45 checkclnum(struct bootblock *boot, int fat, cl_t cl, cl_t *next)  in checkclnum()  argument
47 	if (*next >= (CLUST_RSRVD&boot->ClustMask))  in checkclnum()
48 		*next |= ~boot->ClustMask;  in checkclnum()
49 	if (*next == CLUST_FREE) {  in checkclnum()
53 	if (*next == CLUST_BAD) {  in checkclnum()
57 	if (*next < CLUST_FIRST  in checkclnum()
58 	    || (*next >= boot->NumClusters && *next < CLUST_EOFS)) {  in checkclnum()
61 		      *next < CLUST_RSRVD ? "out of range" : "reserved",  in checkclnum()
62 		      *next&boot->ClustMask);  in checkclnum()
64 			*next = CLUST_EOF;  in checkclnum()
153 			fat[cl].next = p[0] + (p[1] << 8)  in readfat()
155 			fat[cl].next &= boot->ClustMask;  in readfat()
156 			ret |= checkclnum(boot, no, cl, &fat[cl].next);  in readfat()
161 			fat[cl].next = p[0] + (p[1] << 8);  in readfat()
162 			ret |= checkclnum(boot, no, cl, &fat[cl].next);  in readfat()
167 			fat[cl].next = (p[0] + (p[1] << 8)) & 0x0fff;  in readfat()
168 			ret |= checkclnum(boot, no, cl, &fat[cl].next);  in readfat()
172 			fat[cl].next = ((p[1] >> 4) + (p[2] << 4)) & 0x0fff;  in readfat()
173 			ret |= checkclnum(boot, no, cl, &fat[cl].next);  in readfat()
282 		if (first[cl].next != second[cl].next)  in comparefat()
283 			ret |= clustdiffer(cl, &first[cl].next, &second[cl].next, fatnum);  in comparefat()
295 		q = fat[p].next;  in clearchain()
296 		fat[p].next = fat[p].head = CLUST_FREE;  in clearchain()
314 		    p = fat[p].next) {  in tryclear()
340 		    || fat[head].next == CLUST_FREE  in checkfat()
341 		    || fat[head].next == CLUST_BAD)  in checkfat()
348 		     p = fat[p].next) {  in checkfat()
354 		fat[head].length = fat[head].next == CLUST_FREE ? 0 : len;  in checkfat()
369 		     (n = fat[p].next) >= CLUST_FIRST && n < boot->NumClusters;  in checkfat()
381 			ret |= tryclear(boot, fat, head, &fat[p].next);  in checkfat()
387 			ret |= tryclear(boot, fat, head, &fat[p].next);  in checkfat()
393 			ret |= tryclear(boot, fat, head, &fat[p].next);  in checkfat()
398 		conf = tryclear(boot, fat, head, &fat[p].next);  in checkfat()
406 				     p = fat[p].next) {  in checkfat()
466 			if (fat[cl].next == CLUST_FREE)  in writefat()
468 			*p++ = (u_char)fat[cl].next;  in writefat()
469 			*p++ = (u_char)(fat[cl].next >> 8);  in writefat()
470 			*p++ = (u_char)(fat[cl].next >> 16);  in writefat()
472 			*p++ |= (fat[cl].next >> 24)&0x0f;  in writefat()
475 			if (fat[cl].next == CLUST_FREE)  in writefat()
477 			*p++ = (u_char)fat[cl].next;  in writefat()
478 			*p++ = (u_char)(fat[cl].next >> 8);  in writefat()
481 			if (fat[cl].next == CLUST_FREE)  in writefat()
483 			*p++ = (u_char)fat[cl].next;  in writefat()
484 			*p = (u_char)((fat[cl].next >> 8) & 0xf);  in writefat()
488 			if (fat[cl].next == CLUST_FREE)  in writefat()
490 			*p++ |= (u_char)(fat[cl].next << 4);  in writefat()
491 			*p++ = (u_char)(fat[cl].next >> 4);  in writefat()
521 		    || fat[head].next == CLUST_FREE  in checklost()
522 		    || (fat[head].next >= CLUST_RSRVD  in checklost()
523 			&& fat[head].next < CLUST_EOFS)  in checklost()
552 		    fat[boot->FSNext].next != CLUST_FREE)) {  in checklost()
557 					if (fat[head].next == CLUST_FREE) {  in checklost()