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>
19 0dc99502 2005-01-14 devnull #define MaxBlock (1UL<<31)
21 056fe1ba 2003-11-23 devnull static char EBadEntry[] = "bad VtEntry";
22 056fe1ba 2003-11-23 devnull static char ENotDir[] = "walk in non-directory";
23 056fe1ba 2003-11-23 devnull static char ETooBig[] = "file too big";
24 e5d47e6e 2004-12-28 devnull /* static char EBadAddr[] = "bad address"; */
25 056fe1ba 2003-11-23 devnull static char ELabelMismatch[] = "label mismatch";
27 056fe1ba 2003-11-23 devnull static int sizetodepth(uvlong s, int psize, int dsize);
28 056fe1ba 2003-11-23 devnull static VtBlock *fileload(VtFile *r, VtEntry *e);
29 056fe1ba 2003-11-23 devnull static int shrinkdepth(VtFile*, VtBlock*, VtEntry*, int);
30 056fe1ba 2003-11-23 devnull static int shrinksize(VtFile*, VtEntry*, uvlong);
31 056fe1ba 2003-11-23 devnull static int growdepth(VtFile*, VtBlock*, VtEntry*, int);
33 056fe1ba 2003-11-23 devnull #define ISLOCKED(r) ((r)->b != nil)
34 056fe1ba 2003-11-23 devnull #define DEPTH(t) ((t)&VtTypeDepthMask)
36 056fe1ba 2003-11-23 devnull static VtFile *
37 056fe1ba 2003-11-23 devnull vtfilealloc(VtCache *c, VtBlock *b, VtFile *p, u32int offset, int mode)
40 056fe1ba 2003-11-23 devnull u32int size;
41 056fe1ba 2003-11-23 devnull VtEntry e;
42 056fe1ba 2003-11-23 devnull VtFile *r;
44 056fe1ba 2003-11-23 devnull assert(p==nil || ISLOCKED(p));
46 056fe1ba 2003-11-23 devnull if(p == nil){
47 056fe1ba 2003-11-23 devnull assert(offset == 0);
50 056fe1ba 2003-11-23 devnull epb = p->dsize / VtEntrySize;
52 056fe1ba 2003-11-23 devnull if(b->type != VtDirType)
53 056fe1ba 2003-11-23 devnull goto Bad;
56 056fe1ba 2003-11-23 devnull * a non-active entry is the only thing that
57 056fe1ba 2003-11-23 devnull * can legitimately happen here. all the others
58 056fe1ba 2003-11-23 devnull * get prints.
60 056fe1ba 2003-11-23 devnull if(vtentryunpack(&e, b->data, offset % epb) < 0){
61 056fe1ba 2003-11-23 devnull fprint(2, "vtentryunpack failed\n");
62 056fe1ba 2003-11-23 devnull goto Bad;
64 056fe1ba 2003-11-23 devnull if(!(e.flags & VtEntryActive)){
65 056fe1ba 2003-11-23 devnull if(0)fprint(2, "not active\n");
66 056fe1ba 2003-11-23 devnull goto Bad;
68 056fe1ba 2003-11-23 devnull if(e.psize < 256 || e.dsize < 256){
69 056fe1ba 2003-11-23 devnull fprint(2, "psize %ud dsize %ud\n", e.psize, e.dsize);
70 056fe1ba 2003-11-23 devnull goto Bad;
73 056fe1ba 2003-11-23 devnull if(DEPTH(e.type) < sizetodepth(e.size, e.psize, e.dsize)){
74 056fe1ba 2003-11-23 devnull fprint(2, "depth %ud size %llud psize %ud dsize %ud\n",
75 056fe1ba 2003-11-23 devnull DEPTH(e.type), e.size, e.psize, e.dsize);
76 056fe1ba 2003-11-23 devnull goto Bad;
79 056fe1ba 2003-11-23 devnull size = vtcacheblocksize(c);
80 056fe1ba 2003-11-23 devnull if(e.dsize > size || e.psize > size){
81 056fe1ba 2003-11-23 devnull fprint(2, "psize %ud dsize %ud blocksize %ud\n", e.psize, e.dsize, size);
82 056fe1ba 2003-11-23 devnull goto Bad;
85 056fe1ba 2003-11-23 devnull r = vtmallocz(sizeof(VtFile));
86 056fe1ba 2003-11-23 devnull r->c = c;
87 056fe1ba 2003-11-23 devnull r->mode = mode;
88 056fe1ba 2003-11-23 devnull r->dsize = e.dsize;
89 056fe1ba 2003-11-23 devnull r->gen = e.gen;
90 d23a617a 2004-03-15 devnull r->dir = (e.type & VtTypeBaseMask) == VtDirType;
91 056fe1ba 2003-11-23 devnull r->ref = 1;
92 056fe1ba 2003-11-23 devnull r->parent = p;
94 056fe1ba 2003-11-23 devnull qlock(&p->lk);
95 056fe1ba 2003-11-23 devnull assert(mode == VtOREAD || p->mode == VtORDWR);
96 056fe1ba 2003-11-23 devnull p->ref++;
97 056fe1ba 2003-11-23 devnull qunlock(&p->lk);
99 7cb74894 2004-06-17 devnull assert(b->addr != NilBlock);
100 7cb74894 2004-06-17 devnull r->local = 1;
102 056fe1ba 2003-11-23 devnull memmove(r->score, b->score, VtScoreSize);
103 056fe1ba 2003-11-23 devnull r->offset = offset;
104 056fe1ba 2003-11-23 devnull r->epb = epb;
106 056fe1ba 2003-11-23 devnull return r;
108 056fe1ba 2003-11-23 devnull werrstr(EBadEntry);
109 056fe1ba 2003-11-23 devnull return nil;
113 056fe1ba 2003-11-23 devnull VtFile *
114 056fe1ba 2003-11-23 devnull vtfileroot(VtCache *c, u32int addr, int mode)
116 056fe1ba 2003-11-23 devnull VtFile *r;
117 056fe1ba 2003-11-23 devnull VtBlock *b;
119 056fe1ba 2003-11-23 devnull b = vtcachelocal(c, addr, VtDirType);
120 056fe1ba 2003-11-23 devnull if(b == nil)
121 056fe1ba 2003-11-23 devnull return nil;
122 056fe1ba 2003-11-23 devnull r = vtfilealloc(c, b, nil, 0, mode);
123 056fe1ba 2003-11-23 devnull vtblockput(b);
124 056fe1ba 2003-11-23 devnull return r;
128 056fe1ba 2003-11-23 devnull vtfileopenroot(VtCache *c, VtEntry *e)
130 056fe1ba 2003-11-23 devnull VtBlock *b;
131 056fe1ba 2003-11-23 devnull VtFile *f;
133 056fe1ba 2003-11-23 devnull b = vtcacheallocblock(c, VtDirType);
134 056fe1ba 2003-11-23 devnull if(b == nil)
135 056fe1ba 2003-11-23 devnull return nil;
137 056fe1ba 2003-11-23 devnull vtentrypack(e, b->data, 0);
138 056fe1ba 2003-11-23 devnull f = vtfilealloc(c, b, nil, 0, VtORDWR);
139 056fe1ba 2003-11-23 devnull vtblockput(b);
140 056fe1ba 2003-11-23 devnull return f;
143 056fe1ba 2003-11-23 devnull VtFile *
144 056fe1ba 2003-11-23 devnull vtfilecreateroot(VtCache *c, int psize, int dsize, int type)
146 056fe1ba 2003-11-23 devnull VtEntry e;
148 056fe1ba 2003-11-23 devnull memset(&e, 0, sizeof e);
149 056fe1ba 2003-11-23 devnull e.flags = VtEntryActive;
150 056fe1ba 2003-11-23 devnull e.psize = psize;
151 056fe1ba 2003-11-23 devnull e.dsize = dsize;
152 d23a617a 2004-03-15 devnull e.type = type;
153 056fe1ba 2003-11-23 devnull memmove(e.score, vtzeroscore, VtScoreSize);
155 056fe1ba 2003-11-23 devnull return vtfileopenroot(c, &e);
158 056fe1ba 2003-11-23 devnull VtFile *
159 056fe1ba 2003-11-23 devnull vtfileopen(VtFile *r, u32int offset, int mode)
161 056fe1ba 2003-11-23 devnull ulong bn;
162 056fe1ba 2003-11-23 devnull VtBlock *b;
164 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
165 056fe1ba 2003-11-23 devnull if(!r->dir){
166 056fe1ba 2003-11-23 devnull werrstr(ENotDir);
167 056fe1ba 2003-11-23 devnull return nil;
170 056fe1ba 2003-11-23 devnull bn = offset/(r->dsize/VtEntrySize);
172 056fe1ba 2003-11-23 devnull b = vtfileblock(r, bn, mode);
173 056fe1ba 2003-11-23 devnull if(b == nil)
174 056fe1ba 2003-11-23 devnull return nil;
175 056fe1ba 2003-11-23 devnull r = vtfilealloc(r->c, b, r, offset, mode);
176 056fe1ba 2003-11-23 devnull vtblockput(b);
177 056fe1ba 2003-11-23 devnull return r;
180 056fe1ba 2003-11-23 devnull VtFile *
181 056fe1ba 2003-11-23 devnull vtfilecreate(VtFile *r, int psize, int dsize, int dir)
184 056fe1ba 2003-11-23 devnull VtBlock *b;
185 056fe1ba 2003-11-23 devnull u32int bn, size;
186 056fe1ba 2003-11-23 devnull VtEntry e;
187 056fe1ba 2003-11-23 devnull int epb;
188 056fe1ba 2003-11-23 devnull VtFile *rr;
189 056fe1ba 2003-11-23 devnull u32int offset;
191 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
192 c5eb6860 2004-06-16 devnull assert(psize <= VtMaxLumpSize);
193 c5eb6860 2004-06-16 devnull assert(dsize <= VtMaxLumpSize);
195 056fe1ba 2003-11-23 devnull if(!r->dir){
196 056fe1ba 2003-11-23 devnull werrstr(ENotDir);
197 056fe1ba 2003-11-23 devnull return nil;
200 056fe1ba 2003-11-23 devnull epb = r->dsize/VtEntrySize;
202 056fe1ba 2003-11-23 devnull size = vtfilegetdirsize(r);
204 056fe1ba 2003-11-23 devnull * look at a random block to see if we can find an empty entry
206 056fe1ba 2003-11-23 devnull offset = lnrand(size+1);
207 056fe1ba 2003-11-23 devnull offset -= offset % epb;
209 056fe1ba 2003-11-23 devnull /* try the given block and then try the last block */
210 056fe1ba 2003-11-23 devnull for(;;){
211 056fe1ba 2003-11-23 devnull bn = offset/epb;
212 056fe1ba 2003-11-23 devnull b = vtfileblock(r, bn, VtORDWR);
213 056fe1ba 2003-11-23 devnull if(b == nil)
214 056fe1ba 2003-11-23 devnull return nil;
215 056fe1ba 2003-11-23 devnull for(i=offset%r->epb; i<epb; i++){
216 056fe1ba 2003-11-23 devnull if(vtentryunpack(&e, b->data, i) < 0)
217 056fe1ba 2003-11-23 devnull continue;
218 056fe1ba 2003-11-23 devnull if((e.flags&VtEntryActive) == 0 && e.gen != ~0)
219 056fe1ba 2003-11-23 devnull goto Found;
221 056fe1ba 2003-11-23 devnull vtblockput(b);
222 056fe1ba 2003-11-23 devnull if(offset == size){
223 056fe1ba 2003-11-23 devnull fprint(2, "vtfilecreate: cannot happen\n");
224 056fe1ba 2003-11-23 devnull werrstr("vtfilecreate: cannot happen");
225 056fe1ba 2003-11-23 devnull return nil;
227 056fe1ba 2003-11-23 devnull offset = size;
231 056fe1ba 2003-11-23 devnull /* found an entry - gen already set */
232 056fe1ba 2003-11-23 devnull e.psize = psize;
233 056fe1ba 2003-11-23 devnull e.dsize = dsize;
234 056fe1ba 2003-11-23 devnull e.flags = VtEntryActive;
235 056fe1ba 2003-11-23 devnull e.type = dir ? VtDirType : VtDataType;
236 056fe1ba 2003-11-23 devnull e.size = 0;
237 056fe1ba 2003-11-23 devnull memmove(e.score, vtzeroscore, VtScoreSize);
238 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, i);
240 056fe1ba 2003-11-23 devnull offset = bn*epb + i;
241 056fe1ba 2003-11-23 devnull if(offset+1 > size){
242 056fe1ba 2003-11-23 devnull if(vtfilesetdirsize(r, offset+1) < 0){
243 056fe1ba 2003-11-23 devnull vtblockput(b);
244 056fe1ba 2003-11-23 devnull return nil;
248 056fe1ba 2003-11-23 devnull rr = vtfilealloc(r->c, b, r, offset, VtORDWR);
249 056fe1ba 2003-11-23 devnull vtblockput(b);
250 056fe1ba 2003-11-23 devnull return rr;
253 056fe1ba 2003-11-23 devnull static int
254 056fe1ba 2003-11-23 devnull vtfilekill(VtFile *r, int doremove)
256 056fe1ba 2003-11-23 devnull VtEntry e;
257 056fe1ba 2003-11-23 devnull VtBlock *b;
259 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
260 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
261 056fe1ba 2003-11-23 devnull if(b == nil)
262 056fe1ba 2003-11-23 devnull return -1;
264 056fe1ba 2003-11-23 devnull if(doremove==0 && e.size == 0){
265 056fe1ba 2003-11-23 devnull /* already truncated */
266 056fe1ba 2003-11-23 devnull vtblockput(b);
267 056fe1ba 2003-11-23 devnull return 0;
270 056fe1ba 2003-11-23 devnull if(doremove){
271 056fe1ba 2003-11-23 devnull if(e.gen != ~0)
272 056fe1ba 2003-11-23 devnull e.gen++;
273 056fe1ba 2003-11-23 devnull e.dsize = 0;
274 056fe1ba 2003-11-23 devnull e.psize = 0;
275 056fe1ba 2003-11-23 devnull e.flags = 0;
277 056fe1ba 2003-11-23 devnull e.flags &= ~VtEntryLocal;
278 056fe1ba 2003-11-23 devnull e.type = 0;
279 056fe1ba 2003-11-23 devnull e.size = 0;
280 056fe1ba 2003-11-23 devnull memmove(e.score, vtzeroscore, VtScoreSize);
281 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, r->offset % r->epb);
282 056fe1ba 2003-11-23 devnull vtblockput(b);
284 056fe1ba 2003-11-23 devnull if(doremove){
285 056fe1ba 2003-11-23 devnull vtfileunlock(r);
286 056fe1ba 2003-11-23 devnull vtfileclose(r);
289 056fe1ba 2003-11-23 devnull return 0;
293 056fe1ba 2003-11-23 devnull vtfileremove(VtFile *r)
295 056fe1ba 2003-11-23 devnull return vtfilekill(r, 1);
299 056fe1ba 2003-11-23 devnull vtfiletruncate(VtFile *r)
301 056fe1ba 2003-11-23 devnull return vtfilekill(r, 0);
305 056fe1ba 2003-11-23 devnull vtfilegetsize(VtFile *r)
307 056fe1ba 2003-11-23 devnull VtEntry e;
308 056fe1ba 2003-11-23 devnull VtBlock *b;
310 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
311 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
312 056fe1ba 2003-11-23 devnull if(b == nil)
313 056fe1ba 2003-11-23 devnull return ~(uvlong)0;
314 056fe1ba 2003-11-23 devnull vtblockput(b);
316 056fe1ba 2003-11-23 devnull return e.size;
319 056fe1ba 2003-11-23 devnull static int
320 056fe1ba 2003-11-23 devnull shrinksize(VtFile *r, VtEntry *e, uvlong size)
322 056fe1ba 2003-11-23 devnull int i, depth, type, isdir, ppb;
323 056fe1ba 2003-11-23 devnull uvlong ptrsz;
324 056fe1ba 2003-11-23 devnull uchar score[VtScoreSize];
325 056fe1ba 2003-11-23 devnull VtBlock *b;
327 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, e->score, e->type);
328 056fe1ba 2003-11-23 devnull if(b == nil)
329 056fe1ba 2003-11-23 devnull return -1;
331 056fe1ba 2003-11-23 devnull ptrsz = e->dsize;
332 056fe1ba 2003-11-23 devnull ppb = e->psize/VtScoreSize;
333 056fe1ba 2003-11-23 devnull type = e->type;
334 056fe1ba 2003-11-23 devnull depth = DEPTH(type);
335 056fe1ba 2003-11-23 devnull for(i=0; i+1<depth; i++)
336 056fe1ba 2003-11-23 devnull ptrsz *= ppb;
338 056fe1ba 2003-11-23 devnull isdir = r->dir;
339 056fe1ba 2003-11-23 devnull while(depth > 0){
340 056fe1ba 2003-11-23 devnull if(b->addr == NilBlock){
341 056fe1ba 2003-11-23 devnull /* not worth copying the block just so we can zero some of it */
342 056fe1ba 2003-11-23 devnull vtblockput(b);
343 056fe1ba 2003-11-23 devnull return -1;
347 056fe1ba 2003-11-23 devnull * invariant: each pointer in the tree rooted at b accounts for ptrsz bytes
350 056fe1ba 2003-11-23 devnull /* zero the pointers to unnecessary blocks */
351 056fe1ba 2003-11-23 devnull i = (size+ptrsz-1)/ptrsz;
352 056fe1ba 2003-11-23 devnull for(; i<ppb; i++)
353 056fe1ba 2003-11-23 devnull memmove(b->data+i*VtScoreSize, vtzeroscore, VtScoreSize);
355 056fe1ba 2003-11-23 devnull /* recurse (go around again) on the partially necessary block */
356 056fe1ba 2003-11-23 devnull i = size/ptrsz;
357 056fe1ba 2003-11-23 devnull size = size%ptrsz;
358 056fe1ba 2003-11-23 devnull if(size == 0){
359 056fe1ba 2003-11-23 devnull vtblockput(b);
360 056fe1ba 2003-11-23 devnull return 0;
362 056fe1ba 2003-11-23 devnull ptrsz /= ppb;
364 056fe1ba 2003-11-23 devnull memmove(score, b->data+i*VtScoreSize, VtScoreSize);
365 056fe1ba 2003-11-23 devnull vtblockput(b);
366 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, score, type);
367 056fe1ba 2003-11-23 devnull if(b == nil)
368 056fe1ba 2003-11-23 devnull return -1;
371 056fe1ba 2003-11-23 devnull if(b->addr == NilBlock){
372 056fe1ba 2003-11-23 devnull vtblockput(b);
373 056fe1ba 2003-11-23 devnull return -1;
377 056fe1ba 2003-11-23 devnull * No one ever truncates BtDir blocks.
379 056fe1ba 2003-11-23 devnull if(depth==0 && !isdir && e->dsize > size)
380 056fe1ba 2003-11-23 devnull memset(b->data+size, 0, e->dsize-size);
381 056fe1ba 2003-11-23 devnull vtblockput(b);
382 056fe1ba 2003-11-23 devnull return 0;
386 056fe1ba 2003-11-23 devnull vtfilesetsize(VtFile *r, uvlong size)
388 056fe1ba 2003-11-23 devnull int depth, edepth;
389 056fe1ba 2003-11-23 devnull VtEntry e;
390 056fe1ba 2003-11-23 devnull VtBlock *b;
392 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
393 056fe1ba 2003-11-23 devnull if(size == 0)
394 056fe1ba 2003-11-23 devnull return vtfiletruncate(r);
396 056fe1ba 2003-11-23 devnull if(size > VtMaxFileSize || size > ((uvlong)MaxBlock)*r->dsize){
397 056fe1ba 2003-11-23 devnull werrstr(ETooBig);
398 056fe1ba 2003-11-23 devnull return -1;
401 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
402 056fe1ba 2003-11-23 devnull if(b == nil)
403 056fe1ba 2003-11-23 devnull return -1;
405 056fe1ba 2003-11-23 devnull /* quick out */
406 056fe1ba 2003-11-23 devnull if(e.size == size){
407 056fe1ba 2003-11-23 devnull vtblockput(b);
408 056fe1ba 2003-11-23 devnull return 0;
411 056fe1ba 2003-11-23 devnull depth = sizetodepth(size, e.psize, e.dsize);
412 056fe1ba 2003-11-23 devnull edepth = DEPTH(e.type);
413 056fe1ba 2003-11-23 devnull if(depth < edepth){
414 056fe1ba 2003-11-23 devnull if(shrinkdepth(r, b, &e, depth) < 0){
415 056fe1ba 2003-11-23 devnull vtblockput(b);
416 056fe1ba 2003-11-23 devnull return -1;
418 056fe1ba 2003-11-23 devnull }else if(depth > edepth){
419 056fe1ba 2003-11-23 devnull if(growdepth(r, b, &e, depth) < 0){
420 056fe1ba 2003-11-23 devnull vtblockput(b);
421 056fe1ba 2003-11-23 devnull return -1;
425 056fe1ba 2003-11-23 devnull if(size < e.size)
426 056fe1ba 2003-11-23 devnull shrinksize(r, &e, size);
428 056fe1ba 2003-11-23 devnull e.size = size;
429 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, r->offset % r->epb);
430 056fe1ba 2003-11-23 devnull vtblockput(b);
432 056fe1ba 2003-11-23 devnull return 0;
436 056fe1ba 2003-11-23 devnull vtfilesetdirsize(VtFile *r, u32int ds)
438 056fe1ba 2003-11-23 devnull uvlong size;
439 056fe1ba 2003-11-23 devnull int epb;
441 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
442 056fe1ba 2003-11-23 devnull epb = r->dsize/VtEntrySize;
444 056fe1ba 2003-11-23 devnull size = (uvlong)r->dsize*(ds/epb);
445 056fe1ba 2003-11-23 devnull size += VtEntrySize*(ds%epb);
446 056fe1ba 2003-11-23 devnull return vtfilesetsize(r, size);
450 056fe1ba 2003-11-23 devnull vtfilegetdirsize(VtFile *r)
452 056fe1ba 2003-11-23 devnull ulong ds;
453 056fe1ba 2003-11-23 devnull uvlong size;
454 056fe1ba 2003-11-23 devnull int epb;
456 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
457 056fe1ba 2003-11-23 devnull epb = r->dsize/VtEntrySize;
459 056fe1ba 2003-11-23 devnull size = vtfilegetsize(r);
460 056fe1ba 2003-11-23 devnull ds = epb*(size/r->dsize);
461 056fe1ba 2003-11-23 devnull ds += (size%r->dsize)/VtEntrySize;
462 056fe1ba 2003-11-23 devnull return ds;
466 056fe1ba 2003-11-23 devnull vtfilegetentry(VtFile *r, VtEntry *e)
468 056fe1ba 2003-11-23 devnull VtBlock *b;
470 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
471 056fe1ba 2003-11-23 devnull b = fileload(r, e);
472 056fe1ba 2003-11-23 devnull if(b == nil)
473 056fe1ba 2003-11-23 devnull return -1;
474 056fe1ba 2003-11-23 devnull vtblockput(b);
476 056fe1ba 2003-11-23 devnull return 0;
480 056fe1ba 2003-11-23 devnull vtfilesetentry(VtFile *r, VtEntry *e)
482 056fe1ba 2003-11-23 devnull VtBlock *b;
483 056fe1ba 2003-11-23 devnull VtEntry ee;
485 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
486 056fe1ba 2003-11-23 devnull b = fileload(r, &ee);
487 056fe1ba 2003-11-23 devnull if(b == nil)
488 056fe1ba 2003-11-23 devnull return -1;
489 056fe1ba 2003-11-23 devnull vtentrypack(e, b->data, r->offset % r->epb);
490 056fe1ba 2003-11-23 devnull vtblockput(b);
491 056fe1ba 2003-11-23 devnull return 0;
494 056fe1ba 2003-11-23 devnull static VtBlock *
495 056fe1ba 2003-11-23 devnull blockwalk(VtBlock *p, int index, VtCache *c, int mode, VtEntry *e)
497 056fe1ba 2003-11-23 devnull VtBlock *b;
498 056fe1ba 2003-11-23 devnull int type;
499 056fe1ba 2003-11-23 devnull uchar *score;
500 056fe1ba 2003-11-23 devnull VtEntry oe;
502 056fe1ba 2003-11-23 devnull switch(p->type){
503 056fe1ba 2003-11-23 devnull case VtDataType:
504 056fe1ba 2003-11-23 devnull assert(0);
505 056fe1ba 2003-11-23 devnull case VtDirType:
506 056fe1ba 2003-11-23 devnull type = e->type;
507 056fe1ba 2003-11-23 devnull score = e->score;
509 056fe1ba 2003-11-23 devnull default:
510 056fe1ba 2003-11-23 devnull type = p->type - 1;
511 056fe1ba 2003-11-23 devnull score = p->data+index*VtScoreSize;
514 056fe1ba 2003-11-23 devnull //print("walk from %V/%d ty %d to %V ty %d\n", p->score, index, p->type, score, type);
516 056fe1ba 2003-11-23 devnull if(mode == VtOWRITE && vtglobaltolocal(score) == NilBlock){
517 056fe1ba 2003-11-23 devnull b = vtcacheallocblock(c, type);
519 056fe1ba 2003-11-23 devnull goto HaveCopy;
521 056fe1ba 2003-11-23 devnull b = vtcacheglobal(c, score, type);
523 056fe1ba 2003-11-23 devnull if(b == nil || mode == VtOREAD)
524 056fe1ba 2003-11-23 devnull return b;
526 056fe1ba 2003-11-23 devnull if(vtglobaltolocal(b->score) != NilBlock)
527 056fe1ba 2003-11-23 devnull return b;
529 056fe1ba 2003-11-23 devnull oe = *e;
532 056fe1ba 2003-11-23 devnull * Copy on write.
534 056fe1ba 2003-11-23 devnull e->flags |= VtEntryLocal;
536 056fe1ba 2003-11-23 devnull b = vtblockcopy(b/*, e->tag, fs->ehi, fs->elo*/);
537 056fe1ba 2003-11-23 devnull if(b == nil)
538 056fe1ba 2003-11-23 devnull return nil;
540 056fe1ba 2003-11-23 devnull HaveCopy:
541 056fe1ba 2003-11-23 devnull if(p->type == VtDirType){
542 056fe1ba 2003-11-23 devnull memmove(e->score, b->score, VtScoreSize);
543 056fe1ba 2003-11-23 devnull vtentrypack(e, p->data, index);
545 056fe1ba 2003-11-23 devnull memmove(p->data+index*VtScoreSize, b->score, VtScoreSize);
547 056fe1ba 2003-11-23 devnull return b;
551 056fe1ba 2003-11-23 devnull * Change the depth of the VtFile r.
552 056fe1ba 2003-11-23 devnull * The entry e for r is contained in block p.
554 056fe1ba 2003-11-23 devnull static int
555 056fe1ba 2003-11-23 devnull growdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
557 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
558 056fe1ba 2003-11-23 devnull VtEntry oe;
560 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
561 056fe1ba 2003-11-23 devnull assert(depth <= VtPointerDepth);
563 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, e->score, e->type);
564 056fe1ba 2003-11-23 devnull if(b == nil)
565 056fe1ba 2003-11-23 devnull return -1;
567 056fe1ba 2003-11-23 devnull oe = *e;
570 056fe1ba 2003-11-23 devnull * Keep adding layers until we get to the right depth
571 056fe1ba 2003-11-23 devnull * or an error occurs.
573 056fe1ba 2003-11-23 devnull while(DEPTH(e->type) < depth){
574 056fe1ba 2003-11-23 devnull bb = vtcacheallocblock(r->c, e->type+1);
575 056fe1ba 2003-11-23 devnull if(bb == nil)
577 056fe1ba 2003-11-23 devnull memmove(bb->data, b->score, VtScoreSize);
578 056fe1ba 2003-11-23 devnull memmove(e->score, bb->score, VtScoreSize);
579 056fe1ba 2003-11-23 devnull e->type++;
580 056fe1ba 2003-11-23 devnull e->flags |= VtEntryLocal;
581 056fe1ba 2003-11-23 devnull vtblockput(b);
585 056fe1ba 2003-11-23 devnull vtentrypack(e, p->data, r->offset % r->epb);
586 056fe1ba 2003-11-23 devnull vtblockput(b);
588 056fe1ba 2003-11-23 devnull if(DEPTH(e->type) == depth)
589 056fe1ba 2003-11-23 devnull return 0;
590 056fe1ba 2003-11-23 devnull return -1;
593 056fe1ba 2003-11-23 devnull static int
594 056fe1ba 2003-11-23 devnull shrinkdepth(VtFile *r, VtBlock *p, VtEntry *e, int depth)
596 056fe1ba 2003-11-23 devnull VtBlock *b, *nb, *ob, *rb;
597 056fe1ba 2003-11-23 devnull VtEntry oe;
599 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
600 056fe1ba 2003-11-23 devnull assert(depth <= VtPointerDepth);
602 056fe1ba 2003-11-23 devnull rb = vtcacheglobal(r->c, e->score, e->type);
603 056fe1ba 2003-11-23 devnull if(rb == nil)
604 056fe1ba 2003-11-23 devnull return 0;
607 056fe1ba 2003-11-23 devnull * Walk down to the new root block.
608 056fe1ba 2003-11-23 devnull * We may stop early, but something is better than nothing.
610 056fe1ba 2003-11-23 devnull oe = *e;
612 056fe1ba 2003-11-23 devnull ob = nil;
614 056fe1ba 2003-11-23 devnull for(; DEPTH(e->type) > depth; e->type--){
615 056fe1ba 2003-11-23 devnull nb = vtcacheglobal(r->c, b->data, e->type-1);
616 056fe1ba 2003-11-23 devnull if(nb == nil)
618 056fe1ba 2003-11-23 devnull if(ob!=nil && ob!=rb)
619 056fe1ba 2003-11-23 devnull vtblockput(ob);
624 056fe1ba 2003-11-23 devnull if(b == rb){
625 056fe1ba 2003-11-23 devnull vtblockput(rb);
626 056fe1ba 2003-11-23 devnull return 0;
630 056fe1ba 2003-11-23 devnull * Right now, e points at the root block rb, b is the new root block,
631 056fe1ba 2003-11-23 devnull * and ob points at b. To update:
633 056fe1ba 2003-11-23 devnull * (i) change e to point at b
634 056fe1ba 2003-11-23 devnull * (ii) zero the pointer ob -> b
635 056fe1ba 2003-11-23 devnull * (iii) free the root block
637 056fe1ba 2003-11-23 devnull * p (the block containing e) must be written before
638 056fe1ba 2003-11-23 devnull * anything else.
641 056fe1ba 2003-11-23 devnull /* (i) */
642 056fe1ba 2003-11-23 devnull memmove(e->score, b->score, VtScoreSize);
643 056fe1ba 2003-11-23 devnull vtentrypack(e, p->data, r->offset % r->epb);
645 056fe1ba 2003-11-23 devnull /* (ii) */
646 056fe1ba 2003-11-23 devnull memmove(ob->data, vtzeroscore, VtScoreSize);
648 056fe1ba 2003-11-23 devnull /* (iii) */
649 056fe1ba 2003-11-23 devnull vtblockput(rb);
650 056fe1ba 2003-11-23 devnull if(ob!=nil && ob!=rb)
651 056fe1ba 2003-11-23 devnull vtblockput(ob);
652 056fe1ba 2003-11-23 devnull vtblockput(b);
654 056fe1ba 2003-11-23 devnull if(DEPTH(e->type) == depth)
655 056fe1ba 2003-11-23 devnull return 0;
656 056fe1ba 2003-11-23 devnull return -1;
659 056fe1ba 2003-11-23 devnull static int
660 056fe1ba 2003-11-23 devnull mkindices(VtEntry *e, u32int bn, int *index)
662 056fe1ba 2003-11-23 devnull int i, np;
664 59a96820 2004-06-17 devnull memset(index, 0, (VtPointerDepth+1)*sizeof(int));
666 056fe1ba 2003-11-23 devnull np = e->psize/VtScoreSize;
667 056fe1ba 2003-11-23 devnull for(i=0; bn > 0; i++){
668 056fe1ba 2003-11-23 devnull if(i >= VtPointerDepth){
669 d23a617a 2004-03-15 devnull werrstr("bad address 0x%lux", (ulong)bn);
670 056fe1ba 2003-11-23 devnull return -1;
672 056fe1ba 2003-11-23 devnull index[i] = bn % np;
673 056fe1ba 2003-11-23 devnull bn /= np;
675 056fe1ba 2003-11-23 devnull return i;
678 056fe1ba 2003-11-23 devnull VtBlock *
679 056fe1ba 2003-11-23 devnull vtfileblock(VtFile *r, u32int bn, int mode)
681 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
682 056fe1ba 2003-11-23 devnull int index[VtPointerDepth+1];
683 056fe1ba 2003-11-23 devnull VtEntry e;
687 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
688 056fe1ba 2003-11-23 devnull assert(bn != NilBlock);
690 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
691 056fe1ba 2003-11-23 devnull if(b == nil)
692 056fe1ba 2003-11-23 devnull return nil;
694 056fe1ba 2003-11-23 devnull i = mkindices(&e, bn, index);
695 056fe1ba 2003-11-23 devnull if(i < 0)
696 056fe1ba 2003-11-23 devnull return nil;
697 056fe1ba 2003-11-23 devnull if(i > DEPTH(e.type)){
698 056fe1ba 2003-11-23 devnull if(mode == VtOREAD){
699 d23a617a 2004-03-15 devnull werrstr("bad address 0x%lux", (ulong)bn);
700 056fe1ba 2003-11-23 devnull goto Err;
702 056fe1ba 2003-11-23 devnull index[i] = 0;
703 056fe1ba 2003-11-23 devnull if(growdepth(r, b, &e, i) < 0)
704 056fe1ba 2003-11-23 devnull goto Err;
707 056fe1ba 2003-11-23 devnull assert(b->type == VtDirType);
709 056fe1ba 2003-11-23 devnull index[DEPTH(e.type)] = r->offset % r->epb;
711 056fe1ba 2003-11-23 devnull /* mode for intermediate block */
712 056fe1ba 2003-11-23 devnull m = mode;
713 056fe1ba 2003-11-23 devnull if(m == VtOWRITE)
714 056fe1ba 2003-11-23 devnull m = VtORDWR;
716 056fe1ba 2003-11-23 devnull for(i=DEPTH(e.type); i>=0; i--){
717 056fe1ba 2003-11-23 devnull bb = blockwalk(b, index[i], r->c, i==0 ? mode : m, &e);
718 056fe1ba 2003-11-23 devnull if(bb == nil)
719 056fe1ba 2003-11-23 devnull goto Err;
720 056fe1ba 2003-11-23 devnull vtblockput(b);
723 056fe1ba 2003-11-23 devnull return b;
725 056fe1ba 2003-11-23 devnull vtblockput(b);
726 056fe1ba 2003-11-23 devnull return nil;
730 d23a617a 2004-03-15 devnull vtfileblockscore(VtFile *r, u32int bn, uchar score[VtScoreSize])
732 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
733 056fe1ba 2003-11-23 devnull int index[VtPointerDepth+1];
734 056fe1ba 2003-11-23 devnull VtEntry e;
737 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
738 056fe1ba 2003-11-23 devnull assert(bn != NilBlock);
740 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
741 056fe1ba 2003-11-23 devnull if(b == nil)
742 056fe1ba 2003-11-23 devnull return -1;
744 056fe1ba 2003-11-23 devnull i = mkindices(&e, bn, index);
745 056fe1ba 2003-11-23 devnull if(i < 0){
746 056fe1ba 2003-11-23 devnull vtblockput(b);
747 056fe1ba 2003-11-23 devnull return -1;
749 056fe1ba 2003-11-23 devnull if(i > DEPTH(e.type)){
750 056fe1ba 2003-11-23 devnull memmove(score, vtzeroscore, VtScoreSize);
751 056fe1ba 2003-11-23 devnull vtblockput(b);
752 056fe1ba 2003-11-23 devnull return 0;
755 056fe1ba 2003-11-23 devnull index[DEPTH(e.type)] = r->offset % r->epb;
757 056fe1ba 2003-11-23 devnull for(i=DEPTH(e.type); i>=1; i--){
758 056fe1ba 2003-11-23 devnull bb = blockwalk(b, index[i], r->c, VtOREAD, &e);
759 056fe1ba 2003-11-23 devnull if(bb == nil)
760 056fe1ba 2003-11-23 devnull goto Err;
761 056fe1ba 2003-11-23 devnull vtblockput(b);
763 056fe1ba 2003-11-23 devnull if(memcmp(b->score, vtzeroscore, VtScoreSize) == 0)
767 056fe1ba 2003-11-23 devnull memmove(score, b->data+index[0]*VtScoreSize, VtScoreSize);
768 056fe1ba 2003-11-23 devnull vtblockput(b);
769 056fe1ba 2003-11-23 devnull return 0;
772 056fe1ba 2003-11-23 devnull vtblockput(b);
773 056fe1ba 2003-11-23 devnull return -1;
777 056fe1ba 2003-11-23 devnull vtfileincref(VtFile *r)
779 056fe1ba 2003-11-23 devnull qlock(&r->lk);
780 056fe1ba 2003-11-23 devnull r->ref++;
781 056fe1ba 2003-11-23 devnull qunlock(&r->lk);
785 056fe1ba 2003-11-23 devnull vtfileclose(VtFile *r)
787 056fe1ba 2003-11-23 devnull if(r == nil)
789 056fe1ba 2003-11-23 devnull qlock(&r->lk);
790 056fe1ba 2003-11-23 devnull r->ref--;
791 056fe1ba 2003-11-23 devnull if(r->ref){
792 056fe1ba 2003-11-23 devnull qunlock(&r->lk);
795 056fe1ba 2003-11-23 devnull assert(r->ref == 0);
796 056fe1ba 2003-11-23 devnull qunlock(&r->lk);
797 056fe1ba 2003-11-23 devnull if(r->parent)
798 056fe1ba 2003-11-23 devnull vtfileclose(r->parent);
799 056fe1ba 2003-11-23 devnull memset(r, ~0, sizeof(*r));
800 056fe1ba 2003-11-23 devnull vtfree(r);
804 056fe1ba 2003-11-23 devnull * Retrieve the block containing the entry for r.
805 056fe1ba 2003-11-23 devnull * If a snapshot has happened, we might need
806 056fe1ba 2003-11-23 devnull * to get a new copy of the block. We avoid this
807 056fe1ba 2003-11-23 devnull * in the common case by caching the score for
808 056fe1ba 2003-11-23 devnull * the block and the last epoch in which it was valid.
810 056fe1ba 2003-11-23 devnull * We use r->mode to tell the difference between active
811 056fe1ba 2003-11-23 devnull * file system VtFiles (VtORDWR) and VtFiles for the
812 056fe1ba 2003-11-23 devnull * snapshot file system (VtOREAD).
814 056fe1ba 2003-11-23 devnull static VtBlock*
815 056fe1ba 2003-11-23 devnull fileloadblock(VtFile *r, int mode)
817 056fe1ba 2003-11-23 devnull char e[ERRMAX];
818 056fe1ba 2003-11-23 devnull u32int addr;
819 056fe1ba 2003-11-23 devnull VtBlock *b;
821 056fe1ba 2003-11-23 devnull switch(r->mode){
822 056fe1ba 2003-11-23 devnull default:
823 056fe1ba 2003-11-23 devnull assert(0);
824 056fe1ba 2003-11-23 devnull case VtORDWR:
825 056fe1ba 2003-11-23 devnull assert(r->mode == VtORDWR);
826 056fe1ba 2003-11-23 devnull if(r->local == 1){
827 056fe1ba 2003-11-23 devnull b = vtcacheglobal(r->c, r->score, VtDirType);
828 056fe1ba 2003-11-23 devnull if(b == nil)
829 056fe1ba 2003-11-23 devnull return nil;
830 056fe1ba 2003-11-23 devnull return b;
832 056fe1ba 2003-11-23 devnull assert(r->parent != nil);
833 056fe1ba 2003-11-23 devnull if(vtfilelock(r->parent, VtORDWR) < 0)
834 056fe1ba 2003-11-23 devnull return nil;
835 056fe1ba 2003-11-23 devnull b = vtfileblock(r->parent, r->offset/r->epb, VtORDWR);
836 056fe1ba 2003-11-23 devnull vtfileunlock(r->parent);
837 056fe1ba 2003-11-23 devnull if(b == nil)
838 056fe1ba 2003-11-23 devnull return nil;
839 056fe1ba 2003-11-23 devnull memmove(r->score, b->score, VtScoreSize);
840 056fe1ba 2003-11-23 devnull r->local = 1;
841 056fe1ba 2003-11-23 devnull return b;
843 056fe1ba 2003-11-23 devnull case VtOREAD:
844 056fe1ba 2003-11-23 devnull if(mode == VtORDWR){
845 056fe1ba 2003-11-23 devnull werrstr("read/write lock of read-only file");
846 056fe1ba 2003-11-23 devnull return nil;
848 056fe1ba 2003-11-23 devnull addr = vtglobaltolocal(r->score);
849 056fe1ba 2003-11-23 devnull if(addr == NilBlock)
850 056fe1ba 2003-11-23 devnull return vtcacheglobal(r->c, r->score, VtDirType);
852 056fe1ba 2003-11-23 devnull b = vtcachelocal(r->c, addr, VtDirType);
854 056fe1ba 2003-11-23 devnull return b;
857 056fe1ba 2003-11-23 devnull * If it failed because the epochs don't match, the block has been
858 056fe1ba 2003-11-23 devnull * archived and reclaimed. Rewalk from the parent and get the
859 056fe1ba 2003-11-23 devnull * new pointer. This can't happen in the VtORDWR case
860 056fe1ba 2003-11-23 devnull * above because blocks in the current epoch don't get
861 056fe1ba 2003-11-23 devnull * reclaimed. The fact that we're VtOREAD means we're
862 056fe1ba 2003-11-23 devnull * a snapshot. (Or else the file system is read-only, but then
863 056fe1ba 2003-11-23 devnull * the archiver isn't going around deleting blocks.)
865 056fe1ba 2003-11-23 devnull rerrstr(e, sizeof e);
866 056fe1ba 2003-11-23 devnull if(strcmp(e, ELabelMismatch) == 0){
867 056fe1ba 2003-11-23 devnull if(vtfilelock(r->parent, VtOREAD) < 0)
868 056fe1ba 2003-11-23 devnull return nil;
869 056fe1ba 2003-11-23 devnull b = vtfileblock(r->parent, r->offset/r->epb, VtOREAD);
870 056fe1ba 2003-11-23 devnull vtfileunlock(r->parent);
872 056fe1ba 2003-11-23 devnull fprint(2, "vtfilealloc: lost %V found %V\n",
873 056fe1ba 2003-11-23 devnull r->score, b->score);
874 056fe1ba 2003-11-23 devnull memmove(r->score, b->score, VtScoreSize);
875 056fe1ba 2003-11-23 devnull return b;
878 056fe1ba 2003-11-23 devnull return nil;
883 056fe1ba 2003-11-23 devnull vtfilelock(VtFile *r, int mode)
885 056fe1ba 2003-11-23 devnull VtBlock *b;
887 056fe1ba 2003-11-23 devnull if(mode == -1)
888 056fe1ba 2003-11-23 devnull mode = r->mode;
890 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
891 056fe1ba 2003-11-23 devnull if(b == nil)
892 056fe1ba 2003-11-23 devnull return -1;
894 056fe1ba 2003-11-23 devnull * The fact that we are holding b serves as the
895 056fe1ba 2003-11-23 devnull * lock entitling us to write to r->b.
897 056fe1ba 2003-11-23 devnull assert(r->b == nil);
898 056fe1ba 2003-11-23 devnull r->b = b;
899 056fe1ba 2003-11-23 devnull return 0;
903 056fe1ba 2003-11-23 devnull * Lock two (usually sibling) VtFiles. This needs special care
904 056fe1ba 2003-11-23 devnull * because the Entries for both vtFiles might be in the same block.
905 056fe1ba 2003-11-23 devnull * We also try to lock blocks in left-to-right order within the tree.
908 056fe1ba 2003-11-23 devnull vtfilelock2(VtFile *r, VtFile *rr, int mode)
910 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
912 056fe1ba 2003-11-23 devnull if(rr == nil)
913 056fe1ba 2003-11-23 devnull return vtfilelock(r, mode);
915 056fe1ba 2003-11-23 devnull if(mode == -1)
916 056fe1ba 2003-11-23 devnull mode = r->mode;
918 056fe1ba 2003-11-23 devnull if(r->parent==rr->parent && r->offset/r->epb == rr->offset/rr->epb){
919 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
920 056fe1ba 2003-11-23 devnull if(b == nil)
921 056fe1ba 2003-11-23 devnull return -1;
922 056fe1ba 2003-11-23 devnull vtblockduplock(b);
924 056fe1ba 2003-11-23 devnull }else if(r->parent==rr->parent || r->offset > rr->offset){
925 056fe1ba 2003-11-23 devnull bb = fileloadblock(rr, mode);
926 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
928 056fe1ba 2003-11-23 devnull b = fileloadblock(r, mode);
929 056fe1ba 2003-11-23 devnull bb = fileloadblock(rr, mode);
931 056fe1ba 2003-11-23 devnull if(b == nil || bb == nil){
933 056fe1ba 2003-11-23 devnull vtblockput(b);
935 056fe1ba 2003-11-23 devnull vtblockput(bb);
936 056fe1ba 2003-11-23 devnull return -1;
940 056fe1ba 2003-11-23 devnull * The fact that we are holding b and bb serves
941 056fe1ba 2003-11-23 devnull * as the lock entitling us to write to r->b and rr->b.
943 056fe1ba 2003-11-23 devnull r->b = b;
944 056fe1ba 2003-11-23 devnull rr->b = bb;
945 056fe1ba 2003-11-23 devnull return 0;
949 056fe1ba 2003-11-23 devnull vtfileunlock(VtFile *r)
951 056fe1ba 2003-11-23 devnull VtBlock *b;
953 056fe1ba 2003-11-23 devnull if(r->b == nil){
954 056fe1ba 2003-11-23 devnull fprint(2, "vtfileunlock: already unlocked\n");
955 056fe1ba 2003-11-23 devnull abort();
957 056fe1ba 2003-11-23 devnull b = r->b;
958 056fe1ba 2003-11-23 devnull r->b = nil;
959 056fe1ba 2003-11-23 devnull vtblockput(b);
962 056fe1ba 2003-11-23 devnull static VtBlock*
963 056fe1ba 2003-11-23 devnull fileload(VtFile *r, VtEntry *e)
965 056fe1ba 2003-11-23 devnull VtBlock *b;
967 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
968 056fe1ba 2003-11-23 devnull b = r->b;
969 056fe1ba 2003-11-23 devnull if(vtentryunpack(e, b->data, r->offset % r->epb) < 0)
970 056fe1ba 2003-11-23 devnull return nil;
971 056fe1ba 2003-11-23 devnull vtblockduplock(b);
972 056fe1ba 2003-11-23 devnull return b;
975 056fe1ba 2003-11-23 devnull static int
976 056fe1ba 2003-11-23 devnull sizetodepth(uvlong s, int psize, int dsize)
981 056fe1ba 2003-11-23 devnull /* determine pointer depth */
982 056fe1ba 2003-11-23 devnull np = psize/VtScoreSize;
983 056fe1ba 2003-11-23 devnull s = (s + dsize - 1)/dsize;
984 056fe1ba 2003-11-23 devnull for(d = 0; s > 1; d++)
985 056fe1ba 2003-11-23 devnull s = (s + np - 1)/np;
986 056fe1ba 2003-11-23 devnull return d;
990 056fe1ba 2003-11-23 devnull vtfileread(VtFile *f, void *data, long count, vlong offset)
992 056fe1ba 2003-11-23 devnull int frag;
993 056fe1ba 2003-11-23 devnull VtBlock *b;
994 056fe1ba 2003-11-23 devnull VtEntry e;
996 056fe1ba 2003-11-23 devnull assert(ISLOCKED(f));
998 056fe1ba 2003-11-23 devnull vtfilegetentry(f, &e);
999 056fe1ba 2003-11-23 devnull if(count == 0)
1000 056fe1ba 2003-11-23 devnull return 0;
1001 056fe1ba 2003-11-23 devnull if(count < 0 || offset < 0){
1002 056fe1ba 2003-11-23 devnull werrstr("vtfileread: bad offset or count");
1003 056fe1ba 2003-11-23 devnull return -1;
1005 056fe1ba 2003-11-23 devnull if(offset >= e.size)
1006 056fe1ba 2003-11-23 devnull return 0;
1008 056fe1ba 2003-11-23 devnull if(offset+count > e.size)
1009 056fe1ba 2003-11-23 devnull count = e.size - offset;
1011 056fe1ba 2003-11-23 devnull frag = offset % e.dsize;
1012 056fe1ba 2003-11-23 devnull if(frag+count > e.dsize)
1013 056fe1ba 2003-11-23 devnull count = e.dsize - frag;
1015 056fe1ba 2003-11-23 devnull b = vtfileblock(f, offset/e.dsize, VtOREAD);
1016 056fe1ba 2003-11-23 devnull if(b == nil)
1017 056fe1ba 2003-11-23 devnull return -1;
1019 056fe1ba 2003-11-23 devnull memmove(data, b->data+frag, count);
1020 056fe1ba 2003-11-23 devnull vtblockput(b);
1021 056fe1ba 2003-11-23 devnull return count;
1024 056fe1ba 2003-11-23 devnull static long
1025 056fe1ba 2003-11-23 devnull filewrite1(VtFile *f, void *data, long count, vlong offset)
1027 056fe1ba 2003-11-23 devnull int frag, m;
1028 056fe1ba 2003-11-23 devnull VtBlock *b;
1029 056fe1ba 2003-11-23 devnull VtEntry e;
1031 056fe1ba 2003-11-23 devnull vtfilegetentry(f, &e);
1032 056fe1ba 2003-11-23 devnull if(count < 0 || offset < 0){
1033 056fe1ba 2003-11-23 devnull werrstr("vtfilewrite: bad offset or count");
1034 056fe1ba 2003-11-23 devnull return -1;
1037 056fe1ba 2003-11-23 devnull frag = offset % e.dsize;
1038 056fe1ba 2003-11-23 devnull if(frag+count > e.dsize)
1039 056fe1ba 2003-11-23 devnull count = e.dsize - frag;
1041 056fe1ba 2003-11-23 devnull m = VtORDWR;
1042 056fe1ba 2003-11-23 devnull if(frag == 0 && count == e.dsize)
1043 056fe1ba 2003-11-23 devnull m = VtOWRITE;
1045 056fe1ba 2003-11-23 devnull b = vtfileblock(f, offset/e.dsize, m);
1046 056fe1ba 2003-11-23 devnull if(b == nil)
1047 056fe1ba 2003-11-23 devnull return -1;
1049 056fe1ba 2003-11-23 devnull memmove(b->data+frag, data, count);
1051 056fe1ba 2003-11-23 devnull if(offset+count > e.size){
1052 056fe1ba 2003-11-23 devnull vtfilegetentry(f, &e);
1053 056fe1ba 2003-11-23 devnull e.size = offset+count;
1054 056fe1ba 2003-11-23 devnull vtfilesetentry(f, &e);
1057 056fe1ba 2003-11-23 devnull vtblockput(b);
1058 056fe1ba 2003-11-23 devnull return count;
1062 056fe1ba 2003-11-23 devnull vtfilewrite(VtFile *f, void *data, long count, vlong offset)
1064 056fe1ba 2003-11-23 devnull long tot, m;
1066 056fe1ba 2003-11-23 devnull assert(ISLOCKED(f));
1068 056fe1ba 2003-11-23 devnull tot = 0;
1070 056fe1ba 2003-11-23 devnull while(tot < count){
1071 056fe1ba 2003-11-23 devnull m = filewrite1(f, (char*)data+tot, count-tot, offset+tot);
1072 056fe1ba 2003-11-23 devnull if(m <= 0)
1074 056fe1ba 2003-11-23 devnull tot += m;
1076 056fe1ba 2003-11-23 devnull if(tot==0)
1077 056fe1ba 2003-11-23 devnull return m;
1078 056fe1ba 2003-11-23 devnull return tot;
1081 056fe1ba 2003-11-23 devnull static int
1082 056fe1ba 2003-11-23 devnull flushblock(VtCache *c, VtBlock *bb, uchar score[VtScoreSize], int ppb, int epb,
1083 056fe1ba 2003-11-23 devnull int type)
1085 056fe1ba 2003-11-23 devnull u32int addr;
1086 056fe1ba 2003-11-23 devnull VtBlock *b;
1087 056fe1ba 2003-11-23 devnull VtEntry e;
1090 056fe1ba 2003-11-23 devnull addr = vtglobaltolocal(score);
1091 056fe1ba 2003-11-23 devnull if(addr == NilBlock)
1092 056fe1ba 2003-11-23 devnull return 0;
1094 056fe1ba 2003-11-23 devnull if(bb){
1095 056fe1ba 2003-11-23 devnull b = bb;
1096 056fe1ba 2003-11-23 devnull if(memcmp(b->score, score, VtScoreSize) != 0)
1097 056fe1ba 2003-11-23 devnull abort();
1099 056fe1ba 2003-11-23 devnull if((b = vtcachelocal(c, addr, type)) == nil)
1100 056fe1ba 2003-11-23 devnull return -1;
1102 056fe1ba 2003-11-23 devnull switch(type){
1103 056fe1ba 2003-11-23 devnull case VtDataType:
1106 056fe1ba 2003-11-23 devnull case VtDirType:
1107 056fe1ba 2003-11-23 devnull for(i=0; i<epb; i++){
1108 056fe1ba 2003-11-23 devnull if(vtentryunpack(&e, b->data, i) < 0)
1109 056fe1ba 2003-11-23 devnull goto Err;
1110 056fe1ba 2003-11-23 devnull if(flushblock(c, nil, e.score, e.psize/VtScoreSize, e.dsize/VtEntrySize,
1111 056fe1ba 2003-11-23 devnull e.type) < 0)
1112 056fe1ba 2003-11-23 devnull goto Err;
1116 056fe1ba 2003-11-23 devnull default: /* VtPointerTypeX */
1117 056fe1ba 2003-11-23 devnull for(i=0; i<ppb; i++){
1118 056fe1ba 2003-11-23 devnull if(flushblock(c, nil, b->data+VtScoreSize*i, ppb, epb, type-1) < 0)
1119 056fe1ba 2003-11-23 devnull goto Err;
1124 056fe1ba 2003-11-23 devnull if(vtblockwrite(b) < 0)
1125 056fe1ba 2003-11-23 devnull goto Err;
1126 056fe1ba 2003-11-23 devnull memmove(score, b->score, VtScoreSize);
1127 056fe1ba 2003-11-23 devnull if(b != bb)
1128 056fe1ba 2003-11-23 devnull vtblockput(b);
1129 056fe1ba 2003-11-23 devnull return 0;
1132 056fe1ba 2003-11-23 devnull if(b != bb)
1133 056fe1ba 2003-11-23 devnull vtblockput(b);
1134 056fe1ba 2003-11-23 devnull return -1;
1138 056fe1ba 2003-11-23 devnull vtfileflush(VtFile *f)
1140 056fe1ba 2003-11-23 devnull int ret;
1141 056fe1ba 2003-11-23 devnull VtBlock *b;
1142 056fe1ba 2003-11-23 devnull VtEntry e;
1144 056fe1ba 2003-11-23 devnull assert(ISLOCKED(f));
1145 056fe1ba 2003-11-23 devnull b = fileload(f, &e);
1146 056fe1ba 2003-11-23 devnull if(!(e.flags&VtEntryLocal)){
1147 056fe1ba 2003-11-23 devnull vtblockput(b);
1148 056fe1ba 2003-11-23 devnull return 0;
1151 056fe1ba 2003-11-23 devnull ret = flushblock(f->c, nil, e.score, e.psize/VtScoreSize, e.dsize/VtEntrySize,
1152 056fe1ba 2003-11-23 devnull e.type);
1153 7cb74894 2004-06-17 devnull if(ret < 0){
1154 056fe1ba 2003-11-23 devnull vtblockput(b);
1155 056fe1ba 2003-11-23 devnull return -1;
1158 056fe1ba 2003-11-23 devnull vtentrypack(&e, b->data, f->offset % f->epb);
1159 056fe1ba 2003-11-23 devnull vtblockput(b);
1160 056fe1ba 2003-11-23 devnull return 0;
1164 056fe1ba 2003-11-23 devnull vtfileflushbefore(VtFile *r, u64int offset)
1166 056fe1ba 2003-11-23 devnull VtBlock *b, *bb;
1167 056fe1ba 2003-11-23 devnull VtEntry e;
1168 59a96820 2004-06-17 devnull int i, base, depth, ppb, epb, doflush;
1169 59a96820 2004-06-17 devnull int index[VtPointerDepth+1], j, ret;
1170 056fe1ba 2003-11-23 devnull VtBlock *bi[VtPointerDepth+2];
1171 056fe1ba 2003-11-23 devnull uchar *score;
1173 056fe1ba 2003-11-23 devnull assert(ISLOCKED(r));
1174 056fe1ba 2003-11-23 devnull if(offset == 0)
1175 056fe1ba 2003-11-23 devnull return 0;
1177 056fe1ba 2003-11-23 devnull b = fileload(r, &e);
1178 056fe1ba 2003-11-23 devnull if(b == nil)
1179 056fe1ba 2003-11-23 devnull return -1;
1182 59a96820 2004-06-17 devnull * compute path through tree for the last written byte and the next one.
1184 056fe1ba 2003-11-23 devnull ret = -1;
1185 056fe1ba 2003-11-23 devnull memset(bi, 0, sizeof bi);
1186 056fe1ba 2003-11-23 devnull depth = DEPTH(e.type);
1187 056fe1ba 2003-11-23 devnull bi[depth+1] = b;
1188 056fe1ba 2003-11-23 devnull i = mkindices(&e, (offset-1)/e.dsize, index);
1189 056fe1ba 2003-11-23 devnull if(i < 0)
1190 056fe1ba 2003-11-23 devnull goto Err;
1191 056fe1ba 2003-11-23 devnull if(i > depth)
1192 056fe1ba 2003-11-23 devnull goto Err;
1193 056fe1ba 2003-11-23 devnull ppb = e.psize / VtScoreSize;
1194 056fe1ba 2003-11-23 devnull epb = e.dsize / VtEntrySize;
1197 59a96820 2004-06-17 devnull * load the blocks along the last written byte
1199 056fe1ba 2003-11-23 devnull index[depth] = r->offset % r->epb;
1200 056fe1ba 2003-11-23 devnull for(i=depth; i>=0; i--){
1201 056fe1ba 2003-11-23 devnull bb = blockwalk(b, index[i], r->c, VtORDWR, &e);
1202 056fe1ba 2003-11-23 devnull if(bb == nil)
1203 056fe1ba 2003-11-23 devnull goto Err;
1204 056fe1ba 2003-11-23 devnull bi[i] = bb;
1205 056fe1ba 2003-11-23 devnull b = bb;
1207 056fe1ba 2003-11-23 devnull ret = 0;
1210 59a96820 2004-06-17 devnull * walk up the path from leaf to root, flushing anything that
1211 59a96820 2004-06-17 devnull * has been finished.
1213 056fe1ba 2003-11-23 devnull base = e.type&~VtTypeDepthMask;
1214 005ee04b 2004-06-17 devnull for(i=0; i<=depth; i++){
1215 59a96820 2004-06-17 devnull doflush = 0;
1216 056fe1ba 2003-11-23 devnull if(i == 0){
1217 59a96820 2004-06-17 devnull /* leaf: data or dir block */
1218 59a96820 2004-06-17 devnull if(offset%e.dsize == 0)
1219 59a96820 2004-06-17 devnull doflush = 1;
1222 59a96820 2004-06-17 devnull * interior node: pointer blocks.
1223 59a96820 2004-06-17 devnull * specifically, b = bi[i] is a block whose index[i-1]'th entry
1224 59a96820 2004-06-17 devnull * points at bi[i-1].
1226 056fe1ba 2003-11-23 devnull b = bi[i];
1229 59a96820 2004-06-17 devnull * the index entries up to but not including index[i-1] point at
1230 59a96820 2004-06-17 devnull * finished blocks, so flush them for sure.
1232 056fe1ba 2003-11-23 devnull for(j=0; j<index[i-1]; j++)
1233 056fe1ba 2003-11-23 devnull if(flushblock(r->c, nil, b->data+j*VtScoreSize, ppb, epb, base+i-1) < 0)
1234 056fe1ba 2003-11-23 devnull goto Err;
1237 59a96820 2004-06-17 devnull * if index[i-1] is the last entry in the block and is global
1238 59a96820 2004-06-17 devnull * (i.e. the kid is flushed), then we can flush this block.
1240 59a96820 2004-06-17 devnull if(j==ppb-1 && vtglobaltolocal(b->data+j*VtScoreSize)==NilBlock)
1241 59a96820 2004-06-17 devnull doflush = 1;
1243 59a96820 2004-06-17 devnull if(doflush){
1244 056fe1ba 2003-11-23 devnull if(i == depth)
1245 056fe1ba 2003-11-23 devnull score = e.score;
1247 056fe1ba 2003-11-23 devnull score = bi[i+1]->data+index[i]*VtScoreSize;
1248 056fe1ba 2003-11-23 devnull if(flushblock(r->c, bi[i], score, ppb, epb, base+i) < 0)
1249 056fe1ba 2003-11-23 devnull goto Err;
1254 056fe1ba 2003-11-23 devnull /* top: entry. do this always so that the score is up-to-date */
1255 056fe1ba 2003-11-23 devnull vtentrypack(&e, bi[depth+1]->data, index[depth]);
1256 056fe1ba 2003-11-23 devnull for(i=0; i<nelem(bi); i++)
1257 056fe1ba 2003-11-23 devnull if(bi[i])
1258 056fe1ba 2003-11-23 devnull vtblockput(bi[i]);
1259 056fe1ba 2003-11-23 devnull return ret;
