xref: /openbmc/linux/fs/jffs2/dir.c (revision c0e297dc)
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(d_inode(dentry));
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(d_inode(dentry), 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(d_inode(old_dentry)->i_sb);
245 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
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 (d_is_dir(old_dentry))
256 		return -EPERM;
257 
258 	/* XXX: This is ugly */
259 	type = (d_inode(old_dentry)->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(d_inode(old_dentry), ++f->inocache->pino_nlink);
268 		mutex_unlock(&f->sem);
269 		d_instantiate(dentry, d_inode(old_dentry));
270 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
271 		ihold(d_inode(old_dentry));
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 	inode->i_link = f->target;
358 
359 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
360 		  __func__, (char *)f->target);
361 
362 	/* No data here. Only a metadata node, which will be
363 	   obsoleted by the first data write
364 	*/
365 	f->metadata = fn;
366 	mutex_unlock(&f->sem);
367 
368 	jffs2_complete_reservation(c);
369 
370 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
371 	if (ret)
372 		goto fail;
373 
374 	ret = jffs2_init_acl_post(inode);
375 	if (ret)
376 		goto fail;
377 
378 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
379 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
380 	if (ret)
381 		goto fail;
382 
383 	rd = jffs2_alloc_raw_dirent();
384 	if (!rd) {
385 		/* Argh. Now we treat it like a normal delete */
386 		jffs2_complete_reservation(c);
387 		ret = -ENOMEM;
388 		goto fail;
389 	}
390 
391 	dir_f = JFFS2_INODE_INFO(dir_i);
392 	mutex_lock(&dir_f->sem);
393 
394 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
395 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
396 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
397 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
398 
399 	rd->pino = cpu_to_je32(dir_i->i_ino);
400 	rd->version = cpu_to_je32(++dir_f->highest_version);
401 	rd->ino = cpu_to_je32(inode->i_ino);
402 	rd->mctime = cpu_to_je32(get_seconds());
403 	rd->nsize = namelen;
404 	rd->type = DT_LNK;
405 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
406 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
407 
408 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
409 
410 	if (IS_ERR(fd)) {
411 		/* dirent failed to write. Delete the inode normally
412 		   as if it were the final unlink() */
413 		jffs2_complete_reservation(c);
414 		jffs2_free_raw_dirent(rd);
415 		mutex_unlock(&dir_f->sem);
416 		ret = PTR_ERR(fd);
417 		goto fail;
418 	}
419 
420 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
421 
422 	jffs2_free_raw_dirent(rd);
423 
424 	/* Link the fd into the inode's list, obsoleting an old
425 	   one if necessary. */
426 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
427 
428 	mutex_unlock(&dir_f->sem);
429 	jffs2_complete_reservation(c);
430 
431 	unlock_new_inode(inode);
432 	d_instantiate(dentry, inode);
433 	return 0;
434 
435  fail:
436 	iget_failed(inode);
437 	return ret;
438 }
439 
440 
441 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
442 {
443 	struct jffs2_inode_info *f, *dir_f;
444 	struct jffs2_sb_info *c;
445 	struct inode *inode;
446 	struct jffs2_raw_inode *ri;
447 	struct jffs2_raw_dirent *rd;
448 	struct jffs2_full_dnode *fn;
449 	struct jffs2_full_dirent *fd;
450 	int namelen;
451 	uint32_t alloclen;
452 	int ret;
453 
454 	mode |= S_IFDIR;
455 
456 	ri = jffs2_alloc_raw_inode();
457 	if (!ri)
458 		return -ENOMEM;
459 
460 	c = JFFS2_SB_INFO(dir_i->i_sb);
461 
462 	/* Try to reserve enough space for both node and dirent.
463 	 * Just the node will do for now, though
464 	 */
465 	namelen = dentry->d_name.len;
466 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
467 				  JFFS2_SUMMARY_INODE_SIZE);
468 
469 	if (ret) {
470 		jffs2_free_raw_inode(ri);
471 		return ret;
472 	}
473 
474 	inode = jffs2_new_inode(dir_i, mode, ri);
475 
476 	if (IS_ERR(inode)) {
477 		jffs2_free_raw_inode(ri);
478 		jffs2_complete_reservation(c);
479 		return PTR_ERR(inode);
480 	}
481 
482 	inode->i_op = &jffs2_dir_inode_operations;
483 	inode->i_fop = &jffs2_dir_operations;
484 
485 	f = JFFS2_INODE_INFO(inode);
486 
487 	/* Directories get nlink 2 at start */
488 	set_nlink(inode, 2);
489 	/* but ic->pino_nlink is the parent ino# */
490 	f->inocache->pino_nlink = dir_i->i_ino;
491 
492 	ri->data_crc = cpu_to_je32(0);
493 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
494 
495 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
496 
497 	jffs2_free_raw_inode(ri);
498 
499 	if (IS_ERR(fn)) {
500 		/* Eeek. Wave bye bye */
501 		mutex_unlock(&f->sem);
502 		jffs2_complete_reservation(c);
503 		ret = PTR_ERR(fn);
504 		goto fail;
505 	}
506 	/* No data here. Only a metadata node, which will be
507 	   obsoleted by the first data write
508 	*/
509 	f->metadata = fn;
510 	mutex_unlock(&f->sem);
511 
512 	jffs2_complete_reservation(c);
513 
514 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
515 	if (ret)
516 		goto fail;
517 
518 	ret = jffs2_init_acl_post(inode);
519 	if (ret)
520 		goto fail;
521 
522 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
523 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
524 	if (ret)
525 		goto fail;
526 
527 	rd = jffs2_alloc_raw_dirent();
528 	if (!rd) {
529 		/* Argh. Now we treat it like a normal delete */
530 		jffs2_complete_reservation(c);
531 		ret = -ENOMEM;
532 		goto fail;
533 	}
534 
535 	dir_f = JFFS2_INODE_INFO(dir_i);
536 	mutex_lock(&dir_f->sem);
537 
538 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
539 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
540 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
541 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
542 
543 	rd->pino = cpu_to_je32(dir_i->i_ino);
544 	rd->version = cpu_to_je32(++dir_f->highest_version);
545 	rd->ino = cpu_to_je32(inode->i_ino);
546 	rd->mctime = cpu_to_je32(get_seconds());
547 	rd->nsize = namelen;
548 	rd->type = DT_DIR;
549 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
550 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
551 
552 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
553 
554 	if (IS_ERR(fd)) {
555 		/* dirent failed to write. Delete the inode normally
556 		   as if it were the final unlink() */
557 		jffs2_complete_reservation(c);
558 		jffs2_free_raw_dirent(rd);
559 		mutex_unlock(&dir_f->sem);
560 		ret = PTR_ERR(fd);
561 		goto fail;
562 	}
563 
564 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
565 	inc_nlink(dir_i);
566 
567 	jffs2_free_raw_dirent(rd);
568 
569 	/* Link the fd into the inode's list, obsoleting an old
570 	   one if necessary. */
571 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
572 
573 	mutex_unlock(&dir_f->sem);
574 	jffs2_complete_reservation(c);
575 
576 	unlock_new_inode(inode);
577 	d_instantiate(dentry, inode);
578 	return 0;
579 
580  fail:
581 	iget_failed(inode);
582 	return ret;
583 }
584 
585 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
586 {
587 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
588 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
589 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
590 	struct jffs2_full_dirent *fd;
591 	int ret;
592 	uint32_t now = get_seconds();
593 
594 	for (fd = f->dents ; fd; fd = fd->next) {
595 		if (fd->ino)
596 			return -ENOTEMPTY;
597 	}
598 
599 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
600 			      dentry->d_name.len, f, now);
601 	if (!ret) {
602 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
603 		clear_nlink(d_inode(dentry));
604 		drop_nlink(dir_i);
605 	}
606 	return ret;
607 }
608 
609 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
610 {
611 	struct jffs2_inode_info *f, *dir_f;
612 	struct jffs2_sb_info *c;
613 	struct inode *inode;
614 	struct jffs2_raw_inode *ri;
615 	struct jffs2_raw_dirent *rd;
616 	struct jffs2_full_dnode *fn;
617 	struct jffs2_full_dirent *fd;
618 	int namelen;
619 	union jffs2_device_node dev;
620 	int devlen = 0;
621 	uint32_t alloclen;
622 	int ret;
623 
624 	if (!new_valid_dev(rdev))
625 		return -EINVAL;
626 
627 	ri = jffs2_alloc_raw_inode();
628 	if (!ri)
629 		return -ENOMEM;
630 
631 	c = JFFS2_SB_INFO(dir_i->i_sb);
632 
633 	if (S_ISBLK(mode) || S_ISCHR(mode))
634 		devlen = jffs2_encode_dev(&dev, rdev);
635 
636 	/* Try to reserve enough space for both node and dirent.
637 	 * Just the node will do for now, though
638 	 */
639 	namelen = dentry->d_name.len;
640 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
641 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
642 
643 	if (ret) {
644 		jffs2_free_raw_inode(ri);
645 		return ret;
646 	}
647 
648 	inode = jffs2_new_inode(dir_i, mode, ri);
649 
650 	if (IS_ERR(inode)) {
651 		jffs2_free_raw_inode(ri);
652 		jffs2_complete_reservation(c);
653 		return PTR_ERR(inode);
654 	}
655 	inode->i_op = &jffs2_file_inode_operations;
656 	init_special_inode(inode, inode->i_mode, rdev);
657 
658 	f = JFFS2_INODE_INFO(inode);
659 
660 	ri->dsize = ri->csize = cpu_to_je32(devlen);
661 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
662 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
663 
664 	ri->compr = JFFS2_COMPR_NONE;
665 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
666 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
667 
668 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
669 
670 	jffs2_free_raw_inode(ri);
671 
672 	if (IS_ERR(fn)) {
673 		/* Eeek. Wave bye bye */
674 		mutex_unlock(&f->sem);
675 		jffs2_complete_reservation(c);
676 		ret = PTR_ERR(fn);
677 		goto fail;
678 	}
679 	/* No data here. Only a metadata node, which will be
680 	   obsoleted by the first data write
681 	*/
682 	f->metadata = fn;
683 	mutex_unlock(&f->sem);
684 
685 	jffs2_complete_reservation(c);
686 
687 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
688 	if (ret)
689 		goto fail;
690 
691 	ret = jffs2_init_acl_post(inode);
692 	if (ret)
693 		goto fail;
694 
695 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
696 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
697 	if (ret)
698 		goto fail;
699 
700 	rd = jffs2_alloc_raw_dirent();
701 	if (!rd) {
702 		/* Argh. Now we treat it like a normal delete */
703 		jffs2_complete_reservation(c);
704 		ret = -ENOMEM;
705 		goto fail;
706 	}
707 
708 	dir_f = JFFS2_INODE_INFO(dir_i);
709 	mutex_lock(&dir_f->sem);
710 
711 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
712 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
713 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
714 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
715 
716 	rd->pino = cpu_to_je32(dir_i->i_ino);
717 	rd->version = cpu_to_je32(++dir_f->highest_version);
718 	rd->ino = cpu_to_je32(inode->i_ino);
719 	rd->mctime = cpu_to_je32(get_seconds());
720 	rd->nsize = namelen;
721 
722 	/* XXX: This is ugly. */
723 	rd->type = (mode & S_IFMT) >> 12;
724 
725 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
726 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
727 
728 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
729 
730 	if (IS_ERR(fd)) {
731 		/* dirent failed to write. Delete the inode normally
732 		   as if it were the final unlink() */
733 		jffs2_complete_reservation(c);
734 		jffs2_free_raw_dirent(rd);
735 		mutex_unlock(&dir_f->sem);
736 		ret = PTR_ERR(fd);
737 		goto fail;
738 	}
739 
740 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
741 
742 	jffs2_free_raw_dirent(rd);
743 
744 	/* Link the fd into the inode's list, obsoleting an old
745 	   one if necessary. */
746 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
747 
748 	mutex_unlock(&dir_f->sem);
749 	jffs2_complete_reservation(c);
750 
751 	unlock_new_inode(inode);
752 	d_instantiate(dentry, inode);
753 	return 0;
754 
755  fail:
756 	iget_failed(inode);
757 	return ret;
758 }
759 
760 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
761 			 struct inode *new_dir_i, struct dentry *new_dentry)
762 {
763 	int ret;
764 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
765 	struct jffs2_inode_info *victim_f = NULL;
766 	uint8_t type;
767 	uint32_t now;
768 
769 	/* The VFS will check for us and prevent trying to rename a
770 	 * file over a directory and vice versa, but if it's a directory,
771 	 * the VFS can't check whether the victim is empty. The filesystem
772 	 * needs to do that for itself.
773 	 */
774 	if (d_really_is_positive(new_dentry)) {
775 		victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
776 		if (d_is_dir(new_dentry)) {
777 			struct jffs2_full_dirent *fd;
778 
779 			mutex_lock(&victim_f->sem);
780 			for (fd = victim_f->dents; fd; fd = fd->next) {
781 				if (fd->ino) {
782 					mutex_unlock(&victim_f->sem);
783 					return -ENOTEMPTY;
784 				}
785 			}
786 			mutex_unlock(&victim_f->sem);
787 		}
788 	}
789 
790 	/* XXX: We probably ought to alloc enough space for
791 	   both nodes at the same time. Writing the new link,
792 	   then getting -ENOSPC, is quite bad :)
793 	*/
794 
795 	/* Make a hard link */
796 
797 	/* XXX: This is ugly */
798 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
799 	if (!type) type = DT_REG;
800 
801 	now = get_seconds();
802 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
803 			    d_inode(old_dentry)->i_ino, type,
804 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
805 
806 	if (ret)
807 		return ret;
808 
809 	if (victim_f) {
810 		/* There was a victim. Kill it off nicely */
811 		if (d_is_dir(new_dentry))
812 			clear_nlink(d_inode(new_dentry));
813 		else
814 			drop_nlink(d_inode(new_dentry));
815 		/* Don't oops if the victim was a dirent pointing to an
816 		   inode which didn't exist. */
817 		if (victim_f->inocache) {
818 			mutex_lock(&victim_f->sem);
819 			if (d_is_dir(new_dentry))
820 				victim_f->inocache->pino_nlink = 0;
821 			else
822 				victim_f->inocache->pino_nlink--;
823 			mutex_unlock(&victim_f->sem);
824 		}
825 	}
826 
827 	/* If it was a directory we moved, and there was no victim,
828 	   increase i_nlink on its new parent */
829 	if (d_is_dir(old_dentry) && !victim_f)
830 		inc_nlink(new_dir_i);
831 
832 	/* Unlink the original */
833 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
834 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
835 
836 	/* We don't touch inode->i_nlink */
837 
838 	if (ret) {
839 		/* Oh shit. We really ought to make a single node which can do both atomically */
840 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
841 		mutex_lock(&f->sem);
842 		inc_nlink(d_inode(old_dentry));
843 		if (f->inocache && !d_is_dir(old_dentry))
844 			f->inocache->pino_nlink++;
845 		mutex_unlock(&f->sem);
846 
847 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
848 			  __func__, ret);
849 		/* Might as well let the VFS know */
850 		d_instantiate(new_dentry, d_inode(old_dentry));
851 		ihold(d_inode(old_dentry));
852 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
853 		return ret;
854 	}
855 
856 	if (d_is_dir(old_dentry))
857 		drop_nlink(old_dir_i);
858 
859 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
860 
861 	return 0;
862 }
863 
864