[PATCH v3 2/3] block: add a s390-only biodasdinfo method

Stefan Haberland
2020-05-08T13:15:14Z

From: Christoph Hellwig <hch@lst.de>

The IBM partition parser needs to query the DASD driver for details that
are very s390 specific. Instead of using ioctl_by_bdev with a fake user
space pointer just add a s390-specific method to get the information
directly.

Signed-off-by: Christoph Hellwig <hch@lst.de>
[sth@linux.ibm.com: remove fop, add gendisk check, export funcion]
Signed-off-by: Stefan Haberland <sth@linux.ibm.com>
---
drivers/s390/block/dasd_int.h | 1 +
drivers/s390/block/dasd_ioctl.c | 21 +++++++++++++++++++++
include/linux/blkdev.h | 1 +
3 files changed, 23 insertions(+)

diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h
index fa552f9f1666..6eac7b11c75b 100644
--- a/drivers/s390/block/dasd_int.h
+++ b/drivers/s390/block/dasd_int.h
@@ -845,6 +845,7 @@ void dasd_destroy_partitions(struct dasd_block *);

/* externals in dasd_ioctl.c */
int dasd_ioctl(struct block_device *, fmode_t, unsigned int, unsigned long);
+int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info);

/* externals in dasd_proc.c */
int dasd_proc_init(void);
diff --git a/drivers/s390/block/dasd_ioctl.c b/drivers/s390/block/dasd_ioctl.c
index dabcb4ce92da..d29045a37b92 100644
--- a/drivers/s390/block/dasd_ioctl.c
+++ b/drivers/s390/block/dasd_ioctl.c
@@ -666,3 +666,24 @@ int dasd_ioctl(struct block_device *bdev, fmode_t mode,
dasd_put_device(base);
return rc;
}
+
+int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info)
+{
+ struct dasd_device *base;
+ int error;
+
+ /*
+ * we might get called externaly, so check if the gendisk belongs
+ * to a DASD by checking the fops pointer
+ */
+ if (disk->fops != &dasd_device_operations)
+ return -EINVAL;
+
+ base = dasd_device_from_gendisk(disk);
+ if (!base)
+ return -ENODEV;
+ error = __dasd_ioctl_information(base->block, info);
+ dasd_put_device(base);
+ return error;
+}
+EXPORT_SYMBOL(dasd_biodasdinfo);
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 32868fbedc9e..915465aa8e43 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -43,6 +43,7 @@ struct pr_ops;
struct rq_qos;
struct blk_queue_stats;
struct blk_stat_callback;
+struct dasd_information2_t;

#define BLKDEV_MIN_RQ 4
#define BLKDEV_MAX_RQ 128 /* Default maximum */
--
2.17.1