Root/fs/udf/partition.c

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
30uint32_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: "
37              "invalid partition\n", 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
47uint32_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 "
64              "(%d max %d)\n", 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
96translate:
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
107inline 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
113uint32_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
153int 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
276out:
277    mutex_unlock(&sbi->s_alloc_mutex);
278    return ret;
279}
280
281static 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
306uint32_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) {
325        udf_warning(sb, __func__, "error reading from METADATA, "
326            "trying to read from MIRROR");
327        inode = mdata->s_mirror_fe;
328        if (!inode)
329            return 0xFFFFFFFF;
330        retblk = udf_try_read_meta(inode, block, partition, offset);
331    }
332
333    return retblk;
334}
335

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