xref: /openbmc/linux/fs/hfs/catalog.c (revision 2cf1c348)
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 	/*
101 	 * Fail early and avoid ENOSPC during the btree operations. We may
102 	 * have to split the root node at most once.
103 	 */
104 	err = hfs_bmap_reserve(fd.tree, 2 * fd.tree->depth);
105 	if (err)
106 		goto err2;
107 
108 	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
109 	entry_size = hfs_cat_build_thread(sb, &entry, S_ISDIR(inode->i_mode) ?
110 			HFS_CDR_THD : HFS_CDR_FTH,
111 			dir->i_ino, str);
112 	err = hfs_brec_find(&fd);
113 	if (err != -ENOENT) {
114 		if (!err)
115 			err = -EEXIST;
116 		goto err2;
117 	}
118 	err = hfs_brec_insert(&fd, &entry, entry_size);
119 	if (err)
120 		goto err2;
121 
122 	hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
123 	entry_size = hfs_cat_build_record(&entry, cnid, inode);
124 	err = hfs_brec_find(&fd);
125 	if (err != -ENOENT) {
126 		/* panic? */
127 		if (!err)
128 			err = -EEXIST;
129 		goto err1;
130 	}
131 	err = hfs_brec_insert(&fd, &entry, entry_size);
132 	if (err)
133 		goto err1;
134 
135 	dir->i_size++;
136 	dir->i_mtime = dir->i_ctime = current_time(dir);
137 	mark_inode_dirty(dir);
138 	hfs_find_exit(&fd);
139 	return 0;
140 
141 err1:
142 	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
143 	if (!hfs_brec_find(&fd))
144 		hfs_brec_remove(&fd);
145 err2:
146 	hfs_find_exit(&fd);
147 	return err;
148 }
149 
150 /*
151  * hfs_cat_compare()
152  *
153  * Description:
154  *   This is the comparison function used for the catalog B-tree.  In
155  *   comparing catalog B-tree entries, the parent id is the most
156  *   significant field (compared as unsigned ints).  The name field is
157  *   the least significant (compared in "Macintosh lexical order",
158  *   see hfs_strcmp() in string.c)
159  * Input Variable(s):
160  *   struct hfs_cat_key *key1: pointer to the first key to compare
161  *   struct hfs_cat_key *key2: pointer to the second key to compare
162  * Output Variable(s):
163  *   NONE
164  * Returns:
165  *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
166  * Preconditions:
167  *   key1 and key2 point to "valid" (struct hfs_cat_key)s.
168  * Postconditions:
169  *   This function has no side-effects
170  */
171 int hfs_cat_keycmp(const btree_key *key1, const btree_key *key2)
172 {
173 	__be32 k1p, k2p;
174 
175 	k1p = key1->cat.ParID;
176 	k2p = key2->cat.ParID;
177 
178 	if (k1p != k2p)
179 		return be32_to_cpu(k1p) < be32_to_cpu(k2p) ? -1 : 1;
180 
181 	return hfs_strcmp(key1->cat.CName.name, key1->cat.CName.len,
182 			  key2->cat.CName.name, key2->cat.CName.len);
183 }
184 
185 /* Try to get a catalog entry for given catalog id */
186 // move to read_super???
187 int hfs_cat_find_brec(struct super_block *sb, u32 cnid,
188 		      struct hfs_find_data *fd)
189 {
190 	hfs_cat_rec rec;
191 	int res, len, type;
192 
193 	hfs_cat_build_key(sb, fd->search_key, cnid, NULL);
194 	res = hfs_brec_read(fd, &rec, sizeof(rec));
195 	if (res)
196 		return res;
197 
198 	type = rec.type;
199 	if (type != HFS_CDR_THD && type != HFS_CDR_FTH) {
200 		pr_err("found bad thread record in catalog\n");
201 		return -EIO;
202 	}
203 
204 	fd->search_key->cat.ParID = rec.thread.ParID;
205 	len = fd->search_key->cat.CName.len = rec.thread.CName.len;
206 	if (len > HFS_NAMELEN) {
207 		pr_err("bad catalog namelength\n");
208 		return -EIO;
209 	}
210 	memcpy(fd->search_key->cat.CName.name, rec.thread.CName.name, len);
211 	return hfs_brec_find(fd);
212 }
213 
214 
215 /*
216  * hfs_cat_delete()
217  *
218  * Delete the indicated file or directory.
219  * The associated thread is also removed unless ('with_thread'==0).
220  */
221 int hfs_cat_delete(u32 cnid, struct inode *dir, const struct qstr *str)
222 {
223 	struct super_block *sb;
224 	struct hfs_find_data fd;
225 	struct hfs_readdir_data *rd;
226 	int res, type;
227 
228 	hfs_dbg(CAT_MOD, "delete_cat: %s,%u\n", str ? str->name : NULL, cnid);
229 	sb = dir->i_sb;
230 	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
231 	if (res)
232 		return res;
233 
234 	hfs_cat_build_key(sb, fd.search_key, dir->i_ino, str);
235 	res = hfs_brec_find(&fd);
236 	if (res)
237 		goto out;
238 
239 	type = hfs_bnode_read_u8(fd.bnode, fd.entryoffset);
240 	if (type == HFS_CDR_FIL) {
241 		struct hfs_cat_file file;
242 		hfs_bnode_read(fd.bnode, &file, fd.entryoffset, sizeof(file));
243 		if (be32_to_cpu(file.FlNum) == cnid) {
244 #if 0
245 			hfs_free_fork(sb, &file, HFS_FK_DATA);
246 #endif
247 			hfs_free_fork(sb, &file, HFS_FK_RSRC);
248 		}
249 	}
250 
251 	/* we only need to take spinlock for exclusion with ->release() */
252 	spin_lock(&HFS_I(dir)->open_dir_lock);
253 	list_for_each_entry(rd, &HFS_I(dir)->open_dir_list, list) {
254 		if (fd.tree->keycmp(fd.search_key, (void *)&rd->key) < 0)
255 			rd->file->f_pos--;
256 	}
257 	spin_unlock(&HFS_I(dir)->open_dir_lock);
258 
259 	res = hfs_brec_remove(&fd);
260 	if (res)
261 		goto out;
262 
263 	hfs_cat_build_key(sb, fd.search_key, cnid, NULL);
264 	res = hfs_brec_find(&fd);
265 	if (!res) {
266 		res = hfs_brec_remove(&fd);
267 		if (res)
268 			goto out;
269 	}
270 
271 	dir->i_size--;
272 	dir->i_mtime = dir->i_ctime = current_time(dir);
273 	mark_inode_dirty(dir);
274 	res = 0;
275 out:
276 	hfs_find_exit(&fd);
277 
278 	return res;
279 }
280 
281 /*
282  * hfs_cat_move()
283  *
284  * Rename a file or directory, possibly to a new directory.
285  * If the destination exists it is removed and a
286  * (struct hfs_cat_entry) for it is returned in '*result'.
287  */
288 int hfs_cat_move(u32 cnid, struct inode *src_dir, const struct qstr *src_name,
289 		 struct inode *dst_dir, const struct qstr *dst_name)
290 {
291 	struct super_block *sb;
292 	struct hfs_find_data src_fd, dst_fd;
293 	union hfs_cat_rec entry;
294 	int entry_size, type;
295 	int err;
296 
297 	hfs_dbg(CAT_MOD, "rename_cat: %u - %lu,%s - %lu,%s\n",
298 		cnid, src_dir->i_ino, src_name->name,
299 		dst_dir->i_ino, dst_name->name);
300 	sb = src_dir->i_sb;
301 	err = hfs_find_init(HFS_SB(sb)->cat_tree, &src_fd);
302 	if (err)
303 		return err;
304 	dst_fd = src_fd;
305 
306 	/*
307 	 * Fail early and avoid ENOSPC during the btree operations. We may
308 	 * have to split the root node at most once.
309 	 */
310 	err = hfs_bmap_reserve(src_fd.tree, 2 * src_fd.tree->depth);
311 	if (err)
312 		goto out;
313 
314 	/* find the old dir entry and read the data */
315 	hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
316 	err = hfs_brec_find(&src_fd);
317 	if (err)
318 		goto out;
319 	if (src_fd.entrylength > sizeof(entry) || src_fd.entrylength < 0) {
320 		err = -EIO;
321 		goto out;
322 	}
323 
324 	hfs_bnode_read(src_fd.bnode, &entry, src_fd.entryoffset,
325 			    src_fd.entrylength);
326 
327 	/* create new dir entry with the data from the old entry */
328 	hfs_cat_build_key(sb, dst_fd.search_key, dst_dir->i_ino, dst_name);
329 	err = hfs_brec_find(&dst_fd);
330 	if (err != -ENOENT) {
331 		if (!err)
332 			err = -EEXIST;
333 		goto out;
334 	}
335 
336 	err = hfs_brec_insert(&dst_fd, &entry, src_fd.entrylength);
337 	if (err)
338 		goto out;
339 	dst_dir->i_size++;
340 	dst_dir->i_mtime = dst_dir->i_ctime = current_time(dst_dir);
341 	mark_inode_dirty(dst_dir);
342 
343 	/* finally remove the old entry */
344 	hfs_cat_build_key(sb, src_fd.search_key, src_dir->i_ino, src_name);
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 	src_dir->i_size--;
352 	src_dir->i_mtime = src_dir->i_ctime = current_time(src_dir);
353 	mark_inode_dirty(src_dir);
354 
355 	type = entry.type;
356 	if (type == HFS_CDR_FIL && !(entry.file.Flags & HFS_FIL_THD))
357 		goto out;
358 
359 	/* remove old thread entry */
360 	hfs_cat_build_key(sb, src_fd.search_key, cnid, NULL);
361 	err = hfs_brec_find(&src_fd);
362 	if (err)
363 		goto out;
364 	err = hfs_brec_remove(&src_fd);
365 	if (err)
366 		goto out;
367 
368 	/* create new thread entry */
369 	hfs_cat_build_key(sb, dst_fd.search_key, cnid, NULL);
370 	entry_size = hfs_cat_build_thread(sb, &entry, type == HFS_CDR_FIL ? HFS_CDR_FTH : HFS_CDR_THD,
371 					dst_dir->i_ino, dst_name);
372 	err = hfs_brec_find(&dst_fd);
373 	if (err != -ENOENT) {
374 		if (!err)
375 			err = -EEXIST;
376 		goto out;
377 	}
378 	err = hfs_brec_insert(&dst_fd, &entry, entry_size);
379 out:
380 	hfs_bnode_put(dst_fd.bnode);
381 	hfs_find_exit(&src_fd);
382 	return err;
383 }
384