4 * Copyright (C) 1997, Stephen Tweedie
6 * Provide stub functions for unreadable inodes
10 #include <linux/stat.h>
11 #include <linux/sched.h>
14 * The follow_link operation is special: it must behave as a no-op
15 * so that a bad root inode can at least be unmounted. To do this
16 * we must dput() the base and return the dentry with a dget().
18 static int bad_follow_link(struct dentry *dent, struct nameidata *nd)
20 return vfs_follow_link(nd, ERR_PTR(-EIO));
23 static int return_EIO(void)
28 #define EIO_ERROR ((void *) (return_EIO))
30 static struct file_operations bad_file_ops =
47 struct inode_operations bad_inode_ops =
59 follow_link: bad_follow_link,
61 permission: EIO_ERROR,
62 revalidate: EIO_ERROR,
67 * When a filesystem is unable to read an inode due to an I/O error in
68 * its read_inode() function, it can call make_bad_inode() to return a
69 * set of stubs which will return EIO errors as required.
71 * We only need to do limited initialisation: all other fields are
72 * preinitialised to zero automatically.
76 * make_bad_inode - mark an inode bad due to an I/O error
77 * @inode: Inode to mark bad
79 * When an inode cannot be read due to a media or remote network
80 * failure this function makes the inode "bad" and causes I/O operations
81 * on it to fail from this point on.
84 void make_bad_inode(struct inode * inode)
86 inode->i_mode = S_IFREG;
87 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
88 inode->i_op = &bad_inode_ops;
89 inode->i_fop = &bad_file_ops;
93 * This tests whether an inode has been flagged as bad. The test uses
94 * &bad_inode_ops to cover the case of invalidated inodes as well as
95 * those created by make_bad_inode() above.
99 * is_bad_inode - is an inode errored
100 * @inode: inode to test
102 * Returns true if the inode in question has been marked as bad.
105 int is_bad_inode(struct inode * inode)
107 return (inode->i_op == &bad_inode_ops);