306 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			306 lines
		
	
	
		
			7.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0-or-later */
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| /*
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|  * RDMA Network Block Driver
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|  *
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|  * Copyright (c) 2014 - 2018 ProfitBricks GmbH. All rights reserved.
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|  * Copyright (c) 2018 - 2019 1&1 IONOS Cloud GmbH. All rights reserved.
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|  * Copyright (c) 2019 - 2020 1&1 IONOS SE. All rights reserved.
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|  */
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| #ifndef RNBD_PROTO_H
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| #define RNBD_PROTO_H
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| 
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| #include <linux/types.h>
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| #include <linux/blk-mq.h>
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| #include <linux/limits.h>
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| #include <linux/inet.h>
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| #include <linux/in.h>
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| #include <linux/in6.h>
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| #include <rdma/ib.h>
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| 
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| #define RNBD_PROTO_VER_MAJOR 2
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| #define RNBD_PROTO_VER_MINOR 0
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| 
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| /* The default port number the RTRS server is listening on. */
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| #define RTRS_PORT 1234
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| 
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| /**
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|  * enum rnbd_msg_types - RNBD message types
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|  * @RNBD_MSG_SESS_INFO:	initial session info from client to server
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|  * @RNBD_MSG_SESS_INFO_RSP:	initial session info from server to client
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|  * @RNBD_MSG_OPEN:		open (map) device request
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|  * @RNBD_MSG_OPEN_RSP:		response to an @RNBD_MSG_OPEN
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|  * @RNBD_MSG_IO:		block IO request operation
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|  * @RNBD_MSG_CLOSE:		close (unmap) device request
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|  */
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| enum rnbd_msg_type {
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| 	RNBD_MSG_SESS_INFO,
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| 	RNBD_MSG_SESS_INFO_RSP,
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| 	RNBD_MSG_OPEN,
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| 	RNBD_MSG_OPEN_RSP,
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| 	RNBD_MSG_IO,
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| 	RNBD_MSG_CLOSE,
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| };
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| 
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| /**
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|  * struct rnbd_msg_hdr - header of RNBD messages
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|  * @type:	Message type, valid values see: enum rnbd_msg_types
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|  */
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| struct rnbd_msg_hdr {
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| 	__le16		type;
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| 	__le16		__padding;
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| };
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| 
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| /**
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|  * We allow to map RO many times and RW only once. We allow to map yet another
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|  * time RW, if MIGRATION is provided (second RW export can be required for
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|  * example for VM migration)
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|  */
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| enum rnbd_access_mode {
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| 	RNBD_ACCESS_RO,
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| 	RNBD_ACCESS_RW,
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| 	RNBD_ACCESS_MIGRATION,
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| };
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| 
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| /**
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|  * struct rnbd_msg_sess_info - initial session info from client to server
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|  * @hdr:		message header
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|  * @ver:		RNBD protocol version
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|  */
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| struct rnbd_msg_sess_info {
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| 	struct rnbd_msg_hdr hdr;
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| 	u8		ver;
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| 	u8		reserved[31];
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| };
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| 
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| /**
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|  * struct rnbd_msg_sess_info_rsp - initial session info from server to client
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|  * @hdr:		message header
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|  * @ver:		RNBD protocol version
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|  */
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| struct rnbd_msg_sess_info_rsp {
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| 	struct rnbd_msg_hdr hdr;
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| 	u8		ver;
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| 	u8		reserved[31];
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| };
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| 
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| /**
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|  * struct rnbd_msg_open - request to open a remote device.
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|  * @hdr:		message header
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|  * @access_mode:	the mode to open remote device, valid values see:
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|  *			enum rnbd_access_mode
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|  * @device_name:	device path on remote side
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|  */
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| struct rnbd_msg_open {
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| 	struct rnbd_msg_hdr hdr;
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| 	u8		access_mode;
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| 	u8		resv1;
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| 	s8		dev_name[NAME_MAX];
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| 	u8		reserved[3];
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| };
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| 
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| /**
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|  * struct rnbd_msg_close - request to close a remote device.
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|  * @hdr:	message header
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|  * @device_id:	device_id on server side to identify the device
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|  */
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| struct rnbd_msg_close {
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| 	struct rnbd_msg_hdr hdr;
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| 	__le32		device_id;
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| };
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| 
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| enum rnbd_cache_policy {
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| 	RNBD_FUA = 1 << 0,
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| 	RNBD_WRITEBACK = 1 << 1,
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| };
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| 
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| /**
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|  * struct rnbd_msg_open_rsp - response message to RNBD_MSG_OPEN
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|  * @hdr:		message header
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|  * @device_id:		device_id on server side to identify the device
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|  * @nsectors:		number of sectors in the usual 512b unit
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|  * @max_hw_sectors:	max hardware sectors in the usual 512b unit
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|  * @max_write_same_sectors: max sectors for WRITE SAME in the 512b unit
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|  * @max_discard_sectors: max. sectors that can be discarded at once in 512b
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|  * unit.
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|  * @discard_granularity: size of the internal discard allocation unit in bytes
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|  * @discard_alignment: offset from internal allocation assignment in bytes
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|  * @physical_block_size: physical block size device supports in bytes
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|  * @logical_block_size: logical block size device supports in bytes
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|  * @max_segments:	max segments hardware support in one transfer
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|  * @secure_discard:	supports secure discard
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|  * @obsolete_rotational: obsolete, not in used.
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|  * @cache_policy: 	support write-back caching or FUA?
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|  */
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| struct rnbd_msg_open_rsp {
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| 	struct rnbd_msg_hdr	hdr;
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| 	__le32			device_id;
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| 	__le64			nsectors;
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| 	__le32			max_hw_sectors;
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| 	__le32			max_write_same_sectors;
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| 	__le32			max_discard_sectors;
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| 	__le32			discard_granularity;
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| 	__le32			discard_alignment;
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| 	__le16			physical_block_size;
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| 	__le16			logical_block_size;
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| 	__le16			max_segments;
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| 	__le16			secure_discard;
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| 	u8			obsolete_rotational;
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| 	u8			cache_policy;
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| 	u8			reserved[10];
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| };
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| 
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| /**
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|  * struct rnbd_msg_io - message for I/O read/write
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|  * @hdr:	message header
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|  * @device_id:	device_id on server side to find the right device
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|  * @sector:	bi_sector attribute from struct bio
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|  * @rw:		valid values are defined in enum rnbd_io_flags
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|  * @bi_size:    number of bytes for I/O read/write
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|  * @prio:       priority
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|  */
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| struct rnbd_msg_io {
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| 	struct rnbd_msg_hdr hdr;
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| 	__le32		device_id;
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| 	__le64		sector;
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| 	__le32		rw;
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| 	__le32		bi_size;
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| 	__le16		prio;
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| };
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| 
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| #define RNBD_OP_BITS  8
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| #define RNBD_OP_MASK  ((1 << RNBD_OP_BITS) - 1)
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| 
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| /**
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|  * enum rnbd_io_flags - RNBD request types from rq_flag_bits
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|  * @RNBD_OP_READ:	     read sectors from the device
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|  * @RNBD_OP_WRITE:	     write sectors to the device
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|  * @RNBD_OP_FLUSH:	     flush the volatile write cache
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|  * @RNBD_OP_DISCARD:        discard sectors
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|  * @RNBD_OP_SECURE_ERASE:   securely erase sectors
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|  * @RNBD_OP_WRITE_SAME:     write the same sectors many times
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| 
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|  * @RNBD_F_SYNC:	     request is sync (sync write or read)
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|  * @RNBD_F_FUA:             forced unit access
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|  */
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| enum rnbd_io_flags {
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| 
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| 	/* Operations */
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| 
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| 	RNBD_OP_READ		= 0,
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| 	RNBD_OP_WRITE		= 1,
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| 	RNBD_OP_FLUSH		= 2,
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| 	RNBD_OP_DISCARD	= 3,
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| 	RNBD_OP_SECURE_ERASE	= 4,
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| 	RNBD_OP_WRITE_SAME	= 5,
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| 
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| 	RNBD_OP_LAST,
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| 
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| 	/* Flags */
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| 
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| 	RNBD_F_SYNC  = 1<<(RNBD_OP_BITS + 0),
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| 	RNBD_F_FUA   = 1<<(RNBD_OP_BITS + 1),
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| 
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| 	RNBD_F_ALL   = (RNBD_F_SYNC | RNBD_F_FUA)
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| 
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| };
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| 
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| static inline u32 rnbd_op(u32 flags)
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| {
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| 	return flags & RNBD_OP_MASK;
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| }
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| 
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| static inline u32 rnbd_flags(u32 flags)
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| {
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| 	return flags & ~RNBD_OP_MASK;
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| }
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| 
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| static inline bool rnbd_flags_supported(u32 flags)
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| {
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| 	u32 op;
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| 
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| 	op = rnbd_op(flags);
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| 	flags = rnbd_flags(flags);
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| 
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| 	if (op >= RNBD_OP_LAST)
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| 		return false;
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| 	if (flags & ~RNBD_F_ALL)
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| 		return false;
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| 
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| 	return true;
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| }
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| 
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| static inline blk_opf_t rnbd_to_bio_flags(u32 rnbd_opf)
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| {
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| 	blk_opf_t bio_opf;
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| 
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| 	switch (rnbd_op(rnbd_opf)) {
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| 	case RNBD_OP_READ:
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| 		bio_opf = REQ_OP_READ;
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| 		break;
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| 	case RNBD_OP_WRITE:
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| 		bio_opf = REQ_OP_WRITE;
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| 		break;
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| 	case RNBD_OP_FLUSH:
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| 		bio_opf = REQ_OP_WRITE | REQ_PREFLUSH;
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| 		break;
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| 	case RNBD_OP_DISCARD:
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| 		bio_opf = REQ_OP_DISCARD;
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| 		break;
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| 	case RNBD_OP_SECURE_ERASE:
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| 		bio_opf = REQ_OP_SECURE_ERASE;
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| 		break;
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| 	default:
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| 		WARN(1, "Unknown RNBD type: %d (flags %d)\n",
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| 		     rnbd_op(rnbd_opf), rnbd_opf);
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| 		bio_opf = 0;
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| 	}
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| 
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| 	if (rnbd_opf & RNBD_F_SYNC)
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| 		bio_opf |= REQ_SYNC;
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| 
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| 	if (rnbd_opf & RNBD_F_FUA)
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| 		bio_opf |= REQ_FUA;
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| 
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| 	return bio_opf;
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| }
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| 
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| static inline u32 rq_to_rnbd_flags(struct request *rq)
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| {
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| 	u32 rnbd_opf;
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| 
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| 	switch (req_op(rq)) {
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| 	case REQ_OP_READ:
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| 		rnbd_opf = RNBD_OP_READ;
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| 		break;
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| 	case REQ_OP_WRITE:
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| 		rnbd_opf = RNBD_OP_WRITE;
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| 		break;
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| 	case REQ_OP_DISCARD:
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| 		rnbd_opf = RNBD_OP_DISCARD;
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| 		break;
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| 	case REQ_OP_SECURE_ERASE:
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| 		rnbd_opf = RNBD_OP_SECURE_ERASE;
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| 		break;
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| 	case REQ_OP_FLUSH:
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| 		rnbd_opf = RNBD_OP_FLUSH;
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| 		break;
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| 	default:
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| 		WARN(1, "Unknown request type %d (flags %llu)\n",
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| 		     (__force u32)req_op(rq),
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| 		     (__force unsigned long long)rq->cmd_flags);
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| 		rnbd_opf = 0;
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| 	}
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| 
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| 	if (op_is_sync(rq->cmd_flags))
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| 		rnbd_opf |= RNBD_F_SYNC;
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| 
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| 	if (op_is_flush(rq->cmd_flags))
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| 		rnbd_opf |= RNBD_F_FUA;
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| 
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| 	return rnbd_opf;
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| }
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| 
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| const char *rnbd_access_mode_str(enum rnbd_access_mode mode);
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| 
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| #endif /* RNBD_PROTO_H */
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