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/* SPDX-License-Identifier: GPL-2.0 */
/*
* This file is part of the Distributed Network Block Device 3
*
* Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
*
* This file may be licensed under the terms of the
* GNU General Public License Version 2 (the ``GPL'').
*
* Software distributed under the License is distributed
* on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
* express or implied. See the GPL for the specific language
* governing rights and limitations.
*
* You should have received a copy of the GPL along with this
* program. If not, go to http://www.gnu.org/licenses/gpl.html
* or write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#ifndef BLK_H_
#define BLK_H_
#include "dnbd3_main.h"
/* define blkdev file system operation type */
#define DNBD3_REQ_OP_FS REQ_TYPE_FS
/* define blkdev special operation type */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define DNBD3_REQ_OP_SPECIAL REQ_OP_DRV_IN
#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4, 2, 0) || \
RHEL_CHECK_VERSION(RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(7, 3))
#define DNBD3_REQ_OP_SPECIAL REQ_TYPE_DRV_PRIV
#else
#define DNBD3_REQ_OP_SPECIAL REQ_TYPE_SPECIAL
#endif
/* define blkdev read operation type */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define DNBD3_DEV_READ REQ_OP_READ
#else
#define DNBD3_DEV_READ DNBD3_REQ_OP_FS
#endif
/* define blkdev write operation type */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define DNBD3_DEV_WRITE REQ_OP_WRITE
#else
#define DNBD3_DEV_WRITE DNBD3_REQ_OP_FS
#endif
/* define command and blkdev operation access macros */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define DNBD3_REQ_FLAG_BITS REQ_FLAG_BITS
/* cmd_flags and cmd_type are merged into cmd_flags now */
/* sanity check to avoid overriding of request bits */
#if DNBD3_REQ_FLAG_BITS > 24
#error "Fix CMD bitshift"
#endif
/* pack command into cmd_flags field by shifting CMD_* into unused bits of cmd_flags */
#define dnbd3_cmd_to_priv(req, cmd) \
((req)->cmd_flags = DNBD3_REQ_OP_SPECIAL | ((cmd) << DNBD3_REQ_FLAG_BITS))
#define dnbd3_priv_to_cmd(req) \
((req)->cmd_flags >> DNBD3_REQ_FLAG_BITS)
#define dnbd3_req_op(req) \
req_op(req)
#else
/* pack command into cmd_type and cmd_flags field separated */
#define dnbd3_cmd_to_priv(req, cmd) \
do { \
(req)->cmd_type = DNBD3_REQ_OP_SPECIAL; \
(req)->cmd_flags = (cmd); \
} while (0)
#define dnbd3_priv_to_cmd(req) \
((req)->cmd_flags)
#define dnbd3_req_op(req) \
((req)->cmd_type)
#endif
/* define dnbd3_req_read(req) boolean expression */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define dnbd3_req_read(req) \
(req_op(req) == DNBD3_DEV_READ)
#else
#define dnbd3_req_read(req) \
(rq_data_dir(req) == READ)
#endif
/* define dnbd3_req_write(req) boolean expression */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define dnbd3_req_write(req) \
(req_op(req) == DNBD3_DEV_WRITE)
#else
#define dnbd3_req_write(req) \
(rq_data_dir(req) == WRITE)
#endif
/* define dnbd3_req_fs(req) boolean expression */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define dnbd3_req_fs(req) \
(dnbd3_req_read(req) || dnbd3_req_write(req))
#else
#define dnbd3_req_fs(req) \
(dnbd3_req_op(req) == DNBD3_REQ_OP_FS)
#endif
/* define dnbd3_req_special(req) boolean expression */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
#define dnbd3_req_special(req) \
blk_rq_is_private(req)
#else
#define dnbd3_req_special(req) \
(dnbd3_req_op(req) == DNBD3_REQ_OP_SPECIAL)
#endif
int dnbd3_blk_add_device(dnbd3_device_t *dev, int minor);
int dnbd3_blk_del_device(dnbd3_device_t *dev);
void dnbd3_blk_fail_all_requests(dnbd3_device_t *dev);
#endif /* BLK_H_ */
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