xref: /openbmc/linux/fs/udf/partition.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 
29 uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
30 			uint16_t partition, uint32_t offset)
31 {
32 	struct udf_sb_info *sbi = UDF_SB(sb);
33 	struct udf_part_map *map;
34 	if (partition >= sbi->s_partitions) {
35 		udf_debug("block=%d, partition=%d, offset=%d: "
36 			  "invalid partition\n", block, partition, offset);
37 		return 0xFFFFFFFF;
38 	}
39 	map = &sbi->s_partmaps[partition];
40 	if (map->s_partition_func)
41 		return map->s_partition_func(sb, block, partition, offset);
42 	else
43 		return map->s_partition_root + block + offset;
44 }
45 
46 uint32_t udf_get_pblock_virt15(struct super_block *sb, uint32_t block,
47 			       uint16_t partition, uint32_t offset)
48 {
49 	struct buffer_head *bh = NULL;
50 	uint32_t newblock;
51 	uint32_t index;
52 	uint32_t loc;
53 	struct udf_sb_info *sbi = UDF_SB(sb);
54 	struct udf_part_map *map;
55 	struct udf_virtual_data *vdata;
56 	struct udf_inode_info *iinfo = UDF_I(sbi->s_vat_inode);
57 
58 	map = &sbi->s_partmaps[partition];
59 	vdata = &map->s_type_specific.s_virtual;
60 
61 	if (block > vdata->s_num_entries) {
62 		udf_debug("Trying to access block beyond end of VAT "
63 			  "(%d max %d)\n", block, vdata->s_num_entries);
64 		return 0xFFFFFFFF;
65 	}
66 
67 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
68 		loc = le32_to_cpu(((__le32 *)(iinfo->i_ext.i_data +
69 			vdata->s_start_offset))[block]);
70 		goto translate;
71 	}
72 	index = (sb->s_blocksize - vdata->s_start_offset) / sizeof(uint32_t);
73 	if (block >= index) {
74 		block -= index;
75 		newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
76 		index = block % (sb->s_blocksize / sizeof(uint32_t));
77 	} else {
78 		newblock = 0;
79 		index = vdata->s_start_offset / sizeof(uint32_t) + block;
80 	}
81 
82 	loc = udf_block_map(sbi->s_vat_inode, newblock);
83 
84 	bh = sb_bread(sb, loc);
85 	if (!bh) {
86 		udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
87 			  sb, block, partition, loc, index);
88 		return 0xFFFFFFFF;
89 	}
90 
91 	loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
92 
93 	brelse(bh);
94 
95 translate:
96 	if (iinfo->i_location.partitionReferenceNum == partition) {
97 		udf_debug("recursive call to udf_get_pblock!\n");
98 		return 0xFFFFFFFF;
99 	}
100 
101 	return udf_get_pblock(sb, loc,
102 			      iinfo->i_location.partitionReferenceNum,
103 			      offset);
104 }
105 
106 inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block,
107 				      uint16_t partition, uint32_t offset)
108 {
109 	return udf_get_pblock_virt15(sb, block, partition, offset);
110 }
111 
112 uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block,
113 			       uint16_t partition, uint32_t offset)
114 {
115 	int i;
116 	struct sparingTable *st = NULL;
117 	struct udf_sb_info *sbi = UDF_SB(sb);
118 	struct udf_part_map *map;
119 	uint32_t packet;
120 	struct udf_sparing_data *sdata;
121 
122 	map = &sbi->s_partmaps[partition];
123 	sdata = &map->s_type_specific.s_sparing;
124 	packet = (block + offset) & ~(sdata->s_packet_len - 1);
125 
126 	for (i = 0; i < 4; i++) {
127 		if (sdata->s_spar_map[i] != NULL) {
128 			st = (struct sparingTable *)
129 					sdata->s_spar_map[i]->b_data;
130 			break;
131 		}
132 	}
133 
134 	if (st) {
135 		for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
136 			struct sparingEntry *entry = &st->mapEntry[i];
137 			u32 origLoc = le32_to_cpu(entry->origLocation);
138 			if (origLoc >= 0xFFFFFFF0)
139 				break;
140 			else if (origLoc == packet)
141 				return le32_to_cpu(entry->mappedLocation) +
142 					((block + offset) &
143 						(sdata->s_packet_len - 1));
144 			else if (origLoc > packet)
145 				break;
146 		}
147 	}
148 
149 	return map->s_partition_root + block + offset;
150 }
151 
152 int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
153 {
154 	struct udf_sparing_data *sdata;
155 	struct sparingTable *st = NULL;
156 	struct sparingEntry mapEntry;
157 	uint32_t packet;
158 	int i, j, k, l;
159 	struct udf_sb_info *sbi = UDF_SB(sb);
160 	u16 reallocationTableLen;
161 	struct buffer_head *bh;
162 
163 	for (i = 0; i < sbi->s_partitions; i++) {
164 		struct udf_part_map *map = &sbi->s_partmaps[i];
165 		if (old_block > map->s_partition_root &&
166 		    old_block < map->s_partition_root + map->s_partition_len) {
167 			sdata = &map->s_type_specific.s_sparing;
168 			packet = (old_block - map->s_partition_root) &
169 						~(sdata->s_packet_len - 1);
170 
171 			for (j = 0; j < 4; j++)
172 				if (sdata->s_spar_map[j] != NULL) {
173 					st = (struct sparingTable *)
174 						sdata->s_spar_map[j]->b_data;
175 					break;
176 				}
177 
178 			if (!st)
179 				return 1;
180 
181 			reallocationTableLen =
182 					le16_to_cpu(st->reallocationTableLen);
183 			for (k = 0; k < reallocationTableLen; k++) {
184 				struct sparingEntry *entry = &st->mapEntry[k];
185 				u32 origLoc = le32_to_cpu(entry->origLocation);
186 
187 				if (origLoc == 0xFFFFFFFF) {
188 					for (; j < 4; j++) {
189 						int len;
190 						bh = sdata->s_spar_map[j];
191 						if (!bh)
192 							continue;
193 
194 						st = (struct sparingTable *)
195 								bh->b_data;
196 						entry->origLocation =
197 							cpu_to_le32(packet);
198 						len =
199 						  sizeof(struct sparingTable) +
200 						  reallocationTableLen *
201 						  sizeof(struct sparingEntry);
202 						udf_update_tag((char *)st, len);
203 						mark_buffer_dirty(bh);
204 					}
205 					*new_block = le32_to_cpu(
206 							entry->mappedLocation) +
207 						     ((old_block -
208 							map->s_partition_root) &
209 						     (sdata->s_packet_len - 1));
210 					return 0;
211 				} else if (origLoc == packet) {
212 					*new_block = le32_to_cpu(
213 							entry->mappedLocation) +
214 						     ((old_block -
215 							map->s_partition_root) &
216 						     (sdata->s_packet_len - 1));
217 					return 0;
218 				} else if (origLoc > packet)
219 					break;
220 			}
221 
222 			for (l = k; l < reallocationTableLen; l++) {
223 				struct sparingEntry *entry = &st->mapEntry[l];
224 				u32 origLoc = le32_to_cpu(entry->origLocation);
225 
226 				if (origLoc != 0xFFFFFFFF)
227 					continue;
228 
229 				for (; j < 4; j++) {
230 					bh = sdata->s_spar_map[j];
231 					if (!bh)
232 						continue;
233 
234 					st = (struct sparingTable *)bh->b_data;
235 					mapEntry = st->mapEntry[l];
236 					mapEntry.origLocation =
237 							cpu_to_le32(packet);
238 					memmove(&st->mapEntry[k + 1],
239 						&st->mapEntry[k],
240 						(l - k) *
241 						sizeof(struct sparingEntry));
242 					st->mapEntry[k] = mapEntry;
243 					udf_update_tag((char *)st,
244 						sizeof(struct sparingTable) +
245 						reallocationTableLen *
246 						sizeof(struct sparingEntry));
247 					mark_buffer_dirty(bh);
248 				}
249 				*new_block =
250 					le32_to_cpu(
251 					      st->mapEntry[k].mappedLocation) +
252 					((old_block - map->s_partition_root) &
253 					 (sdata->s_packet_len - 1));
254 				return 0;
255 			}
256 
257 			return 1;
258 		} /* if old_block */
259 	}
260 
261 	if (i == sbi->s_partitions) {
262 		/* outside of partitions */
263 		/* for now, fail =) */
264 		return 1;
265 	}
266 
267 	return 0;
268 }
269 
270 static uint32_t udf_try_read_meta(struct inode *inode, uint32_t block,
271 					uint16_t partition, uint32_t offset)
272 {
273 	struct super_block *sb = inode->i_sb;
274 	struct udf_part_map *map;
275 	struct kernel_lb_addr eloc;
276 	uint32_t elen;
277 	sector_t ext_offset;
278 	struct extent_position epos = {};
279 	uint32_t phyblock;
280 
281 	if (inode_bmap(inode, block, &epos, &eloc, &elen, &ext_offset) !=
282 						(EXT_RECORDED_ALLOCATED >> 30))
283 		phyblock = 0xFFFFFFFF;
284 	else {
285 		map = &UDF_SB(sb)->s_partmaps[partition];
286 		/* map to sparable/physical partition desc */
287 		phyblock = udf_get_pblock(sb, eloc.logicalBlockNum,
288 			map->s_partition_num, ext_offset + offset);
289 	}
290 
291 	brelse(epos.bh);
292 	return phyblock;
293 }
294 
295 uint32_t udf_get_pblock_meta25(struct super_block *sb, uint32_t block,
296 				uint16_t partition, uint32_t offset)
297 {
298 	struct udf_sb_info *sbi = UDF_SB(sb);
299 	struct udf_part_map *map;
300 	struct udf_meta_data *mdata;
301 	uint32_t retblk;
302 	struct inode *inode;
303 
304 	udf_debug("READING from METADATA\n");
305 
306 	map = &sbi->s_partmaps[partition];
307 	mdata = &map->s_type_specific.s_metadata;
308 	inode = mdata->s_metadata_fe ? : mdata->s_mirror_fe;
309 
310 	/* We shouldn't mount such media... */
311 	BUG_ON(!inode);
312 	retblk = udf_try_read_meta(inode, block, partition, offset);
313 	if (retblk == 0xFFFFFFFF) {
314 		udf_warning(sb, __func__, "error reading from METADATA, "
315 			"trying to read from MIRROR");
316 		inode = mdata->s_mirror_fe;
317 		if (!inode)
318 			return 0xFFFFFFFF;
319 		retblk = udf_try_read_meta(inode, block, partition, offset);
320 	}
321 
322 	return retblk;
323 }
324