4 * Copyright (C) 1997, Stephen Tweedie
6 * Provide stub functions for unreadable inodes
8 * Fabian Frederick : August 2003 - All file operations assigned to EIO
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>
19 * The follow_link operation is special: it must behave as a no-op
20 * so that a bad root inode can at least be unmounted. To do this
21 * we must dput() the base and return the dentry with a dget().
23 static int bad_follow_link(struct dentry *dent, struct nameidata *nd)
25 nd_set_link(nd, ERR_PTR(-EIO));
29 static int return_EIO(void)
34 #define EIO_ERROR ((void *) (return_EIO))
36 static struct file_operations bad_file_ops =
39 .aio_read = EIO_ERROR,
42 .aio_write = EIO_ERROR,
51 .aio_fsync = EIO_ERROR,
56 .sendfile = EIO_ERROR,
57 .sendpage = EIO_ERROR,
58 .get_unmapped_area = EIO_ERROR,
61 struct inode_operations bad_inode_ops =
72 .readlink = EIO_ERROR,
73 .follow_link = bad_follow_link,
74 .truncate = EIO_ERROR,
75 .permission = EIO_ERROR,
78 .setxattr = EIO_ERROR,
79 .getxattr = EIO_ERROR,
80 .listxattr = EIO_ERROR,
81 .removexattr = EIO_ERROR,
86 * When a filesystem is unable to read an inode due to an I/O error in
87 * its read_inode() function, it can call make_bad_inode() to return a
88 * set of stubs which will return EIO errors as required.
90 * We only need to do limited initialisation: all other fields are
91 * preinitialised to zero automatically.
95 * make_bad_inode - mark an inode bad due to an I/O error
96 * @inode: Inode to mark bad
98 * When an inode cannot be read due to a media or remote network
99 * failure this function makes the inode "bad" and causes I/O operations
100 * on it to fail from this point on.
103 void make_bad_inode(struct inode * inode)
105 remove_inode_hash(inode);
107 inode->i_mode = S_IFREG;
108 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
109 inode->i_op = &bad_inode_ops;
110 inode->i_fop = &bad_file_ops;
112 EXPORT_SYMBOL(make_bad_inode);
115 * This tests whether an inode has been flagged as bad. The test uses
116 * &bad_inode_ops to cover the case of invalidated inodes as well as
117 * those created by make_bad_inode() above.
121 * is_bad_inode - is an inode errored
122 * @inode: inode to test
124 * Returns true if the inode in question has been marked as bad.
127 int is_bad_inode(struct inode * inode)
129 return (inode->i_op == &bad_inode_ops);
132 EXPORT_SYMBOL(is_bad_inode);