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) 2013 by Delphix. All rights reserved.
  24  */
  25
  26 #ifndef _SYS_DNODE_H
  27 #define _SYS_DNODE_H
  28
  29 #include <sys/zfs_context.h>
  30 #include <sys/avl.h>
  31 #include <sys/spa.h>
  32 #include <sys/txg.h>
  33 #include <sys/zio.h>
  34 #include <sys/refcount.h>
  35 #include <sys/dmu_zfetch.h>
  36 #include <sys/zrlock.h>
  37
  38 #ifdef  __cplusplus
  39 extern "C" {
  40 #endif
  41
  42 /*
  43  * dnode_hold() flags.
  44  */
  45 #define DNODE_MUST_BE_ALLOCATED 1
  46 #define DNODE_MUST_BE_FREE      2
  47
  48 /*
  49  * dnode_next_offset() flags.
  50  */
  51 #define DNODE_FIND_HOLE         1
  52 #define DNODE_FIND_BACKWARDS    2
  53 #define DNODE_FIND_HAVELOCK     4
  54
  55 /*
  56  * Fixed constants.
  57  */
  58 #define DNODE_SHIFT             9       /* 512 bytes */
  59 #define DN_MIN_INDBLKSHIFT      10      /* 1k */
  60 #define DN_MAX_INDBLKSHIFT      14      /* 16k */
  61 #define DNODE_BLOCK_SHIFT       14      /* 16k */
  62 #define DNODE_CORE_SIZE         64      /* 64 bytes for dnode sans blkptrs */
  63 #define DN_MAX_OBJECT_SHIFT     48      /* 256 trillion (zfs_fid_t limit) */
  64 #define DN_MAX_OFFSET_SHIFT     64      /* 2^64 bytes in a dnode */
  65
  66 /*
  67  * dnode id flags
  68  *
  69  * Note: a file will never ever have its
  70  * ids moved from bonus->spill
  71  * and only in a crypto environment would it be on spill
  72  */
  73 #define DN_ID_CHKED_BONUS       0x1
  74 #define DN_ID_CHKED_SPILL       0x2
  75 #define DN_ID_OLD_EXIST         0x4
  76 #define DN_ID_NEW_EXIST         0x8
  77
  78 /*
  79  * Derived constants.
  80  */
  81 #define DNODE_SIZE      (1 << DNODE_SHIFT)
  82 #define DN_MAX_NBLKPTR  ((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
  83 #define DN_MAX_BONUSLEN (DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
  84 #define DN_MAX_OBJECT   (1ULL << DN_MAX_OBJECT_SHIFT)
  85 #define DN_ZERO_BONUSLEN        (DN_MAX_BONUSLEN + 1)
  86 #define DN_KILL_SPILLBLK (1)
  87
  88 #define DNODES_PER_BLOCK_SHIFT  (DNODE_BLOCK_SHIFT - DNODE_SHIFT)
  89 #define DNODES_PER_BLOCK        (1ULL << DNODES_PER_BLOCK_SHIFT)
  90 #define DNODES_PER_LEVEL_SHIFT  (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
  91 #define DNODES_PER_LEVEL        (1ULL << DNODES_PER_LEVEL_SHIFT)
  92
  93 /* The +2 here is a cheesy way to round up */
  94 #define DN_MAX_LEVELS   (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
  95         (DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
  96
  97 #define DN_BONUS(dnp)   ((void*)((dnp)->dn_bonus + \
  98         (((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
  99
 100 #define DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
 101         (dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
 102
 103 #define EPB(blkshift, typeshift)        (1 << (blkshift - typeshift))
 104
 105 struct dmu_buf_impl;
 106 struct objset;
 107 struct zio;
 108
 109 enum dnode_dirtycontext {
 110         DN_UNDIRTIED,
 111         DN_DIRTY_OPEN,
 112         DN_DIRTY_SYNC
 113 };
 114
 115 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
 116 #define DNODE_FLAG_USED_BYTES           (1<<0)
 117 #define DNODE_FLAG_USERUSED_ACCOUNTED   (1<<1)
 118
 119 /* Does dnode have a SA spill blkptr in bonus? */
 120 #define DNODE_FLAG_SPILL_BLKPTR (1<<2)
 121
 122 typedef struct dnode_phys {
 123         uint8_t dn_type;                /* dmu_object_type_t */
 124         uint8_t dn_indblkshift;         /* ln2(indirect block size) */
 125         uint8_t dn_nlevels;             /* 1=dn_blkptr->data blocks */
 126         uint8_t dn_nblkptr;             /* length of dn_blkptr */
 127         uint8_t dn_bonustype;           /* type of data in bonus buffer */
 128         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 129         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 130         uint8_t dn_flags;               /* DNODE_FLAG_* */
 131         uint16_t dn_datablkszsec;       /* data block size in 512b sectors */
 132         uint16_t dn_bonuslen;           /* length of dn_bonus */
 133         uint8_t dn_pad2[4];
 134
 135         /* accounting is protected by dn_dirty_mtx */
 136         uint64_t dn_maxblkid;           /* largest allocated block ID */
 137         uint64_t dn_used;               /* bytes (or sectors) of disk space */
 138
 139         uint64_t dn_pad3[4];
 140
 141         /*
 142          * The tail region is 448 bytes, and there are three ways to
 143          * look at it.
 144          *
 145          * 0       64      128     192     256     320     384     448 (offset)
 146          * +---------------+---------------+---------------+-------+
 147          * | dn_blkptr[0]  | dn_blkptr[1]  | dn_blkptr[2]  | /     |
 148          * +---------------+---------------+---------------+-------+
 149          * | dn_blkptr[0]  | dn_bonus[0..319]                      |
 150          * +---------------+-----------------------+---------------+
 151          * | dn_blkptr[0]  | /                     | dn_spill      |
 152          * +---------------+-----------------------+---------------+
 153          */
 154         union {
 155                 blkptr_t dn_blkptr[1+DN_MAX_BONUSLEN/sizeof (blkptr_t)];
 156                 struct {
 157                         blkptr_t __dn_ignore1;
 158                         uint8_t dn_bonus[DN_MAX_BONUSLEN];
 159                 };
 160                 struct {
 161                         blkptr_t __dn_ignore2;
 162                         uint8_t __dn_ignore3[DN_MAX_BONUSLEN-sizeof (blkptr_t)];
 163                         blkptr_t dn_spill;
 164                 };
 165         };
 166 } dnode_phys_t;
 167
 168 typedef struct dnode {
 169         /*
 170          * Protects the structure of the dnode, including the number of levels
 171          * of indirection (dn_nlevels), dn_maxblkid, and dn_next_*
 172          */
 173         krwlock_t dn_struct_rwlock;
 174
 175         /* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
 176         list_node_t dn_link;
 177
 178         /* immutable: */
 179         struct objset *dn_objset;
 180         uint64_t dn_object;
 181         struct dmu_buf_impl *dn_dbuf;
 182         struct dnode_handle *dn_handle;
 183         dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
 184
 185         /*
 186          * Copies of stuff in dn_phys.  They're valid in the open
 187          * context (eg. even before the dnode is first synced).
 188          * Where necessary, these are protected by dn_struct_rwlock.
 189          */
 190         dmu_object_type_t dn_type;      /* object type */
 191         uint16_t dn_bonuslen;           /* bonus length */
 192         uint8_t dn_bonustype;           /* bonus type */
 193         uint8_t dn_nblkptr;             /* number of blkptrs (immutable) */
 194         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 195         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 196         uint8_t dn_nlevels;
 197         uint8_t dn_indblkshift;
 198         uint8_t dn_datablkshift;        /* zero if blksz not power of 2! */
 199         uint8_t dn_moved;               /* Has this dnode been moved? */
 200         uint16_t dn_datablkszsec;       /* in 512b sectors */
 201         uint32_t dn_datablksz;          /* in bytes */
 202         uint64_t dn_maxblkid;
 203         uint8_t dn_next_type[TXG_SIZE];
 204         uint8_t dn_next_nblkptr[TXG_SIZE];
 205         uint8_t dn_next_nlevels[TXG_SIZE];
 206         uint8_t dn_next_indblkshift[TXG_SIZE];
 207         uint8_t dn_next_bonustype[TXG_SIZE];
 208         uint8_t dn_rm_spillblk[TXG_SIZE];       /* for removing spill blk */
 209         uint16_t dn_next_bonuslen[TXG_SIZE];
 210         uint32_t dn_next_blksz[TXG_SIZE];       /* next block size in bytes */
 211
 212         /* protected by dn_dbufs_mtx; declared here to fill 32-bit hole */
 213         uint32_t dn_dbufs_count;        /* count of dn_dbufs */
 214         /* There are no level-0 blocks of this blkid or higher in dn_dbufs */
 215         uint64_t dn_unlisted_l0_blkid;
 216
 217         /* protected by os_lock: */
 218         list_node_t dn_dirty_link[TXG_SIZE];    /* next on dataset's dirty */
 219
 220         /* protected by dn_mtx: */
 221         kmutex_t dn_mtx;
 222         list_t dn_dirty_records[TXG_SIZE];
 223         avl_tree_t dn_ranges[TXG_SIZE];
 224         uint64_t dn_allocated_txg;
 225         uint64_t dn_free_txg;
 226         uint64_t dn_assigned_txg;
 227         kcondvar_t dn_notxholds;
 228         enum dnode_dirtycontext dn_dirtyctx;
 229         uint8_t *dn_dirtyctx_firstset;          /* dbg: contents meaningless */
 230
 231         /* protected by own devices */
 232         refcount_t dn_tx_holds;
 233         refcount_t dn_holds;
 234
 235         kmutex_t dn_dbufs_mtx;
 236         list_t dn_dbufs;                /* descendent dbufs */
 237
 238         /* protected by dn_struct_rwlock */
 239         struct dmu_buf_impl *dn_bonus;  /* bonus buffer dbuf */
 240
 241         boolean_t dn_have_spill;        /* have spill or are spilling */
 242
 243         /* parent IO for current sync write */
 244         zio_t *dn_zio;
 245
 246         /* used in syncing context */
 247         uint64_t dn_oldused;    /* old phys used bytes */
 248         uint64_t dn_oldflags;   /* old phys dn_flags */
 249         uint64_t dn_olduid, dn_oldgid;
 250         uint64_t dn_newuid, dn_newgid;
 251         int dn_id_flags;
 252
 253         /* holds prefetch structure */
 254         struct zfetch   dn_zfetch;
 255 } dnode_t;
 256
 257 /*
 258  * Adds a level of indirection between the dbuf and the dnode to avoid
 259  * iterating descendent dbufs in dnode_move(). Handles are not allocated
 260  * individually, but as an array of child dnodes in dnode_hold_impl().
 261  */
 262 typedef struct dnode_handle {
 263         /* Protects dnh_dnode from modification by dnode_move(). */
 264         zrlock_t dnh_zrlock;
 265         dnode_t *dnh_dnode;
 266 } dnode_handle_t;
 267
 268 typedef struct dnode_children {
 269         size_t dnc_count;               /* number of children */
 270         dnode_handle_t dnc_children[1]; /* sized dynamically */
 271 } dnode_children_t;
 272
 273 typedef struct free_range {
 274         avl_node_t fr_node;
 275         uint64_t fr_blkid;
 276         uint64_t fr_nblks;
 277 } free_range_t;
 278
 279 dnode_t *dnode_special_open(struct objset *dd, dnode_phys_t *dnp,
 280     uint64_t object, dnode_handle_t *dnh);
 281 void dnode_special_close(dnode_handle_t *dnh);
 282
 283 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
 284 void dnode_setbonus_type(dnode_t *dn, dmu_object_type_t, dmu_tx_t *tx);
 285 void dnode_rm_spill(dnode_t *dn, dmu_tx_t *tx);
 286
 287 int dnode_hold(struct objset *dd, uint64_t object,
 288     void *ref, dnode_t **dnp);
 289 int dnode_hold_impl(struct objset *dd, uint64_t object, int flag,
 290     void *ref, dnode_t **dnp);
 291 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
 292 void dnode_rele(dnode_t *dn, void *ref);
 293 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
 294 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
 295 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
 296     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
 297 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
 298     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
 299 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
 300 void dnode_byteswap(dnode_phys_t *dnp);
 301 void dnode_buf_byteswap(void *buf, size_t size);
 302 void dnode_verify(dnode_t *dn);
 303 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
 304 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
 305 void dnode_clear_range(dnode_t *dn, uint64_t blkid,
 306     uint64_t nblks, dmu_tx_t *tx);
 307 void dnode_diduse_space(dnode_t *dn, int64_t space);
 308 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
 309 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
 310 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
 311 void dnode_init(void);
 312 void dnode_fini(void);
 313 int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
 314     int minlvl, uint64_t blkfill, uint64_t txg);
 315 void dnode_evict_dbufs(dnode_t *dn);
 316
 317 #ifdef ZFS_DEBUG
 318
 319 /*
 320  * There should be a ## between the string literal and fmt, to make it
 321  * clear that we're joining two strings together, but that piece of shit
 322  * gcc doesn't support that preprocessor token.
 323  */
 324 #define dprintf_dnode(dn, fmt, ...) do { \
 325         if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
 326         char __db_buf[32]; \
 327         uint64_t __db_obj = (dn)->dn_object; \
 328         if (__db_obj == DMU_META_DNODE_OBJECT) \
 329                 (void) strcpy(__db_buf, "mdn"); \
 330         else \
 331                 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
 332                     (u_longlong_t)__db_obj);\
 333         dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
 334             __db_buf, __VA_ARGS__); \
 335         } \
 336 _NOTE(CONSTCOND) } while (0)
 337
 338 #define DNODE_VERIFY(dn)                dnode_verify(dn)
 339 #define FREE_VERIFY(db, start, end, tx) free_verify(db, start, end, tx)
 340
 341 #else
 342
 343 #define dprintf_dnode(db, fmt, ...)
 344 #define DNODE_VERIFY(dn)
 345 #define FREE_VERIFY(db, start, end, tx)
 346
 347 #endif
 348
 349 #ifdef  __cplusplus
 350 }
 351 #endif
 352
 353 #endif  /* _SYS_DNODE_H */