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 int bad_file_ioctl (struct inode *inode, struct file *filp,
  59                         unsigned int cmd, unsigned long arg)
  60 {
  61         return -EIO;
  62 }
  63
  64 static long bad_file_unlocked_ioctl(struct file *file, unsigned cmd,
  65                         unsigned long arg)
  66 {
  67         return -EIO;
  68 }
  69
  70 static long bad_file_compat_ioctl(struct file *file, unsigned int cmd,
  71                         unsigned long arg)
  72 {
  73         return -EIO;
  74 }
  75
  76 static int bad_file_mmap(struct file *file, struct vm_area_struct *vma)
  77 {
  78         return -EIO;
  79 }
  80
  81 static int bad_file_open(struct inode *inode, struct file *filp)
  82 {
  83         return -EIO;
  84 }
  85
  86 static int bad_file_flush(struct file *file, fl_owner_t id)
  87 {
  88         return -EIO;
  89 }
  90
  91 static int bad_file_release(struct inode *inode, struct file *filp)
  92 {
  93         return -EIO;
  94 }
  95
  96 static int bad_file_fsync(struct file *file, int datasync)
  97 {
  98         return -EIO;
  99 }
 100
 101 static int bad_file_aio_fsync(struct kiocb *iocb, int datasync)
 102 {
 103         return -EIO;
 104 }
 105
 106 static int bad_file_fasync(int fd, struct file *filp, int on)
 107 {
 108         return -EIO;
 109 }
 110
 111 static int bad_file_lock(struct file *file, int cmd, struct file_lock *fl)
 112 {
 113         return -EIO;
 114 }
 115
 116 static ssize_t bad_file_sendpage(struct file *file, struct page *page,
 117                         int off, size_t len, loff_t *pos, int more)
 118 {
 119         return -EIO;
 120 }
 121
 122 static unsigned long bad_file_get_unmapped_area(struct file *file,
 123                                 unsigned long addr, unsigned long len,
 124                                 unsigned long pgoff, unsigned long flags)
 125 {
 126         return -EIO;
 127 }
 128
 129 static int bad_file_check_flags(int flags)
 130 {
 131         return -EIO;
 132 }
 133
 134 static int bad_file_flock(struct file *filp, int cmd, struct file_lock *fl)
 135 {
 136         return -EIO;
 137 }
 138
 139 static ssize_t bad_file_splice_write(struct pipe_inode_info *pipe,
 140                         struct file *out, loff_t *ppos, size_t len,
 141                         unsigned int flags)
 142 {
 143         return -EIO;
 144 }
 145
 146 static ssize_t bad_file_splice_read(struct file *in, loff_t *ppos,
 147                         struct pipe_inode_info *pipe, size_t len,
 148                         unsigned int flags)
 149 {
 150         return -EIO;
 151 }
 152
 153 static const struct file_operations bad_file_ops =
 154 {
 155         .llseek         = bad_file_llseek,
 156         .read           = bad_file_read,
 157         .write          = bad_file_write,
 158         .aio_read       = bad_file_aio_read,
 159         .aio_write      = bad_file_aio_write,
 160         .readdir        = bad_file_readdir,
 161         .poll           = bad_file_poll,
 162         .ioctl          = bad_file_ioctl,
 163         .unlocked_ioctl = bad_file_unlocked_ioctl,
 164         .compat_ioctl   = bad_file_compat_ioctl,
 165         .mmap           = bad_file_mmap,
 166         .open           = bad_file_open,
 167         .flush          = bad_file_flush,
 168         .release        = bad_file_release,
 169         .fsync          = bad_file_fsync,
 170         .aio_fsync      = bad_file_aio_fsync,
 171         .fasync         = bad_file_fasync,
 172         .lock           = bad_file_lock,
 173         .sendpage       = bad_file_sendpage,
 174         .get_unmapped_area = bad_file_get_unmapped_area,
 175         .check_flags    = bad_file_check_flags,
 176         .flock          = bad_file_flock,
 177         .splice_write   = bad_file_splice_write,
 178         .splice_read    = bad_file_splice_read,
 179 };
 180
 181 static int bad_inode_create (struct inode *dir, struct dentry *dentry,
 182                 int mode, struct nameidata *nd)
 183 {
 184         return -EIO;
 185 }
 186
 187 static struct dentry *bad_inode_lookup(struct inode *dir,
 188                         struct dentry *dentry, struct nameidata *nd)
 189 {
 190         return ERR_PTR(-EIO);
 191 }
 192
 193 static int bad_inode_link (struct dentry *old_dentry, struct inode *dir,
 194                 struct dentry *dentry)
 195 {
 196         return -EIO;
 197 }
 198
 199 static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
 200 {
 201         return -EIO;
 202 }
 203
 204 static int bad_inode_symlink (struct inode *dir, struct dentry *dentry,
 205                 const char *symname)
 206 {
 207         return -EIO;
 208 }
 209
 210 static int bad_inode_mkdir(struct inode *dir, struct dentry *dentry,
 211                         int mode)
 212 {
 213         return -EIO;
 214 }
 215
 216 static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
 217 {
 218         return -EIO;
 219 }
 220
 221 static int bad_inode_mknod (struct inode *dir, struct dentry *dentry,
 222                         int mode, dev_t rdev)
 223 {
 224         return -EIO;
 225 }
 226
 227 static int bad_inode_rename (struct inode *old_dir, struct dentry *old_dentry,
 228                 struct inode *new_dir, struct dentry *new_dentry)
 229 {
 230         return -EIO;
 231 }
 232
 233 static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
 234                 int buflen)
 235 {
 236         return -EIO;
 237 }
 238
 239 static int bad_inode_permission(struct inode *inode, int mask)
 240 {
 241         return -EIO;
 242 }
 243
 244 static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
 245                         struct kstat *stat)
 246 {
 247         return -EIO;
 248 }
 249
 250 static int bad_inode_setattr(struct dentry *direntry, struct iattr *attrs)
 251 {
 252         return -EIO;
 253 }
 254
 255 static int bad_inode_setxattr(struct dentry *dentry, const char *name,
 256                 const void *value, size_t size, int flags)
 257 {
 258         return -EIO;
 259 }
 260
 261 static ssize_t bad_inode_getxattr(struct dentry *dentry, const char *name,
 262                         void *buffer, size_t size)
 263 {
 264         return -EIO;
 265 }
 266
 267 static ssize_t bad_inode_listxattr(struct dentry *dentry, char *buffer,
 268                         size_t buffer_size)
 269 {
 270         return -EIO;
 271 }
 272
 273 static int bad_inode_removexattr(struct dentry *dentry, const char *name)
 274 {
 275         return -EIO;
 276 }
 277
 278 static const struct inode_operations bad_inode_ops =
 279 {
 280         .create         = bad_inode_create,
 281         .lookup         = bad_inode_lookup,
 282         .link           = bad_inode_link,
 283         .unlink         = bad_inode_unlink,
 284         .symlink        = bad_inode_symlink,
 285         .mkdir          = bad_inode_mkdir,
 286         .rmdir          = bad_inode_rmdir,
 287         .mknod          = bad_inode_mknod,
 288         .rename         = bad_inode_rename,
 289         .readlink       = bad_inode_readlink,
 290         /* follow_link must be no-op, otherwise unmounting this inode
 291            won't work */
 292         /* put_link returns void */
 293         /* truncate returns void */
 294         .permission     = bad_inode_permission,
 295         .getattr        = bad_inode_getattr,
 296         .setattr        = bad_inode_setattr,
 297         .setxattr       = bad_inode_setxattr,
 298         .getxattr       = bad_inode_getxattr,
 299         .listxattr      = bad_inode_listxattr,
 300         .removexattr    = bad_inode_removexattr,
 301         /* truncate_range returns void */
 302 };
 303
 304
 305 /*
 306  * When a filesystem is unable to read an inode due to an I/O error in
 307  * its read_inode() function, it can call make_bad_inode() to return a
 308  * set of stubs which will return EIO errors as required.
 309  *
 310  * We only need to do limited initialisation: all other fields are
 311  * preinitialised to zero automatically.
 312  */
 313
 314 /**
 315  *      make_bad_inode - mark an inode bad due to an I/O error
 316  *      @inode: Inode to mark bad
 317  *
 318  *      When an inode cannot be read due to a media or remote network
 319  *      failure this function makes the inode "bad" and causes I/O operations
 320  *      on it to fail from this point on.
 321  */
 322
 323 void make_bad_inode(struct inode *inode)
 324 {
 325         remove_inode_hash(inode);
 326
 327         inode->i_mode = S_IFREG;
 328         inode->i_atime = inode->i_mtime = inode->i_ctime =
 329                 current_fs_time(inode->i_sb);
 330         inode->i_op = &bad_inode_ops;
 331         inode->i_fop = &bad_file_ops;
 332 }
 333 EXPORT_SYMBOL(make_bad_inode);
 334
 335 /*
 336  * This tests whether an inode has been flagged as bad. The test uses
 337  * &bad_inode_ops to cover the case of invalidated inodes as well as
 338  * those created by make_bad_inode() above.
 339  */
 340
 341 /**
 342  *      is_bad_inode - is an inode errored
 343  *      @inode: inode to test
 344  *
 345  *      Returns true if the inode in question has been marked as bad.
 346  */
 347
 348 int is_bad_inode(struct inode *inode)
 349 {
 350         return (inode->i_op == &bad_inode_ops);
 351 }
 352
 353 EXPORT_SYMBOL(is_bad_inode);
 354
 355 /**
 356  * iget_failed - Mark an under-construction inode as dead and release it
 357  * @inode: The inode to discard
 358  *
 359  * Mark an under-construction inode as dead and release it.
 360  */
 361 void iget_failed(struct inode *inode)
 362 {
 363         make_bad_inode(inode);
 364         unlock_new_inode(inode);
 365         iput(inode);
 366 }
 367 EXPORT_SYMBOL(iget_failed);