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, 2014 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      14      /* 16k */
  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_MIN_SIZE          (1 << DNODE_SHIFT)
  83 #define DNODE_MAX_SIZE          (1 << DNODE_BLOCK_SHIFT)
  84 #define DNODE_BLOCK_SIZE        (1 << DNODE_BLOCK_SHIFT)
  85 #define DNODE_MIN_SLOTS         (DNODE_MIN_SIZE >> DNODE_SHIFT)
  86 #define DNODE_MAX_SLOTS         (DNODE_MAX_SIZE >> DNODE_SHIFT)
  87 #define DN_BONUS_SIZE(dnsize)   ((dnsize) - DNODE_CORE_SIZE - \
  88         (1 << SPA_BLKPTRSHIFT))
  89 #define DN_SLOTS_TO_BONUSLEN(slots)     DN_BONUS_SIZE((slots) << DNODE_SHIFT)
  90 #define DN_OLD_MAX_BONUSLEN     (DN_BONUS_SIZE(DNODE_MIN_SIZE))
  91 #define DN_MAX_NBLKPTR  ((DNODE_MIN_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
  92 #define DN_MAX_OBJECT   (1ULL << DN_MAX_OBJECT_SHIFT)
  93 #define DN_ZERO_BONUSLEN        (DN_BONUS_SIZE(DNODE_MAX_SIZE) + 1)
  94 #define DN_KILL_SPILLBLK (1)
  95
  96 #define DNODES_PER_BLOCK_SHIFT  (DNODE_BLOCK_SHIFT - DNODE_SHIFT)
  97 #define DNODES_PER_BLOCK        (1ULL << DNODES_PER_BLOCK_SHIFT)
  98 #define DNODES_PER_LEVEL_SHIFT  (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
  99 #define DNODES_PER_LEVEL        (1ULL << DNODES_PER_LEVEL_SHIFT)
 100
 101 /* The +2 here is a cheesy way to round up */
 102 #define DN_MAX_LEVELS   (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
 103         (DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
 104
 105 #define DN_BONUS(dnp)   ((void*)((dnp)->dn_bonus + \
 106         (((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
 107
 108 #define DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
 109         (dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
 110
 111 #define EPB(blkshift, typeshift)        (1 << (blkshift - typeshift))
 112
 113 struct dmu_buf_impl;
 114 struct objset;
 115 struct zio;
 116
 117 enum dnode_dirtycontext {
 118         DN_UNDIRTIED,
 119         DN_DIRTY_OPEN,
 120         DN_DIRTY_SYNC
 121 };
 122
 123 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
 124 #define DNODE_FLAG_USED_BYTES           (1<<0)
 125 #define DNODE_FLAG_USERUSED_ACCOUNTED   (1<<1)
 126
 127 /* Does dnode have a SA spill blkptr in bonus? */
 128 #define DNODE_FLAG_SPILL_BLKPTR (1<<2)
 129
 130 typedef struct dnode_phys {
 131         uint8_t dn_type;                /* dmu_object_type_t */
 132         uint8_t dn_indblkshift;         /* ln2(indirect block size) */
 133         uint8_t dn_nlevels;             /* 1=dn_blkptr->data blocks */
 134         uint8_t dn_nblkptr;             /* length of dn_blkptr */
 135         uint8_t dn_bonustype;           /* type of data in bonus buffer */
 136         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 137         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 138         uint8_t dn_flags;               /* DNODE_FLAG_* */
 139         uint16_t dn_datablkszsec;       /* data block size in 512b sectors */
 140         uint16_t dn_bonuslen;           /* length of dn_bonus */
 141         uint8_t dn_extra_slots;         /* # of subsequent slots consumed */
 142         uint8_t dn_pad2[3];
 143
 144         /* accounting is protected by dn_dirty_mtx */
 145         uint64_t dn_maxblkid;           /* largest allocated block ID */
 146         uint64_t dn_used;               /* bytes (or sectors) of disk space */
 147
 148         uint64_t dn_pad3[4];
 149
 150         /*
 151          * The tail region is 448 bytes for a 512 byte dnode, and
 152          * correspondingly larger for larger dnode sizes. The spill
 153          * block pointer, when present, is always at the end of the tail
 154          * region. There are three ways this space may be used, using
 155          * a 512 byte dnode for this diagram:
 156          *
 157          * 0       64      128     192     256     320     384     448 (offset)
 158          * +---------------+---------------+---------------+-------+
 159          * | dn_blkptr[0]  | dn_blkptr[1]  | dn_blkptr[2]  | /     |
 160          * +---------------+---------------+---------------+-------+
 161          * | dn_blkptr[0]  | dn_bonus[0..319]                      |
 162          * +---------------+-----------------------+---------------+
 163          * | dn_blkptr[0]  | dn_bonus[0..191]      | dn_spill      |
 164          * +---------------+-----------------------+---------------+
 165          */
 166         union {
 167                 blkptr_t dn_blkptr[1+DN_OLD_MAX_BONUSLEN/sizeof (blkptr_t)];
 168                 struct {
 169                         blkptr_t __dn_ignore1;
 170                         uint8_t dn_bonus[DN_OLD_MAX_BONUSLEN];
 171                 };
 172                 struct {
 173                         blkptr_t __dn_ignore2;
 174                         uint8_t __dn_ignore3[DN_OLD_MAX_BONUSLEN -
 175                             sizeof (blkptr_t)];
 176                         blkptr_t dn_spill;
 177                 };
 178         };
 179 } dnode_phys_t;
 180
 181 #define DN_SPILL_BLKPTR(dnp)    (blkptr_t *)((char *)(dnp) + \
 182         (((dnp)->dn_extra_slots + 1) << DNODE_SHIFT) - (1 << SPA_BLKPTRSHIFT))
 183
 184 typedef struct dnode {
 185         /*
 186          * Protects the structure of the dnode, including the number of levels
 187          * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
 188          */
 189         krwlock_t dn_struct_rwlock;
 190
 191         /* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
 192         list_node_t dn_link;
 193
 194         /* immutable: */
 195         struct objset *dn_objset;
 196         uint64_t dn_object;
 197         struct dmu_buf_impl *dn_dbuf;
 198         struct dnode_handle *dn_handle;
 199         dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
 200
 201         /*
 202          * Copies of stuff in dn_phys.  They're valid in the open
 203          * context (eg. even before the dnode is first synced).
 204          * Where necessary, these are protected by dn_struct_rwlock.
 205          */
 206         dmu_object_type_t dn_type;      /* object type */
 207         uint16_t dn_bonuslen;           /* bonus length */
 208         uint8_t dn_bonustype;           /* bonus type */
 209         uint8_t dn_nblkptr;             /* number of blkptrs (immutable) */
 210         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 211         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 212         uint8_t dn_nlevels;
 213         uint8_t dn_indblkshift;
 214         uint8_t dn_datablkshift;        /* zero if blksz not power of 2! */
 215         uint8_t dn_moved;               /* Has this dnode been moved? */
 216         uint16_t dn_datablkszsec;       /* in 512b sectors */
 217         uint32_t dn_datablksz;          /* in bytes */
 218         uint64_t dn_maxblkid;
 219         uint8_t dn_next_type[TXG_SIZE];
 220         uint8_t dn_num_slots;           /* metadnode slots consumed on disk */
 221         uint8_t dn_next_nblkptr[TXG_SIZE];
 222         uint8_t dn_next_nlevels[TXG_SIZE];
 223         uint8_t dn_next_indblkshift[TXG_SIZE];
 224         uint8_t dn_next_bonustype[TXG_SIZE];
 225         uint8_t dn_rm_spillblk[TXG_SIZE];       /* for removing spill blk */
 226         uint16_t dn_next_bonuslen[TXG_SIZE];
 227         uint32_t dn_next_blksz[TXG_SIZE];       /* next block size in bytes */
 228
 229         /* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */
 230         uint32_t dn_dbufs_count;        /* count of dn_dbufs */
 231         /* There are no level-0 blocks of this blkid or higher in dn_dbufs */
 232         uint64_t dn_unlisted_l0_blkid;
 233
 234         /* protected by os_lock: */
 235         list_node_t dn_dirty_link[TXG_SIZE];    /* next on dataset's dirty */
 236
 237         /* protected by dn_mtx: */
 238         kmutex_t dn_mtx;
 239         list_t dn_dirty_records[TXG_SIZE];
 240         struct range_tree *dn_free_ranges[TXG_SIZE];
 241         uint64_t dn_allocated_txg;
 242         uint64_t dn_free_txg;
 243         uint64_t dn_assigned_txg;
 244         kcondvar_t dn_notxholds;
 245         enum dnode_dirtycontext dn_dirtyctx;
 246         uint8_t *dn_dirtyctx_firstset;          /* dbg: contents meaningless */
 247
 248         /* protected by own devices */
 249         refcount_t dn_tx_holds;
 250         refcount_t dn_holds;
 251
 252         kmutex_t dn_dbufs_mtx;
 253         /*
 254          * Descendent dbufs, ordered by dbuf_compare. Note that dn_dbufs
 255          * can contain multiple dbufs of the same (level, blkid) when a
 256          * dbuf is marked DB_EVICTING without being removed from
 257          * dn_dbufs. To maintain the avl invariant that there cannot be
 258          * duplicate entries, we order the dbufs by an arbitrary value -
 259          * their address in memory. This means that dn_dbufs cannot be used to
 260          * directly look up a dbuf. Instead, callers must use avl_walk, have
 261          * a reference to the dbuf, or look up a non-existant node with
 262          * db_state = DB_SEARCH (see dbuf_free_range for an example).
 263          */
 264         avl_tree_t dn_dbufs;
 265
 266         /* protected by dn_struct_rwlock */
 267         struct dmu_buf_impl *dn_bonus;  /* bonus buffer dbuf */
 268
 269         boolean_t dn_have_spill;        /* have spill or are spilling */
 270
 271         /* parent IO for current sync write */
 272         zio_t *dn_zio;
 273
 274         /* used in syncing context */
 275         uint64_t dn_oldused;    /* old phys used bytes */
 276         uint64_t dn_oldflags;   /* old phys dn_flags */
 277         uint64_t dn_olduid, dn_oldgid;
 278         uint64_t dn_newuid, dn_newgid;
 279         int dn_id_flags;
 280
 281         /* holds prefetch structure */
 282         struct zfetch   dn_zfetch;
 283 } dnode_t;
 284
 285 /*
 286  * Adds a level of indirection between the dbuf and the dnode to avoid
 287  * iterating descendent dbufs in dnode_move(). Handles are not allocated
 288  * individually, but as an array of child dnodes in dnode_hold_impl().
 289  */
 290 typedef struct dnode_handle {
 291         /* Protects dnh_dnode from modification by dnode_move(). */
 292         zrlock_t dnh_zrlock;
 293         dnode_t *dnh_dnode;
 294 } dnode_handle_t;
 295
 296 typedef struct dnode_children {
 297         dmu_buf_user_t dnc_dbu;         /* User evict data */
 298         size_t dnc_count;               /* number of children */
 299         dnode_handle_t dnc_children[];  /* sized dynamically */
 300 } dnode_children_t;
 301
 302 typedef struct free_range {
 303         avl_node_t fr_node;
 304         uint64_t fr_blkid;
 305         uint64_t fr_nblks;
 306 } free_range_t;
 307
 308 void dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
 309     uint64_t object, dnode_handle_t *dnh);
 310 void dnode_special_close(dnode_handle_t *dnh);
 311
 312 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
 313 void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
 314 void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
 315
 316 int dnode_hold(struct objset *dd, uint64_t object,
 317     void *ref, dnode_t **dnp);
 318 int dnode_hold_impl(struct objset *dd, uint64_t object, int flag, int dn_slots,
 319     void *ref, dnode_t **dnp);
 320 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
 321 void dnode_rele(dnode_t *dn, void *ref);
 322 void dnode_rele_and_unlock(dnode_t *dn, void *tag);
 323 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
 324 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
 325 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
 326     dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx);
 327 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
 328     dmu_object_type_t bonustype, int bonuslen, int dn_slots, dmu_tx_t *tx);
 329 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
 330 void dnode_byteswap(dnode_phys_t *dnp);
 331 void dnode_buf_byteswap(void *buf, size_t size);
 332 void dnode_verify(dnode_t *dn);
 333 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
 334 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
 335 void dnode_diduse_space(dnode_t *dn, int64_t space);
 336 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
 337 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
 338 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
 339 void dnode_init(void);
 340 void dnode_fini(void);
 341 int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
 342     int minlvl, uint64_t blkfill, uint64_t txg);
 343 void dnode_evict_dbufs(dnode_t *dn);
 344 void dnode_evict_bonus(dnode_t *dn);
 345
 346 #ifdef ZFS_DEBUG
 347
 348 /*
 349  * There should be a ## between the string literal and fmt, to make it
 350  * clear that we're joining two strings together, but that piece of shit
 351  * gcc doesn't support that preprocessor token.
 352  */
 353 #define dprintf_dnode(dn, fmt, ...) do { \
 354         if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
 355         char __db_buf[32]; \
 356         uint64_t __db_obj = (dn)->dn_object; \
 357         if (__db_obj == DMU_META_DNODE_OBJECT) \
 358                 (void) strcpy(__db_buf, "mdn"); \
 359         else \
 360                 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
 361                     (u_longlong_t)__db_obj);\
 362         dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
 363             __db_buf, __VA_ARGS__); \
 364         } \
 365 _NOTE(CONSTCOND) } while (0)
 366
 367 #define DNODE_VERIFY(dn)                dnode_verify(dn)
 368 #define FREE_VERIFY(db, start, end, tx) free_verify(db, start, end, tx)
 369
 370 #else
 371
 372 #define dprintf_dnode(db, fmt, ...)
 373 #define DNODE_VERIFY(dn)
 374 #define FREE_VERIFY(db, start, end, tx)
 375
 376 #endif
 377
 378 #ifdef  __cplusplus
 379 }
 380 #endif
 381
 382 #endif  /* _SYS_DNODE_H */