xref: /openbmc/linux/fs/jffs2/dir.c (revision afc98d90)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/fs.h>
18 #include <linux/crc32.h>
19 #include <linux/jffs2.h>
20 #include "jffs2_fs_i.h"
21 #include "jffs2_fs_sb.h"
22 #include <linux/time.h>
23 #include "nodelist.h"
24 
25 static int jffs2_readdir (struct file *, struct dir_context *);
26 
27 static int jffs2_create (struct inode *,struct dentry *,umode_t,
28 			 bool);
29 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
30 				    unsigned int);
31 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
32 static int jffs2_unlink (struct inode *,struct dentry *);
33 static int jffs2_symlink (struct inode *,struct dentry *,const char *);
34 static int jffs2_mkdir (struct inode *,struct dentry *,umode_t);
35 static int jffs2_rmdir (struct inode *,struct dentry *);
36 static int jffs2_mknod (struct inode *,struct dentry *,umode_t,dev_t);
37 static int jffs2_rename (struct inode *, struct dentry *,
38 			 struct inode *, struct dentry *);
39 
40 const struct file_operations jffs2_dir_operations =
41 {
42 	.read =		generic_read_dir,
43 	.iterate =	jffs2_readdir,
44 	.unlocked_ioctl=jffs2_ioctl,
45 	.fsync =	jffs2_fsync,
46 	.llseek =	generic_file_llseek,
47 };
48 
49 
50 const struct inode_operations jffs2_dir_inode_operations =
51 {
52 	.create =	jffs2_create,
53 	.lookup =	jffs2_lookup,
54 	.link =		jffs2_link,
55 	.unlink =	jffs2_unlink,
56 	.symlink =	jffs2_symlink,
57 	.mkdir =	jffs2_mkdir,
58 	.rmdir =	jffs2_rmdir,
59 	.mknod =	jffs2_mknod,
60 	.rename =	jffs2_rename,
61 	.get_acl =	jffs2_get_acl,
62 	.set_acl =	jffs2_set_acl,
63 	.setattr =	jffs2_setattr,
64 	.setxattr =	jffs2_setxattr,
65 	.getxattr =	jffs2_getxattr,
66 	.listxattr =	jffs2_listxattr,
67 	.removexattr =	jffs2_removexattr
68 };
69 
70 /***********************************************************************/
71 
72 
73 /* We keep the dirent list sorted in increasing order of name hash,
74    and we use the same hash function as the dentries. Makes this
75    nice and simple
76 */
77 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
78 				   unsigned int flags)
79 {
80 	struct jffs2_inode_info *dir_f;
81 	struct jffs2_full_dirent *fd = NULL, *fd_list;
82 	uint32_t ino = 0;
83 	struct inode *inode = NULL;
84 
85 	jffs2_dbg(1, "jffs2_lookup()\n");
86 
87 	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
88 		return ERR_PTR(-ENAMETOOLONG);
89 
90 	dir_f = JFFS2_INODE_INFO(dir_i);
91 
92 	mutex_lock(&dir_f->sem);
93 
94 	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
95 	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= target->d_name.hash; fd_list = fd_list->next) {
96 		if (fd_list->nhash == target->d_name.hash &&
97 		    (!fd || fd_list->version > fd->version) &&
98 		    strlen(fd_list->name) == target->d_name.len &&
99 		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
100 			fd = fd_list;
101 		}
102 	}
103 	if (fd)
104 		ino = fd->ino;
105 	mutex_unlock(&dir_f->sem);
106 	if (ino) {
107 		inode = jffs2_iget(dir_i->i_sb, ino);
108 		if (IS_ERR(inode))
109 			pr_warn("iget() failed for ino #%u\n", ino);
110 	}
111 
112 	return d_splice_alias(inode, target);
113 }
114 
115 /***********************************************************************/
116 
117 
118 static int jffs2_readdir(struct file *file, struct dir_context *ctx)
119 {
120 	struct inode *inode = file_inode(file);
121 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
122 	struct jffs2_full_dirent *fd;
123 	unsigned long curofs = 1;
124 
125 	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino);
126 
127 	if (!dir_emit_dots(file, ctx))
128 		return 0;
129 
130 	mutex_lock(&f->sem);
131 	for (fd = f->dents; fd; fd = fd->next) {
132 		curofs++;
133 		/* First loop: curofs = 2; pos = 2 */
134 		if (curofs < ctx->pos) {
135 			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
136 				  fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);
137 			continue;
138 		}
139 		if (!fd->ino) {
140 			jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
141 				  fd->name);
142 			ctx->pos++;
143 			continue;
144 		}
145 		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
146 			  (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
147 		if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))
148 			break;
149 		ctx->pos++;
150 	}
151 	mutex_unlock(&f->sem);
152 	return 0;
153 }
154 
155 /***********************************************************************/
156 
157 
158 static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
159 			umode_t mode, bool excl)
160 {
161 	struct jffs2_raw_inode *ri;
162 	struct jffs2_inode_info *f, *dir_f;
163 	struct jffs2_sb_info *c;
164 	struct inode *inode;
165 	int ret;
166 
167 	ri = jffs2_alloc_raw_inode();
168 	if (!ri)
169 		return -ENOMEM;
170 
171 	c = JFFS2_SB_INFO(dir_i->i_sb);
172 
173 	jffs2_dbg(1, "%s()\n", __func__);
174 
175 	inode = jffs2_new_inode(dir_i, mode, ri);
176 
177 	if (IS_ERR(inode)) {
178 		jffs2_dbg(1, "jffs2_new_inode() failed\n");
179 		jffs2_free_raw_inode(ri);
180 		return PTR_ERR(inode);
181 	}
182 
183 	inode->i_op = &jffs2_file_inode_operations;
184 	inode->i_fop = &jffs2_file_operations;
185 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
186 	inode->i_mapping->nrpages = 0;
187 
188 	f = JFFS2_INODE_INFO(inode);
189 	dir_f = JFFS2_INODE_INFO(dir_i);
190 
191 	/* jffs2_do_create() will want to lock it, _after_ reserving
192 	   space and taking c-alloc_sem. If we keep it locked here,
193 	   lockdep gets unhappy (although it's a false positive;
194 	   nothing else will be looking at this inode yet so there's
195 	   no chance of AB-BA deadlock involving its f->sem). */
196 	mutex_unlock(&f->sem);
197 
198 	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
199 	if (ret)
200 		goto fail;
201 
202 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
203 
204 	jffs2_free_raw_inode(ri);
205 
206 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
207 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
208 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
209 
210 	unlock_new_inode(inode);
211 	d_instantiate(dentry, inode);
212 	return 0;
213 
214  fail:
215 	iget_failed(inode);
216 	jffs2_free_raw_inode(ri);
217 	return ret;
218 }
219 
220 /***********************************************************************/
221 
222 
223 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
224 {
225 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
226 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
227 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(dentry->d_inode);
228 	int ret;
229 	uint32_t now = get_seconds();
230 
231 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
232 			      dentry->d_name.len, dead_f, now);
233 	if (dead_f->inocache)
234 		set_nlink(dentry->d_inode, dead_f->inocache->pino_nlink);
235 	if (!ret)
236 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
237 	return ret;
238 }
239 /***********************************************************************/
240 
241 
242 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
243 {
244 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_inode->i_sb);
245 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
246 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
247 	int ret;
248 	uint8_t type;
249 	uint32_t now;
250 
251 	/* Don't let people make hard links to bad inodes. */
252 	if (!f->inocache)
253 		return -EIO;
254 
255 	if (S_ISDIR(old_dentry->d_inode->i_mode))
256 		return -EPERM;
257 
258 	/* XXX: This is ugly */
259 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
260 	if (!type) type = DT_REG;
261 
262 	now = get_seconds();
263 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
264 
265 	if (!ret) {
266 		mutex_lock(&f->sem);
267 		set_nlink(old_dentry->d_inode, ++f->inocache->pino_nlink);
268 		mutex_unlock(&f->sem);
269 		d_instantiate(dentry, old_dentry->d_inode);
270 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
271 		ihold(old_dentry->d_inode);
272 	}
273 	return ret;
274 }
275 
276 /***********************************************************************/
277 
278 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
279 {
280 	struct jffs2_inode_info *f, *dir_f;
281 	struct jffs2_sb_info *c;
282 	struct inode *inode;
283 	struct jffs2_raw_inode *ri;
284 	struct jffs2_raw_dirent *rd;
285 	struct jffs2_full_dnode *fn;
286 	struct jffs2_full_dirent *fd;
287 	int namelen;
288 	uint32_t alloclen;
289 	int ret, targetlen = strlen(target);
290 
291 	/* FIXME: If you care. We'd need to use frags for the target
292 	   if it grows much more than this */
293 	if (targetlen > 254)
294 		return -ENAMETOOLONG;
295 
296 	ri = jffs2_alloc_raw_inode();
297 
298 	if (!ri)
299 		return -ENOMEM;
300 
301 	c = JFFS2_SB_INFO(dir_i->i_sb);
302 
303 	/* Try to reserve enough space for both node and dirent.
304 	 * Just the node will do for now, though
305 	 */
306 	namelen = dentry->d_name.len;
307 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
308 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
309 
310 	if (ret) {
311 		jffs2_free_raw_inode(ri);
312 		return ret;
313 	}
314 
315 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
316 
317 	if (IS_ERR(inode)) {
318 		jffs2_free_raw_inode(ri);
319 		jffs2_complete_reservation(c);
320 		return PTR_ERR(inode);
321 	}
322 
323 	inode->i_op = &jffs2_symlink_inode_operations;
324 
325 	f = JFFS2_INODE_INFO(inode);
326 
327 	inode->i_size = targetlen;
328 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
329 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
330 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
331 
332 	ri->compr = JFFS2_COMPR_NONE;
333 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
334 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
335 
336 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
337 
338 	jffs2_free_raw_inode(ri);
339 
340 	if (IS_ERR(fn)) {
341 		/* Eeek. Wave bye bye */
342 		mutex_unlock(&f->sem);
343 		jffs2_complete_reservation(c);
344 		ret = PTR_ERR(fn);
345 		goto fail;
346 	}
347 
348 	/* We use f->target field to store the target path. */
349 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
350 	if (!f->target) {
351 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
352 		mutex_unlock(&f->sem);
353 		jffs2_complete_reservation(c);
354 		ret = -ENOMEM;
355 		goto fail;
356 	}
357 
358 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
359 		  __func__, (char *)f->target);
360 
361 	/* No data here. Only a metadata node, which will be
362 	   obsoleted by the first data write
363 	*/
364 	f->metadata = fn;
365 	mutex_unlock(&f->sem);
366 
367 	jffs2_complete_reservation(c);
368 
369 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
370 	if (ret)
371 		goto fail;
372 
373 	ret = jffs2_init_acl_post(inode);
374 	if (ret)
375 		goto fail;
376 
377 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
378 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
379 	if (ret)
380 		goto fail;
381 
382 	rd = jffs2_alloc_raw_dirent();
383 	if (!rd) {
384 		/* Argh. Now we treat it like a normal delete */
385 		jffs2_complete_reservation(c);
386 		ret = -ENOMEM;
387 		goto fail;
388 	}
389 
390 	dir_f = JFFS2_INODE_INFO(dir_i);
391 	mutex_lock(&dir_f->sem);
392 
393 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
394 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
395 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
396 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
397 
398 	rd->pino = cpu_to_je32(dir_i->i_ino);
399 	rd->version = cpu_to_je32(++dir_f->highest_version);
400 	rd->ino = cpu_to_je32(inode->i_ino);
401 	rd->mctime = cpu_to_je32(get_seconds());
402 	rd->nsize = namelen;
403 	rd->type = DT_LNK;
404 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
405 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
406 
407 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
408 
409 	if (IS_ERR(fd)) {
410 		/* dirent failed to write. Delete the inode normally
411 		   as if it were the final unlink() */
412 		jffs2_complete_reservation(c);
413 		jffs2_free_raw_dirent(rd);
414 		mutex_unlock(&dir_f->sem);
415 		ret = PTR_ERR(fd);
416 		goto fail;
417 	}
418 
419 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
420 
421 	jffs2_free_raw_dirent(rd);
422 
423 	/* Link the fd into the inode's list, obsoleting an old
424 	   one if necessary. */
425 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
426 
427 	mutex_unlock(&dir_f->sem);
428 	jffs2_complete_reservation(c);
429 
430 	unlock_new_inode(inode);
431 	d_instantiate(dentry, inode);
432 	return 0;
433 
434  fail:
435 	iget_failed(inode);
436 	return ret;
437 }
438 
439 
440 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
441 {
442 	struct jffs2_inode_info *f, *dir_f;
443 	struct jffs2_sb_info *c;
444 	struct inode *inode;
445 	struct jffs2_raw_inode *ri;
446 	struct jffs2_raw_dirent *rd;
447 	struct jffs2_full_dnode *fn;
448 	struct jffs2_full_dirent *fd;
449 	int namelen;
450 	uint32_t alloclen;
451 	int ret;
452 
453 	mode |= S_IFDIR;
454 
455 	ri = jffs2_alloc_raw_inode();
456 	if (!ri)
457 		return -ENOMEM;
458 
459 	c = JFFS2_SB_INFO(dir_i->i_sb);
460 
461 	/* Try to reserve enough space for both node and dirent.
462 	 * Just the node will do for now, though
463 	 */
464 	namelen = dentry->d_name.len;
465 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
466 				  JFFS2_SUMMARY_INODE_SIZE);
467 
468 	if (ret) {
469 		jffs2_free_raw_inode(ri);
470 		return ret;
471 	}
472 
473 	inode = jffs2_new_inode(dir_i, mode, ri);
474 
475 	if (IS_ERR(inode)) {
476 		jffs2_free_raw_inode(ri);
477 		jffs2_complete_reservation(c);
478 		return PTR_ERR(inode);
479 	}
480 
481 	inode->i_op = &jffs2_dir_inode_operations;
482 	inode->i_fop = &jffs2_dir_operations;
483 
484 	f = JFFS2_INODE_INFO(inode);
485 
486 	/* Directories get nlink 2 at start */
487 	set_nlink(inode, 2);
488 	/* but ic->pino_nlink is the parent ino# */
489 	f->inocache->pino_nlink = dir_i->i_ino;
490 
491 	ri->data_crc = cpu_to_je32(0);
492 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
493 
494 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
495 
496 	jffs2_free_raw_inode(ri);
497 
498 	if (IS_ERR(fn)) {
499 		/* Eeek. Wave bye bye */
500 		mutex_unlock(&f->sem);
501 		jffs2_complete_reservation(c);
502 		ret = PTR_ERR(fn);
503 		goto fail;
504 	}
505 	/* No data here. Only a metadata node, which will be
506 	   obsoleted by the first data write
507 	*/
508 	f->metadata = fn;
509 	mutex_unlock(&f->sem);
510 
511 	jffs2_complete_reservation(c);
512 
513 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
514 	if (ret)
515 		goto fail;
516 
517 	ret = jffs2_init_acl_post(inode);
518 	if (ret)
519 		goto fail;
520 
521 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
522 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
523 	if (ret)
524 		goto fail;
525 
526 	rd = jffs2_alloc_raw_dirent();
527 	if (!rd) {
528 		/* Argh. Now we treat it like a normal delete */
529 		jffs2_complete_reservation(c);
530 		ret = -ENOMEM;
531 		goto fail;
532 	}
533 
534 	dir_f = JFFS2_INODE_INFO(dir_i);
535 	mutex_lock(&dir_f->sem);
536 
537 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
538 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
539 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
540 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
541 
542 	rd->pino = cpu_to_je32(dir_i->i_ino);
543 	rd->version = cpu_to_je32(++dir_f->highest_version);
544 	rd->ino = cpu_to_je32(inode->i_ino);
545 	rd->mctime = cpu_to_je32(get_seconds());
546 	rd->nsize = namelen;
547 	rd->type = DT_DIR;
548 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
549 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
550 
551 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
552 
553 	if (IS_ERR(fd)) {
554 		/* dirent failed to write. Delete the inode normally
555 		   as if it were the final unlink() */
556 		jffs2_complete_reservation(c);
557 		jffs2_free_raw_dirent(rd);
558 		mutex_unlock(&dir_f->sem);
559 		ret = PTR_ERR(fd);
560 		goto fail;
561 	}
562 
563 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
564 	inc_nlink(dir_i);
565 
566 	jffs2_free_raw_dirent(rd);
567 
568 	/* Link the fd into the inode's list, obsoleting an old
569 	   one if necessary. */
570 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
571 
572 	mutex_unlock(&dir_f->sem);
573 	jffs2_complete_reservation(c);
574 
575 	unlock_new_inode(inode);
576 	d_instantiate(dentry, inode);
577 	return 0;
578 
579  fail:
580 	iget_failed(inode);
581 	return ret;
582 }
583 
584 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
585 {
586 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
587 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
588 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
589 	struct jffs2_full_dirent *fd;
590 	int ret;
591 	uint32_t now = get_seconds();
592 
593 	for (fd = f->dents ; fd; fd = fd->next) {
594 		if (fd->ino)
595 			return -ENOTEMPTY;
596 	}
597 
598 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
599 			      dentry->d_name.len, f, now);
600 	if (!ret) {
601 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
602 		clear_nlink(dentry->d_inode);
603 		drop_nlink(dir_i);
604 	}
605 	return ret;
606 }
607 
608 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
609 {
610 	struct jffs2_inode_info *f, *dir_f;
611 	struct jffs2_sb_info *c;
612 	struct inode *inode;
613 	struct jffs2_raw_inode *ri;
614 	struct jffs2_raw_dirent *rd;
615 	struct jffs2_full_dnode *fn;
616 	struct jffs2_full_dirent *fd;
617 	int namelen;
618 	union jffs2_device_node dev;
619 	int devlen = 0;
620 	uint32_t alloclen;
621 	int ret;
622 
623 	if (!new_valid_dev(rdev))
624 		return -EINVAL;
625 
626 	ri = jffs2_alloc_raw_inode();
627 	if (!ri)
628 		return -ENOMEM;
629 
630 	c = JFFS2_SB_INFO(dir_i->i_sb);
631 
632 	if (S_ISBLK(mode) || S_ISCHR(mode))
633 		devlen = jffs2_encode_dev(&dev, rdev);
634 
635 	/* Try to reserve enough space for both node and dirent.
636 	 * Just the node will do for now, though
637 	 */
638 	namelen = dentry->d_name.len;
639 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
640 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
641 
642 	if (ret) {
643 		jffs2_free_raw_inode(ri);
644 		return ret;
645 	}
646 
647 	inode = jffs2_new_inode(dir_i, mode, ri);
648 
649 	if (IS_ERR(inode)) {
650 		jffs2_free_raw_inode(ri);
651 		jffs2_complete_reservation(c);
652 		return PTR_ERR(inode);
653 	}
654 	inode->i_op = &jffs2_file_inode_operations;
655 	init_special_inode(inode, inode->i_mode, rdev);
656 
657 	f = JFFS2_INODE_INFO(inode);
658 
659 	ri->dsize = ri->csize = cpu_to_je32(devlen);
660 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
661 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
662 
663 	ri->compr = JFFS2_COMPR_NONE;
664 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
665 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
666 
667 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
668 
669 	jffs2_free_raw_inode(ri);
670 
671 	if (IS_ERR(fn)) {
672 		/* Eeek. Wave bye bye */
673 		mutex_unlock(&f->sem);
674 		jffs2_complete_reservation(c);
675 		ret = PTR_ERR(fn);
676 		goto fail;
677 	}
678 	/* No data here. Only a metadata node, which will be
679 	   obsoleted by the first data write
680 	*/
681 	f->metadata = fn;
682 	mutex_unlock(&f->sem);
683 
684 	jffs2_complete_reservation(c);
685 
686 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
687 	if (ret)
688 		goto fail;
689 
690 	ret = jffs2_init_acl_post(inode);
691 	if (ret)
692 		goto fail;
693 
694 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
695 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
696 	if (ret)
697 		goto fail;
698 
699 	rd = jffs2_alloc_raw_dirent();
700 	if (!rd) {
701 		/* Argh. Now we treat it like a normal delete */
702 		jffs2_complete_reservation(c);
703 		ret = -ENOMEM;
704 		goto fail;
705 	}
706 
707 	dir_f = JFFS2_INODE_INFO(dir_i);
708 	mutex_lock(&dir_f->sem);
709 
710 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
711 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
712 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
713 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
714 
715 	rd->pino = cpu_to_je32(dir_i->i_ino);
716 	rd->version = cpu_to_je32(++dir_f->highest_version);
717 	rd->ino = cpu_to_je32(inode->i_ino);
718 	rd->mctime = cpu_to_je32(get_seconds());
719 	rd->nsize = namelen;
720 
721 	/* XXX: This is ugly. */
722 	rd->type = (mode & S_IFMT) >> 12;
723 
724 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
725 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
726 
727 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
728 
729 	if (IS_ERR(fd)) {
730 		/* dirent failed to write. Delete the inode normally
731 		   as if it were the final unlink() */
732 		jffs2_complete_reservation(c);
733 		jffs2_free_raw_dirent(rd);
734 		mutex_unlock(&dir_f->sem);
735 		ret = PTR_ERR(fd);
736 		goto fail;
737 	}
738 
739 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
740 
741 	jffs2_free_raw_dirent(rd);
742 
743 	/* Link the fd into the inode's list, obsoleting an old
744 	   one if necessary. */
745 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
746 
747 	mutex_unlock(&dir_f->sem);
748 	jffs2_complete_reservation(c);
749 
750 	unlock_new_inode(inode);
751 	d_instantiate(dentry, inode);
752 	return 0;
753 
754  fail:
755 	iget_failed(inode);
756 	return ret;
757 }
758 
759 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
760 			 struct inode *new_dir_i, struct dentry *new_dentry)
761 {
762 	int ret;
763 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
764 	struct jffs2_inode_info *victim_f = NULL;
765 	uint8_t type;
766 	uint32_t now;
767 
768 	/* The VFS will check for us and prevent trying to rename a
769 	 * file over a directory and vice versa, but if it's a directory,
770 	 * the VFS can't check whether the victim is empty. The filesystem
771 	 * needs to do that for itself.
772 	 */
773 	if (new_dentry->d_inode) {
774 		victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);
775 		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
776 			struct jffs2_full_dirent *fd;
777 
778 			mutex_lock(&victim_f->sem);
779 			for (fd = victim_f->dents; fd; fd = fd->next) {
780 				if (fd->ino) {
781 					mutex_unlock(&victim_f->sem);
782 					return -ENOTEMPTY;
783 				}
784 			}
785 			mutex_unlock(&victim_f->sem);
786 		}
787 	}
788 
789 	/* XXX: We probably ought to alloc enough space for
790 	   both nodes at the same time. Writing the new link,
791 	   then getting -ENOSPC, is quite bad :)
792 	*/
793 
794 	/* Make a hard link */
795 
796 	/* XXX: This is ugly */
797 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
798 	if (!type) type = DT_REG;
799 
800 	now = get_seconds();
801 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
802 			    old_dentry->d_inode->i_ino, type,
803 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
804 
805 	if (ret)
806 		return ret;
807 
808 	if (victim_f) {
809 		/* There was a victim. Kill it off nicely */
810 		if (S_ISDIR(new_dentry->d_inode->i_mode))
811 			clear_nlink(new_dentry->d_inode);
812 		else
813 			drop_nlink(new_dentry->d_inode);
814 		/* Don't oops if the victim was a dirent pointing to an
815 		   inode which didn't exist. */
816 		if (victim_f->inocache) {
817 			mutex_lock(&victim_f->sem);
818 			if (S_ISDIR(new_dentry->d_inode->i_mode))
819 				victim_f->inocache->pino_nlink = 0;
820 			else
821 				victim_f->inocache->pino_nlink--;
822 			mutex_unlock(&victim_f->sem);
823 		}
824 	}
825 
826 	/* If it was a directory we moved, and there was no victim,
827 	   increase i_nlink on its new parent */
828 	if (S_ISDIR(old_dentry->d_inode->i_mode) && !victim_f)
829 		inc_nlink(new_dir_i);
830 
831 	/* Unlink the original */
832 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
833 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
834 
835 	/* We don't touch inode->i_nlink */
836 
837 	if (ret) {
838 		/* Oh shit. We really ought to make a single node which can do both atomically */
839 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
840 		mutex_lock(&f->sem);
841 		inc_nlink(old_dentry->d_inode);
842 		if (f->inocache && !S_ISDIR(old_dentry->d_inode->i_mode))
843 			f->inocache->pino_nlink++;
844 		mutex_unlock(&f->sem);
845 
846 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
847 			  __func__, ret);
848 		/* Might as well let the VFS know */
849 		d_instantiate(new_dentry, old_dentry->d_inode);
850 		ihold(old_dentry->d_inode);
851 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
852 		return ret;
853 	}
854 
855 	if (S_ISDIR(old_dentry->d_inode->i_mode))
856 		drop_nlink(old_dir_i);
857 
858 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
859 
860 	return 0;
861 }
862 
863