xref: /openbmc/linux/fs/jffs2/dir.c (revision 41cce647)
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/fs.h>
15 #include <linux/crc32.h>
16 #include <linux/jffs2.h>
17 #include "jffs2_fs_i.h"
18 #include "jffs2_fs_sb.h"
19 #include <linux/time.h>
20 #include "nodelist.h"
21 
22 static int jffs2_readdir (struct file *, void *, filldir_t);
23 
24 static int jffs2_create (struct inode *,struct dentry *,int,
25 			 struct nameidata *);
26 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
27 				    struct nameidata *);
28 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
29 static int jffs2_unlink (struct inode *,struct dentry *);
30 static int jffs2_symlink (struct inode *,struct dentry *,const char *);
31 static int jffs2_mkdir (struct inode *,struct dentry *,int);
32 static int jffs2_rmdir (struct inode *,struct dentry *);
33 static int jffs2_mknod (struct inode *,struct dentry *,int,dev_t);
34 static int jffs2_rename (struct inode *, struct dentry *,
35 			 struct inode *, struct dentry *);
36 
37 const struct file_operations jffs2_dir_operations =
38 {
39 	.read =		generic_read_dir,
40 	.readdir =	jffs2_readdir,
41 	.unlocked_ioctl=jffs2_ioctl,
42 	.fsync =	jffs2_fsync,
43 	.llseek =	generic_file_llseek,
44 };
45 
46 
47 const struct inode_operations jffs2_dir_inode_operations =
48 {
49 	.create =	jffs2_create,
50 	.lookup =	jffs2_lookup,
51 	.link =		jffs2_link,
52 	.unlink =	jffs2_unlink,
53 	.symlink =	jffs2_symlink,
54 	.mkdir =	jffs2_mkdir,
55 	.rmdir =	jffs2_rmdir,
56 	.mknod =	jffs2_mknod,
57 	.rename =	jffs2_rename,
58 	.check_acl =	jffs2_check_acl,
59 	.setattr =	jffs2_setattr,
60 	.setxattr =	jffs2_setxattr,
61 	.getxattr =	jffs2_getxattr,
62 	.listxattr =	jffs2_listxattr,
63 	.removexattr =	jffs2_removexattr
64 };
65 
66 /***********************************************************************/
67 
68 
69 /* We keep the dirent list sorted in increasing order of name hash,
70    and we use the same hash function as the dentries. Makes this
71    nice and simple
72 */
73 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
74 				   struct nameidata *nd)
75 {
76 	struct jffs2_inode_info *dir_f;
77 	struct jffs2_sb_info *c;
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 	c = JFFS2_SB_INFO(dir_i->i_sb);
89 
90 	mutex_lock(&dir_f->sem);
91 
92 	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
93 	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= target->d_name.hash; fd_list = fd_list->next) {
94 		if (fd_list->nhash == target->d_name.hash &&
95 		    (!fd || fd_list->version > fd->version) &&
96 		    strlen(fd_list->name) == target->d_name.len &&
97 		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
98 			fd = fd_list;
99 		}
100 	}
101 	if (fd)
102 		ino = fd->ino;
103 	mutex_unlock(&dir_f->sem);
104 	if (ino) {
105 		inode = jffs2_iget(dir_i->i_sb, ino);
106 		if (IS_ERR(inode)) {
107 			printk(KERN_WARNING "iget() failed for ino #%u\n", ino);
108 			return ERR_CAST(inode);
109 		}
110 	}
111 
112 	return d_splice_alias(inode, target);
113 }
114 
115 /***********************************************************************/
116 
117 
118 static int jffs2_readdir(struct file *filp, void *dirent, filldir_t filldir)
119 {
120 	struct jffs2_inode_info *f;
121 	struct jffs2_sb_info *c;
122 	struct inode *inode = filp->f_path.dentry->d_inode;
123 	struct jffs2_full_dirent *fd;
124 	unsigned long offset, curofs;
125 
126 	D1(printk(KERN_DEBUG "jffs2_readdir() for dir_i #%lu\n", filp->f_path.dentry->d_inode->i_ino));
127 
128 	f = JFFS2_INODE_INFO(inode);
129 	c = JFFS2_SB_INFO(inode->i_sb);
130 
131 	offset = filp->f_pos;
132 
133 	if (offset == 0) {
134 		D1(printk(KERN_DEBUG "Dirent 0: \".\", ino #%lu\n", inode->i_ino));
135 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
136 			goto out;
137 		offset++;
138 	}
139 	if (offset == 1) {
140 		unsigned long pino = parent_ino(filp->f_path.dentry);
141 		D1(printk(KERN_DEBUG "Dirent 1: \"..\", ino #%lu\n", pino));
142 		if (filldir(dirent, "..", 2, 1, pino, DT_DIR) < 0)
143 			goto out;
144 		offset++;
145 	}
146 
147 	curofs=1;
148 	mutex_lock(&f->sem);
149 	for (fd = f->dents; fd; fd = fd->next) {
150 
151 		curofs++;
152 		/* First loop: curofs = 2; offset = 2 */
153 		if (curofs < offset) {
154 			D2(printk(KERN_DEBUG "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
155 				  fd->name, fd->ino, fd->type, curofs, offset));
156 			continue;
157 		}
158 		if (!fd->ino) {
159 			D2(printk(KERN_DEBUG "Skipping deletion dirent \"%s\"\n", fd->name));
160 			offset++;
161 			continue;
162 		}
163 		D2(printk(KERN_DEBUG "Dirent %ld: \"%s\", ino #%u, type %d\n", offset, fd->name, fd->ino, fd->type));
164 		if (filldir(dirent, fd->name, strlen(fd->name), offset, fd->ino, fd->type) < 0)
165 			break;
166 		offset++;
167 	}
168 	mutex_unlock(&f->sem);
169  out:
170 	filp->f_pos = offset;
171 	return 0;
172 }
173 
174 /***********************************************************************/
175 
176 
177 static int jffs2_create(struct inode *dir_i, struct dentry *dentry, int mode,
178 			struct nameidata *nd)
179 {
180 	struct jffs2_raw_inode *ri;
181 	struct jffs2_inode_info *f, *dir_f;
182 	struct jffs2_sb_info *c;
183 	struct inode *inode;
184 	int ret;
185 
186 	ri = jffs2_alloc_raw_inode();
187 	if (!ri)
188 		return -ENOMEM;
189 
190 	c = JFFS2_SB_INFO(dir_i->i_sb);
191 
192 	D1(printk(KERN_DEBUG "jffs2_create()\n"));
193 
194 	inode = jffs2_new_inode(dir_i, mode, ri);
195 
196 	if (IS_ERR(inode)) {
197 		D1(printk(KERN_DEBUG "jffs2_new_inode() failed\n"));
198 		jffs2_free_raw_inode(ri);
199 		return PTR_ERR(inode);
200 	}
201 
202 	inode->i_op = &jffs2_file_inode_operations;
203 	inode->i_fop = &jffs2_file_operations;
204 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
205 	inode->i_mapping->nrpages = 0;
206 
207 	f = JFFS2_INODE_INFO(inode);
208 	dir_f = JFFS2_INODE_INFO(dir_i);
209 
210 	/* jffs2_do_create() will want to lock it, _after_ reserving
211 	   space and taking c-alloc_sem. If we keep it locked here,
212 	   lockdep gets unhappy (although it's a false positive;
213 	   nothing else will be looking at this inode yet so there's
214 	   no chance of AB-BA deadlock involving its f->sem). */
215 	mutex_unlock(&f->sem);
216 
217 	ret = jffs2_do_create(c, dir_f, f, ri,
218 			      dentry->d_name.name, dentry->d_name.len);
219 	if (ret)
220 		goto fail;
221 
222 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
223 
224 	jffs2_free_raw_inode(ri);
225 
226 	D1(printk(KERN_DEBUG "jffs2_create: Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
227 		  inode->i_ino, inode->i_mode, inode->i_nlink,
228 		  f->inocache->pino_nlink, inode->i_mapping->nrpages));
229 
230 	d_instantiate(dentry, inode);
231 	unlock_new_inode(inode);
232 	return 0;
233 
234  fail:
235 	iget_failed(inode);
236 	jffs2_free_raw_inode(ri);
237 	return ret;
238 }
239 
240 /***********************************************************************/
241 
242 
243 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
244 {
245 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
246 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
247 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(dentry->d_inode);
248 	int ret;
249 	uint32_t now = get_seconds();
250 
251 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
252 			      dentry->d_name.len, dead_f, now);
253 	if (dead_f->inocache)
254 		dentry->d_inode->i_nlink = dead_f->inocache->pino_nlink;
255 	if (!ret)
256 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
257 	return ret;
258 }
259 /***********************************************************************/
260 
261 
262 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
263 {
264 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_inode->i_sb);
265 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
266 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
267 	int ret;
268 	uint8_t type;
269 	uint32_t now;
270 
271 	/* Don't let people make hard links to bad inodes. */
272 	if (!f->inocache)
273 		return -EIO;
274 
275 	if (S_ISDIR(old_dentry->d_inode->i_mode))
276 		return -EPERM;
277 
278 	/* XXX: This is ugly */
279 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
280 	if (!type) type = DT_REG;
281 
282 	now = get_seconds();
283 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
284 
285 	if (!ret) {
286 		mutex_lock(&f->sem);
287 		old_dentry->d_inode->i_nlink = ++f->inocache->pino_nlink;
288 		mutex_unlock(&f->sem);
289 		d_instantiate(dentry, old_dentry->d_inode);
290 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
291 		atomic_inc(&old_dentry->d_inode->i_count);
292 	}
293 	return ret;
294 }
295 
296 /***********************************************************************/
297 
298 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
299 {
300 	struct jffs2_inode_info *f, *dir_f;
301 	struct jffs2_sb_info *c;
302 	struct inode *inode;
303 	struct jffs2_raw_inode *ri;
304 	struct jffs2_raw_dirent *rd;
305 	struct jffs2_full_dnode *fn;
306 	struct jffs2_full_dirent *fd;
307 	int namelen;
308 	uint32_t alloclen;
309 	int ret, targetlen = strlen(target);
310 
311 	/* FIXME: If you care. We'd need to use frags for the target
312 	   if it grows much more than this */
313 	if (targetlen > 254)
314 		return -ENAMETOOLONG;
315 
316 	ri = jffs2_alloc_raw_inode();
317 
318 	if (!ri)
319 		return -ENOMEM;
320 
321 	c = JFFS2_SB_INFO(dir_i->i_sb);
322 
323 	/* Try to reserve enough space for both node and dirent.
324 	 * Just the node will do for now, though
325 	 */
326 	namelen = dentry->d_name.len;
327 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
328 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
329 
330 	if (ret) {
331 		jffs2_free_raw_inode(ri);
332 		return ret;
333 	}
334 
335 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
336 
337 	if (IS_ERR(inode)) {
338 		jffs2_free_raw_inode(ri);
339 		jffs2_complete_reservation(c);
340 		return PTR_ERR(inode);
341 	}
342 
343 	inode->i_op = &jffs2_symlink_inode_operations;
344 
345 	f = JFFS2_INODE_INFO(inode);
346 
347 	inode->i_size = targetlen;
348 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
349 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
350 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
351 
352 	ri->compr = JFFS2_COMPR_NONE;
353 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
354 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
355 
356 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
357 
358 	jffs2_free_raw_inode(ri);
359 
360 	if (IS_ERR(fn)) {
361 		/* Eeek. Wave bye bye */
362 		mutex_unlock(&f->sem);
363 		jffs2_complete_reservation(c);
364 		ret = PTR_ERR(fn);
365 		goto fail;
366 	}
367 
368 	/* We use f->target field to store the target path. */
369 	f->target = kmalloc(targetlen + 1, GFP_KERNEL);
370 	if (!f->target) {
371 		printk(KERN_WARNING "Can't allocate %d bytes of memory\n", targetlen + 1);
372 		mutex_unlock(&f->sem);
373 		jffs2_complete_reservation(c);
374 		ret = -ENOMEM;
375 		goto fail;
376 	}
377 
378 	memcpy(f->target, target, targetlen + 1);
379 	D1(printk(KERN_DEBUG "jffs2_symlink: symlink's target '%s' cached\n", (char *)f->target));
380 
381 	/* No data here. Only a metadata node, which will be
382 	   obsoleted by the first data write
383 	*/
384 	f->metadata = fn;
385 	mutex_unlock(&f->sem);
386 
387 	jffs2_complete_reservation(c);
388 
389 	ret = jffs2_init_security(inode, dir_i);
390 	if (ret)
391 		goto fail;
392 
393 	ret = jffs2_init_acl_post(inode);
394 	if (ret)
395 		goto fail;
396 
397 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
398 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
399 	if (ret)
400 		goto fail;
401 
402 	rd = jffs2_alloc_raw_dirent();
403 	if (!rd) {
404 		/* Argh. Now we treat it like a normal delete */
405 		jffs2_complete_reservation(c);
406 		ret = -ENOMEM;
407 		goto fail;
408 	}
409 
410 	dir_f = JFFS2_INODE_INFO(dir_i);
411 	mutex_lock(&dir_f->sem);
412 
413 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
414 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
415 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
416 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
417 
418 	rd->pino = cpu_to_je32(dir_i->i_ino);
419 	rd->version = cpu_to_je32(++dir_f->highest_version);
420 	rd->ino = cpu_to_je32(inode->i_ino);
421 	rd->mctime = cpu_to_je32(get_seconds());
422 	rd->nsize = namelen;
423 	rd->type = DT_LNK;
424 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
425 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
426 
427 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
428 
429 	if (IS_ERR(fd)) {
430 		/* dirent failed to write. Delete the inode normally
431 		   as if it were the final unlink() */
432 		jffs2_complete_reservation(c);
433 		jffs2_free_raw_dirent(rd);
434 		mutex_unlock(&dir_f->sem);
435 		ret = PTR_ERR(fd);
436 		goto fail;
437 	}
438 
439 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
440 
441 	jffs2_free_raw_dirent(rd);
442 
443 	/* Link the fd into the inode's list, obsoleting an old
444 	   one if necessary. */
445 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
446 
447 	mutex_unlock(&dir_f->sem);
448 	jffs2_complete_reservation(c);
449 
450 	d_instantiate(dentry, inode);
451 	unlock_new_inode(inode);
452 	return 0;
453 
454  fail:
455 	iget_failed(inode);
456 	return ret;
457 }
458 
459 
460 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int mode)
461 {
462 	struct jffs2_inode_info *f, *dir_f;
463 	struct jffs2_sb_info *c;
464 	struct inode *inode;
465 	struct jffs2_raw_inode *ri;
466 	struct jffs2_raw_dirent *rd;
467 	struct jffs2_full_dnode *fn;
468 	struct jffs2_full_dirent *fd;
469 	int namelen;
470 	uint32_t alloclen;
471 	int ret;
472 
473 	mode |= S_IFDIR;
474 
475 	ri = jffs2_alloc_raw_inode();
476 	if (!ri)
477 		return -ENOMEM;
478 
479 	c = JFFS2_SB_INFO(dir_i->i_sb);
480 
481 	/* Try to reserve enough space for both node and dirent.
482 	 * Just the node will do for now, though
483 	 */
484 	namelen = dentry->d_name.len;
485 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
486 				  JFFS2_SUMMARY_INODE_SIZE);
487 
488 	if (ret) {
489 		jffs2_free_raw_inode(ri);
490 		return ret;
491 	}
492 
493 	inode = jffs2_new_inode(dir_i, mode, ri);
494 
495 	if (IS_ERR(inode)) {
496 		jffs2_free_raw_inode(ri);
497 		jffs2_complete_reservation(c);
498 		return PTR_ERR(inode);
499 	}
500 
501 	inode->i_op = &jffs2_dir_inode_operations;
502 	inode->i_fop = &jffs2_dir_operations;
503 
504 	f = JFFS2_INODE_INFO(inode);
505 
506 	/* Directories get nlink 2 at start */
507 	inode->i_nlink = 2;
508 	/* but ic->pino_nlink is the parent ino# */
509 	f->inocache->pino_nlink = dir_i->i_ino;
510 
511 	ri->data_crc = cpu_to_je32(0);
512 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
513 
514 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
515 
516 	jffs2_free_raw_inode(ri);
517 
518 	if (IS_ERR(fn)) {
519 		/* Eeek. Wave bye bye */
520 		mutex_unlock(&f->sem);
521 		jffs2_complete_reservation(c);
522 		ret = PTR_ERR(fn);
523 		goto fail;
524 	}
525 	/* No data here. Only a metadata node, which will be
526 	   obsoleted by the first data write
527 	*/
528 	f->metadata = fn;
529 	mutex_unlock(&f->sem);
530 
531 	jffs2_complete_reservation(c);
532 
533 	ret = jffs2_init_security(inode, dir_i);
534 	if (ret)
535 		goto fail;
536 
537 	ret = jffs2_init_acl_post(inode);
538 	if (ret)
539 		goto fail;
540 
541 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
542 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
543 	if (ret)
544 		goto fail;
545 
546 	rd = jffs2_alloc_raw_dirent();
547 	if (!rd) {
548 		/* Argh. Now we treat it like a normal delete */
549 		jffs2_complete_reservation(c);
550 		ret = -ENOMEM;
551 		goto fail;
552 	}
553 
554 	dir_f = JFFS2_INODE_INFO(dir_i);
555 	mutex_lock(&dir_f->sem);
556 
557 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
558 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
559 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
560 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
561 
562 	rd->pino = cpu_to_je32(dir_i->i_ino);
563 	rd->version = cpu_to_je32(++dir_f->highest_version);
564 	rd->ino = cpu_to_je32(inode->i_ino);
565 	rd->mctime = cpu_to_je32(get_seconds());
566 	rd->nsize = namelen;
567 	rd->type = DT_DIR;
568 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
569 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
570 
571 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
572 
573 	if (IS_ERR(fd)) {
574 		/* dirent failed to write. Delete the inode normally
575 		   as if it were the final unlink() */
576 		jffs2_complete_reservation(c);
577 		jffs2_free_raw_dirent(rd);
578 		mutex_unlock(&dir_f->sem);
579 		ret = PTR_ERR(fd);
580 		goto fail;
581 	}
582 
583 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
584 	inc_nlink(dir_i);
585 
586 	jffs2_free_raw_dirent(rd);
587 
588 	/* Link the fd into the inode's list, obsoleting an old
589 	   one if necessary. */
590 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
591 
592 	mutex_unlock(&dir_f->sem);
593 	jffs2_complete_reservation(c);
594 
595 	d_instantiate(dentry, inode);
596 	unlock_new_inode(inode);
597 	return 0;
598 
599  fail:
600 	iget_failed(inode);
601 	return ret;
602 }
603 
604 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
605 {
606 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
607 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
608 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
609 	struct jffs2_full_dirent *fd;
610 	int ret;
611 	uint32_t now = get_seconds();
612 
613 	for (fd = f->dents ; fd; fd = fd->next) {
614 		if (fd->ino)
615 			return -ENOTEMPTY;
616 	}
617 
618 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
619 			      dentry->d_name.len, f, now);
620 	if (!ret) {
621 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
622 		clear_nlink(dentry->d_inode);
623 		drop_nlink(dir_i);
624 	}
625 	return ret;
626 }
627 
628 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, dev_t rdev)
629 {
630 	struct jffs2_inode_info *f, *dir_f;
631 	struct jffs2_sb_info *c;
632 	struct inode *inode;
633 	struct jffs2_raw_inode *ri;
634 	struct jffs2_raw_dirent *rd;
635 	struct jffs2_full_dnode *fn;
636 	struct jffs2_full_dirent *fd;
637 	int namelen;
638 	union jffs2_device_node dev;
639 	int devlen = 0;
640 	uint32_t alloclen;
641 	int ret;
642 
643 	if (!new_valid_dev(rdev))
644 		return -EINVAL;
645 
646 	ri = jffs2_alloc_raw_inode();
647 	if (!ri)
648 		return -ENOMEM;
649 
650 	c = JFFS2_SB_INFO(dir_i->i_sb);
651 
652 	if (S_ISBLK(mode) || S_ISCHR(mode))
653 		devlen = jffs2_encode_dev(&dev, rdev);
654 
655 	/* Try to reserve enough space for both node and dirent.
656 	 * Just the node will do for now, though
657 	 */
658 	namelen = dentry->d_name.len;
659 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
660 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
661 
662 	if (ret) {
663 		jffs2_free_raw_inode(ri);
664 		return ret;
665 	}
666 
667 	inode = jffs2_new_inode(dir_i, mode, ri);
668 
669 	if (IS_ERR(inode)) {
670 		jffs2_free_raw_inode(ri);
671 		jffs2_complete_reservation(c);
672 		return PTR_ERR(inode);
673 	}
674 	inode->i_op = &jffs2_file_inode_operations;
675 	init_special_inode(inode, inode->i_mode, rdev);
676 
677 	f = JFFS2_INODE_INFO(inode);
678 
679 	ri->dsize = ri->csize = cpu_to_je32(devlen);
680 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
681 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
682 
683 	ri->compr = JFFS2_COMPR_NONE;
684 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
685 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
686 
687 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
688 
689 	jffs2_free_raw_inode(ri);
690 
691 	if (IS_ERR(fn)) {
692 		/* Eeek. Wave bye bye */
693 		mutex_unlock(&f->sem);
694 		jffs2_complete_reservation(c);
695 		ret = PTR_ERR(fn);
696 		goto fail;
697 	}
698 	/* No data here. Only a metadata node, which will be
699 	   obsoleted by the first data write
700 	*/
701 	f->metadata = fn;
702 	mutex_unlock(&f->sem);
703 
704 	jffs2_complete_reservation(c);
705 
706 	ret = jffs2_init_security(inode, dir_i);
707 	if (ret)
708 		goto fail;
709 
710 	ret = jffs2_init_acl_post(inode);
711 	if (ret)
712 		goto fail;
713 
714 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
715 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
716 	if (ret)
717 		goto fail;
718 
719 	rd = jffs2_alloc_raw_dirent();
720 	if (!rd) {
721 		/* Argh. Now we treat it like a normal delete */
722 		jffs2_complete_reservation(c);
723 		ret = -ENOMEM;
724 		goto fail;
725 	}
726 
727 	dir_f = JFFS2_INODE_INFO(dir_i);
728 	mutex_lock(&dir_f->sem);
729 
730 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
731 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
732 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
733 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
734 
735 	rd->pino = cpu_to_je32(dir_i->i_ino);
736 	rd->version = cpu_to_je32(++dir_f->highest_version);
737 	rd->ino = cpu_to_je32(inode->i_ino);
738 	rd->mctime = cpu_to_je32(get_seconds());
739 	rd->nsize = namelen;
740 
741 	/* XXX: This is ugly. */
742 	rd->type = (mode & S_IFMT) >> 12;
743 
744 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
745 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
746 
747 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
748 
749 	if (IS_ERR(fd)) {
750 		/* dirent failed to write. Delete the inode normally
751 		   as if it were the final unlink() */
752 		jffs2_complete_reservation(c);
753 		jffs2_free_raw_dirent(rd);
754 		mutex_unlock(&dir_f->sem);
755 		ret = PTR_ERR(fd);
756 		goto fail;
757 	}
758 
759 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
760 
761 	jffs2_free_raw_dirent(rd);
762 
763 	/* Link the fd into the inode's list, obsoleting an old
764 	   one if necessary. */
765 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
766 
767 	mutex_unlock(&dir_f->sem);
768 	jffs2_complete_reservation(c);
769 
770 	d_instantiate(dentry, inode);
771 	unlock_new_inode(inode);
772 	return 0;
773 
774  fail:
775 	iget_failed(inode);
776 	return ret;
777 }
778 
779 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
780 			 struct inode *new_dir_i, struct dentry *new_dentry)
781 {
782 	int ret;
783 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
784 	struct jffs2_inode_info *victim_f = NULL;
785 	uint8_t type;
786 	uint32_t now;
787 
788 	/* The VFS will check for us and prevent trying to rename a
789 	 * file over a directory and vice versa, but if it's a directory,
790 	 * the VFS can't check whether the victim is empty. The filesystem
791 	 * needs to do that for itself.
792 	 */
793 	if (new_dentry->d_inode) {
794 		victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);
795 		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
796 			struct jffs2_full_dirent *fd;
797 
798 			mutex_lock(&victim_f->sem);
799 			for (fd = victim_f->dents; fd; fd = fd->next) {
800 				if (fd->ino) {
801 					mutex_unlock(&victim_f->sem);
802 					return -ENOTEMPTY;
803 				}
804 			}
805 			mutex_unlock(&victim_f->sem);
806 		}
807 	}
808 
809 	/* XXX: We probably ought to alloc enough space for
810 	   both nodes at the same time. Writing the new link,
811 	   then getting -ENOSPC, is quite bad :)
812 	*/
813 
814 	/* Make a hard link */
815 
816 	/* XXX: This is ugly */
817 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
818 	if (!type) type = DT_REG;
819 
820 	now = get_seconds();
821 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
822 			    old_dentry->d_inode->i_ino, type,
823 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
824 
825 	if (ret)
826 		return ret;
827 
828 	if (victim_f) {
829 		/* There was a victim. Kill it off nicely */
830 		drop_nlink(new_dentry->d_inode);
831 		/* Don't oops if the victim was a dirent pointing to an
832 		   inode which didn't exist. */
833 		if (victim_f->inocache) {
834 			mutex_lock(&victim_f->sem);
835 			if (S_ISDIR(new_dentry->d_inode->i_mode))
836 				victim_f->inocache->pino_nlink = 0;
837 			else
838 				victim_f->inocache->pino_nlink--;
839 			mutex_unlock(&victim_f->sem);
840 		}
841 	}
842 
843 	/* If it was a directory we moved, and there was no victim,
844 	   increase i_nlink on its new parent */
845 	if (S_ISDIR(old_dentry->d_inode->i_mode) && !victim_f)
846 		inc_nlink(new_dir_i);
847 
848 	/* Unlink the original */
849 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
850 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
851 
852 	/* We don't touch inode->i_nlink */
853 
854 	if (ret) {
855 		/* Oh shit. We really ought to make a single node which can do both atomically */
856 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
857 		mutex_lock(&f->sem);
858 		inc_nlink(old_dentry->d_inode);
859 		if (f->inocache && !S_ISDIR(old_dentry->d_inode->i_mode))
860 			f->inocache->pino_nlink++;
861 		mutex_unlock(&f->sem);
862 
863 		printk(KERN_NOTICE "jffs2_rename(): Link succeeded, unlink failed (err %d). You now have a hard link\n", ret);
864 		/* Might as well let the VFS know */
865 		d_instantiate(new_dentry, old_dentry->d_inode);
866 		atomic_inc(&old_dentry->d_inode->i_count);
867 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
868 		return ret;
869 	}
870 
871 	if (S_ISDIR(old_dentry->d_inode->i_mode))
872 		drop_nlink(old_dir_i);
873 
874 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
875 
876 	return 0;
877 }
878 
879