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 <asm/uaccess.h>
  19
  20 int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  21                 unsigned long arg)
  22 {
  23         struct ext4_inode_info *ei = EXT4_I(inode);
  24         unsigned int flags;
  25         unsigned short rsv_window_size;
  26
  27         ext4_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  28
  29         switch (cmd) {
  30         case EXT4_IOC_GETFLAGS:
  31                 flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
  32                 return put_user(flags, (int __user *) arg);
  33         case EXT4_IOC_SETFLAGS: {
  34                 handle_t *handle = NULL;
  35                 int err;
  36                 struct ext4_iloc iloc;
  37                 unsigned int oldflags;
  38                 unsigned int jflag;
  39
  40                 if (IS_RDONLY(inode))
  41                         return -EROFS;
  42
  43                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  44                         return -EACCES;
  45
  46                 if (get_user(flags, (int __user *) arg))
  47                         return -EFAULT;
  48
  49                 if (!S_ISDIR(inode->i_mode))
  50                         flags &= ~EXT4_DIRSYNC_FL;
  51
  52                 mutex_lock(&inode->i_mutex);
  53                 oldflags = ei->i_flags;
  54
  55                 /* The JOURNAL_DATA flag is modifiable only by root */
  56                 jflag = flags & EXT4_JOURNAL_DATA_FL;
  57
  58                 /*
  59                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  60                  * the relevant capability.
  61                  *
  62                  * This test looks nicer. Thanks to Pauline Middelink
  63                  */
  64                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
  65                         if (!capable(CAP_LINUX_IMMUTABLE)) {
  66                                 mutex_unlock(&inode->i_mutex);
  67                                 return -EPERM;
  68                         }
  69                 }
  70
  71                 /*
  72                  * The JOURNAL_DATA flag can only be changed by
  73                  * the relevant capability.
  74                  */
  75                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  76                         if (!capable(CAP_SYS_RESOURCE)) {
  77                                 mutex_unlock(&inode->i_mutex);
  78                                 return -EPERM;
  79                         }
  80                 }
  81
  82
  83                 handle = ext4_journal_start(inode, 1);
  84                 if (IS_ERR(handle)) {
  85                         mutex_unlock(&inode->i_mutex);
  86                         return PTR_ERR(handle);
  87                 }
  88                 if (IS_SYNC(inode))
  89                         handle->h_sync = 1;
  90                 err = ext4_reserve_inode_write(handle, inode, &iloc);
  91                 if (err)
  92                         goto flags_err;
  93
  94                 flags = flags & EXT4_FL_USER_MODIFIABLE;
  95                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
  96                 ei->i_flags = flags;
  97
  98                 ext4_set_inode_flags(inode);
  99                 inode->i_ctime = CURRENT_TIME_SEC;
 100
 101                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 102 flags_err:
 103                 ext4_journal_stop(handle);
 104                 if (err) {
 105                         mutex_unlock(&inode->i_mutex);
 106                         return err;
 107                 }
 108
 109                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 110                         err = ext4_change_inode_journal_flag(inode, jflag);
 111                 mutex_unlock(&inode->i_mutex);
 112                 return err;
 113         }
 114         case EXT4_IOC_GETVERSION:
 115         case EXT4_IOC_GETVERSION_OLD:
 116                 return put_user(inode->i_generation, (int __user *) arg);
 117         case EXT4_IOC_SETVERSION:
 118         case EXT4_IOC_SETVERSION_OLD: {
 119                 handle_t *handle;
 120                 struct ext4_iloc iloc;
 121                 __u32 generation;
 122                 int err;
 123
 124                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 125                         return -EPERM;
 126                 if (IS_RDONLY(inode))
 127                         return -EROFS;
 128                 if (get_user(generation, (int __user *) arg))
 129                         return -EFAULT;
 130
 131                 handle = ext4_journal_start(inode, 1);
 132                 if (IS_ERR(handle))
 133                         return PTR_ERR(handle);
 134                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 135                 if (err == 0) {
 136                         inode->i_ctime = CURRENT_TIME_SEC;
 137                         inode->i_generation = generation;
 138                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 139                 }
 140                 ext4_journal_stop(handle);
 141                 return err;
 142         }
 143 #ifdef CONFIG_JBD_DEBUG
 144         case EXT4_IOC_WAIT_FOR_READONLY:
 145                 /*
 146                  * This is racy - by the time we're woken up and running,
 147                  * the superblock could be released.  And the module could
 148                  * have been unloaded.  So sue me.
 149                  *
 150                  * Returns 1 if it slept, else zero.
 151                  */
 152                 {
 153                         struct super_block *sb = inode->i_sb;
 154                         DECLARE_WAITQUEUE(wait, current);
 155                         int ret = 0;
 156
 157                         set_current_state(TASK_INTERRUPTIBLE);
 158                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 159                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 160                                 schedule();
 161                                 ret = 1;
 162                         }
 163                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 164                         return ret;
 165                 }
 166 #endif
 167         case EXT4_IOC_GETRSVSZ:
 168                 if (test_opt(inode->i_sb, RESERVATION)
 169                         && S_ISREG(inode->i_mode)
 170                         && ei->i_block_alloc_info) {
 171                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 172                         return put_user(rsv_window_size, (int __user *)arg);
 173                 }
 174                 return -ENOTTY;
 175         case EXT4_IOC_SETRSVSZ: {
 176
 177                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 178                         return -ENOTTY;
 179
 180                 if (IS_RDONLY(inode))
 181                         return -EROFS;
 182
 183                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 184                         return -EACCES;
 185
 186                 if (get_user(rsv_window_size, (int __user *)arg))
 187                         return -EFAULT;
 188
 189                 if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
 190                         rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
 191
 192                 /*
 193                  * need to allocate reservation structure for this inode
 194                  * before set the window size
 195                  */
 196                 mutex_lock(&ei->truncate_mutex);
 197                 if (!ei->i_block_alloc_info)
 198                         ext4_init_block_alloc_info(inode);
 199
 200                 if (ei->i_block_alloc_info){
 201                         struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 202                         rsv->rsv_goal_size = rsv_window_size;
 203                 }
 204                 mutex_unlock(&ei->truncate_mutex);
 205                 return 0;
 206         }
 207         case EXT4_IOC_GROUP_EXTEND: {
 208                 ext4_fsblk_t n_blocks_count;
 209                 struct super_block *sb = inode->i_sb;
 210                 int err;
 211
 212                 if (!capable(CAP_SYS_RESOURCE))
 213                         return -EPERM;
 214
 215                 if (IS_RDONLY(inode))
 216                         return -EROFS;
 217
 218                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 219                         return -EFAULT;
 220
 221                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 222                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 223                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 224                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 225
 226                 return err;
 227         }
 228         case EXT4_IOC_GROUP_ADD: {
 229                 struct ext4_new_group_data input;
 230                 struct super_block *sb = inode->i_sb;
 231                 int err;
 232
 233                 if (!capable(CAP_SYS_RESOURCE))
 234                         return -EPERM;
 235
 236                 if (IS_RDONLY(inode))
 237                         return -EROFS;
 238
 239                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 240                                 sizeof(input)))
 241                         return -EFAULT;
 242
 243                 err = ext4_group_add(sb, &input);
 244                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 245                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 246                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 247
 248                 return err;
 249         }
 250
 251         default:
 252                 return -ENOTTY;
 253         }
 254 }
 255
 256 #ifdef CONFIG_COMPAT
 257 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 258 {
 259         struct inode *inode = file->f_path.dentry->d_inode;
 260         int ret;
 261
 262         /* These are just misnamed, they actually get/put from/to user an int */
 263         switch (cmd) {
 264         case EXT4_IOC32_GETFLAGS:
 265                 cmd = EXT4_IOC_GETFLAGS;
 266                 break;
 267         case EXT4_IOC32_SETFLAGS:
 268                 cmd = EXT4_IOC_SETFLAGS;
 269                 break;
 270         case EXT4_IOC32_GETVERSION:
 271                 cmd = EXT4_IOC_GETVERSION;
 272                 break;
 273         case EXT4_IOC32_SETVERSION:
 274                 cmd = EXT4_IOC_SETVERSION;
 275                 break;
 276         case EXT4_IOC32_GROUP_EXTEND:
 277                 cmd = EXT4_IOC_GROUP_EXTEND;
 278                 break;
 279         case EXT4_IOC32_GETVERSION_OLD:
 280                 cmd = EXT4_IOC_GETVERSION_OLD;
 281                 break;
 282         case EXT4_IOC32_SETVERSION_OLD:
 283                 cmd = EXT4_IOC_SETVERSION_OLD;
 284                 break;
 285 #ifdef CONFIG_JBD_DEBUG
 286         case EXT4_IOC32_WAIT_FOR_READONLY:
 287                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 288                 break;
 289 #endif
 290         case EXT4_IOC32_GETRSVSZ:
 291                 cmd = EXT4_IOC_GETRSVSZ;
 292                 break;
 293         case EXT4_IOC32_SETRSVSZ:
 294                 cmd = EXT4_IOC_SETRSVSZ;
 295                 break;
 296         case EXT4_IOC_GROUP_ADD:
 297                 break;
 298         default:
 299                 return -ENOIOCTLCMD;
 300         }
 301         lock_kernel();
 302         ret = ext4_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 303         unlock_kernel();
 304         return ret;
 305 }
 306 #endif