xref: /openbmc/linux/fs/jffs2/dir.c (revision 18afb028)
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 mnt_idmap *, struct inode *,
28 		         struct dentry *, umode_t, 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 mnt_idmap *, struct inode *,
34 			  struct dentry *, const char *);
35 static int jffs2_mkdir (struct mnt_idmap *, struct inode *,struct dentry *,
36 			umode_t);
37 static int jffs2_rmdir (struct inode *,struct dentry *);
38 static int jffs2_mknod (struct mnt_idmap *, struct inode *,struct dentry *,
39 			umode_t,dev_t);
40 static int jffs2_rename (struct mnt_idmap *, struct inode *,
41 			 struct dentry *, struct inode *, struct dentry *,
42 			 unsigned int);
43 
44 const struct file_operations jffs2_dir_operations =
45 {
46 	.read =		generic_read_dir,
47 	.iterate_shared=jffs2_readdir,
48 	.unlocked_ioctl=jffs2_ioctl,
49 	.fsync =	jffs2_fsync,
50 	.llseek =	generic_file_llseek,
51 };
52 
53 
54 const struct inode_operations jffs2_dir_inode_operations =
55 {
56 	.create =	jffs2_create,
57 	.lookup =	jffs2_lookup,
58 	.link =		jffs2_link,
59 	.unlink =	jffs2_unlink,
60 	.symlink =	jffs2_symlink,
61 	.mkdir =	jffs2_mkdir,
62 	.rmdir =	jffs2_rmdir,
63 	.mknod =	jffs2_mknod,
64 	.rename =	jffs2_rename,
65 	.get_inode_acl =	jffs2_get_acl,
66 	.set_acl =	jffs2_set_acl,
67 	.setattr =	jffs2_setattr,
68 	.listxattr =	jffs2_listxattr,
69 };
70 
71 /***********************************************************************/
72 
73 
74 /* We keep the dirent list sorted in increasing order of name hash,
75    and we use the same hash function as the dentries. Makes this
76    nice and simple
77 */
78 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
79 				   unsigned int flags)
80 {
81 	struct jffs2_inode_info *dir_f;
82 	struct jffs2_full_dirent *fd = NULL, *fd_list;
83 	uint32_t ino = 0;
84 	struct inode *inode = NULL;
85 	unsigned int nhash;
86 
87 	jffs2_dbg(1, "jffs2_lookup()\n");
88 
89 	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
90 		return ERR_PTR(-ENAMETOOLONG);
91 
92 	dir_f = JFFS2_INODE_INFO(dir_i);
93 
94 	/* The 'nhash' on the fd_list is not the same as the dentry hash */
95 	nhash = full_name_hash(NULL, target->d_name.name, target->d_name.len);
96 
97 	mutex_lock(&dir_f->sem);
98 
99 	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
100 	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= nhash; fd_list = fd_list->next) {
101 		if (fd_list->nhash == nhash &&
102 		    (!fd || fd_list->version > fd->version) &&
103 		    strlen(fd_list->name) == target->d_name.len &&
104 		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
105 			fd = fd_list;
106 		}
107 	}
108 	if (fd)
109 		ino = fd->ino;
110 	mutex_unlock(&dir_f->sem);
111 	if (ino) {
112 		inode = jffs2_iget(dir_i->i_sb, ino);
113 		if (IS_ERR(inode))
114 			pr_warn("iget() failed for ino #%u\n", ino);
115 	}
116 
117 	return d_splice_alias(inode, target);
118 }
119 
120 /***********************************************************************/
121 
122 
123 static int jffs2_readdir(struct file *file, struct dir_context *ctx)
124 {
125 	struct inode *inode = file_inode(file);
126 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
127 	struct jffs2_full_dirent *fd;
128 	unsigned long curofs = 1;
129 
130 	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino);
131 
132 	if (!dir_emit_dots(file, ctx))
133 		return 0;
134 
135 	mutex_lock(&f->sem);
136 	for (fd = f->dents; fd; fd = fd->next) {
137 		curofs++;
138 		/* First loop: curofs = 2; pos = 2 */
139 		if (curofs < ctx->pos) {
140 			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
141 				  fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);
142 			continue;
143 		}
144 		if (!fd->ino) {
145 			jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
146 				  fd->name);
147 			ctx->pos++;
148 			continue;
149 		}
150 		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
151 			  (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
152 		if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))
153 			break;
154 		ctx->pos++;
155 	}
156 	mutex_unlock(&f->sem);
157 	return 0;
158 }
159 
160 /***********************************************************************/
161 
162 
163 static int jffs2_create(struct mnt_idmap *idmap, struct inode *dir_i,
164 			struct dentry *dentry, umode_t mode, bool excl)
165 {
166 	struct jffs2_raw_inode *ri;
167 	struct jffs2_inode_info *f, *dir_f;
168 	struct jffs2_sb_info *c;
169 	struct inode *inode;
170 	int ret;
171 
172 	ri = jffs2_alloc_raw_inode();
173 	if (!ri)
174 		return -ENOMEM;
175 
176 	c = JFFS2_SB_INFO(dir_i->i_sb);
177 
178 	jffs2_dbg(1, "%s()\n", __func__);
179 
180 	inode = jffs2_new_inode(dir_i, mode, ri);
181 
182 	if (IS_ERR(inode)) {
183 		jffs2_dbg(1, "jffs2_new_inode() failed\n");
184 		jffs2_free_raw_inode(ri);
185 		return PTR_ERR(inode);
186 	}
187 
188 	inode->i_op = &jffs2_file_inode_operations;
189 	inode->i_fop = &jffs2_file_operations;
190 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
191 	inode->i_mapping->nrpages = 0;
192 
193 	f = JFFS2_INODE_INFO(inode);
194 	dir_f = JFFS2_INODE_INFO(dir_i);
195 
196 	/* jffs2_do_create() will want to lock it, _after_ reserving
197 	   space and taking c-alloc_sem. If we keep it locked here,
198 	   lockdep gets unhappy (although it's a false positive;
199 	   nothing else will be looking at this inode yet so there's
200 	   no chance of AB-BA deadlock involving its f->sem). */
201 	mutex_unlock(&f->sem);
202 
203 	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
204 	if (ret)
205 		goto fail;
206 
207 	dir_i->i_mtime = inode_set_ctime_to_ts(dir_i,
208 					       ITIME(je32_to_cpu(ri->ctime)));
209 
210 	jffs2_free_raw_inode(ri);
211 
212 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
213 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
214 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
215 
216 	d_instantiate_new(dentry, inode);
217 	return 0;
218 
219  fail:
220 	iget_failed(inode);
221 	jffs2_free_raw_inode(ri);
222 	return ret;
223 }
224 
225 /***********************************************************************/
226 
227 
228 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
229 {
230 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
231 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
232 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
233 	int ret;
234 	uint32_t now = JFFS2_NOW();
235 
236 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
237 			      dentry->d_name.len, dead_f, now);
238 	if (dead_f->inocache)
239 		set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
240 	if (!ret)
241 		dir_i->i_mtime = inode_set_ctime_to_ts(dir_i, ITIME(now));
242 	return ret;
243 }
244 /***********************************************************************/
245 
246 
247 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
248 {
249 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb);
250 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
251 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
252 	int ret;
253 	uint8_t type;
254 	uint32_t now;
255 
256 	/* Don't let people make hard links to bad inodes. */
257 	if (!f->inocache)
258 		return -EIO;
259 
260 	if (d_is_dir(old_dentry))
261 		return -EPERM;
262 
263 	/* XXX: This is ugly */
264 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
265 	if (!type) type = DT_REG;
266 
267 	now = JFFS2_NOW();
268 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
269 
270 	if (!ret) {
271 		mutex_lock(&f->sem);
272 		set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
273 		mutex_unlock(&f->sem);
274 		d_instantiate(dentry, d_inode(old_dentry));
275 		dir_i->i_mtime = inode_set_ctime_to_ts(dir_i, ITIME(now));
276 		ihold(d_inode(old_dentry));
277 	}
278 	return ret;
279 }
280 
281 /***********************************************************************/
282 
283 static int jffs2_symlink (struct mnt_idmap *idmap, struct inode *dir_i,
284 			  struct dentry *dentry, const char *target)
285 {
286 	struct jffs2_inode_info *f, *dir_f;
287 	struct jffs2_sb_info *c;
288 	struct inode *inode;
289 	struct jffs2_raw_inode *ri;
290 	struct jffs2_raw_dirent *rd;
291 	struct jffs2_full_dnode *fn;
292 	struct jffs2_full_dirent *fd;
293 	int namelen;
294 	uint32_t alloclen;
295 	int ret, targetlen = strlen(target);
296 
297 	/* FIXME: If you care. We'd need to use frags for the target
298 	   if it grows much more than this */
299 	if (targetlen > 254)
300 		return -ENAMETOOLONG;
301 
302 	ri = jffs2_alloc_raw_inode();
303 
304 	if (!ri)
305 		return -ENOMEM;
306 
307 	c = JFFS2_SB_INFO(dir_i->i_sb);
308 
309 	/* Try to reserve enough space for both node and dirent.
310 	 * Just the node will do for now, though
311 	 */
312 	namelen = dentry->d_name.len;
313 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
314 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
315 
316 	if (ret) {
317 		jffs2_free_raw_inode(ri);
318 		return ret;
319 	}
320 
321 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
322 
323 	if (IS_ERR(inode)) {
324 		jffs2_free_raw_inode(ri);
325 		jffs2_complete_reservation(c);
326 		return PTR_ERR(inode);
327 	}
328 
329 	inode->i_op = &jffs2_symlink_inode_operations;
330 
331 	f = JFFS2_INODE_INFO(inode);
332 
333 	inode->i_size = targetlen;
334 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
335 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
336 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
337 
338 	ri->compr = JFFS2_COMPR_NONE;
339 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
340 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
341 
342 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
343 
344 	jffs2_free_raw_inode(ri);
345 
346 	if (IS_ERR(fn)) {
347 		/* Eeek. Wave bye bye */
348 		mutex_unlock(&f->sem);
349 		jffs2_complete_reservation(c);
350 		ret = PTR_ERR(fn);
351 		goto fail;
352 	}
353 
354 	/* We use f->target field to store the target path. */
355 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
356 	if (!f->target) {
357 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
358 		mutex_unlock(&f->sem);
359 		jffs2_complete_reservation(c);
360 		ret = -ENOMEM;
361 		goto fail;
362 	}
363 	inode->i_link = f->target;
364 
365 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
366 		  __func__, (char *)f->target);
367 
368 	/* No data here. Only a metadata node, which will be
369 	   obsoleted by the first data write
370 	*/
371 	f->metadata = fn;
372 	mutex_unlock(&f->sem);
373 
374 	jffs2_complete_reservation(c);
375 
376 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
377 	if (ret)
378 		goto fail;
379 
380 	ret = jffs2_init_acl_post(inode);
381 	if (ret)
382 		goto fail;
383 
384 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
385 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
386 	if (ret)
387 		goto fail;
388 
389 	rd = jffs2_alloc_raw_dirent();
390 	if (!rd) {
391 		/* Argh. Now we treat it like a normal delete */
392 		jffs2_complete_reservation(c);
393 		ret = -ENOMEM;
394 		goto fail;
395 	}
396 
397 	dir_f = JFFS2_INODE_INFO(dir_i);
398 	mutex_lock(&dir_f->sem);
399 
400 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
401 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
402 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
403 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
404 
405 	rd->pino = cpu_to_je32(dir_i->i_ino);
406 	rd->version = cpu_to_je32(++dir_f->highest_version);
407 	rd->ino = cpu_to_je32(inode->i_ino);
408 	rd->mctime = cpu_to_je32(JFFS2_NOW());
409 	rd->nsize = namelen;
410 	rd->type = DT_LNK;
411 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
412 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
413 
414 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
415 
416 	if (IS_ERR(fd)) {
417 		/* dirent failed to write. Delete the inode normally
418 		   as if it were the final unlink() */
419 		jffs2_complete_reservation(c);
420 		jffs2_free_raw_dirent(rd);
421 		mutex_unlock(&dir_f->sem);
422 		ret = PTR_ERR(fd);
423 		goto fail;
424 	}
425 
426 	dir_i->i_mtime = inode_set_ctime_to_ts(dir_i,
427 					       ITIME(je32_to_cpu(rd->mctime)));
428 
429 	jffs2_free_raw_dirent(rd);
430 
431 	/* Link the fd into the inode's list, obsoleting an old
432 	   one if necessary. */
433 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
434 
435 	mutex_unlock(&dir_f->sem);
436 	jffs2_complete_reservation(c);
437 
438 	d_instantiate_new(dentry, inode);
439 	return 0;
440 
441  fail:
442 	iget_failed(inode);
443 	return ret;
444 }
445 
446 
447 static int jffs2_mkdir (struct mnt_idmap *idmap, struct inode *dir_i,
448 		        struct dentry *dentry, umode_t mode)
449 {
450 	struct jffs2_inode_info *f, *dir_f;
451 	struct jffs2_sb_info *c;
452 	struct inode *inode;
453 	struct jffs2_raw_inode *ri;
454 	struct jffs2_raw_dirent *rd;
455 	struct jffs2_full_dnode *fn;
456 	struct jffs2_full_dirent *fd;
457 	int namelen;
458 	uint32_t alloclen;
459 	int ret;
460 
461 	mode |= S_IFDIR;
462 
463 	ri = jffs2_alloc_raw_inode();
464 	if (!ri)
465 		return -ENOMEM;
466 
467 	c = JFFS2_SB_INFO(dir_i->i_sb);
468 
469 	/* Try to reserve enough space for both node and dirent.
470 	 * Just the node will do for now, though
471 	 */
472 	namelen = dentry->d_name.len;
473 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
474 				  JFFS2_SUMMARY_INODE_SIZE);
475 
476 	if (ret) {
477 		jffs2_free_raw_inode(ri);
478 		return ret;
479 	}
480 
481 	inode = jffs2_new_inode(dir_i, mode, ri);
482 
483 	if (IS_ERR(inode)) {
484 		jffs2_free_raw_inode(ri);
485 		jffs2_complete_reservation(c);
486 		return PTR_ERR(inode);
487 	}
488 
489 	inode->i_op = &jffs2_dir_inode_operations;
490 	inode->i_fop = &jffs2_dir_operations;
491 
492 	f = JFFS2_INODE_INFO(inode);
493 
494 	/* Directories get nlink 2 at start */
495 	set_nlink(inode, 2);
496 	/* but ic->pino_nlink is the parent ino# */
497 	f->inocache->pino_nlink = dir_i->i_ino;
498 
499 	ri->data_crc = cpu_to_je32(0);
500 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
501 
502 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
503 
504 	jffs2_free_raw_inode(ri);
505 
506 	if (IS_ERR(fn)) {
507 		/* Eeek. Wave bye bye */
508 		mutex_unlock(&f->sem);
509 		jffs2_complete_reservation(c);
510 		ret = PTR_ERR(fn);
511 		goto fail;
512 	}
513 	/* No data here. Only a metadata node, which will be
514 	   obsoleted by the first data write
515 	*/
516 	f->metadata = fn;
517 	mutex_unlock(&f->sem);
518 
519 	jffs2_complete_reservation(c);
520 
521 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
522 	if (ret)
523 		goto fail;
524 
525 	ret = jffs2_init_acl_post(inode);
526 	if (ret)
527 		goto fail;
528 
529 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
530 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
531 	if (ret)
532 		goto fail;
533 
534 	rd = jffs2_alloc_raw_dirent();
535 	if (!rd) {
536 		/* Argh. Now we treat it like a normal delete */
537 		jffs2_complete_reservation(c);
538 		ret = -ENOMEM;
539 		goto fail;
540 	}
541 
542 	dir_f = JFFS2_INODE_INFO(dir_i);
543 	mutex_lock(&dir_f->sem);
544 
545 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
546 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
547 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
548 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
549 
550 	rd->pino = cpu_to_je32(dir_i->i_ino);
551 	rd->version = cpu_to_je32(++dir_f->highest_version);
552 	rd->ino = cpu_to_je32(inode->i_ino);
553 	rd->mctime = cpu_to_je32(JFFS2_NOW());
554 	rd->nsize = namelen;
555 	rd->type = DT_DIR;
556 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
557 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
558 
559 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
560 
561 	if (IS_ERR(fd)) {
562 		/* dirent failed to write. Delete the inode normally
563 		   as if it were the final unlink() */
564 		jffs2_complete_reservation(c);
565 		jffs2_free_raw_dirent(rd);
566 		mutex_unlock(&dir_f->sem);
567 		ret = PTR_ERR(fd);
568 		goto fail;
569 	}
570 
571 	dir_i->i_mtime = inode_set_ctime_to_ts(dir_i,
572 					       ITIME(je32_to_cpu(rd->mctime)));
573 	inc_nlink(dir_i);
574 
575 	jffs2_free_raw_dirent(rd);
576 
577 	/* Link the fd into the inode's list, obsoleting an old
578 	   one if necessary. */
579 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
580 
581 	mutex_unlock(&dir_f->sem);
582 	jffs2_complete_reservation(c);
583 
584 	d_instantiate_new(dentry, inode);
585 	return 0;
586 
587  fail:
588 	iget_failed(inode);
589 	return ret;
590 }
591 
592 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
593 {
594 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
595 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
596 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
597 	struct jffs2_full_dirent *fd;
598 	int ret;
599 	uint32_t now = JFFS2_NOW();
600 
601 	mutex_lock(&f->sem);
602 	for (fd = f->dents ; fd; fd = fd->next) {
603 		if (fd->ino) {
604 			mutex_unlock(&f->sem);
605 			return -ENOTEMPTY;
606 		}
607 	}
608 	mutex_unlock(&f->sem);
609 
610 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
611 			      dentry->d_name.len, f, now);
612 	if (!ret) {
613 		dir_i->i_mtime = inode_set_ctime_to_ts(dir_i, ITIME(now));
614 		clear_nlink(d_inode(dentry));
615 		drop_nlink(dir_i);
616 	}
617 	return ret;
618 }
619 
620 static int jffs2_mknod (struct mnt_idmap *idmap, struct inode *dir_i,
621 		        struct dentry *dentry, umode_t mode, dev_t rdev)
622 {
623 	struct jffs2_inode_info *f, *dir_f;
624 	struct jffs2_sb_info *c;
625 	struct inode *inode;
626 	struct jffs2_raw_inode *ri;
627 	struct jffs2_raw_dirent *rd;
628 	struct jffs2_full_dnode *fn;
629 	struct jffs2_full_dirent *fd;
630 	int namelen;
631 	union jffs2_device_node dev;
632 	int devlen = 0;
633 	uint32_t alloclen;
634 	int ret;
635 
636 	ri = jffs2_alloc_raw_inode();
637 	if (!ri)
638 		return -ENOMEM;
639 
640 	c = JFFS2_SB_INFO(dir_i->i_sb);
641 
642 	if (S_ISBLK(mode) || S_ISCHR(mode))
643 		devlen = jffs2_encode_dev(&dev, rdev);
644 
645 	/* Try to reserve enough space for both node and dirent.
646 	 * Just the node will do for now, though
647 	 */
648 	namelen = dentry->d_name.len;
649 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
650 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
651 
652 	if (ret) {
653 		jffs2_free_raw_inode(ri);
654 		return ret;
655 	}
656 
657 	inode = jffs2_new_inode(dir_i, mode, ri);
658 
659 	if (IS_ERR(inode)) {
660 		jffs2_free_raw_inode(ri);
661 		jffs2_complete_reservation(c);
662 		return PTR_ERR(inode);
663 	}
664 	inode->i_op = &jffs2_file_inode_operations;
665 	init_special_inode(inode, inode->i_mode, rdev);
666 
667 	f = JFFS2_INODE_INFO(inode);
668 
669 	ri->dsize = ri->csize = cpu_to_je32(devlen);
670 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
671 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
672 
673 	ri->compr = JFFS2_COMPR_NONE;
674 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
675 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
676 
677 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
678 
679 	jffs2_free_raw_inode(ri);
680 
681 	if (IS_ERR(fn)) {
682 		/* Eeek. Wave bye bye */
683 		mutex_unlock(&f->sem);
684 		jffs2_complete_reservation(c);
685 		ret = PTR_ERR(fn);
686 		goto fail;
687 	}
688 	/* No data here. Only a metadata node, which will be
689 	   obsoleted by the first data write
690 	*/
691 	f->metadata = fn;
692 	mutex_unlock(&f->sem);
693 
694 	jffs2_complete_reservation(c);
695 
696 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
697 	if (ret)
698 		goto fail;
699 
700 	ret = jffs2_init_acl_post(inode);
701 	if (ret)
702 		goto fail;
703 
704 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
705 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
706 	if (ret)
707 		goto fail;
708 
709 	rd = jffs2_alloc_raw_dirent();
710 	if (!rd) {
711 		/* Argh. Now we treat it like a normal delete */
712 		jffs2_complete_reservation(c);
713 		ret = -ENOMEM;
714 		goto fail;
715 	}
716 
717 	dir_f = JFFS2_INODE_INFO(dir_i);
718 	mutex_lock(&dir_f->sem);
719 
720 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
721 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
722 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
723 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
724 
725 	rd->pino = cpu_to_je32(dir_i->i_ino);
726 	rd->version = cpu_to_je32(++dir_f->highest_version);
727 	rd->ino = cpu_to_je32(inode->i_ino);
728 	rd->mctime = cpu_to_je32(JFFS2_NOW());
729 	rd->nsize = namelen;
730 
731 	/* XXX: This is ugly. */
732 	rd->type = (mode & S_IFMT) >> 12;
733 
734 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
735 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
736 
737 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
738 
739 	if (IS_ERR(fd)) {
740 		/* dirent failed to write. Delete the inode normally
741 		   as if it were the final unlink() */
742 		jffs2_complete_reservation(c);
743 		jffs2_free_raw_dirent(rd);
744 		mutex_unlock(&dir_f->sem);
745 		ret = PTR_ERR(fd);
746 		goto fail;
747 	}
748 
749 	dir_i->i_mtime = inode_set_ctime_to_ts(dir_i,
750 					       ITIME(je32_to_cpu(rd->mctime)));
751 
752 	jffs2_free_raw_dirent(rd);
753 
754 	/* Link the fd into the inode's list, obsoleting an old
755 	   one if necessary. */
756 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
757 
758 	mutex_unlock(&dir_f->sem);
759 	jffs2_complete_reservation(c);
760 
761 	d_instantiate_new(dentry, inode);
762 	return 0;
763 
764  fail:
765 	iget_failed(inode);
766 	return ret;
767 }
768 
769 static int jffs2_rename (struct mnt_idmap *idmap,
770 			 struct inode *old_dir_i, struct dentry *old_dentry,
771 			 struct inode *new_dir_i, struct dentry *new_dentry,
772 			 unsigned int flags)
773 {
774 	int ret;
775 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
776 	struct jffs2_inode_info *victim_f = NULL;
777 	uint8_t type;
778 	uint32_t now;
779 
780 	if (flags & ~RENAME_NOREPLACE)
781 		return -EINVAL;
782 
783 	/* The VFS will check for us and prevent trying to rename a
784 	 * file over a directory and vice versa, but if it's a directory,
785 	 * the VFS can't check whether the victim is empty. The filesystem
786 	 * needs to do that for itself.
787 	 */
788 	if (d_really_is_positive(new_dentry)) {
789 		victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
790 		if (d_is_dir(new_dentry)) {
791 			struct jffs2_full_dirent *fd;
792 
793 			mutex_lock(&victim_f->sem);
794 			for (fd = victim_f->dents; fd; fd = fd->next) {
795 				if (fd->ino) {
796 					mutex_unlock(&victim_f->sem);
797 					return -ENOTEMPTY;
798 				}
799 			}
800 			mutex_unlock(&victim_f->sem);
801 		}
802 	}
803 
804 	/* XXX: We probably ought to alloc enough space for
805 	   both nodes at the same time. Writing the new link,
806 	   then getting -ENOSPC, is quite bad :)
807 	*/
808 
809 	/* Make a hard link */
810 
811 	/* XXX: This is ugly */
812 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
813 	if (!type) type = DT_REG;
814 
815 	now = JFFS2_NOW();
816 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
817 			    d_inode(old_dentry)->i_ino, type,
818 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
819 
820 	if (ret)
821 		return ret;
822 
823 	if (victim_f) {
824 		/* There was a victim. Kill it off nicely */
825 		if (d_is_dir(new_dentry))
826 			clear_nlink(d_inode(new_dentry));
827 		else
828 			drop_nlink(d_inode(new_dentry));
829 		/* Don't oops if the victim was a dirent pointing to an
830 		   inode which didn't exist. */
831 		if (victim_f->inocache) {
832 			mutex_lock(&victim_f->sem);
833 			if (d_is_dir(new_dentry))
834 				victim_f->inocache->pino_nlink = 0;
835 			else
836 				victim_f->inocache->pino_nlink--;
837 			mutex_unlock(&victim_f->sem);
838 		}
839 	}
840 
841 	/* If it was a directory we moved, and there was no victim,
842 	   increase i_nlink on its new parent */
843 	if (d_is_dir(old_dentry) && !victim_f)
844 		inc_nlink(new_dir_i);
845 
846 	/* Unlink the original */
847 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
848 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
849 
850 	/* We don't touch inode->i_nlink */
851 
852 	if (ret) {
853 		/* Oh shit. We really ought to make a single node which can do both atomically */
854 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
855 		mutex_lock(&f->sem);
856 		inc_nlink(d_inode(old_dentry));
857 		if (f->inocache && !d_is_dir(old_dentry))
858 			f->inocache->pino_nlink++;
859 		mutex_unlock(&f->sem);
860 
861 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
862 			  __func__, ret);
863 		/*
864 		 * We can't keep the target in dcache after that.
865 		 * For one thing, we can't afford dentry aliases for directories.
866 		 * For another, if there was a victim, we _can't_ set new inode
867 		 * for that sucker and we have to trigger mount eviction - the
868 		 * caller won't do it on its own since we are returning an error.
869 		 */
870 		d_invalidate(new_dentry);
871 		new_dir_i->i_mtime = inode_set_ctime_to_ts(new_dir_i,
872 							   ITIME(now));
873 		return ret;
874 	}
875 
876 	if (d_is_dir(old_dentry))
877 		drop_nlink(old_dir_i);
878 
879 	old_dir_i->i_mtime = inode_set_ctime_to_ts(old_dir_i, ITIME(now));
880 	new_dir_i->i_mtime = inode_set_ctime_to_ts(new_dir_i, ITIME(now));
881 
882 	return 0;
883 }
884 
885