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/mount.h>
  12 #include <linux/jbd2.h>
  13 #include <linux/capability.h>
  14 #include <linux/ext4_fs.h>
  15 #include <linux/ext4_jbd2.h>
  16 #include <linux/time.h>
  17 #include <linux/compat.h>
  18 #include <linux/smp_lock.h>
  19 #include <linux/vs_tag.h>
  20 #include <asm/uaccess.h>
  21
  22 int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  23                 unsigned long arg)
  24 {
  25         struct ext4_inode_info *ei = EXT4_I(inode);
  26         unsigned int flags;
  27         unsigned short rsv_window_size;
  28
  29         ext4_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  30
  31         switch (cmd) {
  32         case EXT4_IOC_GETFLAGS:
  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_RDONLY(inode) ||
  43                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
  44                         return -EROFS;
  45
  46                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  47                         return -EACCES;
  48
  49                 if (get_user(flags, (int __user *) arg))
  50                         return -EFAULT;
  51
  52                 if (!S_ISDIR(inode->i_mode))
  53                         flags &= ~EXT4_DIRSYNC_FL;
  54
  55                 mutex_lock(&inode->i_mutex);
  56                 oldflags = ei->i_flags;
  57
  58                 /* The JOURNAL_DATA flag is modifiable only by root */
  59                 jflag = flags & EXT4_JOURNAL_DATA_FL;
  60
  61                 /*
  62                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  63                  * the relevant capability.
  64                  *
  65                  * This test looks nicer. Thanks to Pauline Middelink
  66                  */
  67                 if ((oldflags & EXT4_IMMUTABLE_FL) ||
  68                         ((flags ^ oldflags) & (EXT4_APPEND_FL |
  69                         EXT4_IMMUTABLE_FL | EXT4_IUNLINK_FL))) {
  70                         if (!capable(CAP_LINUX_IMMUTABLE)) {
  71                                 mutex_unlock(&inode->i_mutex);
  72                                 return -EPERM;
  73                         }
  74                 }
  75
  76                 /*
  77                  * The JOURNAL_DATA flag can only be changed by
  78                  * the relevant capability.
  79                  */
  80                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL)) {
  81                         if (!capable(CAP_SYS_RESOURCE)) {
  82                                 mutex_unlock(&inode->i_mutex);
  83                                 return -EPERM;
  84                         }
  85                 }
  86
  87
  88                 handle = ext4_journal_start(inode, 1);
  89                 if (IS_ERR(handle)) {
  90                         mutex_unlock(&inode->i_mutex);
  91                         return PTR_ERR(handle);
  92                 }
  93                 if (IS_SYNC(inode))
  94                         handle->h_sync = 1;
  95                 err = ext4_reserve_inode_write(handle, inode, &iloc);
  96                 if (err)
  97                         goto flags_err;
  98
  99                 flags = flags & EXT4_FL_USER_MODIFIABLE;
 100                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 101                 ei->i_flags = flags;
 102
 103                 ext4_set_inode_flags(inode);
 104                 inode->i_ctime = CURRENT_TIME_SEC;
 105
 106                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 107 flags_err:
 108                 ext4_journal_stop(handle);
 109                 if (err) {
 110                         mutex_unlock(&inode->i_mutex);
 111                         return err;
 112                 }
 113
 114                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 115                         err = ext4_change_inode_journal_flag(inode, jflag);
 116                 mutex_unlock(&inode->i_mutex);
 117                 return err;
 118         }
 119         case EXT4_IOC_GETVERSION:
 120         case EXT4_IOC_GETVERSION_OLD:
 121                 return put_user(inode->i_generation, (int __user *) arg);
 122         case EXT4_IOC_SETVERSION:
 123         case EXT4_IOC_SETVERSION_OLD: {
 124                 handle_t *handle;
 125                 struct ext4_iloc iloc;
 126                 __u32 generation;
 127                 int err;
 128
 129                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 130                         return -EPERM;
 131                 if (IS_RDONLY(inode) ||
 132                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 133                         return -EROFS;
 134                 if (get_user(generation, (int __user *) arg))
 135                         return -EFAULT;
 136
 137                 handle = ext4_journal_start(inode, 1);
 138                 if (IS_ERR(handle))
 139                         return PTR_ERR(handle);
 140                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 141                 if (err == 0) {
 142                         inode->i_ctime = CURRENT_TIME_SEC;
 143                         inode->i_generation = generation;
 144                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 145                 }
 146                 ext4_journal_stop(handle);
 147                 return err;
 148         }
 149 #ifdef CONFIG_JBD_DEBUG
 150         case EXT4_IOC_WAIT_FOR_READONLY:
 151                 /*
 152                  * This is racy - by the time we're woken up and running,
 153                  * the superblock could be released.  And the module could
 154                  * have been unloaded.  So sue me.
 155                  *
 156                  * Returns 1 if it slept, else zero.
 157                  */
 158                 {
 159                         struct super_block *sb = inode->i_sb;
 160                         DECLARE_WAITQUEUE(wait, current);
 161                         int ret = 0;
 162
 163                         set_current_state(TASK_INTERRUPTIBLE);
 164                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 165                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 166                                 schedule();
 167                                 ret = 1;
 168                         }
 169                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 170                         return ret;
 171                 }
 172 #endif
 173         case EXT4_IOC_GETRSVSZ:
 174                 if (test_opt(inode->i_sb, RESERVATION)
 175                         && S_ISREG(inode->i_mode)
 176                         && ei->i_block_alloc_info) {
 177                         rsv_window_size = ei->i_block_alloc_info->rsv_window_node.rsv_goal_size;
 178                         return put_user(rsv_window_size, (int __user *)arg);
 179                 }
 180                 return -ENOTTY;
 181         case EXT4_IOC_SETRSVSZ: {
 182
 183                 if (!test_opt(inode->i_sb, RESERVATION) ||!S_ISREG(inode->i_mode))
 184                         return -ENOTTY;
 185
 186                 if (IS_RDONLY(inode) ||
 187                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 188                         return -EROFS;
 189
 190                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
 191                         return -EACCES;
 192
 193                 if (get_user(rsv_window_size, (int __user *)arg))
 194                         return -EFAULT;
 195
 196                 if (rsv_window_size > EXT4_MAX_RESERVE_BLOCKS)
 197                         rsv_window_size = EXT4_MAX_RESERVE_BLOCKS;
 198
 199                 /*
 200                  * need to allocate reservation structure for this inode
 201                  * before set the window size
 202                  */
 203                 mutex_lock(&ei->truncate_mutex);
 204                 if (!ei->i_block_alloc_info)
 205                         ext4_init_block_alloc_info(inode);
 206
 207                 if (ei->i_block_alloc_info){
 208                         struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
 209                         rsv->rsv_goal_size = rsv_window_size;
 210                 }
 211                 mutex_unlock(&ei->truncate_mutex);
 212                 return 0;
 213         }
 214         case EXT4_IOC_GROUP_EXTEND: {
 215                 ext4_fsblk_t n_blocks_count;
 216                 struct super_block *sb = inode->i_sb;
 217                 int err;
 218
 219                 if (!capable(CAP_SYS_RESOURCE))
 220                         return -EPERM;
 221
 222                 if (IS_RDONLY(inode) ||
 223                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 224                         return -EROFS;
 225
 226                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 227                         return -EFAULT;
 228
 229                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 230                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 231                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 232                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 233
 234                 return err;
 235         }
 236         case EXT4_IOC_GROUP_ADD: {
 237                 struct ext4_new_group_data input;
 238                 struct super_block *sb = inode->i_sb;
 239                 int err;
 240
 241                 if (!capable(CAP_SYS_RESOURCE))
 242                         return -EPERM;
 243
 244                 if (IS_RDONLY(inode) ||
 245                         (filp && MNT_IS_RDONLY(filp->f_vfsmnt)))
 246                         return -EROFS;
 247
 248                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 249                                 sizeof(input)))
 250                         return -EFAULT;
 251
 252                 err = ext4_group_add(sb, &input);
 253                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 254                 jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 255                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 256
 257                 return err;
 258         }
 259
 260 #if defined(CONFIG_VSERVER_LEGACY) && !defined(CONFIG_TAGGING_NONE)
 261         case EXT4_IOC_SETTAG: {
 262                 handle_t *handle;
 263                 struct ext4_iloc iloc;
 264                 int tag;
 265                 int err;
 266
 267                 /* fixme: if stealth, return -ENOTTY */
 268                 if (!capable(CAP_CONTEXT))
 269                         return -EPERM;
 270                 if (IS_RDONLY(inode))
 271                         return -EROFS;
 272                 if (!(inode->i_sb->s_flags & MS_TAGGED))
 273                         return -ENOSYS;
 274                 if (get_user(tag, (int __user *) arg))
 275                         return -EFAULT;
 276
 277                 handle = ext4_journal_start(inode, 1);
 278                 if (IS_ERR(handle))
 279                         return PTR_ERR(handle);
 280                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 281                 if (err)
 282                         return err;
 283
 284                 inode->i_tag = (tag & 0xFFFF);
 285                 inode->i_ctime = CURRENT_TIME;
 286
 287                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 288                 ext4_journal_stop(handle);
 289                 return err;
 290         }
 291 #endif
 292
 293         default:
 294                 return -ENOTTY;
 295         }
 296 }
 297
 298 #ifdef CONFIG_COMPAT
 299 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 300 {
 301         struct inode *inode = file->f_path.dentry->d_inode;
 302         int ret;
 303
 304         /* These are just misnamed, they actually get/put from/to user an int */
 305         switch (cmd) {
 306         case EXT4_IOC32_GETFLAGS:
 307                 cmd = EXT4_IOC_GETFLAGS;
 308                 break;
 309         case EXT4_IOC32_SETFLAGS:
 310                 cmd = EXT4_IOC_SETFLAGS;
 311                 break;
 312         case EXT4_IOC32_GETVERSION:
 313                 cmd = EXT4_IOC_GETVERSION;
 314                 break;
 315         case EXT4_IOC32_SETVERSION:
 316                 cmd = EXT4_IOC_SETVERSION;
 317                 break;
 318         case EXT4_IOC32_GROUP_EXTEND:
 319                 cmd = EXT4_IOC_GROUP_EXTEND;
 320                 break;
 321         case EXT4_IOC32_GETVERSION_OLD:
 322                 cmd = EXT4_IOC_GETVERSION_OLD;
 323                 break;
 324         case EXT4_IOC32_SETVERSION_OLD:
 325                 cmd = EXT4_IOC_SETVERSION_OLD;
 326                 break;
 327 #ifdef CONFIG_JBD_DEBUG
 328         case EXT4_IOC32_WAIT_FOR_READONLY:
 329                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 330                 break;
 331 #endif
 332         case EXT4_IOC32_GETRSVSZ:
 333                 cmd = EXT4_IOC_GETRSVSZ;
 334                 break;
 335         case EXT4_IOC32_SETRSVSZ:
 336                 cmd = EXT4_IOC_SETRSVSZ;
 337                 break;
 338         case EXT4_IOC_GROUP_ADD:
 339                 break;
 340         default:
 341                 return -ENOIOCTLCMD;
 342         }
 343         lock_kernel();
 344         ret = ext4_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
 345         unlock_kernel();
 346         return ret;
 347 }
 348 #endif