| 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 <afsconfig.h> |
| 11 | #include <afs/param.h> |
| 12 | #include <afs/stds.h> |
| 13 | |
| 14 | #include <roken.h> |
| 15 | |
| 16 | #include <ubik.h> |
| 17 | #include <afs/bubasics.h> |
| 18 | |
| 19 | #include "budb_errs.h" |
| 20 | #include "database.h" |
| 21 | #include "budb_internal.h" |
| 22 | |
| 23 | /* block and structure allocation routines */ |
| 24 | |
| 25 | static int nEntries[NBLOCKTYPES]; |
| 26 | static int sizeEntries[NBLOCKTYPES]; |
| 27 | |
| 28 | afs_int32 |
| 29 | InitDBalloc(void) |
| 30 | { |
| 31 | nEntries[0] = 0; |
| 32 | sizeEntries[0] = 0; |
| 33 | |
| 34 | nEntries[volFragment_BLOCK] = NvolFragmentS; |
| 35 | nEntries[volInfo_BLOCK] = NvolInfoS; |
| 36 | nEntries[tape_BLOCK] = NtapeS; |
| 37 | nEntries[dump_BLOCK] = NdumpS; |
| 38 | |
| 39 | sizeEntries[volFragment_BLOCK] = sizeof(struct vfBlock_frag); |
| 40 | sizeEntries[volInfo_BLOCK] = sizeof(struct viBlock_info); |
| 41 | sizeEntries[tape_BLOCK] = sizeof(struct tBlock_tape); |
| 42 | sizeEntries[dump_BLOCK] = sizeof(struct dBlock_dump); |
| 43 | |
| 44 | return 0; |
| 45 | } |
| 46 | |
| 47 | /* AllocBlock |
| 48 | * allocate a (basic) database block. Extends the database if |
| 49 | * no free blocks are available. |
| 50 | * exit: |
| 51 | * 0 - aP points to a cleared block |
| 52 | * n - error |
| 53 | */ |
| 54 | |
| 55 | afs_int32 |
| 56 | AllocBlock(struct ubik_trans *ut, |
| 57 | struct block *block, /* copy of data */ |
| 58 | dbadr *aP) /* db addr of block */ |
| 59 | { |
| 60 | dbadr a; |
| 61 | |
| 62 | if (db.h.freePtrs[0] == 0) { |
| 63 | /* if there are no free blocks, extend the database */ |
| 64 | LogDebug(2, "AllocBlock: extending db\n"); |
| 65 | |
| 66 | a = ntohl(db.h.eofPtr); |
| 67 | if (set_header_word(ut, eofPtr, htonl(a + BLOCKSIZE))) |
| 68 | return BUDB_IO; |
| 69 | } else { |
| 70 | a = ntohl(db.h.freePtrs[0]); |
| 71 | if (dbread(ut, a, (char *)block, sizeof(block->h)) /* read hdr */ |
| 72 | ||set_header_word(ut, freePtrs[0], block->h.next) /* set next */ |
| 73 | ) |
| 74 | return BUDB_IO; |
| 75 | } |
| 76 | |
| 77 | /* clear and return the block */ |
| 78 | memset(block, 0, sizeof(*block)); |
| 79 | *aP = a; |
| 80 | return 0; |
| 81 | } |
| 82 | |
| 83 | /* FreeBlock |
| 84 | * Free a basic block |
| 85 | * entry: |
| 86 | * bh - block header ptr. Memory copy of the block header. |
| 87 | * a - disk address of the block |
| 88 | */ |
| 89 | |
| 90 | afs_int32 |
| 91 | FreeBlock(struct ubik_trans *ut, |
| 92 | struct blockHeader *bh, /* copy of data */ |
| 93 | dbadr a) /* db address of block */ |
| 94 | { |
| 95 | if (a != BlockBase(a)) |
| 96 | db_panic("Block addr no good"); |
| 97 | memset(bh, 0, sizeof(*bh)); |
| 98 | bh->next = db.h.freePtrs[0]; |
| 99 | if (set_header_word(ut, freePtrs[0], htonl(a)) |
| 100 | || dbwrite(ut, a, (char *)bh, sizeof(*bh))) |
| 101 | return BUDB_IO; |
| 102 | return 0; |
| 103 | } |
| 104 | |
| 105 | |
| 106 | /* AllocStructure |
| 107 | * entry: |
| 108 | * type - type of structure to allocate |
| 109 | * related - address of related block |
| 110 | * saP - db addr of structure |
| 111 | * s - structure data |
| 112 | */ |
| 113 | |
| 114 | afs_int32 |
| 115 | AllocStructure(struct ubik_trans *ut, char type, dbadr related, dbadr *saP, void *s) |
| 116 | { |
| 117 | dbadr a; /* block addr */ |
| 118 | struct block b; /* copy of data */ |
| 119 | int i; /* block structure array index */ |
| 120 | afs_int32 *bs; /* ptr to first word of structure */ |
| 121 | int nFree; |
| 122 | |
| 123 | if ((type == 0) |
| 124 | || (type > MAX_STRUCTURE_BLOCK_TYPE) |
| 125 | ) { |
| 126 | db_panic("bad structure type"); |
| 127 | } |
| 128 | bs = (afs_int32 *) b.a; /* ptr to first structure of block */ |
| 129 | |
| 130 | if (db.h.freePtrs[(int) type] == 0) { |
| 131 | /* no free items of specified type */ |
| 132 | |
| 133 | if (AllocBlock(ut, &b, &a) |
| 134 | || set_header_word(ut, freePtrs[(int) type], htonl(a)) |
| 135 | ) { |
| 136 | return BUDB_IO; |
| 137 | } |
| 138 | |
| 139 | b.h.next = 0; |
| 140 | b.h.type = type; |
| 141 | b.h.flags = 0; |
| 142 | b.h.nFree = ntohs(nEntries[(int) type] - 1); |
| 143 | *bs = 1; /* not free anymore */ |
| 144 | |
| 145 | if (dbwrite(ut, a, (char *)&b, sizeof(b))) |
| 146 | return BUDB_IO; |
| 147 | LogDebug(2, "AllocStructure: allocated new block\n"); |
| 148 | } else { |
| 149 | int count = 10; |
| 150 | |
| 151 | /* Only do 10 (or so) at a time, to avoid transactions which modify |
| 152 | * many buffer. |
| 153 | */ |
| 154 | |
| 155 | while (1) { |
| 156 | a = ntohl(db.h.freePtrs[(int) type]); |
| 157 | if (dbread(ut, a, (char *)&b, sizeof(b))) |
| 158 | return BUDB_IO; |
| 159 | |
| 160 | nFree = ntohs(b.h.nFree); |
| 161 | if (nFree == 0) |
| 162 | db_panic("nFree is zero"); |
| 163 | |
| 164 | /* Completely empty blocks go to generic free list if there are |
| 165 | * more blocks on this free list |
| 166 | */ |
| 167 | if (b.h.next && (nFree == nEntries[(int) type]) && (count-- > 0)) { |
| 168 | if (set_header_word(ut, freePtrs[(int) type], b.h.next) |
| 169 | || FreeBlock(ut, &b.h, a) |
| 170 | ) { |
| 171 | return BUDB_IO; |
| 172 | } |
| 173 | LogDebug(2, "AllocStrucure: add to free block list\n"); |
| 174 | } else { |
| 175 | /* we found a free structure */ |
| 176 | if (nFree == 1) { |
| 177 | /* if last free one: unthread block */ |
| 178 | if (set_header_word(ut, freePtrs[(int) type], b.h.next)) |
| 179 | return BUDB_IO; |
| 180 | } |
| 181 | break; |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | /* find the free structure - arbitrarily uses first word as |
| 186 | * allocated/free status. PA. |
| 187 | */ |
| 188 | i = 0; |
| 189 | while (*bs) { |
| 190 | i++; |
| 191 | bs = (afs_int32 *) ((char *)bs + sizeEntries[(int) type]); |
| 192 | } |
| 193 | |
| 194 | if (i >= nEntries[(int) type]) |
| 195 | db_panic("free count inconsistent with block"); |
| 196 | |
| 197 | b.h.nFree = htons(nFree - 1); |
| 198 | if (dbwrite(ut, a, (char *)&b, sizeof(b.h))) |
| 199 | return BUDB_IO; |
| 200 | } |
| 201 | *(afs_int32 *) s = 1; /* make sure structure is not free */ |
| 202 | *saP = a + ((char *)bs - (char *)&b); |
| 203 | |
| 204 | LogDebug(3, "allocated at %d, block at %d, offset %ld\n", *saP, a, |
| 205 | (long int)((char *)bs - (char *)&b)); |
| 206 | /* caller must write back at least first word of structure */ |
| 207 | return 0; |
| 208 | } |
| 209 | |
| 210 | |
| 211 | |
| 212 | afs_int32 |
| 213 | FreeStructure(struct ubik_trans *ut, |
| 214 | char type, /* type of structure to allocate */ |
| 215 | dbadr sa) /* db addr of structure */ |
| 216 | { |
| 217 | struct blockHeader bh; /* header of containing block */ |
| 218 | dbadr a; /* db address of block */ |
| 219 | int nFree; /* new free structures count */ |
| 220 | afs_int32 freeWord; |
| 221 | |
| 222 | if ((type == 0) || (type > MAX_STRUCTURE_BLOCK_TYPE)) |
| 223 | db_panic("bad structure type"); |
| 224 | |
| 225 | a = BlockBase(sa); |
| 226 | if (dbread(ut, a, (char *)&bh, sizeof(bh))) |
| 227 | return BUDB_IO; |
| 228 | if (type != bh.type) |
| 229 | db_panic("block and structure of different types"); |
| 230 | |
| 231 | bh.nFree = htons(nFree = ntohs(bh.nFree) + 1); |
| 232 | if (nFree > nEntries[(int) type]) |
| 233 | db_panic("free count too large"); |
| 234 | if (nFree == 1) { /* add to free list for type */ |
| 235 | bh.next = db.h.freePtrs[(int) type]; |
| 236 | if (set_header_word(ut, freePtrs[(int) type], htonl(a))) |
| 237 | return BUDB_IO; |
| 238 | } |
| 239 | |
| 240 | /* mark the structure as free, and write out block header */ |
| 241 | if (set_word_offset(ut, sa, &freeWord, 0, 0) |
| 242 | || dbwrite(ut, a, (char *)&bh, sizeof(bh))) |
| 243 | return BUDB_IO; |
| 244 | return 0; |
| 245 | } |