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/ext4_fs.h>
  14 #include <linux/ext4_jbd2.h>
  15 #include <linux/time.h>
  16 #include <linux/compat.h>
  17 #include <linux/smp_lock.h>
  18 #include <linux/mount.h>
  19 #include <asm/uaccess.h>
  20
  21 int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  22                 unsigned long arg)
  23 {
  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;
  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
  86                 handle = ext4_journal_start(inode, 1);
  87                 if (IS_ERR(handle)) {
  88                         err = PTR_ERR(handle);
  89                         goto flags_out;
  90                 }
  91                 if (IS_SYNC(inode))
  92                         handle->h_sync = 1;
  93                 err = ext4_reserve_inode_write(handle, inode, &iloc);
  94                 if (err)
  95                         goto flags_err;
  96
  97                 flags = flags & EXT4_FL_USER_MODIFIABLE;
  98                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
  99                 ei->i_flags = flags;
 100
 101                 ext4_set_inode_flags(inode);
 102                 inode->i_ctime = ext4_current_time(inode);
 103
 104                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 105 flags_err:
 106                 ext4_journal_stop(handle);
 107                 if (err)
 108                         goto flags_out;
 109
 110                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 111                         err = ext4_change_inode_journal_flag(inode, jflag);
 112 flags_out:
 113                 mutex_unlock(&inode->i_mutex);
 114                 mnt_drop_write(filp->f_path.mnt);
 115                 return err;
 116         }
 117         case EXT4_IOC_GETVERSION:
 118         case EXT4_IOC_GETVERSION_OLD:
 119                 return put_user(inode->i_generation, (int __user *) arg);
 120         case EXT4_IOC_SETVERSION:
 121         case EXT4_IOC_SETVERSION_OLD: {
 122                 handle_t *handle;
 123                 struct ext4_iloc iloc;
 124                 __u32 generation;
 125                 int err;
 126
 127                 if (!is_owner_or_cap(inode))
 128                         return -EPERM;
 129
 130                 err = mnt_want_write(filp->f_path.mnt);
 131                 if (err)
 132                         return err;
 133                 if (get_user(generation, (int __user *) arg)) {
 134                         err = -EFAULT;
 135                         goto setversion_out;
 136                 }
 137
 138                 handle = ext4_journal_start(inode, 1);
 139                 if (IS_ERR(handle)) {
 140                         err = PTR_ERR(handle);
 141                         goto setversion_out;
 142                 }
 143                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 144                 if (err == 0) {
 145                         inode->i_ctime = ext4_current_time(inode);
 146                         inode->i_generation = generation;
 147                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 148                 }
 149                 ext4_journal_stop(handle);
 150 setversion_out:
 151                 mnt_drop_write(filp->f_path.mnt);
 152                 return err;
 153         }
 154 #ifdef CONFIG_JBD2_DEBUG
 155         case EXT4_IOC_WAIT_FOR_READONLY:
 156                 /*
 157                  * This is racy - by the time we're woken up and running,
 158                  * the superblock could be released.  And the module could
 159                  * have been unloaded.  So sue me.
 160                  *
 161                  * Returns 1 if it slept, else zero.
 162                  */
 163                 {
 164                         struct super_block *sb = inode->i_sb;
 165                         DECLARE_WAITQUEUE(wait, current);
 166                         int ret = 0;
 167
 168                         set_current_state(TASK_INTERRUPTIBLE);
 169                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 170                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 171                                 schedule();
 172                                 ret = 1;
 173                         }
 174                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 175                         return ret;
 176                 }
 177 #endif
 178         case EXT4_IOC_GETRSVSZ:
 179                 if (test_opt(inode->i_sb, RESERVATION)
 180                         && S_ISREG(inode->i_mode)
 181                         && ei->i_block_alloc_info) {
 182                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 183                         return put_user(rsv_window_size, (int __user *)arg);
 184                 }
 185                 return -ENOTTY;
 186         case EXT4_IOC_SETRSVSZ: {
 187                 int err;
 188
 189                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 190                         return -ENOTTY;
 191
 192                 if (!is_owner_or_cap(inode))
 193                         return -EACCES;
 194
 195                 if (get_user(rsv_window_size, (int __user *)arg))
 196                         return -EFAULT;
 197
 198                 err = mnt_want_write(filp->f_path.mnt);
 199                 if (err)
 200                         return err;
 201
 202                 if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
 203                         rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
 204
 205                 /*
 206                  * need to allocate reservation structure for this inode
 207                  * before set the window size
 208                  */
 209                 down_write(&ei->i_data_sem);
 210                 if (!ei->i_block_alloc_info)
 211                         ext4_init_block_alloc_info(inode);
 212
 213                 if (ei->i_block_alloc_info){
 214                         struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 215                         rsv->rsv_goal_size = rsv_window_size;
 216                 }
 217                 up_write(&ei->i_data_sem);
 218                 mnt_drop_write(filp->f_path.mnt);
 219                 return 0;
 220         }
 221         case EXT4_IOC_GROUP_EXTEND: {
 222                 ext4_fsblk_t n_blocks_count;
 223                 struct super_block *sb = inode->i_sb;
 224                 int err;
 225
 226                 if (!capable(CAP_SYS_RESOURCE))
 227                         return -EPERM;
 228
 229                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 230                         return -EFAULT;
 231
 232                 err = mnt_want_write(filp->f_path.mnt);
 233                 if (err)
 234                         return err;
 235
 236                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 237                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 238                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 239                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 240                 mnt_drop_write(filp->f_path.mnt);
 241
 242                 return err;
 243         }
 244         case EXT4_IOC_GROUP_ADD: {
 245                 struct ext4_new_group_data input;
 246                 struct super_block *sb = inode->i_sb;
 247                 int err;
 248
 249                 if (!capable(CAP_SYS_RESOURCE))
 250                         return -EPERM;
 251
 252                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 253                                 sizeof(input)))
 254                         return -EFAULT;
 255
 256                 err = mnt_want_write(filp->f_path.mnt);
 257                 if (err)
 258                         return err;
 259
 260                 err = ext4_group_add(sb, &input);
 261                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 262                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 263                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 264                 mnt_drop_write(filp->f_path.mnt);
 265
 266                 return err;
 267         }
 268
 269         case EXT4_IOC_MIGRATE:
 270                 return ext4_ext_migrate(inode, filp, cmd, arg);
 271
 272         default:
 273                 return -ENOTTY;
 274         }
 275 }
 276
 277 #ifdef CONFIG_COMPAT
 278 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 279 {
 280         struct inode *inode = file->f_path.dentry->d_inode;
 281         int ret;
 282
 283         /* These are just misnamed, they actually get/put from/to user an int */
 284         switch (cmd) {
 285         case EXT4_IOC32_GETFLAGS:
 286                 cmd = EXT4_IOC_GETFLAGS;
 287                 break;
 288         case EXT4_IOC32_SETFLAGS:
 289                 cmd = EXT4_IOC_SETFLAGS;
 290                 break;
 291         case EXT4_IOC32_GETVERSION:
 292                 cmd = EXT4_IOC_GETVERSION;
 293                 break;
 294         case EXT4_IOC32_SETVERSION:
 295                 cmd = EXT4_IOC_SETVERSION;
 296                 break;
 297         case EXT4_IOC32_GROUP_EXTEND:
 298                 cmd = EXT4_IOC_GROUP_EXTEND;
 299                 break;
 300         case EXT4_IOC32_GETVERSION_OLD:
 301                 cmd = EXT4_IOC_GETVERSION_OLD;
 302                 break;
 303         case EXT4_IOC32_SETVERSION_OLD:
 304                 cmd = EXT4_IOC_SETVERSION_OLD;
 305                 break;
 306 #ifdef CONFIG_JBD2_DEBUG
 307         case EXT4_IOC32_WAIT_FOR_READONLY:
 308                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 309                 break;
 310 #endif
 311         case EXT4_IOC32_GETRSVSZ:
 312                 cmd = EXT4_IOC_GETRSVSZ;
 313                 break;
 314         case EXT4_IOC32_SETRSVSZ:
 315                 cmd = EXT4_IOC_SETRSVSZ;
 316                 break;
 317         case EXT4_IOC_GROUP_ADD:
 318                 break;
 319         default:
 320                 return -ENOIOCTLCMD;
 321         }
 322         lock_kernel();
 323         ret = ext4_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 324         unlock_kernel();
 325         return ret;
 326 }
 327 #endif