root/fs/ext2/ioctl.c

DEFINITIONS

1. ext2_ioctl
2. ext2_compat_ioctl

/*
 * linux/fs/ext2/ioctl.c
 *
 * Copyright (C) 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 */

#include "ext2.h"
#include <linux/capability.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/compat.h>
#include <linux/mount.h>
#include <linux/smp_lock.h>
#include <asm/current.h>
#include <asm/uaccess.h>


long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
        struct inode *inode = filp->f_dentry->d_inode;
        struct ext2_inode_info *ei = EXT2_I(inode);
        unsigned int flags;
        unsigned short rsv_window_size;
        int ret;

        ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);

        switch (cmd) {
        case EXT2_IOC_GETFLAGS:
                ext2_get_inode_flags(ei);
                flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
                return put_user(flags, (int __user *) arg);
        case EXT2_IOC_SETFLAGS: {
                unsigned int oldflags;

                ret = mnt_want_write(filp->f_path.mnt);
                if (ret)
                        return ret;

                if (!is_owner_or_cap(inode)) {
                        ret = -EACCES;
                        goto setflags_out;
                }

                if (get_user(flags, (int __user *) arg)) {
                        ret = -EFAULT;
                        goto setflags_out;
                }

                if (!S_ISDIR(inode->i_mode))
                        flags &= ~EXT2_DIRSYNC_FL;

                mutex_lock(&inode->i_mutex);
                /* Is it quota file? Do not allow user to mess with it */
                if (IS_NOQUOTA(inode)) {
                        mutex_unlock(&inode->i_mutex);
                        ret = -EPERM;
                        goto setflags_out;
                }
                oldflags = ei->i_flags;

                /*
                 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
                 * the relevant capability.
                 *
                 * This test looks nicer. Thanks to Pauline Middelink
                 */
                if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
                        if (!capable(CAP_LINUX_IMMUTABLE)) {
                                mutex_unlock(&inode->i_mutex);
                                ret = -EPERM;
                                goto setflags_out;
                        }
                }

                flags = flags & EXT2_FL_USER_MODIFIABLE;
                flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
                ei->i_flags = flags;
                mutex_unlock(&inode->i_mutex);

                ext2_set_inode_flags(inode);
                inode->i_ctime = CURRENT_TIME_SEC;
                mark_inode_dirty(inode);
setflags_out:
                mnt_drop_write(filp->f_path.mnt);
                return ret;
        }
        case EXT2_IOC_GETVERSION:
                return put_user(inode->i_generation, (int __user *) arg);
        case EXT2_IOC_SETVERSION:
                if (!is_owner_or_cap(inode))
                        return -EPERM;
                ret = mnt_want_write(filp->f_path.mnt);
                if (ret)
                        return ret;
                if (get_user(inode->i_generation, (int __user *) arg)) {
                        ret = -EFAULT;
                } else {
                        inode->i_ctime = CURRENT_TIME_SEC;
                        mark_inode_dirty(inode);
                }
                mnt_drop_write(filp->f_path.mnt);
                return ret;
        case EXT2_IOC_GETRSVSZ:
                if (test_opt(inode->i_sb, RESERVATION)
                        && S_ISREG(inode->i_mode)
                        && ei->i_block_alloc_info) {
                        rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
                        return put_user(rsv_window_size, (int __user *)arg);
                }
                return -ENOTTY;
        case EXT2_IOC_SETRSVSZ: {

                if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
                        return -ENOTTY;

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

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

                ret = mnt_want_write(filp->f_path.mnt);
                if (ret)
                        return ret;

                if (rsv_window_size > EXT2_MAX_RESERVE_BLOCKS)
                        rsv_window_size = EXT2_MAX_RESERVE_BLOCKS;

                /*
                 * need to allocate reservation structure for this inode
                 * before set the window size
                 */
                /*
                 * XXX What lock should protect the rsv_goal_size?
                 * Accessed in ext2_get_block only.  ext3 uses i_truncate.
                 */
                mutex_lock(&ei->truncate_mutex);
                if (!ei->i_block_alloc_info)
                        ext2_init_block_alloc_info(inode);

                if (ei->i_block_alloc_info){
                        struct ext2_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
                        rsv->rsv_goal_size = rsv_window_size;
                }
                mutex_unlock(&ei->truncate_mutex);
                mnt_drop_write(filp->f_path.mnt);
                return 0;
        }
        default:
                return -ENOTTY;
        }
}

#ifdef CONFIG_COMPAT
long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
        /* These are just misnamed, they actually get/put from/to user an int */
        switch (cmd) {
        case EXT2_IOC32_GETFLAGS:
                cmd = EXT2_IOC_GETFLAGS;
                break;
        case EXT2_IOC32_SETFLAGS:
                cmd = EXT2_IOC_SETFLAGS;
                break;
        case EXT2_IOC32_GETVERSION:
                cmd = EXT2_IOC_GETVERSION;
                break;
        case EXT2_IOC32_SETVERSION:
                cmd = EXT2_IOC_SETVERSION;
                break;
        default:
                return -ENOIOCTLCMD;
        }
        return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}
#endif