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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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
     23  * Copyright (c) 2012, 2016 by Delphix. All rights reserved.
     24  * Copyright (c) 2014 Spectra Logic Corporation, All rights reserved.
     25  */
     26 
     27 #ifndef	_SYS_DNODE_H
     28 #define	_SYS_DNODE_H
     29 
     30 #include <sys/zfs_context.h>
     31 #include <sys/avl.h>
     32 #include <sys/spa.h>
     33 #include <sys/txg.h>
     34 #include <sys/zio.h>
     35 #include <sys/refcount.h>
     36 #include <sys/dmu_zfetch.h>
     37 #include <sys/zrlock.h>
     38 
     39 #ifdef	__cplusplus
     40 extern "C" {
     41 #endif
     42 
     43 /*
     44  * dnode_hold() flags.
     45  */
     46 #define	DNODE_MUST_BE_ALLOCATED	1
     47 #define	DNODE_MUST_BE_FREE	2
     48 
     49 /*
     50  * dnode_next_offset() flags.
     51  */
     52 #define	DNODE_FIND_HOLE		1
     53 #define	DNODE_FIND_BACKWARDS	2
     54 #define	DNODE_FIND_HAVELOCK	4
     55 
     56 /*
     57  * Fixed constants.
     58  */
     59 #define	DNODE_SHIFT		9	/* 512 bytes */
     60 #define	DN_MIN_INDBLKSHIFT	12	/* 4k */
     61 #define	DN_MAX_INDBLKSHIFT	17	/* 128k */
     62 #define	DNODE_BLOCK_SHIFT	14	/* 16k */
     63 #define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
     64 #define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
     65 #define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
     66 
     67 /*
     68  * dnode id flags
     69  *
     70  * Note: a file will never ever have its
     71  * ids moved from bonus->spill
     72  * and only in a crypto environment would it be on spill
     73  */
     74 #define	DN_ID_CHKED_BONUS	0x1
     75 #define	DN_ID_CHKED_SPILL	0x2
     76 #define	DN_ID_OLD_EXIST		0x4
     77 #define	DN_ID_NEW_EXIST		0x8
     78 
     79 /*
     80  * Derived constants.
     81  */
     82 #define	DNODE_SIZE	(1 << DNODE_SHIFT)
     83 #define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
     84 #define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
     85 #define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
     86 #define	DN_ZERO_BONUSLEN	(DN_MAX_BONUSLEN + 1)
     87 #define	DN_KILL_SPILLBLK (1)
     88 
     89 #define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
     90 #define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
     91 
     92 /*
     93  * This is inaccurate if the indblkshift of the particular object is not the
     94  * max.  But it's only used by userland to calculate the zvol reservation.
     95  */
     96 #define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
     97 #define	DNODES_PER_LEVEL	(1ULL << DNODES_PER_LEVEL_SHIFT)
     98 
     99 /* The +2 here is a cheesy way to round up */
    100 #define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
    101 	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
    102 
    103 #define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
    104 	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
    105 
    106 #define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
    107 	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
    108 
    109 #define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))
    110 
    111 struct dmu_buf_impl;
    112 struct objset;
    113 struct zio;
    114 
    115 enum dnode_dirtycontext {
    116 	DN_UNDIRTIED,
    117 	DN_DIRTY_OPEN,
    118 	DN_DIRTY_SYNC
    119 };
    120 
    121 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
    122 #define	DNODE_FLAG_USED_BYTES		(1<<0)
    123 #define	DNODE_FLAG_USERUSED_ACCOUNTED	(1<<1)
    124 
    125 /* Does dnode have a SA spill blkptr in bonus? */
    126 #define	DNODE_FLAG_SPILL_BLKPTR	(1<<2)
    127 
    128 typedef struct dnode_phys {
    129 	uint8_t dn_type;		/* dmu_object_type_t */
    130 	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
    131 	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
    132 	uint8_t dn_nblkptr;		/* length of dn_blkptr */
    133 	uint8_t dn_bonustype;		/* type of data in bonus buffer */
    134 	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
    135 	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
    136 	uint8_t dn_flags;		/* DNODE_FLAG_* */
    137 	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
    138 	uint16_t dn_bonuslen;		/* length of dn_bonus */
    139 	uint8_t dn_pad2[4];
    140 
    141 	/* accounting is protected by dn_dirty_mtx */
    142 	uint64_t dn_maxblkid;		/* largest allocated block ID */
    143 	uint64_t dn_used;		/* bytes (or sectors) of disk space */
    144 
    145 	uint64_t dn_pad3[4];
    146 
    147 	blkptr_t dn_blkptr[1];
    148 	uint8_t dn_bonus[DN_MAX_BONUSLEN - sizeof (blkptr_t)];
    149 	blkptr_t dn_spill;
    150 } dnode_phys_t;
    151 
    152 struct dnode {
    153 	/*
    154 	 * Protects the structure of the dnode, including the number of levels
    155 	 * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
    156 	 */
    157 	krwlock_t dn_struct_rwlock;
    158 
    159 	/* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
    160 	list_node_t dn_link;
    161 
    162 	/* immutable: */
    163 	struct objset *dn_objset;
    164 	uint64_t dn_object;
    165 	struct dmu_buf_impl *dn_dbuf;
    166 	struct dnode_handle *dn_handle;
    167 	dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
    168 
    169 	/*
    170 	 * Copies of stuff in dn_phys.  They're valid in the open
    171 	 * context (eg. even before the dnode is first synced).
    172 	 * Where necessary, these are protected by dn_struct_rwlock.
    173 	 */
    174 	dmu_object_type_t dn_type;	/* object type */
    175 	uint16_t dn_bonuslen;		/* bonus length */
    176 	uint8_t dn_bonustype;		/* bonus type */
    177 	uint8_t dn_nblkptr;		/* number of blkptrs (immutable) */
    178 	uint8_t dn_checksum;		/* ZIO_CHECKSUM type */
    179 	uint8_t dn_compress;		/* ZIO_COMPRESS type */
    180 	uint8_t dn_nlevels;
    181 	uint8_t dn_indblkshift;
    182 	uint8_t dn_datablkshift;	/* zero if blksz not power of 2! */
    183 	uint8_t dn_moved;		/* Has this dnode been moved? */
    184 	uint16_t dn_datablkszsec;	/* in 512b sectors */
    185 	uint32_t dn_datablksz;		/* in bytes */
    186 	uint64_t dn_maxblkid;
    187 	uint8_t dn_next_type[TXG_SIZE];
    188 	uint8_t dn_next_nblkptr[TXG_SIZE];
    189 	uint8_t dn_next_nlevels[TXG_SIZE];
    190 	uint8_t dn_next_indblkshift[TXG_SIZE];
    191 	uint8_t dn_next_bonustype[TXG_SIZE];
    192 	uint8_t dn_rm_spillblk[TXG_SIZE];	/* for removing spill blk */
    193 	uint16_t dn_next_bonuslen[TXG_SIZE];
    194 	uint32_t dn_next_blksz[TXG_SIZE];	/* next block size in bytes */
    195 
    196 	/* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */
    197 	uint32_t dn_dbufs_count;	/* count of dn_dbufs */
    198 
    199 	/* protected by os_lock: */
    200 	list_node_t dn_dirty_link[TXG_SIZE];	/* next on dataset's dirty */
    201 
    202 	/* protected by dn_mtx: */
    203 	kmutex_t dn_mtx;
    204 	list_t dn_dirty_records[TXG_SIZE];
    205 	struct range_tree *dn_free_ranges[TXG_SIZE];
    206 	uint64_t dn_allocated_txg;
    207 	uint64_t dn_free_txg;
    208 	uint64_t dn_assigned_txg;
    209 	kcondvar_t dn_notxholds;
    210 	enum dnode_dirtycontext dn_dirtyctx;
    211 	uint8_t *dn_dirtyctx_firstset;		/* dbg: contents meaningless */
    212 
    213 	/* protected by own devices */
    214 	refcount_t dn_tx_holds;
    215 	refcount_t dn_holds;
    216 
    217 	kmutex_t dn_dbufs_mtx;
    218 	/*
    219 	 * Descendent dbufs, ordered by dbuf_compare. Note that dn_dbufs
    220 	 * can contain multiple dbufs of the same (level, blkid) when a
    221 	 * dbuf is marked DB_EVICTING without being removed from
    222 	 * dn_dbufs. To maintain the avl invariant that there cannot be
    223 	 * duplicate entries, we order the dbufs by an arbitrary value -
    224 	 * their address in memory. This means that dn_dbufs cannot be used to
    225 	 * directly look up a dbuf. Instead, callers must use avl_walk, have
    226 	 * a reference to the dbuf, or look up a non-existant node with
    227 	 * db_state = DB_SEARCH (see dbuf_free_range for an example).
    228 	 */
    229 	avl_tree_t dn_dbufs;
    230 
    231 	/* protected by dn_struct_rwlock */
    232 	struct dmu_buf_impl *dn_bonus;	/* bonus buffer dbuf */
    233 
    234 	boolean_t dn_have_spill;	/* have spill or are spilling */
    235 
    236 	/* parent IO for current sync write */
    237 	zio_t *dn_zio;
    238 
    239 	/* used in syncing context */
    240 	uint64_t dn_oldused;	/* old phys used bytes */
    241 	uint64_t dn_oldflags;	/* old phys dn_flags */
    242 	uint64_t dn_olduid, dn_oldgid;
    243 	uint64_t dn_newuid, dn_newgid;
    244 	int dn_id_flags;
    245 
    246 	/* holds prefetch structure */
    247 	struct zfetch	dn_zfetch;
    248 };
    249 
    250 /*
    251  * Adds a level of indirection between the dbuf and the dnode to avoid
    252  * iterating descendent dbufs in dnode_move(). Handles are not allocated
    253  * individually, but as an array of child dnodes in dnode_hold_impl().
    254  */
    255 typedef struct dnode_handle {
    256 	/* Protects dnh_dnode from modification by dnode_move(). */
    257 	zrlock_t dnh_zrlock;
    258 	dnode_t *dnh_dnode;
    259 } dnode_handle_t;
    260 
    261 typedef struct dnode_children {
    262 	dmu_buf_user_t dnc_dbu;		/* User evict data */
    263 	size_t dnc_count;		/* number of children */
    264 	dnode_handle_t dnc_children[];	/* sized dynamically */
    265 } dnode_children_t;
    266 
    267 typedef struct free_range {
    268 	avl_node_t fr_node;
    269 	uint64_t fr_blkid;
    270 	uint64_t fr_nblks;
    271 } free_range_t;
    272 
    273 void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
    274     uint64_t object, dnode_handle_t *dnh);
    275 void dnode_special_close(dnode_handle_t *dnh);
    276 
    277 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
    278 void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
    279 void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
    280 
    281 int dnode_hold(struct objset *dd, uint64_t object,
    282     void *ref, dnode_t **dnp);
    283 int dnode_hold_impl(struct objset *dd, uint64_t object, int flag,
    284     void *ref, dnode_t **dnp);
    285 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
    286 void dnode_rele(dnode_t *dn, void *ref);
    287 void dnode_rele_and_unlock(dnode_t *dn, void *tag);
    288 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
    289 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
    290 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
    291     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
    292 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
    293     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
    294 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
    295 void dnode_byteswap(dnode_phys_t *dnp);
    296 void dnode_buf_byteswap(void *buf, size_t size);
    297 void dnode_verify(dnode_t *dn);
    298 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
    299 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
    300 void dnode_diduse_space(dnode_t *dn, int64_t space);
    301 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
    302 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
    303 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
    304 void dnode_init(void);
    305 void dnode_fini(void);
    306 int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
    307     int minlvl, uint64_t blkfill, uint64_t txg);
    308 void dnode_evict_dbufs(dnode_t *dn);
    309 void dnode_evict_bonus(dnode_t *dn);
    310 
    311 #define	DNODE_IS_CACHEABLE(_dn)						\
    312 	((_dn)->dn_objset->os_primary_cache == ZFS_CACHE_ALL ||		\
    313 	(DMU_OT_IS_METADATA((_dn)->dn_type) &&				\
    314 	(_dn)->dn_objset->os_primary_cache == ZFS_CACHE_METADATA))
    315 
    316 #define	DNODE_META_IS_CACHEABLE(_dn)					\
    317 	((_dn)->dn_objset->os_primary_cache == ZFS_CACHE_ALL ||		\
    318 	(_dn)->dn_objset->os_primary_cache == ZFS_CACHE_METADATA)
    319 
    320 #ifdef ZFS_DEBUG
    321 
    322 /*
    323  * There should be a ## between the string literal and fmt, to make it
    324  * clear that we're joining two strings together, but that piece of shit
    325  * gcc doesn't support that preprocessor token.
    326  */
    327 #define	dprintf_dnode(dn, fmt, ...) do { \
    328 	if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
    329 	char __db_buf[32]; \
    330 	uint64_t __db_obj = (dn)->dn_object; \
    331 	if (__db_obj == DMU_META_DNODE_OBJECT) \
    332 		(void) strcpy(__db_buf, "mdn"); \
    333 	else \
    334 		(void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
    335 		    (u_longlong_t)__db_obj);\
    336 	dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
    337 	    __db_buf, __VA_ARGS__); \
    338 	} \
    339 _NOTE(CONSTCOND) } while (0)
    340 
    341 #define	DNODE_VERIFY(dn)		dnode_verify(dn)
    342 #define	FREE_VERIFY(db, start, end, tx)	free_verify(db, start, end, tx)
    343 
    344 #else
    345 
    346 #define	dprintf_dnode(db, fmt, ...)
    347 #define	DNODE_VERIFY(dn)
    348 #define	FREE_VERIFY(db, start, end, tx)
    349 
    350 #endif
    351 
    352 #ifdef	__cplusplus
    353 }
    354 #endif
    355 
    356 #endif	/* _SYS_DNODE_H */
    357