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/mount.h>
  16 #include <linux/file.h>
  17 #include <asm/uaccess.h>
  18 #include "ext4_jbd2.h"
  19 #include "ext4.h"
  20
  21 long 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                 flags = ext4_mask_flags(inode->i_mode, flags);
  52
  53                 err = -EPERM;
  54                 mutex_lock(&inode->i_mutex);
  55                 /* Is it quota file? Do not allow user to mess with it */
  56                 if (IS_NOQUOTA(inode))
  57                         goto flags_out;
  58
  59                 oldflags = ei->i_flags;
  60
  61                 /* The JOURNAL_DATA flag is modifiable only by root */
  62                 jflag = flags & EXT4_JOURNAL_DATA_FL;
  63
  64                 /*
  65                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  66                  * the relevant capability.
  67                  *
  68                  * This test looks nicer. Thanks to Pauline Middelink
  69                  */
  70                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
  71                         if (!capable(CAP_LINUX_IMMUTABLE))
  72                                 goto flags_out;
  73                 }
  74
  75                 /*
  76                  * The JOURNAL_DATA flag can only be changed by
  77                  * the relevant capability.
  78                  */
  79                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  80                         if (!capable(CAP_SYS_RESOURCE))
  81                                 goto flags_out;
  82                 }
  83                 if (oldflags & EXT4_EXTENTS_FL) {
  84                         /* We don't support clearning extent flags */
  85                         if (!(flags & EXT4_EXTENTS_FL)) {
  86                                 err = -EOPNOTSUPP;
  87                                 goto flags_out;
  88                         }
  89                 } else if (flags & EXT4_EXTENTS_FL) {
  90                         /* migrate the file */
  91                         migrate = 1;
  92                         flags &= ~EXT4_EXTENTS_FL;
  93                 }
  94
  95                 handle = ext4_journal_start(inode, 1);
  96                 if (IS_ERR(handle)) {
  97                         err = PTR_ERR(handle);
  98                         goto flags_out;
  99                 }
 100                 if (IS_SYNC(inode))
 101                         ext4_handle_sync(handle);
 102                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 103                 if (err)
 104                         goto flags_err;
 105
 106                 flags = flags & EXT4_FL_USER_MODIFIABLE;
 107                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 108                 ei->i_flags = flags;
 109
 110                 ext4_set_inode_flags(inode);
 111                 inode->i_ctime = ext4_current_time(inode);
 112
 113                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 114 flags_err:
 115                 ext4_journal_stop(handle);
 116                 if (err)
 117                         goto flags_out;
 118
 119                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 120                         err = ext4_change_inode_journal_flag(inode, jflag);
 121                 if (err)
 122                         goto flags_out;
 123                 if (migrate)
 124                         err = ext4_ext_migrate(inode);
 125 flags_out:
 126                 mutex_unlock(&inode->i_mutex);
 127                 mnt_drop_write(filp->f_path.mnt);
 128                 return err;
 129         }
 130         case EXT4_IOC_GETVERSION:
 131         case EXT4_IOC_GETVERSION_OLD:
 132                 return put_user(inode->i_generation, (int __user *) arg);
 133         case EXT4_IOC_SETVERSION:
 134         case EXT4_IOC_SETVERSION_OLD: {
 135                 handle_t *handle;
 136                 struct ext4_iloc iloc;
 137                 __u32 generation;
 138                 int err;
 139
 140                 if (!is_owner_or_cap(inode))
 141                         return -EPERM;
 142
 143                 err = mnt_want_write(filp->f_path.mnt);
 144                 if (err)
 145                         return err;
 146                 if (get_user(generation, (int __user *) arg)) {
 147                         err = -EFAULT;
 148                         goto setversion_out;
 149                 }
 150
 151                 handle = ext4_journal_start(inode, 1);
 152                 if (IS_ERR(handle)) {
 153                         err = PTR_ERR(handle);
 154                         goto setversion_out;
 155                 }
 156                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 157                 if (err == 0) {
 158                         inode->i_ctime = ext4_current_time(inode);
 159                         inode->i_generation = generation;
 160                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 161                 }
 162                 ext4_journal_stop(handle);
 163 setversion_out:
 164                 mnt_drop_write(filp->f_path.mnt);
 165                 return err;
 166         }
 167 #ifdef CONFIG_JBD2_DEBUG
 168         case EXT4_IOC_WAIT_FOR_READONLY:
 169                 /*
 170                  * This is racy - by the time we're woken up and running,
 171                  * the superblock could be released.  And the module could
 172                  * have been unloaded.  So sue me.
 173                  *
 174                  * Returns 1 if it slept, else zero.
 175                  */
 176                 {
 177                         struct super_block *sb = inode->i_sb;
 178                         DECLARE_WAITQUEUE(wait, current);
 179                         int ret = 0;
 180
 181                         set_current_state(TASK_INTERRUPTIBLE);
 182                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 183                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 184                                 schedule();
 185                                 ret = 1;
 186                         }
 187                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 188                         return ret;
 189                 }
 190 #endif
 191         case EXT4_IOC_GROUP_EXTEND: {
 192                 ext4_fsblk_t n_blocks_count;
 193                 struct super_block *sb = inode->i_sb;
 194                 int err, err2;
 195
 196                 if (!capable(CAP_SYS_RESOURCE))
 197                         return -EPERM;
 198
 199                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 200                         return -EFAULT;
 201
 202                 err = mnt_want_write(filp->f_path.mnt);
 203                 if (err)
 204                         return err;
 205
 206                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 207                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 208                 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 209                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 210                 if (err == 0)
 211                         err = err2;
 212                 mnt_drop_write(filp->f_path.mnt);
 213
 214                 return err;
 215         }
 216
 217         case EXT4_IOC_MOVE_EXT: {
 218                 struct move_extent me;
 219                 struct file *donor_filp;
 220                 int err;
 221
 222                 if (copy_from_user(&me,
 223                         (struct move_extent __user *)arg, sizeof(me)))
 224                         return -EFAULT;
 225
 226                 donor_filp = fget(me.donor_fd);
 227                 if (!donor_filp)
 228                         return -EBADF;
 229
 230                 if (!capable(CAP_DAC_OVERRIDE)) {
 231                         if ((current->real_cred->fsuid != inode->i_uid) ||
 232                                 !(inode->i_mode & S_IRUSR) ||
 233                                 !(donor_filp->f_dentry->d_inode->i_mode &
 234                                 S_IRUSR)) {
 235                                 fput(donor_filp);
 236                                 return -EACCES;
 237                         }
 238                 }
 239
 240                 err = ext4_move_extents(filp, donor_filp, me.orig_start,
 241                                         me.donor_start, me.len, &me.moved_len);
 242                 fput(donor_filp);
 243
 244                 if (!err)
 245                         if (copy_to_user((struct move_extent *)arg,
 246                                 &me, sizeof(me)))
 247                                 return -EFAULT;
 248                 return err;
 249         }
 250
 251         case EXT4_IOC_GROUP_ADD: {
 252                 struct ext4_new_group_data input;
 253                 struct super_block *sb = inode->i_sb;
 254                 int err, err2;
 255
 256                 if (!capable(CAP_SYS_RESOURCE))
 257                         return -EPERM;
 258
 259                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 260                                 sizeof(input)))
 261                         return -EFAULT;
 262
 263                 err = mnt_want_write(filp->f_path.mnt);
 264                 if (err)
 265                         return err;
 266
 267                 err = ext4_group_add(sb, &input);
 268                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 269                 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 270                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 271                 if (err == 0)
 272                         err = err2;
 273                 mnt_drop_write(filp->f_path.mnt);
 274
 275                 return err;
 276         }
 277
 278         case EXT4_IOC_MIGRATE:
 279         {
 280                 int err;
 281                 if (!is_owner_or_cap(inode))
 282                         return -EACCES;
 283
 284                 err = mnt_want_write(filp->f_path.mnt);
 285                 if (err)
 286                         return err;
 287                 /*
 288                  * inode_mutex prevent write and truncate on the file.
 289                  * Read still goes through. We take i_data_sem in
 290                  * ext4_ext_swap_inode_data before we switch the
 291                  * inode format to prevent read.
 292                  */
 293                 mutex_lock(&(inode->i_mutex));
 294                 err = ext4_ext_migrate(inode);
 295                 mutex_unlock(&(inode->i_mutex));
 296                 mnt_drop_write(filp->f_path.mnt);
 297                 return err;
 298         }
 299
 300         case EXT4_IOC_ALLOC_DA_BLKS:
 301         {
 302                 int err;
 303                 if (!is_owner_or_cap(inode))
 304                         return -EACCES;
 305
 306                 err = mnt_want_write(filp->f_path.mnt);
 307                 if (err)
 308                         return err;
 309                 err = ext4_alloc_da_blocks(inode);
 310                 mnt_drop_write(filp->f_path.mnt);
 311                 return err;
 312         }
 313
 314         default:
 315                 return -ENOTTY;
 316         }
 317 }
 318
 319 #ifdef CONFIG_COMPAT
 320 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 321 {
 322         /* These are just misnamed, they actually get/put from/to user an int */
 323         switch (cmd) {
 324         case EXT4_IOC32_GETFLAGS:
 325                 cmd = EXT4_IOC_GETFLAGS;
 326                 break;
 327         case EXT4_IOC32_SETFLAGS:
 328                 cmd = EXT4_IOC_SETFLAGS;
 329                 break;
 330         case EXT4_IOC32_GETVERSION:
 331                 cmd = EXT4_IOC_GETVERSION;
 332                 break;
 333         case EXT4_IOC32_SETVERSION:
 334                 cmd = EXT4_IOC_SETVERSION;
 335                 break;
 336         case EXT4_IOC32_GROUP_EXTEND:
 337                 cmd = EXT4_IOC_GROUP_EXTEND;
 338                 break;
 339         case EXT4_IOC32_GETVERSION_OLD:
 340                 cmd = EXT4_IOC_GETVERSION_OLD;
 341                 break;
 342         case EXT4_IOC32_SETVERSION_OLD:
 343                 cmd = EXT4_IOC_SETVERSION_OLD;
 344                 break;
 345 #ifdef CONFIG_JBD2_DEBUG
 346         case EXT4_IOC32_WAIT_FOR_READONLY:
 347                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 348                 break;
 349 #endif
 350         case EXT4_IOC32_GETRSVSZ:
 351                 cmd = EXT4_IOC_GETRSVSZ;
 352                 break;
 353         case EXT4_IOC32_SETRSVSZ:
 354                 cmd = EXT4_IOC_SETRSVSZ;
 355                 break;
 356         case EXT4_IOC_GROUP_ADD:
 357                 break;
 358         default:
 359                 return -ENOIOCTLCMD;
 360         }
 361         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 362 }
 363 #endif