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 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  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
  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  * Derived constants.
  67  */
  68 #define DNODE_SIZE      (1 << DNODE_SHIFT)
  69 #define DN_MAX_NBLKPTR  ((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
  70 #define DN_MAX_BONUSLEN (DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
  71 #define DN_MAX_OBJECT   (1ULL << DN_MAX_OBJECT_SHIFT)
  72 #define DN_ZERO_BONUSLEN        (DN_MAX_BONUSLEN + 1)
  73
  74 #define DNODES_PER_BLOCK_SHIFT  (DNODE_BLOCK_SHIFT - DNODE_SHIFT)
  75 #define DNODES_PER_BLOCK        (1ULL << DNODES_PER_BLOCK_SHIFT)
  76 #define DNODES_PER_LEVEL_SHIFT  (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
  77
  78 /* The +2 here is a cheesy way to round up */
  79 #define DN_MAX_LEVELS   (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
  80         (DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
  81
  82 #define DN_BONUS(dnp)   ((void*)((dnp)->dn_bonus + \
  83         (((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
  84
  85 #define DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
  86         (dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
  87
  88 #define EPB(blkshift, typeshift)        (1 << (blkshift - typeshift))
  89
  90 struct dmu_buf_impl;
  91 struct objset_impl;
  92 struct zio;
  93
  94 enum dnode_dirtycontext {
  95         DN_UNDIRTIED,
  96         DN_DIRTY_OPEN,
  97         DN_DIRTY_SYNC
  98 };
  99
 100 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
 101 #define DNODE_FLAG_USED_BYTES           (1<<0)
 102 #define DNODE_FLAG_USERUSED_ACCOUNTED   (1<<1)
 103
 104 typedef struct dnode_phys {
 105         uint8_t dn_type;                /* dmu_object_type_t */
 106         uint8_t dn_indblkshift;         /* ln2(indirect block size) */
 107         uint8_t dn_nlevels;             /* 1=dn_blkptr->data blocks */
 108         uint8_t dn_nblkptr;             /* length of dn_blkptr */
 109         uint8_t dn_bonustype;           /* type of data in bonus buffer */
 110         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 111         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 112         uint8_t dn_flags;               /* DNODE_FLAG_* */
 113         uint16_t dn_datablkszsec;       /* data block size in 512b sectors */
 114         uint16_t dn_bonuslen;           /* length of dn_bonus */
 115         uint8_t dn_pad2[4];
 116
 117         /* accounting is protected by dn_dirty_mtx */
 118         uint64_t dn_maxblkid;           /* largest allocated block ID */
 119         uint64_t dn_used;               /* bytes (or sectors) of disk space */
 120
 121         uint64_t dn_pad3[4];
 122
 123         blkptr_t dn_blkptr[1];
 124         uint8_t dn_bonus[DN_MAX_BONUSLEN];
 125 } dnode_phys_t;
 126
 127 typedef struct dnode {
 128         /*
 129          * dn_struct_rwlock protects the structure of the dnode,
 130          * including the number of levels of indirection (dn_nlevels),
 131          * dn_maxblkid, and dn_next_*
 132          */
 133         krwlock_t dn_struct_rwlock;
 134
 135         /* Our link on dn_objset->os_dnodes list; protected by os_lock.  */
 136         list_node_t dn_link;
 137
 138         /* immutable: */
 139         struct objset_impl *dn_objset;
 140         uint64_t dn_object;
 141         struct dmu_buf_impl *dn_dbuf;
 142         dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
 143
 144         /*
 145          * Copies of stuff in dn_phys.  They're valid in the open
 146          * context (eg. even before the dnode is first synced).
 147          * Where necessary, these are protected by dn_struct_rwlock.
 148          */
 149         dmu_object_type_t dn_type;      /* object type */
 150         uint16_t dn_bonuslen;           /* bonus length */
 151         uint8_t dn_bonustype;           /* bonus type */
 152         uint8_t dn_nblkptr;             /* number of blkptrs (immutable) */
 153         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 154         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 155         uint8_t dn_nlevels;
 156         uint8_t dn_indblkshift;
 157         uint8_t dn_datablkshift;        /* zero if blksz not power of 2! */
 158         uint16_t dn_datablkszsec;       /* in 512b sectors */
 159         uint32_t dn_datablksz;          /* in bytes */
 160         uint64_t dn_maxblkid;
 161         uint8_t dn_next_nblkptr[TXG_SIZE];
 162         uint8_t dn_next_nlevels[TXG_SIZE];
 163         uint8_t dn_next_indblkshift[TXG_SIZE];
 164         uint16_t dn_next_bonuslen[TXG_SIZE];
 165         uint32_t dn_next_blksz[TXG_SIZE];       /* next block size in bytes */
 166
 167         /* protected by os_lock: */
 168         list_node_t dn_dirty_link[TXG_SIZE];    /* next on dataset's dirty */
 169
 170         /* protected by dn_mtx: */
 171         kmutex_t dn_mtx;
 172         list_t dn_dirty_records[TXG_SIZE];
 173         avl_tree_t dn_ranges[TXG_SIZE];
 174         uint64_t dn_allocated_txg;
 175         uint64_t dn_free_txg;
 176         uint64_t dn_assigned_txg;
 177         kcondvar_t dn_notxholds;
 178         enum dnode_dirtycontext dn_dirtyctx;
 179         uint8_t *dn_dirtyctx_firstset;          /* dbg: contents meaningless */
 180
 181         /* protected by own devices */
 182         refcount_t dn_tx_holds;
 183         refcount_t dn_holds;
 184
 185         kmutex_t dn_dbufs_mtx;
 186         list_t dn_dbufs;                /* linked list of descendent dbuf_t's */
 187         struct dmu_buf_impl *dn_bonus;  /* bonus buffer dbuf */
 188
 189         /* parent IO for current sync write */
 190         zio_t *dn_zio;
 191
 192         /* used in syncing context */
 193         dnode_phys_t *dn_oldphys;
 194
 195         /* holds prefetch structure */
 196         struct zfetch   dn_zfetch;
 197 } dnode_t;
 198
 199 typedef struct free_range {
 200         avl_node_t fr_node;
 201         uint64_t fr_blkid;
 202         uint64_t fr_nblks;
 203 } free_range_t;
 204
 205 dnode_t *dnode_special_open(struct objset_impl *dd, dnode_phys_t *dnp,
 206     uint64_t object);
 207 void dnode_special_close(dnode_t *dn);
 208
 209 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
 210 int dnode_hold(struct objset_impl *dd, uint64_t object,
 211     void *ref, dnode_t **dnp);
 212 int dnode_hold_impl(struct objset_impl *dd, uint64_t object, int flag,
 213     void *ref, dnode_t **dnp);
 214 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
 215 void dnode_rele(dnode_t *dn, void *ref);
 216 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
 217 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
 218 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
 219     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
 220 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
 221     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
 222 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
 223 void dnode_byteswap(dnode_phys_t *dnp);
 224 void dnode_buf_byteswap(void *buf, size_t size);
 225 void dnode_verify(dnode_t *dn);
 226 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
 227 uint64_t dnode_current_max_length(dnode_t *dn);
 228 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
 229 void dnode_clear_range(dnode_t *dn, uint64_t blkid,
 230     uint64_t nblks, dmu_tx_t *tx);
 231 void dnode_diduse_space(dnode_t *dn, int64_t space);
 232 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
 233 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx, boolean_t);
 234 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
 235 void dnode_init(void);
 236 void dnode_fini(void);
 237 int dnode_next_offset(dnode_t *dn, int flags, uint64_t *off,
 238     int minlvl, uint64_t blkfill, uint64_t txg);
 239 void dnode_evict_dbufs(dnode_t *dn);
 240
 241 #ifdef ZFS_DEBUG
 242
 243 /*
 244  * There should be a ## between the string literal and fmt, to make it
 245  * clear that we're joining two strings together, but that piece of shit
 246  * gcc doesn't support that preprocessor token.
 247  */
 248 #define dprintf_dnode(dn, fmt, ...) do { \
 249         if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
 250         char __db_buf[32]; \
 251         uint64_t __db_obj = (dn)->dn_object; \
 252         if (__db_obj == DMU_META_DNODE_OBJECT) \
 253                 (void) strcpy(__db_buf, "mdn"); \
 254         else \
 255                 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
 256                     (u_longlong_t)__db_obj);\
 257         dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
 258             __db_buf, __VA_ARGS__); \
 259         } \
 260 _NOTE(CONSTCOND) } while (0)
 261
 262 #define DNODE_VERIFY(dn)                dnode_verify(dn)
 263 #define FREE_VERIFY(db, start, end, tx) free_verify(db, start, end, tx)
 264
 265 #else
 266
 267 #define dprintf_dnode(db, fmt, ...)
 268 #define DNODE_VERIFY(dn)
 269 #define FREE_VERIFY(db, start, end, tx)
 270
 271 #endif
 272
 273 #ifdef  __cplusplus
 274 }
 275 #endif
 276
 277 #endif  /* _SYS_DNODE_H */