Root/fs/bad_inode.c

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/module.h>
13#include <linux/stat.h>
14#include <linux/time.h>
15#include <linux/namei.h>
16#include <linux/poll.h>
17
18
19static loff_t bad_file_llseek(struct file *file, loff_t offset, int origin)
20{
21    return -EIO;
22}
23
24static ssize_t bad_file_read(struct file *filp, char __user *buf,
25            size_t size, loff_t *ppos)
26{
27        return -EIO;
28}
29
30static ssize_t bad_file_write(struct file *filp, const char __user *buf,
31            size_t siz, loff_t *ppos)
32{
33        return -EIO;
34}
35
36static ssize_t bad_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
37            unsigned long nr_segs, loff_t pos)
38{
39    return -EIO;
40}
41
42static ssize_t bad_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
43            unsigned long nr_segs, loff_t pos)
44{
45    return -EIO;
46}
47
48static int bad_file_readdir(struct file *filp, void *dirent, filldir_t filldir)
49{
50    return -EIO;
51}
52
53static unsigned int bad_file_poll(struct file *filp, poll_table *wait)
54{
55    return POLLERR;
56}
57
58static long bad_file_unlocked_ioctl(struct file *file, unsigned cmd,
59            unsigned long arg)
60{
61    return -EIO;
62}
63
64static long bad_file_compat_ioctl(struct file *file, unsigned int cmd,
65            unsigned long arg)
66{
67    return -EIO;
68}
69
70static int bad_file_mmap(struct file *file, struct vm_area_struct *vma)
71{
72    return -EIO;
73}
74
75static int bad_file_open(struct inode *inode, struct file *filp)
76{
77    return -EIO;
78}
79
80static int bad_file_flush(struct file *file, fl_owner_t id)
81{
82    return -EIO;
83}
84
85static int bad_file_release(struct inode *inode, struct file *filp)
86{
87    return -EIO;
88}
89
90static int bad_file_fsync(struct file *file, int datasync)
91{
92    return -EIO;
93}
94
95static int bad_file_aio_fsync(struct kiocb *iocb, int datasync)
96{
97    return -EIO;
98}
99
100static int bad_file_fasync(int fd, struct file *filp, int on)
101{
102    return -EIO;
103}
104
105static int bad_file_lock(struct file *file, int cmd, struct file_lock *fl)
106{
107    return -EIO;
108}
109
110static ssize_t bad_file_sendpage(struct file *file, struct page *page,
111            int off, size_t len, loff_t *pos, int more)
112{
113    return -EIO;
114}
115
116static unsigned long bad_file_get_unmapped_area(struct file *file,
117                unsigned long addr, unsigned long len,
118                unsigned long pgoff, unsigned long flags)
119{
120    return -EIO;
121}
122
123static int bad_file_check_flags(int flags)
124{
125    return -EIO;
126}
127
128static int bad_file_flock(struct file *filp, int cmd, struct file_lock *fl)
129{
130    return -EIO;
131}
132
133static ssize_t bad_file_splice_write(struct pipe_inode_info *pipe,
134            struct file *out, loff_t *ppos, size_t len,
135            unsigned int flags)
136{
137    return -EIO;
138}
139
140static ssize_t bad_file_splice_read(struct file *in, loff_t *ppos,
141            struct pipe_inode_info *pipe, size_t len,
142            unsigned int flags)
143{
144    return -EIO;
145}
146
147static const struct file_operations bad_file_ops =
148{
149    .llseek = bad_file_llseek,
150    .read = bad_file_read,
151    .write = bad_file_write,
152    .aio_read = bad_file_aio_read,
153    .aio_write = bad_file_aio_write,
154    .readdir = bad_file_readdir,
155    .poll = bad_file_poll,
156    .unlocked_ioctl = bad_file_unlocked_ioctl,
157    .compat_ioctl = bad_file_compat_ioctl,
158    .mmap = bad_file_mmap,
159    .open = bad_file_open,
160    .flush = bad_file_flush,
161    .release = bad_file_release,
162    .fsync = bad_file_fsync,
163    .aio_fsync = bad_file_aio_fsync,
164    .fasync = bad_file_fasync,
165    .lock = bad_file_lock,
166    .sendpage = bad_file_sendpage,
167    .get_unmapped_area = bad_file_get_unmapped_area,
168    .check_flags = bad_file_check_flags,
169    .flock = bad_file_flock,
170    .splice_write = bad_file_splice_write,
171    .splice_read = bad_file_splice_read,
172};
173
174static int bad_inode_create (struct inode *dir, struct dentry *dentry,
175        int mode, struct nameidata *nd)
176{
177    return -EIO;
178}
179
180static struct dentry *bad_inode_lookup(struct inode *dir,
181            struct dentry *dentry, struct nameidata *nd)
182{
183    return ERR_PTR(-EIO);
184}
185
186static int bad_inode_link (struct dentry *old_dentry, struct inode *dir,
187        struct dentry *dentry)
188{
189    return -EIO;
190}
191
192static int bad_inode_unlink(struct inode *dir, struct dentry *dentry)
193{
194    return -EIO;
195}
196
197static int bad_inode_symlink (struct inode *dir, struct dentry *dentry,
198        const char *symname)
199{
200    return -EIO;
201}
202
203static int bad_inode_mkdir(struct inode *dir, struct dentry *dentry,
204            int mode)
205{
206    return -EIO;
207}
208
209static int bad_inode_rmdir (struct inode *dir, struct dentry *dentry)
210{
211    return -EIO;
212}
213
214static int bad_inode_mknod (struct inode *dir, struct dentry *dentry,
215            int mode, dev_t rdev)
216{
217    return -EIO;
218}
219
220static int bad_inode_rename (struct inode *old_dir, struct dentry *old_dentry,
221        struct inode *new_dir, struct dentry *new_dentry)
222{
223    return -EIO;
224}
225
226static int bad_inode_readlink(struct dentry *dentry, char __user *buffer,
227        int buflen)
228{
229    return -EIO;
230}
231
232static int bad_inode_permission(struct inode *inode, int mask, unsigned int flags)
233{
234    return -EIO;
235}
236
237static int bad_inode_getattr(struct vfsmount *mnt, struct dentry *dentry,
238            struct kstat *stat)
239{
240    return -EIO;
241}
242
243static int bad_inode_setattr(struct dentry *direntry, struct iattr *attrs)
244{
245    return -EIO;
246}
247
248static int bad_inode_setxattr(struct dentry *dentry, const char *name,
249        const void *value, size_t size, int flags)
250{
251    return -EIO;
252}
253
254static ssize_t bad_inode_getxattr(struct dentry *dentry, const char *name,
255            void *buffer, size_t size)
256{
257    return -EIO;
258}
259
260static ssize_t bad_inode_listxattr(struct dentry *dentry, char *buffer,
261            size_t buffer_size)
262{
263    return -EIO;
264}
265
266static int bad_inode_removexattr(struct dentry *dentry, const char *name)
267{
268    return -EIO;
269}
270
271static const struct inode_operations bad_inode_ops =
272{
273    .create = bad_inode_create,
274    .lookup = bad_inode_lookup,
275    .link = bad_inode_link,
276    .unlink = bad_inode_unlink,
277    .symlink = bad_inode_symlink,
278    .mkdir = bad_inode_mkdir,
279    .rmdir = bad_inode_rmdir,
280    .mknod = bad_inode_mknod,
281    .rename = bad_inode_rename,
282    .readlink = bad_inode_readlink,
283    /* follow_link must be no-op, otherwise unmounting this inode
284       won't work */
285    /* put_link returns void */
286    /* truncate returns void */
287    .permission = bad_inode_permission,
288    .getattr = bad_inode_getattr,
289    .setattr = bad_inode_setattr,
290    .setxattr = bad_inode_setxattr,
291    .getxattr = bad_inode_getxattr,
292    .listxattr = bad_inode_listxattr,
293    .removexattr = bad_inode_removexattr,
294    /* truncate_range returns void */
295};
296
297
298/*
299 * When a filesystem is unable to read an inode due to an I/O error in
300 * its read_inode() function, it can call make_bad_inode() to return a
301 * set of stubs which will return EIO errors as required.
302 *
303 * We only need to do limited initialisation: all other fields are
304 * preinitialised to zero automatically.
305 */
306 
307/**
308 * make_bad_inode - mark an inode bad due to an I/O error
309 * @inode: Inode to mark bad
310 *
311 * When an inode cannot be read due to a media or remote network
312 * failure this function makes the inode "bad" and causes I/O operations
313 * on it to fail from this point on.
314 */
315 
316void make_bad_inode(struct inode *inode)
317{
318    remove_inode_hash(inode);
319
320    inode->i_mode = S_IFREG;
321    inode->i_atime = inode->i_mtime = inode->i_ctime =
322        current_fs_time(inode->i_sb);
323    inode->i_op = &bad_inode_ops;
324    inode->i_fop = &bad_file_ops;
325}
326EXPORT_SYMBOL(make_bad_inode);
327
328/*
329 * This tests whether an inode has been flagged as bad. The test uses
330 * &bad_inode_ops to cover the case of invalidated inodes as well as
331 * those created by make_bad_inode() above.
332 */
333 
334/**
335 * is_bad_inode - is an inode errored
336 * @inode: inode to test
337 *
338 * Returns true if the inode in question has been marked as bad.
339 */
340 
341int is_bad_inode(struct inode *inode)
342{
343    return (inode->i_op == &bad_inode_ops);
344}
345
346EXPORT_SYMBOL(is_bad_inode);
347
348/**
349 * iget_failed - Mark an under-construction inode as dead and release it
350 * @inode: The inode to discard
351 *
352 * Mark an under-construction inode as dead and release it.
353 */
354void iget_failed(struct inode *inode)
355{
356    make_bad_inode(inode);
357    unlock_new_inode(inode);
358    iput(inode);
359}
360EXPORT_SYMBOL(iget_failed);
361

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