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Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
[wrt350n-kernel.git] / fs / coda / dir.c
blob9ddf5ed62162fdf767fbf30ff3d2f0cff82ad8e7
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/file.h>
16 #include <linux/stat.h>
17 #include <linux/errno.h>
18 #include <linux/string.h>
19 #include <linux/smp_lock.h>
20
21 #include <asm/uaccess.h>
22
23 #include <linux/coda.h>
24 #include <linux/coda_linux.h>
25 #include <linux/coda_psdev.h>
26 #include <linux/coda_fs_i.h>
27 #include <linux/coda_cache.h>
28 #include <linux/coda_proc.h>
29
30 #include "coda_int.h"
31
32 /* dir inode-ops */
33 static int coda_create(struct inode *dir, struct dentry *new, int mode, struct nameidata *nd);
34 static struct dentry *coda_lookup(struct inode *dir, struct dentry *target, struct nameidata *nd);
35 static int coda_link(struct dentry *old_dentry, struct inode *dir_inode,
36 struct dentry *entry);
37 static int coda_unlink(struct inode *dir_inode, struct dentry *entry);
38 static int coda_symlink(struct inode *dir_inode, struct dentry *entry,
39 const char *symname);
40 static int coda_mkdir(struct inode *dir_inode, struct dentry *entry, int mode);
41 static int coda_rmdir(struct inode *dir_inode, struct dentry *entry);
42 static int coda_rename(struct inode *old_inode, struct dentry *old_dentry,
43 struct inode *new_inode, struct dentry *new_dentry);
44
45 /* dir file-ops */
46 static int coda_readdir(struct file *file, void *dirent, filldir_t filldir);
47
48 /* dentry ops */
49 static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd);
50 static int coda_dentry_delete(struct dentry *);
51
52 /* support routines */
53 static int coda_venus_readdir(struct file *filp, filldir_t filldir,
54 void *dirent, struct dentry *dir);
55
56 /* same as fs/bad_inode.c */
57 static int coda_return_EIO(void)
58 {
59 return -EIO;
60 }
61 #define CODA_EIO_ERROR ((void *) (coda_return_EIO))
62
63 static struct dentry_operations coda_dentry_operations =
64 {
65 .d_revalidate = coda_dentry_revalidate,
66 .d_delete = coda_dentry_delete,
67 };
68
69 const struct inode_operations coda_dir_inode_operations =
70 {
71 .create = coda_create,
72 .lookup = coda_lookup,
73 .link = coda_link,
74 .unlink = coda_unlink,
75 .symlink = coda_symlink,
76 .mkdir = coda_mkdir,
77 .rmdir = coda_rmdir,
78 .mknod = CODA_EIO_ERROR,
79 .rename = coda_rename,
80 .permission = coda_permission,
81 .getattr = coda_getattr,
82 .setattr = coda_setattr,
83 };
84
85 const struct file_operations coda_dir_operations = {
86 .llseek = generic_file_llseek,
87 .read = generic_read_dir,
88 .readdir = coda_readdir,
89 .open = coda_open,
90 .flush = coda_flush,
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 *res_inode = NULL;
101 struct CodaFid resfid = { { 0, } };
102 int dropme = 0; /* to indicate entry should not be cached */
103 int type = 0;
104 int error = 0;
105 const char *name = entry->d_name.name;
106 size_t length = entry->d_name.len;
107
108 if ( length > CODA_MAXNAMLEN ) {
109 printk("name too long: lookup, %s (%*s)\n",
110 coda_i2s(dir), (int)length, name);
111 return ERR_PTR(-ENAMETOOLONG);
112 }
113
114 lock_kernel();
115 /* control object, create inode on the fly */
116 if (coda_isroot(dir) && coda_iscontrol(name, length)) {
117 error = coda_cnode_makectl(&res_inode, dir->i_sb);
118 dropme = 1;
119 goto exit;
120 }
121
122 error = venus_lookup(dir->i_sb, coda_i2f(dir),
123 (const char *)name, length, &type, &resfid);
124
125 res_inode = NULL;
126 if (!error) {
127 if (type & CODA_NOCACHE) {
128 type &= (~CODA_NOCACHE);
129 dropme = 1;
130 }
131
132 error = coda_cnode_make(&res_inode, &resfid, dir->i_sb);
133 if (error) {
134 unlock_kernel();
135 return ERR_PTR(error);
136 }
137 } else if (error != -ENOENT) {
138 unlock_kernel();
139 return ERR_PTR(error);
140 }
141
142 exit:
143 entry->d_time = 0;
144 entry->d_op = &coda_dentry_operations;
145 d_add(entry, res_inode);
146 if ( dropme ) {
147 d_drop(entry);
148 coda_flag_inode(res_inode, C_VATTR);
149 }
150 unlock_kernel();
151 return NULL;
152 }
153
154
155 int coda_permission(struct inode *inode, int mask, struct nameidata *nd)
156 {
157 int error = 0;
158
159 if (!mask)
160 return 0;
161
162 lock_kernel();
163
164 coda_vfs_stat.permission++;
165
166 if (coda_cache_check(inode, mask))
167 goto out;
168
169 error = venus_access(inode->i_sb, coda_i2f(inode), mask);
170
171 if (!error)
172 coda_cache_enter(inode, mask);
173
174 out:
175 unlock_kernel();
176
177 return error;
178 }
179
180
181 static inline void coda_dir_changed(struct inode *dir, int link)
182 {
183 #ifdef REQUERY_VENUS_FOR_MTIME
184 /* invalidate the directory cnode's attributes so we refetch the
185 * attributes from venus next time the inode is referenced */
186 coda_flag_inode(dir, C_VATTR);
187 #else
188 /* optimistically we can also act as if our nose bleeds. The
189 * granularity of the mtime is coarse anyways so we might actually be
190 * right most of the time. Note: we only do this for directories. */
191 dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
192 #endif
193 if (link)
194 dir->i_nlink += link;
195 }
196
197 /* creation routines: create, mknod, mkdir, link, symlink */
198 static int coda_create(struct inode *dir, struct dentry *de, int mode, struct nameidata *nd)
199 {
200 int error=0;
201 const char *name=de->d_name.name;
202 int length=de->d_name.len;
203 struct inode *inode;
204 struct CodaFid newfid;
205 struct coda_vattr attrs;
206
207 lock_kernel();
208 coda_vfs_stat.create++;
209
210 if (coda_isroot(dir) && coda_iscontrol(name, length)) {
211 unlock_kernel();
212 return -EPERM;
213 }
214
215 error = venus_create(dir->i_sb, coda_i2f(dir), name, length,
216 0, mode, &newfid, &attrs);
217
218 if ( error ) {
219 unlock_kernel();
220 d_drop(de);
221 return error;
222 }
223
224 inode = coda_iget(dir->i_sb, &newfid, &attrs);
225 if ( IS_ERR(inode) ) {
226 unlock_kernel();
227 d_drop(de);
228 return PTR_ERR(inode);
229 }
230
231 /* invalidate the directory cnode's attributes */
232 coda_dir_changed(dir, 0);
233 unlock_kernel();
234 d_instantiate(de, inode);
235 return 0;
236 }
237
238 static int coda_mkdir(struct inode *dir, struct dentry *de, int mode)
239 {
240 struct inode *inode;
241 struct coda_vattr attrs;
242 const char *name = de->d_name.name;
243 int len = de->d_name.len;
244 int error;
245 struct CodaFid newfid;
246
247 lock_kernel();
248 coda_vfs_stat.mkdir++;
249
250 if (coda_isroot(dir) && coda_iscontrol(name, len)) {
251 unlock_kernel();
252 return -EPERM;
253 }
254
255 attrs.va_mode = mode;
256 error = venus_mkdir(dir->i_sb, coda_i2f(dir),
257 name, len, &newfid, &attrs);
258
259 if ( error ) {
260 unlock_kernel();
261 d_drop(de);
262 return error;
263 }
264
265 inode = coda_iget(dir->i_sb, &newfid, &attrs);
266 if ( IS_ERR(inode) ) {
267 unlock_kernel();
268 d_drop(de);
269 return PTR_ERR(inode);
270 }
271
272 /* invalidate the directory cnode's attributes */
273 coda_dir_changed(dir, 1);
274 unlock_kernel();
275 d_instantiate(de, inode);
276 return 0;
277 }
278
279 /* try to make de an entry in dir_inodde linked to source_de */
280 static int coda_link(struct dentry *source_de, struct inode *dir_inode,
281 struct dentry *de)
282 {
283 struct inode *inode = source_de->d_inode;
284 const char * name = de->d_name.name;
285 int len = de->d_name.len;
286 int error;
287
288 lock_kernel();
289 coda_vfs_stat.link++;
290
291 if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
292 unlock_kernel();
293 return -EPERM;
294 }
295
296 error = venus_link(dir_inode->i_sb, coda_i2f(inode),
297 coda_i2f(dir_inode), (const char *)name, len);
298
299 if (error) {
300 d_drop(de);
301 goto out;
302 }
303
304 coda_dir_changed(dir_inode, 0);
305 atomic_inc(&inode->i_count);
306 d_instantiate(de, inode);
307 inc_nlink(inode);
308
309 out:
310 unlock_kernel();
311 return(error);
312 }
313
314
315 static int coda_symlink(struct inode *dir_inode, struct dentry *de,
316 const char *symname)
317 {
318 const char *name = de->d_name.name;
319 int len = de->d_name.len;
320 int symlen;
321 int error=0;
322
323 lock_kernel();
324 coda_vfs_stat.symlink++;
325
326 if (coda_isroot(dir_inode) && coda_iscontrol(name, len)) {
327 unlock_kernel();
328 return -EPERM;
329 }
330
331 symlen = strlen(symname);
332 if ( symlen > CODA_MAXPATHLEN ) {
333 unlock_kernel();
334 return -ENAMETOOLONG;
335 }
336
337 /*
338 * This entry is now negative. Since we do not create
339 * an inode for the entry we have to drop it.
340 */
341 d_drop(de);
342 error = venus_symlink(dir_inode->i_sb, coda_i2f(dir_inode), name, len,
343 symname, symlen);
344
345 /* mtime is no good anymore */
346 if ( !error )
347 coda_dir_changed(dir_inode, 0);
348
349 unlock_kernel();
350 return error;
351 }
352
353 /* destruction routines: unlink, rmdir */
354 int coda_unlink(struct inode *dir, struct dentry *de)
355 {
356 int error;
357 const char *name = de->d_name.name;
358 int len = de->d_name.len;
359
360 lock_kernel();
361 coda_vfs_stat.unlink++;
362
363 error = venus_remove(dir->i_sb, coda_i2f(dir), name, len);
364 if ( error ) {
365 unlock_kernel();
366 return error;
367 }
368
369 coda_dir_changed(dir, 0);
370 drop_nlink(de->d_inode);
371 unlock_kernel();
372
373 return 0;
374 }
375
376 int coda_rmdir(struct inode *dir, struct dentry *de)
377 {
378 const char *name = de->d_name.name;
379 int len = de->d_name.len;
380 int error;
381
382 lock_kernel();
383 coda_vfs_stat.rmdir++;
384
385 if (!d_unhashed(de)) {
386 unlock_kernel();
387 return -EBUSY;
388 }
389 error = venus_rmdir(dir->i_sb, coda_i2f(dir), name, len);
390
391 if ( error ) {
392 unlock_kernel();
393 return error;
394 }
395
396 coda_dir_changed(dir, -1);
397 drop_nlink(de->d_inode);
398 d_delete(de);
399 unlock_kernel();
400
401 return 0;
402 }
403
404 /* rename */
405 static int coda_rename(struct inode *old_dir, struct dentry *old_dentry,
406 struct inode *new_dir, struct dentry *new_dentry)
407 {
408 const char *old_name = old_dentry->d_name.name;
409 const char *new_name = new_dentry->d_name.name;
410 int old_length = old_dentry->d_name.len;
411 int new_length = new_dentry->d_name.len;
412 int link_adjust = 0;
413 int error;
414
415 lock_kernel();
416 coda_vfs_stat.rename++;
417
418 error = venus_rename(old_dir->i_sb, coda_i2f(old_dir),
419 coda_i2f(new_dir), old_length, new_length,
420 (const char *) old_name, (const char *)new_name);
421
422 if ( !error ) {
423 if ( new_dentry->d_inode ) {
424 if ( S_ISDIR(new_dentry->d_inode->i_mode) )
425 link_adjust = 1;
426
427 coda_dir_changed(old_dir, -link_adjust);
428 coda_dir_changed(new_dir, link_adjust);
429 coda_flag_inode(new_dentry->d_inode, C_VATTR);
430 } else {
431 coda_flag_inode(old_dir, C_VATTR);
432 coda_flag_inode(new_dir, C_VATTR);
433 }
434 }
435 unlock_kernel();
436
437 return error;
438 }
439
440
441 /* file operations for directories */
442 int coda_readdir(struct file *coda_file, void *dirent, filldir_t filldir)
443 {
444 struct dentry *coda_dentry = coda_file->f_path.dentry;
445 struct coda_file_info *cfi;
446 struct file *host_file;
447 struct inode *host_inode;
448 int ret;
449
450 cfi = CODA_FTOC(coda_file);
451 BUG_ON(!cfi || cfi->cfi_magic != CODA_MAGIC);
452 host_file = cfi->cfi_container;
453
454 coda_vfs_stat.readdir++;
455
456 host_inode = host_file->f_path.dentry->d_inode;
457 mutex_lock(&host_inode->i_mutex);
458 host_file->f_pos = coda_file->f_pos;
459
460 if (!host_file->f_op->readdir) {
461 /* Venus: we must read Venus dirents from the file */
462 ret = coda_venus_readdir(host_file, filldir, dirent, coda_dentry);
463 } else {
464 /* potemkin case: we were handed a directory inode. */
465 /* Yuk, we can't call vfs_readdir because we are already
466 * holding the inode semaphore. */
467 ret = -ENOTDIR;
468 if (!host_file->f_op || !host_file->f_op->readdir)
469 goto out;
470
471 ret = -ENOENT;
472 if (!IS_DEADDIR(host_inode)) {
473 ret = host_file->f_op->readdir(host_file, filldir, dirent);
474 file_accessed(host_file);
475 }
476 }
477 out:
478 coda_file->f_pos = host_file->f_pos;
479 mutex_unlock(&host_inode->i_mutex);
480
481 return ret;
482 }
483
484 static inline unsigned int CDT2DT(unsigned char cdt)
485 {
486 unsigned int dt;
487
488 switch(cdt) {
489 case CDT_UNKNOWN: dt = DT_UNKNOWN; break;
490 case CDT_FIFO: dt = DT_FIFO; break;
491 case CDT_CHR: dt = DT_CHR; break;
492 case CDT_DIR: dt = DT_DIR; break;
493 case CDT_BLK: dt = DT_BLK; break;
494 case CDT_REG: dt = DT_REG; break;
495 case CDT_LNK: dt = DT_LNK; break;
496 case CDT_SOCK: dt = DT_SOCK; break;
497 case CDT_WHT: dt = DT_WHT; break;
498 default: dt = DT_UNKNOWN; break;
499 }
500 return dt;
501 }
502
503 /* support routines */
504 static int coda_venus_readdir(struct file *filp, filldir_t filldir,
505 void *dirent, struct dentry *dir)
506 {
507 int result = 0; /* # of entries returned */
508 struct venus_dirent *vdir;
509 unsigned long vdir_size =
510 (unsigned long)(&((struct venus_dirent *)0)->d_name);
511 unsigned int type;
512 struct qstr name;
513 ino_t ino;
514 int ret, i;
515
516 vdir = kmalloc(sizeof(*vdir), GFP_KERNEL);
517 if (!vdir) return -ENOMEM;
518
519 i = filp->f_pos;
520 switch(i) {
521 case 0:
522 ret = filldir(dirent, ".", 1, 0, dir->d_inode->i_ino, DT_DIR);
523 if (ret < 0) break;
524 result++;
525 filp->f_pos++;
526 /* fallthrough */
527 case 1:
528 ret = filldir(dirent, "..", 2, 1, dir->d_parent->d_inode->i_ino, DT_DIR);
529 if (ret < 0) break;
530 result++;
531 filp->f_pos++;
532 /* fallthrough */
533 default:
534 while (1) {
535 /* read entries from the directory file */
536 ret = kernel_read(filp, filp->f_pos - 2, (char *)vdir,
537 sizeof(*vdir));
538 if (ret < 0) {
539 printk("coda_venus_readdir: read dir failed %d\n", ret);
540 break;
541 }
542 if (ret == 0) break; /* end of directory file reached */
543
544 /* catch truncated reads */
545 if (ret < vdir_size || ret < vdir_size + vdir->d_namlen) {
546 printk("coda_venus_readdir: short read: %ld\n",
547 filp->f_path.dentry->d_inode->i_ino);
548 ret = -EBADF;
549 break;
550 }
551 /* validate whether the directory file actually makes sense */
552 if (vdir->d_reclen < vdir_size + vdir->d_namlen) {
553 printk("coda_venus_readdir: Invalid dir: %ld\n",
554 filp->f_path.dentry->d_inode->i_ino);
555 ret = -EBADF;
556 break;
557 }
558
559 name.len = vdir->d_namlen;
560 name.name = vdir->d_name;
561
562 /* Make sure we skip '.' and '..', we already got those */
563 if (name.name[0] == '.' && (name.len == 1 ||
564 (vdir->d_name[1] == '.' && name.len == 2)))
565 vdir->d_fileno = name.len = 0;
566
567 /* skip null entries */
568 if (vdir->d_fileno && name.len) {
569 /* try to look up this entry in the dcache, that way
570 * userspace doesn't have to worry about breaking
571 * getcwd by having mismatched inode numbers for
572 * internal volume mountpoints. */
573 ino = find_inode_number(dir, &name);
574 if (!ino) ino = vdir->d_fileno;
575
576 type = CDT2DT(vdir->d_type);
577 ret = filldir(dirent, name.name, name.len, filp->f_pos,
578 ino, type);
579 /* failure means no space for filling in this round */
580 if (ret < 0) break;
581 result++;
582 }
583 /* we'll always have progress because d_reclen is unsigned and
584 * we've already established it is non-zero. */
585 filp->f_pos += vdir->d_reclen;
586 }
587 }
588 kfree(vdir);
589 return result ? result : ret;
590 }
591
592 /* called when a cache lookup succeeds */
593 static int coda_dentry_revalidate(struct dentry *de, struct nameidata *nd)
594 {
595 struct inode *inode = de->d_inode;
596 struct coda_inode_info *cii;
597
598 if (!inode)
599 return 1;
600 lock_kernel();
601 if (coda_isroot(inode))
602 goto out;
603 if (is_bad_inode(inode))
604 goto bad;
605
606 cii = ITOC(de->d_inode);
607 if (!(cii->c_flags & (C_PURGE | C_FLUSH)))
608 goto out;
609
610 shrink_dcache_parent(de);
611
612 /* propagate for a flush */
613 if (cii->c_flags & C_FLUSH)
614 coda_flag_inode_children(inode, C_FLUSH);
615
616 if (atomic_read(&de->d_count) > 1)
617 /* pretend it's valid, but don't change the flags */
618 goto out;
619
620 /* clear the flags. */
621 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
622
623 bad:
624 unlock_kernel();
625 return 0;
626 out:
627 unlock_kernel();
628 return 1;
629 }
630
631 /*
632 * This is the callback from dput() when d_count is going to 0.
633 * We use this to unhash dentries with bad inodes.
634 */
635 static int coda_dentry_delete(struct dentry * dentry)
636 {
637 int flags;
638
639 if (!dentry->d_inode)
640 return 0;
641
642 flags = (ITOC(dentry->d_inode)->c_flags) & C_PURGE;
643 if (is_bad_inode(dentry->d_inode) || flags) {
644 return 1;
645 }
646 return 0;
647 }
648
649
650
651 /*
652 * This is called when we want to check if the inode has
653 * changed on the server. Coda makes this easy since the
654 * cache manager Venus issues a downcall to the kernel when this
655 * happens
656 */
657 int coda_revalidate_inode(struct dentry *dentry)
658 {
659 struct coda_vattr attr;
660 int error = 0;
661 int old_mode;
662 ino_t old_ino;
663 struct inode *inode = dentry->d_inode;
664 struct coda_inode_info *cii = ITOC(inode);
665
666 lock_kernel();
667 if ( !cii->c_flags )
668 goto ok;
669
670 if (cii->c_flags & (C_VATTR | C_PURGE | C_FLUSH)) {
671 error = venus_getattr(inode->i_sb, &(cii->c_fid), &attr);
672 if ( error )
673 goto return_bad;
674
675 /* this inode may be lost if:
676 - it's ino changed
677 - type changes must be permitted for repair and
678 missing mount points.
679 */
680 old_mode = inode->i_mode;
681 old_ino = inode->i_ino;
682 coda_vattr_to_iattr(inode, &attr);
683
684 if ((old_mode & S_IFMT) != (inode->i_mode & S_IFMT)) {
685 printk("Coda: inode %ld, fid %s changed type!\n",
686 inode->i_ino, coda_f2s(&(cii->c_fid)));
687 }
688
689 /* the following can happen when a local fid is replaced
690 with a global one, here we lose and declare the inode bad */
691 if (inode->i_ino != old_ino)
692 goto return_bad;
693
694 coda_flag_inode_children(inode, C_FLUSH);
695 cii->c_flags &= ~(C_VATTR | C_PURGE | C_FLUSH);
696 }
697
698 ok:
699 unlock_kernel();
700 return 0;
701
702 return_bad:
703 unlock_kernel();
704 return -EIO;
705 }
WRT350N Kernel Patches