LXR linux/fs/ext4/ioctl.c

   1/*
   2 * linux/fs/ext4/ioctl.c
   3 *
   4 * Copyright (C) 1993, 1994, 1995
   5 * Remy Card (card@masi.ibp.fr)
   6 * Laboratoire MASI - Institut Blaise Pascal
   7 * Universite Pierre et Marie Curie (Paris VI)
   8 */
   9
  10#include <linux/fs.h>
  11#include <linux/jbd2.h>
  12#include <linux/capability.h>
  13#include <linux/time.h>
  14#include <linux/compat.h>
  15#include <linux/smp_lock.h>
  16#include <linux/mount.h>
  17#include <asm/uaccess.h>
  18#include "ext4_jbd2.h"
  19#include "ext4.h"
  20
  21long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
  22{
  23        struct inode *inode = filp->f_dentry->d_inode;
  24        struct ext4_inode_info *ei = EXT4_I(inode);
  25        unsigned int flags;
  26
  27        ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
  28
  29        switch (cmd) {
  30        case EXT4_IOC_GETFLAGS:
  31                ext4_get_inode_flags(ei);
  32                flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
  33                return put_user(flags, (int __user *) arg);
  34        case EXT4_IOC_SETFLAGS: {
  35                handle_t *handle = NULL;
  36                int err, migrate = 0;
  37                struct ext4_iloc iloc;
  38                unsigned int oldflags;
  39                unsigned int jflag;
  40
  41                if (!is_owner_or_cap(inode))
  42                        return -EACCES;
  43
  44                if (get_user(flags, (int __user *) arg))
  45                        return -EFAULT;
  46
  47                err = mnt_want_write(filp->f_path.mnt);
  48                if (err)
  49                        return err;
  50
  51                if (!S_ISDIR(inode->i_mode))
  52                        flags &= ~EXT4_DIRSYNC_FL;
  53
  54                err = -EPERM;
  55                mutex_lock(&inode->i_mutex);
  56                /* Is it quota file? Do not allow user to mess with it */
  57                if (IS_NOQUOTA(inode))
  58                        goto flags_out;
  59
  60                oldflags = ei->i_flags;
  61
  62                /* The JOURNAL_DATA flag is modifiable only by root */
  63                jflag = flags & EXT4_JOURNAL_DATA_FL;
  64
  65                /*
  66                 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  67                 * the relevant capability.
  68                 *
  69                 * This test looks nicer. Thanks to Pauline Middelink
  70                 */
  71                if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
  72                        if (!capable(CAP_LINUX_IMMUTABLE))
  73                                goto flags_out;
  74                }
  75
  76                /*
  77                 * The JOURNAL_DATA flag can only be changed by
  78                 * the relevant capability.
  79                 */
  80                if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  81                        if (!capable(CAP_SYS_RESOURCE))
  82                                goto flags_out;
  83                }
  84                if (oldflags & EXT4_EXTENTS_FL) {
  85                        /* We don't support clearning extent flags */
  86                        if (!(flags & EXT4_EXTENTS_FL)) {
  87                                err = -EOPNOTSUPP;
  88                                goto flags_out;
  89                        }
  90                } else if (flags & EXT4_EXTENTS_FL) {
  91                        /* migrate the file */
  92                        migrate = 1;
  93                        flags &= ~EXT4_EXTENTS_FL;
  94                }
  95
  96                handle = ext4_journal_start(inode, 1);
  97                if (IS_ERR(handle)) {
  98                        err = PTR_ERR(handle);
  99                        goto flags_out;
 100                }
 101                if (IS_SYNC(inode))
 102                        handle->h_sync = 1;
 103                err = ext4_reserve_inode_write(handle, inode, &iloc);
 104                if (err)
 105                        goto flags_err;
 106
 107                flags = flags & EXT4_FL_USER_MODIFIABLE;
 108                flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 109                ei->i_flags = flags;
 110
 111                ext4_set_inode_flags(inode);
 112                inode->i_ctime = ext4_current_time(inode);
 113
 114                err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 115flags_err:
 116                ext4_journal_stop(handle);
 117                if (err)
 118                        goto flags_out;
 119
 120                if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 121                        err = ext4_change_inode_journal_flag(inode, jflag);
 122                if (err)
 123                        goto flags_out;
 124                if (migrate)
 125                        err = ext4_ext_migrate(inode);
 126flags_out:
 127                mutex_unlock(&inode->i_mutex);
 128                mnt_drop_write(filp->f_path.mnt);
 129                return err;
 130        }
 131        case EXT4_IOC_GETVERSION:
 132        case EXT4_IOC_GETVERSION_OLD:
 133                return put_user(inode->i_generation, (int __user *) arg);
 134        case EXT4_IOC_SETVERSION:
 135        case EXT4_IOC_SETVERSION_OLD: {
 136                handle_t *handle;
 137                struct ext4_iloc iloc;
 138                __u32 generation;
 139                int err;
 140
 141                if (!is_owner_or_cap(inode))
 142                        return -EPERM;
 143
 144                err = mnt_want_write(filp->f_path.mnt);
 145                if (err)
 146                        return err;
 147                if (get_user(generation, (int __user *) arg)) {
 148                        err = -EFAULT;
 149                        goto setversion_out;
 150                }
 151
 152                handle = ext4_journal_start(inode, 1);
 153                if (IS_ERR(handle)) {
 154                        err = PTR_ERR(handle);
 155                        goto setversion_out;
 156                }
 157                err = ext4_reserve_inode_write(handle, inode, &iloc);
 158                if (err == 0) {
 159                        inode->i_ctime = ext4_current_time(inode);
 160                        inode->i_generation = generation;
 161                        err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 162                }
 163                ext4_journal_stop(handle);
 164setversion_out:
 165                mnt_drop_write(filp->f_path.mnt);
 166                return err;
 167        }
 168#ifdef CONFIG_JBD2_DEBUG
 169        case EXT4_IOC_WAIT_FOR_READONLY:
 170                /*
 171                 * This is racy - by the time we're woken up and running,
 172                 * the superblock could be released.  And the module could
 173                 * have been unloaded.  So sue me.
 174                 *
 175                 * Returns 1 if it slept, else zero.
 176                 */
 177                {
 178                        struct super_block *sb = inode->i_sb;
 179                        DECLARE_WAITQUEUE(wait, current);
 180                        int ret = 0;
 181
 182                        set_current_state(TASK_INTERRUPTIBLE);
 183                        add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 184                        if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 185                                schedule();
 186                                ret = 1;
 187                        }
 188                        remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 189                        return ret;
 190                }
 191#endif
 192        case EXT4_IOC_GROUP_EXTEND: {
 193                ext4_fsblk_t n_blocks_count;
 194                struct super_block *sb = inode->i_sb;
 195                int err, err2;
 196
 197                if (!capable(CAP_SYS_RESOURCE))
 198                        return -EPERM;
 199
 200                if (get_user(n_blocks_count, (__u32 __user *)arg))
 201                        return -EFAULT;
 202
 203                err = mnt_want_write(filp->f_path.mnt);
 204                if (err)
 205                        return err;
 206
 207                err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 208                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 209                err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 210                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 211                if (err == 0)
 212                        err = err2;
 213                mnt_drop_write(filp->f_path.mnt);
 214
 215                return err;
 216        }
 217        case EXT4_IOC_GROUP_ADD: {
 218                struct ext4_new_group_data input;
 219                struct super_block *sb = inode->i_sb;
 220                int err, err2;
 221
 222                if (!capable(CAP_SYS_RESOURCE))
 223                        return -EPERM;
 224
 225                if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 226                                sizeof(input)))
 227                        return -EFAULT;
 228
 229                err = mnt_want_write(filp->f_path.mnt);
 230                if (err)
 231                        return err;
 232
 233                err = ext4_group_add(sb, &input);
 234                jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 235                err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 236                jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 237                if (err == 0)
 238                        err = err2;
 239                mnt_drop_write(filp->f_path.mnt);
 240
 241                return err;
 242        }
 243
 244        case EXT4_IOC_MIGRATE:
 245        {
 246                int err;
 247                if (!is_owner_or_cap(inode))
 248                        return -EACCES;
 249
 250                err = mnt_want_write(filp->f_path.mnt);
 251                if (err)
 252                        return err;
 253                /*
 254                 * inode_mutex prevent write and truncate on the file.
 255                 * Read still goes through. We take i_data_sem in
 256                 * ext4_ext_swap_inode_data before we switch the
 257                 * inode format to prevent read.
 258                 */
 259                mutex_lock(&(inode->i_mutex));
 260                err = ext4_ext_migrate(inode);
 261                mutex_unlock(&(inode->i_mutex));
 262                mnt_drop_write(filp->f_path.mnt);
 263                return err;
 264        }
 265
 266        default:
 267                return -ENOTTY;
 268        }
 269}
 270
 271#ifdef CONFIG_COMPAT
 272long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 273{
 274        /* These are just misnamed, they actually get/put from/to user an int */
 275        switch (cmd) {
 276        case EXT4_IOC32_GETFLAGS:
 277                cmd = EXT4_IOC_GETFLAGS;
 278                break;
 279        case EXT4_IOC32_SETFLAGS:
 280                cmd = EXT4_IOC_SETFLAGS;
 281                break;
 282        case EXT4_IOC32_GETVERSION:
 283                cmd = EXT4_IOC_GETVERSION;
 284                break;
 285        case EXT4_IOC32_SETVERSION:
 286                cmd = EXT4_IOC_SETVERSION;
 287                break;
 288        case EXT4_IOC32_GROUP_EXTEND:
 289                cmd = EXT4_IOC_GROUP_EXTEND;
 290                break;
 291        case EXT4_IOC32_GETVERSION_OLD:
 292                cmd = EXT4_IOC_GETVERSION_OLD;
 293                break;
 294        case EXT4_IOC32_SETVERSION_OLD:
 295                cmd = EXT4_IOC_SETVERSION_OLD;
 296                break;
 297#ifdef CONFIG_JBD2_DEBUG
 298        case EXT4_IOC32_WAIT_FOR_READONLY:
 299                cmd = EXT4_IOC_WAIT_FOR_READONLY;
 300                break;
 301#endif
 302        case EXT4_IOC32_GETRSVSZ:
 303                cmd = EXT4_IOC_GETRSVSZ;
 304                break;
 305        case EXT4_IOC32_SETRSVSZ:
 306                cmd = EXT4_IOC_SETRSVSZ;
 307                break;
 308        case EXT4_IOC_GROUP_ADD:
 309                break;
 310        default:
 311                return -ENOIOCTLCMD;
 312        }
 313        return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 314}
 315#endif
 316