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
  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, migrate = 0;
  37                 struct ext4_iloc iloc;
  38                 unsigned int oldflags;
  39                 unsigned int jflag;
  40
  41                 if (!is_owner_or_cap(inode))
  42                         return -EACCES;
  43
  44                 if (get_user(flags, (int __user *) arg))
  45                         return -EFAULT;
  46
  47                 err = mnt_want_write(filp->f_path.mnt);
  48                 if (err)
  49                         return err;
  50
  51                 if (!S_ISDIR(inode->i_mode))
  52                         flags &= ~EXT4_DIRSYNC_FL;
  53
  54                 err = -EPERM;
  55                 mutex_lock(&inode->i_mutex);
  56                 /* Is it quota file? Do not allow user to mess with it */
  57                 if (IS_NOQUOTA(inode))
  58                         goto flags_out;
  59
  60                 oldflags = ei->i_flags;
  61
  62                 /* The JOURNAL_DATA flag is modifiable only by root */
  63                 jflag = flags & EXT4_JOURNAL_DATA_FL;
  64
  65                 /*
  66                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  67                  * the relevant capability.
  68                  *
  69                  * This test looks nicer. Thanks to Pauline Middelink
  70                  */
  71                 if ((flags ^ oldflags) & (EXT4_APPEND_FL | EXT4_IMMUTABLE_FL)) {
  72                         if (!capable(CAP_LINUX_IMMUTABLE))
  73                                 goto flags_out;
  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                                 goto flags_out;
  83                 }
  84                 if (oldflags & EXT4_EXTENTS_FL) {
  85                         /* We don't support clearning extent flags */
  86                         if (!(flags & EXT4_EXTENTS_FL)) {
  87                                 err = -EOPNOTSUPP;
  88                                 goto flags_out;
  89                         }
  90                 } else if (flags & EXT4_EXTENTS_FL) {
  91                         /* migrate the file */
  92                         migrate = 1;
  93                         flags &= ~EXT4_EXTENTS_FL;
  94                 }
  95
  96                 handle = ext4_journal_start(inode, 1);
  97                 if (IS_ERR(handle)) {
  98                         err = PTR_ERR(handle);
  99                         goto flags_out;
 100                 }
 101                 if (IS_SYNC(inode))
 102                         ext4_handle_sync(handle);
 103                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 104                 if (err)
 105                         goto flags_err;
 106
 107                 flags = flags & EXT4_FL_USER_MODIFIABLE;
 108                 flags |= oldflags & ~EXT4_FL_USER_MODIFIABLE;
 109                 ei->i_flags = flags;
 110
 111                 ext4_set_inode_flags(inode);
 112                 inode->i_ctime = ext4_current_time(inode);
 113
 114                 err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 115 flags_err:
 116                 ext4_journal_stop(handle);
 117                 if (err)
 118                         goto flags_out;
 119
 120                 if ((jflag ^ oldflags) & (EXT4_JOURNAL_DATA_FL))
 121                         err = ext4_change_inode_journal_flag(inode, jflag);
 122                 if (err)
 123                         goto flags_out;
 124                 if (migrate)
 125                         err = ext4_ext_migrate(inode);
 126 flags_out:
 127                 mutex_unlock(&inode->i_mutex);
 128                 mnt_drop_write(filp->f_path.mnt);
 129                 return err;
 130         }
 131         case EXT4_IOC_GETVERSION:
 132         case EXT4_IOC_GETVERSION_OLD:
 133                 return put_user(inode->i_generation, (int __user *) arg);
 134         case EXT4_IOC_SETVERSION:
 135         case EXT4_IOC_SETVERSION_OLD: {
 136                 handle_t *handle;
 137                 struct ext4_iloc iloc;
 138                 __u32 generation;
 139                 int err;
 140
 141                 if (!is_owner_or_cap(inode))
 142                         return -EPERM;
 143
 144                 err = mnt_want_write(filp->f_path.mnt);
 145                 if (err)
 146                         return err;
 147                 if (get_user(generation, (int __user *) arg)) {
 148                         err = -EFAULT;
 149                         goto setversion_out;
 150                 }
 151
 152                 handle = ext4_journal_start(inode, 1);
 153                 if (IS_ERR(handle)) {
 154                         err = PTR_ERR(handle);
 155                         goto setversion_out;
 156                 }
 157                 err = ext4_reserve_inode_write(handle, inode, &iloc);
 158                 if (err == 0) {
 159                         inode->i_ctime = ext4_current_time(inode);
 160                         inode->i_generation = generation;
 161                         err = ext4_mark_iloc_dirty(handle, inode, &iloc);
 162                 }
 163                 ext4_journal_stop(handle);
 164 setversion_out:
 165                 mnt_drop_write(filp->f_path.mnt);
 166                 return err;
 167         }
 168 #ifdef CONFIG_JBD2_DEBUG
 169         case EXT4_IOC_WAIT_FOR_READONLY:
 170                 /*
 171                  * This is racy - by the time we're woken up and running,
 172                  * the superblock could be released.  And the module could
 173                  * have been unloaded.  So sue me.
 174                  *
 175                  * Returns 1 if it slept, else zero.
 176                  */
 177                 {
 178                         struct super_block *sb = inode->i_sb;
 179                         DECLARE_WAITQUEUE(wait, current);
 180                         int ret = 0;
 181
 182                         set_current_state(TASK_INTERRUPTIBLE);
 183                         add_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 184                         if (timer_pending(&EXT4_SB(sb)->turn_ro_timer)) {
 185                                 schedule();
 186                                 ret = 1;
 187                         }
 188                         remove_wait_queue(&EXT4_SB(sb)->ro_wait_queue, &wait);
 189                         return ret;
 190                 }
 191 #endif
 192         case EXT4_IOC_GROUP_EXTEND: {
 193                 ext4_fsblk_t n_blocks_count;
 194                 struct super_block *sb = inode->i_sb;
 195                 int err, err2;
 196
 197                 if (!capable(CAP_SYS_RESOURCE))
 198                         return -EPERM;
 199
 200                 if (get_user(n_blocks_count, (__u32 __user *)arg))
 201                         return -EFAULT;
 202
 203                 err = mnt_want_write(filp->f_path.mnt);
 204                 if (err)
 205                         return err;
 206
 207                 err = ext4_group_extend(sb, EXT4_SB(sb)->s_es, n_blocks_count);
 208                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 209                 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 210                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 211                 if (err == 0)
 212                         err = err2;
 213                 mnt_drop_write(filp->f_path.mnt);
 214
 215                 return err;
 216         }
 217         case EXT4_IOC_GROUP_ADD: {
 218                 struct ext4_new_group_data input;
 219                 struct super_block *sb = inode->i_sb;
 220                 int err, err2;
 221
 222                 if (!capable(CAP_SYS_RESOURCE))
 223                         return -EPERM;
 224
 225                 if (copy_from_user(&input, (struct ext4_new_group_input __user *)arg,
 226                                 sizeof(input)))
 227                         return -EFAULT;
 228
 229                 err = mnt_want_write(filp->f_path.mnt);
 230                 if (err)
 231                         return err;
 232
 233                 err = ext4_group_add(sb, &input);
 234                 jbd2_journal_lock_updates(EXT4_SB(sb)->s_journal);
 235                 err2 = jbd2_journal_flush(EXT4_SB(sb)->s_journal);
 236                 jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
 237                 if (err == 0)
 238                         err = err2;
 239                 mnt_drop_write(filp->f_path.mnt);
 240
 241                 return err;
 242         }
 243
 244         case EXT4_IOC_MIGRATE:
 245         {
 246                 int err;
 247                 if (!is_owner_or_cap(inode))
 248                         return -EACCES;
 249
 250                 err = mnt_want_write(filp->f_path.mnt);
 251                 if (err)
 252                         return err;
 253                 /*
 254                  * inode_mutex prevent write and truncate on the file.
 255                  * Read still goes through. We take i_data_sem in
 256                  * ext4_ext_swap_inode_data before we switch the
 257                  * inode format to prevent read.
 258                  */
 259                 mutex_lock(&(inode->i_mutex));
 260                 err = ext4_ext_migrate(inode);
 261                 mutex_unlock(&(inode->i_mutex));
 262                 mnt_drop_write(filp->f_path.mnt);
 263                 return err;
 264         }
 265
 266         default:
 267                 return -ENOTTY;
 268         }
 269 }
 270
 271 #ifdef CONFIG_COMPAT
 272 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 273 {
 274         /* These are just misnamed, they actually get/put from/to user an int */
 275         switch (cmd) {
 276         case EXT4_IOC32_GETFLAGS:
 277                 cmd = EXT4_IOC_GETFLAGS;
 278                 break;
 279         case EXT4_IOC32_SETFLAGS:
 280                 cmd = EXT4_IOC_SETFLAGS;
 281                 break;
 282         case EXT4_IOC32_GETVERSION:
 283                 cmd = EXT4_IOC_GETVERSION;
 284                 break;
 285         case EXT4_IOC32_SETVERSION:
 286                 cmd = EXT4_IOC_SETVERSION;
 287                 break;
 288         case EXT4_IOC32_GROUP_EXTEND:
 289                 cmd = EXT4_IOC_GROUP_EXTEND;
 290                 break;
 291         case EXT4_IOC32_GETVERSION_OLD:
 292                 cmd = EXT4_IOC_GETVERSION_OLD;
 293                 break;
 294         case EXT4_IOC32_SETVERSION_OLD:
 295                 cmd = EXT4_IOC_SETVERSION_OLD;
 296                 break;
 297 #ifdef CONFIG_JBD2_DEBUG
 298         case EXT4_IOC32_WAIT_FOR_READONLY:
 299                 cmd = EXT4_IOC_WAIT_FOR_READONLY;
 300                 break;
 301 #endif
 302         case EXT4_IOC32_GETRSVSZ:
 303                 cmd = EXT4_IOC_GETRSVSZ;
 304                 break;
 305         case EXT4_IOC32_SETRSVSZ:
 306                 cmd = EXT4_IOC_SETRSVSZ;
 307                 break;
 308         case EXT4_IOC_GROUP_ADD:
 309                 break;
 310         default:
 311                 return -ENOIOCTLCMD;
 312         }
 313         return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 314 }
 315 #endif