xref: /openbmc/linux/fs/jffs2/dir.c (revision d8c76e6f)
1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright (C) 2001-2003 Red Hat, Inc.
5  *
6  * Created by David Woodhouse <dwmw2@infradead.org>
7  *
8  * For licensing information, see the file 'LICENCE' in this directory.
9  *
10  * $Id: dir.c,v 1.90 2005/11/07 11:14:39 gleixner Exp $
11  *
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/slab.h>
16 #include <linux/sched.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 *, void *, filldir_t);
26 
27 static int jffs2_create (struct inode *,struct dentry *,int,
28 			 struct nameidata *);
29 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
30 				    struct nameidata *);
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 *,int);
35 static int jffs2_rmdir (struct inode *,struct dentry *);
36 static int jffs2_mknod (struct inode *,struct dentry *,int,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 	.readdir =	jffs2_readdir,
44 	.ioctl =	jffs2_ioctl,
45 	.fsync =	jffs2_fsync
46 };
47 
48 
49 struct inode_operations jffs2_dir_inode_operations =
50 {
51 	.create =	jffs2_create,
52 	.lookup =	jffs2_lookup,
53 	.link =		jffs2_link,
54 	.unlink =	jffs2_unlink,
55 	.symlink =	jffs2_symlink,
56 	.mkdir =	jffs2_mkdir,
57 	.rmdir =	jffs2_rmdir,
58 	.mknod =	jffs2_mknod,
59 	.rename =	jffs2_rename,
60 	.permission =	jffs2_permission,
61 	.setattr =	jffs2_setattr,
62 	.setxattr =	jffs2_setxattr,
63 	.getxattr =	jffs2_getxattr,
64 	.listxattr =	jffs2_listxattr,
65 	.removexattr =	jffs2_removexattr
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 				   struct nameidata *nd)
77 {
78 	struct jffs2_inode_info *dir_f;
79 	struct jffs2_sb_info *c;
80 	struct jffs2_full_dirent *fd = NULL, *fd_list;
81 	uint32_t ino = 0;
82 	struct inode *inode = NULL;
83 
84 	D1(printk(KERN_DEBUG "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 	c = JFFS2_SB_INFO(dir_i->i_sb);
91 
92 	down(&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 	up(&dir_f->sem);
106 	if (ino) {
107 		inode = iget(dir_i->i_sb, ino);
108 		if (!inode) {
109 			printk(KERN_WARNING "iget() failed for ino #%u\n", ino);
110 			return (ERR_PTR(-EIO));
111 		}
112 	}
113 
114 	d_add(target, inode);
115 
116 	return NULL;
117 }
118 
119 /***********************************************************************/
120 
121 
122 static int jffs2_readdir(struct file *filp, void *dirent, filldir_t filldir)
123 {
124 	struct jffs2_inode_info *f;
125 	struct jffs2_sb_info *c;
126 	struct inode *inode = filp->f_dentry->d_inode;
127 	struct jffs2_full_dirent *fd;
128 	unsigned long offset, curofs;
129 
130 	D1(printk(KERN_DEBUG "jffs2_readdir() for dir_i #%lu\n", filp->f_dentry->d_inode->i_ino));
131 
132 	f = JFFS2_INODE_INFO(inode);
133 	c = JFFS2_SB_INFO(inode->i_sb);
134 
135 	offset = filp->f_pos;
136 
137 	if (offset == 0) {
138 		D1(printk(KERN_DEBUG "Dirent 0: \".\", ino #%lu\n", inode->i_ino));
139 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR) < 0)
140 			goto out;
141 		offset++;
142 	}
143 	if (offset == 1) {
144 		unsigned long pino = parent_ino(filp->f_dentry);
145 		D1(printk(KERN_DEBUG "Dirent 1: \"..\", ino #%lu\n", pino));
146 		if (filldir(dirent, "..", 2, 1, pino, DT_DIR) < 0)
147 			goto out;
148 		offset++;
149 	}
150 
151 	curofs=1;
152 	down(&f->sem);
153 	for (fd = f->dents; fd; fd = fd->next) {
154 
155 		curofs++;
156 		/* First loop: curofs = 2; offset = 2 */
157 		if (curofs < offset) {
158 			D2(printk(KERN_DEBUG "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
159 				  fd->name, fd->ino, fd->type, curofs, offset));
160 			continue;
161 		}
162 		if (!fd->ino) {
163 			D2(printk(KERN_DEBUG "Skipping deletion dirent \"%s\"\n", fd->name));
164 			offset++;
165 			continue;
166 		}
167 		D2(printk(KERN_DEBUG "Dirent %ld: \"%s\", ino #%u, type %d\n", offset, fd->name, fd->ino, fd->type));
168 		if (filldir(dirent, fd->name, strlen(fd->name), offset, fd->ino, fd->type) < 0)
169 			break;
170 		offset++;
171 	}
172 	up(&f->sem);
173  out:
174 	filp->f_pos = offset;
175 	return 0;
176 }
177 
178 /***********************************************************************/
179 
180 
181 static int jffs2_create(struct inode *dir_i, struct dentry *dentry, int mode,
182 			struct nameidata *nd)
183 {
184 	struct jffs2_raw_inode *ri;
185 	struct jffs2_inode_info *f, *dir_f;
186 	struct jffs2_sb_info *c;
187 	struct inode *inode;
188 	int ret;
189 
190 	ri = jffs2_alloc_raw_inode();
191 	if (!ri)
192 		return -ENOMEM;
193 
194 	c = JFFS2_SB_INFO(dir_i->i_sb);
195 
196 	D1(printk(KERN_DEBUG "jffs2_create()\n"));
197 
198 	inode = jffs2_new_inode(dir_i, mode, ri);
199 
200 	if (IS_ERR(inode)) {
201 		D1(printk(KERN_DEBUG "jffs2_new_inode() failed\n"));
202 		jffs2_free_raw_inode(ri);
203 		return PTR_ERR(inode);
204 	}
205 
206 	inode->i_op = &jffs2_file_inode_operations;
207 	inode->i_fop = &jffs2_file_operations;
208 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
209 	inode->i_mapping->nrpages = 0;
210 
211 	f = JFFS2_INODE_INFO(inode);
212 	dir_f = JFFS2_INODE_INFO(dir_i);
213 
214 	ret = jffs2_do_create(c, dir_f, f, ri,
215 			      dentry->d_name.name, dentry->d_name.len);
216 
217 	if (ret)
218 		goto fail;
219 
220 	ret = jffs2_init_security(inode, dir_i);
221 	if (ret)
222 		goto fail;
223 	ret = jffs2_init_acl(inode, dir_i);
224 	if (ret)
225 		goto fail;
226 
227 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
228 
229 	jffs2_free_raw_inode(ri);
230 	d_instantiate(dentry, inode);
231 
232 	D1(printk(KERN_DEBUG "jffs2_create: Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
233 		  inode->i_ino, inode->i_mode, inode->i_nlink, f->inocache->nlink, inode->i_mapping->nrpages));
234 	return 0;
235 
236  fail:
237 	make_bad_inode(inode);
238 	iput(inode);
239 	jffs2_free_raw_inode(ri);
240 	return ret;
241 }
242 
243 /***********************************************************************/
244 
245 
246 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
247 {
248 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
249 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
250 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(dentry->d_inode);
251 	int ret;
252 	uint32_t now = get_seconds();
253 
254 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
255 			      dentry->d_name.len, dead_f, now);
256 	if (dead_f->inocache)
257 		dentry->d_inode->i_nlink = dead_f->inocache->nlink;
258 	if (!ret)
259 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
260 	return ret;
261 }
262 /***********************************************************************/
263 
264 
265 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
266 {
267 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_inode->i_sb);
268 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
269 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
270 	int ret;
271 	uint8_t type;
272 	uint32_t now;
273 
274 	/* Don't let people make hard links to bad inodes. */
275 	if (!f->inocache)
276 		return -EIO;
277 
278 	if (S_ISDIR(old_dentry->d_inode->i_mode))
279 		return -EPERM;
280 
281 	/* XXX: This is ugly */
282 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
283 	if (!type) type = DT_REG;
284 
285 	now = get_seconds();
286 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
287 
288 	if (!ret) {
289 		down(&f->sem);
290 		old_dentry->d_inode->i_nlink = ++f->inocache->nlink;
291 		up(&f->sem);
292 		d_instantiate(dentry, old_dentry->d_inode);
293 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
294 		atomic_inc(&old_dentry->d_inode->i_count);
295 	}
296 	return ret;
297 }
298 
299 /***********************************************************************/
300 
301 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
302 {
303 	struct jffs2_inode_info *f, *dir_f;
304 	struct jffs2_sb_info *c;
305 	struct inode *inode;
306 	struct jffs2_raw_inode *ri;
307 	struct jffs2_raw_dirent *rd;
308 	struct jffs2_full_dnode *fn;
309 	struct jffs2_full_dirent *fd;
310 	int namelen;
311 	uint32_t alloclen;
312 	int ret, targetlen = strlen(target);
313 
314 	/* FIXME: If you care. We'd need to use frags for the target
315 	   if it grows much more than this */
316 	if (targetlen > 254)
317 		return -EINVAL;
318 
319 	ri = jffs2_alloc_raw_inode();
320 
321 	if (!ri)
322 		return -ENOMEM;
323 
324 	c = JFFS2_SB_INFO(dir_i->i_sb);
325 
326 	/* Try to reserve enough space for both node and dirent.
327 	 * Just the node will do for now, though
328 	 */
329 	namelen = dentry->d_name.len;
330 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
331 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
332 
333 	if (ret) {
334 		jffs2_free_raw_inode(ri);
335 		return ret;
336 	}
337 
338 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
339 
340 	if (IS_ERR(inode)) {
341 		jffs2_free_raw_inode(ri);
342 		jffs2_complete_reservation(c);
343 		return PTR_ERR(inode);
344 	}
345 
346 	inode->i_op = &jffs2_symlink_inode_operations;
347 
348 	f = JFFS2_INODE_INFO(inode);
349 
350 	inode->i_size = targetlen;
351 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
352 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
353 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
354 
355 	ri->compr = JFFS2_COMPR_NONE;
356 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
357 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
358 
359 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
360 
361 	jffs2_free_raw_inode(ri);
362 
363 	if (IS_ERR(fn)) {
364 		/* Eeek. Wave bye bye */
365 		up(&f->sem);
366 		jffs2_complete_reservation(c);
367 		jffs2_clear_inode(inode);
368 		return PTR_ERR(fn);
369 	}
370 
371 	/* We use f->target field to store the target path. */
372 	f->target = kmalloc(targetlen + 1, GFP_KERNEL);
373 	if (!f->target) {
374 		printk(KERN_WARNING "Can't allocate %d bytes of memory\n", targetlen + 1);
375 		up(&f->sem);
376 		jffs2_complete_reservation(c);
377 		jffs2_clear_inode(inode);
378 		return -ENOMEM;
379 	}
380 
381 	memcpy(f->target, target, targetlen + 1);
382 	D1(printk(KERN_DEBUG "jffs2_symlink: symlink's target '%s' cached\n", (char *)f->target));
383 
384 	/* No data here. Only a metadata node, which will be
385 	   obsoleted by the first data write
386 	*/
387 	f->metadata = fn;
388 	up(&f->sem);
389 
390 	jffs2_complete_reservation(c);
391 
392 	ret = jffs2_init_security(inode, dir_i);
393 	if (ret) {
394 		jffs2_clear_inode(inode);
395 		return ret;
396 	}
397 	ret = jffs2_init_acl(inode, dir_i);
398 	if (ret) {
399 		jffs2_clear_inode(inode);
400 		return ret;
401 	}
402 
403 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
404 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
405 	if (ret) {
406 		/* Eep. */
407 		jffs2_clear_inode(inode);
408 		return ret;
409 	}
410 
411 	rd = jffs2_alloc_raw_dirent();
412 	if (!rd) {
413 		/* Argh. Now we treat it like a normal delete */
414 		jffs2_complete_reservation(c);
415 		jffs2_clear_inode(inode);
416 		return -ENOMEM;
417 	}
418 
419 	dir_f = JFFS2_INODE_INFO(dir_i);
420 	down(&dir_f->sem);
421 
422 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
423 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
424 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
425 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
426 
427 	rd->pino = cpu_to_je32(dir_i->i_ino);
428 	rd->version = cpu_to_je32(++dir_f->highest_version);
429 	rd->ino = cpu_to_je32(inode->i_ino);
430 	rd->mctime = cpu_to_je32(get_seconds());
431 	rd->nsize = namelen;
432 	rd->type = DT_LNK;
433 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
434 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
435 
436 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
437 
438 	if (IS_ERR(fd)) {
439 		/* dirent failed to write. Delete the inode normally
440 		   as if it were the final unlink() */
441 		jffs2_complete_reservation(c);
442 		jffs2_free_raw_dirent(rd);
443 		up(&dir_f->sem);
444 		jffs2_clear_inode(inode);
445 		return PTR_ERR(fd);
446 	}
447 
448 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
449 
450 	jffs2_free_raw_dirent(rd);
451 
452 	/* Link the fd into the inode's list, obsoleting an old
453 	   one if necessary. */
454 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
455 
456 	up(&dir_f->sem);
457 	jffs2_complete_reservation(c);
458 
459 	d_instantiate(dentry, inode);
460 	return 0;
461 }
462 
463 
464 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, int mode)
465 {
466 	struct jffs2_inode_info *f, *dir_f;
467 	struct jffs2_sb_info *c;
468 	struct inode *inode;
469 	struct jffs2_raw_inode *ri;
470 	struct jffs2_raw_dirent *rd;
471 	struct jffs2_full_dnode *fn;
472 	struct jffs2_full_dirent *fd;
473 	int namelen;
474 	uint32_t alloclen;
475 	int ret;
476 
477 	mode |= S_IFDIR;
478 
479 	ri = jffs2_alloc_raw_inode();
480 	if (!ri)
481 		return -ENOMEM;
482 
483 	c = JFFS2_SB_INFO(dir_i->i_sb);
484 
485 	/* Try to reserve enough space for both node and dirent.
486 	 * Just the node will do for now, though
487 	 */
488 	namelen = dentry->d_name.len;
489 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
490 				  JFFS2_SUMMARY_INODE_SIZE);
491 
492 	if (ret) {
493 		jffs2_free_raw_inode(ri);
494 		return ret;
495 	}
496 
497 	inode = jffs2_new_inode(dir_i, mode, ri);
498 
499 	if (IS_ERR(inode)) {
500 		jffs2_free_raw_inode(ri);
501 		jffs2_complete_reservation(c);
502 		return PTR_ERR(inode);
503 	}
504 
505 	inode->i_op = &jffs2_dir_inode_operations;
506 	inode->i_fop = &jffs2_dir_operations;
507 	/* Directories get nlink 2 at start */
508 	inode->i_nlink = 2;
509 
510 	f = JFFS2_INODE_INFO(inode);
511 
512 	ri->data_crc = cpu_to_je32(0);
513 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
514 
515 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
516 
517 	jffs2_free_raw_inode(ri);
518 
519 	if (IS_ERR(fn)) {
520 		/* Eeek. Wave bye bye */
521 		up(&f->sem);
522 		jffs2_complete_reservation(c);
523 		jffs2_clear_inode(inode);
524 		return PTR_ERR(fn);
525 	}
526 	/* No data here. Only a metadata node, which will be
527 	   obsoleted by the first data write
528 	*/
529 	f->metadata = fn;
530 	up(&f->sem);
531 
532 	jffs2_complete_reservation(c);
533 
534 	ret = jffs2_init_security(inode, dir_i);
535 	if (ret) {
536 		jffs2_clear_inode(inode);
537 		return ret;
538 	}
539 	ret = jffs2_init_acl(inode, dir_i);
540 	if (ret) {
541 		jffs2_clear_inode(inode);
542 		return ret;
543 	}
544 
545 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
546 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
547 	if (ret) {
548 		/* Eep. */
549 		jffs2_clear_inode(inode);
550 		return ret;
551 	}
552 
553 	rd = jffs2_alloc_raw_dirent();
554 	if (!rd) {
555 		/* Argh. Now we treat it like a normal delete */
556 		jffs2_complete_reservation(c);
557 		jffs2_clear_inode(inode);
558 		return -ENOMEM;
559 	}
560 
561 	dir_f = JFFS2_INODE_INFO(dir_i);
562 	down(&dir_f->sem);
563 
564 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
565 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
566 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
567 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
568 
569 	rd->pino = cpu_to_je32(dir_i->i_ino);
570 	rd->version = cpu_to_je32(++dir_f->highest_version);
571 	rd->ino = cpu_to_je32(inode->i_ino);
572 	rd->mctime = cpu_to_je32(get_seconds());
573 	rd->nsize = namelen;
574 	rd->type = DT_DIR;
575 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
576 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
577 
578 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
579 
580 	if (IS_ERR(fd)) {
581 		/* dirent failed to write. Delete the inode normally
582 		   as if it were the final unlink() */
583 		jffs2_complete_reservation(c);
584 		jffs2_free_raw_dirent(rd);
585 		up(&dir_f->sem);
586 		jffs2_clear_inode(inode);
587 		return PTR_ERR(fd);
588 	}
589 
590 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
591 	inc_nlink(dir_i);
592 
593 	jffs2_free_raw_dirent(rd);
594 
595 	/* Link the fd into the inode's list, obsoleting an old
596 	   one if necessary. */
597 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
598 
599 	up(&dir_f->sem);
600 	jffs2_complete_reservation(c);
601 
602 	d_instantiate(dentry, inode);
603 	return 0;
604 }
605 
606 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
607 {
608 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(dentry->d_inode);
609 	struct jffs2_full_dirent *fd;
610 	int ret;
611 
612 	for (fd = f->dents ; fd; fd = fd->next) {
613 		if (fd->ino)
614 			return -ENOTEMPTY;
615 	}
616 	ret = jffs2_unlink(dir_i, dentry);
617 	if (!ret)
618 		drop_nlink(dir_i);
619 	return ret;
620 }
621 
622 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, int mode, dev_t rdev)
623 {
624 	struct jffs2_inode_info *f, *dir_f;
625 	struct jffs2_sb_info *c;
626 	struct inode *inode;
627 	struct jffs2_raw_inode *ri;
628 	struct jffs2_raw_dirent *rd;
629 	struct jffs2_full_dnode *fn;
630 	struct jffs2_full_dirent *fd;
631 	int namelen;
632 	union jffs2_device_node dev;
633 	int devlen = 0;
634 	uint32_t alloclen;
635 	int ret;
636 
637 	if (!new_valid_dev(rdev))
638 		return -EINVAL;
639 
640 	ri = jffs2_alloc_raw_inode();
641 	if (!ri)
642 		return -ENOMEM;
643 
644 	c = JFFS2_SB_INFO(dir_i->i_sb);
645 
646 	if (S_ISBLK(mode) || S_ISCHR(mode))
647 		devlen = jffs2_encode_dev(&dev, rdev);
648 
649 	/* Try to reserve enough space for both node and dirent.
650 	 * Just the node will do for now, though
651 	 */
652 	namelen = dentry->d_name.len;
653 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
654 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
655 
656 	if (ret) {
657 		jffs2_free_raw_inode(ri);
658 		return ret;
659 	}
660 
661 	inode = jffs2_new_inode(dir_i, mode, ri);
662 
663 	if (IS_ERR(inode)) {
664 		jffs2_free_raw_inode(ri);
665 		jffs2_complete_reservation(c);
666 		return PTR_ERR(inode);
667 	}
668 	inode->i_op = &jffs2_file_inode_operations;
669 	init_special_inode(inode, inode->i_mode, rdev);
670 
671 	f = JFFS2_INODE_INFO(inode);
672 
673 	ri->dsize = ri->csize = cpu_to_je32(devlen);
674 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
675 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
676 
677 	ri->compr = JFFS2_COMPR_NONE;
678 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
679 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
680 
681 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
682 
683 	jffs2_free_raw_inode(ri);
684 
685 	if (IS_ERR(fn)) {
686 		/* Eeek. Wave bye bye */
687 		up(&f->sem);
688 		jffs2_complete_reservation(c);
689 		jffs2_clear_inode(inode);
690 		return PTR_ERR(fn);
691 	}
692 	/* No data here. Only a metadata node, which will be
693 	   obsoleted by the first data write
694 	*/
695 	f->metadata = fn;
696 	up(&f->sem);
697 
698 	jffs2_complete_reservation(c);
699 
700 	ret = jffs2_init_security(inode, dir_i);
701 	if (ret) {
702 		jffs2_clear_inode(inode);
703 		return ret;
704 	}
705 	ret = jffs2_init_acl(inode, dir_i);
706 	if (ret) {
707 		jffs2_clear_inode(inode);
708 		return ret;
709 	}
710 
711 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
712 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
713 	if (ret) {
714 		/* Eep. */
715 		jffs2_clear_inode(inode);
716 		return ret;
717 	}
718 
719 	rd = jffs2_alloc_raw_dirent();
720 	if (!rd) {
721 		/* Argh. Now we treat it like a normal delete */
722 		jffs2_complete_reservation(c);
723 		jffs2_clear_inode(inode);
724 		return -ENOMEM;
725 	}
726 
727 	dir_f = JFFS2_INODE_INFO(dir_i);
728 	down(&dir_f->sem);
729 
730 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
731 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
732 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
733 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
734 
735 	rd->pino = cpu_to_je32(dir_i->i_ino);
736 	rd->version = cpu_to_je32(++dir_f->highest_version);
737 	rd->ino = cpu_to_je32(inode->i_ino);
738 	rd->mctime = cpu_to_je32(get_seconds());
739 	rd->nsize = namelen;
740 
741 	/* XXX: This is ugly. */
742 	rd->type = (mode & S_IFMT) >> 12;
743 
744 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
745 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
746 
747 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
748 
749 	if (IS_ERR(fd)) {
750 		/* dirent failed to write. Delete the inode normally
751 		   as if it were the final unlink() */
752 		jffs2_complete_reservation(c);
753 		jffs2_free_raw_dirent(rd);
754 		up(&dir_f->sem);
755 		jffs2_clear_inode(inode);
756 		return PTR_ERR(fd);
757 	}
758 
759 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
760 
761 	jffs2_free_raw_dirent(rd);
762 
763 	/* Link the fd into the inode's list, obsoleting an old
764 	   one if necessary. */
765 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
766 
767 	up(&dir_f->sem);
768 	jffs2_complete_reservation(c);
769 
770 	d_instantiate(dentry, inode);
771 
772 	return 0;
773 }
774 
775 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
776                         struct inode *new_dir_i, struct dentry *new_dentry)
777 {
778 	int ret;
779 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
780 	struct jffs2_inode_info *victim_f = NULL;
781 	uint8_t type;
782 	uint32_t now;
783 
784 	/* The VFS will check for us and prevent trying to rename a
785 	 * file over a directory and vice versa, but if it's a directory,
786 	 * the VFS can't check whether the victim is empty. The filesystem
787 	 * needs to do that for itself.
788 	 */
789 	if (new_dentry->d_inode) {
790 		victim_f = JFFS2_INODE_INFO(new_dentry->d_inode);
791 		if (S_ISDIR(new_dentry->d_inode->i_mode)) {
792 			struct jffs2_full_dirent *fd;
793 
794 			down(&victim_f->sem);
795 			for (fd = victim_f->dents; fd; fd = fd->next) {
796 				if (fd->ino) {
797 					up(&victim_f->sem);
798 					return -ENOTEMPTY;
799 				}
800 			}
801 			up(&victim_f->sem);
802 		}
803 	}
804 
805 	/* XXX: We probably ought to alloc enough space for
806 	   both nodes at the same time. Writing the new link,
807 	   then getting -ENOSPC, is quite bad :)
808 	*/
809 
810 	/* Make a hard link */
811 
812 	/* XXX: This is ugly */
813 	type = (old_dentry->d_inode->i_mode & S_IFMT) >> 12;
814 	if (!type) type = DT_REG;
815 
816 	now = get_seconds();
817 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
818 			    old_dentry->d_inode->i_ino, type,
819 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
820 
821 	if (ret)
822 		return ret;
823 
824 	if (victim_f) {
825 		/* There was a victim. Kill it off nicely */
826 		drop_nlink(new_dentry->d_inode);
827 		/* Don't oops if the victim was a dirent pointing to an
828 		   inode which didn't exist. */
829 		if (victim_f->inocache) {
830 			down(&victim_f->sem);
831 			victim_f->inocache->nlink--;
832 			up(&victim_f->sem);
833 		}
834 	}
835 
836 	/* If it was a directory we moved, and there was no victim,
837 	   increase i_nlink on its new parent */
838 	if (S_ISDIR(old_dentry->d_inode->i_mode) && !victim_f)
839 		inc_nlink(new_dir_i);
840 
841 	/* Unlink the original */
842 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
843 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
844 
845 	/* We don't touch inode->i_nlink */
846 
847 	if (ret) {
848 		/* Oh shit. We really ought to make a single node which can do both atomically */
849 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(old_dentry->d_inode);
850 		down(&f->sem);
851 		inc_nlink(old_dentry->d_inode);
852 		if (f->inocache)
853 			f->inocache->nlink++;
854 		up(&f->sem);
855 
856 		printk(KERN_NOTICE "jffs2_rename(): Link succeeded, unlink failed (err %d). You now have a hard link\n", ret);
857 		/* Might as well let the VFS know */
858 		d_instantiate(new_dentry, old_dentry->d_inode);
859 		atomic_inc(&old_dentry->d_inode->i_count);
860 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
861 		return ret;
862 	}
863 
864 	if (S_ISDIR(old_dentry->d_inode->i_mode))
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