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
  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         unsigned short rsv_window_size;
  27
  28         ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
  29
  30         switch (cmd) {
  31         case EXT4_IOC_GETFLAGS:
  32                 ext4_get_inode_flags(ei);
  33                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
  34                 return put_user(flags, (int __user *) arg);
  35         case EXT4_IOC_SETFLAGS: {
  36                 handle_t *handle = NULL;
  37                 int err, migrate = 0;
  38                 struct ext4_iloc iloc;
  39                 unsigned int oldflags;
  40                 unsigned int jflag;
  41
  42                 if (!is_owner_or_cap(inode))
  43                         return -EACCES;
  44
  45                 if (get_user(flags, (int __user *) arg))
  46                         return -EFAULT;
  47
  48                 err = mnt_want_write(filp->f_path.mnt);
  49                 if (err)
  50                         return err;
  51
  52                 if (!S_ISDIR(inode->i_mode))
  53                         flags &= ~EXT4_DIRSYNC_FL;
  54
  55                 err = -EPERM;
  56                 mutex_lock(&inode->i_mutex);
  57                 /* Is it quota file? Do not allow user to mess with it */
  58                 if (IS_NOQUOTA(inode))
  59                         goto flags_out;
  60
  61                 oldflags = ei->i_flags;
  62
  63                 /* The JOURNAL_DATA flag is modifiable only by root */
  64                 jflag = flags & EXT4_JOURNAL_DATA_FL;
  65
  66                 /*
  67                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  68                  * the relevant capability.
  69                  *
  70                  * This test looks nicer. Thanks to Pauline Middelink
  71                  */
  72                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
  73                         if (!capable(CAP_LINUX_IMMUTABLE))
  74                                 goto flags_out;
  75                 }
  76
  77                 /*
  78                  * The JOURNAL_DATA flag can only be changed by
  79                  * the relevant capability.
  80                  */
  81                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  82                         if (!capable(CAP_SYS_RESOURCE))
  83                                 goto flags_out;
  84                 }
  85                 if (oldflags & EXT4_EXTENTS_FL) {
  86                         /* We don't support clearning extent flags */
  87                         if (!(flags & EXT4_EXTENTS_FL)) {
  88                                 err = -EOPNOTSUPP;
  89                                 goto flags_out;
  90                         }
  91                 } else if (flags & EXT4_EXTENTS_FL) {
  92                         /* migrate the file */
  93                         migrate = 1;
  94                         flags &= ~EXT4_EXTENTS_FL;
  95                 }
  96
  97                 handle = ext4_journal_start(inode, 1);
  98                 if (IS_ERR(handle)) {
  99                         err = PTR_ERR(handle);
 100                         goto flags_out;
 101                 }
 102                 if (IS_SYNC(inode))
 103                         handle->h_sync = 1;
 104                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 105                 if (err)
 106                         goto flags_err;
 107
 108                 flags = flags & EXT4_FL_USER_MODIFIABLE;
 109                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 110                 ei->i_flags = flags;
 111
 112                 ext4_set_inode_flags(inode);
 113                 inode->i_ctime = ext4_current_time(inode);
 114
 115                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 116 flags_err:
 117                 ext4_journal_stop(handle);
 118                 if (err)
 119                         goto flags_out;
 120
 121                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 122                         err = ext4_change_inode_journal_flag(inode, jflag);
 123                 if (err)
 124                         goto flags_out;
 125                 if (migrate)
 126                         err = ext4_ext_migrate(inode);
 127 flags_out:
 128                 mutex_unlock(&inode->i_mutex);
 129                 mnt_drop_write(filp->f_path.mnt);
 130                 return err;
 131         }
 132         case EXT4_IOC_GETVERSION:
 133         case EXT4_IOC_GETVERSION_OLD:
 134                 return put_user(inode->i_generation, (int __user *) arg);
 135         case EXT4_IOC_SETVERSION:
 136         case EXT4_IOC_SETVERSION_OLD: {
 137                 handle_t *handle;
 138                 struct ext4_iloc iloc;
 139                 __u32 generation;
 140                 int err;
 141
 142                 if (!is_owner_or_cap(inode))
 143                         return -EPERM;
 144
 145                 err = mnt_want_write(filp->f_path.mnt);
 146                 if (err)
 147                         return err;
 148                 if (get_user(generation, (int __user *) arg)) {
 149                         err = -EFAULT;
 150                         goto setversion_out;
 151                 }
 152
 153                 handle = ext4_journal_start(inode, 1);
 154                 if (IS_ERR(handle)) {
 155                         err = PTR_ERR(handle);
 156                         goto setversion_out;
 157                 }
 158                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 159                 if (err == 0) {
 160                         inode->i_ctime = ext4_current_time(inode);
 161                         inode->i_generation = generation;
 162                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 163                 }
 164                 ext4_journal_stop(handle);
 165 setversion_out:
 166                 mnt_drop_write(filp->f_path.mnt);
 167                 return err;
 168         }
 169 #ifdef CONFIG_JBD2_DEBUG
 170         case EXT4_IOC_WAIT_FOR_READONLY:
 171                 /*
 172                  * This is racy - by the time we're woken up and running,
 173                  * the superblock could be released.  And the module could
 174                  * have been unloaded.  So sue me.
 175                  *
 176                  * Returns 1 if it slept, else zero.
 177                  */
 178                 {
 179                         struct super_block *sb = inode->i_sb;
 180                         DECLARE_WAITQUEUE(wait, current);
 181                         int ret = 0;
 182
 183                         set_current_state(TASK_INTERRUPTIBLE);
 184                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 185                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 186                                 schedule();
 187                                 ret = 1;
 188                         }
 189                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 190                         return ret;
 191                 }
 192 #endif
 193         case EXT4_IOC_GETRSVSZ:
 194                 if (test_opt(inode->i_sb, RESERVATION)
 195                         && S_ISREG(inode->i_mode)
 196                         && ei->i_block_alloc_info) {
 197                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 198                         return put_user(rsv_window_size, (int __user *)arg);
 199                 }
 200                 return -ENOTTY;
 201         case EXT4_IOC_SETRSVSZ: {
 202                 int err;
 203
 204                 if (!test_opt(inode->i_sb, RESERVATION) || !S_ISREG(inode->i_mode))
 205                         return -ENOTTY;
 206
 207                 if (!is_owner_or_cap(inode))
 208                         return -EACCES;
 209
 210                 if (get_user(rsv_window_size, (int __user *)arg))
 211                         return -EFAULT;
 212
 213                 err = mnt_want_write(filp->f_path.mnt);
 214                 if (err)
 215                         return err;
 216
 217                 if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
 218                         rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
 219
 220                 /*
 221                  * need to allocate reservation structure for this inode
 222                  * before set the window size
 223                  */
 224                 down_write(&ei->i_data_sem);
 225                 if (!ei->i_block_alloc_info)
 226                         ext4_init_block_alloc_info(inode);
 227
 228                 if (ei->i_block_alloc_info){
 229                         struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 230                         rsv->rsv_goal_size = rsv_window_size;
 231                 }
 232                 up_write(&ei->i_data_sem);
 233                 mnt_drop_write(filp->f_path.mnt);
 234                 return 0;
 235         }
 236         case EXT4_IOC_GROUP_EXTEND: {
 237                 ext4_fsblk_t n_blocks_count;
 238                 struct super_block *sb = inode->i_sb;
 239                 int err;
 240
 241                 if (!capable(CAP_SYS_RESOURCE))
 242                         return -EPERM;
 243
 244                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 245                         return -EFAULT;
 246
 247                 err = mnt_want_write(filp->f_path.mnt);
 248                 if (err)
 249                         return err;
 250
 251                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 252                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 253                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 254                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 255                 mnt_drop_write(filp->f_path.mnt);
 256
 257                 return err;
 258         }
 259         case EXT4_IOC_GROUP_ADD: {
 260                 struct ext4_new_group_data input;
 261                 struct super_block *sb = inode->i_sb;
 262                 int err;
 263
 264                 if (!capable(CAP_SYS_RESOURCE))
 265                         return -EPERM;
 266
 267                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 268                                 sizeof(input)))
 269                         return -EFAULT;
 270
 271                 err = mnt_want_write(filp->f_path.mnt);
 272                 if (err)
 273                         return err;
 274
 275                 err = ext4_group_add(sb, &input);
 276                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 277                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 278                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 279                 mnt_drop_write(filp->f_path.mnt);
 280
 281                 return err;
 282         }
 283
 284         case EXT4_IOC_MIGRATE:
 285         {
 286                 int err;
 287                 if (!is_owner_or_cap(inode))
 288                         return -EACCES;
 289
 290                 err = mnt_want_write(filp->f_path.mnt);
 291                 if (err)
 292                         return err;
 293                 /*
 294                  * inode_mutex prevent write and truncate on the file.
 295                  * Read still goes through. We take i_data_sem in
 296                  * ext4_ext_swap_inode_data before we switch the
 297                  * inode format to prevent read.
 298                  */
 299                 mutex_lock(&(inode->i_mutex));
 300                 err = ext4_ext_migrate(inode);
 301                 mutex_unlock(&(inode->i_mutex));
 302                 mnt_drop_write(filp->f_path.mnt);
 303                 return err;
 304         }
 305
 306         default:
 307                 return -ENOTTY;
 308         }
 309 }
 310
 311 #ifdef CONFIG_COMPAT
 312 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 313 {
 314         /* These are just misnamed, they actually get/put from/to user an int */
 315         switch (cmd) {
 316         case EXT4_IOC32_GETFLAGS:
 317                 cmd = EXT4_IOC_GETFLAGS;
 318                 break;
 319         case EXT4_IOC32_SETFLAGS:
 320                 cmd = EXT4_IOC_SETFLAGS;
 321                 break;
 322         case EXT4_IOC32_GETVERSION:
 323                 cmd = EXT4_IOC_GETVERSION;
 324                 break;
 325         case EXT4_IOC32_SETVERSION:
 326                 cmd = EXT4_IOC_SETVERSION;
 327                 break;
 328         case EXT4_IOC32_GROUP_EXTEND:
 329                 cmd = EXT4_IOC_GROUP_EXTEND;
 330                 break;
 331         case EXT4_IOC32_GETVERSION_OLD:
 332                 cmd = EXT4_IOC_GETVERSION_OLD;
 333                 break;
 334         case EXT4_IOC32_SETVERSION_OLD:
 335                 cmd = EXT4_IOC_SETVERSION_OLD;
 336                 break;
 337 #ifdef CONFIG_JBD2_DEBUG
 338         case EXT4_IOC32_WAIT_FOR_READONLY:
 339                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 340                 break;
 341 #endif
 342         case EXT4_IOC32_GETRSVSZ:
 343                 cmd = EXT4_IOC_GETRSVSZ;
 344                 break;
 345         case EXT4_IOC32_SETRSVSZ:
 346                 cmd = EXT4_IOC_SETRSVSZ;
 347                 break;
 348         case EXT4_IOC_GROUP_ADD:
 349                 break;
 350         default:
 351                 return -ENOIOCTLCMD;
 352         }
 353         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 354 }
 355 #endif