xfs_ioctl.c

linux-2.6.15.6

/*
 * 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_fs.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir.h"
#include "xfs_dir2.h"
#include "xfs_alloc.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_dir_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dir2_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_rtalloc.h"
#include "xfs_itable.h"
#include "xfs_error.h"
#include "xfs_rw.h"
#include "xfs_acl.h"
#include "xfs_cap.h"
#include "xfs_mac.h"
#include "xfs_attr.h"
#include "xfs_bmap.h"
#include "xfs_buf_item.h"
#include "xfs_utils.h"
#include "xfs_dfrag.h"
#include "xfs_fsops.h"

#include <linux/dcache.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/pagemap.h>

/*
 * xfs_find_handle maps from userspace xfs_fsop_handlereq structure to
 * a file or fs handle.
 *
 * XFS_IOC_PATH_TO_FSHANDLE
 *    returns fs handle for a mount point or path within that mount point
 * XFS_IOC_FD_TO_HANDLE
 *    returns full handle for a FD opened in user space
 * XFS_IOC_PATH_TO_HANDLE
 *    returns full handle for a path
 */
STATIC int
xfs_find_handle(
	unsigned int		cmd,
	void			__user *arg)
{
	int			hsize;
	xfs_handle_t		handle;
	xfs_fsop_handlereq_t	hreq;
	struct inode		*inode;
	struct vnode		*vp;

	if (copy_from_user(&hreq, arg, sizeof(hreq)))
		return -XFS_ERROR(EFAULT);

	memset((char *)&handle, 0, sizeof(handle));

	switch (cmd) {
	case XFS_IOC_PATH_TO_FSHANDLE:
	case XFS_IOC_PATH_TO_HANDLE: {
		struct nameidata	nd;
		int			error;

		error = user_path_walk_link((const char __user *)hreq.path, &nd);
		if (error)
			return error;

		ASSERT(nd.dentry);
		ASSERT(nd.dentry->d_inode);
		inode = igrab(nd.dentry->d_inode);
		path_release(&nd);
		break;
	}

	case XFS_IOC_FD_TO_HANDLE: {
		struct file	*file;

		file = fget(hreq.fd);
		if (!file)
		    return -EBADF;

		ASSERT(file->f_dentry);
		ASSERT(file->f_dentry->d_inode);
		inode = igrab(file->f_dentry->d_inode);
		fput(file);
		break;
	}

	default:
		ASSERT(0);
		return -XFS_ERROR(EINVAL);
	}

	if (inode->i_sb->s_magic != XFS_SB_MAGIC) {
		/* we're not in XFS anymore, Toto */
		iput(inode);
		return -XFS_ERROR(EINVAL);
	}

	switch (inode->i_mode & S_IFMT) {
	case S_IFREG:
	case S_IFDIR:
	case S_IFLNK:
		break;
	default:
		iput(inode);
		return -XFS_ERROR(EBADF);
	}

	/* we need the vnode */
	vp = LINVFS_GET_VP(inode);

	/* now we can grab the fsid */
	memcpy(&handle.ha_fsid, vp->v_vfsp->vfs_altfsid, sizeof(xfs_fsid_t));
	hsize = sizeof(xfs_fsid_t);

	if (cmd != XFS_IOC_PATH_TO_FSHANDLE) {
		xfs_inode_t	*ip;
		bhv_desc_t	*bhv;
		int		lock_mode;

		/* need to get access to the xfs_inode to read the generation */
		bhv = vn_bhv_lookup_unlocked(VN_BHV_HEAD(vp), &xfs_vnodeops);
		ASSERT(bhv);
		ip = XFS_BHVTOI(bhv);
		ASSERT(ip);
		lock_mode = xfs_ilock_map_shared(ip);

		/* fill in fid section of handle from inode */
		handle.ha_fid.xfs_fid_len = sizeof(xfs_fid_t) -
					    sizeof(handle.ha_fid.xfs_fid_len);
		handle.ha_fid.xfs_fid_pad = 0;
		handle.ha_fid.xfs_fid_gen = ip->i_d.di_gen;
		handle.ha_fid.xfs_fid_ino = ip->i_ino;

		xfs_iunlock_map_shared(ip, lock_mode);

		hsize = XFS_HSIZE(handle);
	}

	/* now copy our handle into the user buffer & write out the size */
	if (copy_to_user(hreq.ohandle, &handle, hsize) ||
	    copy_to_user(hreq.ohandlen, &hsize, sizeof(__s32))) {
		iput(inode);
		return -XFS_ERROR(EFAULT);
	}

	iput(inode);
	return 0;
}


/*
 * Convert userspace handle data into vnode (and inode).
 * We [ab]use the fact that all the fsop_handlereq ioctl calls
 * have a data structure argument whose first component is always
 * a xfs_fsop_handlereq_t, so we can cast to and from this type.
 * This allows us to optimise the copy_from_user calls and gives
 * a handy, shared routine.
 *
 * If no error, caller must always VN_RELE the returned vp.
 */
STATIC int
xfs_vget_fsop_handlereq(
	xfs_mount_t		*mp,
	struct inode		*parinode,	/* parent inode pointer    */
	xfs_fsop_handlereq_t	*hreq,
	vnode_t			**vp,
	struct inode		**inode)
{
	void			__user *hanp;
	size_t			hlen;
	xfs_fid_t		*xfid;
	xfs_handle_t		*handlep;
	xfs_handle_t		handle;
	xfs_inode_t		*ip;
	struct inode		*inodep;
	vnode_t			*vpp;
	xfs_ino_t		ino;
	__u32			igen;
	int			error;

	/*
	 * Only allow handle opens under a directory.
	 */
	if (!S_ISDIR(parinode->i_mode))
		return XFS_ERROR(ENOTDIR);

	hanp = hreq->ihandle;
	hlen = hreq->ihandlen;
	handlep = &handle;

	if (hlen < sizeof(handlep->ha_fsid) || hlen > sizeof(*handlep))
		return XFS_ERROR(EINVAL);
	if (copy_from_user(handlep, hanp, hlen))
		return XFS_ERROR(EFAULT);
	if (hlen < sizeof(*handlep))
		memset(((char *)handlep) + hlen, 0, sizeof(*handlep) - hlen);
	if (hlen > sizeof(handlep->ha_fsid)) {
		if (handlep->ha_fid.xfs_fid_len !=
				(hlen - sizeof(handlep->ha_fsid)
					- sizeof(handlep->ha_fid.xfs_fid_len))
		    || handlep->ha_fid.xfs_fid_pad)
			return XFS_ERROR(EINVAL);
	}

	/*
	 * Crack the handle, obtain the inode # & generation #
	 */
	xfid = (struct xfs_fid *)&handlep->ha_fid;
	if (xfid->xfs_fid_len == sizeof(*xfid) - sizeof(xfid->xfs_fid_len)) {
		ino  = xfid->xfs_fid_ino;
		igen = xfid->xfs_fid_gen;
	} else {
		return XFS_ERROR(EINVAL);
	}

	/*
	 * Get the XFS inode, building a vnode to go with it.
	 */
	error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, 0);
	if (error)
		return error;
	if (ip == NULL)
		return XFS_ERROR(EIO);
	if (ip->i_d.di_mode == 0 || ip->i_d.di_gen != igen) {
		xfs_iput_new(ip, XFS_ILOCK_SHARED);
		return XFS_ERROR(ENOENT);
	}

	vpp = XFS_ITOV(ip);
	inodep = LINVFS_GET_IP(vpp);
	xfs_iunlock(ip, XFS_ILOCK_SHARED);

	*vp = vpp;
	*inode = inodep;
	return 0;
}

STATIC int
xfs_open_by_handle(
	xfs_mount_t		*mp,
	void			__user *arg,
	struct file		*parfilp,
	struct inode		*parinode)
{
	int			error;
	int			new_fd;
	int			permflag;
	struct file		*filp;
	struct inode		*inode;
	struct dentry		*dentry;
	vnode_t			*vp;
	xfs_fsop_handlereq_t	hreq;

	if (!capable(CAP_SYS_ADMIN))
		return -XFS_ERROR(EPERM);
	if (copy_from_user(&hreq, arg, sizeof(xfs_fsop_handlereq_t)))
		return -XFS_ERROR(EFAULT);

	error = xfs_vget_fsop_handlereq(mp, parinode, &hreq, &vp, &inode);
	if (error)
		return -error;

	/* Restrict xfs_open_by_handle to directories & regular files. */
	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))) {
		iput(inode);
		return -XFS_ERROR(EINVAL);
	}

#if BITS_PER_LONG != 32
	hreq.oflags |= O_LARGEFILE;
#endif
	/* Put open permission in namei format. */
	permflag = hreq.oflags;
	if ((permflag+1) & O_ACCMODE)
		permflag++;
	if (permflag & O_TRUNC)
		permflag |= 2;

	if ((!(permflag & O_APPEND) || (permflag & O_TRUNC)) &&
	    (permflag & FMODE_WRITE) && IS_APPEND(inode)) {
		iput(inode);
		return -XFS_ERROR(EPERM);
	}

	if ((permflag & FMODE_WRITE) && IS_IMMUTABLE(inode)) {
		iput(inode);
		return -XFS_ERROR(EACCES);
	}

	/* Can't write directories. */
	if ( S_ISDIR(inode->i_mode) && (permflag & FMODE_WRITE)) {
		iput(inode);
		return -XFS_ERROR(EISDIR);
	}

	if ((new_fd = get_unused_fd()) < 0) {
		iput(inode);
		return new_fd;
	}

	dentry = d_alloc_anon(inode);
	if (dentry == NULL) {
		iput(inode);
		put_unused_fd(new_fd);
		return -XFS_ERROR(ENOMEM);
	}

	/* Ensure umount returns EBUSY on umounts while this file is open. */
	mntget(parfilp->f_vfsmnt);

	/* Create file pointer. */
	filp = dentry_open(dentry, parfilp->f_vfsmnt, hreq.oflags);
	if (IS_ERR(filp)) {
		put_unused_fd(new_fd);
		return -XFS_ERROR(-PTR_ERR(filp));
	}
	if (inode->i_mode & S_IFREG)
		filp->f_op = &linvfs_invis_file_operations;

	fd_install(new_fd, filp);
	return new_fd;
}

STATIC int
xfs_readlink_by_handle(
	xfs_mount_t		*mp,
	void			__user *arg,
	struct file		*parfilp,
	struct inode		*parinode)
{
	int			error;
	struct iovec		aiov;
	struct uio		auio;
	struct inode		*inode;
	xfs_fsop_handlereq_t	hreq;
	vnode_t			*vp;
	__u32			olen;

	if (!capable(CAP_SYS_ADMIN))
		return -XFS_ERROR(EPERM);
	if (copy_from_user(&hreq, arg, sizeof(xfs_fsop_handlereq_t)))
		return -XFS_ERROR(EFAULT);

	error = xfs_vget_fsop_handlereq(mp, parinode, &hreq, &vp, &inode);
	if (error)
		return -error;

	/* Restrict this handle operation to symlinks only. */
	if (!S_ISLNK(inode->i_mode)) {
		VN_RELE(vp);
		return -XFS_ERROR(EINVAL);
	}

	if (copy_from_user(&olen, hreq.ohandlen, sizeof(__u32))) {
		VN_RELE(vp);
		return -XFS_ERROR(EFAULT);
	}
	aiov.iov_len	= olen;
	aiov.iov_base	= hreq.ohandle;

	auio.uio_iov	= &aiov;
	auio.uio_iovcnt	= 1;
	auio.uio_offset	= 0;
	auio.uio_segflg	= UIO_USERSPACE;
	auio.uio_resid	= olen;

	VOP_READLINK(vp, &auio, IO_INVIS, NULL, error);

	VN_RELE(vp);
	return (olen - auio.uio_resid);
}

STATIC int
xfs_fssetdm_by_handle(
	xfs_mount_t		*mp,
	void			__user *arg,
	struct file		*parfilp,
	struct inode		*parinode)
{
	int			error;
	struct fsdmidata	fsd;
	xfs_fsop_setdm_handlereq_t dmhreq;
	struct inode		*inode;
	bhv_desc_t		*bdp;
	vnode_t			*vp;

	if (!capable(CAP_MKNOD))
		return -XFS_ERROR(EPERM);
	if (copy_from_user(&dmhreq, arg, sizeof(xfs_fsop_setdm_handlereq_t)))
		return -XFS_ERROR(EFAULT);

	error = xfs_vget_fsop_handlereq(mp, parinode, &dmhreq.hreq, &vp, &inode);
	if (error)
		return -error;

	if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) {
		VN_RELE(vp);
		return -XFS_ERROR(EPERM);
	}

	if (copy_from_user(&fsd, dmhreq.data, sizeof(fsd))) {
		VN_RELE(vp);
		return -XFS_ERROR(EFAULT);
	}

	bdp = bhv_base_unlocked(VN_BHV_HEAD(vp));
	error = xfs_set_dmattrs(bdp, fsd.fsd_dmevmask, fsd.fsd_dmstate, NULL);

	VN_RELE(vp);
	if (error)
		return -error;
	return 0;
}

STATIC int
xfs_attrlist_by_handle(
	xfs_mount_t		*mp,
	void			__user *arg,
	struct file		*parfilp,
	struct inode		*parinode)
{
	int			error;
	attrlist_cursor_kern_t	*cursor;
	xfs_fsop_attrlist_handlereq_t al_hreq;
	struct inode		*inode;
	vnode_t			*vp;
	char			*kbuf;

	if (!capable(CAP_SYS_ADMIN))
		return -XFS_ERROR(EPERM);
	if (copy_from_user(&al_hreq, arg, sizeof(xfs_fsop_attrlist_handlereq_t)))
		return -XFS_ERROR(EFAULT);
	if (al_hreq.buflen > XATTR_LIST_MAX)
		return -XFS_ERROR(EINVAL);

	error = xfs_vget_fsop_handlereq(mp, parinode, &al_hreq.hreq,
			&vp, &inode);
	if (error)
		goto out;

	kbuf = kmalloc(al_hreq.buflen, GFP_KERNEL);
	if (!kbuf)
		goto out_vn_rele;

	cursor = (attrlist_cursor_kern_t *)&al_hreq.pos;
	VOP_ATTR_LIST(vp, kbuf, al_hreq.buflen, al_hreq.flags,
			cursor, NULL, error);
	if (error)
		goto out_kfree;

	if (copy_to_user(al_hreq.buffer, kbuf, al_hreq.buflen))
		error = -EFAULT;

 out_kfree:
	kfree(kbuf);
 out_vn_rele:
	VN_RELE(vp);
 out:
	return -error;
}

STATIC int
xfs_attrmulti_attr_get(
	struct vnode		*vp,
	char			*name,
	char			__user *ubuf,
	__uint32_t		*len,
	__uint32_t		flags)
{
	char			*kbuf;
	int			error = EFAULT;
	
	if (*len > XATTR_SIZE_MAX)
		return EINVAL;
	kbuf = kmalloc(*len, GFP_KERNEL);
	if (!kbuf)
		return ENOMEM;

	VOP_ATTR_GET(vp, name, kbuf, len, flags, NULL, error);
	if (error)
		goto out_kfree;

	if (copy_to_user(ubuf, kbuf, *len))
		error = EFAULT;

 out_kfree:
	kfree(kbuf);
	return error;
}

STATIC int
xfs_attrmulti_attr_set(
	struct vnode		*vp,
	char			*name,
	const char		__user *ubuf,
	__uint32_t		len,
	__uint32_t		flags)
{
	char			*kbuf;
	int			error = EFAULT;

	if (IS_IMMUTABLE(&vp->v_inode) || IS_APPEND(&vp->v_inode))
		return EPERM;
	if (len > XATTR_SIZE_MAX)
		return EINVAL;

	kbuf = kmalloc(len, GFP_KERNEL);
	if (!kbuf)
		return ENOMEM;

	if (copy_from_user(kbuf, ubuf, len))
		goto out_kfree;
			
	VOP_ATTR_SET(vp, name, kbuf, len, flags, NULL, error);

 out_kfree:
	kfree(kbuf);
	return error;
}

STATIC int
xfs_attrmulti_attr_remove(
	struct vnode		*vp,
	char			*name,
	__uint32_t		flags)
{
	int			error;

	if (IS_IMMUTABLE(&vp->v_inode) || IS_APPEND(&vp->v_inode))
		return EPERM;

	VOP_ATTR_REMOVE(vp, name, flags, NULL, error);
	return error;
}

STATIC int
xfs_attrmulti_by_handle(
	xfs_mount_t		*mp,
	void			__user *arg,
	struct file		*parfilp,
	struct inode		*parinode)
{
	int			error;
	xfs_attr_multiop_t	*ops;
	xfs_fsop_attrmulti_handlereq_t am_hreq;
	struct inode		*inode;
	vnode_t			*vp;
	unsigned int		i, size;
	char			*attr_name;

	if (!capable(CAP_SYS_ADMIN))
		return -XFS_ERROR(EPERM);
	if (copy_from_user(&am_hreq, arg, sizeof(xfs_fsop_attrmulti_handlereq_t)))
		return -XFS_ERROR(EFAULT);

	error = xfs_vget_fsop_handlereq(mp, parinode, &am_hreq.hreq, &vp, &inode);
	if (error)
		goto out;

	error = E2BIG;
	size = am_hreq.opcount * sizeof(attr_multiop_t);
	if (!size || size > 16 * PAGE_SIZE)
		goto out_vn_rele;

	error = ENOMEM;
	ops = kmalloc(size, GFP_KERNEL);
	if (!ops)
		goto out_vn_rele;

	error = EFAULT;
	if (copy_from_user(ops, am_hreq.ops, size))
		goto out_kfree_ops;

	attr_name = kmalloc(MAXNAMELEN, GFP_KERNEL);
	if (!attr_name)
		goto out_kfree_ops;


	error = 0;
	for (i = 0; i < am_hreq.opcount; i++) {
		ops[i].am_error = strncpy_from_user(attr_name,
				ops[i].am_attrname, MAXNAMELEN);
		if (ops[i].am_error == 0 || ops[i].am_error == MAXNAMELEN)
			error = -ERANGE;
		if (ops[i].am_error < 0)
			break;

		switch (ops[i].am_opcode) {
		case ATTR_OP_GET:
			ops[i].am_error = xfs_attrmulti_attr_get(vp,
					attr_name, ops[i].am_attrvalue,
					&ops[i].am_length, ops[i].am_flags);
			break;
		case ATTR_OP_SET:
			ops[i].am_error = xfs_attrmulti_attr_set(vp,
					attr_name, ops[i].am_attrvalue,
					ops[i].am_length, ops[i].am_flags);
			break;
		case ATTR_OP_REMOVE:
			ops[i].am_error = xfs_attrmulti_attr_remove(vp,
					attr_name, ops[i].am_flags);
			break;
		default:
			ops[i].am_error = EINVAL;
		}
	}

	if (copy_to_user(am_hreq.ops, ops, size))
		error = XFS_ERROR(EFAULT);

	kfree(attr_name);
 out_kfree_ops:
	kfree(ops);
 out_vn_rele:
	VN_RELE(vp);
 out:
	return -error;
}

/* prototypes for a few of the stack-hungry cases that have
 * their own functions.  Functions are defined after their use
 * so gcc doesn't get fancy and inline them with -03 */

STATIC int
xfs_ioc_space(
	bhv_desc_t		*bdp,
	vnode_t			*vp,
	struct file		*filp,
	int			flags,
	unsigned int		cmd,
	void			__user *arg);

STATIC int
xfs_ioc_bulkstat(
	xfs_mount_t		*mp,
	unsigned int		cmd,