#include "u.h"#include "lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "io.h"#include "ureg.h"#include "error.h" #include "sd.h" void	loopdev(char*, int); typedef struct Ctlr Ctlr;struct Ctlr{	Ctlr	*next;	Ctlr	*prev;		QLock	lk;	SDev	*sdev; 	Chan	*c;	int		mode;	uvlong	qidpath;}; static	Lock	ctlrlock;static	Ctlr	*ctlrhead;static	Ctlr	*ctlrtail; SDifc sdloopifc; static SDev*looppnp(void){	return nil;} /* * Cannot error. * Check that unit is available. * Return 1 if so, 0 if not. */static intloopverify(SDunit *u){		return 1;} /* * Cannot error. * Check that unit is online. * If media changed, return 2. * If ready, return 1. * If not ready, return 0. */static intlooponline(SDunit *unit){	uchar buf[sizeof(Dir)+100];	Chan *c;	SDev *sdev;	Ctlr *ctlr;	Dir dir;	long n;		if(waserror())		return 0; 	sdev = unit->dev;	ctlr = sdev->ctlr;	c = ctlr->c;	n = devtab[c->type]->stat(c, buf, sizeof buf);	if(convM2D(buf, n, &dir, nil) == 0)		error("internal error: stat error in looponline");	if(ctlr->qidpath != dir.qid.path){		unit->sectors = dir.length/512;		unit->secsize = 512;		ctlr->qidpath = dir.qid.path;		poperror();		return 2;	}	poperror();	return 1;} static intlooprio(SDreq *r){	SDev *sdev;	SDunit *unit;	Ctlr *ctlr;	uchar *cmd;	uvlong lba;	long count, n;	Chan *c;	int status; 	unit = r->unit;	sdev = unit->dev;	ctlr = sdev->ctlr;	cmd = r->cmd; 	if((status = sdfakescsi(r, nil, 0)) != SDnostatus){#warning "Need to check for SDcheck in sdloop.";		/* XXX check for SDcheck here */		r->status = status;		return status;	} 	switch(cmd[0]){	case 0x28:	/* read */	case 0x2A:	/* write */		break;	default:		print("%s: bad cmd 0x%.2ux\n", unit->perm.name, cmd[0]);		r->status = SDcheck;		return SDcheck;	} 	lba = (cmd[2]<<24)|(cmd[3]<<16)|(cmd[4]<<8)|cmd[5];	count = (cmd[7]<<8)|cmd[8];	if(r->data == nil)		return SDok;	if(r->dlen < count*512)		count = r->dlen/512; 	c = ctlr->c;	if(cmd[0] == 0x28)		n = devtab[c->type]->read(c, r->data, count*512, lba*512);	else		n = devtab[c->type]->write(c, r->data, count*512, lba*512);	r->rlen = n;	return SDok;} static intlooprctl(SDunit *unit, char *p, int l){	Ctlr *ctlr;	char *e, *op;		ctlr = unit->dev->ctlr;	e = p+l;	op = p;		p = seprint(p, e, "loop %s %s\n", ctlr->mode == ORDWR ? "rw" : "ro", chanpath(ctlr->c));	p = seprint(p, e, "geometry %llud 512\n", unit->sectors*512);	return p - op;} static intloopwctl(SDunit *u, Cmdbuf *cmd){	cmderror(cmd, Ebadarg);	return 0;} static voidloopclear1(Ctlr *ctlr){	lock(&ctlrlock);	if(ctlr->prev)		ctlr->prev->next = ctlr->next;	else		ctlrhead = ctlr;	if(ctlr->next)		ctlr->next->prev = ctlr->prev;	else		ctlrtail = ctlr->prev;	unlock(&ctlrlock);		cclose(ctlr->c);	free(ctlr);} static voidloopclear(SDev *sdev){	loopclear1(sdev->ctlr);} static char*looprtopctl(SDev *s, char *p, char *e){	Ctlr *c;	char *r; 	c = s->ctlr;	r = "ro";	if(c->mode == ORDWR)		r = "rw";	return seprint(p, e, "%s loop %s %s\n", s->name, r, chanpath(c->c));} static intloopwtopctl(SDev *sdev, Cmdbuf *cb){	int mode; 	mode = 0;	if(cb->nf != 2)		cmderror(cb, Ebadarg);	if(strcmp(cb->f[0], "rw") == 0)		mode = ORDWR;	else if(strcmp(cb->f[0], "ro") == 0)		mode = OREAD;	else		cmderror(cb, Ebadarg);		loopdev(cb->f[1], mode);	return 0;} voidloopdev(char *name, int mode){	Chan *c;	Ctlr *volatile ctlr;	SDev *volatile sdev; 	c = namec(name, Aopen, mode, 0);	ctlr = nil;	sdev = nil;	if(waserror()){		cclose(c);		if(ctlr)			free(ctlr);		if(sdev)			free(sdev);		nexterror();	} 	ctlr = smalloc(sizeof *ctlr);	sdev = smalloc(sizeof *sdev);	sdev->ifc = &sdloopifc;	sdev->ctlr = ctlr;	sdev->nunit = 1;	sdev->idno = '0';	ctlr->sdev = sdev;	ctlr->c = c;	ctlr->mode = mode;	poperror(); 	lock(&ctlrlock);	ctlr->next = nil;	ctlr->prev = ctlrtail;	ctlrtail = ctlr;	if(ctlr->prev)		ctlr->prev->next = ctlr;	else		ctlrhead = ctlr;	unlock(&ctlrlock);		sdadddevs(sdev);}  SDifc sdloopifc = {	"loop", 	looppnp,	nil,		/* legacy */	nil,		/* enable */	nil,		/* disable */ 	loopverify,	looponline,	looprio,	looprctl,	loopwctl, 	scsibio,	nil,	/* probe */	loopclear,	/* clear */	looprtopctl,	loopwtopctl,}; SDifc *sdifc[] = {	&sdloopifc,	nil};