path: root/fs/nilfs2/ioctl.c

/*
 * ioctl.c - NILFS ioctl operations.
 *
 * Copyright (C) 2007, 2008 Nippon Telegraph and Telephone Corporation.
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will 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 to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Written by Koji Sato <koji@osrg.net>.
 */

#include <linux/fs.h>
#include <linux/wait.h>
#include <linux/smp_lock.h>	/* lock_kernel(), unlock_kernel() */
#include <linux/capability.h>	/* capable() */
#include <linux/uaccess.h>	/* copy_from_user(), copy_to_user() */
#include <linux/nilfs2_fs.h>
#include "nilfs.h"
#include "segment.h"
#include "bmap.h"
#include "cpfile.h"
#include "sufile.h"
#include "dat.h"


static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
				 struct nilfs_argv *argv, int dir,
				 ssize_t (*dofunc)(struct the_nilfs *,
						   __u64 *, int,
						   void *, size_t, size_t))
{
	void *buf;
	size_t maxmembs, total, n;
	ssize_t nr;
	int ret, i;
	__u64 pos, ppos;

	if (argv->v_nmembs == 0)
		return 0;

	if (argv->v_size > PAGE_SIZE)
		return -EINVAL;

	buf = (void *)__get_free_pages(GFP_NOFS, 0);
	if (unlikely(!buf))
		return -ENOMEM;
	maxmembs = PAGE_SIZE / argv->v_size;

	ret = 0;
	total = 0;
	pos = argv->v_index;
	for (i = 0; i < argv->v_nmembs; i += n) {
		n = (argv->v_nmembs - i < maxmembs) ?
			argv->v_nmembs - i : maxmembs;
		if ((dir & _IOC_WRITE) &&
		    copy_from_user(buf,
			    (void __user *)argv->v_base + argv->v_size * i,
			    argv->v_size * n)) {
			ret = -EFAULT;
			break;
		}
		ppos = pos;
		nr = (*dofunc)(nilfs, &pos, argv->v_flags, buf, argv->v_size,
			       n);
		if (nr < 0) {
			ret = nr;
			break;
		}
		if ((dir & _IOC_READ) &&
		    copy_to_user(
			    (void __user *)argv->v_base + argv->v_size * i,
			    buf, argv->v_size * nr)) {
			ret = -EFAULT;
			break;
		}
		total += nr;
		if ((size_t)nr < n)
			break;
		if (pos == ppos)
			pos += n;
	}
	argv->v_nmembs = total;

	free_pages((unsigned long)buf, 0);
	return ret;
}

static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
				     unsigned int cmd, void __user *argp)
{
	struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
	struct nilfs_transaction_info ti;
	struct nilfs_cpmode cpmode;
	int ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	if (copy_from_user(&cpmode, argp, sizeof(cpmode)))
		return -EFAULT;

	nilfs_transaction_begin(inode->i_sb, &ti, 0);
	ret = nilfs_cpfile_change_cpmode(
		cpfile, cpmode.cm_cno, cpmode.cm_mode);
	if (unlikely(ret < 0)) {
		nilfs_transaction_abort(inode->i_sb);
		return ret;
	}
	nilfs_transaction_commit(inode->i_sb); /* never fails */
	return ret;
}

static int
nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
			      unsigned int cmd, void __user *argp)
{
	struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
	struct nilfs_transaction_info ti;
	__u64 cno;
	int ret;

	if (!capable(CAP_SYS_ADMIN))
		return -EPERM;
	if (copy_from_user(&cno, argp, sizeof(cno)))
		return -EFAULT;

	nilfs_transaction_begin(inode->i_sb, &ti, 0);
	ret = nilfs_cpfile_delete_checkpoint(cpfile