xref: /linux/fs/hfsplus/dir.c (revision 8ec3b8432e4fe8d452f88f1ed9a3450e715bb797)
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 
19 static inline void hfsplus_instantiate(struct dentry *dentry,
20 				       struct inode *inode, u32 cnid)
21 {
22 	dentry->d_fsdata = (void *)(unsigned long)cnid;
23 	d_instantiate(dentry, inode);
24 }
25 
26 /* Find the entry inside dir named dentry->d_name */
27 static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
28 				     struct nameidata *nd)
29 {
30 	struct inode *inode = NULL;
31 	struct hfs_find_data fd;
32 	struct super_block *sb;
33 	hfsplus_cat_entry entry;
34 	int err;
35 	u32 cnid, linkid = 0;
36 	u16 type;
37 
38 	sb = dir->i_sb;
39 
40 	dentry->d_fsdata = NULL;
41 	hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
42 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
43 again:
44 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
45 	if (err) {
46 		if (err == -ENOENT) {
47 			hfs_find_exit(&fd);
48 			/* No such entry */
49 			inode = NULL;
50 			goto out;
51 		}
52 		goto fail;
53 	}
54 	type = be16_to_cpu(entry.type);
55 	if (type == HFSPLUS_FOLDER) {
56 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
57 			err = -EIO;
58 			goto fail;
59 		}
60 		cnid = be32_to_cpu(entry.folder.id);
61 		dentry->d_fsdata = (void *)(unsigned long)cnid;
62 	} else if (type == HFSPLUS_FILE) {
63 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
64 			err = -EIO;
65 			goto fail;
66 		}
67 		cnid = be32_to_cpu(entry.file.id);
68 		if (entry.file.user_info.fdType ==
69 				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
70 				entry.file.user_info.fdCreator ==
71 				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
72 				(entry.file.create_date ==
73 					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
74 						create_date ||
75 				entry.file.create_date ==
76 					HFSPLUS_I(sb->s_root->d_inode)->
77 						create_date) &&
78 				HFSPLUS_SB(sb)->hidden_dir) {
79 			struct qstr str;
80 			char name[32];
81 
82 			if (dentry->d_fsdata) {
83 				/*
84 				 * We found a link pointing to another link,
85 				 * so ignore it and treat it as regular file.
86 				 */
87 				cnid = (unsigned long)dentry->d_fsdata;
88 				linkid = 0;
89 			} else {
90 				dentry->d_fsdata = (void *)(unsigned long)cnid;
91 				linkid =
92 					be32_to_cpu(entry.file.permissions.dev);
93 				str.len = sprintf(name, "iNode%d", linkid);
94 				str.name = name;
95 				hfsplus_cat_build_key(sb, fd.search_key,
96 					HFSPLUS_SB(sb)->hidden_dir->i_ino,
97 					&str);
98 				goto again;
99 			}
100 		} else if (!dentry->d_fsdata)
101 			dentry->d_fsdata = (void *)(unsigned long)cnid;
102 	} else {
103 		printk(KERN_ERR "hfs: invalid catalog entry type in lookup\n");
104 		err = -EIO;
105 		goto fail;
106 	}
107 	hfs_find_exit(&fd);
108 	inode = hfsplus_iget(dir->i_sb, cnid);
109 	if (IS_ERR(inode))
110 		return ERR_CAST(inode);
111 	if (S_ISREG(inode->i_mode))
112 		HFSPLUS_I(inode)->linkid = linkid;
113 out:
114 	d_add(dentry, inode);
115 	return NULL;
116 fail:
117 	hfs_find_exit(&fd);
118 	return ERR_PTR(err);
119 }
120 
121 static int hfsplus_readdir(struct file *filp, void *dirent, filldir_t filldir)
122 {
123 	struct inode *inode = filp->f_path.dentry->d_inode;
124 	struct super_block *sb = inode->i_sb;
125 	int len, err;
126 	char strbuf[HFSPLUS_MAX_STRLEN + 1];
127 	hfsplus_cat_entry entry;
128 	struct hfs_find_data fd;
129 	struct hfsplus_readdir_data *rd;
130 	u16 type;
131 
132 	if (filp->f_pos >= inode->i_size)
133 		return 0;
134 
135 	hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
136 	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
137 	err = hfs_brec_find(&fd);
138 	if (err)
139 		goto out;
140 
141 	switch ((u32)filp->f_pos) {
142 	case 0:
143 		/* This is completely artificial... */
144 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
145 			goto out;
146 		filp->f_pos++;
147 		/* fall through */
148 	case 1:
149 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
150 			fd.entrylength);
151 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
152 			printk(KERN_ERR "hfs: bad catalog folder thread\n");
153 			err = -EIO;
154 			goto out;
155 		}
156 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
157 			printk(KERN_ERR "hfs: truncated catalog thread\n");
158 			err = -EIO;
159 			goto out;
160 		}
161 		if (filldir(dirent, "..", 2, 1,
162 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
163 			goto out;
164 		filp->f_pos++;
165 		/* fall through */
166 	default:
167 		if (filp->f_pos >= inode->i_size)
168 			goto out;
169 		err = hfs_brec_goto(&fd, filp->f_pos - 1);
170 		if (err)
171 			goto out;
172 	}
173 
174 	for (;;) {
175 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
176 			printk(KERN_ERR "hfs: walked past end of dir\n");
177 			err = -EIO;
178 			goto out;
179 		}
180 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
181 			fd.entrylength);
182 		type = be16_to_cpu(entry.type);
183 		len = HFSPLUS_MAX_STRLEN;
184 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
185 		if (err)
186 			goto out;
187 		if (type == HFSPLUS_FOLDER) {
188 			if (fd.entrylength <
189 					sizeof(struct hfsplus_cat_folder)) {
190 				printk(KERN_ERR "hfs: small dir entry\n");
191 				err = -EIO;
192 				goto out;
193 			}
194 			if (HFSPLUS_SB(sb)->hidden_dir &&
195 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
196 					be32_to_cpu(entry.folder.id))
197 				goto next;
198 			if (filldir(dirent, strbuf, len, filp->f_pos,
199 				    be32_to_cpu(entry.folder.id), DT_DIR))
200 				break;
201 		} else if (type == HFSPLUS_FILE) {
202 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
203 				printk(KERN_ERR "hfs: small file entry\n");
204 				err = -EIO;
205 				goto out;
206 			}
207 			if (filldir(dirent, strbuf, len, filp->f_pos,
208 				    be32_to_cpu(entry.file.id), DT_REG))
209 				break;
210 		} else {
211 			printk(KERN_ERR "hfs: bad catalog entry type\n");
212 			err = -EIO;
213 			goto out;
214 		}
215 next:
216 		filp->f_pos++;
217 		if (filp->f_pos >= inode->i_size)
218 			goto out;
219 		err = hfs_brec_goto(&fd, 1);
220 		if (err)
221 			goto out;
222 	}
223 	rd = filp->private_data;
224 	if (!rd) {
225 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
226 		if (!rd) {
227 			err = -ENOMEM;
228 			goto out;
229 		}
230 		filp->private_data = rd;
231 		rd->file = filp;
232 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
233 	}
234 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
235 out:
236 	hfs_find_exit(&fd);
237 	return err;
238 }
239 
240 static int hfsplus_dir_release(struct inode *inode, struct file *file)
241 {
242 	struct hfsplus_readdir_data *rd = file->private_data;
243 	if (rd) {
244 		mutex_lock(&inode->i_mutex);
245 		list_del(&rd->list);
246 		mutex_unlock(&inode->i_mutex);
247 		kfree(rd);
248 	}
249 	return 0;
250 }
251 
252 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
253 			struct dentry *dst_dentry)
254 {
255 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
256 	struct inode *inode = src_dentry->d_inode;
257 	struct inode *src_dir = src_dentry->d_parent->d_inode;
258 	struct qstr str;
259 	char name[32];
260 	u32 cnid, id;
261 	int res;
262 
263 	if (HFSPLUS_IS_RSRC(inode))
264 		return -EPERM;
265 	if (!S_ISREG(inode->i_mode))
266 		return -EPERM;
267 
268 	mutex_lock(&sbi->vh_mutex);
269 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
270 		for (;;) {
271 			get_random_bytes(&id, sizeof(cnid));
272 			id &= 0x3fffffff;
273 			str.name = name;
274 			str.len = sprintf(name, "iNode%d", id);
275 			res = hfsplus_rename_cat(inode->i_ino,
276 						 src_dir, &src_dentry->d_name,
277 						 sbi->hidden_dir, &str);
278 			if (!res)
279 				break;
280 			if (res != -EEXIST)
281 				goto out;
282 		}
283 		HFSPLUS_I(inode)->linkid = id;
284 		cnid = sbi->next_cnid++;
285 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
286 		res = hfsplus_create_cat(cnid, src_dir,
287 			&src_dentry->d_name, inode);
288 		if (res)
289 			/* panic? */
290 			goto out;
291 		sbi->file_count++;
292 	}
293 	cnid = sbi->next_cnid++;
294 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
295 	if (res)
296 		goto out;
297 
298 	inc_nlink(inode);
299 	hfsplus_instantiate(dst_dentry, inode, cnid);
300 	ihold(inode);
301 	inode->i_ctime = CURRENT_TIME_SEC;
302 	mark_inode_dirty(inode);
303 	sbi->file_count++;
304 	dst_dir->i_sb->s_dirt = 1;
305 out:
306 	mutex_unlock(&sbi->vh_mutex);
307 	return res;
308 }
309 
310 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
311 {
312 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
313 	struct inode *inode = dentry->d_inode;
314 	struct qstr str;
315 	char name[32];
316 	u32 cnid;
317 	int res;
318 
319 	if (HFSPLUS_IS_RSRC(inode))
320 		return -EPERM;
321 
322 	mutex_lock(&sbi->vh_mutex);
323 	cnid = (u32)(unsigned long)dentry->d_fsdata;
324 	if (inode->i_ino == cnid &&
325 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
326 		str.name = name;
327 		str.len = sprintf(name, "temp%lu", inode->i_ino);
328 		res = hfsplus_rename_cat(inode->i_ino,
329 					 dir, &dentry->d_name,
330 					 sbi->hidden_dir, &str);
331 		if (!res) {
332 			inode->i_flags |= S_DEAD;
333 			drop_nlink(inode);
334 		}
335 		goto out;
336 	}
337 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
338 	if (res)
339 		goto out;
340 
341 	if (inode->i_nlink > 0)
342 		drop_nlink(inode);
343 	if (inode->i_ino == cnid)
344 		clear_nlink(inode);
345 	if (!inode->i_nlink) {
346 		if (inode->i_ino != cnid) {
347 			sbi->file_count--;
348 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
349 				res = hfsplus_delete_cat(inode->i_ino,
350 							 sbi->hidden_dir,
351 							 NULL);
352 				if (!res)
353 					hfsplus_delete_inode(inode);
354 			} else
355 				inode->i_flags |= S_DEAD;
356 		} else
357 			hfsplus_delete_inode(inode);
358 	} else
359 		sbi->file_count--;
360 	inode->i_ctime = CURRENT_TIME_SEC;
361 	mark_inode_dirty(inode);
362 out:
363 	mutex_unlock(&sbi->vh_mutex);
364 	return res;
365 }
366 
367 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
368 {
369 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
370 	struct inode *inode = dentry->d_inode;
371 	int res;
372 
373 	if (inode->i_size != 2)
374 		return -ENOTEMPTY;
375 
376 	mutex_lock(&sbi->vh_mutex);
377 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
378 	if (res)
379 		goto out;
380 	clear_nlink(inode);
381 	inode->i_ctime = CURRENT_TIME_SEC;
382 	hfsplus_delete_inode(inode);
383 	mark_inode_dirty(inode);
384 out:
385 	mutex_unlock(&sbi->vh_mutex);
386 	return res;
387 }
388 
389 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
390 			   const char *symname)
391 {
392 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
393 	struct inode *inode;
394 	int res = -ENOSPC;
395 
396 	mutex_lock(&sbi->vh_mutex);
397 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
398 	if (!inode)
399 		goto out;
400 
401 	res = page_symlink(inode, symname, strlen(symname) + 1);
402 	if (res)
403 		goto out_err;
404 
405 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
406 	if (res)
407 		goto out_err;
408 
409 	hfsplus_instantiate(dentry, inode, inode->i_ino);
410 	mark_inode_dirty(inode);
411 	goto out;
412 
413 out_err:
414 	inode->i_nlink = 0;
415 	hfsplus_delete_inode(inode);
416 	iput(inode);
417 out:
418 	mutex_unlock(&sbi->vh_mutex);
419 	return res;
420 }
421 
422 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
423 			 int mode, dev_t rdev)
424 {
425 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
426 	struct inode *inode;
427 	int res = -ENOSPC;
428 
429 	mutex_lock(&sbi->vh_mutex);
430 	inode = hfsplus_new_inode(dir->i_sb, mode);
431 	if (!inode)
432 		goto out;
433 
434 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
435 		init_special_inode(inode, mode, rdev);
436 
437 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
438 	if (res) {
439 		inode->i_nlink = 0;
440 		hfsplus_delete_inode(inode);
441 		iput(inode);
442 		goto out;
443 	}
444 
445 	hfsplus_instantiate(dentry, inode, inode->i_ino);
446 	mark_inode_dirty(inode);
447 out:
448 	mutex_unlock(&sbi->vh_mutex);
449 	return res;
450 }
451 
452 static int hfsplus_create(struct inode *dir, struct dentry *dentry, int mode,
453 			  struct nameidata *nd)
454 {
455 	return hfsplus_mknod(dir, dentry, mode, 0);
456 }
457 
458 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, int mode)
459 {
460 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
461 }
462 
463 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
464 			  struct inode *new_dir, struct dentry *new_dentry)
465 {
466 	int res;
467 
468 	/* Unlink destination if it already exists */
469 	if (new_dentry->d_inode) {
470 		if (S_ISDIR(new_dentry->d_inode->i_mode))
471 			res = hfsplus_rmdir(new_dir, new_dentry);
472 		else
473 			res = hfsplus_unlink(new_dir, new_dentry);
474 		if (res)
475 			return res;
476 	}
477 
478 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
479 				 old_dir, &old_dentry->d_name,
480 				 new_dir, &new_dentry->d_name);
481 	if (!res)
482 		new_dentry->d_fsdata = old_dentry->d_fsdata;
483 	return res;
484 }
485 
486 const struct inode_operations hfsplus_dir_inode_operations = {
487 	.lookup		= hfsplus_lookup,
488 	.create		= hfsplus_create,
489 	.link		= hfsplus_link,
490 	.unlink		= hfsplus_unlink,
491 	.mkdir		= hfsplus_mkdir,
492 	.rmdir		= hfsplus_rmdir,
493 	.symlink	= hfsplus_symlink,
494 	.mknod		= hfsplus_mknod,
495 	.rename		= hfsplus_rename,
496 };
497 
498 const struct file_operations hfsplus_dir_operations = {
499 	.fsync		= hfsplus_file_fsync,
500 	.read		= generic_read_dir,
501 	.readdir	= hfsplus_readdir,
502 	.unlocked_ioctl = hfsplus_ioctl,
503 	.llseek		= generic_file_llseek,
504 	.release	= hfsplus_dir_release,
505 };
506