xref: /openbmc/linux/fs/jffs2/dir.c (revision ca79522c)
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 *, void *, filldir_t);
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 	.readdir =	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 	.setattr =	jffs2_setattr,
63 	.setxattr =	jffs2_setxattr,
64 	.getxattr =	jffs2_getxattr,
65 	.listxattr =	jffs2_listxattr,
66 	.removexattr =	jffs2_removexattr
67 };
68 
69 /***********************************************************************/
70 
71 
72 /* We keep the dirent list sorted in increasing order of name hash,
73    and we use the same hash function as the dentries. Makes this
74    nice and simple
75 */
76 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
77 				   unsigned int flags)
78 {
79 	struct jffs2_inode_info *dir_f;
80 	struct jffs2_full_dirent *fd = NULL, *fd_list;
81 	uint32_t ino = 0;
82 	struct inode *inode = NULL;
83 
84 	jffs2_dbg(1, "jffs2_lookup()\n");
85 
86 	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
87 		return ERR_PTR(-ENAMETOOLONG);
88 
89 	dir_f = JFFS2_INODE_INFO(dir_i);
90 
91 	mutex_lock(&dir_f->sem);
92 
93 	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
94 	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= target->d_name.hash; fd_list = fd_list->next) {
95 		if (fd_list->nhash == target->d_name.hash &&
96 		    (!fd || fd_list->version > fd->version) &&
97 		    strlen(fd_list->name) == target->d_name.len &&
98 		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
99 			fd = fd_list;
100 		}
101 	}
102 	if (fd)
103 		ino = fd->ino;
104 	mutex_unlock(&dir_f->sem);
105 	if (ino) {
106 		inode = jffs2_iget(dir_i->i_sb, ino);
107 		if (IS_ERR(inode))
108 			pr_warn("iget() failed for ino #%u\n", ino);
109 	}
110 
111 	return d_splice_alias(inode, target);
112 }
113 
114 /***********************************************************************/
115 
116 
117 static int jffs2_readdir(struct file *filp, void *dirent, filldir_t filldir)
118 {
119 	struct jffs2_inode_info *f;
120 	struct inode *inode = file_inode(filp);
121 	struct jffs2_full_dirent *fd;
122 	unsigned long offset, curofs;
123 
124 	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n",
125 		  file_inode(filp)->i_ino);
126 
127 	f = JFFS2_INODE_INFO(inode);
128 
129 	offset = filp->f_pos;
130 
131 	if (offset == 0) {
132 		jffs2_dbg(1, "Dirent 0: \".\", ino #%lu\n", inode->i_ino);
133 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
134 			goto out;
135 		offset++;
136 	}
137 	if (offset == 1) {
138 		unsigned long pino = parent_ino(filp->f_path.dentry);
139 		jffs2_dbg(1, "Dirent 1: \"..\", ino #%lu\n", pino);
140 		if (filldir(dirent, "..", 2, 1, pino, DT_DIR) < 0)
141 			goto out;
142 		offset++;
143 	}
144 
145 	curofs=1;
146 	mutex_lock(&f->sem);
147 	for (fd = f->dents; fd; fd = fd->next) {
148 
149 		curofs++;
150 		/* First loop: curofs = 2; offset = 2 */
151 		if (curofs < offset) {
152 			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
153 				  fd->name, fd->ino, fd->type, curofs, offset);
154 			continue;
155 		}
156 		if (!fd->ino) {
157 			jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
158 				  fd->name);
159 			offset++;
160 			continue;
161 		}
162 		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
163 			  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,
178 			umode_t mode, bool excl)
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 	jffs2_dbg(1, "%s()\n", __func__);
193 
194 	inode = jffs2_new_inode(dir_i, mode, ri);
195 
196 	if (IS_ERR(inode)) {
197 		jffs2_dbg(1, "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, &dentry->d_name);
218 	if (ret)
219 		goto fail;
220 
221 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
222 
223 	jffs2_free_raw_inode(ri);
224 
225 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
226 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
227 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
228 
229 	unlock_new_inode(inode);
230 	d_instantiate(dentry, inode);
231 	return 0;
232 
233  fail:
234 	iget_failed(inode);
235 	jffs2_free_raw_inode(ri);
236 	return ret;
237 }
238 
239 /***********************************************************************/
240 
241 
242 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
243 {
244 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
245 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
246 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(dentry->d_inode);
247 	int ret;
248 	uint32_t now = get_seconds();
249 
250 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
251 			      dentry->d_name.len, dead_f, now);
252 	if (dead_f->inocache)
253 		set_nlink(dentry->d_inode, dead_f->inocache->pino_nlink);
254 	if (!ret)
255 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
256 	return ret;
257 }
258 /***********************************************************************/
259 
260 
261 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
262 {
263 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_inode->i_sb);
264 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
265 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
266 	int ret;
267 	uint8_t type;
268 	uint32_t now;
269 
270 	/* Don't let people make hard links to bad inodes. */
271 	if (!f->inocache)
272 		return -EIO;
273 
274 	if (S_ISDIR(old_dentry->d_inode->i_mode))
275 		return -EPERM;
276 
277 	/* XXX: This is ugly */
278 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
279 	if (!type) type = DT_REG;
280 
281 	now = get_seconds();
282 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
283 
284 	if (!ret) {
285 		mutex_lock(&f->sem);
286 		set_nlink(old_dentry->d_inode, ++f->inocache->pino_nlink);
287 		mutex_unlock(&f->sem);
288 		d_instantiate(dentry, old_dentry->d_inode);
289 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
290 		ihold(old_dentry->d_inode);
291 	}
292 	return ret;
293 }
294 
295 /***********************************************************************/
296 
297 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
298 {
299 	struct jffs2_inode_info *f, *dir_f;
300 	struct jffs2_sb_info *c;
301 	struct inode *inode;
302 	struct jffs2_raw_inode *ri;
303 	struct jffs2_raw_dirent *rd;
304 	struct jffs2_full_dnode *fn;
305 	struct jffs2_full_dirent *fd;
306 	int namelen;
307 	uint32_t alloclen;
308 	int ret, targetlen = strlen(target);
309 
310 	/* FIXME: If you care. We'd need to use frags for the target
311 	   if it grows much more than this */
312 	if (targetlen > 254)
313 		return -ENAMETOOLONG;
314 
315 	ri = jffs2_alloc_raw_inode();
316 
317 	if (!ri)
318 		return -ENOMEM;
319 
320 	c = JFFS2_SB_INFO(dir_i->i_sb);
321 
322 	/* Try to reserve enough space for both node and dirent.
323 	 * Just the node will do for now, though
324 	 */
325 	namelen = dentry->d_name.len;
326 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
327 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
328 
329 	if (ret) {
330 		jffs2_free_raw_inode(ri);
331 		return ret;
332 	}
333 
334 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
335 
336 	if (IS_ERR(inode)) {
337 		jffs2_free_raw_inode(ri);
338 		jffs2_complete_reservation(c);
339 		return PTR_ERR(inode);
340 	}
341 
342 	inode->i_op = &jffs2_symlink_inode_operations;
343 
344 	f = JFFS2_INODE_INFO(inode);
345 
346 	inode->i_size = targetlen;
347 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
348 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
349 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
350 
351 	ri->compr = JFFS2_COMPR_NONE;
352 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
353 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
354 
355 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
356 
357 	jffs2_free_raw_inode(ri);
358 
359 	if (IS_ERR(fn)) {
360 		/* Eeek. Wave bye bye */
361 		mutex_unlock(&f->sem);
362 		jffs2_complete_reservation(c);
363 		ret = PTR_ERR(fn);
364 		goto fail;
365 	}
366 
367 	/* We use f->target field to store the target path. */
368 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
369 	if (!f->target) {
370 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
371 		mutex_unlock(&f->sem);
372 		jffs2_complete_reservation(c);
373 		ret = -ENOMEM;
374 		goto fail;
375 	}
376 
377 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
378 		  __func__, (char *)f->target);
379 
380 	/* No data here. Only a metadata node, which will be
381 	   obsoleted by the first data write
382 	*/
383 	f->metadata = fn;
384 	mutex_unlock(&f->sem);
385 
386 	jffs2_complete_reservation(c);
387 
388 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
389 	if (ret)
390 		goto fail;
391 
392 	ret = jffs2_init_acl_post(inode);
393 	if (ret)
394 		goto fail;
395 
396 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
397 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
398 	if (ret)
399 		goto fail;
400 
401 	rd = jffs2_alloc_raw_dirent();
402 	if (!rd) {
403 		/* Argh. Now we treat it like a normal delete */
404 		jffs2_complete_reservation(c);
405 		ret = -ENOMEM;
406 		goto fail;
407 	}
408 
409 	dir_f = JFFS2_INODE_INFO(dir_i);
410 	mutex_lock(&dir_f->sem);
411 
412 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
413 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
414 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
415 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
416 
417 	rd->pino = cpu_to_je32(dir_i->i_ino);
418 	rd->version = cpu_to_je32(++dir_f->highest_version);
419 	rd->ino = cpu_to_je32(inode->i_ino);
420 	rd->mctime = cpu_to_je32(get_seconds());
421 	rd->nsize = namelen;
422 	rd->type = DT_LNK;
423 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
424 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
425 
426 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
427 
428 	if (IS_ERR(fd)) {
429 		/* dirent failed to write. Delete the inode normally
430 		   as if it were the final unlink() */
431 		jffs2_complete_reservation(c);
432 		jffs2_free_raw_dirent(rd);
433 		mutex_unlock(&dir_f->sem);
434 		ret = PTR_ERR(fd);
435 		goto fail;
436 	}
437 
438 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
439 
440 	jffs2_free_raw_dirent(rd);
441 
442 	/* Link the fd into the inode's list, obsoleting an old
443 	   one if necessary. */
444 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
445 
446 	mutex_unlock(&dir_f->sem);
447 	jffs2_complete_reservation(c);
448 
449 	unlock_new_inode(inode);
450 	d_instantiate(dentry, inode);
451 	return 0;
452 
453  fail:
454 	iget_failed(inode);
455 	return ret;
456 }
457 
458 
459 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
460 {
461 	struct jffs2_inode_info *f, *dir_f;
462 	struct jffs2_sb_info *c;
463 	struct inode *inode;
464 	struct jffs2_raw_inode *ri;
465 	struct jffs2_raw_dirent *rd;
466 	struct jffs2_full_dnode *fn;
467 	struct jffs2_full_dirent *fd;
468 	int namelen;
469 	uint32_t alloclen;
470 	int ret;
471 
472 	mode |= S_IFDIR;
473 
474 	ri = jffs2_alloc_raw_inode();
475 	if (!ri)
476 		return -ENOMEM;
477 
478 	c = JFFS2_SB_INFO(dir_i->i_sb);
479 
480 	/* Try to reserve enough space for both node and dirent.
481 	 * Just the node will do for now, though
482 	 */
483 	namelen = dentry->d_name.len;
484 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
485 				  JFFS2_SUMMARY_INODE_SIZE);
486 
487 	if (ret) {
488 		jffs2_free_raw_inode(ri);
489 		return ret;
490 	}
491 
492 	inode = jffs2_new_inode(dir_i, mode, ri);
493 
494 	if (IS_ERR(inode)) {
495 		jffs2_free_raw_inode(ri);
496 		jffs2_complete_reservation(c);
497 		return PTR_ERR(inode);
498 	}
499 
500 	inode->i_op = &jffs2_dir_inode_operations;
501 	inode->i_fop = &jffs2_dir_operations;
502 
503 	f = JFFS2_INODE_INFO(inode);
504 
505 	/* Directories get nlink 2 at start */
506 	set_nlink(inode, 2);
507 	/* but ic->pino_nlink is the parent ino# */
508 	f->inocache->pino_nlink = dir_i->i_ino;
509 
510 	ri->data_crc = cpu_to_je32(0);
511 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
512 
513 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
514 
515 	jffs2_free_raw_inode(ri);
516 
517 	if (IS_ERR(fn)) {
518 		/* Eeek. Wave bye bye */
519 		mutex_unlock(&f->sem);
520 		jffs2_complete_reservation(c);
521 		ret = PTR_ERR(fn);
522 		goto fail;
523 	}
524 	/* No data here. Only a metadata node, which will be
525 	   obsoleted by the first data write
526 	*/
527 	f->metadata = fn;
528 	mutex_unlock(&f->sem);
529 
530 	jffs2_complete_reservation(c);
531 
532 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
533 	if (ret)
534 		goto fail;
535 
536 	ret = jffs2_init_acl_post(inode);
537 	if (ret)
538 		goto fail;
539 
540 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
541 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
542 	if (ret)
543 		goto fail;
544 
545 	rd = jffs2_alloc_raw_dirent();
546 	if (!rd) {
547 		/* Argh. Now we treat it like a normal delete */
548 		jffs2_complete_reservation(c);
549 		ret = -ENOMEM;
550 		goto fail;
551 	}
552 
553 	dir_f = JFFS2_INODE_INFO(dir_i);
554 	mutex_lock(&dir_f->sem);
555 
556 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
557 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
558 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
559 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
560 
561 	rd->pino = cpu_to_je32(dir_i->i_ino);
562 	rd->version = cpu_to_je32(++dir_f->highest_version);
563 	rd->ino = cpu_to_je32(inode->i_ino);
564 	rd->mctime = cpu_to_je32(get_seconds());
565 	rd->nsize = namelen;
566 	rd->type = DT_DIR;
567 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
568 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
569 
570 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
571 
572 	if (IS_ERR(fd)) {
573 		/* dirent failed to write. Delete the inode normally
574 		   as if it were the final unlink() */
575 		jffs2_complete_reservation(c);
576 		jffs2_free_raw_dirent(rd);
577 		mutex_unlock(&dir_f->sem);
578 		ret = PTR_ERR(fd);
579 		goto fail;
580 	}
581 
582 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
583 	inc_nlink(dir_i);
584 
585 	jffs2_free_raw_dirent(rd);
586 
587 	/* Link the fd into the inode's list, obsoleting an old
588 	   one if necessary. */
589 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
590 
591 	mutex_unlock(&dir_f->sem);
592 	jffs2_complete_reservation(c);
593 
594 	unlock_new_inode(inode);
595 	d_instantiate(dentry, inode);
596 	return 0;
597 
598  fail:
599 	iget_failed(inode);
600 	return ret;
601 }
602 
603 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
604 {
605 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
606 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
607 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
608 	struct jffs2_full_dirent *fd;
609 	int ret;
610 	uint32_t now = get_seconds();
611 
612 	for (fd = f->dents ; fd; fd = fd->next) {
613 		if (fd->ino)
614 			return -ENOTEMPTY;
615 	}
616 
617 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
618 			      dentry->d_name.len, f, now);
619 	if (!ret) {
620 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
621 		clear_nlink(dentry->d_inode);
622 		drop_nlink(dir_i);
623 	}
624 	return ret;
625 }
626 
627 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
628 {
629 	struct jffs2_inode_info *f, *dir_f;
630 	struct jffs2_sb_info *c;
631 	struct inode *inode;
632 	struct jffs2_raw_inode *ri;
633 	struct jffs2_raw_dirent *rd;
634 	struct jffs2_full_dnode *fn;
635 	struct jffs2_full_dirent *fd;
636 	int namelen;
637 	union jffs2_device_node dev;
638 	int devlen = 0;
639 	uint32_t alloclen;
640 	int ret;
641 
642 	if (!new_valid_dev(rdev))
643 		return -EINVAL;
644 
645 	ri = jffs2_alloc_raw_inode();
646 	if (!ri)
647 		return -ENOMEM;
648 
649 	c = JFFS2_SB_INFO(dir_i->i_sb);
650 
651 	if (S_ISBLK(mode) || S_ISCHR(mode))
652 		devlen = jffs2_encode_dev(&dev, rdev);
653 
654 	/* Try to reserve enough space for both node and dirent.
655 	 * Just the node will do for now, though
656 	 */
657 	namelen = dentry->d_name.len;
658 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
659 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
660 
661 	if (ret) {
662 		jffs2_free_raw_inode(ri);
663 		return ret;
664 	}
665 
666 	inode = jffs2_new_inode(dir_i, mode, ri);
667 
668 	if (IS_ERR(inode)) {
669 		jffs2_free_raw_inode(ri);
670 		jffs2_complete_reservation(c);
671 		return PTR_ERR(inode);
672 	}
673 	inode->i_op = &jffs2_file_inode_operations;
674 	init_special_inode(inode, inode->i_mode, rdev);
675 
676 	f = JFFS2_INODE_INFO(inode);
677 
678 	ri->dsize = ri->csize = cpu_to_je32(devlen);
679 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
680 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
681 
682 	ri->compr = JFFS2_COMPR_NONE;
683 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
684 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
685 
686 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
687 
688 	jffs2_free_raw_inode(ri);
689 
690 	if (IS_ERR(fn)) {
691 		/* Eeek. Wave bye bye */
692 		mutex_unlock(&f->sem);
693 		jffs2_complete_reservation(c);
694 		ret = PTR_ERR(fn);
695 		goto fail;
696 	}
697 	/* No data here. Only a metadata node, which will be
698 	   obsoleted by the first data write
699 	*/
700 	f->metadata = fn;
701 	mutex_unlock(&f->sem);
702 
703 	jffs2_complete_reservation(c);
704 
705 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
706 	if (ret)
707 		goto fail;
708 
709 	ret = jffs2_init_acl_post(inode);
710 	if (ret)
711 		goto fail;
712 
713 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
714 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
715 	if (ret)
716 		goto fail;
717 
718 	rd = jffs2_alloc_raw_dirent();
719 	if (!rd) {
720 		/* Argh. Now we treat it like a normal delete */
721 		jffs2_complete_reservation(c);
722 		ret = -ENOMEM;
723 		goto fail;
724 	}
725 
726 	dir_f = JFFS2_INODE_INFO(dir_i);
727 	mutex_lock(&dir_f->sem);
728 
729 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
730 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
731 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
732 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
733 
734 	rd->pino = cpu_to_je32(dir_i->i_ino);
735 	rd->version = cpu_to_je32(++dir_f->highest_version);
736 	rd->ino = cpu_to_je32(inode->i_ino);
737 	rd->mctime = cpu_to_je32(get_seconds());
738 	rd->nsize = namelen;
739 
740 	/* XXX: This is ugly. */
741 	rd->type = (mode & S_IFMT) >> 12;
742 
743 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
744 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
745 
746 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
747 
748 	if (IS_ERR(fd)) {
749 		/* dirent failed to write. Delete the inode normally
750 		   as if it were the final unlink() */
751 		jffs2_complete_reservation(c);
752 		jffs2_free_raw_dirent(rd);
753 		mutex_unlock(&dir_f->sem);
754 		ret = PTR_ERR(fd);
755 		goto fail;
756 	}
757 
758 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
759 
760 	jffs2_free_raw_dirent(rd);
761 
762 	/* Link the fd into the inode's list, obsoleting an old
763 	   one if necessary. */
764 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
765 
766 	mutex_unlock(&dir_f->sem);
767 	jffs2_complete_reservation(c);
768 
769 	unlock_new_inode(inode);
770 	d_instantiate(dentry, inode);
771 	return 0;
772 
773  fail:
774 	iget_failed(inode);
775 	return ret;
776 }
777 
778 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
779 			 struct inode *new_dir_i, struct dentry *new_dentry)
780 {
781 	int ret;
782 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
783 	struct jffs2_inode_info *victim_f = NULL;
784 	uint8_t type;
785 	uint32_t now;
786 
787 	/* The VFS will check for us and prevent trying to rename a
788 	 * file over a directory and vice versa, but if it's a directory,
789 	 * the VFS can't check whether the victim is empty. The filesystem
790 	 * needs to do that for itself.
791 	 */
792 	if (new_dentry->d_inode) {
793 		victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);
794 		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
795 			struct jffs2_full_dirent *fd;
796 
797 			mutex_lock(&victim_f->sem);
798 			for (fd = victim_f->dents; fd; fd = fd->next) {
799 				if (fd->ino) {
800 					mutex_unlock(&victim_f->sem);
801 					return -ENOTEMPTY;
802 				}
803 			}
804 			mutex_unlock(&victim_f->sem);
805 		}
806 	}
807 
808 	/* XXX: We probably ought to alloc enough space for
809 	   both nodes at the same time. Writing the new link,
810 	   then getting -ENOSPC, is quite bad :)
811 	*/
812 
813 	/* Make a hard link */
814 
815 	/* XXX: This is ugly */
816 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
817 	if (!type) type = DT_REG;
818 
819 	now = get_seconds();
820 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
821 			    old_dentry->d_inode->i_ino, type,
822 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
823 
824 	if (ret)
825 		return ret;
826 
827 	if (victim_f) {
828 		/* There was a victim. Kill it off nicely */
829 		if (S_ISDIR(new_dentry->d_inode->i_mode))
830 			clear_nlink(new_dentry->d_inode);
831 		else
832 			drop_nlink(new_dentry->d_inode);
833 		/* Don't oops if the victim was a dirent pointing to an
834 		   inode which didn't exist. */
835 		if (victim_f->inocache) {
836 			mutex_lock(&victim_f->sem);
837 			if (S_ISDIR(new_dentry->d_inode->i_mode))
838 				victim_f->inocache->pino_nlink = 0;
839 			else
840 				victim_f->inocache->pino_nlink--;
841 			mutex_unlock(&victim_f->sem);
842 		}
843 	}
844 
845 	/* If it was a directory we moved, and there was no victim,
846 	   increase i_nlink on its new parent */
847 	if (S_ISDIR(old_dentry->d_inode->i_mode) && !victim_f)
848 		inc_nlink(new_dir_i);
849 
850 	/* Unlink the original */
851 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
852 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
853 
854 	/* We don't touch inode->i_nlink */
855 
856 	if (ret) {
857 		/* Oh shit. We really ought to make a single node which can do both atomically */
858 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
859 		mutex_lock(&f->sem);
860 		inc_nlink(old_dentry->d_inode);
861 		if (f->inocache && !S_ISDIR(old_dentry->d_inode->i_mode))
862 			f->inocache->pino_nlink++;
863 		mutex_unlock(&f->sem);
864 
865 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
866 			  __func__, ret);
867 		/* Might as well let the VFS know */
868 		d_instantiate(new_dentry, old_dentry->d_inode);
869 		ihold(old_dentry->d_inode);
870 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
871 		return ret;
872 	}
873 
874 	if (S_ISDIR(old_dentry->d_inode->i_mode))
875 		drop_nlink(old_dir_i);
876 
877 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
878 
879 	return 0;
880 }
881 
882