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Change linvfs_readdir to allocate a buffer, call xfs to fill it, and
then call the filldir function on each entry. This is instead of doing the
filldir deep in the bowels of xfs which causes locking problems.

/*
 * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
 * 
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 * 
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * 
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 * 
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write the Free Software Foundation, Inc., 59
 * Temple Place - Suite 330, Boston MA 02111-1307, USA.
 * 
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 * 
 * http://www.sgi.com 
 * 
 * For further information regarding this notice, see: 
 * 
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include <xfs.h>
#include <linux/dcache.h>
#include <linux/pagemap.h>
#include <linux/slab.h>


STATIC long long linvfs_file_lseek(
	struct file *file,
	loff_t offset,
	int origin)
{
	struct inode *inode = file->f_dentry->d_inode;
	vnode_t *vp;
	struct vattr vattr;
	loff_t old_off = offset;
	int error;

	vp = LINVFS_GET_VP(inode);

	ASSERT(vp);

	switch (origin) {
		case 2:
			vattr.va_mask = AT_SIZE;
			VOP_GETATTR(vp, &vattr, 0, get_current_cred(), error);
			if (error)
				return -error;

			offset += vattr.va_size;
			break;
		case 1:
			offset += file->f_pos;
	}

	/* All for the sake of seeing if we are too big */
	VOP_SEEK(vp, old_off, &offset, error);

	if (error)
		return -error;

	if (offset != file->f_pos) {
		file->f_pos = offset;
		file->f_version = ++event;
		file->f_reada = 0;
	}

	return offset;
}

STATIC ssize_t linvfs_read(
	struct file *filp,
	char *buf,
	size_t size,
	loff_t *offset)
{
	struct inode *inode;
	vnode_t *vp;
	int rv;
        uio_t uio;
        iovec_t iov;
	
	if (!filp || !filp->f_dentry ||
			!(inode = filp->f_dentry->d_inode)) {
		printk("EXIT linvfs_read -EBADF\n");
		return -EBADF;
	}

	inode = filp->f_dentry->d_inode;

	vp = LINVFS_GET_VP(inode);

	ASSERT(vp);

        uio.uio_iov = &iov;
        uio.uio_offset = *offset;
        uio.uio_fp = filp;
        uio.uio_iovcnt = 1;
        uio.uio_iov->iov_base = buf;
        uio.uio_iov->iov_len = uio.uio_resid = size;

	XFS_STATS_INC(xs_read_calls);
	XFS_STATS64_ADD(xs_read_bytes, size);
        
	VOP_READ(vp, &uio, 0, NULL, NULL, rv);
        *offset = uio.uio_offset;
        
	return(rv);
}


STATIC ssize_t linvfs_write(
	struct file *filp,
	const char *buf,
	size_t size,
	loff_t *offset)
{
	struct inode *inode;
	loff_t	pos;
	vnode_t *vp;
	int	err;
	int	pb_flags = 0; /* Flags to pass bmap calls */

        uio_t uio;
        iovec_t iov;
	
	if (!filp || !filp->f_dentry ||
			!(inode = filp->f_dentry->d_inode)) {
		printk("EXIT linvfs_write -EBADF\n");
		return -EBADF;
	}

	inode = filp->f_dentry->d_inode;

	down(&inode->i_sem);

	err = -EINVAL;

	pos = *offset;
	if (pos < 0)
		goto out;

	err = filp->f_error;
	if (err) {
		filp->f_error = 0;
		goto out;
	}

	if (filp->f_flags & O_APPEND)
		pos = inode->i_size;

	/*
	 * Handle O_SYNC writes
	 * The real work gets done in xfs_write()
	 */
	 
	if (filp->f_flags & O_SYNC) {
		pb_flags |= PBF_SYNC;
	}

	XFS_STATS_INC(xs_write_calls);
	XFS_STATS64_ADD(xs_write_bytes, size);

	vp = LINVFS_GET_VP(inode);

	ASSERT(vp);
        
        uio.uio_iov = &iov;
        uio.uio_offset = pos;
        uio.uio_fp = filp;
        uio.uio_iovcnt = 1;
        uio.uio_iov->iov_base = (void *)buf;
        uio.uio_iov->iov_len = uio.uio_resid = size;
        
	VOP_WRITE(vp, &uio, pb_flags, NULL, NULL, err);
        *offset = pos = uio.uio_offset;
        
out:
	up(&inode->i_sem);
	return(err);
}


STATIC int linvfs_open(
	struct inode *inode,
	struct file *filp)
{
	vnode_t *vp = LINVFS_GET_VP(inode);
	vnode_t *newvp;
	int	error;

	ASSERT(vp);

	VOP_OPEN(vp, &newvp, 0, get_current_cred(), error);

	return -error;
}


STATIC int linvfs_release(
	struct inode *inode,
	struct file *filp)
{
	vnode_t *vp = LINVFS_GET_VP(inode);
	int	error = 0;

	if (vp) {
		VOP_RELEASE(vp, error);
	}

	return -error;
}


STATIC int linvfs_fsync(
	struct file *filp,
	struct dentry *dentry,
	int datasync)
{
	struct inode *inode = filp->f_dentry->d_inode;
	vnode_t *vp = LINVFS_GET_VP(inode);
	int	error;
	int	flags = FSYNC_WAIT;

	if (datasync)
		flags |= FSYNC_DATA;

	ASSERT(vp);

	VOP_FSYNC(vp, flags, get_current_cred(),
		(off_t)0, (off_t)-1, error);

	if (error)
		return -error;

	return 0;
}

/*
 * linvfs_readdir maps to VOP_READDIR().
 * We need to build a uio, cred, ...
 */

#define nextdp(dp)      ((struct dirent *)((char *)(dp) + (dp)->d_reclen))

STATIC int linvfs_readdir(
	struct file *filp,
	void *dirent,
	filldir_t filldir)
{
	int			error = 0;
	vnode_t			*vp;
	uio_t			uio;
	iovec_t			iov;
	int			eof = 0;
	cred_t			cred;		/* Temporary cred workaround */
	caddr_t			read_buf;
	int			size = 0;
	size_t			rlen = PAGE_CACHE_SIZE << 2;
	off_t			start_offset;
	dirent_t		*dbp = NULL;

        vp = LINVFS_GET_VP(filp->f_dentry->d_inode);

	ASSERT(vp);
	/* Try fairly hard to get memory */
	do {
		if ((read_buf = (caddr_t)kmalloc(rlen, GFP_KERNEL)))
			break;
		rlen >>= 1;
	} while (rlen >= 1024);

	if (read_buf == NULL)
		return -ENOMEM;

	uio.uio_iov = &iov;
	uio.uio_fmode = filp->f_mode;
	uio.uio_segflg = UIO_SYSSPACE;
	uio.uio_offset = filp->f_pos;

	while (!eof) {
		uio.uio_resid = iov.iov_len = rlen;
		iov.iov_base = read_buf;
		uio.uio_iovcnt = 1;

		start_offset = uio.uio_offset;
		
		VOP_READDIR(vp, &uio, &cred, &eof, error);
		if ((uio.uio_offset == start_offset) || error) {
			size = 0;
			break;
		}

		size = rlen - uio.uio_resid;
		dbp = (dirent_t *)read_buf;
		while (size > 0) {
			size -= dbp->d_reclen;
			if (filldir(dirent, dbp->d_name, dbp->d_reclen,
					dbp->d_off, (linux_ino_t) dbp->d_ino,
					DT_UNKNOWN)) {
				goto done;
			}
			dbp = nextdp(dbp);
		}
	}
done:
	if (!error) {
		if (size == 0)
			filp->f_pos = uio.uio_offset;
		else if (dbp)
			filp->f_pos = dbp->d_off;
	}

	kfree(read_buf);
	return -error;
}


int linvfs_generic_file_mmap(struct file *filp, struct vm_area_struct *vma)
{
	vnode_t	*vp;
	int	ret;

	ret = generic_file_mmap(filp, vma);
	if (!ret) {
		vattr_t va, *vap;

		vap = &va;
		vap->va_mask = AT_UPDATIME;

		vp = LINVFS_GET_VP(filp->f_dentry->d_inode);

		ASSERT(vp);

		VOP_SETATTR(vp, vap, AT_UPDATIME, NULL, ret);
	}
	return(ret);
}


STATIC int linvfs_ioctl(
	struct inode	*inode,
	struct file	*filp,
	unsigned int	cmd,
	unsigned long	arg)
{
	int	error;
	vnode_t	*vp = LINVFS_GET_VP(inode);


	ASSERT(vp);

	VOP_IOCTL(vp, inode, filp, cmd, arg, error);

	/* NOTE:  some of the ioctl's return positive #'s as a
	 *	  byte count indicating success, such as
	 *	  readlink_by_handle.  So we don't "sign flip"
	 *	  like most other routines.  This means true
	 *	  errors need to be returned as a negative value.
	 */
	return error;
}




struct file_operations linvfs_file_operations =
{
	llseek:		linvfs_file_lseek,
	read:		linvfs_read,  
	write:		linvfs_write,
	ioctl:		linvfs_ioctl,
	mmap:		linvfs_generic_file_mmap,
	open:		linvfs_open,
	release:	linvfs_release,
	fsync:		linvfs_fsync,
};

struct file_operations linvfs_dir_operations = {
	read:		generic_read_dir,
	readdir:	linvfs_readdir,
	ioctl:		linvfs_ioctl,
	fsync:		linvfs_fsync,
};