| /* |
| * linux/fs/bad_inode.c |
| * |
| * Copyright (C) 1997, Stephen Tweedie |
| * |
| * Provide stub functions for unreadable inodes |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/stat.h> |
| #include <linux/time.h> |
| #include <linux/smp_lock.h> |
| |
| /* |
| * The follow_link operation is special: it must behave as a no-op |
| * so that a bad root inode can at least be unmounted. To do this |
| * we must dput() the base and return the dentry with a dget(). |
| */ |
| static int bad_follow_link(struct dentry *dent, struct nameidata *nd) |
| { |
| return vfs_follow_link(nd, ERR_PTR(-EIO)); |
| } |
| |
| static int return_EIO(void) |
| { |
| return -EIO; |
| } |
| |
| #define EIO_ERROR ((void *) (return_EIO)) |
| |
| static struct file_operations bad_file_ops = |
| { |
| llseek: EIO_ERROR, |
| read: EIO_ERROR, |
| write: EIO_ERROR, |
| readdir: EIO_ERROR, |
| poll: EIO_ERROR, |
| ioctl: EIO_ERROR, |
| mmap: EIO_ERROR, |
| open: EIO_ERROR, |
| flush: EIO_ERROR, |
| release: EIO_ERROR, |
| fsync: EIO_ERROR, |
| fasync: EIO_ERROR, |
| lock: EIO_ERROR, |
| }; |
| |
| struct inode_operations bad_inode_ops = |
| { |
| create: EIO_ERROR, |
| lookup: EIO_ERROR, |
| link: EIO_ERROR, |
| unlink: EIO_ERROR, |
| symlink: EIO_ERROR, |
| mkdir: EIO_ERROR, |
| rmdir: EIO_ERROR, |
| mknod: EIO_ERROR, |
| rename: EIO_ERROR, |
| readlink: EIO_ERROR, |
| follow_link: bad_follow_link, |
| truncate: EIO_ERROR, |
| permission: EIO_ERROR, |
| getattr: EIO_ERROR, |
| }; |
| |
| |
| /* |
| * When a filesystem is unable to read an inode due to an I/O error in |
| * its read_inode() function, it can call make_bad_inode() to return a |
| * set of stubs which will return EIO errors as required. |
| * |
| * We only need to do limited initialisation: all other fields are |
| * preinitialised to zero automatically. |
| */ |
| |
| /** |
| * make_bad_inode - mark an inode bad due to an I/O error |
| * @inode: Inode to mark bad |
| * |
| * When an inode cannot be read due to a media or remote network |
| * failure this function makes the inode "bad" and causes I/O operations |
| * on it to fail from this point on. |
| */ |
| |
| void make_bad_inode(struct inode * inode) |
| { |
| inode->i_mode = S_IFREG; |
| inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; |
| inode->i_op = &bad_inode_ops; |
| inode->i_fop = &bad_file_ops; |
| } |
| |
| /* |
| * This tests whether an inode has been flagged as bad. The test uses |
| * &bad_inode_ops to cover the case of invalidated inodes as well as |
| * those created by make_bad_inode() above. |
| */ |
| |
| /** |
| * is_bad_inode - is an inode errored |
| * @inode: inode to test |
| * |
| * Returns true if the inode in question has been marked as bad. |
| */ |
| |
| int is_bad_inode(struct inode * inode) |
| { |
| return (inode->i_op == &bad_inode_ops); |
| } |