xref: /linux/fs/jffs2/dir.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6  *
7  * Created by David Woodhouse <dwmw2@infradead.org>
8  *
9  * For licensing information, see the file 'LICENCE' in this directory.
10  *
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/slab.h>
15 #include <linux/fs.h>
16 #include <linux/crc32.h>
17 #include <linux/jffs2.h>
18 #include "jffs2_fs_i.h"
19 #include "jffs2_fs_sb.h"
20 #include <linux/time.h>
21 #include "nodelist.h"
22 
23 static int jffs2_readdir (struct file *, void *, filldir_t);
24 
25 static int jffs2_create (struct inode *,struct dentry *,int,
26 			 struct nameidata *);
27 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
28 				    struct nameidata *);
29 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
30 static int jffs2_unlink (struct inode *,struct dentry *);
31 static int jffs2_symlink (struct inode *,struct dentry *,const char *);
32 static int jffs2_mkdir (struct inode *,struct dentry *,int);
33 static int jffs2_rmdir (struct inode *,struct dentry *);
34 static int jffs2_mknod (struct inode *,struct dentry *,int,dev_t);
35 static int jffs2_rename (struct inode *, struct dentry *,
36 			 struct inode *, struct dentry *);
37 
38 const struct file_operations jffs2_dir_operations =
39 {
40 	.read =		generic_read_dir,
41 	.readdir =	jffs2_readdir,
42 	.unlocked_ioctl=jffs2_ioctl,
43 	.fsync =	jffs2_fsync,
44 	.llseek =	generic_file_llseek,
45 };
46 
47 
48 const struct inode_operations jffs2_dir_inode_operations =
49 {
50 	.create =	jffs2_create,
51 	.lookup =	jffs2_lookup,
52 	.link =		jffs2_link,
53 	.unlink =	jffs2_unlink,
54 	.symlink =	jffs2_symlink,
55 	.mkdir =	jffs2_mkdir,
56 	.rmdir =	jffs2_rmdir,
57 	.mknod =	jffs2_mknod,
58 	.rename =	jffs2_rename,
59 	.get_acl =	jffs2_get_acl,
60 	.setattr =	jffs2_setattr,
61 	.setxattr =	jffs2_setxattr,
62 	.getxattr =	jffs2_getxattr,
63 	.listxattr =	jffs2_listxattr,
64 	.removexattr =	jffs2_removexattr
65 };
66 
67 /***********************************************************************/
68 
69 
70 /* We keep the dirent list sorted in increasing order of name hash,
71    and we use the same hash function as the dentries. Makes this
72    nice and simple
73 */
74 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
75 				   struct nameidata *nd)
76 {
77 	struct jffs2_inode_info *dir_f;
78 	struct jffs2_full_dirent *fd = NULL, *fd_list;
79 	uint32_t ino = 0;
80 	struct inode *inode = NULL;
81 
82 	D1(printk(KERN_DEBUG "jffs2_lookup()\n"));
83 
84 	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
85 		return ERR_PTR(-ENAMETOOLONG);
86 
87 	dir_f = JFFS2_INODE_INFO(dir_i);
88 
89 	mutex_lock(&dir_f->sem);
90 
91 	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
92 	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= target->d_name.hash; fd_list = fd_list->next) {
93 		if (fd_list->nhash == target->d_name.hash &&
94 		    (!fd || fd_list->version > fd->version) &&
95 		    strlen(fd_list->name) == target->d_name.len &&
96 		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
97 			fd = fd_list;
98 		}
99 	}
100 	if (fd)
101 		ino = fd->ino;
102 	mutex_unlock(&dir_f->sem);
103 	if (ino) {
104 		inode = jffs2_iget(dir_i->i_sb, ino);
105 		if (IS_ERR(inode))
106 			printk(KERN_WARNING "iget() failed for ino #%u\n", ino);
107 	}
108 
109 	return d_splice_alias(inode, target);
110 }
111 
112 /***********************************************************************/
113 
114 
115 static int jffs2_readdir(struct file *filp, void *dirent, filldir_t filldir)
116 {
117 	struct jffs2_inode_info *f;
118 	struct inode *inode = filp->f_path.dentry->d_inode;
119 	struct jffs2_full_dirent *fd;
120 	unsigned long offset, curofs;
121 
122 	D1(printk(KERN_DEBUG "jffs2_readdir() for dir_i #%lu\n", filp->f_path.dentry->d_inode->i_ino));
123 
124 	f = JFFS2_INODE_INFO(inode);
125 
126 	offset = filp->f_pos;
127 
128 	if (offset == 0) {
129 		D1(printk(KERN_DEBUG "Dirent 0: \".\", ino #%lu\n", inode->i_ino));
130 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
131 			goto out;
132 		offset++;
133 	}
134 	if (offset == 1) {
135 		unsigned long pino = parent_ino(filp->f_path.dentry);
136 		D1(printk(KERN_DEBUG "Dirent 1: \"..\", ino #%lu\n", pino));
137 		if (filldir(dirent, "..", 2, 1, pino, DT_DIR) < 0)
138 			goto out;
139 		offset++;
140 	}
141 
142 	curofs=1;
143 	mutex_lock(&f->sem);
144 	for (fd = f->dents; fd; fd = fd->next) {
145 
146 		curofs++;
147 		/* First loop: curofs = 2; offset = 2 */
148 		if (curofs < offset) {
149 			D2(printk(KERN_DEBUG "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
150 				  fd->name, fd->ino, fd->type, curofs, offset));
151 			continue;
152 		}
153 		if (!fd->ino) {
154 			D2(printk(KERN_DEBUG "Skipping deletion dirent \"%s\"\n", fd->name));
155 			offset++;
156 			continue;
157 		}
158 		D2(printk(KERN_DEBUG "Dirent %ld: \"%s\", ino #%u, type %d\n", offset, fd->name, fd->ino, fd->type));
159 		if (filldir(dirent, fd->name, strlen(fd->name), offset, fd->ino, fd->type) < 0)
160 			break;
161 		offset++;
162 	}
163 	mutex_unlock(&f->sem);
164  out:
165 	filp->f_pos = offset;
166 	return 0;
167 }
168 
169 /***********************************************************************/
170 
171 
172 static int jffs2_create(struct inode *dir_i, struct dentry *dentry, int mode,
173 			struct nameidata *nd)
174 {
175 	struct jffs2_raw_inode *ri;
176 	struct jffs2_inode_info *f, *dir_f;
177 	struct jffs2_sb_info *c;
178 	struct inode *inode;
179 	int ret;
180 
181 	ri = jffs2_alloc_raw_inode();
182 	if (!ri)
183 		return -ENOMEM;
184 
185 	c = JFFS2_SB_INFO(dir_i->i_sb);
186 
187 	D1(printk(KERN_DEBUG "jffs2_create()\n"));
188 
189 	inode = jffs2_new_inode(dir_i, mode, ri);
190 
191 	if (IS_ERR(inode)) {
192 		D1(printk(KERN_DEBUG "jffs2_new_inode() failed\n"));
193 		jffs2_free_raw_inode(ri);
194 		return PTR_ERR(inode);
195 	}
196 
197 	inode->i_op = &jffs2_file_inode_operations;
198 	inode->i_fop = &jffs2_file_operations;
199 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
200 	inode->i_mapping->nrpages = 0;
201 
202 	f = JFFS2_INODE_INFO(inode);
203 	dir_f = JFFS2_INODE_INFO(dir_i);
204 
205 	/* jffs2_do_create() will want to lock it, _after_ reserving
206 	   space and taking c-alloc_sem. If we keep it locked here,
207 	   lockdep gets unhappy (although it's a false positive;
208 	   nothing else will be looking at this inode yet so there's
209 	   no chance of AB-BA deadlock involving its f->sem). */
210 	mutex_unlock(&f->sem);
211 
212 	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
213 	if (ret)
214 		goto fail;
215 
216 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
217 
218 	jffs2_free_raw_inode(ri);
219 
220 	D1(printk(KERN_DEBUG "jffs2_create: Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
221 		  inode->i_ino, inode->i_mode, inode->i_nlink,
222 		  f->inocache->pino_nlink, inode->i_mapping->nrpages));
223 
224 	d_instantiate(dentry, inode);
225 	unlock_new_inode(inode);
226 	return 0;
227 
228  fail:
229 	iget_failed(inode);
230 	jffs2_free_raw_inode(ri);
231 	return ret;
232 }
233 
234 /***********************************************************************/
235 
236 
237 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
238 {
239 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
240 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
241 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(dentry->d_inode);
242 	int ret;
243 	uint32_t now = get_seconds();
244 
245 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
246 			      dentry->d_name.len, dead_f, now);
247 	if (dead_f->inocache)
248 		dentry->d_inode->i_nlink = dead_f->inocache->pino_nlink;
249 	if (!ret)
250 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
251 	return ret;
252 }
253 /***********************************************************************/
254 
255 
256 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
257 {
258 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_inode->i_sb);
259 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
260 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
261 	int ret;
262 	uint8_t type;
263 	uint32_t now;
264 
265 	/* Don't let people make hard links to bad inodes. */
266 	if (!f->inocache)
267 		return -EIO;
268 
269 	if (S_ISDIR(old_dentry->d_inode->i_mode))
270 		return -EPERM;
271 
272 	/* XXX: This is ugly */
273 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
274 	if (!type) type = DT_REG;
275 
276 	now = get_seconds();
277 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
278 
279 	if (!ret) {
280 		mutex_lock(&f->sem);
281 		old_dentry->d_inode->i_nlink = ++f->inocache->pino_nlink;
282 		mutex_unlock(&f->sem);
283 		d_instantiate(dentry, old_dentry->d_inode);
284 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
285 		ihold(old_dentry->d_inode);
286 	}
287 	return ret;
288 }
289 
290 /***********************************************************************/
291 
292 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
293 {
294 	struct jffs2_inode_info *f, *dir_f;
295 	struct jffs2_sb_info *c;
296 	struct inode *inode;
297 	struct jffs2_raw_inode *ri;
298 	struct jffs2_raw_dirent *rd;
299 	struct jffs2_full_dnode *fn;
300 	struct jffs2_full_dirent *fd;
301 	int namelen;
302 	uint32_t alloclen;
303 	int ret, targetlen = strlen(target);
304 
305 	/* FIXME: If you care. We'd need to use frags for the target
306 	   if it grows much more than this */
307 	if (targetlen > 254)
308 		return -ENAMETOOLONG;
309 
310 	ri = jffs2_alloc_raw_inode();
311 
312 	if (!ri)
313 		return -ENOMEM;
314 
315 	c = JFFS2_SB_INFO(dir_i->i_sb);
316 
317 	/* Try to reserve enough space for both node and dirent.
318 	 * Just the node will do for now, though
319 	 */
320 	namelen = dentry->d_name.len;
321 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
322 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
323 
324 	if (ret) {
325 		jffs2_free_raw_inode(ri);
326 		return ret;
327 	}
328 
329 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
330 
331 	if (IS_ERR(inode)) {
332 		jffs2_free_raw_inode(ri);
333 		jffs2_complete_reservation(c);
334 		return PTR_ERR(inode);
335 	}
336 
337 	inode->i_op = &jffs2_symlink_inode_operations;
338 
339 	f = JFFS2_INODE_INFO(inode);
340 
341 	inode->i_size = targetlen;
342 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
343 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
344 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
345 
346 	ri->compr = JFFS2_COMPR_NONE;
347 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
348 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
349 
350 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
351 
352 	jffs2_free_raw_inode(ri);
353 
354 	if (IS_ERR(fn)) {
355 		/* Eeek. Wave bye bye */
356 		mutex_unlock(&f->sem);
357 		jffs2_complete_reservation(c);
358 		ret = PTR_ERR(fn);
359 		goto fail;
360 	}
361 
362 	/* We use f->target field to store the target path. */
363 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
364 	if (!f->target) {
365 		printk(KERN_WARNING "Can't allocate %d bytes of memory\n", targetlen + 1);
366 		mutex_unlock(&f->sem);
367 		jffs2_complete_reservation(c);
368 		ret = -ENOMEM;
369 		goto fail;
370 	}
371 
372 	D1(printk(KERN_DEBUG "jffs2_symlink: symlink's target '%s' cached\n", (char *)f->target));
373 
374 	/* No data here. Only a metadata node, which will be
375 	   obsoleted by the first data write
376 	*/
377 	f->metadata = fn;
378 	mutex_unlock(&f->sem);
379 
380 	jffs2_complete_reservation(c);
381 
382 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
383 	if (ret)
384 		goto fail;
385 
386 	ret = jffs2_init_acl_post(inode);
387 	if (ret)
388 		goto fail;
389 
390 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
391 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
392 	if (ret)
393 		goto fail;
394 
395 	rd = jffs2_alloc_raw_dirent();
396 	if (!rd) {
397 		/* Argh. Now we treat it like a normal delete */
398 		jffs2_complete_reservation(c);
399 		ret = -ENOMEM;
400 		goto fail;
401 	}
402 
403 	dir_f = JFFS2_INODE_INFO(dir_i);
404 	mutex_lock(&dir_f->sem);
405 
406 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
407 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
408 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
409 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
410 
411 	rd->pino = cpu_to_je32(dir_i->i_ino);
412 	rd->version = cpu_to_je32(++dir_f->highest_version);
413 	rd->ino = cpu_to_je32(inode->i_ino);
414 	rd->mctime = cpu_to_je32(get_seconds());
415 	rd->nsize = namelen;
416 	rd->type = DT_LNK;
417 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
418 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
419 
420 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
421 
422 	if (IS_ERR(fd)) {
423 		/* dirent failed to write. Delete the inode normally
424 		   as if it were the final unlink() */
425 		jffs2_complete_reservation(c);
426 		jffs2_free_raw_dirent(rd);
427 		mutex_unlock(&dir_f->sem);
428 		ret = PTR_ERR(fd);
429 		goto fail;
430 	}
431 
432 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
433 
434 	jffs2_free_raw_dirent(rd);
435 
436 	/* Link the fd into the inode's list, obsoleting an old
437 	   one if necessary. */
438 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
439 
440 	mutex_unlock(&dir_f->sem);
441 	jffs2_complete_reservation(c);
442 
443 	d_instantiate(dentry, inode);
444 	unlock_new_inode(inode);
445 	return 0;
446 
447  fail:
448 	iget_failed(inode);
449 	return ret;
450 }
451 
452 
453 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int mode)
454 {
455 	struct jffs2_inode_info *f, *dir_f;
456 	struct jffs2_sb_info *c;
457 	struct inode *inode;
458 	struct jffs2_raw_inode *ri;
459 	struct jffs2_raw_dirent *rd;
460 	struct jffs2_full_dnode *fn;
461 	struct jffs2_full_dirent *fd;
462 	int namelen;
463 	uint32_t alloclen;
464 	int ret;
465 
466 	mode |= S_IFDIR;
467 
468 	ri = jffs2_alloc_raw_inode();
469 	if (!ri)
470 		return -ENOMEM;
471 
472 	c = JFFS2_SB_INFO(dir_i->i_sb);
473 
474 	/* Try to reserve enough space for both node and dirent.
475 	 * Just the node will do for now, though
476 	 */
477 	namelen = dentry->d_name.len;
478 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
479 				  JFFS2_SUMMARY_INODE_SIZE);
480 
481 	if (ret) {
482 		jffs2_free_raw_inode(ri);
483 		return ret;
484 	}
485 
486 	inode = jffs2_new_inode(dir_i, mode, ri);
487 
488 	if (IS_ERR(inode)) {
489 		jffs2_free_raw_inode(ri);
490 		jffs2_complete_reservation(c);
491 		return PTR_ERR(inode);
492 	}
493 
494 	inode->i_op = &jffs2_dir_inode_operations;
495 	inode->i_fop = &jffs2_dir_operations;
496 
497 	f = JFFS2_INODE_INFO(inode);
498 
499 	/* Directories get nlink 2 at start */
500 	inode->i_nlink = 2;
501 	/* but ic->pino_nlink is the parent ino# */
502 	f->inocache->pino_nlink = dir_i->i_ino;
503 
504 	ri->data_crc = cpu_to_je32(0);
505 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
506 
507 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
508 
509 	jffs2_free_raw_inode(ri);
510 
511 	if (IS_ERR(fn)) {
512 		/* Eeek. Wave bye bye */
513 		mutex_unlock(&f->sem);
514 		jffs2_complete_reservation(c);
515 		ret = PTR_ERR(fn);
516 		goto fail;
517 	}
518 	/* No data here. Only a metadata node, which will be
519 	   obsoleted by the first data write
520 	*/
521 	f->metadata = fn;
522 	mutex_unlock(&f->sem);
523 
524 	jffs2_complete_reservation(c);
525 
526 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
527 	if (ret)
528 		goto fail;
529 
530 	ret = jffs2_init_acl_post(inode);
531 	if (ret)
532 		goto fail;
533 
534 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
535 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
536 	if (ret)
537 		goto fail;
538 
539 	rd = jffs2_alloc_raw_dirent();
540 	if (!rd) {
541 		/* Argh. Now we treat it like a normal delete */
542 		jffs2_complete_reservation(c);
543 		ret = -ENOMEM;
544 		goto fail;
545 	}
546 
547 	dir_f = JFFS2_INODE_INFO(dir_i);
548 	mutex_lock(&dir_f->sem);
549 
550 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
551 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
552 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
553 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
554 
555 	rd->pino = cpu_to_je32(dir_i->i_ino);
556 	rd->version = cpu_to_je32(++dir_f->highest_version);
557 	rd->ino = cpu_to_je32(inode->i_ino);
558 	rd->mctime = cpu_to_je32(get_seconds());
559 	rd->nsize = namelen;
560 	rd->type = DT_DIR;
561 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
562 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
563 
564 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
565 
566 	if (IS_ERR(fd)) {
567 		/* dirent failed to write. Delete the inode normally
568 		   as if it were the final unlink() */
569 		jffs2_complete_reservation(c);
570 		jffs2_free_raw_dirent(rd);
571 		mutex_unlock(&dir_f->sem);
572 		ret = PTR_ERR(fd);
573 		goto fail;
574 	}
575 
576 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
577 	inc_nlink(dir_i);
578 
579 	jffs2_free_raw_dirent(rd);
580 
581 	/* Link the fd into the inode's list, obsoleting an old
582 	   one if necessary. */
583 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
584 
585 	mutex_unlock(&dir_f->sem);
586 	jffs2_complete_reservation(c);
587 
588 	d_instantiate(dentry, inode);
589 	unlock_new_inode(inode);
590 	return 0;
591 
592  fail:
593 	iget_failed(inode);
594 	return ret;
595 }
596 
597 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
598 {
599 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
600 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
601 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
602 	struct jffs2_full_dirent *fd;
603 	int ret;
604 	uint32_t now = get_seconds();
605 
606 	for (fd = f->dents ; fd; fd = fd->next) {
607 		if (fd->ino)
608 			return -ENOTEMPTY;
609 	}
610 
611 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
612 			      dentry->d_name.len, f, now);
613 	if (!ret) {
614 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
615 		clear_nlink(dentry->d_inode);
616 		drop_nlink(dir_i);
617 	}
618 	return ret;
619 }
620 
621 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, dev_t rdev)
622 {
623 	struct jffs2_inode_info *f, *dir_f;
624 	struct jffs2_sb_info *c;
625 	struct inode *inode;
626 	struct jffs2_raw_inode *ri;
627 	struct jffs2_raw_dirent *rd;
628 	struct jffs2_full_dnode *fn;
629 	struct jffs2_full_dirent *fd;
630 	int namelen;
631 	union jffs2_device_node dev;
632 	int devlen = 0;
633 	uint32_t alloclen;
634 	int ret;
635 
636 	if (!new_valid_dev(rdev))
637 		return -EINVAL;
638 
639 	ri = jffs2_alloc_raw_inode();
640 	if (!ri)
641 		return -ENOMEM;
642 
643 	c = JFFS2_SB_INFO(dir_i->i_sb);
644 
645 	if (S_ISBLK(mode) || S_ISCHR(mode))
646 		devlen = jffs2_encode_dev(&dev, rdev);
647 
648 	/* Try to reserve enough space for both node and dirent.
649 	 * Just the node will do for now, though
650 	 */
651 	namelen = dentry->d_name.len;
652 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
653 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
654 
655 	if (ret) {
656 		jffs2_free_raw_inode(ri);
657 		return ret;
658 	}
659 
660 	inode = jffs2_new_inode(dir_i, mode, ri);
661 
662 	if (IS_ERR(inode)) {
663 		jffs2_free_raw_inode(ri);
664 		jffs2_complete_reservation(c);
665 		return PTR_ERR(inode);
666 	}
667 	inode->i_op = &jffs2_file_inode_operations;
668 	init_special_inode(inode, inode->i_mode, rdev);
669 
670 	f = JFFS2_INODE_INFO(inode);
671 
672 	ri->dsize = ri->csize = cpu_to_je32(devlen);
673 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
674 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
675 
676 	ri->compr = JFFS2_COMPR_NONE;
677 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
678 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
679 
680 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
681 
682 	jffs2_free_raw_inode(ri);
683 
684 	if (IS_ERR(fn)) {
685 		/* Eeek. Wave bye bye */
686 		mutex_unlock(&f->sem);
687 		jffs2_complete_reservation(c);
688 		ret = PTR_ERR(fn);
689 		goto fail;
690 	}
691 	/* No data here. Only a metadata node, which will be
692 	   obsoleted by the first data write
693 	*/
694 	f->metadata = fn;
695 	mutex_unlock(&f->sem);
696 
697 	jffs2_complete_reservation(c);
698 
699 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
700 	if (ret)
701 		goto fail;
702 
703 	ret = jffs2_init_acl_post(inode);
704 	if (ret)
705 		goto fail;
706 
707 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
708 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
709 	if (ret)
710 		goto fail;
711 
712 	rd = jffs2_alloc_raw_dirent();
713 	if (!rd) {
714 		/* Argh. Now we treat it like a normal delete */
715 		jffs2_complete_reservation(c);
716 		ret = -ENOMEM;
717 		goto fail;
718 	}
719 
720 	dir_f = JFFS2_INODE_INFO(dir_i);
721 	mutex_lock(&dir_f->sem);
722 
723 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
724 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
725 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
726 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
727 
728 	rd->pino = cpu_to_je32(dir_i->i_ino);
729 	rd->version = cpu_to_je32(++dir_f->highest_version);
730 	rd->ino = cpu_to_je32(inode->i_ino);
731 	rd->mctime = cpu_to_je32(get_seconds());
732 	rd->nsize = namelen;
733 
734 	/* XXX: This is ugly. */
735 	rd->type = (mode & S_IFMT) >> 12;
736 
737 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
738 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
739 
740 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
741 
742 	if (IS_ERR(fd)) {
743 		/* dirent failed to write. Delete the inode normally
744 		   as if it were the final unlink() */
745 		jffs2_complete_reservation(c);
746 		jffs2_free_raw_dirent(rd);
747 		mutex_unlock(&dir_f->sem);
748 		ret = PTR_ERR(fd);
749 		goto fail;
750 	}
751 
752 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
753 
754 	jffs2_free_raw_dirent(rd);
755 
756 	/* Link the fd into the inode's list, obsoleting an old
757 	   one if necessary. */
758 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
759 
760 	mutex_unlock(&dir_f->sem);
761 	jffs2_complete_reservation(c);
762 
763 	d_instantiate(dentry, inode);
764 	unlock_new_inode(inode);
765 	return 0;
766 
767  fail:
768 	iget_failed(inode);
769 	return ret;
770 }
771 
772 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
773 			 struct inode *new_dir_i, struct dentry *new_dentry)
774 {
775 	int ret;
776 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
777 	struct jffs2_inode_info *victim_f = NULL;
778 	uint8_t type;
779 	uint32_t now;
780 
781 	/* The VFS will check for us and prevent trying to rename a
782 	 * file over a directory and vice versa, but if it's a directory,
783 	 * the VFS can't check whether the victim is empty. The filesystem
784 	 * needs to do that for itself.
785 	 */
786 	if (new_dentry->d_inode) {
787 		victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);
788 		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
789 			struct jffs2_full_dirent *fd;
790 
791 			mutex_lock(&victim_f->sem);
792 			for (fd = victim_f->dents; fd; fd = fd->next) {
793 				if (fd->ino) {
794 					mutex_unlock(&victim_f->sem);
795 					return -ENOTEMPTY;
796 				}
797 			}
798 			mutex_unlock(&victim_f->sem);
799 		}
800 	}
801 
802 	/* XXX: We probably ought to alloc enough space for
803 	   both nodes at the same time. Writing the new link,
804 	   then getting -ENOSPC, is quite bad :)
805 	*/
806 
807 	/* Make a hard link */
808 
809 	/* XXX: This is ugly */
810 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
811 	if (!type) type = DT_REG;
812 
813 	now = get_seconds();
814 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
815 			    old_dentry->d_inode->i_ino, type,
816 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
817 
818 	if (ret)
819 		return ret;
820 
821 	if (victim_f) {
822 		/* There was a victim. Kill it off nicely */
823 		if (S_ISDIR(new_dentry->d_inode->i_mode))
824 			clear_nlink(new_dentry->d_inode);
825 		else
826 			drop_nlink(new_dentry->d_inode);
827 		/* Don't oops if the victim was a dirent pointing to an
828 		   inode which didn't exist. */
829 		if (victim_f->inocache) {
830 			mutex_lock(&victim_f->sem);
831 			if (S_ISDIR(new_dentry->d_inode->i_mode))
832 				victim_f->inocache->pino_nlink = 0;
833 			else
834 				victim_f->inocache->pino_nlink--;
835 			mutex_unlock(&victim_f->sem);
836 		}
837 	}
838 
839 	/* If it was a directory we moved, and there was no victim,
840 	   increase i_nlink on its new parent */
841 	if (S_ISDIR(old_dentry->d_inode->i_mode) && !victim_f)
842 		inc_nlink(new_dir_i);
843 
844 	/* Unlink the original */
845 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
846 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
847 
848 	/* We don't touch inode->i_nlink */
849 
850 	if (ret) {
851 		/* Oh shit. We really ought to make a single node which can do both atomically */
852 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
853 		mutex_lock(&f->sem);
854 		inc_nlink(old_dentry->d_inode);
855 		if (f->inocache && !S_ISDIR(old_dentry->d_inode->i_mode))
856 			f->inocache->pino_nlink++;
857 		mutex_unlock(&f->sem);
858 
859 		printk(KERN_NOTICE "jffs2_rename(): Link succeeded, unlink failed (err %d). You now have a hard link\n", ret);
860 		/* Might as well let the VFS know */
861 		d_instantiate(new_dentry, old_dentry->d_inode);
862 		ihold(old_dentry->d_inode);
863 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
864 		return ret;
865 	}
866 
867 	if (S_ISDIR(old_dentry->d_inode->i_mode))
868 		drop_nlink(old_dir_i);
869 
870 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
871 
872 	return 0;
873 }
874 
875