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linux-next/include/linux/bsg-lib.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

80 lines
2.1 KiB
C

/*
* BSG helper library
*
* Copyright (C) 2008 James Smart, Emulex Corporation
* Copyright (C) 2011 Red Hat, Inc. All rights reserved.
* Copyright (C) 2011 Mike Christie
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef _BLK_BSG_
#define _BLK_BSG_
#include <linux/blkdev.h>
#include <scsi/scsi_request.h>
struct request;
struct device;
struct scatterlist;
struct request_queue;
struct bsg_buffer {
unsigned int payload_len;
int sg_cnt;
struct scatterlist *sg_list;
};
struct bsg_job {
struct device *dev;
struct kref kref;
unsigned int timeout;
/* Transport/driver specific request/reply structs */
void *request;
void *reply;
unsigned int request_len;
unsigned int reply_len;
/*
* On entry : reply_len indicates the buffer size allocated for
* the reply.
*
* Upon completion : the message handler must set reply_len
* to indicates the size of the reply to be returned to the
* caller.
*/
/* DMA payloads for the request/response */
struct bsg_buffer request_payload;
struct bsg_buffer reply_payload;
int result;
unsigned int reply_payload_rcv_len;
void *dd_data; /* Used for driver-specific storage */
};
void bsg_job_done(struct bsg_job *job, int result,
unsigned int reply_payload_rcv_len);
struct request_queue *bsg_setup_queue(struct device *dev, const char *name,
bsg_job_fn *job_fn, int dd_job_size);
void bsg_job_put(struct bsg_job *job);
int __must_check bsg_job_get(struct bsg_job *job);
#endif