WebSVN – HelenOS – Diff – /branches/dynload/uspace/srv/fs/fat/fat_fat.c



        if (lastc)
            *lastc = clst;  /* remember the last cluster number */
        fsec = (clst * sizeof(fat_cluster_t)) / bps;
        fidx = clst % (bps / sizeof(fat_cluster_t));
        /* read FAT1 */
        b = block_get(dev_handle, rscnt + fsec, BLOCK_FLAGS_NONE);
        clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
        assert(clst != FAT_CLST_BAD);
        block_put(b);
        clusters++;
    }

 * @param bs        Buffer holding the boot sector of the file system.
 * @param dev_handle    Device handle of the file system.
 * @param firstc    First cluster used by the file. Can be zero if the file
 *          is empty.
 * @param bn        Block number.
 * @param flags     Flags passed to libblock.
 *
 * @return      Block structure holding the requested block.
 */
block_t *
_fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
    bn_t bn, int flags)
{
    block_t *b;
    unsigned bps;
    unsigned rscnt;     /* block address of the first FAT */
    unsigned rde;

    ssa = rscnt + bs->fatcnt * sf + rds;
 
    if (firstc == FAT_CLST_ROOT) {
        /* root directory special case */
        assert(bn < rds);
        b = block_get(dev_handle, rscnt + bs->fatcnt * sf + bn, flags);
        return b;
    }
 
    max_clusters = bn / bs->spc;
    clusters = fat_cluster_walk(bs, dev_handle, firstc, &lastc,
        max_clusters);
    assert(clusters == max_clusters);
 
    b = block_get(dev_handle, ssa + (lastc - FAT_CLST_FIRST) * bs->spc +
        bn % bs->spc, flags);
 
    return b;
}
 
/** Fill the gap between EOF and a new file position.

    boundary = ROUND_UP(nodep->size, bps * spc);
 
    /* zero out already allocated space */
    for (o = nodep->size - 1; o < pos && o < boundary;
        o = ALIGN_DOWN(o + bps, bps)) {
            int flags = (o % bps == 0) ?
            BLOCK_FLAGS_NOREAD : BLOCK_FLAGS_NONE;
        b = fat_block_get(bs, nodep, o / bps, flags);
        memset(b->data + o % bps, 0, bps - o % bps);
        b->dirty = true;        /* need to sync node */
        block_put(b);
    }
   

        return;
   
    /* zero out the initial part of the new cluster chain */
    for (o = boundary; o < pos; o += bps) {
        b = _fat_block_get(bs, nodep->idx->dev_handle, mcl,
            (o - boundary) / bps, BLOCK_FLAGS_NOREAD);
        memset(b->data, 0, min(bps, pos - o));
        b->dirty = true;        /* need to sync node */
        block_put(b);
    }
}

    fat_cluster_t *cp, value;
 
    bps = uint16_t_le2host(bs->bps);
    rscnt = uint16_t_le2host(bs->rscnt);
 
    b = block_get(dev_handle, rscnt + (clst * sizeof(fat_cluster_t)) / bps,
        BLOCK_FLAGS_NONE);
    cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
    value = uint16_t_le2host(*cp);
    block_put(b);
   
    return value;

    rscnt = uint16_t_le2host(bs->rscnt);
    sf = uint16_t_le2host(bs->sec_per_fat);
 
    assert(fatno < bs->fatcnt);
    b = block_get(dev_handle, rscnt + sf * fatno +
        (clst * sizeof(fat_cluster_t)) / bps, BLOCK_FLAGS_NONE);
    cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
    *cp = host2uint16_t_le(value);
    b->dirty = true;        /* need to sync block */
    block_put(b);
}

    /*
     * Search FAT1 for unused clusters.
     */
    futex_down(&fat_alloc_lock);
    for (b = 0, cl = 0; b < sf; blk++) {
        blk = block_get(dev_handle, rscnt + b, BLOCK_FLAGS_NOREAD);
        for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) {
            fat_cluster_t *clst = (fat_cluster_t *)blk->data + c;
            if (uint16_t_le2host(*clst) == FAT_CLST_RES0) {
                /*
                 * The cluster is free. Put it into our stack

Rev 3588	Rev 3598
Line 92...	Line 92...
92	if (lastc)	92	if (lastc)
93	lastc = clst; / remember the last cluster number */	93	lastc = clst; / remember the last cluster number */
94	fsec = (clst * sizeof(fat_cluster_t)) / bps;	94	fsec = (clst * sizeof(fat_cluster_t)) / bps;
95	fidx = clst % (bps / sizeof(fat_cluster_t));	95	fidx = clst % (bps / sizeof(fat_cluster_t));
96	/* read FAT1 */	96	/* read FAT1 */
97	b = block_get(dev_handle, rscnt + fsec);	97	b = block_get(dev_handle, rscnt + fsec, BLOCK_FLAGS_NONE);
98	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);	98	clst = uint16_t_le2host(((fat_cluster_t *)b->data)[fidx]);
99	assert(clst != FAT_CLST_BAD);	99	assert(clst != FAT_CLST_BAD);
100	block_put(b);	100	block_put(b);
101	clusters++;	101	clusters++;
102	}	102	}
Line 112...	Line 112...
112	* @param bs Buffer holding the boot sector of the file system.	112	* @param bs Buffer holding the boot sector of the file system.
113	* @param dev_handle Device handle of the file system.	113	* @param dev_handle Device handle of the file system.
114	* @param firstc First cluster used by the file. Can be zero if the file	114	* @param firstc First cluster used by the file. Can be zero if the file
115	* is empty.	115	* is empty.
116	* @param bn Block number.	116	* @param bn Block number.
-		117	* @param flags Flags passed to libblock.
117	*	118	*
118	* @return Block structure holding the requested block.	119	* @return Block structure holding the requested block.
119	*/	120	*/
120	block_t *	121	block_t *
121	_fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,	122	_fat_block_get(fat_bs_t *bs, dev_handle_t dev_handle, fat_cluster_t firstc,
122	bn_t bn)	123	bn_t bn, int flags)
123	{	124	{
124	block_t *b;	125	block_t *b;
125	unsigned bps;	126	unsigned bps;
126	unsigned rscnt; /* block address of the first FAT */	127	unsigned rscnt; /* block address of the first FAT */
127	unsigned rde;	128	unsigned rde;
Line 141...	Line 142...
141	ssa = rscnt + bs->fatcnt * sf + rds;	142	ssa = rscnt + bs->fatcnt * sf + rds;
142		143
143	if (firstc == FAT_CLST_ROOT) {	144	if (firstc == FAT_CLST_ROOT) {
144	/* root directory special case */	145	/* root directory special case */
145	assert(bn < rds);	146	assert(bn < rds);
146	b = block_get(dev_handle, rscnt + bs->fatcnt * sf + bn);	147	b = block_get(dev_handle, rscnt + bs->fatcnt * sf + bn, flags);
147	return b;	148	return b;
148	}	149	}
149		150
150	max_clusters = bn / bs->spc;	151	max_clusters = bn / bs->spc;
151	clusters = fat_cluster_walk(bs, dev_handle, firstc, &lastc,	152	clusters = fat_cluster_walk(bs, dev_handle, firstc, &lastc,
152	max_clusters);	153	max_clusters);
153	assert(clusters == max_clusters);	154	assert(clusters == max_clusters);
154		155
155	b = block_get(dev_handle, ssa + (lastc - FAT_CLST_FIRST) * bs->spc +	156	b = block_get(dev_handle, ssa + (lastc - FAT_CLST_FIRST) * bs->spc +
156	bn % bs->spc);	157	bn % bs->spc, flags);
157		158
158	return b;	159	return b;
159	}	160	}
160		161
161	/** Fill the gap between EOF and a new file position.	162	/** Fill the gap between EOF and a new file position.
Line 181...	Line 182...
181	boundary = ROUND_UP(nodep->size, bps * spc);	182	boundary = ROUND_UP(nodep->size, bps * spc);
182		183
183	/* zero out already allocated space */	184	/* zero out already allocated space */
184	for (o = nodep->size - 1; o < pos && o < boundary;	185	for (o = nodep->size - 1; o < pos && o < boundary;
185	o = ALIGN_DOWN(o + bps, bps)) {	186	o = ALIGN_DOWN(o + bps, bps)) {
-		187	int flags = (o % bps == 0) ?
-		188	BLOCK_FLAGS_NOREAD : BLOCK_FLAGS_NONE;
186	b = fat_block_get(bs, nodep, o / bps);	189	b = fat_block_get(bs, nodep, o / bps, flags);
187	memset(b->data + o % bps, 0, bps - o % bps);	190	memset(b->data + o % bps, 0, bps - o % bps);
188	b->dirty = true; /* need to sync node */	191	b->dirty = true; /* need to sync node */
189	block_put(b);	192	block_put(b);
190	}	193	}
191		194
Line 193...	Line 196...
193	return;	196	return;
194		197
195	/* zero out the initial part of the new cluster chain */	198	/* zero out the initial part of the new cluster chain */
196	for (o = boundary; o < pos; o += bps) {	199	for (o = boundary; o < pos; o += bps) {
197	b = _fat_block_get(bs, nodep->idx->dev_handle, mcl,	200	b = _fat_block_get(bs, nodep->idx->dev_handle, mcl,
198	(o - boundary) / bps);	201	(o - boundary) / bps, BLOCK_FLAGS_NOREAD);
199	memset(b->data, 0, min(bps, pos - o));	202	memset(b->data, 0, min(bps, pos - o));
200	b->dirty = true; /* need to sync node */	203	b->dirty = true; /* need to sync node */
201	block_put(b);	204	block_put(b);
202	}	205	}
203	}	206	}
Line 219...	Line 222...
219	fat_cluster_t *cp, value;	222	fat_cluster_t *cp, value;
220		223
221	bps = uint16_t_le2host(bs->bps);	224	bps = uint16_t_le2host(bs->bps);
222	rscnt = uint16_t_le2host(bs->rscnt);	225	rscnt = uint16_t_le2host(bs->rscnt);
223		226
224	b = block_get(dev_handle, rscnt + (clst * sizeof(fat_cluster_t)) / bps);	227	b = block_get(dev_handle, rscnt + (clst * sizeof(fat_cluster_t)) / bps,
-		228	BLOCK_FLAGS_NONE);
225	cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));	229	cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
226	value = uint16_t_le2host(*cp);	230	value = uint16_t_le2host(*cp);
227	block_put(b);	231	block_put(b);
228		232
229	return value;	233	return value;
Line 251...	Line 255...
251	rscnt = uint16_t_le2host(bs->rscnt);	255	rscnt = uint16_t_le2host(bs->rscnt);
252	sf = uint16_t_le2host(bs->sec_per_fat);	256	sf = uint16_t_le2host(bs->sec_per_fat);
253		257
254	assert(fatno < bs->fatcnt);	258	assert(fatno < bs->fatcnt);
255	b = block_get(dev_handle, rscnt + sf * fatno +	259	b = block_get(dev_handle, rscnt + sf * fatno +
256	(clst * sizeof(fat_cluster_t)) / bps);	260	(clst * sizeof(fat_cluster_t)) / bps, BLOCK_FLAGS_NONE);
257	cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));	261	cp = (fat_cluster_t *)b->data + clst % (bps / sizeof(fat_cluster_t));
258	*cp = host2uint16_t_le(value);	262	*cp = host2uint16_t_le(value);
259	b->dirty = true; /* need to sync block */	263	b->dirty = true; /* need to sync block */
260	block_put(b);	264	block_put(b);
261	}	265	}
Line 321...	Line 325...
321	/*	325	/*
322	* Search FAT1 for unused clusters.	326	* Search FAT1 for unused clusters.
323	*/	327	*/
324	futex_down(&fat_alloc_lock);	328	futex_down(&fat_alloc_lock);
325	for (b = 0, cl = 0; b < sf; blk++) {	329	for (b = 0, cl = 0; b < sf; blk++) {
326	blk = block_get(dev_handle, rscnt + b);	330	blk = block_get(dev_handle, rscnt + b, BLOCK_FLAGS_NOREAD);
327	for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) {	331	for (c = 0; c < bps / sizeof(fat_cluster_t); c++, cl++) {
328	fat_cluster_t clst = (fat_cluster_t )blk->data + c;	332	fat_cluster_t clst = (fat_cluster_t )blk->data + c;
329	if (uint16_t_le2host(*clst) == FAT_CLST_RES0) {	333	if (uint16_t_le2host(*clst) == FAT_CLST_RES0) {
330	/*	334	/*
331	* The cluster is free. Put it into our stack	335	* The cluster is free. Put it into our stack

Subversion Repositories HelenOS

(root)/branches/dynload/uspace/srv/fs/fat/fat_fat.c – Rev 3588 → 3598