xref: /openbmc/linux/fs/jffs2/dir.c (revision da320f05)
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 *,umode_t,
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 *,umode_t);
33 static int jffs2_rmdir (struct inode *,struct dentry *);
34 static int jffs2_mknod (struct inode *,struct dentry *,umode_t,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 	jffs2_dbg(1, "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 			pr_warn("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 	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n",
123 		  filp->f_path.dentry->d_inode->i_ino);
124 
125 	f = JFFS2_INODE_INFO(inode);
126 
127 	offset = filp->f_pos;
128 
129 	if (offset == 0) {
130 		jffs2_dbg(1, "Dirent 0: \".\", ino #%lu\n", inode->i_ino);
131 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
132 			goto out;
133 		offset++;
134 	}
135 	if (offset == 1) {
136 		unsigned long pino = parent_ino(filp->f_path.dentry);
137 		jffs2_dbg(1, "Dirent 1: \"..\", ino #%lu\n", pino);
138 		if (filldir(dirent, "..", 2, 1, pino, DT_DIR) < 0)
139 			goto out;
140 		offset++;
141 	}
142 
143 	curofs=1;
144 	mutex_lock(&f->sem);
145 	for (fd = f->dents; fd; fd = fd->next) {
146 
147 		curofs++;
148 		/* First loop: curofs = 2; offset = 2 */
149 		if (curofs < offset) {
150 			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
151 				  fd->name, fd->ino, fd->type, curofs, offset);
152 			continue;
153 		}
154 		if (!fd->ino) {
155 			jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
156 				  fd->name);
157 			offset++;
158 			continue;
159 		}
160 		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
161 			  offset, fd->name, fd->ino, fd->type);
162 		if (filldir(dirent, fd->name, strlen(fd->name), offset, fd->ino, fd->type) < 0)
163 			break;
164 		offset++;
165 	}
166 	mutex_unlock(&f->sem);
167  out:
168 	filp->f_pos = offset;
169 	return 0;
170 }
171 
172 /***********************************************************************/
173 
174 
175 static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
176 			umode_t mode, struct nameidata *nd)
177 {
178 	struct jffs2_raw_inode *ri;
179 	struct jffs2_inode_info *f, *dir_f;
180 	struct jffs2_sb_info *c;
181 	struct inode *inode;
182 	int ret;
183 
184 	ri = jffs2_alloc_raw_inode();
185 	if (!ri)
186 		return -ENOMEM;
187 
188 	c = JFFS2_SB_INFO(dir_i->i_sb);
189 
190 	jffs2_dbg(1, "%s()\n", __func__);
191 
192 	inode = jffs2_new_inode(dir_i, mode, ri);
193 
194 	if (IS_ERR(inode)) {
195 		jffs2_dbg(1, "jffs2_new_inode() failed\n");
196 		jffs2_free_raw_inode(ri);
197 		return PTR_ERR(inode);
198 	}
199 
200 	inode->i_op = &jffs2_file_inode_operations;
201 	inode->i_fop = &jffs2_file_operations;
202 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
203 	inode->i_mapping->nrpages = 0;
204 
205 	f = JFFS2_INODE_INFO(inode);
206 	dir_f = JFFS2_INODE_INFO(dir_i);
207 
208 	/* jffs2_do_create() will want to lock it, _after_ reserving
209 	   space and taking c-alloc_sem. If we keep it locked here,
210 	   lockdep gets unhappy (although it's a false positive;
211 	   nothing else will be looking at this inode yet so there's
212 	   no chance of AB-BA deadlock involving its f->sem). */
213 	mutex_unlock(&f->sem);
214 
215 	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
216 	if (ret)
217 		goto fail;
218 
219 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
220 
221 	jffs2_free_raw_inode(ri);
222 
223 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
224 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
225 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
226 
227 	d_instantiate(dentry, inode);
228 	unlock_new_inode(inode);
229 	return 0;
230 
231  fail:
232 	iget_failed(inode);
233 	jffs2_free_raw_inode(ri);
234 	return ret;
235 }
236 
237 /***********************************************************************/
238 
239 
240 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
241 {
242 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
243 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
244 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(dentry->d_inode);
245 	int ret;
246 	uint32_t now = get_seconds();
247 
248 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
249 			      dentry->d_name.len, dead_f, now);
250 	if (dead_f->inocache)
251 		set_nlink(dentry->d_inode, dead_f->inocache->pino_nlink);
252 	if (!ret)
253 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
254 	return ret;
255 }
256 /***********************************************************************/
257 
258 
259 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
260 {
261 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_inode->i_sb);
262 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
263 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
264 	int ret;
265 	uint8_t type;
266 	uint32_t now;
267 
268 	/* Don't let people make hard links to bad inodes. */
269 	if (!f->inocache)
270 		return -EIO;
271 
272 	if (S_ISDIR(old_dentry->d_inode->i_mode))
273 		return -EPERM;
274 
275 	/* XXX: This is ugly */
276 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
277 	if (!type) type = DT_REG;
278 
279 	now = get_seconds();
280 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
281 
282 	if (!ret) {
283 		mutex_lock(&f->sem);
284 		set_nlink(old_dentry->d_inode, ++f->inocache->pino_nlink);
285 		mutex_unlock(&f->sem);
286 		d_instantiate(dentry, old_dentry->d_inode);
287 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
288 		ihold(old_dentry->d_inode);
289 	}
290 	return ret;
291 }
292 
293 /***********************************************************************/
294 
295 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
296 {
297 	struct jffs2_inode_info *f, *dir_f;
298 	struct jffs2_sb_info *c;
299 	struct inode *inode;
300 	struct jffs2_raw_inode *ri;
301 	struct jffs2_raw_dirent *rd;
302 	struct jffs2_full_dnode *fn;
303 	struct jffs2_full_dirent *fd;
304 	int namelen;
305 	uint32_t alloclen;
306 	int ret, targetlen = strlen(target);
307 
308 	/* FIXME: If you care. We'd need to use frags for the target
309 	   if it grows much more than this */
310 	if (targetlen > 254)
311 		return -ENAMETOOLONG;
312 
313 	ri = jffs2_alloc_raw_inode();
314 
315 	if (!ri)
316 		return -ENOMEM;
317 
318 	c = JFFS2_SB_INFO(dir_i->i_sb);
319 
320 	/* Try to reserve enough space for both node and dirent.
321 	 * Just the node will do for now, though
322 	 */
323 	namelen = dentry->d_name.len;
324 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
325 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
326 
327 	if (ret) {
328 		jffs2_free_raw_inode(ri);
329 		return ret;
330 	}
331 
332 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
333 
334 	if (IS_ERR(inode)) {
335 		jffs2_free_raw_inode(ri);
336 		jffs2_complete_reservation(c);
337 		return PTR_ERR(inode);
338 	}
339 
340 	inode->i_op = &jffs2_symlink_inode_operations;
341 
342 	f = JFFS2_INODE_INFO(inode);
343 
344 	inode->i_size = targetlen;
345 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
346 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
347 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
348 
349 	ri->compr = JFFS2_COMPR_NONE;
350 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
351 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
352 
353 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
354 
355 	jffs2_free_raw_inode(ri);
356 
357 	if (IS_ERR(fn)) {
358 		/* Eeek. Wave bye bye */
359 		mutex_unlock(&f->sem);
360 		jffs2_complete_reservation(c);
361 		ret = PTR_ERR(fn);
362 		goto fail;
363 	}
364 
365 	/* We use f->target field to store the target path. */
366 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
367 	if (!f->target) {
368 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
369 		mutex_unlock(&f->sem);
370 		jffs2_complete_reservation(c);
371 		ret = -ENOMEM;
372 		goto fail;
373 	}
374 
375 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
376 		  __func__, (char *)f->target);
377 
378 	/* No data here. Only a metadata node, which will be
379 	   obsoleted by the first data write
380 	*/
381 	f->metadata = fn;
382 	mutex_unlock(&f->sem);
383 
384 	jffs2_complete_reservation(c);
385 
386 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
387 	if (ret)
388 		goto fail;
389 
390 	ret = jffs2_init_acl_post(inode);
391 	if (ret)
392 		goto fail;
393 
394 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
395 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
396 	if (ret)
397 		goto fail;
398 
399 	rd = jffs2_alloc_raw_dirent();
400 	if (!rd) {
401 		/* Argh. Now we treat it like a normal delete */
402 		jffs2_complete_reservation(c);
403 		ret = -ENOMEM;
404 		goto fail;
405 	}
406 
407 	dir_f = JFFS2_INODE_INFO(dir_i);
408 	mutex_lock(&dir_f->sem);
409 
410 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
411 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
412 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
413 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
414 
415 	rd->pino = cpu_to_je32(dir_i->i_ino);
416 	rd->version = cpu_to_je32(++dir_f->highest_version);
417 	rd->ino = cpu_to_je32(inode->i_ino);
418 	rd->mctime = cpu_to_je32(get_seconds());
419 	rd->nsize = namelen;
420 	rd->type = DT_LNK;
421 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
422 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
423 
424 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
425 
426 	if (IS_ERR(fd)) {
427 		/* dirent failed to write. Delete the inode normally
428 		   as if it were the final unlink() */
429 		jffs2_complete_reservation(c);
430 		jffs2_free_raw_dirent(rd);
431 		mutex_unlock(&dir_f->sem);
432 		ret = PTR_ERR(fd);
433 		goto fail;
434 	}
435 
436 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
437 
438 	jffs2_free_raw_dirent(rd);
439 
440 	/* Link the fd into the inode's list, obsoleting an old
441 	   one if necessary. */
442 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
443 
444 	mutex_unlock(&dir_f->sem);
445 	jffs2_complete_reservation(c);
446 
447 	d_instantiate(dentry, inode);
448 	unlock_new_inode(inode);
449 	return 0;
450 
451  fail:
452 	iget_failed(inode);
453 	return ret;
454 }
455 
456 
457 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
458 {
459 	struct jffs2_inode_info *f, *dir_f;
460 	struct jffs2_sb_info *c;
461 	struct inode *inode;
462 	struct jffs2_raw_inode *ri;
463 	struct jffs2_raw_dirent *rd;
464 	struct jffs2_full_dnode *fn;
465 	struct jffs2_full_dirent *fd;
466 	int namelen;
467 	uint32_t alloclen;
468 	int ret;
469 
470 	mode |= S_IFDIR;
471 
472 	ri = jffs2_alloc_raw_inode();
473 	if (!ri)
474 		return -ENOMEM;
475 
476 	c = JFFS2_SB_INFO(dir_i->i_sb);
477 
478 	/* Try to reserve enough space for both node and dirent.
479 	 * Just the node will do for now, though
480 	 */
481 	namelen = dentry->d_name.len;
482 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
483 				  JFFS2_SUMMARY_INODE_SIZE);
484 
485 	if (ret) {
486 		jffs2_free_raw_inode(ri);
487 		return ret;
488 	}
489 
490 	inode = jffs2_new_inode(dir_i, mode, ri);
491 
492 	if (IS_ERR(inode)) {
493 		jffs2_free_raw_inode(ri);
494 		jffs2_complete_reservation(c);
495 		return PTR_ERR(inode);
496 	}
497 
498 	inode->i_op = &jffs2_dir_inode_operations;
499 	inode->i_fop = &jffs2_dir_operations;
500 
501 	f = JFFS2_INODE_INFO(inode);
502 
503 	/* Directories get nlink 2 at start */
504 	set_nlink(inode, 2);
505 	/* but ic->pino_nlink is the parent ino# */
506 	f->inocache->pino_nlink = dir_i->i_ino;
507 
508 	ri->data_crc = cpu_to_je32(0);
509 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
510 
511 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
512 
513 	jffs2_free_raw_inode(ri);
514 
515 	if (IS_ERR(fn)) {
516 		/* Eeek. Wave bye bye */
517 		mutex_unlock(&f->sem);
518 		jffs2_complete_reservation(c);
519 		ret = PTR_ERR(fn);
520 		goto fail;
521 	}
522 	/* No data here. Only a metadata node, which will be
523 	   obsoleted by the first data write
524 	*/
525 	f->metadata = fn;
526 	mutex_unlock(&f->sem);
527 
528 	jffs2_complete_reservation(c);
529 
530 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
531 	if (ret)
532 		goto fail;
533 
534 	ret = jffs2_init_acl_post(inode);
535 	if (ret)
536 		goto fail;
537 
538 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
539 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
540 	if (ret)
541 		goto fail;
542 
543 	rd = jffs2_alloc_raw_dirent();
544 	if (!rd) {
545 		/* Argh. Now we treat it like a normal delete */
546 		jffs2_complete_reservation(c);
547 		ret = -ENOMEM;
548 		goto fail;
549 	}
550 
551 	dir_f = JFFS2_INODE_INFO(dir_i);
552 	mutex_lock(&dir_f->sem);
553 
554 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
555 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
556 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
557 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
558 
559 	rd->pino = cpu_to_je32(dir_i->i_ino);
560 	rd->version = cpu_to_je32(++dir_f->highest_version);
561 	rd->ino = cpu_to_je32(inode->i_ino);
562 	rd->mctime = cpu_to_je32(get_seconds());
563 	rd->nsize = namelen;
564 	rd->type = DT_DIR;
565 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
566 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
567 
568 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
569 
570 	if (IS_ERR(fd)) {
571 		/* dirent failed to write. Delete the inode normally
572 		   as if it were the final unlink() */
573 		jffs2_complete_reservation(c);
574 		jffs2_free_raw_dirent(rd);
575 		mutex_unlock(&dir_f->sem);
576 		ret = PTR_ERR(fd);
577 		goto fail;
578 	}
579 
580 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
581 	inc_nlink(dir_i);
582 
583 	jffs2_free_raw_dirent(rd);
584 
585 	/* Link the fd into the inode's list, obsoleting an old
586 	   one if necessary. */
587 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
588 
589 	mutex_unlock(&dir_f->sem);
590 	jffs2_complete_reservation(c);
591 
592 	d_instantiate(dentry, inode);
593 	unlock_new_inode(inode);
594 	return 0;
595 
596  fail:
597 	iget_failed(inode);
598 	return ret;
599 }
600 
601 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
602 {
603 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
604 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
605 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
606 	struct jffs2_full_dirent *fd;
607 	int ret;
608 	uint32_t now = get_seconds();
609 
610 	for (fd = f->dents ; fd; fd = fd->next) {
611 		if (fd->ino)
612 			return -ENOTEMPTY;
613 	}
614 
615 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
616 			      dentry->d_name.len, f, now);
617 	if (!ret) {
618 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
619 		clear_nlink(dentry->d_inode);
620 		drop_nlink(dir_i);
621 	}
622 	return ret;
623 }
624 
625 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
626 {
627 	struct jffs2_inode_info *f, *dir_f;
628 	struct jffs2_sb_info *c;
629 	struct inode *inode;
630 	struct jffs2_raw_inode *ri;
631 	struct jffs2_raw_dirent *rd;
632 	struct jffs2_full_dnode *fn;
633 	struct jffs2_full_dirent *fd;
634 	int namelen;
635 	union jffs2_device_node dev;
636 	int devlen = 0;
637 	uint32_t alloclen;
638 	int ret;
639 
640 	if (!new_valid_dev(rdev))
641 		return -EINVAL;
642 
643 	ri = jffs2_alloc_raw_inode();
644 	if (!ri)
645 		return -ENOMEM;
646 
647 	c = JFFS2_SB_INFO(dir_i->i_sb);
648 
649 	if (S_ISBLK(mode) || S_ISCHR(mode))
650 		devlen = jffs2_encode_dev(&dev, rdev);
651 
652 	/* Try to reserve enough space for both node and dirent.
653 	 * Just the node will do for now, though
654 	 */
655 	namelen = dentry->d_name.len;
656 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
657 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
658 
659 	if (ret) {
660 		jffs2_free_raw_inode(ri);
661 		return ret;
662 	}
663 
664 	inode = jffs2_new_inode(dir_i, mode, ri);
665 
666 	if (IS_ERR(inode)) {
667 		jffs2_free_raw_inode(ri);
668 		jffs2_complete_reservation(c);
669 		return PTR_ERR(inode);
670 	}
671 	inode->i_op = &jffs2_file_inode_operations;
672 	init_special_inode(inode, inode->i_mode, rdev);
673 
674 	f = JFFS2_INODE_INFO(inode);
675 
676 	ri->dsize = ri->csize = cpu_to_je32(devlen);
677 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
678 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
679 
680 	ri->compr = JFFS2_COMPR_NONE;
681 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
682 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
683 
684 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
685 
686 	jffs2_free_raw_inode(ri);
687 
688 	if (IS_ERR(fn)) {
689 		/* Eeek. Wave bye bye */
690 		mutex_unlock(&f->sem);
691 		jffs2_complete_reservation(c);
692 		ret = PTR_ERR(fn);
693 		goto fail;
694 	}
695 	/* No data here. Only a metadata node, which will be
696 	   obsoleted by the first data write
697 	*/
698 	f->metadata = fn;
699 	mutex_unlock(&f->sem);
700 
701 	jffs2_complete_reservation(c);
702 
703 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
704 	if (ret)
705 		goto fail;
706 
707 	ret = jffs2_init_acl_post(inode);
708 	if (ret)
709 		goto fail;
710 
711 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
712 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
713 	if (ret)
714 		goto fail;
715 
716 	rd = jffs2_alloc_raw_dirent();
717 	if (!rd) {
718 		/* Argh. Now we treat it like a normal delete */
719 		jffs2_complete_reservation(c);
720 		ret = -ENOMEM;
721 		goto fail;
722 	}
723 
724 	dir_f = JFFS2_INODE_INFO(dir_i);
725 	mutex_lock(&dir_f->sem);
726 
727 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
728 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
729 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
730 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
731 
732 	rd->pino = cpu_to_je32(dir_i->i_ino);
733 	rd->version = cpu_to_je32(++dir_f->highest_version);
734 	rd->ino = cpu_to_je32(inode->i_ino);
735 	rd->mctime = cpu_to_je32(get_seconds());
736 	rd->nsize = namelen;
737 
738 	/* XXX: This is ugly. */
739 	rd->type = (mode & S_IFMT) >> 12;
740 
741 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
742 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
743 
744 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
745 
746 	if (IS_ERR(fd)) {
747 		/* dirent failed to write. Delete the inode normally
748 		   as if it were the final unlink() */
749 		jffs2_complete_reservation(c);
750 		jffs2_free_raw_dirent(rd);
751 		mutex_unlock(&dir_f->sem);
752 		ret = PTR_ERR(fd);
753 		goto fail;
754 	}
755 
756 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
757 
758 	jffs2_free_raw_dirent(rd);
759 
760 	/* Link the fd into the inode's list, obsoleting an old
761 	   one if necessary. */
762 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
763 
764 	mutex_unlock(&dir_f->sem);
765 	jffs2_complete_reservation(c);
766 
767 	d_instantiate(dentry, inode);
768 	unlock_new_inode(inode);
769 	return 0;
770 
771  fail:
772 	iget_failed(inode);
773 	return ret;
774 }
775 
776 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
777 			 struct inode *new_dir_i, struct dentry *new_dentry)
778 {
779 	int ret;
780 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
781 	struct jffs2_inode_info *victim_f = NULL;
782 	uint8_t type;
783 	uint32_t now;
784 
785 	/* The VFS will check for us and prevent trying to rename a
786 	 * file over a directory and vice versa, but if it's a directory,
787 	 * the VFS can't check whether the victim is empty. The filesystem
788 	 * needs to do that for itself.
789 	 */
790 	if (new_dentry->d_inode) {
791 		victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);
792 		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
793 			struct jffs2_full_dirent *fd;
794 
795 			mutex_lock(&victim_f->sem);
796 			for (fd = victim_f->dents; fd; fd = fd->next) {
797 				if (fd->ino) {
798 					mutex_unlock(&victim_f->sem);
799 					return -ENOTEMPTY;
800 				}
801 			}
802 			mutex_unlock(&victim_f->sem);
803 		}
804 	}
805 
806 	/* XXX: We probably ought to alloc enough space for
807 	   both nodes at the same time. Writing the new link,
808 	   then getting -ENOSPC, is quite bad :)
809 	*/
810 
811 	/* Make a hard link */
812 
813 	/* XXX: This is ugly */
814 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
815 	if (!type) type = DT_REG;
816 
817 	now = get_seconds();
818 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
819 			    old_dentry->d_inode->i_ino, type,
820 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
821 
822 	if (ret)
823 		return ret;
824 
825 	if (victim_f) {
826 		/* There was a victim. Kill it off nicely */
827 		if (S_ISDIR(new_dentry->d_inode->i_mode))
828 			clear_nlink(new_dentry->d_inode);
829 		else
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 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
864 			  __func__, ret);
865 		/* Might as well let the VFS know */
866 		d_instantiate(new_dentry, old_dentry->d_inode);
867 		ihold(old_dentry->d_inode);
868 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
869 		return ret;
870 	}
871 
872 	if (S_ISDIR(old_dentry->d_inode->i_mode))
873 		drop_nlink(old_dir_i);
874 
875 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
876 
877 	return 0;
878 }
879 
880