include/sys/dnode.h

   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 /*
  62  * If we ever increase this value beyond 20, we need to revisit all logic that
  63  * does x << level * ebps to handle overflow.  With a 1M indirect block size,
  64  * 4 levels of indirect blocks would not be able to guarantee addressing an
  65  * entire object, so 5 levels will be used, but 5 * (20 - 7) = 65.
  66  */
  67 #define DN_MAX_INDBLKSHIFT      14      /* 16k */
  68 #define DNODE_BLOCK_SHIFT       14      /* 16k */
  69 #define DNODE_CORE_SIZE         64      /* 64 bytes for dnode sans blkptrs */
  70 #define DN_MAX_OBJECT_SHIFT     48      /* 256 trillion (zfs_fid_t limit) */
  71 #define DN_MAX_OFFSET_SHIFT     64      /* 2^64 bytes in a dnode */
  72
  73 /*
  74  * dnode id flags
  75  *
  76  * Note: a file will never ever have its
  77  * ids moved from bonus->spill
  78  * and only in a crypto environment would it be on spill
  79  */
  80 #define DN_ID_CHKED_BONUS       0x1
  81 #define DN_ID_CHKED_SPILL       0x2
  82 #define DN_ID_OLD_EXIST         0x4
  83 #define DN_ID_NEW_EXIST         0x8
  84
  85 /*
  86  * Derived constants.
  87  */
  88 #define DNODE_MIN_SIZE          (1 << DNODE_SHIFT)
  89 #define DNODE_MAX_SIZE          (1 << DNODE_BLOCK_SHIFT)
  90 #define DNODE_BLOCK_SIZE        (1 << DNODE_BLOCK_SHIFT)
  91 #define DNODE_MIN_SLOTS         (DNODE_MIN_SIZE >> DNODE_SHIFT)
  92 #define DNODE_MAX_SLOTS         (DNODE_MAX_SIZE >> DNODE_SHIFT)
  93 #define DN_BONUS_SIZE(dnsize)   ((dnsize) - DNODE_CORE_SIZE - \
  94         (1 << SPA_BLKPTRSHIFT))
  95 #define DN_SLOTS_TO_BONUSLEN(slots)     DN_BONUS_SIZE((slots) << DNODE_SHIFT)
  96 #define DN_OLD_MAX_BONUSLEN     (DN_BONUS_SIZE(DNODE_MIN_SIZE))
  97 #define DN_MAX_NBLKPTR  ((DNODE_MIN_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
  98 #define DN_MAX_OBJECT   (1ULL << DN_MAX_OBJECT_SHIFT)
  99 #define DN_ZERO_BONUSLEN        (DN_BONUS_SIZE(DNODE_MAX_SIZE) + 1)
 100 #define DN_KILL_SPILLBLK (1)
 101
 102 #define DNODES_PER_BLOCK_SHIFT  (DNODE_BLOCK_SHIFT - DNODE_SHIFT)
 103 #define DNODES_PER_BLOCK        (1ULL << DNODES_PER_BLOCK_SHIFT)
 104 #define DNODES_PER_LEVEL_SHIFT  (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
 105 #define DNODES_PER_LEVEL        (1ULL << DNODES_PER_LEVEL_SHIFT)
 106
 107 /* The +2 here is a cheesy way to round up */
 108 #define DN_MAX_LEVELS   (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
 109         (DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
 110
 111 #define DN_BONUS(dnp)   ((void*)((dnp)->dn_bonus + \
 112         (((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
 113
 114 #define DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
 115         (dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
 116
 117 #define EPB(blkshift, typeshift)        (1 << (blkshift - typeshift))
 118
 119 struct dmu_buf_impl;
 120 struct objset;
 121 struct zio;
 122
 123 enum dnode_dirtycontext {
 124         DN_UNDIRTIED,
 125         DN_DIRTY_OPEN,
 126         DN_DIRTY_SYNC
 127 };
 128
 129 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
 130 #define DNODE_FLAG_USED_BYTES           (1<<0)
 131 #define DNODE_FLAG_USERUSED_ACCOUNTED   (1<<1)
 132
 133 /* Does dnode have a SA spill blkptr in bonus? */
 134 #define DNODE_FLAG_SPILL_BLKPTR (1<<2)
 135
 136 typedef struct dnode_phys {
 137         uint8_t dn_type;                /* dmu_object_type_t */
 138         uint8_t dn_indblkshift;         /* ln2(indirect block size) */
 139         uint8_t dn_nlevels;             /* 1=dn_blkptr->data blocks */
 140         uint8_t dn_nblkptr;             /* length of dn_blkptr */
 141         uint8_t dn_bonustype;           /* type of data in bonus buffer */
 142         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 143         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 144         uint8_t dn_flags;               /* DNODE_FLAG_* */
 145         uint16_t dn_datablkszsec;       /* data block size in 512b sectors */
 146         uint16_t dn_bonuslen;           /* length of dn_bonus */
 147         uint8_t dn_extra_slots;         /* # of subsequent slots consumed */
 148         uint8_t dn_pad2[3];
 149
 150         /* accounting is protected by dn_dirty_mtx */
 151         uint64_t dn_maxblkid;           /* largest allocated block ID */
 152         uint64_t dn_used;               /* bytes (or sectors) of disk space */
 153
 154         uint64_t dn_pad3[4];
 155
 156         /*
 157          * The tail region is 448 bytes for a 512 byte dnode, and
 158          * correspondingly larger for larger dnode sizes. The spill
 159          * block pointer, when present, is always at the end of the tail
 160          * region. There are three ways this space may be used, using
 161          * a 512 byte dnode for this diagram:
 162          *
 163          * 0       64      128     192     256     320     384     448 (offset)
 164          * +---------------+---------------+---------------+-------+
 165          * | dn_blkptr[0]  | dn_blkptr[1]  | dn_blkptr[2]  | /     |
 166          * +---------------+---------------+---------------+-------+
 167          * | dn_blkptr[0]  | dn_bonus[0..319]                      |
 168          * +---------------+-----------------------+---------------+
 169          * | dn_blkptr[0]  | dn_bonus[0..191]      | dn_spill      |
 170          * +---------------+-----------------------+---------------+
 171          */
 172         union {
 173                 blkptr_t dn_blkptr[1+DN_OLD_MAX_BONUSLEN/sizeof (blkptr_t)];
 174                 struct {
 175                         blkptr_t __dn_ignore1;
 176                         uint8_t dn_bonus[DN_OLD_MAX_BONUSLEN];
 177                 };
 178                 struct {
 179                         blkptr_t __dn_ignore2;
 180                         uint8_t __dn_ignore3[DN_OLD_MAX_BONUSLEN -
 181                             sizeof (blkptr_t)];
 182                         blkptr_t dn_spill;
 183                 };
 184         };
 185 } dnode_phys_t;
 186
 187 #define DN_SPILL_BLKPTR(dnp)    (blkptr_t *)((char *)(dnp) + \
 188         (((dnp)->dn_extra_slots + 1) << DNODE_SHIFT) - (1 << SPA_BLKPTRSHIFT))
 189
 190 struct dnode {
 191         /*
 192          * Protects the structure of the dnode, including the number of levels
 193          * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
 194          */
 195         krwlock_t dn_struct_rwlock;
 196
 197         /* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
 198         list_node_t dn_link;
 199
 200         /* immutable: */
 201         struct objset *dn_objset;
 202         uint64_t dn_object;
 203         struct dmu_buf_impl *dn_dbuf;
 204         struct dnode_handle *dn_handle;
 205         dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
 206
 207         /*
 208          * Copies of stuff in dn_phys.  They're valid in the open
 209          * context (eg. even before the dnode is first synced).
 210          * Where necessary, these are protected by dn_struct_rwlock.
 211          */
 212         dmu_object_type_t dn_type;      /* object type */
 213         uint16_t dn_bonuslen;           /* bonus length */
 214         uint8_t dn_bonustype;           /* bonus type */
 215         uint8_t dn_nblkptr;             /* number of blkptrs (immutable) */
 216         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 217         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 218         uint8_t dn_nlevels;
 219         uint8_t dn_indblkshift;
 220         uint8_t dn_datablkshift;        /* zero if blksz not power of 2! */
 221         uint8_t dn_moved;               /* Has this dnode been moved? */
 222         uint16_t dn_datablkszsec;       /* in 512b sectors */
 223         uint32_t dn_datablksz;          /* in bytes */
 224         uint64_t dn_maxblkid;
 225         uint8_t dn_next_type[TXG_SIZE];
 226         uint8_t dn_num_slots;           /* metadnode slots consumed on disk */
 227         uint8_t dn_next_nblkptr[TXG_SIZE];
 228         uint8_t dn_next_nlevels[TXG_SIZE];
 229         uint8_t dn_next_indblkshift[TXG_SIZE];
 230         uint8_t dn_next_bonustype[TXG_SIZE];
 231         uint8_t dn_rm_spillblk[TXG_SIZE];       /* for removing spill blk */
 232         uint16_t dn_next_bonuslen[TXG_SIZE];
 233         uint32_t dn_next_blksz[TXG_SIZE];       /* next block size in bytes */
 234
 235         /* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */
 236         uint32_t dn_dbufs_count;        /* count of dn_dbufs */
 237         /* There are no level-0 blocks of this blkid or higher in dn_dbufs */
 238         uint64_t dn_unlisted_l0_blkid;
 239
 240         /* protected by os_lock: */
 241         list_node_t dn_dirty_link[TXG_SIZE];    /* next on dataset's dirty */
 242
 243         /* protected by dn_mtx: */
 244         kmutex_t dn_mtx;
 245         list_t dn_dirty_records[TXG_SIZE];
 246         struct range_tree *dn_free_ranges[TXG_SIZE];
 247         uint64_t dn_allocated_txg;
 248         uint64_t dn_free_txg;
 249         uint64_t dn_assigned_txg;
 250         kcondvar_t dn_notxholds;
 251         enum dnode_dirtycontext dn_dirtyctx;
 252         uint8_t *dn_dirtyctx_firstset;          /* dbg: contents meaningless */
 253
 254         /* protected by own devices */
 255         refcount_t dn_tx_holds;
 256         refcount_t dn_holds;
 257
 258         kmutex_t dn_dbufs_mtx;
 259         /*
 260          * Descendent dbufs, ordered by dbuf_compare. Note that dn_dbufs
 261          * can contain multiple dbufs of the same (level, blkid) when a
 262          * dbuf is marked DB_EVICTING without being removed from
 263          * dn_dbufs. To maintain the avl invariant that there cannot be
 264          * duplicate entries, we order the dbufs by an arbitrary value -
 265          * their address in memory. This means that dn_dbufs cannot be used to
 266          * directly look up a dbuf. Instead, callers must use avl_walk, have
 267          * a reference to the dbuf, or look up a non-existant node with
 268          * db_state = DB_SEARCH (see dbuf_free_range for an example).
 269          */
 270         avl_tree_t dn_dbufs;
 271
 272         /* protected by dn_struct_rwlock */
 273         struct dmu_buf_impl *dn_bonus;  /* bonus buffer dbuf */
 274
 275         boolean_t dn_have_spill;        /* have spill or are spilling */
 276
 277         /* parent IO for current sync write */
 278         zio_t *dn_zio;
 279
 280         /* used in syncing context */
 281         uint64_t dn_oldused;    /* old phys used bytes */
 282         uint64_t dn_oldflags;   /* old phys dn_flags */
 283         uint64_t dn_olduid, dn_oldgid;
 284         uint64_t dn_newuid, dn_newgid;
 285         int dn_id_flags;
 286
 287         /* holds prefetch structure */
 288         struct zfetch   dn_zfetch;
 289 };
 290
 291 /*
 292  * Adds a level of indirection between the dbuf and the dnode to avoid
 293  * iterating descendent dbufs in dnode_move(). Handles are not allocated
 294  * individually, but as an array of child dnodes in dnode_hold_impl().
 295  */
 296 typedef struct dnode_handle {
 297         /* Protects dnh_dnode from modification by dnode_move(). */
 298         zrlock_t dnh_zrlock;
 299         dnode_t *dnh_dnode;
 300 } dnode_handle_t;
 301
 302 typedef struct dnode_children {
 303         dmu_buf_user_t dnc_dbu;         /* User evict data */
 304         size_t dnc_count;               /* number of children */
 305         dnode_handle_t dnc_children[];  /* sized dynamically */
 306 } dnode_children_t;
 307
 308 typedef struct free_range {
 309         avl_node_t fr_node;
 310         uint64_t fr_blkid;
 311         uint64_t fr_nblks;
 312 } free_range_t;
 313
 314 void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
 315     uint64_t object, dnode_handle_t *dnh);
 316 void dnode_special_close(dnode_handle_t *dnh);
 317
 318 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
 319 void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
 320 void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
 321
 322 int dnode_hold(struct objset *dd, uint64_t object,
 323     void *ref, dnode_t **dnp);
 324 int dnode_hold_impl(struct objset *dd, uint64_t object, int flag, int dn_slots,
 325     void *ref, dnode_t **dnp);
 326 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
 327 void dnode_rele(dnode_t *dn, void *ref);
 328 void dnode_rele_and_unlock(dnode_t *dn, void *tag);
 329 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
 330 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
 331 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
 332     dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx);
 333 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
 334     dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx);
 335 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
 336 void dnode_byteswap(dnode_phys_t *dnp);
 337 void dnode_buf_byteswap(void *buf, size_t size);
 338 void dnode_verify(dnode_t *dn);
 339 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
 340 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
 341 void dnode_diduse_space(dnode_t *dn, int64_t space);
 342 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
 343 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
 344 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
 345 void dnode_init(void);
 346 void dnode_fini(void);
 347 int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
 348     int minlvl, uint64_t blkfill, uint64_t txg);
 349 void dnode_evict_dbufs(dnode_t *dn);
 350 void dnode_evict_bonus(dnode_t *dn);
 351
 352 #ifdef ZFS_DEBUG
 353
 354 /*
 355  * There should be a ## between the string literal and fmt, to make it
 356  * clear that we're joining two strings together, but that piece of shit
 357  * gcc doesn't support that preprocessor token.
 358  */
 359 #define dprintf_dnode(dn, fmt, ...) do { \
 360         if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
 361         char __db_buf[32]; \
 362         uint64_t __db_obj = (dn)->dn_object; \
 363         if (__db_obj == DMU_META_DNODE_OBJECT) \
 364                 (void) strcpy(__db_buf, "mdn"); \
 365         else \
 366                 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
 367                     (u_longlong_t)__db_obj);\
 368         dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
 369             __db_buf, __VA_ARGS__); \
 370         } \
 371 _NOTE(CONSTCOND) } while (0)
 372
 373 #define DNODE_VERIFY(dn)                dnode_verify(dn)
 374 #define FREE_VERIFY(db, start, end, tx) free_verify(db, start, end, tx)
 375
 376 #else
 377
 378 #define dprintf_dnode(db, fmt, ...)
 379 #define DNODE_VERIFY(dn)
 380 #define FREE_VERIFY(db, start, end, tx)
 381
 382 #endif
 383
 384 #ifdef  __cplusplus
 385 }
 386 #endif
 387
 388 #endif  /* _SYS_DNODE_H */