ioctl.c

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/*
 * linux/fs/jfs/ioctl.c
 *
 * Copyright (C) 2006 Herbert Poetzl
 * adapted from Remy Card's ext2/ioctl.c
 */

#include <linux/fs.h>
#include <linux/ctype.h>
#include <linux/capability.h>
#include <linux/mount.h>
#include <linux/time.h>
#include <linux/sched.h>
#include <linux/blkdev.h>
#include <asm/current.h>
#include <asm/uaccess.h>

#include "jfs_filsys.h"
#include "jfs_debug.h"
#include "jfs_incore.h"
#include "jfs_dinode.h"
#include "jfs_inode.h"
#include "jfs_dmap.h"
#include "jfs_discard.h"

static struct {
    long jfs_flag;
    long ext2_flag;
} jfs_map[] = {
    {JFS_NOATIME_FL,    FS_NOATIME_FL},
    {JFS_DIRSYNC_FL,    FS_DIRSYNC_FL},
    {JFS_SYNC_FL,       FS_SYNC_FL},
    {JFS_SECRM_FL,      FS_SECRM_FL},
    {JFS_UNRM_FL,       FS_UNRM_FL},
    {JFS_APPEND_FL,     FS_APPEND_FL},
    {JFS_IMMUTABLE_FL,  FS_IMMUTABLE_FL},
    {0, 0},
};

static long jfs_map_ext2(unsigned long flags, int from)
{
    int index=0;
    long mapped=0;

    while (jfs_map[index].jfs_flag) {
        if (from) {
            if (jfs_map[index].ext2_flag & flags)
                mapped |= jfs_map[index].jfs_flag;
        } else {
            if (jfs_map[index].jfs_flag & flags)
                mapped |= jfs_map[index].ext2_flag;
        }
        index++;
    }
    return mapped;
}


long jfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
    struct inode *inode = filp->f_dentry->d_inode;
    struct jfs_inode_info *jfs_inode = JFS_IP(inode);
    unsigned int flags;

    switch (cmd) {
    case JFS_IOC_GETFLAGS:
        jfs_get_inode_flags(jfs_inode);
        flags = jfs_inode->mode2 & JFS_FL_USER_VISIBLE;
        flags = jfs_map_ext2(flags, 0);
        return put_user(flags, (int __user *) arg);
    case JFS_IOC_SETFLAGS: {
        unsigned int oldflags;
        int err;

        err = mnt_want_write_file(filp);
        if (err)
            return err;

        if (!inode_owner_or_capable(inode)) {
            err = -EACCES;
            goto setflags_out;
        }
        if (get_user(flags, (int __user *) arg)) {
            err = -EFAULT;
            goto setflags_out;
        }

        flags = jfs_map_ext2(flags, 1);
        if (!S_ISDIR(inode->i_mode))
            flags &= ~JFS_DIRSYNC_FL;

        /* Is it quota file? Do not allow user to mess with it */
        if (IS_NOQUOTA(inode)) {
            err = -EPERM;
            goto setflags_out;
        }

        /* Lock against other parallel changes of flags */
        mutex_lock(&inode->i_mutex);

        jfs_get_inode_flags(jfs_inode);
        oldflags = jfs_inode->mode2;

        /*
         * The IMMUTABLE and APPEND_ONLY flags can only be changed by
         * the relevant capability.
         */
        if ((oldflags & JFS_IMMUTABLE_FL) ||
            ((flags ^ oldflags) &
            (JFS_APPEND_FL | JFS_IMMUTABLE_FL))) {
            if (!capable(CAP_LINUX_IMMUTABLE)) {
                mutex_unlock(&inode->i_mutex);
                err = -EPERM;
                goto setflags_out;
            }
        }

        flags = flags & JFS_FL_USER_MODIFIABLE;
        flags |= oldflags & ~JFS_FL_USER_MODIFIABLE;
        jfs_inode->mode2 = flags;

        jfs_set_inode_flags(inode);
        mutex_unlock(&inode->i_mutex);
        inode->i_ctime = CURRENT_TIME_SEC;
        mark_inode_dirty(inode);
setflags_out:
        mnt_drop_write_file(filp);
        return err;
    }

    case FITRIM:
    {
        struct super_block *sb = inode->i_sb;
        struct request_queue *q = bdev_get_queue(sb->s_bdev);
        struct fstrim_range range;
        s64 ret = 0;

        if (!capable(CAP_SYS_ADMIN))
            return -EPERM;

        if (!blk_queue_discard(q)) {
            jfs_warn("FITRIM not supported on device");
            return -EOPNOTSUPP;
        }

        if (copy_from_user(&range, (struct fstrim_range __user *)arg,
            sizeof(range)))
            return -EFAULT;

        range.minlen = max_t(unsigned int, range.minlen,
            q->limits.discard_granularity);

        ret = jfs_ioc_trim(inode, &range);
        if (ret < 0)
            return ret;

        if (copy_to_user((struct fstrim_range __user *)arg, &range,
            sizeof(range)))
            return -EFAULT;

        return 0;
    }

    default:
        return -ENOTTY;
    }
}

#ifdef CONFIG_COMPAT
long jfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
    /* While these ioctl numbers defined with 'long' and have different
     * numbers than the 64bit ABI,
     * the actual implementation only deals with ints and is compatible.
     */
    switch (cmd) {
    case JFS_IOC_GETFLAGS32:
        cmd = JFS_IOC_GETFLAGS;
        break;
    case JFS_IOC_SETFLAGS32:
        cmd = JFS_IOC_SETFLAGS;
        break;
    case FITRIM:
        cmd = FITRIM;
        break;
    }
    return jfs_ioctl(filp, cmd, arg);
}
#endif