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1
/*
1
/*
2
 * Copyright (c) 2008 Jakub Jermar
2
 * Copyright (c) 2008 Jakub Jermar
3
 * All rights reserved.
3
 * All rights reserved.
4
 *
4
 *
5
 * Redistribution and use in source and binary forms, with or without
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
6
 * modification, are permitted provided that the following conditions
7
 * are met:
7
 * are met:
8
 *
8
 *
9
 * - Redistributions of source code must retain the above copyright
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
15
 *   derived from this software without specific prior written permission.
16
 *
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
27
 */
28
 
28
 
29
/** @addtogroup fs
29
/** @addtogroup fs
30
 * @{
30
 * @{
31
 */
31
 */
32
 
32
 
33
/**
33
/**
34
 * @file    fat_fat.c
34
 * @file    fat_fat.c
35
 * @brief   Functions that manipulate the File Allocation Tables.
35
 * @brief   Functions that manipulate the File Allocation Tables.
36
 */
36
 */
37
 
37
 
38
#include "fat_fat.h"
38
#include "fat_fat.h"
39
#include "fat_dentry.h"
39
#include "fat_dentry.h"
40
#include "fat.h"
40
#include "fat.h"
41
#include "../../vfs/vfs.h"
41
#include "../../vfs/vfs.h"
42
#include <libfs.h>
42
#include <libfs.h>
43
#include <libblock.h>
43
#include <libblock.h>
44
#include <errno.h>
44
#include <errno.h>
45
#include <byteorder.h>
45
#include <byteorder.h>
46
#include <align.h>
46
#include <align.h>
47
#include <assert.h>
47
#include <assert.h>
48
#include <futex.h>
48
#include <futex.h>
49
 
49
 
50
/**
50
/**
51
 * The fat_alloc_lock futex protects all copies of the File Allocation Table
51
 * The fat_alloc_lock futex protects all copies of the File Allocation Table
52
 * during allocation of clusters. The lock does not have to be held durring
52
 * during allocation of clusters. The lock does not have to be held durring
53
 * deallocation of clusters.
53
 * deallocation of clusters.
54
 */  
54
 */  
55
static futex_t fat_alloc_lock = FUTEX_INITIALIZER;
55
static futex_t fat_alloc_lock = FUTEX_INITIALIZER;
56
 
56
 
57
/** Read block from file located on a FAT file system.
57
/** Read block from file located on a FAT file system.
58
 *
58
 *
59
 * @param bs        Buffer holding the boot sector of the file system.
59
 * @param bs        Buffer holding the boot sector of the file system.
60
 * @param dev_handle    Device handle of the file system.
60
 * @param dev_handle    Device handle of the file system.
61
 * @param firstc    First cluster used by the file. Can be zero if the file
61
 * @param firstc    First cluster used by the file. Can be zero if the file
62
 *          is empty.
62
 *          is empty.
63
 * @param offset    Offset in blocks.
63
 * @param offset    Offset in blocks.
64
 *
64
 *
65
 * @return      Block structure holding the requested block.
65
 * @return      Block structure holding the requested block.
66
 */
66
 */
67
block_t *
67
block_t *
68
_fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
68
_fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
69
    off_t offset)
69
    off_t offset)
70
{
70
{
71
    block_t *b;
71
    block_t *b;
72
    unsigned bps;
72
    unsigned bps;
73
    unsigned spc;
73
    unsigned spc;
74
    unsigned rscnt;     /* block address of the first FAT */
74
    unsigned rscnt;     /* block address of the first FAT */
75
    unsigned fatcnt;
75
    unsigned fatcnt;
76
    unsigned rde;
76
    unsigned rde;
77
    unsigned rds;       /* root directory size */
77
    unsigned rds;       /* root directory size */
78
    unsigned sf;
78
    unsigned sf;
79
    unsigned ssa;       /* size of the system area */
79
    unsigned ssa;       /* size of the system area */
80
    unsigned clusters;
80
    unsigned clusters;
81
    fat_cluster_t clst = firstc;
81
    fat_cluster_t clst = firstc;
82
    unsigned i;
82
    unsigned i;
83
 
83
 
84
    bps = uint16_t_le2host(bs->bps);
84
    bps = uint16_t_le2host(bs->bps);
85
    spc = bs->spc;
85
    spc = bs->spc;
86
    rscnt = uint16_t_le2host(bs->rscnt);
86
    rscnt = uint16_t_le2host(bs->rscnt);
87
    fatcnt = bs->fatcnt;
87
    fatcnt = bs->fatcnt;
88
    rde = uint16_t_le2host(bs->root_ent_max);
88
    rde = uint16_t_le2host(bs->root_ent_max);
89
    sf = uint16_t_le2host(bs->sec_per_fat);
89
    sf = uint16_t_le2host(bs->sec_per_fat);
90
 
90
 
91
    rds = (sizeof(fat_dentry_t) * rde) / bps;
91
    rds = (sizeof(fat_dentry_t) * rde) / bps;
92
    rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
92
    rds += ((sizeof(fat_dentry_t) * rde) % bps != 0);
93
    ssa = rscnt + fatcnt * sf + rds;
93
    ssa = rscnt + fatcnt * sf + rds;
94
 
94
 
95
    if (firstc == FAT_CLST_ROOT) {
95
    if (firstc == FAT_CLST_ROOT) {
96
        /* root directory special case */
96
        /* root directory special case */
97
        assert(offset < rds);
97
        assert(offset < rds);
98
        b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps);
98
        b = block_get(dev_handle, rscnt + fatcnt * sf + offset, bps);
99
        return b;
99
        return b;
100
    }
100
    }
101
 
101
 
102
    clusters = offset / spc;
102
    clusters = offset / spc;
103
    for (i = 0; i < clusters; i++) {
103
    for (i = 0; i < clusters; i++) {
104
        unsigned fsec;  /* sector offset relative to FAT1 */
104
        unsigned fsec;  /* sector offset relative to FAT1 */
105
        unsigned fidx;  /* FAT1 entry index */
105
        unsigned fidx;  /* FAT1 entry index */
106
 
106
 
107
        assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);
107
        assert(clst >= FAT_CLST_FIRST && clst < FAT_CLST_BAD);
108
        fsec = (clst * sizeof(fat_cluster_t)) / bps;
108
        fsec = (clst * sizeof(fat_cluster_t)) / bps;
109
        fidx = clst % (bps / sizeof(fat_cluster_t));
109
        fidx = clst % (bps / sizeof(fat_cluster_t));
110
        /* read FAT1 */
110
        /* read FAT1 */
111
        b = block_get(dev_handle, rscnt + fsec, bps);
111
        b = block_get(dev_handle, rscnt + fsec, bps);
112
        clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
112
        clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
113
        assert(clst != FAT_CLST_BAD);
113
        assert(clst != FAT_CLST_BAD);
114
        assert(clst < FAT_CLST_LAST1);
114
        assert(clst < FAT_CLST_LAST1);
115
        block_put(b);
115
        block_put(b);
116
    }
116
    }
117
 
117
 
118
    b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
118
    b = block_get(dev_handle, ssa + (clst - FAT_CLST_FIRST) * spc +
119
        offset % spc, bps);
119
        offset % spc, bps);
120
 
120
 
121
    return b;
121
    return b;
122
}
122
}
123
 
123
 
124
/** Return number of blocks allocated to a file.
124
/** Return number of blocks allocated to a file.
125
 *
125
 *
126
 * @param bs        Buffer holding the boot sector for the file.
126
 * @param bs        Buffer holding the boot sector for the file.
127
 * @param dev_handle    Device handle of the device with the file.
127
 * @param dev_handle    Device handle of the device with the file.
128
 * @param firstc    First cluster of the file.
128
 * @param firstc    First cluster of the file.
129
 * @param lastc     If non-NULL, output argument holding the
129
 * @param lastc     If non-NULL, output argument holding the
130
 *          last cluster.
130
 *          last cluster.
131
 *
131
 *
132
 * @return      Number of blocks allocated to the file.
132
 * @return      Number of blocks allocated to the file.
133
 */
133
 */
134
uint16_t
134
uint16_t
135
_fat_blcks_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
135
_fat_blcks_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
136
    fat_cluster_t *lastc)
136
    fat_cluster_t *lastc)
137
{
137
{
138
    block_t *b;
138
    block_t *b;
139
    unsigned bps;
139
    unsigned bps;
140
    unsigned spc;
140
    unsigned spc;
141
    unsigned rscnt;     /* block address of the first FAT */
141
    unsigned rscnt;     /* block address of the first FAT */
142
    unsigned clusters = 0;
142
    unsigned clusters = 0;
143
    fat_cluster_t clst = firstc;
143
    fat_cluster_t clst = firstc;
144
 
144
 
145
    bps = uint16_t_le2host(bs->bps);
145
    bps = uint16_t_le2host(bs->bps);
146
    spc = bs->spc;
146
    spc = bs->spc;
147
    rscnt = uint16_t_le2host(bs->rscnt);
147
    rscnt = uint16_t_le2host(bs->rscnt);
148
 
148
 
149
    if (firstc == FAT_CLST_RES0) {
149
    if (firstc == FAT_CLST_RES0) {
150
        /* No space allocated to the file. */
150
        /* No space allocated to the file. */
151
        if (lastc)
151
        if (lastc)
152
            *lastc = firstc;
152
            *lastc = firstc;
153
        return 0;
153
        return 0;
154
    }
154
    }
155
 
155
 
156
    while (clst < FAT_CLST_LAST1) {
156
    while (clst < FAT_CLST_LAST1) {
157
        unsigned fsec;  /* sector offset relative to FAT1 */
157
        unsigned fsec;  /* sector offset relative to FAT1 */
158
        unsigned fidx;  /* FAT1 entry index */
158
        unsigned fidx;  /* FAT1 entry index */
159
 
159
 
160
        assert(clst >= FAT_CLST_FIRST);
160
        assert(clst >= FAT_CLST_FIRST);
161
        if (lastc)
161
        if (lastc)
162
            *lastc = clst;      /* remember the last cluster */
162
            *lastc = clst;      /* remember the last cluster */
163
        fsec = (clst * sizeof(fat_cluster_t)) / bps;
163
        fsec = (clst * sizeof(fat_cluster_t)) / bps;
164
        fidx = clst % (bps / sizeof(fat_cluster_t));
164
        fidx = clst % (bps / sizeof(fat_cluster_t));
165
        /* read FAT1 */
165
        /* read FAT1 */
166
        b = block_get(dev_handle, rscnt + fsec, bps);
166
        b = block_get(dev_handle, rscnt + fsec, bps);
167
        clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
167
        clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
168
        assert(clst != FAT_CLST_BAD);
168
        assert(clst != FAT_CLST_BAD);
169
        block_put(b);
169
        block_put(b);
170
        clusters++;
170
        clusters++;
171
    }
171
    }
172
 
172
 
173
    if (lastc)
173
    if (lastc)
174
        *lastc = clst;
174
        *lastc = clst;
175
    return clusters * spc;
175
    return clusters * spc;
176
}
176
}
177
 
177
 
178
/** Fill the gap between EOF and a new file position.
178
/** Fill the gap between EOF and a new file position.
179
 *
179
 *
180
 * @param bs        Buffer holding the boot sector for nodep.
180
 * @param bs        Buffer holding the boot sector for nodep.
181
 * @param nodep     FAT node with the gap.
181
 * @param nodep     FAT node with the gap.
182
 * @param mcl       First cluster in an independent cluster chain that will
182
 * @param mcl       First cluster in an independent cluster chain that will
183
 *          be later appended to the end of the node's own cluster
183
 *          be later appended to the end of the node's own cluster
184
 *          chain. If pos is still in the last allocated cluster,
184
 *          chain. If pos is still in the last allocated cluster,
185
 *          this argument is ignored.
185
 *          this argument is ignored.
186
 * @param pos       Position in the last node block.
186
 * @param pos       Position in the last node block.
187
 */
187
 */
188
void fat_fill_gap(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl, off_t pos)
188
void fat_fill_gap(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl, off_t pos)
189
{
189
{
190
    uint16_t bps;
190
    uint16_t bps;
191
    unsigned spc;
191
    unsigned spc;
192
    block_t *b;
192
    block_t *b;
193
    off_t o, boundary;
193
    off_t o, boundary;
194
 
194
 
195
    bps = uint16_t_le2host(bs->bps);
195
    bps = uint16_t_le2host(bs->bps);
196
    spc = bs->spc;
196
    spc = bs->spc;
197
   
197
   
198
    boundary = ROUND_UP(nodep->size, bps * spc);
198
    boundary = ROUND_UP(nodep->size, bps * spc);
199
 
199
 
200
    /* zero out already allocated space */
200
    /* zero out already allocated space */
201
    for (o = nodep->size - 1; o < pos && o < boundary;
201
    for (o = nodep->size - 1; o < pos && o < boundary;
202
        o = ALIGN_DOWN(o + bps, bps)) {
202
        o = ALIGN_DOWN(o + bps, bps)) {
203
        b = fat_block_get(bs, nodep, o / bps);
203
        b = fat_block_get(bs, nodep, o / bps);
204
        memset(b->data + o % bps, 0, bps - o % bps);
204
        memset(b->data + o % bps, 0, bps - o % bps);
205
        b->dirty = true;        /* need to sync node */
205
        b->dirty = true;        /* need to sync node */
206
        block_put(b);
206
        block_put(b);
207
    }
207
    }
208
   
208
   
209
    if (o >= pos)
209
    if (o >= pos)
210
        return;
210
        return;
211
   
211
   
212
    /* zero out the initial part of the new cluster chain */
212
    /* zero out the initial part of the new cluster chain */
213
    for (o = boundary; o < pos; o += bps) {
213
    for (o = boundary; o < pos; o += bps) {
214
        b = _fat_block_get(bs, nodep->idx->dev_handle, mcl,
214
        b = _fat_block_get(bs, nodep->idx->dev_handle, mcl,
215
            (o - boundary) / bps);
215
            (o - boundary) / bps);
216
        memset(b->data, 0, min(bps, pos - o));
216
        memset(b->data, 0, min(bps, pos - o));
217
        b->dirty = true;        /* need to sync node */
217
        b->dirty = true;        /* need to sync node */
218
        block_put(b);
218
        block_put(b);
219
    }
219
    }
220
}
220
}
221
 
221
 
222
/** Mark cluster in one instance of FAT.
222
/** Mark cluster in one instance of FAT.
223
 *
223
 *
224
 * @param bs        Buffer holding the boot sector for the file system.
224
 * @param bs        Buffer holding the boot sector for the file system.
225
 * @param dev_handle    Device handle for the file system.
225
 * @param dev_handle    Device handle for the file system.
226
 * @param fatno     Number of the FAT instance where to make the change.
226
 * @param fatno     Number of the FAT instance where to make the change.
227
 * @param clst      Cluster which is to be marked.
227
 * @param clst      Cluster which is to be marked.
228
 * @param value     Value mark the cluster with.
228
 * @param value     Value mark the cluster with.
229
 */
229
 */
230
void
230
void
231
fat_mark_cluster(fat_bs_t *bs, dev_handle_t dev_handle, unsigned fatno,
231
fat_mark_cluster(fat_bs_t *bs, dev_handle_t dev_handle, unsigned fatno,
232
    fat_cluster_t clst, fat_cluster_t value)
232
    fat_cluster_t clst, fat_cluster_t value)
233
{
233
{
234
    block_t *b;
234
    block_t *b;
235
    uint16_t bps;
235
    uint16_t bps;
236
    uint16_t rscnt;
236
    uint16_t rscnt;
237
    uint16_t sf;
237
    uint16_t sf;
238
    fat_cluster_t *cp;
238
    fat_cluster_t *cp;
239
 
239
 
240
    bps = uint16_t_le2host(bs->bps);
240
    bps = uint16_t_le2host(bs->bps);
241
    rscnt = uint16_t_le2host(bs->rscnt);
241
    rscnt = uint16_t_le2host(bs->rscnt);
242
    sf = uint16_t_le2host(bs->sec_per_fat);
242
    sf = uint16_t_le2host(bs->sec_per_fat);
243
 
243
 
244
    assert(fatno < bs->fatcnt);
244
    assert(fatno < bs->fatcnt);
245
    b = block_get(dev_handle, rscnt + sf * fatno +
245
    b = block_get(dev_handle, rscnt + sf * fatno +
246
        (clst * sizeof(fat_cluster_t)) / bps, bps);
246
        (clst * sizeof(fat_cluster_t)) / bps, bps);
247
    cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
247
    cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
248
    *cp = host2uint16_t_le(value);
248
    *cp = host2uint16_t_le(value);
249
    b->dirty = true;        /* need to sync block */
249
    b->dirty = true;        /* need to sync block */
250
    block_put(b);
250
    block_put(b);
251
}
251
}
252
 
252
 
253
/** Replay the allocatoin of clusters in all shadow instances of FAT.
253
/** Replay the allocatoin of clusters in all shadow instances of FAT.
254
 *
254
 *
255
 * @param bs        Buffer holding the boot sector of the file system.
255
 * @param bs        Buffer holding the boot sector of the file system.
256
 * @param dev_handle    Device handle of the file system.
256
 * @param dev_handle    Device handle of the file system.
257
 * @param lifo      Chain of allocated clusters.
257
 * @param lifo      Chain of allocated clusters.
258
 * @param nclsts    Number of clusters in the lifo chain.
258
 * @param nclsts    Number of clusters in the lifo chain.
259
 */
259
 */
260
void fat_alloc_shadow_clusters(fat_bs_t *bs, dev_handle_t dev_handle,
260
void fat_alloc_shadow_clusters(fat_bs_t *bs, dev_handle_t dev_handle,
261
    fat_cluster_t *lifo, unsigned nclsts)
261
    fat_cluster_t *lifo, unsigned nclsts)
262
{
262
{
263
    uint8_t fatno;
263
    uint8_t fatno;
264
    unsigned c;
264
    unsigned c;
265
 
265
 
266
    for (fatno = FAT1 + 1; fatno < bs->fatcnt; fatno++) {
266
    for (fatno = FAT1 + 1; fatno < bs->fatcnt; fatno++) {
267
        for (c = 0; c < nclsts; c++) {
267
        for (c = 0; c < nclsts; c++) {
268
            fat_mark_cluster(bs, dev_handle, fatno, lifo[c],
268
            fat_mark_cluster(bs, dev_handle, fatno, lifo[c],
269
                c == 0 ? FAT_CLST_LAST1 : lifo[c - 1]);
269
                c == 0 ? FAT_CLST_LAST1 : lifo[c - 1]);
270
        }
270
        }
271
    }
271
    }
272
}
272
}
273
 
273
 
274
/** Allocate clusters in FAT1.
274
/** Allocate clusters in FAT1.
275
 *
275
 *
276
 * This function will attempt to allocate the requested number of clusters in
276
 * This function will attempt to allocate the requested number of clusters in
277
 * the first FAT instance.  The FAT will be altered so that the allocated
277
 * the first FAT instance.  The FAT will be altered so that the allocated
278
 * clusters form an independent chain (i.e. a chain which does not belong to any
278
 * clusters form an independent chain (i.e. a chain which does not belong to any
279
 * file yet).
279
 * file yet).
280
 *
280
 *
281
 * @param bs        Buffer holding the boot sector of the file system.
281
 * @param bs        Buffer holding the boot sector of the file system.
282
 * @param dev_handle    Device handle of the file system.
282
 * @param dev_handle    Device handle of the file system.
283
 * @param nclsts    Number of clusters to allocate.
283
 * @param nclsts    Number of clusters to allocate.
284
 * @param mcl       Output parameter where the first cluster in the chain
284
 * @param mcl       Output parameter where the first cluster in the chain
285
 *          will be returned.
285
 *          will be returned.
286
 * @param lcl       Output parameter where the last cluster in the chain
286
 * @param lcl       Output parameter where the last cluster in the chain
287
 *          will be returned.
287
 *          will be returned.
288
 *
288
 *
289
 * @return      EOK on success, a negative error code otherwise.
289
 * @return      EOK on success, a negative error code otherwise.
290
 */
290
 */
291
int
291
int
292
fat_alloc_clusters(fat_bs_t *bs, dev_handle_t dev_handle, unsigned nclsts,
292
fat_alloc_clusters(fat_bs_t *bs, dev_handle_t dev_handle, unsigned nclsts,
293
    fat_cluster_t *mcl, fat_cluster_t *lcl)
293
    fat_cluster_t *mcl, fat_cluster_t *lcl)
294
{
294
{
295
    uint16_t bps;
295
    uint16_t bps;
296
    uint16_t rscnt;
296
    uint16_t rscnt;
297
    uint16_t sf;
297
    uint16_t sf;
298
    block_t *blk;
298
    block_t *blk;
299
    fat_cluster_t *lifo;    /* stack for storing free cluster numbers */
299
    fat_cluster_t *lifo;    /* stack for storing free cluster numbers */
300
    unsigned found = 0; /* top of the free cluster number stack */
300
    unsigned found = 0; /* top of the free cluster number stack */
301
    unsigned b, c, cl;
301
    unsigned b, c, cl;
302
 
302
 
303
    lifo = (fat_cluster_t *) malloc(nclsts * sizeof(fat_cluster_t));
303
    lifo = (fat_cluster_t *) malloc(nclsts * sizeof(fat_cluster_t));
304
    if (lifo)
304
    if (lifo)
305
        return ENOMEM;
305
        return ENOMEM;
306
   
306
   
307
    bps = uint16_t_le2host(bs->bps);
307
    bps = uint16_t_le2host(bs->bps);
308
    rscnt = uint16_t_le2host(bs->rscnt);
308
    rscnt = uint16_t_le2host(bs->rscnt);
309
    sf = uint16_t_le2host(bs->sec_per_fat);
309
    sf = uint16_t_le2host(bs->sec_per_fat);
310
   
310
   
311
    /*
311
    /*
312
     * Search FAT1 for unused clusters.
312
     * Search FAT1 for unused clusters.
313
     */
313
     */
314
    futex_down(&fat_alloc_lock);
314
    futex_down(&fat_alloc_lock);
315
    for (b = 0, cl = 0; b < sf; blk++) {
315
    for (b = 0, cl = 0; b < sf; blk++) {
316
        blk = block_get(dev_handle, rscnt + b, bps);
316
        blk = block_get(dev_handle, rscnt + b, bps);
317
        for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) {
317
        for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) {
318
            fat_cluster_t *clst = (fat_cluster_t *)blk->data + c;
318
            fat_cluster_t *clst = (fat_cluster_t *)blk->data + c;
319
            if (uint16_t_le2host(*clst) == FAT_CLST_RES0) {
319
            if (uint16_t_le2host(*clst) == FAT_CLST_RES0) {
320
                /*
320
                /*
321
                 * The cluster is free. Put it into our stack
321
                 * The cluster is free. Put it into our stack
322
                 * of found clusters and mark it as non-free.
322
                 * of found clusters and mark it as non-free.
323
                 */
323
                 */
324
                lifo[found] = cl;
324
                lifo[found] = cl;
325
                *clst = (found == 0) ?
325
                *clst = (found == 0) ?
326
                    host2uint16_t_le(FAT_CLST_LAST1) :
326
                    host2uint16_t_le(FAT_CLST_LAST1) :
327
                    host2uint16_t_le(lifo[found - 1]);
327
                    host2uint16_t_le(lifo[found - 1]);
328
                blk->dirty = true;  /* need to sync block */
328
                blk->dirty = true;  /* need to sync block */
329
                if (++found == nclsts) {
329
                if (++found == nclsts) {
330
                    /* we are almost done */
330
                    /* we are almost done */
331
                    block_put(blk);
331
                    block_put(blk);
332
                    /* update the shadow copies of FAT */
332
                    /* update the shadow copies of FAT */
333
                    fat_alloc_shadow_clusters(bs,
333
                    fat_alloc_shadow_clusters(bs,
334
                        dev_handle, lifo, nclsts);
334
                        dev_handle, lifo, nclsts);
335
                    *mcl = lifo[found - 1];
335
                    *mcl = lifo[found - 1];
336
                    *lcl = lifo[0];
336
                    *lcl = lifo[0];
337
                    free(lifo);
337
                    free(lifo);
338
                    futex_up(&fat_alloc_lock);
338
                    futex_up(&fat_alloc_lock);
339
                    return EOK;
339
                    return EOK;
340
                }
340
                }
341
            }
341
            }
342
        }
342
        }
343
        block_put(blk);
343
        block_put(blk);
344
    }
344
    }
345
    futex_up(&fat_alloc_lock);
345
    futex_up(&fat_alloc_lock);
346
 
346
 
347
    /*
347
    /*
348
     * We could not find enough clusters. Now we need to free the clusters
348
     * We could not find enough clusters. Now we need to free the clusters
349
     * we have allocated so far.
349
     * we have allocated so far.
350
     */
350
     */
351
    while (found--) {
351
    while (found--) {
352
        fat_mark_cluster(bs, dev_handle, FAT1, lifo[found],
352
        fat_mark_cluster(bs, dev_handle, FAT1, lifo[found],
353
            FAT_CLST_RES0);
353
            FAT_CLST_RES0);
354
    }
354
    }
355
   
355
   
356
    free(lifo);
356
    free(lifo);
357
    return ENOSPC;
357
    return ENOSPC;
358
}
358
}
359
 
359
 
360
/** Append a cluster chain to the last file cluster in all FATs.
360
/** Append a cluster chain to the last file cluster in all FATs.
361
 *
361
 *
362
 * @param bs        Buffer holding boot sector of the file system.
362
 * @param bs        Buffer holding boot sector of the file system.
363
 * @param nodep     Node representing the file.
363
 * @param nodep     Node representing the file.
364
 * @param mcl       First cluster of the cluster chain to append.
364
 * @param mcl       First cluster of the cluster chain to append.
365
 */
365
 */
366
void fat_append_clusters(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl)
366
void fat_append_clusters(fat_bs_t *bs, fat_node_t *nodep, fat_cluster_t mcl)
367
{
367
{
368
    dev_handle_t dev_handle = nodep->idx->dev_handle;
368
    dev_handle_t dev_handle = nodep->idx->dev_handle;
369
    fat_cluster_t lcl;
369
    fat_cluster_t lcl;
370
    uint8_t fatno;
370
    uint8_t fatno;
371
 
371
 
372
    if (_fat_blcks_get(bs, dev_handle, nodep->firstc, &lcl) == 0) {
372
    if (_fat_blcks_get(bs, dev_handle, nodep->firstc, &lcl) == 0) {
373
        nodep->firstc = host2uint16_t_le(mcl);
373
        nodep->firstc = host2uint16_t_le(mcl);
374
        nodep->dirty = true;        /* need to sync node */
374
        nodep->dirty = true;        /* need to sync node */
375
        return;
375
        return;
376
    }
376
    }
377
 
377
 
378
    for (fatno = FAT1; fatno < bs->fatcnt; fatno++)
378
    for (fatno = FAT1; fatno < bs->fatcnt; fatno++)
379
        fat_mark_cluster(bs, nodep->idx->dev_handle, fatno, lcl, mcl);
379
        fat_mark_cluster(bs, nodep->idx->dev_handle, fatno, lcl, mcl);
380
}
380
}
381
 
381
 
382
/**
382
/**
383
 * @}
383
 * @}
384
 */
384
 */
385
 
385