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1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6  *
7  * Created by David Woodhouse <dwmw2@infradead.org>
8  *
9  * For licensing information, see the file 'LICENCE' in this directory.
10  *
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/kernel.h>
16 #include <linux/slab.h>
17 #include <linux/fs.h>
18 #include <linux/crc32.h>
19 #include <linux/jffs2.h>
20 #include "jffs2_fs_i.h"
21 #include "jffs2_fs_sb.h"
22 #include <linux/time.h>
23 #include "nodelist.h"
24 
25 static int jffs2_readdir (struct file *, struct dir_context *);
26 
27 static int jffs2_create (struct inode *,struct dentry *,umode_t,
28 			 bool);
29 static struct dentry *jffs2_lookup (struct inode *,struct dentry *,
30 				    unsigned int);
31 static int jffs2_link (struct dentry *,struct inode *,struct dentry *);
32 static int jffs2_unlink (struct inode *,struct dentry *);
33 static int jffs2_symlink (struct inode *,struct dentry *,const char *);
34 static int jffs2_mkdir (struct inode *,struct dentry *,umode_t);
35 static int jffs2_rmdir (struct inode *,struct dentry *);
36 static int jffs2_mknod (struct inode *,struct dentry *,umode_t,dev_t);
37 static int jffs2_rename (struct inode *, struct dentry *,
38 			 struct inode *, struct dentry *);
39 
40 const struct file_operations jffs2_dir_operations =
41 {
42 	.read =		generic_read_dir,
43 	.iterate =	jffs2_readdir,
44 	.unlocked_ioctl=jffs2_ioctl,
45 	.fsync =	jffs2_fsync,
46 	.llseek =	generic_file_llseek,
47 };
48 
49 
50 const struct inode_operations jffs2_dir_inode_operations =
51 {
52 	.create =	jffs2_create,
53 	.lookup =	jffs2_lookup,
54 	.link =		jffs2_link,
55 	.unlink =	jffs2_unlink,
56 	.symlink =	jffs2_symlink,
57 	.mkdir =	jffs2_mkdir,
58 	.rmdir =	jffs2_rmdir,
59 	.mknod =	jffs2_mknod,
60 	.rename =	jffs2_rename,
61 	.get_acl =	jffs2_get_acl,
62 	.set_acl =	jffs2_set_acl,
63 	.setattr =	jffs2_setattr,
64 	.setxattr =	jffs2_setxattr,
65 	.getxattr =	jffs2_getxattr,
66 	.listxattr =	jffs2_listxattr,
67 	.removexattr =	jffs2_removexattr
68 };
69 
70 /***********************************************************************/
71 
72 
73 /* We keep the dirent list sorted in increasing order of name hash,
74    and we use the same hash function as the dentries. Makes this
75    nice and simple
76 */
jffs2_lookup(struct inode * dir_i,struct dentry * target,unsigned int flags)77 static struct dentry *jffs2_lookup(struct inode *dir_i, struct dentry *target,
78 				   unsigned int flags)
79 {
80 	struct jffs2_inode_info *dir_f;
81 	struct jffs2_full_dirent *fd = NULL, *fd_list;
82 	uint32_t ino = 0;
83 	struct inode *inode = NULL;
84 
85 	jffs2_dbg(1, "jffs2_lookup()\n");
86 
87 	if (target->d_name.len > JFFS2_MAX_NAME_LEN)
88 		return ERR_PTR(-ENAMETOOLONG);
89 
90 	dir_f = JFFS2_INODE_INFO(dir_i);
91 
92 	mutex_lock(&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 	mutex_unlock(&dir_f->sem);
106 	if (ino) {
107 		inode = jffs2_iget(dir_i->i_sb, ino);
108 		if (IS_ERR(inode))
109 			pr_warn("iget() failed for ino #%u\n", ino);
110 	}
111 
112 	return d_splice_alias(inode, target);
113 }
114 
115 /***********************************************************************/
116 
117 
jffs2_readdir(struct file * file,struct dir_context * ctx)118 static int jffs2_readdir(struct file *file, struct dir_context *ctx)
119 {
120 	struct inode *inode = file_inode(file);
121 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
122 	struct jffs2_full_dirent *fd;
123 	unsigned long curofs = 1;
124 
125 	jffs2_dbg(1, "jffs2_readdir() for dir_i #%lu\n", inode->i_ino);
126 
127 	if (!dir_emit_dots(file, ctx))
128 		return 0;
129 
130 	mutex_lock(&f->sem);
131 	for (fd = f->dents; fd; fd = fd->next) {
132 		curofs++;
133 		/* First loop: curofs = 2; pos = 2 */
134 		if (curofs < ctx->pos) {
135 			jffs2_dbg(2, "Skipping dirent: \"%s\", ino #%u, type %d, because curofs %ld < offset %ld\n",
136 				  fd->name, fd->ino, fd->type, curofs, (unsigned long)ctx->pos);
137 			continue;
138 		}
139 		if (!fd->ino) {
140 			jffs2_dbg(2, "Skipping deletion dirent \"%s\"\n",
141 				  fd->name);
142 			ctx->pos++;
143 			continue;
144 		}
145 		jffs2_dbg(2, "Dirent %ld: \"%s\", ino #%u, type %d\n",
146 			  (unsigned long)ctx->pos, fd->name, fd->ino, fd->type);
147 		if (!dir_emit(ctx, fd->name, strlen(fd->name), fd->ino, fd->type))
148 			break;
149 		ctx->pos++;
150 	}
151 	mutex_unlock(&f->sem);
152 	return 0;
153 }
154 
155 /***********************************************************************/
156 
157 
jffs2_create(struct inode * dir_i,struct dentry * dentry,umode_t mode,bool excl)158 static int jffs2_create(struct inode *dir_i, struct dentry *dentry,
159 			umode_t mode, bool excl)
160 {
161 	struct jffs2_raw_inode *ri;
162 	struct jffs2_inode_info *f, *dir_f;
163 	struct jffs2_sb_info *c;
164 	struct inode *inode;
165 	int ret;
166 
167 	ri = jffs2_alloc_raw_inode();
168 	if (!ri)
169 		return -ENOMEM;
170 
171 	c = JFFS2_SB_INFO(dir_i->i_sb);
172 
173 	jffs2_dbg(1, "%s()\n", __func__);
174 
175 	inode = jffs2_new_inode(dir_i, mode, ri);
176 
177 	if (IS_ERR(inode)) {
178 		jffs2_dbg(1, "jffs2_new_inode() failed\n");
179 		jffs2_free_raw_inode(ri);
180 		return PTR_ERR(inode);
181 	}
182 
183 	inode->i_op = &jffs2_file_inode_operations;
184 	inode->i_fop = &jffs2_file_operations;
185 	inode->i_mapping->a_ops = &jffs2_file_address_operations;
186 	inode->i_mapping->nrpages = 0;
187 
188 	f = JFFS2_INODE_INFO(inode);
189 	dir_f = JFFS2_INODE_INFO(dir_i);
190 
191 	/* jffs2_do_create() will want to lock it, _after_ reserving
192 	   space and taking c-alloc_sem. If we keep it locked here,
193 	   lockdep gets unhappy (although it's a false positive;
194 	   nothing else will be looking at this inode yet so there's
195 	   no chance of AB-BA deadlock involving its f->sem). */
196 	mutex_unlock(&f->sem);
197 
198 	ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name);
199 	if (ret)
200 		goto fail;
201 
202 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(ri->ctime));
203 
204 	jffs2_free_raw_inode(ri);
205 
206 	jffs2_dbg(1, "%s(): Created ino #%lu with mode %o, nlink %d(%d). nrpages %ld\n",
207 		  __func__, inode->i_ino, inode->i_mode, inode->i_nlink,
208 		  f->inocache->pino_nlink, inode->i_mapping->nrpages);
209 
210 	d_instantiate_new(dentry, inode);
211 	return 0;
212 
213  fail:
214 	iget_failed(inode);
215 	jffs2_free_raw_inode(ri);
216 	return ret;
217 }
218 
219 /***********************************************************************/
220 
221 
jffs2_unlink(struct inode * dir_i,struct dentry * dentry)222 static int jffs2_unlink(struct inode *dir_i, struct dentry *dentry)
223 {
224 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
225 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
226 	struct jffs2_inode_info *dead_f = JFFS2_INODE_INFO(d_inode(dentry));
227 	int ret;
228 	uint32_t now = get_seconds();
229 
230 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
231 			      dentry->d_name.len, dead_f, now);
232 	if (dead_f->inocache)
233 		set_nlink(d_inode(dentry), dead_f->inocache->pino_nlink);
234 	if (!ret)
235 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
236 	return ret;
237 }
238 /***********************************************************************/
239 
240 
jffs2_link(struct dentry * old_dentry,struct inode * dir_i,struct dentry * dentry)241 static int jffs2_link (struct dentry *old_dentry, struct inode *dir_i, struct dentry *dentry)
242 {
243 	struct jffs2_sb_info *c = JFFS2_SB_INFO(d_inode(old_dentry)->i_sb);
244 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
245 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
246 	int ret;
247 	uint8_t type;
248 	uint32_t now;
249 
250 	/* Don't let people make hard links to bad inodes. */
251 	if (!f->inocache)
252 		return -EIO;
253 
254 	if (d_is_dir(old_dentry))
255 		return -EPERM;
256 
257 	/* XXX: This is ugly */
258 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
259 	if (!type) type = DT_REG;
260 
261 	now = get_seconds();
262 	ret = jffs2_do_link(c, dir_f, f->inocache->ino, type, dentry->d_name.name, dentry->d_name.len, now);
263 
264 	if (!ret) {
265 		mutex_lock(&f->sem);
266 		set_nlink(d_inode(old_dentry), ++f->inocache->pino_nlink);
267 		mutex_unlock(&f->sem);
268 		d_instantiate(dentry, d_inode(old_dentry));
269 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
270 		ihold(d_inode(old_dentry));
271 	}
272 	return ret;
273 }
274 
275 /***********************************************************************/
276 
jffs2_symlink(struct inode * dir_i,struct dentry * dentry,const char * target)277 static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char *target)
278 {
279 	struct jffs2_inode_info *f, *dir_f;
280 	struct jffs2_sb_info *c;
281 	struct inode *inode;
282 	struct jffs2_raw_inode *ri;
283 	struct jffs2_raw_dirent *rd;
284 	struct jffs2_full_dnode *fn;
285 	struct jffs2_full_dirent *fd;
286 	int namelen;
287 	uint32_t alloclen;
288 	int ret, targetlen = strlen(target);
289 
290 	/* FIXME: If you care. We'd need to use frags for the target
291 	   if it grows much more than this */
292 	if (targetlen > 254)
293 		return -ENAMETOOLONG;
294 
295 	ri = jffs2_alloc_raw_inode();
296 
297 	if (!ri)
298 		return -ENOMEM;
299 
300 	c = JFFS2_SB_INFO(dir_i->i_sb);
301 
302 	/* Try to reserve enough space for both node and dirent.
303 	 * Just the node will do for now, though
304 	 */
305 	namelen = dentry->d_name.len;
306 	ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen,
307 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
308 
309 	if (ret) {
310 		jffs2_free_raw_inode(ri);
311 		return ret;
312 	}
313 
314 	inode = jffs2_new_inode(dir_i, S_IFLNK | S_IRWXUGO, ri);
315 
316 	if (IS_ERR(inode)) {
317 		jffs2_free_raw_inode(ri);
318 		jffs2_complete_reservation(c);
319 		return PTR_ERR(inode);
320 	}
321 
322 	inode->i_op = &jffs2_symlink_inode_operations;
323 
324 	f = JFFS2_INODE_INFO(inode);
325 
326 	inode->i_size = targetlen;
327 	ri->isize = ri->dsize = ri->csize = cpu_to_je32(inode->i_size);
328 	ri->totlen = cpu_to_je32(sizeof(*ri) + inode->i_size);
329 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
330 
331 	ri->compr = JFFS2_COMPR_NONE;
332 	ri->data_crc = cpu_to_je32(crc32(0, target, targetlen));
333 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
334 
335 	fn = jffs2_write_dnode(c, f, ri, target, targetlen, ALLOC_NORMAL);
336 
337 	jffs2_free_raw_inode(ri);
338 
339 	if (IS_ERR(fn)) {
340 		/* Eeek. Wave bye bye */
341 		mutex_unlock(&f->sem);
342 		jffs2_complete_reservation(c);
343 		ret = PTR_ERR(fn);
344 		goto fail;
345 	}
346 
347 	/* We use f->target field to store the target path. */
348 	f->target = kmemdup(target, targetlen + 1, GFP_KERNEL);
349 	if (!f->target) {
350 		pr_warn("Can't allocate %d bytes of memory\n", targetlen + 1);
351 		mutex_unlock(&f->sem);
352 		jffs2_complete_reservation(c);
353 		ret = -ENOMEM;
354 		goto fail;
355 	}
356 	inode->i_link = f->target;
357 
358 	jffs2_dbg(1, "%s(): symlink's target '%s' cached\n",
359 		  __func__, (char *)f->target);
360 
361 	/* No data here. Only a metadata node, which will be
362 	   obsoleted by the first data write
363 	*/
364 	f->metadata = fn;
365 	mutex_unlock(&f->sem);
366 
367 	jffs2_complete_reservation(c);
368 
369 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
370 	if (ret)
371 		goto fail;
372 
373 	ret = jffs2_init_acl_post(inode);
374 	if (ret)
375 		goto fail;
376 
377 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
378 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
379 	if (ret)
380 		goto fail;
381 
382 	rd = jffs2_alloc_raw_dirent();
383 	if (!rd) {
384 		/* Argh. Now we treat it like a normal delete */
385 		jffs2_complete_reservation(c);
386 		ret = -ENOMEM;
387 		goto fail;
388 	}
389 
390 	dir_f = JFFS2_INODE_INFO(dir_i);
391 	mutex_lock(&dir_f->sem);
392 
393 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
394 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
395 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
396 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
397 
398 	rd->pino = cpu_to_je32(dir_i->i_ino);
399 	rd->version = cpu_to_je32(++dir_f->highest_version);
400 	rd->ino = cpu_to_je32(inode->i_ino);
401 	rd->mctime = cpu_to_je32(get_seconds());
402 	rd->nsize = namelen;
403 	rd->type = DT_LNK;
404 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
405 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
406 
407 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
408 
409 	if (IS_ERR(fd)) {
410 		/* dirent failed to write. Delete the inode normally
411 		   as if it were the final unlink() */
412 		jffs2_complete_reservation(c);
413 		jffs2_free_raw_dirent(rd);
414 		mutex_unlock(&dir_f->sem);
415 		ret = PTR_ERR(fd);
416 		goto fail;
417 	}
418 
419 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
420 
421 	jffs2_free_raw_dirent(rd);
422 
423 	/* Link the fd into the inode's list, obsoleting an old
424 	   one if necessary. */
425 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
426 
427 	mutex_unlock(&dir_f->sem);
428 	jffs2_complete_reservation(c);
429 
430 	d_instantiate_new(dentry, inode);
431 	return 0;
432 
433  fail:
434 	iget_failed(inode);
435 	return ret;
436 }
437 
438 
jffs2_mkdir(struct inode * dir_i,struct dentry * dentry,umode_t mode)439 static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode)
440 {
441 	struct jffs2_inode_info *f, *dir_f;
442 	struct jffs2_sb_info *c;
443 	struct inode *inode;
444 	struct jffs2_raw_inode *ri;
445 	struct jffs2_raw_dirent *rd;
446 	struct jffs2_full_dnode *fn;
447 	struct jffs2_full_dirent *fd;
448 	int namelen;
449 	uint32_t alloclen;
450 	int ret;
451 
452 	mode |= S_IFDIR;
453 
454 	ri = jffs2_alloc_raw_inode();
455 	if (!ri)
456 		return -ENOMEM;
457 
458 	c = JFFS2_SB_INFO(dir_i->i_sb);
459 
460 	/* Try to reserve enough space for both node and dirent.
461 	 * Just the node will do for now, though
462 	 */
463 	namelen = dentry->d_name.len;
464 	ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL,
465 				  JFFS2_SUMMARY_INODE_SIZE);
466 
467 	if (ret) {
468 		jffs2_free_raw_inode(ri);
469 		return ret;
470 	}
471 
472 	inode = jffs2_new_inode(dir_i, mode, ri);
473 
474 	if (IS_ERR(inode)) {
475 		jffs2_free_raw_inode(ri);
476 		jffs2_complete_reservation(c);
477 		return PTR_ERR(inode);
478 	}
479 
480 	inode->i_op = &jffs2_dir_inode_operations;
481 	inode->i_fop = &jffs2_dir_operations;
482 
483 	f = JFFS2_INODE_INFO(inode);
484 
485 	/* Directories get nlink 2 at start */
486 	set_nlink(inode, 2);
487 	/* but ic->pino_nlink is the parent ino# */
488 	f->inocache->pino_nlink = dir_i->i_ino;
489 
490 	ri->data_crc = cpu_to_je32(0);
491 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
492 
493 	fn = jffs2_write_dnode(c, f, ri, NULL, 0, ALLOC_NORMAL);
494 
495 	jffs2_free_raw_inode(ri);
496 
497 	if (IS_ERR(fn)) {
498 		/* Eeek. Wave bye bye */
499 		mutex_unlock(&f->sem);
500 		jffs2_complete_reservation(c);
501 		ret = PTR_ERR(fn);
502 		goto fail;
503 	}
504 	/* No data here. Only a metadata node, which will be
505 	   obsoleted by the first data write
506 	*/
507 	f->metadata = fn;
508 	mutex_unlock(&f->sem);
509 
510 	jffs2_complete_reservation(c);
511 
512 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
513 	if (ret)
514 		goto fail;
515 
516 	ret = jffs2_init_acl_post(inode);
517 	if (ret)
518 		goto fail;
519 
520 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
521 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
522 	if (ret)
523 		goto fail;
524 
525 	rd = jffs2_alloc_raw_dirent();
526 	if (!rd) {
527 		/* Argh. Now we treat it like a normal delete */
528 		jffs2_complete_reservation(c);
529 		ret = -ENOMEM;
530 		goto fail;
531 	}
532 
533 	dir_f = JFFS2_INODE_INFO(dir_i);
534 	mutex_lock(&dir_f->sem);
535 
536 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
537 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
538 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
539 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
540 
541 	rd->pino = cpu_to_je32(dir_i->i_ino);
542 	rd->version = cpu_to_je32(++dir_f->highest_version);
543 	rd->ino = cpu_to_je32(inode->i_ino);
544 	rd->mctime = cpu_to_je32(get_seconds());
545 	rd->nsize = namelen;
546 	rd->type = DT_DIR;
547 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
548 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
549 
550 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
551 
552 	if (IS_ERR(fd)) {
553 		/* dirent failed to write. Delete the inode normally
554 		   as if it were the final unlink() */
555 		jffs2_complete_reservation(c);
556 		jffs2_free_raw_dirent(rd);
557 		mutex_unlock(&dir_f->sem);
558 		ret = PTR_ERR(fd);
559 		goto fail;
560 	}
561 
562 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
563 	inc_nlink(dir_i);
564 
565 	jffs2_free_raw_dirent(rd);
566 
567 	/* Link the fd into the inode's list, obsoleting an old
568 	   one if necessary. */
569 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
570 
571 	mutex_unlock(&dir_f->sem);
572 	jffs2_complete_reservation(c);
573 
574 	d_instantiate_new(dentry, inode);
575 	return 0;
576 
577  fail:
578 	iget_failed(inode);
579 	return ret;
580 }
581 
jffs2_rmdir(struct inode * dir_i,struct dentry * dentry)582 static int jffs2_rmdir (struct inode *dir_i, struct dentry *dentry)
583 {
584 	struct jffs2_sb_info *c = JFFS2_SB_INFO(dir_i->i_sb);
585 	struct jffs2_inode_info *dir_f = JFFS2_INODE_INFO(dir_i);
586 	struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(dentry));
587 	struct jffs2_full_dirent *fd;
588 	int ret;
589 	uint32_t now = get_seconds();
590 
591 	mutex_lock(&f->sem);
592 	for (fd = f->dents ; fd; fd = fd->next) {
593 		if (fd->ino) {
594 			mutex_unlock(&f->sem);
595 			return -ENOTEMPTY;
596 		}
597 	}
598 	mutex_unlock(&f->sem);
599 
600 	ret = jffs2_do_unlink(c, dir_f, dentry->d_name.name,
601 			      dentry->d_name.len, f, now);
602 	if (!ret) {
603 		dir_i->i_mtime = dir_i->i_ctime = ITIME(now);
604 		clear_nlink(d_inode(dentry));
605 		drop_nlink(dir_i);
606 	}
607 	return ret;
608 }
609 
jffs2_mknod(struct inode * dir_i,struct dentry * dentry,umode_t mode,dev_t rdev)610 static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode, dev_t rdev)
611 {
612 	struct jffs2_inode_info *f, *dir_f;
613 	struct jffs2_sb_info *c;
614 	struct inode *inode;
615 	struct jffs2_raw_inode *ri;
616 	struct jffs2_raw_dirent *rd;
617 	struct jffs2_full_dnode *fn;
618 	struct jffs2_full_dirent *fd;
619 	int namelen;
620 	union jffs2_device_node dev;
621 	int devlen = 0;
622 	uint32_t alloclen;
623 	int ret;
624 
625 	ri = jffs2_alloc_raw_inode();
626 	if (!ri)
627 		return -ENOMEM;
628 
629 	c = JFFS2_SB_INFO(dir_i->i_sb);
630 
631 	if (S_ISBLK(mode) || S_ISCHR(mode))
632 		devlen = jffs2_encode_dev(&dev, rdev);
633 
634 	/* Try to reserve enough space for both node and dirent.
635 	 * Just the node will do for now, though
636 	 */
637 	namelen = dentry->d_name.len;
638 	ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen,
639 				  ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
640 
641 	if (ret) {
642 		jffs2_free_raw_inode(ri);
643 		return ret;
644 	}
645 
646 	inode = jffs2_new_inode(dir_i, mode, ri);
647 
648 	if (IS_ERR(inode)) {
649 		jffs2_free_raw_inode(ri);
650 		jffs2_complete_reservation(c);
651 		return PTR_ERR(inode);
652 	}
653 	inode->i_op = &jffs2_file_inode_operations;
654 	init_special_inode(inode, inode->i_mode, rdev);
655 
656 	f = JFFS2_INODE_INFO(inode);
657 
658 	ri->dsize = ri->csize = cpu_to_je32(devlen);
659 	ri->totlen = cpu_to_je32(sizeof(*ri) + devlen);
660 	ri->hdr_crc = cpu_to_je32(crc32(0, ri, sizeof(struct jffs2_unknown_node)-4));
661 
662 	ri->compr = JFFS2_COMPR_NONE;
663 	ri->data_crc = cpu_to_je32(crc32(0, &dev, devlen));
664 	ri->node_crc = cpu_to_je32(crc32(0, ri, sizeof(*ri)-8));
665 
666 	fn = jffs2_write_dnode(c, f, ri, (char *)&dev, devlen, ALLOC_NORMAL);
667 
668 	jffs2_free_raw_inode(ri);
669 
670 	if (IS_ERR(fn)) {
671 		/* Eeek. Wave bye bye */
672 		mutex_unlock(&f->sem);
673 		jffs2_complete_reservation(c);
674 		ret = PTR_ERR(fn);
675 		goto fail;
676 	}
677 	/* No data here. Only a metadata node, which will be
678 	   obsoleted by the first data write
679 	*/
680 	f->metadata = fn;
681 	mutex_unlock(&f->sem);
682 
683 	jffs2_complete_reservation(c);
684 
685 	ret = jffs2_init_security(inode, dir_i, &dentry->d_name);
686 	if (ret)
687 		goto fail;
688 
689 	ret = jffs2_init_acl_post(inode);
690 	if (ret)
691 		goto fail;
692 
693 	ret = jffs2_reserve_space(c, sizeof(*rd)+namelen, &alloclen,
694 				  ALLOC_NORMAL, JFFS2_SUMMARY_DIRENT_SIZE(namelen));
695 	if (ret)
696 		goto fail;
697 
698 	rd = jffs2_alloc_raw_dirent();
699 	if (!rd) {
700 		/* Argh. Now we treat it like a normal delete */
701 		jffs2_complete_reservation(c);
702 		ret = -ENOMEM;
703 		goto fail;
704 	}
705 
706 	dir_f = JFFS2_INODE_INFO(dir_i);
707 	mutex_lock(&dir_f->sem);
708 
709 	rd->magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
710 	rd->nodetype = cpu_to_je16(JFFS2_NODETYPE_DIRENT);
711 	rd->totlen = cpu_to_je32(sizeof(*rd) + namelen);
712 	rd->hdr_crc = cpu_to_je32(crc32(0, rd, sizeof(struct jffs2_unknown_node)-4));
713 
714 	rd->pino = cpu_to_je32(dir_i->i_ino);
715 	rd->version = cpu_to_je32(++dir_f->highest_version);
716 	rd->ino = cpu_to_je32(inode->i_ino);
717 	rd->mctime = cpu_to_je32(get_seconds());
718 	rd->nsize = namelen;
719 
720 	/* XXX: This is ugly. */
721 	rd->type = (mode & S_IFMT) >> 12;
722 
723 	rd->node_crc = cpu_to_je32(crc32(0, rd, sizeof(*rd)-8));
724 	rd->name_crc = cpu_to_je32(crc32(0, dentry->d_name.name, namelen));
725 
726 	fd = jffs2_write_dirent(c, dir_f, rd, dentry->d_name.name, namelen, ALLOC_NORMAL);
727 
728 	if (IS_ERR(fd)) {
729 		/* dirent failed to write. Delete the inode normally
730 		   as if it were the final unlink() */
731 		jffs2_complete_reservation(c);
732 		jffs2_free_raw_dirent(rd);
733 		mutex_unlock(&dir_f->sem);
734 		ret = PTR_ERR(fd);
735 		goto fail;
736 	}
737 
738 	dir_i->i_mtime = dir_i->i_ctime = ITIME(je32_to_cpu(rd->mctime));
739 
740 	jffs2_free_raw_dirent(rd);
741 
742 	/* Link the fd into the inode's list, obsoleting an old
743 	   one if necessary. */
744 	jffs2_add_fd_to_list(c, fd, &dir_f->dents);
745 
746 	mutex_unlock(&dir_f->sem);
747 	jffs2_complete_reservation(c);
748 
749 	d_instantiate_new(dentry, inode);
750 	return 0;
751 
752  fail:
753 	iget_failed(inode);
754 	return ret;
755 }
756 
jffs2_rename(struct inode * old_dir_i,struct dentry * old_dentry,struct inode * new_dir_i,struct dentry * new_dentry)757 static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry,
758 			 struct inode *new_dir_i, struct dentry *new_dentry)
759 {
760 	int ret;
761 	struct jffs2_sb_info *c = JFFS2_SB_INFO(old_dir_i->i_sb);
762 	struct jffs2_inode_info *victim_f = NULL;
763 	uint8_t type;
764 	uint32_t now;
765 
766 	/* The VFS will check for us and prevent trying to rename a
767 	 * file over a directory and vice versa, but if it's a directory,
768 	 * the VFS can't check whether the victim is empty. The filesystem
769 	 * needs to do that for itself.
770 	 */
771 	if (d_really_is_positive(new_dentry)) {
772 		victim_f = JFFS2_INODE_INFO(d_inode(new_dentry));
773 		if (d_is_dir(new_dentry)) {
774 			struct jffs2_full_dirent *fd;
775 
776 			mutex_lock(&victim_f->sem);
777 			for (fd = victim_f->dents; fd; fd = fd->next) {
778 				if (fd->ino) {
779 					mutex_unlock(&victim_f->sem);
780 					return -ENOTEMPTY;
781 				}
782 			}
783 			mutex_unlock(&victim_f->sem);
784 		}
785 	}
786 
787 	/* XXX: We probably ought to alloc enough space for
788 	   both nodes at the same time. Writing the new link,
789 	   then getting -ENOSPC, is quite bad :)
790 	*/
791 
792 	/* Make a hard link */
793 
794 	/* XXX: This is ugly */
795 	type = (d_inode(old_dentry)->i_mode & S_IFMT) >> 12;
796 	if (!type) type = DT_REG;
797 
798 	now = get_seconds();
799 	ret = jffs2_do_link(c, JFFS2_INODE_INFO(new_dir_i),
800 			    d_inode(old_dentry)->i_ino, type,
801 			    new_dentry->d_name.name, new_dentry->d_name.len, now);
802 
803 	if (ret)
804 		return ret;
805 
806 	if (victim_f) {
807 		/* There was a victim. Kill it off nicely */
808 		if (d_is_dir(new_dentry))
809 			clear_nlink(d_inode(new_dentry));
810 		else
811 			drop_nlink(d_inode(new_dentry));
812 		/* Don't oops if the victim was a dirent pointing to an
813 		   inode which didn't exist. */
814 		if (victim_f->inocache) {
815 			mutex_lock(&victim_f->sem);
816 			if (d_is_dir(new_dentry))
817 				victim_f->inocache->pino_nlink = 0;
818 			else
819 				victim_f->inocache->pino_nlink--;
820 			mutex_unlock(&victim_f->sem);
821 		}
822 	}
823 
824 	/* If it was a directory we moved, and there was no victim,
825 	   increase i_nlink on its new parent */
826 	if (d_is_dir(old_dentry) && !victim_f)
827 		inc_nlink(new_dir_i);
828 
829 	/* Unlink the original */
830 	ret = jffs2_do_unlink(c, JFFS2_INODE_INFO(old_dir_i),
831 			      old_dentry->d_name.name, old_dentry->d_name.len, NULL, now);
832 
833 	/* We don't touch inode->i_nlink */
834 
835 	if (ret) {
836 		/* Oh shit. We really ought to make a single node which can do both atomically */
837 		struct jffs2_inode_info *f = JFFS2_INODE_INFO(d_inode(old_dentry));
838 		mutex_lock(&f->sem);
839 		inc_nlink(d_inode(old_dentry));
840 		if (f->inocache && !d_is_dir(old_dentry))
841 			f->inocache->pino_nlink++;
842 		mutex_unlock(&f->sem);
843 
844 		pr_notice("%s(): Link succeeded, unlink failed (err %d). You now have a hard link\n",
845 			  __func__, ret);
846 		/*
847 		 * We can't keep the target in dcache after that.
848 		 * For one thing, we can't afford dentry aliases for directories.
849 		 * For another, if there was a victim, we _can't_ set new inode
850 		 * for that sucker and we have to trigger mount eviction - the
851 		 * caller won't do it on its own since we are returning an error.
852 		 */
853 		d_invalidate(new_dentry);
854 		new_dir_i->i_mtime = new_dir_i->i_ctime = ITIME(now);
855 		return ret;
856 	}
857 
858 	if (d_is_dir(old_dentry))
859 		drop_nlink(old_dir_i);
860 
861 	new_dir_i->i_mtime = new_dir_i->i_ctime = old_dir_i->i_mtime = old_dir_i->i_ctime = ITIME(now);
862 
863 	return 0;
864 }
865 
866