mount.c (22.10.09)
exFAT file system implementation library.
- Copyright (C) 2009, 2010 Andrew Nayenko
+ Copyright (C) 2010-2012 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
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
-#define _XOPEN_SOURCE /* for tzset() in Linux */
-#include <time.h>
static uint64_t rootdir_size(const struct exfat* ef)
{
ef->noatime = match_option(options, "noatime");
}
-static int verify_vbr_checksum(void* sector, off_t sector_size, int fd)
+static int verify_vbr_checksum(struct exfat_dev* dev, void* sector,
+ off_t sector_size)
{
uint32_t vbr_checksum;
int i;
- exfat_read_raw(sector, sector_size, 0, fd);
+ exfat_pread(dev, sector, sector_size, 0);
vbr_checksum = exfat_vbr_start_checksum(sector, sector_size);
for (i = 1; i < 11; i++)
{
- exfat_read_raw(sector, sector_size, i * sector_size, fd);
+ exfat_pread(dev, sector, sector_size, i * sector_size);
vbr_checksum = exfat_vbr_add_checksum(sector, sector_size,
vbr_checksum);
}
- exfat_read_raw(sector, sector_size, i * sector_size, fd);
+ exfat_pread(dev, sector, sector_size, i * sector_size);
for (i = 0; i < sector_size / sizeof(vbr_checksum); i++)
if (le32_to_cpu(((const le32_t*) sector)[i]) != vbr_checksum)
{
return 0;
}
+static int commit_super_block(const struct exfat* ef)
+{
+ exfat_pwrite(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0);
+ return exfat_fsync(ef->dev);
+}
+
+static int prepare_super_block(const struct exfat* ef)
+{
+ if (le16_to_cpu(ef->sb->volume_state) & EXFAT_STATE_MOUNTED)
+ exfat_warn("volume was not unmounted cleanly");
+
+ if (ef->ro)
+ return 0;
+
+ ef->sb->volume_state = cpu_to_le16(
+ le16_to_cpu(ef->sb->volume_state) | EXFAT_STATE_MOUNTED);
+ return commit_super_block(ef);
+}
+
int exfat_mount(struct exfat* ef, const char* spec, const char* options)
{
int rc;
- tzset();
+ exfat_tzset();
memset(ef, 0, sizeof(struct exfat));
+ parse_options(ef, options);
+
+ ef->dev = exfat_open(spec, ef->ro);
+ if (ef->dev == NULL)
+ {
+ if (ef->ro || !match_option(options, "ro_fallback"))
+ return -EIO;
+ ef->dev = exfat_open(spec, 1);
+ if (ef->dev == NULL)
+ return -EIO;
+ exfat_warn("device is write-protected, mounting read-only");
+ ef->ro_fallback = ef->ro = 1;
+ }
+
ef->sb = malloc(sizeof(struct exfat_super_block));
if (ef->sb == NULL)
{
- exfat_error("memory allocation failed");
+ exfat_close(ef->dev);
+ exfat_error("failed to allocate memory for the super block");
return -ENOMEM;
}
memset(ef->sb, 0, sizeof(struct exfat_super_block));
- parse_options(ef, options);
-
- ef->fd = exfat_open(spec, ef->ro);
- if (ef->fd < 0)
- {
- free(ef->sb);
- return -EIO;
- }
-
- exfat_read_raw(ef->sb, sizeof(struct exfat_super_block), 0, ef->fd);
+ exfat_pread(ef->dev, ef->sb, sizeof(struct exfat_super_block), 0);
if (memcmp(ef->sb->oem_name, "EXFAT ", 8) != 0)
{
- close(ef->fd);
+ exfat_close(ef->dev);
free(ef->sb);
exfat_error("exFAT file system is not found");
return -EIO;
}
if (ef->sb->version.major != 1 || ef->sb->version.minor != 0)
{
- close(ef->fd);
+ exfat_close(ef->dev);
exfat_error("unsupported exFAT version: %hhu.%hhu",
ef->sb->version.major, ef->sb->version.minor);
free(ef->sb);
}
if (ef->sb->fat_count != 1)
{
- close(ef->fd);
+ exfat_close(ef->dev);
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)
{
- close(ef->fd);
+ exfat_close(ef->dev);
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_sector = malloc(SECTOR_SIZE(*ef->sb));
- if (ef->zero_sector == NULL)
+ ef->zero_cluster = malloc(CLUSTER_SIZE(*ef->sb));
+ if (ef->zero_cluster == NULL)
{
- close(ef->fd);
+ exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to allocate zero sector");
return -ENOMEM;
}
- /* use zero_sector as a temporary buffer for VBR checksum verification */
- if (verify_vbr_checksum(ef->zero_sector, SECTOR_SIZE(*ef->sb), ef->fd) != 0)
+ /* 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)
{
- free(ef->zero_sector);
- close(ef->fd);
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
- memset(ef->zero_sector, 0, SECTOR_SIZE(*ef->sb));
+ memset(ef->zero_cluster, 0, CLUSTER_SIZE(*ef->sb));
ef->root = malloc(sizeof(struct exfat_node));
if (ef->root == NULL)
{
- free(ef->zero_sector);
- close(ef->fd);
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
free(ef->sb);
exfat_error("failed to allocate root node");
return -ENOMEM;
goto error;
}
+ if (prepare_super_block(ef) != 0)
+ goto error;
+
return 0;
error:
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
free(ef->root);
- free(ef->zero_sector);
- close(ef->fd);
+ free(ef->zero_cluster);
+ exfat_close(ef->dev);
free(ef->sb);
return -EIO;
}
+static void finalize_super_block(struct exfat* ef)
+{
+ if (ef->ro)
+ return;
+
+ ef->sb->volume_state = cpu_to_le16(
+ le16_to_cpu(ef->sb->volume_state) & ~EXFAT_STATE_MOUNTED);
+
+ /* Some implementations set the percentage of allocated space to 0xff
+ on FS creation and never update it. In this case leave it as is. */
+ if (ef->sb->allocated_percent != 0xff)
+ {
+ uint32_t free, total;
+
+ free = exfat_count_free_clusters(ef);
+ total = le32_to_cpu(ef->sb->cluster_count);
+ ef->sb->allocated_percent = ((total - free) * 100 + total / 2) / total;
+ }
+
+ commit_super_block(ef);
+}
+
void exfat_unmount(struct exfat* ef)
{
exfat_put_node(ef, ef->root);
exfat_reset_cache(ef);
free(ef->root);
ef->root = NULL;
- free(ef->zero_sector);
- ef->zero_sector = 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;
- if (fsync(ef->fd) < 0)
- exfat_error("fsync failed");
- if (close(ef->fd) < 0)
- exfat_error("close failed");
- ef->fd = 0;
free(ef->sb);
ef->sb = NULL;
free(ef->upcase);
projects / sven / exfat-utils.git / blobdiff