146 #define bytsec(fs, n)	((n) >> (fs)->sshift)  argument
147 #define secbyt(fs, s)	((s) << (fs)->sshift)  argument
148 #define depsec(fs)	(1 << (fs)->dshift)  argument
149 #define entsec(fs, e)	((e) >> (fs)->dshift)  argument
150 #define bytblk(fs, n)	((n) >> (fs)->bshift)  argument
151 #define blkbyt(fs, b)	((b) << (fs)->bshift)  argument
152 #define secblk(fs, s)	((s) >> ((fs)->bshift - (fs)->sshift))  argument
153 #define blksec(fs, b)	((b) << ((fs)->bshift - (fs)->sshift))  argument
156 #define blkoff(fs, b)	(secbyt(fs, (fs)->lsndta) + \  argument
157 			blkbyt(fs, (b) - LOCLUS))
160 #define blklsn(fs, b)  ((fs)->lsndta + blksec(fs, (b) - LOCLUS))  argument
168 #define okclus(fs, c)  ((c) >= LOCLUS && (c) <= (fs)->xclus)  argument
188 dos_read_fatblk(DOS_FS *fs, u_int blknum)  in dos_read_fatblk()  argument
195 	max_offset_in_fat = secbyt(fs, (daddr_t)fs->spf);  in dos_read_fatblk()
203 		err = ioget(fs, fs->lsnfat + bytsec(fs, offset_in_fat),  in dos_read_fatblk()
204 		    fs->fatbuf, io_size);  in dos_read_fatblk()
206 			fs->fatbuf_blknum = ((u_int)(-1));  in dos_read_fatblk()
211 		memset(fs->fatbuf + io_size, 0, FATBLKSZ - io_size);  in dos_read_fatblk()
213 	fs->fatbuf_blknum = blknum;  in dos_read_fatblk()
221 dos_mount_impl(DOS_FS *fs, struct open_file *fd)  in dos_mount_impl()  argument
227 	fs->fd = fd;  in dos_mount_impl()
238 	if ((err = ioget(fs, 0, buf, secsz)) ||  in dos_mount_impl()
239 	    (err = parsebs(fs, (DOS_BS *)buf))) {  in dos_mount_impl()
243 	fs->secbuf = buf;  in dos_mount_impl()
245 	if ((fs->fatbuf = malloc(FATBLKSZ)) == NULL) {  in dos_mount_impl()
249 	err = dos_read_fatblk(fs, 0);  in dos_mount_impl()
252 		free(fs->fatbuf);  in dos_mount_impl()
256 	fs->root = dot[0];  in dos_mount_impl()
257 	fs->root.name[0] = ' ';  in dos_mount_impl()
258 	if (fs->fatsz == 32) {  in dos_mount_impl()
259 		fs->root.clus[0] = fs->rdcl & 0xff;  in dos_mount_impl()
260 		fs->root.clus[1] = (fs->rdcl >> 8) & 0xff;  in dos_mount_impl()
261 		fs->root.dex.h_clus[0] = (fs->rdcl >> 16) & 0xff;  in dos_mount_impl()
262 		fs->root.dex.h_clus[1] = (fs->rdcl >> 24) & 0xff;  in dos_mount_impl()
270 	char *fs;  in dos_mount()  local
284 	if (asprintf(&fs, "%s%s", dev, path) < 0)  in dos_mount()
287 	mnt->dos_fd = open(fs, O_RDONLY);  in dos_mount()
288 	free(fs);  in dos_mount()
295 		mnt->dos_fs = df->fs;  in dos_mount()
330 dos_unmount_impl(DOS_FS *fs)  in dos_unmount_impl()  argument
332 	if (fs->links)  in dos_unmount_impl()
334 	free(fs->secbuf);  in dos_unmount_impl()
335 	free(fs->fatbuf);  in dos_unmount_impl()
336 	free(fs);  in dos_unmount_impl()
348 	DOS_FS *fs = NULL;  in dos_open()  local
362 		if ((fs = calloc(1, sizeof(DOS_FS))) == NULL)  in dos_open()
364 		if ((err = dos_mount_impl(fs, fd))) {  in dos_open()
365 			free(fs);  in dos_open()
369 		fs = mnt->dos_fs;  in dos_open()
372 	if ((err = namede(fs, path, &de))) {  in dos_open()
374 			dos_unmount_impl(fs);  in dos_open()
378 	clus = stclus(fs->fatsz, de);  in dos_open()
383 	    (clus && !okclus(fs, clus))) {  in dos_open()
385 			dos_unmount_impl(fs);  in dos_open()
391 			dos_unmount_impl(fs);  in dos_open()
394 	f->fs = fs;  in dos_open()
395 	fs->links++;  in dos_open()
422 	if ((size = fsize(f->fs, &f->de)) == -1)  in dos_read()
427 	if ((clus = stclus(f->fs->fatsz, &f->de)))  in dos_read()
428 		off &= f->fs->bsize - 1;  in dos_read()
435 				n = bytblk(f->fs, f->offset);  in dos_read()
439 			if ((err = fatget(f->fs, &c)))  in dos_read()
441 			if (!okclus(f->fs, c)) {  in dos_read()
446 		if (!clus || (n = f->fs->bsize - off) > cnt)  in dos_read()
449 			off += blkoff(f->fs, (uint64_t)c);  in dos_read()
451 			off += secbyt(f->fs, f->fs->lsndir);  in dos_read()
452 		err = ioread(f->fs, off, buf, n);  in dos_read()
509 	DOS_FS *fs = f->fs;  in dos_close()  local
511 	f->fs->links--;  in dos_close()
513 	dos_unmount_impl(fs);  in dos_close()
530 	if ((sb->st_size = fsize(f->fs, &f->de)) == -1)  in dos_stat()
629 parsebs(DOS_FS *fs, DOS_BS *bs)  in parsebs()  argument
642 		fs->sshift = ffs(cv2(bs->bpb.secsiz)) - 1;  in parsebs()
649 	if (!(fs->spc = bs->bpb.spc) || fs->spc & (fs->spc - 1))  in parsebs()
651 	fs->bsize = secbyt(fs, fs->spc);  in parsebs()
652 	fs->bshift = ffs(fs->bsize) - 1;  in parsebs()
653 	fs->dshift = ffs(secbyt(fs, 1) / sizeof (DOS_DE)) - 1;  in parsebs()
654 	fs->dirents = cv2(bs->bpb.dirents);  in parsebs()
655 	fs->spf = cv2(bs->bpb.spf);  in parsebs()
656 	fs->lsnfat = cv2(bs->bpb.ressec);  in parsebs()
658 	if (fs->spf != 0) {  in parsebs()
661 		if (fs->dirents == 0)  in parsebs()
664 		fs->spf = cv4(bs->bpb.fstype.f32.lspf);  in parsebs()
665 		if (fs->spf == 0)  in parsebs()
669 		fs->rdcl = cv4(bs->bpb.fstype.f32.rdcl);  in parsebs()
670 		if (fs->rdcl < LOCLUS)  in parsebs()
674 	RootDirSectors = ((fs->dirents * sizeof (DOS_DE)) +  in parsebs()
675 	    (secbyt(fs, 1) - 1)) / secbyt(fs, 1);  in parsebs()
677 	fs->lsndir = fs->lsnfat + fs->spf * bs->bpb.fats;  in parsebs()
678 	fs->lsndta = fs->lsndir + RootDirSectors;  in parsebs()
681 	if (fs->lsndta > sc)  in parsebs()
683 	if ((fs->xclus = secblk(fs, sc - fs->lsndta) + 1) < LOCLUS)  in parsebs()
685 	fs->fatsz = fs->dirents ? fs->xclus < 0xff6 ? 12 : 16 : 32;  in parsebs()
686 	sc = (secbyt(fs, fs->spf) << 1) / (fs->fatsz >> 2) - 1;  in parsebs()
687 	if (fs->xclus > sc)  in parsebs()
688 		fs->xclus = sc;  in parsebs()
696 namede(DOS_FS *fs, const char *path, DOS_DE **dep)  in namede()  argument
705 	de = &fs->root;  in namede()
720 		if ((err = lookup(fs, stclus(fs->fatsz, de), name, &de)))  in namede()
731 lookup(DOS_FS *fs, u_int clus, const char *name, DOS_DE **dep)  in lookup()  argument
745 	if (!clus && fs->fatsz == 32)  in lookup()
746 		clus = fs->rdcl;  in lookup()
747 	nsec = !clus ? entsec(fs, fs->dirents) : fs->spc;  in lookup()
750 	dir = (DOS_DIR *)fs->secbuf;  in lookup()
753 			lsec = fs->lsndir;  in lookup()
754 		else if (okclus(fs, clus))  in lookup()
755 			lsec = blklsn(fs, clus);  in lookup()
759 			if ((err = ioget(fs, lsec + sec, dir,  in lookup()
760 			    secbyt(fs, 1))))  in lookup()
762 			for (ent = 0; ent < depsec(fs); ent++) {  in lookup()
808 		if ((err = fatget(fs, &clus)))  in lookup()
810 		if (fatend(fs->fatsz, clus))  in lookup()
878 fsize(DOS_FS *fs, DOS_DE *de)  in fsize()  argument
885 		if (!(c = stclus(fs->fatsz, de))) {  in fsize()
886 			size = fs->dirents * sizeof(DOS_DE);  in fsize()
888 			if ((n = fatcnt(fs, c)) == -1)  in fsize()
890 			size = blkbyt(fs, n);  in fsize()
900 fatcnt(DOS_FS *fs, u_int c)  in fatcnt()  argument
904 	for (n = 0; okclus(fs, c); n++)  in fatcnt()
905 		if (fatget(fs, &c))  in fatcnt()
907 	return (fatend(fs->fatsz, c) ? n : -1);  in fatcnt()
915 fatget(DOS_FS *fs, u_int *c)  in fatget()  argument
927 	offset = fatoff(fs->fatsz, val_in);  in fatget()
928 	nbyte = fs->fatsz != 32 ? 2 : 4;  in fatget()
929 	if (offset + nbyte > secbyt(fs, fs->spf))  in fatget()
935 	if (blknum != fs->fatbuf_blknum) {  in fatget()
936 		err = dos_read_fatblk(fs, blknum);  in fatget()
940 	p_entry = fs->fatbuf + offset;  in fatget()
943 	switch (fs->fatsz) {  in fatget()
978 ioread(DOS_FS *fs, uint64_t offset, void *buf, size_t nbyte)  in ioread()  argument
985 	secsiz = secbyt(fs, 1);  in ioread()
991 		err = ioget(fs, bytsec(fs, offset), fs->secbuf, secsiz);  in ioread()
994 		memcpy(s, fs->secbuf + off, n);  in ioread()
1001 		if ((err = ioget(fs, bytsec(fs, offset), s, nbyte)))  in ioread()
1007 		err = ioget(fs, bytsec(fs, offset), fs->secbuf, secsiz);  in ioread()
1010 		memcpy(s, fs->secbuf, n);  in ioread()
1020 ioget(DOS_FS *fs, daddr_t lsec, void *buf, size_t size)  in ioget()  argument
1024 	struct open_file *fd = fs->fd;  in ioget()
1029 	lsec = secbyt(fs, lsec) >> 9;  in ioget()