xref: /openbmc/linux/fs/jffs2/dir.c (revision 20a55463)
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 = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
208 
209 	jffs2_free_raw_inode(ri);
210 
211 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
212 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
213 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
214 
215 	d_instantiate_new(dentry, inode);
216 	return 0;
217 
218  fail:
219 	iget_failed(inode);
220 	jffs2_free_raw_inode(ri);
221 	return ret;
222 }
223 
224 /***********************************************************************/
225 
226 
227 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
228 {
229 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
230 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
231 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
232 	int ret;
233 	uint32_t now = JFFS2_NOW();
234 
235 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
236 			      dentry->d_name.len, dead_f, now);
237 	if (dead_f->inocache)
238 		set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
239 	if (!ret)
240 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
241 	return ret;
242 }
243 /***********************************************************************/
244 
245 
246 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
247 {
248 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dentry->d_sb);
249 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
250 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
251 	int ret;
252 	uint8_t type;
253 	uint32_t now;
254 
255 	/* Don't let people make hard links to bad inodes. */
256 	if (!f->inocache)
257 		return -EIO;
258 
259 	if (d_is_dir(old_dentry))
260 		return -EPERM;
261 
262 	/* XXX: This is ugly */
263 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
264 	if (!type) type = DT_REG;
265 
266 	now = JFFS2_NOW();
267 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
268 
269 	if (!ret) {
270 		mutex_lock(&f->sem);
271 		set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
272 		mutex_unlock(&f->sem);
273 		d_instantiate(dentry, d_inode(old_dentry));
274 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
275 		ihold(d_inode(old_dentry));
276 	}
277 	return ret;
278 }
279 
280 /***********************************************************************/
281 
282 static int jffs2_symlink (struct mnt_idmap *idmap, struct inode *dir_i,
283 			  struct dentry *dentry, const char *target)
284 {
285 	struct jffs2_inode_info *f, *dir_f;
286 	struct jffs2_sb_info *c;
287 	struct inode *inode;
288 	struct jffs2_raw_inode *ri;
289 	struct jffs2_raw_dirent *rd;
290 	struct jffs2_full_dnode *fn;
291 	struct jffs2_full_dirent *fd;
292 	int namelen;
293 	uint32_t alloclen;
294 	int ret, targetlen = strlen(target);
295 
296 	/* FIXME: If you care. We'd need to use frags for the target
297 	   if it grows much more than this */
298 	if (targetlen > 254)
299 		return -ENAMETOOLONG;
300 
301 	ri = jffs2_alloc_raw_inode();
302 
303 	if (!ri)
304 		return -ENOMEM;
305 
306 	c = JFFS2_SB_INFO(dir_i->i_sb);
307 
308 	/* Try to reserve enough space for both node and dirent.
309 	 * Just the node will do for now, though
310 	 */
311 	namelen = dentry->d_name.len;
312 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
313 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
314 
315 	if (ret) {
316 		jffs2_free_raw_inode(ri);
317 		return ret;
318 	}
319 
320 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
321 
322 	if (IS_ERR(inode)) {
323 		jffs2_free_raw_inode(ri);
324 		jffs2_complete_reservation(c);
325 		return PTR_ERR(inode);
326 	}
327 
328 	inode->i_op = &jffs2_symlink_inode_operations;
329 
330 	f = JFFS2_INODE_INFO(inode);
331 
332 	inode->i_size = targetlen;
333 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
334 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
335 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
336 
337 	ri->compr = JFFS2_COMPR_NONE;
338 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
339 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
340 
341 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
342 
343 	jffs2_free_raw_inode(ri);
344 
345 	if (IS_ERR(fn)) {
346 		/* Eeek. Wave bye bye */
347 		mutex_unlock(&f->sem);
348 		jffs2_complete_reservation(c);
349 		ret = PTR_ERR(fn);
350 		goto fail;
351 	}
352 
353 	/* We use f->target field to store the target path. */
354 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
355 	if (!f->target) {
356 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
357 		mutex_unlock(&f->sem);
358 		jffs2_complete_reservation(c);
359 		ret = -ENOMEM;
360 		goto fail;
361 	}
362 	inode->i_link = f->target;
363 
364 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
365 		  __func__, (char *)f->target);
366 
367 	/* No data here. Only a metadata node, which will be
368 	   obsoleted by the first data write
369 	*/
370 	f->metadata = fn;
371 	mutex_unlock(&f->sem);
372 
373 	jffs2_complete_reservation(c);
374 
375 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
376 	if (ret)
377 		goto fail;
378 
379 	ret = jffs2_init_acl_post(inode);
380 	if (ret)
381 		goto fail;
382 
383 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
384 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
385 	if (ret)
386 		goto fail;
387 
388 	rd = jffs2_alloc_raw_dirent();
389 	if (!rd) {
390 		/* Argh. Now we treat it like a normal delete */
391 		jffs2_complete_reservation(c);
392 		ret = -ENOMEM;
393 		goto fail;
394 	}
395 
396 	dir_f = JFFS2_INODE_INFO(dir_i);
397 	mutex_lock(&dir_f->sem);
398 
399 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
400 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
401 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
402 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
403 
404 	rd->pino = cpu_to_je32(dir_i->i_ino);
405 	rd->version = cpu_to_je32(++dir_f->highest_version);
406 	rd->ino = cpu_to_je32(inode->i_ino);
407 	rd->mctime = cpu_to_je32(JFFS2_NOW());
408 	rd->nsize = namelen;
409 	rd->type = DT_LNK;
410 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
411 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
412 
413 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
414 
415 	if (IS_ERR(fd)) {
416 		/* dirent failed to write. Delete the inode normally
417 		   as if it were the final unlink() */
418 		jffs2_complete_reservation(c);
419 		jffs2_free_raw_dirent(rd);
420 		mutex_unlock(&dir_f->sem);
421 		ret = PTR_ERR(fd);
422 		goto fail;
423 	}
424 
425 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
426 
427 	jffs2_free_raw_dirent(rd);
428 
429 	/* Link the fd into the inode's list, obsoleting an old
430 	   one if necessary. */
431 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
432 
433 	mutex_unlock(&dir_f->sem);
434 	jffs2_complete_reservation(c);
435 
436 	d_instantiate_new(dentry, inode);
437 	return 0;
438 
439  fail:
440 	iget_failed(inode);
441 	return ret;
442 }
443 
444 
445 static int jffs2_mkdir (struct mnt_idmap *idmap, struct inode *dir_i,
446 		        struct dentry *dentry, umode_t mode)
447 {
448 	struct jffs2_inode_info *f, *dir_f;
449 	struct jffs2_sb_info *c;
450 	struct inode *inode;
451 	struct jffs2_raw_inode *ri;
452 	struct jffs2_raw_dirent *rd;
453 	struct jffs2_full_dnode *fn;
454 	struct jffs2_full_dirent *fd;
455 	int namelen;
456 	uint32_t alloclen;
457 	int ret;
458 
459 	mode |= S_IFDIR;
460 
461 	ri = jffs2_alloc_raw_inode();
462 	if (!ri)
463 		return -ENOMEM;
464 
465 	c = JFFS2_SB_INFO(dir_i->i_sb);
466 
467 	/* Try to reserve enough space for both node and dirent.
468 	 * Just the node will do for now, though
469 	 */
470 	namelen = dentry->d_name.len;
471 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
472 				  JFFS2_SUMMARY_INODE_SIZE);
473 
474 	if (ret) {
475 		jffs2_free_raw_inode(ri);
476 		return ret;
477 	}
478 
479 	inode = jffs2_new_inode(dir_i, mode, ri);
480 
481 	if (IS_ERR(inode)) {
482 		jffs2_free_raw_inode(ri);
483 		jffs2_complete_reservation(c);
484 		return PTR_ERR(inode);
485 	}
486 
487 	inode->i_op = &jffs2_dir_inode_operations;
488 	inode->i_fop = &jffs2_dir_operations;
489 
490 	f = JFFS2_INODE_INFO(inode);
491 
492 	/* Directories get nlink 2 at start */
493 	set_nlink(inode, 2);
494 	/* but ic->pino_nlink is the parent ino# */
495 	f->inocache->pino_nlink = dir_i->i_ino;
496 
497 	ri->data_crc = cpu_to_je32(0);
498 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
499 
500 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
501 
502 	jffs2_free_raw_inode(ri);
503 
504 	if (IS_ERR(fn)) {
505 		/* Eeek. Wave bye bye */
506 		mutex_unlock(&f->sem);
507 		jffs2_complete_reservation(c);
508 		ret = PTR_ERR(fn);
509 		goto fail;
510 	}
511 	/* No data here. Only a metadata node, which will be
512 	   obsoleted by the first data write
513 	*/
514 	f->metadata = fn;
515 	mutex_unlock(&f->sem);
516 
517 	jffs2_complete_reservation(c);
518 
519 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
520 	if (ret)
521 		goto fail;
522 
523 	ret = jffs2_init_acl_post(inode);
524 	if (ret)
525 		goto fail;
526 
527 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
528 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
529 	if (ret)
530 		goto fail;
531 
532 	rd = jffs2_alloc_raw_dirent();
533 	if (!rd) {
534 		/* Argh. Now we treat it like a normal delete */
535 		jffs2_complete_reservation(c);
536 		ret = -ENOMEM;
537 		goto fail;
538 	}
539 
540 	dir_f = JFFS2_INODE_INFO(dir_i);
541 	mutex_lock(&dir_f->sem);
542 
543 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
544 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
545 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
546 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
547 
548 	rd->pino = cpu_to_je32(dir_i->i_ino);
549 	rd->version = cpu_to_je32(++dir_f->highest_version);
550 	rd->ino = cpu_to_je32(inode->i_ino);
551 	rd->mctime = cpu_to_je32(JFFS2_NOW());
552 	rd->nsize = namelen;
553 	rd->type = DT_DIR;
554 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
555 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
556 
557 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
558 
559 	if (IS_ERR(fd)) {
560 		/* dirent failed to write. Delete the inode normally
561 		   as if it were the final unlink() */
562 		jffs2_complete_reservation(c);
563 		jffs2_free_raw_dirent(rd);
564 		mutex_unlock(&dir_f->sem);
565 		ret = PTR_ERR(fd);
566 		goto fail;
567 	}
568 
569 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
570 	inc_nlink(dir_i);
571 
572 	jffs2_free_raw_dirent(rd);
573 
574 	/* Link the fd into the inode's list, obsoleting an old
575 	   one if necessary. */
576 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
577 
578 	mutex_unlock(&dir_f->sem);
579 	jffs2_complete_reservation(c);
580 
581 	d_instantiate_new(dentry, inode);
582 	return 0;
583 
584  fail:
585 	iget_failed(inode);
586 	return ret;
587 }
588 
589 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
590 {
591 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
592 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
593 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
594 	struct jffs2_full_dirent *fd;
595 	int ret;
596 	uint32_t now = JFFS2_NOW();
597 
598 	mutex_lock(&f->sem);
599 	for (fd = f->dents ; fd; fd = fd->next) {
600 		if (fd->ino) {
601 			mutex_unlock(&f->sem);
602 			return -ENOTEMPTY;
603 		}
604 	}
605 	mutex_unlock(&f->sem);
606 
607 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
608 			      dentry->d_name.len, f, now);
609 	if (!ret) {
610 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
611 		clear_nlink(d_inode(dentry));
612 		drop_nlink(dir_i);
613 	}
614 	return ret;
615 }
616 
617 static int jffs2_mknod (struct mnt_idmap *idmap, struct inode *dir_i,
618 		        struct dentry *dentry, umode_t mode, dev_t rdev)
619 {
620 	struct jffs2_inode_info *f, *dir_f;
621 	struct jffs2_sb_info *c;
622 	struct inode *inode;
623 	struct jffs2_raw_inode *ri;
624 	struct jffs2_raw_dirent *rd;
625 	struct jffs2_full_dnode *fn;
626 	struct jffs2_full_dirent *fd;
627 	int namelen;
628 	union jffs2_device_node dev;
629 	int devlen = 0;
630 	uint32_t alloclen;
631 	int ret;
632 
633 	ri = jffs2_alloc_raw_inode();
634 	if (!ri)
635 		return -ENOMEM;
636 
637 	c = JFFS2_SB_INFO(dir_i->i_sb);
638 
639 	if (S_ISBLK(mode) || S_ISCHR(mode))
640 		devlen = jffs2_encode_dev(&dev, rdev);
641 
642 	/* Try to reserve enough space for both node and dirent.
643 	 * Just the node will do for now, though
644 	 */
645 	namelen = dentry->d_name.len;
646 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
647 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
648 
649 	if (ret) {
650 		jffs2_free_raw_inode(ri);
651 		return ret;
652 	}
653 
654 	inode = jffs2_new_inode(dir_i, mode, ri);
655 
656 	if (IS_ERR(inode)) {
657 		jffs2_free_raw_inode(ri);
658 		jffs2_complete_reservation(c);
659 		return PTR_ERR(inode);
660 	}
661 	inode->i_op = &jffs2_file_inode_operations;
662 	init_special_inode(inode, inode->i_mode, rdev);
663 
664 	f = JFFS2_INODE_INFO(inode);
665 
666 	ri->dsize = ri->csize = cpu_to_je32(devlen);
667 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
668 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
669 
670 	ri->compr = JFFS2_COMPR_NONE;
671 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
672 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
673 
674 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
675 
676 	jffs2_free_raw_inode(ri);
677 
678 	if (IS_ERR(fn)) {
679 		/* Eeek. Wave bye bye */
680 		mutex_unlock(&f->sem);
681 		jffs2_complete_reservation(c);
682 		ret = PTR_ERR(fn);
683 		goto fail;
684 	}
685 	/* No data here. Only a metadata node, which will be
686 	   obsoleted by the first data write
687 	*/
688 	f->metadata = fn;
689 	mutex_unlock(&f->sem);
690 
691 	jffs2_complete_reservation(c);
692 
693 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
694 	if (ret)
695 		goto fail;
696 
697 	ret = jffs2_init_acl_post(inode);
698 	if (ret)
699 		goto fail;
700 
701 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
702 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
703 	if (ret)
704 		goto fail;
705 
706 	rd = jffs2_alloc_raw_dirent();
707 	if (!rd) {
708 		/* Argh. Now we treat it like a normal delete */
709 		jffs2_complete_reservation(c);
710 		ret = -ENOMEM;
711 		goto fail;
712 	}
713 
714 	dir_f = JFFS2_INODE_INFO(dir_i);
715 	mutex_lock(&dir_f->sem);
716 
717 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
718 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
719 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
720 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
721 
722 	rd->pino = cpu_to_je32(dir_i->i_ino);
723 	rd->version = cpu_to_je32(++dir_f->highest_version);
724 	rd->ino = cpu_to_je32(inode->i_ino);
725 	rd->mctime = cpu_to_je32(JFFS2_NOW());
726 	rd->nsize = namelen;
727 
728 	/* XXX: This is ugly. */
729 	rd->type = (mode & S_IFMT) >> 12;
730 
731 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
732 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
733 
734 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
735 
736 	if (IS_ERR(fd)) {
737 		/* dirent failed to write. Delete the inode normally
738 		   as if it were the final unlink() */
739 		jffs2_complete_reservation(c);
740 		jffs2_free_raw_dirent(rd);
741 		mutex_unlock(&dir_f->sem);
742 		ret = PTR_ERR(fd);
743 		goto fail;
744 	}
745 
746 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
747 
748 	jffs2_free_raw_dirent(rd);
749 
750 	/* Link the fd into the inode's list, obsoleting an old
751 	   one if necessary. */
752 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
753 
754 	mutex_unlock(&dir_f->sem);
755 	jffs2_complete_reservation(c);
756 
757 	d_instantiate_new(dentry, inode);
758 	return 0;
759 
760  fail:
761 	iget_failed(inode);
762 	return ret;
763 }
764 
765 static int jffs2_rename (struct mnt_idmap *idmap,
766 			 struct inode *old_dir_i, struct dentry *old_dentry,
767 			 struct inode *new_dir_i, struct dentry *new_dentry,
768 			 unsigned int flags)
769 {
770 	int ret;
771 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
772 	struct jffs2_inode_info *victim_f = NULL;
773 	uint8_t type;
774 	uint32_t now;
775 
776 	if (flags & ~RENAME_NOREPLACE)
777 		return -EINVAL;
778 
779 	/* The VFS will check for us and prevent trying to rename a
780 	 * file over a directory and vice versa, but if it's a directory,
781 	 * the VFS can't check whether the victim is empty. The filesystem
782 	 * needs to do that for itself.
783 	 */
784 	if (d_really_is_positive(new_dentry)) {
785 		victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
786 		if (d_is_dir(new_dentry)) {
787 			struct jffs2_full_dirent *fd;
788 
789 			mutex_lock(&victim_f->sem);
790 			for (fd = victim_f->dents; fd; fd = fd->next) {
791 				if (fd->ino) {
792 					mutex_unlock(&victim_f->sem);
793 					return -ENOTEMPTY;
794 				}
795 			}
796 			mutex_unlock(&victim_f->sem);
797 		}
798 	}
799 
800 	/* XXX: We probably ought to alloc enough space for
801 	   both nodes at the same time. Writing the new link,
802 	   then getting -ENOSPC, is quite bad :)
803 	*/
804 
805 	/* Make a hard link */
806 
807 	/* XXX: This is ugly */
808 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
809 	if (!type) type = DT_REG;
810 
811 	now = JFFS2_NOW();
812 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
813 			    d_inode(old_dentry)->i_ino, type,
814 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
815 
816 	if (ret)
817 		return ret;
818 
819 	if (victim_f) {
820 		/* There was a victim. Kill it off nicely */
821 		if (d_is_dir(new_dentry))
822 			clear_nlink(d_inode(new_dentry));
823 		else
824 			drop_nlink(d_inode(new_dentry));
825 		/* Don't oops if the victim was a dirent pointing to an
826 		   inode which didn't exist. */
827 		if (victim_f->inocache) {
828 			mutex_lock(&victim_f->sem);
829 			if (d_is_dir(new_dentry))
830 				victim_f->inocache->pino_nlink = 0;
831 			else
832 				victim_f->inocache->pino_nlink--;
833 			mutex_unlock(&victim_f->sem);
834 		}
835 	}
836 
837 	/* If it was a directory we moved, and there was no victim,
838 	   increase i_nlink on its new parent */
839 	if (d_is_dir(old_dentry) && !victim_f)
840 		inc_nlink(new_dir_i);
841 
842 	/* Unlink the original */
843 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
844 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
845 
846 	/* We don't touch inode->i_nlink */
847 
848 	if (ret) {
849 		/* Oh shit. We really ought to make a single node which can do both atomically */
850 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
851 		mutex_lock(&f->sem);
852 		inc_nlink(d_inode(old_dentry));
853 		if (f->inocache && !d_is_dir(old_dentry))
854 			f->inocache->pino_nlink++;
855 		mutex_unlock(&f->sem);
856 
857 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
858 			  __func__, ret);
859 		/*
860 		 * We can't keep the target in dcache after that.
861 		 * For one thing, we can't afford dentry aliases for directories.
862 		 * For another, if there was a victim, we _can't_ set new inode
863 		 * for that sucker and we have to trigger mount eviction - the
864 		 * caller won't do it on its own since we are returning an error.
865 		 */
866 		d_invalidate(new_dentry);
867 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
868 		return ret;
869 	}
870 
871 	if (d_is_dir(old_dentry))
872 		drop_nlink(old_dir_i);
873 
874 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
875 
876 	return 0;
877 }
878 
879