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	err = hfsplus_cat_build_key(sb, fd.search_key, dir->i_ino,
48			&dentry->d_name);
49	if (unlikely(err < 0))
50		goto fail;
51again:
52	err = hfs_brec_read(&fd, &entry, sizeof(entry));
53	if (err) {
54		if (err == -ENOENT) {
55			hfs_find_exit(&fd);
56			/* No such entry */
57			inode = NULL;
58			goto out;
59		}
60		goto fail;
61	}
62	type = be16_to_cpu(entry.type);
63	if (type == HFSPLUS_FOLDER) {
64		if (fd.entrylength < sizeof(struct hfsplus_cat_folder)) {
65			err = -EIO;
66			goto fail;
67		}
68		cnid = be32_to_cpu(entry.folder.id);
69		dentry->d_fsdata = (void *)(unsigned long)cnid;
70	} else if (type == HFSPLUS_FILE) {
71		if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
72			err = -EIO;
73			goto fail;
74		}
75		cnid = be32_to_cpu(entry.file.id);
76		if (entry.file.user_info.fdType ==
77				cpu_to_be32(HFSP_HARDLINK_TYPE) &&
78				entry.file.user_info.fdCreator ==
79				cpu_to_be32(HFSP_HFSPLUS_CREATOR) &&
80				(entry.file.create_date ==
81					HFSPLUS_I(HFSPLUS_SB(sb)->hidden_dir)->
82						create_date ||
83				entry.file.create_date ==
84					HFSPLUS_I(d_inode(sb->s_root))->
85						create_date) &&
86				HFSPLUS_SB(sb)->hidden_dir) {
87			struct qstr str;
88			char name[32];
89
90			if (dentry->d_fsdata) {
91				/*
92				 * We found a link pointing to another link,
93				 * so ignore it and treat it as regular file.
94				 */
95				cnid = (unsigned long)dentry->d_fsdata;
96				linkid = 0;
97			} else {
98				dentry->d_fsdata = (void *)(unsigned long)cnid;
99				linkid =
100					be32_to_cpu(entry.file.permissions.dev);
101				str.len = sprintf(name, "iNode%d", linkid);
102				str.name = name;
103				err = hfsplus_cat_build_key(sb, fd.search_key,
104					HFSPLUS_SB(sb)->hidden_dir->i_ino,
105					&str);
106				if (unlikely(err < 0))
107					goto fail;
108				goto again;
109			}
110		} else if (!dentry->d_fsdata)
111			dentry->d_fsdata = (void *)(unsigned long)cnid;
112	} else {
113		pr_err("invalid catalog entry type in lookup\n");
114		err = -EIO;
115		goto fail;
116	}
117	hfs_find_exit(&fd);
118	inode = hfsplus_iget(dir->i_sb, cnid);
119	if (IS_ERR(inode))
120		return ERR_CAST(inode);
121	if (S_ISREG(inode->i_mode))
122		HFSPLUS_I(inode)->linkid = linkid;
123out:
124	d_add(dentry, inode);
125	return NULL;
126fail:
127	hfs_find_exit(&fd);
128	return ERR_PTR(err);
129}
130
131static int hfsplus_readdir(struct file *file, struct dir_context *ctx)
132{
133	struct inode *inode = file_inode(file);
134	struct super_block *sb = inode->i_sb;
135	int len, err;
136	char *strbuf;
137	hfsplus_cat_entry entry;
138	struct hfs_find_data fd;
139	struct hfsplus_readdir_data *rd;
140	u16 type;
141
142	if (file->f_pos >= inode->i_size)
143		return 0;
144
145	err = hfs_find_init(HFSPLUS_SB(sb)->cat_tree, &fd);
146	if (err)
147		return err;
148	strbuf = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN + 1, GFP_KERNEL);
149	if (!strbuf) {
150		err = -ENOMEM;
151		goto out;
152	}
153	hfsplus_cat_build_key_with_cnid(sb, fd.search_key, inode->i_ino);
154	err = hfs_brec_find(&fd, hfs_find_rec_by_key);
155	if (err)
156		goto out;
157
158	if (ctx->pos == 0) {
159		/* This is completely artificial... */
160		if (!dir_emit_dot(file, ctx))
161			goto out;
162		ctx->pos = 1;
163	}
164	if (ctx->pos == 1) {
165		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
166			err = -EIO;
167			goto out;
168		}
169
170		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
171			fd.entrylength);
172		if (be16_to_cpu(entry.type) != HFSPLUS_FOLDER_THREAD) {
173			pr_err("bad catalog folder thread\n");
174			err = -EIO;
175			goto out;
176		}
177		if (fd.entrylength < HFSPLUS_MIN_THREAD_SZ) {
178			pr_err("truncated catalog thread\n");
179			err = -EIO;
180			goto out;
181		}
182		if (!dir_emit(ctx, "..", 2,
183			    be32_to_cpu(entry.thread.parentID), DT_DIR))
184			goto out;
185		ctx->pos = 2;
186	}
187	if (ctx->pos >= inode->i_size)
188		goto out;
189	err = hfs_brec_goto(&fd, ctx->pos - 1);
190	if (err)
191		goto out;
192	for (;;) {
193		if (be32_to_cpu(fd.key->cat.parent) != inode->i_ino) {
194			pr_err("walked past end of dir\n");
195			err = -EIO;
196			goto out;
197		}
198
199		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
200			err = -EIO;
201			goto out;
202		}
203
204		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset,
205			fd.entrylength);
206		type = be16_to_cpu(entry.type);
207		len = NLS_MAX_CHARSET_SIZE * HFSPLUS_MAX_STRLEN;
208		err = hfsplus_uni2asc(sb, &fd.key->cat.name, strbuf, &len);
209		if (err)
210			goto out;
211		if (type == HFSPLUS_FOLDER) {
212			if (fd.entrylength <
213					sizeof(struct hfsplus_cat_folder)) {
214				pr_err("small dir entry\n");
215				err = -EIO;
216				goto out;
217			}
218			if (HFSPLUS_SB(sb)->hidden_dir &&
219			    HFSPLUS_SB(sb)->hidden_dir->i_ino ==
220					be32_to_cpu(entry.folder.id))
221				goto next;
222			if (!dir_emit(ctx, strbuf, len,
223				    be32_to_cpu(entry.folder.id), DT_DIR))
224				break;
225		} else if (type == HFSPLUS_FILE) {
226			u16 mode;
227			unsigned type = DT_UNKNOWN;
228
229			if (fd.entrylength < sizeof(struct hfsplus_cat_file)) {
230				pr_err("small file entry\n");
231				err = -EIO;
232				goto out;
233			}
234
235			mode = be16_to_cpu(entry.file.permissions.mode);
236			if (S_ISREG(mode))
237				type = DT_REG;
238			else if (S_ISLNK(mode))
239				type = DT_LNK;
240			else if (S_ISFIFO(mode))
241				type = DT_FIFO;
242			else if (S_ISCHR(mode))
243				type = DT_CHR;
244			else if (S_ISBLK(mode))
245				type = DT_BLK;
246			else if (S_ISSOCK(mode))
247				type = DT_SOCK;
248
249			if (!dir_emit(ctx, strbuf, len,
250				      be32_to_cpu(entry.file.id), type))
251				break;
252		} else {
253			pr_err("bad catalog entry type\n");
254			err = -EIO;
255			goto out;
256		}
257next:
258		ctx->pos++;
259		if (ctx->pos >= inode->i_size)
260			goto out;
261		err = hfs_brec_goto(&fd, 1);
262		if (err)
263			goto out;
264	}
265	rd = file->private_data;
266	if (!rd) {
267		rd = kmalloc(sizeof(struct hfsplus_readdir_data), GFP_KERNEL);
268		if (!rd) {
269			err = -ENOMEM;
270			goto out;
271		}
272		file->private_data = rd;
273		rd->file = file;
274		list_add(&rd->list, &HFSPLUS_I(inode)->open_dir_list);
275	}
276	memcpy(&rd->key, fd.key, sizeof(struct hfsplus_cat_key));
277out:
278	kfree(strbuf);
279	hfs_find_exit(&fd);
280	return err;
281}
282
283static int hfsplus_dir_release(struct inode *inode, struct file *file)
284{
285	struct hfsplus_readdir_data *rd = file->private_data;
286	if (rd) {
287		mutex_lock(&inode->i_mutex);
288		list_del(&rd->list);
289		mutex_unlock(&inode->i_mutex);
290		kfree(rd);
291	}
292	return 0;
293}
294
295static int hfsplus_link(struct dentry *src_dentry, struct inode *dst_dir,
296			struct dentry *dst_dentry)
297{
298	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dst_dir->i_sb);
299	struct inode *inode = d_inode(src_dentry);
300	struct inode *src_dir = d_inode(src_dentry->d_parent);
301	struct qstr str;
302	char name[32];
303	u32 cnid, id;
304	int res;
305
306	if (HFSPLUS_IS_RSRC(inode))
307		return -EPERM;
308	if (!S_ISREG(inode->i_mode))
309		return -EPERM;
310
311	mutex_lock(&sbi->vh_mutex);
312	if (inode->i_ino == (u32)(unsigned long)src_dentry->d_fsdata) {
313		for (;;) {
314			get_random_bytes(&id, sizeof(cnid));
315			id &= 0x3fffffff;
316			str.name = name;
317			str.len = sprintf(name, "iNode%d", id);
318			res = hfsplus_rename_cat(inode->i_ino,
319						 src_dir, &src_dentry->d_name,
320						 sbi->hidden_dir, &str);
321			if (!res)
322				break;
323			if (res != -EEXIST)
324				goto out;
325		}
326		HFSPLUS_I(inode)->linkid = id;
327		cnid = sbi->next_cnid++;
328		src_dentry->d_fsdata = (void *)(unsigned long)cnid;
329		res = hfsplus_create_cat(cnid, src_dir,
330			&src_dentry->d_name, inode);
331		if (res)
332			/* panic? */
333			goto out;
334		sbi->file_count++;
335	}
336	cnid = sbi->next_cnid++;
337	res = hfsplus_create_cat(cnid, dst_dir, &dst_dentry->d_name, inode);
338	if (res)
339		goto out;
340
341	inc_nlink(inode);
342	hfsplus_instantiate(dst_dentry, inode, cnid);
343	ihold(inode);
344	inode->i_ctime = CURRENT_TIME_SEC;
345	mark_inode_dirty(inode);
346	sbi->file_count++;
347	hfsplus_mark_mdb_dirty(dst_dir->i_sb);
348out:
349	mutex_unlock(&sbi->vh_mutex);
350	return res;
351}
352
353static int hfsplus_unlink(struct inode *dir, struct dentry *dentry)
354{
355	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
356	struct inode *inode = d_inode(dentry);
357	struct qstr str;
358	char name[32];
359	u32 cnid;
360	int res;
361
362	if (HFSPLUS_IS_RSRC(inode))
363		return -EPERM;
364
365	mutex_lock(&sbi->vh_mutex);
366	cnid = (u32)(unsigned long)dentry->d_fsdata;
367	if (inode->i_ino == cnid &&
368	    atomic_read(&HFSPLUS_I(inode)->opencnt)) {
369		str.name = name;
370		str.len = sprintf(name, "temp%lu", inode->i_ino);
371		res = hfsplus_rename_cat(inode->i_ino,
372					 dir, &dentry->d_name,
373					 sbi->hidden_dir, &str);
374		if (!res) {
375			inode->i_flags |= S_DEAD;
376			drop_nlink(inode);
377		}
378		goto out;
379	}
380	res = hfsplus_delete_cat(cnid, dir, &dentry->d_name);
381	if (res)
382		goto out;
383
384	if (inode->i_nlink > 0)
385		drop_nlink(inode);
386	if (inode->i_ino == cnid)
387		clear_nlink(inode);
388	if (!inode->i_nlink) {
389		if (inode->i_ino != cnid) {
390			sbi->file_count--;
391			if (!atomic_read(&HFSPLUS_I(inode)->opencnt)) {
392				res = hfsplus_delete_cat(inode->i_ino,
393							 sbi->hidden_dir,
394							 NULL);
395				if (!res)
396					hfsplus_delete_inode(inode);
397			} else
398				inode->i_flags |= S_DEAD;
399		} else
400			hfsplus_delete_inode(inode);
401	} else
402		sbi->file_count--;
403	inode->i_ctime = CURRENT_TIME_SEC;
404	mark_inode_dirty(inode);
405out:
406	mutex_unlock(&sbi->vh_mutex);
407	return res;
408}
409
410static int hfsplus_rmdir(struct inode *dir, struct dentry *dentry)
411{
412	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
413	struct inode *inode = d_inode(dentry);
414	int res;
415
416	if (inode->i_size != 2)
417		return -ENOTEMPTY;
418
419	mutex_lock(&sbi->vh_mutex);
420	res = hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
421	if (res)
422		goto out;
423	clear_nlink(inode);
424	inode->i_ctime = CURRENT_TIME_SEC;
425	hfsplus_delete_inode(inode);
426	mark_inode_dirty(inode);
427out:
428	mutex_unlock(&sbi->vh_mutex);
429	return res;
430}
431
432static int hfsplus_symlink(struct inode *dir, struct dentry *dentry,
433			   const char *symname)
434{
435	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
436	struct inode *inode;
437	int res = -ENOMEM;
438
439	mutex_lock(&sbi->vh_mutex);
440	inode = hfsplus_new_inode(dir->i_sb, S_IFLNK | S_IRWXUGO);
441	if (!inode)
442		goto out;
443
444	res = page_symlink(inode, symname, strlen(symname) + 1);
445	if (res)
446		goto out_err;
447
448	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
449	if (res)
450		goto out_err;
451
452	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
453	if (res == -EOPNOTSUPP)
454		res = 0; /* Operation is not supported. */
455	else if (res) {
456		/* Try to delete anyway without error analysis. */
457		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
458		goto out_err;
459	}
460
461	hfsplus_instantiate(dentry, inode, inode->i_ino);
462	mark_inode_dirty(inode);
463	goto out;
464
465out_err:
466	clear_nlink(inode);
467	hfsplus_delete_inode(inode);
468	iput(inode);
469out:
470	mutex_unlock(&sbi->vh_mutex);
471	return res;
472}
473
474static int hfsplus_mknod(struct inode *dir, struct dentry *dentry,
475			 umode_t mode, dev_t rdev)
476{
477	struct hfsplus_sb_info *sbi = HFSPLUS_SB(dir->i_sb);
478	struct inode *inode;
479	int res = -ENOMEM;
480
481	mutex_lock(&sbi->vh_mutex);
482	inode = hfsplus_new_inode(dir->i_sb, mode);
483	if (!inode)
484		goto out;
485
486	if (S_ISBLK(mode) || S_ISCHR(mode) || S_ISFIFO(mode) || S_ISSOCK(mode))
487		init_special_inode(inode, mode, rdev);
488
489	res = hfsplus_create_cat(inode->i_ino, dir, &dentry->d_name, inode);
490	if (res)
491		goto failed_mknod;
492
493	res = hfsplus_init_inode_security(inode, dir, &dentry->d_name);
494	if (res == -EOPNOTSUPP)
495		res = 0; /* Operation is not supported. */
496	else if (res) {
497		/* Try to delete anyway without error analysis. */
498		hfsplus_delete_cat(inode->i_ino, dir, &dentry->d_name);
499		goto failed_mknod;
500	}
501
502	hfsplus_instantiate(dentry, inode, inode->i_ino);
503	mark_inode_dirty(inode);
504	goto out;
505
506failed_mknod:
507	clear_nlink(inode);
508	hfsplus_delete_inode(inode);
509	iput(inode);
510out:
511	mutex_unlock(&sbi->vh_mutex);
512	return res;
513}
514
515static int hfsplus_create(struct inode *dir, struct dentry *dentry, umode_t mode,
516			  bool excl)
517{
518	return hfsplus_mknod(dir, dentry, mode, 0);
519}
520
521static int hfsplus_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
522{
523	return hfsplus_mknod(dir, dentry, mode | S_IFDIR, 0);
524}
525
526static int hfsplus_rename(struct inode *old_dir, struct dentry *old_dentry,
527			  struct inode *new_dir, struct dentry *new_dentry)
528{
529	int res;
530
531	/* Unlink destination if it already exists */
532	if (d_really_is_positive(new_dentry)) {
533		if (d_is_dir(new_dentry))
534			res = hfsplus_rmdir(new_dir, new_dentry);
535		else
536			res = hfsplus_unlink(new_dir, new_dentry);
537		if (res)
538			return res;
539	}
540
541	res = hfsplus_rename_cat((u32)(unsigned long)old_dentry->d_fsdata,
542				 old_dir, &old_dentry->d_name,
543				 new_dir, &new_dentry->d_name);
544	if (!res)
545		new_dentry->d_fsdata = old_dentry->d_fsdata;
546	return res;
547}
548
549const struct inode_operations hfsplus_dir_inode_operations = {
550	.lookup			= hfsplus_lookup,
551	.create			= hfsplus_create,
552	.link			= hfsplus_link,
553	.unlink			= hfsplus_unlink,
554	.mkdir			= hfsplus_mkdir,
555	.rmdir			= hfsplus_rmdir,
556	.symlink		= hfsplus_symlink,
557	.mknod			= hfsplus_mknod,
558	.rename			= hfsplus_rename,
559	.setxattr		= generic_setxattr,
560	.getxattr		= generic_getxattr,
561	.listxattr		= hfsplus_listxattr,
562	.removexattr		= generic_removexattr,
563#ifdef CONFIG_HFSPLUS_FS_POSIX_ACL
564	.get_acl		= hfsplus_get_posix_acl,
565	.set_acl		= hfsplus_set_posix_acl,
566#endif
567};
568
569const struct file_operations hfsplus_dir_operations = {
570	.fsync		= hfsplus_file_fsync,
571	.read		= generic_read_dir,
572	.iterate	= hfsplus_readdir,
573	.unlocked_ioctl = hfsplus_ioctl,
574	.llseek		= generic_file_llseek,
575	.release	= hfsplus_dir_release,
576};
577