xref: /linux/fs/jffs2/dir.c (revision 69050f8d6d075dc01af7a5f2f550a8067510366f)
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/filelock.h>
19 #include <linux/crc32.h>
20 #include <linux/jffs2.h>
21 #include "jffs2_fs_i.h"
22 #include "jffs2_fs_sb.h"
23 #include <linux/time.h>
24 #include "nodelist.h"
25 
26 static int jffs2_readdir (struct file *, struct dir_context *);
27 
28 static int jffs2_create (struct mnt_idmap *, struct inode *,
29 		         struct dentry *, umode_t, bool);
30 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
31 				    unsigned int);
32 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
33 static int jffs2_unlink (struct inode *,struct dentry *);
34 static int jffs2_symlink (struct mnt_idmap *, struct inode *,
35 			  struct dentry *, const char *);
36 static struct dentry *jffs2_mkdir (struct mnt_idmap *, struct inode *,struct dentry *,
37 				   umode_t);
38 static int jffs2_rmdir (struct inode *,struct dentry *);
39 static int jffs2_mknod (struct mnt_idmap *, struct inode *,struct dentry *,
40 			umode_t,dev_t);
41 static int jffs2_rename (struct mnt_idmap *, struct inode *,
42 			 struct dentry *, struct inode *, struct dentry *,
43 			 unsigned int);
44 
45 const struct file_operations jffs2_dir_operations =
46 {
47 	.read =		generic_read_dir,
48 	.iterate_shared=jffs2_readdir,
49 	.unlocked_ioctl=jffs2_ioctl,
50 	.fsync =	jffs2_fsync,
51 	.llseek =	generic_file_llseek,
52 	.setlease =	generic_setlease,
53 };
54 
55 
56 const struct inode_operations jffs2_dir_inode_operations =
57 {
58 	.create =	jffs2_create,
59 	.lookup =	jffs2_lookup,
60 	.link =		jffs2_link,
61 	.unlink =	jffs2_unlink,
62 	.symlink =	jffs2_symlink,
63 	.mkdir =	jffs2_mkdir,
64 	.rmdir =	jffs2_rmdir,
65 	.mknod =	jffs2_mknod,
66 	.rename =	jffs2_rename,
67 	.get_inode_acl =	jffs2_get_acl,
68 	.set_acl =	jffs2_set_acl,
69 	.setattr =	jffs2_setattr,
70 	.listxattr =	jffs2_listxattr,
71 };
72 
73 /***********************************************************************/
74 
75 
76 /* We keep the dirent list sorted in increasing order of name hash,
77    and we use the same hash function as the dentries. Makes this
78    nice and simple
79 */
80 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
81 				   unsigned int flags)
82 {
83 	struct jffs2_inode_info *dir_f;
84 	struct jffs2_full_dirent *fd = NULL, *fd_list;
85 	uint32_t ino = 0;
86 	struct inode *inode = NULL;
87 	unsigned int nhash;
88 
89 	jffs2_dbg(1, "jffs2_lookup()\n");
90 
91 	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
92 		return ERR_PTR(-ENAMETOOLONG);
93 
94 	dir_f = JFFS2_INODE_INFO(dir_i);
95 
96 	/* The 'nhash' on the fd_list is not the same as the dentry hash */
97 	nhash = full_name_hash(NULL, target->d_name.name, target->d_name.len);
98 
99 	mutex_lock(&dir_f->sem);
100 
101 	/* NB: The 2.2 backport will need to explicitly check for '.' and '..' here */
102 	for (fd_list = dir_f->dents; fd_list && fd_list->nhash <= nhash; fd_list = fd_list->next) {
103 		if (fd_list->nhash == nhash &&
104 		    (!fd || fd_list->version > fd->version) &&
105 		    strlen(fd_list->name) == target->d_name.len &&
106 		    !strncmp(fd_list->name, target->d_name.name, target->d_name.len)) {
107 			fd = fd_list;
108 		}
109 	}
110 	if (fd)
111 		ino = fd->ino;
112 	mutex_unlock(&dir_f->sem);
113 	if (ino) {
114 		inode = jffs2_iget(dir_i->i_sb, ino);
115 		if (IS_ERR(inode))
116 			pr_warn("iget() failed for ino #%u\n", ino);
117 	}
118 
119 	return d_splice_alias(inode, target);
120 }
121 
122 /***********************************************************************/
123 
124 
125 static int jffs2_readdir(struct file *file, struct dir_context *ctx)
126 {
127 	struct inode *inode = file_inode(file);
128 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
129 	struct jffs2_full_dirent *fd;
130 	unsigned long curofs = 1;
131 
132 	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino);
133 
134 	if (!dir_emit_dots(file, ctx))
135 		return 0;
136 
137 	mutex_lock(&f->sem);
138 	for (fd = f->dents; fd; fd = fd->next) {
139 		curofs++;
140 		/* First loop: curofs = 2; pos = 2 */
141 		if (curofs < ctx->pos) {
142 			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
143 				  fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);
144 			continue;
145 		}
146 		if (!fd->ino) {
147 			jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
148 				  fd->name);
149 			ctx->pos++;
150 			continue;
151 		}
152 		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
153 			  (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
154 		if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))
155 			break;
156 		ctx->pos++;
157 	}
158 	mutex_unlock(&f->sem);
159 	return 0;
160 }
161 
162 /***********************************************************************/
163 
164 
165 static int jffs2_create(struct mnt_idmap *idmap, struct inode *dir_i,
166 			struct dentry *dentry, umode_t mode, bool excl)
167 {
168 	struct jffs2_raw_inode *ri;
169 	struct jffs2_inode_info *f, *dir_f;
170 	struct jffs2_sb_info *c;
171 	struct inode *inode;
172 	int ret;
173 
174 	ri = jffs2_alloc_raw_inode();
175 	if (!ri)
176 		return -ENOMEM;
177 
178 	c = JFFS2_SB_INFO(dir_i->i_sb);
179 
180 	jffs2_dbg(1, "%s()\n", __func__);
181 
182 	inode = jffs2_new_inode(dir_i, mode, ri);
183 
184 	if (IS_ERR(inode)) {
185 		jffs2_dbg(1, "jffs2_new_inode() failed\n");
186 		jffs2_free_raw_inode(ri);
187 		return PTR_ERR(inode);
188 	}
189 
190 	inode->i_op = &jffs2_file_inode_operations;
191 	inode->i_fop = &jffs2_file_operations;
192 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
193 	inode->i_mapping->nrpages = 0;
194 
195 	f = JFFS2_INODE_INFO(inode);
196 	dir_f = JFFS2_INODE_INFO(dir_i);
197 
198 	/* jffs2_do_create() will want to lock it, _after_ reserving
199 	   space and taking c-alloc_sem. If we keep it locked here,
200 	   lockdep gets unhappy (although it's a false positive;
201 	   nothing else will be looking at this inode yet so there's
202 	   no chance of AB-BA deadlock involving its f->sem). */
203 	mutex_unlock(&f->sem);
204 
205 	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
206 	if (ret)
207 		goto fail;
208 
209 	inode_set_mtime_to_ts(dir_i,
210 			      inode_set_ctime_to_ts(dir_i, ITIME(je32_to_cpu(ri->ctime))));
211 
212 	jffs2_free_raw_inode(ri);
213 
214 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
215 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
216 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
217 
218 	d_instantiate_new(dentry, inode);
219 	return 0;
220 
221  fail:
222 	iget_failed(inode);
223 	jffs2_free_raw_inode(ri);
224 	return ret;
225 }
226 
227 /***********************************************************************/
228 
229 
230 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
231 {
232 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
233 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
234 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
235 	int ret;
236 	uint32_t now = JFFS2_NOW();
237 
238 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
239 			      dentry->d_name.len, dead_f, now);
240 	if (dead_f->inocache)
241 		set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
242 	if (!ret)
243 		inode_set_mtime_to_ts(dir_i,
244 				      inode_set_ctime_to_ts(dir_i, ITIME(now)));
245 	return ret;
246 }
247 /***********************************************************************/
248 
249 
250 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
251 {
252 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb);
253 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
254 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
255 	int ret;
256 	uint8_t type;
257 	uint32_t now;
258 
259 	/* Don't let people make hard links to bad inodes. */
260 	if (!f->inocache)
261 		return -EIO;
262 
263 	if (d_is_dir(old_dentry))
264 		return -EPERM;
265 
266 	/* XXX: This is ugly */
267 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
268 	if (!type) type = DT_REG;
269 
270 	now = JFFS2_NOW();
271 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
272 
273 	if (!ret) {
274 		mutex_lock(&f->sem);
275 		set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
276 		mutex_unlock(&f->sem);
277 		d_instantiate(dentry, d_inode(old_dentry));
278 		inode_set_mtime_to_ts(dir_i,
279 				      inode_set_ctime_to_ts(dir_i, ITIME(now)));
280 		ihold(d_inode(old_dentry));
281 	}
282 	return ret;
283 }
284 
285 /***********************************************************************/
286 
287 static int jffs2_symlink (struct mnt_idmap *idmap, struct inode *dir_i,
288 			  struct dentry *dentry, const char *target)
289 {
290 	struct jffs2_inode_info *f, *dir_f;
291 	struct jffs2_sb_info *c;
292 	struct inode *inode;
293 	struct jffs2_raw_inode *ri;
294 	struct jffs2_raw_dirent *rd;
295 	struct jffs2_full_dnode *fn;
296 	struct jffs2_full_dirent *fd;
297 	int namelen;
298 	uint32_t alloclen;
299 	int ret, targetlen = strlen(target);
300 
301 	/* FIXME: If you care. We'd need to use frags for the target
302 	   if it grows much more than this */
303 	if (targetlen > 254)
304 		return -ENAMETOOLONG;
305 
306 	ri = jffs2_alloc_raw_inode();
307 
308 	if (!ri)
309 		return -ENOMEM;
310 
311 	c = JFFS2_SB_INFO(dir_i->i_sb);
312 
313 	/* Try to reserve enough space for both node and dirent.
314 	 * Just the node will do for now, though
315 	 */
316 	namelen = dentry->d_name.len;
317 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
318 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
319 
320 	if (ret) {
321 		jffs2_free_raw_inode(ri);
322 		return ret;
323 	}
324 
325 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
326 
327 	if (IS_ERR(inode)) {
328 		jffs2_free_raw_inode(ri);
329 		jffs2_complete_reservation(c);
330 		return PTR_ERR(inode);
331 	}
332 
333 	inode->i_op = &jffs2_symlink_inode_operations;
334 
335 	f = JFFS2_INODE_INFO(inode);
336 
337 	inode->i_size = targetlen;
338 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
339 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
340 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
341 
342 	ri->compr = JFFS2_COMPR_NONE;
343 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
344 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
345 
346 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
347 
348 	jffs2_free_raw_inode(ri);
349 
350 	if (IS_ERR(fn)) {
351 		/* Eeek. Wave bye bye */
352 		mutex_unlock(&f->sem);
353 		jffs2_complete_reservation(c);
354 		ret = PTR_ERR(fn);
355 		goto fail;
356 	}
357 
358 	/* We use f->target field to store the target path. */
359 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
360 	if (!f->target) {
361 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
362 		mutex_unlock(&f->sem);
363 		jffs2_complete_reservation(c);
364 		ret = -ENOMEM;
365 		goto fail;
366 	}
367 	inode->i_link = f->target;
368 
369 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
370 		  __func__, (char *)f->target);
371 
372 	/* No data here. Only a metadata node, which will be
373 	   obsoleted by the first data write
374 	*/
375 	f->metadata = fn;
376 	mutex_unlock(&f->sem);
377 
378 	jffs2_complete_reservation(c);
379 
380 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
381 	if (ret)
382 		goto fail;
383 
384 	ret = jffs2_init_acl_post(inode);
385 	if (ret)
386 		goto fail;
387 
388 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
389 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
390 	if (ret)
391 		goto fail;
392 
393 	rd = jffs2_alloc_raw_dirent();
394 	if (!rd) {
395 		/* Argh. Now we treat it like a normal delete */
396 		jffs2_complete_reservation(c);
397 		ret = -ENOMEM;
398 		goto fail;
399 	}
400 
401 	dir_f = JFFS2_INODE_INFO(dir_i);
402 	mutex_lock(&dir_f->sem);
403 
404 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
405 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
406 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
407 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
408 
409 	rd->pino = cpu_to_je32(dir_i->i_ino);
410 	rd->version = cpu_to_je32(++dir_f->highest_version);
411 	rd->ino = cpu_to_je32(inode->i_ino);
412 	rd->mctime = cpu_to_je32(JFFS2_NOW());
413 	rd->nsize = namelen;
414 	rd->type = DT_LNK;
415 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
416 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
417 
418 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
419 
420 	if (IS_ERR(fd)) {
421 		/* dirent failed to write. Delete the inode normally
422 		   as if it were the final unlink() */
423 		jffs2_complete_reservation(c);
424 		jffs2_free_raw_dirent(rd);
425 		mutex_unlock(&dir_f->sem);
426 		ret = PTR_ERR(fd);
427 		goto fail;
428 	}
429 
430 	inode_set_mtime_to_ts(dir_i,
431 			      inode_set_ctime_to_ts(dir_i, ITIME(je32_to_cpu(rd->mctime))));
432 
433 	jffs2_free_raw_dirent(rd);
434 
435 	/* Link the fd into the inode's list, obsoleting an old
436 	   one if necessary. */
437 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
438 
439 	mutex_unlock(&dir_f->sem);
440 	jffs2_complete_reservation(c);
441 
442 	d_instantiate_new(dentry, inode);
443 	return 0;
444 
445  fail:
446 	iget_failed(inode);
447 	return ret;
448 }
449 
450 
451 static struct dentry *jffs2_mkdir (struct mnt_idmap *idmap, struct inode *dir_i,
452 				   struct dentry *dentry, umode_t mode)
453 {
454 	struct jffs2_inode_info *f, *dir_f;
455 	struct jffs2_sb_info *c;
456 	struct inode *inode;
457 	struct jffs2_raw_inode *ri;
458 	struct jffs2_raw_dirent *rd;
459 	struct jffs2_full_dnode *fn;
460 	struct jffs2_full_dirent *fd;
461 	int namelen;
462 	uint32_t alloclen;
463 	int ret;
464 
465 	mode |= S_IFDIR;
466 
467 	ri = jffs2_alloc_raw_inode();
468 	if (!ri)
469 		return ERR_PTR(-ENOMEM);
470 
471 	c = JFFS2_SB_INFO(dir_i->i_sb);
472 
473 	/* Try to reserve enough space for both node and dirent.
474 	 * Just the node will do for now, though
475 	 */
476 	namelen = dentry->d_name.len;
477 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
478 				  JFFS2_SUMMARY_INODE_SIZE);
479 
480 	if (ret) {
481 		jffs2_free_raw_inode(ri);
482 		return ERR_PTR(ret);
483 	}
484 
485 	inode = jffs2_new_inode(dir_i, mode, ri);
486 
487 	if (IS_ERR(inode)) {
488 		jffs2_free_raw_inode(ri);
489 		jffs2_complete_reservation(c);
490 		return ERR_CAST(inode);
491 	}
492 
493 	inode->i_op = &jffs2_dir_inode_operations;
494 	inode->i_fop = &jffs2_dir_operations;
495 
496 	f = JFFS2_INODE_INFO(inode);
497 
498 	/* Directories get nlink 2 at start */
499 	set_nlink(inode, 2);
500 	/* but ic->pino_nlink is the parent ino# */
501 	f->inocache->pino_nlink = dir_i->i_ino;
502 
503 	ri->data_crc = cpu_to_je32(0);
504 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
505 
506 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
507 
508 	jffs2_free_raw_inode(ri);
509 
510 	if (IS_ERR(fn)) {
511 		/* Eeek. Wave bye bye */
512 		mutex_unlock(&f->sem);
513 		jffs2_complete_reservation(c);
514 		ret = PTR_ERR(fn);
515 		goto fail;
516 	}
517 	/* No data here. Only a metadata node, which will be
518 	   obsoleted by the first data write
519 	*/
520 	f->metadata = fn;
521 	mutex_unlock(&f->sem);
522 
523 	jffs2_complete_reservation(c);
524 
525 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
526 	if (ret)
527 		goto fail;
528 
529 	ret = jffs2_init_acl_post(inode);
530 	if (ret)
531 		goto fail;
532 
533 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
534 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
535 	if (ret)
536 		goto fail;
537 
538 	rd = jffs2_alloc_raw_dirent();
539 	if (!rd) {
540 		/* Argh. Now we treat it like a normal delete */
541 		jffs2_complete_reservation(c);
542 		ret = -ENOMEM;
543 		goto fail;
544 	}
545 
546 	dir_f = JFFS2_INODE_INFO(dir_i);
547 	mutex_lock(&dir_f->sem);
548 
549 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
550 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
551 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
552 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
553 
554 	rd->pino = cpu_to_je32(dir_i->i_ino);
555 	rd->version = cpu_to_je32(++dir_f->highest_version);
556 	rd->ino = cpu_to_je32(inode->i_ino);
557 	rd->mctime = cpu_to_je32(JFFS2_NOW());
558 	rd->nsize = namelen;
559 	rd->type = DT_DIR;
560 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
561 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
562 
563 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
564 
565 	if (IS_ERR(fd)) {
566 		/* dirent failed to write. Delete the inode normally
567 		   as if it were the final unlink() */
568 		jffs2_complete_reservation(c);
569 		jffs2_free_raw_dirent(rd);
570 		mutex_unlock(&dir_f->sem);
571 		ret = PTR_ERR(fd);
572 		goto fail;
573 	}
574 
575 	inode_set_mtime_to_ts(dir_i,
576 			      inode_set_ctime_to_ts(dir_i, ITIME(je32_to_cpu(rd->mctime))));
577 	inc_nlink(dir_i);
578 
579 	jffs2_free_raw_dirent(rd);
580 
581 	/* Link the fd into the inode's list, obsoleting an old
582 	   one if necessary. */
583 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
584 
585 	mutex_unlock(&dir_f->sem);
586 	jffs2_complete_reservation(c);
587 
588 	d_instantiate_new(dentry, inode);
589 	return NULL;
590 
591  fail:
592 	iget_failed(inode);
593 	return ERR_PTR(ret);
594 }
595 
596 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
597 {
598 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
599 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
600 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
601 	struct jffs2_full_dirent *fd;
602 	int ret;
603 	uint32_t now = JFFS2_NOW();
604 
605 	mutex_lock(&f->sem);
606 	for (fd = f->dents ; fd; fd = fd->next) {
607 		if (fd->ino) {
608 			mutex_unlock(&f->sem);
609 			return -ENOTEMPTY;
610 		}
611 	}
612 	mutex_unlock(&f->sem);
613 
614 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
615 			      dentry->d_name.len, f, now);
616 	if (!ret) {
617 		inode_set_mtime_to_ts(dir_i,
618 				      inode_set_ctime_to_ts(dir_i, ITIME(now)));
619 		clear_nlink(d_inode(dentry));
620 		drop_nlink(dir_i);
621 	}
622 	return ret;
623 }
624 
625 static int jffs2_mknod (struct mnt_idmap *idmap, struct inode *dir_i,
626 		        struct dentry *dentry, umode_t mode, dev_t rdev)
627 {
628 	struct jffs2_inode_info *f, *dir_f;
629 	struct jffs2_sb_info *c;
630 	struct inode *inode;
631 	struct jffs2_raw_inode *ri;
632 	struct jffs2_raw_dirent *rd;
633 	struct jffs2_full_dnode *fn;
634 	struct jffs2_full_dirent *fd;
635 	int namelen;
636 	union jffs2_device_node dev;
637 	int devlen = 0;
638 	uint32_t alloclen;
639 	int ret;
640 
641 	ri = jffs2_alloc_raw_inode();
642 	if (!ri)
643 		return -ENOMEM;
644 
645 	c = JFFS2_SB_INFO(dir_i->i_sb);
646 
647 	if (S_ISBLK(mode) || S_ISCHR(mode))
648 		devlen = jffs2_encode_dev(&dev, rdev);
649 
650 	/* Try to reserve enough space for both node and dirent.
651 	 * Just the node will do for now, though
652 	 */
653 	namelen = dentry->d_name.len;
654 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
655 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
656 
657 	if (ret) {
658 		jffs2_free_raw_inode(ri);
659 		return ret;
660 	}
661 
662 	inode = jffs2_new_inode(dir_i, mode, ri);
663 
664 	if (IS_ERR(inode)) {
665 		jffs2_free_raw_inode(ri);
666 		jffs2_complete_reservation(c);
667 		return PTR_ERR(inode);
668 	}
669 	inode->i_op = &jffs2_file_inode_operations;
670 	init_special_inode(inode, inode->i_mode, rdev);
671 
672 	f = JFFS2_INODE_INFO(inode);
673 
674 	ri->dsize = ri->csize = cpu_to_je32(devlen);
675 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
676 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
677 
678 	ri->compr = JFFS2_COMPR_NONE;
679 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
680 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
681 
682 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
683 
684 	jffs2_free_raw_inode(ri);
685 
686 	if (IS_ERR(fn)) {
687 		/* Eeek. Wave bye bye */
688 		mutex_unlock(&f->sem);
689 		jffs2_complete_reservation(c);
690 		ret = PTR_ERR(fn);
691 		goto fail;
692 	}
693 	/* No data here. Only a metadata node, which will be
694 	   obsoleted by the first data write
695 	*/
696 	f->metadata = fn;
697 	mutex_unlock(&f->sem);
698 
699 	jffs2_complete_reservation(c);
700 
701 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
702 	if (ret)
703 		goto fail;
704 
705 	ret = jffs2_init_acl_post(inode);
706 	if (ret)
707 		goto fail;
708 
709 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
710 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
711 	if (ret)
712 		goto fail;
713 
714 	rd = jffs2_alloc_raw_dirent();
715 	if (!rd) {
716 		/* Argh. Now we treat it like a normal delete */
717 		jffs2_complete_reservation(c);
718 		ret = -ENOMEM;
719 		goto fail;
720 	}
721 
722 	dir_f = JFFS2_INODE_INFO(dir_i);
723 	mutex_lock(&dir_f->sem);
724 
725 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
726 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
727 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
728 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
729 
730 	rd->pino = cpu_to_je32(dir_i->i_ino);
731 	rd->version = cpu_to_je32(++dir_f->highest_version);
732 	rd->ino = cpu_to_je32(inode->i_ino);
733 	rd->mctime = cpu_to_je32(JFFS2_NOW());
734 	rd->nsize = namelen;
735 
736 	/* XXX: This is ugly. */
737 	rd->type = (mode & S_IFMT) >> 12;
738 
739 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
740 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
741 
742 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
743 
744 	if (IS_ERR(fd)) {
745 		/* dirent failed to write. Delete the inode normally
746 		   as if it were the final unlink() */
747 		jffs2_complete_reservation(c);
748 		jffs2_free_raw_dirent(rd);
749 		mutex_unlock(&dir_f->sem);
750 		ret = PTR_ERR(fd);
751 		goto fail;
752 	}
753 
754 	inode_set_mtime_to_ts(dir_i,
755 			      inode_set_ctime_to_ts(dir_i, ITIME(je32_to_cpu(rd->mctime))));
756 
757 	jffs2_free_raw_dirent(rd);
758 
759 	/* Link the fd into the inode's list, obsoleting an old
760 	   one if necessary. */
761 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
762 
763 	mutex_unlock(&dir_f->sem);
764 	jffs2_complete_reservation(c);
765 
766 	d_instantiate_new(dentry, inode);
767 	return 0;
768 
769  fail:
770 	iget_failed(inode);
771 	return ret;
772 }
773 
774 static int jffs2_rename (struct mnt_idmap *idmap,
775 			 struct inode *old_dir_i, struct dentry *old_dentry,
776 			 struct inode *new_dir_i, struct dentry *new_dentry,
777 			 unsigned int flags)
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 	if (flags & ~RENAME_NOREPLACE)
786 		return -EINVAL;
787 
788 	/* The VFS will check for us and prevent trying to rename a
789 	 * file over a directory and vice versa, but if it's a directory,
790 	 * the VFS can't check whether the victim is empty. The filesystem
791 	 * needs to do that for itself.
792 	 */
793 	if (d_really_is_positive(new_dentry)) {
794 		victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
795 		if (d_is_dir(new_dentry)) {
796 			struct jffs2_full_dirent *fd;
797 
798 			mutex_lock(&victim_f->sem);
799 			for (fd = victim_f->dents; fd; fd = fd->next) {
800 				if (fd->ino) {
801 					mutex_unlock(&victim_f->sem);
802 					return -ENOTEMPTY;
803 				}
804 			}
805 			mutex_unlock(&victim_f->sem);
806 		}
807 	}
808 
809 	/* XXX: We probably ought to alloc enough space for
810 	   both nodes at the same time. Writing the new link,
811 	   then getting -ENOSPC, is quite bad :)
812 	*/
813 
814 	/* Make a hard link */
815 
816 	/* XXX: This is ugly */
817 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
818 	if (!type) type = DT_REG;
819 
820 	now = JFFS2_NOW();
821 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
822 			    d_inode(old_dentry)->i_ino, type,
823 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
824 
825 	if (ret)
826 		return ret;
827 
828 	if (victim_f) {
829 		/* There was a victim. Kill it off nicely */
830 		if (d_is_dir(new_dentry))
831 			clear_nlink(d_inode(new_dentry));
832 		else
833 			drop_nlink(d_inode(new_dentry));
834 		/* Don't oops if the victim was a dirent pointing to an
835 		   inode which didn't exist. */
836 		if (victim_f->inocache) {
837 			mutex_lock(&victim_f->sem);
838 			if (d_is_dir(new_dentry))
839 				victim_f->inocache->pino_nlink = 0;
840 			else
841 				victim_f->inocache->pino_nlink--;
842 			mutex_unlock(&victim_f->sem);
843 		}
844 	}
845 
846 	/* If it was a directory we moved, and there was no victim,
847 	   increase i_nlink on its new parent */
848 	if (d_is_dir(old_dentry) && !victim_f)
849 		inc_nlink(new_dir_i);
850 
851 	/* Unlink the original */
852 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
853 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
854 
855 	/* We don't touch inode->i_nlink */
856 
857 	if (ret) {
858 		/* Oh shit. We really ought to make a single node which can do both atomically */
859 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
860 		mutex_lock(&f->sem);
861 		inc_nlink(d_inode(old_dentry));
862 		if (f->inocache && !d_is_dir(old_dentry))
863 			f->inocache->pino_nlink++;
864 		mutex_unlock(&f->sem);
865 
866 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
867 			  __func__, ret);
868 		/*
869 		 * We can't keep the target in dcache after that.
870 		 * For one thing, we can't afford dentry aliases for directories.
871 		 * For another, if there was a victim, we _can't_ set new inode
872 		 * for that sucker and we have to trigger mount eviction - the
873 		 * caller won't do it on its own since we are returning an error.
874 		 */
875 		d_invalidate(new_dentry);
876 		inode_set_mtime_to_ts(new_dir_i,
877 				      inode_set_ctime_to_ts(new_dir_i, ITIME(now)));
878 		return ret;
879 	}
880 
881 	if (d_is_dir(old_dentry))
882 		drop_nlink(old_dir_i);
883 
884 	inode_set_mtime_to_ts(old_dir_i,
885 			      inode_set_ctime_to_ts(old_dir_i, ITIME(now)));
886 	inode_set_mtime_to_ts(new_dir_i,
887 			      inode_set_ctime_to_ts(new_dir_i, ITIME(now)));
888 
889 	return 0;
890 }
891 
892