bio->bio_offset;
 295                 if (nmp->nm_flag & NFSMNT_RDIRPLUS) {
 296                         error = nfs_readdirplusrpc(vp, uiop, cr);
 297                         if (error == NFSERR_NOTSUPP)
 298                                 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
 299                 }
 300                 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
 301                         error = nfs_readdirrpc(vp, uiop, cr);
 302                 if (error == 0 && uiop->uio_resid == (size_t)bp->b_bcount)
 303                         bp->b_flags |= B_INVAL;
 304                 break;
 305 */
 306             default:
 307                 kprintf("nwfs_doio:  type %x unexpected\n",vp->v_type);
 308                 break;
 309             };
 310             if (error) {
 311                 bp->b_flags |= B_ERROR;
 312                 bp->b_error = error;
 313             }
 314         } else { /* write */
 315             KKASSERT(bp->b_cmd == BUF_CMD_WRITE);
 316             if (bio->bio_offset + bp->b_dirtyend > np->n_size)
 317                 bp->b_dirtyend = np->n_size - bio->bio_offset;
 318
 319             if (bp->b_dirtyend > bp->b_dirtyoff) {
 320                 io.iov_len = uiop->uio_resid =
 321                         (size_t)(bp->b_dirtyend - bp->b_dirtyoff);
 322                 uiop->uio_offset = bio->bio_offset + bp->b_dirtyoff;
 323                 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
 324                 uiop->uio_rw = UIO_WRITE;
 325                 error = ncp_write(NWFSTOCONN(nmp), &np->n_fh, uiop, cr);
 326
 327                 /*
 328                  * For an interrupted write, the buffer is still valid
 329                  * and the write hasn't been pushed to the server yet,
 330                  * so we can't set B_ERROR and report the interruption
 331                  * by setting B_EINTR. For the async case, B_EINTR
 332                  * is not relevant, so the rpc attempt is essentially
 333                  * a noop.  For the case of a V3 write rpc not being
 334                  * committed to stable storage, the block is still
 335                  * dirty and requires either a commit rpc or another
 336                  * write rpc with iomode == NFSV3WRITE_FILESYNC before
 337                  * the block is reused. This is indicated by setting
 338                  * the B_DELWRI and B_NEEDCOMMIT flags.
 339                  */
 340                 if (error == EINTR
 341                     || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
 342
 343                         crit_enter();
 344                         bp->b_flags &= ~(B_INVAL|B_NOCACHE);
 345                         if ((bp->b_flags & B_PAGING) == 0)
 346                             bdirty(bp);
 347                         bp->b_flags |= B_EINTR;
 348                         crit_exit();
 349                 } else {
 350                         if (error) {
 351                                 bp->b_flags |= B_ERROR;
 352                                 bp->b_error /*= np->n_error */= error;
 353 /*                              np->n_flag |= NWRITEERR;*/
 354                         }
 355                         bp->b_dirtyoff = bp->b_dirtyend = 0;
 356                 }
 357             } else {
 358                 bp->b_resid = 0;
 359                 biodone(bio);
 360                 return (0);
 361             }
 362         }
 363         bp->b_resid = (int)uiop->uio_resid;
 364         biodone(bio);
 365         return (error);
 366 }
 367
 368 /*
 369  * Vnode op for VM getpages.
 370  * Wish wish .... get rid from multiple IO routines
 371  *
 372  * nwfs_getpages(struct vnode *a_vp, vm_page_t *a_m, int a_count,
 373  *               int a_reqpage, vm_ooffset_t a_offset)
 374  */
 375 int
 376 nwfs_getpages(struct vop_getpages_args *ap)
 377 {
 378 #ifndef NWFS_RWCACHE
 379         return vnode_pager_generic_getpages(ap->a_vp, ap->a_m, ap->a_count,
 380                 ap->a_reqpage);
 381 #else
 382         int i, error, npages;
 383         size_t nextoff, toff;
 384         size_t count;
 385         size_t size;
 386         struct uio uio;
 387         struct iovec iov;
 388         vm_offset_t kva;
 389         struct buf *bp;
 390         struct vnode *vp;
 391         struct thread *td = curthread;  /* XXX */
 392         struct ucred *cred;
 393         struct nwmount *nmp;
 394         struct nwnode *np;
 395         vm_page_t *pages;
 396
 397         KKASSERT(td->td_proc);
 398         cred = td->td_proc->p_ucred;
 399
 400         vp = ap->a_vp;
 401         np = VTONW(vp);
 402         nmp = VFSTONWFS(vp->v_mount);
 403         pages = ap->a_m;
 404         count = (size_t)ap->a_count;
 405
 406         if (vp->v_object == NULL) {
 407                 kprintf("nwfs_getpages: called with non-merged cache vnode??\n");
 408                 return VM_PAGER_ERROR;
 409         }
 410
 411         bp = getpbuf(&nwfs_pbuf_freecnt);
 412         npages = btoc(count);
 413         kva = (vm_offset_t) bp->b_data;
 414         pmap_qenter(kva, pages, npages);
 415
 416         iov.iov_base = (caddr_t) kva;
 417         iov.iov_len = count;
 418         uio.uio_iov = &iov;
 419         uio.uio_iovcnt = 1;
 420         uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
 421         uio.uio_resid = count;
 422         uio.uio_segflg = UIO_SYSSPACE;
 423         uio.uio_rw = UIO_READ;
 424         uio.uio_td = td;
 425
 426         error = ncp_read(NWFSTOCONN(nmp), &np->n_fh, &uio,cred);
 427         pmap_qremove(kva, npages);
 428
 429         relpbuf(bp, &nwfs_pbuf_freecnt);
 430
 431         if (error && (uio.uio_resid == count)) {
 432                 kprintf("nwfs_getpages: error %d\n",error);
 433                 for (i = 0; i < npages; i++) {
 434                         if (ap->a_reqpage != i)
 435                                 vnode_pager_freepage(pages[i]);
 436                 }
 437                 return VM_PAGER_ERROR;
 438         }
 439
 440         size = count - uio.uio_resid;
 441
 442         for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
 443                 vm_page_t m;
 444                 nextoff = toff + PAGE_SIZE;
 445                 m = pages[i];
 446
 447                 m->flags &= ~PG_ZERO;
 448
 449                 if (nextoff <= size) {
 450                         m->valid = VM_PAGE_BITS_ALL;
 451                         m->dirty = 0;
 452                 } else {
 453                         int nvalid = ((size + DEV_BSIZE - 1) - toff) & ~(DEV_BSIZE - 1);
 454                         vm_page_set_validclean(m, 0, nvalid);
 455                 }
 456
 457                 if (i != ap->a_reqpage) {
 458                         /*
 459                          * Whether or not to leave the page activated is up in
 460                          * the air, but we should put the page on a page queue
 461                          * somewhere (it already is in the object).  Result:
 462                          * It appears that emperical results show that
 463                          * deactivating pages is best.
 464                          */
 465
 466                         /*
 467                          * Just in case someone was asking for this page we
 468                          * now tell them that it is ok to use.
 469                          */
 470                         if (!error) {
 471                                 if (m->flags & PG_WANTED)
 472                                         vm_page_activate(m);
 473                                 else
 474                                         vm_page_deactivate(m);
 475                                 vm_page_wakeup(m);
 476                         } else {
 477                                 vnode_pager_freepage(m);
 478                         }
 479                 }
 480         }
 481         return 0;
 482 #endif /* NWFS_RWCACHE */
 483 }
 484
 485 /*
 486  * Vnode op for VM putpages.
 487  * possible bug: all IO done in sync mode
 488  * Note that vop_close always invalidate pages before close, so it's
 489  * not necessary to open vnode.
 490  *
 491  * nwfs_putpages(struct vnode *a_vp, vm_page_t *a_m, int a_count,
 492  *               int a_sync, int *a_rtvals, vm_ooffset_t a_offset)
 493  */
 494 int
 495 nwfs_putpages(struct vop_putpages_args *ap)
 496 {
 497         int error;
 498         struct thread *td = curthread;  /* XXX */
 499         struct vnode *vp = ap->a_vp;
 500         struct ucred *cred;
 501
 502 #ifndef NWFS_RWCACHE
 503         KKASSERT(td->td_proc);
 504         cred = td->td_proc->p_ucred;            /* XXX */
 505         VOP_OPEN(vp, FWRITE, cred, NULL);
 506         error = vnode_pager_generic_putpages(ap->a_vp, ap->a_m, ap->a_count,
 507                 ap->a_sync, ap->a_rtvals);
 508         VOP_CLOSE(vp, FWRITE, cred);
 509         return error;
 510 #else
 511         struct uio uio;
 512         struct iovec iov;
 513         vm_offset_t kva;
 514         struct buf *bp;
 515         int i, npages, count;
 516         int *rtvals;
 517         struct nwmount *nmp;
 518         struct nwnode *np;
 519         vm_page_t *pages;
 520
 521         KKASSERT(td->td_proc);
 522         cred = td->td_proc->p_ucred;            /* XXX */
 523
 524 /*      VOP_OPEN(vp, FWRITE, cred, NULL);*/
 525         np = VTONW(vp);
 526         nmp = VFSTONWFS(vp->v_mount);
 527         pages = ap->a_m;
 528         count = ap->a_count;
 529         rtvals = ap->a_rtvals;
 530         npages = btoc(count);
 531
 532         for (i = 0; i < npages; i++) {
 533                 rtvals[i] = VM_PAGER_AGAIN;
 534         }
 535
 536         bp = getpbuf(&nwfs_pbuf_freecnt);
 537         kva = (vm_offset_t) bp->b_data;
 538         pmap_qenter(kva, pages, npages);
 539
 540         iov.iov_base = (caddr_t) kva;
 541         iov.iov_len = count;
 542         uio.uio_iov = &iov;
 543         uio.uio_iovcnt = 1;
 544         uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
 545         uio.uio_resid = count;
 546         uio.uio_segflg = UIO_SYSSPACE;
 547         uio.uio_rw = UIO_WRITE;
 548         uio.uio_td = td;
 549         NCPVNDEBUG("ofs=%d,resid=%d\n",(int)uio.uio_offset, uio.uio_resid);
 550
 551         error = ncp_write(NWFSTOCONN(nmp), &np->n_fh, &uio, cred);
 552 /*      VOP_CLOSE(vp, FWRITE, cred);*/
 553         NCPVNDEBUG("paged write done: %d\n", error);
 554
 555         pmap_qremove(kva, npages);
 556         relpbuf(bp, &nwfs_pbuf_freecnt);
 557
 558         if (!error) {
 559                 int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE;
 560                 for (i = 0; i < nwritten; i++) {
 561                         rtvals[i] = VM_PAGER_OK;
 562                         pages[i]->dirty = 0;
 563                 }
 564         }
 565         return rtvals[0];
 566 #endif /* NWFS_RWCACHE */
 567 }
 568 /*
 569  * Flush and invalidate all dirty buffers. If another process is already
 570  * doing the flush, just wait for completion.
 571  */
 572 int
 573 nwfs_vinvalbuf(struct vnode *vp, int flags, int intrflg)
 574 {
 575         struct nwnode *np = VTONW(vp);
 576 /*      struct nwmount *nmp = VTONWFS(vp);*/
 577         int error = 0, slpflag, slptimeo;
 578
 579         if (vp->v_flag & VRECLAIMED) {
 580                 return (0);
 581         }
 582         if (intrflg) {
 583                 slpflag = PCATCH;
 584                 slptimeo = 2 * hz;
 585         } else {
 586                 slpflag = 0;
 587                 slptimeo = 0;
 588         }
 589         while (np->n_flag & NFLUSHINPROG) {
 590                 np->n_flag |= NFLUSHWANT;
 591                 error = tsleep((caddr_t)&np->n_flag, 0, "nwfsvinv", slptimeo);
 592                 error = ncp_chkintr(NWFSTOCONN(VTONWFS(vp)), curthread);
 593                 if (error == EINTR && intrflg)
 594                         return EINTR;
 595         }
 596         np->n_flag |= NFLUSHINPROG;
 597         error = vinvalbuf(vp, flags, slpflag, 0);
 598         while (error) {
 599                 if (intrflg && (error == ERESTART || error == EINTR)) {
 600                         np->n_flag &= ~NFLUSHINPROG;
 601                         if (np->n_flag & NFLUSHWANT) {
 602                                 np->n_flag &= ~NFLUSHWANT;
 603                                 wakeup((caddr_t)&np->n_flag);
 604                         }
 605                         return EINTR;
 606                 }
 607                 error = vinvalbuf(vp, flags, slpflag, 0);
 608         }
 609         np->n_flag &= ~(NMODIFIED | NFLUSHINPROG);
 610         if (np->n_flag & NFLUSHWANT) {
 611                 np->n_flag &= ~NFLUSHWANT;
 612                 wakeup((caddr_t)&np->n_flag);
 613         }
 614         return (error);
 615 }