Commit 6e09a48e authored by Ben Walker's avatar Ben Walker Committed by Daniel Verkamp
Browse files

bdev: Separate the module header from the public header 



Bdev modules need a separate interface than public
consumers of the blockdevs.

Change-Id: I581ee493570c114f7e96b31a425bc077a791c71e
Signed-off-by: default avatarBen Walker <benjamin.walker@intel.com>
parent ecb6e49d

include/spdk/bdev.h

+3 −129
Original line number Diff line number Diff line
@@ -56,40 +56,6 @@ 


struct spdk_bdev_io;



/** \page block_backend_modules Block Device Backend Modules



To implement a backend block device driver, a number of functions

dictated by struct spdk_bdev_fn_table must be provided.



The module should register itself using SPDK_BDEV_MODULE_REGISTER or

SPDK_VBDEV_MODULE_REGISTER to define the parameters for the module.



Use SPDK_BDEV_MODULE_REGISTER for all block backends that are real disks.

Any virtual backends such as RAID, partitioning, etc. should use

SPDK_VBDEV_MODULE_REGISTER.



<hr>



In the module initialization code, the config file sections can be parsed to

acquire custom configuration parameters. For example, if the config file has

a section such as below:

<blockquote><pre>

[MyBE]

  MyParam 1234

</pre></blockquote>



The value can be extracted as the example below:

<blockquote><pre>

struct spdk_conf_section *sp = spdk_conf_find_section(NULL, "MyBe");

int my_param = spdk_conf_section_get_intval(sp, "MyParam");

</pre></blockquote>



The backend initialization routine also need to create "disks". A virtual

representation of each LUN must be constructed. Mainly a struct spdk_bdev

must be passed to the bdev database via spdk_bdev_register().



*/



/**

 * \brief SPDK block device.

 *
@@ -320,53 +286,8 @@ struct spdk_bdev_io { 
	/* No members may be added after driver_ctx! */

};



/** Block device module */

struct spdk_bdev_module_if {

	/**

	 * Initialization function for the module.  Called by the spdk

	 * application during startup.

	 *

	 * Modules are required to define this function.

	 */

	int (*module_init)(void);



	/**

	 * Finish function for the module.  Called by the spdk application

	 * before the spdk application exits to perform any necessary cleanup.

	 *

	 * Modules are not required to define this function.

	 */

	void (*module_fini)(void);



	/**

	 * Function called to return a text string representing the

	 * module's configuration options for inclusion in a configuration file.

	 */

	void (*config_text)(FILE *fp);



	/** Name for the modules being defined. */

	const char *module_name;



	/**

	 * Returns the allocation size required for the backend for uses such as local

	 * command structs, local SGL, iovecs, or other user context.

	 */

	int (*get_ctx_size)(void);



	TAILQ_ENTRY(spdk_bdev_module_if) tailq;

};



/* The blockdev API has two distinct parts. The first portion of the API

 * is to be used by the layer above the blockdev in order to communicate

 * with it. The second portion of the API is to be used by the blockdev

 * modules themselves to perform operations like completing I/O.

 */



/* The following functions are intended to be called from the upper layer

 * that is using the blockdev layer.

 */



struct spdk_bdev *spdk_bdev_get_by_name(const char *bdev_name);

void spdk_bdev_unregister(struct spdk_bdev *bdev);



struct spdk_bdev *spdk_bdev_first(void);

struct spdk_bdev *spdk_bdev_next(struct spdk_bdev *prev);
@@ -392,55 +313,8 @@ struct spdk_bdev_io *spdk_bdev_flush(struct spdk_bdev *bdev, 
				     spdk_bdev_io_completion_cb cb, void *cb_arg);

int spdk_bdev_io_submit(struct spdk_bdev_io *bdev_io);

void spdk_bdev_do_work(void *ctx);

int spdk_bdev_reset(struct spdk_bdev *bdev, enum spdk_bdev_reset_type reset_type,

		    spdk_bdev_io_completion_cb cb, void *cb_arg);



/* The remaining functions are intended to be called from within

 * blockdev modules.

 */

void spdk_bdev_register(struct spdk_bdev *bdev);

void spdk_bdev_unregister(struct spdk_bdev *bdev);

int spdk_bdev_free_io(struct spdk_bdev_io *bdev_io);

void spdk_bdev_io_get_rbuf(struct spdk_bdev_io *bdev_io, spdk_bdev_io_get_rbuf_cb cb);

struct spdk_bdev_io *spdk_bdev_get_io(void);

struct spdk_bdev_io *spdk_bdev_get_child_io(struct spdk_bdev_io *parent,

		struct spdk_bdev *bdev,

		spdk_bdev_io_completion_cb cb,

		void *cb_arg);

void spdk_bdev_io_complete(struct spdk_bdev_io *bdev_io,

			   enum spdk_bdev_io_status status);

void spdk_bdev_module_list_add(struct spdk_bdev_module_if *bdev_module);

void spdk_vbdev_module_list_add(struct spdk_bdev_module_if *vbdev_module);



static inline struct spdk_bdev_io *

spdk_bdev_io_from_ctx(void *ctx)

{

	return (struct spdk_bdev_io *)

	       ((uintptr_t)ctx - offsetof(struct spdk_bdev_io, driver_ctx));

}



#define SPDK_BDEV_MODULE_REGISTER(init_fn, fini_fn, config_fn, ctx_size_fn)			\

	static struct spdk_bdev_module_if init_fn ## _if = {					\

	.module_init 	= init_fn,								\

	.module_fini	= fini_fn,								\

	.config_text	= config_fn,								\

	.get_ctx_size	= ctx_size_fn,                                				\

	};  											\

	__attribute__((constructor)) static void init_fn ## _init(void)  			\

	{                                                           				\

	    spdk_bdev_module_list_add(&init_fn ## _if);                  			\

	}



#define SPDK_VBDEV_MODULE_REGISTER(init_fn, fini_fn, config_fn, ctx_size_fn)			\

	static struct spdk_bdev_module_if init_fn ## _if = {					\

	.module_init 	= init_fn,								\

	.module_fini	= fini_fn,								\

	.config_text	= config_fn,								\

	.get_ctx_size	= ctx_size_fn,                                				\

	};  											\

	__attribute__((constructor)) static void init_fn ## _init(void)  			\

	{                                                           				\

	    spdk_vbdev_module_list_add(&init_fn ## _if);                  			\

	}

int spdk_bdev_reset(struct spdk_bdev *bdev, enum spdk_bdev_reset_type,

		    spdk_bdev_io_completion_cb cb, void *cb_arg);



#endif /* SPDK_BDEV_H_ */

lib/bdev/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -34,7 +34,7 @@ 
SPDK_ROOT_DIR := $(abspath $(CURDIR)/../..)

include $(SPDK_ROOT_DIR)/mk/spdk.common.mk



CFLAGS += $(DPDK_INC)

CFLAGS += $(DPDK_INC) -I.

C_SRCS = bdev.c

LIBNAME = bdev

lib/bdev/aio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
SPDK_ROOT_DIR := $(abspath $(CURDIR)/../../..)

include $(SPDK_ROOT_DIR)/mk/spdk.common.mk



CFLAGS += -I$(SPDK_ROOT_DIR)/lib/bdev/

C_SRCS = blockdev_aio.c blockdev_aio_rpc.c

LIBNAME = bdev_aio

lib/bdev/aio/blockdev_aio.h

+2 −0
Original line number Diff line number Diff line
@@ -40,6 +40,8 @@ 
#include "spdk/queue.h"

#include "spdk/bdev.h"



#include "bdev_module.h"



struct blockdev_aio_task {

	struct iocb			iocb;

	uint64_t			len;

lib/bdev/bdev.c

+2 −0
Original line number Diff line number Diff line
@@ -49,6 +49,8 @@ 
#include "spdk/log.h"

#include "spdk/queue.h"



#include "bdev_module.h"



#define SPDK_BDEV_IO_POOL_SIZE	(64 * 1024)

#define RBUF_SMALL_POOL_SIZE	8192

#define RBUF_LARGE_POOL_SIZE	1024