/*

 * CDDL HEADER START

 *

 * The contents of this file are subject to the terms of the

 * Common Development and Distribution License (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 2007 Sun Microsystems, Inc.  All rights reserved.

 * Use is subject to license terms.

 */

#ifndef	_SYS_DNODE_H

#define	_SYS_DNODE_H

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

#include <sys/zfs_context.h>

#include <sys/avl.h>

#include <sys/spa.h>

#include <sys/txg.h>

#include <sys/zio.h>

#include <sys/refcount.h>

#include <sys/dmu_zfetch.h>

#ifdef	__cplusplus

extern "C" {

#endif

/*

 * Flags.

 */

#define	DNODE_MUST_BE_ALLOCATED	1

#define	DNODE_MUST_BE_FREE	2

/*

 * Fixed constants.

 */

#define	DNODE_SHIFT		9	/* 512 bytes */

#define	DN_MIN_INDBLKSHIFT	10	/* 1k */

#define	DN_MAX_INDBLKSHIFT	14	/* 16k */

#define	DNODE_BLOCK_SHIFT	14	/* 16k */

#define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */

#define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */

#define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */

/*

 * Derived constants.

 */

#define	DNODE_SIZE	(1 << DNODE_SHIFT)

#define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)

#define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))

#define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)

#define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)

#define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)

#define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)

/* The +2 here is a cheesy way to round up */

#define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \

	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))

#define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \

	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))

#define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \

	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)

#define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))

struct dmu_buf_impl;

struct objset_impl;

struct zio;

enum dnode_dirtycontext {

	DN_UNDIRTIED,

	DN_DIRTY_OPEN,

	DN_DIRTY_SYNC

};

/* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */

#define	DNODE_FLAG_USED_BYTES	(1<<0)

typedef struct dnode_phys {

	uint8_t dn_type;		/* dmu_object_type_t */

	uint8_t dn_indblkshift;		/* ln2(indirect block size) */

	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */

	uint8_t dn_nblkptr;		/* length of dn_blkptr */

	uint8_t dn_bonustype;		/* type of data in bonus buffer */

	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */

	uint8_t	dn_compress;		/* ZIO_COMPRESS type */

	uint8_t dn_flags;		/* DNODE_FLAG_* */

	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */

	uint16_t dn_bonuslen;		/* length of dn_bonus */

	uint8_t dn_pad2[4];

	/* accounting is protected by dn_dirty_mtx */

	uint64_t dn_maxblkid;		/* largest allocated block ID */

	uint64_t dn_used;		/* bytes (or sectors) of disk space */

	uint64_t dn_pad3[4];

	blkptr_t dn_blkptr[1];

	uint8_t dn_bonus[DN_MAX_BONUSLEN];

} dnode_phys_t;

typedef struct dnode {

	/*

	 * dn_struct_rwlock protects the structure of the dnode,

	 * including the number of levels of indirection (dn_nlevels),

	 * dn_maxblkid, and dn_next_*

	 */

	krwlock_t dn_struct_rwlock;

	/*

	 * Our link on dataset's dd_dnodes list.

	 * Protected by dd_accounting_mtx.

	 */

	list_node_t dn_link;

	/* immutable: */

	struct objset_impl *dn_objset;

	uint64_t dn_object;

	struct dmu_buf_impl *dn_dbuf;

	dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */

	/*

	 * Copies of stuff in dn_phys.  They're valid in the open

	 * context (eg. even before the dnode is first synced).

	 * Where necessary, these are protected by dn_struct_rwlock.

	 */

	dmu_object_type_t dn_type;	/* object type */

	uint16_t dn_bonuslen;		/* bonus length */

	uint8_t dn_bonustype;		/* bonus type */

	uint8_t dn_nblkptr;		/* number of blkptrs (immutable) */

	uint8_t dn_checksum;		/* ZIO_CHECKSUM type */

	uint8_t dn_compress;		/* ZIO_COMPRESS type */

	uint8_t dn_nlevels;

	uint8_t dn_indblkshift;

	uint8_t dn_datablkshift;	/* zero if blksz not power of 2! */

	uint16_t dn_datablkszsec;	/* in 512b sectors */

	uint32_t dn_datablksz;		/* in bytes */

	uint64_t dn_maxblkid;

	uint8_t dn_next_nlevels[TXG_SIZE];

	uint8_t dn_next_indblkshift[TXG_SIZE];

	uint32_t dn_next_blksz[TXG_SIZE];	/* next block size in bytes */

	/* protected by os_lock: */

	list_node_t dn_dirty_link[TXG_SIZE];	/* next on dataset's dirty */

	/* protected by dn_mtx: */

	kmutex_t dn_mtx;

	list_t dn_dirty_records[TXG_SIZE];

	avl_tree_t dn_ranges[TXG_SIZE];

	uint64_t dn_allocated_txg;

	uint64_t dn_free_txg;

	uint64_t dn_assigned_txg;

	kcondvar_t dn_notxholds;

	enum dnode_dirtycontext dn_dirtyctx;

	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */

	/* protected by own devices */

	refcount_t dn_tx_holds;

	refcount_t dn_holds;

	kmutex_t dn_dbufs_mtx;

	list_t dn_dbufs;		/* linked list of descendent dbuf_t's */

	struct dmu_buf_impl *dn_bonus;	/* bonus buffer dbuf */

	/* parent IO for current sync write */

	zio_t *dn_zio;

	/* holds prefetch structure */

	struct zfetch	dn_zfetch;

} dnode_t;

typedef struct free_range {

	avl_node_t fr_node;

	uint64_t fr_blkid;

	uint64_t fr_nblks;

} free_range_t;

dnode_t *dnode_special_open(struct objset_impl *dd, dnode_phys_t *dnp,

    uint64_t object);

void dnode_special_close(dnode_t *dn);

int dnode_hold(struct objset_impl *dd, uint64_t object,

    void *ref, dnode_t **dnp);

int dnode_hold_impl(struct objset_impl *dd, uint64_t object, int flag,

    void *ref, dnode_t **dnp);

void dnode_rele(dnode_t *dn, void *ref);

void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);

void dnode_sync(dnode_t *dn, dmu_tx_t *tx);

void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,

    dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);

void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,

    dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);

void dnode_free(dnode_t *dn, dmu_tx_t *tx);

void dnode_byteswap(dnode_phys_t *dnp);

void dnode_buf_byteswap(void *buf, size_t size);

void dnode_verify(dnode_t *dn);

int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);

uint64_t dnode_current_max_length(dnode_t *dn);

void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);

void dnode_clear_range(dnode_t *dn, uint64_t blkid,

    uint64_t nblks, dmu_tx_t *tx);

void dnode_diduse_space(dnode_t *dn, int64_t space);

void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);

void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx);

uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);

void dnode_init(void);

void dnode_fini(void);

int dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *off, int minlvl,

    uint64_t blkfill, uint64_t txg);

#ifdef ZFS_DEBUG

/*

 * There should be a ## between the string literal and fmt, to make it

 * clear that we're joining two strings together, but that piece of shit

 * gcc doesn't support that preprocessor token.

 */

#define	dprintf_dnode(dn, fmt, ...) do { \

	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \

	char __db_buf[32]; \

	uint64_t __db_obj = (dn)->dn_object; \

	if (__db_obj == DMU_META_DNODE_OBJECT) \

		(void) strcpy(__db_buf, "mdn"); \

	else \

		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \

		    (u_longlong_t)__db_obj);\

	dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \

	    __db_buf, __VA_ARGS__); \

	} \

_NOTE(CONSTCOND) } while (0)

#define	DNODE_VERIFY(dn)		dnode_verify(dn)

#define	FREE_VERIFY(db, start, end, tx)	free_verify(db, start, end, tx)

#else

#define	dprintf_dnode(db, fmt, ...)

#define	DNODE_VERIFY(dn)

#define	FREE_VERIFY(db, start, end, tx)

#endif

#ifdef	__cplusplus

}

#endif

#endif	/* _SYS_DNODE_H */