/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _ZIO_H
#define	_ZIO_H

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <sys/zfs_context.h>
#include <sys/spa.h>
#include <sys/txg.h>
#include <sys/avl.h>
#include <sys/dkio.h>
#include <sys/fs/zfs.h>

#ifdef	__cplusplus
extern "C" {
#endif

#define	ZBT_MAGIC	0x210da7ab10c7a11ULL	/* zio data bloc tail */

typedef struct zio_block_tail {
	uint64_t	zbt_magic;	/* for validation, endianness	*/
	zio_cksum_t	zbt_cksum;	/* 256-bit checksum		*/
} zio_block_tail_t;

/*
 * Gang block headers are self-checksumming and contain an array
 * of block pointers.
 */
#define	SPA_GANGBLOCKSIZE	SPA_MINBLOCKSIZE
#define	SPA_GBH_NBLKPTRS	((SPA_GANGBLOCKSIZE - \
	sizeof (zio_block_tail_t)) / sizeof (blkptr_t))
#define	SPA_GBH_FILLER		((SPA_GANGBLOCKSIZE - \
	sizeof (zio_block_tail_t) - \
	(SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
	sizeof (uint64_t))

#define	ZIO_GET_DVA(zio)	(&(zio)->io_bp->blk_dva[(zio)->io_dva_index])
#define	ZIO_GET_IOSIZE(zio)	\
	(DVA_GET_GANG(ZIO_GET_DVA(zio)) ? \
	SPA_GANGBLOCKSIZE : BP_GET_PSIZE((zio)->io_bp))

typedef struct zio_gbh {
	blkptr_t		zg_blkptr[SPA_GBH_NBLKPTRS];
	uint64_t		zg_filler[SPA_GBH_FILLER];
	zio_block_tail_t	zg_tail;
} zio_gbh_phys_t;

enum zio_checksum {
	ZIO_CHECKSUM_INHERIT = 0,
	ZIO_CHECKSUM_ON,
	ZIO_CHECKSUM_OFF,
	ZIO_CHECKSUM_LABEL,
	ZIO_CHECKSUM_GANG_HEADER,
	ZIO_CHECKSUM_ZILOG,
	ZIO_CHECKSUM_FLETCHER_2,
	ZIO_CHECKSUM_FLETCHER_4,
	ZIO_CHECKSUM_SHA256,
	ZIO_CHECKSUM_FUNCTIONS
};

#define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_2
#define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON

enum zio_compress {
	ZIO_COMPRESS_INHERIT = 0,
	ZIO_COMPRESS_ON,
	ZIO_COMPRESS_OFF,
	ZIO_COMPRESS_LZJB,
	ZIO_COMPRESS_FUNCTIONS
};

#define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
#define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF

#define	ZIO_PRIORITY_NOW		(zio_priority_table[0])
#define	ZIO_PRIORITY_SYNC_READ		(zio_priority_table[1])
#define	ZIO_PRIORITY_SYNC_WRITE		(zio_priority_table[2])
#define	ZIO_PRIORITY_ASYNC_READ		(zio_priority_table[3])
#define	ZIO_PRIORITY_ASYNC_WRITE	(zio_priority_table[4])
#define	ZIO_PRIORITY_FREE		(zio_priority_table[5])
#define	ZIO_PRIORITY_CACHE_FILL		(zio_priority_table[6])
#define	ZIO_PRIORITY_LOG_WRITE		(zio_priority_table[7])
#define	ZIO_PRIORITY_RESILVER		(zio_priority_table[8])
#define	ZIO_PRIORITY_SCRUB		(zio_priority_table[9])
#define	ZIO_PRIORITY_TABLE_SIZE		10

#define	ZIO_FLAG_MUSTSUCCEED		0x0000
#define	ZIO_FLAG_CANFAIL		0x0001
#define	ZIO_FLAG_FAILFAST		0x0002
#define	ZIO_FLAG_CONFIG_HELD		0x0004

#define	ZIO_FLAG_DONT_CACHE		0x0010
#define	ZIO_FLAG_DONT_QUEUE		0x0020
#define	ZIO_FLAG_DONT_PROPAGATE		0x0040
#define	ZIO_FLAG_DONT_RETRY		0x0080

#define	ZIO_FLAG_PHYSICAL		0x0100
#define	ZIO_FLAG_IO_BYPASS		0x0200
#define	ZIO_FLAG_IO_REPAIR		0x0400
#define	ZIO_FLAG_SPECULATIVE		0x0800

#define	ZIO_FLAG_RESILVER		0x1000
#define	ZIO_FLAG_SCRUB			0x2000

#define	ZIO_FLAG_GANG_INHERIT		\
	(ZIO_FLAG_CANFAIL |		\
	ZIO_FLAG_FAILFAST |		\
	ZIO_FLAG_CONFIG_HELD |		\
	ZIO_FLAG_DONT_RETRY |		\
	ZIO_FLAG_IO_REPAIR |		\
	ZIO_FLAG_SPECULATIVE |		\
	ZIO_FLAG_RESILVER |		\
	ZIO_FLAG_SCRUB)

#define	ZIO_FLAG_VDEV_INHERIT		\
	(ZIO_FLAG_GANG_INHERIT |	\
	ZIO_FLAG_DONT_CACHE |		\
	ZIO_FLAG_PHYSICAL)

/*
 * We'll take the unused errno 'EBADE' (from the Convergent graveyard)
 * to indicate checksum errors.
 */
#define	ECKSUM	EBADE

typedef struct zio zio_t;
typedef void zio_done_func_t(zio_t *zio);
typedef struct zio_transform zio_transform_t;

extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
extern char *zio_type_name[ZIO_TYPES];

struct zio {
	/* Core information about this I/O */
	zio_t		*io_parent;
	zio_t		*io_root;
	spa_t		*io_spa;
	int		io_checksum;
	int		io_compress;
	int		io_dva_index;
	uint64_t	io_txg;
	blkptr_t	*io_bp;
	blkptr_t	io_bp_copy;
	zio_t		*io_child;
	zio_t		*io_sibling_prev;
	zio_t		*io_sibling_next;
	zio_transform_t *io_transform_stack;

	/* Callback info */
	zio_done_func_t	*io_done;
	void		*io_private;
	blkptr_t	io_bp_orig;

	/* Data represented by this I/O */
	void		*io_data;
	uint64_t	io_size;

	/* Stuff for the vdev stack */
	vdev_t		*io_vd;
	void		*io_vsd;
	uint64_t	io_offset;
	uint64_t	io_deadline;
	uint64_t	io_timestamp;
	avl_node_t	io_offset_node;
	avl_node_t	io_deadline_node;
	avl_tree_t	*io_vdev_tree;
	zio_t		*io_delegate_list;
	zio_t		*io_delegate_next;
	zio_t		*io_retry_next;
	list_node_t	io_pending;

	/* Internal pipeline state */
	int		io_flags;
	uint8_t		io_type;
	uint8_t		io_stage;
	uint8_t		io_stalled;
	uint8_t		io_priority;
	struct dk_callback io_dk_callback;
	int		io_cmd;
	int		io_retries;
	int		io_error;
	uint32_t	io_numerrors;
	uint32_t	io_pipeline;
	uint32_t	io_async_stages;
	uint64_t	io_children_notready;
	uint64_t	io_children_notdone;
	void		*io_waiter;
	kmutex_t	io_lock;
	kcondvar_t	io_cv;
};

extern zio_t *zio_null(zio_t *pio, spa_t *spa,
    zio_done_func_t *done, void *private, int flags);

extern zio_t *zio_root(spa_t *spa,
    zio_done_func_t *done, void *private, int flags);

extern zio_t *zio_read(zio_t *pio, spa_t *spa, blkptr_t *bp, void *data,
    uint64_t size, zio_done_func_t *done, void *private,
    int priority, int flags);

extern zio_t *zio_write(zio_t *pio, spa_t *spa, int checksum, int compress,
    uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
    zio_done_func_t *done, void *private, int priority, int flags);

extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, int checksum,
    uint64_t txg, blkptr_t *bp, void *data, uint64_t size,
    zio_done_func_t *done, void *private, int priority, int flags);

extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
    zio_done_func_t *done, void *private);

extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
    zio_done_func_t *done, void *private);

extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
    zio_done_func_t *done, void *private, int priority, int flags);

extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
    uint64_t size, void *data, int checksum,
    zio_done_func_t *done, void *private, int priority, int flags);

extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
    uint64_t size, void *data, int checksum,
    zio_done_func_t *done, void *private, int priority, int flags);

extern int zio_alloc_blk(spa_t *spa, int checksum, uint64_t size,
    blkptr_t *bp, uint64_t txg);
extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);

extern int zio_wait(zio_t *zio);
extern void zio_nowait(zio_t *zio);

extern void *zio_buf_alloc(size_t size);
extern void zio_buf_free(void *buf, size_t size);

/*
 * Move an I/O to the next stage of the pipeline and execute that stage.
 * There's no locking on io_stage because there's no legitimate way for
 * multiple threads to be attempting to process the same I/O.
 */
extern void zio_next_stage(zio_t *zio);
extern void zio_next_stage_async(zio_t *zio);
extern void zio_wait_children_done(zio_t *zio);

/*
 * Delegate I/O to a child vdev.
 */
extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
    uint64_t offset, void *data, uint64_t size, int type, int priority,
    int flags, zio_done_func_t *done, void *private);

extern void zio_vdev_io_bypass(zio_t *zio);
extern void zio_vdev_io_reissue(zio_t *zio);
extern void zio_vdev_io_redone(zio_t *zio);

extern void zio_checksum_verified(zio_t *zio);
extern void zio_set_gang_verifier(zio_t *zio, zio_cksum_t *zcp);

extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
extern uint8_t zio_compress_select(uint8_t child, uint8_t parent);

/*
 * Initial setup and teardown.
 */
extern void zio_init(void);
extern void zio_fini(void);

#ifdef	__cplusplus
}
#endif

#endif	/* _ZIO_H */