xref: /openbmc/linux/fs/udf/partition.c (revision c21b37f6)
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/udf_fs.h>
28 #include <linux/slab.h>
29 #include <linux/buffer_head.h>
30 
31 inline uint32_t udf_get_pblock(struct super_block *sb, uint32_t block,
32 			       uint16_t partition, uint32_t offset)
33 {
34 	if (partition >= UDF_SB_NUMPARTS(sb)) {
35 		udf_debug("block=%d, partition=%d, offset=%d: invalid partition\n",
36 			  block, partition, offset);
37 		return 0xFFFFFFFF;
38 	}
39 	if (UDF_SB_PARTFUNC(sb, partition))
40 		return UDF_SB_PARTFUNC(sb, partition)(sb, block, partition, offset);
41 	else
42 		return UDF_SB_PARTROOT(sb, partition) + block + offset;
43 }
44 
45 uint32_t udf_get_pblock_virt15(struct super_block *sb, uint32_t block,
46 			       uint16_t partition, uint32_t offset)
47 {
48 	struct buffer_head *bh = NULL;
49 	uint32_t newblock;
50 	uint32_t index;
51 	uint32_t loc;
52 
53 	index = (sb->s_blocksize - UDF_SB_TYPEVIRT(sb,partition).s_start_offset) / sizeof(uint32_t);
54 
55 	if (block > UDF_SB_TYPEVIRT(sb,partition).s_num_entries) {
56 		udf_debug("Trying to access block beyond end of VAT (%d max %d)\n",
57 			  block, UDF_SB_TYPEVIRT(sb,partition).s_num_entries);
58 		return 0xFFFFFFFF;
59 	}
60 
61 	if (block >= index) {
62 		block -= index;
63 		newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
64 		index = block % (sb->s_blocksize / sizeof(uint32_t));
65 	} else {
66 		newblock = 0;
67 		index = UDF_SB_TYPEVIRT(sb,partition).s_start_offset / sizeof(uint32_t) + block;
68 	}
69 
70 	loc = udf_block_map(UDF_SB_VAT(sb), newblock);
71 
72 	if (!(bh = sb_bread(sb, loc))) {
73 		udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
74 			  sb, block, partition, loc, index);
75 		return 0xFFFFFFFF;
76 	}
77 
78 	loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
79 
80 	brelse(bh);
81 
82 	if (UDF_I_LOCATION(UDF_SB_VAT(sb)).partitionReferenceNum == partition) {
83 		udf_debug("recursive call to udf_get_pblock!\n");
84 		return 0xFFFFFFFF;
85 	}
86 
87 	return udf_get_pblock(sb, loc,
88 			      UDF_I_LOCATION(UDF_SB_VAT(sb)).partitionReferenceNum,
89 			      offset);
90 }
91 
92 inline uint32_t udf_get_pblock_virt20(struct super_block * sb, uint32_t block,
93 				      uint16_t partition, uint32_t offset)
94 {
95 	return udf_get_pblock_virt15(sb, block, partition, offset);
96 }
97 
98 uint32_t udf_get_pblock_spar15(struct super_block * sb, uint32_t block,
99 			       uint16_t partition, uint32_t offset)
100 {
101 	int i;
102 	struct sparingTable *st = NULL;
103 	uint32_t packet = (block + offset) & ~(UDF_SB_TYPESPAR(sb,partition).s_packet_len - 1);
104 
105 	for (i = 0; i < 4; i++) {
106 		if (UDF_SB_TYPESPAR(sb,partition).s_spar_map[i] != NULL) {
107 			st = (struct sparingTable *)UDF_SB_TYPESPAR(sb,partition).s_spar_map[i]->b_data;
108 			break;
109 		}
110 	}
111 
112 	if (st) {
113 		for (i = 0; i < le16_to_cpu(st->reallocationTableLen); i++) {
114 			if (le32_to_cpu(st->mapEntry[i].origLocation) >= 0xFFFFFFF0) {
115 				break;
116 			} else if (le32_to_cpu(st->mapEntry[i].origLocation) == packet) {
117 				return le32_to_cpu(st->mapEntry[i].mappedLocation) +
118 					((block + offset) & (UDF_SB_TYPESPAR(sb,partition).s_packet_len - 1));
119 			} else if (le32_to_cpu(st->mapEntry[i].origLocation) > packet) {
120 				break;
121 			}
122 		}
123 	}
124 
125 	return UDF_SB_PARTROOT(sb,partition) + block + offset;
126 }
127 
128 int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
129 {
130 	struct udf_sparing_data *sdata;
131 	struct sparingTable *st = NULL;
132 	struct sparingEntry mapEntry;
133 	uint32_t packet;
134 	int i, j, k, l;
135 
136 	for (i = 0; i < UDF_SB_NUMPARTS(sb); i++) {
137 		if (old_block > UDF_SB_PARTROOT(sb,i) &&
138 		    old_block < UDF_SB_PARTROOT(sb,i) + UDF_SB_PARTLEN(sb,i)) {
139 			sdata = &UDF_SB_TYPESPAR(sb,i);
140 			packet = (old_block - UDF_SB_PARTROOT(sb,i)) & ~(sdata->s_packet_len - 1);
141 
142 			for (j = 0; j < 4; j++) {
143 				if (UDF_SB_TYPESPAR(sb,i).s_spar_map[j] != NULL) {
144 					st = (struct sparingTable *)sdata->s_spar_map[j]->b_data;
145 					break;
146 				}
147 			}
148 
149 			if (!st)
150 				return 1;
151 
152 			for (k = 0; k < le16_to_cpu(st->reallocationTableLen); k++) {
153 				if (le32_to_cpu(st->mapEntry[k].origLocation) == 0xFFFFFFFF) {
154 					for (; j < 4; j++) {
155 						if (sdata->s_spar_map[j]) {
156 							st = (struct sparingTable *)sdata->s_spar_map[j]->b_data;
157 							st->mapEntry[k].origLocation = cpu_to_le32(packet);
158 							udf_update_tag((char *)st, sizeof(struct sparingTable) + le16_to_cpu(st->reallocationTableLen) * sizeof(struct sparingEntry));
159 							mark_buffer_dirty(sdata->s_spar_map[j]);
160 						}
161 					}
162 					*new_block = le32_to_cpu(st->mapEntry[k].mappedLocation) +
163 						((old_block - UDF_SB_PARTROOT(sb,i)) & (sdata->s_packet_len - 1));
164 					return 0;
165 				} else if (le32_to_cpu(st->mapEntry[k].origLocation) == packet) {
166 					*new_block = le32_to_cpu(st->mapEntry[k].mappedLocation) +
167 						((old_block - UDF_SB_PARTROOT(sb,i)) & (sdata->s_packet_len - 1));
168 					return 0;
169 				} else if (le32_to_cpu(st->mapEntry[k].origLocation) > packet) {
170 					break;
171 				}
172 			}
173 
174 			for (l = k; l < le16_to_cpu(st->reallocationTableLen); l++) {
175 				if (le32_to_cpu(st->mapEntry[l].origLocation) == 0xFFFFFFFF) {
176 					for (; j < 4; j++) {
177 						if (sdata->s_spar_map[j]) {
178 							st = (struct sparingTable *)sdata->s_spar_map[j]->b_data;
179 							mapEntry = st->mapEntry[l];
180 							mapEntry.origLocation = cpu_to_le32(packet);
181 							memmove(&st->mapEntry[k + 1], &st->mapEntry[k], (l - k) * sizeof(struct sparingEntry));
182 							st->mapEntry[k] = mapEntry;
183 							udf_update_tag((char *)st, sizeof(struct sparingTable) + le16_to_cpu(st->reallocationTableLen) * sizeof(struct sparingEntry));
184 							mark_buffer_dirty(sdata->s_spar_map[j]);
185 						}
186 					}
187 					*new_block = le32_to_cpu(st->mapEntry[k].mappedLocation) +
188 						((old_block - UDF_SB_PARTROOT(sb,i)) & (sdata->s_packet_len - 1));
189 					return 0;
190 				}
191 			}
192 
193 			return 1;
194 		} /* if old_block */
195 	}
196 
197 	if (i == UDF_SB_NUMPARTS(sb)) {
198 		/* outside of partitions */
199 		/* for now, fail =) */
200 		return 1;
201 	}
202 
203 	return 0;
204 }
205