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/export.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 whence)
  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 *file, struct dir_context *ctx)
  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, loff_t start, loff_t end,
  91                           int datasync)
  92 {
  93         return -EIO;
  94 }
  95
  96 static int bad_file_aio_fsync(struct kiocb *iocb, int datasync)
  97 {
  98         return -EIO;
  99 }
 100
 101 static int bad_file_fasync(int fd, struct file *filp, int on)
 102 {
 103         return -EIO;
 104 }
 105
 106 static int bad_file_lock(struct file *file, int cmd, struct file_lock *fl)
 107 {
 108         return -EIO;
 109 }
 110
 111 static ssize_t bad_file_sendpage(struct file *file, struct page *page,
 112                         int off, size_t len, loff_t *pos, int more)
 113 {
 114         return -EIO;
 115 }
 116
 117 static unsigned long bad_file_get_unmapped_area(struct file *file,
 118                                 unsigned long addr, unsigned long len,
 119                                 unsigned long pgoff, unsigned long flags)
 120 {
 121         return -EIO;
 122 }
 123
 124 static int bad_file_check_flags(int flags)
 125 {
 126         return -EIO;
 127 }
 128
 129 static int bad_file_flock(struct file *filp, int cmd, struct file_lock *fl)
 130 {
 131         return -EIO;
 132 }
 133
 134 static ssize_t bad_file_splice_write(struct pipe_inode_info *pipe,
 135                         struct file *out, loff_t *ppos, size_t len,
 136                         unsigned int flags)
 137 {
 138         return -EIO;
 139 }
 140
 141 static ssize_t bad_file_splice_read(struct file *in, loff_t *ppos,
 142                         struct pipe_inode_info *pipe, size_t len,
 143                         unsigned int flags)
 144 {
 145         return -EIO;
 146 }
 147
 148 static const struct file_operations bad_file_ops =
 149 {
 150         .llseek         = bad_file_llseek,
 151         .read           = bad_file_read,
 152         .write          = bad_file_write,
 153         .aio_read       = bad_file_aio_read,
 154         .aio_write      = bad_file_aio_write,
 155         .iterate        = bad_file_readdir,
 156         .poll           = bad_file_poll,
 157         .unlocked_ioctl = bad_file_unlocked_ioctl,
 158         .compat_ioctl   = bad_file_compat_ioctl,
 159         .mmap           = bad_file_mmap,
 160         .open           = bad_file_open,
 161         .flush          = bad_file_flush,
 162         .release        = bad_file_release,
 163         .fsync          = bad_file_fsync,
 164         .aio_fsync      = bad_file_aio_fsync,
 165         .fasync         = bad_file_fasync,
 166         .lock           = bad_file_lock,
 167         .sendpage       = bad_file_sendpage,
 168         .get_unmapped_area = bad_file_get_unmapped_area,
 169         .check_flags    = bad_file_check_flags,
 170         .flock          = bad_file_flock,
 171         .splice_write   = bad_file_splice_write,
 172         .splice_read    = bad_file_splice_read,
 173 };
 174
 175 static int bad_inode_create (struct inode *dir, struct dentry *dentry,
 176                 umode_t mode, bool excl)
 177 {
 178         return -EIO;
 179 }
 180
 181 static struct dentry *bad_inode_lookup(struct inode *dir,
 182                         struct dentry *dentry, unsigned int flags)
 183 {
 184         return ERR_PTR(-EIO);
 185 }
 186
 187 static int bad_inode_link (struct dentry *old_dentry, struct inode *dir,
 188                 struct dentry *dentry)
 189 {
 190         return -EIO;
 191 }
 192
 193 static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
 194 {
 195         return -EIO;
 196 }
 197
 198 static int bad_inode_symlink (struct inode *dir, struct dentry *dentry,
 199                 const char *symname)
 200 {
 201         return -EIO;
 202 }
 203
 204 static int bad_inode_mkdir(struct inode *dir, struct dentry *dentry,
 205                         umode_t mode)
 206 {
 207         return -EIO;
 208 }
 209
 210 static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
 211 {
 212         return -EIO;
 213 }
 214
 215 static int bad_inode_mknod (struct inode *dir, struct dentry *dentry,
 216                         umode_t mode, dev_t rdev)
 217 {
 218         return -EIO;
 219 }
 220
 221 static int bad_inode_rename2(struct inode *old_dir, struct dentry *old_dentry,
 222                              struct inode *new_dir, struct dentry *new_dentry,
 223                              unsigned int flags)
 224 {
 225         return -EIO;
 226 }
 227
 228 static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
 229                 int buflen)
 230 {
 231         return -EIO;
 232 }
 233
 234 static int bad_inode_permission(struct inode *inode, int mask)
 235 {
 236         return -EIO;
 237 }
 238
 239 static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
 240                         struct kstat *stat)
 241 {
 242         return -EIO;
 243 }
 244
 245 static int bad_inode_setattr(struct dentry *direntry, struct iattr *attrs)
 246 {
 247         return -EIO;
 248 }
 249
 250 static int bad_inode_setxattr(struct dentry *dentry, const char *name,
 251                 const void *value, size_t size, int flags)
 252 {
 253         return -EIO;
 254 }
 255
 256 static ssize_t bad_inode_getxattr(struct dentry *dentry, const char *name,
 257                         void *buffer, size_t size)
 258 {
 259         return -EIO;
 260 }
 261
 262 static ssize_t bad_inode_listxattr(struct dentry *dentry, char *buffer,
 263                         size_t buffer_size)
 264 {
 265         return -EIO;
 266 }
 267
 268 static int bad_inode_removexattr(struct dentry *dentry, const char *name)
 269 {
 270         return -EIO;
 271 }
 272
 273 static const struct inode_operations bad_inode_ops =
 274 {
 275         .create         = bad_inode_create,
 276         .lookup         = bad_inode_lookup,
 277         .link           = bad_inode_link,
 278         .unlink         = bad_inode_unlink,
 279         .symlink        = bad_inode_symlink,
 280         .mkdir          = bad_inode_mkdir,
 281         .rmdir          = bad_inode_rmdir,
 282         .mknod          = bad_inode_mknod,
 283         .rename2        = bad_inode_rename2,
 284         .readlink       = bad_inode_readlink,
 285         /* follow_link must be no-op, otherwise unmounting this inode
 286            won't work */
 287         /* put_link returns void */
 288         /* truncate returns void */
 289         .permission     = bad_inode_permission,
 290         .getattr        = bad_inode_getattr,
 291         .setattr        = bad_inode_setattr,
 292         .setxattr       = bad_inode_setxattr,
 293         .getxattr       = bad_inode_getxattr,
 294         .listxattr      = bad_inode_listxattr,
 295         .removexattr    = bad_inode_removexattr,
 296 };
 297
 298
 299 /*
 300  * When a filesystem is unable to read an inode due to an I/O error in
 301  * its read_inode() function, it can call make_bad_inode() to return a
 302  * set of stubs which will return EIO errors as required.
 303  *
 304  * We only need to do limited initialisation: all other fields are
 305  * preinitialised to zero automatically.
 306  */
 307
 308 /**
 309  *      make_bad_inode - mark an inode bad due to an I/O error
 310  *      @inode: Inode to mark bad
 311  *
 312  *      When an inode cannot be read due to a media or remote network
 313  *      failure this function makes the inode "bad" and causes I/O operations
 314  *      on it to fail from this point on.
 315  */
 316
 317 void make_bad_inode(struct inode *inode)
 318 {
 319         remove_inode_hash(inode);
 320
 321         inode->i_mode = S_IFREG;
 322         inode->i_atime = inode->i_mtime = inode->i_ctime =
 323                 current_fs_time(inode->i_sb);
 324         inode->i_op = &bad_inode_ops;
 325         inode->i_fop = &bad_file_ops;
 326 }
 327 EXPORT_SYMBOL(make_bad_inode);
 328
 329 /*
 330  * This tests whether an inode has been flagged as bad. The test uses
 331  * &bad_inode_ops to cover the case of invalidated inodes as well as
 332  * those created by make_bad_inode() above.
 333  */
 334
 335 /**
 336  *      is_bad_inode - is an inode errored
 337  *      @inode: inode to test
 338  *
 339  *      Returns true if the inode in question has been marked as bad.
 340  */
 341
 342 int is_bad_inode(struct inode *inode)
 343 {
 344         return (inode->i_op == &bad_inode_ops);
 345 }
 346
 347 EXPORT_SYMBOL(is_bad_inode);
 348
 349 /**
 350  * iget_failed - Mark an under-construction inode as dead and release it
 351  * @inode: The inode to discard
 352  *
 353  * Mark an under-construction inode as dead and release it.
 354  */
 355 void iget_failed(struct inode *inode)
 356 {
 357         make_bad_inode(inode);
 358         unlock_new_inode(inode);
 359         iput(inode);
 360 }
 361 EXPORT_SYMBOL(iget_failed);