fs/bad_inode.c

   1 /*
   2  *  linux/fs/bad_inode.c
   3  *
   4  *  Copyright (C) 1997, Stephen Tweedie
   5  *
   6  *  Provide stub functions for unreadable inodes
   7  *
   8  *  Fabian Frederick : August 2003 - All file operations assigned to EIO
   9  */
  10
  11 #include <linux/fs.h>
  12 #include <linux/module.h>
  13 #include <linux/stat.h>
  14 #include <linux/time.h>
  15 #include <linux/namei.h>
  16 #include <linux/poll.h>
  17
  18
  19 static loff_t bad_file_llseek(struct file *file, loff_t offset, int origin)
  20 {
  21         return -EIO;
  22 }
  23
  24 static ssize_t bad_file_read(struct file *filp, char __user *buf,
  25                         size_t size, loff_t *ppos)
  26 {
  27         return -EIO;
  28 }
  29
  30 static ssize_t bad_file_write(struct file *filp, const char __user *buf,
  31                         size_t siz, loff_t *ppos)
  32 {
  33         return -EIO;
  34 }
  35
  36 static ssize_t bad_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
  37                         unsigned long nr_segs, loff_t pos)
  38 {
  39         return -EIO;
  40 }
  41
  42 static ssize_t bad_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
  43                         unsigned long nr_segs, loff_t pos)
  44 {
  45         return -EIO;
  46 }
  47
  48 static int bad_file_readdir(struct file *filp, void *dirent, filldir_t filldir)
  49 {
  50         return -EIO;
  51 }
  52
  53 static unsigned int bad_file_poll(struct file *filp, poll_table *wait)
  54 {
  55         return POLLERR;
  56 }
  57
  58 static long bad_file_unlocked_ioctl(struct file *file, unsigned cmd,
  59                         unsigned long arg)
  60 {
  61         return -EIO;
  62 }
  63
  64 static long bad_file_compat_ioctl(struct file *file, unsigned int cmd,
  65                         unsigned long arg)
  66 {
  67         return -EIO;
  68 }
  69
  70 static int bad_file_mmap(struct file *file, struct vm_area_struct *vma)
  71 {
  72         return -EIO;
  73 }
  74
  75 static int bad_file_open(struct inode *inode, struct file *filp)
  76 {
  77         return -EIO;
  78 }
  79
  80 static int bad_file_flush(struct file *file, fl_owner_t id)
  81 {
  82         return -EIO;
  83 }
  84
  85 static int bad_file_release(struct inode *inode, struct file *filp)
  86 {
  87         return -EIO;
  88 }
  89
  90 static int bad_file_fsync(struct file *file, int datasync)
  91 {
  92         return -EIO;
  93 }
  94
  95 static int bad_file_aio_fsync(struct kiocb *iocb, int datasync)
  96 {
  97         return -EIO;
  98 }
  99
 100 static int bad_file_fasync(int fd, struct file *filp, int on)
 101 {
 102         return -EIO;
 103 }
 104
 105 static int bad_file_lock(struct file *file, int cmd, struct file_lock *fl)
 106 {
 107         return -EIO;
 108 }
 109
 110 static ssize_t bad_file_sendpage(struct file *file, struct page *page,
 111                         int off, size_t len, loff_t *pos, int more)
 112 {
 113         return -EIO;
 114 }
 115
 116 static unsigned long bad_file_get_unmapped_area(struct file *file,
 117                                 unsigned long addr, unsigned long len,
 118                                 unsigned long pgoff, unsigned long flags)
 119 {
 120         return -EIO;
 121 }
 122
 123 static int bad_file_check_flags(int flags)
 124 {
 125         return -EIO;
 126 }
 127
 128 static int bad_file_flock(struct file *filp, int cmd, struct file_lock *fl)
 129 {
 130         return -EIO;
 131 }
 132
 133 static ssize_t bad_file_splice_write(struct pipe_inode_info *pipe,
 134                         struct file *out, loff_t *ppos, size_t len,
 135                         unsigned int flags)
 136 {
 137         return -EIO;
 138 }
 139
 140 static ssize_t bad_file_splice_read(struct file *in, loff_t *ppos,
 141                         struct pipe_inode_info *pipe, size_t len,
 142                         unsigned int flags)
 143 {
 144         return -EIO;
 145 }
 146
 147 static const struct file_operations bad_file_ops =
 148 {
 149         .llseek         = bad_file_llseek,
 150         .read           = bad_file_read,
 151         .write          = bad_file_write,
 152         .aio_read       = bad_file_aio_read,
 153         .aio_write      = bad_file_aio_write,
 154         .readdir        = bad_file_readdir,
 155         .poll           = bad_file_poll,
 156         .unlocked_ioctl = bad_file_unlocked_ioctl,
 157         .compat_ioctl   = bad_file_compat_ioctl,
 158         .mmap           = bad_file_mmap,
 159         .open           = bad_file_open,
 160         .flush          = bad_file_flush,
 161         .release        = bad_file_release,
 162         .fsync          = bad_file_fsync,
 163         .aio_fsync      = bad_file_aio_fsync,
 164         .fasync         = bad_file_fasync,
 165         .lock           = bad_file_lock,
 166         .sendpage       = bad_file_sendpage,
 167         .get_unmapped_area = bad_file_get_unmapped_area,
 168         .check_flags    = bad_file_check_flags,
 169         .flock          = bad_file_flock,
 170         .splice_write   = bad_file_splice_write,
 171         .splice_read    = bad_file_splice_read,
 172 };
 173
 174 static int bad_inode_create (struct inode *dir, struct dentry *dentry,
 175                 int mode, struct nameidata *nd)
 176 {
 177         return -EIO;
 178 }
 179
 180 static struct dentry *bad_inode_lookup(struct inode *dir,
 181                         struct dentry *dentry, struct nameidata *nd)
 182 {
 183         return ERR_PTR(-EIO);
 184 }
 185
 186 static int bad_inode_link (struct dentry *old_dentry, struct inode *dir,
 187                 struct dentry *dentry)
 188 {
 189         return -EIO;
 190 }
 191
 192 static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
 193 {
 194         return -EIO;
 195 }
 196
 197 static int bad_inode_symlink (struct inode *dir, struct dentry *dentry,
 198                 const char *symname)
 199 {
 200         return -EIO;
 201 }
 202
 203 static int bad_inode_mkdir(struct inode *dir, struct dentry *dentry,
 204                         int mode)
 205 {
 206         return -EIO;
 207 }
 208
 209 static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
 210 {
 211         return -EIO;
 212 }
 213
 214 static int bad_inode_mknod (struct inode *dir, struct dentry *dentry,
 215                         int mode, dev_t rdev)
 216 {
 217         return -EIO;
 218 }
 219
 220 static int bad_inode_rename (struct inode *old_dir, struct dentry *old_dentry,
 221                 struct inode *new_dir, struct dentry *new_dentry)
 222 {
 223         return -EIO;
 224 }
 225
 226 static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
 227                 int buflen)
 228 {
 229         return -EIO;
 230 }
 231
 232 static int bad_inode_permission(struct inode *inode, int mask, unsigned int flags)
 233 {
 234         if (flags & IPERM_FLAG_RCU)
 235                 return -ECHILD;
 236
 237         return -EIO;
 238 }
 239
 240 static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
 241                         struct kstat *stat)
 242 {
 243         return -EIO;
 244 }
 245
 246 static int bad_inode_setattr(struct dentry *direntry, struct iattr *attrs)
 247 {
 248         return -EIO;
 249 }
 250
 251 static int bad_inode_setxattr(struct dentry *dentry, const char *name,
 252                 const void *value, size_t size, int flags)
 253 {
 254         return -EIO;
 255 }
 256
 257 static ssize_t bad_inode_getxattr(struct dentry *dentry, const char *name,
 258                         void *buffer, size_t size)
 259 {
 260         return -EIO;
 261 }
 262
 263 static ssize_t bad_inode_listxattr(struct dentry *dentry, char *buffer,
 264                         size_t buffer_size)
 265 {
 266         return -EIO;
 267 }
 268
 269 static int bad_inode_removexattr(struct dentry *dentry, const char *name)
 270 {
 271         return -EIO;
 272 }
 273
 274 static const struct inode_operations bad_inode_ops =
 275 {
 276         .create         = bad_inode_create,
 277         .lookup         = bad_inode_lookup,
 278         .link           = bad_inode_link,
 279         .unlink         = bad_inode_unlink,
 280         .symlink        = bad_inode_symlink,
 281         .mkdir          = bad_inode_mkdir,
 282         .rmdir          = bad_inode_rmdir,
 283         .mknod          = bad_inode_mknod,
 284         .rename         = bad_inode_rename,
 285         .readlink       = bad_inode_readlink,
 286         /* follow_link must be no-op, otherwise unmounting this inode
 287            won't work */
 288         /* put_link returns void */
 289         /* truncate returns void */
 290         .permission     = bad_inode_permission,
 291         .getattr        = bad_inode_getattr,
 292         .setattr        = bad_inode_setattr,
 293         .setxattr       = bad_inode_setxattr,
 294         .getxattr       = bad_inode_getxattr,
 295         .listxattr      = bad_inode_listxattr,
 296         .removexattr    = bad_inode_removexattr,
 297         /* truncate_range returns void */
 298 };
 299
 300
 301 /*
 302  * When a filesystem is unable to read an inode due to an I/O error in
 303  * its read_inode() function, it can call make_bad_inode() to return a
 304  * set of stubs which will return EIO errors as required.
 305  *
 306  * We only need to do limited initialisation: all other fields are
 307  * preinitialised to zero automatically.
 308  */
 309
 310 /**
 311  *      make_bad_inode - mark an inode bad due to an I/O error
 312  *      @inode: Inode to mark bad
 313  *
 314  *      When an inode cannot be read due to a media or remote network
 315  *      failure this function makes the inode "bad" and causes I/O operations
 316  *      on it to fail from this point on.
 317  */
 318
 319 void make_bad_inode(struct inode *inode)
 320 {
 321         remove_inode_hash(inode);
 322
 323         inode->i_mode = S_IFREG;
 324         inode->i_atime = inode->i_mtime = inode->i_ctime =
 325                 current_fs_time(inode->i_sb);
 326         inode->i_op = &bad_inode_ops;
 327         inode->i_fop = &bad_file_ops;
 328 }
 329 EXPORT_SYMBOL(make_bad_inode);
 330
 331 /*
 332  * This tests whether an inode has been flagged as bad. The test uses
 333  * &bad_inode_ops to cover the case of invalidated inodes as well as
 334  * those created by make_bad_inode() above.
 335  */
 336
 337 /**
 338  *      is_bad_inode - is an inode errored
 339  *      @inode: inode to test
 340  *
 341  *      Returns true if the inode in question has been marked as bad.
 342  */
 343
 344 int is_bad_inode(struct inode *inode)
 345 {
 346         return (inode->i_op == &bad_inode_ops);
 347 }
 348
 349 EXPORT_SYMBOL(is_bad_inode);
 350
 351 /**
 352  * iget_failed - Mark an under-construction inode as dead and release it
 353  * @inode: The inode to discard
 354  *
 355  * Mark an under-construction inode as dead and release it.
 356  */
 357 void iget_failed(struct inode *inode)
 358 {
 359         make_bad_inode(inode);
 360         unlock_new_inode(inode);
 361         iput(inode);
 362 }
 363 EXPORT_SYMBOL(iget_failed);