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Merge branch 'for-rmk' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / coda / dir.c
1
2 /*
3 * Directory operations for Coda filesystem
4 * Original version: (C) 1996 P. Braam and M. Callahan
5 * Rewritten for Linux 2.1. (C) 1997 Carnegie Mellon University
6 *
7 * Carnegie Mellon encourages users to contribute improvements to
8 * the Coda project. Contact Peter Braam (coda@cs.cmu.edu).
9 */
10
11 #include <linux/types.h>
12 #include <linux/kernel.h>
13 #include <linux/time.h>
14 #include <linux/fs.h>
15 #include <linux/slab.h>
16 #include <linux/file.h>
17 #include <linux/stat.h>
18 #include <linux/errno.h>
19 #include <linux/string.h>
20 #include <linux/spinlock.h>
21 #include <linux/namei.h>
22
23 #include <asm/uaccess.h>
24
25 #include <linux/coda.h>
26 #include <linux/coda_linux.h>
27 #include <linux/coda_psdev.h>
28 #include <linux/coda_fs_i.h>
29 #include <linux/coda_cache.h>
30
31 #include "coda_int.h"
32
33 /* dir inode-ops */
34 static int coda_create(struct inode *dir, struct dentry *new, int mode, struct nameidata *nd);
35 static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, struct nameidata *nd);
36 static int coda_link(struct dentry *old_dentry, struct inode *dir_inode,
37 struct dentry *entry);
38 static int coda_unlink(struct inode *dir_inode, struct dentry *entry);
39 static int coda_symlink(struct inode *dir_inode, struct dentry *entry,
40 const char *symname);
41 static int coda_mkdir(struct inode *dir_inode, struct dentry *entry, int mode);
42 static int coda_rmdir(struct inode *dir_inode, struct dentry *entry);
43 static int coda_rename(struct inode *old_inode, struct dentry *old_dentry,
44 struct inode *new_inode, struct dentry *new_dentry);
45
46 /* dir file-ops */
47 static int coda_readdir(struct file *file, void *buf, filldir_t filldir);
48
49 /* dentry ops */
50 static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd);
51 static int coda_dentry_delete(const struct dentry *);
52
53 /* support routines */
54 static int coda_venus_readdir(struct file *coda_file, void *buf,
55 filldir_t filldir);
56
57 /* same as fs/bad_inode.c */
58 static int coda_return_EIO(void)
59 {
60 return -EIO;
61 }
62 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
63
64 static const struct dentry_operations coda_dentry_operations =
65 {
66 .d_revalidate = coda_dentry_revalidate,
67 .d_delete = coda_dentry_delete,
68 };
69
70 const struct inode_operations coda_dir_inode_operations =
71 {
72 .create = coda_create,
73 .lookup = coda_lookup,
74 .link = coda_link,
75 .unlink = coda_unlink,
76 .symlink = coda_symlink,
77 .mkdir = coda_mkdir,
78 .rmdir = coda_rmdir,
79 .mknod = CODA_EIO_ERROR,
80 .rename = coda_rename,
81 .permission = coda_permission,
82 .getattr = coda_getattr,
83 .setattr = coda_setattr,
84 };
85
86 const struct file_operations coda_dir_operations = {
87 .llseek = generic_file_llseek,
88 .read = generic_read_dir,
89 .readdir = coda_readdir,
90 .open = coda_open,
91 .release = coda_release,
92 .fsync = coda_fsync,
93 };
94
95
96 /* inode operations for directories */
97 /* access routines: lookup, readlink, permission */
98 static struct dentry *coda_lookup(struct inode *dir, struct dentry *entry, struct nameidata *nd)
99 {
100 struct inode *inode = NULL;
101 struct CodaFid resfid = { { 0, } };
102 int type = 0;
103 int error = 0;
104 const char *name = entry->d_name.name;
105 size_t length = entry->d_name.len;
106
107 if (length > CODA_MAXNAMLEN) {
108 printk(KERN_ERR "name too long: lookup, %s (%*s)\n",
109 coda_i2s(dir), (int)length, name);
110 return ERR_PTR(-ENAMETOOLONG);
111 }
112
113 /* control object, create inode on the fly */
114 if (coda_isroot(dir) && coda_iscontrol(name, length)) {
115 error = coda_cnode_makectl(&inode, dir->i_sb);
116 type = CODA_NOCACHE;
117 goto exit;
118 }
119
120 error = venus_lookup(dir->i_sb, coda_i2f(dir), name, length,
121 &type, &resfid);
122 if (!error)
123 error = coda_cnode_make(&inode, &resfid, dir->i_sb);
124
125 if (error && error != -ENOENT)
126 return ERR_PTR(error);
127
128 exit:
129 d_set_d_op(entry, &coda_dentry_operations);
130
131 if (inode && (type & CODA_NOCACHE))
132 coda_flag_inode(inode, C_VATTR | C_PURGE);
133
134 return d_splice_alias(inode, entry);
135 }
136
137
138 int coda_permission(struct inode *inode, int mask, unsigned int flags)
139 {
140 int error;
141
142 if (flags & IPERM_FLAG_RCU)
143 return -ECHILD;
144
145 mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
146
147 if (!mask)
148 return 0;
149
150 if ((mask & MAY_EXEC) && !execute_ok(inode))
151 return -EACCES;
152
153 if (coda_cache_check(inode, mask))
154 return 0;
155
156 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
157
158 if (!error)
159 coda_cache_enter(inode, mask);
160
161 return error;
162 }
163
164
165 static inline void coda_dir_update_mtime(struct inode *dir)
166 {
167 #ifdef REQUERY_VENUS_FOR_MTIME
168 /* invalidate the directory cnode's attributes so we refetch the
169 * attributes from venus next time the inode is referenced */
170 coda_flag_inode(dir, C_VATTR);
171 #else
172 /* optimistically we can also act as if our nose bleeds. The
173 * granularity of the mtime is coarse anyways so we might actually be
174 * right most of the time. Note: we only do this for directories. */
175 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
176 #endif
177 }
178
179 /* we have to wrap inc_nlink/drop_nlink because sometimes userspace uses a
180 * trick to fool GNU find's optimizations. If we can't be sure of the link
181 * (because of volume mount points) we set i_nlink to 1 which forces find
182 * to consider every child as a possible directory. We should also never
183 * see an increment or decrement for deleted directories where i_nlink == 0 */
184 static inline void coda_dir_inc_nlink(struct inode *dir)
185 {
186 if (dir->i_nlink >= 2)
187 inc_nlink(dir);
188 }
189
190 static inline void coda_dir_drop_nlink(struct inode *dir)
191 {
192 if (dir->i_nlink > 2)
193 drop_nlink(dir);
194 }
195
196 /* creation routines: create, mknod, mkdir, link, symlink */
197 static int coda_create(struct inode *dir, struct dentry *de, int mode, struct nameidata *nd)
198 {
199 int error;
200 const char *name=de->d_name.name;
201 int length=de->d_name.len;
202 struct inode *inode;
203 struct CodaFid newfid;
204 struct coda_vattr attrs;
205
206 if (coda_isroot(dir) && coda_iscontrol(name, length))
207 return -EPERM;
208
209 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
210 0, mode, &newfid, &attrs);
211 if (error)
212 goto err_out;
213
214 inode = coda_iget(dir->i_sb, &newfid, &attrs);
215 if (IS_ERR(inode)) {
216 error = PTR_ERR(inode);
217 goto err_out;
218 }
219
220 /* invalidate the directory cnode's attributes */
221 coda_dir_update_mtime(dir);
222 d_instantiate(de, inode);
223 return 0;
224 err_out:
225 d_drop(de);
226 return error;
227 }
228
229 static int coda_mkdir(struct inode *dir, struct dentry *de, int mode)
230 {
231 struct inode *inode;
232 struct coda_vattr attrs;
233 const char *name = de->d_name.name;
234 int len = de->d_name.len;
235 int error;
236 struct CodaFid newfid;
237
238 if (coda_isroot(dir) && coda_iscontrol(name, len))
239 return -EPERM;
240
241 attrs.va_mode = mode;
242 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
243 name, len, &newfid, &attrs);
244 if (error)
245 goto err_out;
246
247 inode = coda_iget(dir->i_sb, &newfid, &attrs);
248 if (IS_ERR(inode)) {
249 error = PTR_ERR(inode);
250 goto err_out;
251 }
252
253 /* invalidate the directory cnode's attributes */
254 coda_dir_inc_nlink(dir);
255 coda_dir_update_mtime(dir);
256 d_instantiate(de, inode);
257 return 0;
258 err_out:
259 d_drop(de);
260 return error;
261 }
262
263 /* try to make de an entry in dir_inodde linked to source_de */
264 static int coda_link(struct dentry *source_de, struct inode *dir_inode,
265 struct dentry *de)
266 {
267 struct inode *inode = source_de->d_inode;
268 const char * name = de->d_name.name;
269 int len = de->d_name.len;
270 int error;
271
272 if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
273 return -EPERM;
274
275 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
276 coda_i2f(dir_inode), (const char *)name, len);
277 if (error) {
278 d_drop(de);
279 return error;
280 }
281
282 coda_dir_update_mtime(dir_inode);
283 ihold(inode);
284 d_instantiate(de, inode);
285 inc_nlink(inode);
286 return 0;
287 }
288
289
290 static int coda_symlink(struct inode *dir_inode, struct dentry *de,
291 const char *symname)
292 {
293 const char *name = de->d_name.name;
294 int len = de->d_name.len;
295 int symlen;
296 int error;
297
298 if (coda_isroot(dir_inode) && coda_iscontrol(name, len))
299 return -EPERM;
300
301 symlen = strlen(symname);
302 if (symlen > CODA_MAXPATHLEN)
303 return -ENAMETOOLONG;
304
305 /*
306 * This entry is now negative. Since we do not create
307 * an inode for the entry we have to drop it.
308 */
309 d_drop(de);
310 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
311 symname, symlen);
312
313 /* mtime is no good anymore */
314 if (!error)
315 coda_dir_update_mtime(dir_inode);
316
317 return error;
318 }
319
320 /* destruction routines: unlink, rmdir */
321 static int coda_unlink(struct inode *dir, struct dentry *de)
322 {
323 int error;
324 const char *name = de->d_name.name;
325 int len = de->d_name.len;
326
327 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
328 if (error)
329 return error;
330
331 coda_dir_update_mtime(dir);
332 drop_nlink(de->d_inode);
333 return 0;
334 }
335
336 static int coda_rmdir(struct inode *dir, struct dentry *de)
337 {
338 const char *name = de->d_name.name;
339 int len = de->d_name.len;
340 int error;
341
342 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
343 if (!error) {
344 /* VFS may delete the child */
345 if (de->d_inode)
346 de->d_inode->i_nlink = 0;
347
348 /* fix the link count of the parent */
349 coda_dir_drop_nlink(dir);
350 coda_dir_update_mtime(dir);
351 }
352 return error;
353 }
354
355 /* rename */
356 static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
357 struct inode *new_dir, struct dentry *new_dentry)
358 {
359 const char *old_name = old_dentry->d_name.name;
360 const char *new_name = new_dentry->d_name.name;
361 int old_length = old_dentry->d_name.len;
362 int new_length = new_dentry->d_name.len;
363 int error;
364
365 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
366 coda_i2f(new_dir), old_length, new_length,
367 (const char *) old_name, (const char *)new_name);
368 if (!error) {
369 if (new_dentry->d_inode) {
370 if (S_ISDIR(new_dentry->d_inode->i_mode)) {
371 coda_dir_drop_nlink(old_dir);
372 coda_dir_inc_nlink(new_dir);
373 }
374 coda_dir_update_mtime(old_dir);
375 coda_dir_update_mtime(new_dir);
376 coda_flag_inode(new_dentry->d_inode, C_VATTR);
377 } else {
378 coda_flag_inode(old_dir, C_VATTR);
379 coda_flag_inode(new_dir, C_VATTR);
380 }
381 }
382 return error;
383 }
384
385
386 /* file operations for directories */
387 static int coda_readdir(struct file *coda_file, void *buf, filldir_t filldir)
388 {
389 struct coda_file_info *cfi;
390 struct file *host_file;
391 int ret;
392
393 cfi = CODA_FTOC(coda_file);
394 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
395 host_file = cfi->cfi_container;
396
397 if (!host_file->f_op)
398 return -ENOTDIR;
399
400 if (host_file->f_op->readdir)
401 {
402 /* potemkin case: we were handed a directory inode.
403 * We can't use vfs_readdir because we have to keep the file
404 * position in sync between the coda_file and the host_file.
405 * and as such we need grab the inode mutex. */
406 struct inode *host_inode = host_file->f_path.dentry->d_inode;
407
408 mutex_lock(&host_inode->i_mutex);
409 host_file->f_pos = coda_file->f_pos;
410
411 ret = -ENOENT;
412 if (!IS_DEADDIR(host_inode)) {
413 ret = host_file->f_op->readdir(host_file, buf, filldir);
414 file_accessed(host_file);
415 }
416
417 coda_file->f_pos = host_file->f_pos;
418 mutex_unlock(&host_inode->i_mutex);
419 }
420 else /* Venus: we must read Venus dirents from a file */
421 ret = coda_venus_readdir(coda_file, buf, filldir);
422
423 return ret;
424 }
425
426 static inline unsigned int CDT2DT(unsigned char cdt)
427 {
428 unsigned int dt;
429
430 switch(cdt) {
431 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
432 case CDT_FIFO: dt = DT_FIFO; break;
433 case CDT_CHR: dt = DT_CHR; break;
434 case CDT_DIR: dt = DT_DIR; break;
435 case CDT_BLK: dt = DT_BLK; break;
436 case CDT_REG: dt = DT_REG; break;
437 case CDT_LNK: dt = DT_LNK; break;
438 case CDT_SOCK: dt = DT_SOCK; break;
439 case CDT_WHT: dt = DT_WHT; break;
440 default: dt = DT_UNKNOWN; break;
441 }
442 return dt;
443 }
444
445 /* support routines */
446 static int coda_venus_readdir(struct file *coda_file, void *buf,
447 filldir_t filldir)
448 {
449 int result = 0; /* # of entries returned */
450 struct coda_file_info *cfi;
451 struct coda_inode_info *cii;
452 struct file *host_file;
453 struct dentry *de;
454 struct venus_dirent *vdir;
455 unsigned long vdir_size =
456 (unsigned long)(&((struct venus_dirent *)0)->d_name);
457 unsigned int type;
458 struct qstr name;
459 ino_t ino;
460 int ret;
461
462 cfi = CODA_FTOC(coda_file);
463 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
464 host_file = cfi->cfi_container;
465
466 de = coda_file->f_path.dentry;
467 cii = ITOC(de->d_inode);
468
469 vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
470 if (!vdir) return -ENOMEM;
471
472 if (coda_file->f_pos == 0) {
473 ret = filldir(buf, ".", 1, 0, de->d_inode->i_ino, DT_DIR);
474 if (ret < 0)
475 goto out;
476 result++;
477 coda_file->f_pos++;
478 }
479 if (coda_file->f_pos == 1) {
480 ret = filldir(buf, "..", 2, 1, de->d_parent->d_inode->i_ino, DT_DIR);
481 if (ret < 0)
482 goto out;
483 result++;
484 coda_file->f_pos++;
485 }
486 while (1) {
487 /* read entries from the directory file */
488 ret = kernel_read(host_file, coda_file->f_pos - 2, (char *)vdir,
489 sizeof(*vdir));
490 if (ret < 0) {
491 printk(KERN_ERR "coda readdir: read dir %s failed %d\n",
492 coda_f2s(&cii->c_fid), ret);
493 break;
494 }
495 if (ret == 0) break; /* end of directory file reached */
496
497 /* catch truncated reads */
498 if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
499 printk(KERN_ERR "coda readdir: short read on %s\n",
500 coda_f2s(&cii->c_fid));
501 ret = -EBADF;
502 break;
503 }
504 /* validate whether the directory file actually makes sense */
505 if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
506 printk(KERN_ERR "coda readdir: invalid dir %s\n",
507 coda_f2s(&cii->c_fid));
508 ret = -EBADF;
509 break;
510 }
511
512 name.len = vdir->d_namlen;
513 name.name = vdir->d_name;
514
515 /* Make sure we skip '.' and '..', we already got those */
516 if (name.name[0] == '.' && (name.len == 1 ||
517 (vdir->d_name[1] == '.' && name.len == 2)))
518 vdir->d_fileno = name.len = 0;
519
520 /* skip null entries */
521 if (vdir->d_fileno && name.len) {
522 /* try to look up this entry in the dcache, that way
523 * userspace doesn't have to worry about breaking
524 * getcwd by having mismatched inode numbers for
525 * internal volume mountpoints. */
526 ino = find_inode_number(de, &name);
527 if (!ino) ino = vdir->d_fileno;
528
529 type = CDT2DT(vdir->d_type);
530 ret = filldir(buf, name.name, name.len,
531 coda_file->f_pos, ino, type);
532 /* failure means no space for filling in this round */
533 if (ret < 0) break;
534 result++;
535 }
536 /* we'll always have progress because d_reclen is unsigned and
537 * we've already established it is non-zero. */
538 coda_file->f_pos += vdir->d_reclen;
539 }
540 out:
541 kfree(vdir);
542 return result ? result : ret;
543 }
544
545 /* called when a cache lookup succeeds */
546 static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
547 {
548 struct inode *inode;
549 struct coda_inode_info *cii;
550
551 if (nd->flags & LOOKUP_RCU)
552 return -ECHILD;
553
554 inode = de->d_inode;
555 if (!inode || coda_isroot(inode))
556 goto out;
557 if (is_bad_inode(inode))
558 goto bad;
559
560 cii = ITOC(de->d_inode);
561 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
562 goto out;
563
564 shrink_dcache_parent(de);
565
566 /* propagate for a flush */
567 if (cii->c_flags & C_FLUSH)
568 coda_flag_inode_children(inode, C_FLUSH);
569
570 if (de->d_count > 1)
571 /* pretend it's valid, but don't change the flags */
572 goto out;
573
574 /* clear the flags. */
575 spin_lock(&cii->c_lock);
576 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
577 spin_unlock(&cii->c_lock);
578 bad:
579 return 0;
580 out:
581 return 1;
582 }
583
584 /*
585 * This is the callback from dput() when d_count is going to 0.
586 * We use this to unhash dentries with bad inodes.
587 */
588 static int coda_dentry_delete(const struct dentry * dentry)
589 {
590 int flags;
591
592 if (!dentry->d_inode)
593 return 0;
594
595 flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
596 if (is_bad_inode(dentry->d_inode) || flags) {
597 return 1;
598 }
599 return 0;
600 }
601
602
603
604 /*
605 * This is called when we want to check if the inode has
606 * changed on the server. Coda makes this easy since the
607 * cache manager Venus issues a downcall to the kernel when this
608 * happens
609 */
610 int coda_revalidate_inode(struct dentry *dentry)
611 {
612 struct coda_vattr attr;
613 int error;
614 int old_mode;
615 ino_t old_ino;
616 struct inode *inode = dentry->d_inode;
617 struct coda_inode_info *cii = ITOC(inode);
618
619 if (!cii->c_flags)
620 return 0;
621
622 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
623 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
624 if (error)
625 return -EIO;
626
627 /* this inode may be lost if:
628 - it's ino changed
629 - type changes must be permitted for repair and
630 missing mount points.
631 */
632 old_mode = inode->i_mode;
633 old_ino = inode->i_ino;
634 coda_vattr_to_iattr(inode, &attr);
635
636 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
637 printk("Coda: inode %ld, fid %s changed type!\n",
638 inode->i_ino, coda_f2s(&(cii->c_fid)));
639 }
640
641 /* the following can happen when a local fid is replaced
642 with a global one, here we lose and declare the inode bad */
643 if (inode->i_ino != old_ino)
644 return -EIO;
645
646 coda_flag_inode_children(inode, C_FLUSH);
647
648 spin_lock(&cii->c_lock);
649 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
650 spin_unlock(&cii->c_lock);
651 }
652 return 0;
653 }
kernel source for telekom puls (alcatel/mediatek)