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#include <linux/nls.h>
16
17#include "hfsplus_fs.h"
18#include "hfsplus_raw.h"
19#include "xattr.h"
20#include "acl.h"
21
22static inline void hfsplus_instantiate(struct dentry *dentry,
23				       struct inode *inode, u32 cnid)
24{
25	dentry->d_fsdata = (void *)(unsigned long)cnid;
26	d_instantiate(dentry, inode);
27}
28
29/* Find the entry inside dir named dentry->d_name */
30static struct dentry *hfsplus_lookup(struct inode *dir, struct dentry *dentry,
31				     unsigned int flags)
32{
33	struct inode *inode = NULL;
34	struct hfs_find_data fd;
35	struct super_block *sb;
36	hfsplus_cat_entry entry;
37	int err;
38	u32 cnid, linkid = 0;
39	u16 type;
40
41	sb = dir->i_sb;
42
43	dentry->d_fsdata = NULL;
44	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
45	if (err)
46		return ERR_PTR(err);
47	hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino, &dentry->d_name);
48again:
49	err = hfs_brec_read(&fd, &entry, sizeof(entry));
50	if (err) {
51		if (err == -ENOENT) {
52			hfs_find_exit(&fd);
53			/* No such entry */
54			inode = NULL;
55			goto out;
56		}
57		goto fail;
58	}
59	type = be16_to_cpu(entry.type);
60	if (type == HFSPLUS_FOLDER) {
61		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
62			err = -EIO;
63			goto fail;
64		}
65		cnid = be32_to_cpu(entry.folder.id);
66		dentry->d_fsdata = (void *)(unsigned long)cnid;
67	} else if (type == HFSPLUS_FILE) {
68		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
69			err = -EIO;
70			goto fail;
71		}
72		cnid = be32_to_cpu(entry.file.id);
73		if (entry.file.user_info.fdType ==
74				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
75				entry.file.user_info.fdCreator ==
76				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
77				(entry.file.create_date ==
78					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
79						create_date ||
80				entry.file.create_date ==
81					HFSPLUS_I(sb->s_root->d_inode)->
82						create_date) &&
83				HFSPLUS_SB(sb)->hidden_dir) {
84			struct qstr str;
85			char name[32];
86
87			if (dentry->d_fsdata) {
88				/*
89				 * We found a link pointing to another link,
90				 * so ignore it and treat it as regular file.
91				 */
92				cnid = (unsigned long)dentry->d_fsdata;
93				linkid = 0;
94			} else {
95				dentry->d_fsdata = (void *)(unsigned long)cnid;
96				linkid =
97					be32_to_cpu(entry.file.permissions.dev);
98				str.len = sprintf(name, "iNode%d", linkid);
99				str.name = name;
100				hfsplus_cat_build_key(sb, fd.search_key,
101					HFSPLUS_SB(sb)->hidden_dir->i_ino,
102					&str);
103				goto again;
104			}
105		} else if (!dentry->d_fsdata)
106			dentry->d_fsdata = (void *)(unsigned long)cnid;
107	} else {
108		pr_err("invalid catalog entry type in lookup\n");
109		err = -EIO;
110		goto fail;
111	}
112	hfs_find_exit(&fd);
113	inode = hfsplus_iget(dir->i_sb, cnid);
114	if (IS_ERR(inode))
115		return ERR_CAST(inode);
116	if (S_ISREG(inode->i_mode))
117		HFSPLUS_I(inode)->linkid = linkid;
118out:
119	d_add(dentry, inode);
120	return NULL;
121fail:
122	hfs_find_exit(&fd);
123	return ERR_PTR(err);
124}
125
126static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
127{
128	struct inode *inode = file_inode(file);
129	struct super_block *sb = inode->i_sb;
130	int len, err;
131	char *strbuf;
132	hfsplus_cat_entry entry;
133	struct hfs_find_data fd;
134	struct hfsplus_readdir_data *rd;
135	u16 type;
136
137	if (file->f_pos >= inode->i_size)
138		return 0;
139
140	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
141	if (err)
142		return err;
143	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
144	if (!strbuf) {
145		err = -ENOMEM;
146		goto out;
147	}
148	hfsplus_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
149	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
150	if (err)
151		goto out;
152
153	if (ctx->pos == 0) {
154		/* This is completely artificial... */
155		if (!dir_emit_dot(file, ctx))
156			goto out;
157		ctx->pos = 1;
158	}
159	if (ctx->pos == 1) {
160		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
161			err = -EIO;
162			goto out;
163		}
164
165		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
166			fd.entrylength);
167		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
168			pr_err("bad catalog folder thread\n");
169			err = -EIO;
170			goto out;
171		}
172		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
173			pr_err("truncated catalog thread\n");
174			err = -EIO;
175			goto out;
176		}
177		if (!dir_emit(ctx, "..", 2,
178			    be32_to_cpu(entry.thread.parentID), DT_DIR))
179			goto out;
180		ctx->pos = 2;
181	}
182	if (ctx->pos >= inode->i_size)
183		goto out;
184	err = hfs_brec_goto(&fd, ctx->pos - 1);
185	if (err)
186		goto out;
187	for (;;) {
188		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
189			pr_err("walked past end of dir\n");
190			err = -EIO;
191			goto out;
192		}
193
194		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
195			err = -EIO;
196			goto out;
197		}
198
199		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
200			fd.entrylength);
201		type = be16_to_cpu(entry.type);
202		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
203		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
204		if (err)
205			goto out;
206		if (type == HFSPLUS_FOLDER) {
207			if (fd.entrylength <
208					sizeof(struct hfsplus_cat_folder)) {
209				pr_err("small dir entry\n");
210				err = -EIO;
211				goto out;
212			}
213			if (HFSPLUS_SB(sb)->hidden_dir &&
214			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
215					be32_to_cpu(entry.folder.id))
216				goto next;
217			if (!dir_emit(ctx, strbuf, len,
218				    be32_to_cpu(entry.folder.id), DT_DIR))
219				break;
220		} else if (type == HFSPLUS_FILE) {
221			u16 mode;
222			unsigned type = DT_UNKNOWN;
223
224			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
225				pr_err("small file entry\n");
226				err = -EIO;
227				goto out;
228			}
229
230			mode = be16_to_cpu(entry.file.permissions.mode);
231			if (S_ISREG(mode))
232				type = DT_REG;
233			else if (S_ISLNK(mode))
234				type = DT_LNK;
235			else if (S_ISFIFO(mode))
236				type = DT_FIFO;
237			else if (S_ISCHR(mode))
238				type = DT_CHR;
239			else if (S_ISBLK(mode))
240				type = DT_BLK;
241			else if (S_ISSOCK(mode))
242				type = DT_SOCK;
243
244			if (!dir_emit(ctx, strbuf, len,
245				      be32_to_cpu(entry.file.id), type))
246				break;
247		} else {
248			pr_err("bad catalog entry type\n");
249			err = -EIO;
250			goto out;
251		}
252next:
253		ctx->pos++;
254		if (ctx->pos >= inode->i_size)
255			goto out;
256		err = hfs_brec_goto(&fd, 1);
257		if (err)
258			goto out;
259	}
260	rd = file->private_data;
261	if (!rd) {
262		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
263		if (!rd) {
264			err = -ENOMEM;
265			goto out;
266		}
267		file->private_data = rd;
268		rd->file = file;
269		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
270	}
271	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
272out:
273	kfree(strbuf);
274	hfs_find_exit(&fd);
275	return err;
276}
277
278static int hfsplus_dir_release(struct inode *inode, struct file *file)
279{
280	struct hfsplus_readdir_data *rd = file->private_data;
281	if (rd) {
282		mutex_lock(&inode->i_mutex);
283		list_del(&rd->list);
284		mutex_unlock(&inode->i_mutex);
285		kfree(rd);
286	}
287	return 0;
288}
289
290static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
291			struct dentry *dst_dentry)
292{
293	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
294	struct inode *inode = src_dentry->d_inode;
295	struct inode *src_dir = src_dentry->d_parent->d_inode;
296	struct qstr str;
297	char name[32];
298	u32 cnid, id;
299	int res;
300
301	if (HFSPLUS_IS_RSRC(inode))
302		return -EPERM;
303	if (!S_ISREG(inode->i_mode))
304		return -EPERM;
305
306	mutex_lock(&sbi->vh_mutex);
307	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
308		for (;;) {
309			get_random_bytes(&id, sizeof(cnid));
310			id &= 0x3fffffff;
311			str.name = name;
312			str.len = sprintf(name, "iNode%d", id);
313			res = hfsplus_rename_cat(inode->i_ino,
314						 src_dir, &src_dentry->d_name,
315						 sbi->hidden_dir, &str);
316			if (!res)
317				break;
318			if (res != -EEXIST)
319				goto out;
320		}
321		HFSPLUS_I(inode)->linkid = id;
322		cnid = sbi->next_cnid++;
323		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
324		res = hfsplus_create_cat(cnid, src_dir,
325			&src_dentry->d_name, inode);
326		if (res)
327			/* panic? */
328			goto out;
329		sbi->file_count++;
330	}
331	cnid = sbi->next_cnid++;
332	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
333	if (res)
334		goto out;
335
336	inc_nlink(inode);
337	hfsplus_instantiate(dst_dentry, inode, cnid);
338	ihold(inode);
339	inode->i_ctime = CURRENT_TIME_SEC;
340	mark_inode_dirty(inode);
341	sbi->file_count++;
342	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
343out:
344	mutex_unlock(&sbi->vh_mutex);
345	return res;
346}
347
348static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
349{
350	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
351	struct inode *inode = dentry->d_inode;
352	struct qstr str;
353	char name[32];
354	u32 cnid;
355	int res;
356
357	if (HFSPLUS_IS_RSRC(inode))
358		return -EPERM;
359
360	mutex_lock(&sbi->vh_mutex);
361	cnid = (u32)(unsigned long)dentry->d_fsdata;
362	if (inode->i_ino == cnid &&
363	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
364		str.name = name;
365		str.len = sprintf(name, "temp%lu", inode->i_ino);
366		res = hfsplus_rename_cat(inode->i_ino,
367					 dir, &dentry->d_name,
368					 sbi->hidden_dir, &str);
369		if (!res) {
370			inode->i_flags |= S_DEAD;
371			drop_nlink(inode);
372		}
373		goto out;
374	}
375	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
376	if (res)
377		goto out;
378
379	if (inode->i_nlink > 0)
380		drop_nlink(inode);
381	if (inode->i_ino == cnid)
382		clear_nlink(inode);
383	if (!inode->i_nlink) {
384		if (inode->i_ino != cnid) {
385			sbi->file_count--;
386			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
387				res = hfsplus_delete_cat(inode->i_ino,
388							 sbi->hidden_dir,
389							 NULL);
390				if (!res)
391					hfsplus_delete_inode(inode);
392			} else
393				inode->i_flags |= S_DEAD;
394		} else
395			hfsplus_delete_inode(inode);
396	} else
397		sbi->file_count--;
398	inode->i_ctime = CURRENT_TIME_SEC;
399	mark_inode_dirty(inode);
400out:
401	mutex_unlock(&sbi->vh_mutex);
402	return res;
403}
404
405static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
406{
407	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
408	struct inode *inode = dentry->d_inode;
409	int res;
410
411	if (inode->i_size != 2)
412		return -ENOTEMPTY;
413
414	mutex_lock(&sbi->vh_mutex);
415	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
416	if (res)
417		goto out;
418	clear_nlink(inode);
419	inode->i_ctime = CURRENT_TIME_SEC;
420	hfsplus_delete_inode(inode);
421	mark_inode_dirty(inode);
422out:
423	mutex_unlock(&sbi->vh_mutex);
424	return res;
425}
426
427static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
428			   const char *symname)
429{
430	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
431	struct inode *inode;
432	int res = -ENOSPC;
433
434	mutex_lock(&sbi->vh_mutex);
435	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
436	if (!inode)
437		goto out;
438
439	res = page_symlink(inode, symname, strlen(symname) + 1);
440	if (res)
441		goto out_err;
442
443	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
444	if (res)
445		goto out_err;
446
447	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
448	if (res == -EOPNOTSUPP)
449		res = 0; /* Operation is not supported. */
450	else if (res) {
451		/* Try to delete anyway without error analysis. */
452		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
453		goto out_err;
454	}
455
456	hfsplus_instantiate(dentry, inode, inode->i_ino);
457	mark_inode_dirty(inode);
458	goto out;
459
460out_err:
461	clear_nlink(inode);
462	hfsplus_delete_inode(inode);
463	iput(inode);
464out:
465	mutex_unlock(&sbi->vh_mutex);
466	return res;
467}
468
469static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
470			 umode_t mode, dev_t rdev)
471{
472	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
473	struct inode *inode;
474	int res = -ENOSPC;
475
476	mutex_lock(&sbi->vh_mutex);
477	inode = hfsplus_new_inode(dir->i_sb, mode);
478	if (!inode)
479		goto out;
480
481	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
482		init_special_inode(inode, mode, rdev);
483
484	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
485	if (res)
486		goto failed_mknod;
487
488	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
489	if (res == -EOPNOTSUPP)
490		res = 0; /* Operation is not supported. */
491	else if (res) {
492		/* Try to delete anyway without error analysis. */
493		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
494		goto failed_mknod;
495	}
496
497	hfsplus_instantiate(dentry, inode, inode->i_ino);
498	mark_inode_dirty(inode);
499	goto out;
500
501failed_mknod:
502	clear_nlink(inode);
503	hfsplus_delete_inode(inode);
504	iput(inode);
505out:
506	mutex_unlock(&sbi->vh_mutex);
507	return res;
508}
509
510static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
511			  bool excl)
512{
513	return hfsplus_mknod(dir, dentry, mode, 0);
514}
515
516static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
517{
518	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
519}
520
521static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
522			  struct inode *new_dir, struct dentry *new_dentry)
523{
524	int res;
525
526	/* Unlink destination if it already exists */
527	if (new_dentry->d_inode) {
528		if (S_ISDIR(new_dentry->d_inode->i_mode))
529			res = hfsplus_rmdir(new_dir, new_dentry);
530		else
531			res = hfsplus_unlink(new_dir, new_dentry);
532		if (res)
533			return res;
534	}
535
536	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
537				 old_dir, &old_dentry->d_name,
538				 new_dir, &new_dentry->d_name);
539	if (!res)
540		new_dentry->d_fsdata = old_dentry->d_fsdata;
541	return res;
542}
543
544const struct inode_operations hfsplus_dir_inode_operations = {
545	.lookup			= hfsplus_lookup,
546	.create			= hfsplus_create,
547	.link			= hfsplus_link,
548	.unlink			= hfsplus_unlink,
549	.mkdir			= hfsplus_mkdir,
550	.rmdir			= hfsplus_rmdir,
551	.symlink		= hfsplus_symlink,
552	.mknod			= hfsplus_mknod,
553	.rename			= hfsplus_rename,
554	.setxattr		= generic_setxattr,
555	.getxattr		= generic_getxattr,
556	.listxattr		= hfsplus_listxattr,
557	.removexattr		= generic_removexattr,
558#ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
559	.get_acl		= hfsplus_get_posix_acl,
560	.set_acl		= hfsplus_set_posix_acl,
561#endif
562};
563
564const struct file_operations hfsplus_dir_operations = {
565	.fsync		= hfsplus_file_fsync,
566	.read		= generic_read_dir,
567	.iterate	= hfsplus_readdir,
568	.unlocked_ioctl = hfsplus_ioctl,
569	.llseek		= generic_file_llseek,
570	.release	= hfsplus_dir_release,
571};
572