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 <linux/string.h>
10 #include "hpfs_fn.h"
11 
12 /* Remove external extended attributes. ano specifies whether a is a
13    direct sector where eas starts or an anode */
14 
hpfs_ea_ext_remove(struct super_block * s,secno a,int ano,unsigned len)15 void hpfs_ea_ext_remove(struct super_block *s, secno a, int ano, unsigned len)
16 {
17 	unsigned pos = 0;
18 	while (pos < len) {
19 		char ex[4 + 255 + 1 + 8];
20 		struct extended_attribute *ea = (struct extended_attribute *)ex;
21 		if (pos + 4 > len) {
22 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
23 				ano ? "anode" : "sectors", a, len);
24 			return;
25 		}
26 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return;
27 		if (ea->indirect) {
28 			if (ea->valuelen != 8) {
29 				hpfs_error(s, "ea->indirect set while ea->valuelen!=8, %s %08x, pos %08x",
30 					ano ? "anode" : "sectors", a, pos);
31 				return;
32 			}
33 			if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 9, ex+4))
34 				return;
35 			hpfs_ea_remove(s, ea_sec(ea), ea->anode, ea_len(ea));
36 		}
37 		pos += ea->namelen + ea->valuelen + 5;
38 	}
39 	if (!ano) hpfs_free_sectors(s, a, (len+511) >> 9);
40 	else {
41 		struct buffer_head *bh;
42 		struct anode *anode;
43 		if ((anode = hpfs_map_anode(s, a, &bh))) {
44 			hpfs_remove_btree(s, &anode->btree);
45 			brelse(bh);
46 			hpfs_free_sectors(s, a, 1);
47 		}
48 	}
49 }
50 
get_indirect_ea(struct super_block * s,int ano,secno a,int size)51 static char *get_indirect_ea(struct super_block *s, int ano, secno a, int size)
52 {
53 	char *ret;
54 	if (!(ret = kmalloc(size + 1, GFP_KERNEL))) {
55 		printk("HPFS: out of memory for EA\n");
56 		return NULL;
57 	}
58 	if (hpfs_ea_read(s, a, ano, 0, size, ret)) {
59 		kfree(ret);
60 		return NULL;
61 	}
62 	ret[size] = 0;
63 	return ret;
64 }
65 
set_indirect_ea(struct super_block * s,int ano,secno a,char * data,int size)66 static void set_indirect_ea(struct super_block *s, int ano, secno a, char *data,
67 			    int size)
68 {
69 	hpfs_ea_write(s, a, ano, 0, size, data);
70 }
71 
72 /* Read an extended attribute named 'key' into the provided buffer */
73 
hpfs_read_ea(struct super_block * s,struct fnode * fnode,char * key,char * buf,int size)74 int hpfs_read_ea(struct super_block *s, struct fnode *fnode, char *key,
75 		char *buf, int size)
76 {
77 	unsigned pos;
78 	int ano, len;
79 	secno a;
80 	struct extended_attribute *ea;
81 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
82 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
83 		if (!strcmp(ea->name, key)) {
84 			if (ea->indirect)
85 				goto indirect;
86 			if (ea->valuelen >= size)
87 				return -EINVAL;
88 			memcpy(buf, ea_data(ea), ea->valuelen);
89 			buf[ea->valuelen] = 0;
90 			return 0;
91 		}
92 	a = fnode->ea_secno;
93 	len = fnode->ea_size_l;
94 	ano = fnode->ea_anode;
95 	pos = 0;
96 	while (pos < len) {
97 		char ex[4 + 255 + 1 + 8];
98 		ea = (struct extended_attribute *)ex;
99 		if (pos + 4 > len) {
100 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
101 				ano ? "anode" : "sectors", a, len);
102 			return -EIO;
103 		}
104 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return -EIO;
105 		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea->indirect ? 8 : 0), ex + 4))
106 			return -EIO;
107 		if (!strcmp(ea->name, key)) {
108 			if (ea->indirect)
109 				goto indirect;
110 			if (ea->valuelen >= size)
111 				return -EINVAL;
112 			if (hpfs_ea_read(s, a, ano, pos + 4 + ea->namelen + 1, ea->valuelen, buf))
113 				return -EIO;
114 			buf[ea->valuelen] = 0;
115 			return 0;
116 		}
117 		pos += ea->namelen + ea->valuelen + 5;
118 	}
119 	return -ENOENT;
120 indirect:
121 	if (ea_len(ea) >= size)
122 		return -EINVAL;
123 	if (hpfs_ea_read(s, ea_sec(ea), ea->anode, 0, ea_len(ea), buf))
124 		return -EIO;
125 	buf[ea_len(ea)] = 0;
126 	return 0;
127 }
128 
129 /* Read an extended attribute named 'key' */
hpfs_get_ea(struct super_block * s,struct fnode * fnode,char * key,int * size)130 char *hpfs_get_ea(struct super_block *s, struct fnode *fnode, char *key, int *size)
131 {
132 	char *ret;
133 	unsigned pos;
134 	int ano, len;
135 	secno a;
136 	struct extended_attribute *ea;
137 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
138 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
139 		if (!strcmp(ea->name, key)) {
140 			if (ea->indirect)
141 				return get_indirect_ea(s, ea->anode, ea_sec(ea), *size = ea_len(ea));
142 			if (!(ret = kmalloc((*size = ea->valuelen) + 1, GFP_KERNEL))) {
143 				printk("HPFS: out of memory for EA\n");
144 				return NULL;
145 			}
146 			memcpy(ret, ea_data(ea), ea->valuelen);
147 			ret[ea->valuelen] = 0;
148 			return ret;
149 		}
150 	a = fnode->ea_secno;
151 	len = fnode->ea_size_l;
152 	ano = fnode->ea_anode;
153 	pos = 0;
154 	while (pos < len) {
155 		char ex[4 + 255 + 1 + 8];
156 		ea = (struct extended_attribute *)ex;
157 		if (pos + 4 > len) {
158 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
159 				ano ? "anode" : "sectors", a, len);
160 			return NULL;
161 		}
162 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return NULL;
163 		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea->indirect ? 8 : 0), ex + 4))
164 			return NULL;
165 		if (!strcmp(ea->name, key)) {
166 			if (ea->indirect)
167 				return get_indirect_ea(s, ea->anode, ea_sec(ea), *size = ea_len(ea));
168 			if (!(ret = kmalloc((*size = ea->valuelen) + 1, GFP_KERNEL))) {
169 				printk("HPFS: out of memory for EA\n");
170 				return NULL;
171 			}
172 			if (hpfs_ea_read(s, a, ano, pos + 4 + ea->namelen + 1, ea->valuelen, ret)) {
173 				kfree(ret);
174 				return NULL;
175 			}
176 			ret[ea->valuelen] = 0;
177 			return ret;
178 		}
179 		pos += ea->namelen + ea->valuelen + 5;
180 	}
181 	return NULL;
182 }
183 
184 /*
185  * Update or create extended attribute 'key' with value 'data'. Note that
186  * when this ea exists, it MUST have the same size as size of data.
187  * This driver can't change sizes of eas ('cause I just don't need it).
188  */
189 
hpfs_set_ea(struct inode * inode,struct fnode * fnode,char * key,char * data,int size)190 void hpfs_set_ea(struct inode *inode, struct fnode *fnode, char *key, char *data, int size)
191 {
192 	fnode_secno fno = inode->i_ino;
193 	struct super_block *s = inode->i_sb;
194 	unsigned pos;
195 	int ano, len;
196 	secno a;
197 	unsigned char h[4];
198 	struct extended_attribute *ea;
199 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
200 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
201 		if (!strcmp(ea->name, key)) {
202 			if (ea->indirect) {
203 				if (ea_len(ea) == size)
204 					set_indirect_ea(s, ea->anode, ea_sec(ea), data, size);
205 			} else if (ea->valuelen == size) {
206 				memcpy(ea_data(ea), data, size);
207 			}
208 			return;
209 		}
210 	a = fnode->ea_secno;
211 	len = fnode->ea_size_l;
212 	ano = fnode->ea_anode;
213 	pos = 0;
214 	while (pos < len) {
215 		char ex[4 + 255 + 1 + 8];
216 		ea = (struct extended_attribute *)ex;
217 		if (pos + 4 > len) {
218 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
219 				ano ? "anode" : "sectors", a, len);
220 			return;
221 		}
222 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return;
223 		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea->indirect ? 8 : 0), ex + 4))
224 			return;
225 		if (!strcmp(ea->name, key)) {
226 			if (ea->indirect) {
227 				if (ea_len(ea) == size)
228 					set_indirect_ea(s, ea->anode, ea_sec(ea), data, size);
229 			}
230 			else {
231 				if (ea->valuelen == size)
232 					hpfs_ea_write(s, a, ano, pos + 4 + ea->namelen + 1, size, data);
233 			}
234 			return;
235 		}
236 		pos += ea->namelen + ea->valuelen + 5;
237 	}
238 	if (!fnode->ea_offs) {
239 		/*if (fnode->ea_size_s) {
240 			hpfs_error(s, "fnode %08x: ea_size_s == %03x, ea_offs == 0",
241 				inode->i_ino, fnode->ea_size_s);
242 			return;
243 		}*/
244 		fnode->ea_offs = 0xc4;
245 	}
246 	if (fnode->ea_offs < 0xc4 || fnode->ea_offs + fnode->acl_size_s + fnode->ea_size_s > 0x200) {
247 		hpfs_error(s, "fnode %08x: ea_offs == %03x, ea_size_s == %03x",
248 			inode->i_ino, 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 	inode->i_hpfs_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