tffs.c - plan9port - [fork] Plan 9 from user space
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tffs.c (19246B)
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1 #include <u.h>
2 #include <libc.h>
3 #include <thread.h>
4 #include <sunrpc.h>
5 #include <nfs3.h>
6 #include <diskfs.h>
7 #include "ffs.h"
8
9 #define BADBNO ((u64int)~0ULL)
10
11 #define checkcg 0
12 #define debug 0
13
14 static int checkfsblk(Fsblk*);
15 static int checkcgblk(Cgblk*);
16 static Block *ffsblockread(Fsys*, u64int);
17 static int ffssync(Fsys*);
18 static void ffsclose(Fsys*);
19
20 static u64int ffsxfileblock(Fsys *fs, Nfs3Handle *h, u64int offset);
21 static Nfs3Status ffsroot(Fsys*, Nfs3Handle*);
22 static Nfs3Status ffsgetattr(Fsys*, SunAuthUnix *au, Nfs3Handle*, Nfs3Attr*);
23 static Nfs3Status ffslookup(Fsys*, SunAuthUnix *au, Nfs3Handle*, char*, Nfs3Handle*);
24 static Nfs3Status ffsreadfile(Fsys*, SunAuthUnix *au, Nfs3Handle*, u32int, u64int, uchar**, u32int*, u1int*);
25 static Nfs3Status ffsreadlink(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, char **link);
26 static Nfs3Status ffsreaddir(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, u32int, u64int, uchar**, u32int*, u1int*);
27 static Nfs3Status ffsaccess(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, u32int want, u32int *got, Nfs3Attr *attr);
28
29 Fsys*
30 fsysopenffs(Disk *disk)
31 {
32 Ffs *fs;
33 Fsys *fsys;
34
35 fsys = emalloc(sizeof(Fsys));
36 fs = emalloc(sizeof(Ffs));
37 fs->disk = disk;
38 fsys->priv = fs;
39 fsys->type = "ffs";
40 fsys->_readblock = ffsblockread;
41 fsys->_sync = ffssync;
42 fsys->_root = ffsroot;
43 fsys->_getattr = ffsgetattr;
44 fsys->_access = ffsaccess;
45 fsys->_lookup = ffslookup;
46 fsys->_readfile = ffsreadfile;
47 fsys->_readlink = ffsreadlink;
48 fsys->_readdir = ffsreaddir;
49 fsys->_close = ffsclose;
50 fsys->fileblock = ffsxfileblock;
51
52 if(ffssync(fsys) < 0)
53 goto error;
54
55 return fsys;
56
57 error:
58 ffsclose(fsys);
59 return nil;
60 }
61
62 static Cgblk*
63 ffscylgrp(Ffs *fs, u32int i, Block **pb)
64 {
65 Block *b;
66 Cgblk *cg;
67
68 if(i >= fs->ncg)
69 return nil;
70
71 b = diskread(fs->disk, fs->blocksize, (u64int)fs->cg[i].cgblkno*fs->blocksize);
72 if(b == nil)
73 return nil;
74 cg = (Cgblk*)b->data;
75 if(checkcgblk(cg) < 0){
76 fprint(2, "checkcgblk %d %lud: %r\n", i, (ulong)fs->cg[i].cgblkno);
77 blockput(b);
78 return nil;
79 }
80 *pb = b;
81 return cg;
82 }
83
84 static int
85 ffssync(Fsys *fsys)
86 {
87 int i;
88 int off[] = { SBOFF, SBOFF2, SBOFFPIGGY };
89 Block *b, *cgb;
90 Cgblk *cgblk;
91 Cylgrp *cg;
92 Disk *disk;
93 Ffs *fs;
94 Fsblk *fsblk;
95
96 fs = fsys->priv;
97 disk = fs->disk;
98
99 /*
100 * Read super block.
101 */
102 b = nil;
103 for(i=0; i<nelem(off); i++){
104 if((b = diskread(disk, SBSIZE, off[i])) == nil)
105 goto error;
106 fsblk = (Fsblk*)b->data;
107 // fprint(2, "offset of magic: %ld\n", offsetof(Fsblk, magic));
108 if((fs->ufs = checkfsblk(fsblk)) > 0)
109 goto okay;
110 blockput(b);
111 b = nil;
112 }
113 goto error;
114
115 okay:
116 fs->blocksize = fsblk->blocksize;
117 fs->nblock = (fsblk->nfrag+fsblk->fragsperblock-1) / fsblk->fragsperblock;
118 fs->fragsize = fsblk->fragsize;
119 fs->fragspergroup = fsblk->fragspergroup;
120 fs->fragsperblock = fsblk->fragsperblock;
121 fs->inosperblock = fsblk->inosperblock;
122 fs->inospergroup = fsblk->inospergroup;
123
124 fs->nfrag = fsblk->nfrag;
125 fs->ndfrag = fsblk->ndfrag;
126 /*
127 * used to use
128 * fs->blockspergroup = (u64int)fsblk->_cylspergroup *
129 * fsblk->secspercyl * BYTESPERSEC / fsblk->blocksize;
130 * for UFS1, but this should work for both UFS1 and UFS2
131 */
132 fs->blockspergroup = (u64int)fsblk->fragspergroup / fsblk->fragsperblock;
133 fs->ncg = fsblk->ncg;
134
135 fsys->blocksize = fs->blocksize;
136 fsys->nblock = fs->nblock;
137
138 if(debug) fprint(2, "ffs %lld %d-byte blocks, %d cylinder groups\n",
139 fs->nblock, fs->blocksize, fs->ncg);
140 if(debug) fprint(2, "\tinospergroup %d perblock %d blockspergroup %lld\n",
141 fs->inospergroup, fs->inosperblock, fs->blockspergroup);
142
143 if(fs->cg == nil)
144 fs->cg = emalloc(fs->ncg*sizeof(Cylgrp));
145 for(i=0; i<fs->ncg; i++){
146 cg = &fs->cg[i];
147 if(fs->ufs == 2)
148 cg->bno = (u64int)fs->blockspergroup*i;
149 else
150 cg->bno = fs->blockspergroup*i + fsblk->_cgoffset * (i & ~fsblk->_cgmask);
151 cg->cgblkno = cg->bno + fsblk->cfragno/fs->fragsperblock;
152 cg->ibno = cg->bno + fsblk->ifragno/fs->fragsperblock;
153 cg->dbno = cg->bno + fsblk->dfragno/fs->fragsperblock;
154
155 if(checkcg){
156 if((cgb = diskread(disk, fs->blocksize, (u64int)cg->cgblkno*fs->blocksize)) == nil)
157 goto error;
158
159 cgblk = (Cgblk*)cgb->data;
160 if(checkcgblk(cgblk) < 0){
161 blockput(cgb);
162 goto error;
163 }
164 if(cgblk->nfrag % fs->fragsperblock && i != fs->ncg-1){
165 werrstr("fractional number of blocks in non-last cylinder group %d", cgblk->nfrag);
166 blockput(cgb);
167 goto error;
168 }
169 /* cg->nfrag = cgblk->nfrag; */
170 /* cg->nblock = (cgblk->nfrag+fs->fragsperblock-1) / fs->fragsperblock; */
171 /* fprint(2, "cg #%d: cgblk %lud, %d blocks, %d inodes\n", cgblk->num, (ulong)cg->cgblkno, cg->nblock, cg->nino); */
172 }
173 }
174 blockput(b);
175 return 0;
176
177 error:
178 blockput(b);
179 return -1;
180 }
181
182 static void
183 ffsclose(Fsys *fsys)
184 {
185 Ffs *fs;
186
187 fs = fsys->priv;
188 if(fs->cg)
189 free(fs->cg);
190 free(fs);
191 free(fsys);
192 }
193
194 static int
195 checkfsblk(Fsblk *super)
196 {
197 // fprint(2, "ffs magic 0x%ux\n", super->magic);
198 if(super->magic == FSMAGIC){
199 super->time = super->_time;
200 super->nfrag = super->_nfrag;
201 super->ndfrag = super->_ndfrag;
202 super->flags = super->_flags;
203 return 1;
204 }
205 if(super->magic == FSMAGIC2){
206 return 2;
207 }
208
209 werrstr("bad super block");
210 return -1;
211 }
212
213 static int
214 checkcgblk(Cgblk *cg)
215 {
216 if(cg->magic != CGMAGIC){
217 werrstr("bad cylinder group block");
218 return -1;
219 }
220 return 0;
221 }
222
223 /*
224 * Read block #bno from the disk, zeroing unused data.
225 * If there is no data whatsoever, it's okay to return nil.
226 */
227 int nskipx;
228 static Block*
229 ffsblockread(Fsys *fsys, u64int bno)
230 {
231 int i, o;
232 u8int *fmap;
233 int frag, fsize, avail;
234 Block *b;
235 Cgblk *cgblk;
236 Ffs *fs;
237
238 fs = fsys->priv;
239 i = bno / fs->blockspergroup;
240 o = bno % fs->blockspergroup;
241 if(i >= fs->ncg)
242 return nil;
243
244 if((cgblk = ffscylgrp(fs, i, &b)) == nil)
245 return nil;
246
247 fmap = (u8int*)cgblk+cgblk->fmapoff;
248 frag = fs->fragsperblock;
249 switch(frag){
250 default:
251 sysfatal("bad frag");
252 case 8:
253 avail = fmap[o];
254 break;
255 case 4:
256 avail = (fmap[o>>1] >> ((o&1)*4)) & 0xF;
257 break;
258 case 2:
259 avail = (fmap[o>>2] >> ((o&3)*2)) & 0x3;
260 break;
261 case 1:
262 avail = (fmap[o>>3] >> (o&7)) & 0x1;
263 break;
264 }
265 blockput(b);
266
267 if(avail == ((1<<frag)-1))
268 {
269 nskipx++;
270 return nil;
271 }
272 if((b = diskread(fs->disk, fs->blocksize, bno*fs->blocksize)) == nil){
273 fprint(2, "diskread failed!!!\n");
274 return nil;
275 }
276
277 fsize = fs->fragsize;
278 for(i=0; i<frag; i++)
279 if(avail & (1<<i))
280 memset(b->data + fsize*i, 0, fsize);
281 return b;
282 }
283
284 static Block*
285 ffsdatablock(Ffs *fs, u64int bno, int size)
286 {
287 int fsize;
288 u64int diskaddr;
289 Block *b;
290
291 if(bno == 0)
292 return nil;
293
294 fsize = size;
295 if(fsize < fs->fragsize)
296 fsize = fs->fragsize;
297
298 if(bno >= fs->nfrag){
299 fprint(2, "ffs: request for block %#lux; nfrag %#llux\n", (ulong)bno, fs->nfrag);
300 return nil;
301 }
302 diskaddr = (u64int)bno*fs->fragsize;
303 b = diskread(fs->disk, fsize, diskaddr);
304 if(b == nil){
305 fprint(2, "ffs: disk i/o at %#llux for %#ux: %r\n", diskaddr, fsize);
306 return nil;
307 }
308 if(b->len < fsize){
309 fprint(2, "ffs: disk i/o at %#llux for %#ux got %#ux\n", diskaddr, fsize,
310 b->len);
311 blockput(b);
312 return nil;
313 }
314
315 return b;
316 }
317
318 static u64int
319 ifetch(Ffs *fs, u64int bno, u32int off)
320 {
321 Block *b;
322
323 if(bno == BADBNO)
324 return BADBNO;
325 b = ffsdatablock(fs, bno, fs->blocksize);
326 if(b == nil)
327 return BADBNO;
328 if(fs->ufs == 2)
329 bno = ((u64int*)b->data)[off];
330 else
331 bno = ((u32int*)b->data)[off];
332 blockput(b);
333 return bno;
334 }
335
336 static u64int
337 ffsfileblockno(Ffs *fs, Inode *ino, u64int bno)
338 {
339 int ppb;
340
341 if(bno < NDADDR){
342 if(debug) fprint(2, "ffsfileblock %lud: direct %#lux\n", (ulong)bno, (ulong)ino->db[bno]);
343 return ino->db[bno];
344 }
345 bno -= NDADDR;
346 ppb = fs->blocksize/4;
347
348 if(bno < ppb) /* single indirect */
349 return ifetch(fs, ino->ib[0], bno);
350 bno -= ppb;
351
352 if(bno < ppb*ppb)
353 return ifetch(fs, ifetch(fs, ino->ib[1], bno/ppb), bno%ppb);
354 bno -= ppb*ppb;
355
356 if(bno/ppb/ppb/ppb == 0) /* bno < ppb*ppb*ppb w/o overflow */
357 return ifetch(fs, ifetch(fs, ifetch(fs, ino->ib[2], bno/ppb/ppb), (bno/ppb)%ppb), bno%ppb);
358
359 fprint(2, "ffsfileblock %llud: way too big\n", bno+NDADDR+ppb+ppb*ppb);
360 return BADBNO;
361 }
362
363 static Block*
364 ffsfileblock(Ffs *fs, Inode *ino, u64int bno, int size)
365 {
366 u64int b;
367
368 b = ffsfileblockno(fs, ino, bno);
369 if(b == ~0)
370 return nil;
371 return ffsdatablock(fs, b, size);
372 }
373
374 /*
375 * NFS handles are 4-byte inode number.
376 */
377 static void
378 mkhandle(Nfs3Handle *h, u64int ino)
379 {
380 h->h[0] = ino >> 24;
381 h->h[1] = ino >> 16;
382 h->h[2] = ino >> 8;
383 h->h[3] = ino;
384 h->len = 4;
385 }
386
387 static u32int
388 byte2u32(uchar *p)
389 {
390 return (p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3];
391 }
392
393 static u64int lastiaddr; /* debugging */
394
395 static void
396 inode1to2(Inode1 *i1, Inode *i2)
397 {
398 int i;
399
400 memset(i2, 0, sizeof *i2);
401 i2->mode = i1->mode;
402 i2->nlink = i1->nlink;
403 i2->size = i1->size;
404 i2->atime = i1->atime;
405 i2->atimensec = i1->atimensec;
406 i2->mtime = i1->mtime;
407 i2->mtimensec = i1->mtimensec;
408 i2->ctime = i1->ctime;
409 i2->ctimensec = i1->ctimensec;
410 for(i=0; i<NDADDR; i++)
411 i2->db[i] = i1->db[i];
412 for(i=0; i<NIADDR; i++)
413 i2->ib[i] = i1->ib[i];
414 i2->flags = i1->flags;
415 i2->nblock = i1->nblock;
416 i2->gen = i1->gen;
417 i2->uid = i1->uid;
418 i2->gid = i1->gid;
419 }
420
421 static Nfs3Status
422 handle2ino(Ffs *fs, Nfs3Handle *h, u32int *pinum, Inode *ino)
423 {
424 int i;
425 u32int ioff;
426 u32int inum;
427 u64int iaddr;
428 Block *b;
429 Cylgrp *cg;
430 Inode1 ino1;
431
432 if(h->len != 4)
433 return Nfs3ErrBadHandle;
434 inum = byte2u32(h->h);
435 if(pinum)
436 *pinum = inum;
437 if(debug) print("inum %d...", (int)inum);
438
439 /* fetch inode from disk */
440 i = inum / fs->inospergroup;
441 ioff = inum % fs->inospergroup;
442 if(debug)print("cg %d off %d...", i, (int)ioff);
443 if(i >= fs->ncg)
444 return Nfs3ErrBadHandle;
445 cg = &fs->cg[i];
446
447 if(debug) print("cg->ibno %lld ufs %d...", cg->ibno, fs->ufs);
448 iaddr = (cg->ibno+ioff/fs->inosperblock)*(vlong)fs->blocksize;
449 ioff = ioff%fs->inosperblock;
450 if((b = diskread(fs->disk, fs->blocksize, iaddr)) == nil)
451 return Nfs3ErrIo;
452 if(fs->ufs == 2){
453 *ino = ((Inode*)b->data)[ioff];
454 lastiaddr = iaddr+ioff*sizeof(Inode);
455 }else{
456 ino1 = ((Inode1*)b->data)[ioff];
457 inode1to2(&ino1, ino);
458 lastiaddr = iaddr+ioff*sizeof(Inode1);
459 }
460 blockput(b);
461 return Nfs3Ok;
462 }
463
464 static Nfs3Status
465 ffsroot(Fsys *fsys, Nfs3Handle *h)
466 {
467 USED(fsys);
468 mkhandle(h, 2);
469 return Nfs3Ok;
470 }
471
472 static Nfs3Status
473 ino2attr(Ffs *fs, Inode *ino, u32int inum, Nfs3Attr *attr)
474 {
475 u32int rdev;
476
477 attr->type = -1;
478 switch(ino->mode&IFMT){
479 case IFIFO:
480 attr->type = Nfs3FileFifo;
481 break;
482 case IFCHR:
483 attr->type = Nfs3FileChar;
484 break;
485 case IFDIR:
486 attr->type = Nfs3FileDir;
487 break;
488 case IFBLK:
489 attr->type = Nfs3FileBlock;
490 break;
491 case IFREG:
492 attr->type = Nfs3FileReg;
493 break;
494 case IFLNK:
495 attr->type = Nfs3FileSymlink;
496 break;
497 case IFSOCK:
498 attr->type = Nfs3FileSocket;
499 break;
500 case IFWHT:
501 default:
502 return Nfs3ErrBadHandle;
503 }
504
505 attr->mode = ino->mode&07777;
506 attr->nlink = ino->nlink;
507 attr->uid = ino->uid;
508 attr->gid = ino->gid;
509 attr->size = ino->size;
510 attr->used = ino->nblock*fs->blocksize;
511 if(attr->type==Nfs3FileBlock || attr->type==Nfs3FileChar){
512 rdev = ino->db[0];
513 attr->major = (rdev>>8)&0xFF;
514 attr->minor = rdev & 0xFFFF00FF;
515 }else{
516 attr->major = 0;
517 attr->minor = 0;
518 }
519 attr->fsid = 0;
520 attr->fileid = inum;
521 attr->atime.sec = ino->atime;
522 attr->atime.nsec = ino->atimensec;
523 attr->mtime.sec = ino->mtime;
524 attr->mtime.nsec = ino->mtimensec;
525 attr->ctime.sec = ino->ctime;
526 attr->ctime.nsec = ino->ctimensec;
527 return Nfs3Ok;
528 }
529
530 static int
531 ingroup(SunAuthUnix *au, uint gid)
532 {
533 int i;
534
535 for(i=0; i<au->ng; i++)
536 if(au->g[i] == gid)
537 return 1;
538 return 0;
539 }
540
541 static Nfs3Status
542 inoperm(Inode *ino, SunAuthUnix *au, int need)
543 {
544 int have;
545
546 if(au == nil)
547 return Nfs3Ok;
548
549 have = ino->mode&0777;
550 if(ino->uid == au->uid)
551 have >>= 6;
552 else if(ino->gid == au->gid || ingroup(au, ino->gid))
553 have >>= 3;
554
555 if((have&need) != need)
556 return Nfs3ErrNotOwner; /* really EPERM */
557 return Nfs3Ok;
558 }
559
560 static Nfs3Status
561 ffsgetattr(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, Nfs3Attr *attr)
562 {
563 Inode ino;
564 u32int inum;
565 Ffs *fs;
566 Nfs3Status ok;
567
568 fs = fsys->priv;
569 if((ok = handle2ino(fs, h, &inum, &ino)) != Nfs3Ok)
570 return ok;
571
572 USED(au); /* anyone can getattr */
573
574 return ino2attr(fs, &ino, inum, attr);
575 }
576
577 static Nfs3Status
578 ffsaccess(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, u32int want, u32int *got, Nfs3Attr *attr)
579 {
580 int have;
581 Inode ino;
582 u32int inum;
583 Ffs *fs;
584 Nfs3Status ok;
585
586 fs = fsys->priv;
587 if((ok = handle2ino(fs, h, &inum, &ino)) != Nfs3Ok)
588 return ok;
589
590 have = ino.mode&0777;
591 if(ino.uid == au->uid)
592 have >>= 6;
593 else if(ino.gid == au->gid || ingroup(au, ino.gid))
594 have >>= 3;
595
596 *got = 0;
597 if((want&Nfs3AccessRead) && (have&AREAD))
598 *got |= Nfs3AccessRead;
599 if((want&Nfs3AccessLookup) && (ino.mode&IFMT)==IFDIR && (have&AEXEC))
600 *got |= Nfs3AccessLookup;
601 if((want&Nfs3AccessExecute) && (ino.mode&IFMT)!=IFDIR && (have&AEXEC))
602 *got |= Nfs3AccessExecute;
603
604 return ino2attr(fs, &ino, inum, attr);
605 }
606
607 static Nfs3Status
608 ffslookup(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, char *name, Nfs3Handle *nh)
609 {
610 u32int nblock;
611 u32int i;
612 uchar *p, *ep;
613 Dirent *de;
614 Inode ino;
615 Block *b;
616 Ffs *fs;
617 Nfs3Status ok;
618 int len, want;
619
620 fs = fsys->priv;
621 if((ok = handle2ino(fs, h, nil, &ino)) != Nfs3Ok)
622 return ok;
623
624 if((ino.mode&IFMT) != IFDIR)
625 return Nfs3ErrNotDir;
626
627 if((ok = inoperm(&ino, au, AEXEC)) != Nfs3Ok)
628 return ok;
629
630 len = strlen(name);
631 nblock = (ino.size+fs->blocksize-1) / fs->blocksize;
632 for(i=0; i<nblock; i++){
633 if(i==nblock-1)
634 want = ino.size % fs->blocksize;
635 else
636 want = fs->blocksize;
637 b = ffsfileblock(fs, &ino, i, want);
638 if(b == nil)
639 continue;
640 p = b->data;
641 ep = p+b->len;
642 while(p < ep){
643 de = (Dirent*)p;
644 if(de->reclen == 0){
645 if(debug)
646 fprint(2, "reclen 0 at offset %d of %d\n", (int)(p-b->data), b->len);
647 break;
648 }
649 p += de->reclen;
650 if(p > ep){
651 if(debug)
652 fprint(2, "bad len %d at offset %d of %d\n", de->reclen, (int)(p-b->data), b->len);
653 break;
654 }
655 if(de->ino == 0)
656 continue;
657 if(4+2+2+de->namlen > de->reclen){
658 if(debug)
659 fprint(2, "bad namelen %d at offset %d of %d\n", de->namlen, (int)(p-b->data), b->len);
660 break;
661 }
662 if(de->namlen == len && memcmp(de->name, name, len) == 0){
663 mkhandle(nh, de->ino);
664 blockput(b);
665 return Nfs3Ok;
666 }
667 }
668 blockput(b);
669 }
670 return Nfs3ErrNoEnt;
671 }
672
673 static Nfs3Status
674 ffsreaddir(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, u32int count, u64int cookie, uchar **pdata, u32int *pcount, u1int *peof)
675 {
676 u32int nblock;
677 u32int i;
678 int off, done;
679 uchar *data, *dp, *dep, *p, *ep, *ndp;
680 Dirent *de;
681 Inode ino;
682 Block *b;
683 Ffs *fs;
684 Nfs3Status ok;
685 Nfs3Entry e;
686 int want;
687
688 fs = fsys->priv;
689 if((ok = handle2ino(fs, h, nil, &ino)) != Nfs3Ok)
690 return ok;
691
692 if((ino.mode&IFMT) != IFDIR)
693 return Nfs3ErrNotDir;
694
695 if((ok = inoperm(&ino, au, AREAD)) != Nfs3Ok)
696 return ok;
697
698 if(cookie >= ino.size){
699 *peof = 1;
700 *pcount = 0;
701 *pdata = 0;
702 return Nfs3Ok;
703 }
704
705 dp = malloc(count);
706 data = dp;
707 if(dp == nil)
708 return Nfs3ErrNoMem;
709 dep = dp+count;
710 *peof = 0;
711 nblock = (ino.size+fs->blocksize-1) / fs->blocksize;
712 i = cookie/fs->blocksize;
713 off = cookie%fs->blocksize;
714 done = 0;
715 for(; i<nblock && !done; i++){
716 if(i==nblock-1)
717 want = ino.size % fs->blocksize;
718 else
719 want = fs->blocksize;
720 b = ffsfileblock(fs, &ino, i, want);
721 if(b == nil)
722 continue;
723 p = b->data;
724 ep = p+b->len;
725 memset(&e, 0, sizeof e);
726 while(p < ep){
727 de = (Dirent*)p;
728 if(de->reclen == 0){
729 if(debug) fprint(2, "reclen 0 at offset %d of %d\n", (int)(p-b->data), b->len);
730 break;
731 }
732 p += de->reclen;
733 if(p > ep){
734 if(debug) fprint(2, "reclen %d at offset %d of %d\n", de->reclen, (int)(p-b->data), b->len);
735 break;
736 }
737 if(de->ino == 0){
738 if(debug) fprint(2, "zero inode\n");
739 continue;
740 }
741 if(4+2+2+de->namlen > de->reclen){
742 if(debug) fprint(2, "bad namlen %d reclen %d at offset %d of %d\n", de->namlen, de->reclen, (int)(p-b->data), b->len);
743 break;
744 }
745 if(de->name[de->namlen] != 0){
746 if(debug) fprint(2, "bad name %d %.*s\n", de->namlen, de->namlen, de->name);
747 continue;
748 }
749 if(debug) print("%s/%d ", de->name, (int)de->ino);
750 if((uchar*)de - b->data < off)
751 continue;
752 e.fileid = de->ino;
753 e.name = de->name;
754 e.namelen = de->namlen;
755 e.cookie = (u64int)i*fs->blocksize + (p - b->data);
756 if(nfs3entrypack(dp, dep, &ndp, &e) < 0){
757 done = 1;
758 break;
759 }
760 dp = ndp;
761 }
762 off = 0;
763 blockput(b);
764 }
765 if(i==nblock)
766 *peof = 1;
767
768 *pcount = dp - data;
769 *pdata = data;
770 return Nfs3Ok;
771 }
772
773 static u64int
774 ffsxfileblock(Fsys *fsys, Nfs3Handle *h, u64int offset)
775 {
776 u64int bno;
777 Inode ino;
778 Nfs3Status ok;
779 Ffs *fs;
780
781 fs = fsys->priv;
782 if((ok = handle2ino(fs, h, nil, &ino)) != Nfs3Ok){
783 nfs3errstr(ok);
784 return 0;
785 }
786 if(offset == 1) /* clumsy hack for debugging */
787 return lastiaddr;
788 if(offset >= ino.size){
789 werrstr("beyond end of file");
790 return 0;
791 }
792 bno = offset/fs->blocksize;
793 bno = ffsfileblockno(fs, &ino, bno);
794 if(bno == ~0)
795 return 0;
796 return bno*(u64int)fs->fragsize;
797 }
798
799 static Nfs3Status
800 ffsreadfile(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, u32int count,
801 u64int offset, uchar **pdata, u32int *pcount, u1int *peof)
802 {
803 uchar *data;
804 Block *b;
805 Ffs *fs;
806 int off, want, fragcount;
807 Inode ino;
808 Nfs3Status ok;
809
810 fs = fsys->priv;
811 if((ok = handle2ino(fs, h, nil, &ino)) != Nfs3Ok)
812 return ok;
813
814 if((ok = inoperm(&ino, au, AREAD)) != Nfs3Ok)
815 return ok;
816
817 if(offset >= ino.size){
818 *pdata = 0;
819 *pcount = 0;
820 *peof = 1;
821 return Nfs3Ok;
822 }
823 if(offset+count > ino.size)
824 count = ino.size-offset;
825 if(offset/fs->blocksize != (offset+count-1)/fs->blocksize)
826 count = fs->blocksize - offset%fs->blocksize;
827
828 data = malloc(count);
829 if(data == nil)
830 return Nfs3ErrNoMem;
831
832 want = offset%fs->blocksize+count;
833 if(want%fs->fragsize)
834 want += fs->fragsize - want%fs->fragsize;
835
836 b = ffsfileblock(fs, &ino, offset/fs->blocksize, want);
837 if(b == nil){
838 /* BUG: distinguish sparse file from I/O error */
839 memset(data, 0, count);
840 }else{
841 off = offset%fs->blocksize;
842 fragcount = count; /* need signed variable */
843 if(off+fragcount > b->len){
844 fragcount = b->len - off;
845 if(fragcount < 0)
846 fragcount = 0;
847 }
848 if(fragcount > 0)
849 memmove(data, b->data+off, fragcount);
850 count = fragcount;
851 blockput(b);
852 }
853 *peof = (offset+count == ino.size);
854 *pcount = count;
855 *pdata = data;
856 return Nfs3Ok;
857 }
858
859 static Nfs3Status
860 ffsreadlink(Fsys *fsys, SunAuthUnix *au, Nfs3Handle *h, char **link)
861 {
862 Ffs *fs;
863 Nfs3Status ok;
864 int len;
865 Inode ino;
866 Block *b;
867
868 fs = fsys->priv;
869 if((ok = handle2ino(fs, h, nil, &ino)) != Nfs3Ok)
870 return ok;
871 if((ok = inoperm(&ino, au, AREAD)) != Nfs3Ok)
872 return ok;
873
874 if(ino.size > 1024)
875 return Nfs3ErrIo;
876 len = ino.size;
877
878 if(ino.nblock != 0){
879 /* assumes symlink fits in one block */
880 b = ffsfileblock(fs, &ino, 0, len);
881 if(b == nil)
882 return Nfs3ErrIo;
883 if(memchr(b->data, 0, len) != nil){
884 blockput(b);
885 return Nfs3ErrIo;
886 }
887 *link = malloc(len+1);
888 if(*link == 0){
889 blockput(b);
890 return Nfs3ErrNoMem;
891 }
892 memmove(*link, b->data, len);
893 (*link)[len] = 0;
894 blockput(b);
895 return Nfs3Ok;
896 }
897
898 if(len > sizeof ino.db + sizeof ino.ib)
899 return Nfs3ErrIo;
900
901 *link = malloc(len+1);
902 if(*link == 0)
903 return Nfs3ErrNoMem;
904 memmove(*link, ino.db, ino.size);
905 (*link)[len] = 0;
906 return Nfs3Ok;
907 }