xref: /linux/fs/afs/dir.c (revision f8324e20f8289dffc646d64366332e05eaacab25)
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/pagemap.h>
17 #include <linux/ctype.h>
18 #include <linux/sched.h>
19 #include "internal.h"
20 
21 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
22 				 struct nameidata *nd);
23 static int afs_dir_open(struct inode *inode, struct file *file);
24 static int afs_readdir(struct file *file, void *dirent, filldir_t filldir);
25 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd);
26 static int afs_d_delete(struct dentry *dentry);
27 static void afs_d_release(struct dentry *dentry);
28 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
29 				  loff_t fpos, u64 ino, unsigned dtype);
30 static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
31 		      struct nameidata *nd);
32 static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
33 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
34 static int afs_unlink(struct inode *dir, struct dentry *dentry);
35 static int afs_link(struct dentry *from, struct inode *dir,
36 		    struct dentry *dentry);
37 static int afs_symlink(struct inode *dir, struct dentry *dentry,
38 		       const char *content);
39 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
40 		      struct inode *new_dir, struct dentry *new_dentry);
41 
42 const struct file_operations afs_dir_file_operations = {
43 	.open		= afs_dir_open,
44 	.release	= afs_release,
45 	.readdir	= afs_readdir,
46 	.lock		= afs_lock,
47 	.llseek		= generic_file_llseek,
48 };
49 
50 const struct inode_operations afs_dir_inode_operations = {
51 	.create		= afs_create,
52 	.lookup		= afs_lookup,
53 	.link		= afs_link,
54 	.unlink		= afs_unlink,
55 	.symlink	= afs_symlink,
56 	.mkdir		= afs_mkdir,
57 	.rmdir		= afs_rmdir,
58 	.rename		= afs_rename,
59 	.permission	= afs_permission,
60 	.getattr	= afs_getattr,
61 	.setattr	= afs_setattr,
62 };
63 
64 static const struct dentry_operations afs_fs_dentry_operations = {
65 	.d_revalidate	= afs_d_revalidate,
66 	.d_delete	= afs_d_delete,
67 	.d_release	= afs_d_release,
68 };
69 
70 #define AFS_DIR_HASHTBL_SIZE	128
71 #define AFS_DIR_DIRENT_SIZE	32
72 #define AFS_DIRENT_PER_BLOCK	64
73 
74 union afs_dirent {
75 	struct {
76 		uint8_t		valid;
77 		uint8_t		unused[1];
78 		__be16		hash_next;
79 		__be32		vnode;
80 		__be32		unique;
81 		uint8_t		name[16];
82 		uint8_t		overflow[4];	/* if any char of the name (inc
83 						 * NUL) reaches here, consume
84 						 * the next dirent too */
85 	} u;
86 	uint8_t	extended_name[32];
87 };
88 
89 /* AFS directory page header (one at the beginning of every 2048-byte chunk) */
90 struct afs_dir_pagehdr {
91 	__be16		npages;
92 	__be16		magic;
93 #define AFS_DIR_MAGIC htons(1234)
94 	uint8_t		nentries;
95 	uint8_t		bitmap[8];
96 	uint8_t		pad[19];
97 };
98 
99 /* directory block layout */
100 union afs_dir_block {
101 
102 	struct afs_dir_pagehdr pagehdr;
103 
104 	struct {
105 		struct afs_dir_pagehdr	pagehdr;
106 		uint8_t			alloc_ctrs[128];
107 		/* dir hash table */
108 		uint16_t		hashtable[AFS_DIR_HASHTBL_SIZE];
109 	} hdr;
110 
111 	union afs_dirent dirents[AFS_DIRENT_PER_BLOCK];
112 };
113 
114 /* layout on a linux VM page */
115 struct afs_dir_page {
116 	union afs_dir_block blocks[PAGE_SIZE / sizeof(union afs_dir_block)];
117 };
118 
119 struct afs_lookup_cookie {
120 	struct afs_fid	fid;
121 	const char	*name;
122 	size_t		nlen;
123 	int		found;
124 };
125 
126 /*
127  * check that a directory page is valid
128  */
129 static inline void afs_dir_check_page(struct inode *dir, struct page *page)
130 {
131 	struct afs_dir_page *dbuf;
132 	loff_t latter;
133 	int tmp, qty;
134 
135 #if 0
136 	/* check the page count */
137 	qty = desc.size / sizeof(dbuf->blocks[0]);
138 	if (qty == 0)
139 		goto error;
140 
141 	if (page->index == 0 && qty != ntohs(dbuf->blocks[0].pagehdr.npages)) {
142 		printk("kAFS: %s(%lu): wrong number of dir blocks %d!=%hu\n",
143 		       __func__, dir->i_ino, qty,
144 		       ntohs(dbuf->blocks[0].pagehdr.npages));
145 		goto error;
146 	}
147 #endif
148 
149 	/* determine how many magic numbers there should be in this page */
150 	latter = dir->i_size - page_offset(page);
151 	if (latter >= PAGE_SIZE)
152 		qty = PAGE_SIZE;
153 	else
154 		qty = latter;
155 	qty /= sizeof(union afs_dir_block);
156 
157 	/* check them */
158 	dbuf = page_address(page);
159 	for (tmp = 0; tmp < qty; tmp++) {
160 		if (dbuf->blocks[tmp].pagehdr.magic != AFS_DIR_MAGIC) {
161 			printk("kAFS: %s(%lu): bad magic %d/%d is %04hx\n",
162 			       __func__, dir->i_ino, tmp, qty,
163 			       ntohs(dbuf->blocks[tmp].pagehdr.magic));
164 			goto error;
165 		}
166 	}
167 
168 	SetPageChecked(page);
169 	return;
170 
171 error:
172 	SetPageChecked(page);
173 	SetPageError(page);
174 }
175 
176 /*
177  * discard a page cached in the pagecache
178  */
179 static inline void afs_dir_put_page(struct page *page)
180 {
181 	kunmap(page);
182 	page_cache_release(page);
183 }
184 
185 /*
186  * get a page into the pagecache
187  */
188 static struct page *afs_dir_get_page(struct inode *dir, unsigned long index,
189 				     struct key *key)
190 {
191 	struct page *page;
192 	_enter("{%lu},%lu", dir->i_ino, index);
193 
194 	page = read_cache_page(dir->i_mapping, index, afs_page_filler, key);
195 	if (!IS_ERR(page)) {
196 		kmap(page);
197 		if (!PageChecked(page))
198 			afs_dir_check_page(dir, page);
199 		if (PageError(page))
200 			goto fail;
201 	}
202 	return page;
203 
204 fail:
205 	afs_dir_put_page(page);
206 	_leave(" = -EIO");
207 	return ERR_PTR(-EIO);
208 }
209 
210 /*
211  * open an AFS directory file
212  */
213 static int afs_dir_open(struct inode *inode, struct file *file)
214 {
215 	_enter("{%lu}", inode->i_ino);
216 
217 	BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
218 	BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
219 
220 	if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(inode)->flags))
221 		return -ENOENT;
222 
223 	return afs_open(inode, file);
224 }
225 
226 /*
227  * deal with one block in an AFS directory
228  */
229 static int afs_dir_iterate_block(unsigned *fpos,
230 				 union afs_dir_block *block,
231 				 unsigned blkoff,
232 				 void *cookie,
233 				 filldir_t filldir)
234 {
235 	union afs_dirent *dire;
236 	unsigned offset, next, curr;
237 	size_t nlen;
238 	int tmp, ret;
239 
240 	_enter("%u,%x,%p,,",*fpos,blkoff,block);
241 
242 	curr = (*fpos - blkoff) / sizeof(union afs_dirent);
243 
244 	/* walk through the block, an entry at a time */
245 	for (offset = AFS_DIRENT_PER_BLOCK - block->pagehdr.nentries;
246 	     offset < AFS_DIRENT_PER_BLOCK;
247 	     offset = next
248 	     ) {
249 		next = offset + 1;
250 
251 		/* skip entries marked unused in the bitmap */
252 		if (!(block->pagehdr.bitmap[offset / 8] &
253 		      (1 << (offset % 8)))) {
254 			_debug("ENT[%Zu.%u]: unused",
255 			       blkoff / sizeof(union afs_dir_block), offset);
256 			if (offset >= curr)
257 				*fpos = blkoff +
258 					next * sizeof(union afs_dirent);
259 			continue;
260 		}
261 
262 		/* got a valid entry */
263 		dire = &block->dirents[offset];
264 		nlen = strnlen(dire->u.name,
265 			       sizeof(*block) -
266 			       offset * sizeof(union afs_dirent));
267 
268 		_debug("ENT[%Zu.%u]: %s %Zu \"%s\"",
269 		       blkoff / sizeof(union afs_dir_block), offset,
270 		       (offset < curr ? "skip" : "fill"),
271 		       nlen, dire->u.name);
272 
273 		/* work out where the next possible entry is */
274 		for (tmp = nlen; tmp > 15; tmp -= sizeof(union afs_dirent)) {
275 			if (next >= AFS_DIRENT_PER_BLOCK) {
276 				_debug("ENT[%Zu.%u]:"
277 				       " %u travelled beyond end dir block"
278 				       " (len %u/%Zu)",
279 				       blkoff / sizeof(union afs_dir_block),
280 				       offset, next, tmp, nlen);
281 				return -EIO;
282 			}
283 			if (!(block->pagehdr.bitmap[next / 8] &
284 			      (1 << (next % 8)))) {
285 				_debug("ENT[%Zu.%u]:"
286 				       " %u unmarked extension (len %u/%Zu)",
287 				       blkoff / sizeof(union afs_dir_block),
288 				       offset, next, tmp, nlen);
289 				return -EIO;
290 			}
291 
292 			_debug("ENT[%Zu.%u]: ext %u/%Zu",
293 			       blkoff / sizeof(union afs_dir_block),
294 			       next, tmp, nlen);
295 			next++;
296 		}
297 
298 		/* skip if starts before the current position */
299 		if (offset < curr)
300 			continue;
301 
302 		/* found the next entry */
303 		ret = filldir(cookie,
304 			      dire->u.name,
305 			      nlen,
306 			      blkoff + offset * sizeof(union afs_dirent),
307 			      ntohl(dire->u.vnode),
308 			      filldir == afs_lookup_filldir ?
309 			      ntohl(dire->u.unique) : DT_UNKNOWN);
310 		if (ret < 0) {
311 			_leave(" = 0 [full]");
312 			return 0;
313 		}
314 
315 		*fpos = blkoff + next * sizeof(union afs_dirent);
316 	}
317 
318 	_leave(" = 1 [more]");
319 	return 1;
320 }
321 
322 /*
323  * iterate through the data blob that lists the contents of an AFS directory
324  */
325 static int afs_dir_iterate(struct inode *dir, unsigned *fpos, void *cookie,
326 			   filldir_t filldir, struct key *key)
327 {
328 	union afs_dir_block *dblock;
329 	struct afs_dir_page *dbuf;
330 	struct page *page;
331 	unsigned blkoff, limit;
332 	int ret;
333 
334 	_enter("{%lu},%u,,", dir->i_ino, *fpos);
335 
336 	if (test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dir)->flags)) {
337 		_leave(" = -ESTALE");
338 		return -ESTALE;
339 	}
340 
341 	/* round the file position up to the next entry boundary */
342 	*fpos += sizeof(union afs_dirent) - 1;
343 	*fpos &= ~(sizeof(union afs_dirent) - 1);
344 
345 	/* walk through the blocks in sequence */
346 	ret = 0;
347 	while (*fpos < dir->i_size) {
348 		blkoff = *fpos & ~(sizeof(union afs_dir_block) - 1);
349 
350 		/* fetch the appropriate page from the directory */
351 		page = afs_dir_get_page(dir, blkoff / PAGE_SIZE, key);
352 		if (IS_ERR(page)) {
353 			ret = PTR_ERR(page);
354 			break;
355 		}
356 
357 		limit = blkoff & ~(PAGE_SIZE - 1);
358 
359 		dbuf = page_address(page);
360 
361 		/* deal with the individual blocks stashed on this page */
362 		do {
363 			dblock = &dbuf->blocks[(blkoff % PAGE_SIZE) /
364 					       sizeof(union afs_dir_block)];
365 			ret = afs_dir_iterate_block(fpos, dblock, blkoff,
366 						    cookie, filldir);
367 			if (ret != 1) {
368 				afs_dir_put_page(page);
369 				goto out;
370 			}
371 
372 			blkoff += sizeof(union afs_dir_block);
373 
374 		} while (*fpos < dir->i_size && blkoff < limit);
375 
376 		afs_dir_put_page(page);
377 		ret = 0;
378 	}
379 
380 out:
381 	_leave(" = %d", ret);
382 	return ret;
383 }
384 
385 /*
386  * read an AFS directory
387  */
388 static int afs_readdir(struct file *file, void *cookie, filldir_t filldir)
389 {
390 	unsigned fpos;
391 	int ret;
392 
393 	_enter("{%Ld,{%lu}}",
394 	       file->f_pos, file->f_path.dentry->d_inode->i_ino);
395 
396 	ASSERT(file->private_data != NULL);
397 
398 	fpos = file->f_pos;
399 	ret = afs_dir_iterate(file->f_path.dentry->d_inode, &fpos,
400 			      cookie, filldir, file->private_data);
401 	file->f_pos = fpos;
402 
403 	_leave(" = %d", ret);
404 	return ret;
405 }
406 
407 /*
408  * search the directory for a name
409  * - if afs_dir_iterate_block() spots this function, it'll pass the FID
410  *   uniquifier through dtype
411  */
412 static int afs_lookup_filldir(void *_cookie, const char *name, int nlen,
413 			      loff_t fpos, u64 ino, unsigned dtype)
414 {
415 	struct afs_lookup_cookie *cookie = _cookie;
416 
417 	_enter("{%s,%Zu},%s,%u,,%llu,%u",
418 	       cookie->name, cookie->nlen, name, nlen,
419 	       (unsigned long long) ino, dtype);
420 
421 	/* insanity checks first */
422 	BUILD_BUG_ON(sizeof(union afs_dir_block) != 2048);
423 	BUILD_BUG_ON(sizeof(union afs_dirent) != 32);
424 
425 	if (cookie->nlen != nlen || memcmp(cookie->name, name, nlen) != 0) {
426 		_leave(" = 0 [no]");
427 		return 0;
428 	}
429 
430 	cookie->fid.vnode = ino;
431 	cookie->fid.unique = dtype;
432 	cookie->found = 1;
433 
434 	_leave(" = -1 [found]");
435 	return -1;
436 }
437 
438 /*
439  * do a lookup in a directory
440  * - just returns the FID the dentry name maps to if found
441  */
442 static int afs_do_lookup(struct inode *dir, struct dentry *dentry,
443 			 struct afs_fid *fid, struct key *key)
444 {
445 	struct afs_lookup_cookie cookie;
446 	struct afs_super_info *as;
447 	unsigned fpos;
448 	int ret;
449 
450 	_enter("{%lu},%p{%s},", dir->i_ino, dentry, dentry->d_name.name);
451 
452 	as = dir->i_sb->s_fs_info;
453 
454 	/* search the directory */
455 	cookie.name	= dentry->d_name.name;
456 	cookie.nlen	= dentry->d_name.len;
457 	cookie.fid.vid	= as->volume->vid;
458 	cookie.found	= 0;
459 
460 	fpos = 0;
461 	ret = afs_dir_iterate(dir, &fpos, &cookie, afs_lookup_filldir,
462 			      key);
463 	if (ret < 0) {
464 		_leave(" = %d [iter]", ret);
465 		return ret;
466 	}
467 
468 	ret = -ENOENT;
469 	if (!cookie.found) {
470 		_leave(" = -ENOENT [not found]");
471 		return -ENOENT;
472 	}
473 
474 	*fid = cookie.fid;
475 	_leave(" = 0 { vn=%u u=%u }", fid->vnode, fid->unique);
476 	return 0;
477 }
478 
479 /*
480  * look up an entry in a directory
481  */
482 static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
483 				 struct nameidata *nd)
484 {
485 	struct afs_vnode *vnode;
486 	struct afs_fid fid;
487 	struct inode *inode;
488 	struct key *key;
489 	int ret;
490 
491 	vnode = AFS_FS_I(dir);
492 
493 	_enter("{%x:%u},%p{%s},",
494 	       vnode->fid.vid, vnode->fid.vnode, dentry, dentry->d_name.name);
495 
496 	ASSERTCMP(dentry->d_inode, ==, NULL);
497 
498 	if (dentry->d_name.len >= AFSNAMEMAX) {
499 		_leave(" = -ENAMETOOLONG");
500 		return ERR_PTR(-ENAMETOOLONG);
501 	}
502 
503 	if (test_bit(AFS_VNODE_DELETED, &vnode->flags)) {
504 		_leave(" = -ESTALE");
505 		return ERR_PTR(-ESTALE);
506 	}
507 
508 	key = afs_request_key(vnode->volume->cell);
509 	if (IS_ERR(key)) {
510 		_leave(" = %ld [key]", PTR_ERR(key));
511 		return ERR_CAST(key);
512 	}
513 
514 	ret = afs_validate(vnode, key);
515 	if (ret < 0) {
516 		key_put(key);
517 		_leave(" = %d [val]", ret);
518 		return ERR_PTR(ret);
519 	}
520 
521 	ret = afs_do_lookup(dir, dentry, &fid, key);
522 	if (ret < 0) {
523 		key_put(key);
524 		if (ret == -ENOENT) {
525 			d_add(dentry, NULL);
526 			_leave(" = NULL [negative]");
527 			return NULL;
528 		}
529 		_leave(" = %d [do]", ret);
530 		return ERR_PTR(ret);
531 	}
532 	dentry->d_fsdata = (void *)(unsigned long) vnode->status.data_version;
533 
534 	/* instantiate the dentry */
535 	inode = afs_iget(dir->i_sb, key, &fid, NULL, NULL);
536 	key_put(key);
537 	if (IS_ERR(inode)) {
538 		_leave(" = %ld", PTR_ERR(inode));
539 		return ERR_CAST(inode);
540 	}
541 
542 	dentry->d_op = &afs_fs_dentry_operations;
543 
544 	d_add(dentry, inode);
545 	_leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
546 	       fid.vnode,
547 	       fid.unique,
548 	       dentry->d_inode->i_ino,
549 	       (unsigned long long)dentry->d_inode->i_version);
550 
551 	return NULL;
552 }
553 
554 /*
555  * check that a dentry lookup hit has found a valid entry
556  * - NOTE! the hit can be a negative hit too, so we can't assume we have an
557  *   inode
558  */
559 static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
560 {
561 	struct afs_vnode *vnode, *dir;
562 	struct afs_fid uninitialized_var(fid);
563 	struct dentry *parent;
564 	struct key *key;
565 	void *dir_version;
566 	int ret;
567 
568 	vnode = AFS_FS_I(dentry->d_inode);
569 
570 	if (dentry->d_inode)
571 		_enter("{v={%x:%u} n=%s fl=%lx},",
572 		       vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name,
573 		       vnode->flags);
574 	else
575 		_enter("{neg n=%s}", dentry->d_name.name);
576 
577 	key = afs_request_key(AFS_FS_S(dentry->d_sb)->volume->cell);
578 	if (IS_ERR(key))
579 		key = NULL;
580 
581 	/* lock down the parent dentry so we can peer at it */
582 	parent = dget_parent(dentry);
583 	if (!parent->d_inode)
584 		goto out_bad;
585 
586 	dir = AFS_FS_I(parent->d_inode);
587 
588 	/* validate the parent directory */
589 	if (test_bit(AFS_VNODE_MODIFIED, &dir->flags))
590 		afs_validate(dir, key);
591 
592 	if (test_bit(AFS_VNODE_DELETED, &dir->flags)) {
593 		_debug("%s: parent dir deleted", dentry->d_name.name);
594 		goto out_bad;
595 	}
596 
597 	dir_version = (void *) (unsigned long) dir->status.data_version;
598 	if (dentry->d_fsdata == dir_version)
599 		goto out_valid; /* the dir contents are unchanged */
600 
601 	_debug("dir modified");
602 
603 	/* search the directory for this vnode */
604 	ret = afs_do_lookup(&dir->vfs_inode, dentry, &fid, key);
605 	switch (ret) {
606 	case 0:
607 		/* the filename maps to something */
608 		if (!dentry->d_inode)
609 			goto out_bad;
610 		if (is_bad_inode(dentry->d_inode)) {
611 			printk("kAFS: afs_d_revalidate: %s/%s has bad inode\n",
612 			       parent->d_name.name, dentry->d_name.name);
613 			goto out_bad;
614 		}
615 
616 		/* if the vnode ID has changed, then the dirent points to a
617 		 * different file */
618 		if (fid.vnode != vnode->fid.vnode) {
619 			_debug("%s: dirent changed [%u != %u]",
620 			       dentry->d_name.name, fid.vnode,
621 			       vnode->fid.vnode);
622 			goto not_found;
623 		}
624 
625 		/* if the vnode ID uniqifier has changed, then the file has
626 		 * been deleted and replaced, and the original vnode ID has
627 		 * been reused */
628 		if (fid.unique != vnode->fid.unique) {
629 			_debug("%s: file deleted (uq %u -> %u I:%llu)",
630 			       dentry->d_name.name, fid.unique,
631 			       vnode->fid.unique,
632 			       (unsigned long long)dentry->d_inode->i_version);
633 			spin_lock(&vnode->lock);
634 			set_bit(AFS_VNODE_DELETED, &vnode->flags);
635 			spin_unlock(&vnode->lock);
636 			goto not_found;
637 		}
638 		goto out_valid;
639 
640 	case -ENOENT:
641 		/* the filename is unknown */
642 		_debug("%s: dirent not found", dentry->d_name.name);
643 		if (dentry->d_inode)
644 			goto not_found;
645 		goto out_valid;
646 
647 	default:
648 		_debug("failed to iterate dir %s: %d",
649 		       parent->d_name.name, ret);
650 		goto out_bad;
651 	}
652 
653 out_valid:
654 	dentry->d_fsdata = dir_version;
655 out_skip:
656 	dput(parent);
657 	key_put(key);
658 	_leave(" = 1 [valid]");
659 	return 1;
660 
661 	/* the dirent, if it exists, now points to a different vnode */
662 not_found:
663 	spin_lock(&dentry->d_lock);
664 	dentry->d_flags |= DCACHE_NFSFS_RENAMED;
665 	spin_unlock(&dentry->d_lock);
666 
667 out_bad:
668 	if (dentry->d_inode) {
669 		/* don't unhash if we have submounts */
670 		if (have_submounts(dentry))
671 			goto out_skip;
672 	}
673 
674 	_debug("dropping dentry %s/%s",
675 	       parent->d_name.name, dentry->d_name.name);
676 	shrink_dcache_parent(dentry);
677 	d_drop(dentry);
678 	dput(parent);
679 	key_put(key);
680 
681 	_leave(" = 0 [bad]");
682 	return 0;
683 }
684 
685 /*
686  * allow the VFS to enquire as to whether a dentry should be unhashed (mustn't
687  * sleep)
688  * - called from dput() when d_count is going to 0.
689  * - return 1 to request dentry be unhashed, 0 otherwise
690  */
691 static int afs_d_delete(struct dentry *dentry)
692 {
693 	_enter("%s", dentry->d_name.name);
694 
695 	if (dentry->d_flags & DCACHE_NFSFS_RENAMED)
696 		goto zap;
697 
698 	if (dentry->d_inode &&
699 	    test_bit(AFS_VNODE_DELETED, &AFS_FS_I(dentry->d_inode)->flags))
700 			goto zap;
701 
702 	_leave(" = 0 [keep]");
703 	return 0;
704 
705 zap:
706 	_leave(" = 1 [zap]");
707 	return 1;
708 }
709 
710 /*
711  * handle dentry release
712  */
713 static void afs_d_release(struct dentry *dentry)
714 {
715 	_enter("%s", dentry->d_name.name);
716 }
717 
718 /*
719  * create a directory on an AFS filesystem
720  */
721 static int afs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
722 {
723 	struct afs_file_status status;
724 	struct afs_callback cb;
725 	struct afs_server *server;
726 	struct afs_vnode *dvnode, *vnode;
727 	struct afs_fid fid;
728 	struct inode *inode;
729 	struct key *key;
730 	int ret;
731 
732 	dvnode = AFS_FS_I(dir);
733 
734 	_enter("{%x:%u},{%s},%o",
735 	       dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
736 
737 	ret = -ENAMETOOLONG;
738 	if (dentry->d_name.len >= AFSNAMEMAX)
739 		goto error;
740 
741 	key = afs_request_key(dvnode->volume->cell);
742 	if (IS_ERR(key)) {
743 		ret = PTR_ERR(key);
744 		goto error;
745 	}
746 
747 	mode |= S_IFDIR;
748 	ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
749 			       mode, &fid, &status, &cb, &server);
750 	if (ret < 0)
751 		goto mkdir_error;
752 
753 	inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
754 	if (IS_ERR(inode)) {
755 		/* ENOMEM at a really inconvenient time - just abandon the new
756 		 * directory on the server */
757 		ret = PTR_ERR(inode);
758 		goto iget_error;
759 	}
760 
761 	/* apply the status report we've got for the new vnode */
762 	vnode = AFS_FS_I(inode);
763 	spin_lock(&vnode->lock);
764 	vnode->update_cnt++;
765 	spin_unlock(&vnode->lock);
766 	afs_vnode_finalise_status_update(vnode, server);
767 	afs_put_server(server);
768 
769 	d_instantiate(dentry, inode);
770 	if (d_unhashed(dentry)) {
771 		_debug("not hashed");
772 		d_rehash(dentry);
773 	}
774 	key_put(key);
775 	_leave(" = 0");
776 	return 0;
777 
778 iget_error:
779 	afs_put_server(server);
780 mkdir_error:
781 	key_put(key);
782 error:
783 	d_drop(dentry);
784 	_leave(" = %d", ret);
785 	return ret;
786 }
787 
788 /*
789  * remove a directory from an AFS filesystem
790  */
791 static int afs_rmdir(struct inode *dir, struct dentry *dentry)
792 {
793 	struct afs_vnode *dvnode, *vnode;
794 	struct key *key;
795 	int ret;
796 
797 	dvnode = AFS_FS_I(dir);
798 
799 	_enter("{%x:%u},{%s}",
800 	       dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name);
801 
802 	ret = -ENAMETOOLONG;
803 	if (dentry->d_name.len >= AFSNAMEMAX)
804 		goto error;
805 
806 	key = afs_request_key(dvnode->volume->cell);
807 	if (IS_ERR(key)) {
808 		ret = PTR_ERR(key);
809 		goto error;
810 	}
811 
812 	ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, true);
813 	if (ret < 0)
814 		goto rmdir_error;
815 
816 	if (dentry->d_inode) {
817 		vnode = AFS_FS_I(dentry->d_inode);
818 		clear_nlink(&vnode->vfs_inode);
819 		set_bit(AFS_VNODE_DELETED, &vnode->flags);
820 		afs_discard_callback_on_delete(vnode);
821 	}
822 
823 	key_put(key);
824 	_leave(" = 0");
825 	return 0;
826 
827 rmdir_error:
828 	key_put(key);
829 error:
830 	_leave(" = %d", ret);
831 	return ret;
832 }
833 
834 /*
835  * remove a file from an AFS filesystem
836  */
837 static int afs_unlink(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 	if (dentry->d_inode) {
859 		vnode = AFS_FS_I(dentry->d_inode);
860 
861 		/* make sure we have a callback promise on the victim */
862 		ret = afs_validate(vnode, key);
863 		if (ret < 0)
864 			goto error;
865 	}
866 
867 	ret = afs_vnode_remove(dvnode, key, dentry->d_name.name, false);
868 	if (ret < 0)
869 		goto remove_error;
870 
871 	if (dentry->d_inode) {
872 		/* if the file wasn't deleted due to excess hard links, the
873 		 * fileserver will break the callback promise on the file - if
874 		 * it had one - before it returns to us, and if it was deleted,
875 		 * it won't
876 		 *
877 		 * however, if we didn't have a callback promise outstanding,
878 		 * or it was outstanding on a different server, then it won't
879 		 * break it either...
880 		 */
881 		vnode = AFS_FS_I(dentry->d_inode);
882 		if (test_bit(AFS_VNODE_DELETED, &vnode->flags))
883 			_debug("AFS_VNODE_DELETED");
884 		if (test_bit(AFS_VNODE_CB_BROKEN, &vnode->flags))
885 			_debug("AFS_VNODE_CB_BROKEN");
886 		set_bit(AFS_VNODE_CB_BROKEN, &vnode->flags);
887 		ret = afs_validate(vnode, key);
888 		_debug("nlink %d [val %d]", vnode->vfs_inode.i_nlink, ret);
889 	}
890 
891 	key_put(key);
892 	_leave(" = 0");
893 	return 0;
894 
895 remove_error:
896 	key_put(key);
897 error:
898 	_leave(" = %d", ret);
899 	return ret;
900 }
901 
902 /*
903  * create a regular file on an AFS filesystem
904  */
905 static int afs_create(struct inode *dir, struct dentry *dentry, int mode,
906 		      struct nameidata *nd)
907 {
908 	struct afs_file_status status;
909 	struct afs_callback cb;
910 	struct afs_server *server;
911 	struct afs_vnode *dvnode, *vnode;
912 	struct afs_fid fid;
913 	struct inode *inode;
914 	struct key *key;
915 	int ret;
916 
917 	dvnode = AFS_FS_I(dir);
918 
919 	_enter("{%x:%u},{%s},%o,",
920 	       dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name, mode);
921 
922 	ret = -ENAMETOOLONG;
923 	if (dentry->d_name.len >= AFSNAMEMAX)
924 		goto error;
925 
926 	key = afs_request_key(dvnode->volume->cell);
927 	if (IS_ERR(key)) {
928 		ret = PTR_ERR(key);
929 		goto error;
930 	}
931 
932 	mode |= S_IFREG;
933 	ret = afs_vnode_create(dvnode, key, dentry->d_name.name,
934 			       mode, &fid, &status, &cb, &server);
935 	if (ret < 0)
936 		goto create_error;
937 
938 	inode = afs_iget(dir->i_sb, key, &fid, &status, &cb);
939 	if (IS_ERR(inode)) {
940 		/* ENOMEM at a really inconvenient time - just abandon the new
941 		 * directory on the server */
942 		ret = PTR_ERR(inode);
943 		goto iget_error;
944 	}
945 
946 	/* apply the status report we've got for the new vnode */
947 	vnode = AFS_FS_I(inode);
948 	spin_lock(&vnode->lock);
949 	vnode->update_cnt++;
950 	spin_unlock(&vnode->lock);
951 	afs_vnode_finalise_status_update(vnode, server);
952 	afs_put_server(server);
953 
954 	d_instantiate(dentry, inode);
955 	if (d_unhashed(dentry)) {
956 		_debug("not hashed");
957 		d_rehash(dentry);
958 	}
959 	key_put(key);
960 	_leave(" = 0");
961 	return 0;
962 
963 iget_error:
964 	afs_put_server(server);
965 create_error:
966 	key_put(key);
967 error:
968 	d_drop(dentry);
969 	_leave(" = %d", ret);
970 	return ret;
971 }
972 
973 /*
974  * create a hard link between files in an AFS filesystem
975  */
976 static int afs_link(struct dentry *from, struct inode *dir,
977 		    struct dentry *dentry)
978 {
979 	struct afs_vnode *dvnode, *vnode;
980 	struct key *key;
981 	int ret;
982 
983 	vnode = AFS_FS_I(from->d_inode);
984 	dvnode = AFS_FS_I(dir);
985 
986 	_enter("{%x:%u},{%x:%u},{%s}",
987 	       vnode->fid.vid, vnode->fid.vnode,
988 	       dvnode->fid.vid, dvnode->fid.vnode,
989 	       dentry->d_name.name);
990 
991 	ret = -ENAMETOOLONG;
992 	if (dentry->d_name.len >= AFSNAMEMAX)
993 		goto error;
994 
995 	key = afs_request_key(dvnode->volume->cell);
996 	if (IS_ERR(key)) {
997 		ret = PTR_ERR(key);
998 		goto error;
999 	}
1000 
1001 	ret = afs_vnode_link(dvnode, vnode, key, dentry->d_name.name);
1002 	if (ret < 0)
1003 		goto link_error;
1004 
1005 	atomic_inc(&vnode->vfs_inode.i_count);
1006 	d_instantiate(dentry, &vnode->vfs_inode);
1007 	key_put(key);
1008 	_leave(" = 0");
1009 	return 0;
1010 
1011 link_error:
1012 	key_put(key);
1013 error:
1014 	d_drop(dentry);
1015 	_leave(" = %d", ret);
1016 	return ret;
1017 }
1018 
1019 /*
1020  * create a symlink in an AFS filesystem
1021  */
1022 static int afs_symlink(struct inode *dir, struct dentry *dentry,
1023 		       const char *content)
1024 {
1025 	struct afs_file_status status;
1026 	struct afs_server *server;
1027 	struct afs_vnode *dvnode, *vnode;
1028 	struct afs_fid fid;
1029 	struct inode *inode;
1030 	struct key *key;
1031 	int ret;
1032 
1033 	dvnode = AFS_FS_I(dir);
1034 
1035 	_enter("{%x:%u},{%s},%s",
1036 	       dvnode->fid.vid, dvnode->fid.vnode, dentry->d_name.name,
1037 	       content);
1038 
1039 	ret = -ENAMETOOLONG;
1040 	if (dentry->d_name.len >= AFSNAMEMAX)
1041 		goto error;
1042 
1043 	ret = -EINVAL;
1044 	if (strlen(content) >= AFSPATHMAX)
1045 		goto error;
1046 
1047 	key = afs_request_key(dvnode->volume->cell);
1048 	if (IS_ERR(key)) {
1049 		ret = PTR_ERR(key);
1050 		goto error;
1051 	}
1052 
1053 	ret = afs_vnode_symlink(dvnode, key, dentry->d_name.name, content,
1054 				&fid, &status, &server);
1055 	if (ret < 0)
1056 		goto create_error;
1057 
1058 	inode = afs_iget(dir->i_sb, key, &fid, &status, NULL);
1059 	if (IS_ERR(inode)) {
1060 		/* ENOMEM at a really inconvenient time - just abandon the new
1061 		 * directory on the server */
1062 		ret = PTR_ERR(inode);
1063 		goto iget_error;
1064 	}
1065 
1066 	/* apply the status report we've got for the new vnode */
1067 	vnode = AFS_FS_I(inode);
1068 	spin_lock(&vnode->lock);
1069 	vnode->update_cnt++;
1070 	spin_unlock(&vnode->lock);
1071 	afs_vnode_finalise_status_update(vnode, server);
1072 	afs_put_server(server);
1073 
1074 	d_instantiate(dentry, inode);
1075 	if (d_unhashed(dentry)) {
1076 		_debug("not hashed");
1077 		d_rehash(dentry);
1078 	}
1079 	key_put(key);
1080 	_leave(" = 0");
1081 	return 0;
1082 
1083 iget_error:
1084 	afs_put_server(server);
1085 create_error:
1086 	key_put(key);
1087 error:
1088 	d_drop(dentry);
1089 	_leave(" = %d", ret);
1090 	return ret;
1091 }
1092 
1093 /*
1094  * rename a file in an AFS filesystem and/or move it between directories
1095  */
1096 static int afs_rename(struct inode *old_dir, struct dentry *old_dentry,
1097 		      struct inode *new_dir, struct dentry *new_dentry)
1098 {
1099 	struct afs_vnode *orig_dvnode, *new_dvnode, *vnode;
1100 	struct key *key;
1101 	int ret;
1102 
1103 	vnode = AFS_FS_I(old_dentry->d_inode);
1104 	orig_dvnode = AFS_FS_I(old_dir);
1105 	new_dvnode = AFS_FS_I(new_dir);
1106 
1107 	_enter("{%x:%u},{%x:%u},{%x:%u},{%s}",
1108 	       orig_dvnode->fid.vid, orig_dvnode->fid.vnode,
1109 	       vnode->fid.vid, vnode->fid.vnode,
1110 	       new_dvnode->fid.vid, new_dvnode->fid.vnode,
1111 	       new_dentry->d_name.name);
1112 
1113 	ret = -ENAMETOOLONG;
1114 	if (new_dentry->d_name.len >= AFSNAMEMAX)
1115 		goto error;
1116 
1117 	key = afs_request_key(orig_dvnode->volume->cell);
1118 	if (IS_ERR(key)) {
1119 		ret = PTR_ERR(key);
1120 		goto error;
1121 	}
1122 
1123 	ret = afs_vnode_rename(orig_dvnode, new_dvnode, key,
1124 			       old_dentry->d_name.name,
1125 			       new_dentry->d_name.name);
1126 	if (ret < 0)
1127 		goto rename_error;
1128 	key_put(key);
1129 	_leave(" = 0");
1130 	return 0;
1131 
1132 rename_error:
1133 	key_put(key);
1134 error:
1135 	d_drop(new_dentry);
1136 	_leave(" = %d", ret);
1137 	return ret;
1138 }
1139