+
+off_t exfat_get_root_entry_offset(struct exfat_blk_dev *bd)
+{
+ struct pbr *bs;
+ int nbytes;
+ unsigned int cluster_size, sector_size;
+ off_t root_clu_off;
+
+ bs = (struct pbr *)malloc(EXFAT_MAX_SECTOR_SIZE);
+ if (!bs) {
+ exfat_err("failed to allocate memory\n");
+ return -ENOMEM;
+ }
+
+ nbytes = exfat_read(bd->dev_fd, bs, EXFAT_MAX_SECTOR_SIZE, 0);
+ if (nbytes != EXFAT_MAX_SECTOR_SIZE) {
+ exfat_err("boot sector read failed: %d\n", errno);
+ free(bs);
+ return -1;
+ }
+
+ if (memcmp(bs->bpb.oem_name, "EXFAT ", 8) != 0) {
+ exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\n");
+ free(bs);
+ return -1;
+ }
+
+ sector_size = 1 << bs->bsx.sect_size_bits;
+ cluster_size = (1 << bs->bsx.sect_per_clus_bits) * sector_size;
+ root_clu_off = le32_to_cpu(bs->bsx.clu_offset) * sector_size +
+ (le32_to_cpu(bs->bsx.root_cluster) - EXFAT_RESERVED_CLUSTERS) *
+ cluster_size;
+ free(bs);
+
+ return root_clu_off;
+}
+
+char *exfat_conv_volume_label(struct exfat_dentry *vol_entry)
+{
+ char *volume_label;
+ __le16 disk_label[VOLUME_LABEL_MAX_LEN];
+
+ volume_label = malloc(VOLUME_LABEL_BUFFER_SIZE);
+ if (!volume_label)
+ return NULL;
+
+ memcpy(disk_label, vol_entry->vol_label, sizeof(disk_label));
+ memset(volume_label, 0, VOLUME_LABEL_BUFFER_SIZE);
+ if (exfat_utf16_dec(disk_label, vol_entry->vol_char_cnt*2,
+ volume_label, VOLUME_LABEL_BUFFER_SIZE) < 0) {
+ exfat_err("failed to decode volume label\n");
+ free(volume_label);
+ return NULL;
+ }
+
+ return volume_label;
+}
+
+int exfat_read_volume_label(struct exfat *exfat)
+{
+ struct exfat_dentry *dentry;
+ int err;
+ __le16 disk_label[VOLUME_LABEL_MAX_LEN];
+ struct exfat_lookup_filter filter = {
+ .in.type = EXFAT_VOLUME,
+ .in.filter = NULL,
+ };
+
+ err = exfat_lookup_dentry_set(exfat, exfat->root, &filter);
+ if (err)
+ return err;
+
+ dentry = filter.out.dentry_set;
+
+ if (dentry->vol_char_cnt == 0)
+ goto out;
+
+ if (dentry->vol_char_cnt > VOLUME_LABEL_MAX_LEN) {
+ exfat_err("too long label. %d\n", dentry->vol_char_cnt);
+ err = -EINVAL;
+ goto out;
+ }
+
+ memcpy(disk_label, dentry->vol_label, sizeof(disk_label));
+ if (exfat_utf16_dec(disk_label, dentry->vol_char_cnt*2,
+ exfat->volume_label, sizeof(exfat->volume_label)) < 0) {
+ exfat_err("failed to decode volume label\n");
+ err = -EINVAL;
+ goto out;
+ }
+
+ exfat_info("label: %s\n", exfat->volume_label);
+out:
+ free(filter.out.dentry_set);
+ return err;
+}
+
+int exfat_set_volume_label(struct exfat *exfat, char *label_input)
+{
+ struct exfat_dentry *pvol;
+ struct exfat_dentry_loc loc;
+ __u16 volume_label[VOLUME_LABEL_MAX_LEN];
+ int volume_label_len, dcount, err;
+
+ struct exfat_lookup_filter filter = {
+ .in.type = EXFAT_VOLUME,
+ .in.filter = NULL,
+ };
+
+ err = exfat_lookup_dentry_set(exfat, exfat->root, &filter);
+ if (!err) {
+ pvol = filter.out.dentry_set;
+ dcount = filter.out.dentry_count;
+ memset(pvol->vol_label, 0, sizeof(pvol->vol_label));
+ } else {
+ pvol = calloc(sizeof(struct exfat_dentry), 1);
+ if (!pvol)
+ return -ENOMEM;
+
+ dcount = 1;
+ pvol->type = EXFAT_VOLUME;
+ }
+
+ volume_label_len = exfat_utf16_enc(label_input,
+ volume_label, sizeof(volume_label));
+ if (volume_label_len < 0) {
+ exfat_err("failed to encode volume label\n");
+ free(pvol);
+ return -1;
+ }
+
+ memcpy(pvol->vol_label, volume_label, volume_label_len);
+ pvol->vol_char_cnt = volume_label_len/2;
+
+ loc.parent = exfat->root;
+ loc.file_offset = filter.out.file_offset;
+ loc.dev_offset = filter.out.dev_offset;
+ err = exfat_add_dentry_set(exfat, &loc, pvol, dcount, false);
+ exfat_info("new label: %s\n", label_input);
+
+ free(pvol);
+
+ return err;
+}
+
+int exfat_read_sector(struct exfat_blk_dev *bd, void *buf, unsigned int sec_off)
+{
+ int ret;
+ unsigned long long offset =
+ (unsigned long long)sec_off * bd->sector_size;
+
+ ret = pread(bd->dev_fd, buf, bd->sector_size, offset);
+ if (ret < 0) {
+ exfat_err("read failed, sec_off : %u\n", sec_off);
+ return -1;
+ }
+ return 0;
+}
+
+int exfat_write_sector(struct exfat_blk_dev *bd, void *buf,
+ unsigned int sec_off)
+{
+ int bytes;
+ unsigned long long offset =
+ (unsigned long long)sec_off * bd->sector_size;
+
+ bytes = pwrite(bd->dev_fd, buf, bd->sector_size, offset);
+ if (bytes != (int)bd->sector_size) {
+ exfat_err("write failed, sec_off : %u, bytes : %d\n", sec_off,
+ bytes);
+ return -1;
+ }
+ return 0;
+}
+
+int exfat_write_checksum_sector(struct exfat_blk_dev *bd,
+ unsigned int checksum, bool is_backup)
+{
+ __le32 *checksum_buf;
+ int ret = 0;
+ unsigned int i;
+ unsigned int sec_idx = CHECKSUM_SEC_IDX;
+
+ checksum_buf = malloc(bd->sector_size);
+ if (!checksum_buf)
+ return -1;
+
+ if (is_backup)
+ sec_idx += BACKUP_BOOT_SEC_IDX;
+
+ for (i = 0; i < bd->sector_size / sizeof(int); i++)
+ checksum_buf[i] = cpu_to_le32(checksum);
+
+ ret = exfat_write_sector(bd, checksum_buf, sec_idx);
+ if (ret) {
+ exfat_err("checksum sector write failed\n");
+ goto free;
+ }
+
+free:
+ free(checksum_buf);
+ return ret;
+}
+
+int exfat_show_volume_serial(int fd)
+{
+ struct pbr *ppbr;
+ int ret;
+
+ ppbr = malloc(EXFAT_MAX_SECTOR_SIZE);
+ if (!ppbr) {
+ exfat_err("Cannot allocate pbr: out of memory\n");
+ return -1;
+ }
+
+ /* read main boot sector */
+ ret = exfat_read(fd, (char *)ppbr, EXFAT_MAX_SECTOR_SIZE, 0);
+ if (ret < 0) {
+ exfat_err("main boot sector read failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ if (memcmp(ppbr->bpb.oem_name, "EXFAT ", 8) != 0) {
+ exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ exfat_info("volume serial : 0x%x\n", ppbr->bsx.vol_serial);
+
+free_ppbr:
+ free(ppbr);
+ return ret;
+}
+
+static int exfat_update_boot_checksum(struct exfat_blk_dev *bd, bool is_backup)
+{
+ unsigned int checksum = 0;
+ int ret, sec_idx, backup_sec_idx = 0;
+ unsigned char *buf;
+
+ buf = malloc(bd->sector_size);
+ if (!buf) {
+ exfat_err("Cannot allocate pbr: out of memory\n");
+ return -1;
+ }
+
+ if (is_backup)
+ backup_sec_idx = BACKUP_BOOT_SEC_IDX;
+
+ for (sec_idx = BOOT_SEC_IDX; sec_idx < CHECKSUM_SEC_IDX; sec_idx++) {
+ bool is_boot_sec = false;
+
+ ret = exfat_read_sector(bd, buf, sec_idx + backup_sec_idx);
+ if (ret < 0) {
+ exfat_err("sector(%d) read failed\n", sec_idx);
+ ret = -1;
+ goto free_buf;
+ }
+
+ if (sec_idx == BOOT_SEC_IDX)
+ is_boot_sec = true;
+
+ boot_calc_checksum(buf, bd->sector_size, is_boot_sec,
+ &checksum);
+ }
+
+ ret = exfat_write_checksum_sector(bd, checksum, is_backup);
+
+free_buf:
+ free(buf);
+
+ return ret;
+}
+
+int exfat_set_volume_serial(struct exfat_blk_dev *bd,
+ struct exfat_user_input *ui)
+{
+ int ret;
+ struct pbr *ppbr;
+
+ ppbr = malloc(EXFAT_MAX_SECTOR_SIZE);
+ if (!ppbr) {
+ exfat_err("Cannot allocate pbr: out of memory\n");
+ return -1;
+ }
+
+ /* read main boot sector */
+ ret = exfat_read(bd->dev_fd, (char *)ppbr, EXFAT_MAX_SECTOR_SIZE,
+ BOOT_SEC_IDX);
+ if (ret < 0) {
+ exfat_err("main boot sector read failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ if (memcmp(ppbr->bpb.oem_name, "EXFAT ", 8) != 0) {
+ exfat_err("Bad fs_name in boot sector, which does not describe a valid exfat filesystem\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ bd->sector_size = 1 << ppbr->bsx.sect_size_bits;
+ ppbr->bsx.vol_serial = ui->volume_serial;
+
+ /* update main boot sector */
+ ret = exfat_write_sector(bd, (char *)ppbr, BOOT_SEC_IDX);
+ if (ret < 0) {
+ exfat_err("main boot sector write failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ /* update backup boot sector */
+ ret = exfat_write_sector(bd, (char *)ppbr, BACKUP_BOOT_SEC_IDX);
+ if (ret < 0) {
+ exfat_err("backup boot sector write failed\n");
+ ret = -1;
+ goto free_ppbr;
+ }
+
+ ret = exfat_update_boot_checksum(bd, 0);
+ if (ret < 0) {
+ exfat_err("main checksum update failed\n");
+ goto free_ppbr;
+ }
+
+ ret = exfat_update_boot_checksum(bd, 1);
+ if (ret < 0)
+ exfat_err("backup checksum update failed\n");
+free_ppbr:
+ free(ppbr);
+
+ exfat_info("New volume serial : 0x%x\n", ui->volume_serial);
+
+ return ret;
+}
+
+unsigned int exfat_clus_to_blk_dev_off(struct exfat_blk_dev *bd,
+ unsigned int clu_off_sectnr, unsigned int clu)
+{
+ return clu_off_sectnr * bd->sector_size +
+ (clu - EXFAT_RESERVED_CLUSTERS) * bd->cluster_size;
+}
+
+int exfat_get_next_clus(struct exfat *exfat, clus_t clus, clus_t *next)
+{
+ off_t offset;
+
+ *next = EXFAT_EOF_CLUSTER;
+
+ if (!exfat_heap_clus(exfat, clus))
+ return -EINVAL;
+
+ offset = (off_t)le32_to_cpu(exfat->bs->bsx.fat_offset) <<
+ exfat->bs->bsx.sect_size_bits;
+ offset += sizeof(clus_t) * clus;
+
+ if (exfat_read(exfat->blk_dev->dev_fd, next, sizeof(*next), offset)
+ != sizeof(*next))
+ return -EIO;
+ *next = le32_to_cpu(*next);
+ return 0;
+}
+
+int exfat_get_inode_next_clus(struct exfat *exfat, struct exfat_inode *node,
+ clus_t clus, clus_t *next)
+{
+ *next = EXFAT_EOF_CLUSTER;
+
+ if (node->is_contiguous) {
+ if (!exfat_heap_clus(exfat, clus))
+ return -EINVAL;
+ *next = clus + 1;
+ return 0;
+ }
+
+ return exfat_get_next_clus(exfat, clus, next);
+}
+
+int exfat_set_fat(struct exfat *exfat, clus_t clus, clus_t next_clus)
+{
+ off_t offset;
+
+ offset = le32_to_cpu(exfat->bs->bsx.fat_offset) <<
+ exfat->bs->bsx.sect_size_bits;
+ offset += sizeof(clus_t) * clus;
+
+ if (exfat_write(exfat->blk_dev->dev_fd, &next_clus, sizeof(next_clus),
+ offset) != sizeof(next_clus))
+ return -EIO;
+ return 0;
+}
+
+off_t exfat_s2o(struct exfat *exfat, off_t sect)
+{
+ return sect << exfat->bs->bsx.sect_size_bits;
+}
+
+off_t exfat_c2o(struct exfat *exfat, unsigned int clus)
+{
+ if (clus < EXFAT_FIRST_CLUSTER)
+ return ~0L;
+
+ return exfat_s2o(exfat, le32_to_cpu(exfat->bs->bsx.clu_offset) +
+ ((off_t)(clus - EXFAT_FIRST_CLUSTER) <<
+ exfat->bs->bsx.sect_per_clus_bits));
+}
+
+int exfat_o2c(struct exfat *exfat, off_t device_offset,
+ unsigned int *clu, unsigned int *offset)
+{
+ off_t heap_offset;
+
+ heap_offset = exfat_s2o(exfat, le32_to_cpu(exfat->bs->bsx.clu_offset));
+ if (device_offset < heap_offset)
+ return -ERANGE;
+
+ *clu = (unsigned int)((device_offset - heap_offset) /
+ exfat->clus_size) + EXFAT_FIRST_CLUSTER;
+ if (!exfat_heap_clus(exfat, *clu))
+ return -ERANGE;
+ *offset = (device_offset - heap_offset) % exfat->clus_size;
+ return 0;
+}
+
+bool exfat_heap_clus(struct exfat *exfat, clus_t clus)
+{
+ return clus >= EXFAT_FIRST_CLUSTER &&
+ (clus - EXFAT_FIRST_CLUSTER) < exfat->clus_count;
+}
+
+int exfat_root_clus_count(struct exfat *exfat)
+{
+ struct exfat_inode *node = exfat->root;
+ clus_t clus, next;
+ int clus_count = 0;
+
+ if (!exfat_heap_clus(exfat, node->first_clus))
+ return -EIO;
+
+ clus = node->first_clus;
+ do {
+ if (exfat_bitmap_get(exfat->alloc_bitmap, clus))
+ return -EINVAL;
+
+ exfat_bitmap_set(exfat->alloc_bitmap, clus);
+
+ if (exfat_get_inode_next_clus(exfat, node, clus, &next)) {
+ exfat_err("ERROR: failed to read the fat entry of root");
+ return -EIO;
+ }
+
+ if (next != EXFAT_EOF_CLUSTER && !exfat_heap_clus(exfat, next))
+ return -EINVAL;
+
+ clus = next;
+ clus_count++;
+ } while (clus != EXFAT_EOF_CLUSTER);
+
+ node->size = clus_count * exfat->clus_size;
+ return 0;
+}
+
+int read_boot_sect(struct exfat_blk_dev *bdev, struct pbr **bs)
+{
+ struct pbr *pbr;
+ int err = 0;
+ unsigned int sect_size, clu_size;
+
+ pbr = malloc(sizeof(struct pbr));
+
+ if (exfat_read(bdev->dev_fd, pbr, sizeof(*pbr), 0) !=
+ (ssize_t)sizeof(*pbr)) {
+ exfat_err("failed to read a boot sector\n");
+ err = -EIO;
+ goto err;
+ }
+
+ err = -EINVAL;
+ if (memcmp(pbr->bpb.oem_name, "EXFAT ", 8) != 0) {
+ exfat_err("failed to find exfat file system\n");
+ goto err;
+ }
+
+ sect_size = 1 << pbr->bsx.sect_size_bits;
+ clu_size = 1 << (pbr->bsx.sect_size_bits +
+ pbr->bsx.sect_per_clus_bits);
+
+ if (sect_size < 512 || sect_size > 4 * KB) {
+ exfat_err("too small or big sector size: %d\n",
+ sect_size);
+ goto err;
+ }
+
+ if (clu_size < sect_size || clu_size > 32 * MB) {
+ exfat_err("too small or big cluster size: %d\n",
+ clu_size);
+ goto err;
+ }
+
+ *bs = pbr;
+ return 0;
+err:
+ free(pbr);
+ return err;
+}