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 static int bad_file_open(struct inode *inode, struct file *filp)
  19 {
  20         return -EIO;
  21 }
  22
  23 static const struct file_operations bad_file_ops =
  24 {
  25         .open           = bad_file_open,
  26 };
  27
  28 static int bad_inode_create (struct inode *dir, struct dentry *dentry,
  29                 umode_t mode, bool excl)
  30 {
  31         return -EIO;
  32 }
  33
  34 static struct dentry *bad_inode_lookup(struct inode *dir,
  35                         struct dentry *dentry, unsigned int flags)
  36 {
  37         return ERR_PTR(-EIO);
  38 }
  39
  40 static int bad_inode_link (struct dentry *old_dentry, struct inode *dir,
  41                 struct dentry *dentry)
  42 {
  43         return -EIO;
  44 }
  45
  46 static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
  47 {
  48         return -EIO;
  49 }
  50
  51 static int bad_inode_symlink (struct inode *dir, struct dentry *dentry,
  52                 const char *symname)
  53 {
  54         return -EIO;
  55 }
  56
  57 static int bad_inode_mkdir(struct inode *dir, struct dentry *dentry,
  58                         umode_t mode)
  59 {
  60         return -EIO;
  61 }
  62
  63 static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
  64 {
  65         return -EIO;
  66 }
  67
  68 static int bad_inode_mknod (struct inode *dir, struct dentry *dentry,
  69                         umode_t mode, dev_t rdev)
  70 {
  71         return -EIO;
  72 }
  73
  74 static int bad_inode_rename2(struct inode *old_dir, struct dentry *old_dentry,
  75                              struct inode *new_dir, struct dentry *new_dentry,
  76                              unsigned int flags)
  77 {
  78         return -EIO;
  79 }
  80
  81 static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
  82                 int buflen)
  83 {
  84         return -EIO;
  85 }
  86
  87 static int bad_inode_permission(struct inode *inode, int mask)
  88 {
  89         return -EIO;
  90 }
  91
  92 static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
  93                         struct kstat *stat)
  94 {
  95         return -EIO;
  96 }
  97
  98 static int bad_inode_setattr(struct dentry *direntry, struct iattr *attrs)
  99 {
 100         return -EIO;
 101 }
 102
 103 static int bad_inode_setxattr(struct dentry *dentry, const char *name,
 104                 const void *value, size_t size, int flags)
 105 {
 106         return -EIO;
 107 }
 108
 109 static ssize_t bad_inode_getxattr(struct dentry *dentry, const char *name,
 110                         void *buffer, size_t size)
 111 {
 112         return -EIO;
 113 }
 114
 115 static ssize_t bad_inode_listxattr(struct dentry *dentry, char *buffer,
 116                         size_t buffer_size)
 117 {
 118         return -EIO;
 119 }
 120
 121 static int bad_inode_removexattr(struct dentry *dentry, const char *name)
 122 {
 123         return -EIO;
 124 }
 125
 126 static const struct inode_operations bad_inode_ops =
 127 {
 128         .create         = bad_inode_create,
 129         .lookup         = bad_inode_lookup,
 130         .link           = bad_inode_link,
 131         .unlink         = bad_inode_unlink,
 132         .symlink        = bad_inode_symlink,
 133         .mkdir          = bad_inode_mkdir,
 134         .rmdir          = bad_inode_rmdir,
 135         .mknod          = bad_inode_mknod,
 136         .rename2        = bad_inode_rename2,
 137         .readlink       = bad_inode_readlink,
 138         /* follow_link must be no-op, otherwise unmounting this inode
 139            won't work */
 140         /* put_link returns void */
 141         /* truncate returns void */
 142         .permission     = bad_inode_permission,
 143         .getattr        = bad_inode_getattr,
 144         .setattr        = bad_inode_setattr,
 145         .setxattr       = bad_inode_setxattr,
 146         .getxattr       = bad_inode_getxattr,
 147         .listxattr      = bad_inode_listxattr,
 148         .removexattr    = bad_inode_removexattr,
 149 };
 150
 151
 152 /*
 153  * When a filesystem is unable to read an inode due to an I/O error in
 154  * its read_inode() function, it can call make_bad_inode() to return a
 155  * set of stubs which will return EIO errors as required.
 156  *
 157  * We only need to do limited initialisation: all other fields are
 158  * preinitialised to zero automatically.
 159  */
 160
 161 /**
 162  *      make_bad_inode - mark an inode bad due to an I/O error
 163  *      @inode: Inode to mark bad
 164  *
 165  *      When an inode cannot be read due to a media or remote network
 166  *      failure this function makes the inode "bad" and causes I/O operations
 167  *      on it to fail from this point on.
 168  */
 169
 170 void make_bad_inode(struct inode *inode)
 171 {
 172         remove_inode_hash(inode);
 173
 174         inode->i_mode = S_IFREG;
 175         inode->i_atime = inode->i_mtime = inode->i_ctime =
 176                 current_fs_time(inode->i_sb);
 177         inode->i_op = &bad_inode_ops;
 178         inode->i_fop = &bad_file_ops;
 179 }
 180 EXPORT_SYMBOL(make_bad_inode);
 181
 182 /*
 183  * This tests whether an inode has been flagged as bad. The test uses
 184  * &bad_inode_ops to cover the case of invalidated inodes as well as
 185  * those created by make_bad_inode() above.
 186  */
 187
 188 /**
 189  *      is_bad_inode - is an inode errored
 190  *      @inode: inode to test
 191  *
 192  *      Returns true if the inode in question has been marked as bad.
 193  */
 194
 195 bool is_bad_inode(struct inode *inode)
 196 {
 197         return (inode->i_op == &bad_inode_ops);
 198 }
 199
 200 EXPORT_SYMBOL(is_bad_inode);
 201
 202 /**
 203  * iget_failed - Mark an under-construction inode as dead and release it
 204  * @inode: The inode to discard
 205  *
 206  * Mark an under-construction inode as dead and release it.
 207  */
 208 void iget_failed(struct inode *inode)
 209 {
 210         make_bad_inode(inode);
 211         unlock_new_inode(inode);
 212         iput(inode);
 213 }
 214 EXPORT_SYMBOL(iget_failed);