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805e021f CE |
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 | } |