xref: /linux/fs/udf/partition.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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, uint16_t partition, uint32_t offset)
32 {
33 	if (partition >= UDF_SB_NUMPARTS(sb))
34 	{
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, uint16_t partition, uint32_t offset)
46 {
47 	struct buffer_head *bh = NULL;
48 	uint32_t newblock;
49 	uint32_t index;
50 	uint32_t loc;
51 
52 	index = (sb->s_blocksize - UDF_SB_TYPEVIRT(sb,partition).s_start_offset) / sizeof(uint32_t);
53 
54 	if (block > UDF_SB_TYPEVIRT(sb,partition).s_num_entries)
55 	{
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 	{
63 		block -= index;
64 		newblock = 1 + (block / (sb->s_blocksize / sizeof(uint32_t)));
65 		index = block % (sb->s_blocksize / sizeof(uint32_t));
66 	}
67 	else
68 	{
69 		newblock = 0;
70 		index = UDF_SB_TYPEVIRT(sb,partition).s_start_offset / sizeof(uint32_t) + block;
71 	}
72 
73 	loc = udf_block_map(UDF_SB_VAT(sb), newblock);
74 
75 	if (!(bh = sb_bread(sb, loc)))
76 	{
77 		udf_debug("get_pblock(UDF_VIRTUAL_MAP:%p,%d,%d) VAT: %d[%d]\n",
78 			sb, block, partition, loc, index);
79 		return 0xFFFFFFFF;
80 	}
81 
82 	loc = le32_to_cpu(((__le32 *)bh->b_data)[index]);
83 
84 	udf_release_data(bh);
85 
86 	if (UDF_I_LOCATION(UDF_SB_VAT(sb)).partitionReferenceNum == partition)
87 	{
88 		udf_debug("recursive call to udf_get_pblock!\n");
89 		return 0xFFFFFFFF;
90 	}
91 
92 	return udf_get_pblock(sb, loc, UDF_I_LOCATION(UDF_SB_VAT(sb)).partitionReferenceNum, offset);
93 }
94 
95 inline uint32_t udf_get_pblock_virt20(struct super_block *sb, uint32_t block, uint16_t partition, uint32_t offset)
96 {
97 	return udf_get_pblock_virt15(sb, block, partition, offset);
98 }
99 
100 uint32_t udf_get_pblock_spar15(struct super_block *sb, uint32_t block, uint16_t partition, uint32_t offset)
101 {
102 	int i;
103 	struct sparingTable *st = NULL;
104 	uint32_t packet = (block + offset) & ~(UDF_SB_TYPESPAR(sb,partition).s_packet_len - 1);
105 
106 	for (i=0; i<4; i++)
107 	{
108 		if (UDF_SB_TYPESPAR(sb,partition).s_spar_map[i] != NULL)
109 		{
110 			st = (struct sparingTable *)UDF_SB_TYPESPAR(sb,partition).s_spar_map[i]->b_data;
111 			break;
112 		}
113 	}
114 
115 	if (st)
116 	{
117 		for (i=0; i<le16_to_cpu(st->reallocationTableLen); i++)
118 		{
119 			if (le32_to_cpu(st->mapEntry[i].origLocation) >= 0xFFFFFFF0)
120 				break;
121 			else if (le32_to_cpu(st->mapEntry[i].origLocation) == packet)
122 			{
123 				return le32_to_cpu(st->mapEntry[i].mappedLocation) +
124 					((block + offset) & (UDF_SB_TYPESPAR(sb,partition).s_packet_len - 1));
125 			}
126 			else if (le32_to_cpu(st->mapEntry[i].origLocation) > packet)
127 				break;
128 		}
129 	}
130 	return UDF_SB_PARTROOT(sb,partition) + block + offset;
131 }
132 
133 int udf_relocate_blocks(struct super_block *sb, long old_block, long *new_block)
134 {
135 	struct udf_sparing_data *sdata;
136 	struct sparingTable *st = NULL;
137 	struct sparingEntry mapEntry;
138 	uint32_t packet;
139 	int i, j, k, l;
140 
141 	for (i=0; i<UDF_SB_NUMPARTS(sb); i++)
142 	{
143 		if (old_block > UDF_SB_PARTROOT(sb,i) &&
144 		    old_block < UDF_SB_PARTROOT(sb,i) + UDF_SB_PARTLEN(sb,i))
145 		{
146 			sdata = &UDF_SB_TYPESPAR(sb,i);
147 			packet = (old_block - UDF_SB_PARTROOT(sb,i)) & ~(sdata->s_packet_len - 1);
148 
149 			for (j=0; j<4; j++)
150 			{
151 				if (UDF_SB_TYPESPAR(sb,i).s_spar_map[j] != NULL)
152 				{
153 					st = (struct sparingTable *)sdata->s_spar_map[j]->b_data;
154 					break;
155 				}
156 			}
157 
158 			if (!st)
159 				return 1;
160 
161 			for (k=0; k<le16_to_cpu(st->reallocationTableLen); k++)
162 			{
163 				if (le32_to_cpu(st->mapEntry[k].origLocation) == 0xFFFFFFFF)
164 				{
165 					for (; j<4; j++)
166 					{
167 						if (sdata->s_spar_map[j])
168 						{
169 							st = (struct sparingTable *)sdata->s_spar_map[j]->b_data;
170 							st->mapEntry[k].origLocation = cpu_to_le32(packet);
171 							udf_update_tag((char *)st, sizeof(struct sparingTable) + le16_to_cpu(st->reallocationTableLen) * sizeof(struct sparingEntry));
172 							mark_buffer_dirty(sdata->s_spar_map[j]);
173 						}
174 					}
175 					*new_block = le32_to_cpu(st->mapEntry[k].mappedLocation) +
176 						((old_block - UDF_SB_PARTROOT(sb,i)) & (sdata->s_packet_len - 1));
177 					return 0;
178 				}
179 				else if (le32_to_cpu(st->mapEntry[k].origLocation) == packet)
180 				{
181 					*new_block = le32_to_cpu(st->mapEntry[k].mappedLocation) +
182 						((old_block - UDF_SB_PARTROOT(sb,i)) & (sdata->s_packet_len - 1));
183 					return 0;
184 				}
185 				else if (le32_to_cpu(st->mapEntry[k].origLocation) > packet)
186 					break;
187 			}
188 			for (l=k; l<le16_to_cpu(st->reallocationTableLen); l++)
189 			{
190 				if (le32_to_cpu(st->mapEntry[l].origLocation) == 0xFFFFFFFF)
191 				{
192 					for (; j<4; j++)
193 					{
194 						if (sdata->s_spar_map[j])
195 						{
196 							st = (struct sparingTable *)sdata->s_spar_map[j]->b_data;
197 							mapEntry = st->mapEntry[l];
198 							mapEntry.origLocation = cpu_to_le32(packet);
199 							memmove(&st->mapEntry[k+1], &st->mapEntry[k], (l-k)*sizeof(struct sparingEntry));
200 							st->mapEntry[k] = mapEntry;
201 							udf_update_tag((char *)st, sizeof(struct sparingTable) + le16_to_cpu(st->reallocationTableLen) * sizeof(struct sparingEntry));
202 							mark_buffer_dirty(sdata->s_spar_map[j]);
203 						}
204 					}
205 					*new_block = le32_to_cpu(st->mapEntry[k].mappedLocation) +
206 						((old_block - UDF_SB_PARTROOT(sb,i)) & (sdata->s_packet_len - 1));
207 					return 0;
208 				}
209 			}
210 			return 1;
211 		}
212 	}
213 	if (i == UDF_SB_NUMPARTS(sb))
214 	{
215 		/* outside of partitions */
216 		/* for now, fail =) */
217 		return 1;
218 	}
219 
220 	return 0;
221 }
222