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