xref: /openbmc/linux/fs/hfsplus/dir.c (revision 90e61690) 
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_op = &hfsplus_dentry_operations;
41 	dentry->d_fsdata = NULL;
42 	hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
43 	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
44 again:
45 	err = hfs_brec_read(&fd, &entry, sizeof(entry));
46 	if (err) {
47 		if (err == -ENOENT) {
48 			hfs_find_exit(&fd);
49 			/* No such entry */
50 			inode = NULL;
51 			goto out;
52 		}
53 		goto fail;
54 	}
55 	type = be16_to_cpu(entry.type);
56 	if (type == HFSPLUS_FOLDER) {
57 		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
58 			err = -EIO;
59 			goto fail;
60 		}
61 		cnid = be32_to_cpu(entry.folder.id);
62 		dentry->d_fsdata = (void *)(unsigned long)cnid;
63 	} else if (type == HFSPLUS_FILE) {
64 		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
65 			err = -EIO;
66 			goto fail;
67 		}
68 		cnid = be32_to_cpu(entry.file.id);
69 		if (entry.file.user_info.fdType == cpu_to_be32(HFSP_HARDLINK_TYPE) &&
70 		    entry.file.user_info.fdCreator == cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
71 		    (entry.file.create_date == HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->create_date ||
72 		     entry.file.create_date == HFSPLUS_I(sb->s_root->d_inode)->create_date) &&
73 		    HFSPLUS_SB(sb)->hidden_dir) {
74 			struct qstr str;
75 			char name[32];
76 
77 			if (dentry->d_fsdata) {
78 				/*
79 				 * We found a link pointing to another link,
80 				 * so ignore it and treat it as regular file.
81 				 */
82 				cnid = (unsigned long)dentry->d_fsdata;
83 				linkid = 0;
84 			} else {
85 				dentry->d_fsdata = (void *)(unsigned long)cnid;
86 				linkid = be32_to_cpu(entry.file.permissions.dev);
87 				str.len = sprintf(name, "iNode%d", linkid);
88 				str.name = name;
89 				hfsplus_cat_build_key(sb, fd.search_key,
90 					HFSPLUS_SB(sb)->hidden_dir->i_ino, &str);
91 				goto again;
92 			}
93 		} else if (!dentry->d_fsdata)
94 			dentry->d_fsdata = (void *)(unsigned long)cnid;
95 	} else {
96 		printk(KERN_ERR "hfs: invalid catalog entry type in lookup\n");
97 		err = -EIO;
98 		goto fail;
99 	}
100 	hfs_find_exit(&fd);
101 	inode = hfsplus_iget(dir->i_sb, cnid);
102 	if (IS_ERR(inode))
103 		return ERR_CAST(inode);
104 	if (S_ISREG(inode->i_mode))
105 		HFSPLUS_I(inode)->linkid = linkid;
106 out:
107 	d_add(dentry, inode);
108 	return NULL;
109 fail:
110 	hfs_find_exit(&fd);
111 	return ERR_PTR(err);
112 }
113 
114 static int hfsplus_readdir(struct file *filp, void *dirent, filldir_t filldir)
115 {
116 	struct inode *inode = filp->f_path.dentry->d_inode;
117 	struct super_block *sb = inode->i_sb;
118 	int len, err;
119 	char strbuf[HFSPLUS_MAX_STRLEN + 1];
120 	hfsplus_cat_entry entry;
121 	struct hfs_find_data fd;
122 	struct hfsplus_readdir_data *rd;
123 	u16 type;
124 
125 	if (filp->f_pos >= inode->i_size)
126 		return 0;
127 
128 	hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
129 	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
130 	err = hfs_brec_find(&fd);
131 	if (err)
132 		goto out;
133 
134 	switch ((u32)filp->f_pos) {
135 	case 0:
136 		/* This is completely artificial... */
137 		if (filldir(dirent, ".", 1, 0, inode->i_ino, DT_DIR))
138 			goto out;
139 		filp->f_pos++;
140 		/* fall through */
141 	case 1:
142 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
143 		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
144 			printk(KERN_ERR "hfs: bad catalog folder thread\n");
145 			err = -EIO;
146 			goto out;
147 		}
148 		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
149 			printk(KERN_ERR "hfs: truncated catalog thread\n");
150 			err = -EIO;
151 			goto out;
152 		}
153 		if (filldir(dirent, "..", 2, 1,
154 			    be32_to_cpu(entry.thread.parentID), DT_DIR))
155 			goto out;
156 		filp->f_pos++;
157 		/* fall through */
158 	default:
159 		if (filp->f_pos >= inode->i_size)
160 			goto out;
161 		err = hfs_brec_goto(&fd, filp->f_pos - 1);
162 		if (err)
163 			goto out;
164 	}
165 
166 	for (;;) {
167 		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
168 			printk(KERN_ERR "hfs: walked past end of dir\n");
169 			err = -EIO;
170 			goto out;
171 		}
172 		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
173 		type = be16_to_cpu(entry.type);
174 		len = HFSPLUS_MAX_STRLEN;
175 		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
176 		if (err)
177 			goto out;
178 		if (type == HFSPLUS_FOLDER) {
179 			if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
180 				printk(KERN_ERR "hfs: small dir entry\n");
181 				err = -EIO;
182 				goto out;
183 			}
184 			if (HFSPLUS_SB(sb)->hidden_dir &&
185 			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
186 					be32_to_cpu(entry.folder.id))
187 				goto next;
188 			if (filldir(dirent, strbuf, len, filp->f_pos,
189 				    be32_to_cpu(entry.folder.id), DT_DIR))
190 				break;
191 		} else if (type == HFSPLUS_FILE) {
192 			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
193 				printk(KERN_ERR "hfs: small file entry\n");
194 				err = -EIO;
195 				goto out;
196 			}
197 			if (filldir(dirent, strbuf, len, filp->f_pos,
198 				    be32_to_cpu(entry.file.id), DT_REG))
199 				break;
200 		} else {
201 			printk(KERN_ERR "hfs: bad catalog entry type\n");
202 			err = -EIO;
203 			goto out;
204 		}
205 	next:
206 		filp->f_pos++;
207 		if (filp->f_pos >= inode->i_size)
208 			goto out;
209 		err = hfs_brec_goto(&fd, 1);
210 		if (err)
211 			goto out;
212 	}
213 	rd = filp->private_data;
214 	if (!rd) {
215 		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
216 		if (!rd) {
217 			err = -ENOMEM;
218 			goto out;
219 		}
220 		filp->private_data = rd;
221 		rd->file = filp;
222 		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
223 	}
224 	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
225 out:
226 	hfs_find_exit(&fd);
227 	return err;
228 }
229 
230 static int hfsplus_dir_release(struct inode *inode, struct file *file)
231 {
232 	struct hfsplus_readdir_data *rd = file->private_data;
233 	if (rd) {
234 		mutex_lock(&inode->i_mutex);
235 		list_del(&rd->list);
236 		mutex_unlock(&inode->i_mutex);
237 		kfree(rd);
238 	}
239 	return 0;
240 }
241 
242 static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
243 			struct dentry *dst_dentry)
244 {
245 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
246 	struct inode *inode = src_dentry->d_inode;
247 	struct inode *src_dir = src_dentry->d_parent->d_inode;
248 	struct qstr str;
249 	char name[32];
250 	u32 cnid, id;
251 	int res;
252 
253 	if (HFSPLUS_IS_RSRC(inode))
254 		return -EPERM;
255 	if (!S_ISREG(inode->i_mode))
256 		return -EPERM;
257 
258 	mutex_lock(&sbi->vh_mutex);
259 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
260 		for (;;) {
261 			get_random_bytes(&id, sizeof(cnid));
262 			id &= 0x3fffffff;
263 			str.name = name;
264 			str.len = sprintf(name, "iNode%d", id);
265 			res = hfsplus_rename_cat(inode->i_ino,
266 						 src_dir, &src_dentry->d_name,
267 						 sbi->hidden_dir, &str);
268 			if (!res)
269 				break;
270 			if (res != -EEXIST)
271 				goto out;
272 		}
273 		HFSPLUS_I(inode)->linkid = id;
274 		cnid = sbi->next_cnid++;
275 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
276 		res = hfsplus_create_cat(cnid, src_dir, &src_dentry->d_name, inode);
277 		if (res)
278 			/* panic? */
279 			goto out;
280 		sbi->file_count++;
281 	}
282 	cnid = sbi->next_cnid++;
283 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
284 	if (res)
285 		goto out;
286 
287 	inc_nlink(inode);
288 	hfsplus_instantiate(dst_dentry, inode, cnid);
289 	atomic_inc(&inode->i_count);
290 	inode->i_ctime = CURRENT_TIME_SEC;
291 	mark_inode_dirty(inode);
292 	sbi->file_count++;
293 	dst_dir->i_sb->s_dirt = 1;
294 out:
295 	mutex_unlock(&sbi->vh_mutex);
296 	return res;
297 }
298 
299 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
300 {
301 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
302 	struct inode *inode = dentry->d_inode;
303 	struct qstr str;
304 	char name[32];
305 	u32 cnid;
306 	int res;
307 
308 	if (HFSPLUS_IS_RSRC(inode))
309 		return -EPERM;
310 
311 	mutex_lock(&sbi->vh_mutex);
312 	cnid = (u32)(unsigned long)dentry->d_fsdata;
313 	if (inode->i_ino == cnid &&
314 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
315 		str.name = name;
316 		str.len = sprintf(name, "temp%lu", inode->i_ino);
317 		res = hfsplus_rename_cat(inode->i_ino,
318 					 dir, &dentry->d_name,
319 					 sbi->hidden_dir, &str);
320 		if (!res)
321 			inode->i_flags |= S_DEAD;
322 		goto out;
323 	}
324 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
325 	if (res)
326 		goto out;
327 
328 	if (inode->i_nlink > 0)
329 		drop_nlink(inode);
330 	if (inode->i_ino == cnid)
331 		clear_nlink(inode);
332 	if (!inode->i_nlink) {
333 		if (inode->i_ino != cnid) {
334 			sbi->file_count--;
335 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
336 				res = hfsplus_delete_cat(inode->i_ino,
337 							 sbi->hidden_dir,
338 							 NULL);
339 				if (!res)
340 					hfsplus_delete_inode(inode);
341 			} else
342 				inode->i_flags |= S_DEAD;
343 		} else
344 			hfsplus_delete_inode(inode);
345 	} else
346 		sbi->file_count--;
347 	inode->i_ctime = CURRENT_TIME_SEC;
348 	mark_inode_dirty(inode);
349 out:
350 	mutex_unlock(&sbi->vh_mutex);
351 	return res;
352 }
353 
354 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
355 {
356 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
357 	struct inode *inode = dentry->d_inode;
358 	int res;
359 
360 	if (inode->i_size != 2)
361 		return -ENOTEMPTY;
362 
363 	mutex_lock(&sbi->vh_mutex);
364 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
365 	if (res)
366 		goto out;
367 	clear_nlink(inode);
368 	inode->i_ctime = CURRENT_TIME_SEC;
369 	hfsplus_delete_inode(inode);
370 	mark_inode_dirty(inode);
371 out:
372 	mutex_unlock(&sbi->vh_mutex);
373 	return res;
374 }
375 
376 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
377 			   const char *symname)
378 {
379 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
380 	struct inode *inode;
381 	int res = -ENOSPC;
382 
383 	mutex_lock(&sbi->vh_mutex);
384 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
385 	if (!inode)
386 		goto out;
387 
388 	res = page_symlink(inode, symname, strlen(symname) + 1);
389 	if (res)
390 		goto out_err;
391 
392 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
393 	if (res)
394 		goto out_err;
395 
396 	hfsplus_instantiate(dentry, inode, inode->i_ino);
397 	mark_inode_dirty(inode);
398 	goto out;
399 
400 out_err:
401 	inode->i_nlink = 0;
402 	hfsplus_delete_inode(inode);
403 	iput(inode);
404 out:
405 	mutex_unlock(&sbi->vh_mutex);
406 	return res;
407 }
408 
409 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
410 			 int mode, dev_t rdev)
411 {
412 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
413 	struct inode *inode;
414 	int res = -ENOSPC;
415 
416 	mutex_lock(&sbi->vh_mutex);
417 	inode = hfsplus_new_inode(dir->i_sb, mode);
418 	if (!inode)
419 		goto out;
420 
421 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
422 		init_special_inode(inode, mode, rdev);
423 
424 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
425 	if (res) {
426 		inode->i_nlink = 0;
427 		hfsplus_delete_inode(inode);
428 		iput(inode);
429 		goto out;
430 	}
431 
432 	hfsplus_instantiate(dentry, inode, inode->i_ino);
433 	mark_inode_dirty(inode);
434 out:
435 	mutex_unlock(&sbi->vh_mutex);
436 	return res;
437 }
438 
439 static int hfsplus_create(struct inode *dir, struct dentry *dentry, int mode,
440 			  struct nameidata *nd)
441 {
442 	return hfsplus_mknod(dir, dentry, mode, 0);
443 }
444 
445 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, int mode)
446 {
447 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
448 }
449 
450 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
451 			  struct inode *new_dir, struct dentry *new_dentry)
452 {
453 	int res;
454 
455 	/* Unlink destination if it already exists */
456 	if (new_dentry->d_inode) {
457 		if (S_ISDIR(new_dentry->d_inode->i_mode))
458 			res = hfsplus_rmdir(new_dir, new_dentry);
459 		else
460 			res = hfsplus_unlink(new_dir, new_dentry);
461 		if (res)
462 			return res;
463 	}
464 
465 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
466 				 old_dir, &old_dentry->d_name,
467 				 new_dir, &new_dentry->d_name);
468 	if (!res)
469 		new_dentry->d_fsdata = old_dentry->d_fsdata;
470 	return res;
471 }
472 
473 const struct inode_operations hfsplus_dir_inode_operations = {
474 	.lookup		= hfsplus_lookup,
475 	.create		= hfsplus_create,
476 	.link		= hfsplus_link,
477 	.unlink		= hfsplus_unlink,
478 	.mkdir		= hfsplus_mkdir,
479 	.rmdir		= hfsplus_rmdir,
480 	.symlink	= hfsplus_symlink,
481 	.mknod		= hfsplus_mknod,
482 	.rename		= hfsplus_rename,
483 };
484 
485 const struct file_operations hfsplus_dir_operations = {
486 	.read		= generic_read_dir,
487 	.readdir	= hfsplus_readdir,
488 	.unlocked_ioctl = hfsplus_ioctl,
489 	.llseek		= generic_file_llseek,
490 	.release	= hfsplus_dir_release,
491 };
492