src/budb/database.h

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 #include <afs/auth.h>
  11 #include <afs/bubasics.h>
  12 #include <lock.h>
  13 #include "budb.h"
  14
  15 #if !defined(offsetof)
  16 #include <stddef.h>             /* for definition of offsetof() */
  17 #endif
  18
  19 typedef afs_uint32 dbadr;
  20
  21 struct hashTable {
  22     afs_int32 functionType;     /* type of hash function */
  23     afs_int32 threadOffset;     /* Byte offset of hash thread */
  24     afs_int32 entries;          /* number of entries in hash table */
  25     afs_int32 length;           /* number of hash table slots */
  26     dbadr table;                /* pointer to actual table */
  27     afs_int32 progress;         /* number empty buckets in oldTable */
  28     afs_int32 oldLength;        /* slots in old table */
  29     dbadr oldTable;             /* old table */
  30 };
  31
  32 /* text blocks and related structures */
  33
  34 struct textBlock {
  35     afs_uint32 version;         /* for access consistency checks */
  36     afs_int32 size;             /* size in bytes */
  37     dbadr textAddr;             /* list of blocks */
  38     afs_int32 newsize;          /* replacement size */
  39     dbadr newTextAddr;          /* list of new blocks */
  40 };
  41
  42 struct db_lockS {
  43     afs_int32 type;             /* user defined - for consistency checks */
  44     afs_int32 lockState;        /* locked/free */
  45     afs_int32 lockTime;         /* when locked */
  46     afs_int32 expires;          /* when timeout expires */
  47     afs_int32 instanceId;       /* user instance id */
  48     int lockHost;               /* locking host, if possible */
  49 };
  50
  51 typedef struct db_lockS db_lockT;
  52 typedef db_lockT *db_lockP;
  53
  54 /* hash table function types */
  55 #define HT_dumpIden_FUNCTION    1
  56 #define HT_dumpName_FUNCTION    2
  57 #define HT_tapeName_FUNCTION    3
  58 #define HT_volName_FUNCTION     4
  59
  60 #define HT_MAX_FUNCTION         4
  61
  62 /* block types */
  63
  64 #define free_BLOCK              0
  65 #define volFragment_BLOCK       1
  66 #define volInfo_BLOCK           2
  67 #define tape_BLOCK              3
  68 #define dump_BLOCK              4
  69 #define MAX_STRUCTURE_BLOCK_TYPE 4
  70 #define hashTable_BLOCK         5
  71 #define text_BLOCK              6
  72 #define NBLOCKTYPES             7
  73
  74 /* This defines root pointers to all parts of the database.  It is allocated
  75    starting at location zero. */
  76
  77 #define BUDB_VERSION 1
  78
  79 struct dbHeader {
  80     afs_int32 version;          /* database version number */
  81     dumpId lastDumpId;          /* last dump id value */
  82     afs_uint32 lastTapeId;      /* last tape id allocated */
  83     afs_uint32 lastInstanceId;  /* last instance Id handed out */
  84     dbadr freePtrs[NBLOCKTYPES];        /* pointers to free blocks */
  85     dbadr eofPtr;               /* first free byte in db */
  86     afs_int32 nHTBuckets;       /* size of hashtable blocks */
  87     Date lastUpdate;            /* time of last change to database */
  88     afs_int32 ptrs[10];         /* spare pointers */
  89     struct hashTable volName;   /* hash tables */
  90     struct hashTable tapeName;
  91     struct hashTable dumpName;
  92     struct hashTable dumpIden;
  93     db_lockT textLocks[TB_MAX]; /* locks for text blocks */
  94     struct textBlock textBlock[TB_MAX]; /* raw text information */
  95     afs_int32 words[10];        /* spare words */
  96     afs_int32 checkVersion;     /* version# for consistency checking */
  97 };
  98
  99 /* The database is composed of several types of structures of different sizes.
 100    To simplify recovery from crashes, allocation is done in fixed size blocks.
 101    All structures in a block are of the same type.  Each block has a header
 102    which identifies its type, a count of the number of free structures, and a
 103    pointer to the next block of the same type. */
 104
 105 #define BLOCKSIZE 2048
 106 #define BlockBase(a)                                                    \
 107         ((((a) - sizeof(struct dbHeader)) & ~(BLOCKSIZE-1)) +           \
 108          sizeof(struct dbHeader))
 109
 110 struct blockHeader {
 111     char type;                  /* type: implies structure size */
 112     char flags;                 /* miscellaneous bits */
 113     short nFree;                /* number of free structures */
 114     dbadr next;                 /* next free block same type */
 115 };
 116
 117 #define BLOCK_DATA_SIZE (BLOCKSIZE-sizeof(struct blockHeader))
 118
 119 struct block {
 120     struct blockHeader h;
 121     char a[BLOCKSIZE - sizeof(struct blockHeader)];
 122 };
 123
 124 #define NhtBucketS ((BLOCKSIZE-sizeof(struct blockHeader))/sizeof(dbadr))
 125 struct htBlock {
 126     struct blockHeader h;
 127     dbadr bucket[NhtBucketS];
 128 };
 129
 130 /* The database contains one volFragment for every occurence of volume data on
 131  * any tape. */
 132
 133 #define VOLFRAGMENTFLAGS 0xffff
 134 struct volFragment {
 135     dbadr vol;                  /* full volume info */
 136     dbadr sameNameChain;        /* next with same vol info */
 137     dbadr tape;                 /* tape containing this fragment */
 138     dbadr sameTapeChain;        /* next fragment on tape */
 139
 140     afs_int32 position;         /* on tape */
 141     Date clone;                 /* clone date of volume */
 142     Date incTime;               /* time for incremental; 0 => full */
 143     afs_int32 startByte;        /* first byte of volume in this frag */
 144     afs_uint32 nBytes;          /* bytes in fragment */
 145     short flags;                /* miscellaneous bits */
 146     short sequence;             /* seq of frag in dumped volume */
 147 };
 148 #define NvolFragmentS 45
 149 struct vfBlock {
 150     struct blockHeader h;
 151     struct {
 152         struct volFragment s;
 153         char pad[4];
 154     } a[NvolFragmentS];
 155 };
 156
 157
 158 /* This represents additional information about a file system volume that
 159  * changes relatively infrequently.  Its purpose is to minimize the size of the
 160  * folFragment structure. */
 161
 162 #define VOLINFOFLAGS 0xffff0000
 163 struct volInfo {
 164     char name[BU_MAXNAMELEN];   /* name of volume: the hash key */
 165     afs_int32 flags;            /* miscellaneous bits */
 166     afs_int32 id;               /* read-write volume's id */
 167     char server[BU_MAXHOSTLEN]; /* file server */
 168     afs_int32 partition;        /* disk partition on server */
 169     afs_int32 nFrags;           /* number of fragments on list */
 170
 171     dbadr nameHashChain;        /* for volume name hash table */
 172     dbadr sameNameHead;         /* volInfo of first struct this name */
 173     dbadr sameNameChain;        /* next volume with this name */
 174     dbadr firstFragment;        /* all volFragment with this volInfo */
 175 };
 176 #define NvolInfoS 20
 177 struct viBlock {
 178     struct blockHeader h;
 179     struct {
 180         struct volInfo s;
 181         char pad[4];
 182     } a[NvolInfoS];
 183 };
 184
 185
 186 /* The tape structure represents information of every physical tape in the
 187  * backup system.  Some of the data may persist event though the tape's
 188  * contents are repeatedly overwritten. */
 189
 190 struct tape {
 191     char name[BU_MAXTAPELEN];   /* name of physical tape */
 192     afs_int32 flags;            /* miscellaneous bits */
 193     Date written;               /* tape writing started */
 194     Date expires;               /* expiration date */
 195     afs_uint32 nMBytes;         /* length of tape in Mbytes */
 196     afs_uint32 nBytes;          /* remainder of Mbytes  */
 197     afs_int32 nFiles;           /*  ditto for  EOFs */
 198     afs_int32 nVolumes;         /*  ditto for  volume fragments */
 199     afs_int32 seq;              /* sequence in tapeSet */
 200
 201     afs_uint32 labelpos;        /* Position of the tape label */
 202     afs_int32 useCount;         /* # of times used */
 203     afs_int32 useKBytes;        /* How much of tape is used (in KBytes) */
 204
 205     dbadr nameHashChain;        /* for tape name hash table */
 206     dbadr dump;                 /* dump (tapeSet) this is part of */
 207     dbadr nextTape;             /* next tape in dump (tapeSet) */
 208     dbadr firstVol;             /* first volume fragment on tape */
 209 };
 210
 211 #define NtapeS 20
 212 struct tBlock {
 213     struct blockHeader h;
 214     struct {
 215         struct tape s;
 216         char pad[8];
 217     } a[NtapeS];
 218 };
 219
 220 /* The structure describes every dump operation whose contents are still availe
 221  * on at least one tape.
 222  */
 223
 224 struct dump {
 225     /* similar to budb_dumpEntry */
 226     afs_int32 id;               /* unique identifier for dump */
 227     dumpId parent;              /* parent dump */
 228     afs_int32 level;            /* dump level */
 229     afs_int32 flags;            /* miscellaneous bits */
 230     char volumeSet[BU_MAXNAMELEN];      /* name of volume that was dumped */
 231     char dumpPath[BU_MAX_DUMP_PATH];    /* "path" name of dump level */
 232     char dumpName[BU_MAXNAMELEN];       /* dump name */
 233     Date created;               /* time dump initiated */
 234 /*  Date  incTime;                      target time for incremental dumps */
 235     afs_int32 nVolumes;         /* number of volumes in dump */
 236     struct budb_tapeSet tapes;  /* tapes for this dump */
 237     struct ktc_principal dumper;        /* user doing dump */
 238     afs_uint32 initialDumpID;   /* The dumpid of the initisl dump (for appended dumps) */
 239     dbadr appendedDumpChain;    /* Ptr to dump appended to this dump */
 240
 241     dbadr idHashChain;          /* for dump id hash table */
 242     dbadr nameHashChain;        /* for dump name hash table */
 243     dbadr firstTape;            /* first tape in dump (tapeSet) */
 244 };
 245
 246 typedef struct dump dbDumpT;
 247 typedef dbDumpT *dbDumpP;
 248
 249 #define NdumpS 3
 250 struct dBlock {
 251     struct blockHeader h;
 252     struct {
 253         struct dump s;
 254         char pad[44];
 255     } a[NdumpS];
 256 };
 257
 258 /* This structure is used to cache the hash table blocks for a database hash
 259    table.  The htBlock structure is modified slightly to accomodate this
 260    mechanism.  On disk the next ptr links the consecutive blocks of the hash
 261    table together.  In memory this information is inferred */
 262
 263 struct memoryHTBlock {
 264     int valid;                  /* block needs to be read in */
 265     dbadr a;                    /* where stored in db */
 266     struct htBlock b;
 267 };
 268
 269 struct memoryHashTable {
 270     struct hashTable *ht;       /* ptr to appropriate db.h hashtable */
 271     /* these are host byte order version of the corresponding HT fields */
 272     int threadOffset;           /* Byte offset of hash thread */
 273     int length;                 /* number of hash table slots */
 274     int oldLength;              /* slots in old table */
 275     int progress;               /* number empty buckets in oldTable */
 276     /* these are the memory copies of the hash table buckets */
 277     int size;                   /* allocated size of array */
 278     struct memoryHTBlock *(*blocks);    /* ptr to array of ht block pointers */
 279     int oldSize;                /*  ditto for old HT */
 280     struct memoryHTBlock *(*oldBlocks);
 281 };
 282
 283 struct memoryDB {               /* in core copies of database structures */
 284     struct Lock lock;
 285     Date readTime;
 286     struct dbHeader h;
 287     struct memoryHashTable volName;
 288     struct memoryHashTable tapeName;
 289     struct memoryHashTable dumpName;
 290     struct memoryHashTable dumpIden;
 291     struct textBlock textBlock[TB_NUM];
 292 };
 293 extern struct memoryDB db;
 294
 295 #define set_header_word(ut,field,value) \
 296         ( \
 297             (db.h.field) = (value), \
 298             dbwrite((ut), ((char *)&(db.h.field) - (char *)&db.h), \
 299                     ((char *)&(db.h.field)), sizeof(afs_int32)) \
 300         )
 301
 302 #define set_word_offset(ut,a,b,offset,value)                          \
 303     dbwrite ((ut), (a)+(offset),                                      \
 304              (*(afs_int32 *)((char *)(b) + (offset)) = (value),       \
 305               (char *)((char *)(b) + (offset))),                      \
 306              sizeof(afs_int32))
 307
 308 #define set_word_addr(ut,a,b,addr,value)                              \
 309     dbwrite ((ut), (a)+((char *)(addr) - (char *)(b)),                \
 310              (*(afs_int32 *)(addr) = (value),                         \
 311               (char *)(addr)),                                        \
 312              sizeof(afs_int32))
 313
 314 #ifdef notdef
 315 /* simple min/max macros */
 316 #define MIN(x,y)        ((x) < (y) ? (x) : (y))
 317 #define MAX(x,y)        ((x) > (y) ? (x) : (y))
 318 #endif /* notdef */
 319
 320 struct memoryHashTable *ht_GetType(int type, int *e_sizeP);
 321 extern afs_uint32 ht_HashEntry(struct memoryHashTable *mht, char *e);
 322 extern dbadr ht_LookupBucket(struct ubik_trans *ut,
 323                              struct memoryHashTable *mht,
 324                              afs_uint32 hash, int old);
 325
 326 extern afs_int32 dbwrite(struct ubik_trans *ut, afs_int32 pos, void *buff, afs_int32 len);
 327 extern afs_int32 dbread(struct ubik_trans *ut, afs_int32 pos, void *buff, afs_int32 len);
 328 extern afs_int32 cdbread(struct ubik_trans *ut, int type, afs_int32 pos, void *buff, afs_int32 len);
 329 extern void db_panic(char *reason) AFS_NORETURN;
 330 extern void ht_Reset(struct memoryHashTable *mht);