xref: /openbmc/linux/fs/hpfs/ea.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  linux/fs/hpfs/ea.c
4  *
5  *  Mikulas Patocka (mikulas@artax.karlin.mff.cuni.cz), 1998-1999
6  *
7  *  handling extended attributes
8  */
9 
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 
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(ea)) {
28 			if (ea_valuelen(ea) != 8) {
29 				hpfs_error(s, "ea_indirect(ea) 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_in_anode(ea), ea_len(ea));
36 		}
37 		pos += ea->namelen + ea_valuelen(ea) + 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 
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_NOFS))) {
55 		pr_err("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 
66 static void set_indirect_ea(struct super_block *s, int ano, secno a,
67 			    const char *data, 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 
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 	char ex[4 + 255 + 1 + 8];
81 	struct extended_attribute *ea;
82 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
83 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
84 		if (!strcmp(ea->name, key)) {
85 			if (ea_indirect(ea))
86 				goto indirect;
87 			if (ea_valuelen(ea) >= size)
88 				return -EINVAL;
89 			memcpy(buf, ea_data(ea), ea_valuelen(ea));
90 			buf[ea_valuelen(ea)] = 0;
91 			return 0;
92 		}
93 	a = le32_to_cpu(fnode->ea_secno);
94 	len = le32_to_cpu(fnode->ea_size_l);
95 	ano = fnode_in_anode(fnode);
96 	pos = 0;
97 	while (pos < len) {
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(ea) ? 8 : 0), ex + 4))
106 			return -EIO;
107 		if (!strcmp(ea->name, key)) {
108 			if (ea_indirect(ea))
109 				goto indirect;
110 			if (ea_valuelen(ea) >= size)
111 				return -EINVAL;
112 			if (hpfs_ea_read(s, a, ano, pos + 4 + ea->namelen + 1, ea_valuelen(ea), buf))
113 				return -EIO;
114 			buf[ea_valuelen(ea)] = 0;
115 			return 0;
116 		}
117 		pos += ea->namelen + ea_valuelen(ea) + 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_in_anode(ea), 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' */
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(ea))
141 				return get_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), *size = ea_len(ea));
142 			if (!(ret = kmalloc((*size = ea_valuelen(ea)) + 1, GFP_NOFS))) {
143 				pr_err("out of memory for EA\n");
144 				return NULL;
145 			}
146 			memcpy(ret, ea_data(ea), ea_valuelen(ea));
147 			ret[ea_valuelen(ea)] = 0;
148 			return ret;
149 		}
150 	a = le32_to_cpu(fnode->ea_secno);
151 	len = le32_to_cpu(fnode->ea_size_l);
152 	ano = fnode_in_anode(fnode);
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(ea) ? 8 : 0), ex + 4))
164 			return NULL;
165 		if (!strcmp(ea->name, key)) {
166 			if (ea_indirect(ea))
167 				return get_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), *size = ea_len(ea));
168 			if (!(ret = kmalloc((*size = ea_valuelen(ea)) + 1, GFP_NOFS))) {
169 				pr_err("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(ea), ret)) {
173 				kfree(ret);
174 				return NULL;
175 			}
176 			ret[ea_valuelen(ea)] = 0;
177 			return ret;
178 		}
179 		pos += ea->namelen + ea_valuelen(ea) + 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 
190 void hpfs_set_ea(struct inode *inode, struct fnode *fnode, const char *key,
191 		 const char *data, int size)
192 {
193 	fnode_secno fno = inode->i_ino;
194 	struct super_block *s = inode->i_sb;
195 	unsigned pos;
196 	int ano, len;
197 	secno a;
198 	unsigned char h[4];
199 	struct extended_attribute *ea;
200 	struct extended_attribute *ea_end = fnode_end_ea(fnode);
201 	for (ea = fnode_ea(fnode); ea < ea_end; ea = next_ea(ea))
202 		if (!strcmp(ea->name, key)) {
203 			if (ea_indirect(ea)) {
204 				if (ea_len(ea) == size)
205 					set_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), data, size);
206 			} else if (ea_valuelen(ea) == size) {
207 				memcpy(ea_data(ea), data, size);
208 			}
209 			return;
210 		}
211 	a = le32_to_cpu(fnode->ea_secno);
212 	len = le32_to_cpu(fnode->ea_size_l);
213 	ano = fnode_in_anode(fnode);
214 	pos = 0;
215 	while (pos < len) {
216 		char ex[4 + 255 + 1 + 8];
217 		ea = (struct extended_attribute *)ex;
218 		if (pos + 4 > len) {
219 			hpfs_error(s, "EAs don't end correctly, %s %08x, len %08x",
220 				ano ? "anode" : "sectors", a, len);
221 			return;
222 		}
223 		if (hpfs_ea_read(s, a, ano, pos, 4, ex)) return;
224 		if (hpfs_ea_read(s, a, ano, pos + 4, ea->namelen + 1 + (ea_indirect(ea) ? 8 : 0), ex + 4))
225 			return;
226 		if (!strcmp(ea->name, key)) {
227 			if (ea_indirect(ea)) {
228 				if (ea_len(ea) == size)
229 					set_indirect_ea(s, ea_in_anode(ea), ea_sec(ea), data, size);
230 			}
231 			else {
232 				if (ea_valuelen(ea) == size)
233 					hpfs_ea_write(s, a, ano, pos + 4 + ea->namelen + 1, size, data);
234 			}
235 			return;
236 		}
237 		pos += ea->namelen + ea_valuelen(ea) + 5;
238 	}
239 	if (!le16_to_cpu(fnode->ea_offs)) {
240 		/*if (le16_to_cpu(fnode->ea_size_s)) {
241 			hpfs_error(s, "fnode %08x: ea_size_s == %03x, ea_offs == 0",
242 				inode->i_ino, le16_to_cpu(fnode->ea_size_s));
243 			return;
244 		}*/
245 		fnode->ea_offs = cpu_to_le16(0xc4);
246 	}
247 	if (le16_to_cpu(fnode->ea_offs) < 0xc4 || le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) > 0x200) {
248 		hpfs_error(s, "fnode %08lx: ea_offs == %03x, ea_size_s == %03x",
249 			(unsigned long)inode->i_ino,
250 			le16_to_cpu(fnode->ea_offs), le16_to_cpu(fnode->ea_size_s));
251 		return;
252 	}
253 	if ((le16_to_cpu(fnode->ea_size_s) || !le32_to_cpu(fnode->ea_size_l)) &&
254 	     le16_to_cpu(fnode->ea_offs) + le16_to_cpu(fnode->acl_size_s) + le16_to_cpu(fnode->ea_size_s) + strlen(key) + size + 5 <= 0x200) {
255 		ea = fnode_end_ea(fnode);
256 		*(char *)ea = 0;
257 		ea->namelen = strlen(key);
258 		ea->valuelen_lo = size;
259 		ea->valuelen_hi = size >> 8;
260 		strcpy(ea->name, key);
261 		memcpy(ea_data(ea), data, size);
262 		fnode->ea_size_s = cpu_to_le16(le16_to_cpu(fnode->ea_size_s) + strlen(key) + size + 5);
263 		goto ret;
264 	}
265 	/* Most the code here is 99.9993422% unused. I hope there are no bugs.
266 	   But what .. HPFS.IFS has also bugs in ea management. */
267 	if (le16_to_cpu(fnode->ea_size_s) && !le32_to_cpu(fnode->ea_size_l)) {
268 		secno n;
269 		struct buffer_head *bh;
270 		char *data;
271 		if (!(n = hpfs_alloc_sector(s, fno, 1, 0))) return;
272 		if (!(data = hpfs_get_sector(s, n, &bh))) {
273 			hpfs_free_sectors(s, n, 1);
274 			return;
275 		}
276 		memcpy(data, fnode_ea(fnode), le16_to_cpu(fnode->ea_size_s));
277 		fnode->ea_size_l = cpu_to_le32(le16_to_cpu(fnode->ea_size_s));
278 		fnode->ea_size_s = cpu_to_le16(0);
279 		fnode->ea_secno = cpu_to_le32(n);
280 		fnode->flags &= ~FNODE_anode;
281 		mark_buffer_dirty(bh);
282 		brelse(bh);
283 	}
284 	pos = le32_to_cpu(fnode->ea_size_l) + 5 + strlen(key) + size;
285 	len = (le32_to_cpu(fnode->ea_size_l) + 511) >> 9;
286 	if (pos >= 30000) goto bail;
287 	while (((pos + 511) >> 9) > len) {
288 		if (!len) {
289 			secno q = hpfs_alloc_sector(s, fno, 1, 0);
290 			if (!q) goto bail;
291 			fnode->ea_secno = cpu_to_le32(q);
292 			fnode->flags &= ~FNODE_anode;
293 			len++;
294 		} else if (!fnode_in_anode(fnode)) {
295 			if (hpfs_alloc_if_possible(s, le32_to_cpu(fnode->ea_secno) + len)) {
296 				len++;
297 			} else {
298 				/* Aargh... don't know how to create ea anodes :-( */
299 				/*struct buffer_head *bh;
300 				struct anode *anode;
301 				anode_secno a_s;
302 				if (!(anode = hpfs_alloc_anode(s, fno, &a_s, &bh)))
303 					goto bail;
304 				anode->up = cpu_to_le32(fno);
305 				anode->btree.fnode_parent = 1;
306 				anode->btree.n_free_nodes--;
307 				anode->btree.n_used_nodes++;
308 				anode->btree.first_free = cpu_to_le16(le16_to_cpu(anode->btree.first_free) + 12);
309 				anode->u.external[0].disk_secno = cpu_to_le32(le32_to_cpu(fnode->ea_secno));
310 				anode->u.external[0].file_secno = cpu_to_le32(0);
311 				anode->u.external[0].length = cpu_to_le32(len);
312 				mark_buffer_dirty(bh);
313 				brelse(bh);
314 				fnode->flags |= FNODE_anode;
315 				fnode->ea_secno = cpu_to_le32(a_s);*/
316 				secno new_sec;
317 				int i;
318 				if (!(new_sec = hpfs_alloc_sector(s, fno, 1, 1 - ((pos + 511) >> 9))))
319 					goto bail;
320 				for (i = 0; i < len; i++) {
321 					struct buffer_head *bh1, *bh2;
322 					void *b1, *b2;
323 					if (!(b1 = hpfs_map_sector(s, le32_to_cpu(fnode->ea_secno) + i, &bh1, len - i - 1))) {
324 						hpfs_free_sectors(s, new_sec, (pos + 511) >> 9);
325 						goto bail;
326 					}
327 					if (!(b2 = hpfs_get_sector(s, new_sec + i, &bh2))) {
328 						brelse(bh1);
329 						hpfs_free_sectors(s, new_sec, (pos + 511) >> 9);
330 						goto bail;
331 					}
332 					memcpy(b2, b1, 512);
333 					brelse(bh1);
334 					mark_buffer_dirty(bh2);
335 					brelse(bh2);
336 				}
337 				hpfs_free_sectors(s, le32_to_cpu(fnode->ea_secno), len);
338 				fnode->ea_secno = cpu_to_le32(new_sec);
339 				len = (pos + 511) >> 9;
340 			}
341 		}
342 		if (fnode_in_anode(fnode)) {
343 			if (hpfs_add_sector_to_btree(s, le32_to_cpu(fnode->ea_secno),
344 						     0, len) != -1) {
345 				len++;
346 			} else {
347 				goto bail;
348 			}
349 		}
350 	}
351 	h[0] = 0;
352 	h[1] = strlen(key);
353 	h[2] = size & 0xff;
354 	h[3] = size >> 8;
355 	if (hpfs_ea_write(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l), 4, h)) goto bail;
356 	if (hpfs_ea_write(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l) + 4, h[1] + 1, key)) goto bail;
357 	if (hpfs_ea_write(s, le32_to_cpu(fnode->ea_secno), fnode_in_anode(fnode), le32_to_cpu(fnode->ea_size_l) + 5 + h[1], size, data)) goto bail;
358 	fnode->ea_size_l = cpu_to_le32(pos);
359 	ret:
360 	hpfs_i(inode)->i_ea_size += 5 + strlen(key) + size;
361 	return;
362 	bail:
363 	if (le32_to_cpu(fnode->ea_secno))
364 		if (fnode_in_anode(fnode)) hpfs_truncate_btree(s, le32_to_cpu(fnode->ea_secno), 1, (le32_to_cpu(fnode->ea_size_l) + 511) >> 9);
365 		else hpfs_free_sectors(s, le32_to_cpu(fnode->ea_secno) + ((le32_to_cpu(fnode->ea_size_l) + 511) >> 9), len - ((le32_to_cpu(fnode->ea_size_l) + 511) >> 9));
366 	else fnode->ea_secno = fnode->ea_size_l = cpu_to_le32(0);
367 }
368 
369