xref: /openbmc/linux/fs/hfs/catalog.c (revision 4beec1d7)
1 /*
2  *  linux/fs/hfs/catalog.c
3  *
4  * Copyright (C) 1995-1997  Paul H. Hargrove
5  * (C) 2003 Ardis Technologies <roman@ardistech.com>
6  * This file may be distributed under the terms of the GNU General Public License.
7  *
8  * This file contains the functions related to the catalog B-tree.
9  *
10  * Cache code shamelessly stolen from
11  *     linux/fs/inode.c Copyright (C) 1991, 1992  Linus Torvalds
12  *     re-shamelessly stolen Copyright (C) 1997 Linus Torvalds
13  */
14 
15 #include "hfs_fs.h"
16 #include "btree.h"
17 
18 /*
19  * hfs_cat_build_key()
20  *
21  * Given the ID of the parent and the name build a search key.
22  */
23 void hfs_cat_build_key(struct super_block *sb, btree_key *key, u32 parent, const struct qstr *name)
24 {
25 	key->cat.reserved = 0;
26 	key->cat.ParID = cpu_to_be32(parent);
27 	if (name) {
28 		hfs_asc2mac(sb, &key->cat.CName, name);
29 		key->key_len = 6 + key->cat.CName.len;
30 	} else {
31 		memset(&key->cat.CName, 0, sizeof(struct hfs_name));
32 		key->key_len = 6;
33 	}
34 }
35 
36 static int hfs_cat_build_record(hfs_cat_rec *rec, u32 cnid, struct inode *inode)
37 {
38 	__be32 mtime = hfs_mtime();
39 
40 	memset(rec, 0, sizeof(*rec));
41 	if (S_ISDIR(inode->i_mode)) {
42 		rec->type = HFS_CDR_DIR;
43 		rec->dir.DirID = cpu_to_be32(cnid);
44 		rec->dir.CrDat = mtime;
45 		rec->dir.MdDat = mtime;
46 		rec->dir.BkDat = 0;
47 		rec->dir.UsrInfo.frView = cpu_to_be16(0xff);
48 		return sizeof(struct hfs_cat_dir);
49 	} else {
50 		/* init some fields for the file record */
51 		rec->type = HFS_CDR_FIL;
52 		rec->file.Flags = HFS_FIL_USED | HFS_FIL_THD;
53 		if (!(inode->i_mode & S_IWUSR))
54 			rec->file.Flags |= HFS_FIL_LOCK;
55 		rec->file.FlNum = cpu_to_be32(cnid);
56 		rec->file.CrDat = mtime;
57 		rec->file.MdDat = mtime;
58 		rec->file.BkDat = 0;
59 		rec->file.UsrWds.fdType = HFS_SB(inode->i_sb)->s_type;
60 		rec->file.UsrWds.fdCreator = HFS_SB(inode->i_sb)->s_creator;
61 		return sizeof(struct hfs_cat_file);
62 	}
63 }
64 
65 static int hfs_cat_build_thread(struct super_block *sb,
66 				hfs_cat_rec *rec, int type,
67 				u32 parentid, const struct qstr *name)
68 {
69 	rec->type = type;
70 	memset(rec->thread.reserved, 0, sizeof(rec->thread.reserved));
71 	rec->thread.ParID = cpu_to_be32(parentid);
72 	hfs_asc2mac(sb, &rec->thread.CName, name);
73 	return sizeof(struct hfs_cat_thread);
74 }
75 
76 /*
77  * create_entry()
78  *
79  * Add a new file or directory to the catalog B-tree and
80  * return a (struct hfs_cat_entry) for it in '*result'.
81  */
82 int hfs_cat_create(u32 cnid, struct inode *dir, const struct qstr *str, struct inode *inode)
83 {
84 	struct hfs_find_data fd;
85 	struct super_block *sb;
86 	union hfs_cat_rec entry;
87 	int entry_size;
88 	int err;
89 
90 	hfs_dbg(CAT_MOD, "create_cat: %s,%u(%d)\n",
91 		str->name, cnid, inode->i_nlink);
92 	if (dir->i_size >= HFS_MAX_VALENCE)
93 		return -ENOSPC;
94 
95 	sb = dir->i_sb;
96 	err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
97 	if (err)
98 		return err;
99 
100 	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
101 	entry_size = hfs_cat_build_thread(sb, &entry, S_ISDIR(inode->i_mode) ?
102 			HFS_CDR_THD : HFS_CDR_FTH,
103 			dir->i_ino, str);
104 	err = hfs_brec_find(&fd);
105 	if (err != -ENOENT) {
106 		if (!err)
107 			err = -EEXIST;
108 		goto err2;
109 	}
110 	err = hfs_brec_insert(&fd, &entry, entry_size);
111 	if (err)
112 		goto err2;
113 
114 	hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
115 	entry_size = hfs_cat_build_record(&entry, cnid, inode);
116 	err = hfs_brec_find(&fd);
117 	if (err != -ENOENT) {
118 		/* panic? */
119 		if (!err)
120 			err = -EEXIST;
121 		goto err1;
122 	}
123 	err = hfs_brec_insert(&fd, &entry, entry_size);
124 	if (err)
125 		goto err1;
126 
127 	dir->i_size++;
128 	dir->i_mtime = dir->i_ctime = current_time(dir);
129 	mark_inode_dirty(dir);
130 	hfs_find_exit(&fd);
131 	return 0;
132 
133 err1:
134 	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
135 	if (!hfs_brec_find(&fd))
136 		hfs_brec_remove(&fd);
137 err2:
138 	hfs_find_exit(&fd);
139 	return err;
140 }
141 
142 /*
143  * hfs_cat_compare()
144  *
145  * Description:
146  *   This is the comparison function used for the catalog B-tree.  In
147  *   comparing catalog B-tree entries, the parent id is the most
148  *   significant field (compared as unsigned ints).  The name field is
149  *   the least significant (compared in "Macintosh lexical order",
150  *   see hfs_strcmp() in string.c)
151  * Input Variable(s):
152  *   struct hfs_cat_key *key1: pointer to the first key to compare
153  *   struct hfs_cat_key *key2: pointer to the second key to compare
154  * Output Variable(s):
155  *   NONE
156  * Returns:
157  *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
158  * Preconditions:
159  *   key1 and key2 point to "valid" (struct hfs_cat_key)s.
160  * Postconditions:
161  *   This function has no side-effects
162  */
163 int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2)
164 {
165 	__be32 k1p, k2p;
166 
167 	k1p = key1->cat.ParID;
168 	k2p = key2->cat.ParID;
169 
170 	if (k1p != k2p)
171 		return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1;
172 
173 	return hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len,
174 			  key2->cat.CName.name, key2->cat.CName.len);
175 }
176 
177 /* Try to get a catalog entry for given catalog id */
178 // move to read_super???
179 int hfs_cat_find_brec(struct super_block *sb, u32 cnid,
180 		      struct hfs_find_data *fd)
181 {
182 	hfs_cat_rec rec;
183 	int res, len, type;
184 
185 	hfs_cat_build_key(sb, fd->search_key, cnid, NULL);
186 	res = hfs_brec_read(fd, &rec, sizeof(rec));
187 	if (res)
188 		return res;
189 
190 	type = rec.type;
191 	if (type != HFS_CDR_THD && type != HFS_CDR_FTH) {
192 		pr_err("found bad thread record in catalog\n");
193 		return -EIO;
194 	}
195 
196 	fd->search_key->cat.ParID = rec.thread.ParID;
197 	len = fd->search_key->cat.CName.len = rec.thread.CName.len;
198 	if (len > HFS_NAMELEN) {
199 		pr_err("bad catalog namelength\n");
200 		return -EIO;
201 	}
202 	memcpy(fd->search_key->cat.CName.name, rec.thread.CName.name, len);
203 	return hfs_brec_find(fd);
204 }
205 
206 
207 /*
208  * hfs_cat_delete()
209  *
210  * Delete the indicated file or directory.
211  * The associated thread is also removed unless ('with_thread'==0).
212  */
213 int hfs_cat_delete(u32 cnid, struct inode *dir, const struct qstr *str)
214 {
215 	struct super_block *sb;
216 	struct hfs_find_data fd;
217 	struct hfs_readdir_data *rd;
218 	int res, type;
219 
220 	hfs_dbg(CAT_MOD, "delete_cat: %s,%u\n", str ? str->name : NULL, cnid);
221 	sb = dir->i_sb;
222 	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
223 	if (res)
224 		return res;
225 
226 	hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
227 	res = hfs_brec_find(&fd);
228 	if (res)
229 		goto out;
230 
231 	type = hfs_bnode_read_u8(fd.bnode, fd.entryoffset);
232 	if (type == HFS_CDR_FIL) {
233 		struct hfs_cat_file file;
234 		hfs_bnode_read(fd.bnode, &file, fd.entryoffset, sizeof(file));
235 		if (be32_to_cpu(file.FlNum) == cnid) {
236 #if 0
237 			hfs_free_fork(sb, &file, HFS_FK_DATA);
238 #endif
239 			hfs_free_fork(sb, &file, HFS_FK_RSRC);
240 		}
241 	}
242 
243 	/* we only need to take spinlock for exclusion with ->release() */
244 	spin_lock(&HFS_I(dir)->open_dir_lock);
245 	list_for_each_entry(rd, &HFS_I(dir)->open_dir_list, list) {
246 		if (fd.tree->keycmp(fd.search_key, (void *)&rd->key) < 0)
247 			rd->file->f_pos--;
248 	}
249 	spin_unlock(&HFS_I(dir)->open_dir_lock);
250 
251 	res = hfs_brec_remove(&fd);
252 	if (res)
253 		goto out;
254 
255 	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
256 	res = hfs_brec_find(&fd);
257 	if (!res) {
258 		res = hfs_brec_remove(&fd);
259 		if (res)
260 			goto out;
261 	}
262 
263 	dir->i_size--;
264 	dir->i_mtime = dir->i_ctime = current_time(dir);
265 	mark_inode_dirty(dir);
266 	res = 0;
267 out:
268 	hfs_find_exit(&fd);
269 
270 	return res;
271 }
272 
273 /*
274  * hfs_cat_move()
275  *
276  * Rename a file or directory, possibly to a new directory.
277  * If the destination exists it is removed and a
278  * (struct hfs_cat_entry) for it is returned in '*result'.
279  */
280 int hfs_cat_move(u32 cnid, struct inode *src_dir, const struct qstr *src_name,
281 		 struct inode *dst_dir, const struct qstr *dst_name)
282 {
283 	struct super_block *sb;
284 	struct hfs_find_data src_fd, dst_fd;
285 	union hfs_cat_rec entry;
286 	int entry_size, type;
287 	int err;
288 
289 	hfs_dbg(CAT_MOD, "rename_cat: %u - %lu,%s - %lu,%s\n",
290 		cnid, src_dir->i_ino, src_name->name,
291 		dst_dir->i_ino, dst_name->name);
292 	sb = src_dir->i_sb;
293 	err = hfs_find_init(HFS_SB(sb)->cat_tree, &src_fd);
294 	if (err)
295 		return err;
296 	dst_fd = src_fd;
297 
298 	/* find the old dir entry and read the data */
299 	hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
300 	err = hfs_brec_find(&src_fd);
301 	if (err)
302 		goto out;
303 	if (src_fd.entrylength > sizeof(entry) || src_fd.entrylength < 0) {
304 		err = -EIO;
305 		goto out;
306 	}
307 
308 	hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset,
309 			    src_fd.entrylength);
310 
311 	/* create new dir entry with the data from the old entry */
312 	hfs_cat_build_key(sb, dst_fd.search_key, dst_dir->i_ino, dst_name);
313 	err = hfs_brec_find(&dst_fd);
314 	if (err != -ENOENT) {
315 		if (!err)
316 			err = -EEXIST;
317 		goto out;
318 	}
319 
320 	err = hfs_brec_insert(&dst_fd, &entry, src_fd.entrylength);
321 	if (err)
322 		goto out;
323 	dst_dir->i_size++;
324 	dst_dir->i_mtime = dst_dir->i_ctime = current_time(dst_dir);
325 	mark_inode_dirty(dst_dir);
326 
327 	/* finally remove the old entry */
328 	hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
329 	err = hfs_brec_find(&src_fd);
330 	if (err)
331 		goto out;
332 	err = hfs_brec_remove(&src_fd);
333 	if (err)
334 		goto out;
335 	src_dir->i_size--;
336 	src_dir->i_mtime = src_dir->i_ctime = current_time(src_dir);
337 	mark_inode_dirty(src_dir);
338 
339 	type = entry.type;
340 	if (type == HFS_CDR_FIL && !(entry.file.Flags & HFS_FIL_THD))
341 		goto out;
342 
343 	/* remove old thread entry */
344 	hfs_cat_build_key(sb, src_fd.search_key, cnid, NULL);
345 	err = hfs_brec_find(&src_fd);
346 	if (err)
347 		goto out;
348 	err = hfs_brec_remove(&src_fd);
349 	if (err)
350 		goto out;
351 
352 	/* create new thread entry */
353 	hfs_cat_build_key(sb, dst_fd.search_key, cnid, NULL);
354 	entry_size = hfs_cat_build_thread(sb, &entry, type == HFS_CDR_FIL ? HFS_CDR_FTH : HFS_CDR_THD,
355 					dst_dir->i_ino, dst_name);
356 	err = hfs_brec_find(&dst_fd);
357 	if (err != -ENOENT) {
358 		if (!err)
359 			err = -EEXIST;
360 		goto out;
361 	}
362 	err = hfs_brec_insert(&dst_fd, &entry, entry_size);
363 out:
364 	hfs_bnode_put(dst_fd.bnode);
365 	hfs_find_exit(&src_fd);
366 	return err;
367 }
368