2 056fe1ba 2003-11-23 devnull * Manage tree of VtFiles stored in the block cache.
4 056fe1ba 2003-11-23 devnull * The single point of truth for the info about the VtFiles themselves
5 056fe1ba 2003-11-23 devnull * is the block data. Because of this, there is no explicit locking of
6 056fe1ba 2003-11-23 devnull * VtFile structures, and indeed there may be more than one VtFile
7 056fe1ba 2003-11-23 devnull * structure for a given Venti file. They synchronize through the
8 056fe1ba 2003-11-23 devnull * block cache.
10 056fe1ba 2003-11-23 devnull * This is a bit simpler than fossil because there are no epochs
11 056fe1ba 2003-11-23 devnull * or tags or anything else. Just mutable local blocks and immutable
12 056fe1ba 2003-11-23 devnull * Venti blocks.
15 056fe1ba 2003-11-23 devnull #include <u.h>
16 056fe1ba 2003-11-23 devnull #include <libc.h>
17 056fe1ba 2003-11-23 devnull #include <venti.h>
21 056fe1ba 2003-11-23 devnull MaxBlock = (1UL<<31),
24 056fe1ba 2003-11-23 devnull static char EBadEntry[] = "bad VtEntry";
25 056fe1ba 2003-11-23 devnull static char ENotDir[] = "walk in non-directory";
26 056fe1ba 2003-11-23 devnull static char ETooBig[] = "file too big";
27 056fe1ba 2003-11-23 devnull static char EBadAddr[] = "bad address";
28 056fe1ba 2003-11-23 devnull static char ELabelMismatch[] = "label mismatch";
30 056fe1ba 2003-11-23 devnull static int sizetodepth(uvlong s, int psize, int dsize);
31 056fe1ba 2003-11-23 devnull static VtBlock *fileload(VtFile *r, VtEntry *e);
32 056fe1ba 2003-11-23 devnull static int shrinkdepth(VtFile*, VtBlock*, VtEntry*, int);
33 056fe1ba 2003-11-23 devnull static int shrinksize(VtFile*, VtEntry*, uvlong);
34 056fe1ba 2003-11-23 devnull static int growdepth(VtFile*, VtBlock*, VtEntry*, int);
36 056fe1ba 2003-11-23 devnull #define ISLOCKED(r) ((r)->b != nil)
37 056fe1ba 2003-11-23 devnull #define DEPTH(t) ((t)&VtTypeDepthMask)
39 056fe1ba 2003-11-23 devnull static VtFile *
40 056fe1ba 2003-11-23 devnull vtfilealloc(VtCache *c, VtBlock *b, VtFile *p, u32int offset, int mode)
43 056fe1ba 2003-11-23 devnull u32int size;
44 056fe1ba 2003-11-23 devnull VtEntry e;
45 056fe1ba 2003-11-23 devnull VtFile *r;
47 056fe1ba 2003-11-23 devnull assert(p==nil || ISLOCKED(p));
49 056fe1ba 2003-11-23 devnull if(p == nil){
50 056fe1ba 2003-11-23 devnull assert(offset == 0);
53 056fe1ba 2003-11-23 devnull epb = p->dsize / VtEntrySize;
55 056fe1ba 2003-11-23 devnull if(b->type != VtDirType)
56 056fe1ba 2003-11-23 devnull goto Bad;
59 056fe1ba 2003-11-23 devnull * a non-active entry is the only thing that
60 056fe1ba 2003-11-23 devnull * can legitimately happen here. all the others
61 056fe1ba 2003-11-23 devnull * get prints.
63 056fe1ba 2003-11-23 devnull if(vtentryunpack(&e, b->data, offset % epb) < 0){
64 056fe1ba 2003-11-23 devnull fprint(2, "vtentryunpack failed\n");
65 056fe1ba 2003-11-23 devnull goto Bad;
67 056fe1ba 2003-11-23 devnull if(!(e.flags & VtEntryActive)){
68 056fe1ba 2003-11-23 devnull if(0)fprint(2, "not active\n");
69 056fe1ba 2003-11-23 devnull goto Bad;
71 056fe1ba 2003-11-23 devnull if(e.psize < 256 || e.dsize < 256){
72 056fe1ba 2003-11-23 devnull fprint(2, "psize %ud dsize %ud\n", e.psize, e.dsize);
73 056fe1ba 2003-11-23 devnull goto Bad;
76 056fe1ba 2003-11-23 devnull if(DEPTH(e.type) < sizetodepth(e.size, e.psize, e.dsize)){
77 056fe1ba 2003-11-23 devnull fprint(2, "depth %ud size %llud psize %ud dsize %ud\n",
78 056fe1ba 2003-11-23 devnull DEPTH(e.type), e.size, e.psize, e.dsize);
79 056fe1ba 2003-11-23 devnull goto Bad;
82 056fe1ba 2003-11-23 devnull size = vtcacheblocksize(c);
83 056fe1ba 2003-11-23 devnull if(e.dsize > size || e.psize > size){
84 056fe1ba 2003-11-23 devnull fprint(2, "psize %ud dsize %ud blocksize %ud\n", e.psize, e.dsize, size);
85 056fe1ba 2003-11-23 devnull goto Bad;
88 056fe1ba 2003-11-23 devnull r = vtmallocz(sizeof(VtFile));
89 056fe1ba 2003-11-23 devnull r->c = c;
90 056fe1ba 2003-11-23 devnull r->mode = mode;
91 056fe1ba 2003-11-23 devnull r->dsize = e.dsize;
92 056fe1ba 2003-11-23 devnull r->gen = e.gen;
93 d23a617a 2004-03-15 devnull r->dir = (e.type & VtTypeBaseMask) == VtDirType;
94 056fe1ba 2003-11-23 devnull r->ref = 1;
95 056fe1ba 2003-11-23 devnull r->parent = p;
97 056fe1ba 2003-11-23 devnull qlock(&p->lk);
98 056fe1ba 2003-11-23 devnull assert(mode == VtOREAD || p->mode == VtORDWR);
99 056fe1ba 2003-11-23 devnull p->ref++;
100 056fe1ba 2003-11-23 devnull qunlock(&p->lk);
102 7cb74894 2004-06-17 devnull assert(b->addr != NilBlock);
103 7cb74894 2004-06-17 devnull r->local = 1;
105 056fe1ba 2003-11-23 devnull memmove(r->score, b->score, VtScoreSize);
106 056fe1ba 2003-11-23 devnull r->offset = offset;
107 056fe1ba 2003-11-23 devnull r->epb = epb;
109 056fe1ba 2003-11-23 devnull return r;
111 056fe1ba 2003-11-23 devnull werrstr(EBadEntry);
112 056fe1ba 2003-11-23 devnull return nil;
116 056fe1ba 2003-11-23 devnull VtFile *
117 056fe1ba 2003-11-23 devnull vtfileroot(VtCache *c, u32int addr, int mode)
119 056fe1ba 2003-11-23 devnull VtFile *r;
120 056fe1ba 2003-11-23 devnull VtBlock *b;
122 056fe1ba 2003-11-23 devnull b = vtcachelocal(c, addr, VtDirType);
123 056fe1ba 2003-11-23 devnull if(b == nil)
124 056fe1ba 2003-11-23 devnull return nil;
125 056fe1ba 2003-11-23 devnull r = vtfilealloc(c, b, nil, 0, mode);
126 056fe1ba 2003-11-23 devnull vtblockput(b);
127 056fe1ba 2003-11-23 devnull return r;
131 056fe1ba 2003-11-23 devnull vtfileopenroot(VtCache *c, VtEntry *e)
133 056fe1ba 2003-11-23 devnull VtBlock *b;
134 056fe1ba 2003-11-23 devnull VtFile *f;
136 056fe1ba 2003-11-23 devnull b = vtcacheallocblock(c, VtDirType);
137 056fe1ba 2003-11-23 devnull if(b == nil)
138 056fe1ba 2003-11-23 devnull return nil;
140 056fe1ba 2003-11-23 devnull vtentrypack(e, b->data, 0);
141 056fe1ba 2003-11-23 devnull f = vtfilealloc(c, b, nil, 0, VtORDWR);
142 056fe1ba 2003-11-23 devnull vtblockput(b);
143 056fe1ba 2003-11-23 devnull return f;
146 056fe1ba 2003-11-23 devnull VtFile *
147 056fe1ba 2003-11-23 devnull vtfilecreateroot(VtCache *c, int psize, int dsize, int type)
149 056fe1ba 2003-11-23 devnull VtEntry e;
151 056fe1ba 2003-11-23 devnull memset(&e, 0, sizeof e);
152 056fe1ba 2003-11-23 devnull e.flags = VtEntryActive;
153 056fe1ba 2003-11-23 devnull e.psize = psize;
154 056fe1ba 2003-11-23 devnull e.dsize = dsize;
155 d23a617a 2004-03-15 devnull e.type = type;
156 056fe1ba 2003-11-23 devnull memmove(e.score, vtzeroscore, VtScoreSize);
158 056fe1ba 2003-11-23 devnull return vtfileopenroot(c, &e);
161 056fe1ba 2003-11-23 devnull VtFile *
162 056fe1ba 2003-11-23 devnull vtfileopen(VtFile *r, u32int offset, int mode)
164 056fe1ba 2003-11-23 devnull ulong bn;
165 056fe1ba 2003-11-23 devnull VtBlock *b;
167 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
168 056fe1ba 2003-11-23 devnull if(!r->dir){
169 056fe1ba 2003-11-23 devnull werrstr(ENotDir);
170 056fe1ba 2003-11-23 devnull return nil;
173 056fe1ba 2003-11-23 devnull bn = offset/(r->dsize/VtEntrySize);
175 056fe1ba 2003-11-23 devnull b = vtfileblock(r, bn, mode);
176 056fe1ba 2003-11-23 devnull if(b == nil)
177 056fe1ba 2003-11-23 devnull return nil;
178 056fe1ba 2003-11-23 devnull r = vtfilealloc(r->c, b, r, offset, mode);
179 056fe1ba 2003-11-23 devnull vtblockput(b);
180 056fe1ba 2003-11-23 devnull return r;
183 056fe1ba 2003-11-23 devnull VtFile *
184 056fe1ba 2003-11-23 devnull vtfilecreate(VtFile *r, int psize, int dsize, int dir)
187 056fe1ba 2003-11-23 devnull VtBlock *b;
188 056fe1ba 2003-11-23 devnull u32int bn, size;
189 056fe1ba 2003-11-23 devnull VtEntry e;
190 056fe1ba 2003-11-23 devnull int epb;
191 056fe1ba 2003-11-23 devnull VtFile *rr;
192 056fe1ba 2003-11-23 devnull u32int offset;
194 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
195 c5eb6860 2004-06-16 devnull assert(psize <= VtMaxLumpSize);
196 c5eb6860 2004-06-16 devnull assert(dsize <= VtMaxLumpSize);
198 056fe1ba 2003-11-23 devnull if(!r->dir){
199 056fe1ba 2003-11-23 devnull werrstr(ENotDir);
200 056fe1ba 2003-11-23 devnull return nil;
203 056fe1ba 2003-11-23 devnull epb = r->dsize/VtEntrySize;
205 056fe1ba 2003-11-23 devnull size = vtfilegetdirsize(r);
207 056fe1ba 2003-11-23 devnull * look at a random block to see if we can find an empty entry
209 056fe1ba 2003-11-23 devnull offset = lnrand(size+1);
210 056fe1ba 2003-11-23 devnull offset -= offset % epb;
212 056fe1ba 2003-11-23 devnull /* try the given block and then try the last block */
213 056fe1ba 2003-11-23 devnull for(;;){
214 056fe1ba 2003-11-23 devnull bn = offset/epb;
215 056fe1ba 2003-11-23 devnull b = vtfileblock(r, bn, VtORDWR);
216 056fe1ba 2003-11-23 devnull if(b == nil)
217 056fe1ba 2003-11-23 devnull return nil;
218 056fe1ba 2003-11-23 devnull for(i=offset%r->epb; i<epb; i++){
219 056fe1ba 2003-11-23 devnull if(vtentryunpack(&e, b->data, i) < 0)
220 056fe1ba 2003-11-23 devnull continue;
221 056fe1ba 2003-11-23 devnull if((e.flags&VtEntryActive) == 0 && e.gen != ~0)
222 056fe1ba 2003-11-23 devnull goto Found;
224 056fe1ba 2003-11-23 devnull vtblockput(b);
225 056fe1ba 2003-11-23 devnull if(offset == size){
226 056fe1ba 2003-11-23 devnull fprint(2, "vtfilecreate: cannot happen\n");
227 056fe1ba 2003-11-23 devnull werrstr("vtfilecreate: cannot happen");
228 056fe1ba 2003-11-23 devnull return nil;
230 056fe1ba 2003-11-23 devnull offset = size;
234 056fe1ba 2003-11-23 devnull /* found an entry - gen already set */
235 056fe1ba 2003-11-23 devnull e.psize = psize;
236 056fe1ba 2003-11-23 devnull e.dsize = dsize;
237 056fe1ba 2003-11-23 devnull e.flags = VtEntryActive;
238 056fe1ba 2003-11-23 devnull e.type = dir ? VtDirType : VtDataType;
239 056fe1ba 2003-11-23 devnull e.size = 0;
240 056fe1ba 2003-11-23 devnull memmove(e.score, vtzeroscore, VtScoreSize);
241 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, i);
243 056fe1ba 2003-11-23 devnull offset = bn*epb + i;
244 056fe1ba 2003-11-23 devnull if(offset+1 > size){
245 056fe1ba 2003-11-23 devnull if(vtfilesetdirsize(r, offset+1) < 0){
246 056fe1ba 2003-11-23 devnull vtblockput(b);
247 056fe1ba 2003-11-23 devnull return nil;
251 056fe1ba 2003-11-23 devnull rr = vtfilealloc(r->c, b, r, offset, VtORDWR);
252 056fe1ba 2003-11-23 devnull vtblockput(b);
253 056fe1ba 2003-11-23 devnull return rr;
256 056fe1ba 2003-11-23 devnull static int
257 056fe1ba 2003-11-23 devnull vtfilekill(VtFile *r, int doremove)
259 056fe1ba 2003-11-23 devnull VtEntry e;
260 056fe1ba 2003-11-23 devnull VtBlock *b;
262 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
263 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
264 056fe1ba 2003-11-23 devnull if(b == nil)
265 056fe1ba 2003-11-23 devnull return -1;
267 056fe1ba 2003-11-23 devnull if(doremove==0 && e.size == 0){
268 056fe1ba 2003-11-23 devnull /* already truncated */
269 056fe1ba 2003-11-23 devnull vtblockput(b);
270 056fe1ba 2003-11-23 devnull return 0;
273 056fe1ba 2003-11-23 devnull if(doremove){
274 056fe1ba 2003-11-23 devnull if(e.gen != ~0)
275 056fe1ba 2003-11-23 devnull e.gen++;
276 056fe1ba 2003-11-23 devnull e.dsize = 0;
277 056fe1ba 2003-11-23 devnull e.psize = 0;
278 056fe1ba 2003-11-23 devnull e.flags = 0;
280 056fe1ba 2003-11-23 devnull e.flags &= ~VtEntryLocal;
281 056fe1ba 2003-11-23 devnull e.type = 0;
282 056fe1ba 2003-11-23 devnull e.size = 0;
283 056fe1ba 2003-11-23 devnull memmove(e.score, vtzeroscore, VtScoreSize);
284 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, r->offset % r->epb);
285 056fe1ba 2003-11-23 devnull vtblockput(b);
287 056fe1ba 2003-11-23 devnull if(doremove){
288 056fe1ba 2003-11-23 devnull vtfileunlock(r);
289 056fe1ba 2003-11-23 devnull vtfileclose(r);
292 056fe1ba 2003-11-23 devnull return 0;
296 056fe1ba 2003-11-23 devnull vtfileremove(VtFile *r)
298 056fe1ba 2003-11-23 devnull return vtfilekill(r, 1);
302 056fe1ba 2003-11-23 devnull vtfiletruncate(VtFile *r)
304 056fe1ba 2003-11-23 devnull return vtfilekill(r, 0);
308 056fe1ba 2003-11-23 devnull vtfilegetsize(VtFile *r)
310 056fe1ba 2003-11-23 devnull VtEntry e;
311 056fe1ba 2003-11-23 devnull VtBlock *b;
313 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
314 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
315 056fe1ba 2003-11-23 devnull if(b == nil)
316 056fe1ba 2003-11-23 devnull return ~(uvlong)0;
317 056fe1ba 2003-11-23 devnull vtblockput(b);
319 056fe1ba 2003-11-23 devnull return e.size;
322 056fe1ba 2003-11-23 devnull static int
323 056fe1ba 2003-11-23 devnull shrinksize(VtFile *r, VtEntry *e, uvlong size)
325 056fe1ba 2003-11-23 devnull int i, depth, type, isdir, ppb;
326 056fe1ba 2003-11-23 devnull uvlong ptrsz;
327 056fe1ba 2003-11-23 devnull uchar score[VtScoreSize];
328 056fe1ba 2003-11-23 devnull VtBlock *b;
330 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, e->score, e->type);
331 056fe1ba 2003-11-23 devnull if(b == nil)
332 056fe1ba 2003-11-23 devnull return -1;
334 056fe1ba 2003-11-23 devnull ptrsz = e->dsize;
335 056fe1ba 2003-11-23 devnull ppb = e->psize/VtScoreSize;
336 056fe1ba 2003-11-23 devnull type = e->type;
337 056fe1ba 2003-11-23 devnull depth = DEPTH(type);
338 056fe1ba 2003-11-23 devnull for(i=0; i+1<depth; i++)
339 056fe1ba 2003-11-23 devnull ptrsz *= ppb;
341 056fe1ba 2003-11-23 devnull isdir = r->dir;
342 056fe1ba 2003-11-23 devnull while(depth > 0){
343 056fe1ba 2003-11-23 devnull if(b->addr == NilBlock){
344 056fe1ba 2003-11-23 devnull /* not worth copying the block just so we can zero some of it */
345 056fe1ba 2003-11-23 devnull vtblockput(b);
346 056fe1ba 2003-11-23 devnull return -1;
350 056fe1ba 2003-11-23 devnull * invariant: each pointer in the tree rooted at b accounts for ptrsz bytes
353 056fe1ba 2003-11-23 devnull /* zero the pointers to unnecessary blocks */
354 056fe1ba 2003-11-23 devnull i = (size+ptrsz-1)/ptrsz;
355 056fe1ba 2003-11-23 devnull for(; i<ppb; i++)
356 056fe1ba 2003-11-23 devnull memmove(b->data+i*VtScoreSize, vtzeroscore, VtScoreSize);
358 056fe1ba 2003-11-23 devnull /* recurse (go around again) on the partially necessary block */
359 056fe1ba 2003-11-23 devnull i = size/ptrsz;
360 056fe1ba 2003-11-23 devnull size = size%ptrsz;
361 056fe1ba 2003-11-23 devnull if(size == 0){
362 056fe1ba 2003-11-23 devnull vtblockput(b);
363 056fe1ba 2003-11-23 devnull return 0;
365 056fe1ba 2003-11-23 devnull ptrsz /= ppb;
367 056fe1ba 2003-11-23 devnull memmove(score, b->data+i*VtScoreSize, VtScoreSize);
368 056fe1ba 2003-11-23 devnull vtblockput(b);
369 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, score, type);
370 056fe1ba 2003-11-23 devnull if(b == nil)
371 056fe1ba 2003-11-23 devnull return -1;
374 056fe1ba 2003-11-23 devnull if(b->addr == NilBlock){
375 056fe1ba 2003-11-23 devnull vtblockput(b);
376 056fe1ba 2003-11-23 devnull return -1;
380 056fe1ba 2003-11-23 devnull * No one ever truncates BtDir blocks.
382 056fe1ba 2003-11-23 devnull if(depth==0 && !isdir && e->dsize > size)
383 056fe1ba 2003-11-23 devnull memset(b->data+size, 0, e->dsize-size);
384 056fe1ba 2003-11-23 devnull vtblockput(b);
385 056fe1ba 2003-11-23 devnull return 0;
389 056fe1ba 2003-11-23 devnull vtfilesetsize(VtFile *r, uvlong size)
391 056fe1ba 2003-11-23 devnull int depth, edepth;
392 056fe1ba 2003-11-23 devnull VtEntry e;
393 056fe1ba 2003-11-23 devnull VtBlock *b;
395 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
396 056fe1ba 2003-11-23 devnull if(size == 0)
397 056fe1ba 2003-11-23 devnull return vtfiletruncate(r);
399 056fe1ba 2003-11-23 devnull if(size > VtMaxFileSize || size > ((uvlong)MaxBlock)*r->dsize){
400 056fe1ba 2003-11-23 devnull werrstr(ETooBig);
401 056fe1ba 2003-11-23 devnull return -1;
404 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
405 056fe1ba 2003-11-23 devnull if(b == nil)
406 056fe1ba 2003-11-23 devnull return -1;
408 056fe1ba 2003-11-23 devnull /* quick out */
409 056fe1ba 2003-11-23 devnull if(e.size == size){
410 056fe1ba 2003-11-23 devnull vtblockput(b);
411 056fe1ba 2003-11-23 devnull return 0;
414 056fe1ba 2003-11-23 devnull depth = sizetodepth(size, e.psize, e.dsize);
415 056fe1ba 2003-11-23 devnull edepth = DEPTH(e.type);
416 056fe1ba 2003-11-23 devnull if(depth < edepth){
417 056fe1ba 2003-11-23 devnull if(shrinkdepth(r, b, &e, depth) < 0){
418 056fe1ba 2003-11-23 devnull vtblockput(b);
419 056fe1ba 2003-11-23 devnull return -1;
421 056fe1ba 2003-11-23 devnull }else if(depth > edepth){
422 056fe1ba 2003-11-23 devnull if(growdepth(r, b, &e, depth) < 0){
423 056fe1ba 2003-11-23 devnull vtblockput(b);
424 056fe1ba 2003-11-23 devnull return -1;
428 056fe1ba 2003-11-23 devnull if(size < e.size)
429 056fe1ba 2003-11-23 devnull shrinksize(r, &e, size);
431 056fe1ba 2003-11-23 devnull e.size = size;
432 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, r->offset % r->epb);
433 056fe1ba 2003-11-23 devnull vtblockput(b);
435 056fe1ba 2003-11-23 devnull return 0;
439 056fe1ba 2003-11-23 devnull vtfilesetdirsize(VtFile *r, u32int ds)
441 056fe1ba 2003-11-23 devnull uvlong size;
442 056fe1ba 2003-11-23 devnull int epb;
444 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
445 056fe1ba 2003-11-23 devnull epb = r->dsize/VtEntrySize;
447 056fe1ba 2003-11-23 devnull size = (uvlong)r->dsize*(ds/epb);
448 056fe1ba 2003-11-23 devnull size += VtEntrySize*(ds%epb);
449 056fe1ba 2003-11-23 devnull return vtfilesetsize(r, size);
453 056fe1ba 2003-11-23 devnull vtfilegetdirsize(VtFile *r)
455 056fe1ba 2003-11-23 devnull ulong ds;
456 056fe1ba 2003-11-23 devnull uvlong size;
457 056fe1ba 2003-11-23 devnull int epb;
459 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
460 056fe1ba 2003-11-23 devnull epb = r->dsize/VtEntrySize;
462 056fe1ba 2003-11-23 devnull size = vtfilegetsize(r);
463 056fe1ba 2003-11-23 devnull ds = epb*(size/r->dsize);
464 056fe1ba 2003-11-23 devnull ds += (size%r->dsize)/VtEntrySize;
465 056fe1ba 2003-11-23 devnull return ds;
469 056fe1ba 2003-11-23 devnull vtfilegetentry(VtFile *r, VtEntry *e)
471 056fe1ba 2003-11-23 devnull VtBlock *b;
473 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
474 056fe1ba 2003-11-23 devnull b = fileload(r, e);
475 056fe1ba 2003-11-23 devnull if(b == nil)
476 056fe1ba 2003-11-23 devnull return -1;
477 056fe1ba 2003-11-23 devnull vtblockput(b);
479 056fe1ba 2003-11-23 devnull return 0;
483 056fe1ba 2003-11-23 devnull vtfilesetentry(VtFile *r, VtEntry *e)
485 056fe1ba 2003-11-23 devnull VtBlock *b;
486 056fe1ba 2003-11-23 devnull VtEntry ee;
488 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
489 056fe1ba 2003-11-23 devnull b = fileload(r, &ee);
490 056fe1ba 2003-11-23 devnull if(b == nil)
491 056fe1ba 2003-11-23 devnull return -1;
492 056fe1ba 2003-11-23 devnull vtentrypack(e, b->data, r->offset % r->epb);
493 056fe1ba 2003-11-23 devnull vtblockput(b);
494 056fe1ba 2003-11-23 devnull return 0;
497 056fe1ba 2003-11-23 devnull static VtBlock *
498 056fe1ba 2003-11-23 devnull blockwalk(VtBlock *p, int index, VtCache *c, int mode, VtEntry *e)
500 056fe1ba 2003-11-23 devnull VtBlock *b;
501 056fe1ba 2003-11-23 devnull int type;
502 056fe1ba 2003-11-23 devnull uchar *score;
503 056fe1ba 2003-11-23 devnull VtEntry oe;
505 056fe1ba 2003-11-23 devnull switch(p->type){
506 056fe1ba 2003-11-23 devnull case VtDataType:
507 056fe1ba 2003-11-23 devnull assert(0);
508 056fe1ba 2003-11-23 devnull case VtDirType:
509 056fe1ba 2003-11-23 devnull type = e->type;
510 056fe1ba 2003-11-23 devnull score = e->score;
512 056fe1ba 2003-11-23 devnull default:
513 056fe1ba 2003-11-23 devnull type = p->type - 1;
514 056fe1ba 2003-11-23 devnull score = p->data+index*VtScoreSize;
517 056fe1ba 2003-11-23 devnull //print("walk from %V/%d ty %d to %V ty %d\n", p->score, index, p->type, score, type);
519 056fe1ba 2003-11-23 devnull if(mode == VtOWRITE && vtglobaltolocal(score) == NilBlock){
520 056fe1ba 2003-11-23 devnull b = vtcacheallocblock(c, type);
522 056fe1ba 2003-11-23 devnull goto HaveCopy;
524 056fe1ba 2003-11-23 devnull b = vtcacheglobal(c, score, type);
526 056fe1ba 2003-11-23 devnull if(b == nil || mode == VtOREAD)
527 056fe1ba 2003-11-23 devnull return b;
529 056fe1ba 2003-11-23 devnull if(vtglobaltolocal(b->score) != NilBlock)
530 056fe1ba 2003-11-23 devnull return b;
532 056fe1ba 2003-11-23 devnull oe = *e;
535 056fe1ba 2003-11-23 devnull * Copy on write.
537 056fe1ba 2003-11-23 devnull e->flags |= VtEntryLocal;
539 056fe1ba 2003-11-23 devnull b = vtblockcopy(b/*, e->tag, fs->ehi, fs->elo*/);
540 056fe1ba 2003-11-23 devnull if(b == nil)
541 056fe1ba 2003-11-23 devnull return nil;
543 056fe1ba 2003-11-23 devnull HaveCopy:
544 056fe1ba 2003-11-23 devnull if(p->type == VtDirType){
545 056fe1ba 2003-11-23 devnull memmove(e->score, b->score, VtScoreSize);
546 056fe1ba 2003-11-23 devnull vtentrypack(e, p->data, index);
548 056fe1ba 2003-11-23 devnull memmove(p->data+index*VtScoreSize, b->score, VtScoreSize);
550 056fe1ba 2003-11-23 devnull return b;
554 056fe1ba 2003-11-23 devnull * Change the depth of the VtFile r.
555 056fe1ba 2003-11-23 devnull * The entry e for r is contained in block p.
557 056fe1ba 2003-11-23 devnull static int
558 056fe1ba 2003-11-23 devnull growdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
560 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
561 056fe1ba 2003-11-23 devnull VtEntry oe;
563 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
564 056fe1ba 2003-11-23 devnull assert(depth <= VtPointerDepth);
566 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, e->score, e->type);
567 056fe1ba 2003-11-23 devnull if(b == nil)
568 056fe1ba 2003-11-23 devnull return -1;
570 056fe1ba 2003-11-23 devnull oe = *e;
573 056fe1ba 2003-11-23 devnull * Keep adding layers until we get to the right depth
574 056fe1ba 2003-11-23 devnull * or an error occurs.
576 056fe1ba 2003-11-23 devnull while(DEPTH(e->type) < depth){
577 056fe1ba 2003-11-23 devnull bb = vtcacheallocblock(r->c, e->type+1);
578 056fe1ba 2003-11-23 devnull if(bb == nil)
580 056fe1ba 2003-11-23 devnull memmove(bb->data, b->score, VtScoreSize);
581 056fe1ba 2003-11-23 devnull memmove(e->score, bb->score, VtScoreSize);
582 056fe1ba 2003-11-23 devnull e->type++;
583 056fe1ba 2003-11-23 devnull e->flags |= VtEntryLocal;
584 056fe1ba 2003-11-23 devnull vtblockput(b);
588 056fe1ba 2003-11-23 devnull vtentrypack(e, p->data, r->offset % r->epb);
589 056fe1ba 2003-11-23 devnull vtblockput(b);
591 056fe1ba 2003-11-23 devnull if(DEPTH(e->type) == depth)
592 056fe1ba 2003-11-23 devnull return 0;
593 056fe1ba 2003-11-23 devnull return -1;
596 056fe1ba 2003-11-23 devnull static int
597 056fe1ba 2003-11-23 devnull shrinkdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
599 056fe1ba 2003-11-23 devnull VtBlock *b, *nb, *ob, *rb;
600 056fe1ba 2003-11-23 devnull VtEntry oe;
602 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
603 056fe1ba 2003-11-23 devnull assert(depth <= VtPointerDepth);
605 056fe1ba 2003-11-23 devnull rb = vtcacheglobal(r->c, e->score, e->type);
606 056fe1ba 2003-11-23 devnull if(rb == nil)
607 056fe1ba 2003-11-23 devnull return 0;
610 056fe1ba 2003-11-23 devnull * Walk down to the new root block.
611 056fe1ba 2003-11-23 devnull * We may stop early, but something is better than nothing.
613 056fe1ba 2003-11-23 devnull oe = *e;
615 056fe1ba 2003-11-23 devnull ob = nil;
617 056fe1ba 2003-11-23 devnull for(; DEPTH(e->type) > depth; e->type--){
618 056fe1ba 2003-11-23 devnull nb = vtcacheglobal(r->c, b->data, e->type-1);
619 056fe1ba 2003-11-23 devnull if(nb == nil)
621 056fe1ba 2003-11-23 devnull if(ob!=nil && ob!=rb)
622 056fe1ba 2003-11-23 devnull vtblockput(ob);
627 056fe1ba 2003-11-23 devnull if(b == rb){
628 056fe1ba 2003-11-23 devnull vtblockput(rb);
629 056fe1ba 2003-11-23 devnull return 0;
633 056fe1ba 2003-11-23 devnull * Right now, e points at the root block rb, b is the new root block,
634 056fe1ba 2003-11-23 devnull * and ob points at b. To update:
636 056fe1ba 2003-11-23 devnull * (i) change e to point at b
637 056fe1ba 2003-11-23 devnull * (ii) zero the pointer ob -> b
638 056fe1ba 2003-11-23 devnull * (iii) free the root block
640 056fe1ba 2003-11-23 devnull * p (the block containing e) must be written before
641 056fe1ba 2003-11-23 devnull * anything else.
644 056fe1ba 2003-11-23 devnull /* (i) */
645 056fe1ba 2003-11-23 devnull memmove(e->score, b->score, VtScoreSize);
646 056fe1ba 2003-11-23 devnull vtentrypack(e, p->data, r->offset % r->epb);
648 056fe1ba 2003-11-23 devnull /* (ii) */
649 056fe1ba 2003-11-23 devnull memmove(ob->data, vtzeroscore, VtScoreSize);
651 056fe1ba 2003-11-23 devnull /* (iii) */
652 056fe1ba 2003-11-23 devnull vtblockput(rb);
653 056fe1ba 2003-11-23 devnull if(ob!=nil && ob!=rb)
654 056fe1ba 2003-11-23 devnull vtblockput(ob);
655 056fe1ba 2003-11-23 devnull vtblockput(b);
657 056fe1ba 2003-11-23 devnull if(DEPTH(e->type) == depth)
658 056fe1ba 2003-11-23 devnull return 0;
659 056fe1ba 2003-11-23 devnull return -1;
662 056fe1ba 2003-11-23 devnull static int
663 056fe1ba 2003-11-23 devnull mkindices(VtEntry *e, u32int bn, int *index)
665 056fe1ba 2003-11-23 devnull int i, np;
667 59a96820 2004-06-17 devnull memset(index, 0, (VtPointerDepth+1)*sizeof(int));
669 056fe1ba 2003-11-23 devnull np = e->psize/VtScoreSize;
670 056fe1ba 2003-11-23 devnull for(i=0; bn > 0; i++){
671 056fe1ba 2003-11-23 devnull if(i >= VtPointerDepth){
672 d23a617a 2004-03-15 devnull werrstr("bad address 0x%lux", (ulong)bn);
673 056fe1ba 2003-11-23 devnull return -1;
675 056fe1ba 2003-11-23 devnull index[i] = bn % np;
676 056fe1ba 2003-11-23 devnull bn /= np;
678 056fe1ba 2003-11-23 devnull return i;
681 056fe1ba 2003-11-23 devnull VtBlock *
682 056fe1ba 2003-11-23 devnull vtfileblock(VtFile *r, u32int bn, int mode)
684 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
685 056fe1ba 2003-11-23 devnull int index[VtPointerDepth+1];
686 056fe1ba 2003-11-23 devnull VtEntry e;
690 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
691 056fe1ba 2003-11-23 devnull assert(bn != NilBlock);
693 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
694 056fe1ba 2003-11-23 devnull if(b == nil)
695 056fe1ba 2003-11-23 devnull return nil;
697 056fe1ba 2003-11-23 devnull i = mkindices(&e, bn, index);
698 056fe1ba 2003-11-23 devnull if(i < 0)
699 056fe1ba 2003-11-23 devnull return nil;
700 056fe1ba 2003-11-23 devnull if(i > DEPTH(e.type)){
701 056fe1ba 2003-11-23 devnull if(mode == VtOREAD){
702 d23a617a 2004-03-15 devnull werrstr("bad address 0x%lux", (ulong)bn);
703 056fe1ba 2003-11-23 devnull goto Err;
705 056fe1ba 2003-11-23 devnull index[i] = 0;
706 056fe1ba 2003-11-23 devnull if(growdepth(r, b, &e, i) < 0)
707 056fe1ba 2003-11-23 devnull goto Err;
710 056fe1ba 2003-11-23 devnull assert(b->type == VtDirType);
712 056fe1ba 2003-11-23 devnull index[DEPTH(e.type)] = r->offset % r->epb;
714 056fe1ba 2003-11-23 devnull /* mode for intermediate block */
715 056fe1ba 2003-11-23 devnull m = mode;
716 056fe1ba 2003-11-23 devnull if(m == VtOWRITE)
717 056fe1ba 2003-11-23 devnull m = VtORDWR;
719 056fe1ba 2003-11-23 devnull for(i=DEPTH(e.type); i>=0; i--){
720 056fe1ba 2003-11-23 devnull bb = blockwalk(b, index[i], r->c, i==0 ? mode : m, &e);
721 056fe1ba 2003-11-23 devnull if(bb == nil)
722 056fe1ba 2003-11-23 devnull goto Err;
723 056fe1ba 2003-11-23 devnull vtblockput(b);
726 056fe1ba 2003-11-23 devnull return b;
728 056fe1ba 2003-11-23 devnull vtblockput(b);
729 056fe1ba 2003-11-23 devnull return nil;
733 d23a617a 2004-03-15 devnull vtfileblockscore(VtFile *r, u32int bn, uchar score[VtScoreSize])
735 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
736 056fe1ba 2003-11-23 devnull int index[VtPointerDepth+1];
737 056fe1ba 2003-11-23 devnull VtEntry e;
740 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
741 056fe1ba 2003-11-23 devnull assert(bn != NilBlock);
743 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
744 056fe1ba 2003-11-23 devnull if(b == nil)
745 056fe1ba 2003-11-23 devnull return -1;
747 056fe1ba 2003-11-23 devnull i = mkindices(&e, bn, index);
748 056fe1ba 2003-11-23 devnull if(i < 0){
749 056fe1ba 2003-11-23 devnull vtblockput(b);
750 056fe1ba 2003-11-23 devnull return -1;
752 056fe1ba 2003-11-23 devnull if(i > DEPTH(e.type)){
753 056fe1ba 2003-11-23 devnull memmove(score, vtzeroscore, VtScoreSize);
754 056fe1ba 2003-11-23 devnull vtblockput(b);
755 056fe1ba 2003-11-23 devnull return 0;
758 056fe1ba 2003-11-23 devnull index[DEPTH(e.type)] = r->offset % r->epb;
760 056fe1ba 2003-11-23 devnull for(i=DEPTH(e.type); i>=1; i--){
761 056fe1ba 2003-11-23 devnull bb = blockwalk(b, index[i], r->c, VtOREAD, &e);
762 056fe1ba 2003-11-23 devnull if(bb == nil)
763 056fe1ba 2003-11-23 devnull goto Err;
764 056fe1ba 2003-11-23 devnull vtblockput(b);
766 056fe1ba 2003-11-23 devnull if(memcmp(b->score, vtzeroscore, VtScoreSize) == 0)
770 056fe1ba 2003-11-23 devnull memmove(score, b->data+index[0]*VtScoreSize, VtScoreSize);
771 056fe1ba 2003-11-23 devnull vtblockput(b);
772 056fe1ba 2003-11-23 devnull return 0;
775 056fe1ba 2003-11-23 devnull vtblockput(b);
776 056fe1ba 2003-11-23 devnull return -1;
780 056fe1ba 2003-11-23 devnull vtfileincref(VtFile *r)
782 056fe1ba 2003-11-23 devnull qlock(&r->lk);
783 056fe1ba 2003-11-23 devnull r->ref++;
784 056fe1ba 2003-11-23 devnull qunlock(&r->lk);
788 056fe1ba 2003-11-23 devnull vtfileclose(VtFile *r)
790 056fe1ba 2003-11-23 devnull if(r == nil)
792 056fe1ba 2003-11-23 devnull qlock(&r->lk);
793 056fe1ba 2003-11-23 devnull r->ref--;
794 056fe1ba 2003-11-23 devnull if(r->ref){
795 056fe1ba 2003-11-23 devnull qunlock(&r->lk);
798 056fe1ba 2003-11-23 devnull assert(r->ref == 0);
799 056fe1ba 2003-11-23 devnull qunlock(&r->lk);
800 056fe1ba 2003-11-23 devnull if(r->parent)
801 056fe1ba 2003-11-23 devnull vtfileclose(r->parent);
802 056fe1ba 2003-11-23 devnull memset(r, ~0, sizeof(*r));
803 056fe1ba 2003-11-23 devnull vtfree(r);
807 056fe1ba 2003-11-23 devnull * Retrieve the block containing the entry for r.
808 056fe1ba 2003-11-23 devnull * If a snapshot has happened, we might need
809 056fe1ba 2003-11-23 devnull * to get a new copy of the block. We avoid this
810 056fe1ba 2003-11-23 devnull * in the common case by caching the score for
811 056fe1ba 2003-11-23 devnull * the block and the last epoch in which it was valid.
813 056fe1ba 2003-11-23 devnull * We use r->mode to tell the difference between active
814 056fe1ba 2003-11-23 devnull * file system VtFiles (VtORDWR) and VtFiles for the
815 056fe1ba 2003-11-23 devnull * snapshot file system (VtOREAD).
817 056fe1ba 2003-11-23 devnull static VtBlock*
818 056fe1ba 2003-11-23 devnull fileloadblock(VtFile *r, int mode)
820 056fe1ba 2003-11-23 devnull char e[ERRMAX];
821 056fe1ba 2003-11-23 devnull u32int addr;
822 056fe1ba 2003-11-23 devnull VtBlock *b;
824 056fe1ba 2003-11-23 devnull switch(r->mode){
825 056fe1ba 2003-11-23 devnull default:
826 056fe1ba 2003-11-23 devnull assert(0);
827 056fe1ba 2003-11-23 devnull case VtORDWR:
828 056fe1ba 2003-11-23 devnull assert(r->mode == VtORDWR);
829 056fe1ba 2003-11-23 devnull if(r->local == 1){
830 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, r->score, VtDirType);
831 056fe1ba 2003-11-23 devnull if(b == nil)
832 056fe1ba 2003-11-23 devnull return nil;
833 056fe1ba 2003-11-23 devnull return b;
835 056fe1ba 2003-11-23 devnull assert(r->parent != nil);
836 056fe1ba 2003-11-23 devnull if(vtfilelock(r->parent, VtORDWR) < 0)
837 056fe1ba 2003-11-23 devnull return nil;
838 056fe1ba 2003-11-23 devnull b = vtfileblock(r->parent, r->offset/r->epb, VtORDWR);
839 056fe1ba 2003-11-23 devnull vtfileunlock(r->parent);
840 056fe1ba 2003-11-23 devnull if(b == nil)
841 056fe1ba 2003-11-23 devnull return nil;
842 056fe1ba 2003-11-23 devnull memmove(r->score, b->score, VtScoreSize);
843 056fe1ba 2003-11-23 devnull r->local = 1;
844 056fe1ba 2003-11-23 devnull return b;
846 056fe1ba 2003-11-23 devnull case VtOREAD:
847 056fe1ba 2003-11-23 devnull if(mode == VtORDWR){
848 056fe1ba 2003-11-23 devnull werrstr("read/write lock of read-only file");
849 056fe1ba 2003-11-23 devnull return nil;
851 056fe1ba 2003-11-23 devnull addr = vtglobaltolocal(r->score);
852 056fe1ba 2003-11-23 devnull if(addr == NilBlock)
853 056fe1ba 2003-11-23 devnull return vtcacheglobal(r->c, r->score, VtDirType);
855 056fe1ba 2003-11-23 devnull b = vtcachelocal(r->c, addr, VtDirType);
857 056fe1ba 2003-11-23 devnull return b;
860 056fe1ba 2003-11-23 devnull * If it failed because the epochs don't match, the block has been
861 056fe1ba 2003-11-23 devnull * archived and reclaimed. Rewalk from the parent and get the
862 056fe1ba 2003-11-23 devnull * new pointer. This can't happen in the VtORDWR case
863 056fe1ba 2003-11-23 devnull * above because blocks in the current epoch don't get
864 056fe1ba 2003-11-23 devnull * reclaimed. The fact that we're VtOREAD means we're
865 056fe1ba 2003-11-23 devnull * a snapshot. (Or else the file system is read-only, but then
866 056fe1ba 2003-11-23 devnull * the archiver isn't going around deleting blocks.)
868 056fe1ba 2003-11-23 devnull rerrstr(e, sizeof e);
869 056fe1ba 2003-11-23 devnull if(strcmp(e, ELabelMismatch) == 0){
870 056fe1ba 2003-11-23 devnull if(vtfilelock(r->parent, VtOREAD) < 0)
871 056fe1ba 2003-11-23 devnull return nil;
872 056fe1ba 2003-11-23 devnull b = vtfileblock(r->parent, r->offset/r->epb, VtOREAD);
873 056fe1ba 2003-11-23 devnull vtfileunlock(r->parent);
875 056fe1ba 2003-11-23 devnull fprint(2, "vtfilealloc: lost %V found %V\n",
876 056fe1ba 2003-11-23 devnull r->score, b->score);
877 056fe1ba 2003-11-23 devnull memmove(r->score, b->score, VtScoreSize);
878 056fe1ba 2003-11-23 devnull return b;
881 056fe1ba 2003-11-23 devnull return nil;
886 056fe1ba 2003-11-23 devnull vtfilelock(VtFile *r, int mode)
888 056fe1ba 2003-11-23 devnull VtBlock *b;
890 056fe1ba 2003-11-23 devnull if(mode == -1)
891 056fe1ba 2003-11-23 devnull mode = r->mode;
893 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
894 056fe1ba 2003-11-23 devnull if(b == nil)
895 056fe1ba 2003-11-23 devnull return -1;
897 056fe1ba 2003-11-23 devnull * The fact that we are holding b serves as the
898 056fe1ba 2003-11-23 devnull * lock entitling us to write to r->b.
900 056fe1ba 2003-11-23 devnull assert(r->b == nil);
901 056fe1ba 2003-11-23 devnull r->b = b;
902 056fe1ba 2003-11-23 devnull return 0;
906 056fe1ba 2003-11-23 devnull * Lock two (usually sibling) VtFiles. This needs special care
907 056fe1ba 2003-11-23 devnull * because the Entries for both vtFiles might be in the same block.
908 056fe1ba 2003-11-23 devnull * We also try to lock blocks in left-to-right order within the tree.
911 056fe1ba 2003-11-23 devnull vtfilelock2(VtFile *r, VtFile *rr, int mode)
913 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
915 056fe1ba 2003-11-23 devnull if(rr == nil)
916 056fe1ba 2003-11-23 devnull return vtfilelock(r, mode);
918 056fe1ba 2003-11-23 devnull if(mode == -1)
919 056fe1ba 2003-11-23 devnull mode = r->mode;
921 056fe1ba 2003-11-23 devnull if(r->parent==rr->parent && r->offset/r->epb == rr->offset/rr->epb){
922 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
923 056fe1ba 2003-11-23 devnull if(b == nil)
924 056fe1ba 2003-11-23 devnull return -1;
925 056fe1ba 2003-11-23 devnull vtblockduplock(b);
927 056fe1ba 2003-11-23 devnull }else if(r->parent==rr->parent || r->offset > rr->offset){
928 056fe1ba 2003-11-23 devnull bb = fileloadblock(rr, mode);
929 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
931 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
932 056fe1ba 2003-11-23 devnull bb = fileloadblock(rr, mode);
934 056fe1ba 2003-11-23 devnull if(b == nil || bb == nil){
936 056fe1ba 2003-11-23 devnull vtblockput(b);
938 056fe1ba 2003-11-23 devnull vtblockput(bb);
939 056fe1ba 2003-11-23 devnull return -1;
943 056fe1ba 2003-11-23 devnull * The fact that we are holding b and bb serves
944 056fe1ba 2003-11-23 devnull * as the lock entitling us to write to r->b and rr->b.
946 056fe1ba 2003-11-23 devnull r->b = b;
947 056fe1ba 2003-11-23 devnull rr->b = bb;
948 056fe1ba 2003-11-23 devnull return 0;
952 056fe1ba 2003-11-23 devnull vtfileunlock(VtFile *r)
954 056fe1ba 2003-11-23 devnull VtBlock *b;
956 056fe1ba 2003-11-23 devnull if(r->b == nil){
957 056fe1ba 2003-11-23 devnull fprint(2, "vtfileunlock: already unlocked\n");
958 056fe1ba 2003-11-23 devnull abort();
960 056fe1ba 2003-11-23 devnull b = r->b;
961 056fe1ba 2003-11-23 devnull r->b = nil;
962 056fe1ba 2003-11-23 devnull vtblockput(b);
965 056fe1ba 2003-11-23 devnull static VtBlock*
966 056fe1ba 2003-11-23 devnull fileload(VtFile *r, VtEntry *e)
968 056fe1ba 2003-11-23 devnull VtBlock *b;
970 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
971 056fe1ba 2003-11-23 devnull b = r->b;
972 056fe1ba 2003-11-23 devnull if(vtentryunpack(e, b->data, r->offset % r->epb) < 0)
973 056fe1ba 2003-11-23 devnull return nil;
974 056fe1ba 2003-11-23 devnull vtblockduplock(b);
975 056fe1ba 2003-11-23 devnull return b;
978 056fe1ba 2003-11-23 devnull static int
979 056fe1ba 2003-11-23 devnull sizetodepth(uvlong s, int psize, int dsize)
984 056fe1ba 2003-11-23 devnull /* determine pointer depth */
985 056fe1ba 2003-11-23 devnull np = psize/VtScoreSize;
986 056fe1ba 2003-11-23 devnull s = (s + dsize - 1)/dsize;
987 056fe1ba 2003-11-23 devnull for(d = 0; s > 1; d++)
988 056fe1ba 2003-11-23 devnull s = (s + np - 1)/np;
989 056fe1ba 2003-11-23 devnull return d;
993 056fe1ba 2003-11-23 devnull vtfileread(VtFile *f, void *data, long count, vlong offset)
995 056fe1ba 2003-11-23 devnull int frag;
996 056fe1ba 2003-11-23 devnull VtBlock *b;
997 056fe1ba 2003-11-23 devnull VtEntry e;
999 056fe1ba 2003-11-23 devnull assert(ISLOCKED(f));
1001 056fe1ba 2003-11-23 devnull vtfilegetentry(f, &e);
1002 056fe1ba 2003-11-23 devnull if(count == 0)
1003 056fe1ba 2003-11-23 devnull return 0;
1004 056fe1ba 2003-11-23 devnull if(count < 0 || offset < 0){
1005 056fe1ba 2003-11-23 devnull werrstr("vtfileread: bad offset or count");
1006 056fe1ba 2003-11-23 devnull return -1;
1008 056fe1ba 2003-11-23 devnull if(offset >= e.size)
1009 056fe1ba 2003-11-23 devnull return 0;
1011 056fe1ba 2003-11-23 devnull if(offset+count > e.size)
1012 056fe1ba 2003-11-23 devnull count = e.size - offset;
1014 056fe1ba 2003-11-23 devnull frag = offset % e.dsize;
1015 056fe1ba 2003-11-23 devnull if(frag+count > e.dsize)
1016 056fe1ba 2003-11-23 devnull count = e.dsize - frag;
1018 056fe1ba 2003-11-23 devnull b = vtfileblock(f, offset/e.dsize, VtOREAD);
1019 056fe1ba 2003-11-23 devnull if(b == nil)
1020 056fe1ba 2003-11-23 devnull return -1;
1022 056fe1ba 2003-11-23 devnull memmove(data, b->data+frag, count);
1023 056fe1ba 2003-11-23 devnull vtblockput(b);
1024 056fe1ba 2003-11-23 devnull return count;
1027 056fe1ba 2003-11-23 devnull static long
1028 056fe1ba 2003-11-23 devnull filewrite1(VtFile *f, void *data, long count, vlong offset)
1030 056fe1ba 2003-11-23 devnull int frag, m;
1031 056fe1ba 2003-11-23 devnull VtBlock *b;
1032 056fe1ba 2003-11-23 devnull VtEntry e;
1034 056fe1ba 2003-11-23 devnull vtfilegetentry(f, &e);
1035 056fe1ba 2003-11-23 devnull if(count < 0 || offset < 0){
1036 056fe1ba 2003-11-23 devnull werrstr("vtfilewrite: bad offset or count");
1037 056fe1ba 2003-11-23 devnull return -1;
1040 056fe1ba 2003-11-23 devnull frag = offset % e.dsize;
1041 056fe1ba 2003-11-23 devnull if(frag+count > e.dsize)
1042 056fe1ba 2003-11-23 devnull count = e.dsize - frag;
1044 056fe1ba 2003-11-23 devnull m = VtORDWR;
1045 056fe1ba 2003-11-23 devnull if(frag == 0 && count == e.dsize)
1046 056fe1ba 2003-11-23 devnull m = VtOWRITE;
1048 056fe1ba 2003-11-23 devnull b = vtfileblock(f, offset/e.dsize, m);
1049 056fe1ba 2003-11-23 devnull if(b == nil)
1050 056fe1ba 2003-11-23 devnull return -1;
1052 056fe1ba 2003-11-23 devnull memmove(b->data+frag, data, count);
1054 056fe1ba 2003-11-23 devnull if(offset+count > e.size){
1055 056fe1ba 2003-11-23 devnull vtfilegetentry(f, &e);
1056 056fe1ba 2003-11-23 devnull e.size = offset+count;
1057 056fe1ba 2003-11-23 devnull vtfilesetentry(f, &e);
1060 056fe1ba 2003-11-23 devnull vtblockput(b);
1061 056fe1ba 2003-11-23 devnull return count;
1065 056fe1ba 2003-11-23 devnull vtfilewrite(VtFile *f, void *data, long count, vlong offset)
1067 056fe1ba 2003-11-23 devnull long tot, m;
1069 056fe1ba 2003-11-23 devnull assert(ISLOCKED(f));
1071 056fe1ba 2003-11-23 devnull tot = 0;
1073 056fe1ba 2003-11-23 devnull while(tot < count){
1074 056fe1ba 2003-11-23 devnull m = filewrite1(f, (char*)data+tot, count-tot, offset+tot);
1075 056fe1ba 2003-11-23 devnull if(m <= 0)
1077 056fe1ba 2003-11-23 devnull tot += m;
1079 056fe1ba 2003-11-23 devnull if(tot==0)
1080 056fe1ba 2003-11-23 devnull return m;
1081 056fe1ba 2003-11-23 devnull return tot;
1084 056fe1ba 2003-11-23 devnull static int
1085 056fe1ba 2003-11-23 devnull flushblock(VtCache *c, VtBlock *bb, uchar score[VtScoreSize], int ppb, int epb,
1086 056fe1ba 2003-11-23 devnull int type)
1088 056fe1ba 2003-11-23 devnull u32int addr;
1089 056fe1ba 2003-11-23 devnull VtBlock *b;
1090 056fe1ba 2003-11-23 devnull VtEntry e;
1093 056fe1ba 2003-11-23 devnull addr = vtglobaltolocal(score);
1094 056fe1ba 2003-11-23 devnull if(addr == NilBlock)
1095 056fe1ba 2003-11-23 devnull return 0;
1097 056fe1ba 2003-11-23 devnull if(bb){
1098 056fe1ba 2003-11-23 devnull b = bb;
1099 056fe1ba 2003-11-23 devnull if(memcmp(b->score, score, VtScoreSize) != 0)
1100 056fe1ba 2003-11-23 devnull abort();
1102 056fe1ba 2003-11-23 devnull if((b = vtcachelocal(c, addr, type)) == nil)
1103 056fe1ba 2003-11-23 devnull return -1;
1105 056fe1ba 2003-11-23 devnull switch(type){
1106 056fe1ba 2003-11-23 devnull case VtDataType:
1109 056fe1ba 2003-11-23 devnull case VtDirType:
1110 056fe1ba 2003-11-23 devnull for(i=0; i<epb; i++){
1111 056fe1ba 2003-11-23 devnull if(vtentryunpack(&e, b->data, i) < 0)
1112 056fe1ba 2003-11-23 devnull goto Err;
1113 056fe1ba 2003-11-23 devnull if(flushblock(c, nil, e.score, e.psize/VtScoreSize, e.dsize/VtEntrySize,
1114 056fe1ba 2003-11-23 devnull e.type) < 0)
1115 056fe1ba 2003-11-23 devnull goto Err;
1119 056fe1ba 2003-11-23 devnull default: /* VtPointerTypeX */
1120 056fe1ba 2003-11-23 devnull for(i=0; i<ppb; i++){
1121 056fe1ba 2003-11-23 devnull if(flushblock(c, nil, b->data+VtScoreSize*i, ppb, epb, type-1) < 0)
1122 056fe1ba 2003-11-23 devnull goto Err;
1127 056fe1ba 2003-11-23 devnull if(vtblockwrite(b) < 0)
1128 056fe1ba 2003-11-23 devnull goto Err;
1129 056fe1ba 2003-11-23 devnull memmove(score, b->score, VtScoreSize);
1130 056fe1ba 2003-11-23 devnull if(b != bb)
1131 056fe1ba 2003-11-23 devnull vtblockput(b);
1132 056fe1ba 2003-11-23 devnull return 0;
1135 056fe1ba 2003-11-23 devnull if(b != bb)
1136 056fe1ba 2003-11-23 devnull vtblockput(b);
1137 056fe1ba 2003-11-23 devnull return -1;
1141 056fe1ba 2003-11-23 devnull vtfileflush(VtFile *f)
1143 056fe1ba 2003-11-23 devnull int ret;
1144 056fe1ba 2003-11-23 devnull VtBlock *b;
1145 056fe1ba 2003-11-23 devnull VtEntry e;
1147 056fe1ba 2003-11-23 devnull assert(ISLOCKED(f));
1148 056fe1ba 2003-11-23 devnull b = fileload(f, &e);
1149 056fe1ba 2003-11-23 devnull if(!(e.flags&VtEntryLocal)){
1150 056fe1ba 2003-11-23 devnull vtblockput(b);
1151 056fe1ba 2003-11-23 devnull return 0;
1154 056fe1ba 2003-11-23 devnull ret = flushblock(f->c, nil, e.score, e.psize/VtScoreSize, e.dsize/VtEntrySize,
1155 056fe1ba 2003-11-23 devnull e.type);
1156 7cb74894 2004-06-17 devnull if(ret < 0){
1157 056fe1ba 2003-11-23 devnull vtblockput(b);
1158 056fe1ba 2003-11-23 devnull return -1;
1161 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, f->offset % f->epb);
1162 056fe1ba 2003-11-23 devnull vtblockput(b);
1163 056fe1ba 2003-11-23 devnull return 0;
1167 056fe1ba 2003-11-23 devnull vtfileflushbefore(VtFile *r, u64int offset)
1169 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
1170 056fe1ba 2003-11-23 devnull VtEntry e;
1171 59a96820 2004-06-17 devnull int i, base, depth, ppb, epb, doflush;
1172 59a96820 2004-06-17 devnull int index[VtPointerDepth+1], j, ret;
1173 056fe1ba 2003-11-23 devnull VtBlock *bi[VtPointerDepth+2];
1174 056fe1ba 2003-11-23 devnull uchar *score;
1176 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
1177 056fe1ba 2003-11-23 devnull if(offset == 0)
1178 056fe1ba 2003-11-23 devnull return 0;
1180 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
1181 056fe1ba 2003-11-23 devnull if(b == nil)
1182 056fe1ba 2003-11-23 devnull return -1;
1185 59a96820 2004-06-17 devnull * compute path through tree for the last written byte and the next one.
1187 056fe1ba 2003-11-23 devnull ret = -1;
1188 056fe1ba 2003-11-23 devnull memset(bi, 0, sizeof bi);
1189 056fe1ba 2003-11-23 devnull depth = DEPTH(e.type);
1190 056fe1ba 2003-11-23 devnull bi[depth+1] = b;
1191 056fe1ba 2003-11-23 devnull i = mkindices(&e, (offset-1)/e.dsize, index);
1192 056fe1ba 2003-11-23 devnull if(i < 0)
1193 056fe1ba 2003-11-23 devnull goto Err;
1194 056fe1ba 2003-11-23 devnull if(i > depth)
1195 056fe1ba 2003-11-23 devnull goto Err;
1196 056fe1ba 2003-11-23 devnull ppb = e.psize / VtScoreSize;
1197 056fe1ba 2003-11-23 devnull epb = e.dsize / VtEntrySize;
1200 59a96820 2004-06-17 devnull * load the blocks along the last written byte
1202 056fe1ba 2003-11-23 devnull index[depth] = r->offset % r->epb;
1203 056fe1ba 2003-11-23 devnull for(i=depth; i>=0; i--){
1204 056fe1ba 2003-11-23 devnull bb = blockwalk(b, index[i], r->c, VtORDWR, &e);
1205 056fe1ba 2003-11-23 devnull if(bb == nil)
1206 056fe1ba 2003-11-23 devnull goto Err;
1207 056fe1ba 2003-11-23 devnull bi[i] = bb;
1208 056fe1ba 2003-11-23 devnull b = bb;
1210 056fe1ba 2003-11-23 devnull ret = 0;
1213 59a96820 2004-06-17 devnull * walk up the path from leaf to root, flushing anything that
1214 59a96820 2004-06-17 devnull * has been finished.
1216 056fe1ba 2003-11-23 devnull base = e.type&~VtTypeDepthMask;
1217 005ee04b 2004-06-17 devnull for(i=0; i<=depth; i++){
1218 59a96820 2004-06-17 devnull doflush = 0;
1219 056fe1ba 2003-11-23 devnull if(i == 0){
1220 59a96820 2004-06-17 devnull /* leaf: data or dir block */
1221 59a96820 2004-06-17 devnull if(offset%e.dsize == 0)
1222 59a96820 2004-06-17 devnull doflush = 1;
1225 59a96820 2004-06-17 devnull * interior node: pointer blocks.
1226 59a96820 2004-06-17 devnull * specifically, b = bi[i] is a block whose index[i-1]'th entry
1227 59a96820 2004-06-17 devnull * points at bi[i-1].
1229 056fe1ba 2003-11-23 devnull b = bi[i];
1232 59a96820 2004-06-17 devnull * the index entries up to but not including index[i-1] point at
1233 59a96820 2004-06-17 devnull * finished blocks, so flush them for sure.
1235 056fe1ba 2003-11-23 devnull for(j=0; j<index[i-1]; j++)
1236 056fe1ba 2003-11-23 devnull if(flushblock(r->c, nil, b->data+j*VtScoreSize, ppb, epb, base+i-1) < 0)
1237 056fe1ba 2003-11-23 devnull goto Err;
1240 59a96820 2004-06-17 devnull * if index[i-1] is the last entry in the block and is global
1241 59a96820 2004-06-17 devnull * (i.e. the kid is flushed), then we can flush this block.
1243 59a96820 2004-06-17 devnull if(j==ppb-1 && vtglobaltolocal(b->data+j*VtScoreSize)==NilBlock)
1244 59a96820 2004-06-17 devnull doflush = 1;
1246 59a96820 2004-06-17 devnull if(doflush){
1247 056fe1ba 2003-11-23 devnull if(i == depth)
1248 056fe1ba 2003-11-23 devnull score = e.score;
1250 056fe1ba 2003-11-23 devnull score = bi[i+1]->data+index[i]*VtScoreSize;
1251 056fe1ba 2003-11-23 devnull if(flushblock(r->c, bi[i], score, ppb, epb, base+i) < 0)
1252 056fe1ba 2003-11-23 devnull goto Err;
1257 056fe1ba 2003-11-23 devnull /* top: entry. do this always so that the score is up-to-date */
1258 056fe1ba 2003-11-23 devnull vtentrypack(&e, bi[depth+1]->data, index[depth]);
1259 056fe1ba 2003-11-23 devnull for(i=0; i<nelem(bi); i++)
1260 056fe1ba 2003-11-23 devnull if(bi[i])
1261 056fe1ba 2003-11-23 devnull vtblockput(bi[i]);
1262 056fe1ba 2003-11-23 devnull return ret;
