+/*
+ * Copyright (c) 1989 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Rick Macklem at The University of Guelph.
+ *
+ * Redistribution and use in source and binary forms are permitted
+ * provided that the above copyright notice and this paragraph are
+ * duplicated in all such forms and that any documentation,
+ * advertising materials, and other materials related to such
+ * distribution and use acknowledge that the software was developed
+ * by the University of California, Berkeley. The name of the
+ * University may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * @(#)nfs_bio.c 7.1 (Berkeley) %G%
+ */
+
+#include "param.h"
+#include "user.h"
+#include "buf.h"
+#include "vnode.h"
+#include "trace.h"
+#include "mount.h"
+#include "nfsnode.h"
+#include "nfsiom.h"
+
+/* True and false, how exciting */
+#define TRUE 1
+#define FALSE 0
+
+/*
+ * Vnode op for read using bio
+ * Any similarity to readip() is purely coincidental
+ */
+nfs_read(vp, uio, offp, ioflag, cred)
+ register struct vnode *vp;
+ struct uio *uio;
+ off_t *offp;
+ int ioflag;
+ struct ucred *cred;
+{
+ register struct nfsnode *np = VTONFS(vp);
+ struct buf *bp;
+ struct vattr vattr;
+ daddr_t lbn, bn, rablock;
+ int error = 0;
+ int diff;
+ long n, on;
+ int count;
+
+ if (!(ioflag & IO_NODELOCKED))
+ nfs_lock(vp);
+ uio->uio_offset = *offp;
+ /*
+ * Avoid caching directories. Once everything is using getdirentries()
+ * this will never happen anyhow.
+ */
+ if (vp->v_type == VDIR) {
+ error = nfs_readrpc(vp, uio, offp, cred);
+ goto out;
+ }
+ count = uio->uio_resid;
+ if (uio->uio_rw != UIO_READ)
+ panic("nfs_read mode");
+ if (vp->v_type != VREG)
+ panic("nfs_read type");
+ if (uio->uio_resid == 0)
+ goto out;
+ if (uio->uio_offset < 0) {
+ error = EINVAL;
+ goto out;
+ }
+ /*
+ * If the file's modify time on the server has changed since the
+ * last read rpc or you have written to the file,
+ * you may have lost data cache consistency with the
+ * server, so flush all of the file's data out of the cache.
+ * This will implicitly bring the modify time up to date, since
+ * up to date attributes are returned in the reply to any write rpc's
+ * NB: This implies that cache data can be read when up to
+ * NFS_ATTRTIMEO seconds out of date. If you find that you need current
+ * attributes this could be forced by setting n_attrstamp to 0 before
+ * the nfs_getattr() call.
+ */
+ if (np->n_flag & NMODIFIED) {
+ np->n_flag &= ~NMODIFIED;
+ if (error = nfs_blkflush(vp, (daddr_t)0, np->n_size, FALSE))
+ goto out;
+ if (error = nfs_getattr(vp, &vattr, cred))
+ goto out;
+ np->n_size = vattr.va_size;
+ np->n_mtime = vattr.va_mtime.tv_sec;
+ } else {
+ if (error = nfs_getattr(vp, &vattr, cred))
+ goto out;
+ if (np->n_mtime != vattr.va_mtime.tv_sec) {
+ if (error = nfs_blkflush(vp, (daddr_t)0, np->n_size, FALSE))
+ goto out;
+ np->n_size = vattr.va_size;
+ np->n_mtime = vattr.va_mtime.tv_sec;
+ }
+ }
+ do {
+ lbn = uio->uio_offset >> NFS_BIOSHIFT;
+ on = uio->uio_offset & (NFS_BIOSIZE-1);
+ n = MIN((unsigned)(NFS_BIOSIZE - on), uio->uio_resid);
+ diff = np->n_size - uio->uio_offset;
+ if (diff <= 0)
+ goto out;
+ if (diff < n)
+ n = diff;
+ bn = lbn*(NFS_BIOSIZE/DEV_BSIZE);
+ rablock = (lbn+1)*(NFS_BIOSIZE/DEV_BSIZE);
+ if (np->n_lastr+1 == lbn)
+ error = breada(vp, bn, NFS_BIOSIZE, rablock, NFS_BIOSIZE,
+ cred, &bp);
+ else
+ error = bread(vp, bn, NFS_BIOSIZE, cred, &bp);
+ np->n_lastr = lbn;
+ if (bp->b_resid) {
+ diff = (on >= (NFS_BIOSIZE-bp->b_resid)) ? 0 :
+ (NFS_BIOSIZE-bp->b_resid-on);
+ n = MIN(n, diff);
+ }
+ if (error) {
+ brelse(bp);
+ goto out;
+ }
+ if (n > 0)
+ error = uiomove(bp->b_un.b_addr + on, (int)n, uio);
+ if (n+on == NFS_BIOSIZE || uio->uio_offset == np->n_size)
+ bp->b_flags |= B_AGE;
+ brelse(bp);
+ } while (error == 0 && uio->uio_resid > 0 && n != 0);
+out:
+ *offp = uio->uio_offset;
+ if ((ioflag & IO_NODELOCKED) == 0)
+ nfs_unlock(vp);
+ return (error);
+}
+
+/*
+ * Vnode op for write using bio
+ */
+nfs_write(vp, uio, offp, ioflag, cred)
+ register struct vnode *vp;
+ register struct uio *uio;
+ off_t *offp;
+ int ioflag;
+ struct ucred *cred;
+{
+ struct buf *bp;
+ struct nfsnode *np = VTONFS(vp);
+ daddr_t lbn, bn;
+ int i, n, on;
+ int flags, count, size;
+ int error = 0;
+ int cnt;
+ u_long osize;
+
+ if ((ioflag & IO_NODELOCKED) == 0)
+ nfs_lock(vp);
+ /* Should we try and do this ?? */
+ if (vp->v_type == VREG && (ioflag & IO_APPEND))
+ *offp = np->n_size;
+ uio->uio_offset = *offp;
+ cnt = uio->uio_resid;
+#ifdef notdef
+ osize = np->n_size;
+#endif
+ if (uio->uio_rw != UIO_WRITE)
+ panic("nfs_write mode");
+ if (vp->v_type != VREG)
+ panic("nfs_write type");
+ if (uio->uio_offset < 0) {
+ error = EINVAL;
+ goto out;
+ }
+ if (uio->uio_resid == 0)
+ goto out;
+ /*
+ * 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 (vp->v_type == VREG &&
+ uio->uio_offset + uio->uio_resid >
+ u.u_rlimit[RLIMIT_FSIZE].rlim_cur) {
+ psignal(u.u_procp, SIGXFSZ);
+ error = EFBIG;
+ goto out;
+ }
+ np->n_flag |= NMODIFIED;
+ do {
+ lbn = uio->uio_offset >> NFS_BIOSHIFT;
+ on = uio->uio_offset & (NFS_BIOSIZE-1);
+ n = MIN((unsigned)(NFS_BIOSIZE - on), uio->uio_resid);
+ if (uio->uio_offset+n > np->n_size)
+ np->n_size = uio->uio_offset+n;
+ bn = lbn*(NFS_BIOSIZE/DEV_BSIZE);
+ count = howmany(NFS_BIOSIZE, CLBYTES);
+ for (i = 0; i < count; i++)
+ munhash(vp, bn + i * CLBYTES / DEV_BSIZE);
+ bp = getblk(vp, bn, NFS_BIOSIZE);
+ if (bp->b_wcred == NOCRED) {
+ crhold(cred);
+ bp->b_wcred = cred;
+ }
+ if (bp->b_dirtyend > 0) {
+ /*
+ * Iff 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
+ */
+ if (on <= bp->b_dirtyend && (on+n) >= bp->b_dirtyoff) {
+ bp->b_dirtyoff = MIN(on, bp->b_dirtyoff);
+ bp->b_dirtyend = MAX((on+n), bp->b_dirtyend);
+ } else {
+ /*
+ * Like bwrite() but without the brelse
+ */
+ bp->b_flags &= ~(B_READ | B_DONE |
+ B_ERROR | B_DELWRI | B_ASYNC);
+ u.u_ru.ru_oublock++;
+ VOP_STRATEGY(bp);
+ error = biowait(bp);
+ if (bp->b_flags & B_ERROR) {
+ brelse(bp);
+ if (bp->b_error)
+ error = bp->b_error;
+ else
+ error = EIO;
+ goto out;
+ }
+ bp->b_dirtyoff = on;
+ bp->b_dirtyend = on+n;
+ }
+ } else {
+ bp->b_dirtyoff = on;
+ bp->b_dirtyend = on+n;
+ }
+ if (error = uiomove(bp->b_un.b_addr + on, n, uio))
+ goto out;
+ if ((n+on) == NFS_BIOSIZE) {
+ bp->b_flags |= B_AGE;
+ bawrite(bp);
+ } else {
+ bdwrite(bp);
+ }
+ } while (error == 0 && uio->uio_resid > 0 && n != 0);
+#ifdef notdef
+ /* Should we try and do this for nfs ?? */
+ if (error && (ioflag & IO_UNIT))
+ np->n_size = osize;
+ else
+#endif
+ *offp += cnt - uio->uio_resid;
+out:
+ if ((ioflag & IO_NODELOCKED) == 0)
+ nfs_unlock(vp);
+ return (error);
+}
+
+/*
+ * Flush and invalidate all of the buffers associated with the blocks of vp
+ */
+nfs_blkflush(vp, blkno, size, invalidate)
+ struct vnode *vp;
+ daddr_t blkno;
+ long size;
+ int invalidate;
+{
+ register struct buf *ep;
+ struct buf *dp;
+ daddr_t curblkno, last;
+ int s, error, allerrors = 0;
+
+ last = blkno + btodb(size);
+ for (curblkno = blkno; curblkno <= last;
+ curblkno += (NFS_BIOSIZE / DEV_BSIZE)) {
+ dp = BUFHASH(vp, curblkno);
+loop:
+ for (ep = dp->b_forw; ep != dp; ep = ep->b_forw) {
+ if (ep->b_vp != vp || (ep->b_flags & B_INVAL))
+ continue;
+ if (curblkno != ep->b_blkno)
+ continue;
+ s = splbio();
+ if (ep->b_flags & B_BUSY) {
+ ep->b_flags |= B_WANTED;
+ sleep((caddr_t)ep, PRIBIO+1);
+ splx(s);
+ goto loop;
+ }
+ splx(s);
+ notavail(ep);
+ if (ep->b_flags & B_DELWRI) {
+ ep->b_flags &= ~B_ASYNC;
+ if (error = bwrite(ep))
+ allerrors = error;
+ goto loop;
+ }
+ if (invalidate) {
+ ep->b_flags |= B_INVAL;
+ brelvp(ep);
+ }
+ brelse(ep);
+ }
+ }
+ return (allerrors);
+}
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