xref: /openbmc/linux/fs/hfsplus/dir.c (revision 7b6d864b) 
1 /*
2  *  linux/fs/hfsplus/dir.c
3  *
4  * Copyright (C) 2001
5  * Brad Boyer (flar@allandria.com)
6  * (C) 2003 Ardis Technologies <roman@ardistech.com>
7  *
8  * Handling of directories
9  */
10 
11 #include <linux/errno.h>
12 #include <linux/fs.h>
13 #include <linux/slab.h>
14 #include <linux/random.h>
15 
16 #include "hfsplus_fs.h"
17 #include "hfsplus_raw.h"
18 #include "xattr.h"
19 
20 static inline void hfsplus_instantiate(struct dentry *dentry,
21 				       struct inode *inode, u32 cnid)
22 {
23 	dentry->d_fsdata = (void *)(unsigned long)cnid;
24 	d_instantiate(dentry, inode);
25 }
26 
27 /* Find the entry inside dir named dentry->d_name */
28 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
29 				     unsigned int flags)
30 {
31 	struct inode *inode = NULL;
32 	struct hfs_find_data fd;
33 	struct super_block *sb;
34 	hfsplus_cat_entry entry;
35 	int err;
36 	u32 cnid, linkid = 0;
37 	u16 type;
38 
39 	sb = dir->i_sb;
40 
41 	dentry->d_fsdata = NULL;
42 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
43 	if (err)
44 		return ERR_PTR(err);
45 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
46 again:
47 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
48 	if (err) {
49 		if (err == -ENOENT) {
50 			hfs_find_exit(&fd);
51 			/* No such entry */
52 			inode = NULL;
53 			goto out;
54 		}
55 		goto fail;
56 	}
57 	type = be16_to_cpu(entry.type);
58 	if (type == HFSPLUS_FOLDER) {
59 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
60 			err = -EIO;
61 			goto fail;
62 		}
63 		cnid = be32_to_cpu(entry.folder.id);
64 		dentry->d_fsdata = (void *)(unsigned long)cnid;
65 	} else if (type == HFSPLUS_FILE) {
66 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
67 			err = -EIO;
68 			goto fail;
69 		}
70 		cnid = be32_to_cpu(entry.file.id);
71 		if (entry.file.user_info.fdType ==
72 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
73 				entry.file.user_info.fdCreator ==
74 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
75 				(entry.file.create_date ==
76 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
77 						create_date ||
78 				entry.file.create_date ==
79 					HFSPLUS_I(sb->s_root->d_inode)->
80 						create_date) &&
81 				HFSPLUS_SB(sb)->hidden_dir) {
82 			struct qstr str;
83 			char name[32];
84 
85 			if (dentry->d_fsdata) {
86 				/*
87 				 * We found a link pointing to another link,
88 				 * so ignore it and treat it as regular file.
89 				 */
90 				cnid = (unsigned long)dentry->d_fsdata;
91 				linkid = 0;
92 			} else {
93 				dentry->d_fsdata = (void *)(unsigned long)cnid;
94 				linkid =
95 					be32_to_cpu(entry.file.permissions.dev);
96 				str.len = sprintf(name, "iNode%d", linkid);
97 				str.name = name;
98 				hfsplus_cat_build_key(sb, fd.search_key,
99 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
100 					&str);
101 				goto again;
102 			}
103 		} else if (!dentry->d_fsdata)
104 			dentry->d_fsdata = (void *)(unsigned long)cnid;
105 	} else {
106 		pr_err("invalid catalog entry type in lookup\n");
107 		err = -EIO;
108 		goto fail;
109 	}
110 	hfs_find_exit(&fd);
111 	inode = hfsplus_iget(dir->i_sb, cnid);
112 	if (IS_ERR(inode))
113 		return ERR_CAST(inode);
114 	if (S_ISREG(inode->i_mode))
115 		HFSPLUS_I(inode)->linkid = linkid;
116 out:
117 	d_add(dentry, inode);
118 	return NULL;
119 fail:
120 	hfs_find_exit(&fd);
121 	return ERR_PTR(err);
122 }
123 
124 static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
125 {
126 	struct inode *inode = file_inode(file);
127 	struct super_block *sb = inode->i_sb;
128 	int len, err;
129 	char strbuf[HFSPLUS_MAX_STRLEN + 1];
130 	hfsplus_cat_entry entry;
131 	struct hfs_find_data fd;
132 	struct hfsplus_readdir_data *rd;
133 	u16 type;
134 
135 	if (file->f_pos >= inode->i_size)
136 		return 0;
137 
138 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
139 	if (err)
140 		return err;
141 	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
142 	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
143 	if (err)
144 		goto out;
145 
146 	if (ctx->pos == 0) {
147 		/* This is completely artificial... */
148 		if (!dir_emit_dot(file, ctx))
149 			goto out;
150 		ctx->pos = 1;
151 	}
152 	if (ctx->pos == 1) {
153 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
154 			err = -EIO;
155 			goto out;
156 		}
157 
158 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
159 			fd.entrylength);
160 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
161 			pr_err("bad catalog folder thread\n");
162 			err = -EIO;
163 			goto out;
164 		}
165 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
166 			pr_err("truncated catalog thread\n");
167 			err = -EIO;
168 			goto out;
169 		}
170 		if (!dir_emit(ctx, "..", 2,
171 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
172 			goto out;
173 		ctx->pos = 2;
174 	}
175 	if (ctx->pos >= inode->i_size)
176 		goto out;
177 	err = hfs_brec_goto(&fd, ctx->pos - 1);
178 	if (err)
179 		goto out;
180 	for (;;) {
181 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
182 			pr_err("walked past end of dir\n");
183 			err = -EIO;
184 			goto out;
185 		}
186 
187 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
188 			err = -EIO;
189 			goto out;
190 		}
191 
192 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
193 			fd.entrylength);
194 		type = be16_to_cpu(entry.type);
195 		len = HFSPLUS_MAX_STRLEN;
196 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
197 		if (err)
198 			goto out;
199 		if (type == HFSPLUS_FOLDER) {
200 			if (fd.entrylength <
201 					sizeof(struct hfsplus_cat_folder)) {
202 				pr_err("small dir entry\n");
203 				err = -EIO;
204 				goto out;
205 			}
206 			if (HFSPLUS_SB(sb)->hidden_dir &&
207 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
208 					be32_to_cpu(entry.folder.id))
209 				goto next;
210 			if (!dir_emit(ctx, strbuf, len,
211 				    be32_to_cpu(entry.folder.id), DT_DIR))
212 				break;
213 		} else if (type == HFSPLUS_FILE) {
214 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
215 				pr_err("small file entry\n");
216 				err = -EIO;
217 				goto out;
218 			}
219 			if (!dir_emit(ctx, strbuf, len,
220 				    be32_to_cpu(entry.file.id), DT_REG))
221 				break;
222 		} else {
223 			pr_err("bad catalog entry type\n");
224 			err = -EIO;
225 			goto out;
226 		}
227 next:
228 		ctx->pos++;
229 		if (ctx->pos >= inode->i_size)
230 			goto out;
231 		err = hfs_brec_goto(&fd, 1);
232 		if (err)
233 			goto out;
234 	}
235 	rd = file->private_data;
236 	if (!rd) {
237 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
238 		if (!rd) {
239 			err = -ENOMEM;
240 			goto out;
241 		}
242 		file->private_data = rd;
243 		rd->file = file;
244 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
245 	}
246 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
247 out:
248 	hfs_find_exit(&fd);
249 	return err;
250 }
251 
252 static int hfsplus_dir_release(struct inode *inode, struct file *file)
253 {
254 	struct hfsplus_readdir_data *rd = file->private_data;
255 	if (rd) {
256 		mutex_lock(&inode->i_mutex);
257 		list_del(&rd->list);
258 		mutex_unlock(&inode->i_mutex);
259 		kfree(rd);
260 	}
261 	return 0;
262 }
263 
264 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
265 			struct dentry *dst_dentry)
266 {
267 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
268 	struct inode *inode = src_dentry->d_inode;
269 	struct inode *src_dir = src_dentry->d_parent->d_inode;
270 	struct qstr str;
271 	char name[32];
272 	u32 cnid, id;
273 	int res;
274 
275 	if (HFSPLUS_IS_RSRC(inode))
276 		return -EPERM;
277 	if (!S_ISREG(inode->i_mode))
278 		return -EPERM;
279 
280 	mutex_lock(&sbi->vh_mutex);
281 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
282 		for (;;) {
283 			get_random_bytes(&id, sizeof(cnid));
284 			id &= 0x3fffffff;
285 			str.name = name;
286 			str.len = sprintf(name, "iNode%d", id);
287 			res = hfsplus_rename_cat(inode->i_ino,
288 						 src_dir, &src_dentry->d_name,
289 						 sbi->hidden_dir, &str);
290 			if (!res)
291 				break;
292 			if (res != -EEXIST)
293 				goto out;
294 		}
295 		HFSPLUS_I(inode)->linkid = id;
296 		cnid = sbi->next_cnid++;
297 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
298 		res = hfsplus_create_cat(cnid, src_dir,
299 			&src_dentry->d_name, inode);
300 		if (res)
301 			/* panic? */
302 			goto out;
303 		sbi->file_count++;
304 	}
305 	cnid = sbi->next_cnid++;
306 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
307 	if (res)
308 		goto out;
309 
310 	inc_nlink(inode);
311 	hfsplus_instantiate(dst_dentry, inode, cnid);
312 	ihold(inode);
313 	inode->i_ctime = CURRENT_TIME_SEC;
314 	mark_inode_dirty(inode);
315 	sbi->file_count++;
316 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
317 out:
318 	mutex_unlock(&sbi->vh_mutex);
319 	return res;
320 }
321 
322 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
323 {
324 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
325 	struct inode *inode = dentry->d_inode;
326 	struct qstr str;
327 	char name[32];
328 	u32 cnid;
329 	int res;
330 
331 	if (HFSPLUS_IS_RSRC(inode))
332 		return -EPERM;
333 
334 	mutex_lock(&sbi->vh_mutex);
335 	cnid = (u32)(unsigned long)dentry->d_fsdata;
336 	if (inode->i_ino == cnid &&
337 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
338 		str.name = name;
339 		str.len = sprintf(name, "temp%lu", inode->i_ino);
340 		res = hfsplus_rename_cat(inode->i_ino,
341 					 dir, &dentry->d_name,
342 					 sbi->hidden_dir, &str);
343 		if (!res) {
344 			inode->i_flags |= S_DEAD;
345 			drop_nlink(inode);
346 		}
347 		goto out;
348 	}
349 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
350 	if (res)
351 		goto out;
352 
353 	if (inode->i_nlink > 0)
354 		drop_nlink(inode);
355 	if (inode->i_ino == cnid)
356 		clear_nlink(inode);
357 	if (!inode->i_nlink) {
358 		if (inode->i_ino != cnid) {
359 			sbi->file_count--;
360 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
361 				res = hfsplus_delete_cat(inode->i_ino,
362 							 sbi->hidden_dir,
363 							 NULL);
364 				if (!res)
365 					hfsplus_delete_inode(inode);
366 			} else
367 				inode->i_flags |= S_DEAD;
368 		} else
369 			hfsplus_delete_inode(inode);
370 	} else
371 		sbi->file_count--;
372 	inode->i_ctime = CURRENT_TIME_SEC;
373 	mark_inode_dirty(inode);
374 out:
375 	mutex_unlock(&sbi->vh_mutex);
376 	return res;
377 }
378 
379 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
380 {
381 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
382 	struct inode *inode = dentry->d_inode;
383 	int res;
384 
385 	if (inode->i_size != 2)
386 		return -ENOTEMPTY;
387 
388 	mutex_lock(&sbi->vh_mutex);
389 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
390 	if (res)
391 		goto out;
392 	clear_nlink(inode);
393 	inode->i_ctime = CURRENT_TIME_SEC;
394 	hfsplus_delete_inode(inode);
395 	mark_inode_dirty(inode);
396 out:
397 	mutex_unlock(&sbi->vh_mutex);
398 	return res;
399 }
400 
401 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
402 			   const char *symname)
403 {
404 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
405 	struct inode *inode;
406 	int res = -ENOSPC;
407 
408 	mutex_lock(&sbi->vh_mutex);
409 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
410 	if (!inode)
411 		goto out;
412 
413 	res = page_symlink(inode, symname, strlen(symname) + 1);
414 	if (res)
415 		goto out_err;
416 
417 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
418 	if (res)
419 		goto out_err;
420 
421 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
422 	if (res == -EOPNOTSUPP)
423 		res = 0; /* Operation is not supported. */
424 	else if (res) {
425 		/* Try to delete anyway without error analysis. */
426 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
427 		goto out_err;
428 	}
429 
430 	hfsplus_instantiate(dentry, inode, inode->i_ino);
431 	mark_inode_dirty(inode);
432 	goto out;
433 
434 out_err:
435 	clear_nlink(inode);
436 	hfsplus_delete_inode(inode);
437 	iput(inode);
438 out:
439 	mutex_unlock(&sbi->vh_mutex);
440 	return res;
441 }
442 
443 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
444 			 umode_t mode, dev_t rdev)
445 {
446 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
447 	struct inode *inode;
448 	int res = -ENOSPC;
449 
450 	mutex_lock(&sbi->vh_mutex);
451 	inode = hfsplus_new_inode(dir->i_sb, mode);
452 	if (!inode)
453 		goto out;
454 
455 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
456 		init_special_inode(inode, mode, rdev);
457 
458 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
459 	if (res)
460 		goto failed_mknod;
461 
462 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
463 	if (res == -EOPNOTSUPP)
464 		res = 0; /* Operation is not supported. */
465 	else if (res) {
466 		/* Try to delete anyway without error analysis. */
467 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
468 		goto failed_mknod;
469 	}
470 
471 	hfsplus_instantiate(dentry, inode, inode->i_ino);
472 	mark_inode_dirty(inode);
473 	goto out;
474 
475 failed_mknod:
476 	clear_nlink(inode);
477 	hfsplus_delete_inode(inode);
478 	iput(inode);
479 out:
480 	mutex_unlock(&sbi->vh_mutex);
481 	return res;
482 }
483 
484 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
485 			  bool excl)
486 {
487 	return hfsplus_mknod(dir, dentry, mode, 0);
488 }
489 
490 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
491 {
492 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
493 }
494 
495 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
496 			  struct inode *new_dir, struct dentry *new_dentry)
497 {
498 	int res;
499 
500 	/* Unlink destination if it already exists */
501 	if (new_dentry->d_inode) {
502 		if (S_ISDIR(new_dentry->d_inode->i_mode))
503 			res = hfsplus_rmdir(new_dir, new_dentry);
504 		else
505 			res = hfsplus_unlink(new_dir, new_dentry);
506 		if (res)
507 			return res;
508 	}
509 
510 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
511 				 old_dir, &old_dentry->d_name,
512 				 new_dir, &new_dentry->d_name);
513 	if (!res)
514 		new_dentry->d_fsdata = old_dentry->d_fsdata;
515 	return res;
516 }
517 
518 const struct inode_operations hfsplus_dir_inode_operations = {
519 	.lookup			= hfsplus_lookup,
520 	.create			= hfsplus_create,
521 	.link			= hfsplus_link,
522 	.unlink			= hfsplus_unlink,
523 	.mkdir			= hfsplus_mkdir,
524 	.rmdir			= hfsplus_rmdir,
525 	.symlink		= hfsplus_symlink,
526 	.mknod			= hfsplus_mknod,
527 	.rename			= hfsplus_rename,
528 	.setxattr		= generic_setxattr,
529 	.getxattr		= generic_getxattr,
530 	.listxattr		= hfsplus_listxattr,
531 	.removexattr		= hfsplus_removexattr,
532 };
533 
534 const struct file_operations hfsplus_dir_operations = {
535 	.fsync		= hfsplus_file_fsync,
536 	.read		= generic_read_dir,
537 	.iterate	= hfsplus_readdir,
538 	.unlocked_ioctl = hfsplus_ioctl,
539 	.llseek		= generic_file_llseek,
540 	.release	= hfsplus_dir_release,
541 };
542