xref: /openbmc/linux/fs/hfsplus/dir.c (revision 89755dca) 
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)->dev = 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 
256 	mutex_lock(&sbi->vh_mutex);
257 	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
258 		for (;;) {
259 			get_random_bytes(&id, sizeof(cnid));
260 			id &= 0x3fffffff;
261 			str.name = name;
262 			str.len = sprintf(name, "iNode%d", id);
263 			res = hfsplus_rename_cat(inode->i_ino,
264 						 src_dir, &src_dentry->d_name,
265 						 sbi->hidden_dir, &str);
266 			if (!res)
267 				break;
268 			if (res != -EEXIST)
269 				goto out;
270 		}
271 		HFSPLUS_I(inode)->dev = id;
272 		cnid = sbi->next_cnid++;
273 		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
274 		res = hfsplus_create_cat(cnid, src_dir, &src_dentry->d_name, inode);
275 		if (res)
276 			/* panic? */
277 			goto out;
278 		sbi->file_count++;
279 	}
280 	cnid = sbi->next_cnid++;
281 	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
282 	if (res)
283 		goto out;
284 
285 	inc_nlink(inode);
286 	hfsplus_instantiate(dst_dentry, inode, cnid);
287 	atomic_inc(&inode->i_count);
288 	inode->i_ctime = CURRENT_TIME_SEC;
289 	mark_inode_dirty(inode);
290 	sbi->file_count++;
291 	dst_dir->i_sb->s_dirt = 1;
292 out:
293 	mutex_unlock(&sbi->vh_mutex);
294 	return res;
295 }
296 
297 static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
298 {
299 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
300 	struct inode *inode = dentry->d_inode;
301 	struct qstr str;
302 	char name[32];
303 	u32 cnid;
304 	int res;
305 
306 	if (HFSPLUS_IS_RSRC(inode))
307 		return -EPERM;
308 
309 	mutex_lock(&sbi->vh_mutex);
310 	cnid = (u32)(unsigned long)dentry->d_fsdata;
311 	if (inode->i_ino == cnid &&
312 	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
313 		str.name = name;
314 		str.len = sprintf(name, "temp%lu", inode->i_ino);
315 		res = hfsplus_rename_cat(inode->i_ino,
316 					 dir, &dentry->d_name,
317 					 sbi->hidden_dir, &str);
318 		if (!res)
319 			inode->i_flags |= S_DEAD;
320 		goto out;
321 	}
322 	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
323 	if (res)
324 		goto out;
325 
326 	if (inode->i_nlink > 0)
327 		drop_nlink(inode);
328 	if (inode->i_ino == cnid)
329 		clear_nlink(inode);
330 	if (!inode->i_nlink) {
331 		if (inode->i_ino != cnid) {
332 			sbi->file_count--;
333 			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
334 				res = hfsplus_delete_cat(inode->i_ino,
335 							 sbi->hidden_dir,
336 							 NULL);
337 				if (!res)
338 					hfsplus_delete_inode(inode);
339 			} else
340 				inode->i_flags |= S_DEAD;
341 		} else
342 			hfsplus_delete_inode(inode);
343 	} else
344 		sbi->file_count--;
345 	inode->i_ctime = CURRENT_TIME_SEC;
346 	mark_inode_dirty(inode);
347 out:
348 	mutex_unlock(&sbi->vh_mutex);
349 	return res;
350 }
351 
352 static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
353 {
354 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
355 	struct inode *inode = dentry->d_inode;
356 	int res;
357 
358 	if (inode->i_size != 2)
359 		return -ENOTEMPTY;
360 
361 	mutex_lock(&sbi->vh_mutex);
362 	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
363 	if (res)
364 		goto out;
365 	clear_nlink(inode);
366 	inode->i_ctime = CURRENT_TIME_SEC;
367 	hfsplus_delete_inode(inode);
368 	mark_inode_dirty(inode);
369 out:
370 	mutex_unlock(&sbi->vh_mutex);
371 	return res;
372 }
373 
374 static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
375 			   const char *symname)
376 {
377 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
378 	struct inode *inode;
379 	int res = -ENOSPC;
380 
381 	mutex_lock(&sbi->vh_mutex);
382 	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
383 	if (!inode)
384 		goto out;
385 
386 	res = page_symlink(inode, symname, strlen(symname) + 1);
387 	if (res)
388 		goto out_err;
389 
390 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
391 	if (res)
392 		goto out_err;
393 
394 	hfsplus_instantiate(dentry, inode, inode->i_ino);
395 	mark_inode_dirty(inode);
396 	goto out;
397 
398 out_err:
399 	inode->i_nlink = 0;
400 	hfsplus_delete_inode(inode);
401 	iput(inode);
402 out:
403 	mutex_unlock(&sbi->vh_mutex);
404 	return res;
405 }
406 
407 static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
408 			 int mode, dev_t rdev)
409 {
410 	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
411 	struct inode *inode;
412 	int res = -ENOSPC;
413 
414 	mutex_lock(&sbi->vh_mutex);
415 	inode = hfsplus_new_inode(dir->i_sb, mode);
416 	if (!inode)
417 		goto out;
418 
419 	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
420 	if (res) {
421 		inode->i_nlink = 0;
422 		hfsplus_delete_inode(inode);
423 		iput(inode);
424 		goto out;
425 	}
426 
427 	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
428 		init_special_inode(inode, mode, rdev);
429 
430 	hfsplus_instantiate(dentry, inode, inode->i_ino);
431 	mark_inode_dirty(inode);
432 out:
433 	mutex_unlock(&sbi->vh_mutex);
434 	return res;
435 }
436 
437 static int hfsplus_create(struct inode *dir, struct dentry *dentry, int mode,
438 			  struct nameidata *nd)
439 {
440 	return hfsplus_mknod(dir, dentry, mode, 0);
441 }
442 
443 static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, int mode)
444 {
445 	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
446 }
447 
448 static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
449 			  struct inode *new_dir, struct dentry *new_dentry)
450 {
451 	int res;
452 
453 	/* Unlink destination if it already exists */
454 	if (new_dentry->d_inode) {
455 		res = hfsplus_unlink(new_dir, new_dentry);
456 		if (res)
457 			return res;
458 	}
459 
460 	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
461 				 old_dir, &old_dentry->d_name,
462 				 new_dir, &new_dentry->d_name);
463 	if (!res)
464 		new_dentry->d_fsdata = old_dentry->d_fsdata;
465 	return res;
466 }
467 
468 const struct inode_operations hfsplus_dir_inode_operations = {
469 	.lookup		= hfsplus_lookup,
470 	.create		= hfsplus_create,
471 	.link		= hfsplus_link,
472 	.unlink		= hfsplus_unlink,
473 	.mkdir		= hfsplus_mkdir,
474 	.rmdir		= hfsplus_rmdir,
475 	.symlink	= hfsplus_symlink,
476 	.mknod		= hfsplus_mknod,
477 	.rename		= hfsplus_rename,
478 };
479 
480 const struct file_operations hfsplus_dir_operations = {
481 	.read		= generic_read_dir,
482 	.readdir	= hfsplus_readdir,
483 	.unlocked_ioctl = hfsplus_ioctl,
484 	.llseek		= generic_file_llseek,
485 	.release	= hfsplus_dir_release,
486 };
487