mount.c (22.10.09)
exFAT file system implementation library.
- Copyright (C) 2010-2013 Andrew Nayenko
+ Free exFAT implementation.
+ Copyright (C) 2010-2015 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"
#include <string.h>
#include <stdlib.h>
#include <errno.h>
+#include <inttypes.h>
#include <unistd.h>
#include <sys/types.h>
static uint64_t rootdir_size(const struct exfat* ef)
{
- uint64_t clusters = 0;
+ uint32_t clusters = 0;
+ uint32_t clusters_max = le32_to_cpu(ef->sb->cluster_count);
cluster_t rootdir_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
- while (!CLUSTER_INVALID(rootdir_cluster))
+ /* Iterate all clusters of the root directory to calculate its size.
+ It can't be contiguous because there is no flag to indicate this. */
+ do
{
- clusters++;
- /* root directory cannot be contiguous because there is no flag
- to indicate this */
+ if (clusters == clusters_max) /* infinite loop detected */
+ {
+ exfat_error("root directory cannot occupy all %d clusters",
+ clusters);
+ return 0;
+ }
+ if (CLUSTER_INVALID(rootdir_cluster))
+ {
+ exfat_error("bad cluster %#x while reading root directory",
+ rootdir_cluster);
+ return 0;
+ }
rootdir_cluster = exfat_next_cluster(ef, ef->root, rootdir_cluster);
+ clusters++;
}
- return clusters * CLUSTER_SIZE(*ef->sb);
+ while (rootdir_cluster != EXFAT_CLUSTER_END);
+
+ return (uint64_t) clusters * CLUSTER_SIZE(*ef->sb);
}
static const char* get_option(const char* options, const char* option_name)
static void parse_options(struct exfat* ef, const char* options)
{
- int sys_umask = umask(0);
int opt_umask;
- umask(sys_umask); /* restore umask */
- opt_umask = get_int_option(options, "umask", 8, sys_umask);
- ef->dmask = get_int_option(options, "dmask", 8, opt_umask) & 0777;
- ef->fmask = get_int_option(options, "fmask", 8, opt_umask) & 0777;
+ opt_umask = get_int_option(options, "umask", 8, 0);
+ ef->dmask = get_int_option(options, "dmask", 8, opt_umask);
+ ef->fmask = get_int_option(options, "fmask", 8, opt_umask);
ef->uid = get_int_option(options, "uid", 10, geteuid());
ef->gid = get_int_option(options, "gid", 10, getegid());
ef->noatime = match_option(options, "noatime");
}
-static int verify_vbr_checksum(struct exfat_dev* dev, void* sector,
+static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,
off_t sector_size)
{
uint32_t vbr_checksum;
int i;
- exfat_pread(dev, sector, sector_size, 0);
+ if (exfat_pread(dev, sector, sector_size, 0) < 0)
+ {
+ exfat_error("failed to read boot sector");
+ return false;
+ }
vbr_checksum = exfat_vbr_start_checksum(sector, sector_size);
for (i = 1; i < 11; i++)
{
- exfat_pread(dev, sector, sector_size, i * sector_size);
+ if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+ {
+ exfat_error("failed to read VBR sector");
+ return false;
+ }
vbr_checksum = exfat_vbr_add_checksum(sector, sector_size,
vbr_checksum);
}
- exfat_pread(dev, sector, sector_size, i * sector_size);
+ if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+ {
+ exfat_error("failed to read VBR checksum sector");
+ return false;
+ }
for (i = 0; i < sector_size / sizeof(vbr_checksum); i++)
if (le32_to_cpu(((const le32_t*) sector)[i]) != vbr_checksum)
{
exfat_error("invalid VBR checksum 0x%x (expected 0x%x)",
le32_to_cpu(((const le32_t*) sector)[i]), vbr_checksum);
- return 1;
+ return false;
}
- return 0;
+ return true;
}
static int commit_super_block(const struct exfat* ef)
{
- exfat_pwrite(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0);
+ if (exfat_pwrite(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)
+ {
+ exfat_error("failed to write super block");
+ return 1;
+ }
return exfat_fsync(ef->dev);
}
}
memset(ef->sb, 0, sizeof(struct exfat_super_block));
- exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0);
- if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0)
+ if (exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)
{
exfat_close(ef->dev);
free(ef->sb);
- exfat_error("exFAT file system is not found");
+ exfat_error("failed to read boot sector");
return -EIO;
}
- if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
+ if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0)
{
exfat_close(ef->dev);
- exfat_error("unsupported exFAT version: %hhu.%hhu",
- ef->sb->version.major, ef->sb->version.minor);
free(ef->sb);
+ exfat_error("exFAT file system is not found");
return -EIO;
}
- if (ef->sb->fat_count != 1)
+ /* sector cannot be smaller than 512 bytes */
+ if (ef->sb->sector_bits < 9)
{
exfat_close(ef->dev);
+ exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
free(ef->sb);
- exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
return -EIO;
}
/* officially exFAT supports cluster size up to 32 MB */
if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
{
exfat_close(ef->dev);
+ exfat_error("too big cluster size: 2^(%hhd+%hhd)",
+ ef->sb->sector_bits, ef->sb->spc_bits);
free(ef->sb);
- exfat_error("too big cluster size: 2^%d",
- (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);
return -EIO;
}
-
ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
if (ef->zero_cluster == NULL)
{
return -ENOMEM;
}
/* use zero_cluster as a temporary buffer for VBR checksum verification */
- if (verify_vbr_checksum(ef->dev, ef->zero_cluster,
- SECTOR_SIZE(*ef->sb)) != 0)
+ if (!verify_vbr_checksum(ef->dev, ef->zero_cluster, SECTOR_SIZE(*ef->sb)))
{
free(ef->zero_cluster);
exfat_close(ef->dev);
return -EIO;
}
memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
+ if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
+ {
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
+ exfat_error("unsupported exFAT version: %hhu.%hhu",
+ ef->sb->version.major, ef->sb->version.minor);
+ free(ef->sb);
+ return -EIO;
+ }
+ if (ef->sb->fat_count != 1)
+ {
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
+ exfat_error("unsupported FAT count: %hhu", ef->sb->fat_count);
+ free(ef->sb);
+ return -EIO;
+ }
+ if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+ exfat_get_size(ef->dev))
+ {
+ /* this can cause I/O errors later but we don't fail mounting to let
+ user rescue data */
+ exfat_warn("file system is larger than underlying device: "
+ "%"PRIu64" > %"PRIu64,
+ le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
+ exfat_get_size(ef->dev));
+ }
ef->root = malloc(sizeof(struct exfat_node));
if (ef->root == NULL)
ef->root->fptr_cluster = ef->root->start_cluster;
ef->root->name[0] = cpu_to_le16('\0');
ef->root->size = rootdir_size(ef);
+ if (ef->root->size == 0)
+ {
+ free(ef->root);
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
+ free(ef->sb);
+ return -EIO;
+ }
/* exFAT does not have time attributes for the root directory */
ef->root->mtime = 0;
ef->root->atime = 0;
ef->sb->allocated_percent = ((total - free) * 100 + total / 2) / total;
}
- commit_super_block(ef);
+ commit_super_block(ef); /* ignore return code */
}
void exfat_unmount(struct exfat* ef)
{
+ exfat_flush(ef); /* ignore return code */
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
free(ef->root);
projects / sven / exfat-utils.git / blobdiff