zfs/lib/libzcommon/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 2007 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 #pragma ident   "@(#)dnode.h    1.12    07/08/26 SMI"
  30
  31 #include <sys/zfs_context.h>
  32 #include <sys/avl.h>
  33 #include <sys/spa.h>
  34 #include <sys/txg.h>
  35 #include <sys/zio.h>
  36 #include <sys/refcount.h>
  37 #include <sys/dmu_zfetch.h>
  38
  39 #ifdef  __cplusplus
  40 extern "C" {
  41 #endif
  42
  43 /*
  44  * Flags.
  45  */
  46 #define DNODE_MUST_BE_ALLOCATED 1
  47 #define DNODE_MUST_BE_FREE      2
  48
  49 /*
  50  * Fixed constants.
  51  */
  52 #define DNODE_SHIFT             9       /* 512 bytes */
  53 #define DN_MIN_INDBLKSHIFT      10      /* 1k */
  54 #define DN_MAX_INDBLKSHIFT      14      /* 16k */
  55 #define DNODE_BLOCK_SHIFT       14      /* 16k */
  56 #define DNODE_CORE_SIZE         64      /* 64 bytes for dnode sans blkptrs */
  57 #define DN_MAX_OBJECT_SHIFT     48      /* 256 trillion (zfs_fid_t limit) */
  58 #define DN_MAX_OFFSET_SHIFT     64      /* 2^64 bytes in a dnode */
  59
  60 /*
  61  * Derived constants.
  62  */
  63 #define DNODE_SIZE      (1 << DNODE_SHIFT)
  64 #define DN_MAX_NBLKPTR  ((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
  65 #define DN_MAX_BONUSLEN (DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
  66 #define DN_MAX_OBJECT   (1ULL << DN_MAX_OBJECT_SHIFT)
  67 #define DN_ZERO_BONUSLEN        (DN_MAX_BONUSLEN + 1)
  68
  69 #define DNODES_PER_BLOCK_SHIFT  (DNODE_BLOCK_SHIFT - DNODE_SHIFT)
  70 #define DNODES_PER_BLOCK        (1ULL << DNODES_PER_BLOCK_SHIFT)
  71 #define DNODES_PER_LEVEL_SHIFT  (DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
  72
  73 /* The +2 here is a cheesy way to round up */
  74 #define DN_MAX_LEVELS   (2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
  75         (DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
  76
  77 #define DN_BONUS(dnp)   ((void*)((dnp)->dn_bonus + \
  78         (((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
  79
  80 #define DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
  81         (dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
  82
  83 #define EPB(blkshift, typeshift)        (1 << (blkshift - typeshift))
  84
  85 struct dmu_buf_impl;
  86 struct objset_impl;
  87 struct zio;
  88
  89 enum dnode_dirtycontext {
  90         DN_UNDIRTIED,
  91         DN_DIRTY_OPEN,
  92         DN_DIRTY_SYNC
  93 };
  94
  95 /* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
  96 #define DNODE_FLAG_USED_BYTES   (1<<0)
  97
  98 typedef struct dnode_phys {
  99         uint8_t dn_type;                /* dmu_object_type_t */
 100         uint8_t dn_indblkshift;         /* ln2(indirect block size) */
 101         uint8_t dn_nlevels;             /* 1=dn_blkptr->data blocks */
 102         uint8_t dn_nblkptr;             /* length of dn_blkptr */
 103         uint8_t dn_bonustype;           /* type of data in bonus buffer */
 104         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 105         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 106         uint8_t dn_flags;               /* DNODE_FLAG_* */
 107         uint16_t dn_datablkszsec;       /* data block size in 512b sectors */
 108         uint16_t dn_bonuslen;           /* length of dn_bonus */
 109         uint8_t dn_pad2[4];
 110
 111         /* accounting is protected by dn_dirty_mtx */
 112         uint64_t dn_maxblkid;           /* largest allocated block ID */
 113         uint64_t dn_used;               /* bytes (or sectors) of disk space */
 114
 115         uint64_t dn_pad3[4];
 116
 117         blkptr_t dn_blkptr[1];
 118         uint8_t dn_bonus[DN_MAX_BONUSLEN];
 119 } dnode_phys_t;
 120
 121 typedef struct dnode {
 122         /*
 123          * dn_struct_rwlock protects the structure of the dnode,
 124          * including the number of levels of indirection (dn_nlevels),
 125          * dn_maxblkid, and dn_next_*
 126          */
 127         krwlock_t dn_struct_rwlock;
 128
 129         /*
 130          * Our link on dataset's dd_dnodes list.
 131          * Protected by dd_accounting_mtx.
 132          */
 133         list_node_t dn_link;
 134
 135         /* immutable: */
 136         struct objset_impl *dn_objset;
 137         uint64_t dn_object;
 138         struct dmu_buf_impl *dn_dbuf;
 139         dnode_phys_t *dn_phys; /* pointer into dn->dn_dbuf->db.db_data */
 140
 141         /*
 142          * Copies of stuff in dn_phys.  They're valid in the open
 143          * context (eg. even before the dnode is first synced).
 144          * Where necessary, these are protected by dn_struct_rwlock.
 145          */
 146         dmu_object_type_t dn_type;      /* object type */
 147         uint16_t dn_bonuslen;           /* bonus length */
 148         uint8_t dn_bonustype;           /* bonus type */
 149         uint8_t dn_nblkptr;             /* number of blkptrs (immutable) */
 150         uint8_t dn_checksum;            /* ZIO_CHECKSUM type */
 151         uint8_t dn_compress;            /* ZIO_COMPRESS type */
 152         uint8_t dn_nlevels;
 153         uint8_t dn_indblkshift;
 154         uint8_t dn_datablkshift;        /* zero if blksz not power of 2! */
 155         uint16_t dn_datablkszsec;       /* in 512b sectors */
 156         uint32_t dn_datablksz;          /* in bytes */
 157         uint64_t dn_maxblkid;
 158         uint8_t dn_next_nlevels[TXG_SIZE];
 159         uint8_t dn_next_indblkshift[TXG_SIZE];
 160         uint16_t dn_next_bonuslen[TXG_SIZE];
 161         uint32_t dn_next_blksz[TXG_SIZE];       /* next block size in bytes */
 162
 163         /* protected by os_lock: */
 164         list_node_t dn_dirty_link[TXG_SIZE];    /* next on dataset's dirty */
 165
 166         /* protected by dn_mtx: */
 167         kmutex_t dn_mtx;
 168         list_t dn_dirty_records[TXG_SIZE];
 169         avl_tree_t dn_ranges[TXG_SIZE];
 170         uint64_t dn_allocated_txg;
 171         uint64_t dn_free_txg;
 172         uint64_t dn_assigned_txg;
 173         kcondvar_t dn_notxholds;
 174         enum dnode_dirtycontext dn_dirtyctx;
 175         uint8_t *dn_dirtyctx_firstset;          /* dbg: contents meaningless */
 176
 177         /* protected by own devices */
 178         refcount_t dn_tx_holds;
 179         refcount_t dn_holds;
 180
 181         kmutex_t dn_dbufs_mtx;
 182         list_t dn_dbufs;                /* linked list of descendent dbuf_t's */
 183         struct dmu_buf_impl *dn_bonus;  /* bonus buffer dbuf */
 184
 185         /* parent IO for current sync write */
 186         zio_t *dn_zio;
 187
 188         /* holds prefetch structure */
 189         struct zfetch   dn_zfetch;
 190 } dnode_t;
 191
 192 typedef struct free_range {
 193         avl_node_t fr_node;
 194         uint64_t fr_blkid;
 195         uint64_t fr_nblks;
 196 } free_range_t;
 197
 198 dnode_t *dnode_special_open(struct objset_impl *dd, dnode_phys_t *dnp,
 199     uint64_t object);
 200 void dnode_special_close(dnode_t *dn);
 201
 202 void dnode_setbonuslen(dnode_t *dn, int newsize, dmu_tx_t *tx);
 203 int dnode_hold(struct objset_impl *dd, uint64_t object,
 204     void *ref, dnode_t **dnp);
 205 int dnode_hold_impl(struct objset_impl *dd, uint64_t object, int flag,
 206     void *ref, dnode_t **dnp);
 207 boolean_t dnode_add_ref(dnode_t *dn, void *ref);
 208 void dnode_rele(dnode_t *dn, void *ref);
 209 void dnode_setdirty(dnode_t *dn, dmu_tx_t *tx);
 210 void dnode_sync(dnode_t *dn, dmu_tx_t *tx);
 211 void dnode_allocate(dnode_t *dn, dmu_object_type_t ot, int blocksize, int ibs,
 212     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
 213 void dnode_reallocate(dnode_t *dn, dmu_object_type_t ot, int blocksize,
 214     dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
 215 void dnode_free(dnode_t *dn, dmu_tx_t *tx);
 216 void dnode_byteswap(dnode_phys_t *dnp);
 217 void dnode_buf_byteswap(void *buf, size_t size);
 218 void dnode_verify(dnode_t *dn);
 219 int dnode_set_blksz(dnode_t *dn, uint64_t size, int ibs, dmu_tx_t *tx);
 220 uint64_t dnode_current_max_length(dnode_t *dn);
 221 void dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx);
 222 void dnode_clear_range(dnode_t *dn, uint64_t blkid,
 223     uint64_t nblks, dmu_tx_t *tx);
 224 void dnode_diduse_space(dnode_t *dn, int64_t space);
 225 void dnode_willuse_space(dnode_t *dn, int64_t space, dmu_tx_t *tx);
 226 void dnode_new_blkid(dnode_t *dn, uint64_t blkid, dmu_tx_t *tx);
 227 uint64_t dnode_block_freed(dnode_t *dn, uint64_t blkid);
 228 void dnode_init(void);
 229 void dnode_fini(void);
 230 int dnode_next_offset(dnode_t *dn, boolean_t hole, uint64_t *off, int minlvl,
 231     uint64_t blkfill, uint64_t txg);
 232 void dnode_evict_dbufs(dnode_t *dn);
 233
 234 #ifdef ZFS_DEBUG
 235
 236 /*
 237  * There should be a ## between the string literal and fmt, to make it
 238  * clear that we're joining two strings together, but that piece of shit
 239  * gcc doesn't support that preprocessor token.
 240  */
 241 #define dprintf_dnode(dn, fmt, ...) do { \
 242         if (zfs_flags & ZFS_DEBUG_DPRINTF) { \
 243         char __db_buf[32]; \
 244         uint64_t __db_obj = (dn)->dn_object; \
 245         if (__db_obj == DMU_META_DNODE_OBJECT) \
 246                 (void) strcpy(__db_buf, "mdn"); \
 247         else \
 248                 (void) snprintf(__db_buf, sizeof (__db_buf), "%lld", \
 249                     (u_longlong_t)__db_obj);\
 250         dprintf_ds((dn)->dn_objset->os_dsl_dataset, "obj=%s " fmt, \
 251             __db_buf, __VA_ARGS__); \
 252         } \
 253 _NOTE(CONSTCOND) } while (0)
 254
 255 #define DNODE_VERIFY(dn)                dnode_verify(dn)
 256 #define FREE_VERIFY(db, start, end, tx) free_verify(db, start, end, tx)
 257
 258 #else
 259
 260 #define dprintf_dnode(db, fmt, ...)
 261 #define DNODE_VERIFY(dn)
 262 #define FREE_VERIFY(db, start, end, tx)
 263
 264 #endif
 265
 266 #ifdef  __cplusplus
 267 }
 268 #endif
 269
 270 #endif  /* _SYS_DNODE_H */