xref: /openbmc/linux/fs/hfsplus/dir.c (revision 37be287c) 
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 #include "acl.h"
20 
21 static inline void hfsplus_instantiate(struct dentry *dentry,
22 				       struct inode *inode, u32 cnid)
23 {
24 	dentry->d_fsdata = (void *)(unsigned long)cnid;
25 	d_instantiate(dentry, inode);
26 }
27 
28 /* Find the entry inside dir named dentry->d_name */
29 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
30 				     unsigned int flags)
31 {
32 	struct inode *inode = NULL;
33 	struct hfs_find_data fd;
34 	struct super_block *sb;
35 	hfsplus_cat_entry entry;
36 	int err;
37 	u32 cnid, linkid = 0;
38 	u16 type;
39 
40 	sb = dir->i_sb;
41 
42 	dentry->d_fsdata = NULL;
43 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
44 	if (err)
45 		return ERR_PTR(err);
46 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
47 again:
48 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
49 	if (err) {
50 		if (err == -ENOENT) {
51 			hfs_find_exit(&fd);
52 			/* No such entry */
53 			inode = NULL;
54 			goto out;
55 		}
56 		goto fail;
57 	}
58 	type = be16_to_cpu(entry.type);
59 	if (type == HFSPLUS_FOLDER) {
60 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
61 			err = -EIO;
62 			goto fail;
63 		}
64 		cnid = be32_to_cpu(entry.folder.id);
65 		dentry->d_fsdata = (void *)(unsigned long)cnid;
66 	} else if (type == HFSPLUS_FILE) {
67 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
68 			err = -EIO;
69 			goto fail;
70 		}
71 		cnid = be32_to_cpu(entry.file.id);
72 		if (entry.file.user_info.fdType ==
73 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
74 				entry.file.user_info.fdCreator ==
75 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
76 				(entry.file.create_date ==
77 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
78 						create_date ||
79 				entry.file.create_date ==
80 					HFSPLUS_I(sb->s_root->d_inode)->
81 						create_date) &&
82 				HFSPLUS_SB(sb)->hidden_dir) {
83 			struct qstr str;
84 			char name[32];
85 
86 			if (dentry->d_fsdata) {
87 				/*
88 				 * We found a link pointing to another link,
89 				 * so ignore it and treat it as regular file.
90 				 */
91 				cnid = (unsigned long)dentry->d_fsdata;
92 				linkid = 0;
93 			} else {
94 				dentry->d_fsdata = (void *)(unsigned long)cnid;
95 				linkid =
96 					be32_to_cpu(entry.file.permissions.dev);
97 				str.len = sprintf(name, "iNode%d", linkid);
98 				str.name = name;
99 				hfsplus_cat_build_key(sb, fd.search_key,
100 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
101 					&str);
102 				goto again;
103 			}
104 		} else if (!dentry->d_fsdata)
105 			dentry->d_fsdata = (void *)(unsigned long)cnid;
106 	} else {
107 		pr_err("invalid catalog entry type in lookup\n");
108 		err = -EIO;
109 		goto fail;
110 	}
111 	hfs_find_exit(&fd);
112 	inode = hfsplus_iget(dir->i_sb, cnid);
113 	if (IS_ERR(inode))
114 		return ERR_CAST(inode);
115 	if (S_ISREG(inode->i_mode))
116 		HFSPLUS_I(inode)->linkid = linkid;
117 out:
118 	d_add(dentry, inode);
119 	return NULL;
120 fail:
121 	hfs_find_exit(&fd);
122 	return ERR_PTR(err);
123 }
124 
125 static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
126 {
127 	struct inode *inode = file_inode(file);
128 	struct super_block *sb = inode->i_sb;
129 	int len, err;
130 	char strbuf[HFSPLUS_MAX_STRLEN + 1];
131 	hfsplus_cat_entry entry;
132 	struct hfs_find_data fd;
133 	struct hfsplus_readdir_data *rd;
134 	u16 type;
135 
136 	if (file->f_pos >= inode->i_size)
137 		return 0;
138 
139 	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
140 	if (err)
141 		return err;
142 	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
143 	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
144 	if (err)
145 		goto out;
146 
147 	if (ctx->pos == 0) {
148 		/* This is completely artificial... */
149 		if (!dir_emit_dot(file, ctx))
150 			goto out;
151 		ctx->pos = 1;
152 	}
153 	if (ctx->pos == 1) {
154 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
155 			err = -EIO;
156 			goto out;
157 		}
158 
159 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
160 			fd.entrylength);
161 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
162 			pr_err("bad catalog folder thread\n");
163 			err = -EIO;
164 			goto out;
165 		}
166 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
167 			pr_err("truncated catalog thread\n");
168 			err = -EIO;
169 			goto out;
170 		}
171 		if (!dir_emit(ctx, "..", 2,
172 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
173 			goto out;
174 		ctx->pos = 2;
175 	}
176 	if (ctx->pos >= inode->i_size)
177 		goto out;
178 	err = hfs_brec_goto(&fd, ctx->pos - 1);
179 	if (err)
180 		goto out;
181 	for (;;) {
182 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
183 			pr_err("walked past end of dir\n");
184 			err = -EIO;
185 			goto out;
186 		}
187 
188 		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
189 			err = -EIO;
190 			goto out;
191 		}
192 
193 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
194 			fd.entrylength);
195 		type = be16_to_cpu(entry.type);
196 		len = HFSPLUS_MAX_STRLEN;
197 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
198 		if (err)
199 			goto out;
200 		if (type == HFSPLUS_FOLDER) {
201 			if (fd.entrylength <
202 					sizeof(struct hfsplus_cat_folder)) {
203 				pr_err("small dir entry\n");
204 				err = -EIO;
205 				goto out;
206 			}
207 			if (HFSPLUS_SB(sb)->hidden_dir &&
208 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
209 					be32_to_cpu(entry.folder.id))
210 				goto next;
211 			if (!dir_emit(ctx, strbuf, len,
212 				    be32_to_cpu(entry.folder.id), DT_DIR))
213 				break;
214 		} else if (type == HFSPLUS_FILE) {
215 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
216 				pr_err("small file entry\n");
217 				err = -EIO;
218 				goto out;
219 			}
220 			if (!dir_emit(ctx, strbuf, len,
221 				    be32_to_cpu(entry.file.id), DT_REG))
222 				break;
223 		} else {
224 			pr_err("bad catalog entry type\n");
225 			err = -EIO;
226 			goto out;
227 		}
228 next:
229 		ctx->pos++;
230 		if (ctx->pos >= inode->i_size)
231 			goto out;
232 		err = hfs_brec_goto(&fd, 1);
233 		if (err)
234 			goto out;
235 	}
236 	rd = file->private_data;
237 	if (!rd) {
238 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
239 		if (!rd) {
240 			err = -ENOMEM;
241 			goto out;
242 		}
243 		file->private_data = rd;
244 		rd->file = file;
245 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
246 	}
247 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
248 out:
249 	hfs_find_exit(&fd);
250 	return err;
251 }
252 
253 static int hfsplus_dir_release(struct inode *inode, struct file *file)
254 {
255 	struct hfsplus_readdir_data *rd = file->private_data;
256 	if (rd) {
257 		mutex_lock(&inode->i_mutex);
258 		list_del(&rd->list);
259 		mutex_unlock(&inode->i_mutex);
260 		kfree(rd);
261 	}
262 	return 0;
263 }
264 
265 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
266 			struct dentry *dst_dentry)
267 {
268 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
269 	struct inode *inode = src_dentry->d_inode;
270 	struct inode *src_dir = src_dentry->d_parent->d_inode;
271 	struct qstr str;
272 	char name[32];
273 	u32 cnid, id;
274 	int res;
275 
276 	if (HFSPLUS_IS_RSRC(inode))
277 		return -EPERM;
278 	if (!S_ISREG(inode->i_mode))
279 		return -EPERM;
280 
281 	mutex_lock(&sbi->vh_mutex);
282 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
283 		for (;;) {
284 			get_random_bytes(&id, sizeof(cnid));
285 			id &= 0x3fffffff;
286 			str.name = name;
287 			str.len = sprintf(name, "iNode%d", id);
288 			res = hfsplus_rename_cat(inode->i_ino,
289 						 src_dir, &src_dentry->d_name,
290 						 sbi->hidden_dir, &str);
291 			if (!res)
292 				break;
293 			if (res != -EEXIST)
294 				goto out;
295 		}
296 		HFSPLUS_I(inode)->linkid = id;
297 		cnid = sbi->next_cnid++;
298 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
299 		res = hfsplus_create_cat(cnid, src_dir,
300 			&src_dentry->d_name, inode);
301 		if (res)
302 			/* panic? */
303 			goto out;
304 		sbi->file_count++;
305 	}
306 	cnid = sbi->next_cnid++;
307 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
308 	if (res)
309 		goto out;
310 
311 	inc_nlink(inode);
312 	hfsplus_instantiate(dst_dentry, inode, cnid);
313 	ihold(inode);
314 	inode->i_ctime = CURRENT_TIME_SEC;
315 	mark_inode_dirty(inode);
316 	sbi->file_count++;
317 	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
318 out:
319 	mutex_unlock(&sbi->vh_mutex);
320 	return res;
321 }
322 
323 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
324 {
325 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
326 	struct inode *inode = dentry->d_inode;
327 	struct qstr str;
328 	char name[32];
329 	u32 cnid;
330 	int res;
331 
332 	if (HFSPLUS_IS_RSRC(inode))
333 		return -EPERM;
334 
335 	mutex_lock(&sbi->vh_mutex);
336 	cnid = (u32)(unsigned long)dentry->d_fsdata;
337 	if (inode->i_ino == cnid &&
338 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
339 		str.name = name;
340 		str.len = sprintf(name, "temp%lu", inode->i_ino);
341 		res = hfsplus_rename_cat(inode->i_ino,
342 					 dir, &dentry->d_name,
343 					 sbi->hidden_dir, &str);
344 		if (!res) {
345 			inode->i_flags |= S_DEAD;
346 			drop_nlink(inode);
347 		}
348 		goto out;
349 	}
350 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
351 	if (res)
352 		goto out;
353 
354 	if (inode->i_nlink > 0)
355 		drop_nlink(inode);
356 	if (inode->i_ino == cnid)
357 		clear_nlink(inode);
358 	if (!inode->i_nlink) {
359 		if (inode->i_ino != cnid) {
360 			sbi->file_count--;
361 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
362 				res = hfsplus_delete_cat(inode->i_ino,
363 							 sbi->hidden_dir,
364 							 NULL);
365 				if (!res)
366 					hfsplus_delete_inode(inode);
367 			} else
368 				inode->i_flags |= S_DEAD;
369 		} else
370 			hfsplus_delete_inode(inode);
371 	} else
372 		sbi->file_count--;
373 	inode->i_ctime = CURRENT_TIME_SEC;
374 	mark_inode_dirty(inode);
375 out:
376 	mutex_unlock(&sbi->vh_mutex);
377 	return res;
378 }
379 
380 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
381 {
382 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
383 	struct inode *inode = dentry->d_inode;
384 	int res;
385 
386 	if (inode->i_size != 2)
387 		return -ENOTEMPTY;
388 
389 	mutex_lock(&sbi->vh_mutex);
390 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
391 	if (res)
392 		goto out;
393 	clear_nlink(inode);
394 	inode->i_ctime = CURRENT_TIME_SEC;
395 	hfsplus_delete_inode(inode);
396 	mark_inode_dirty(inode);
397 out:
398 	mutex_unlock(&sbi->vh_mutex);
399 	return res;
400 }
401 
402 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
403 			   const char *symname)
404 {
405 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
406 	struct inode *inode;
407 	int res = -ENOSPC;
408 
409 	mutex_lock(&sbi->vh_mutex);
410 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
411 	if (!inode)
412 		goto out;
413 
414 	res = page_symlink(inode, symname, strlen(symname) + 1);
415 	if (res)
416 		goto out_err;
417 
418 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
419 	if (res)
420 		goto out_err;
421 
422 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
423 	if (res == -EOPNOTSUPP)
424 		res = 0; /* Operation is not supported. */
425 	else if (res) {
426 		/* Try to delete anyway without error analysis. */
427 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
428 		goto out_err;
429 	}
430 
431 	hfsplus_instantiate(dentry, inode, inode->i_ino);
432 	mark_inode_dirty(inode);
433 	goto out;
434 
435 out_err:
436 	clear_nlink(inode);
437 	hfsplus_delete_inode(inode);
438 	iput(inode);
439 out:
440 	mutex_unlock(&sbi->vh_mutex);
441 	return res;
442 }
443 
444 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
445 			 umode_t mode, dev_t rdev)
446 {
447 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
448 	struct inode *inode;
449 	int res = -ENOSPC;
450 
451 	mutex_lock(&sbi->vh_mutex);
452 	inode = hfsplus_new_inode(dir->i_sb, mode);
453 	if (!inode)
454 		goto out;
455 
456 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
457 		init_special_inode(inode, mode, rdev);
458 
459 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
460 	if (res)
461 		goto failed_mknod;
462 
463 	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
464 	if (res == -EOPNOTSUPP)
465 		res = 0; /* Operation is not supported. */
466 	else if (res) {
467 		/* Try to delete anyway without error analysis. */
468 		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
469 		goto failed_mknod;
470 	}
471 
472 	hfsplus_instantiate(dentry, inode, inode->i_ino);
473 	mark_inode_dirty(inode);
474 	goto out;
475 
476 failed_mknod:
477 	clear_nlink(inode);
478 	hfsplus_delete_inode(inode);
479 	iput(inode);
480 out:
481 	mutex_unlock(&sbi->vh_mutex);
482 	return res;
483 }
484 
485 static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
486 			  bool excl)
487 {
488 	return hfsplus_mknod(dir, dentry, mode, 0);
489 }
490 
491 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
492 {
493 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
494 }
495 
496 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
497 			  struct inode *new_dir, struct dentry *new_dentry)
498 {
499 	int res;
500 
501 	/* Unlink destination if it already exists */
502 	if (new_dentry->d_inode) {
503 		if (S_ISDIR(new_dentry->d_inode->i_mode))
504 			res = hfsplus_rmdir(new_dir, new_dentry);
505 		else
506 			res = hfsplus_unlink(new_dir, new_dentry);
507 		if (res)
508 			return res;
509 	}
510 
511 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
512 				 old_dir, &old_dentry->d_name,
513 				 new_dir, &new_dentry->d_name);
514 	if (!res)
515 		new_dentry->d_fsdata = old_dentry->d_fsdata;
516 	return res;
517 }
518 
519 const struct inode_operations hfsplus_dir_inode_operations = {
520 	.lookup			= hfsplus_lookup,
521 	.create			= hfsplus_create,
522 	.link			= hfsplus_link,
523 	.unlink			= hfsplus_unlink,
524 	.mkdir			= hfsplus_mkdir,
525 	.rmdir			= hfsplus_rmdir,
526 	.symlink		= hfsplus_symlink,
527 	.mknod			= hfsplus_mknod,
528 	.rename			= hfsplus_rename,
529 	.setxattr		= generic_setxattr,
530 	.getxattr		= generic_getxattr,
531 	.listxattr		= hfsplus_listxattr,
532 	.removexattr		= generic_removexattr,
533 #ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
534 	.get_acl		= hfsplus_get_posix_acl,
535 	.set_acl		= hfsplus_set_posix_acl,
536 #endif
537 };
538 
539 const struct file_operations hfsplus_dir_operations = {
540 	.fsync		= hfsplus_file_fsync,
541 	.read		= generic_read_dir,
542 	.iterate	= hfsplus_readdir,
543 	.unlocked_ioctl = hfsplus_ioctl,
544 	.llseek		= generic_file_llseek,
545 	.release	= hfsplus_dir_release,
546 };
547