exFAT file system implementation library.
Free exFAT implementation.
- Copyright (C) 2010-2014 Andrew Nayenko
+ Copyright (C) 2010-2018 Andrew Nayenko
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
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(*ef->sb, 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++;
}
- if (rootdir_cluster != EXFAT_CLUSTER_END)
- {
- exfat_error("bad cluster %#x while reading root directory",
- rootdir_cluster);
- return 0;
- }
- 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");
+
+ switch (get_int_option(options, "repair", 10, 0))
+ {
+ case 1:
+ ef->repair = EXFAT_REPAIR_ASK;
+ break;
+ case 2:
+ ef->repair = EXFAT_REPAIR_YES;
+ break;
+ default:
+ ef->repair = EXFAT_REPAIR_NO;
+ break;
+ }
}
-static bool verify_vbr_checksum(struct exfat_dev* dev, void* sector,
- off_t sector_size)
+static bool verify_vbr_checksum(const struct exfat* ef, void* sector)
{
+ off_t sector_size = SECTOR_SIZE(*ef->sb);
uint32_t vbr_checksum;
int i;
- if (exfat_pread(dev, sector, sector_size, 0) < 0)
+ if (exfat_pread(ef->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++)
{
- if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+ if (exfat_pread(ef->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);
}
- if (exfat_pread(dev, sector, sector_size, i * sector_size) < 0)
+ if (exfat_pread(ef->dev, sector, sector_size, i * sector_size) < 0)
{
exfat_error("failed to read VBR checksum sector");
return false;
{
exfat_error("invalid VBR checksum 0x%x (expected 0x%x)",
le32_to_cpu(((const le32_t*) sector)[i]), vbr_checksum);
- return false;
+ if (!EXFAT_REPAIR(invalid_vbr_checksum, ef, sector, vbr_checksum))
+ return false;
}
return true;
}
return commit_super_block(ef);
}
+static void exfat_free(struct exfat* ef)
+{
+ exfat_close(ef->dev); /* first of all, close the descriptor */
+ ef->dev = NULL; /* struct exfat_dev is freed by exfat_close() */
+ free(ef->root);
+ ef->root = NULL;
+ free(ef->zero_cluster);
+ ef->zero_cluster = NULL;
+ free(ef->cmap.chunk);
+ ef->cmap.chunk = NULL;
+ free(ef->upcase);
+ ef->upcase = NULL;
+ free(ef->sb);
+ ef->sb = NULL;
+}
+
int exfat_mount(struct exfat* ef, const char* spec, const char* options)
{
int rc;
ef->sb = malloc(sizeof(struct exfat_super_block));
if (ef->sb == NULL)
{
- exfat_close(ef->dev);
exfat_error("failed to allocate memory for the super block");
+ exfat_free(ef);
return -ENOMEM;
}
memset(ef->sb, 0, sizeof(struct exfat_super_block));
if (exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0) < 0)
{
- exfat_close(ef->dev);
- free(ef->sb);
exfat_error("failed to read boot sector");
+ exfat_free(ef);
return -EIO;
}
if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0)
{
- exfat_close(ef->dev);
- free(ef->sb);
exfat_error("exFAT file system is not found");
+ exfat_free(ef);
+ return -EIO;
+ }
+ /* sector cannot be smaller than 512 bytes */
+ if (ef->sb->sector_bits < 9)
+ {
+ exfat_error("too small sector size: 2^%hhd", ef->sb->sector_bits);
+ exfat_free(ef);
+ return -EIO;
+ }
+ /* officially exFAT supports cluster size up to 32 MB */
+ if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
+ {
+ exfat_error("too big cluster size: 2^(%hhd+%hhd)",
+ ef->sb->sector_bits, ef->sb->spc_bits);
+ exfat_free(ef);
return -EIO;
}
ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
if (ef->zero_cluster == NULL)
{
- exfat_close(ef->dev);
- free(ef->sb);
exfat_error("failed to allocate zero sector");
+ exfat_free(ef);
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)))
+ if (!verify_vbr_checksum(ef, ef->zero_cluster))
{
- free(ef->zero_cluster);
- exfat_close(ef->dev);
- free(ef->sb);
+ exfat_free(ef);
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);
+ exfat_free(ef);
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);
+ exfat_free(ef);
return -EIO;
}
- /* officially exFAT supports cluster size up to 32 MB */
- if ((int) ef->sb->sector_bits + (int) ef->sb->spc_bits > 25)
+ if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+ exfat_get_size(ef->dev))
{
- free(ef->zero_cluster);
- exfat_close(ef->dev);
- exfat_error("too big cluster size: 2^%d",
- (int) ef->sb->sector_bits + (int) ef->sb->spc_bits);
- free(ef->sb);
- return -EIO;
+ /* this can cause I/O errors later but we don't fail mounting to let
+ user rescue data */
+ exfat_warn("file system in sectors is larger than device: "
+ "%"PRIu64" * %d > %"PRIu64,
+ le64_to_cpu(ef->sb->sector_count), SECTOR_SIZE(*ef->sb),
+ exfat_get_size(ef->dev));
}
- if (le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb) >
+ if ((off_t) le32_to_cpu(ef->sb->cluster_count) * CLUSTER_SIZE(*ef->sb) >
exfat_get_size(ef->dev))
{
- free(ef->zero_cluster);
- exfat_error("file system is larger than underlying device: "
- "%"PRIu64" > %"PRIu64,
- le64_to_cpu(ef->sb->sector_count) * SECTOR_SIZE(*ef->sb),
+ exfat_error("file system in clusters is larger than device: "
+ "%u * %d > %"PRIu64,
+ le32_to_cpu(ef->sb->cluster_count), CLUSTER_SIZE(*ef->sb),
exfat_get_size(ef->dev));
- exfat_close(ef->dev);
- free(ef->sb);
+ exfat_free(ef);
return -EIO;
}
ef->root = malloc(sizeof(struct exfat_node));
if (ef->root == NULL)
{
- free(ef->zero_cluster);
- exfat_close(ef->dev);
- free(ef->sb);
exfat_error("failed to allocate root node");
+ exfat_free(ef);
return -ENOMEM;
}
memset(ef->root, 0, sizeof(struct exfat_node));
- ef->root->flags = EXFAT_ATTRIB_DIR;
+ ef->root->attrib = EXFAT_ATTRIB_DIR;
ef->root->start_cluster = le32_to_cpu(ef->sb->rootdir_cluster);
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);
+ exfat_free(ef);
return -EIO;
}
/* exFAT does not have time attributes for the root directory */
error:
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
- free(ef->root);
- free(ef->zero_cluster);
- exfat_close(ef->dev);
- free(ef->sb);
+ exfat_free(ef);
return -EIO;
}
void exfat_unmount(struct exfat* ef)
{
- exfat_flush(ef); /* ignore return code */
+ exfat_flush_nodes(ef); /* ignore return code */
+ exfat_flush(ef); /* ignore return code */
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
- free(ef->root);
- ef->root = NULL;
finalize_super_block(ef);
- exfat_close(ef->dev); /* close descriptor immediately after fsync */
- ef->dev = NULL;
- free(ef->zero_cluster);
- ef->zero_cluster = NULL;
- free(ef->cmap.chunk);
- ef->cmap.chunk = NULL;
- free(ef->sb);
- ef->sb = NULL;
- free(ef->upcase);
- ef->upcase = NULL;
- ef->upcase_chars = 0;
+ exfat_free(ef); /* will close the descriptor */
}
projects / sven / exfat-utils.git / blobdiff