fs/xfs/linux-2.6/xfs_file.c - linux - Git at Google

 /*
  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
  * All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms 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.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write the Free Software Foundation,
  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 #include "xfs.h"
 #include "xfs_bit.h"
 #include "xfs_log.h"
 #include "xfs_inum.h"
 #include "xfs_sb.h"
 #include "xfs_ag.h"
 #include "xfs_dir2.h"
 #include "xfs_trans.h"
 #include "xfs_dmapi.h"
 #include "xfs_mount.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_alloc_btree.h"
 #include "xfs_ialloc_btree.h"
 #include "xfs_alloc.h"
 #include "xfs_btree.h"
 #include "xfs_attr_sf.h"
 #include "xfs_dir2_sf.h"
 #include "xfs_dinode.h"
 #include "xfs_inode.h"
 #include "xfs_error.h"
 #include "xfs_rw.h"
 #include "xfs_ioctl32.h"

 #include <linux/dcache.h>
 #include <linux/smp_lock.h>

 static struct vm_operations_struct xfs_file_vm_ops;
 #ifdef CONFIG_XFS_DMAPI
 static struct vm_operations_struct xfs_dmapi_file_vm_ops;
 #endif

 STATIC_INLINE ssize_t
 __xfs_file_read(
 	struct kiocb		*iocb,
 	const struct iovec	*iov,
 	unsigned long		nr_segs,
 	int			ioflags,
 	loff_t			pos)
 {
 	struct file		*file = iocb->ki_filp;
 	bhv_vnode_t		*vp = vn_from_inode(file->f_path.dentry->d_inode);

 	BUG_ON(iocb->ki_pos != pos);
 	if (unlikely(file->f_flags & O_DIRECT))
 		ioflags |= IO_ISDIRECT;
 	return bhv_vop_read(vp, iocb, iov, nr_segs, &iocb->ki_pos,
 				ioflags, NULL);
 }

 STATIC ssize_t
 xfs_file_aio_read(
 	struct kiocb		*iocb,
 	const struct iovec	*iov,
 	unsigned long		nr_segs,
 	loff_t			pos)
 {
 	return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO, pos);
 }

 STATIC ssize_t
 xfs_file_aio_read_invis(
 	struct kiocb		*iocb,
 	const struct iovec	*iov,
 	unsigned long		nr_segs,
 	loff_t			pos)
 {
 	return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
 }

 STATIC_INLINE ssize_t
 __xfs_file_write(
 	struct kiocb		*iocb,
 	const struct iovec	*iov,
 	unsigned long		nr_segs,
 	int			ioflags,
 	loff_t			pos)
 {
 	struct file	*file = iocb->ki_filp;
 	struct inode	*inode = file->f_mapping->host;
 	bhv_vnode_t	*vp = vn_from_inode(inode);

 	BUG_ON(iocb->ki_pos != pos);
 	if (unlikely(file->f_flags & O_DIRECT))
 		ioflags |= IO_ISDIRECT;
 	return bhv_vop_write(vp, iocb, iov, nr_segs, &iocb->ki_pos,
 				ioflags, NULL);
 }

 STATIC ssize_t
 xfs_file_aio_write(
 	struct kiocb		*iocb,
 	const struct iovec	*iov,
 	unsigned long		nr_segs,
 	loff_t			pos)
 {
 	return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO, pos);
 }

 STATIC ssize_t
 xfs_file_aio_write_invis(
 	struct kiocb		*iocb,
 	const struct iovec	*iov,
 	unsigned long		nr_segs,
 	loff_t			pos)
 {
 	return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO|IO_INVIS, pos);
 }

 STATIC ssize_t
 xfs_file_splice_read(
 	struct file		*infilp,
 	loff_t			*ppos,
 	struct pipe_inode_info	*pipe,
 	size_t			len,
 	unsigned int		flags)
 {
 	return bhv_vop_splice_read(vn_from_inode(infilp->f_path.dentry->d_inode),
 				   infilp, ppos, pipe, len, flags, 0, NULL);
 }

 STATIC ssize_t
 xfs_file_splice_read_invis(
 	struct file		*infilp,
 	loff_t			*ppos,
 	struct pipe_inode_info	*pipe,
 	size_t			len,
 	unsigned int		flags)
 {
 	return bhv_vop_splice_read(vn_from_inode(infilp->f_path.dentry->d_inode),
 				   infilp, ppos, pipe, len, flags, IO_INVIS,
 				   NULL);
 }

 STATIC ssize_t
 xfs_file_splice_write(
 	struct pipe_inode_info	*pipe,
 	struct file		*outfilp,
 	loff_t			*ppos,
 	size_t			len,
 	unsigned int		flags)
 {
 	return bhv_vop_splice_write(vn_from_inode(outfilp->f_path.dentry->d_inode),
 				    pipe, outfilp, ppos, len, flags, 0, NULL);
 }

 STATIC ssize_t
 xfs_file_splice_write_invis(
 	struct pipe_inode_info	*pipe,
 	struct file		*outfilp,
 	loff_t			*ppos,
 	size_t			len,
 	unsigned int		flags)
 {
 	return bhv_vop_splice_write(vn_from_inode(outfilp->f_path.dentry->d_inode),
 				    pipe, outfilp, ppos, len, flags, IO_INVIS,
 				    NULL);
 }

 STATIC int
 xfs_file_open(
 	struct inode	*inode,
 	struct file	*filp)
 {
 	if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
 		return -EFBIG;
 	return -bhv_vop_open(vn_from_inode(inode), NULL);
 }

 STATIC int
 xfs_file_release(
 	struct inode	*inode,
 	struct file	*filp)
 {
 	bhv_vnode_t	*vp = vn_from_inode(inode);

 	if (vp)
 		return -bhv_vop_release(vp);
 	return 0;
 }

 STATIC int
 xfs_file_fsync(
 	struct file	*filp,
 	struct dentry	*dentry,
 	int		datasync)
 {
 	bhv_vnode_t	*vp = vn_from_inode(dentry->d_inode);
 	int		flags = FSYNC_WAIT;

 	if (datasync)
 		flags |= FSYNC_DATA;
 	if (VN_TRUNC(vp))
 		VUNTRUNCATE(vp);
 	return -bhv_vop_fsync(vp, flags, NULL, (xfs_off_t)0, (xfs_off_t)-1);
 }

 #ifdef CONFIG_XFS_DMAPI
 STATIC int
 xfs_vm_fault(
 	struct vm_area_struct	*vma,
 	struct vm_fault	*vmf)
 {
 	struct inode	*inode = vma->vm_file->f_path.dentry->d_inode;
 	bhv_vnode_t	*vp = vn_from_inode(inode);

 	ASSERT_ALWAYS(vp->v_vfsp->vfs_flag & VFS_DMI);
 	if (XFS_SEND_MMAP(XFS_VFSTOM(vp->v_vfsp), vma, 0))
 		return VM_FAULT_SIGBUS;
 	return filemap_fault(vma, vmf);
 }
 #endif /* CONFIG_XFS_DMAPI */

 STATIC int
 xfs_file_readdir(
 	struct file	*filp,
 	void		*dirent,
 	filldir_t	filldir)
 {
 	int		error = 0;
 	bhv_vnode_t	*vp = vn_from_inode(filp->f_path.dentry->d_inode);
 	uio_t		uio;
 	iovec_t		iov;
 	int		eof = 0;
 	caddr_t		read_buf;
 	int		namelen, size = 0;
 	size_t		rlen = PAGE_CACHE_SIZE;
 	xfs_off_t	start_offset, curr_offset;
 	xfs_dirent_t	*dbp = NULL;

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

 	if (read_buf == NULL)
 		return -ENOMEM;

 	uio.uio_iov = &iov;
 	uio.uio_segflg = UIO_SYSSPACE;
 	curr_offset = filp->f_pos;
 	if (filp->f_pos != 0x7fffffff)
 		uio.uio_offset = filp->f_pos;
 	else
 		uio.uio_offset = 0xffffffff;

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

 		start_offset = uio.uio_offset;

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

 		size = rlen - uio.uio_resid;
 		dbp = (xfs_dirent_t *)read_buf;
 		while (size > 0) {
 			namelen = strlen(dbp->d_name);

 			if (filldir(dirent, dbp->d_name, namelen,
 					(loff_t) curr_offset & 0x7fffffff,
 					(ino_t) dbp->d_ino,
 					DT_UNKNOWN)) {
 				goto done;
 			}
 			size -= dbp->d_reclen;
 			curr_offset = (loff_t)dbp->d_off /* & 0x7fffffff */;
 			dbp = (xfs_dirent_t *)((char *)dbp + dbp->d_reclen);
 		}
 	}
 done:
 	if (!error) {
 		if (size == 0)
 			filp->f_pos = uio.uio_offset & 0x7fffffff;
 		else if (dbp)
 			filp->f_pos = curr_offset;
 	}

 	kfree(read_buf);
 	return -error;
 }

 STATIC int
 xfs_file_mmap(
 	struct file	*filp,
 	struct vm_area_struct *vma)
 {
 	vma->vm_ops = &xfs_file_vm_ops;
 	vma->vm_flags |= VM_CAN_NONLINEAR;

 #ifdef CONFIG_XFS_DMAPI
 	if (vn_from_inode(filp->f_path.dentry->d_inode)->v_vfsp->vfs_flag & VFS_DMI)
 		vma->vm_ops = &xfs_dmapi_file_vm_ops;
 #endif /* CONFIG_XFS_DMAPI */

 	file_accessed(filp);
 	return 0;
 }

 STATIC long
 xfs_file_ioctl(
 	struct file	*filp,
 	unsigned int	cmd,
 	unsigned long	p)
 {
 	int		error;
 	struct inode	*inode = filp->f_path.dentry->d_inode;
 	bhv_vnode_t	*vp = vn_from_inode(inode);

 	error = bhv_vop_ioctl(vp, inode, filp, 0, cmd, (void __user *)p);
 	VMODIFY(vp);

 	/* 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;
 }

 STATIC long
 xfs_file_ioctl_invis(
 	struct file	*filp,
 	unsigned int	cmd,
 	unsigned long	p)
 {
 	int		error;
 	struct inode	*inode = filp->f_path.dentry->d_inode;
 	bhv_vnode_t	*vp = vn_from_inode(inode);

 	error = bhv_vop_ioctl(vp, inode, filp, IO_INVIS, cmd, (void __user *)p);
 	VMODIFY(vp);

 	/* 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;
 }

 #ifdef CONFIG_XFS_DMAPI
 #ifdef HAVE_VMOP_MPROTECT
 STATIC int
 xfs_vm_mprotect(
 	struct vm_area_struct *vma,
 	unsigned int	newflags)
 {
 	bhv_vnode_t	*vp = vn_from_inode(vma->vm_file->f_path.dentry->d_inode);
 	int		error = 0;

 	if (vp->v_vfsp->vfs_flag & VFS_DMI) {
 		if ((vma->vm_flags & VM_MAYSHARE) &&
 		    (newflags & VM_WRITE) && !(vma->vm_flags & VM_WRITE)) {
 			xfs_mount_t	*mp = XFS_VFSTOM(vp->v_vfsp);

 			error = XFS_SEND_MMAP(mp, vma, VM_WRITE);
 		    }
 	}
 	return error;
 }
 #endif /* HAVE_VMOP_MPROTECT */
 #endif /* CONFIG_XFS_DMAPI */

 #ifdef HAVE_FOP_OPEN_EXEC
 /* If the user is attempting to execute a file that is offline then
  * we have to trigger a DMAPI READ event before the file is marked as busy
  * otherwise the invisible I/O will not be able to write to the file to bring
  * it back online.
  */
 STATIC int
 xfs_file_open_exec(
 	struct inode	*inode)
 {
 	bhv_vnode_t	*vp = vn_from_inode(inode);

 	if (unlikely(vp->v_vfsp->vfs_flag & VFS_DMI)) {
 		xfs_mount_t	*mp = XFS_VFSTOM(vp->v_vfsp);
 		xfs_inode_t	*ip = xfs_vtoi(vp);

 		if (!ip)
 			return -EINVAL;
 		if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ))
 			return -XFS_SEND_DATA(mp, DM_EVENT_READ, vp,
 					       0, 0, 0, NULL);
 	}
 	return 0;
 }
 #endif /* HAVE_FOP_OPEN_EXEC */

 const struct file_operations xfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
 	.aio_read	= xfs_file_aio_read,
 	.aio_write	= xfs_file_aio_write,
 	.splice_read	= xfs_file_splice_read,
 	.splice_write	= xfs_file_splice_write,
 	.unlocked_ioctl	= xfs_file_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= xfs_file_compat_ioctl,
 #endif
 	.mmap		= xfs_file_mmap,
 	.open		= xfs_file_open,
 	.release	= xfs_file_release,
 	.fsync		= xfs_file_fsync,
 #ifdef HAVE_FOP_OPEN_EXEC
 	.open_exec	= xfs_file_open_exec,
 #endif
 };

 const struct file_operations xfs_invis_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read		= do_sync_read,
 	.write		= do_sync_write,
 	.aio_read	= xfs_file_aio_read_invis,
 	.aio_write	= xfs_file_aio_write_invis,
 	.splice_read	= xfs_file_splice_read_invis,
 	.splice_write	= xfs_file_splice_write_invis,
 	.unlocked_ioctl	= xfs_file_ioctl_invis,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= xfs_file_compat_invis_ioctl,
 #endif
 	.mmap		= xfs_file_mmap,
 	.open		= xfs_file_open,
 	.release	= xfs_file_release,
 	.fsync		= xfs_file_fsync,
 };


 const struct file_operations xfs_dir_file_operations = {
 	.read		= generic_read_dir,
 	.readdir	= xfs_file_readdir,
 	.unlocked_ioctl	= xfs_file_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= xfs_file_compat_ioctl,
 #endif
 	.fsync		= xfs_file_fsync,
 };

 static struct vm_operations_struct xfs_file_vm_ops = {
 	.fault		= filemap_fault,
 };

 #ifdef CONFIG_XFS_DMAPI
 static struct vm_operations_struct xfs_dmapi_file_vm_ops = {
 	.fault		= xfs_vm_fault,
 #ifdef HAVE_VMOP_MPROTECT
 	.mprotect	= xfs_vm_mprotect,
 #endif
 };
 #endif /* CONFIG_XFS_DMAPI */
	/*
	* Copyright (c) 2000-2005 Silicon Graphics, Inc.
	* All Rights Reserved.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms 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. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/
	#include "xfs.h"
	#include "xfs_bit.h"
	#include "xfs_log.h"
	#include "xfs_inum.h"
	#include "xfs_sb.h"
	#include "xfs_ag.h"
	#include "xfs_dir2.h"
	#include "xfs_trans.h"
	#include "xfs_dmapi.h"
	#include "xfs_mount.h"
	#include "xfs_bmap_btree.h"
	#include "xfs_alloc_btree.h"
	#include "xfs_ialloc_btree.h"
	#include "xfs_alloc.h"
	#include "xfs_btree.h"
	#include "xfs_attr_sf.h"
	#include "xfs_dir2_sf.h"
	#include "xfs_dinode.h"
	#include "xfs_inode.h"
	#include "xfs_error.h"
	#include "xfs_rw.h"
	#include "xfs_ioctl32.h"

	#include <linux/dcache.h>
	#include <linux/smp_lock.h>

	static struct vm_operations_struct xfs_file_vm_ops;
	#ifdef CONFIG_XFS_DMAPI
	static struct vm_operations_struct xfs_dmapi_file_vm_ops;
	#endif

	STATIC_INLINE ssize_t
	__xfs_file_read(
	struct kiocb *iocb,
	const struct iovec *iov,
	unsigned long nr_segs,
	int ioflags,
	loff_t pos)
	{
	struct file *file = iocb->ki_filp;
	bhv_vnode_t *vp = vn_from_inode(file->f_path.dentry->d_inode);

	BUG_ON(iocb->ki_pos != pos);
	if (unlikely(file->f_flags & O_DIRECT))
	ioflags \|= IO_ISDIRECT;
	return bhv_vop_read(vp, iocb, iov, nr_segs, &iocb->ki_pos,
	ioflags, NULL);
	}

	STATIC ssize_t
	xfs_file_aio_read(
	struct kiocb *iocb,
	const struct iovec *iov,
	unsigned long nr_segs,
	loff_t pos)
	{
	return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO, pos);
	}

	STATIC ssize_t
	xfs_file_aio_read_invis(
	struct kiocb *iocb,
	const struct iovec *iov,
	unsigned long nr_segs,
	loff_t pos)
	{
	return __xfs_file_read(iocb, iov, nr_segs, IO_ISAIO\|IO_INVIS, pos);
	}

	STATIC_INLINE ssize_t
	__xfs_file_write(
	struct kiocb *iocb,
	const struct iovec *iov,
	unsigned long nr_segs,
	int ioflags,
	loff_t pos)
	{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
	bhv_vnode_t *vp = vn_from_inode(inode);

	BUG_ON(iocb->ki_pos != pos);
	if (unlikely(file->f_flags & O_DIRECT))
	ioflags \|= IO_ISDIRECT;
	return bhv_vop_write(vp, iocb, iov, nr_segs, &iocb->ki_pos,
	ioflags, NULL);
	}

	STATIC ssize_t
	xfs_file_aio_write(
	struct kiocb *iocb,
	const struct iovec *iov,
	unsigned long nr_segs,
	loff_t pos)
	{
	return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO, pos);
	}

	STATIC ssize_t
	xfs_file_aio_write_invis(
	struct kiocb *iocb,
	const struct iovec *iov,
	unsigned long nr_segs,
	loff_t pos)
	{
	return __xfs_file_write(iocb, iov, nr_segs, IO_ISAIO\|IO_INVIS, pos);
	}

	STATIC ssize_t
	xfs_file_splice_read(
	struct file *infilp,
	loff_t *ppos,
	struct pipe_inode_info *pipe,
	size_t len,
	unsigned int flags)
	{
	return bhv_vop_splice_read(vn_from_inode(infilp->f_path.dentry->d_inode),
	infilp, ppos, pipe, len, flags, 0, NULL);
	}

	STATIC ssize_t
	xfs_file_splice_read_invis(
	struct file *infilp,
	loff_t *ppos,
	struct pipe_inode_info *pipe,
	size_t len,
	unsigned int flags)
	{
	return bhv_vop_splice_read(vn_from_inode(infilp->f_path.dentry->d_inode),
	infilp, ppos, pipe, len, flags, IO_INVIS,
	NULL);
	}

	STATIC ssize_t
	xfs_file_splice_write(
	struct pipe_inode_info *pipe,
	struct file *outfilp,
	loff_t *ppos,
	size_t len,
	unsigned int flags)
	{
	return bhv_vop_splice_write(vn_from_inode(outfilp->f_path.dentry->d_inode),
	pipe, outfilp, ppos, len, flags, 0, NULL);
	}

	STATIC ssize_t
	xfs_file_splice_write_invis(
	struct pipe_inode_info *pipe,
	struct file *outfilp,
	loff_t *ppos,
	size_t len,
	unsigned int flags)
	{
	return bhv_vop_splice_write(vn_from_inode(outfilp->f_path.dentry->d_inode),
	pipe, outfilp, ppos, len, flags, IO_INVIS,
	NULL);
	}

	STATIC int
	xfs_file_open(
	struct inode *inode,
	struct file *filp)
	{
	if (!(filp->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
	return -EFBIG;
	return -bhv_vop_open(vn_from_inode(inode), NULL);
	}

	STATIC int
	xfs_file_release(
	struct inode *inode,
	struct file *filp)
	{
	bhv_vnode_t *vp = vn_from_inode(inode);

	if (vp)
	return -bhv_vop_release(vp);
	return 0;
	}

	STATIC int
	xfs_file_fsync(
	struct file *filp,
	struct dentry *dentry,
	int datasync)
	{
	bhv_vnode_t *vp = vn_from_inode(dentry->d_inode);
	int flags = FSYNC_WAIT;

	if (datasync)
	flags \|= FSYNC_DATA;
	if (VN_TRUNC(vp))
	VUNTRUNCATE(vp);
	return -bhv_vop_fsync(vp, flags, NULL, (xfs_off_t)0, (xfs_off_t)-1);
	}

	#ifdef CONFIG_XFS_DMAPI
	STATIC int
	xfs_vm_fault(
	struct vm_area_struct *vma,
	struct vm_fault *vmf)
	{
	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
	bhv_vnode_t *vp = vn_from_inode(inode);

	ASSERT_ALWAYS(vp->v_vfsp->vfs_flag & VFS_DMI);
	if (XFS_SEND_MMAP(XFS_VFSTOM(vp->v_vfsp), vma, 0))
	return VM_FAULT_SIGBUS;
	return filemap_fault(vma, vmf);
	}
	#endif /* CONFIG_XFS_DMAPI */

	STATIC int
	xfs_file_readdir(
	struct file *filp,
	void *dirent,
	filldir_t filldir)
	{
	int error = 0;
	bhv_vnode_t *vp = vn_from_inode(filp->f_path.dentry->d_inode);
	uio_t uio;
	iovec_t iov;
	int eof = 0;
	caddr_t read_buf;
	int namelen, size = 0;
	size_t rlen = PAGE_CACHE_SIZE;
	xfs_off_t start_offset, curr_offset;
	xfs_dirent_t *dbp = NULL;

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

	if (read_buf == NULL)
	return -ENOMEM;

	uio.uio_iov = &iov;
	uio.uio_segflg = UIO_SYSSPACE;
	curr_offset = filp->f_pos;
	if (filp->f_pos != 0x7fffffff)
	uio.uio_offset = filp->f_pos;
	else
	uio.uio_offset = 0xffffffff;

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

	start_offset = uio.uio_offset;

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

	size = rlen - uio.uio_resid;
	dbp = (xfs_dirent_t *)read_buf;
	while (size > 0) {
	namelen = strlen(dbp->d_name);

	if (filldir(dirent, dbp->d_name, namelen,
	(loff_t) curr_offset & 0x7fffffff,
	(ino_t) dbp->d_ino,
	DT_UNKNOWN)) {
	goto done;
	}
	size -= dbp->d_reclen;
	curr_offset = (loff_t)dbp->d_off /* & 0x7fffffff */;
	dbp = (xfs_dirent_t )((char )dbp + dbp->d_reclen);
	}
	}
	done:
	if (!error) {
	if (size == 0)
	filp->f_pos = uio.uio_offset & 0x7fffffff;
	else if (dbp)
	filp->f_pos = curr_offset;
	}

	kfree(read_buf);
	return -error;
	}

	STATIC int
	xfs_file_mmap(
	struct file *filp,
	struct vm_area_struct *vma)
	{
	vma->vm_ops = &xfs_file_vm_ops;
	vma->vm_flags \|= VM_CAN_NONLINEAR;

	#ifdef CONFIG_XFS_DMAPI
	if (vn_from_inode(filp->f_path.dentry->d_inode)->v_vfsp->vfs_flag & VFS_DMI)
	vma->vm_ops = &xfs_dmapi_file_vm_ops;
	#endif /* CONFIG_XFS_DMAPI */

	file_accessed(filp);
	return 0;
	}

	STATIC long
	xfs_file_ioctl(
	struct file *filp,
	unsigned int cmd,
	unsigned long p)
	{
	int error;
	struct inode *inode = filp->f_path.dentry->d_inode;
	bhv_vnode_t *vp = vn_from_inode(inode);

	error = bhv_vop_ioctl(vp, inode, filp, 0, cmd, (void __user *)p);
	VMODIFY(vp);

	/* 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;
	}

	STATIC long
	xfs_file_ioctl_invis(
	struct file *filp,
	unsigned int cmd,
	unsigned long p)
	{
	int error;
	struct inode *inode = filp->f_path.dentry->d_inode;
	bhv_vnode_t *vp = vn_from_inode(inode);

	error = bhv_vop_ioctl(vp, inode, filp, IO_INVIS, cmd, (void __user *)p);
	VMODIFY(vp);

	/* 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;
	}

	#ifdef CONFIG_XFS_DMAPI
	#ifdef HAVE_VMOP_MPROTECT
	STATIC int
	xfs_vm_mprotect(
	struct vm_area_struct *vma,
	unsigned int newflags)
	{
	bhv_vnode_t *vp = vn_from_inode(vma->vm_file->f_path.dentry->d_inode);
	int error = 0;

	if (vp->v_vfsp->vfs_flag & VFS_DMI) {
	if ((vma->vm_flags & VM_MAYSHARE) &&
	(newflags & VM_WRITE) && !(vma->vm_flags & VM_WRITE)) {
	xfs_mount_t *mp = XFS_VFSTOM(vp->v_vfsp);

	error = XFS_SEND_MMAP(mp, vma, VM_WRITE);
	}
	}
	return error;
	}
	#endif /* HAVE_VMOP_MPROTECT */
	#endif /* CONFIG_XFS_DMAPI */

	#ifdef HAVE_FOP_OPEN_EXEC
	/* If the user is attempting to execute a file that is offline then
	* we have to trigger a DMAPI READ event before the file is marked as busy
	* otherwise the invisible I/O will not be able to write to the file to bring
	* it back online.
	*/
	STATIC int
	xfs_file_open_exec(
	struct inode *inode)
	{
	bhv_vnode_t *vp = vn_from_inode(inode);

	if (unlikely(vp->v_vfsp->vfs_flag & VFS_DMI)) {
	xfs_mount_t *mp = XFS_VFSTOM(vp->v_vfsp);
	xfs_inode_t *ip = xfs_vtoi(vp);

	if (!ip)
	return -EINVAL;
	if (DM_EVENT_ENABLED(vp->v_vfsp, ip, DM_EVENT_READ))
	return -XFS_SEND_DATA(mp, DM_EVENT_READ, vp,
	0, 0, 0, NULL);
	}
	return 0;
	}
	#endif /* HAVE_FOP_OPEN_EXEC */

	const struct file_operations xfs_file_operations = {
	.llseek = generic_file_llseek,
	.read = do_sync_read,
	.write = do_sync_write,
	.aio_read = xfs_file_aio_read,
	.aio_write = xfs_file_aio_write,
	.splice_read = xfs_file_splice_read,
	.splice_write = xfs_file_splice_write,
	.unlocked_ioctl = xfs_file_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = xfs_file_compat_ioctl,
	#endif
	.mmap = xfs_file_mmap,
	.open = xfs_file_open,
	.release = xfs_file_release,
	.fsync = xfs_file_fsync,
	#ifdef HAVE_FOP_OPEN_EXEC
	.open_exec = xfs_file_open_exec,
	#endif
	};

	const struct file_operations xfs_invis_file_operations = {
	.llseek = generic_file_llseek,
	.read = do_sync_read,
	.write = do_sync_write,
	.aio_read = xfs_file_aio_read_invis,
	.aio_write = xfs_file_aio_write_invis,
	.splice_read = xfs_file_splice_read_invis,
	.splice_write = xfs_file_splice_write_invis,
	.unlocked_ioctl = xfs_file_ioctl_invis,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = xfs_file_compat_invis_ioctl,
	#endif
	.mmap = xfs_file_mmap,
	.open = xfs_file_open,
	.release = xfs_file_release,
	.fsync = xfs_file_fsync,
	};


	const struct file_operations xfs_dir_file_operations = {
	.read = generic_read_dir,
	.readdir = xfs_file_readdir,
	.unlocked_ioctl = xfs_file_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = xfs_file_compat_ioctl,
	#endif
	.fsync = xfs_file_fsync,
	};

	static struct vm_operations_struct xfs_file_vm_ops = {
	.fault = filemap_fault,
	};

	#ifdef CONFIG_XFS_DMAPI
	static struct vm_operations_struct xfs_dmapi_file_vm_ops = {
	.fault = xfs_vm_fault,
	#ifdef HAVE_VMOP_MPROTECT
	.mprotect = xfs_vm_mprotect,
	#endif
	};
	#endif /* CONFIG_XFS_DMAPI */