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-rw-r--r--fs/udf/lowlevel.c62
1 files changed, 62 insertions, 0 deletions
diff --git a/fs/udf/lowlevel.c b/fs/udf/lowlevel.c
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+++ b/fs/udf/lowlevel.c
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+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * lowlevel.c
+ *
+ * PURPOSE
+ * Low Level Device Routines for the UDF filesystem
+ *
+ * COPYRIGHT
+ * (C) 1999-2001 Ben Fennema
+ *
+ * HISTORY
+ *
+ * 03/26/99 blf Created.
+ */
+
+#include "udfdecl.h"
+
+#include <linux/blkdev.h>
+#include <linux/cdrom.h>
+#include <linux/uaccess.h>
+
+#include "udf_sb.h"
+
+unsigned int udf_get_last_session(struct super_block *sb)
+{
+ struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
+ struct cdrom_multisession ms_info;
+
+ if (!cdi) {
+ udf_debug("CDROMMULTISESSION not supported.\n");
+ return 0;
+ }
+
+ ms_info.addr_format = CDROM_LBA;
+ if (cdrom_multisession(cdi, &ms_info) == 0) {
+ udf_debug("XA disk: %s, vol_desc_start=%d\n",
+ ms_info.xa_flag ? "yes" : "no", ms_info.addr.lba);
+ if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
+ return ms_info.addr.lba;
+ }
+ return 0;
+}
+
+udf_pblk_t udf_get_last_block(struct super_block *sb)
+{
+ struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
+ unsigned long lblock = 0;
+
+ /*
+ * The cdrom layer call failed or returned obviously bogus value?
+ * Try using the device size...
+ */
+ if (!cdi || cdrom_get_last_written(cdi, &lblock) || lblock == 0) {
+ if (sb_bdev_nr_blocks(sb) > ~(udf_pblk_t)0)
+ return 0;
+ lblock = sb_bdev_nr_blocks(sb);
+ }
+
+ if (lblock)
+ return lblock - 1;
+ return 0;
+}