a7500bceb0
- NFS direct IO completely bypasses the buffer and page caches. If a file is open for direct IO all caching is disabled. - Direct IO for Directories will be addressed later. - 2 new NFS directio related sysctls are added. One is a knob to disable NFS direct IO completely (direct IO is enabled by default). The other is to disallow mmaped IO on a file that has at least one O_DIRECT open (see the comment in nfs_vnops.c for more details). The default is to allow mmaps on a file that has O_DIRECT opens. Submitted by: Mohan Srinivasan mohans at yahoo-inc dot com Obtained from: Yahoo!
1709 lines
45 KiB
C
1709 lines
45 KiB
C
/*
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* Copyright (c) 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Rick Macklem at The University of Guelph.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)nfs_bio.c 8.9 (Berkeley) 3/30/95
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/bio.h>
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#include <sys/buf.h>
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#include <sys/kernel.h>
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#include <sys/mount.h>
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#include <sys/proc.h>
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#include <sys/resourcevar.h>
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#include <sys/signalvar.h>
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#include <sys/vmmeter.h>
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#include <sys/vnode.h>
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#include <vm/vm.h>
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#include <vm/vm_extern.h>
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#include <vm/vm_page.h>
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#include <vm/vm_object.h>
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#include <vm/vm_pager.h>
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#include <vm/vnode_pager.h>
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#include <rpc/rpcclnt.h>
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#include <nfs/rpcv2.h>
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#include <nfs/nfsproto.h>
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#include <nfsclient/nfs.h>
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#include <nfsclient/nfsmount.h>
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#include <nfsclient/nfsnode.h>
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#include <nfs4client/nfs4.h>
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static struct buf *nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size,
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struct thread *td);
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static int nfs_directio_write(struct vnode *vp, struct uio *uiop,
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struct ucred *cred, int ioflag);
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extern int nfs_directio_enable;
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extern int nfs_directio_allow_mmap;
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/*
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* Vnode op for VM getpages.
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*/
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int
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nfs_getpages(struct vop_getpages_args *ap)
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{
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int i, error, nextoff, size, toff, count, npages;
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struct uio uio;
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struct iovec iov;
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vm_offset_t kva;
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struct buf *bp;
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struct vnode *vp;
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struct thread *td;
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struct ucred *cred;
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struct nfsmount *nmp;
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vm_object_t object;
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vm_page_t *pages;
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struct nfsnode *np;
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GIANT_REQUIRED;
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vp = ap->a_vp;
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np = VTONFS(vp);
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td = curthread; /* XXX */
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cred = curthread->td_ucred; /* XXX */
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nmp = VFSTONFS(vp->v_mount);
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pages = ap->a_m;
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count = ap->a_count;
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if ((object = vp->v_object) == NULL) {
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printf("nfs_getpages: called with non-merged cache vnode??\n");
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return VM_PAGER_ERROR;
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}
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if (!nfs_directio_allow_mmap && (np->n_flag & NNONCACHE) &&
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(vp->v_type == VREG)) {
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printf("nfs_getpages: called on non-cacheable vnode??\n");
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return VM_PAGER_ERROR;
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}
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if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
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(nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
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/* We'll never get here for v4, because we always have fsinfo */
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(void)nfs_fsinfo(nmp, vp, cred, td);
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}
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npages = btoc(count);
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/*
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* If the requested page is partially valid, just return it and
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* allow the pager to zero-out the blanks. Partially valid pages
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* can only occur at the file EOF.
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*/
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{
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vm_page_t m = pages[ap->a_reqpage];
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VM_OBJECT_LOCK(object);
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vm_page_lock_queues();
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if (m->valid != 0) {
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/* handled by vm_fault now */
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/* vm_page_zero_invalid(m, TRUE); */
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for (i = 0; i < npages; ++i) {
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if (i != ap->a_reqpage)
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vm_page_free(pages[i]);
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}
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vm_page_unlock_queues();
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VM_OBJECT_UNLOCK(object);
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return(0);
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}
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vm_page_unlock_queues();
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VM_OBJECT_UNLOCK(object);
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}
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/*
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* We use only the kva address for the buffer, but this is extremely
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* convienient and fast.
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*/
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bp = getpbuf(&nfs_pbuf_freecnt);
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kva = (vm_offset_t) bp->b_data;
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pmap_qenter(kva, pages, npages);
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cnt.v_vnodein++;
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cnt.v_vnodepgsin += npages;
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iov.iov_base = (caddr_t) kva;
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iov.iov_len = count;
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uio.uio_iov = &iov;
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uio.uio_iovcnt = 1;
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uio.uio_offset = IDX_TO_OFF(pages[0]->pindex);
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uio.uio_resid = count;
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uio.uio_segflg = UIO_SYSSPACE;
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uio.uio_rw = UIO_READ;
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uio.uio_td = td;
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error = (nmp->nm_rpcops->nr_readrpc)(vp, &uio, cred);
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pmap_qremove(kva, npages);
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relpbuf(bp, &nfs_pbuf_freecnt);
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if (error && (uio.uio_resid == count)) {
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printf("nfs_getpages: error %d\n", error);
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VM_OBJECT_LOCK(object);
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vm_page_lock_queues();
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for (i = 0; i < npages; ++i) {
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if (i != ap->a_reqpage)
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vm_page_free(pages[i]);
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}
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vm_page_unlock_queues();
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VM_OBJECT_UNLOCK(object);
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return VM_PAGER_ERROR;
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}
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/*
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* Calculate the number of bytes read and validate only that number
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* of bytes. Note that due to pending writes, size may be 0. This
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* does not mean that the remaining data is invalid!
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*/
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size = count - uio.uio_resid;
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VM_OBJECT_LOCK(object);
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vm_page_lock_queues();
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for (i = 0, toff = 0; i < npages; i++, toff = nextoff) {
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vm_page_t m;
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nextoff = toff + PAGE_SIZE;
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m = pages[i];
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if (nextoff <= size) {
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/*
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* Read operation filled an entire page
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*/
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m->valid = VM_PAGE_BITS_ALL;
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vm_page_undirty(m);
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} else if (size > toff) {
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/*
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* Read operation filled a partial page.
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*/
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m->valid = 0;
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vm_page_set_validclean(m, 0, size - toff);
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/* handled by vm_fault now */
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/* vm_page_zero_invalid(m, TRUE); */
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} else {
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/*
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* Read operation was short. If no error occured
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* we may have hit a zero-fill section. We simply
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* leave valid set to 0.
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*/
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;
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}
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if (i != ap->a_reqpage) {
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/*
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* Whether or not to leave the page activated is up in
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* the air, but we should put the page on a page queue
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* somewhere (it already is in the object). Result:
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* It appears that emperical results show that
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* deactivating pages is best.
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*/
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/*
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* Just in case someone was asking for this page we
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* now tell them that it is ok to use.
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*/
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if (!error) {
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if (m->flags & PG_WANTED)
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vm_page_activate(m);
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else
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vm_page_deactivate(m);
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vm_page_wakeup(m);
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} else {
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vm_page_free(m);
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}
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}
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}
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vm_page_unlock_queues();
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VM_OBJECT_UNLOCK(object);
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return 0;
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}
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/*
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* Vnode op for VM putpages.
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*/
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int
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nfs_putpages(struct vop_putpages_args *ap)
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{
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struct uio uio;
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struct iovec iov;
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vm_offset_t kva;
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struct buf *bp;
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int iomode, must_commit, i, error, npages, count;
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off_t offset;
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int *rtvals;
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struct vnode *vp;
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struct thread *td;
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struct ucred *cred;
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struct nfsmount *nmp;
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struct nfsnode *np;
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vm_page_t *pages;
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GIANT_REQUIRED;
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vp = ap->a_vp;
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np = VTONFS(vp);
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td = curthread; /* XXX */
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cred = curthread->td_ucred; /* XXX */
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nmp = VFSTONFS(vp->v_mount);
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pages = ap->a_m;
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count = ap->a_count;
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rtvals = ap->a_rtvals;
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npages = btoc(count);
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offset = IDX_TO_OFF(pages[0]->pindex);
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if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
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(nmp->nm_state & NFSSTA_GOTFSINFO) == 0) {
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(void)nfs_fsinfo(nmp, vp, cred, td);
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}
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if (!nfs_directio_allow_mmap && (np->n_flag & NNONCACHE) &&
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(vp->v_type == VREG))
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printf("nfs_putpages: called on noncache-able vnode??\n");
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for (i = 0; i < npages; i++)
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rtvals[i] = VM_PAGER_AGAIN;
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/*
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* When putting pages, do not extend file past EOF.
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*/
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if (offset + count > np->n_size) {
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count = np->n_size - offset;
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if (count < 0)
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count = 0;
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}
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/*
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* We use only the kva address for the buffer, but this is extremely
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* convienient and fast.
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*/
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bp = getpbuf(&nfs_pbuf_freecnt);
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kva = (vm_offset_t) bp->b_data;
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pmap_qenter(kva, pages, npages);
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cnt.v_vnodeout++;
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cnt.v_vnodepgsout += count;
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iov.iov_base = (caddr_t) kva;
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iov.iov_len = count;
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uio.uio_iov = &iov;
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uio.uio_iovcnt = 1;
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uio.uio_offset = offset;
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uio.uio_resid = count;
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uio.uio_segflg = UIO_SYSSPACE;
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uio.uio_rw = UIO_WRITE;
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uio.uio_td = td;
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if ((ap->a_sync & VM_PAGER_PUT_SYNC) == 0)
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iomode = NFSV3WRITE_UNSTABLE;
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else
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iomode = NFSV3WRITE_FILESYNC;
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error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred, &iomode, &must_commit);
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pmap_qremove(kva, npages);
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relpbuf(bp, &nfs_pbuf_freecnt);
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if (!error) {
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int nwritten = round_page(count - uio.uio_resid) / PAGE_SIZE;
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for (i = 0; i < nwritten; i++) {
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rtvals[i] = VM_PAGER_OK;
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vm_page_undirty(pages[i]);
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}
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if (must_commit) {
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nfs_clearcommit(vp->v_mount);
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}
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}
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return rtvals[0];
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}
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/*
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* Vnode op for read using bio
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*/
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int
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nfs_bioread(struct vnode *vp, struct uio *uio, int ioflag, struct ucred *cred)
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{
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struct nfsnode *np = VTONFS(vp);
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int biosize, i;
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struct buf *bp = 0, *rabp;
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struct vattr vattr;
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struct thread *td;
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struct nfsmount *nmp = VFSTONFS(vp->v_mount);
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daddr_t lbn, rabn;
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int bcount;
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int seqcount;
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int nra, error = 0, n = 0, on = 0;
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#ifdef DIAGNOSTIC
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if (uio->uio_rw != UIO_READ)
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panic("nfs_read mode");
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#endif
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if (uio->uio_resid == 0)
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return (0);
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if (uio->uio_offset < 0) /* XXX VDIR cookies can be negative */
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return (EINVAL);
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td = uio->uio_td;
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if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
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(nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
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(void)nfs_fsinfo(nmp, vp, cred, td);
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if (vp->v_type != VDIR &&
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(uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
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return (EFBIG);
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if (nfs_directio_enable && (ioflag & IO_DIRECT) && (vp->v_type == VREG))
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/* No caching/ no readaheads. Just read data into the user buffer */
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return nfs_readrpc(vp, uio, cred);
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biosize = vp->v_mount->mnt_stat.f_iosize;
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seqcount = (int)((off_t)(ioflag >> IO_SEQSHIFT) * biosize / BKVASIZE);
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/*
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* For nfs, cache consistency can only be maintained approximately.
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* Although RFC1094 does not specify the criteria, the following is
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* believed to be compatible with the reference port.
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* For nfs:
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* If the file's modify time on the server has changed since the
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* last read rpc or you have written to the file,
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* you may have lost data cache consistency with the
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* server, so flush all of the file's data out of the cache.
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* Then force a getattr rpc to ensure that you have up to date
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* attributes.
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* NB: This implies that cache data can be read when up to
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* NFS_ATTRTIMEO seconds out of date. If you find that you need current
|
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* attributes this could be forced by setting n_attrstamp to 0 before
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* the VOP_GETATTR() call.
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*/
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if (np->n_flag & NMODIFIED) {
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if (vp->v_type != VREG) {
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if (vp->v_type != VDIR)
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panic("nfs: bioread, not dir");
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(nmp->nm_rpcops->nr_invaldir)(vp);
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error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1);
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if (error)
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return (error);
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}
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np->n_attrstamp = 0;
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error = VOP_GETATTR(vp, &vattr, cred, td);
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if (error)
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return (error);
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np->n_mtime = vattr.va_mtime;
|
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} else {
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error = VOP_GETATTR(vp, &vattr, cred, td);
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if (error)
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return (error);
|
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if ((np->n_flag & NSIZECHANGED)
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|| (NFS_TIMESPEC_COMPARE(&np->n_mtime, &vattr.va_mtime))) {
|
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if (vp->v_type == VDIR)
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(nmp->nm_rpcops->nr_invaldir)(vp);
|
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error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1);
|
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if (error)
|
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return (error);
|
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np->n_mtime = vattr.va_mtime;
|
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np->n_flag &= ~NSIZECHANGED;
|
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}
|
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}
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do {
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switch (vp->v_type) {
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case VREG:
|
|
nfsstats.biocache_reads++;
|
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lbn = uio->uio_offset / biosize;
|
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on = uio->uio_offset & (biosize - 1);
|
|
|
|
/*
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|
* Start the read ahead(s), as required.
|
|
* The readahead is kicked off only if sequential access
|
|
* is detected, based on the readahead hint (ra_expect_lbn).
|
|
*/
|
|
if (nmp->nm_readahead > 0 && np->ra_expect_lbn == lbn) {
|
|
for (nra = 0; nra < nmp->nm_readahead && nra < seqcount &&
|
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(off_t)(lbn + 1 + nra) * biosize < np->n_size; nra++) {
|
|
rabn = lbn + 1 + nra;
|
|
if (incore(&vp->v_bufobj, rabn) == NULL) {
|
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rabp = nfs_getcacheblk(vp, rabn, biosize, td);
|
|
if (!rabp) {
|
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error = nfs_sigintr(nmp, NULL, td);
|
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return (error ? error : EINTR);
|
|
}
|
|
if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
|
|
rabp->b_flags |= B_ASYNC;
|
|
rabp->b_iocmd = BIO_READ;
|
|
vfs_busy_pages(rabp, 0);
|
|
if (nfs_asyncio(nmp, rabp, cred, td)) {
|
|
rabp->b_flags |= B_INVAL;
|
|
rabp->b_ioflags |= BIO_ERROR;
|
|
vfs_unbusy_pages(rabp);
|
|
brelse(rabp);
|
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break;
|
|
}
|
|
} else {
|
|
brelse(rabp);
|
|
}
|
|
}
|
|
}
|
|
np->ra_expect_lbn = lbn + 1;
|
|
}
|
|
|
|
/*
|
|
* Obtain the buffer cache block. Figure out the buffer size
|
|
* when we are at EOF. If we are modifying the size of the
|
|
* buffer based on an EOF condition we need to hold
|
|
* nfs_rslock() through obtaining the buffer to prevent
|
|
* a potential writer-appender from messing with n_size.
|
|
* Otherwise we may accidently truncate the buffer and
|
|
* lose dirty data.
|
|
*
|
|
* Note that bcount is *not* DEV_BSIZE aligned.
|
|
*/
|
|
|
|
again:
|
|
bcount = biosize;
|
|
if ((off_t)lbn * biosize >= np->n_size) {
|
|
bcount = 0;
|
|
} else if ((off_t)(lbn + 1) * biosize > np->n_size) {
|
|
bcount = np->n_size - (off_t)lbn * biosize;
|
|
}
|
|
if (bcount != biosize) {
|
|
switch(nfs_rslock(np, td)) {
|
|
case ENOLCK:
|
|
goto again;
|
|
/* not reached */
|
|
case EIO:
|
|
return (EIO);
|
|
case EINTR:
|
|
case ERESTART:
|
|
return(EINTR);
|
|
/* not reached */
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
bp = nfs_getcacheblk(vp, lbn, bcount, td);
|
|
|
|
if (bcount != biosize)
|
|
nfs_rsunlock(np, td);
|
|
if (!bp) {
|
|
error = nfs_sigintr(nmp, NULL, td);
|
|
return (error ? error : EINTR);
|
|
}
|
|
|
|
/*
|
|
* If B_CACHE is not set, we must issue the read. If this
|
|
* fails, we return an error.
|
|
*/
|
|
|
|
if ((bp->b_flags & B_CACHE) == 0) {
|
|
bp->b_iocmd = BIO_READ;
|
|
vfs_busy_pages(bp, 0);
|
|
error = nfs_doio(vp, bp, cred, td);
|
|
if (error) {
|
|
brelse(bp);
|
|
return (error);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* on is the offset into the current bp. Figure out how many
|
|
* bytes we can copy out of the bp. Note that bcount is
|
|
* NOT DEV_BSIZE aligned.
|
|
*
|
|
* Then figure out how many bytes we can copy into the uio.
|
|
*/
|
|
|
|
n = 0;
|
|
if (on < bcount)
|
|
n = min((unsigned)(bcount - on), uio->uio_resid);
|
|
break;
|
|
case VLNK:
|
|
nfsstats.biocache_readlinks++;
|
|
bp = nfs_getcacheblk(vp, (daddr_t)0, NFS_MAXPATHLEN, td);
|
|
if (!bp) {
|
|
error = nfs_sigintr(nmp, NULL, td);
|
|
return (error ? error : EINTR);
|
|
}
|
|
if ((bp->b_flags & B_CACHE) == 0) {
|
|
bp->b_iocmd = BIO_READ;
|
|
vfs_busy_pages(bp, 0);
|
|
error = nfs_doio(vp, bp, cred, td);
|
|
if (error) {
|
|
bp->b_ioflags |= BIO_ERROR;
|
|
brelse(bp);
|
|
return (error);
|
|
}
|
|
}
|
|
n = min(uio->uio_resid, NFS_MAXPATHLEN - bp->b_resid);
|
|
on = 0;
|
|
break;
|
|
case VDIR:
|
|
nfsstats.biocache_readdirs++;
|
|
if (np->n_direofoffset
|
|
&& uio->uio_offset >= np->n_direofoffset) {
|
|
return (0);
|
|
}
|
|
lbn = (uoff_t)uio->uio_offset / NFS_DIRBLKSIZ;
|
|
on = uio->uio_offset & (NFS_DIRBLKSIZ - 1);
|
|
bp = nfs_getcacheblk(vp, lbn, NFS_DIRBLKSIZ, td);
|
|
if (!bp) {
|
|
error = nfs_sigintr(nmp, NULL, td);
|
|
return (error ? error : EINTR);
|
|
}
|
|
if ((bp->b_flags & B_CACHE) == 0) {
|
|
bp->b_iocmd = BIO_READ;
|
|
vfs_busy_pages(bp, 0);
|
|
error = nfs_doio(vp, bp, cred, td);
|
|
if (error) {
|
|
brelse(bp);
|
|
}
|
|
while (error == NFSERR_BAD_COOKIE) {
|
|
(nmp->nm_rpcops->nr_invaldir)(vp);
|
|
error = nfs_vinvalbuf(vp, 0, cred, td, 1);
|
|
/*
|
|
* Yuck! The directory has been modified on the
|
|
* server. The only way to get the block is by
|
|
* reading from the beginning to get all the
|
|
* offset cookies.
|
|
*
|
|
* Leave the last bp intact unless there is an error.
|
|
* Loop back up to the while if the error is another
|
|
* NFSERR_BAD_COOKIE (double yuch!).
|
|
*/
|
|
for (i = 0; i <= lbn && !error; i++) {
|
|
if (np->n_direofoffset
|
|
&& (i * NFS_DIRBLKSIZ) >= np->n_direofoffset)
|
|
return (0);
|
|
bp = nfs_getcacheblk(vp, i, NFS_DIRBLKSIZ, td);
|
|
if (!bp) {
|
|
error = nfs_sigintr(nmp, NULL, td);
|
|
return (error ? error : EINTR);
|
|
}
|
|
if ((bp->b_flags & B_CACHE) == 0) {
|
|
bp->b_iocmd = BIO_READ;
|
|
vfs_busy_pages(bp, 0);
|
|
error = nfs_doio(vp, bp, cred, td);
|
|
/*
|
|
* no error + B_INVAL == directory EOF,
|
|
* use the block.
|
|
*/
|
|
if (error == 0 && (bp->b_flags & B_INVAL))
|
|
break;
|
|
}
|
|
/*
|
|
* An error will throw away the block and the
|
|
* for loop will break out. If no error and this
|
|
* is not the block we want, we throw away the
|
|
* block and go for the next one via the for loop.
|
|
*/
|
|
if (error || i < lbn)
|
|
brelse(bp);
|
|
}
|
|
}
|
|
/*
|
|
* The above while is repeated if we hit another cookie
|
|
* error. If we hit an error and it wasn't a cookie error,
|
|
* we give up.
|
|
*/
|
|
if (error)
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* If not eof and read aheads are enabled, start one.
|
|
* (You need the current block first, so that you have the
|
|
* directory offset cookie of the next block.)
|
|
*/
|
|
if (nmp->nm_readahead > 0 &&
|
|
(bp->b_flags & B_INVAL) == 0 &&
|
|
(np->n_direofoffset == 0 ||
|
|
(lbn + 1) * NFS_DIRBLKSIZ < np->n_direofoffset) &&
|
|
incore(&vp->v_bufobj, lbn + 1) == NULL) {
|
|
rabp = nfs_getcacheblk(vp, lbn + 1, NFS_DIRBLKSIZ, td);
|
|
if (rabp) {
|
|
if ((rabp->b_flags & (B_CACHE|B_DELWRI)) == 0) {
|
|
rabp->b_flags |= B_ASYNC;
|
|
rabp->b_iocmd = BIO_READ;
|
|
vfs_busy_pages(rabp, 0);
|
|
if (nfs_asyncio(nmp, rabp, cred, td)) {
|
|
rabp->b_flags |= B_INVAL;
|
|
rabp->b_ioflags |= BIO_ERROR;
|
|
vfs_unbusy_pages(rabp);
|
|
brelse(rabp);
|
|
}
|
|
} else {
|
|
brelse(rabp);
|
|
}
|
|
}
|
|
}
|
|
/*
|
|
* Unlike VREG files, whos buffer size ( bp->b_bcount ) is
|
|
* chopped for the EOF condition, we cannot tell how large
|
|
* NFS directories are going to be until we hit EOF. So
|
|
* an NFS directory buffer is *not* chopped to its EOF. Now,
|
|
* it just so happens that b_resid will effectively chop it
|
|
* to EOF. *BUT* this information is lost if the buffer goes
|
|
* away and is reconstituted into a B_CACHE state ( due to
|
|
* being VMIO ) later. So we keep track of the directory eof
|
|
* in np->n_direofoffset and chop it off as an extra step
|
|
* right here.
|
|
*/
|
|
n = lmin(uio->uio_resid, NFS_DIRBLKSIZ - bp->b_resid - on);
|
|
if (np->n_direofoffset && n > np->n_direofoffset - uio->uio_offset)
|
|
n = np->n_direofoffset - uio->uio_offset;
|
|
break;
|
|
default:
|
|
printf(" nfs_bioread: type %x unexpected\n", vp->v_type);
|
|
break;
|
|
};
|
|
|
|
if (n > 0) {
|
|
error = uiomove(bp->b_data + on, (int)n, uio);
|
|
}
|
|
switch (vp->v_type) {
|
|
case VREG:
|
|
break;
|
|
case VLNK:
|
|
n = 0;
|
|
break;
|
|
case VDIR:
|
|
break;
|
|
default:
|
|
printf(" nfs_bioread: type %x unexpected\n", vp->v_type);
|
|
}
|
|
brelse(bp);
|
|
} while (error == 0 && uio->uio_resid > 0 && n > 0);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* The NFS write path cannot handle iovecs with len > 1. So we need to
|
|
* break up iovecs accordingly (restricting them to wsize).
|
|
* For the SYNC case, we can do this with 1 copy (user buffer -> mbuf).
|
|
* For the ASYNC case, 2 copies are needed. The first a copy from the
|
|
* user buffer to a staging buffer and then a second copy from the staging
|
|
* buffer to mbufs. This can be optimized by copying from the user buffer
|
|
* directly into mbufs and passing the chain down, but that requires a
|
|
* fair amount of re-working of the relevant codepaths (and can be done
|
|
* later).
|
|
*/
|
|
static int
|
|
nfs_directio_write(vp, uiop, cred, ioflag)
|
|
struct vnode *vp;
|
|
struct uio *uiop;
|
|
struct ucred *cred;
|
|
int ioflag;
|
|
{
|
|
int error;
|
|
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
|
|
struct thread *td = uiop->uio_td;
|
|
int size;
|
|
|
|
if (ioflag & IO_SYNC) {
|
|
int iomode, must_commit;
|
|
struct uio uio;
|
|
struct iovec iov;
|
|
do_sync:
|
|
while (uiop->uio_resid > 0) {
|
|
size = min(uiop->uio_resid, nmp->nm_wsize);
|
|
size = min(uiop->uio_iov->iov_len, size);
|
|
iov.iov_base = uiop->uio_iov->iov_base;
|
|
iov.iov_len = size;
|
|
uio.uio_iov = &iov;
|
|
uio.uio_iovcnt = 1;
|
|
uio.uio_offset = uiop->uio_offset;
|
|
uio.uio_resid = size;
|
|
uio.uio_segflg = UIO_USERSPACE;
|
|
uio.uio_rw = UIO_WRITE;
|
|
uio.uio_td = td;
|
|
iomode = NFSV3WRITE_FILESYNC;
|
|
error = (nmp->nm_rpcops->nr_writerpc)(vp, &uio, cred,
|
|
&iomode, &must_commit);
|
|
KASSERT((must_commit == 0),
|
|
("nfs_directio_write: Did not commit write"));
|
|
if (error)
|
|
return (error);
|
|
uiop->uio_offset += size;
|
|
uiop->uio_resid -= size;
|
|
if (uiop->uio_iov->iov_len <= size) {
|
|
uiop->uio_iovcnt--;
|
|
uiop->uio_iov++;
|
|
} else {
|
|
uiop->uio_iov->iov_base =
|
|
(char *)uiop->uio_iov->iov_base + size;
|
|
uiop->uio_iov->iov_len -= size;
|
|
}
|
|
}
|
|
} else {
|
|
struct uio *t_uio;
|
|
struct iovec *t_iov;
|
|
struct buf *bp;
|
|
|
|
/*
|
|
* Break up the write into blocksize chunks and hand these
|
|
* over to nfsiod's for write back.
|
|
* Unfortunately, this incurs a copy of the data. Since
|
|
* the user could modify the buffer before the write is
|
|
* initiated.
|
|
*
|
|
* The obvious optimization here is that one of the 2 copies
|
|
* in the async write path can be eliminated by copying the
|
|
* data here directly into mbufs and passing the mbuf chain
|
|
* down. But that will require a fair amount of re-working
|
|
* of the code and can be done if there's enough interest
|
|
* in NFS directio access.
|
|
*/
|
|
while (uiop->uio_resid > 0) {
|
|
size = min(uiop->uio_resid, nmp->nm_wsize);
|
|
size = min(uiop->uio_iov->iov_len, size);
|
|
bp = getpbuf(&nfs_pbuf_freecnt);
|
|
t_uio = malloc(sizeof(struct uio), M_NFSDIRECTIO, M_WAITOK);
|
|
t_iov = malloc(sizeof(struct iovec), M_NFSDIRECTIO, M_WAITOK);
|
|
t_iov->iov_base = malloc(size, M_NFSDIRECTIO, M_WAITOK);
|
|
t_iov->iov_len = size;
|
|
t_uio->uio_iov = t_iov;
|
|
t_uio->uio_iovcnt = 1;
|
|
t_uio->uio_offset = uiop->uio_offset;
|
|
t_uio->uio_resid = size;
|
|
t_uio->uio_segflg = UIO_SYSSPACE;
|
|
t_uio->uio_rw = UIO_WRITE;
|
|
t_uio->uio_td = td;
|
|
bcopy(uiop->uio_iov->iov_base, t_iov->iov_base, size);
|
|
bp->b_flags |= B_DIRECT;
|
|
bp->b_iocmd = BIO_WRITE;
|
|
if (cred != NOCRED) {
|
|
crhold(cred);
|
|
bp->b_wcred = cred;
|
|
} else
|
|
bp->b_wcred = NOCRED;
|
|
bp->b_caller1 = (void *)t_uio;
|
|
bp->b_vp = vp;
|
|
vhold(vp);
|
|
error = nfs_asyncio(nmp, bp, NOCRED, td);
|
|
if (error) {
|
|
free(t_iov->iov_base, M_NFSDIRECTIO);
|
|
free(t_iov, M_NFSDIRECTIO);
|
|
free(t_uio, M_NFSDIRECTIO);
|
|
vdrop(bp->b_vp);
|
|
bp->b_vp = NULL;
|
|
relpbuf(bp, &nfs_pbuf_freecnt);
|
|
if (error == EINTR)
|
|
return (error);
|
|
goto do_sync;
|
|
}
|
|
uiop->uio_offset += size;
|
|
uiop->uio_resid -= size;
|
|
if (uiop->uio_iov->iov_len <= size) {
|
|
uiop->uio_iovcnt--;
|
|
uiop->uio_iov++;
|
|
} else {
|
|
uiop->uio_iov->iov_base =
|
|
(char *)uiop->uio_iov->iov_base + size;
|
|
uiop->uio_iov->iov_len -= size;
|
|
}
|
|
}
|
|
}
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Vnode op for write using bio
|
|
*/
|
|
int
|
|
nfs_write(struct vop_write_args *ap)
|
|
{
|
|
int biosize;
|
|
struct uio *uio = ap->a_uio;
|
|
struct thread *td = uio->uio_td;
|
|
struct vnode *vp = ap->a_vp;
|
|
struct nfsnode *np = VTONFS(vp);
|
|
struct ucred *cred = ap->a_cred;
|
|
int ioflag = ap->a_ioflag;
|
|
struct buf *bp;
|
|
struct vattr vattr;
|
|
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
|
|
daddr_t lbn;
|
|
int bcount;
|
|
int n, on, error = 0;
|
|
int haverslock = 0;
|
|
struct proc *p = td?td->td_proc:NULL;
|
|
|
|
GIANT_REQUIRED;
|
|
|
|
#ifdef DIAGNOSTIC
|
|
if (uio->uio_rw != UIO_WRITE)
|
|
panic("nfs_write mode");
|
|
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_td != curthread)
|
|
panic("nfs_write proc");
|
|
#endif
|
|
if (vp->v_type != VREG)
|
|
return (EIO);
|
|
if (np->n_flag & NWRITEERR) {
|
|
np->n_flag &= ~NWRITEERR;
|
|
return (np->n_error);
|
|
}
|
|
if ((nmp->nm_flag & NFSMNT_NFSV3) != 0 &&
|
|
(nmp->nm_state & NFSSTA_GOTFSINFO) == 0)
|
|
(void)nfs_fsinfo(nmp, vp, cred, td);
|
|
|
|
/*
|
|
* Synchronously flush pending buffers if we are in synchronous
|
|
* mode or if we are appending.
|
|
*/
|
|
if (ioflag & (IO_APPEND | IO_SYNC)) {
|
|
if (np->n_flag & NMODIFIED) {
|
|
np->n_attrstamp = 0;
|
|
error = nfs_vinvalbuf(vp, V_SAVE, cred, td, 1);
|
|
if (error)
|
|
return (error);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If IO_APPEND then load uio_offset. We restart here if we cannot
|
|
* get the append lock.
|
|
*/
|
|
restart:
|
|
if (ioflag & IO_APPEND) {
|
|
np->n_attrstamp = 0;
|
|
error = VOP_GETATTR(vp, &vattr, cred, td);
|
|
if (error)
|
|
return (error);
|
|
uio->uio_offset = np->n_size;
|
|
}
|
|
|
|
if (uio->uio_offset < 0)
|
|
return (EINVAL);
|
|
if ((uio->uio_offset + uio->uio_resid) > nmp->nm_maxfilesize)
|
|
return (EFBIG);
|
|
if (uio->uio_resid == 0)
|
|
return (0);
|
|
|
|
if (nfs_directio_enable && (ioflag & IO_DIRECT) && vp->v_type == VREG)
|
|
return nfs_directio_write(vp, uio, cred, ioflag);
|
|
|
|
/*
|
|
* We need to obtain the rslock if we intend to modify np->n_size
|
|
* in order to guarentee the append point with multiple contending
|
|
* writers, to guarentee that no other appenders modify n_size
|
|
* while we are trying to obtain a truncated buffer (i.e. to avoid
|
|
* accidently truncating data written by another appender due to
|
|
* the race), and to ensure that the buffer is populated prior to
|
|
* our extending of the file. We hold rslock through the entire
|
|
* operation.
|
|
*
|
|
* Note that we do not synchronize the case where someone truncates
|
|
* the file while we are appending to it because attempting to lock
|
|
* this case may deadlock other parts of the system unexpectedly.
|
|
*/
|
|
if ((ioflag & IO_APPEND) ||
|
|
uio->uio_offset + uio->uio_resid > np->n_size) {
|
|
switch(nfs_rslock(np, td)) {
|
|
case ENOLCK:
|
|
goto restart;
|
|
/* not reached */
|
|
case EIO:
|
|
return (EIO);
|
|
case EINTR:
|
|
case ERESTART:
|
|
return(EINTR);
|
|
/* not reached */
|
|
default:
|
|
break;
|
|
}
|
|
haverslock = 1;
|
|
}
|
|
|
|
/*
|
|
* Maybe this should be above the vnode op call, but so long as
|
|
* file servers have no limits, i don't think it matters
|
|
*/
|
|
if (p != NULL) {
|
|
PROC_LOCK(p);
|
|
if (uio->uio_offset + uio->uio_resid >
|
|
lim_cur(p, RLIMIT_FSIZE)) {
|
|
psignal(p, SIGXFSZ);
|
|
PROC_UNLOCK(p);
|
|
if (haverslock)
|
|
nfs_rsunlock(np, td);
|
|
return (EFBIG);
|
|
}
|
|
PROC_UNLOCK(p);
|
|
}
|
|
|
|
biosize = vp->v_mount->mnt_stat.f_iosize;
|
|
|
|
do {
|
|
nfsstats.biocache_writes++;
|
|
lbn = uio->uio_offset / biosize;
|
|
on = uio->uio_offset & (biosize-1);
|
|
n = min((unsigned)(biosize - on), uio->uio_resid);
|
|
again:
|
|
/*
|
|
* Handle direct append and file extension cases, calculate
|
|
* unaligned buffer size.
|
|
*/
|
|
|
|
if (uio->uio_offset == np->n_size && n) {
|
|
/*
|
|
* Get the buffer (in its pre-append state to maintain
|
|
* B_CACHE if it was previously set). Resize the
|
|
* nfsnode after we have locked the buffer to prevent
|
|
* readers from reading garbage.
|
|
*/
|
|
bcount = on;
|
|
bp = nfs_getcacheblk(vp, lbn, bcount, td);
|
|
|
|
if (bp != NULL) {
|
|
long save;
|
|
|
|
np->n_size = uio->uio_offset + n;
|
|
np->n_flag |= NMODIFIED;
|
|
vnode_pager_setsize(vp, np->n_size);
|
|
|
|
save = bp->b_flags & B_CACHE;
|
|
bcount += n;
|
|
allocbuf(bp, bcount);
|
|
bp->b_flags |= save;
|
|
}
|
|
} else {
|
|
/*
|
|
* Obtain the locked cache block first, and then
|
|
* adjust the file's size as appropriate.
|
|
*/
|
|
bcount = on + n;
|
|
if ((off_t)lbn * biosize + bcount < np->n_size) {
|
|
if ((off_t)(lbn + 1) * biosize < np->n_size)
|
|
bcount = biosize;
|
|
else
|
|
bcount = np->n_size - (off_t)lbn * biosize;
|
|
}
|
|
bp = nfs_getcacheblk(vp, lbn, bcount, td);
|
|
if (uio->uio_offset + n > np->n_size) {
|
|
np->n_size = uio->uio_offset + n;
|
|
np->n_flag |= NMODIFIED;
|
|
vnode_pager_setsize(vp, np->n_size);
|
|
}
|
|
}
|
|
|
|
if (!bp) {
|
|
error = nfs_sigintr(nmp, NULL, td);
|
|
if (!error)
|
|
error = EINTR;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Issue a READ if B_CACHE is not set. In special-append
|
|
* mode, B_CACHE is based on the buffer prior to the write
|
|
* op and is typically set, avoiding the read. If a read
|
|
* is required in special append mode, the server will
|
|
* probably send us a short-read since we extended the file
|
|
* on our end, resulting in b_resid == 0 and, thusly,
|
|
* B_CACHE getting set.
|
|
*
|
|
* We can also avoid issuing the read if the write covers
|
|
* the entire buffer. We have to make sure the buffer state
|
|
* is reasonable in this case since we will not be initiating
|
|
* I/O. See the comments in kern/vfs_bio.c's getblk() for
|
|
* more information.
|
|
*
|
|
* B_CACHE may also be set due to the buffer being cached
|
|
* normally.
|
|
*/
|
|
|
|
if (on == 0 && n == bcount) {
|
|
bp->b_flags |= B_CACHE;
|
|
bp->b_flags &= ~B_INVAL;
|
|
bp->b_ioflags &= ~BIO_ERROR;
|
|
}
|
|
|
|
if ((bp->b_flags & B_CACHE) == 0) {
|
|
bp->b_iocmd = BIO_READ;
|
|
vfs_busy_pages(bp, 0);
|
|
error = nfs_doio(vp, bp, cred, td);
|
|
if (error) {
|
|
brelse(bp);
|
|
break;
|
|
}
|
|
}
|
|
if (!bp) {
|
|
error = nfs_sigintr(nmp, NULL, td);
|
|
if (!error)
|
|
error = EINTR;
|
|
break;
|
|
}
|
|
if (bp->b_wcred == NOCRED)
|
|
bp->b_wcred = crhold(cred);
|
|
np->n_flag |= NMODIFIED;
|
|
|
|
/*
|
|
* If dirtyend exceeds file size, chop it down. This should
|
|
* not normally occur but there is an append race where it
|
|
* might occur XXX, so we log it.
|
|
*
|
|
* If the chopping creates a reverse-indexed or degenerate
|
|
* situation with dirtyoff/end, we 0 both of them.
|
|
*/
|
|
|
|
if (bp->b_dirtyend > bcount) {
|
|
printf("NFS append race @%lx:%d\n",
|
|
(long)bp->b_blkno * DEV_BSIZE,
|
|
bp->b_dirtyend - bcount);
|
|
bp->b_dirtyend = bcount;
|
|
}
|
|
|
|
if (bp->b_dirtyoff >= bp->b_dirtyend)
|
|
bp->b_dirtyoff = bp->b_dirtyend = 0;
|
|
|
|
/*
|
|
* If the new write will leave a contiguous dirty
|
|
* area, just update the b_dirtyoff and b_dirtyend,
|
|
* otherwise force a write rpc of the old dirty area.
|
|
*
|
|
* While it is possible to merge discontiguous writes due to
|
|
* our having a B_CACHE buffer ( and thus valid read data
|
|
* for the hole), we don't because it could lead to
|
|
* significant cache coherency problems with multiple clients,
|
|
* especially if locking is implemented later on.
|
|
*
|
|
* as an optimization we could theoretically maintain
|
|
* a linked list of discontinuous areas, but we would still
|
|
* have to commit them separately so there isn't much
|
|
* advantage to it except perhaps a bit of asynchronization.
|
|
*/
|
|
|
|
if (bp->b_dirtyend > 0 &&
|
|
(on > bp->b_dirtyend || (on + n) < bp->b_dirtyoff)) {
|
|
if (bwrite(bp) == EINTR) {
|
|
error = EINTR;
|
|
break;
|
|
}
|
|
goto again;
|
|
}
|
|
|
|
error = uiomove((char *)bp->b_data + on, n, uio);
|
|
|
|
/*
|
|
* Since this block is being modified, it must be written
|
|
* again and not just committed. Since write clustering does
|
|
* not work for the stage 1 data write, only the stage 2
|
|
* commit rpc, we have to clear B_CLUSTEROK as well.
|
|
*/
|
|
bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
|
|
|
|
if (error) {
|
|
bp->b_ioflags |= BIO_ERROR;
|
|
brelse(bp);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Only update dirtyoff/dirtyend if not a degenerate
|
|
* condition.
|
|
*/
|
|
if (n) {
|
|
if (bp->b_dirtyend > 0) {
|
|
bp->b_dirtyoff = min(on, bp->b_dirtyoff);
|
|
bp->b_dirtyend = max((on + n), bp->b_dirtyend);
|
|
} else {
|
|
bp->b_dirtyoff = on;
|
|
bp->b_dirtyend = on + n;
|
|
}
|
|
vfs_bio_set_validclean(bp, on, n);
|
|
}
|
|
|
|
/*
|
|
* If IO_SYNC do bwrite().
|
|
*
|
|
* IO_INVAL appears to be unused. The idea appears to be
|
|
* to turn off caching in this case. Very odd. XXX
|
|
*/
|
|
if ((ioflag & IO_SYNC)) {
|
|
if (ioflag & IO_INVAL)
|
|
bp->b_flags |= B_NOCACHE;
|
|
error = bwrite(bp);
|
|
if (error)
|
|
break;
|
|
} else if ((n + on) == biosize) {
|
|
bp->b_flags |= B_ASYNC;
|
|
(void) (nmp->nm_rpcops->nr_writebp)(bp, 0, 0);
|
|
} else {
|
|
bdwrite(bp);
|
|
}
|
|
} while (uio->uio_resid > 0 && n > 0);
|
|
|
|
if (haverslock)
|
|
nfs_rsunlock(np, td);
|
|
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Get an nfs cache block.
|
|
*
|
|
* Allocate a new one if the block isn't currently in the cache
|
|
* and return the block marked busy. If the calling process is
|
|
* interrupted by a signal for an interruptible mount point, return
|
|
* NULL.
|
|
*
|
|
* The caller must carefully deal with the possible B_INVAL state of
|
|
* the buffer. nfs_doio() clears B_INVAL (and nfs_asyncio() clears it
|
|
* indirectly), so synchronous reads can be issued without worrying about
|
|
* the B_INVAL state. We have to be a little more careful when dealing
|
|
* with writes (see comments in nfs_write()) when extending a file past
|
|
* its EOF.
|
|
*/
|
|
static struct buf *
|
|
nfs_getcacheblk(struct vnode *vp, daddr_t bn, int size, struct thread *td)
|
|
{
|
|
struct buf *bp;
|
|
struct mount *mp;
|
|
struct nfsmount *nmp;
|
|
|
|
mp = vp->v_mount;
|
|
nmp = VFSTONFS(mp);
|
|
|
|
if (nmp->nm_flag & NFSMNT_INT) {
|
|
sigset_t oldset;
|
|
|
|
nfs_set_sigmask(td, &oldset);
|
|
bp = getblk(vp, bn, size, PCATCH, 0, 0);
|
|
nfs_restore_sigmask(td, &oldset);
|
|
while (bp == NULL) {
|
|
if (nfs_sigintr(nmp, NULL, td))
|
|
return (NULL);
|
|
bp = getblk(vp, bn, size, 0, 2 * hz, 0);
|
|
}
|
|
} else {
|
|
bp = getblk(vp, bn, size, 0, 0, 0);
|
|
}
|
|
|
|
if (vp->v_type == VREG) {
|
|
int biosize;
|
|
|
|
biosize = mp->mnt_stat.f_iosize;
|
|
bp->b_blkno = bn * (biosize / DEV_BSIZE);
|
|
}
|
|
return (bp);
|
|
}
|
|
|
|
/*
|
|
* Flush and invalidate all dirty buffers. If another process is already
|
|
* doing the flush, just wait for completion.
|
|
*/
|
|
int
|
|
nfs_vinvalbuf(struct vnode *vp, int flags, struct ucred *cred,
|
|
struct thread *td, int intrflg)
|
|
{
|
|
struct nfsnode *np = VTONFS(vp);
|
|
struct nfsmount *nmp = VFSTONFS(vp->v_mount);
|
|
int error = 0, slpflag, slptimeo;
|
|
int old_lock = 0;
|
|
|
|
ASSERT_VOP_LOCKED(vp, "nfs_vinvalbuf");
|
|
|
|
/*
|
|
* XXX This check stops us from needlessly doing a vinvalbuf when
|
|
* being called through vclean(). It is not clear that this is
|
|
* unsafe.
|
|
*/
|
|
if (vp->v_iflag & VI_XLOCK)
|
|
return (0);
|
|
|
|
if ((nmp->nm_flag & NFSMNT_INT) == 0)
|
|
intrflg = 0;
|
|
if (intrflg) {
|
|
slpflag = PCATCH;
|
|
slptimeo = 2 * hz;
|
|
} else {
|
|
slpflag = 0;
|
|
slptimeo = 0;
|
|
}
|
|
|
|
if ((old_lock = VOP_ISLOCKED(vp, td)) != LK_EXCLUSIVE) {
|
|
if (old_lock == LK_SHARED) {
|
|
/* Upgrade to exclusive lock, this might block */
|
|
vn_lock(vp, LK_UPGRADE | LK_RETRY, td);
|
|
} else {
|
|
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Now, flush as required.
|
|
*/
|
|
error = vinvalbuf(vp, flags, cred, td, slpflag, 0);
|
|
while (error) {
|
|
if (intrflg && (error = nfs_sigintr(nmp, NULL, td)))
|
|
goto out;
|
|
error = vinvalbuf(vp, flags, cred, td, 0, slptimeo);
|
|
}
|
|
np->n_flag &= ~NMODIFIED;
|
|
out:
|
|
if (old_lock != LK_EXCLUSIVE) {
|
|
if (old_lock == LK_SHARED) {
|
|
/* Downgrade from exclusive lock, this might block */
|
|
vn_lock(vp, LK_DOWNGRADE, td);
|
|
} else {
|
|
VOP_UNLOCK(vp, 0, td);
|
|
}
|
|
}
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Initiate asynchronous I/O. Return an error if no nfsiods are available.
|
|
* This is mainly to avoid queueing async I/O requests when the nfsiods
|
|
* are all hung on a dead server.
|
|
*
|
|
* Note: nfs_asyncio() does not clear (BIO_ERROR|B_INVAL) but when the bp
|
|
* is eventually dequeued by the async daemon, nfs_doio() *will*.
|
|
*/
|
|
int
|
|
nfs_asyncio(struct nfsmount *nmp, struct buf *bp, struct ucred *cred, struct thread *td)
|
|
{
|
|
int iod;
|
|
int gotiod;
|
|
int slpflag = 0;
|
|
int slptimeo = 0;
|
|
int error, error2;
|
|
|
|
/*
|
|
* Commits are usually short and sweet so lets save some cpu and
|
|
* leave the async daemons for more important rpc's (such as reads
|
|
* and writes).
|
|
*/
|
|
if (bp->b_iocmd == BIO_WRITE && (bp->b_flags & B_NEEDCOMMIT) &&
|
|
(nmp->nm_bufqiods > nfs_numasync / 2)) {
|
|
return(EIO);
|
|
}
|
|
|
|
again:
|
|
if (nmp->nm_flag & NFSMNT_INT)
|
|
slpflag = PCATCH;
|
|
gotiod = FALSE;
|
|
|
|
/*
|
|
* Find a free iod to process this request.
|
|
*/
|
|
for (iod = 0; iod < nfs_numasync; iod++)
|
|
if (nfs_iodwant[iod]) {
|
|
gotiod = TRUE;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Try to create one if none are free.
|
|
*/
|
|
if (!gotiod) {
|
|
iod = nfs_nfsiodnew();
|
|
if (iod != -1)
|
|
gotiod = TRUE;
|
|
}
|
|
|
|
if (gotiod) {
|
|
/*
|
|
* Found one, so wake it up and tell it which
|
|
* mount to process.
|
|
*/
|
|
NFS_DPF(ASYNCIO, ("nfs_asyncio: waking iod %d for mount %p\n",
|
|
iod, nmp));
|
|
nfs_iodwant[iod] = NULL;
|
|
nfs_iodmount[iod] = nmp;
|
|
nmp->nm_bufqiods++;
|
|
wakeup(&nfs_iodwant[iod]);
|
|
}
|
|
|
|
/*
|
|
* If none are free, we may already have an iod working on this mount
|
|
* point. If so, it will process our request.
|
|
*/
|
|
if (!gotiod) {
|
|
if (nmp->nm_bufqiods > 0) {
|
|
NFS_DPF(ASYNCIO,
|
|
("nfs_asyncio: %d iods are already processing mount %p\n",
|
|
nmp->nm_bufqiods, nmp));
|
|
gotiod = TRUE;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we have an iod which can process the request, then queue
|
|
* the buffer.
|
|
*/
|
|
if (gotiod) {
|
|
/*
|
|
* Ensure that the queue never grows too large. We still want
|
|
* to asynchronize so we block rather then return EIO.
|
|
*/
|
|
while (nmp->nm_bufqlen >= 2*nfs_numasync) {
|
|
NFS_DPF(ASYNCIO,
|
|
("nfs_asyncio: waiting for mount %p queue to drain\n", nmp));
|
|
nmp->nm_bufqwant = TRUE;
|
|
error = nfs_tsleep(td, &nmp->nm_bufq, slpflag | PRIBIO,
|
|
"nfsaio", slptimeo);
|
|
if (error) {
|
|
error2 = nfs_sigintr(nmp, NULL, td);
|
|
if (error2)
|
|
return (error2);
|
|
if (slpflag == PCATCH) {
|
|
slpflag = 0;
|
|
slptimeo = 2 * hz;
|
|
}
|
|
}
|
|
/*
|
|
* We might have lost our iod while sleeping,
|
|
* so check and loop if nescessary.
|
|
*/
|
|
if (nmp->nm_bufqiods == 0) {
|
|
NFS_DPF(ASYNCIO,
|
|
("nfs_asyncio: no iods after mount %p queue was drained, looping\n", nmp));
|
|
goto again;
|
|
}
|
|
}
|
|
|
|
if (bp->b_iocmd == BIO_READ) {
|
|
if (bp->b_rcred == NOCRED && cred != NOCRED)
|
|
bp->b_rcred = crhold(cred);
|
|
} else {
|
|
if (bp->b_wcred == NOCRED && cred != NOCRED)
|
|
bp->b_wcred = crhold(cred);
|
|
}
|
|
|
|
if (bp->b_flags & B_REMFREE)
|
|
bremfreef(bp);
|
|
BUF_KERNPROC(bp);
|
|
TAILQ_INSERT_TAIL(&nmp->nm_bufq, bp, b_freelist);
|
|
nmp->nm_bufqlen++;
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* All the iods are busy on other mounts, so return EIO to
|
|
* force the caller to process the i/o synchronously.
|
|
*/
|
|
NFS_DPF(ASYNCIO, ("nfs_asyncio: no iods available, i/o is synchronous\n"));
|
|
return (EIO);
|
|
}
|
|
|
|
void
|
|
nfs_doio_directwrite(struct buf *bp)
|
|
{
|
|
int iomode, must_commit;
|
|
struct uio *uiop = (struct uio *)bp->b_caller1;
|
|
char *iov_base = uiop->uio_iov->iov_base;
|
|
struct nfsmount *nmp = VFSTONFS(bp->b_vp->v_mount);
|
|
|
|
iomode = NFSV3WRITE_FILESYNC;
|
|
uiop->uio_td = NULL; /* NULL since we're in nfsiod */
|
|
(nmp->nm_rpcops->nr_writerpc)(bp->b_vp, uiop, bp->b_wcred, &iomode, &must_commit);
|
|
KASSERT((must_commit == 0), ("nfs_doio_directwrite: Did not commit write"));
|
|
free(iov_base, M_NFSDIRECTIO);
|
|
free(uiop->uio_iov, M_NFSDIRECTIO);
|
|
free(uiop, M_NFSDIRECTIO);
|
|
vdrop(bp->b_vp);
|
|
bp->b_vp = NULL;
|
|
relpbuf(bp, &nfs_pbuf_freecnt);
|
|
}
|
|
|
|
/*
|
|
* Do an I/O operation to/from a cache block. This may be called
|
|
* synchronously or from an nfsiod.
|
|
*/
|
|
int
|
|
nfs_doio(struct vnode *vp, struct buf *bp, struct ucred *cr, struct thread *td)
|
|
{
|
|
struct uio *uiop;
|
|
struct nfsnode *np;
|
|
struct nfsmount *nmp;
|
|
int error = 0, iomode, must_commit = 0;
|
|
struct uio uio;
|
|
struct iovec io;
|
|
struct proc *p = td ? td->td_proc : NULL;
|
|
|
|
np = VTONFS(vp);
|
|
nmp = VFSTONFS(vp->v_mount);
|
|
uiop = &uio;
|
|
uiop->uio_iov = &io;
|
|
uiop->uio_iovcnt = 1;
|
|
uiop->uio_segflg = UIO_SYSSPACE;
|
|
uiop->uio_td = td;
|
|
|
|
/*
|
|
* clear BIO_ERROR and B_INVAL state prior to initiating the I/O. We
|
|
* do this here so we do not have to do it in all the code that
|
|
* calls us.
|
|
*/
|
|
bp->b_flags &= ~B_INVAL;
|
|
bp->b_ioflags &= ~BIO_ERROR;
|
|
|
|
KASSERT(!(bp->b_flags & B_DONE), ("nfs_doio: bp %p already marked done", bp));
|
|
|
|
if (bp->b_iocmd == BIO_READ) {
|
|
io.iov_len = uiop->uio_resid = bp->b_bcount;
|
|
io.iov_base = bp->b_data;
|
|
uiop->uio_rw = UIO_READ;
|
|
|
|
switch (vp->v_type) {
|
|
case VREG:
|
|
uiop->uio_offset = ((off_t)bp->b_blkno) * DEV_BSIZE;
|
|
nfsstats.read_bios++;
|
|
error = (nmp->nm_rpcops->nr_readrpc)(vp, uiop, cr);
|
|
|
|
if (!error) {
|
|
if (uiop->uio_resid) {
|
|
/*
|
|
* If we had a short read with no error, we must have
|
|
* hit a file hole. We should zero-fill the remainder.
|
|
* This can also occur if the server hits the file EOF.
|
|
*
|
|
* Holes used to be able to occur due to pending
|
|
* writes, but that is not possible any longer.
|
|
*/
|
|
int nread = bp->b_bcount - uiop->uio_resid;
|
|
int left = uiop->uio_resid;
|
|
|
|
if (left > 0)
|
|
bzero((char *)bp->b_data + nread, left);
|
|
uiop->uio_resid = 0;
|
|
}
|
|
}
|
|
/* ASSERT_VOP_LOCKED(vp, "nfs_doio"); */
|
|
if (p && (vp->v_vflag & VV_TEXT) &&
|
|
(NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.va_mtime))) {
|
|
PROC_LOCK(p);
|
|
killproc(p, "text file modification");
|
|
PROC_UNLOCK(p);
|
|
}
|
|
break;
|
|
case VLNK:
|
|
uiop->uio_offset = (off_t)0;
|
|
nfsstats.readlink_bios++;
|
|
error = (nmp->nm_rpcops->nr_readlinkrpc)(vp, uiop, cr);
|
|
break;
|
|
case VDIR:
|
|
nfsstats.readdir_bios++;
|
|
uiop->uio_offset = ((u_quad_t)bp->b_lblkno) * NFS_DIRBLKSIZ;
|
|
if ((nmp->nm_flag & NFSMNT_NFSV4) != 0)
|
|
error = nfs4_readdirrpc(vp, uiop, cr);
|
|
else {
|
|
if ((nmp->nm_flag & NFSMNT_RDIRPLUS) != 0) {
|
|
error = nfs_readdirplusrpc(vp, uiop, cr);
|
|
if (error == NFSERR_NOTSUPP)
|
|
nmp->nm_flag &= ~NFSMNT_RDIRPLUS;
|
|
}
|
|
if ((nmp->nm_flag & NFSMNT_RDIRPLUS) == 0)
|
|
error = nfs_readdirrpc(vp, uiop, cr);
|
|
}
|
|
/*
|
|
* end-of-directory sets B_INVAL but does not generate an
|
|
* error.
|
|
*/
|
|
if (error == 0 && uiop->uio_resid == bp->b_bcount)
|
|
bp->b_flags |= B_INVAL;
|
|
break;
|
|
default:
|
|
printf("nfs_doio: type %x unexpected\n", vp->v_type);
|
|
break;
|
|
};
|
|
if (error) {
|
|
bp->b_ioflags |= BIO_ERROR;
|
|
bp->b_error = error;
|
|
}
|
|
} else {
|
|
/*
|
|
* If we only need to commit, try to commit
|
|
*/
|
|
if (bp->b_flags & B_NEEDCOMMIT) {
|
|
int retv;
|
|
off_t off;
|
|
|
|
off = ((u_quad_t)bp->b_blkno) * DEV_BSIZE + bp->b_dirtyoff;
|
|
retv = (nmp->nm_rpcops->nr_commit)(
|
|
vp, off, bp->b_dirtyend-bp->b_dirtyoff,
|
|
bp->b_wcred, td);
|
|
if (retv == 0) {
|
|
bp->b_dirtyoff = bp->b_dirtyend = 0;
|
|
bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
|
|
bp->b_resid = 0;
|
|
bufdone(bp);
|
|
return (0);
|
|
}
|
|
if (retv == NFSERR_STALEWRITEVERF) {
|
|
nfs_clearcommit(vp->v_mount);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Setup for actual write
|
|
*/
|
|
|
|
if ((off_t)bp->b_blkno * DEV_BSIZE + bp->b_dirtyend > np->n_size)
|
|
bp->b_dirtyend = np->n_size - (off_t)bp->b_blkno * DEV_BSIZE;
|
|
|
|
if (bp->b_dirtyend > bp->b_dirtyoff) {
|
|
io.iov_len = uiop->uio_resid = bp->b_dirtyend
|
|
- bp->b_dirtyoff;
|
|
uiop->uio_offset = (off_t)bp->b_blkno * DEV_BSIZE
|
|
+ bp->b_dirtyoff;
|
|
io.iov_base = (char *)bp->b_data + bp->b_dirtyoff;
|
|
uiop->uio_rw = UIO_WRITE;
|
|
nfsstats.write_bios++;
|
|
|
|
if ((bp->b_flags & (B_ASYNC | B_NEEDCOMMIT | B_NOCACHE | B_CLUSTER)) == B_ASYNC)
|
|
iomode = NFSV3WRITE_UNSTABLE;
|
|
else
|
|
iomode = NFSV3WRITE_FILESYNC;
|
|
|
|
error = (nmp->nm_rpcops->nr_writerpc)(vp, uiop, cr, &iomode, &must_commit);
|
|
|
|
/*
|
|
* When setting B_NEEDCOMMIT also set B_CLUSTEROK to try
|
|
* to cluster the buffers needing commit. This will allow
|
|
* the system to submit a single commit rpc for the whole
|
|
* cluster. We can do this even if the buffer is not 100%
|
|
* dirty (relative to the NFS blocksize), so we optimize the
|
|
* append-to-file-case.
|
|
*
|
|
* (when clearing B_NEEDCOMMIT, B_CLUSTEROK must also be
|
|
* cleared because write clustering only works for commit
|
|
* rpc's, not for the data portion of the write).
|
|
*/
|
|
|
|
if (!error && iomode == NFSV3WRITE_UNSTABLE) {
|
|
bp->b_flags |= B_NEEDCOMMIT;
|
|
if (bp->b_dirtyoff == 0
|
|
&& bp->b_dirtyend == bp->b_bcount)
|
|
bp->b_flags |= B_CLUSTEROK;
|
|
} else {
|
|
bp->b_flags &= ~(B_NEEDCOMMIT | B_CLUSTEROK);
|
|
}
|
|
|
|
/*
|
|
* For an interrupted write, the buffer is still valid
|
|
* and the write hasn't been pushed to the server yet,
|
|
* so we can't set BIO_ERROR and report the interruption
|
|
* by setting B_EINTR. For the B_ASYNC case, B_EINTR
|
|
* is not relevant, so the rpc attempt is essentially
|
|
* a noop. For the case of a V3 write rpc not being
|
|
* committed to stable storage, the block is still
|
|
* dirty and requires either a commit rpc or another
|
|
* write rpc with iomode == NFSV3WRITE_FILESYNC before
|
|
* the block is reused. This is indicated by setting
|
|
* the B_DELWRI and B_NEEDCOMMIT flags.
|
|
*
|
|
* If the buffer is marked B_PAGING, it does not reside on
|
|
* the vp's paging queues so we cannot call bdirty(). The
|
|
* bp in this case is not an NFS cache block so we should
|
|
* be safe. XXX
|
|
*/
|
|
if (error == EINTR || error == EIO
|
|
|| (!error && (bp->b_flags & B_NEEDCOMMIT))) {
|
|
int s;
|
|
|
|
s = splbio();
|
|
bp->b_flags &= ~(B_INVAL|B_NOCACHE);
|
|
if ((bp->b_flags & B_PAGING) == 0) {
|
|
bdirty(bp);
|
|
bp->b_flags &= ~B_DONE;
|
|
}
|
|
if (error && (bp->b_flags & B_ASYNC) == 0)
|
|
bp->b_flags |= B_EINTR;
|
|
splx(s);
|
|
} else {
|
|
if (error) {
|
|
bp->b_ioflags |= BIO_ERROR;
|
|
bp->b_error = np->n_error = error;
|
|
np->n_flag |= NWRITEERR;
|
|
}
|
|
bp->b_dirtyoff = bp->b_dirtyend = 0;
|
|
}
|
|
} else {
|
|
bp->b_resid = 0;
|
|
bufdone(bp);
|
|
return (0);
|
|
}
|
|
}
|
|
bp->b_resid = uiop->uio_resid;
|
|
if (must_commit)
|
|
nfs_clearcommit(vp->v_mount);
|
|
bufdone(bp);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Used to aid in handling ftruncate() operations on the NFS client side.
|
|
* Truncation creates a number of special problems for NFS. We have to
|
|
* throw away VM pages and buffer cache buffers that are beyond EOF, and
|
|
* we have to properly handle VM pages or (potentially dirty) buffers
|
|
* that straddle the truncation point.
|
|
*/
|
|
|
|
int
|
|
nfs_meta_setsize(struct vnode *vp, struct ucred *cred, struct thread *td, u_quad_t nsize)
|
|
{
|
|
struct nfsnode *np = VTONFS(vp);
|
|
u_quad_t tsize = np->n_size;
|
|
int biosize = vp->v_mount->mnt_stat.f_iosize;
|
|
int error = 0;
|
|
|
|
np->n_size = nsize;
|
|
|
|
if (np->n_size < tsize) {
|
|
struct buf *bp;
|
|
daddr_t lbn;
|
|
int bufsize;
|
|
|
|
/*
|
|
* vtruncbuf() doesn't get the buffer overlapping the
|
|
* truncation point. We may have a B_DELWRI and/or B_CACHE
|
|
* buffer that now needs to be truncated.
|
|
*/
|
|
error = vtruncbuf(vp, cred, td, nsize, biosize);
|
|
lbn = nsize / biosize;
|
|
bufsize = nsize & (biosize - 1);
|
|
bp = nfs_getcacheblk(vp, lbn, bufsize, td);
|
|
if (!bp)
|
|
return EINTR;
|
|
if (bp->b_dirtyoff > bp->b_bcount)
|
|
bp->b_dirtyoff = bp->b_bcount;
|
|
if (bp->b_dirtyend > bp->b_bcount)
|
|
bp->b_dirtyend = bp->b_bcount;
|
|
bp->b_flags |= B_RELBUF; /* don't leave garbage around */
|
|
brelse(bp);
|
|
} else {
|
|
vnode_pager_setsize(vp, nsize);
|
|
}
|
|
return(error);
|
|
}
|
|
|