cluster.c (03.09.09)
exFAT file system implementation library.
- Copyright (C) 2010-2012 Andrew Nayenko
+ Free exFAT implementation.
+ Copyright (C) 2010-2013 Andrew Nayenko
- This program is free software: you can redistribute it and/or modify
+ This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
+ the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, write to the Free Software Foundation, Inc.,
+ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "exfat.h"
{
node->fptr_cluster = exfat_next_cluster(ef, node, node->fptr_cluster);
if (CLUSTER_INVALID(node->fptr_cluster))
- break;
+ break; /* the caller should handle this and print appropriate
+ error message */
}
node->fptr_index = count;
return node->fptr_cluster;
}
-static cluster_t find_bit_and_set(uint8_t* bitmap, cluster_t start,
- cluster_t end)
+static cluster_t find_bit_and_set(uint8_t* bitmap, size_t start, size_t end)
{
- const cluster_t mid_start = (start + 7) / 8 * 8;
- const cluster_t mid_end = end / 8 * 8;
- cluster_t c;
- cluster_t byte;
-
- for (c = start; c < mid_start; c++)
- if (BMAP_GET(bitmap, c) == 0)
- {
- BMAP_SET(bitmap, c);
- return c + EXFAT_FIRST_DATA_CLUSTER;
- }
-
- for (byte = mid_start / 8; byte < mid_end / 8; byte++)
- if (bitmap[byte] != 0xff)
- {
- cluster_t bit;
-
- for (bit = 0; bit < 8; bit++)
- if (!(bitmap[byte] & (1u << bit)))
- {
- bitmap[byte] |= (1u << bit);
- return byte * 8 + bit + EXFAT_FIRST_DATA_CLUSTER;
- }
- }
-
- for (c = mid_end; c < end; c++)
- if (BMAP_GET(bitmap, c) == 0)
- {
- BMAP_SET(bitmap, c);
- return c + EXFAT_FIRST_DATA_CLUSTER;
- }
+ const size_t start_index = start / 8;
+ const size_t end_index = DIV_ROUND_UP(end, 8);
+ size_t i;
+ size_t c;
+ for (i = start_index; i < end_index; i++)
+ {
+ if (bitmap[i] == 0xff)
+ continue;
+ for (c = MAX(i * 8, start); c < MIN((i + 1) * 8, end); c++)
+ if (BMAP_GET(bitmap, c) == 0)
+ {
+ BMAP_SET(bitmap, c);
+ return c + EXFAT_FIRST_DATA_CLUSTER;
+ }
+ }
return EXFAT_CLUSTER_END;
}
{
exfat_pwrite(ef->dev, ef->cmap.chunk, (ef->cmap.chunk_size + 7) / 8,
exfat_c2o(ef, ef->cmap.start_cluster));
- ef->cmap.dirty = 0;
+ ef->cmap.dirty = false;
}
-static void set_next_cluster(const struct exfat* ef, int contiguous,
+static void set_next_cluster(const struct exfat* ef, bool contiguous,
cluster_t current, cluster_t next)
{
off_t fat_offset;
return EXFAT_CLUSTER_END;
}
- ef->cmap.dirty = 1;
+ ef->cmap.dirty = true;
return cluster;
}
static void free_cluster(struct exfat* ef, cluster_t cluster)
{
if (CLUSTER_INVALID(cluster))
- exfat_bug("attempting to free invalid cluster");
- if (cluster < EXFAT_FIRST_DATA_CLUSTER ||
- cluster - EXFAT_FIRST_DATA_CLUSTER >= ef->cmap.size)
- exfat_bug("bad cluster 0x%x (0x%x)", cluster, ef->cmap.size);
+ exfat_bug("freeing invalid cluster 0x%x", cluster);
+ if (cluster - EXFAT_FIRST_DATA_CLUSTER >= ef->cmap.size)
+ exfat_bug("freeing non-existing cluster 0x%x (0x%x)", cluster,
+ ef->cmap.size);
BMAP_CLR(ef->cmap.chunk, cluster - EXFAT_FIRST_DATA_CLUSTER);
- ef->cmap.dirty = 1;
+ ef->cmap.dirty = true;
}
static void make_noncontiguous(const struct exfat* ef, cluster_t first,
cluster_t c;
for (c = first; c < last; c++)
- set_next_cluster(ef, 0, c, c + 1);
+ set_next_cluster(ef, false, c, c + 1);
}
static int shrink_file(struct exfat* ef, struct exfat_node* node,
previous = exfat_advance_cluster(ef, node, current - 1);
if (CLUSTER_INVALID(previous))
{
- exfat_error("invalid cluster in file");
+ exfat_error("invalid cluster 0x%x while growing", previous);
return -EIO;
}
}
current - difference - 1);
if (CLUSTER_INVALID(last))
{
- exfat_error("invalid cluster in file");
+ exfat_error("invalid cluster 0x%x while shrinking", last);
return -EIO;
}
previous = exfat_next_cluster(ef, node, last);
{
if (CLUSTER_INVALID(previous))
{
- exfat_error("invalid cluster in file");
+ exfat_error("invalid cluster 0x%x while freeing after shrink",
+ previous);
return -EIO;
}
next = exfat_next_cluster(ef, node, previous);
begin / CLUSTER_SIZE(*ef->sb));
if (CLUSTER_INVALID(cluster))
{
- exfat_error("invalid cluster in file");
+ exfat_error("invalid cluster 0x%x while erasing", cluster);
return -EIO;
}
/* erase from the beginning to the closest cluster boundary */
cluster = exfat_next_cluster(ef, node, cluster);
/* the cluster cannot be invalid because we have just allocated it */
if (CLUSTER_INVALID(cluster))
- exfat_bug("invalid cluster in file");
+ exfat_bug("invalid cluster 0x%x after allocation", cluster);
erase_raw(ef, CLUSTER_SIZE(*ef->sb), exfat_c2o(ef, cluster));
cluster_boundary += CLUSTER_SIZE(*ef->sb);
}
return 0;
}
-int exfat_truncate(struct exfat* ef, struct exfat_node* node, uint64_t size)
+int exfat_truncate(struct exfat* ef, struct exfat_node* node, uint64_t size,
+ bool erase)
{
uint32_t c1 = bytes2clusters(ef, node->size);
uint32_t c2 = bytes2clusters(ef, size);
if (rc != 0)
return rc;
- rc = erase_range(ef, node, node->size, size);
- if (rc != 0)
- return rc;
+ if (erase)
+ {
+ rc = erase_range(ef, node, node->size, size);
+ if (rc != 0)
+ return rc;
+ }
exfat_update_mtime(node);
node->size = size;
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