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root/fs/ext4/ioctl.c

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DEFINITIONS

This source file includes following definitions.
  1. ext4_ioctl
  2. ext4_compat_ioctl

/*
 * linux/fs/ext4/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 <linux/fs.h>
#include <linux/jbd2.h>
#include <linux/capability.h>
#include <linux/time.h>
#include <linux/compat.h>
#include <linux/smp_lock.h>
#include <linux/mount.h>
#include <asm/uaccess.h>
#include "ext4_jbd2.h"
#include "ext4.h"

long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
        struct inode *inode = filp->f_dentry->d_inode;
        struct ext4_inode_info *ei = EXT4_I(inode);
        unsigned int flags;

        ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);

        switch (cmd) {
        case EXT4_IOC_GETFLAGS:
                ext4_get_inode_flags(ei);
                flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
                return put_user(flags, (int __user *) arg);
        case EXT4_IOC_SETFLAGS: {
                handle_t *handle = NULL;
                int err, migrate = 0;
                struct ext4_iloc iloc;
                unsigned int oldflags;
                unsigned int jflag;

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

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

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

                if (!S_ISDIR(inode->i_mode))
                        flags &= ~EXT4_DIRSYNC_FL;

                err = -EPERM;
                mutex_lock(&inode->i_mutex);
                /* Is it quota file? Do not allow user to mess with it */
                if (IS_NOQUOTA(inode))
                        goto flags_out;

                oldflags = ei->i_flags;

                /* The JOURNAL_DATA flag is modifiable only by root */
                jflag = flags & EXT4_JOURNAL_DATA_FL;

                /*
                 * 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) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
                        if (!capable(CAP_LINUX_IMMUTABLE))
                                goto flags_out;
                }

                /*
                 * The JOURNAL_DATA flag can only be changed by
                 * the relevant capability.
                 */
                if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
                        if (!capable(CAP_SYS_RESOURCE))
                                goto flags_out;
                }
                if (oldflags & EXT4_EXTENTS_FL) {
                        /* We don't support clearning extent flags */
                        if (!(flags & EXT4_EXTENTS_FL)) {
                                err = -EOPNOTSUPP;
                                goto flags_out;
                        }
                } else if (flags & EXT4_EXTENTS_FL) {
                        /* migrate the file */
                        migrate = 1;
                        flags &= ~EXT4_EXTENTS_FL;
                }

                handle = ext4_journal_start(inode, 1);
                if (IS_ERR(handle)) {
                        err = PTR_ERR(handle);
                        goto flags_out;
                }
                if (IS_SYNC(inode))
                        handle->h_sync = 1;
                err = ext4_reserve_inode_write(handle, inode, &iloc);
                if (err)
                        goto flags_err;

                flags = flags & EXT4_FL_USER_MODIFIABLE;
                flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
                ei->i_flags = flags;

                ext4_set_inode_flags(inode);
                inode->i_ctime = ext4_current_time(inode);

                err = ext4_mark_iloc_dirty(handle, inode, &iloc);
flags_err:
                ext4_journal_stop(handle);
                if (err)
                        goto flags_out;

                if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
                        err = ext4_change_inode_journal_flag(inode, jflag);
                if (err)
                        goto flags_out;
                if (migrate)
                        err = ext4_ext_migrate(inode);
flags_out:
                mutex_unlock(&inode->i_mutex);
                mnt_drop_write(filp->f_path.mnt);
                return err;
        }
        case EXT4_IOC_GETVERSION:
        case EXT4_IOC_GETVERSION_OLD:
                return put_user(inode->i_generation, (int __user *) arg);
        case EXT4_IOC_SETVERSION:
        case EXT4_IOC_SETVERSION_OLD: {
                handle_t *handle;
                struct ext4_iloc iloc;
                __u32 generation;
                int err;

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

                err = mnt_want_write(filp->f_path.mnt);
                if (err)
                        return err;
                if (get_user(generation, (int __user *) arg)) {
                        err = -EFAULT;
                        goto setversion_out;
                }

                handle = ext4_journal_start(inode, 1);
                if (IS_ERR(handle)) {
                        err = PTR_ERR(handle);
                        goto setversion_out;
                }
                err = ext4_reserve_inode_write(handle, inode, &iloc);
                if (err == 0) {
                        inode->i_ctime = ext4_current_time(inode);
                        inode->i_generation = generation;
                        err = ext4_mark_iloc_dirty(handle, inode, &iloc);
                }
                ext4_journal_stop(handle);
setversion_out:
                mnt_drop_write(filp->f_path.mnt);
                return err;
        }
#ifdef CONFIG_JBD2_DEBUG
        case EXT4_IOC_WAIT_FOR_READONLY:
                /*
                 * This is racy - by the time we're woken up and running,
                 * the superblock could be released.  And the module could
                 * have been unloaded.  So sue me.
                 *
                 * Returns 1 if it slept, else zero.
                 */
                {
                        struct super_block *sb = inode->i_sb;
                        DECLARE_WAITQUEUE(wait, current);
                        int ret = 0;

                        set_current_state(TASK_INTERRUPTIBLE);
                        add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
                        if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
                                schedule();
                                ret = 1;
                        }
                        remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
                        return ret;
                }
#endif
        case EXT4_IOC_GROUP_EXTEND: {
                ext4_fsblk_t n_blocks_count;
                struct super_block *sb = inode->i_sb;
                int err, err2;

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

                if (get_user(n_blocks_count, (__u32 __user *)arg))
                        return -EFAULT;

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

                err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
                err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
                if (err == 0)
                        err = err2;
                mnt_drop_write(filp->f_path.mnt);

                return err;
        }
        case EXT4_IOC_GROUP_ADD: {
                struct ext4_new_group_data input;
                struct super_block *sb = inode->i_sb;
                int err, err2;

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

                if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
                                sizeof(input)))
                        return -EFAULT;

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

                err = ext4_group_add(sb, &input);
                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
                err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
                if (err == 0)
                        err = err2;
                mnt_drop_write(filp->f_path.mnt);

                return err;
        }

        case EXT4_IOC_MIGRATE:
        {
                int err;
                if (!is_owner_or_cap(inode))
                        return -EACCES;

                err = mnt_want_write(filp->f_path.mnt);
                if (err)
                        return err;
                /*
                 * inode_mutex prevent write and truncate on the file.
                 * Read still goes through. We take i_data_sem in
                 * ext4_ext_swap_inode_data before we switch the
                 * inode format to prevent read.
                 */
                mutex_lock(&(inode->i_mutex));
                err = ext4_ext_migrate(inode);
                mutex_unlock(&(inode->i_mutex));
                mnt_drop_write(filp->f_path.mnt);
                return err;
        }

        default:
                return -ENOTTY;
        }
}

#ifdef CONFIG_COMPAT
long ext4_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 EXT4_IOC32_GETFLAGS:
                cmd = EXT4_IOC_GETFLAGS;
                break;
        case EXT4_IOC32_SETFLAGS:
                cmd = EXT4_IOC_SETFLAGS;
                break;
        case EXT4_IOC32_GETVERSION:
                cmd = EXT4_IOC_GETVERSION;
                break;
        case EXT4_IOC32_SETVERSION:
                cmd = EXT4_IOC_SETVERSION;
                break;
        case EXT4_IOC32_GROUP_EXTEND:
                cmd = EXT4_IOC_GROUP_EXTEND;
                break;
        case EXT4_IOC32_GETVERSION_OLD:
                cmd = EXT4_IOC_GETVERSION_OLD;
                break;
        case EXT4_IOC32_SETVERSION_OLD:
                cmd = EXT4_IOC_SETVERSION_OLD;
                break;
#ifdef CONFIG_JBD2_DEBUG
        case EXT4_IOC32_WAIT_FOR_READONLY:
                cmd = EXT4_IOC_WAIT_FOR_READONLY;
                break;
#endif
        case EXT4_IOC32_GETRSVSZ:
                cmd = EXT4_IOC_GETRSVSZ;
                break;
        case EXT4_IOC32_SETRSVSZ:
                cmd = EXT4_IOC_SETRSVSZ;
                break;
        case EXT4_IOC_GROUP_ADD:
                break;
        default:
                return -ENOIOCTLCMD;
        }
        return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
}
#endif

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