include/scsi/osd_initiator.h

/*
 * osd_initiator.h - OSD initiator API definition
 *
 * Copyright (C) 2008 Panasas Inc.  All rights reserved.
 *
 * Authors:
 *   Boaz Harrosh <bharrosh@panasas.com>
 *   Benny Halevy <bhalevy@panasas.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2
 *
 */
#ifndef __OSD_INITIATOR_H__
#define __OSD_INITIATOR_H__

#include "osd_protocol.h"
#include "osd_types.h"

#include <linux/blkdev.h>

/* Note: "NI" in comments below means "Not Implemented yet" */

/*
 * Object-based Storage Device.
 * This object represents an OSD device.
 * It is not a full linux device in any way. It is only
 * a place to hang resources associated with a Linux
 * request Q and some default properties.
 */
struct osd_dev {
	struct scsi_device *scsi_device;
	unsigned def_timeout;
};

void osd_dev_init(struct osd_dev *od, struct scsi_device *scsi_device);
void osd_dev_fini(struct osd_dev *od);

struct osd_request;
typedef void (osd_req_done_fn)(struct osd_request *or, void *private);

struct osd_request {
	struct osd_cdb cdb;
	struct osd_data_out_integrity_info out_data_integ;
	struct osd_data_in_integrity_info in_data_integ;

	struct osd_dev *osd_dev;
	struct request *request;

	struct _osd_req_data_segment {
		void *buff;
		unsigned alloc_size; /* 0 here means: don't call kfree */
		unsigned total_bytes;
	} set_attr, enc_get_attr, get_attr;

	struct _osd_io_info {
		struct bio *bio;
		u64 total_bytes;
		struct request *req;
		struct _osd_req_data_segment *last_seg;
		u8 *pad_buff;
	} out, in;

	gfp_t alloc_flags;
	unsigned timeout;
	unsigned retries;
	u8 sense[OSD_MAX_SENSE_LEN];
	enum osd_attributes_mode attributes_mode;

	osd_req_done_fn *async_done;
	void *async_private;
	int async_error;
};

/*
 * How to use the osd library:
 *
 * osd_start_request
 *	Allocates a request.
 *
 * osd_req_*
 *	Call one of, to encode the desired operation.
 *
 * osd_add_{get,set}_attr
 *	Optionally add attributes to the CDB, list or page mode.
 *
 * osd_finalize_request
 *	Computes final data out/in offsets and signs the request,
 *	making it ready for execution.
 *
 * osd_execute_request
 *	May be called to execute it through the block layer. Other wise submit
 *	the associated block request in some other way.
 *
 * After execution:
 * osd_req_decode_sense
 *	Decodes sense information to verify execution results.
 *
 * osd_req_decode_get_attr
 *	Retrieve osd_add_get_attr_list() values if used.
 *
 * osd_end_request
 *	Must be called to deallocate the request.
 */

/**
 * osd_start_request - Allocate and initialize an osd_request
 *
 * @osd_dev:    OSD device that holds the scsi-device and default values
 *              that the request is associated with.
 * @gfp:        The allocation flags to use for request allocation, and all
 *              subsequent allocations. This will be stored at
 *              osd_request->alloc_flags, can be changed by user later
 *
 * Allocate osd_request and initialize all members to the
 * default/initial state.
 */
struct osd_request *osd_start_request(struct osd_dev *od, gfp_t gfp);

enum osd_req_options {
	OSD_REQ_FUA = 0x08,	/* Force Unit Access */
	OSD_REQ_DPO = 0x10,	/* Disable Page Out */

	OSD_REQ_BYPASS_TIMESTAMPS = 0x80,
};

/**
 * osd_finalize_request - Sign request and prepare request for execution
 *
 * @or:		osd_request to prepare
 * @options:	combination of osd_req_options bit flags or 0.
 * @cap:	A Pointer to an OSD_CAP_LEN bytes buffer that is received from
 *              The security manager as capabilities for this cdb.
 * @cap_key:	The cryptographic key used to sign the cdb/data. Can be null
 *              if NOSEC is used.
 *
 * The actual request and bios are only allocated here, so are the get_attr
 * buffers that will receive the returned attributes. Copy's @cap to cdb.
 * Sign the cdb/data with @cap_key.
 */
int osd_finalize_request(struct osd_request *or,
	u8 options, const void *cap, const u8 *cap_key);

/**
 * osd_execute_request - Execute the request synchronously through block-layer
 *
 * @or:		osd_request to Executed
 *
 * Calls blk_execute_rq to q the command and waits for completion.
 */
int osd_execute_request(struct osd_request *or);

/**
 * osd_execute_request_async - Execute the request without waitting.
 *
 * @or:                      - osd_request to Executed
 * @done: (Optional)         - Called at end of execution
 * @private:                 - Will be passed to @done function
 *
 * Calls blk_execute_rq_nowait to queue the command. When execution is done
 * optionally calls @done with @private as parameter. @or->async_error will
 * have the return code
 */
int osd_execute_request_async(struct osd_request *or,
	osd_req_done_fn *done, void *private);

/**
 * osd_end_request - return osd_request to free store
 *
 * @or:		osd_request to free
 *
 * Deallocate all osd_request resources (struct req's, BIOs, buffers, etc.)
 */
void osd_end_request(struct osd_request *or);

/*
 * CDB Encoding
 *
 * Note: call only one of the following methods.
 */

/*
 * Device commands
 */
void osd_req_set_master_seed_xchg(struct osd_request *or, ...);/* NI */
void osd_req_set_master_key(struct osd_request *or, ...);/* NI */

void osd_req_format(struct osd_request *or, u64 tot_capacity);

/* list all partitions
 * @list header must be initialized to zero on first run.
 *
 * Call osd_is_obj_list_done() to find if we got the complete list.
 */
int osd_req_list_dev_partitions(struct osd_request *or,
	osd_id initial_id, struct osd_obj_id_list *list, unsigned nelem);

void osd_req_flush_obsd(struct osd_request *or,
	enum osd_options_flush_scope_values);

void osd_req_perform_scsi_command(struct osd_request *or,
	const u8 *cdb, ...);/* NI */
void osd_req_task_management(struct osd_request *or, ...);/* NI */

/*
 * Partition commands
 */
void osd_req_create_partition(struct osd_request *or, osd_id partition);
void osd_req_remove_partition(struct osd_request *or, osd_id partition);

void osd_req_set_partition_key(struct osd_request *or,
	osd_id partition, u8 new_key_id[OSD_CRYPTO_KEYID_SIZE],
	u8 seed[OSD_CRYPTO_SEED_SIZE]);/* NI */

/* list all collections in the partition
 * @list header must be init to zero on first run.
 *
 * Call osd_is_obj_list_done() to find if we got the complete list.
 */
int osd_req_list_partition_collections(struct osd_request *or,
	osd_id partition, osd_id initial_id, struct osd_obj_id_list *list,
	unsigned nelem);

/* list all objects in the partition
 * @list header must be init to zero on first run.
 *
 * Call osd_is_obj_list_done() to find if we got the complete list.
 */
int osd_req_list_partition_objects(struct osd_request *or,
	osd_id partition, osd_id initial_id, struct osd_obj_id_list *list,
	unsigned nelem);

void osd_req_flush_partition(struct osd_request *or,
	osd_id partition, enum osd_options_flush_scope_values);

/*
 * Collection commands
 */
void osd_req_create_collection(struct osd_request *or,
	const struct osd_obj_id *);/* NI */
void osd_req_remove_collection(struct osd_request *or,
	const struct osd_obj_id *);/* NI */

/* list all objects in the collection */
int osd_req_list_collection_objects(struct osd_request *or,
	const struct osd_obj_id *, osd_id initial_id,
	struct osd_obj_id_list *list, unsigned nelem);

/* V2 only filtered list of objects in the collection */
void osd_req_query(struct osd_request *or, ...);/* NI */

void osd_req_flush_collection(struct osd_request *or,
	const struct osd_obj_id *, enum osd_options_flush_scope_values);

void osd_req_get_member_attrs(struct osd_request *or, ...);/* V2-only NI */
void osd_req_set_member_attrs(struct osd_request *or, ...);/* V2-only NI */

/*
 * Object commands
 */
void osd_req_create_object(struct osd_request *or, struct osd_obj_id *);
void osd_req_remove_object(struct osd_request *or, struct osd_obj_id *);

void osd_req_write(struct osd_request *or,
	const struct osd_obj_id *, struct bio *data_out, u64 offset);
void osd_req_append(struct osd_request *or,
	const struct osd_obj_id *, struct bio *data_out);/* NI */
void osd_req_create_write(struct osd_request *or,
	const struct osd_obj_id *, struct bio *data_out, u64 offset);/* NI */
void osd_req_clear(struct osd_request *or,
	const struct osd_obj_id *, u64 offset, u64 len);/* NI */
void osd_req_punch(struct osd_request *or,
	const struct osd_obj_id *, u64 offset, u64 len);/* V2-only NI */

void osd_req_flush_object(struct osd_request *or,
	const struct osd_obj_id *, enum osd_options_flush_scope_values,
	/*V2*/ u64 offset, /*V2*/ u64 len);

void osd_req_read(struct osd_request *or,
	const struct osd_obj_id *, struct bio *data_in, u64 offset);

/*
 * Root/Partition/Collection/Object Attributes commands
 */

/* get before set */
void osd_req_get_attributes(struct osd_request *or, const struct osd_obj_id *);

/* set before get */
void osd_req_set_attributes(struct osd_request *or, const struct osd_obj_id *);

/*
 * Attributes appended to most commands
 */

/* Attributes List mode (or V2 CDB) */
  /*
   * TODO: In ver2 if at finalize time only one attr was set and no gets,
   * then the Attributes CDB mode is used automatically to save IO.
   */

/* set a list of attributes. */
int osd_req_add_set_attr_list(struct osd_request *or,
	const struct osd_attr *, unsigned nelem);

/* get a list of attributes */
int osd_req_add_get_attr_list(struct osd_request *or,
	const struct osd_attr *, unsigned nelem);

/*
 * Attributes list decoding
 * Must be called after osd_request.request was executed
 * It is called in a loop to decode the returned get_attr
 * (see osd_add_get_attr)
 */
int osd_req_decode_get_attr_list(struct osd_request *or,
	struct osd_attr *, int *nelem, void **iterator);

/* Attributes Page mode */

/*
 * Read an attribute page and optionally set one attribute
 *
 * Retrieves the attribute page directly to a user buffer.
 * @attr_page_data shall stay valid until end of execution.
 * See osd_attributes.h for common page structures
 */
int osd_req_add_get_attr_page(struct osd_request *or,
	u32 page_id, void *attr_page_data, unsigned max_page_len,
	const struct osd_attr *set_one);

#endif /* __OSD_LIB_H__ */