#include <u.h>#include <libc.h>#include <venti.h>#include "cvt.h" static intchecksize(int n){	if(n < 256) {		werrstr("bad block size");		return -1;	}	return 0;} extern int vttobig(ulong); voidvtrootpack(VtRoot *r, uchar *p){	uchar *op = p;	int vers, bsize; 	vers = VtRootVersion;	bsize = r->blocksize;	if(bsize >= (1<<16)) {		vers |= _VtRootVersionBig;		bsize = vttobig(bsize);		if(bsize < 0)			sysfatal("invalid root blocksize: %#x", r->blocksize);	}	U16PUT(p, vers);	p += 2;	memmove(p, r->name, sizeof(r->name));	p += sizeof(r->name);	memmove(p, r->type, sizeof(r->type));	p += sizeof(r->type);	memmove(p, r->score, VtScoreSize);	p +=  VtScoreSize;	U16PUT(p, bsize);	p += 2;	memmove(p, r->prev, VtScoreSize);	p += VtScoreSize; 	assert(p-op == VtRootSize);} intvtrootunpack(VtRoot *r, uchar *p){	uchar *op = p;	uint vers;	memset(r, 0, sizeof(*r)); 	vers = U16GET(p);	if((vers&~_VtRootVersionBig) != VtRootVersion) {		werrstr("unknown root version");		return -1;	}	p += 2;	memmove(r->name, p, sizeof(r->name));	r->name[sizeof(r->name)-1] = 0;	p += sizeof(r->name);	memmove(r->type, p, sizeof(r->type));	r->type[sizeof(r->type)-1] = 0;	p += sizeof(r->type);	memmove(r->score, p, VtScoreSize);	p +=  VtScoreSize;	r->blocksize = U16GET(p);	if(vers & _VtRootVersionBig)		r->blocksize = (r->blocksize >> 5) << (r->blocksize & 31);	if(checksize(r->blocksize) < 0)		return -1;	p += 2;	memmove(r->prev, p, VtScoreSize);	p += VtScoreSize; 	assert(p-op == VtRootSize);	return 0;}