xref: /linux/fs/jffs2/dir.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
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 			 unsigned int);
40 
41 const struct file_operations jffs2_dir_operations =
42 {
43 	.read =		generic_read_dir,
44 	.iterate_shared=jffs2_readdir,
45 	.unlocked_ioctl=jffs2_ioctl,
46 	.fsync =	jffs2_fsync,
47 	.llseek =	generic_file_llseek,
48 };
49 
50 
51 const struct inode_operations jffs2_dir_inode_operations =
52 {
53 	.create =	jffs2_create,
54 	.lookup =	jffs2_lookup,
55 	.link =		jffs2_link,
56 	.unlink =	jffs2_unlink,
57 	.symlink =	jffs2_symlink,
58 	.mkdir =	jffs2_mkdir,
59 	.rmdir =	jffs2_rmdir,
60 	.mknod =	jffs2_mknod,
61 	.rename =	jffs2_rename,
62 	.get_acl =	jffs2_get_acl,
63 	.set_acl =	jffs2_set_acl,
64 	.setattr =	jffs2_setattr,
65 	.listxattr =	jffs2_listxattr,
66 };
67 
68 /***********************************************************************/
69 
70 
71 /* We keep the dirent list sorted in increasing order of name hash,
72    and we use the same hash function as the dentries. Makes this
73    nice and simple
74 */
75 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
76 				   unsigned int flags)
77 {
78 	struct jffs2_inode_info *dir_f;
79 	struct jffs2_full_dirent *fd = NULL, *fd_list;
80 	uint32_t ino = 0;
81 	struct inode *inode = NULL;
82 	unsigned int nhash;
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 	/* The 'nhash' on the fd_list is not the same as the dentry hash */
92 	nhash = full_name_hash(NULL, target->d_name.name, target->d_name.len);
93 
94 	mutex_lock(&dir_f->sem);
95 
96 	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
97 	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= nhash; fd_list = fd_list->next) {
98 		if (fd_list->nhash == nhash &&
99 		    (!fd || fd_list->version > fd->version) &&
100 		    strlen(fd_list->name) == target->d_name.len &&
101 		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
102 			fd = fd_list;
103 		}
104 	}
105 	if (fd)
106 		ino = fd->ino;
107 	mutex_unlock(&dir_f->sem);
108 	if (ino) {
109 		inode = jffs2_iget(dir_i->i_sb, ino);
110 		if (IS_ERR(inode))
111 			pr_warn("iget() failed for ino #%u\n", ino);
112 	}
113 
114 	return d_splice_alias(inode, target);
115 }
116 
117 /***********************************************************************/
118 
119 
120 static int jffs2_readdir(struct file *file, struct dir_context *ctx)
121 {
122 	struct inode *inode = file_inode(file);
123 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
124 	struct jffs2_full_dirent *fd;
125 	unsigned long curofs = 1;
126 
127 	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino);
128 
129 	if (!dir_emit_dots(file, ctx))
130 		return 0;
131 
132 	mutex_lock(&f->sem);
133 	for (fd = f->dents; fd; fd = fd->next) {
134 		curofs++;
135 		/* First loop: curofs = 2; pos = 2 */
136 		if (curofs < ctx->pos) {
137 			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
138 				  fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);
139 			continue;
140 		}
141 		if (!fd->ino) {
142 			jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
143 				  fd->name);
144 			ctx->pos++;
145 			continue;
146 		}
147 		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
148 			  (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
149 		if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))
150 			break;
151 		ctx->pos++;
152 	}
153 	mutex_unlock(&f->sem);
154 	return 0;
155 }
156 
157 /***********************************************************************/
158 
159 
160 static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
161 			umode_t mode, bool excl)
162 {
163 	struct jffs2_raw_inode *ri;
164 	struct jffs2_inode_info *f, *dir_f;
165 	struct jffs2_sb_info *c;
166 	struct inode *inode;
167 	int ret;
168 
169 	ri = jffs2_alloc_raw_inode();
170 	if (!ri)
171 		return -ENOMEM;
172 
173 	c = JFFS2_SB_INFO(dir_i->i_sb);
174 
175 	jffs2_dbg(1, "%s()\n", __func__);
176 
177 	inode = jffs2_new_inode(dir_i, mode, ri);
178 
179 	if (IS_ERR(inode)) {
180 		jffs2_dbg(1, "jffs2_new_inode() failed\n");
181 		jffs2_free_raw_inode(ri);
182 		return PTR_ERR(inode);
183 	}
184 
185 	inode->i_op = &jffs2_file_inode_operations;
186 	inode->i_fop = &jffs2_file_operations;
187 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
188 	inode->i_mapping->nrpages = 0;
189 
190 	f = JFFS2_INODE_INFO(inode);
191 	dir_f = JFFS2_INODE_INFO(dir_i);
192 
193 	/* jffs2_do_create() will want to lock it, _after_ reserving
194 	   space and taking c-alloc_sem. If we keep it locked here,
195 	   lockdep gets unhappy (although it's a false positive;
196 	   nothing else will be looking at this inode yet so there's
197 	   no chance of AB-BA deadlock involving its f->sem). */
198 	mutex_unlock(&f->sem);
199 
200 	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
201 	if (ret)
202 		goto fail;
203 
204 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
205 
206 	jffs2_free_raw_inode(ri);
207 
208 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
209 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
210 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
211 
212 	unlock_new_inode(inode);
213 	d_instantiate(dentry, inode);
214 	return 0;
215 
216  fail:
217 	iget_failed(inode);
218 	jffs2_free_raw_inode(ri);
219 	return ret;
220 }
221 
222 /***********************************************************************/
223 
224 
225 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
226 {
227 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
228 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
229 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
230 	int ret;
231 	uint32_t now = get_seconds();
232 
233 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
234 			      dentry->d_name.len, dead_f, now);
235 	if (dead_f->inocache)
236 		set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
237 	if (!ret)
238 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
239 	return ret;
240 }
241 /***********************************************************************/
242 
243 
244 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
245 {
246 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb);
247 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
248 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
249 	int ret;
250 	uint8_t type;
251 	uint32_t now;
252 
253 	/* Don't let people make hard links to bad inodes. */
254 	if (!f->inocache)
255 		return -EIO;
256 
257 	if (d_is_dir(old_dentry))
258 		return -EPERM;
259 
260 	/* XXX: This is ugly */
261 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
262 	if (!type) type = DT_REG;
263 
264 	now = get_seconds();
265 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
266 
267 	if (!ret) {
268 		mutex_lock(&f->sem);
269 		set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
270 		mutex_unlock(&f->sem);
271 		d_instantiate(dentry, d_inode(old_dentry));
272 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
273 		ihold(d_inode(old_dentry));
274 	}
275 	return ret;
276 }
277 
278 /***********************************************************************/
279 
280 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
281 {
282 	struct jffs2_inode_info *f, *dir_f;
283 	struct jffs2_sb_info *c;
284 	struct inode *inode;
285 	struct jffs2_raw_inode *ri;
286 	struct jffs2_raw_dirent *rd;
287 	struct jffs2_full_dnode *fn;
288 	struct jffs2_full_dirent *fd;
289 	int namelen;
290 	uint32_t alloclen;
291 	int ret, targetlen = strlen(target);
292 
293 	/* FIXME: If you care. We'd need to use frags for the target
294 	   if it grows much more than this */
295 	if (targetlen > 254)
296 		return -ENAMETOOLONG;
297 
298 	ri = jffs2_alloc_raw_inode();
299 
300 	if (!ri)
301 		return -ENOMEM;
302 
303 	c = JFFS2_SB_INFO(dir_i->i_sb);
304 
305 	/* Try to reserve enough space for both node and dirent.
306 	 * Just the node will do for now, though
307 	 */
308 	namelen = dentry->d_name.len;
309 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
310 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
311 
312 	if (ret) {
313 		jffs2_free_raw_inode(ri);
314 		return ret;
315 	}
316 
317 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
318 
319 	if (IS_ERR(inode)) {
320 		jffs2_free_raw_inode(ri);
321 		jffs2_complete_reservation(c);
322 		return PTR_ERR(inode);
323 	}
324 
325 	inode->i_op = &jffs2_symlink_inode_operations;
326 
327 	f = JFFS2_INODE_INFO(inode);
328 
329 	inode->i_size = targetlen;
330 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
331 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
332 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
333 
334 	ri->compr = JFFS2_COMPR_NONE;
335 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
336 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
337 
338 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
339 
340 	jffs2_free_raw_inode(ri);
341 
342 	if (IS_ERR(fn)) {
343 		/* Eeek. Wave bye bye */
344 		mutex_unlock(&f->sem);
345 		jffs2_complete_reservation(c);
346 		ret = PTR_ERR(fn);
347 		goto fail;
348 	}
349 
350 	/* We use f->target field to store the target path. */
351 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
352 	if (!f->target) {
353 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
354 		mutex_unlock(&f->sem);
355 		jffs2_complete_reservation(c);
356 		ret = -ENOMEM;
357 		goto fail;
358 	}
359 	inode->i_link = f->target;
360 
361 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
362 		  __func__, (char *)f->target);
363 
364 	/* No data here. Only a metadata node, which will be
365 	   obsoleted by the first data write
366 	*/
367 	f->metadata = fn;
368 	mutex_unlock(&f->sem);
369 
370 	jffs2_complete_reservation(c);
371 
372 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
373 	if (ret)
374 		goto fail;
375 
376 	ret = jffs2_init_acl_post(inode);
377 	if (ret)
378 		goto fail;
379 
380 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
381 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
382 	if (ret)
383 		goto fail;
384 
385 	rd = jffs2_alloc_raw_dirent();
386 	if (!rd) {
387 		/* Argh. Now we treat it like a normal delete */
388 		jffs2_complete_reservation(c);
389 		ret = -ENOMEM;
390 		goto fail;
391 	}
392 
393 	dir_f = JFFS2_INODE_INFO(dir_i);
394 	mutex_lock(&dir_f->sem);
395 
396 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
397 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
398 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
399 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
400 
401 	rd->pino = cpu_to_je32(dir_i->i_ino);
402 	rd->version = cpu_to_je32(++dir_f->highest_version);
403 	rd->ino = cpu_to_je32(inode->i_ino);
404 	rd->mctime = cpu_to_je32(get_seconds());
405 	rd->nsize = namelen;
406 	rd->type = DT_LNK;
407 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
408 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
409 
410 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
411 
412 	if (IS_ERR(fd)) {
413 		/* dirent failed to write. Delete the inode normally
414 		   as if it were the final unlink() */
415 		jffs2_complete_reservation(c);
416 		jffs2_free_raw_dirent(rd);
417 		mutex_unlock(&dir_f->sem);
418 		ret = PTR_ERR(fd);
419 		goto fail;
420 	}
421 
422 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
423 
424 	jffs2_free_raw_dirent(rd);
425 
426 	/* Link the fd into the inode's list, obsoleting an old
427 	   one if necessary. */
428 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
429 
430 	mutex_unlock(&dir_f->sem);
431 	jffs2_complete_reservation(c);
432 
433 	unlock_new_inode(inode);
434 	d_instantiate(dentry, inode);
435 	return 0;
436 
437  fail:
438 	iget_failed(inode);
439 	return ret;
440 }
441 
442 
443 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
444 {
445 	struct jffs2_inode_info *f, *dir_f;
446 	struct jffs2_sb_info *c;
447 	struct inode *inode;
448 	struct jffs2_raw_inode *ri;
449 	struct jffs2_raw_dirent *rd;
450 	struct jffs2_full_dnode *fn;
451 	struct jffs2_full_dirent *fd;
452 	int namelen;
453 	uint32_t alloclen;
454 	int ret;
455 
456 	mode |= S_IFDIR;
457 
458 	ri = jffs2_alloc_raw_inode();
459 	if (!ri)
460 		return -ENOMEM;
461 
462 	c = JFFS2_SB_INFO(dir_i->i_sb);
463 
464 	/* Try to reserve enough space for both node and dirent.
465 	 * Just the node will do for now, though
466 	 */
467 	namelen = dentry->d_name.len;
468 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
469 				  JFFS2_SUMMARY_INODE_SIZE);
470 
471 	if (ret) {
472 		jffs2_free_raw_inode(ri);
473 		return ret;
474 	}
475 
476 	inode = jffs2_new_inode(dir_i, mode, ri);
477 
478 	if (IS_ERR(inode)) {
479 		jffs2_free_raw_inode(ri);
480 		jffs2_complete_reservation(c);
481 		return PTR_ERR(inode);
482 	}
483 
484 	inode->i_op = &jffs2_dir_inode_operations;
485 	inode->i_fop = &jffs2_dir_operations;
486 
487 	f = JFFS2_INODE_INFO(inode);
488 
489 	/* Directories get nlink 2 at start */
490 	set_nlink(inode, 2);
491 	/* but ic->pino_nlink is the parent ino# */
492 	f->inocache->pino_nlink = dir_i->i_ino;
493 
494 	ri->data_crc = cpu_to_je32(0);
495 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
496 
497 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
498 
499 	jffs2_free_raw_inode(ri);
500 
501 	if (IS_ERR(fn)) {
502 		/* Eeek. Wave bye bye */
503 		mutex_unlock(&f->sem);
504 		jffs2_complete_reservation(c);
505 		ret = PTR_ERR(fn);
506 		goto fail;
507 	}
508 	/* No data here. Only a metadata node, which will be
509 	   obsoleted by the first data write
510 	*/
511 	f->metadata = fn;
512 	mutex_unlock(&f->sem);
513 
514 	jffs2_complete_reservation(c);
515 
516 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
517 	if (ret)
518 		goto fail;
519 
520 	ret = jffs2_init_acl_post(inode);
521 	if (ret)
522 		goto fail;
523 
524 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
525 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
526 	if (ret)
527 		goto fail;
528 
529 	rd = jffs2_alloc_raw_dirent();
530 	if (!rd) {
531 		/* Argh. Now we treat it like a normal delete */
532 		jffs2_complete_reservation(c);
533 		ret = -ENOMEM;
534 		goto fail;
535 	}
536 
537 	dir_f = JFFS2_INODE_INFO(dir_i);
538 	mutex_lock(&dir_f->sem);
539 
540 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
541 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
542 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
543 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
544 
545 	rd->pino = cpu_to_je32(dir_i->i_ino);
546 	rd->version = cpu_to_je32(++dir_f->highest_version);
547 	rd->ino = cpu_to_je32(inode->i_ino);
548 	rd->mctime = cpu_to_je32(get_seconds());
549 	rd->nsize = namelen;
550 	rd->type = DT_DIR;
551 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
552 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
553 
554 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
555 
556 	if (IS_ERR(fd)) {
557 		/* dirent failed to write. Delete the inode normally
558 		   as if it were the final unlink() */
559 		jffs2_complete_reservation(c);
560 		jffs2_free_raw_dirent(rd);
561 		mutex_unlock(&dir_f->sem);
562 		ret = PTR_ERR(fd);
563 		goto fail;
564 	}
565 
566 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
567 	inc_nlink(dir_i);
568 
569 	jffs2_free_raw_dirent(rd);
570 
571 	/* Link the fd into the inode's list, obsoleting an old
572 	   one if necessary. */
573 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
574 
575 	mutex_unlock(&dir_f->sem);
576 	jffs2_complete_reservation(c);
577 
578 	unlock_new_inode(inode);
579 	d_instantiate(dentry, inode);
580 	return 0;
581 
582  fail:
583 	iget_failed(inode);
584 	return ret;
585 }
586 
587 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
588 {
589 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
590 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
591 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
592 	struct jffs2_full_dirent *fd;
593 	int ret;
594 	uint32_t now = get_seconds();
595 
596 	for (fd = f->dents ; fd; fd = fd->next) {
597 		if (fd->ino)
598 			return -ENOTEMPTY;
599 	}
600 
601 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
602 			      dentry->d_name.len, f, now);
603 	if (!ret) {
604 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
605 		clear_nlink(d_inode(dentry));
606 		drop_nlink(dir_i);
607 	}
608 	return ret;
609 }
610 
611 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
612 {
613 	struct jffs2_inode_info *f, *dir_f;
614 	struct jffs2_sb_info *c;
615 	struct inode *inode;
616 	struct jffs2_raw_inode *ri;
617 	struct jffs2_raw_dirent *rd;
618 	struct jffs2_full_dnode *fn;
619 	struct jffs2_full_dirent *fd;
620 	int namelen;
621 	union jffs2_device_node dev;
622 	int devlen = 0;
623 	uint32_t alloclen;
624 	int ret;
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 			 unsigned int flags)
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 	if (flags & ~RENAME_NOREPLACE)
770 		return -EINVAL;
771 
772 	/* The VFS will check for us and prevent trying to rename a
773 	 * file over a directory and vice versa, but if it's a directory,
774 	 * the VFS can't check whether the victim is empty. The filesystem
775 	 * needs to do that for itself.
776 	 */
777 	if (d_really_is_positive(new_dentry)) {
778 		victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
779 		if (d_is_dir(new_dentry)) {
780 			struct jffs2_full_dirent *fd;
781 
782 			mutex_lock(&victim_f->sem);
783 			for (fd = victim_f->dents; fd; fd = fd->next) {
784 				if (fd->ino) {
785 					mutex_unlock(&victim_f->sem);
786 					return -ENOTEMPTY;
787 				}
788 			}
789 			mutex_unlock(&victim_f->sem);
790 		}
791 	}
792 
793 	/* XXX: We probably ought to alloc enough space for
794 	   both nodes at the same time. Writing the new link,
795 	   then getting -ENOSPC, is quite bad :)
796 	*/
797 
798 	/* Make a hard link */
799 
800 	/* XXX: This is ugly */
801 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
802 	if (!type) type = DT_REG;
803 
804 	now = get_seconds();
805 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
806 			    d_inode(old_dentry)->i_ino, type,
807 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
808 
809 	if (ret)
810 		return ret;
811 
812 	if (victim_f) {
813 		/* There was a victim. Kill it off nicely */
814 		if (d_is_dir(new_dentry))
815 			clear_nlink(d_inode(new_dentry));
816 		else
817 			drop_nlink(d_inode(new_dentry));
818 		/* Don't oops if the victim was a dirent pointing to an
819 		   inode which didn't exist. */
820 		if (victim_f->inocache) {
821 			mutex_lock(&victim_f->sem);
822 			if (d_is_dir(new_dentry))
823 				victim_f->inocache->pino_nlink = 0;
824 			else
825 				victim_f->inocache->pino_nlink--;
826 			mutex_unlock(&victim_f->sem);
827 		}
828 	}
829 
830 	/* If it was a directory we moved, and there was no victim,
831 	   increase i_nlink on its new parent */
832 	if (d_is_dir(old_dentry) && !victim_f)
833 		inc_nlink(new_dir_i);
834 
835 	/* Unlink the original */
836 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
837 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
838 
839 	/* We don't touch inode->i_nlink */
840 
841 	if (ret) {
842 		/* Oh shit. We really ought to make a single node which can do both atomically */
843 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
844 		mutex_lock(&f->sem);
845 		inc_nlink(d_inode(old_dentry));
846 		if (f->inocache && !d_is_dir(old_dentry))
847 			f->inocache->pino_nlink++;
848 		mutex_unlock(&f->sem);
849 
850 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
851 			  __func__, ret);
852 		/*
853 		 * We can't keep the target in dcache after that.
854 		 * For one thing, we can't afford dentry aliases for directories.
855 		 * For another, if there was a victim, we _can't_ set new inode
856 		 * for that sucker and we have to trigger mount eviction - the
857 		 * caller won't do it on its own since we are returning an error.
858 		 */
859 		d_invalidate(new_dentry);
860 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
861 		return ret;
862 	}
863 
864 	if (d_is_dir(old_dentry))
865 		drop_nlink(old_dir_i);
866 
867 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
868 
869 	return 0;
870 }
871 
872