kernel_optimize_test/include/linux/bsg.h
Christoph Hellwig 5de815a7ee block: remove parent device reference from struct bsg_class_device
Bsg holding a reference to the parent device may result in a crash if a
bsg file handle is closed after the parent device driver has unloaded.

Holding a reference is not really needed: the parent device must exist
between bsg_register_queue and bsg_unregister_queue.  Before the device
goes away the caller does blk_cleanup_queue so that all in-flight
requests to the device are gone and all new requests cannot pass beyond
the queue.  The queue itself is a refcounted object and it will stay
alive with a bsg file.

Based on analysis, previous patch and changelog from Anatoliy Glagolev.

Reported-by: Anatoliy Glagolev <glagolig@gmail.com>
Reviewed-by: James E.J. Bottomley <jejb@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-29 13:00:25 -06:00

40 lines
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C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_BSG_H
#define _LINUX_BSG_H
#include <uapi/linux/bsg.h>
struct request;
#ifdef CONFIG_BLK_DEV_BSG
struct bsg_ops {
int (*check_proto)(struct sg_io_v4 *hdr);
int (*fill_hdr)(struct request *rq, struct sg_io_v4 *hdr,
fmode_t mode);
int (*complete_rq)(struct request *rq, struct sg_io_v4 *hdr);
void (*free_rq)(struct request *rq);
};
struct bsg_class_device {
struct device *class_dev;
int minor;
struct request_queue *queue;
const struct bsg_ops *ops;
};
int bsg_register_queue(struct request_queue *q, struct device *parent,
const char *name, const struct bsg_ops *ops);
int bsg_scsi_register_queue(struct request_queue *q, struct device *parent);
void bsg_unregister_queue(struct request_queue *q);
#else
static inline int bsg_scsi_register_queue(struct request_queue *q,
struct device *parent)
{
return 0;
}
static inline void bsg_unregister_queue(struct request_queue *q)
{
}
#endif /* CONFIG_BLK_DEV_BSG */
#endif /* _LINUX_BSG_H */