xref: /openbmc/linux/fs/udf/partition.c (revision d0b73b48)
1 /*
2  * partition.c
3  *
4  * PURPOSE
5  *      Partition handling routines for the OSTA-UDF(tm) filesystem.
6  *
7  * COPYRIGHT
8  *      This file is distributed under the terms of the GNU General Public
9  *      License (GPL). Copies of the GPL can be obtained from:
10  *              ftp://prep.ai.mit.edu/pub/gnu/GPL
11  *      Each contributing author retains all rights to their own work.
12  *
13  *  (C) 1998-2001 Ben Fennema
14  *
15  * HISTORY
16  *
17  * 12/06/98 blf  Created file.
18  *
19  */
20 
21 #include "udfdecl.h"
22 #include "udf_sb.h"
23 #include "udf_i.h"
24 
25 #include <linux/fs.h>
26 #include <linux/string.h>
27 #include <linux/buffer_head.h>
28 #include <linux/mutex.h>
29 
30 uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
31 			uint16_t partition, uint32_t offset)
32 {
33 	struct udf_sb_info *sbi = UDF_SB(sb);
34 	struct udf_part_map *map;
35 	if (partition >= sbi->s_partitions) {
36 		udf_debug("block=%d, partition=%d, offset=%d: invalid partition\n",
37 			  block, partition, offset);
38 		return 0xFFFFFFFF;
39 	}
40 	map = &sbi->s_partmaps[partition];
41 	if (map->s_partition_func)
42 		return map->s_partition_func(sb, block, partition, offset);
43 	else
44 		return map->s_partition_root + block + offset;
45 }
46 
47 uint32_t udf_get_pblock_virt15(struct super_block *sb, uint32_t block,
48 			       uint16_t partition, uint32_t offset)
49 {
50 	struct buffer_head *bh = NULL;
51 	uint32_t newblock;
52 	uint32_t index;
53 	uint32_t loc;
54 	struct udf_sb_info *sbi = UDF_SB(sb);
55 	struct udf_part_map *map;
56 	struct udf_virtual_data *vdata;
57 	struct udf_inode_info *iinfo = UDF_I(sbi->s_vat_inode);
58 
59 	map = &sbi->s_partmaps[partition];
60 	vdata = &map->s_type_specific.s_virtual;
61 
62 	if (block > vdata->s_num_entries) {
63 		udf_debug("Trying to access block beyond end of VAT (%d max %d)\n",
64 			  block, vdata->s_num_entries);
65 		return 0xFFFFFFFF;
66 	}
67 
68 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
69 		loc = le32_to_cpu(((__le32 *)(iinfo->i_ext.i_data +
70 			vdata->s_start_offset))[block]);
71 		goto translate;
72 	}
73 	index = (sb->s_blocksize - vdata->s_start_offset) / sizeof(uint32_t);
74 	if (block >= index) {
75 		block -= index;
76 		newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
77 		index = block % (sb->s_blocksize / sizeof(uint32_t));
78 	} else {
79 		newblock = 0;
80 		index = vdata->s_start_offset / sizeof(uint32_t) + block;
81 	}
82 
83 	loc = udf_block_map(sbi->s_vat_inode, newblock);
84 
85 	bh = sb_bread(sb, loc);
86 	if (!bh) {
87 		udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
88 			  sb, block, partition, loc, index);
89 		return 0xFFFFFFFF;
90 	}
91 
92 	loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
93 
94 	brelse(bh);
95 
96 translate:
97 	if (iinfo->i_location.partitionReferenceNum == partition) {
98 		udf_debug("recursive call to udf_get_pblock!\n");
99 		return 0xFFFFFFFF;
100 	}
101 
102 	return udf_get_pblock(sb, loc,
103 			      iinfo->i_location.partitionReferenceNum,
104 			      offset);
105 }
106 
107 inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block,
108 				      uint16_t partition, uint32_t offset)
109 {
110 	return udf_get_pblock_virt15(sb, block, partition, offset);
111 }
112 
113 uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block,
114 			       uint16_t partition, uint32_t offset)
115 {
116 	int i;
117 	struct sparingTable *st = NULL;
118 	struct udf_sb_info *sbi = UDF_SB(sb);
119 	struct udf_part_map *map;
120 	uint32_t packet;
121 	struct udf_sparing_data *sdata;
122 
123 	map = &sbi->s_partmaps[partition];
124 	sdata = &map->s_type_specific.s_sparing;
125 	packet = (block + offset) & ~(sdata->s_packet_len - 1);
126 
127 	for (i = 0; i < 4; i++) {
128 		if (sdata->s_spar_map[i] != NULL) {
129 			st = (struct sparingTable *)
130 					sdata->s_spar_map[i]->b_data;
131 			break;
132 		}
133 	}
134 
135 	if (st) {
136 		for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
137 			struct sparingEntry *entry = &st->mapEntry[i];
138 			u32 origLoc = le32_to_cpu(entry->origLocation);
139 			if (origLoc >= 0xFFFFFFF0)
140 				break;
141 			else if (origLoc == packet)
142 				return le32_to_cpu(entry->mappedLocation) +
143 					((block + offset) &
144 						(sdata->s_packet_len - 1));
145 			else if (origLoc > packet)
146 				break;
147 		}
148 	}
149 
150 	return map->s_partition_root + block + offset;
151 }
152 
153 int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
154 {
155 	struct udf_sparing_data *sdata;
156 	struct sparingTable *st = NULL;
157 	struct sparingEntry mapEntry;
158 	uint32_t packet;
159 	int i, j, k, l;
160 	struct udf_sb_info *sbi = UDF_SB(sb);
161 	u16 reallocationTableLen;
162 	struct buffer_head *bh;
163 	int ret = 0;
164 
165 	mutex_lock(&sbi->s_alloc_mutex);
166 	for (i = 0; i < sbi->s_partitions; i++) {
167 		struct udf_part_map *map = &sbi->s_partmaps[i];
168 		if (old_block > map->s_partition_root &&
169 		    old_block < map->s_partition_root + map->s_partition_len) {
170 			sdata = &map->s_type_specific.s_sparing;
171 			packet = (old_block - map->s_partition_root) &
172 						~(sdata->s_packet_len - 1);
173 
174 			for (j = 0; j < 4; j++)
175 				if (sdata->s_spar_map[j] != NULL) {
176 					st = (struct sparingTable *)
177 						sdata->s_spar_map[j]->b_data;
178 					break;
179 				}
180 
181 			if (!st) {
182 				ret = 1;
183 				goto out;
184 			}
185 
186 			reallocationTableLen =
187 					le16_to_cpu(st->reallocationTableLen);
188 			for (k = 0; k < reallocationTableLen; k++) {
189 				struct sparingEntry *entry = &st->mapEntry[k];
190 				u32 origLoc = le32_to_cpu(entry->origLocation);
191 
192 				if (origLoc == 0xFFFFFFFF) {
193 					for (; j < 4; j++) {
194 						int len;
195 						bh = sdata->s_spar_map[j];
196 						if (!bh)
197 							continue;
198 
199 						st = (struct sparingTable *)
200 								bh->b_data;
201 						entry->origLocation =
202 							cpu_to_le32(packet);
203 						len =
204 						  sizeof(struct sparingTable) +
205 						  reallocationTableLen *
206 						  sizeof(struct sparingEntry);
207 						udf_update_tag((char *)st, len);
208 						mark_buffer_dirty(bh);
209 					}
210 					*new_block = le32_to_cpu(
211 							entry->mappedLocation) +
212 						     ((old_block -
213 							map->s_partition_root) &
214 						     (sdata->s_packet_len - 1));
215 					ret = 0;
216 					goto out;
217 				} else if (origLoc == packet) {
218 					*new_block = le32_to_cpu(
219 							entry->mappedLocation) +
220 						     ((old_block -
221 							map->s_partition_root) &
222 						     (sdata->s_packet_len - 1));
223 					ret = 0;
224 					goto out;
225 				} else if (origLoc > packet)
226 					break;
227 			}
228 
229 			for (l = k; l < reallocationTableLen; l++) {
230 				struct sparingEntry *entry = &st->mapEntry[l];
231 				u32 origLoc = le32_to_cpu(entry->origLocation);
232 
233 				if (origLoc != 0xFFFFFFFF)
234 					continue;
235 
236 				for (; j < 4; j++) {
237 					bh = sdata->s_spar_map[j];
238 					if (!bh)
239 						continue;
240 
241 					st = (struct sparingTable *)bh->b_data;
242 					mapEntry = st->mapEntry[l];
243 					mapEntry.origLocation =
244 							cpu_to_le32(packet);
245 					memmove(&st->mapEntry[k + 1],
246 						&st->mapEntry[k],
247 						(l - k) *
248 						sizeof(struct sparingEntry));
249 					st->mapEntry[k] = mapEntry;
250 					udf_update_tag((char *)st,
251 						sizeof(struct sparingTable) +
252 						reallocationTableLen *
253 						sizeof(struct sparingEntry));
254 					mark_buffer_dirty(bh);
255 				}
256 				*new_block =
257 					le32_to_cpu(
258 					      st->mapEntry[k].mappedLocation) +
259 					((old_block - map->s_partition_root) &
260 					 (sdata->s_packet_len - 1));
261 				ret = 0;
262 				goto out;
263 			}
264 
265 			ret = 1;
266 			goto out;
267 		} /* if old_block */
268 	}
269 
270 	if (i == sbi->s_partitions) {
271 		/* outside of partitions */
272 		/* for now, fail =) */
273 		ret = 1;
274 	}
275 
276 out:
277 	mutex_unlock(&sbi->s_alloc_mutex);
278 	return ret;
279 }
280 
281 static uint32_t udf_try_read_meta(struct inode *inode, uint32_t block,
282 					uint16_t partition, uint32_t offset)
283 {
284 	struct super_block *sb = inode->i_sb;
285 	struct udf_part_map *map;
286 	struct kernel_lb_addr eloc;
287 	uint32_t elen;
288 	sector_t ext_offset;
289 	struct extent_position epos = {};
290 	uint32_t phyblock;
291 
292 	if (inode_bmap(inode, block, &epos, &eloc, &elen, &ext_offset) !=
293 						(EXT_RECORDED_ALLOCATED >> 30))
294 		phyblock = 0xFFFFFFFF;
295 	else {
296 		map = &UDF_SB(sb)->s_partmaps[partition];
297 		/* map to sparable/physical partition desc */
298 		phyblock = udf_get_pblock(sb, eloc.logicalBlockNum,
299 			map->s_partition_num, ext_offset + offset);
300 	}
301 
302 	brelse(epos.bh);
303 	return phyblock;
304 }
305 
306 uint32_t udf_get_pblock_meta25(struct super_block *sb, uint32_t block,
307 				uint16_t partition, uint32_t offset)
308 {
309 	struct udf_sb_info *sbi = UDF_SB(sb);
310 	struct udf_part_map *map;
311 	struct udf_meta_data *mdata;
312 	uint32_t retblk;
313 	struct inode *inode;
314 
315 	udf_debug("READING from METADATA\n");
316 
317 	map = &sbi->s_partmaps[partition];
318 	mdata = &map->s_type_specific.s_metadata;
319 	inode = mdata->s_metadata_fe ? : mdata->s_mirror_fe;
320 
321 	/* We shouldn't mount such media... */
322 	BUG_ON(!inode);
323 	retblk = udf_try_read_meta(inode, block, partition, offset);
324 	if (retblk == 0xFFFFFFFF && mdata->s_metadata_fe) {
325 		udf_warn(sb, "error reading from METADATA, trying to read from MIRROR\n");
326 		if (!(mdata->s_flags & MF_MIRROR_FE_LOADED)) {
327 			mdata->s_mirror_fe = udf_find_metadata_inode_efe(sb,
328 				mdata->s_mirror_file_loc, map->s_partition_num);
329 			mdata->s_flags |= MF_MIRROR_FE_LOADED;
330 		}
331 
332 		inode = mdata->s_mirror_fe;
333 		if (!inode)
334 			return 0xFFFFFFFF;
335 		retblk = udf_try_read_meta(inode, block, partition, offset);
336 	}
337 
338 	return retblk;
339 }
340