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