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