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/smp_lock.h>
  16 #include <linux/namei.h>
  17
  18 static int return_EIO(void)
  19 {
  20         return -EIO;
  21 }
  22
  23 #define EIO_ERROR ((void *) (return_EIO))
  24
  25 static const struct file_operations bad_file_ops =
  26 {
  27         .llseek         = EIO_ERROR,
  28         .aio_read       = EIO_ERROR,
  29         .read           = EIO_ERROR,
  30         .write          = EIO_ERROR,
  31         .aio_write      = EIO_ERROR,
  32         .readdir        = EIO_ERROR,
  33         .poll           = EIO_ERROR,
  34         .ioctl          = EIO_ERROR,
  35         .mmap           = EIO_ERROR,
  36         .open           = EIO_ERROR,
  37         .flush          = EIO_ERROR,
  38         .release        = EIO_ERROR,
  39         .fsync          = EIO_ERROR,
  40         .aio_fsync      = EIO_ERROR,
  41         .fasync         = EIO_ERROR,
  42         .lock           = EIO_ERROR,
  43         .readv          = EIO_ERROR,
  44         .writev         = EIO_ERROR,
  45         .sendfile       = EIO_ERROR,
  46         .sendpage       = EIO_ERROR,
  47         .get_unmapped_area = EIO_ERROR,
  48 };
  49
  50 static struct inode_operations bad_inode_ops =
  51 {
  52         .create         = EIO_ERROR,
  53         .lookup         = EIO_ERROR,
  54         .link           = EIO_ERROR,
  55         .unlink         = EIO_ERROR,
  56         .symlink        = EIO_ERROR,
  57         .mkdir          = EIO_ERROR,
  58         .rmdir          = EIO_ERROR,
  59         .mknod          = EIO_ERROR,
  60         .rename         = EIO_ERROR,
  61         .readlink       = EIO_ERROR,
  62         /* follow_link must be no-op, otherwise unmounting this inode
  63            won't work */
  64         .truncate       = EIO_ERROR,
  65         .permission     = EIO_ERROR,
  66         .getattr        = EIO_ERROR,
  67         .setattr        = EIO_ERROR,
  68         .setxattr       = EIO_ERROR,
  69         .getxattr       = EIO_ERROR,
  70         .listxattr      = EIO_ERROR,
  71         .removexattr    = EIO_ERROR,
  72 };
  73
  74
  75 /*
  76  * When a filesystem is unable to read an inode due to an I/O error in
  77  * its read_inode() function, it can call make_bad_inode() to return a
  78  * set of stubs which will return EIO errors as required.
  79  *
  80  * We only need to do limited initialisation: all other fields are
  81  * preinitialised to zero automatically.
  82  */
  83
  84 /**
  85  *      make_bad_inode - mark an inode bad due to an I/O error
  86  *      @inode: Inode to mark bad
  87  *
  88  *      When an inode cannot be read due to a media or remote network
  89  *      failure this function makes the inode "bad" and causes I/O operations
  90  *      on it to fail from this point on.
  91  */
  92
  93 void make_bad_inode(struct inode * inode)
  94 {
  95         remove_inode_hash(inode);
  96
  97         inode->i_mode = S_IFREG;
  98         inode->i_atime = inode->i_mtime = inode->i_ctime =
  99                 current_fs_time(inode->i_sb);
 100         inode->i_op = &bad_inode_ops;
 101         inode->i_fop = &bad_file_ops;
 102 }
 103 EXPORT_SYMBOL(make_bad_inode);
 104
 105 /*
 106  * This tests whether an inode has been flagged as bad. The test uses
 107  * &bad_inode_ops to cover the case of invalidated inodes as well as
 108  * those created by make_bad_inode() above.
 109  */
 110
 111 /**
 112  *      is_bad_inode - is an inode errored
 113  *      @inode: inode to test
 114  *
 115  *      Returns true if the inode in question has been marked as bad.
 116  */
 117
 118 int is_bad_inode(struct inode * inode)
 119 {
 120         return (inode->i_op == &bad_inode_ops);
 121 }
 122
 123 EXPORT_SYMBOL(is_bad_inode);