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
18static int bad_file_open(struct inode *inode, struct file *filp)
19{
20	return -EIO;
21}
22
23static const struct file_operations bad_file_ops =
24{
25	.open		= bad_file_open,
26};
27
28static int bad_inode_create (struct inode *dir, struct dentry *dentry,
29		umode_t mode, bool excl)
30{
31	return -EIO;
32}
33
34static struct dentry *bad_inode_lookup(struct inode *dir,
35			struct dentry *dentry, unsigned int flags)
36{
37	return ERR_PTR(-EIO);
38}
39
40static int bad_inode_link (struct dentry *old_dentry, struct inode *dir,
41		struct dentry *dentry)
42{
43	return -EIO;
44}
45
46static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
47{
48	return -EIO;
49}
50
51static int bad_inode_symlink (struct inode *dir, struct dentry *dentry,
52		const char *symname)
53{
54	return -EIO;
55}
56
57static int bad_inode_mkdir(struct inode *dir, struct dentry *dentry,
58			umode_t mode)
59{
60	return -EIO;
61}
62
63static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
64{
65	return -EIO;
66}
67
68static int bad_inode_mknod (struct inode *dir, struct dentry *dentry,
69			umode_t mode, dev_t rdev)
70{
71	return -EIO;
72}
73
74static 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
81static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
82		int buflen)
83{
84	return -EIO;
85}
86
87static int bad_inode_permission(struct inode *inode, int mask)
88{
89	return -EIO;
90}
91
92static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
93			struct kstat *stat)
94{
95	return -EIO;
96}
97
98static int bad_inode_setattr(struct dentry *direntry, struct iattr *attrs)
99{
100	return -EIO;
101}
102
103static 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
109static ssize_t bad_inode_getxattr(struct dentry *dentry, const char *name,
110			void *buffer, size_t size)
111{
112	return -EIO;
113}
114
115static ssize_t bad_inode_listxattr(struct dentry *dentry, char *buffer,
116			size_t buffer_size)
117{
118	return -EIO;
119}
120
121static int bad_inode_removexattr(struct dentry *dentry, const char *name)
122{
123	return -EIO;
124}
125
126static 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
170void 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}
180EXPORT_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
195int is_bad_inode(struct inode *inode)
196{
197	return (inode->i_op == &bad_inode_ops);
198}
199
200EXPORT_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 */
208void iget_failed(struct inode *inode)
209{
210	make_bad_inode(inode);
211	unlock_new_inode(inode);
212	iput(inode);
213}
214EXPORT_SYMBOL(iget_failed);
215