xref: /openbmc/linux/fs/bad_inode.c (revision 6dfcd296) 
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 
18 static int bad_file_open(struct inode *inode, struct file *filp)
19 {
20 	return -EIO;
21 }
22 
23 static const struct file_operations bad_file_ops =
24 {
25 	.open		= bad_file_open,
26 };
27 
28 static int bad_inode_create (struct inode *dir, struct dentry *dentry,
29 		umode_t mode, bool excl)
30 {
31 	return -EIO;
32 }
33 
34 static struct dentry *bad_inode_lookup(struct inode *dir,
35 			struct dentry *dentry, unsigned int flags)
36 {
37 	return ERR_PTR(-EIO);
38 }
39 
40 static int bad_inode_link (struct dentry *old_dentry, struct inode *dir,
41 		struct dentry *dentry)
42 {
43 	return -EIO;
44 }
45 
46 static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
47 {
48 	return -EIO;
49 }
50 
51 static int bad_inode_symlink (struct inode *dir, struct dentry *dentry,
52 		const char *symname)
53 {
54 	return -EIO;
55 }
56 
57 static int bad_inode_mkdir(struct inode *dir, struct dentry *dentry,
58 			umode_t mode)
59 {
60 	return -EIO;
61 }
62 
63 static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
64 {
65 	return -EIO;
66 }
67 
68 static int bad_inode_mknod (struct inode *dir, struct dentry *dentry,
69 			umode_t mode, dev_t rdev)
70 {
71 	return -EIO;
72 }
73 
74 static 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 
81 static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
82 		int buflen)
83 {
84 	return -EIO;
85 }
86 
87 static int bad_inode_permission(struct inode *inode, int mask)
88 {
89 	return -EIO;
90 }
91 
92 static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
93 			struct kstat *stat)
94 {
95 	return -EIO;
96 }
97 
98 static int bad_inode_setattr(struct dentry *direntry, struct iattr *attrs)
99 {
100 	return -EIO;
101 }
102 
103 static ssize_t bad_inode_listxattr(struct dentry *dentry, char *buffer,
104 			size_t buffer_size)
105 {
106 	return -EIO;
107 }
108 
109 static const struct inode_operations bad_inode_ops =
110 {
111 	.create		= bad_inode_create,
112 	.lookup		= bad_inode_lookup,
113 	.link		= bad_inode_link,
114 	.unlink		= bad_inode_unlink,
115 	.symlink	= bad_inode_symlink,
116 	.mkdir		= bad_inode_mkdir,
117 	.rmdir		= bad_inode_rmdir,
118 	.mknod		= bad_inode_mknod,
119 	.rename		= bad_inode_rename2,
120 	.readlink	= bad_inode_readlink,
121 	/* follow_link must be no-op, otherwise unmounting this inode
122 	   won't work */
123 	/* put_link returns void */
124 	/* truncate returns void */
125 	.permission	= bad_inode_permission,
126 	.getattr	= bad_inode_getattr,
127 	.setattr	= bad_inode_setattr,
128 	.listxattr	= bad_inode_listxattr,
129 };
130 
131 
132 /*
133  * When a filesystem is unable to read an inode due to an I/O error in
134  * its read_inode() function, it can call make_bad_inode() to return a
135  * set of stubs which will return EIO errors as required.
136  *
137  * We only need to do limited initialisation: all other fields are
138  * preinitialised to zero automatically.
139  */
140 
141 /**
142  *	make_bad_inode - mark an inode bad due to an I/O error
143  *	@inode: Inode to mark bad
144  *
145  *	When an inode cannot be read due to a media or remote network
146  *	failure this function makes the inode "bad" and causes I/O operations
147  *	on it to fail from this point on.
148  */
149 
150 void make_bad_inode(struct inode *inode)
151 {
152 	remove_inode_hash(inode);
153 
154 	inode->i_mode = S_IFREG;
155 	inode->i_atime = inode->i_mtime = inode->i_ctime =
156 		current_time(inode);
157 	inode->i_op = &bad_inode_ops;
158 	inode->i_opflags &= ~IOP_XATTR;
159 	inode->i_fop = &bad_file_ops;
160 }
161 EXPORT_SYMBOL(make_bad_inode);
162 
163 /*
164  * This tests whether an inode has been flagged as bad. The test uses
165  * &bad_inode_ops to cover the case of invalidated inodes as well as
166  * those created by make_bad_inode() above.
167  */
168 
169 /**
170  *	is_bad_inode - is an inode errored
171  *	@inode: inode to test
172  *
173  *	Returns true if the inode in question has been marked as bad.
174  */
175 
176 bool is_bad_inode(struct inode *inode)
177 {
178 	return (inode->i_op == &bad_inode_ops);
179 }
180 
181 EXPORT_SYMBOL(is_bad_inode);
182 
183 /**
184  * iget_failed - Mark an under-construction inode as dead and release it
185  * @inode: The inode to discard
186  *
187  * Mark an under-construction inode as dead and release it.
188  */
189 void iget_failed(struct inode *inode)
190 {
191 	make_bad_inode(inode);
192 	unlock_new_inode(inode);
193 	iput(inode);
194 }
195 EXPORT_SYMBOL(iget_failed);
196