[PATCH 1/8] block: add a cdrom_device_info pointer to struct gendisk

[Christoph Hellwig]

Add a pointer to the CDROM information structure to struct gendisk.
This will allow various removable media file systems to call directly
into the CDROM layer instead of abusing ioctls with kernel pointers.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxx
---
 drivers/block/paride/pcd.c | 2 +-
 drivers/cdrom/cdrom.c      | 5 ++++-
 drivers/cdrom/gdrom.c      | 2 +-
 drivers/ide/ide-cd.c       | 3 +--
 drivers/scsi/sr.c          | 3 +--
 include/linux/cdrom.h      | 2 +-
 include/linux/genhd.h      | 9 +++++++++
 7 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/drivers/block/paride/pcd.c b/drivers/block/paride/pcd.c
index cda5cf917e9af..5124eca90e833 100644
--- a/drivers/block/paride/pcd.c
+++ b/drivers/block/paride/pcd.c
@@ -1032,7 +1032,7 @@ static int __init pcd_init(void)
 
 	for (unit = 0, cd = pcd; unit < PCD_UNITS; unit++, cd++) {
 		if (cd->present) {
-			register_cdrom(&cd->info);
+			register_cdrom(cd->disk, &cd->info);
 			cd->disk->private_data = cd;
 			add_disk(cd->disk);
 		}
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index faca0f346fff2..a1d2112fd283f 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -586,7 +586,7 @@ static int cdrom_mrw_set_lba_space(struct cdrom_device_info *cdi, int space)
 	return 0;
 }
 
-int register_cdrom(struct cdrom_device_info *cdi)
+int register_cdrom(struct gendisk *disk, struct cdrom_device_info *cdi)
 {
 	static char banner_printed;
 	const struct cdrom_device_ops *cdo = cdi->ops;
@@ -601,6 +601,9 @@ int register_cdrom(struct cdrom_device_info *cdi)
 		cdrom_sysctl_register();
 	}
 
+	cdi->disk = disk;
+	disk->cdi = cdi;
+
 	ENSURE(cdo, drive_status, CDC_DRIVE_STATUS);
 	if (cdo->check_events == NULL && cdo->media_changed == NULL)
 		WARN_ON_ONCE(cdo->capability & (CDC_MEDIA_CHANGED | CDC_SELECT_DISC));
diff --git a/drivers/cdrom/gdrom.c b/drivers/cdrom/gdrom.c
index c51292c2a131e..09b0cd292720f 100644
--- a/drivers/cdrom/gdrom.c
+++ b/drivers/cdrom/gdrom.c
@@ -770,7 +770,7 @@ static int probe_gdrom(struct platform_device *devptr)
 		goto probe_fail_no_disk;
 	}
 	probe_gdrom_setupdisk();
-	if (register_cdrom(gd.cd_info)) {
+	if (register_cdrom(gd.disk, gd.cd_info)) {
 		err = -ENODEV;
 		goto probe_fail_cdrom_register;
 	}
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index dcf8b51b47fda..40e124eb918aa 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -1305,8 +1305,7 @@ static int ide_cdrom_register(ide_drive_t *drive, int nslots)
 	if (drive->atapi_flags & IDE_AFLAG_NO_SPEED_SELECT)
 		devinfo->mask |= CDC_SELECT_SPEED;
 
-	devinfo->disk = info->disk;
-	return register_cdrom(devinfo);
+	return register_cdrom(info->disk, devinfo);
 }
 
 static int ide_cdrom_probe_capabilities(ide_drive_t *drive)
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index d2fe3fa470f95..f9b589d60a460 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -794,9 +794,8 @@ static int sr_probe(struct device *dev)
 	set_capacity(disk, cd->capacity);
 	disk->private_data = &cd->driver;
 	disk->queue = sdev->request_queue;
-	cd->cdi.disk = disk;
 
-	if (register_cdrom(&cd->cdi))
+	if (register_cdrom(disk, &cd->cdi))
 		goto fail_put;
 
 	/*
diff --git a/include/linux/cdrom.h b/include/linux/cdrom.h
index 528271c600182..4f74ce050253d 100644
--- a/include/linux/cdrom.h
+++ b/include/linux/cdrom.h
@@ -104,7 +104,7 @@ extern unsigned int cdrom_check_events(struct cdrom_device_info *cdi,
 				       unsigned int clearing);
 extern int cdrom_media_changed(struct cdrom_device_info *);
 
-extern int register_cdrom(struct cdrom_device_info *cdi);
+extern int register_cdrom(struct gendisk *disk, struct cdrom_device_info *cdi);
 extern void unregister_cdrom(struct cdrom_device_info *cdi);
 
 typedef struct {
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index 058d895544c75..f9c226f9546af 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -217,11 +217,20 @@ struct gendisk {
 #ifdef  CONFIG_BLK_DEV_INTEGRITY
 	struct kobject integrity_kobj;
 #endif	/* CONFIG_BLK_DEV_INTEGRITY */
+#if IS_ENABLED(CONFIG_CDROM)
+	struct cdrom_device_info *cdi;
+#endif
 	int node_id;
 	struct badblocks *bb;
 	struct lockdep_map lockdep_map;
 };
 
+#if IS_REACHABLE(CONFIG_CDROM)
+#define disk_to_cdi(disk)	((disk)->cdi)
+#else
+#define disk_to_cdi(disk)	NULL
+#endif
+
 static inline struct gendisk *part_to_disk(struct hd_struct *part)
 {
 	if (likely(part)) {
-- 
2.26.2