/*
 * This file is part of UBIFS.
 *
 * Copyright (C) 2006-2008 Nokia Corporation.
 * Copyright (C) 2006, 2007 University of Szeged, Hungary
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * 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
 *
 * Authors: Zoltan Sogor
 *          Artem Bityutskiy (Битюцкий Артём)
 *          Adrian Hunter
 */

/* This file implements EXT2-compatible extended attribute ioctl() calls */

#include <linux/compat.h>
#include <linux/mount.h>
#include "ubifs.h"

/**
 * ubifs_set_inode_flags - set VFS inode flags.
 * @inode: VFS inode to set flags for
 *
 * This function propagates flags from UBIFS inode object to VFS inode object.
 */
void ubifs_set_inode_flags(struct inode *inode)
{
        unsigned int flags = ubifs_inode(inode)->flags;

        inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);
        if (flags & UBIFS_SYNC_FL)
                inode->i_flags |= S_SYNC;
        if (flags & UBIFS_APPEND_FL)
                inode->i_flags |= S_APPEND;
        if (flags & UBIFS_IMMUTABLE_FL)
                inode->i_flags |= S_IMMUTABLE;
        if (flags & UBIFS_DIRSYNC_FL)
                inode->i_flags |= S_DIRSYNC;
}

/*
 * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
 * @ioctl_flags: flags to convert
 *
 * This function convert ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
 * (@UBIFS_COMPR_FL, etc).
 */
static int ioctl2ubifs(int ioctl_flags)
{
        int ubifs_flags = 0;

        if (ioctl_flags & FS_COMPR_FL)
                ubifs_flags |= UBIFS_COMPR_FL;
        if (ioctl_flags & FS_SYNC_FL)
                ubifs_flags |= UBIFS_SYNC_FL;
        if (ioctl_flags & FS_APPEND_FL)
                ubifs_flags |= UBIFS_APPEND_FL;
        if (ioctl_flags & FS_IMMUTABLE_FL)
                ubifs_flags |= UBIFS_IMMUTABLE_FL;
        if (ioctl_flags & FS_DIRSYNC_FL)
                ubifs_flags |= UBIFS_DIRSYNC_FL;

        return ubifs_flags;
}

/*
 * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
 * @ubifs_flags: flags to convert
 *
 * This function convert UBIFS (@UBIFS_COMPR_FL, etc) to ioctl flags
 * (@FS_COMPR_FL, etc).
 */
static int ubifs2ioctl(int ubifs_flags)
{
        int ioctl_flags = 0;

        if (ubifs_flags & UBIFS_COMPR_FL)
                ioctl_flags |= FS_COMPR_FL;
        if (ubifs_flags & UBIFS_SYNC_FL)
                ioctl_flags |= FS_SYNC_FL;
        if (ubifs_flags & UBIFS_APPEND_FL)
                ioctl_flags |= FS_APPEND_FL;
        if (ubifs_flags & UBIFS_IMMUTABLE_FL)
                ioctl_flags |= FS_IMMUTABLE_FL;
        if (ubifs_flags & UBIFS_DIRSYNC_FL)
                ioctl_flags |= FS_DIRSYNC_FL;

        return ioctl_flags;
}

static int setflags(struct inode *inode, int flags)
{
        int oldflags, err, release;
        struct ubifs_inode *ui = ubifs_inode(inode);
        struct ubifs_info *c = inode->i_sb->s_fs_info;
        struct ubifs_budget_req req = { .dirtied_ino = 1,
                                        .dirtied_ino_d = ui->data_len };

        err = ubifs_budget_space(c, &req);
        if (err)
                return err;

        /*
         * The IMMUTABLE and APPEND_ONLY flags can only be changed by
         * the relevant capability.
         */
        mutex_lock(&ui->ui_mutex);
        oldflags = ubifs2ioctl(ui->flags);
        if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
                if (!capable(CAP_LINUX_IMMUTABLE)) {
                        err = -EPERM;
                        goto out_unlock;
                }
        }

        ui->flags = ioctl2ubifs(flags);
        ubifs_set_inode_flags(inode);
        inode->i_ctime = ubifs_current_time(inode);
        release = ui->dirty;
        mark_inode_dirty_sync(inode);
        mutex_unlock(&ui->ui_mutex);

        if (release)
                ubifs_release_budget(c, &req);
        if (IS_SYNC(inode))
                err = write_inode_now(inode, 1);
        return err;

out_unlock:
        ubifs_err("can't modify inode %lu attributes", inode->i_ino);
        mutex_unlock(&ui->ui_mutex);
        ubifs_release_budget(c, &req);
        return err;
}

long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        int flags, err;
        struct inode *inode = file_inode(file);

        switch (cmd) {
        case FS_IOC_GETFLAGS:
                flags = ubifs2ioctl(ubifs_inode(inode)->flags);

                dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags);
                return put_user(flags, (int __user *) arg);

        case FS_IOC_SETFLAGS: {
                if (IS_RDONLY(inode))
                        return -EROFS;

                if (!inode_owner_or_capable(inode))
                        return -EACCES;

                if (get_user(flags, (int __user *) arg))
                        return -EFAULT;

                if (!S_ISDIR(inode->i_mode))
                        flags &= ~FS_DIRSYNC_FL;

                /*
                 * Make sure the file-system is read-write and make sure it
                 * will not become read-only while we are changing the flags.
                 */
                err = mnt_want_write_file(file);
                if (err)
                        return err;
                dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
                err = setflags(inode, flags);
                mnt_drop_write_file(file);
                return err;
        }

        default:
                return -ENOTTY;
        }
}

#ifdef CONFIG_COMPAT
long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        switch (cmd) {
        case FS_IOC32_GETFLAGS:
                cmd = FS_IOC_GETFLAGS;
                break;
        case FS_IOC32_SETFLAGS:
                cmd = FS_IOC_SETFLAGS;
                break;
        default:
                return -ENOIOCTLCMD;
        }
        return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
}
#endif