fs/msdosfs/msdosfs_fat.c

81 		usemap_alloc(struct msdosfsmount *pmp, u_long cn);
82 static int	usemap_free(struct msdosfsmount *pmp, u_long cn);
136 	u_long cn;
150 	cn = dep->de_StartCluster;
157 	if (cn == MSDOSFSROOT) {
191 	fc_lookup(dep, findcn, &i, &cn);
200 		if ((cn | ~pmp->pm_fatmask) >= CLUST_RSRVD)
202 		byteoffset = FATOFS(pmp, cn);
213 		prevcn = cn;
220 			cn = getulong(bp->b_data + bo);
222 			cn = getushort(bp->b_data + bo);
224 			cn >>= 4;
225 		cn &= pmp->pm_fatmask;
233 		if ((cn | ~pmp->pm_fatmask) >= CLUST_RSRVD)
234 			cn |= ~pmp->pm_fatmask;
237 	if (!MSDOSFSEOF(pmp, cn)) {
241 			*bnp = cntobn(pmp, cn);
243 			*cnp = cn;
244 		fc_setcache(dep, FC_LASTMAP, i, cn);
266 	u_long cn;
272 		cn = dep->de_fc[i].fc_frcn;
273 		if (cn != FCE_EMPTY && cn <= findcn) {
274 			if (closest == NULL || cn > closest->fc_frcn)
386 usemap_alloc(struct msdosfsmount *pmp, u_long cn)
391 	KASSERT(cn <= pmp->pm_maxcluster, ("cn too large %lu %lu", cn,
395 	KASSERT((pmp->pm_inusemap[cn / N_INUSEBITS] &
396 	    (1U << (cn % N_INUSEBITS))) == 0,
397 	    ("Allocating used sector %ld %ld %x", cn, cn % N_INUSEBITS,
398 	    (unsigned)pmp->pm_inusemap[cn / N_INUSEBITS]));
399 	pmp->pm_inusemap[cn / N_INUSEBITS] |= 1U << (cn % N_INUSEBITS);
406 usemap_free(struct msdosfsmount *pmp, u_long cn)
411 	KASSERT(cn <= pmp->pm_maxcluster, ("cn too large %lu %lu", cn,
415 	if ((pmp->pm_inusemap[cn / N_INUSEBITS] &
416 	    (1U << (cn % N_INUSEBITS))) == 0) {
418 		    pmp->pm_mountp->mnt_stat.f_mntonname, cn, cn % N_INUSEBITS,
419 		    (unsigned)pmp->pm_inusemap[cn / N_INUSEBITS]);
425 	pmp->pm_inusemap[cn / N_INUSEBITS] &= ~(1U << (cn % N_INUSEBITS));
454  * cn		- which cluster is of interest
468 fatentry(int function, struct msdosfsmount *pmp, u_long cn, u_long *oldcontents,
478 	    function, pmp, cn, oldcontents, newcontents);
507 	if (cn < CLUST_FIRST || cn > pmp->pm_maxcluster)
510 	byteoffset = FATOFS(pmp, cn);
522 		if (FAT12(pmp) & (cn & 1))
534 			if (cn & 1) {
763 	u_long len, newst, foundl, cn, l;
781 	for (cn = newst; cn <= pmp->pm_maxcluster;) {
782 		idx = cn / N_INUSEBITS;
784 		map |= (1U << (cn % N_INUSEBITS)) - 1;
786 			cn = idx * N_INUSEBITS + ffs(map ^ FULL_RUN) - 1;
787 			if ((l = chainlength(pmp, cn, count)) >= count)
788 				return (chainalloc(pmp, cn, count, fillwith, retcluster, got));
790 				foundcn = cn;
793 			cn += l + 1;
796 		cn += N_INUSEBITS - cn % N_INUSEBITS;
798 	for (cn = 0; cn < newst;) {
799 		idx = cn / N_INUSEBITS;
801 		map |= (1U << (cn % N_INUSEBITS)) - 1;
803 			cn = idx * N_INUSEBITS + ffs(map ^ FULL_RUN) - 1;
804 			if ((l = chainlength(pmp, cn, count)) >= count)
805 				return (chainalloc(pmp, cn, count, fillwith, retcluster, got));
807 				foundcn = cn;
810 			cn += l + 1;
813 		cn += N_INUSEBITS - cn % N_INUSEBITS;
903 	u_long bn, bo, bsize, byteoffset, cn, readcn;
913 	for (cn = 0; cn < (pmp->pm_maxcluster + N_INUSEBITS) / N_INUSEBITS; cn++)
914 		pmp->pm_inusemap[cn] = FULL_RUN;
922 	for (cn = 0; cn <= pmp->pm_maxcluster; cn++) {
923 		byteoffset = FATOFS(pmp, cn);
938 		if (FAT12(pmp) && (cn & 1))
946 		if (cn == 0 && readcn != ((pmp->pm_fatmask & 0xffffff00) |
955 			error = usemap_free(pmp, cn);
965 	for (cn = pmp->pm_maxcluster + 1; cn < (pmp->pm_maxcluster +
966 	    N_INUSEBITS) / N_INUSEBITS; cn++)
967 		pmp->pm_inusemap[cn / N_INUSEBITS] |= 1U << (cn % N_INUSEBITS);
993 	u_long cn, got;
1015 		error = pcbmap(dep, 0xffff, 0, &cn, 0);
1036 			cn = 0;
1038 			cn = dep->de_fc[FC_LASTFC].fc_fsrcn + 1;
1039 		error = clusteralloc(pmp, cn, count, CLUST_EOFE, &cn, &got);
1050 			*ncp = cn;
1055 			dep->de_StartCluster = cn;
1060 					 0, cn);
1062 				clusterfree(pmp, cn);
1072 		fc_setcache(dep, FC_LASTFC, frcn + got - 1, cn + got - 1);
1081 					    cntobn(pmp, cn++),