The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/fs/nfsclient/nfs_clbio.c

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    1 /*-
    2  * Copyright (c) 1989, 1993
    3  *      The Regents of the University of California.  All rights reserved.
    4  *
    5  * This code is derived from software contributed to Berkeley by
    6  * Rick Macklem at The University of Guelph.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  * 4. Neither the name of the University nor the names of its 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 REGENTS 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 REGENTS 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  *      @(#)nfs_bio.c   8.9 (Berkeley) 3/30/95
   33  */
   34 
   35 #include <sys/cdefs.h>
   36 __FBSDID("$FreeBSD: releng/11.1/sys/fs/nfsclient/nfs_clbio.c 317134 2017-04-19 11:13:32Z kib $");
   37 
   38 #include <sys/param.h>
   39 #include <sys/systm.h>
   40 #include <sys/bio.h>
   41 #include <sys/buf.h>
   42 #include <sys/kernel.h>
   43 #include <sys/mount.h>
   44 #include <sys/rwlock.h>
   45 #include <sys/vmmeter.h>
   46 #include <sys/vnode.h>
   47 
   48 #include <vm/vm.h>
   49 #include <vm/vm_param.h>
   50 #include <vm/vm_extern.h>
   51 #include <vm/vm_page.h>
   52 #include <vm/vm_object.h>
   53 #include <vm/vm_pager.h>
   54 #include <vm/vnode_pager.h>
   55 
   56 #include <fs/nfs/nfsport.h>
   57 #include <fs/nfsclient/nfsmount.h>
   58 #include <fs/nfsclient/nfs.h>
   59 #include <fs/nfsclient/nfsnode.h>
   60 #include <fs/nfsclient/nfs_kdtrace.h>
   61 
   62 extern int newnfs_directio_allow_mmap;
   63 extern struct nfsstatsv1 nfsstatsv1;
   64 extern struct mtx ncl_iod_mutex;
   65 extern int ncl_numasync;
   66 extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON];
   67 extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON];
   68 extern int newnfs_directio_enable;
   69 extern int nfs_keep_dirty_on_error;
   70 
   71 int ncl_pbuf_freecnt = -1;      /* start out unlimited */
   72 
   73 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
   74     struct thread *td);
   75 static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
   76     struct ucred *cred, int ioflag);
   77 
   78 /*
   79  * Vnode op for VM getpages.
   80  */
   81 SYSCTL_DECL(_vfs_nfs);
   82 static int use_buf_pager = 0;
   83 SYSCTL_INT(_vfs_nfs, OID_AUTO, use_buf_pager, CTLFLAG_RWTUN,
   84     &use_buf_pager, 0,
   85     "Use buffer pager instead of direct readrpc call");
   86 
   87 static daddr_t
   88 ncl_gbp_getblkno(struct vnode *vp, vm_ooffset_t off)
   89 {
   90 
   91         return (off / vp->v_bufobj.bo_bsize);
   92 }
   93 
   94 static int
   95 ncl_gbp_getblksz(struct vnode *vp, daddr_t lbn)
   96 {
   97         struct nfsnode *np;
   98         u_quad_t nsize;
   99         int biosize, bcount;
  100 
  101         np = VTONFS(vp);
  102         mtx_lock(&np->n_mtx);
  103         nsize = np->n_size;
  104         mtx_unlock(&np->n_mtx);
  105 
  106         biosize = vp->v_bufobj.bo_bsize;
  107         bcount = biosize;
  108         if ((off_t)lbn * biosize >= nsize)
  109                 bcount = 0;
  110         else if ((off_t)(lbn + 1) * biosize > nsize)
  111                 bcount = nsize - (off_t)lbn * biosize;
  112         return (bcount);
  113 }
  114 
  115 int
  116 ncl_getpages(struct vop_getpages_args *ap)
  117 {
  118         int i, error, nextoff, size, toff, count, npages;
  119         struct uio uio;
  120         struct iovec iov;
  121         vm_offset_t kva;
  122         struct buf *bp;
  123         struct vnode *vp;
  124         struct thread *td;
  125         struct ucred *cred;
  126         struct nfsmount *nmp;
  127         vm_object_t object;
  128         vm_page_t *pages;
  129         struct nfsnode *np;
  130 
  131         vp = ap->a_vp;
  132         np = VTONFS(vp);
  133         td = curthread;
  134         cred = curthread->td_ucred;
  135         nmp = VFSTONFS(vp->v_mount);
  136         pages = ap->a_m;
  137         npages = ap->a_count;
  138 
  139         if ((object = vp->v_object) == NULL) {
  140                 printf("ncl_getpages: called with non-merged cache vnode\n");
  141                 return (VM_PAGER_ERROR);
  142         }
  143 
  144         if (newnfs_directio_enable && !newnfs_directio_allow_mmap) {
  145                 mtx_lock(&np->n_mtx);
  146                 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
  147                         mtx_unlock(&np->n_mtx);
  148                         printf("ncl_getpages: called on non-cacheable vnode\n");
  149                         return (VM_PAGER_ERROR);
  150                 } else
  151                         mtx_unlock(&np->n_mtx);
  152         }
  153 
  154         mtx_lock(&nmp->nm_mtx);
  155         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  156             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  157                 mtx_unlock(&nmp->nm_mtx);
  158                 /* We'll never get here for v4, because we always have fsinfo */
  159                 (void)ncl_fsinfo(nmp, vp, cred, td);
  160         } else
  161                 mtx_unlock(&nmp->nm_mtx);
  162 
  163         if (use_buf_pager)
  164                 return (vfs_bio_getpages(vp, pages, npages, ap->a_rbehind,
  165                     ap->a_rahead, ncl_gbp_getblkno, ncl_gbp_getblksz));
  166 
  167         /*
  168          * If the requested page is partially valid, just return it and
  169          * allow the pager to zero-out the blanks.  Partially valid pages
  170          * can only occur at the file EOF.
  171          *
  172          * XXXGL: is that true for NFS, where short read can occur???
  173          */
  174         VM_OBJECT_WLOCK(object);
  175         if (pages[npages - 1]->valid != 0 && --npages == 0)
  176                 goto out;
  177         VM_OBJECT_WUNLOCK(object);
  178 
  179         /*
  180          * We use only the kva address for the buffer, but this is extremely
  181          * convenient and fast.
  182          */
  183         bp = getpbuf(&ncl_pbuf_freecnt);
  184 
  185         kva = (vm_offset_t) bp->b_data;
  186         pmap_qenter(kva, pages, npages);
  187         PCPU_INC(cnt.v_vnodein);
  188         PCPU_ADD(cnt.v_vnodepgsin, npages);
  189 
  190         count = npages << PAGE_SHIFT;
  191         iov.iov_base = (caddr_t) kva;
  192         iov.iov_len = count;
  193         uio.uio_iov = &iov;
  194         uio.uio_iovcnt = 1;
  195         uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
  196         uio.uio_resid = count;
  197         uio.uio_segflg = UIO_SYSSPACE;
  198         uio.uio_rw = UIO_READ;
  199         uio.uio_td = td;
  200 
  201         error = ncl_readrpc(vp, &uio, cred);
  202         pmap_qremove(kva, npages);
  203 
  204         relpbuf(bp, &ncl_pbuf_freecnt);
  205 
  206         if (error && (uio.uio_resid == count)) {
  207                 printf("ncl_getpages: error %d\n", error);
  208                 return (VM_PAGER_ERROR);
  209         }
  210 
  211         /*
  212          * Calculate the number of bytes read and validate only that number
  213          * of bytes.  Note that due to pending writes, size may be 0.  This
  214          * does not mean that the remaining data is invalid!
  215          */
  216 
  217         size = count - uio.uio_resid;
  218         VM_OBJECT_WLOCK(object);
  219         for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
  220                 vm_page_t m;
  221                 nextoff = toff + PAGE_SIZE;
  222                 m = pages[i];
  223 
  224                 if (nextoff <= size) {
  225                         /*
  226                          * Read operation filled an entire page
  227                          */
  228                         m->valid = VM_PAGE_BITS_ALL;
  229                         KASSERT(m->dirty == 0,
  230                             ("nfs_getpages: page %p is dirty", m));
  231                 } else if (size > toff) {
  232                         /*
  233                          * Read operation filled a partial page.
  234                          */
  235                         m->valid = 0;
  236                         vm_page_set_valid_range(m, 0, size - toff);
  237                         KASSERT(m->dirty == 0,
  238                             ("nfs_getpages: page %p is dirty", m));
  239                 } else {
  240                         /*
  241                          * Read operation was short.  If no error
  242                          * occurred we may have hit a zero-fill
  243                          * section.  We leave valid set to 0, and page
  244                          * is freed by vm_page_readahead_finish() if
  245                          * its index is not equal to requested, or
  246                          * page is zeroed and set valid by
  247                          * vm_pager_get_pages() for requested page.
  248                          */
  249                         ;
  250                 }
  251         }
  252 out:
  253         VM_OBJECT_WUNLOCK(object);
  254         if (ap->a_rbehind)
  255                 *ap->a_rbehind = 0;
  256         if (ap->a_rahead)
  257                 *ap->a_rahead = 0;
  258         return (VM_PAGER_OK);
  259 }
  260 
  261 /*
  262  * Vnode op for VM putpages.
  263  */
  264 int
  265 ncl_putpages(struct vop_putpages_args *ap)
  266 {
  267         struct uio uio;
  268         struct iovec iov;
  269         int i, error, npages, count;
  270         off_t offset;
  271         int *rtvals;
  272         struct vnode *vp;
  273         struct thread *td;
  274         struct ucred *cred;
  275         struct nfsmount *nmp;
  276         struct nfsnode *np;
  277         vm_page_t *pages;
  278 
  279         vp = ap->a_vp;
  280         np = VTONFS(vp);
  281         td = curthread;                         /* XXX */
  282         /* Set the cred to n_writecred for the write rpcs. */
  283         if (np->n_writecred != NULL)
  284                 cred = crhold(np->n_writecred);
  285         else
  286                 cred = crhold(curthread->td_ucred);     /* XXX */
  287         nmp = VFSTONFS(vp->v_mount);
  288         pages = ap->a_m;
  289         count = ap->a_count;
  290         rtvals = ap->a_rtvals;
  291         npages = btoc(count);
  292         offset = IDX_TO_OFF(pages[0]->pindex);
  293 
  294         mtx_lock(&nmp->nm_mtx);
  295         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  296             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  297                 mtx_unlock(&nmp->nm_mtx);
  298                 (void)ncl_fsinfo(nmp, vp, cred, td);
  299         } else
  300                 mtx_unlock(&nmp->nm_mtx);
  301 
  302         mtx_lock(&np->n_mtx);
  303         if (newnfs_directio_enable && !newnfs_directio_allow_mmap &&
  304             (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
  305                 mtx_unlock(&np->n_mtx);
  306                 printf("ncl_putpages: called on noncache-able vnode\n");
  307                 mtx_lock(&np->n_mtx);
  308         }
  309 
  310         for (i = 0; i < npages; i++)
  311                 rtvals[i] = VM_PAGER_ERROR;
  312 
  313         /*
  314          * When putting pages, do not extend file past EOF.
  315          */
  316         if (offset + count > np->n_size) {
  317                 count = np->n_size - offset;
  318                 if (count < 0)
  319                         count = 0;
  320         }
  321         mtx_unlock(&np->n_mtx);
  322 
  323         PCPU_INC(cnt.v_vnodeout);
  324         PCPU_ADD(cnt.v_vnodepgsout, count);
  325 
  326         iov.iov_base = unmapped_buf;
  327         iov.iov_len = count;
  328         uio.uio_iov = &iov;
  329         uio.uio_iovcnt = 1;
  330         uio.uio_offset = offset;
  331         uio.uio_resid = count;
  332         uio.uio_segflg = UIO_NOCOPY;
  333         uio.uio_rw = UIO_WRITE;
  334         uio.uio_td = td;
  335 
  336         error = VOP_WRITE(vp, &uio, vnode_pager_putpages_ioflags(ap->a_sync),
  337             cred);
  338         crfree(cred);
  339 
  340         if (error == 0 || !nfs_keep_dirty_on_error)
  341                 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid);
  342         return (rtvals[0]);
  343 }
  344 
  345 /*
  346  * For nfs, cache consistency can only be maintained approximately.
  347  * Although RFC1094 does not specify the criteria, the following is
  348  * believed to be compatible with the reference port.
  349  * For nfs:
  350  * If the file's modify time on the server has changed since the
  351  * last read rpc or you have written to the file,
  352  * you may have lost data cache consistency with the
  353  * server, so flush all of the file's data out of the cache.
  354  * Then force a getattr rpc to ensure that you have up to date
  355  * attributes.
  356  * NB: This implies that cache data can be read when up to
  357  * NFS_ATTRTIMEO seconds out of date. If you find that you need current
  358  * attributes this could be forced by setting n_attrstamp to 0 before
  359  * the VOP_GETATTR() call.
  360  */
  361 static inline int
  362 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
  363 {
  364         int error = 0;
  365         struct vattr vattr;
  366         struct nfsnode *np = VTONFS(vp);
  367         int old_lock;
  368 
  369         /*
  370          * Grab the exclusive lock before checking whether the cache is
  371          * consistent.
  372          * XXX - We can make this cheaper later (by acquiring cheaper locks).
  373          * But for now, this suffices.
  374          */
  375         old_lock = ncl_upgrade_vnlock(vp);
  376         if (vp->v_iflag & VI_DOOMED) {
  377                 error = EBADF;
  378                 goto out;
  379         }
  380 
  381         mtx_lock(&np->n_mtx);
  382         if (np->n_flag & NMODIFIED) {
  383                 mtx_unlock(&np->n_mtx);
  384                 if (vp->v_type != VREG) {
  385                         if (vp->v_type != VDIR)
  386                                 panic("nfs: bioread, not dir");
  387                         ncl_invaldir(vp);
  388                         error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
  389                         if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
  390                                 error = EBADF;
  391                         if (error != 0)
  392                                 goto out;
  393                 }
  394                 np->n_attrstamp = 0;
  395                 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
  396                 error = VOP_GETATTR(vp, &vattr, cred);
  397                 if (error)
  398                         goto out;
  399                 mtx_lock(&np->n_mtx);
  400                 np->n_mtime = vattr.va_mtime;
  401                 mtx_unlock(&np->n_mtx);
  402         } else {
  403                 mtx_unlock(&np->n_mtx);
  404                 error = VOP_GETATTR(vp, &vattr, cred);
  405                 if (error)
  406                         return (error);
  407                 mtx_lock(&np->n_mtx);
  408                 if ((np->n_flag & NSIZECHANGED)
  409                     || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
  410                         mtx_unlock(&np->n_mtx);
  411                         if (vp->v_type == VDIR)
  412                                 ncl_invaldir(vp);
  413                         error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
  414                         if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
  415                                 error = EBADF;
  416                         if (error != 0)
  417                                 goto out;
  418                         mtx_lock(&np->n_mtx);
  419                         np->n_mtime = vattr.va_mtime;
  420                         np->n_flag &= ~NSIZECHANGED;
  421                 }
  422                 mtx_unlock(&np->n_mtx);
  423         }
  424 out:
  425         ncl_downgrade_vnlock(vp, old_lock);
  426         return (error);
  427 }
  428 
  429 /*
  430  * Vnode op for read using bio
  431  */
  432 int
  433 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
  434 {
  435         struct nfsnode *np = VTONFS(vp);
  436         int biosize, i;
  437         struct buf *bp, *rabp;
  438         struct thread *td;
  439         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
  440         daddr_t lbn, rabn;
  441         int bcount;
  442         int seqcount;
  443         int nra, error = 0, n = 0, on = 0;
  444         off_t tmp_off;
  445 
  446         KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode"));
  447         if (uio->uio_resid == 0)
  448                 return (0);
  449         if (uio->uio_offset < 0)        /* XXX VDIR cookies can be negative */
  450                 return (EINVAL);
  451         td = uio->uio_td;
  452 
  453         mtx_lock(&nmp->nm_mtx);
  454         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  455             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  456                 mtx_unlock(&nmp->nm_mtx);
  457                 (void)ncl_fsinfo(nmp, vp, cred, td);
  458                 mtx_lock(&nmp->nm_mtx);
  459         }
  460         if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0)
  461                 (void) newnfs_iosize(nmp);
  462 
  463         tmp_off = uio->uio_offset + uio->uio_resid;
  464         if (vp->v_type != VDIR &&
  465             (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) {
  466                 mtx_unlock(&nmp->nm_mtx);
  467                 return (EFBIG);
  468         }
  469         mtx_unlock(&nmp->nm_mtx);
  470 
  471         if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
  472                 /* No caching/ no readaheads. Just read data into the user buffer */
  473                 return ncl_readrpc(vp, uio, cred);
  474 
  475         biosize = vp->v_bufobj.bo_bsize;
  476         seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
  477 
  478         error = nfs_bioread_check_cons(vp, td, cred);
  479         if (error)
  480                 return error;
  481 
  482         do {
  483             u_quad_t nsize;
  484 
  485             mtx_lock(&np->n_mtx);
  486             nsize = np->n_size;
  487             mtx_unlock(&np->n_mtx);
  488 
  489             switch (vp->v_type) {
  490             case VREG:
  491                 NFSINCRGLOBAL(nfsstatsv1.biocache_reads);
  492                 lbn = uio->uio_offset / biosize;
  493                 on = uio->uio_offset - (lbn * biosize);
  494 
  495                 /*
  496                  * Start the read ahead(s), as required.
  497                  */
  498                 if (nmp->nm_readahead > 0) {
  499                     for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
  500                         (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
  501                         rabn = lbn + 1 + nra;
  502                         if (incore(&vp->v_bufobj, rabn) == NULL) {
  503                             rabp = nfs_getcacheblk(vp, rabn, biosize, td);
  504                             if (!rabp) {
  505                                 error = newnfs_sigintr(nmp, td);
  506                                 return (error ? error : EINTR);
  507                             }
  508                             if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
  509                                 rabp->b_flags |= B_ASYNC;
  510                                 rabp->b_iocmd = BIO_READ;
  511                                 vfs_busy_pages(rabp, 0);
  512                                 if (ncl_asyncio(nmp, rabp, cred, td)) {
  513                                     rabp->b_flags |= B_INVAL;
  514                                     rabp->b_ioflags |= BIO_ERROR;
  515                                     vfs_unbusy_pages(rabp);
  516                                     brelse(rabp);
  517                                     break;
  518                                 }
  519                             } else {
  520                                 brelse(rabp);
  521                             }
  522                         }
  523                     }
  524                 }
  525 
  526                 /* Note that bcount is *not* DEV_BSIZE aligned. */
  527                 bcount = biosize;
  528                 if ((off_t)lbn * biosize >= nsize) {
  529                         bcount = 0;
  530                 } else if ((off_t)(lbn + 1) * biosize > nsize) {
  531                         bcount = nsize - (off_t)lbn * biosize;
  532                 }
  533                 bp = nfs_getcacheblk(vp, lbn, bcount, td);
  534 
  535                 if (!bp) {
  536                         error = newnfs_sigintr(nmp, td);
  537                         return (error ? error : EINTR);
  538                 }
  539 
  540                 /*
  541                  * If B_CACHE is not set, we must issue the read.  If this
  542                  * fails, we return an error.
  543                  */
  544 
  545                 if ((bp->b_flags & B_CACHE) == 0) {
  546                     bp->b_iocmd = BIO_READ;
  547                     vfs_busy_pages(bp, 0);
  548                     error = ncl_doio(vp, bp, cred, td, 0);
  549                     if (error) {
  550                         brelse(bp);
  551                         return (error);
  552                     }
  553                 }
  554 
  555                 /*
  556                  * on is the offset into the current bp.  Figure out how many
  557                  * bytes we can copy out of the bp.  Note that bcount is
  558                  * NOT DEV_BSIZE aligned.
  559                  *
  560                  * Then figure out how many bytes we can copy into the uio.
  561                  */
  562 
  563                 n = 0;
  564                 if (on < bcount)
  565                         n = MIN((unsigned)(bcount - on), uio->uio_resid);
  566                 break;
  567             case VLNK:
  568                 NFSINCRGLOBAL(nfsstatsv1.biocache_readlinks);
  569                 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
  570                 if (!bp) {
  571                         error = newnfs_sigintr(nmp, td);
  572                         return (error ? error : EINTR);
  573                 }
  574                 if ((bp->b_flags & B_CACHE) == 0) {
  575                     bp->b_iocmd = BIO_READ;
  576                     vfs_busy_pages(bp, 0);
  577                     error = ncl_doio(vp, bp, cred, td, 0);
  578                     if (error) {
  579                         bp->b_ioflags |= BIO_ERROR;
  580                         brelse(bp);
  581                         return (error);
  582                     }
  583                 }
  584                 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
  585                 on = 0;
  586                 break;
  587             case VDIR:
  588                 NFSINCRGLOBAL(nfsstatsv1.biocache_readdirs);
  589                 if (np->n_direofoffset
  590                     && uio->uio_offset >= np->n_direofoffset) {
  591                     return (0);
  592                 }
  593                 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
  594                 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
  595                 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
  596                 if (!bp) {
  597                     error = newnfs_sigintr(nmp, td);
  598                     return (error ? error : EINTR);
  599                 }
  600                 if ((bp->b_flags & B_CACHE) == 0) {
  601                     bp->b_iocmd = BIO_READ;
  602                     vfs_busy_pages(bp, 0);
  603                     error = ncl_doio(vp, bp, cred, td, 0);
  604                     if (error) {
  605                             brelse(bp);
  606                     }
  607                     while (error == NFSERR_BAD_COOKIE) {
  608                         ncl_invaldir(vp);
  609                         error = ncl_vinvalbuf(vp, 0, td, 1);
  610                         if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
  611                                 return (EBADF);
  612 
  613                         /*
  614                          * Yuck! The directory has been modified on the
  615                          * server. The only way to get the block is by
  616                          * reading from the beginning to get all the
  617                          * offset cookies.
  618                          *
  619                          * Leave the last bp intact unless there is an error.
  620                          * Loop back up to the while if the error is another
  621                          * NFSERR_BAD_COOKIE (double yuch!).
  622                          */
  623                         for (i = 0; i <= lbn && !error; i++) {
  624                             if (np->n_direofoffset
  625                                 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
  626                                     return (0);
  627                             bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
  628                             if (!bp) {
  629                                 error = newnfs_sigintr(nmp, td);
  630                                 return (error ? error : EINTR);
  631                             }
  632                             if ((bp->b_flags & B_CACHE) == 0) {
  633                                     bp->b_iocmd = BIO_READ;
  634                                     vfs_busy_pages(bp, 0);
  635                                     error = ncl_doio(vp, bp, cred, td, 0);
  636                                     /*
  637                                      * no error + B_INVAL == directory EOF,
  638                                      * use the block.
  639                                      */
  640                                     if (error == 0 && (bp->b_flags & B_INVAL))
  641                                             break;
  642                             }
  643                             /*
  644                              * An error will throw away the block and the
  645                              * for loop will break out.  If no error and this
  646                              * is not the block we want, we throw away the
  647                              * block and go for the next one via the for loop.
  648                              */
  649                             if (error || i < lbn)
  650                                     brelse(bp);
  651                         }
  652                     }
  653                     /*
  654                      * The above while is repeated if we hit another cookie
  655                      * error.  If we hit an error and it wasn't a cookie error,
  656                      * we give up.
  657                      */
  658                     if (error)
  659                             return (error);
  660                 }
  661 
  662                 /*
  663                  * If not eof and read aheads are enabled, start one.
  664                  * (You need the current block first, so that you have the
  665                  *  directory offset cookie of the next block.)
  666                  */
  667                 if (nmp->nm_readahead > 0 &&
  668                     (bp->b_flags & B_INVAL) == 0 &&
  669                     (np->n_direofoffset == 0 ||
  670                     (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
  671                     incore(&vp->v_bufobj, lbn + 1) == NULL) {
  672                         rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
  673                         if (rabp) {
  674                             if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
  675                                 rabp->b_flags |= B_ASYNC;
  676                                 rabp->b_iocmd = BIO_READ;
  677                                 vfs_busy_pages(rabp, 0);
  678                                 if (ncl_asyncio(nmp, rabp, cred, td)) {
  679                                     rabp->b_flags |= B_INVAL;
  680                                     rabp->b_ioflags |= BIO_ERROR;
  681                                     vfs_unbusy_pages(rabp);
  682                                     brelse(rabp);
  683                                 }
  684                             } else {
  685                                 brelse(rabp);
  686                             }
  687                         }
  688                 }
  689                 /*
  690                  * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
  691                  * chopped for the EOF condition, we cannot tell how large
  692                  * NFS directories are going to be until we hit EOF.  So
  693                  * an NFS directory buffer is *not* chopped to its EOF.  Now,
  694                  * it just so happens that b_resid will effectively chop it
  695                  * to EOF.  *BUT* this information is lost if the buffer goes
  696                  * away and is reconstituted into a B_CACHE state ( due to
  697                  * being VMIO ) later.  So we keep track of the directory eof
  698                  * in np->n_direofoffset and chop it off as an extra step
  699                  * right here.
  700                  */
  701                 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
  702                 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
  703                         n = np->n_direofoffset - uio->uio_offset;
  704                 break;
  705             default:
  706                 printf(" ncl_bioread: type %x unexpected\n", vp->v_type);
  707                 bp = NULL;
  708                 break;
  709             }
  710 
  711             if (n > 0) {
  712                     error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio);
  713             }
  714             if (vp->v_type == VLNK)
  715                 n = 0;
  716             if (bp != NULL)
  717                 brelse(bp);
  718         } while (error == 0 && uio->uio_resid > 0 && n > 0);
  719         return (error);
  720 }
  721 
  722 /*
  723  * The NFS write path cannot handle iovecs with len > 1. So we need to
  724  * break up iovecs accordingly (restricting them to wsize).
  725  * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
  726  * For the ASYNC case, 2 copies are needed. The first a copy from the
  727  * user buffer to a staging buffer and then a second copy from the staging
  728  * buffer to mbufs. This can be optimized by copying from the user buffer
  729  * directly into mbufs and passing the chain down, but that requires a
  730  * fair amount of re-working of the relevant codepaths (and can be done
  731  * later).
  732  */
  733 static int
  734 nfs_directio_write(vp, uiop, cred, ioflag)
  735         struct vnode *vp;
  736         struct uio *uiop;
  737         struct ucred *cred;
  738         int ioflag;
  739 {
  740         int error;
  741         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
  742         struct thread *td = uiop->uio_td;
  743         int size;
  744         int wsize;
  745 
  746         mtx_lock(&nmp->nm_mtx);
  747         wsize = nmp->nm_wsize;
  748         mtx_unlock(&nmp->nm_mtx);
  749         if (ioflag & IO_SYNC) {
  750                 int iomode, must_commit;
  751                 struct uio uio;
  752                 struct iovec iov;
  753 do_sync:
  754                 while (uiop->uio_resid > 0) {
  755                         size = MIN(uiop->uio_resid, wsize);
  756                         size = MIN(uiop->uio_iov->iov_len, size);
  757                         iov.iov_base = uiop->uio_iov->iov_base;
  758                         iov.iov_len = size;
  759                         uio.uio_iov = &iov;
  760                         uio.uio_iovcnt = 1;
  761                         uio.uio_offset = uiop->uio_offset;
  762                         uio.uio_resid = size;
  763                         uio.uio_segflg = UIO_USERSPACE;
  764                         uio.uio_rw = UIO_WRITE;
  765                         uio.uio_td = td;
  766                         iomode = NFSWRITE_FILESYNC;
  767                         error = ncl_writerpc(vp, &uio, cred, &iomode,
  768                             &must_commit, 0);
  769                         KASSERT((must_commit == 0),
  770                                 ("ncl_directio_write: Did not commit write"));
  771                         if (error)
  772                                 return (error);
  773                         uiop->uio_offset += size;
  774                         uiop->uio_resid -= size;
  775                         if (uiop->uio_iov->iov_len <= size) {
  776                                 uiop->uio_iovcnt--;
  777                                 uiop->uio_iov++;
  778                         } else {
  779                                 uiop->uio_iov->iov_base =
  780                                         (char *)uiop->uio_iov->iov_base + size;
  781                                 uiop->uio_iov->iov_len -= size;
  782                         }
  783                 }
  784         } else {
  785                 struct uio *t_uio;
  786                 struct iovec *t_iov;
  787                 struct buf *bp;
  788 
  789                 /*
  790                  * Break up the write into blocksize chunks and hand these
  791                  * over to nfsiod's for write back.
  792                  * Unfortunately, this incurs a copy of the data. Since
  793                  * the user could modify the buffer before the write is
  794                  * initiated.
  795                  *
  796                  * The obvious optimization here is that one of the 2 copies
  797                  * in the async write path can be eliminated by copying the
  798                  * data here directly into mbufs and passing the mbuf chain
  799                  * down. But that will require a fair amount of re-working
  800                  * of the code and can be done if there's enough interest
  801                  * in NFS directio access.
  802                  */
  803                 while (uiop->uio_resid > 0) {
  804                         size = MIN(uiop->uio_resid, wsize);
  805                         size = MIN(uiop->uio_iov->iov_len, size);
  806                         bp = getpbuf(&ncl_pbuf_freecnt);
  807                         t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
  808                         t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
  809                         t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
  810                         t_iov->iov_len = size;
  811                         t_uio->uio_iov = t_iov;
  812                         t_uio->uio_iovcnt = 1;
  813                         t_uio->uio_offset = uiop->uio_offset;
  814                         t_uio->uio_resid = size;
  815                         t_uio->uio_segflg = UIO_SYSSPACE;
  816                         t_uio->uio_rw = UIO_WRITE;
  817                         t_uio->uio_td = td;
  818                         KASSERT(uiop->uio_segflg == UIO_USERSPACE ||
  819                             uiop->uio_segflg == UIO_SYSSPACE,
  820                             ("nfs_directio_write: Bad uio_segflg"));
  821                         if (uiop->uio_segflg == UIO_USERSPACE) {
  822                                 error = copyin(uiop->uio_iov->iov_base,
  823                                     t_iov->iov_base, size);
  824                                 if (error != 0)
  825                                         goto err_free;
  826                         } else
  827                                 /*
  828                                  * UIO_SYSSPACE may never happen, but handle
  829                                  * it just in case it does.
  830                                  */
  831                                 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base,
  832                                     size);
  833                         bp->b_flags |= B_DIRECT;
  834                         bp->b_iocmd = BIO_WRITE;
  835                         if (cred != NOCRED) {
  836                                 crhold(cred);
  837                                 bp->b_wcred = cred;
  838                         } else
  839                                 bp->b_wcred = NOCRED;
  840                         bp->b_caller1 = (void *)t_uio;
  841                         bp->b_vp = vp;
  842                         error = ncl_asyncio(nmp, bp, NOCRED, td);
  843 err_free:
  844                         if (error) {
  845                                 free(t_iov->iov_base, M_NFSDIRECTIO);
  846                                 free(t_iov, M_NFSDIRECTIO);
  847                                 free(t_uio, M_NFSDIRECTIO);
  848                                 bp->b_vp = NULL;
  849                                 relpbuf(bp, &ncl_pbuf_freecnt);
  850                                 if (error == EINTR)
  851                                         return (error);
  852                                 goto do_sync;
  853                         }
  854                         uiop->uio_offset += size;
  855                         uiop->uio_resid -= size;
  856                         if (uiop->uio_iov->iov_len <= size) {
  857                                 uiop->uio_iovcnt--;
  858                                 uiop->uio_iov++;
  859                         } else {
  860                                 uiop->uio_iov->iov_base =
  861                                         (char *)uiop->uio_iov->iov_base + size;
  862                                 uiop->uio_iov->iov_len -= size;
  863                         }
  864                 }
  865         }
  866         return (0);
  867 }
  868 
  869 /*
  870  * Vnode op for write using bio
  871  */
  872 int
  873 ncl_write(struct vop_write_args *ap)
  874 {
  875         int biosize;
  876         struct uio *uio = ap->a_uio;
  877         struct thread *td = uio->uio_td;
  878         struct vnode *vp = ap->a_vp;
  879         struct nfsnode *np = VTONFS(vp);
  880         struct ucred *cred = ap->a_cred;
  881         int ioflag = ap->a_ioflag;
  882         struct buf *bp;
  883         struct vattr vattr;
  884         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
  885         daddr_t lbn;
  886         int bcount, noncontig_write, obcount;
  887         int bp_cached, n, on, error = 0, error1, wouldcommit;
  888         size_t orig_resid, local_resid;
  889         off_t orig_size, tmp_off;
  890 
  891         KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
  892         KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
  893             ("ncl_write proc"));
  894         if (vp->v_type != VREG)
  895                 return (EIO);
  896         mtx_lock(&np->n_mtx);
  897         if (np->n_flag & NWRITEERR) {
  898                 np->n_flag &= ~NWRITEERR;
  899                 mtx_unlock(&np->n_mtx);
  900                 return (np->n_error);
  901         } else
  902                 mtx_unlock(&np->n_mtx);
  903         mtx_lock(&nmp->nm_mtx);
  904         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  905             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  906                 mtx_unlock(&nmp->nm_mtx);
  907                 (void)ncl_fsinfo(nmp, vp, cred, td);
  908                 mtx_lock(&nmp->nm_mtx);
  909         }
  910         if (nmp->nm_wsize == 0)
  911                 (void) newnfs_iosize(nmp);
  912         mtx_unlock(&nmp->nm_mtx);
  913 
  914         /*
  915          * Synchronously flush pending buffers if we are in synchronous
  916          * mode or if we are appending.
  917          */
  918         if (ioflag & (IO_APPEND | IO_SYNC)) {
  919                 mtx_lock(&np->n_mtx);
  920                 if (np->n_flag & NMODIFIED) {
  921                         mtx_unlock(&np->n_mtx);
  922 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
  923                         /*
  924                          * Require non-blocking, synchronous writes to
  925                          * dirty files to inform the program it needs
  926                          * to fsync(2) explicitly.
  927                          */
  928                         if (ioflag & IO_NDELAY)
  929                                 return (EAGAIN);
  930 #endif
  931                         np->n_attrstamp = 0;
  932                         KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
  933                         error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
  934                             IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
  935                         if (error == 0 && (vp->v_iflag & VI_DOOMED) != 0)
  936                                 error = EBADF;
  937                         if (error != 0)
  938                                 return (error);
  939                 } else
  940                         mtx_unlock(&np->n_mtx);
  941         }
  942 
  943         orig_resid = uio->uio_resid;
  944         mtx_lock(&np->n_mtx);
  945         orig_size = np->n_size;
  946         mtx_unlock(&np->n_mtx);
  947 
  948         /*
  949          * If IO_APPEND then load uio_offset.  We restart here if we cannot
  950          * get the append lock.
  951          */
  952         if (ioflag & IO_APPEND) {
  953                 np->n_attrstamp = 0;
  954                 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
  955                 error = VOP_GETATTR(vp, &vattr, cred);
  956                 if (error)
  957                         return (error);
  958                 mtx_lock(&np->n_mtx);
  959                 uio->uio_offset = np->n_size;
  960                 mtx_unlock(&np->n_mtx);
  961         }
  962 
  963         if (uio->uio_offset < 0)
  964                 return (EINVAL);
  965         tmp_off = uio->uio_offset + uio->uio_resid;
  966         if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)
  967                 return (EFBIG);
  968         if (uio->uio_resid == 0)
  969                 return (0);
  970 
  971         if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
  972                 return nfs_directio_write(vp, uio, cred, ioflag);
  973 
  974         /*
  975          * Maybe this should be above the vnode op call, but so long as
  976          * file servers have no limits, i don't think it matters
  977          */
  978         if (vn_rlimit_fsize(vp, uio, td))
  979                 return (EFBIG);
  980 
  981         biosize = vp->v_bufobj.bo_bsize;
  982         /*
  983          * Find all of this file's B_NEEDCOMMIT buffers.  If our writes
  984          * would exceed the local maximum per-file write commit size when
  985          * combined with those, we must decide whether to flush,
  986          * go synchronous, or return error.  We don't bother checking
  987          * IO_UNIT -- we just make all writes atomic anyway, as there's
  988          * no point optimizing for something that really won't ever happen.
  989          */
  990         wouldcommit = 0;
  991         if (!(ioflag & IO_SYNC)) {
  992                 int nflag;
  993 
  994                 mtx_lock(&np->n_mtx);
  995                 nflag = np->n_flag;
  996                 mtx_unlock(&np->n_mtx);
  997                 if (nflag & NMODIFIED) {
  998                         BO_LOCK(&vp->v_bufobj);
  999                         if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
 1000                                 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
 1001                                     b_bobufs) {
 1002                                         if (bp->b_flags & B_NEEDCOMMIT)
 1003                                                 wouldcommit += bp->b_bcount;
 1004                                 }
 1005                         }
 1006                         BO_UNLOCK(&vp->v_bufobj);
 1007                 }
 1008         }
 1009 
 1010         do {
 1011                 if (!(ioflag & IO_SYNC)) {
 1012                         wouldcommit += biosize;
 1013                         if (wouldcommit > nmp->nm_wcommitsize) {
 1014                                 np->n_attrstamp = 0;
 1015                                 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 1016                                 error = ncl_vinvalbuf(vp, V_SAVE | ((ioflag &
 1017                                     IO_VMIO) != 0 ? V_VMIO : 0), td, 1);
 1018                                 if (error == 0 &&
 1019                                     (vp->v_iflag & VI_DOOMED) != 0)
 1020                                         error = EBADF;
 1021                                 if (error != 0)
 1022                                         return (error);
 1023                                 wouldcommit = biosize;
 1024                         }
 1025                 }
 1026 
 1027                 NFSINCRGLOBAL(nfsstatsv1.biocache_writes);
 1028                 lbn = uio->uio_offset / biosize;
 1029                 on = uio->uio_offset - (lbn * biosize);
 1030                 n = MIN((unsigned)(biosize - on), uio->uio_resid);
 1031 again:
 1032                 /*
 1033                  * Handle direct append and file extension cases, calculate
 1034                  * unaligned buffer size.
 1035                  */
 1036                 mtx_lock(&np->n_mtx);
 1037                 if ((np->n_flag & NHASBEENLOCKED) == 0 &&
 1038                     (nmp->nm_flag & NFSMNT_NONCONTIGWR) != 0)
 1039                         noncontig_write = 1;
 1040                 else
 1041                         noncontig_write = 0;
 1042                 if ((uio->uio_offset == np->n_size ||
 1043                     (noncontig_write != 0 &&
 1044                     lbn == (np->n_size / biosize) &&
 1045                     uio->uio_offset + n > np->n_size)) && n) {
 1046                         mtx_unlock(&np->n_mtx);
 1047                         /*
 1048                          * Get the buffer (in its pre-append state to maintain
 1049                          * B_CACHE if it was previously set).  Resize the
 1050                          * nfsnode after we have locked the buffer to prevent
 1051                          * readers from reading garbage.
 1052                          */
 1053                         obcount = np->n_size - (lbn * biosize);
 1054                         bp = nfs_getcacheblk(vp, lbn, obcount, td);
 1055 
 1056                         if (bp != NULL) {
 1057                                 long save;
 1058 
 1059                                 mtx_lock(&np->n_mtx);
 1060                                 np->n_size = uio->uio_offset + n;
 1061                                 np->n_flag |= NMODIFIED;
 1062                                 vnode_pager_setsize(vp, np->n_size);
 1063                                 mtx_unlock(&np->n_mtx);
 1064 
 1065                                 save = bp->b_flags & B_CACHE;
 1066                                 bcount = on + n;
 1067                                 allocbuf(bp, bcount);
 1068                                 bp->b_flags |= save;
 1069                                 if (noncontig_write != 0 && on > obcount)
 1070                                         vfs_bio_bzero_buf(bp, obcount, on -
 1071                                             obcount);
 1072                         }
 1073                 } else {
 1074                         /*
 1075                          * Obtain the locked cache block first, and then
 1076                          * adjust the file's size as appropriate.
 1077                          */
 1078                         bcount = on + n;
 1079                         if ((off_t)lbn * biosize + bcount < np->n_size) {
 1080                                 if ((off_t)(lbn + 1) * biosize < np->n_size)
 1081                                         bcount = biosize;
 1082                                 else
 1083                                         bcount = np->n_size - (off_t)lbn * biosize;
 1084                         }
 1085                         mtx_unlock(&np->n_mtx);
 1086                         bp = nfs_getcacheblk(vp, lbn, bcount, td);
 1087                         mtx_lock(&np->n_mtx);
 1088                         if (uio->uio_offset + n > np->n_size) {
 1089                                 np->n_size = uio->uio_offset + n;
 1090                                 np->n_flag |= NMODIFIED;
 1091                                 vnode_pager_setsize(vp, np->n_size);
 1092                         }
 1093                         mtx_unlock(&np->n_mtx);
 1094                 }
 1095 
 1096                 if (!bp) {
 1097                         error = newnfs_sigintr(nmp, td);
 1098                         if (!error)
 1099                                 error = EINTR;
 1100                         break;
 1101                 }
 1102 
 1103                 /*
 1104                  * Issue a READ if B_CACHE is not set.  In special-append
 1105                  * mode, B_CACHE is based on the buffer prior to the write
 1106                  * op and is typically set, avoiding the read.  If a read
 1107                  * is required in special append mode, the server will
 1108                  * probably send us a short-read since we extended the file
 1109                  * on our end, resulting in b_resid == 0 and, thusly,
 1110                  * B_CACHE getting set.
 1111                  *
 1112                  * We can also avoid issuing the read if the write covers
 1113                  * the entire buffer.  We have to make sure the buffer state
 1114                  * is reasonable in this case since we will not be initiating
 1115                  * I/O.  See the comments in kern/vfs_bio.c's getblk() for
 1116                  * more information.
 1117                  *
 1118                  * B_CACHE may also be set due to the buffer being cached
 1119                  * normally.
 1120                  */
 1121 
 1122                 bp_cached = 1;
 1123                 if (on == 0 && n == bcount) {
 1124                         if ((bp->b_flags & B_CACHE) == 0)
 1125                                 bp_cached = 0;
 1126                         bp->b_flags |= B_CACHE;
 1127                         bp->b_flags &= ~B_INVAL;
 1128                         bp->b_ioflags &= ~BIO_ERROR;
 1129                 }
 1130 
 1131                 if ((bp->b_flags & B_CACHE) == 0) {
 1132                         bp->b_iocmd = BIO_READ;
 1133                         vfs_busy_pages(bp, 0);
 1134                         error = ncl_doio(vp, bp, cred, td, 0);
 1135                         if (error) {
 1136                                 brelse(bp);
 1137                                 break;
 1138                         }
 1139                 }
 1140                 if (bp->b_wcred == NOCRED)
 1141                         bp->b_wcred = crhold(cred);
 1142                 mtx_lock(&np->n_mtx);
 1143                 np->n_flag |= NMODIFIED;
 1144                 mtx_unlock(&np->n_mtx);
 1145 
 1146                 /*
 1147                  * If dirtyend exceeds file size, chop it down.  This should
 1148                  * not normally occur but there is an append race where it
 1149                  * might occur XXX, so we log it.
 1150                  *
 1151                  * If the chopping creates a reverse-indexed or degenerate
 1152                  * situation with dirtyoff/end, we 0 both of them.
 1153                  */
 1154 
 1155                 if (bp->b_dirtyend > bcount) {
 1156                         printf("NFS append race @%lx:%d\n",
 1157                             (long)bp->b_blkno * DEV_BSIZE,
 1158                             bp->b_dirtyend - bcount);
 1159                         bp->b_dirtyend = bcount;
 1160                 }
 1161 
 1162                 if (bp->b_dirtyoff >= bp->b_dirtyend)
 1163                         bp->b_dirtyoff = bp->b_dirtyend = 0;
 1164 
 1165                 /*
 1166                  * If the new write will leave a contiguous dirty
 1167                  * area, just update the b_dirtyoff and b_dirtyend,
 1168                  * otherwise force a write rpc of the old dirty area.
 1169                  *
 1170                  * If there has been a file lock applied to this file
 1171                  * or vfs.nfs.old_noncontig_writing is set, do the following:
 1172                  * While it is possible to merge discontiguous writes due to
 1173                  * our having a B_CACHE buffer ( and thus valid read data
 1174                  * for the hole), we don't because it could lead to
 1175                  * significant cache coherency problems with multiple clients,
 1176                  * especially if locking is implemented later on.
 1177                  *
 1178                  * If vfs.nfs.old_noncontig_writing is not set and there has
 1179                  * not been file locking done on this file:
 1180                  * Relax coherency a bit for the sake of performance and
 1181                  * expand the current dirty region to contain the new
 1182                  * write even if it means we mark some non-dirty data as
 1183                  * dirty.
 1184                  */
 1185 
 1186                 if (noncontig_write == 0 && bp->b_dirtyend > 0 &&
 1187                     (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
 1188                         if (bwrite(bp) == EINTR) {
 1189                                 error = EINTR;
 1190                                 break;
 1191                         }
 1192                         goto again;
 1193                 }
 1194 
 1195                 local_resid = uio->uio_resid;
 1196                 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio);
 1197 
 1198                 if (error != 0 && !bp_cached) {
 1199                         /*
 1200                          * This block has no other content then what
 1201                          * possibly was written by the faulty uiomove.
 1202                          * Release it, forgetting the data pages, to
 1203                          * prevent the leak of uninitialized data to
 1204                          * usermode.
 1205                          */
 1206                         bp->b_ioflags |= BIO_ERROR;
 1207                         brelse(bp);
 1208                         uio->uio_offset -= local_resid - uio->uio_resid;
 1209                         uio->uio_resid = local_resid;
 1210                         break;
 1211                 }
 1212 
 1213                 /*
 1214                  * Since this block is being modified, it must be written
 1215                  * again and not just committed.  Since write clustering does
 1216                  * not work for the stage 1 data write, only the stage 2
 1217                  * commit rpc, we have to clear B_CLUSTEROK as well.
 1218                  */
 1219                 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 1220 
 1221                 /*
 1222                  * Get the partial update on the progress made from
 1223                  * uiomove, if an error occurred.
 1224                  */
 1225                 if (error != 0)
 1226                         n = local_resid - uio->uio_resid;
 1227 
 1228                 /*
 1229                  * Only update dirtyoff/dirtyend if not a degenerate
 1230                  * condition.
 1231                  */
 1232                 if (n > 0) {
 1233                         if (bp->b_dirtyend > 0) {
 1234                                 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
 1235                                 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
 1236                         } else {
 1237                                 bp->b_dirtyoff = on;
 1238                                 bp->b_dirtyend = on + n;
 1239                         }
 1240                         vfs_bio_set_valid(bp, on, n);
 1241                 }
 1242 
 1243                 /*
 1244                  * If IO_SYNC do bwrite().
 1245                  *
 1246                  * IO_INVAL appears to be unused.  The idea appears to be
 1247                  * to turn off caching in this case.  Very odd.  XXX
 1248                  */
 1249                 if ((ioflag & IO_SYNC)) {
 1250                         if (ioflag & IO_INVAL)
 1251                                 bp->b_flags |= B_NOCACHE;
 1252                         error1 = bwrite(bp);
 1253                         if (error1 != 0) {
 1254                                 if (error == 0)
 1255                                         error = error1;
 1256                                 break;
 1257                         }
 1258                 } else if ((n + on) == biosize || (ioflag & IO_ASYNC) != 0) {
 1259                         bp->b_flags |= B_ASYNC;
 1260                         (void) ncl_writebp(bp, 0, NULL);
 1261                 } else {
 1262                         bdwrite(bp);
 1263                 }
 1264 
 1265                 if (error != 0)
 1266                         break;
 1267         } while (uio->uio_resid > 0 && n > 0);
 1268 
 1269         if (error != 0) {
 1270                 if (ioflag & IO_UNIT) {
 1271                         VATTR_NULL(&vattr);
 1272                         vattr.va_size = orig_size;
 1273                         /* IO_SYNC is handled implicitely */
 1274                         (void)VOP_SETATTR(vp, &vattr, cred);
 1275                         uio->uio_offset -= orig_resid - uio->uio_resid;
 1276                         uio->uio_resid = orig_resid;
 1277                 }
 1278         }
 1279 
 1280         return (error);
 1281 }
 1282 
 1283 /*
 1284  * Get an nfs cache block.
 1285  *
 1286  * Allocate a new one if the block isn't currently in the cache
 1287  * and return the block marked busy. If the calling process is
 1288  * interrupted by a signal for an interruptible mount point, return
 1289  * NULL.
 1290  *
 1291  * The caller must carefully deal with the possible B_INVAL state of
 1292  * the buffer.  ncl_doio() clears B_INVAL (and ncl_asyncio() clears it
 1293  * indirectly), so synchronous reads can be issued without worrying about
 1294  * the B_INVAL state.  We have to be a little more careful when dealing
 1295  * with writes (see comments in nfs_write()) when extending a file past
 1296  * its EOF.
 1297  */
 1298 static struct buf *
 1299 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
 1300 {
 1301         struct buf *bp;
 1302         struct mount *mp;
 1303         struct nfsmount *nmp;
 1304 
 1305         mp = vp->v_mount;
 1306         nmp = VFSTONFS(mp);
 1307 
 1308         if (nmp->nm_flag & NFSMNT_INT) {
 1309                 sigset_t oldset;
 1310 
 1311                 newnfs_set_sigmask(td, &oldset);
 1312                 bp = getblk(vp, bn, size, PCATCH, 0, 0);
 1313                 newnfs_restore_sigmask(td, &oldset);
 1314                 while (bp == NULL) {
 1315                         if (newnfs_sigintr(nmp, td))
 1316                                 return (NULL);
 1317                         bp = getblk(vp, bn, size, 0, 2 * hz, 0);
 1318                 }
 1319         } else {
 1320                 bp = getblk(vp, bn, size, 0, 0, 0);
 1321         }
 1322 
 1323         if (vp->v_type == VREG)
 1324                 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE);
 1325         return (bp);
 1326 }
 1327 
 1328 /*
 1329  * Flush and invalidate all dirty buffers. If another process is already
 1330  * doing the flush, just wait for completion.
 1331  */
 1332 int
 1333 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
 1334 {
 1335         struct nfsnode *np = VTONFS(vp);
 1336         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 1337         int error = 0, slpflag, slptimeo;
 1338         int old_lock = 0;
 1339 
 1340         ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf");
 1341 
 1342         if ((nmp->nm_flag & NFSMNT_INT) == 0)
 1343                 intrflg = 0;
 1344         if ((nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF))
 1345                 intrflg = 1;
 1346         if (intrflg) {
 1347                 slpflag = PCATCH;
 1348                 slptimeo = 2 * hz;
 1349         } else {
 1350                 slpflag = 0;
 1351                 slptimeo = 0;
 1352         }
 1353 
 1354         old_lock = ncl_upgrade_vnlock(vp);
 1355         if (vp->v_iflag & VI_DOOMED) {
 1356                 /*
 1357                  * Since vgonel() uses the generic vinvalbuf() to flush
 1358                  * dirty buffers and it does not call this function, it
 1359                  * is safe to just return OK when VI_DOOMED is set.
 1360                  */
 1361                 ncl_downgrade_vnlock(vp, old_lock);
 1362                 return (0);
 1363         }
 1364 
 1365         /*
 1366          * Now, flush as required.
 1367          */
 1368         if ((flags & (V_SAVE | V_VMIO)) == V_SAVE &&
 1369              vp->v_bufobj.bo_object != NULL) {
 1370                 VM_OBJECT_WLOCK(vp->v_bufobj.bo_object);
 1371                 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
 1372                 VM_OBJECT_WUNLOCK(vp->v_bufobj.bo_object);
 1373                 /*
 1374                  * If the page clean was interrupted, fail the invalidation.
 1375                  * Not doing so, we run the risk of losing dirty pages in the
 1376                  * vinvalbuf() call below.
 1377                  */
 1378                 if (intrflg && (error = newnfs_sigintr(nmp, td)))
 1379                         goto out;
 1380         }
 1381 
 1382         error = vinvalbuf(vp, flags, slpflag, 0);
 1383         while (error) {
 1384                 if (intrflg && (error = newnfs_sigintr(nmp, td)))
 1385                         goto out;
 1386                 error = vinvalbuf(vp, flags, 0, slptimeo);
 1387         }
 1388         if (NFSHASPNFS(nmp)) {
 1389                 nfscl_layoutcommit(vp, td);
 1390                 /*
 1391                  * Invalidate the attribute cache, since writes to a DS
 1392                  * won't update the size attribute.
 1393                  */
 1394                 mtx_lock(&np->n_mtx);
 1395                 np->n_attrstamp = 0;
 1396         } else
 1397                 mtx_lock(&np->n_mtx);
 1398         if (np->n_directio_asyncwr == 0)
 1399                 np->n_flag &= ~NMODIFIED;
 1400         mtx_unlock(&np->n_mtx);
 1401 out:
 1402         ncl_downgrade_vnlock(vp, old_lock);
 1403         return error;
 1404 }
 1405 
 1406 /*
 1407  * Initiate asynchronous I/O. Return an error if no nfsiods are available.
 1408  * This is mainly to avoid queueing async I/O requests when the nfsiods
 1409  * are all hung on a dead server.
 1410  *
 1411  * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
 1412  * is eventually dequeued by the async daemon, ncl_doio() *will*.
 1413  */
 1414 int
 1415 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
 1416 {
 1417         int iod;
 1418         int gotiod;
 1419         int slpflag = 0;
 1420         int slptimeo = 0;
 1421         int error, error2;
 1422 
 1423         /*
 1424          * Commits are usually short and sweet so lets save some cpu and
 1425          * leave the async daemons for more important rpc's (such as reads
 1426          * and writes).
 1427          *
 1428          * Readdirplus RPCs do vget()s to acquire the vnodes for entries
 1429          * in the directory in order to update attributes. This can deadlock
 1430          * with another thread that is waiting for async I/O to be done by
 1431          * an nfsiod thread while holding a lock on one of these vnodes.
 1432          * To avoid this deadlock, don't allow the async nfsiod threads to
 1433          * perform Readdirplus RPCs.
 1434          */
 1435         mtx_lock(&ncl_iod_mutex);
 1436         if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
 1437              (nmp->nm_bufqiods > ncl_numasync / 2)) ||
 1438             (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) {
 1439                 mtx_unlock(&ncl_iod_mutex);
 1440                 return(EIO);
 1441         }
 1442 again:
 1443         if (nmp->nm_flag & NFSMNT_INT)
 1444                 slpflag = PCATCH;
 1445         gotiod = FALSE;
 1446 
 1447         /*
 1448          * Find a free iod to process this request.
 1449          */
 1450         for (iod = 0; iod < ncl_numasync; iod++)
 1451                 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) {
 1452                         gotiod = TRUE;
 1453                         break;
 1454                 }
 1455 
 1456         /*
 1457          * Try to create one if none are free.
 1458          */
 1459         if (!gotiod)
 1460                 ncl_nfsiodnew();
 1461         else {
 1462                 /*
 1463                  * Found one, so wake it up and tell it which
 1464                  * mount to process.
 1465                  */
 1466                 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n",
 1467                     iod, nmp));
 1468                 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
 1469                 ncl_iodmount[iod] = nmp;
 1470                 nmp->nm_bufqiods++;
 1471                 wakeup(&ncl_iodwant[iod]);
 1472         }
 1473 
 1474         /*
 1475          * If none are free, we may already have an iod working on this mount
 1476          * point.  If so, it will process our request.
 1477          */
 1478         if (!gotiod) {
 1479                 if (nmp->nm_bufqiods > 0) {
 1480                         NFS_DPF(ASYNCIO,
 1481                                 ("ncl_asyncio: %d iods are already processing mount %p\n",
 1482                                  nmp->nm_bufqiods, nmp));
 1483                         gotiod = TRUE;
 1484                 }
 1485         }
 1486 
 1487         /*
 1488          * If we have an iod which can process the request, then queue
 1489          * the buffer.
 1490          */
 1491         if (gotiod) {
 1492                 /*
 1493                  * Ensure that the queue never grows too large.  We still want
 1494                  * to asynchronize so we block rather then return EIO.
 1495                  */
 1496                 while (nmp->nm_bufqlen >= 2*ncl_numasync) {
 1497                         NFS_DPF(ASYNCIO,
 1498                                 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp));
 1499                         nmp->nm_bufqwant = TRUE;
 1500                         error = newnfs_msleep(td, &nmp->nm_bufq,
 1501                             &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio",
 1502                            slptimeo);
 1503                         if (error) {
 1504                                 error2 = newnfs_sigintr(nmp, td);
 1505                                 if (error2) {
 1506                                         mtx_unlock(&ncl_iod_mutex);
 1507                                         return (error2);
 1508                                 }
 1509                                 if (slpflag == PCATCH) {
 1510                                         slpflag = 0;
 1511                                         slptimeo = 2 * hz;
 1512                                 }
 1513                         }
 1514                         /*
 1515                          * We might have lost our iod while sleeping,
 1516                          * so check and loop if necessary.
 1517                          */
 1518                         goto again;
 1519                 }
 1520 
 1521                 /* We might have lost our nfsiod */
 1522                 if (nmp->nm_bufqiods == 0) {
 1523                         NFS_DPF(ASYNCIO,
 1524                                 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
 1525                         goto again;
 1526                 }
 1527 
 1528                 if (bp->b_iocmd == BIO_READ) {
 1529                         if (bp->b_rcred == NOCRED && cred != NOCRED)
 1530                                 bp->b_rcred = crhold(cred);
 1531                 } else {
 1532                         if (bp->b_wcred == NOCRED && cred != NOCRED)
 1533                                 bp->b_wcred = crhold(cred);
 1534                 }
 1535 
 1536                 if (bp->b_flags & B_REMFREE)
 1537                         bremfreef(bp);
 1538                 BUF_KERNPROC(bp);
 1539                 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
 1540                 nmp->nm_bufqlen++;
 1541                 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
 1542                         mtx_lock(&(VTONFS(bp->b_vp))->n_mtx);
 1543                         VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
 1544                         VTONFS(bp->b_vp)->n_directio_asyncwr++;
 1545                         mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx);
 1546                 }
 1547                 mtx_unlock(&ncl_iod_mutex);
 1548                 return (0);
 1549         }
 1550 
 1551         mtx_unlock(&ncl_iod_mutex);
 1552 
 1553         /*
 1554          * All the iods are busy on other mounts, so return EIO to
 1555          * force the caller to process the i/o synchronously.
 1556          */
 1557         NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n"));
 1558         return (EIO);
 1559 }
 1560 
 1561 void
 1562 ncl_doio_directwrite(struct buf *bp)
 1563 {
 1564         int iomode, must_commit;
 1565         struct uio *uiop = (struct uio *)bp->b_caller1;
 1566         char *iov_base = uiop->uio_iov->iov_base;
 1567 
 1568         iomode = NFSWRITE_FILESYNC;
 1569         uiop->uio_td = NULL; /* NULL since we're in nfsiod */
 1570         ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0);
 1571         KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write"));
 1572         free(iov_base, M_NFSDIRECTIO);
 1573         free(uiop->uio_iov, M_NFSDIRECTIO);
 1574         free(uiop, M_NFSDIRECTIO);
 1575         if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
 1576                 struct nfsnode *np = VTONFS(bp->b_vp);
 1577                 mtx_lock(&np->n_mtx);
 1578                 if (NFSHASPNFS(VFSTONFS(vnode_mount(bp->b_vp)))) {
 1579                         /*
 1580                          * Invalidate the attribute cache, since writes to a DS
 1581                          * won't update the size attribute.
 1582                          */
 1583                         np->n_attrstamp = 0;
 1584                 }
 1585                 np->n_directio_asyncwr--;
 1586                 if (np->n_directio_asyncwr == 0) {
 1587                         np->n_flag &= ~NMODIFIED;
 1588                         if ((np->n_flag & NFSYNCWAIT)) {
 1589                                 np->n_flag &= ~NFSYNCWAIT;
 1590                                 wakeup((caddr_t)&np->n_directio_asyncwr);
 1591                         }
 1592                 }
 1593                 mtx_unlock(&np->n_mtx);
 1594         }
 1595         bp->b_vp = NULL;
 1596         relpbuf(bp, &ncl_pbuf_freecnt);
 1597 }
 1598 
 1599 /*
 1600  * Do an I/O operation to/from a cache block. This may be called
 1601  * synchronously or from an nfsiod.
 1602  */
 1603 int
 1604 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
 1605     int called_from_strategy)
 1606 {
 1607         struct uio *uiop;
 1608         struct nfsnode *np;
 1609         struct nfsmount *nmp;
 1610         int error = 0, iomode, must_commit = 0;
 1611         struct uio uio;
 1612         struct iovec io;
 1613         struct proc *p = td ? td->td_proc : NULL;
 1614         uint8_t iocmd;
 1615 
 1616         np = VTONFS(vp);
 1617         nmp = VFSTONFS(vp->v_mount);
 1618         uiop = &uio;
 1619         uiop->uio_iov = &io;
 1620         uiop->uio_iovcnt = 1;
 1621         uiop->uio_segflg = UIO_SYSSPACE;
 1622         uiop->uio_td = td;
 1623 
 1624         /*
 1625          * clear BIO_ERROR and B_INVAL state prior to initiating the I/O.  We
 1626          * do this here so we do not have to do it in all the code that
 1627          * calls us.
 1628          */
 1629         bp->b_flags &= ~B_INVAL;
 1630         bp->b_ioflags &= ~BIO_ERROR;
 1631 
 1632         KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp));
 1633         iocmd = bp->b_iocmd;
 1634         if (iocmd == BIO_READ) {
 1635             io.iov_len = uiop->uio_resid = bp->b_bcount;
 1636             io.iov_base = bp->b_data;
 1637             uiop->uio_rw = UIO_READ;
 1638 
 1639             switch (vp->v_type) {
 1640             case VREG:
 1641                 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
 1642                 NFSINCRGLOBAL(nfsstatsv1.read_bios);
 1643                 error = ncl_readrpc(vp, uiop, cr);
 1644 
 1645                 if (!error) {
 1646                     if (uiop->uio_resid) {
 1647                         /*
 1648                          * If we had a short read with no error, we must have
 1649                          * hit a file hole.  We should zero-fill the remainder.
 1650                          * This can also occur if the server hits the file EOF.
 1651                          *
 1652                          * Holes used to be able to occur due to pending
 1653                          * writes, but that is not possible any longer.
 1654                          */
 1655                         int nread = bp->b_bcount - uiop->uio_resid;
 1656                         ssize_t left = uiop->uio_resid;
 1657 
 1658                         if (left > 0)
 1659                                 bzero((char *)bp->b_data + nread, left);
 1660                         uiop->uio_resid = 0;
 1661                     }
 1662                 }
 1663                 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */
 1664                 if (p && (vp->v_vflag & VV_TEXT)) {
 1665                         mtx_lock(&np->n_mtx);
 1666                         if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) {
 1667                                 mtx_unlock(&np->n_mtx);
 1668                                 PROC_LOCK(p);
 1669                                 killproc(p, "text file modification");
 1670                                 PROC_UNLOCK(p);
 1671                         } else
 1672                                 mtx_unlock(&np->n_mtx);
 1673                 }
 1674                 break;
 1675             case VLNK:
 1676                 uiop->uio_offset = (off_t)0;
 1677                 NFSINCRGLOBAL(nfsstatsv1.readlink_bios);
 1678                 error = ncl_readlinkrpc(vp, uiop, cr);
 1679                 break;
 1680             case VDIR:
 1681                 NFSINCRGLOBAL(nfsstatsv1.readdir_bios);
 1682                 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
 1683                 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
 1684                         error = ncl_readdirplusrpc(vp, uiop, cr, td);
 1685                         if (error == NFSERR_NOTSUPP)
 1686                                 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
 1687                 }
 1688                 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
 1689                         error = ncl_readdirrpc(vp, uiop, cr, td);
 1690                 /*
 1691                  * end-of-directory sets B_INVAL but does not generate an
 1692                  * error.
 1693                  */
 1694                 if (error == 0 && uiop->uio_resid == bp->b_bcount)
 1695                         bp->b_flags |= B_INVAL;
 1696                 break;
 1697             default:
 1698                 printf("ncl_doio:  type %x unexpected\n", vp->v_type);
 1699                 break;
 1700             }
 1701             if (error) {
 1702                 bp->b_ioflags |= BIO_ERROR;
 1703                 bp->b_error = error;
 1704             }
 1705         } else {
 1706             /*
 1707              * If we only need to commit, try to commit
 1708              */
 1709             if (bp->b_flags & B_NEEDCOMMIT) {
 1710                     int retv;
 1711                     off_t off;
 1712 
 1713                     off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
 1714                     retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff,
 1715                         bp->b_wcred, td);
 1716                     if (retv == 0) {
 1717                             bp->b_dirtyoff = bp->b_dirtyend = 0;
 1718                             bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 1719                             bp->b_resid = 0;
 1720                             bufdone(bp);
 1721                             return (0);
 1722                     }
 1723                     if (retv == NFSERR_STALEWRITEVERF) {
 1724                             ncl_clearcommit(vp->v_mount);
 1725                     }
 1726             }
 1727 
 1728             /*
 1729              * Setup for actual write
 1730              */
 1731             mtx_lock(&np->n_mtx);
 1732             if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
 1733                 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
 1734             mtx_unlock(&np->n_mtx);
 1735 
 1736             if (bp->b_dirtyend > bp->b_dirtyoff) {
 1737                 io.iov_len = uiop->uio_resid = bp->b_dirtyend
 1738                     - bp->b_dirtyoff;
 1739                 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
 1740                     + bp->b_dirtyoff;
 1741                 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
 1742                 uiop->uio_rw = UIO_WRITE;
 1743                 NFSINCRGLOBAL(nfsstatsv1.write_bios);
 1744 
 1745                 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
 1746                     iomode = NFSWRITE_UNSTABLE;
 1747                 else
 1748                     iomode = NFSWRITE_FILESYNC;
 1749 
 1750                 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit,
 1751                     called_from_strategy);
 1752 
 1753                 /*
 1754                  * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
 1755                  * to cluster the buffers needing commit.  This will allow
 1756                  * the system to submit a single commit rpc for the whole
 1757                  * cluster.  We can do this even if the buffer is not 100%
 1758                  * dirty (relative to the NFS blocksize), so we optimize the
 1759                  * append-to-file-case.
 1760                  *
 1761                  * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
 1762                  * cleared because write clustering only works for commit
 1763                  * rpc's, not for the data portion of the write).
 1764                  */
 1765 
 1766                 if (!error && iomode == NFSWRITE_UNSTABLE) {
 1767                     bp->b_flags |= B_NEEDCOMMIT;
 1768                     if (bp->b_dirtyoff == 0
 1769                         && bp->b_dirtyend == bp->b_bcount)
 1770                         bp->b_flags |= B_CLUSTEROK;
 1771                 } else {
 1772                     bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 1773                 }
 1774 
 1775                 /*
 1776                  * For an interrupted write, the buffer is still valid
 1777                  * and the write hasn't been pushed to the server yet,
 1778                  * so we can't set BIO_ERROR and report the interruption
 1779                  * by setting B_EINTR. For the B_ASYNC case, B_EINTR
 1780                  * is not relevant, so the rpc attempt is essentially
 1781                  * a noop.  For the case of a V3 write rpc not being
 1782                  * committed to stable storage, the block is still
 1783                  * dirty and requires either a commit rpc or another
 1784                  * write rpc with iomode == NFSV3WRITE_FILESYNC before
 1785                  * the block is reused. This is indicated by setting
 1786                  * the B_DELWRI and B_NEEDCOMMIT flags.
 1787                  *
 1788                  * EIO is returned by ncl_writerpc() to indicate a recoverable
 1789                  * write error and is handled as above, except that
 1790                  * B_EINTR isn't set. One cause of this is a stale stateid
 1791                  * error for the RPC that indicates recovery is required,
 1792                  * when called with called_from_strategy != 0.
 1793                  *
 1794                  * If the buffer is marked B_PAGING, it does not reside on
 1795                  * the vp's paging queues so we cannot call bdirty().  The
 1796                  * bp in this case is not an NFS cache block so we should
 1797                  * be safe. XXX
 1798                  *
 1799                  * The logic below breaks up errors into recoverable and
 1800                  * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
 1801                  * and keep the buffer around for potential write retries.
 1802                  * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
 1803                  * and save the error in the nfsnode. This is less than ideal
 1804                  * but necessary. Keeping such buffers around could potentially
 1805                  * cause buffer exhaustion eventually (they can never be written
 1806                  * out, so will get constantly be re-dirtied). It also causes
 1807                  * all sorts of vfs panics. For non-recoverable write errors,
 1808                  * also invalidate the attrcache, so we'll be forced to go over
 1809                  * the wire for this object, returning an error to user on next
 1810                  * call (most of the time).
 1811                  */
 1812                 if (error == EINTR || error == EIO || error == ETIMEDOUT
 1813                     || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
 1814                         bp->b_flags &= ~(B_INVAL|B_NOCACHE);
 1815                         if ((bp->b_flags & B_PAGING) == 0) {
 1816                             bdirty(bp);
 1817                             bp->b_flags &= ~B_DONE;
 1818                         }
 1819                         if ((error == EINTR || error == ETIMEDOUT) &&
 1820                             (bp->b_flags & B_ASYNC) == 0)
 1821                             bp->b_flags |= B_EINTR;
 1822                 } else {
 1823                     if (error) {
 1824                         bp->b_ioflags |= BIO_ERROR;
 1825                         bp->b_flags |= B_INVAL;
 1826                         bp->b_error = np->n_error = error;
 1827                         mtx_lock(&np->n_mtx);
 1828                         np->n_flag |= NWRITEERR;
 1829                         np->n_attrstamp = 0;
 1830                         KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 1831                         mtx_unlock(&np->n_mtx);
 1832                     }
 1833                     bp->b_dirtyoff = bp->b_dirtyend = 0;
 1834                 }
 1835             } else {
 1836                 bp->b_resid = 0;
 1837                 bufdone(bp);
 1838                 return (0);
 1839             }
 1840         }
 1841         bp->b_resid = uiop->uio_resid;
 1842         if (must_commit)
 1843             ncl_clearcommit(vp->v_mount);
 1844         bufdone(bp);
 1845         return (error);
 1846 }
 1847 
 1848 /*
 1849  * Used to aid in handling ftruncate() operations on the NFS client side.
 1850  * Truncation creates a number of special problems for NFS.  We have to
 1851  * throw away VM pages and buffer cache buffers that are beyond EOF, and
 1852  * we have to properly handle VM pages or (potentially dirty) buffers
 1853  * that straddle the truncation point.
 1854  */
 1855 
 1856 int
 1857 ncl_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
 1858 {
 1859         struct nfsnode *np = VTONFS(vp);
 1860         u_quad_t tsize;
 1861         int biosize = vp->v_bufobj.bo_bsize;
 1862         int error = 0;
 1863 
 1864         mtx_lock(&np->n_mtx);
 1865         tsize = np->n_size;
 1866         np->n_size = nsize;
 1867         mtx_unlock(&np->n_mtx);
 1868 
 1869         if (nsize < tsize) {
 1870                 struct buf *bp;
 1871                 daddr_t lbn;
 1872                 int bufsize;
 1873 
 1874                 /*
 1875                  * vtruncbuf() doesn't get the buffer overlapping the
 1876                  * truncation point.  We may have a B_DELWRI and/or B_CACHE
 1877                  * buffer that now needs to be truncated.
 1878                  */
 1879                 error = vtruncbuf(vp, cred, nsize, biosize);
 1880                 lbn = nsize / biosize;
 1881                 bufsize = nsize - (lbn * biosize);
 1882                 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
 1883                 if (!bp)
 1884                         return EINTR;
 1885                 if (bp->b_dirtyoff > bp->b_bcount)
 1886                         bp->b_dirtyoff = bp->b_bcount;
 1887                 if (bp->b_dirtyend > bp->b_bcount)
 1888                         bp->b_dirtyend = bp->b_bcount;
 1889                 bp->b_flags |= B_RELBUF;  /* don't leave garbage around */
 1890                 brelse(bp);
 1891         } else {
 1892                 vnode_pager_setsize(vp, nsize);
 1893         }
 1894         return(error);
 1895 }
 1896 

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