Beispiel #1
0
static int
vnop_write_9p(struct vnop_write_args *ap)
{
	vnode_t vp;
	node_9p *np;
	uio_t uio;
	user_ssize_t resid;
	off_t eof, zh, zt, off;
	int e, flag;

	TRACE();
	vp = ap->a_vp;
	uio = ap->a_uio;
	np = NTO9P(vp);

	if (vnode_isdir(vp))
		return EISDIR;
	
	off = uio_offset(uio);
	if (off < 0)
		return EINVAL;
	
	resid = uio_resid(uio);
	if (resid == 0)
		return 0;

	flag = ap->a_ioflag;
	if (ISSET(flag, IO_APPEND)) {
		off = np->dir.length;
		uio_setoffset(uio, off);
	}
	nlock_9p(np, NODE_LCK_EXCLUSIVE);
	if (vnode_isnocache(vp) || ISSET(flag, IO_NOCACHE)) {
		ubc_msync(vp, uio_offset(uio), uio_offset(uio)+uio_resid(uio), NULL, UBC_PUSHDIRTY|UBC_SYNC);
		ubc_msync(vp, uio_offset(uio), uio_offset(uio)+uio_resid(uio), NULL, UBC_INVALIDATE);
		e = nwrite_9p(np, uio);
	} else {
		zh = zt = 0;
		eof = MAX(np->dir.length, resid+off);
		if (eof > np->dir.length) {
			if (off > np->dir.length) {
				zh = np->dir.length;
				SET(flag, IO_HEADZEROFILL);
			}
  			zt = (eof + (PAGE_SIZE_64 - 1)) & ~PAGE_MASK_64;
			if (zt > eof) {
				zt = eof;
				SET(flag, IO_TAILZEROFILL);
			}
		}
		e = cluster_write(vp, uio, np->dir.length, eof, zh, zt, flag);
		if (e==0 && eof>np->dir.length) {
			np->dirtimer = 0;
			np->dir.length = eof;
			ubc_setsize(vp, eof);
		}
	}
	nunlock_9p(np);
	return e;
}
Beispiel #2
0
/*
 * Vnode op for writing.
 */
static int
ext2_write(struct vop_write_args *ap)
{
	struct vnode *vp;
	struct uio *uio;
	struct inode *ip;
	struct m_ext2fs *fs;
	struct buf *bp;
	daddr_t lbn;
	off_t osize;
	int blkoffset, error, flags, ioflag, resid, size, seqcount, xfersize;

	ioflag = ap->a_ioflag;
	uio = ap->a_uio;
	vp = ap->a_vp;

	seqcount = ioflag >> IO_SEQSHIFT;
	ip = VTOI(vp);

#ifdef INVARIANTS
	if (uio->uio_rw != UIO_WRITE)
		panic("%s: mode", "ext2_write");
#endif

	switch (vp->v_type) {
	case VREG:
		if (ioflag & IO_APPEND)
			uio->uio_offset = ip->i_size;
		if ((ip->i_flags & APPEND) && uio->uio_offset != ip->i_size)
			return (EPERM);
		/* FALLTHROUGH */
	case VLNK:
		break;
	case VDIR:
		/* XXX differs from ffs -- this is called from ext2_mkdir(). */
		if ((ioflag & IO_SYNC) == 0)
		panic("ext2_write: nonsync dir write");
		break;
	default:
		panic("ext2_write: type %p %d (%jd,%jd)", (void *)vp,
		    vp->v_type, (intmax_t)uio->uio_offset,
		    (intmax_t)uio->uio_resid);
	}

	KASSERT(uio->uio_resid >= 0, ("ext2_write: uio->uio_resid < 0"));
	KASSERT(uio->uio_offset >= 0, ("ext2_write: uio->uio_offset < 0"));
	fs = ip->i_e2fs;
	if ((uoff_t)uio->uio_offset + uio->uio_resid > fs->e2fs_maxfilesize)
		return (EFBIG);
	/*
	 * 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 (vn_rlimit_fsize(vp, uio, uio->uio_td))
		return (EFBIG);

	resid = uio->uio_resid;
	osize = ip->i_size;
	if (seqcount > BA_SEQMAX)
		flags = BA_SEQMAX << BA_SEQSHIFT;
	else
		flags = seqcount << BA_SEQSHIFT;
	if ((ioflag & IO_SYNC) && !DOINGASYNC(vp))
		flags |= IO_SYNC;

	for (error = 0; uio->uio_resid > 0;) {
		lbn = lblkno(fs, uio->uio_offset);
		blkoffset = blkoff(fs, uio->uio_offset);
		xfersize = fs->e2fs_fsize - blkoffset;
		if (uio->uio_resid < xfersize)
			xfersize = uio->uio_resid;
		if (uio->uio_offset + xfersize > ip->i_size)
			vnode_pager_setsize(vp, uio->uio_offset + xfersize);

                /*
		 * We must perform a read-before-write if the transfer size
		 * does not cover the entire buffer.
                 */
		if (fs->e2fs_bsize > xfersize)
			flags |= BA_CLRBUF;
		else
			flags &= ~BA_CLRBUF;
		error = ext2_balloc(ip, lbn, blkoffset + xfersize,
		    ap->a_cred, &bp, flags);
		if (error != 0)
			break;

		/*
		 * If the buffer is not valid and we did not clear garbage
		 * out above, we have to do so here even though the write
		 * covers the entire buffer in order to avoid a mmap()/write
		 * race where another process may see the garbage prior to
		 * the uiomove() for a write replacing it.
		 */
		if ((bp->b_flags & B_CACHE) == 0 && fs->e2fs_bsize <= xfersize)
			vfs_bio_clrbuf(bp);
		if ((ioflag & (IO_SYNC|IO_INVAL)) == (IO_SYNC|IO_INVAL))
			bp->b_flags |= B_NOCACHE;
		if (uio->uio_offset + xfersize > ip->i_size)
			ip->i_size = uio->uio_offset + xfersize;
		size = blksize(fs, ip, lbn) - bp->b_resid;
		if (size < xfersize)
			xfersize = size;

		error =
		    uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
		if (ioflag & (IO_VMIO|IO_DIRECT)) {
			bp->b_flags |= B_RELBUF;
		}

		/*
		 * If IO_SYNC each buffer is written synchronously.  Otherwise
		 * if we have a severe page deficiency write the buffer
		 * asynchronously.  Otherwise try to cluster, and if that
		 * doesn't do it then either do an async write (if O_DIRECT),
		 * or a delayed write (if not).
		 */
		if (ioflag & IO_SYNC) {
			(void)bwrite(bp);
		} else if (vm_page_count_severe() ||
		    buf_dirty_count_severe() ||
		    (ioflag & IO_ASYNC)) {
			bp->b_flags |= B_CLUSTEROK;
			bawrite(bp);
		} else if (xfersize + blkoffset == fs->e2fs_fsize) {
			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
				bp->b_flags |= B_CLUSTEROK;
				cluster_write(vp, bp, ip->i_size, seqcount, 0);
			} else {
				bawrite(bp);
			}
		} else if (ioflag & IO_DIRECT) {
			bp->b_flags |= B_CLUSTEROK;
			bawrite(bp);
		} else {
			bp->b_flags |= B_CLUSTEROK;
			bdwrite(bp);
		}
		if (error || xfersize == 0)
			break;
	}
	/*
	 * If we successfully wrote any data, and we are not the superuser
	 * we clear the setuid and setgid bits as a precaution against
	 * tampering.
	 */
	if ((ip->i_mode & (ISUID | ISGID)) && resid > uio->uio_resid &&
	    ap->a_cred) {
		if (priv_check_cred(ap->a_cred, PRIV_VFS_RETAINSUGID, 0))
			ip->i_mode &= ~(ISUID | ISGID);
	}
	if (error) {
		if (ioflag & IO_UNIT) {
			(void)ext2_truncate(vp, osize,
			    ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}
	}
	if (uio->uio_resid != resid) {
               ip->i_flag |= IN_CHANGE | IN_UPDATE;
               if (ioflag & IO_SYNC)
                       error = ext2_update(vp, 1);
       }
	return (error);
}
// ffs文件系统的写入操作
int
ffs_write(void *v)
{
	struct vop_write_args *ap = v;
	struct vnode *vp;
	struct uio *uio;
	struct inode *ip;
	struct fs *fs;
	struct buf *bp;
	daddr_t lbn;
	off_t osize;
	int blkoffset, error, extended, flags, ioflag, size, xfersize;
	ssize_t resid, overrun;

	extended = 0;
	ioflag = ap->a_ioflag;
	uio = ap->a_uio;
	vp = ap->a_vp;
	ip = VTOI(vp);

#ifdef DIAGNOSTIC
	if (uio->uio_rw != UIO_WRITE)
		panic("ffs_write: mode");
#endif

	/*
	 * If writing 0 bytes, succeed and do not change
	 * update time or file offset (standards compliance)
	 */
	if (uio->uio_resid == 0)
		return (0);

	switch (vp->v_type) {
	case VREG:
		if (ioflag & IO_APPEND)
			uio->uio_offset = DIP(ip, size);
		if ((DIP(ip, flags) & APPEND) && uio->uio_offset != DIP(ip, size))
			return (EPERM);
		/* FALLTHROUGH */
	case VLNK:
		break;
	case VDIR:
		if ((ioflag & IO_SYNC) == 0)
			panic("ffs_write: nonsync dir write");
		break;
	default:
		panic("ffs_write: type");
	}

	fs = ip->i_fs;
	if (uio->uio_offset < 0 ||
	    (u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
		return (EFBIG);

	/* do the filesize rlimit check */
	if ((error = vn_fsizechk(vp, uio, ioflag, &overrun)))
		return (error);

	resid = uio->uio_resid;
	osize = DIP(ip, size);
	flags = ioflag & IO_SYNC ? B_SYNC : 0;

	for (error = 0; uio->uio_resid > 0;) {
		lbn = lblkno(fs, uio->uio_offset);
		blkoffset = blkoff(fs, uio->uio_offset);
		xfersize = fs->fs_bsize - blkoffset;
		if (uio->uio_resid < xfersize)
			xfersize = uio->uio_resid;
		if (fs->fs_bsize > xfersize)
			flags |= B_CLRBUF;
		else
			flags &= ~B_CLRBUF;

		if ((error = UFS_BUF_ALLOC(ip, uio->uio_offset, xfersize,
			 ap->a_cred, flags, &bp)) != 0)
			break;
		if (uio->uio_offset + xfersize > DIP(ip, size)) {
			DIP_ASSIGN(ip, size, uio->uio_offset + xfersize);
			uvm_vnp_setsize(vp, DIP(ip, size));
			extended = 1;
		}
		(void)uvm_vnp_uncache(vp);

		size = blksize(fs, ip, lbn) - bp->b_resid;
		if (size < xfersize)
			xfersize = size;

		error =
		    uiomovei(bp->b_data + blkoffset, xfersize, uio);

		if (error != 0)
			memset(bp->b_data + blkoffset, 0, xfersize);

#if 0
		if (ioflag & IO_NOCACHE)
			bp->b_flags |= B_NOCACHE;
#endif
		if (ioflag & IO_SYNC)
			(void)bwrite(bp);
		else if (xfersize + blkoffset == fs->fs_bsize) {
			if (doclusterwrite)
				cluster_write(bp, &ip->i_ci, DIP(ip, size));
			else
				bawrite(bp);
		} else
			bdwrite(bp);

		if (error || xfersize == 0)
			break;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * If we successfully wrote any data, and we are not the superuser
	 * we clear the setuid and setgid bits as a precaution against
	 * tampering.
	 */
	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
		DIP_ASSIGN(ip, mode, DIP(ip, mode) & ~(ISUID | ISGID));
	if (resid > uio->uio_resid)
		VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
	if (error) {
		if (ioflag & IO_UNIT) {
			(void)UFS_TRUNCATE(ip, osize,
			    ioflag & IO_SYNC, ap->a_cred);
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}
	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
		error = UFS_UPDATE(ip, 1);
	}
	/* correct the result for writes clamped by vn_fsizechk() */
	uio->uio_resid += overrun;
	return (error);
}
Beispiel #4
0
/*
 * Vnode op for writing.
 */
int
ffs_write(void *v)
{
	struct vop_write_args *ap = v;
	struct vnode *vp;
	struct uio *uio;
	struct inode *ip;
	struct fs *fs;
	struct buf *bp;
	struct proc *p;
	daddr64_t lbn;
	off_t osize;
	int blkoffset, error, extended, flags, ioflag, resid, size, xfersize;

	extended = 0;
	ioflag = ap->a_ioflag;
	uio = ap->a_uio;
	vp = ap->a_vp;
	ip = VTOI(vp);

#ifdef DIAGNOSTIC
	if (uio->uio_rw != UIO_WRITE)
		panic("ffs_write: mode");
#endif

	/*
	 * If writing 0 bytes, succeed and do not change
	 * update time or file offset (standards compliance)
	 */
	if (uio->uio_resid == 0)
		return (0);

	switch (vp->v_type) {
	case VREG:
		if (ioflag & IO_APPEND)
			uio->uio_offset = DIP(ip, size);
		if ((DIP(ip, flags) & APPEND) && uio->uio_offset != DIP(ip, size))
			return (EPERM);
		/* FALLTHROUGH */
	case VLNK:
		break;
	case VDIR:
		if ((ioflag & IO_SYNC) == 0)
			panic("ffs_write: nonsync dir write");
		break;
	default:
		panic("ffs_write: type");
	}

	fs = ip->i_fs;
	if (uio->uio_offset < 0 ||
	    (u_int64_t)uio->uio_offset + uio->uio_resid > fs->fs_maxfilesize)
		return (EFBIG);
	/*
	 * Maybe this should be above the vnode op call, but so long as
	 * file servers have no limits, I don't think it matters.
	 */
	p = uio->uio_procp;
	if (vp->v_type == VREG && p && !(ioflag & IO_NOLIMIT) &&
	    uio->uio_offset + uio->uio_resid >
	    p->p_rlimit[RLIMIT_FSIZE].rlim_cur) {
		psignal(p, SIGXFSZ);
		return (EFBIG);
	}

	resid = uio->uio_resid;
	osize = DIP(ip, size);
	flags = ioflag & IO_SYNC ? B_SYNC : 0;

	for (error = 0; uio->uio_resid > 0;) {
		lbn = lblkno(fs, uio->uio_offset);
		blkoffset = blkoff(fs, uio->uio_offset);
		xfersize = fs->fs_bsize - blkoffset;
		if (uio->uio_resid < xfersize)
			xfersize = uio->uio_resid;
		if (fs->fs_bsize > xfersize)
			flags |= B_CLRBUF;
		else
			flags &= ~B_CLRBUF;

		if ((error = UFS_BUF_ALLOC(ip, uio->uio_offset, xfersize,
			 ap->a_cred, flags, &bp)) != 0)
			break;
		if (uio->uio_offset + xfersize > DIP(ip, size)) {
			DIP_ASSIGN(ip, size, uio->uio_offset + xfersize);
			uvm_vnp_setsize(vp, DIP(ip, size));
			extended = 1;
		}
		(void)uvm_vnp_uncache(vp);

		size = blksize(fs, ip, lbn) - bp->b_resid;
		if (size < xfersize)
			xfersize = size;

		error =
		    uiomove((char *)bp->b_data + blkoffset, xfersize, uio);

		if (error != 0)
			bzero((char *)bp->b_data + blkoffset, xfersize);

		if (ioflag & IO_SYNC)
			(void)bwrite(bp);
		else if (xfersize + blkoffset == fs->fs_bsize) {
			if (doclusterwrite)
				cluster_write(bp, &ip->i_ci, DIP(ip, size));
			else
				bawrite(bp);
		} else
			bdwrite(bp);

		if (error || xfersize == 0)
			break;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * If we successfully wrote any data, and we are not the superuser
	 * we clear the setuid and setgid bits as a precaution against
	 * tampering.
	 */
	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
		DIP_ASSIGN(ip, mode, DIP(ip, mode) & ~(ISUID | ISGID));
	if (resid > uio->uio_resid)
		VN_KNOTE(vp, NOTE_WRITE | (extended ? NOTE_EXTEND : 0));
	if (error) {
		if (ioflag & IO_UNIT) {
			(void)UFS_TRUNCATE(ip, osize,
			    ioflag & IO_SYNC, ap->a_cred);
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}
	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
		error = UFS_UPDATE(ip, MNT_WAIT);
	}
	return (error);
}
Beispiel #5
0
/*
 * Vnode op for writing.
 */
int
ext2fs_write(void *v)
{
	struct vop_write_args *ap = v;
	struct vnode *vp;
	struct uio *uio;
	struct inode *ip;
	struct m_ext2fs *fs;
	struct buf *bp;
	int32_t lbn;
	off_t osize;
	int blkoffset, error, flags, ioflag, size, xfersize;
	ssize_t resid, overrun;

	ioflag = ap->a_ioflag;
	uio = ap->a_uio;
	vp = ap->a_vp;
	ip = VTOI(vp);

#ifdef DIAGNOSTIC
	if (uio->uio_rw != UIO_WRITE)
		panic("%s: mode", "ext2fs_write");
#endif

	/*
	 * If writing 0 bytes, succeed and do not change
	 * update time or file offset (standards compliance)
	 */
	if (uio->uio_resid == 0)
		return (0);

	switch (vp->v_type) {
	case VREG:
		if (ioflag & IO_APPEND)
			uio->uio_offset = ext2fs_size(ip);
		if ((ip->i_e2fs_flags & EXT2_APPEND) &&
			uio->uio_offset != ext2fs_size(ip))
			return (EPERM);
		/* FALLTHROUGH */
	case VLNK:
		break;
	case VDIR:
		if ((ioflag & IO_SYNC) == 0)
			panic("%s: nonsync dir write", "ext2fs_write");
		break;
	default:
		panic("%s: type", "ext2fs_write");
	}

	fs = ip->i_e2fs;
	if (uio->uio_offset < 0 ||
		(u_int64_t)uio->uio_offset + uio->uio_resid >
		((u_int64_t)0x80000000 * fs->e2fs_bsize - 1))
		return (EFBIG);

	/* do the filesize rlimit check */
	if ((error = vn_fsizechk(vp, uio, ioflag, &overrun)))
		return (error);

	resid = uio->uio_resid;
	osize = ext2fs_size(ip);
	flags = ioflag & IO_SYNC ? B_SYNC : 0;

	for (error = 0; uio->uio_resid > 0;) {
		lbn = lblkno(fs, uio->uio_offset);
		blkoffset = blkoff(fs, uio->uio_offset);
		xfersize = fs->e2fs_bsize - blkoffset;
		if (uio->uio_resid < xfersize)
			xfersize = uio->uio_resid;
		if (fs->e2fs_bsize > xfersize)
			flags |= B_CLRBUF;
		else
			flags &= ~B_CLRBUF;

		error = ext2fs_buf_alloc(ip,
			lbn, blkoffset + xfersize, ap->a_cred, &bp, flags);
		if (error)
			break;
		if (uio->uio_offset + xfersize > ext2fs_size(ip)) {
			error = ext2fs_setsize(ip, uio->uio_offset + xfersize);
			if (error)
				break;
			uvm_vnp_setsize(vp, ip->i_e2fs_size);
		}
		uvm_vnp_uncache(vp);

		size = fs->e2fs_bsize - bp->b_resid;
		if (size < xfersize)
			xfersize = size;

		error =
			uiomove((char *)bp->b_data + blkoffset, (int)xfersize, uio);
		if (ioflag & IO_SYNC)
			(void)bwrite(bp);
		else if (xfersize + blkoffset == fs->e2fs_bsize) {
			if (doclusterwrite)
				cluster_write(bp, &ip->i_ci, ext2fs_size(ip));
			else
				bawrite(bp);
		} else
			bdwrite(bp);
		if (error || xfersize == 0)
			break;
		ip->i_flag |= IN_CHANGE | IN_UPDATE;
	}
	/*
	 * If we successfully wrote any data, and we are not the superuser
	 * we clear the setuid and setgid bits as a precaution against
	 * tampering.
	 */
	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
		ip->i_e2fs_mode &= ~(ISUID | ISGID);
	if (error) {
		if (ioflag & IO_UNIT) {
			(void)ext2fs_truncate(ip, osize,
				ioflag & IO_SYNC, ap->a_cred);
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}
	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
		error = ext2fs_update(ip, NULL, NULL, 1);
	}
	/* correct the result for writes clamped by vn_fsizechk() */
	uio->uio_resid += overrun;
	return (error);
}
int
xfs_write_file(xfs_inode_t *xip, struct uio *uio, int ioflag)
{
	struct buf	*bp;
	//struct thread	*td;
	daddr_t		lbn;
	off_t		osize = 0;
	off_t		offset= 0;
	int		blkoffset, error, resid, xfersize;
	int		fsblocksize;
	int		seqcount;
	xfs_iomap_t	iomap;
	int		maps = 1;

	xfs_vnode_t	*xvp = XFS_ITOV(xip);
	struct vnode	*vp = xvp->v_vnode;

	xfs_mount_t	*mp = (&xip->i_iocore)->io_mount;

	seqcount = ioflag >> IO_SEQSHIFT;

	memset(&iomap,0,sizeof(xfs_iomap_t));

	/*
	 * 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 0
	td = uio->uio_td;
	if (vp->v_type == VREG && td != NULL) {
		PROC_LOCK(td->td_proc);
		if (uio->uio_offset + uio->uio_resid >
		    lim_cur(td->td_proc, RLIMIT_FSIZE)) {
			psignal(td->td_proc, SIGXFSZ);
			PROC_UNLOCK(td->td_proc);
			return (EFBIG);
		}
		PROC_UNLOCK(td->td_proc);
	}
#endif

	resid = uio->uio_resid;
	offset = uio->uio_offset;
	osize = xip->i_d.di_size;

   /* xfs bmap wants bytes for both offset and size */
	XVOP_BMAP(xvp,
		  uio->uio_offset,
		  uio->uio_resid,
		  BMAPI_WRITE|BMAPI_DIRECT,
		  &iomap, &maps, error);
	if(error) {
		printf("XVOP_BMAP failed\n");
		goto error;
	}

	for (error = 0; uio->uio_resid > 0;) {

		lbn = XFS_B_TO_FSBT(mp, offset);
		blkoffset = XFS_B_FSB_OFFSET(mp, offset);
		xfersize = mp->m_sb.sb_blocksize - blkoffset;
		fsblocksize = mp->m_sb.sb_blocksize;

		if (uio->uio_resid < xfersize)
			xfersize = uio->uio_resid;

		/*
		 * getblk sets buf by  blkno *  bo->bo_bsize
		 * bo_bsize is set from the mnt point fsize
		 * so we call getblk in the case using fsblocks
		 * not basic blocks
		 */

		bp = getblk(vp, lbn, fsblocksize, 0, 0, 0);
		if(!bp) {
			printf("getblk failed\n");
			error = EINVAL;
			break;
		}

		if (!(bp->b_flags & B_CACHE)  && fsblocksize > xfersize)
			vfs_bio_clrbuf(bp);

		if (offset + xfersize >  xip->i_d.di_size) {
			xip->i_d.di_size = offset + xfersize;
			vnode_pager_setsize(vp, offset + fsblocksize);
		}

		/* move the offset for the next itteration of the loop */
		offset += xfersize;

		error = uiomove((char *)bp->b_data + blkoffset, xfersize, uio);

		if ((ioflag & IO_VMIO) &&
		   (LIST_FIRST(&bp->b_dep) == NULL)) /* in ext2fs? */
			bp->b_flags |= B_RELBUF;

		/* force to full direct for now */
		bp->b_flags |= B_DIRECT;
		/* and sync ... the delay path is not pushing data out */
		ioflag |= IO_SYNC;

		if (ioflag & IO_SYNC) {
			(void)bwrite(bp);
		} else if (0 /* RMC xfersize + blkoffset == fs->s_frag_size */) {
			if ((vp->v_mount->mnt_flag & MNT_NOCLUSTERW) == 0) {
				bp->b_flags |= B_CLUSTEROK;
				cluster_write(vp, bp, osize, seqcount);
			} else {
				bawrite(bp);
			}
		} else {
			bp->b_flags |= B_CLUSTEROK;
			bdwrite(bp);
		}
		if (error || xfersize == 0)
			break;
	}
	/*
	 * If we successfully wrote any data, and we are not the superuser
	 * we clear the setuid and setgid bits as a precaution against
	 * tampering.
	 */
#if 0
	if (resid > uio->uio_resid && ap->a_cred && ap->a_cred->cr_uid != 0)
		ip->i_mode &= ~(ISUID | ISGID);
#endif
	if (error) {
		if (ioflag & IO_UNIT) {
#if 0
			(void)ext2_truncate(vp, osize,
			    ioflag & IO_SYNC, ap->a_cred, uio->uio_td);
#endif
			uio->uio_offset -= resid - uio->uio_resid;
			uio->uio_resid = resid;
		}
	} else if (resid > uio->uio_resid && (ioflag & IO_SYNC)) {
		/* Update the vnode here? */
	}

error:
	return error;
}