The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/fs/nfsclient/nfs_clbio.c

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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/9.2/sys/fs/nfsclient/nfs_clbio.c 250257 2013-05-04 21:56:39Z rmacklem $");
   37 
   38 #include "opt_kdtrace.h"
   39 
   40 #include <sys/param.h>
   41 #include <sys/systm.h>
   42 #include <sys/bio.h>
   43 #include <sys/buf.h>
   44 #include <sys/kernel.h>
   45 #include <sys/mount.h>
   46 #include <sys/vmmeter.h>
   47 #include <sys/vnode.h>
   48 
   49 #include <vm/vm.h>
   50 #include <vm/vm_param.h>
   51 #include <vm/vm_extern.h>
   52 #include <vm/vm_page.h>
   53 #include <vm/vm_object.h>
   54 #include <vm/vm_pager.h>
   55 #include <vm/vnode_pager.h>
   56 
   57 #include <fs/nfs/nfsport.h>
   58 #include <fs/nfsclient/nfsmount.h>
   59 #include <fs/nfsclient/nfs.h>
   60 #include <fs/nfsclient/nfsnode.h>
   61 #include <fs/nfsclient/nfs_kdtrace.h>
   62 
   63 extern int newnfs_directio_allow_mmap;
   64 extern struct nfsstats newnfsstats;
   65 extern struct mtx ncl_iod_mutex;
   66 extern int ncl_numasync;
   67 extern enum nfsiod_state ncl_iodwant[NFS_MAXASYNCDAEMON];
   68 extern struct nfsmount *ncl_iodmount[NFS_MAXASYNCDAEMON];
   69 extern int newnfs_directio_enable;
   70 extern int nfs_keep_dirty_on_error;
   71 
   72 int ncl_pbuf_freecnt = -1;      /* start out unlimited */
   73 
   74 static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
   75     struct thread *td);
   76 static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
   77     struct ucred *cred, int ioflag);
   78 
   79 /*
   80  * Vnode op for VM getpages.
   81  */
   82 int
   83 ncl_getpages(struct vop_getpages_args *ap)
   84 {
   85         int i, error, nextoff, size, toff, count, npages;
   86         struct uio uio;
   87         struct iovec iov;
   88         vm_offset_t kva;
   89         struct buf *bp;
   90         struct vnode *vp;
   91         struct thread *td;
   92         struct ucred *cred;
   93         struct nfsmount *nmp;
   94         vm_object_t object;
   95         vm_page_t *pages;
   96         struct nfsnode *np;
   97 
   98         vp = ap->a_vp;
   99         np = VTONFS(vp);
  100         td = curthread;                         /* XXX */
  101         cred = curthread->td_ucred;             /* XXX */
  102         nmp = VFSTONFS(vp->v_mount);
  103         pages = ap->a_m;
  104         count = ap->a_count;
  105 
  106         if ((object = vp->v_object) == NULL) {
  107                 ncl_printf("nfs_getpages: called with non-merged cache vnode??\n");
  108                 return (VM_PAGER_ERROR);
  109         }
  110 
  111         if (newnfs_directio_enable && !newnfs_directio_allow_mmap) {
  112                 mtx_lock(&np->n_mtx);
  113                 if ((np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
  114                         mtx_unlock(&np->n_mtx);
  115                         ncl_printf("nfs_getpages: called on non-cacheable vnode??\n");
  116                         return (VM_PAGER_ERROR);
  117                 } else
  118                         mtx_unlock(&np->n_mtx);
  119         }
  120 
  121         mtx_lock(&nmp->nm_mtx);
  122         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  123             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  124                 mtx_unlock(&nmp->nm_mtx);
  125                 /* We'll never get here for v4, because we always have fsinfo */
  126                 (void)ncl_fsinfo(nmp, vp, cred, td);
  127         } else
  128                 mtx_unlock(&nmp->nm_mtx);
  129 
  130         npages = btoc(count);
  131 
  132         /*
  133          * If the requested page is partially valid, just return it and
  134          * allow the pager to zero-out the blanks.  Partially valid pages
  135          * can only occur at the file EOF.
  136          */
  137         VM_OBJECT_LOCK(object);
  138         if (pages[ap->a_reqpage]->valid != 0) {
  139                 for (i = 0; i < npages; ++i) {
  140                         if (i != ap->a_reqpage) {
  141                                 vm_page_lock(pages[i]);
  142                                 vm_page_free(pages[i]);
  143                                 vm_page_unlock(pages[i]);
  144                         }
  145                 }
  146                 VM_OBJECT_UNLOCK(object);
  147                 return (0);
  148         }
  149         VM_OBJECT_UNLOCK(object);
  150 
  151         /*
  152          * We use only the kva address for the buffer, but this is extremely
  153          * convienient and fast.
  154          */
  155         bp = getpbuf(&ncl_pbuf_freecnt);
  156 
  157         kva = (vm_offset_t) bp->b_data;
  158         pmap_qenter(kva, pages, npages);
  159         PCPU_INC(cnt.v_vnodein);
  160         PCPU_ADD(cnt.v_vnodepgsin, npages);
  161 
  162         iov.iov_base = (caddr_t) kva;
  163         iov.iov_len = count;
  164         uio.uio_iov = &iov;
  165         uio.uio_iovcnt = 1;
  166         uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
  167         uio.uio_resid = count;
  168         uio.uio_segflg = UIO_SYSSPACE;
  169         uio.uio_rw = UIO_READ;
  170         uio.uio_td = td;
  171 
  172         error = ncl_readrpc(vp, &uio, cred);
  173         pmap_qremove(kva, npages);
  174 
  175         relpbuf(bp, &ncl_pbuf_freecnt);
  176 
  177         if (error && (uio.uio_resid == count)) {
  178                 ncl_printf("nfs_getpages: error %d\n", error);
  179                 VM_OBJECT_LOCK(object);
  180                 for (i = 0; i < npages; ++i) {
  181                         if (i != ap->a_reqpage) {
  182                                 vm_page_lock(pages[i]);
  183                                 vm_page_free(pages[i]);
  184                                 vm_page_unlock(pages[i]);
  185                         }
  186                 }
  187                 VM_OBJECT_UNLOCK(object);
  188                 return (VM_PAGER_ERROR);
  189         }
  190 
  191         /*
  192          * Calculate the number of bytes read and validate only that number
  193          * of bytes.  Note that due to pending writes, size may be 0.  This
  194          * does not mean that the remaining data is invalid!
  195          */
  196 
  197         size = count - uio.uio_resid;
  198         VM_OBJECT_LOCK(object);
  199         for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
  200                 vm_page_t m;
  201                 nextoff = toff + PAGE_SIZE;
  202                 m = pages[i];
  203 
  204                 if (nextoff <= size) {
  205                         /*
  206                          * Read operation filled an entire page
  207                          */
  208                         m->valid = VM_PAGE_BITS_ALL;
  209                         KASSERT(m->dirty == 0,
  210                             ("nfs_getpages: page %p is dirty", m));
  211                 } else if (size > toff) {
  212                         /*
  213                          * Read operation filled a partial page.
  214                          */
  215                         m->valid = 0;
  216                         vm_page_set_valid(m, 0, size - toff);
  217                         KASSERT(m->dirty == 0,
  218                             ("nfs_getpages: page %p is dirty", m));
  219                 } else {
  220                         /*
  221                          * Read operation was short.  If no error
  222                          * occured we may have hit a zero-fill
  223                          * section.  We leave valid set to 0, and page
  224                          * is freed by vm_page_readahead_finish() if
  225                          * its index is not equal to requested, or
  226                          * page is zeroed and set valid by
  227                          * vm_pager_get_pages() for requested page.
  228                          */
  229                         ;
  230                 }
  231                 if (i != ap->a_reqpage)
  232                         vm_page_readahead_finish(m);
  233         }
  234         VM_OBJECT_UNLOCK(object);
  235         return (0);
  236 }
  237 
  238 /*
  239  * Vnode op for VM putpages.
  240  */
  241 int
  242 ncl_putpages(struct vop_putpages_args *ap)
  243 {
  244         struct uio uio;
  245         struct iovec iov;
  246         vm_offset_t kva;
  247         struct buf *bp;
  248         int iomode, must_commit, i, error, npages, count;
  249         off_t offset;
  250         int *rtvals;
  251         struct vnode *vp;
  252         struct thread *td;
  253         struct ucred *cred;
  254         struct nfsmount *nmp;
  255         struct nfsnode *np;
  256         vm_page_t *pages;
  257 
  258         vp = ap->a_vp;
  259         np = VTONFS(vp);
  260         td = curthread;                         /* XXX */
  261         /* Set the cred to n_writecred for the write rpcs. */
  262         if (np->n_writecred != NULL)
  263                 cred = crhold(np->n_writecred);
  264         else
  265                 cred = crhold(curthread->td_ucred);     /* XXX */
  266         nmp = VFSTONFS(vp->v_mount);
  267         pages = ap->a_m;
  268         count = ap->a_count;
  269         rtvals = ap->a_rtvals;
  270         npages = btoc(count);
  271         offset = IDX_TO_OFF(pages[0]->pindex);
  272 
  273         mtx_lock(&nmp->nm_mtx);
  274         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  275             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  276                 mtx_unlock(&nmp->nm_mtx);
  277                 (void)ncl_fsinfo(nmp, vp, cred, td);
  278         } else
  279                 mtx_unlock(&nmp->nm_mtx);
  280 
  281         mtx_lock(&np->n_mtx);
  282         if (newnfs_directio_enable && !newnfs_directio_allow_mmap &&
  283             (np->n_flag & NNONCACHE) && (vp->v_type == VREG)) {
  284                 mtx_unlock(&np->n_mtx);
  285                 ncl_printf("ncl_putpages: called on noncache-able vnode??\n");
  286                 mtx_lock(&np->n_mtx);
  287         }
  288 
  289         for (i = 0; i < npages; i++)
  290                 rtvals[i] = VM_PAGER_ERROR;
  291 
  292         /*
  293          * When putting pages, do not extend file past EOF.
  294          */
  295         if (offset + count > np->n_size) {
  296                 count = np->n_size - offset;
  297                 if (count < 0)
  298                         count = 0;
  299         }
  300         mtx_unlock(&np->n_mtx);
  301 
  302         /*
  303          * We use only the kva address for the buffer, but this is extremely
  304          * convienient and fast.
  305          */
  306         bp = getpbuf(&ncl_pbuf_freecnt);
  307 
  308         kva = (vm_offset_t) bp->b_data;
  309         pmap_qenter(kva, pages, npages);
  310         PCPU_INC(cnt.v_vnodeout);
  311         PCPU_ADD(cnt.v_vnodepgsout, count);
  312 
  313         iov.iov_base = (caddr_t) kva;
  314         iov.iov_len = count;
  315         uio.uio_iov = &iov;
  316         uio.uio_iovcnt = 1;
  317         uio.uio_offset = offset;
  318         uio.uio_resid = count;
  319         uio.uio_segflg = UIO_SYSSPACE;
  320         uio.uio_rw = UIO_WRITE;
  321         uio.uio_td = td;
  322 
  323         if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0)
  324             iomode = NFSWRITE_UNSTABLE;
  325         else
  326             iomode = NFSWRITE_FILESYNC;
  327 
  328         error = ncl_writerpc(vp, &uio, cred, &iomode, &must_commit, 0);
  329         crfree(cred);
  330 
  331         pmap_qremove(kva, npages);
  332         relpbuf(bp, &ncl_pbuf_freecnt);
  333 
  334         if (error == 0 || !nfs_keep_dirty_on_error) {
  335                 vnode_pager_undirty_pages(pages, rtvals, count - uio.uio_resid);
  336                 if (must_commit)
  337                         ncl_clearcommit(vp->v_mount);
  338         }
  339         return rtvals[0];
  340 }
  341 
  342 /*
  343  * For nfs, cache consistency can only be maintained approximately.
  344  * Although RFC1094 does not specify the criteria, the following is
  345  * believed to be compatible with the reference port.
  346  * For nfs:
  347  * If the file's modify time on the server has changed since the
  348  * last read rpc or you have written to the file,
  349  * you may have lost data cache consistency with the
  350  * server, so flush all of the file's data out of the cache.
  351  * Then force a getattr rpc to ensure that you have up to date
  352  * attributes.
  353  * NB: This implies that cache data can be read when up to
  354  * NFS_ATTRTIMEO seconds out of date. If you find that you need current
  355  * attributes this could be forced by setting n_attrstamp to 0 before
  356  * the VOP_GETATTR() call.
  357  */
  358 static inline int
  359 nfs_bioread_check_cons(struct vnode *vp, struct thread *td, struct ucred *cred)
  360 {
  361         int error = 0;
  362         struct vattr vattr;
  363         struct nfsnode *np = VTONFS(vp);
  364         int old_lock;
  365 
  366         /*
  367          * Grab the exclusive lock before checking whether the cache is
  368          * consistent.
  369          * XXX - We can make this cheaper later (by acquiring cheaper locks).
  370          * But for now, this suffices.
  371          */
  372         old_lock = ncl_upgrade_vnlock(vp);
  373         if (vp->v_iflag & VI_DOOMED) {
  374                 ncl_downgrade_vnlock(vp, old_lock);
  375                 return (EBADF);
  376         }
  377 
  378         mtx_lock(&np->n_mtx);
  379         if (np->n_flag & NMODIFIED) {
  380                 mtx_unlock(&np->n_mtx);
  381                 if (vp->v_type != VREG) {
  382                         if (vp->v_type != VDIR)
  383                                 panic("nfs: bioread, not dir");
  384                         ncl_invaldir(vp);
  385                         error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
  386                         if (error)
  387                                 goto out;
  388                 }
  389                 np->n_attrstamp = 0;
  390                 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
  391                 error = VOP_GETATTR(vp, &vattr, cred);
  392                 if (error)
  393                         goto out;
  394                 mtx_lock(&np->n_mtx);
  395                 np->n_mtime = vattr.va_mtime;
  396                 mtx_unlock(&np->n_mtx);
  397         } else {
  398                 mtx_unlock(&np->n_mtx);
  399                 error = VOP_GETATTR(vp, &vattr, cred);
  400                 if (error)
  401                         return (error);
  402                 mtx_lock(&np->n_mtx);
  403                 if ((np->n_flag & NSIZECHANGED)
  404                     || (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
  405                         mtx_unlock(&np->n_mtx);
  406                         if (vp->v_type == VDIR)
  407                                 ncl_invaldir(vp);
  408                         error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
  409                         if (error)
  410                                 goto out;
  411                         mtx_lock(&np->n_mtx);
  412                         np->n_mtime = vattr.va_mtime;
  413                         np->n_flag &= ~NSIZECHANGED;
  414                 }
  415                 mtx_unlock(&np->n_mtx);
  416         }
  417 out:
  418         ncl_downgrade_vnlock(vp, old_lock);
  419         return error;
  420 }
  421 
  422 /*
  423  * Vnode op for read using bio
  424  */
  425 int
  426 ncl_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
  427 {
  428         struct nfsnode *np = VTONFS(vp);
  429         int biosize, i;
  430         struct buf *bp, *rabp;
  431         struct thread *td;
  432         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
  433         daddr_t lbn, rabn;
  434         int bcount;
  435         int seqcount;
  436         int nra, error = 0, n = 0, on = 0;
  437         off_t tmp_off;
  438 
  439         KASSERT(uio->uio_rw == UIO_READ, ("ncl_read mode"));
  440         if (uio->uio_resid == 0)
  441                 return (0);
  442         if (uio->uio_offset < 0)        /* XXX VDIR cookies can be negative */
  443                 return (EINVAL);
  444         td = uio->uio_td;
  445 
  446         mtx_lock(&nmp->nm_mtx);
  447         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  448             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  449                 mtx_unlock(&nmp->nm_mtx);
  450                 (void)ncl_fsinfo(nmp, vp, cred, td);
  451                 mtx_lock(&nmp->nm_mtx);
  452         }
  453         if (nmp->nm_rsize == 0 || nmp->nm_readdirsize == 0)
  454                 (void) newnfs_iosize(nmp);
  455 
  456         tmp_off = uio->uio_offset + uio->uio_resid;
  457         if (vp->v_type != VDIR &&
  458             (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)) {
  459                 mtx_unlock(&nmp->nm_mtx);
  460                 return (EFBIG);
  461         }
  462         mtx_unlock(&nmp->nm_mtx);
  463 
  464         if (newnfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
  465                 /* No caching/ no readaheads. Just read data into the user buffer */
  466                 return ncl_readrpc(vp, uio, cred);
  467 
  468         biosize = vp->v_bufobj.bo_bsize;
  469         seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
  470 
  471         error = nfs_bioread_check_cons(vp, td, cred);
  472         if (error)
  473                 return error;
  474 
  475         do {
  476             u_quad_t nsize;
  477 
  478             mtx_lock(&np->n_mtx);
  479             nsize = np->n_size;
  480             mtx_unlock(&np->n_mtx);
  481 
  482             switch (vp->v_type) {
  483             case VREG:
  484                 NFSINCRGLOBAL(newnfsstats.biocache_reads);
  485                 lbn = uio->uio_offset / biosize;
  486                 on = uio->uio_offset & (biosize - 1);
  487 
  488                 /*
  489                  * Start the read ahead(s), as required.
  490                  */
  491                 if (nmp->nm_readahead > 0) {
  492                     for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
  493                         (off_t)(lbn + 1 + nra) * biosize < nsize; nra++) {
  494                         rabn = lbn + 1 + nra;
  495                         if (incore(&vp->v_bufobj, rabn) == NULL) {
  496                             rabp = nfs_getcacheblk(vp, rabn, biosize, td);
  497                             if (!rabp) {
  498                                 error = newnfs_sigintr(nmp, td);
  499                                 return (error ? error : EINTR);
  500                             }
  501                             if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
  502                                 rabp->b_flags |= B_ASYNC;
  503                                 rabp->b_iocmd = BIO_READ;
  504                                 vfs_busy_pages(rabp, 0);
  505                                 if (ncl_asyncio(nmp, rabp, cred, td)) {
  506                                     rabp->b_flags |= B_INVAL;
  507                                     rabp->b_ioflags |= BIO_ERROR;
  508                                     vfs_unbusy_pages(rabp);
  509                                     brelse(rabp);
  510                                     break;
  511                                 }
  512                             } else {
  513                                 brelse(rabp);
  514                             }
  515                         }
  516                     }
  517                 }
  518 
  519                 /* Note that bcount is *not* DEV_BSIZE aligned. */
  520                 bcount = biosize;
  521                 if ((off_t)lbn * biosize >= nsize) {
  522                         bcount = 0;
  523                 } else if ((off_t)(lbn + 1) * biosize > nsize) {
  524                         bcount = nsize - (off_t)lbn * biosize;
  525                 }
  526                 bp = nfs_getcacheblk(vp, lbn, bcount, td);
  527 
  528                 if (!bp) {
  529                         error = newnfs_sigintr(nmp, td);
  530                         return (error ? error : EINTR);
  531                 }
  532 
  533                 /*
  534                  * If B_CACHE is not set, we must issue the read.  If this
  535                  * fails, we return an error.
  536                  */
  537 
  538                 if ((bp->b_flags & B_CACHE) == 0) {
  539                     bp->b_iocmd = BIO_READ;
  540                     vfs_busy_pages(bp, 0);
  541                     error = ncl_doio(vp, bp, cred, td, 0);
  542                     if (error) {
  543                         brelse(bp);
  544                         return (error);
  545                     }
  546                 }
  547 
  548                 /*
  549                  * on is the offset into the current bp.  Figure out how many
  550                  * bytes we can copy out of the bp.  Note that bcount is
  551                  * NOT DEV_BSIZE aligned.
  552                  *
  553                  * Then figure out how many bytes we can copy into the uio.
  554                  */
  555 
  556                 n = 0;
  557                 if (on < bcount)
  558                         n = MIN((unsigned)(bcount - on), uio->uio_resid);
  559                 break;
  560             case VLNK:
  561                 NFSINCRGLOBAL(newnfsstats.biocache_readlinks);
  562                 bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
  563                 if (!bp) {
  564                         error = newnfs_sigintr(nmp, td);
  565                         return (error ? error : EINTR);
  566                 }
  567                 if ((bp->b_flags & B_CACHE) == 0) {
  568                     bp->b_iocmd = BIO_READ;
  569                     vfs_busy_pages(bp, 0);
  570                     error = ncl_doio(vp, bp, cred, td, 0);
  571                     if (error) {
  572                         bp->b_ioflags |= BIO_ERROR;
  573                         brelse(bp);
  574                         return (error);
  575                     }
  576                 }
  577                 n = MIN(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
  578                 on = 0;
  579                 break;
  580             case VDIR:
  581                 NFSINCRGLOBAL(newnfsstats.biocache_readdirs);
  582                 if (np->n_direofoffset
  583                     && uio->uio_offset >= np->n_direofoffset) {
  584                     return (0);
  585                 }
  586                 lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
  587                 on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
  588                 bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
  589                 if (!bp) {
  590                     error = newnfs_sigintr(nmp, td);
  591                     return (error ? error : EINTR);
  592                 }
  593                 if ((bp->b_flags & B_CACHE) == 0) {
  594                     bp->b_iocmd = BIO_READ;
  595                     vfs_busy_pages(bp, 0);
  596                     error = ncl_doio(vp, bp, cred, td, 0);
  597                     if (error) {
  598                             brelse(bp);
  599                     }
  600                     while (error == NFSERR_BAD_COOKIE) {
  601                         ncl_invaldir(vp);
  602                         error = ncl_vinvalbuf(vp, 0, td, 1);
  603                         /*
  604                          * Yuck! The directory has been modified on the
  605                          * server. The only way to get the block is by
  606                          * reading from the beginning to get all the
  607                          * offset cookies.
  608                          *
  609                          * Leave the last bp intact unless there is an error.
  610                          * Loop back up to the while if the error is another
  611                          * NFSERR_BAD_COOKIE (double yuch!).
  612                          */
  613                         for (i = 0; i <= lbn && !error; i++) {
  614                             if (np->n_direofoffset
  615                                 && (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
  616                                     return (0);
  617                             bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
  618                             if (!bp) {
  619                                 error = newnfs_sigintr(nmp, td);
  620                                 return (error ? error : EINTR);
  621                             }
  622                             if ((bp->b_flags & B_CACHE) == 0) {
  623                                     bp->b_iocmd = BIO_READ;
  624                                     vfs_busy_pages(bp, 0);
  625                                     error = ncl_doio(vp, bp, cred, td, 0);
  626                                     /*
  627                                      * no error + B_INVAL == directory EOF,
  628                                      * use the block.
  629                                      */
  630                                     if (error == 0 && (bp->b_flags & B_INVAL))
  631                                             break;
  632                             }
  633                             /*
  634                              * An error will throw away the block and the
  635                              * for loop will break out.  If no error and this
  636                              * is not the block we want, we throw away the
  637                              * block and go for the next one via the for loop.
  638                              */
  639                             if (error || i < lbn)
  640                                     brelse(bp);
  641                         }
  642                     }
  643                     /*
  644                      * The above while is repeated if we hit another cookie
  645                      * error.  If we hit an error and it wasn't a cookie error,
  646                      * we give up.
  647                      */
  648                     if (error)
  649                             return (error);
  650                 }
  651 
  652                 /*
  653                  * If not eof and read aheads are enabled, start one.
  654                  * (You need the current block first, so that you have the
  655                  *  directory offset cookie of the next block.)
  656                  */
  657                 if (nmp->nm_readahead > 0 &&
  658                     (bp->b_flags & B_INVAL) == 0 &&
  659                     (np->n_direofoffset == 0 ||
  660                     (lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
  661                     incore(&vp->v_bufobj, lbn + 1) == NULL) {
  662                         rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
  663                         if (rabp) {
  664                             if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
  665                                 rabp->b_flags |= B_ASYNC;
  666                                 rabp->b_iocmd = BIO_READ;
  667                                 vfs_busy_pages(rabp, 0);
  668                                 if (ncl_asyncio(nmp, rabp, cred, td)) {
  669                                     rabp->b_flags |= B_INVAL;
  670                                     rabp->b_ioflags |= BIO_ERROR;
  671                                     vfs_unbusy_pages(rabp);
  672                                     brelse(rabp);
  673                                 }
  674                             } else {
  675                                 brelse(rabp);
  676                             }
  677                         }
  678                 }
  679                 /*
  680                  * Unlike VREG files, whos buffer size ( bp->b_bcount ) is
  681                  * chopped for the EOF condition, we cannot tell how large
  682                  * NFS directories are going to be until we hit EOF.  So
  683                  * an NFS directory buffer is *not* chopped to its EOF.  Now,
  684                  * it just so happens that b_resid will effectively chop it
  685                  * to EOF.  *BUT* this information is lost if the buffer goes
  686                  * away and is reconstituted into a B_CACHE state ( due to
  687                  * being VMIO ) later.  So we keep track of the directory eof
  688                  * in np->n_direofoffset and chop it off as an extra step
  689                  * right here.
  690                  */
  691                 n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
  692                 if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
  693                         n = np->n_direofoffset - uio->uio_offset;
  694                 break;
  695             default:
  696                 ncl_printf(" ncl_bioread: type %x unexpected\n", vp->v_type);
  697                 bp = NULL;
  698                 break;
  699             };
  700 
  701             if (n > 0) {
  702                     error = vn_io_fault_uiomove(bp->b_data + on, (int)n, uio);
  703             }
  704             if (vp->v_type == VLNK)
  705                 n = 0;
  706             if (bp != NULL)
  707                 brelse(bp);
  708         } while (error == 0 && uio->uio_resid > 0 && n > 0);
  709         return (error);
  710 }
  711 
  712 /*
  713  * The NFS write path cannot handle iovecs with len > 1. So we need to
  714  * break up iovecs accordingly (restricting them to wsize).
  715  * For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
  716  * For the ASYNC case, 2 copies are needed. The first a copy from the
  717  * user buffer to a staging buffer and then a second copy from the staging
  718  * buffer to mbufs. This can be optimized by copying from the user buffer
  719  * directly into mbufs and passing the chain down, but that requires a
  720  * fair amount of re-working of the relevant codepaths (and can be done
  721  * later).
  722  */
  723 static int
  724 nfs_directio_write(vp, uiop, cred, ioflag)
  725         struct vnode *vp;
  726         struct uio *uiop;
  727         struct ucred *cred;
  728         int ioflag;
  729 {
  730         int error;
  731         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
  732         struct thread *td = uiop->uio_td;
  733         int size;
  734         int wsize;
  735 
  736         mtx_lock(&nmp->nm_mtx);
  737         wsize = nmp->nm_wsize;
  738         mtx_unlock(&nmp->nm_mtx);
  739         if (ioflag & IO_SYNC) {
  740                 int iomode, must_commit;
  741                 struct uio uio;
  742                 struct iovec iov;
  743 do_sync:
  744                 while (uiop->uio_resid > 0) {
  745                         size = MIN(uiop->uio_resid, wsize);
  746                         size = MIN(uiop->uio_iov->iov_len, size);
  747                         iov.iov_base = uiop->uio_iov->iov_base;
  748                         iov.iov_len = size;
  749                         uio.uio_iov = &iov;
  750                         uio.uio_iovcnt = 1;
  751                         uio.uio_offset = uiop->uio_offset;
  752                         uio.uio_resid = size;
  753                         uio.uio_segflg = UIO_USERSPACE;
  754                         uio.uio_rw = UIO_WRITE;
  755                         uio.uio_td = td;
  756                         iomode = NFSWRITE_FILESYNC;
  757                         error = ncl_writerpc(vp, &uio, cred, &iomode,
  758                             &must_commit, 0);
  759                         KASSERT((must_commit == 0),
  760                                 ("ncl_directio_write: Did not commit write"));
  761                         if (error)
  762                                 return (error);
  763                         uiop->uio_offset += size;
  764                         uiop->uio_resid -= size;
  765                         if (uiop->uio_iov->iov_len <= size) {
  766                                 uiop->uio_iovcnt--;
  767                                 uiop->uio_iov++;
  768                         } else {
  769                                 uiop->uio_iov->iov_base =
  770                                         (char *)uiop->uio_iov->iov_base + size;
  771                                 uiop->uio_iov->iov_len -= size;
  772                         }
  773                 }
  774         } else {
  775                 struct uio *t_uio;
  776                 struct iovec *t_iov;
  777                 struct buf *bp;
  778 
  779                 /*
  780                  * Break up the write into blocksize chunks and hand these
  781                  * over to nfsiod's for write back.
  782                  * Unfortunately, this incurs a copy of the data. Since
  783                  * the user could modify the buffer before the write is
  784                  * initiated.
  785                  *
  786                  * The obvious optimization here is that one of the 2 copies
  787                  * in the async write path can be eliminated by copying the
  788                  * data here directly into mbufs and passing the mbuf chain
  789                  * down. But that will require a fair amount of re-working
  790                  * of the code and can be done if there's enough interest
  791                  * in NFS directio access.
  792                  */
  793                 while (uiop->uio_resid > 0) {
  794                         size = MIN(uiop->uio_resid, wsize);
  795                         size = MIN(uiop->uio_iov->iov_len, size);
  796                         bp = getpbuf(&ncl_pbuf_freecnt);
  797                         t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
  798                         t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
  799                         t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
  800                         t_iov->iov_len = size;
  801                         t_uio->uio_iov = t_iov;
  802                         t_uio->uio_iovcnt = 1;
  803                         t_uio->uio_offset = uiop->uio_offset;
  804                         t_uio->uio_resid = size;
  805                         t_uio->uio_segflg = UIO_SYSSPACE;
  806                         t_uio->uio_rw = UIO_WRITE;
  807                         t_uio->uio_td = td;
  808                         KASSERT(uiop->uio_segflg == UIO_USERSPACE ||
  809                             uiop->uio_segflg == UIO_SYSSPACE,
  810                             ("nfs_directio_write: Bad uio_segflg"));
  811                         if (uiop->uio_segflg == UIO_USERSPACE) {
  812                                 error = copyin(uiop->uio_iov->iov_base,
  813                                     t_iov->iov_base, size);
  814                                 if (error != 0)
  815                                         goto err_free;
  816                         } else
  817                                 /*
  818                                  * UIO_SYSSPACE may never happen, but handle
  819                                  * it just in case it does.
  820                                  */
  821                                 bcopy(uiop->uio_iov->iov_base, t_iov->iov_base,
  822                                     size);
  823                         bp->b_flags |= B_DIRECT;
  824                         bp->b_iocmd = BIO_WRITE;
  825                         if (cred != NOCRED) {
  826                                 crhold(cred);
  827                                 bp->b_wcred = cred;
  828                         } else
  829                                 bp->b_wcred = NOCRED;
  830                         bp->b_caller1 = (void *)t_uio;
  831                         bp->b_vp = vp;
  832                         error = ncl_asyncio(nmp, bp, NOCRED, td);
  833 err_free:
  834                         if (error) {
  835                                 free(t_iov->iov_base, M_NFSDIRECTIO);
  836                                 free(t_iov, M_NFSDIRECTIO);
  837                                 free(t_uio, M_NFSDIRECTIO);
  838                                 bp->b_vp = NULL;
  839                                 relpbuf(bp, &ncl_pbuf_freecnt);
  840                                 if (error == EINTR)
  841                                         return (error);
  842                                 goto do_sync;
  843                         }
  844                         uiop->uio_offset += size;
  845                         uiop->uio_resid -= size;
  846                         if (uiop->uio_iov->iov_len <= size) {
  847                                 uiop->uio_iovcnt--;
  848                                 uiop->uio_iov++;
  849                         } else {
  850                                 uiop->uio_iov->iov_base =
  851                                         (char *)uiop->uio_iov->iov_base + size;
  852                                 uiop->uio_iov->iov_len -= size;
  853                         }
  854                 }
  855         }
  856         return (0);
  857 }
  858 
  859 /*
  860  * Vnode op for write using bio
  861  */
  862 int
  863 ncl_write(struct vop_write_args *ap)
  864 {
  865         int biosize;
  866         struct uio *uio = ap->a_uio;
  867         struct thread *td = uio->uio_td;
  868         struct vnode *vp = ap->a_vp;
  869         struct nfsnode *np = VTONFS(vp);
  870         struct ucred *cred = ap->a_cred;
  871         int ioflag = ap->a_ioflag;
  872         struct buf *bp;
  873         struct vattr vattr;
  874         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
  875         daddr_t lbn;
  876         int bcount;
  877         int bp_cached, n, on, error = 0, error1;
  878         size_t orig_resid, local_resid;
  879         off_t orig_size, tmp_off;
  880 
  881         KASSERT(uio->uio_rw == UIO_WRITE, ("ncl_write mode"));
  882         KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
  883             ("ncl_write proc"));
  884         if (vp->v_type != VREG)
  885                 return (EIO);
  886         mtx_lock(&np->n_mtx);
  887         if (np->n_flag & NWRITEERR) {
  888                 np->n_flag &= ~NWRITEERR;
  889                 mtx_unlock(&np->n_mtx);
  890                 return (np->n_error);
  891         } else
  892                 mtx_unlock(&np->n_mtx);
  893         mtx_lock(&nmp->nm_mtx);
  894         if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
  895             (nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
  896                 mtx_unlock(&nmp->nm_mtx);
  897                 (void)ncl_fsinfo(nmp, vp, cred, td);
  898                 mtx_lock(&nmp->nm_mtx);
  899         }
  900         if (nmp->nm_wsize == 0)
  901                 (void) newnfs_iosize(nmp);
  902         mtx_unlock(&nmp->nm_mtx);
  903 
  904         /*
  905          * Synchronously flush pending buffers if we are in synchronous
  906          * mode or if we are appending.
  907          */
  908         if (ioflag & (IO_APPEND | IO_SYNC)) {
  909                 mtx_lock(&np->n_mtx);
  910                 if (np->n_flag & NMODIFIED) {
  911                         mtx_unlock(&np->n_mtx);
  912 #ifdef notyet /* Needs matching nonblock semantics elsewhere, too. */
  913                         /*
  914                          * Require non-blocking, synchronous writes to
  915                          * dirty files to inform the program it needs
  916                          * to fsync(2) explicitly.
  917                          */
  918                         if (ioflag & IO_NDELAY)
  919                                 return (EAGAIN);
  920 #endif
  921 flush_and_restart:
  922                         np->n_attrstamp = 0;
  923                         KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
  924                         error = ncl_vinvalbuf(vp, V_SAVE, td, 1);
  925                         if (error)
  926                                 return (error);
  927                 } else
  928                         mtx_unlock(&np->n_mtx);
  929         }
  930 
  931         orig_resid = uio->uio_resid;
  932         mtx_lock(&np->n_mtx);
  933         orig_size = np->n_size;
  934         mtx_unlock(&np->n_mtx);
  935 
  936         /*
  937          * If IO_APPEND then load uio_offset.  We restart here if we cannot
  938          * get the append lock.
  939          */
  940         if (ioflag & IO_APPEND) {
  941                 np->n_attrstamp = 0;
  942                 KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
  943                 error = VOP_GETATTR(vp, &vattr, cred);
  944                 if (error)
  945                         return (error);
  946                 mtx_lock(&np->n_mtx);
  947                 uio->uio_offset = np->n_size;
  948                 mtx_unlock(&np->n_mtx);
  949         }
  950 
  951         if (uio->uio_offset < 0)
  952                 return (EINVAL);
  953         tmp_off = uio->uio_offset + uio->uio_resid;
  954         if (tmp_off > nmp->nm_maxfilesize || tmp_off < uio->uio_offset)
  955                 return (EFBIG);
  956         if (uio->uio_resid == 0)
  957                 return (0);
  958 
  959         if (newnfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
  960                 return nfs_directio_write(vp, uio, cred, ioflag);
  961 
  962         /*
  963          * Maybe this should be above the vnode op call, but so long as
  964          * file servers have no limits, i don't think it matters
  965          */
  966         if (vn_rlimit_fsize(vp, uio, td))
  967                 return (EFBIG);
  968 
  969         biosize = vp->v_bufobj.bo_bsize;
  970         /*
  971          * Find all of this file's B_NEEDCOMMIT buffers.  If our writes
  972          * would exceed the local maximum per-file write commit size when
  973          * combined with those, we must decide whether to flush,
  974          * go synchronous, or return error.  We don't bother checking
  975          * IO_UNIT -- we just make all writes atomic anyway, as there's
  976          * no point optimizing for something that really won't ever happen.
  977          */
  978         if (!(ioflag & IO_SYNC)) {
  979                 int nflag;
  980 
  981                 mtx_lock(&np->n_mtx);
  982                 nflag = np->n_flag;
  983                 mtx_unlock(&np->n_mtx);
  984                 int needrestart = 0;
  985                 if (nmp->nm_wcommitsize < uio->uio_resid) {
  986                         /*
  987                          * If this request could not possibly be completed
  988                          * without exceeding the maximum outstanding write
  989                          * commit size, see if we can convert it into a
  990                          * synchronous write operation.
  991                          */
  992                         if (ioflag & IO_NDELAY)
  993                                 return (EAGAIN);
  994                         ioflag |= IO_SYNC;
  995                         if (nflag & NMODIFIED)
  996                                 needrestart = 1;
  997                 } else if (nflag & NMODIFIED) {
  998                         int wouldcommit = 0;
  999                         BO_LOCK(&vp->v_bufobj);
 1000                         if (vp->v_bufobj.bo_dirty.bv_cnt != 0) {
 1001                                 TAILQ_FOREACH(bp, &vp->v_bufobj.bo_dirty.bv_hd,
 1002                                     b_bobufs) {
 1003                                         if (bp->b_flags & B_NEEDCOMMIT)
 1004                                                 wouldcommit += bp->b_bcount;
 1005                                 }
 1006                         }
 1007                         BO_UNLOCK(&vp->v_bufobj);
 1008                         /*
 1009                          * Since we're not operating synchronously and
 1010                          * bypassing the buffer cache, we are in a commit
 1011                          * and holding all of these buffers whether
 1012                          * transmitted or not.  If not limited, this
 1013                          * will lead to the buffer cache deadlocking,
 1014                          * as no one else can flush our uncommitted buffers.
 1015                          */
 1016                         wouldcommit += uio->uio_resid;
 1017                         /*
 1018                          * If we would initially exceed the maximum
 1019                          * outstanding write commit size, flush and restart.
 1020                          */
 1021                         if (wouldcommit > nmp->nm_wcommitsize)
 1022                                 needrestart = 1;
 1023                 }
 1024                 if (needrestart)
 1025                         goto flush_and_restart;
 1026         }
 1027 
 1028         do {
 1029                 NFSINCRGLOBAL(newnfsstats.biocache_writes);
 1030                 lbn = uio->uio_offset / biosize;
 1031                 on = uio->uio_offset & (biosize-1);
 1032                 n = MIN((unsigned)(biosize - on), uio->uio_resid);
 1033 again:
 1034                 /*
 1035                  * Handle direct append and file extension cases, calculate
 1036                  * unaligned buffer size.
 1037                  */
 1038                 mtx_lock(&np->n_mtx);
 1039                 if (uio->uio_offset == np->n_size && n) {
 1040                         mtx_unlock(&np->n_mtx);
 1041                         /*
 1042                          * Get the buffer (in its pre-append state to maintain
 1043                          * B_CACHE if it was previously set).  Resize the
 1044                          * nfsnode after we have locked the buffer to prevent
 1045                          * readers from reading garbage.
 1046                          */
 1047                         bcount = on;
 1048                         bp = nfs_getcacheblk(vp, lbn, bcount, td);
 1049 
 1050                         if (bp != NULL) {
 1051                                 long save;
 1052 
 1053                                 mtx_lock(&np->n_mtx);
 1054                                 np->n_size = uio->uio_offset + n;
 1055                                 np->n_flag |= NMODIFIED;
 1056                                 vnode_pager_setsize(vp, np->n_size);
 1057                                 mtx_unlock(&np->n_mtx);
 1058 
 1059                                 save = bp->b_flags & B_CACHE;
 1060                                 bcount += n;
 1061                                 allocbuf(bp, bcount);
 1062                                 bp->b_flags |= save;
 1063                         }
 1064                 } else {
 1065                         /*
 1066                          * Obtain the locked cache block first, and then
 1067                          * adjust the file's size as appropriate.
 1068                          */
 1069                         bcount = on + n;
 1070                         if ((off_t)lbn * biosize + bcount < np->n_size) {
 1071                                 if ((off_t)(lbn + 1) * biosize < np->n_size)
 1072                                         bcount = biosize;
 1073                                 else
 1074                                         bcount = np->n_size - (off_t)lbn * biosize;
 1075                         }
 1076                         mtx_unlock(&np->n_mtx);
 1077                         bp = nfs_getcacheblk(vp, lbn, bcount, td);
 1078                         mtx_lock(&np->n_mtx);
 1079                         if (uio->uio_offset + n > np->n_size) {
 1080                                 np->n_size = uio->uio_offset + n;
 1081                                 np->n_flag |= NMODIFIED;
 1082                                 vnode_pager_setsize(vp, np->n_size);
 1083                         }
 1084                         mtx_unlock(&np->n_mtx);
 1085                 }
 1086 
 1087                 if (!bp) {
 1088                         error = newnfs_sigintr(nmp, td);
 1089                         if (!error)
 1090                                 error = EINTR;
 1091                         break;
 1092                 }
 1093 
 1094                 /*
 1095                  * Issue a READ if B_CACHE is not set.  In special-append
 1096                  * mode, B_CACHE is based on the buffer prior to the write
 1097                  * op and is typically set, avoiding the read.  If a read
 1098                  * is required in special append mode, the server will
 1099                  * probably send us a short-read since we extended the file
 1100                  * on our end, resulting in b_resid == 0 and, thusly,
 1101                  * B_CACHE getting set.
 1102                  *
 1103                  * We can also avoid issuing the read if the write covers
 1104                  * the entire buffer.  We have to make sure the buffer state
 1105                  * is reasonable in this case since we will not be initiating
 1106                  * I/O.  See the comments in kern/vfs_bio.c's getblk() for
 1107                  * more information.
 1108                  *
 1109                  * B_CACHE may also be set due to the buffer being cached
 1110                  * normally.
 1111                  */
 1112 
 1113                 bp_cached = 1;
 1114                 if (on == 0 && n == bcount) {
 1115                         if ((bp->b_flags & B_CACHE) == 0)
 1116                                 bp_cached = 0;
 1117                         bp->b_flags |= B_CACHE;
 1118                         bp->b_flags &= ~B_INVAL;
 1119                         bp->b_ioflags &= ~BIO_ERROR;
 1120                 }
 1121 
 1122                 if ((bp->b_flags & B_CACHE) == 0) {
 1123                         bp->b_iocmd = BIO_READ;
 1124                         vfs_busy_pages(bp, 0);
 1125                         error = ncl_doio(vp, bp, cred, td, 0);
 1126                         if (error) {
 1127                                 brelse(bp);
 1128                                 break;
 1129                         }
 1130                 }
 1131                 if (bp->b_wcred == NOCRED)
 1132                         bp->b_wcred = crhold(cred);
 1133                 mtx_lock(&np->n_mtx);
 1134                 np->n_flag |= NMODIFIED;
 1135                 mtx_unlock(&np->n_mtx);
 1136 
 1137                 /*
 1138                  * If dirtyend exceeds file size, chop it down.  This should
 1139                  * not normally occur but there is an append race where it
 1140                  * might occur XXX, so we log it.
 1141                  *
 1142                  * If the chopping creates a reverse-indexed or degenerate
 1143                  * situation with dirtyoff/end, we 0 both of them.
 1144                  */
 1145 
 1146                 if (bp->b_dirtyend > bcount) {
 1147                         ncl_printf("NFS append race @%lx:%d\n",
 1148                             (long)bp->b_blkno * DEV_BSIZE,
 1149                             bp->b_dirtyend - bcount);
 1150                         bp->b_dirtyend = bcount;
 1151                 }
 1152 
 1153                 if (bp->b_dirtyoff >= bp->b_dirtyend)
 1154                         bp->b_dirtyoff = bp->b_dirtyend = 0;
 1155 
 1156                 /*
 1157                  * If the new write will leave a contiguous dirty
 1158                  * area, just update the b_dirtyoff and b_dirtyend,
 1159                  * otherwise force a write rpc of the old dirty area.
 1160                  *
 1161                  * While it is possible to merge discontiguous writes due to
 1162                  * our having a B_CACHE buffer ( and thus valid read data
 1163                  * for the hole), we don't because it could lead to
 1164                  * significant cache coherency problems with multiple clients,
 1165                  * especially if locking is implemented later on.
 1166                  *
 1167                  * As an optimization we could theoretically maintain
 1168                  * a linked list of discontinuous areas, but we would still
 1169                  * have to commit them separately so there isn't much
 1170                  * advantage to it except perhaps a bit of asynchronization.
 1171                  */
 1172 
 1173                 if (bp->b_dirtyend > 0 &&
 1174                     (on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
 1175                         if (bwrite(bp) == EINTR) {
 1176                                 error = EINTR;
 1177                                 break;
 1178                         }
 1179                         goto again;
 1180                 }
 1181 
 1182                 local_resid = uio->uio_resid;
 1183                 error = vn_io_fault_uiomove((char *)bp->b_data + on, n, uio);
 1184 
 1185                 if (error != 0 && !bp_cached) {
 1186                         /*
 1187                          * This block has no other content then what
 1188                          * possibly was written by the faulty uiomove.
 1189                          * Release it, forgetting the data pages, to
 1190                          * prevent the leak of uninitialized data to
 1191                          * usermode.
 1192                          */
 1193                         bp->b_ioflags |= BIO_ERROR;
 1194                         brelse(bp);
 1195                         uio->uio_offset -= local_resid - uio->uio_resid;
 1196                         uio->uio_resid = local_resid;
 1197                         break;
 1198                 }
 1199 
 1200                 /*
 1201                  * Since this block is being modified, it must be written
 1202                  * again and not just committed.  Since write clustering does
 1203                  * not work for the stage 1 data write, only the stage 2
 1204                  * commit rpc, we have to clear B_CLUSTEROK as well.
 1205                  */
 1206                 bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 1207 
 1208                 /*
 1209                  * Get the partial update on the progress made from
 1210                  * uiomove, if an error occured.
 1211                  */
 1212                 if (error != 0)
 1213                         n = local_resid - uio->uio_resid;
 1214 
 1215                 /*
 1216                  * Only update dirtyoff/dirtyend if not a degenerate
 1217                  * condition.
 1218                  */
 1219                 if (n > 0) {
 1220                         if (bp->b_dirtyend > 0) {
 1221                                 bp->b_dirtyoff = min(on, bp->b_dirtyoff);
 1222                                 bp->b_dirtyend = max((on + n), bp->b_dirtyend);
 1223                         } else {
 1224                                 bp->b_dirtyoff = on;
 1225                                 bp->b_dirtyend = on + n;
 1226                         }
 1227                         vfs_bio_set_valid(bp, on, n);
 1228                 }
 1229 
 1230                 /*
 1231                  * If IO_SYNC do bwrite().
 1232                  *
 1233                  * IO_INVAL appears to be unused.  The idea appears to be
 1234                  * to turn off caching in this case.  Very odd.  XXX
 1235                  */
 1236                 if ((ioflag & IO_SYNC)) {
 1237                         if (ioflag & IO_INVAL)
 1238                                 bp->b_flags |= B_NOCACHE;
 1239                         error1 = bwrite(bp);
 1240                         if (error1 != 0) {
 1241                                 if (error == 0)
 1242                                         error = error1;
 1243                                 break;
 1244                         }
 1245                 } else if ((n + on) == biosize) {
 1246                         bp->b_flags |= B_ASYNC;
 1247                         (void) ncl_writebp(bp, 0, NULL);
 1248                 } else {
 1249                         bdwrite(bp);
 1250                 }
 1251 
 1252                 if (error != 0)
 1253                         break;
 1254         } while (uio->uio_resid > 0 && n > 0);
 1255 
 1256         if (error != 0) {
 1257                 if (ioflag & IO_UNIT) {
 1258                         VATTR_NULL(&vattr);
 1259                         vattr.va_size = orig_size;
 1260                         /* IO_SYNC is handled implicitely */
 1261                         (void)VOP_SETATTR(vp, &vattr, cred);
 1262                         uio->uio_offset -= orig_resid - uio->uio_resid;
 1263                         uio->uio_resid = orig_resid;
 1264                 }
 1265         }
 1266 
 1267         return (error);
 1268 }
 1269 
 1270 /*
 1271  * Get an nfs cache block.
 1272  *
 1273  * Allocate a new one if the block isn't currently in the cache
 1274  * and return the block marked busy. If the calling process is
 1275  * interrupted by a signal for an interruptible mount point, return
 1276  * NULL.
 1277  *
 1278  * The caller must carefully deal with the possible B_INVAL state of
 1279  * the buffer.  ncl_doio() clears B_INVAL (and ncl_asyncio() clears it
 1280  * indirectly), so synchronous reads can be issued without worrying about
 1281  * the B_INVAL state.  We have to be a little more careful when dealing
 1282  * with writes (see comments in nfs_write()) when extending a file past
 1283  * its EOF.
 1284  */
 1285 static struct buf *
 1286 nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
 1287 {
 1288         struct buf *bp;
 1289         struct mount *mp;
 1290         struct nfsmount *nmp;
 1291 
 1292         mp = vp->v_mount;
 1293         nmp = VFSTONFS(mp);
 1294 
 1295         if (nmp->nm_flag & NFSMNT_INT) {
 1296                 sigset_t oldset;
 1297 
 1298                 newnfs_set_sigmask(td, &oldset);
 1299                 bp = getblk(vp, bn, size, NFS_PCATCH, 0, 0);
 1300                 newnfs_restore_sigmask(td, &oldset);
 1301                 while (bp == NULL) {
 1302                         if (newnfs_sigintr(nmp, td))
 1303                                 return (NULL);
 1304                         bp = getblk(vp, bn, size, 0, 2 * hz, 0);
 1305                 }
 1306         } else {
 1307                 bp = getblk(vp, bn, size, 0, 0, 0);
 1308         }
 1309 
 1310         if (vp->v_type == VREG)
 1311                 bp->b_blkno = bn * (vp->v_bufobj.bo_bsize / DEV_BSIZE);
 1312         return (bp);
 1313 }
 1314 
 1315 /*
 1316  * Flush and invalidate all dirty buffers. If another process is already
 1317  * doing the flush, just wait for completion.
 1318  */
 1319 int
 1320 ncl_vinvalbuf(struct vnode *vp, int flags, struct thread *td, int intrflg)
 1321 {
 1322         struct nfsnode *np = VTONFS(vp);
 1323         struct nfsmount *nmp = VFSTONFS(vp->v_mount);
 1324         int error = 0, slpflag, slptimeo;
 1325         int old_lock = 0;
 1326 
 1327         ASSERT_VOP_LOCKED(vp, "ncl_vinvalbuf");
 1328 
 1329         if ((nmp->nm_flag & NFSMNT_INT) == 0)
 1330                 intrflg = 0;
 1331         if ((nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF))
 1332                 intrflg = 1;
 1333         if (intrflg) {
 1334                 slpflag = NFS_PCATCH;
 1335                 slptimeo = 2 * hz;
 1336         } else {
 1337                 slpflag = 0;
 1338                 slptimeo = 0;
 1339         }
 1340 
 1341         old_lock = ncl_upgrade_vnlock(vp);
 1342         if (vp->v_iflag & VI_DOOMED) {
 1343                 /*
 1344                  * Since vgonel() uses the generic vinvalbuf() to flush
 1345                  * dirty buffers and it does not call this function, it
 1346                  * is safe to just return OK when VI_DOOMED is set.
 1347                  */
 1348                 ncl_downgrade_vnlock(vp, old_lock);
 1349                 return (0);
 1350         }
 1351 
 1352         /*
 1353          * Now, flush as required.
 1354          */
 1355         if ((flags & V_SAVE) && (vp->v_bufobj.bo_object != NULL)) {
 1356                 VM_OBJECT_LOCK(vp->v_bufobj.bo_object);
 1357                 vm_object_page_clean(vp->v_bufobj.bo_object, 0, 0, OBJPC_SYNC);
 1358                 VM_OBJECT_UNLOCK(vp->v_bufobj.bo_object);
 1359                 /*
 1360                  * If the page clean was interrupted, fail the invalidation.
 1361                  * Not doing so, we run the risk of losing dirty pages in the
 1362                  * vinvalbuf() call below.
 1363                  */
 1364                 if (intrflg && (error = newnfs_sigintr(nmp, td)))
 1365                         goto out;
 1366         }
 1367 
 1368         error = vinvalbuf(vp, flags, slpflag, 0);
 1369         while (error) {
 1370                 if (intrflg && (error = newnfs_sigintr(nmp, td)))
 1371                         goto out;
 1372                 error = vinvalbuf(vp, flags, 0, slptimeo);
 1373         }
 1374         mtx_lock(&np->n_mtx);
 1375         if (np->n_directio_asyncwr == 0)
 1376                 np->n_flag &= ~NMODIFIED;
 1377         mtx_unlock(&np->n_mtx);
 1378 out:
 1379         ncl_downgrade_vnlock(vp, old_lock);
 1380         return error;
 1381 }
 1382 
 1383 /*
 1384  * Initiate asynchronous I/O. Return an error if no nfsiods are available.
 1385  * This is mainly to avoid queueing async I/O requests when the nfsiods
 1386  * are all hung on a dead server.
 1387  *
 1388  * Note: ncl_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
 1389  * is eventually dequeued by the async daemon, ncl_doio() *will*.
 1390  */
 1391 int
 1392 ncl_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
 1393 {
 1394         int iod;
 1395         int gotiod;
 1396         int slpflag = 0;
 1397         int slptimeo = 0;
 1398         int error, error2;
 1399 
 1400         /*
 1401          * Commits are usually short and sweet so lets save some cpu and
 1402          * leave the async daemons for more important rpc's (such as reads
 1403          * and writes).
 1404          *
 1405          * Readdirplus RPCs do vget()s to acquire the vnodes for entries
 1406          * in the directory in order to update attributes. This can deadlock
 1407          * with another thread that is waiting for async I/O to be done by
 1408          * an nfsiod thread while holding a lock on one of these vnodes.
 1409          * To avoid this deadlock, don't allow the async nfsiod threads to
 1410          * perform Readdirplus RPCs.
 1411          */
 1412         mtx_lock(&ncl_iod_mutex);
 1413         if ((bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
 1414              (nmp->nm_bufqiods > ncl_numasync / 2)) ||
 1415             (bp->b_vp->v_type == VDIR && (nmp->nm_flag & NFSMNT_RDIRPLUS))) {
 1416                 mtx_unlock(&ncl_iod_mutex);
 1417                 return(EIO);
 1418         }
 1419 again:
 1420         if (nmp->nm_flag & NFSMNT_INT)
 1421                 slpflag = NFS_PCATCH;
 1422         gotiod = FALSE;
 1423 
 1424         /*
 1425          * Find a free iod to process this request.
 1426          */
 1427         for (iod = 0; iod < ncl_numasync; iod++)
 1428                 if (ncl_iodwant[iod] == NFSIOD_AVAILABLE) {
 1429                         gotiod = TRUE;
 1430                         break;
 1431                 }
 1432 
 1433         /*
 1434          * Try to create one if none are free.
 1435          */
 1436         if (!gotiod)
 1437                 ncl_nfsiodnew();
 1438         else {
 1439                 /*
 1440                  * Found one, so wake it up and tell it which
 1441                  * mount to process.
 1442                  */
 1443                 NFS_DPF(ASYNCIO, ("ncl_asyncio: waking iod %d for mount %p\n",
 1444                     iod, nmp));
 1445                 ncl_iodwant[iod] = NFSIOD_NOT_AVAILABLE;
 1446                 ncl_iodmount[iod] = nmp;
 1447                 nmp->nm_bufqiods++;
 1448                 wakeup(&ncl_iodwant[iod]);
 1449         }
 1450 
 1451         /*
 1452          * If none are free, we may already have an iod working on this mount
 1453          * point.  If so, it will process our request.
 1454          */
 1455         if (!gotiod) {
 1456                 if (nmp->nm_bufqiods > 0) {
 1457                         NFS_DPF(ASYNCIO,
 1458                                 ("ncl_asyncio: %d iods are already processing mount %p\n",
 1459                                  nmp->nm_bufqiods, nmp));
 1460                         gotiod = TRUE;
 1461                 }
 1462         }
 1463 
 1464         /*
 1465          * If we have an iod which can process the request, then queue
 1466          * the buffer.
 1467          */
 1468         if (gotiod) {
 1469                 /*
 1470                  * Ensure that the queue never grows too large.  We still want
 1471                  * to asynchronize so we block rather then return EIO.
 1472                  */
 1473                 while (nmp->nm_bufqlen >= 2*ncl_numasync) {
 1474                         NFS_DPF(ASYNCIO,
 1475                                 ("ncl_asyncio: waiting for mount %p queue to drain\n", nmp));
 1476                         nmp->nm_bufqwant = TRUE;
 1477                         error = newnfs_msleep(td, &nmp->nm_bufq,
 1478                             &ncl_iod_mutex, slpflag | PRIBIO, "nfsaio",
 1479                            slptimeo);
 1480                         if (error) {
 1481                                 error2 = newnfs_sigintr(nmp, td);
 1482                                 if (error2) {
 1483                                         mtx_unlock(&ncl_iod_mutex);
 1484                                         return (error2);
 1485                                 }
 1486                                 if (slpflag == NFS_PCATCH) {
 1487                                         slpflag = 0;
 1488                                         slptimeo = 2 * hz;
 1489                                 }
 1490                         }
 1491                         /*
 1492                          * We might have lost our iod while sleeping,
 1493                          * so check and loop if nescessary.
 1494                          */
 1495                         goto again;
 1496                 }
 1497 
 1498                 /* We might have lost our nfsiod */
 1499                 if (nmp->nm_bufqiods == 0) {
 1500                         NFS_DPF(ASYNCIO,
 1501                                 ("ncl_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
 1502                         goto again;
 1503                 }
 1504 
 1505                 if (bp->b_iocmd == BIO_READ) {
 1506                         if (bp->b_rcred == NOCRED && cred != NOCRED)
 1507                                 bp->b_rcred = crhold(cred);
 1508                 } else {
 1509                         if (bp->b_wcred == NOCRED && cred != NOCRED)
 1510                                 bp->b_wcred = crhold(cred);
 1511                 }
 1512 
 1513                 if (bp->b_flags & B_REMFREE)
 1514                         bremfreef(bp);
 1515                 BUF_KERNPROC(bp);
 1516                 TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
 1517                 nmp->nm_bufqlen++;
 1518                 if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
 1519                         mtx_lock(&(VTONFS(bp->b_vp))->n_mtx);
 1520                         VTONFS(bp->b_vp)->n_flag |= NMODIFIED;
 1521                         VTONFS(bp->b_vp)->n_directio_asyncwr++;
 1522                         mtx_unlock(&(VTONFS(bp->b_vp))->n_mtx);
 1523                 }
 1524                 mtx_unlock(&ncl_iod_mutex);
 1525                 return (0);
 1526         }
 1527 
 1528         mtx_unlock(&ncl_iod_mutex);
 1529 
 1530         /*
 1531          * All the iods are busy on other mounts, so return EIO to
 1532          * force the caller to process the i/o synchronously.
 1533          */
 1534         NFS_DPF(ASYNCIO, ("ncl_asyncio: no iods available, i/o is synchronous\n"));
 1535         return (EIO);
 1536 }
 1537 
 1538 void
 1539 ncl_doio_directwrite(struct buf *bp)
 1540 {
 1541         int iomode, must_commit;
 1542         struct uio *uiop = (struct uio *)bp->b_caller1;
 1543         char *iov_base = uiop->uio_iov->iov_base;
 1544 
 1545         iomode = NFSWRITE_FILESYNC;
 1546         uiop->uio_td = NULL; /* NULL since we're in nfsiod */
 1547         ncl_writerpc(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit, 0);
 1548         KASSERT((must_commit == 0), ("ncl_doio_directwrite: Did not commit write"));
 1549         free(iov_base, M_NFSDIRECTIO);
 1550         free(uiop->uio_iov, M_NFSDIRECTIO);
 1551         free(uiop, M_NFSDIRECTIO);
 1552         if ((bp->b_flags & B_DIRECT) && bp->b_iocmd == BIO_WRITE) {
 1553                 struct nfsnode *np = VTONFS(bp->b_vp);
 1554                 mtx_lock(&np->n_mtx);
 1555                 np->n_directio_asyncwr--;
 1556                 if (np->n_directio_asyncwr == 0) {
 1557                         np->n_flag &= ~NMODIFIED;
 1558                         if ((np->n_flag & NFSYNCWAIT)) {
 1559                                 np->n_flag &= ~NFSYNCWAIT;
 1560                                 wakeup((caddr_t)&np->n_directio_asyncwr);
 1561                         }
 1562                 }
 1563                 mtx_unlock(&np->n_mtx);
 1564         }
 1565         bp->b_vp = NULL;
 1566         relpbuf(bp, &ncl_pbuf_freecnt);
 1567 }
 1568 
 1569 /*
 1570  * Do an I/O operation to/from a cache block. This may be called
 1571  * synchronously or from an nfsiod.
 1572  */
 1573 int
 1574 ncl_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td,
 1575     int called_from_strategy)
 1576 {
 1577         struct uio *uiop;
 1578         struct nfsnode *np;
 1579         struct nfsmount *nmp;
 1580         int error = 0, iomode, must_commit = 0;
 1581         struct uio uio;
 1582         struct iovec io;
 1583         struct proc *p = td ? td->td_proc : NULL;
 1584         uint8_t iocmd;
 1585 
 1586         np = VTONFS(vp);
 1587         nmp = VFSTONFS(vp->v_mount);
 1588         uiop = &uio;
 1589         uiop->uio_iov = &io;
 1590         uiop->uio_iovcnt = 1;
 1591         uiop->uio_segflg = UIO_SYSSPACE;
 1592         uiop->uio_td = td;
 1593 
 1594         /*
 1595          * clear BIO_ERROR and B_INVAL state prior to initiating the I/O.  We
 1596          * do this here so we do not have to do it in all the code that
 1597          * calls us.
 1598          */
 1599         bp->b_flags &= ~B_INVAL;
 1600         bp->b_ioflags &= ~BIO_ERROR;
 1601 
 1602         KASSERT(!(bp->b_flags & B_DONE), ("ncl_doio: bp %p already marked done", bp));
 1603         iocmd = bp->b_iocmd;
 1604         if (iocmd == BIO_READ) {
 1605             io.iov_len = uiop->uio_resid = bp->b_bcount;
 1606             io.iov_base = bp->b_data;
 1607             uiop->uio_rw = UIO_READ;
 1608 
 1609             switch (vp->v_type) {
 1610             case VREG:
 1611                 uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
 1612                 NFSINCRGLOBAL(newnfsstats.read_bios);
 1613                 error = ncl_readrpc(vp, uiop, cr);
 1614 
 1615                 if (!error) {
 1616                     if (uiop->uio_resid) {
 1617                         /*
 1618                          * If we had a short read with no error, we must have
 1619                          * hit a file hole.  We should zero-fill the remainder.
 1620                          * This can also occur if the server hits the file EOF.
 1621                          *
 1622                          * Holes used to be able to occur due to pending
 1623                          * writes, but that is not possible any longer.
 1624                          */
 1625                         int nread = bp->b_bcount - uiop->uio_resid;
 1626                         ssize_t left = uiop->uio_resid;
 1627 
 1628                         if (left > 0)
 1629                                 bzero((char *)bp->b_data + nread, left);
 1630                         uiop->uio_resid = 0;
 1631                     }
 1632                 }
 1633                 /* ASSERT_VOP_LOCKED(vp, "ncl_doio"); */
 1634                 if (p && (vp->v_vflag & VV_TEXT)) {
 1635                         mtx_lock(&np->n_mtx);
 1636                         if (NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime)) {
 1637                                 mtx_unlock(&np->n_mtx);
 1638                                 PROC_LOCK(p);
 1639                                 killproc(p, "text file modification");
 1640                                 PROC_UNLOCK(p);
 1641                         } else
 1642                                 mtx_unlock(&np->n_mtx);
 1643                 }
 1644                 break;
 1645             case VLNK:
 1646                 uiop->uio_offset = (off_t)0;
 1647                 NFSINCRGLOBAL(newnfsstats.readlink_bios);
 1648                 error = ncl_readlinkrpc(vp, uiop, cr);
 1649                 break;
 1650             case VDIR:
 1651                 NFSINCRGLOBAL(newnfsstats.readdir_bios);
 1652                 uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
 1653                 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
 1654                         error = ncl_readdirplusrpc(vp, uiop, cr, td);
 1655                         if (error == NFSERR_NOTSUPP)
 1656                                 nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
 1657                 }
 1658                 if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
 1659                         error = ncl_readdirrpc(vp, uiop, cr, td);
 1660                 /*
 1661                  * end-of-directory sets B_INVAL but does not generate an
 1662                  * error.
 1663                  */
 1664                 if (error == 0 && uiop->uio_resid == bp->b_bcount)
 1665                         bp->b_flags |= B_INVAL;
 1666                 break;
 1667             default:
 1668                 ncl_printf("ncl_doio:  type %x unexpected\n", vp->v_type);
 1669                 break;
 1670             };
 1671             if (error) {
 1672                 bp->b_ioflags |= BIO_ERROR;
 1673                 bp->b_error = error;
 1674             }
 1675         } else {
 1676             /*
 1677              * If we only need to commit, try to commit
 1678              */
 1679             if (bp->b_flags & B_NEEDCOMMIT) {
 1680                     int retv;
 1681                     off_t off;
 1682 
 1683                     off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
 1684                     retv = ncl_commit(vp, off, bp->b_dirtyend-bp->b_dirtyoff,
 1685                         bp->b_wcred, td);
 1686                     if (retv == 0) {
 1687                             bp->b_dirtyoff = bp->b_dirtyend = 0;
 1688                             bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 1689                             bp->b_resid = 0;
 1690                             bufdone(bp);
 1691                             return (0);
 1692                     }
 1693                     if (retv == NFSERR_STALEWRITEVERF) {
 1694                             ncl_clearcommit(vp->v_mount);
 1695                     }
 1696             }
 1697 
 1698             /*
 1699              * Setup for actual write
 1700              */
 1701             mtx_lock(&np->n_mtx);
 1702             if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
 1703                 bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
 1704             mtx_unlock(&np->n_mtx);
 1705 
 1706             if (bp->b_dirtyend > bp->b_dirtyoff) {
 1707                 io.iov_len = uiop->uio_resid = bp->b_dirtyend
 1708                     - bp->b_dirtyoff;
 1709                 uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
 1710                     + bp->b_dirtyoff;
 1711                 io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
 1712                 uiop->uio_rw = UIO_WRITE;
 1713                 NFSINCRGLOBAL(newnfsstats.write_bios);
 1714 
 1715                 if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
 1716                     iomode = NFSWRITE_UNSTABLE;
 1717                 else
 1718                     iomode = NFSWRITE_FILESYNC;
 1719 
 1720                 error = ncl_writerpc(vp, uiop, cr, &iomode, &must_commit,
 1721                     called_from_strategy);
 1722 
 1723                 /*
 1724                  * When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
 1725                  * to cluster the buffers needing commit.  This will allow
 1726                  * the system to submit a single commit rpc for the whole
 1727                  * cluster.  We can do this even if the buffer is not 100%
 1728                  * dirty (relative to the NFS blocksize), so we optimize the
 1729                  * append-to-file-case.
 1730                  *
 1731                  * (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
 1732                  * cleared because write clustering only works for commit
 1733                  * rpc's, not for the data portion of the write).
 1734                  */
 1735 
 1736                 if (!error && iomode == NFSWRITE_UNSTABLE) {
 1737                     bp->b_flags |= B_NEEDCOMMIT;
 1738                     if (bp->b_dirtyoff == 0
 1739                         && bp->b_dirtyend == bp->b_bcount)
 1740                         bp->b_flags |= B_CLUSTEROK;
 1741                 } else {
 1742                     bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
 1743                 }
 1744 
 1745                 /*
 1746                  * For an interrupted write, the buffer is still valid
 1747                  * and the write hasn't been pushed to the server yet,
 1748                  * so we can't set BIO_ERROR and report the interruption
 1749                  * by setting B_EINTR. For the B_ASYNC case, B_EINTR
 1750                  * is not relevant, so the rpc attempt is essentially
 1751                  * a noop.  For the case of a V3 write rpc not being
 1752                  * committed to stable storage, the block is still
 1753                  * dirty and requires either a commit rpc or another
 1754                  * write rpc with iomode == NFSV3WRITE_FILESYNC before
 1755                  * the block is reused. This is indicated by setting
 1756                  * the B_DELWRI and B_NEEDCOMMIT flags.
 1757                  *
 1758                  * EIO is returned by ncl_writerpc() to indicate a recoverable
 1759                  * write error and is handled as above, except that
 1760                  * B_EINTR isn't set. One cause of this is a stale stateid
 1761                  * error for the RPC that indicates recovery is required,
 1762                  * when called with called_from_strategy != 0.
 1763                  *
 1764                  * If the buffer is marked B_PAGING, it does not reside on
 1765                  * the vp's paging queues so we cannot call bdirty().  The
 1766                  * bp in this case is not an NFS cache block so we should
 1767                  * be safe. XXX
 1768                  *
 1769                  * The logic below breaks up errors into recoverable and
 1770                  * unrecoverable. For the former, we clear B_INVAL|B_NOCACHE
 1771                  * and keep the buffer around for potential write retries.
 1772                  * For the latter (eg ESTALE), we toss the buffer away (B_INVAL)
 1773                  * and save the error in the nfsnode. This is less than ideal
 1774                  * but necessary. Keeping such buffers around could potentially
 1775                  * cause buffer exhaustion eventually (they can never be written
 1776                  * out, so will get constantly be re-dirtied). It also causes
 1777                  * all sorts of vfs panics. For non-recoverable write errors,
 1778                  * also invalidate the attrcache, so we'll be forced to go over
 1779                  * the wire for this object, returning an error to user on next
 1780                  * call (most of the time).
 1781                  */
 1782                 if (error == EINTR || error == EIO || error == ETIMEDOUT
 1783                     || (!error && (bp->b_flags & B_NEEDCOMMIT))) {
 1784                         int s;
 1785 
 1786                         s = splbio();
 1787                         bp->b_flags &= ~(B_INVAL|B_NOCACHE);
 1788                         if ((bp->b_flags & B_PAGING) == 0) {
 1789                             bdirty(bp);
 1790                             bp->b_flags &= ~B_DONE;
 1791                         }
 1792                         if ((error == EINTR || error == ETIMEDOUT) &&
 1793                             (bp->b_flags & B_ASYNC) == 0)
 1794                             bp->b_flags |= B_EINTR;
 1795                         splx(s);
 1796                 } else {
 1797                     if (error) {
 1798                         bp->b_ioflags |= BIO_ERROR;
 1799                         bp->b_flags |= B_INVAL;
 1800                         bp->b_error = np->n_error = error;
 1801                         mtx_lock(&np->n_mtx);
 1802                         np->n_flag |= NWRITEERR;
 1803                         np->n_attrstamp = 0;
 1804                         KDTRACE_NFS_ATTRCACHE_FLUSH_DONE(vp);
 1805                         mtx_unlock(&np->n_mtx);
 1806                     }
 1807                     bp->b_dirtyoff = bp->b_dirtyend = 0;
 1808                 }
 1809             } else {
 1810                 bp->b_resid = 0;
 1811                 bufdone(bp);
 1812                 return (0);
 1813             }
 1814         }
 1815         bp->b_resid = uiop->uio_resid;
 1816         if (must_commit)
 1817             ncl_clearcommit(vp->v_mount);
 1818         bufdone(bp);
 1819         return (error);
 1820 }
 1821 
 1822 /*
 1823  * Used to aid in handling ftruncate() operations on the NFS client side.
 1824  * Truncation creates a number of special problems for NFS.  We have to
 1825  * throw away VM pages and buffer cache buffers that are beyond EOF, and
 1826  * we have to properly handle VM pages or (potentially dirty) buffers
 1827  * that straddle the truncation point.
 1828  */
 1829 
 1830 int
 1831 ncl_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
 1832 {
 1833         struct nfsnode *np = VTONFS(vp);
 1834         u_quad_t tsize;
 1835         int biosize = vp->v_bufobj.bo_bsize;
 1836         int error = 0;
 1837 
 1838         mtx_lock(&np->n_mtx);
 1839         tsize = np->n_size;
 1840         np->n_size = nsize;
 1841         mtx_unlock(&np->n_mtx);
 1842 
 1843         if (nsize < tsize) {
 1844                 struct buf *bp;
 1845                 daddr_t lbn;
 1846                 int bufsize;
 1847 
 1848                 /*
 1849                  * vtruncbuf() doesn't get the buffer overlapping the
 1850                  * truncation point.  We may have a B_DELWRI and/or B_CACHE
 1851                  * buffer that now needs to be truncated.
 1852                  */
 1853                 error = vtruncbuf(vp, cred, td, nsize, biosize);
 1854                 lbn = nsize / biosize;
 1855                 bufsize = nsize & (biosize - 1);
 1856                 bp = nfs_getcacheblk(vp, lbn, bufsize, td);
 1857                 if (!bp)
 1858                         return EINTR;
 1859                 if (bp->b_dirtyoff > bp->b_bcount)
 1860                         bp->b_dirtyoff = bp->b_bcount;
 1861                 if (bp->b_dirtyend > bp->b_bcount)
 1862                         bp->b_dirtyend = bp->b_bcount;
 1863                 bp->b_flags |= B_RELBUF;  /* don't leave garbage around */
 1864                 brelse(bp);
 1865         } else {
 1866                 vnode_pager_setsize(vp, nsize);
 1867         }
 1868         return(error);
 1869 }
 1870 

Cache object: 8330f8fe2f94e9d797e72a02b9b44da0


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.