1 /* dir.c: AFS filesystem directory handling
2 *
3 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/fs.h>
16 #include <linux/namei.h>
17 #include <linux/pagemap.h>
18 #include <linux/ctype.h>
19 #include <linux/sched.h>
20 #include "internal.h"
21
22 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
23 struct nameidata *nd);
24 static int afs_dir_open(struct inode *inode, struct file *file);
25 static int afs_readdir(struct file *file, void *dirent, filldir_t filldir);
26 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
27 static int afs_d_delete(const struct dentry *dentry);
28 static void afs_d_release(struct dentry *dentry);
29 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
30 loff_t fpos, u64 ino, unsigned dtype);
31 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
32 struct nameidata *nd);
33 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode);
34 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
35 static int afs_unlink(struct inode *dir, struct dentry *dentry);
36 static int afs_link(struct dentry *from, struct inode *dir,
37 struct dentry *dentry);
38 static int afs_symlink(struct inode *dir, struct dentry *dentry,
39 const char *content);
40 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
41 struct inode *new_dir, struct dentry *new_dentry);
42
43 const struct file_operations afs_dir_file_operations = {
44 .open = afs_dir_open,
45 .release = afs_release,
46 .readdir = afs_readdir,
47 .lock = afs_lock,
48 .llseek = generic_file_llseek,
49 };
50
51 const struct inode_operations afs_dir_inode_operations = {
52 .create = afs_create,
53 .lookup = afs_lookup,
54 .link = afs_link,
55 .unlink = afs_unlink,
56 .symlink = afs_symlink,
57 .mkdir = afs_mkdir,
58 .rmdir = afs_rmdir,
59 .rename = afs_rename,
60 .permission = afs_permission,
61 .getattr = afs_getattr,
62 .setattr = afs_setattr,
63 };
64
65 const struct dentry_operations afs_fs_dentry_operations = {
66 .d_revalidate = afs_d_revalidate,
67 .d_delete = afs_d_delete,
68 .d_release = afs_d_release,
69 .d_automount = afs_d_automount,
70 };
71
72 #define AFS_DIR_HASHTBL_SIZE 128
73 #define AFS_DIR_DIRENT_SIZE 32
74 #define AFS_DIRENT_PER_BLOCK 64
75
76 union afs_dirent {
77 struct {
78 uint8_t valid;
79 uint8_t unused[1];
80 __be16 hash_next;
81 __be32 vnode;
82 __be32 unique;
83 uint8_t name[16];
84 uint8_t overflow[4]; /* if any char of the name (inc
85 * NUL) reaches here, consume
86 * the next dirent too */
87 } u;
88 uint8_t extended_name[32];
89 };
90
91 /* AFS directory page header (one at the beginning of every 2048-byte chunk) */
92 struct afs_dir_pagehdr {
93 __be16 npages;
94 __be16 magic;
95 #define AFS_DIR_MAGIC htons(1234)
96 uint8_t nentries;
97 uint8_t bitmap[8];
98 uint8_t pad[19];
99 };
100
101 /* directory block layout */
102 union afs_dir_block {
103
104 struct afs_dir_pagehdr pagehdr;
105
106 struct {
107 struct afs_dir_pagehdr pagehdr;
108 uint8_t alloc_ctrs[128];
109 /* dir hash table */
110 uint16_t hashtable[AFS_DIR_HASHTBL_SIZE];
111 } hdr;
112
113 union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
114 };
115
116 /* layout on a linux VM page */
117 struct afs_dir_page {
118 union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
119 };
120
121 struct afs_lookup_cookie {
122 struct afs_fid fid;
123 const char *name;
124 size_t nlen;
125 int found;
126 };
127
128 /*
129 * check that a directory page is valid
130 */
afs_dir_check_page(struct inode * dir,struct page * page)131 static inline void afs_dir_check_page(struct inode *dir, struct page *page)
132 {
133 struct afs_dir_page *dbuf;
134 loff_t latter;
135 int tmp, qty;
136
137 #if 0
138 /* check the page count */
139 qty = desc.size / sizeof(dbuf->blocks[0]);
140 if (qty == 0)
141 goto error;
142
143 if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
144 printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
145 __func__, dir->i_ino, qty,
146 ntohs(dbuf->blocks[0].pagehdr.npages));
147 goto error;
148 }
149 #endif
150
151 /* determine how many magic numbers there should be in this page */
152 latter = dir->i_size - page_offset(page);
153 if (latter >= PAGE_SIZE)
154 qty = PAGE_SIZE;
155 else
156 qty = latter;
157 qty /= sizeof(union afs_dir_block);
158
159 /* check them */
160 dbuf = page_address(page);
161 for (tmp = 0; tmp < qty; tmp++) {
162 if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
163 printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
164 __func__, dir->i_ino, tmp, qty,
165 ntohs(dbuf->blocks[tmp].pagehdr.magic));
166 goto error;
167 }
168 }
169
170 SetPageChecked(page);
171 return;
172
173 error:
174 SetPageChecked(page);
175 SetPageError(page);
176 }
177
178 /*
179 * discard a page cached in the pagecache
180 */
afs_dir_put_page(struct page * page)181 static inline void afs_dir_put_page(struct page *page)
182 {
183 kunmap(page);
184 page_cache_release(page);
185 }
186
187 /*
188 * get a page into the pagecache
189 */
afs_dir_get_page(struct inode * dir,unsigned long index,struct key * key)190 static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
191 struct key *key)
192 {
193 struct page *page;
194 _enter("{%lu},%lu", dir->i_ino, index);
195
196 page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);
197 if (!IS_ERR(page)) {
198 kmap(page);
199 if (!PageChecked(page))
200 afs_dir_check_page(dir, page);
201 if (PageError(page))
202 goto fail;
203 }
204 return page;
205
206 fail:
207 afs_dir_put_page(page);
208 _leave(" = -EIO");
209 return ERR_PTR(-EIO);
210 }
211
212 /*
213 * open an AFS directory file
214 */
afs_dir_open(struct inode * inode,struct file * file)215 static int afs_dir_open(struct inode *inode, struct file *file)
216 {
217 _enter("{%lu}", inode->i_ino);
218
219 BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
220 BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
221
222 if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
223 return -ENOENT;
224
225 return afs_open(inode, file);
226 }
227
228 /*
229 * deal with one block in an AFS directory
230 */
afs_dir_iterate_block(unsigned * fpos,union afs_dir_block * block,unsigned blkoff,void * cookie,filldir_t filldir)231 static int afs_dir_iterate_block(unsigned *fpos,
232 union afs_dir_block *block,
233 unsigned blkoff,
234 void *cookie,
235 filldir_t filldir)
236 {
237 union afs_dirent *dire;
238 unsigned offset, next, curr;
239 size_t nlen;
240 int tmp, ret;
241
242 _enter("%u,%x,%p,,",*fpos,blkoff,block);
243
244 curr = (*fpos - blkoff) / sizeof(union afs_dirent);
245
246 /* walk through the block, an entry at a time */
247 for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
248 offset < AFS_DIRENT_PER_BLOCK;
249 offset = next
250 ) {
251 next = offset + 1;
252
253 /* skip entries marked unused in the bitmap */
254 if (!(block->pagehdr.bitmap[offset / 8] &
255 (1 << (offset % 8)))) {
256 _debug("ENT[%Zu.%u]: unused",
257 blkoff / sizeof(union afs_dir_block), offset);
258 if (offset >= curr)
259 *fpos = blkoff +
260 next * sizeof(union afs_dirent);
261 continue;
262 }
263
264 /* got a valid entry */
265 dire = &block->dirents[offset];
266 nlen = strnlen(dire->u.name,
267 sizeof(*block) -
268 offset * sizeof(union afs_dirent));
269
270 _debug("ENT[%Zu.%u]: %s %Zu \"%s\"",
271 blkoff / sizeof(union afs_dir_block), offset,
272 (offset < curr ? "skip" : "fill"),
273 nlen, dire->u.name);
274
275 /* work out where the next possible entry is */
276 for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
277 if (next >= AFS_DIRENT_PER_BLOCK) {
278 _debug("ENT[%Zu.%u]:"
279 " %u travelled beyond end dir block"
280 " (len %u/%Zu)",
281 blkoff / sizeof(union afs_dir_block),
282 offset, next, tmp, nlen);
283 return -EIO;
284 }
285 if (!(block->pagehdr.bitmap[next / 8] &
286 (1 << (next % 8)))) {
287 _debug("ENT[%Zu.%u]:"
288 " %u unmarked extension (len %u/%Zu)",
289 blkoff / sizeof(union afs_dir_block),
290 offset, next, tmp, nlen);
291 return -EIO;
292 }
293
294 _debug("ENT[%Zu.%u]: ext %u/%Zu",
295 blkoff / sizeof(union afs_dir_block),
296 next, tmp, nlen);
297 next++;
298 }
299
300 /* skip if starts before the current position */
301 if (offset < curr)
302 continue;
303
304 /* found the next entry */
305 ret = filldir(cookie,
306 dire->u.name,
307 nlen,
308 blkoff + offset * sizeof(union afs_dirent),
309 ntohl(dire->u.vnode),
310 filldir == afs_lookup_filldir ?
311 ntohl(dire->u.unique) : DT_UNKNOWN);
312 if (ret < 0) {
313 _leave(" = 0 [full]");
314 return 0;
315 }
316
317 *fpos = blkoff + next * sizeof(union afs_dirent);
318 }
319
320 _leave(" = 1 [more]");
321 return 1;
322 }
323
324 /*
325 * iterate through the data blob that lists the contents of an AFS directory
326 */
afs_dir_iterate(struct inode * dir,unsigned * fpos,void * cookie,filldir_t filldir,struct key * key)327 static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
328 filldir_t filldir, struct key *key)
329 {
330 union afs_dir_block *dblock;
331 struct afs_dir_page *dbuf;
332 struct page *page;
333 unsigned blkoff, limit;
334 int ret;
335
336 _enter("{%lu},%u,,", dir->i_ino, *fpos);
337
338 if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
339 _leave(" = -ESTALE");
340 return -ESTALE;
341 }
342
343 /* round the file position up to the next entry boundary */
344 *fpos += sizeof(union afs_dirent) - 1;
345 *fpos &= ~(sizeof(union afs_dirent) - 1);
346
347 /* walk through the blocks in sequence */
348 ret = 0;
349 while (*fpos < dir->i_size) {
350 blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);
351
352 /* fetch the appropriate page from the directory */
353 page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
354 if (IS_ERR(page)) {
355 ret = PTR_ERR(page);
356 break;
357 }
358
359 limit = blkoff & ~(PAGE_SIZE - 1);
360
361 dbuf = page_address(page);
362
363 /* deal with the individual blocks stashed on this page */
364 do {
365 dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
366 sizeof(union afs_dir_block)];
367 ret = afs_dir_iterate_block(fpos, dblock, blkoff,
368 cookie, filldir);
369 if (ret != 1) {
370 afs_dir_put_page(page);
371 goto out;
372 }
373
374 blkoff += sizeof(union afs_dir_block);
375
376 } while (*fpos < dir->i_size && blkoff < limit);
377
378 afs_dir_put_page(page);
379 ret = 0;
380 }
381
382 out:
383 _leave(" = %d", ret);
384 return ret;
385 }
386
387 /*
388 * read an AFS directory
389 */
afs_readdir(struct file * file,void * cookie,filldir_t filldir)390 static int afs_readdir(struct file *file, void *cookie, filldir_t filldir)
391 {
392 unsigned fpos;
393 int ret;
394
395 _enter("{%Ld,{%lu}}",
396 file->f_pos, file->f_path.dentry->d_inode->i_ino);
397
398 ASSERT(file->private_data != NULL);
399
400 fpos = file->f_pos;
401 ret = afs_dir_iterate(file->f_path.dentry->d_inode, &fpos,
402 cookie, filldir, file->private_data);
403 file->f_pos = fpos;
404
405 _leave(" = %d", ret);
406 return ret;
407 }
408
409 /*
410 * search the directory for a name
411 * - if afs_dir_iterate_block() spots this function, it'll pass the FID
412 * uniquifier through dtype
413 */
afs_lookup_filldir(void * _cookie,const char * name,int nlen,loff_t fpos,u64 ino,unsigned dtype)414 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
415 loff_t fpos, u64 ino, unsigned dtype)
416 {
417 struct afs_lookup_cookie *cookie = _cookie;
418
419 _enter("{%s,%Zu},%s,%u,,%llu,%u",
420 cookie->name, cookie->nlen, name, nlen,
421 (unsigned long long) ino, dtype);
422
423 /* insanity checks first */
424 BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
425 BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
426
427 if (cookie->nlen != nlen || memcmp(cookie->name, name, nlen) != 0) {
428 _leave(" = 0 [no]");
429 return 0;
430 }
431
432 cookie->fid.vnode = ino;
433 cookie->fid.unique = dtype;
434 cookie->found = 1;
435
436 _leave(" = -1 [found]");
437 return -1;
438 }
439
440 /*
441 * do a lookup in a directory
442 * - just returns the FID the dentry name maps to if found
443 */
afs_do_lookup(struct inode * dir,struct dentry * dentry,struct afs_fid * fid,struct key * key)444 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
445 struct afs_fid *fid, struct key *key)
446 {
447 struct afs_lookup_cookie cookie;
448 struct afs_super_info *as;
449 unsigned fpos;
450 int ret;
451
452 _enter("{%lu},%p{%s},", dir->i_ino, dentry, dentry->d_name.name);
453
454 as = dir->i_sb->s_fs_info;
455
456 /* search the directory */
457 cookie.name = dentry->d_name.name;
458 cookie.nlen = dentry->d_name.len;
459 cookie.fid.vid = as->volume->vid;
460 cookie.found = 0;
461
462 fpos = 0;
463 ret = afs_dir_iterate(dir, &fpos, &cookie, afs_lookup_filldir,
464 key);
465 if (ret < 0) {
466 _leave(" = %d [iter]", ret);
467 return ret;
468 }
469
470 ret = -ENOENT;
471 if (!cookie.found) {
472 _leave(" = -ENOENT [not found]");
473 return -ENOENT;
474 }
475
476 *fid = cookie.fid;
477 _leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
478 return 0;
479 }
480
481 /*
482 * Try to auto mount the mountpoint with pseudo directory, if the autocell
483 * operation is setted.
484 */
afs_try_auto_mntpt(int ret,struct dentry * dentry,struct inode * dir,struct key * key,struct afs_fid * fid)485 static struct inode *afs_try_auto_mntpt(
486 int ret, struct dentry *dentry, struct inode *dir, struct key *key,
487 struct afs_fid *fid)
488 {
489 const char *devname = dentry->d_name.name;
490 struct afs_vnode *vnode = AFS_FS_I(dir);
491 struct inode *inode;
492
493 _enter("%d, %p{%s}, {%x:%u}, %p",
494 ret, dentry, devname, vnode->fid.vid, vnode->fid.vnode, key);
495
496 if (ret != -ENOENT ||
497 !test_bit(AFS_VNODE_AUTOCELL, &vnode->flags))
498 goto out;
499
500 inode = afs_iget_autocell(dir, devname, strlen(devname), key);
501 if (IS_ERR(inode)) {
502 ret = PTR_ERR(inode);
503 goto out;
504 }
505
506 *fid = AFS_FS_I(inode)->fid;
507 _leave("= %p", inode);
508 return inode;
509
510 out:
511 _leave("= %d", ret);
512 return ERR_PTR(ret);
513 }
514
515 /*
516 * look up an entry in a directory
517 */
afs_lookup(struct inode * dir,struct dentry * dentry,struct nameidata * nd)518 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
519 struct nameidata *nd)
520 {
521 struct afs_vnode *vnode;
522 struct afs_fid fid;
523 struct inode *inode;
524 struct key *key;
525 int ret;
526
527 vnode = AFS_FS_I(dir);
528
529 _enter("{%x:%u},%p{%s},",
530 vnode->fid.vid, vnode->fid.vnode, dentry, dentry->d_name.name);
531
532 ASSERTCMP(dentry->d_inode, ==, NULL);
533
534 if (dentry->d_name.len >= AFSNAMEMAX) {
535 _leave(" = -ENAMETOOLONG");
536 return ERR_PTR(-ENAMETOOLONG);
537 }
538
539 if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
540 _leave(" = -ESTALE");
541 return ERR_PTR(-ESTALE);
542 }
543
544 key = afs_request_key(vnode->volume->cell);
545 if (IS_ERR(key)) {
546 _leave(" = %ld [key]", PTR_ERR(key));
547 return ERR_CAST(key);
548 }
549
550 ret = afs_validate(vnode, key);
551 if (ret < 0) {
552 key_put(key);
553 _leave(" = %d [val]", ret);
554 return ERR_PTR(ret);
555 }
556
557 ret = afs_do_lookup(dir, dentry, &fid, key);
558 if (ret < 0) {
559 inode = afs_try_auto_mntpt(ret, dentry, dir, key, &fid);
560 if (!IS_ERR(inode)) {
561 key_put(key);
562 goto success;
563 }
564
565 ret = PTR_ERR(inode);
566 key_put(key);
567 if (ret == -ENOENT) {
568 d_add(dentry, NULL);
569 _leave(" = NULL [negative]");
570 return NULL;
571 }
572 _leave(" = %d [do]", ret);
573 return ERR_PTR(ret);
574 }
575 dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
576
577 /* instantiate the dentry */
578 inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
579 key_put(key);
580 if (IS_ERR(inode)) {
581 _leave(" = %ld", PTR_ERR(inode));
582 return ERR_CAST(inode);
583 }
584
585 success:
586 d_add(dentry, inode);
587 _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%u }",
588 fid.vnode,
589 fid.unique,
590 dentry->d_inode->i_ino,
591 dentry->d_inode->i_generation);
592
593 return NULL;
594 }
595
596 /*
597 * check that a dentry lookup hit has found a valid entry
598 * - NOTE! the hit can be a negative hit too, so we can't assume we have an
599 * inode
600 */
afs_d_revalidate(struct dentry * dentry,struct nameidata * nd)601 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
602 {
603 struct afs_vnode *vnode, *dir;
604 struct afs_fid uninitialized_var(fid);
605 struct dentry *parent;
606 struct key *key;
607 void *dir_version;
608 int ret;
609
610 if (nd->flags & LOOKUP_RCU)
611 return -ECHILD;
612
613 vnode = AFS_FS_I(dentry->d_inode);
614
615 if (dentry->d_inode)
616 _enter("{v={%x:%u} n=%s fl=%lx},",
617 vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
618 vnode->flags);
619 else
620 _enter("{neg n=%s}", dentry->d_name.name);
621
622 key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
623 if (IS_ERR(key))
624 key = NULL;
625
626 /* lock down the parent dentry so we can peer at it */
627 parent = dget_parent(dentry);
628 if (!parent->d_inode)
629 goto out_bad;
630
631 dir = AFS_FS_I(parent->d_inode);
632
633 /* validate the parent directory */
634 if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
635 afs_validate(dir, key);
636
637 if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
638 _debug("%s: parent dir deleted", dentry->d_name.name);
639 goto out_bad;
640 }
641
642 dir_version = (void *) (unsigned long) dir->status.data_version;
643 if (dentry->d_fsdata == dir_version)
644 goto out_valid; /* the dir contents are unchanged */
645
646 _debug("dir modified");
647
648 /* search the directory for this vnode */
649 ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
650 switch (ret) {
651 case 0:
652 /* the filename maps to something */
653 if (!dentry->d_inode)
654 goto out_bad;
655 if (is_bad_inode(dentry->d_inode)) {
656 printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
657 parent->d_name.name, dentry->d_name.name);
658 goto out_bad;
659 }
660
661 /* if the vnode ID has changed, then the dirent points to a
662 * different file */
663 if (fid.vnode != vnode->fid.vnode) {
664 _debug("%s: dirent changed [%u != %u]",
665 dentry->d_name.name, fid.vnode,
666 vnode->fid.vnode);
667 goto not_found;
668 }
669
670 /* if the vnode ID uniqifier has changed, then the file has
671 * been deleted and replaced, and the original vnode ID has
672 * been reused */
673 if (fid.unique != vnode->fid.unique) {
674 _debug("%s: file deleted (uq %u -> %u I:%u)",
675 dentry->d_name.name, fid.unique,
676 vnode->fid.unique,
677 dentry->d_inode->i_generation);
678 spin_lock(&vnode->lock);
679 set_bit(AFS_VNODE_DELETED, &vnode->flags);
680 spin_unlock(&vnode->lock);
681 goto not_found;
682 }
683 goto out_valid;
684
685 case -ENOENT:
686 /* the filename is unknown */
687 _debug("%s: dirent not found", dentry->d_name.name);
688 if (dentry->d_inode)
689 goto not_found;
690 goto out_valid;
691
692 default:
693 _debug("failed to iterate dir %s: %d",
694 parent->d_name.name, ret);
695 goto out_bad;
696 }
697
698 out_valid:
699 dentry->d_fsdata = dir_version;
700 out_skip:
701 dput(parent);
702 key_put(key);
703 _leave(" = 1 [valid]");
704 return 1;
705
706 /* the dirent, if it exists, now points to a different vnode */
707 not_found:
708 spin_lock(&dentry->d_lock);
709 dentry->d_flags |= DCACHE_NFSFS_RENAMED;
710 spin_unlock(&dentry->d_lock);
711
712 out_bad:
713 if (dentry->d_inode) {
714 /* don't unhash if we have submounts */
715 if (have_submounts(dentry))
716 goto out_skip;
717 }
718
719 _debug("dropping dentry %s/%s",
720 parent->d_name.name, dentry->d_name.name);
721 shrink_dcache_parent(dentry);
722 d_drop(dentry);
723 dput(parent);
724 key_put(key);
725
726 _leave(" = 0 [bad]");
727 return 0;
728 }
729
730 /*
731 * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
732 * sleep)
733 * - called from dput() when d_count is going to 0.
734 * - return 1 to request dentry be unhashed, 0 otherwise
735 */
afs_d_delete(const struct dentry * dentry)736 static int afs_d_delete(const struct dentry *dentry)
737 {
738 _enter("%s", dentry->d_name.name);
739
740 if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
741 goto zap;
742
743 if (dentry->d_inode &&
744 (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dentry->d_inode)->flags) ||
745 test_bit(AFS_VNODE_PSEUDODIR, &AFS_FS_I(dentry->d_inode)->flags)))
746 goto zap;
747
748 _leave(" = 0 [keep]");
749 return 0;
750
751 zap:
752 _leave(" = 1 [zap]");
753 return 1;
754 }
755
756 /*
757 * handle dentry release
758 */
afs_d_release(struct dentry * dentry)759 static void afs_d_release(struct dentry *dentry)
760 {
761 _enter("%s", dentry->d_name.name);
762 }
763
764 /*
765 * create a directory on an AFS filesystem
766 */
afs_mkdir(struct inode * dir,struct dentry * dentry,umode_t mode)767 static int afs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
768 {
769 struct afs_file_status status;
770 struct afs_callback cb;
771 struct afs_server *server;
772 struct afs_vnode *dvnode, *vnode;
773 struct afs_fid fid;
774 struct inode *inode;
775 struct key *key;
776 int ret;
777
778 dvnode = AFS_FS_I(dir);
779
780 _enter("{%x:%u},{%s},%ho",
781 dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
782
783 ret = -ENAMETOOLONG;
784 if (dentry->d_name.len >= AFSNAMEMAX)
785 goto error;
786
787 key = afs_request_key(dvnode->volume->cell);
788 if (IS_ERR(key)) {
789 ret = PTR_ERR(key);
790 goto error;
791 }
792
793 mode |= S_IFDIR;
794 ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
795 mode, &fid, &status, &cb, &server);
796 if (ret < 0)
797 goto mkdir_error;
798
799 inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
800 if (IS_ERR(inode)) {
801 /* ENOMEM at a really inconvenient time - just abandon the new
802 * directory on the server */
803 ret = PTR_ERR(inode);
804 goto iget_error;
805 }
806
807 /* apply the status report we've got for the new vnode */
808 vnode = AFS_FS_I(inode);
809 spin_lock(&vnode->lock);
810 vnode->update_cnt++;
811 spin_unlock(&vnode->lock);
812 afs_vnode_finalise_status_update(vnode, server);
813 afs_put_server(server);
814
815 d_instantiate(dentry, inode);
816 if (d_unhashed(dentry)) {
817 _debug("not hashed");
818 d_rehash(dentry);
819 }
820 key_put(key);
821 _leave(" = 0");
822 return 0;
823
824 iget_error:
825 afs_put_server(server);
826 mkdir_error:
827 key_put(key);
828 error:
829 d_drop(dentry);
830 _leave(" = %d", ret);
831 return ret;
832 }
833
834 /*
835 * remove a directory from an AFS filesystem
836 */
afs_rmdir(struct inode * dir,struct dentry * dentry)837 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
838 {
839 struct afs_vnode *dvnode, *vnode;
840 struct key *key;
841 int ret;
842
843 dvnode = AFS_FS_I(dir);
844
845 _enter("{%x:%u},{%s}",
846 dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
847
848 ret = -ENAMETOOLONG;
849 if (dentry->d_name.len >= AFSNAMEMAX)
850 goto error;
851
852 key = afs_request_key(dvnode->volume->cell);
853 if (IS_ERR(key)) {
854 ret = PTR_ERR(key);
855 goto error;
856 }
857
858 ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
859 if (ret < 0)
860 goto rmdir_error;
861
862 if (dentry->d_inode) {
863 vnode = AFS_FS_I(dentry->d_inode);
864 clear_nlink(&vnode->vfs_inode);
865 set_bit(AFS_VNODE_DELETED, &vnode->flags);
866 afs_discard_callback_on_delete(vnode);
867 }
868
869 key_put(key);
870 _leave(" = 0");
871 return 0;
872
873 rmdir_error:
874 key_put(key);
875 error:
876 _leave(" = %d", ret);
877 return ret;
878 }
879
880 /*
881 * remove a file from an AFS filesystem
882 */
afs_unlink(struct inode * dir,struct dentry * dentry)883 static int afs_unlink(struct inode *dir, struct dentry *dentry)
884 {
885 struct afs_vnode *dvnode, *vnode;
886 struct key *key;
887 int ret;
888
889 dvnode = AFS_FS_I(dir);
890
891 _enter("{%x:%u},{%s}",
892 dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
893
894 ret = -ENAMETOOLONG;
895 if (dentry->d_name.len >= AFSNAMEMAX)
896 goto error;
897
898 key = afs_request_key(dvnode->volume->cell);
899 if (IS_ERR(key)) {
900 ret = PTR_ERR(key);
901 goto error;
902 }
903
904 if (dentry->d_inode) {
905 vnode = AFS_FS_I(dentry->d_inode);
906
907 /* make sure we have a callback promise on the victim */
908 ret = afs_validate(vnode, key);
909 if (ret < 0)
910 goto error;
911 }
912
913 ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
914 if (ret < 0)
915 goto remove_error;
916
917 if (dentry->d_inode) {
918 /* if the file wasn't deleted due to excess hard links, the
919 * fileserver will break the callback promise on the file - if
920 * it had one - before it returns to us, and if it was deleted,
921 * it won't
922 *
923 * however, if we didn't have a callback promise outstanding,
924 * or it was outstanding on a different server, then it won't
925 * break it either...
926 */
927 vnode = AFS_FS_I(dentry->d_inode);
928 if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
929 _debug("AFS_VNODE_DELETED");
930 if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
931 _debug("AFS_VNODE_CB_BROKEN");
932 set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
933 ret = afs_validate(vnode, key);
934 _debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
935 }
936
937 key_put(key);
938 _leave(" = 0");
939 return 0;
940
941 remove_error:
942 key_put(key);
943 error:
944 _leave(" = %d", ret);
945 return ret;
946 }
947
948 /*
949 * create a regular file on an AFS filesystem
950 */
afs_create(struct inode * dir,struct dentry * dentry,umode_t mode,struct nameidata * nd)951 static int afs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
952 struct nameidata *nd)
953 {
954 struct afs_file_status status;
955 struct afs_callback cb;
956 struct afs_server *server;
957 struct afs_vnode *dvnode, *vnode;
958 struct afs_fid fid;
959 struct inode *inode;
960 struct key *key;
961 int ret;
962
963 dvnode = AFS_FS_I(dir);
964
965 _enter("{%x:%u},{%s},%ho,",
966 dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
967
968 ret = -ENAMETOOLONG;
969 if (dentry->d_name.len >= AFSNAMEMAX)
970 goto error;
971
972 key = afs_request_key(dvnode->volume->cell);
973 if (IS_ERR(key)) {
974 ret = PTR_ERR(key);
975 goto error;
976 }
977
978 mode |= S_IFREG;
979 ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
980 mode, &fid, &status, &cb, &server);
981 if (ret < 0)
982 goto create_error;
983
984 inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
985 if (IS_ERR(inode)) {
986 /* ENOMEM at a really inconvenient time - just abandon the new
987 * directory on the server */
988 ret = PTR_ERR(inode);
989 goto iget_error;
990 }
991
992 /* apply the status report we've got for the new vnode */
993 vnode = AFS_FS_I(inode);
994 spin_lock(&vnode->lock);
995 vnode->update_cnt++;
996 spin_unlock(&vnode->lock);
997 afs_vnode_finalise_status_update(vnode, server);
998 afs_put_server(server);
999
1000 d_instantiate(dentry, inode);
1001 if (d_unhashed(dentry)) {
1002 _debug("not hashed");
1003 d_rehash(dentry);
1004 }
1005 key_put(key);
1006 _leave(" = 0");
1007 return 0;
1008
1009 iget_error:
1010 afs_put_server(server);
1011 create_error:
1012 key_put(key);
1013 error:
1014 d_drop(dentry);
1015 _leave(" = %d", ret);
1016 return ret;
1017 }
1018
1019 /*
1020 * create a hard link between files in an AFS filesystem
1021 */
afs_link(struct dentry * from,struct inode * dir,struct dentry * dentry)1022 static int afs_link(struct dentry *from, struct inode *dir,
1023 struct dentry *dentry)
1024 {
1025 struct afs_vnode *dvnode, *vnode;
1026 struct key *key;
1027 int ret;
1028
1029 vnode = AFS_FS_I(from->d_inode);
1030 dvnode = AFS_FS_I(dir);
1031
1032 _enter("{%x:%u},{%x:%u},{%s}",
1033 vnode->fid.vid, vnode->fid.vnode,
1034 dvnode->fid.vid, dvnode->fid.vnode,
1035 dentry->d_name.name);
1036
1037 ret = -ENAMETOOLONG;
1038 if (dentry->d_name.len >= AFSNAMEMAX)
1039 goto error;
1040
1041 key = afs_request_key(dvnode->volume->cell);
1042 if (IS_ERR(key)) {
1043 ret = PTR_ERR(key);
1044 goto error;
1045 }
1046
1047 ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
1048 if (ret < 0)
1049 goto link_error;
1050
1051 ihold(&vnode->vfs_inode);
1052 d_instantiate(dentry, &vnode->vfs_inode);
1053 key_put(key);
1054 _leave(" = 0");
1055 return 0;
1056
1057 link_error:
1058 key_put(key);
1059 error:
1060 d_drop(dentry);
1061 _leave(" = %d", ret);
1062 return ret;
1063 }
1064
1065 /*
1066 * create a symlink in an AFS filesystem
1067 */
afs_symlink(struct inode * dir,struct dentry * dentry,const char * content)1068 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1069 const char *content)
1070 {
1071 struct afs_file_status status;
1072 struct afs_server *server;
1073 struct afs_vnode *dvnode, *vnode;
1074 struct afs_fid fid;
1075 struct inode *inode;
1076 struct key *key;
1077 int ret;
1078
1079 dvnode = AFS_FS_I(dir);
1080
1081 _enter("{%x:%u},{%s},%s",
1082 dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
1083 content);
1084
1085 ret = -ENAMETOOLONG;
1086 if (dentry->d_name.len >= AFSNAMEMAX)
1087 goto error;
1088
1089 ret = -EINVAL;
1090 if (strlen(content) >= AFSPATHMAX)
1091 goto error;
1092
1093 key = afs_request_key(dvnode->volume->cell);
1094 if (IS_ERR(key)) {
1095 ret = PTR_ERR(key);
1096 goto error;
1097 }
1098
1099 ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1100 &fid, &status, &server);
1101 if (ret < 0)
1102 goto create_error;
1103
1104 inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1105 if (IS_ERR(inode)) {
1106 /* ENOMEM at a really inconvenient time - just abandon the new
1107 * directory on the server */
1108 ret = PTR_ERR(inode);
1109 goto iget_error;
1110 }
1111
1112 /* apply the status report we've got for the new vnode */
1113 vnode = AFS_FS_I(inode);
1114 spin_lock(&vnode->lock);
1115 vnode->update_cnt++;
1116 spin_unlock(&vnode->lock);
1117 afs_vnode_finalise_status_update(vnode, server);
1118 afs_put_server(server);
1119
1120 d_instantiate(dentry, inode);
1121 if (d_unhashed(dentry)) {
1122 _debug("not hashed");
1123 d_rehash(dentry);
1124 }
1125 key_put(key);
1126 _leave(" = 0");
1127 return 0;
1128
1129 iget_error:
1130 afs_put_server(server);
1131 create_error:
1132 key_put(key);
1133 error:
1134 d_drop(dentry);
1135 _leave(" = %d", ret);
1136 return ret;
1137 }
1138
1139 /*
1140 * rename a file in an AFS filesystem and/or move it between directories
1141 */
afs_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1142 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1143 struct inode *new_dir, struct dentry *new_dentry)
1144 {
1145 struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1146 struct key *key;
1147 int ret;
1148
1149 vnode = AFS_FS_I(old_dentry->d_inode);
1150 orig_dvnode = AFS_FS_I(old_dir);
1151 new_dvnode = AFS_FS_I(new_dir);
1152
1153 _enter("{%x:%u},{%x:%u},{%x:%u},{%s}",
1154 orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1155 vnode->fid.vid, vnode->fid.vnode,
1156 new_dvnode->fid.vid, new_dvnode->fid.vnode,
1157 new_dentry->d_name.name);
1158
1159 ret = -ENAMETOOLONG;
1160 if (new_dentry->d_name.len >= AFSNAMEMAX)
1161 goto error;
1162
1163 key = afs_request_key(orig_dvnode->volume->cell);
1164 if (IS_ERR(key)) {
1165 ret = PTR_ERR(key);
1166 goto error;
1167 }
1168
1169 ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1170 old_dentry->d_name.name,
1171 new_dentry->d_name.name);
1172 if (ret < 0)
1173 goto rename_error;
1174 key_put(key);
1175 _leave(" = 0");
1176 return 0;
1177
1178 rename_error:
1179 key_put(key);
1180 error:
1181 d_drop(new_dentry);
1182 _leave(" = %d", ret);
1183 return ret;
1184 }
1185