dossrv: Implement support for != 512 sector and track sizes

The iotrack buffer layer always assumed 512 byte sector
size and 9 sectors per track.

To support 4K sector size fats, make the iotrack code
deal with it.

Instead of the fixed size Track structure, we just allocate
the pointers and buffers dynamically, and move the sector
size and tack size in the Xfs structure.

Tracks can still be reused between differnet file-systems
after a purgetrack().

The initial fat header has to be read with devread()
instead of getsect() to determine the sector/track size
of the file-system.

1 files changed, 87 insertions, 94 deletions

diff --git a/sys/src/cmd/dossrv/dossubs.c b/sys/src/cmd/dossrv/dossubs.c
index d77062554..eaabcd8bb 100644
--- a/sys/src/cmd/dossrv/dossubs.c
+++ b/sys/src/cmd/dossrv/dossubs.c
@@ -39,9 +39,10 @@ isdosfs(uchar *buf)
 int
 dosfs(Xfs *xf)
 {
-	Iosect *p, *p1;
-	Dosboot *b;
+	Iosect *p1;
 	Fatinfo *fi;
+	uchar	buf[512];
+	Dosboot *b;
 	Dosboot32 *b32;
 	Dosbpb *bp;
 	long fisec, extflags;
@@ -72,22 +73,28 @@ dosfs(Xfs *xf)
 		isdos['&'] = 1;
 	}
 
-	p = getsect(xf, 0);
-	if(p == nil)
+	/* don't use getsect() before we we determinted real values */
+	xf->sectsize = 512;
+	xf->sect2trk = 9;
+	devread(xf, 0, buf, sizeof(buf));
+
+	if(!isdosfs(buf))
 		return -1;
 
-	b = (Dosboot*)p->iobuf;
-	if(b->clustsize == 0 || isdosfs(p->iobuf) == 0){
-		putsect(p);
+	b = (Dosboot*)buf;
+
+	xf->sectsize = GSHORT(b->sectsize);
+	if(xf->sectsize < 32)
+		return -1;
+
+	xf->sect2trk = GSHORT(b->trksize);
+	if(xf->sect2trk < 1)
 		return -1;
-	}
 
 	bp = malloc(sizeof(Dosbpb));
 	memset(bp, 0, sizeof(Dosbpb));	/* clear lock */
 	xf->ptr = bp;
 	xf->fmt = 1;
-
-	bp->sectsize = GSHORT(b->sectsize);
 	bp->clustsize = b->clustsize;
 	bp->nresrv = GSHORT(b->nresrv);
 	bp->nfats = b->nfats;
@@ -102,13 +109,12 @@ dosfs(Xfs *xf)
 	bp->fatinfo = 0;
 
 	if(bp->fatsize == 0){	/* is FAT32 */
+		b32 = (Dosboot32*)buf;
 		if(chatty)
-			bootsecdump32(2, xf, (Dosboot32*)b);
+			bootsecdump32(2, xf, b32);
 		xf->isfat32 = 1;
-		b32 = (Dosboot32*)b;
 		bp->fatsize = GLONG(b32->fatsize32);
 		if(bp->fatsize == 0){
-			putsect(p);
 			if(chatty)
 				fprint(2, "fatsize 0\n");
 			return -1;
@@ -155,7 +161,7 @@ dosfs(Xfs *xf)
 			bootdump(2, b);
 		bp->rootaddr = bp->fataddr + bp->nfats*bp->fatsize;
 		bp->rootstart = 0;
-		bp->dataaddr = bp->rootaddr + (bp->rootsize*DOSDIRSIZE + bp->sectsize-1)/bp->sectsize;
+		bp->dataaddr = bp->rootaddr + (bp->rootsize*DOSDIRSIZE + xf->sectsize-1)/xf->sectsize;
 		bp->freeptr = FATRESRV;
 	}
 	bp->fatclusters = FATRESRV + (bp->volsize - bp->dataaddr)/bp->clustsize;
@@ -172,7 +178,6 @@ dosfs(Xfs *xf)
 		chat("fat %d: %lld...", i, bp->fataddr+i*bp->fatsize);
 	chat("root: %lld...", bp->rootaddr);
 	chat("data: %lld...", bp->dataaddr);
-	putsect(p);
 	return 0;
 }
 
@@ -215,8 +220,8 @@ getfile(Xfile *f)
 	 */
 	dp->d = nil;
 	if(!isroot(dp->addr)){
-		if(f->qid.path != QIDPATH(dp)){
-			chat("qid mismatch f=%#llux d=%#llux...", f->qid.path, QIDPATH(dp));
+		if(f->qid.path != QIDPATH(dp, f->xf)){
+			chat("qid mismatch f=%#llux d=%#llux...", f->qid.path, QIDPATH(dp, f->xf));
 			putsect(p);
 			errno = Enonexist;
 			return -1;
@@ -265,33 +270,29 @@ putstart(Xfs *xf, Dosdir *d, long start)
 long
 fileclust(Xfile *f, long iclust, int cflag)
 {
-	Dosbpb *bp;
-	Dosptr *dp;
-	Dosdir *d;
-	long start, clust, nskip, next;
-
-	bp = f->xf->ptr;
-	dp = f->ptr;
-	d = dp->d;
-	next = 0;
+	Xfs *xf = f->xf;
+	Dosbpb *bp = xf->ptr;
+	Dosptr *dp = f->ptr;
+	Dosdir *d = dp->d;
+	long start, clust, nskip, next = 0;
 
 	/* 
 	 * asking for the cluster of the root directory
 	 * is not a well-formed question, since the root directory
 	 * does not begin on a cluster boundary.
 	 */
-	if(!f->xf->isfat32 && isroot(dp->addr))
+	if(!xf->isfat32 && isroot(dp->addr))
 		return -1;
 
-	if(f->xf->isfat32 && isroot(dp->addr)){
+	if(xf->isfat32 && isroot(dp->addr)){
 		start = bp->rootstart;
 	}else{
-		start = getstart(f->xf, d);
+		start = getstart(xf, d);
 		if(start == 0){
 			if(!cflag)
 				return -1;
 			mlock(bp);
-			start = falloc(f->xf);
+			start = falloc(xf);
 			unmlock(bp);
 			if(start <= 0)
 				return -1;
@@ -315,7 +316,7 @@ fileclust(Xfile *f, long iclust, int cflag)
 	if(nskip > 0){
 		mlock(bp);
 		while(--nskip >= 0){
-			next = getfat(f->xf, clust);
+			next = getfat(xf, clust);
 			if(chatty > 1)
 				chat("->%#lx", next);
 			if(next > 0){
@@ -329,10 +330,10 @@ fileclust(Xfile *f, long iclust, int cflag)
 					break;
 				/* cfalloc will call putfat for us, since clust may change */
 			} else {
-				next = falloc(f->xf);
+				next = falloc(xf);
 				if(next < 0)
 					break;
-				putfat(f->xf, clust, next);
+				putfat(xf, clust, next);
 			}
 			clust = next;
 		}
@@ -353,14 +354,15 @@ fileclust(Xfile *f, long iclust, int cflag)
 vlong
 fileaddr(Xfile *f, long isect, int cflag)
 {
+	Xfs *xf = f->xf;
 	Dosbpb *bp;
 	Dosptr *dp;
 	long clust;
 
-	bp = f->xf->ptr;
+	bp = xf->ptr;
 	dp = f->ptr;
 	if(!f->xf->isfat32 && isroot(dp->addr)){
-		if(isect*bp->sectsize >= bp->rootsize*DOSDIRSIZE)
+		if(isect*xf->sectsize >= bp->rootsize*DOSDIRSIZE)
 			return -1;
 		return bp->rootaddr + isect;
 	}
@@ -512,14 +514,12 @@ searchdir(Xfile *f, char *name, Dosptr *dp, int cflag, int longtype)
 {
 	Xfs *xf;
 	Iosect *p;
-	Dosbpb *bp;
 	Dosdir *d;
 	char buf[261], *bname;
 	int isect, o, o1, islong, have, need, sum;
 	vlong addr, addr1, addr2, prevaddr, prevaddr1;
 
 	xf = f->xf;
-	bp = xf->ptr;
 	addr1 = -1;
 	addr2 = -1;
 	prevaddr1 = -1;
@@ -548,7 +548,7 @@ searchdir(Xfile *f, char *name, Dosptr *dp, int cflag, int longtype)
 		p = getsect(xf, addr);
 		if(p == nil)
 			break;
-		for(o=0; o<bp->sectsize; o+=DOSDIRSIZE){
+		for(o=0; o<xf->sectsize; o+=DOSDIRSIZE){
 			d = (Dosdir *)&p->iobuf[o];
 			if(d->name[0] == 0x00){
 				chat("end dir(0)...");
@@ -569,7 +569,7 @@ searchdir(Xfile *f, char *name, Dosptr *dp, int cflag, int longtype)
 					prevaddr1 = prevaddr;
 					o1 = o;
 				}
-				if(addr2 < 0 && (bp->sectsize-o)/DOSDIRSIZE + have < need){
+				if(addr2 < 0 && (xf->sectsize-o)/DOSDIRSIZE + have < need){
 					addr2 = fileaddr(f, isect+1, cflag);
 					if(addr2 < 0)
 						goto breakout;
@@ -641,7 +641,6 @@ int
 emptydir(Xfile *f)
 {
 	Xfs *xf = f->xf;
-	Dosbpb *bp = xf->ptr;
 	int isect, o;
 	vlong addr;
 	Iosect *p;
@@ -654,7 +653,7 @@ emptydir(Xfile *f)
 		p = getsect(xf, addr);
 		if(p == nil)
 			return -1;
-		for(o=0; o<bp->sectsize; o+=DOSDIRSIZE){
+		for(o=0; o<xf->sectsize; o+=DOSDIRSIZE){
 			d = (Dosdir *)&p->iobuf[o];
 			if(d->name[0] == 0x00){
 				putsect(p);
@@ -678,7 +677,6 @@ long
 readdir(Xfile *f, void *vbuf, vlong offset, long count)
 {
 	Xfs *xf;
-	Dosbpb *bp;
 	Dir dir;
 	int isect, o, islong, sum;
 	vlong addr;
@@ -691,7 +689,6 @@ readdir(Xfile *f, void *vbuf, vlong offset, long count)
 	buf = vbuf;
 	rcnt = 0;
 	xf = f->xf;
-	bp = xf->ptr;
 	if(count <= 0)
 		return 0;
 	islong = 0;
@@ -704,7 +701,7 @@ readdir(Xfile *f, void *vbuf, vlong offset, long count)
 		p = getsect(xf, addr);
 		if(p == nil)
 			return -1;
-		for(o=0; o<bp->sectsize; o+=DOSDIRSIZE){
+		for(o=0; o<xf->sectsize; o+=DOSDIRSIZE){
 			d = (Dosdir *)&p->iobuf[o];
 			if(d->name[0] == 0x00){
 				putsect(p);
@@ -763,15 +760,14 @@ readdir(Xfile *f, void *vbuf, vlong offset, long count)
 int
 walkup(Xfile *f, Dosptr *ndp)
 {
-	Dosbpb *bp;
-	Dosptr *dp;
+	Xfs *xf = f->xf;
+	Dosbpb *bp = xf->ptr;
+	Dosptr *dp = f->ptr;
 	Dosdir *xd;
 	Iosect *p;
 	long o, so, start, pstart, ppstart, st, ppclust;
 	vlong k;
 
-	bp = f->xf->ptr;
-	dp = f->ptr;
 	memset(ndp, 0, sizeof(Dosptr));
 	ndp->prevaddr = -1;
 	ndp->naddr = -1;
@@ -789,12 +785,12 @@ walkup(Xfile *f, Dosptr *ndp)
 	/*
 	 * find the start of our parent's directory
 	 */
-	p = getsect(f->xf, dp->paddr);
+	p = getsect(xf, dp->paddr);
 	if(p == nil)
 		goto error;
 	xd = (Dosdir *)&p->iobuf[dp->poffset];
 	dirdump(xd);
-	start = getstart(f->xf, xd);
+	start = getstart(xf, xd);
 	chat("start=%#lx...", start);
 	if(start == 0)
 		goto error;
@@ -808,7 +804,7 @@ walkup(Xfile *f, Dosptr *ndp)
 		goto error;
 	xd = (Dosdir *)p->iobuf;
 	dirdump(xd);
-	st = getstart(f->xf, xd);
+	st = getstart(xf, xd);
 	if(xd->name[0]!='.' || xd->name[1]!=' ' || start!=st)
 		goto error;
 
@@ -819,26 +815,26 @@ walkup(Xfile *f, Dosptr *ndp)
 	dirdump(xd);
 	if(xd->name[0] != '.' || xd->name[1] != '.')
 		goto error;
-	pstart = getstart(f->xf, xd);
+	pstart = getstart(xf, xd);
 	putsect(p);
 
 	/*
 	 * we're done if parent is root
 	 */
-	if(pstart == 0 || f->xf->isfat32 && pstart == bp->rootstart)
+	if(pstart == 0 || xf->isfat32 && pstart == bp->rootstart)
 		return 0;
 
 	/*
 	 * verify that parent's . points to itself
 	 */
-	p = getsect(f->xf, clust2sect(bp, pstart));
+	p = getsect(xf, clust2sect(bp, pstart));
 	if(p == nil){
 		chat("getsect %ld failed\n", pstart);
 		goto error;
 	}
 	xd = (Dosdir *)p->iobuf;
 	dirdump(xd);
-	st = getstart(f->xf, xd);
+	st = getstart(xf, xd);
 	if(xd->name[0]!='.' || xd->name[1]!=' ' || pstart!=st)
 		goto error;
 
@@ -849,7 +845,7 @@ walkup(Xfile *f, Dosptr *ndp)
 	dirdump(xd);
 	if(xd->name[0] != '.' || xd->name[1] != '.')
 		goto error;
-	ppstart = getstart(f->xf, xd);
+	ppstart = getstart(xf, xd);
 	putsect(p);
 
 	/*
@@ -857,12 +853,12 @@ walkup(Xfile *f, Dosptr *ndp)
 	 * need this to find parent's parent's addr and offset
 	 */
 	ppclust = ppstart;
-	if(f->xf->isfat32 && ppclust == 0){
+	if(xf->isfat32 && ppclust == 0){
 		ppclust = bp->rootstart;
 		chat("ppclust 0, resetting to rootstart\n");
 	}
 	k = ppclust ? clust2sect(bp, ppclust) : bp->rootaddr;
-	p = getsect(f->xf, k);
+	p = getsect(xf, k);
 	if(p == nil){
 		chat("getsect %lld failed\n", k);
 		goto error;
@@ -870,12 +866,12 @@ walkup(Xfile *f, Dosptr *ndp)
 	xd = (Dosdir *)p->iobuf;
 	dirdump(xd);
 	if(ppstart){
-		st = getstart(f->xf, xd);
+		st = getstart(xf, xd);
 		if(xd->name[0]!='.' || xd->name[1]!=' ' || ppstart!=st)
 			goto error;
 	}
 	for(so=1;; so++){
-		for(o=0; o<bp->sectsize; o+=DOSDIRSIZE){
+		for(o=0; o<xf->sectsize; o+=DOSDIRSIZE){
 			xd = (Dosdir *)&p->iobuf[o];
 			if(xd->name[0] == 0x00){
 				chat("end dir\n");
@@ -883,14 +879,14 @@ walkup(Xfile *f, Dosptr *ndp)
 			}
 			if(xd->name[0] == DOSEMPTY)
 				continue;
-			st = getstart(f->xf, xd);
+			st = getstart(xf, xd);
 			if(st == pstart)
 				goto out;
 		}
 		if(ppclust){
 			if(so%bp->clustsize == 0){
 				mlock(bp);
-				ppclust = getfat(f->xf, ppclust);
+				ppclust = getfat(xf, ppclust);
 				unmlock(bp);
 				if(ppclust < 0){
 					chat("getfat %ld failed\n", ppclust);
@@ -899,12 +895,12 @@ walkup(Xfile *f, Dosptr *ndp)
 			}
 			k = clust2sect(bp, ppclust) + so%bp->clustsize;
 		}else{
-			if(so*bp->sectsize >= bp->rootsize*DOSDIRSIZE)
+			if(so*xf->sectsize >= bp->rootsize*DOSDIRSIZE)
 				goto error;
 			k = bp->rootaddr + so;
 		}
 		putsect(p);
-		p = getsect(f->xf, k);
+		p = getsect(xf, k);
 		if(p == nil){
 			chat("getsect %lld failed\n", k);
 			goto error;
@@ -926,7 +922,6 @@ long
 readfile(Xfile *f, void *vbuf, vlong offset, long count)
 {
 	Xfs *xf = f->xf;
-	Dosbpb *bp = xf->ptr;
 	Dosptr *dp = f->ptr;
 	Dosdir *d = dp->d;
 	int isect, o, c;
@@ -947,13 +942,13 @@ readfile(Xfile *f, void *vbuf, vlong offset, long count)
 		return 0;
 	if(offset+count >= length)
 		count = length - offset;
-	isect = offset/bp->sectsize;
-	o = offset%bp->sectsize;
+	isect = offset/xf->sectsize;
+	o = offset%xf->sectsize;
 	while(count > 0){
 		addr = fileaddr(f, isect++, 0);
 		if(addr < 0)
 			break;
-		c = bp->sectsize - o;
+		c = xf->sectsize - o;
 		if(c > count)
 			c = count;
 		p = getsect(xf, addr);
@@ -989,16 +984,16 @@ writefile(Xfile *f, void *vbuf, vlong offset, long count)
 	rcnt = 0;
 	addr = 0;
 	buf = vbuf;
-	isect = offset/bp->sectsize;
-	o = offset%bp->sectsize;
+	isect = offset/xf->sectsize;
+	o = offset%xf->sectsize;
 	while(count > 0){
 		addr = fileaddr(f, isect++, 1);
 		if(addr < 0)
 			break;
-		c = bp->sectsize - o;
+		c = xf->sectsize - o;
 		if(c > count)
 			c = count;
-		if(c == bp->sectsize){
+		if(c == xf->sectsize){
 			p = getosect(xf, addr);
 			p->flags = 0;
 		}else{
@@ -1020,7 +1015,7 @@ writefile(Xfile *f, void *vbuf, vlong offset, long count)
 	if(rcnt > 0)
 		length = offset+rcnt;
 	else if(dp->addr && dp->clust){
-		c = bp->clustsize*bp->sectsize;
+		c = bp->clustsize*xf->sectsize;
 		if(dp->iclust > (dlen+c-1)/c)
 			length = (ulong)c*dp->iclust;
 	}
@@ -1045,18 +1040,18 @@ truncfile(Xfile *f, vlong length)
 		return -1;
 
 	mlock(bp);
-	clust = getstart(f->xf, d);
+	clust = getstart(xf, d);
 	n = length;
 	if(n <= 0)
-		putstart(f->xf, d, 0);
+		putstart(xf, d, 0);
 	else
-		n -= bp->sectsize;
+		n -= xf->sectsize;
 	while(clust > 0){
 		next = getfat(xf, clust);
 		if(n <= 0)
 			putfat(xf, clust, 0);
 		else
-			n -= bp->clustsize*bp->sectsize;
+			n -= bp->clustsize*xf->sectsize;
 		clust = next;
 	}
 	unmlock(bp);
@@ -1089,7 +1084,7 @@ putdir(Dosdir *d, Dir *dp)
  * creation and access dates
  */
 void
-getdir(Xfs *xfs, Dir *dp, Dosdir *d, vlong addr, int offset)
+getdir(Xfs *xf, Dir *dp, Dosdir *d, vlong addr, int offset)
 {
 	if(d == nil || addr == 0)
 		panic("getdir on root");
@@ -1097,7 +1092,7 @@ getdir(Xfs *xfs, Dir *dp, Dosdir *d, vlong addr, int offset)
 	dp->dev = 0;
 	getname(dp->name, d);
 
-	dp->qid.path = addr*(Sectorsize/DOSDIRSIZE) +
+	dp->qid.path = addr*(xf->sectsize/DOSDIRSIZE) +
 			offset/DOSDIRSIZE;
 	dp->qid.vers = 0;
 
@@ -1116,7 +1111,7 @@ getdir(Xfs *xfs, Dir *dp, Dosdir *d, vlong addr, int offset)
 		dp->length = GLONG(d->length);
 	if(d->attr & DSYSTEM){
 		dp->mode |= DMEXCL;
-		if(iscontig(xfs, d))
+		if(iscontig(xf, d))
 			dp->mode |= DMAPPEND;
 	}
 
@@ -1308,7 +1303,6 @@ aliassum(Dosdir *d)
 int
 putlongname(Xfs *xf, Dosptr *ndp, char *name, char sname[13])
 {
-	Dosbpb *bp;
 	Dosdir tmpd;
 	Rune longname[DOSNAMELEN+1];
 	int i, first, sum, nds, len;
@@ -1317,7 +1311,6 @@ putlongname(Xfs *xf, Dosptr *ndp, char *name, char sname[13])
 	putname(sname, &tmpd);
 	sum = aliassum(&tmpd);
 
-	bp = xf->ptr;
 	first = 1;
 	len = utftorunes(longname, name, DOSNAMELEN);
 	if(chatty){
@@ -1330,7 +1323,7 @@ putlongname(Xfs *xf, Dosptr *ndp, char *name, char sname[13])
 		putnamesect(&ndp->p->iobuf[ndp->offset], longname, nds, first, sum);
 		first = 0;
 		ndp->offset += 32;
-		if(ndp->offset == bp->sectsize){
+		if(ndp->offset == xf->sectsize){
 			chat("long name moving over sector boundary\n");
 			ndp->p->flags |= BMOD;
 			putsect(ndp->p);
@@ -1368,15 +1361,15 @@ getfat(Xfs *xf, long n)
 		return -1;
 	fb = bp->fatbits;
 	k = (fb * n) >> 3;
-	if(k >= bp->fatsize*bp->sectsize)
+	if(k >= bp->fatsize*xf->sectsize)
 		panic("getfat");
-	sect = k/bp->sectsize + bp->fataddr;
-	o = k%bp->sectsize;
+	sect = k/xf->sectsize + bp->fataddr;
+	o = k%xf->sectsize;
 	p = getsect(xf, sect);
 	if(p == nil)
 		return -1;
 	k = p->iobuf[o++];
-	if(o >= bp->sectsize){
+	if(o >= xf->sectsize){
 		putsect(p);
 		p = getsect(xf, sect+1);
 		if(p == nil)
@@ -1426,12 +1419,12 @@ putfat(Xfs *xf, int n, ulong val)
 	if(n < FATRESRV || n >= bp->fatclusters)
 		panic("putfat n=%d", n);
 	k = (bp->fatbits * n) >> 3;
-	if(k >= bp->fatsize*bp->sectsize)
+	if(k >= bp->fatsize*xf->sectsize)
 		panic("putfat");
-	sect = k/bp->sectsize + bp->fataddr;
+	sect = k/xf->sectsize + bp->fataddr;
 	esect = sect + bp->nfats * bp->fatsize;
 	for(; sect<esect; sect+=bp->fatsize){
-		o = k%bp->sectsize;
+		o = k%xf->sectsize;
 		p = getsect(xf, sect);
 		if(p == nil)
 			continue;
@@ -1440,7 +1433,7 @@ putfat(Xfs *xf, int n, ulong val)
 			if(n&1){
 				p->iobuf[o] &= 0x0f;
 				p->iobuf[o++] |= val<<4;
-				if(o >= bp->sectsize){
+				if(o >= xf->sectsize){
 					p->flags |= BMOD;
 					putsect(p);
 					p = getsect(xf, sect+1);
@@ -1451,7 +1444,7 @@ putfat(Xfs *xf, int n, ulong val)
 				p->iobuf[o] = val>>4;
 			}else{
 				p->iobuf[o++] = val;
-				if(o >= bp->sectsize){
+				if(o >= xf->sectsize){
 					p->flags |= BMOD;
 					putsect(p);
 					p = getsect(xf, sect+1);
@@ -1633,7 +1626,7 @@ makecontig(Xfile *f, int nextra)
 				return -1;
 			wp = getosect(xf, ws);
 			assert(wp != nil);
-			memmove(wp->iobuf, rp->iobuf, bp->sectsize);
+			memmove(wp->iobuf, rp->iobuf, xf->sectsize);
 			wp->flags = BMOD;
 			putsect(rp);
 			putsect(wp);
@@ -1702,7 +1695,7 @@ falloc(Xfs *xf)
 	k = clust2sect(bp, n);
 	for(i=0; i<bp->clustsize; i++){
 		p = getosect(xf, k+i);
-		memset(p->iobuf, 0, bp->sectsize);
+		memset(p->iobuf, 0, xf->sectsize);
 		p->flags = BMOD;
 		putsect(p);
 	}