xref: /linux/fs/hpfs/ea.c (revision bcefe12eff5dca6fdfa94ed85e5bee66380d5cd9)
1 /*
2  *  linux/fs/hpfs/ea.c
3  *
4  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
5  *
6  *  handling extended attributes
7  */
8 
9 #include "hpfs_fn.h"
10 
11 /* Remove external extended attributes. ano specifies whether a is a
12    direct sector where eas starts or an anode */
13 
14 void hpfs_ea_ext_remove(struct super_block *s, secno a, int ano, unsigned len)
15 {
16 	unsigned pos = 0;
17 	while (pos < len) {
18 		char ex[4 + 255 + 1 + 8];
19 		struct extended_attribute *ea = (struct extended_attribute *)ex;
20 		if (pos + 4 > len) {
21 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
22 				ano ? "anode" : "sectors", a, len);
23 			return;
24 		}
25 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return;
26 		if (ea->indirect) {
27 			if (ea->valuelen != 8) {
28 				hpfs_error(s, "ea->indirect set while ea->valuelen!=8, %s %08x, pos %08x",
29 					ano ? "anode" : "sectors", a, pos);
30 				return;
31 			}
32 			if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 9, ex+4))
33 				return;
34 			hpfs_ea_remove(s, ea_sec(ea), ea->anode, ea_len(ea));
35 		}
36 		pos += ea->namelen + ea->valuelen + 5;
37 	}
38 	if (!ano) hpfs_free_sectors(s, a, (len+511) >> 9);
39 	else {
40 		struct buffer_head *bh;
41 		struct anode *anode;
42 		if ((anode = hpfs_map_anode(s, a, &bh))) {
43 			hpfs_remove_btree(s, &anode->btree);
44 			brelse(bh);
45 			hpfs_free_sectors(s, a, 1);
46 		}
47 	}
48 }
49 
50 static char *get_indirect_ea(struct super_block *s, int ano, secno a, int size)
51 {
52 	char *ret;
53 	if (!(ret = kmalloc(size + 1, GFP_NOFS))) {
54 		printk("HPFS: out of memory for EA\n");
55 		return NULL;
56 	}
57 	if (hpfs_ea_read(s, a, ano, 0, size, ret)) {
58 		kfree(ret);
59 		return NULL;
60 	}
61 	ret[size] = 0;
62 	return ret;
63 }
64 
65 static void set_indirect_ea(struct super_block *s, int ano, secno a, char *data,
66 			    int size)
67 {
68 	hpfs_ea_write(s, a, ano, 0, size, data);
69 }
70 
71 /* Read an extended attribute named 'key' into the provided buffer */
72 
73 int hpfs_read_ea(struct super_block *s, struct fnode *fnode, char *key,
74 		char *buf, int size)
75 {
76 	unsigned pos;
77 	int ano, len;
78 	secno a;
79 	struct extended_attribute *ea;
80 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
81 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
82 		if (!strcmp(ea->name, key)) {
83 			if (ea->indirect)
84 				goto indirect;
85 			if (ea->valuelen >= size)
86 				return -EINVAL;
87 			memcpy(buf, ea_data(ea), ea->valuelen);
88 			buf[ea->valuelen] = 0;
89 			return 0;
90 		}
91 	a = fnode->ea_secno;
92 	len = fnode->ea_size_l;
93 	ano = fnode->ea_anode;
94 	pos = 0;
95 	while (pos < len) {
96 		char ex[4 + 255 + 1 + 8];
97 		ea = (struct extended_attribute *)ex;
98 		if (pos + 4 > len) {
99 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
100 				ano ? "anode" : "sectors", a, len);
101 			return -EIO;
102 		}
103 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return -EIO;
104 		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea->indirect ? 8 : 0), ex + 4))
105 			return -EIO;
106 		if (!strcmp(ea->name, key)) {
107 			if (ea->indirect)
108 				goto indirect;
109 			if (ea->valuelen >= size)
110 				return -EINVAL;
111 			if (hpfs_ea_read(s, a, ano, pos + 4 + ea->namelen + 1, ea->valuelen, buf))
112 				return -EIO;
113 			buf[ea->valuelen] = 0;
114 			return 0;
115 		}
116 		pos += ea->namelen + ea->valuelen + 5;
117 	}
118 	return -ENOENT;
119 indirect:
120 	if (ea_len(ea) >= size)
121 		return -EINVAL;
122 	if (hpfs_ea_read(s, ea_sec(ea), ea->anode, 0, ea_len(ea), buf))
123 		return -EIO;
124 	buf[ea_len(ea)] = 0;
125 	return 0;
126 }
127 
128 /* Read an extended attribute named 'key' */
129 char *hpfs_get_ea(struct super_block *s, struct fnode *fnode, char *key, int *size)
130 {
131 	char *ret;
132 	unsigned pos;
133 	int ano, len;
134 	secno a;
135 	struct extended_attribute *ea;
136 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
137 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
138 		if (!strcmp(ea->name, key)) {
139 			if (ea->indirect)
140 				return get_indirect_ea(s, ea->anode, ea_sec(ea), *size = ea_len(ea));
141 			if (!(ret = kmalloc((*size = ea->valuelen) + 1, GFP_NOFS))) {
142 				printk("HPFS: out of memory for EA\n");
143 				return NULL;
144 			}
145 			memcpy(ret, ea_data(ea), ea->valuelen);
146 			ret[ea->valuelen] = 0;
147 			return ret;
148 		}
149 	a = fnode->ea_secno;
150 	len = fnode->ea_size_l;
151 	ano = fnode->ea_anode;
152 	pos = 0;
153 	while (pos < len) {
154 		char ex[4 + 255 + 1 + 8];
155 		ea = (struct extended_attribute *)ex;
156 		if (pos + 4 > len) {
157 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
158 				ano ? "anode" : "sectors", a, len);
159 			return NULL;
160 		}
161 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return NULL;
162 		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea->indirect ? 8 : 0), ex + 4))
163 			return NULL;
164 		if (!strcmp(ea->name, key)) {
165 			if (ea->indirect)
166 				return get_indirect_ea(s, ea->anode, ea_sec(ea), *size = ea_len(ea));
167 			if (!(ret = kmalloc((*size = ea->valuelen) + 1, GFP_NOFS))) {
168 				printk("HPFS: out of memory for EA\n");
169 				return NULL;
170 			}
171 			if (hpfs_ea_read(s, a, ano, pos + 4 + ea->namelen + 1, ea->valuelen, ret)) {
172 				kfree(ret);
173 				return NULL;
174 			}
175 			ret[ea->valuelen] = 0;
176 			return ret;
177 		}
178 		pos += ea->namelen + ea->valuelen + 5;
179 	}
180 	return NULL;
181 }
182 
183 /*
184  * Update or create extended attribute 'key' with value 'data'. Note that
185  * when this ea exists, it MUST have the same size as size of data.
186  * This driver can't change sizes of eas ('cause I just don't need it).
187  */
188 
189 void hpfs_set_ea(struct inode *inode, struct fnode *fnode, char *key, char *data, int size)
190 {
191 	fnode_secno fno = inode->i_ino;
192 	struct super_block *s = inode->i_sb;
193 	unsigned pos;
194 	int ano, len;
195 	secno a;
196 	unsigned char h[4];
197 	struct extended_attribute *ea;
198 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
199 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
200 		if (!strcmp(ea->name, key)) {
201 			if (ea->indirect) {
202 				if (ea_len(ea) == size)
203 					set_indirect_ea(s, ea->anode, ea_sec(ea), data, size);
204 			} else if (ea->valuelen == size) {
205 				memcpy(ea_data(ea), data, size);
206 			}
207 			return;
208 		}
209 	a = fnode->ea_secno;
210 	len = fnode->ea_size_l;
211 	ano = fnode->ea_anode;
212 	pos = 0;
213 	while (pos < len) {
214 		char ex[4 + 255 + 1 + 8];
215 		ea = (struct extended_attribute *)ex;
216 		if (pos + 4 > len) {
217 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
218 				ano ? "anode" : "sectors", a, len);
219 			return;
220 		}
221 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return;
222 		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea->indirect ? 8 : 0), ex + 4))
223 			return;
224 		if (!strcmp(ea->name, key)) {
225 			if (ea->indirect) {
226 				if (ea_len(ea) == size)
227 					set_indirect_ea(s, ea->anode, ea_sec(ea), data, size);
228 			}
229 			else {
230 				if (ea->valuelen == size)
231 					hpfs_ea_write(s, a, ano, pos + 4 + ea->namelen + 1, size, data);
232 			}
233 			return;
234 		}
235 		pos += ea->namelen + ea->valuelen + 5;
236 	}
237 	if (!fnode->ea_offs) {
238 		/*if (fnode->ea_size_s) {
239 			hpfs_error(s, "fnode %08x: ea_size_s == %03x, ea_offs == 0",
240 				inode->i_ino, fnode->ea_size_s);
241 			return;
242 		}*/
243 		fnode->ea_offs = 0xc4;
244 	}
245 	if (fnode->ea_offs < 0xc4 || fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s > 0x200) {
246 		hpfs_error(s, "fnode %08lx: ea_offs == %03x, ea_size_s == %03x",
247 			(unsigned long)inode->i_ino,
248 			fnode->ea_offs, fnode->ea_size_s);
249 		return;
250 	}
251 	if ((fnode->ea_size_s || !fnode->ea_size_l) &&
252 	     fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s + strlen(key) + size + 5 <= 0x200) {
253 		ea = fnode_end_ea(fnode);
254 		*(char *)ea = 0;
255 		ea->namelen = strlen(key);
256 		ea->valuelen = size;
257 		strcpy(ea->name, key);
258 		memcpy(ea_data(ea), data, size);
259 		fnode->ea_size_s += strlen(key) + size + 5;
260 		goto ret;
261 	}
262 	/* Most the code here is 99.9993422% unused. I hope there are no bugs.
263 	   But what .. HPFS.IFS has also bugs in ea management. */
264 	if (fnode->ea_size_s && !fnode->ea_size_l) {
265 		secno n;
266 		struct buffer_head *bh;
267 		char *data;
268 		if (!(n = hpfs_alloc_sector(s, fno, 1, 0, 1))) return;
269 		if (!(data = hpfs_get_sector(s, n, &bh))) {
270 			hpfs_free_sectors(s, n, 1);
271 			return;
272 		}
273 		memcpy(data, fnode_ea(fnode), fnode->ea_size_s);
274 		fnode->ea_size_l = fnode->ea_size_s;
275 		fnode->ea_size_s = 0;
276 		fnode->ea_secno = n;
277 		fnode->ea_anode = 0;
278 		mark_buffer_dirty(bh);
279 		brelse(bh);
280 	}
281 	pos = fnode->ea_size_l + 5 + strlen(key) + size;
282 	len = (fnode->ea_size_l + 511) >> 9;
283 	if (pos >= 30000) goto bail;
284 	while (((pos + 511) >> 9) > len) {
285 		if (!len) {
286 			if (!(fnode->ea_secno = hpfs_alloc_sector(s, fno, 1, 0, 1)))
287 				goto bail;
288 			fnode->ea_anode = 0;
289 			len++;
290 		} else if (!fnode->ea_anode) {
291 			if (hpfs_alloc_if_possible(s, fnode->ea_secno + len)) {
292 				len++;
293 			} else {
294 				/* Aargh... don't know how to create ea anodes :-( */
295 				/*struct buffer_head *bh;
296 				struct anode *anode;
297 				anode_secno a_s;
298 				if (!(anode = hpfs_alloc_anode(s, fno, &a_s, &bh)))
299 					goto bail;
300 				anode->up = fno;
301 				anode->btree.fnode_parent = 1;
302 				anode->btree.n_free_nodes--;
303 				anode->btree.n_used_nodes++;
304 				anode->btree.first_free += 12;
305 				anode->u.external[0].disk_secno = fnode->ea_secno;
306 				anode->u.external[0].file_secno = 0;
307 				anode->u.external[0].length = len;
308 				mark_buffer_dirty(bh);
309 				brelse(bh);
310 				fnode->ea_anode = 1;
311 				fnode->ea_secno = a_s;*/
312 				secno new_sec;
313 				int i;
314 				if (!(new_sec = hpfs_alloc_sector(s, fno, 1, 1 - ((pos + 511) >> 9), 1)))
315 					goto bail;
316 				for (i = 0; i < len; i++) {
317 					struct buffer_head *bh1, *bh2;
318 					void *b1, *b2;
319 					if (!(b1 = hpfs_map_sector(s, fnode->ea_secno + i, &bh1, len - i - 1))) {
320 						hpfs_free_sectors(s, new_sec, (pos + 511) >> 9);
321 						goto bail;
322 					}
323 					if (!(b2 = hpfs_get_sector(s, new_sec + i, &bh2))) {
324 						brelse(bh1);
325 						hpfs_free_sectors(s, new_sec, (pos + 511) >> 9);
326 						goto bail;
327 					}
328 					memcpy(b2, b1, 512);
329 					brelse(bh1);
330 					mark_buffer_dirty(bh2);
331 					brelse(bh2);
332 				}
333 				hpfs_free_sectors(s, fnode->ea_secno, len);
334 				fnode->ea_secno = new_sec;
335 				len = (pos + 511) >> 9;
336 			}
337 		}
338 		if (fnode->ea_anode) {
339 			if (hpfs_add_sector_to_btree(s, fnode->ea_secno,
340 						     0, len) != -1) {
341 				len++;
342 			} else {
343 				goto bail;
344 			}
345 		}
346 	}
347 	h[0] = 0;
348 	h[1] = strlen(key);
349 	h[2] = size & 0xff;
350 	h[3] = size >> 8;
351 	if (hpfs_ea_write(s, fnode->ea_secno, fnode->ea_anode, fnode->ea_size_l, 4, h)) goto bail;
352 	if (hpfs_ea_write(s, fnode->ea_secno, fnode->ea_anode, fnode->ea_size_l + 4, h[1] + 1, key)) goto bail;
353 	if (hpfs_ea_write(s, fnode->ea_secno, fnode->ea_anode, fnode->ea_size_l + 5 + h[1], size, data)) goto bail;
354 	fnode->ea_size_l = pos;
355 	ret:
356 	hpfs_i(inode)->i_ea_size += 5 + strlen(key) + size;
357 	return;
358 	bail:
359 	if (fnode->ea_secno)
360 		if (fnode->ea_anode) hpfs_truncate_btree(s, fnode->ea_secno, 1, (fnode->ea_size_l + 511) >> 9);
361 		else hpfs_free_sectors(s, fnode->ea_secno + ((fnode->ea_size_l + 511) >> 9), len - ((fnode->ea_size_l + 511) >> 9));
362 	else fnode->ea_secno = fnode->ea_size_l = 0;
363 }
364 
365