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      1 /*
      2  * CDDL HEADER START
      3  *
      4  * The contents of this file are subject to the terms of the
      5  * Common Development and Distribution License (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 /*
     22  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
     23  * Use is subject to license terms.
     24  */
     25 
     26 #ifndef	_SYS_DNODE_H
     27 #define	_SYS_DNODE_H
     28 
     29 #pragma ident	"@(#)dnode.h	1.12	07/08/26 SMI"
     30 
     31 #include <sys/zfs_context.h>
     32 #include <sys/avl.h>
     33 #include <sys/spa.h>
     34 #include <sys/txg.h>
     35 #include <sys/zio.h>
     36 #include <sys/refcount.h>
     37 #include <sys/dmu_zfetch.h>
     38 
     39 #ifdef	__cplusplus
     40 extern "C" {
     41 #endif
     42 
     43 /*
     44  * Flags.
     45  */
     46 #define	DNODE_MUST_BE_ALLOCATED	1
     47 #define	DNODE_MUST_BE_FREE	2
     48 
     49 /*
     50  * Fixed constants.
     51  */
     52 #define	DNODE_SHIFT		9	/* 512 bytes */
     53 #define	DN_MIN_INDBLKSHIFT	10	/* 1k */
     54 #define	DN_MAX_INDBLKSHIFT	14	/* 16k */
     55 #define	DNODE_BLOCK_SHIFT	14	/* 16k */
     56 #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
     57 #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
     58 #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
     59 
     60 /*
     61  * Derived constants.
     62  */
     63 #define	DNODE_SIZE	(1 << DNODE_SHIFT)
     64 #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
     65 #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
     66 #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
     67 #define	DN_ZERO_BONUSLEN	(DN_MAX_BONUSLEN + 1)
     68 
     69 #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
     70 #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
     71 #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
     72 
     73 /* The +2 here is a cheesy way to round up */
     74 #define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
     75 	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
     76 
     77 #define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
     78 	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
     79 
     80 #define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
     81 	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
     82 
     83 #define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))
     84 
     85 struct dmu_buf_impl;
     86 struct objset_impl;
     87 struct zio;
     88 
     89 enum dnode_dirtycontext {
     90 	DN_UNDIRTIED,
     91 	DN_DIRTY_OPEN,
     92 	DN_DIRTY_SYNC
     93 };
     94 
     95 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
     96 #define	DNODE_FLAG_USED_BYTES	(1<<0)
     97 
     98 typedef struct dnode_phys {
     99 	uint8_t dn_type;		/* dmu_object_type_t */
    100 	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
    101 	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
    102 	uint8_t dn_nblkptr;		/* length of dn_blkptr */
    103 	uint8_t dn_bonustype;		/* type of data in bonus buffer */
    104 	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
    105 	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
    106 	uint8_t dn_flags;		/* DNODE_FLAG_* */
    107 	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
    108 	uint16_t dn_bonuslen;		/* length of dn_bonus */
    109 	uint8_t dn_pad2[4];
    110 
    111 	/* accounting is protected by dn_dirty_mtx */
    112 	uint64_t dn_maxblkid;		/* largest allocated block ID */
    113 	uint64_t dn_used;		/* bytes (or sectors) of disk space */
    114 
    115 	uint64_t dn_pad3[4];
    116 
    117 	blkptr_t dn_blkptr[1];
    118 	uint8_t dn_bonus[DN_MAX_BONUSLEN];
    119 } dnode_phys_t;
    120 
    121 typedef struct dnode {
    122 	/*
    123 	 * dn_struct_rwlock protects the structure of the dnode,
    124 	 * including the number of levels of indirection (dn_nlevels),
    125 	 * dn_maxblkid, and dn_next_*
    126 	 */
    127 	krwlock_t dn_struct_rwlock;
    128 
    129 	/*
    130 	 * Our link on dataset's dd_dnodes list.
    131 	 * Protected by dd_accounting_mtx.
    132 	 */
    133 	list_node_t dn_link;
    134 
    135 	/* immutable: */
    136 	struct objset_impl *dn_objset;
    137 	uint64_t dn_object;
    138 	struct dmu_buf_impl *dn_dbuf;
    139 	dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
    140 
    141 	/*
    142 	 * Copies of stuff in dn_phys.  They're valid in the open
    143 	 * context (eg. even before the dnode is first synced).
    144 	 * Where necessary, these are protected by dn_struct_rwlock.
    145 	 */
    146 	dmu_object_type_t dn_type;	/* object type */
    147 	uint16_t dn_bonuslen;		/* bonus length */
    148 	uint8_t dn_bonustype;		/* bonus type */
    149 	uint8_t dn_nblkptr;		/* number of blkptrs (immutable) */
    150 	uint8_t dn_checksum;		/* ZIO_CHECKSUM type */
    151 	uint8_t dn_compress;		/* ZIO_COMPRESS type */
    152 	uint8_t dn_nlevels;
    153 	uint8_t dn_indblkshift;
    154 	uint8_t dn_datablkshift;	/* zero if blksz not power of 2! */
    155 	uint16_t dn_datablkszsec;	/* in 512b sectors */
    156 	uint32_t dn_datablksz;		/* in bytes */
    157 	uint64_t dn_maxblkid;
    158 	uint8_t dn_next_nlevels[TXG_SIZE];
    159 	uint8_t dn_next_indblkshift[TXG_SIZE];
    160 	uint16_t dn_next_bonuslen[TXG_SIZE];
    161 	uint32_t dn_next_blksz[TXG_SIZE];	/* next block size in bytes */
    162 
    163 	/* protected by os_lock: */
    164 	list_node_t dn_dirty_link[TXG_SIZE];	/* next on dataset's dirty */
    165 
    166 	/* protected by dn_mtx: */
    167 	kmutex_t dn_mtx;
    168 	list_t dn_dirty_records[TXG_SIZE];
    169 	avl_tree_t dn_ranges[TXG_SIZE];
    170 	uint64_t dn_allocated_txg;
    171 	uint64_t dn_free_txg;
    172 	uint64_t dn_assigned_txg;
    173 	kcondvar_t dn_notxholds;
    174 	enum dnode_dirtycontext dn_dirtyctx;
    175 	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */
    176 
    177 	/* protected by own devices */
    178 	refcount_t dn_tx_holds;
    179 	refcount_t dn_holds;
    180 
    181 	kmutex_t dn_dbufs_mtx;
    182 	list_t dn_dbufs;		/* linked list of descendent dbuf_t's */
    183 	struct dmu_buf_impl *dn_bonus;	/* bonus buffer dbuf */
    184 
    185 	/* parent IO for current sync write */
    186 	zio_t *dn_zio;
    187 
    188 	/* holds prefetch structure */
    189 	struct zfetch	dn_zfetch;
    190 } dnode_t;
    191 
    192 typedef struct free_range {
    193 	avl_node_t fr_node;
    194 	uint64_t fr_blkid;
    195 	uint64_t fr_nblks;
    196 } free_range_t;
    197 
    198 dnode_t *dnode_special_open(struct objset_impl *dd, dnode_phys_t *dnp,
    199     uint64_t object);
    200 void dnode_special_close(dnode_t *dn);
    201 
    202 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
    203 int dnode_hold(struct objset_impl *dd, uint64_t object,
    204     void *ref, dnode_t **dnp);
    205 int dnode_hold_impl(struct objset_impl *dd, uint64_t object, int flag,
    206     void *ref, dnode_t **dnp);
    207 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
    208 void dnode_rele(dnode_t *dn, void *ref);
    209 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
    210 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
    211 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
    212     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
    213 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
    214     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
    215 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
    216 void dnode_byteswap(dnode_phys_t *dnp);
    217 void dnode_buf_byteswap(void *buf, size_t size);
    218 void dnode_verify(dnode_t *dn);
    219 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
    220 uint64_t dnode_current_max_length(dnode_t *dn);
    221 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
    222 void dnode_clear_range(dnode_t *dn, uint64_t blkid,
    223     uint64_t nblks, dmu_tx_t *tx);
    224 void dnode_diduse_space(dnode_t *dn, int64_t space);
    225 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
    226 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx);
    227 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
    228 void dnode_init(void);
    229 void dnode_fini(void);
    230 int dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *off, int minlvl,
    231     uint64_t blkfill, uint64_t txg);
    232 void dnode_evict_dbufs(dnode_t *dn);
    233 
    234 #ifdef ZFS_DEBUG
    235 
    236 /*
    237  * There should be a ## between the string literal and fmt, to make it
    238  * clear that we're joining two strings together, but that piece of shit
    239  * gcc doesn't support that preprocessor token.
    240  */
    241 #define	dprintf_dnode(dn, fmt, ...) do { \
    242 	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
    243 	char __db_buf[32]; \
    244 	uint64_t __db_obj = (dn)->dn_object; \
    245 	if (__db_obj == DMU_META_DNODE_OBJECT) \
    246 		(void) strcpy(__db_buf, "mdn"); \
    247 	else \
    248 		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
    249 		    (u_longlong_t)__db_obj);\
    250 	dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
    251 	    __db_buf, __VA_ARGS__); \
    252 	} \
    253 _NOTE(CONSTCOND) } while (0)
    254 
    255 #define	DNODE_VERIFY(dn)		dnode_verify(dn)
    256 #define	FREE_VERIFY(db, start, end, tx)	free_verify(db, start, end, tx)
    257 
    258 #else
    259 
    260 #define	dprintf_dnode(db, fmt, ...)
    261 #define	DNODE_VERIFY(dn)
    262 #define	FREE_VERIFY(db, start, end, tx)
    263 
    264 #endif
    265 
    266 #ifdef	__cplusplus
    267 }
    268 #endif
    269 
    270 #endif	/* _SYS_DNODE_H */
    271