super.c

linux 内核源代码

					UDF_SB_PARTFLAGS(sb,i) |= UDF_PART_FLAG_UNALLOC_TABLE;
					udf_debug("unallocSpaceTable (part %d) @ %ld\n",
						  i, UDF_SB_PARTMAPS(sb)[i].s_uspace.s_table->i_ino);
				}
				if (phd->unallocSpaceBitmap.extLength) {
					UDF_SB_ALLOC_BITMAP(sb, i, s_uspace);
					if (UDF_SB_PARTMAPS(sb)[i].s_uspace.s_bitmap != NULL) {
						UDF_SB_PARTMAPS(sb)[i].s_uspace.s_bitmap->s_extLength =
							le32_to_cpu(phd->unallocSpaceBitmap.extLength);
						UDF_SB_PARTMAPS(sb)[i].s_uspace.s_bitmap->s_extPosition =
							le32_to_cpu(phd->unallocSpaceBitmap.extPosition);
						UDF_SB_PARTFLAGS(sb,i) |= UDF_PART_FLAG_UNALLOC_BITMAP;
						udf_debug("unallocSpaceBitmap (part %d) @ %d\n",
							  i, UDF_SB_PARTMAPS(sb)[i].s_uspace.s_bitmap->s_extPosition);
					}
				}
				if (phd->partitionIntegrityTable.extLength)
					udf_debug("partitionIntegrityTable (part %d)\n", i);
				if (phd->freedSpaceTable.extLength) {
					kernel_lb_addr loc = {
						.logicalBlockNum = le32_to_cpu(phd->freedSpaceTable.extPosition),
						.partitionReferenceNum = i,
					};

					UDF_SB_PARTMAPS(sb)[i].s_fspace.s_table =
						udf_iget(sb, loc);
					if (!UDF_SB_PARTMAPS(sb)[i].s_fspace.s_table) {
						udf_debug("cannot load freedSpaceTable (part %d)\n", i);
						return 1;
					}
					UDF_SB_PARTFLAGS(sb,i) |= UDF_PART_FLAG_FREED_TABLE;
					udf_debug("freedSpaceTable (part %d) @ %ld\n",
						  i, UDF_SB_PARTMAPS(sb)[i].s_fspace.s_table->i_ino);
				}
				if (phd->freedSpaceBitmap.extLength) {
					UDF_SB_ALLOC_BITMAP(sb, i, s_fspace);
					if (UDF_SB_PARTMAPS(sb)[i].s_fspace.s_bitmap != NULL) {
						UDF_SB_PARTMAPS(sb)[i].s_fspace.s_bitmap->s_extLength =
							le32_to_cpu(phd->freedSpaceBitmap.extLength);
						UDF_SB_PARTMAPS(sb)[i].s_fspace.s_bitmap->s_extPosition =
							le32_to_cpu(phd->freedSpaceBitmap.extPosition);
						UDF_SB_PARTFLAGS(sb,i) |= UDF_PART_FLAG_FREED_BITMAP;
						udf_debug("freedSpaceBitmap (part %d) @ %d\n",
							  i, UDF_SB_PARTMAPS(sb)[i].s_fspace.s_bitmap->s_extPosition);
					}
				}
			}
			break;
		}
	}
	if (i == UDF_SB_NUMPARTS(sb)) {
		udf_debug("Partition (%d) not found in partition map\n",
			  le16_to_cpu(p->partitionNumber));
	} else {
		udf_debug("Partition (%d:%d type %x) starts at physical %d, block length %d\n",
			  le16_to_cpu(p->partitionNumber), i, UDF_SB_PARTTYPE(sb,i),
			  UDF_SB_PARTROOT(sb,i), UDF_SB_PARTLEN(sb,i));
	}
	return 0;
}

static int udf_load_logicalvol(struct super_block *sb, struct buffer_head *bh,
			       kernel_lb_addr *fileset)
{
	struct logicalVolDesc *lvd;
	int i, j, offset;
	uint8_t type;

	lvd = (struct logicalVolDesc *)bh->b_data;

	UDF_SB_ALLOC_PARTMAPS(sb, le32_to_cpu(lvd->numPartitionMaps));

	for (i = 0, offset = 0;
	     i < UDF_SB_NUMPARTS(sb) && offset < le32_to_cpu(lvd->mapTableLength);
	     i++, offset += ((struct genericPartitionMap *)&(lvd->partitionMaps[offset]))->partitionMapLength) {
		type = ((struct genericPartitionMap *)&(lvd->partitionMaps[offset]))->partitionMapType;
		if (type == 1) {
			struct genericPartitionMap1 *gpm1 = (struct genericPartitionMap1 *)&(lvd->partitionMaps[offset]);
			UDF_SB_PARTTYPE(sb,i) = UDF_TYPE1_MAP15;
			UDF_SB_PARTVSN(sb,i) = le16_to_cpu(gpm1->volSeqNum);
			UDF_SB_PARTNUM(sb,i) = le16_to_cpu(gpm1->partitionNum);
			UDF_SB_PARTFUNC(sb,i) = NULL;
		} else if (type == 2) {
			struct udfPartitionMap2 *upm2 = (struct udfPartitionMap2 *)&(lvd->partitionMaps[offset]);
			if (!strncmp(upm2->partIdent.ident, UDF_ID_VIRTUAL, strlen(UDF_ID_VIRTUAL))) {
				if (le16_to_cpu(((__le16 *)upm2->partIdent.identSuffix)[0]) == 0x0150) {
					UDF_SB_PARTTYPE(sb,i) = UDF_VIRTUAL_MAP15;
					UDF_SB_PARTFUNC(sb,i) = udf_get_pblock_virt15;
				} else if (le16_to_cpu(((__le16 *)upm2->partIdent.identSuffix)[0]) == 0x0200) {
					UDF_SB_PARTTYPE(sb,i) = UDF_VIRTUAL_MAP20;
					UDF_SB_PARTFUNC(sb,i) = udf_get_pblock_virt20;
				}
			} else if (!strncmp(upm2->partIdent.ident, UDF_ID_SPARABLE, strlen(UDF_ID_SPARABLE))) {
				uint32_t loc;
				uint16_t ident;
				struct sparingTable *st;
				struct sparablePartitionMap *spm = (struct sparablePartitionMap *)&(lvd->partitionMaps[offset]);

				UDF_SB_PARTTYPE(sb,i) = UDF_SPARABLE_MAP15;
				UDF_SB_TYPESPAR(sb,i).s_packet_len = le16_to_cpu(spm->packetLength);
				for (j = 0; j < spm->numSparingTables; j++) {
					loc = le32_to_cpu(spm->locSparingTable[j]);
					UDF_SB_TYPESPAR(sb,i).s_spar_map[j] =
						udf_read_tagged(sb, loc, loc, &ident);
					if (UDF_SB_TYPESPAR(sb,i).s_spar_map[j] != NULL) {
						st = (struct sparingTable *)UDF_SB_TYPESPAR(sb,i).s_spar_map[j]->b_data;
						if (ident != 0 ||
						    strncmp(st->sparingIdent.ident, UDF_ID_SPARING, strlen(UDF_ID_SPARING))) {
							brelse(UDF_SB_TYPESPAR(sb,i).s_spar_map[j]);
							UDF_SB_TYPESPAR(sb,i).s_spar_map[j] = NULL;
						}
					}
				}
				UDF_SB_PARTFUNC(sb,i) = udf_get_pblock_spar15;
			} else {
				udf_debug("Unknown ident: %s\n", upm2->partIdent.ident);
				continue;
			}
			UDF_SB_PARTVSN(sb,i) = le16_to_cpu(upm2->volSeqNum);
			UDF_SB_PARTNUM(sb,i) = le16_to_cpu(upm2->partitionNum);
		}
		udf_debug("Partition (%d:%d) type %d on volume %d\n",
			  i, UDF_SB_PARTNUM(sb,i), type, UDF_SB_PARTVSN(sb,i));
	}

	if (fileset) {
		long_ad *la = (long_ad *)&(lvd->logicalVolContentsUse[0]);

		*fileset = lelb_to_cpu(la->extLocation);
		udf_debug("FileSet found in LogicalVolDesc at block=%d, partition=%d\n",
			  fileset->logicalBlockNum,
			  fileset->partitionReferenceNum);
	}
	if (lvd->integritySeqExt.extLength)
		udf_load_logicalvolint(sb, leea_to_cpu(lvd->integritySeqExt));

	return 0;
}

/*
 * udf_load_logicalvolint
 *
 */
static void udf_load_logicalvolint(struct super_block *sb, kernel_extent_ad loc)
{
	struct buffer_head *bh = NULL;
	uint16_t ident;

	while (loc.extLength > 0 &&
	       (bh = udf_read_tagged(sb, loc.extLocation,
				     loc.extLocation, &ident)) &&
	       ident == TAG_IDENT_LVID) {
		UDF_SB_LVIDBH(sb) = bh;

		if (UDF_SB_LVID(sb)->nextIntegrityExt.extLength)
			udf_load_logicalvolint(sb, leea_to_cpu(UDF_SB_LVID(sb)->nextIntegrityExt));

		if (UDF_SB_LVIDBH(sb) != bh)
			brelse(bh);
		loc.extLength -= sb->s_blocksize;
		loc.extLocation++;
	}
	if (UDF_SB_LVIDBH(sb) != bh)
		brelse(bh);
}

/*
 * udf_process_sequence
 *
 * PURPOSE
 *	Process a main/reserve volume descriptor sequence.
 *
 * PRE-CONDITIONS
 *	sb			Pointer to _locked_ superblock.
 *	block			First block of first extent of the sequence.
 *	lastblock		Lastblock of first extent of the sequence.
 *
 * HISTORY
 *	July 1, 1997 - Andrew E. Mileski
 *	Written, tested, and released.
 */
static int udf_process_sequence(struct super_block *sb, long block, long lastblock,
				 kernel_lb_addr *fileset)
{
	struct buffer_head *bh = NULL;
	struct udf_vds_record vds[VDS_POS_LENGTH];
	struct generic_desc *gd;
	struct volDescPtr *vdp;
	int done = 0;
	int i, j;
	uint32_t vdsn;
	uint16_t ident;
	long next_s = 0, next_e = 0;

	memset(vds, 0, sizeof(struct udf_vds_record) * VDS_POS_LENGTH);

	/* Read the main descriptor sequence */
	for (; (!done && block <= lastblock); block++) {

		bh = udf_read_tagged(sb, block, block, &ident);
		if (!bh)
			break;

		/* Process each descriptor (ISO 13346 3/8.3-8.4) */
		gd = (struct generic_desc *)bh->b_data;
		vdsn = le32_to_cpu(gd->volDescSeqNum);
		switch (ident) {
		case TAG_IDENT_PVD: /* ISO 13346 3/10.1 */
			if (vdsn >= vds[VDS_POS_PRIMARY_VOL_DESC].volDescSeqNum) {
				vds[VDS_POS_PRIMARY_VOL_DESC].volDescSeqNum = vdsn;
				vds[VDS_POS_PRIMARY_VOL_DESC].block = block;
			}
			break;
		case TAG_IDENT_VDP: /* ISO 13346 3/10.3 */
			if (vdsn >= vds[VDS_POS_VOL_DESC_PTR].volDescSeqNum) {
				vds[VDS_POS_VOL_DESC_PTR].volDescSeqNum = vdsn;
				vds[VDS_POS_VOL_DESC_PTR].block = block;

				vdp = (struct volDescPtr *)bh->b_data;
				next_s = le32_to_cpu(vdp->nextVolDescSeqExt.extLocation);
				next_e = le32_to_cpu(vdp->nextVolDescSeqExt.extLength);
				next_e = next_e >> sb->s_blocksize_bits;
				next_e += next_s;
			}
			break;
		case TAG_IDENT_IUVD: /* ISO 13346 3/10.4 */
			if (vdsn >= vds[VDS_POS_IMP_USE_VOL_DESC].volDescSeqNum) {
				vds[VDS_POS_IMP_USE_VOL_DESC].volDescSeqNum = vdsn;
				vds[VDS_POS_IMP_USE_VOL_DESC].block = block;
			}
			break;
		case TAG_IDENT_PD: /* ISO 13346 3/10.5 */
			if (!vds[VDS_POS_PARTITION_DESC].block)
				vds[VDS_POS_PARTITION_DESC].block = block;
			break;
		case TAG_IDENT_LVD: /* ISO 13346 3/10.6 */
			if (vdsn >= vds[VDS_POS_LOGICAL_VOL_DESC].volDescSeqNum) {
				vds[VDS_POS_LOGICAL_VOL_DESC].volDescSeqNum = vdsn;
				vds[VDS_POS_LOGICAL_VOL_DESC].block = block;
			}
			break;
		case TAG_IDENT_USD: /* ISO 13346 3/10.8 */
			if (vdsn >= vds[VDS_POS_UNALLOC_SPACE_DESC].volDescSeqNum) {
				vds[VDS_POS_UNALLOC_SPACE_DESC].volDescSeqNum = vdsn;
				vds[VDS_POS_UNALLOC_SPACE_DESC].block = block;
			}
			break;
		case TAG_IDENT_TD: /* ISO 13346 3/10.9 */
			vds[VDS_POS_TERMINATING_DESC].block = block;
			if (next_e) {
				block = next_s;
				lastblock = next_e;
				next_s = next_e = 0;
			} else {
				done = 1;
			}
			break;
		}
		brelse(bh);
	}
	for (i = 0; i < VDS_POS_LENGTH; i++) {
		if (vds[i].block) {
			bh = udf_read_tagged(sb, vds[i].block, vds[i].block, &ident);

			if (i == VDS_POS_PRIMARY_VOL_DESC) {
				udf_load_pvoldesc(sb, bh);
			} else if (i == VDS_POS_LOGICAL_VOL_DESC) {
				udf_load_logicalvol(sb, bh, fileset);
			} else if (i == VDS_POS_PARTITION_DESC) {
				struct buffer_head *bh2 = NULL;
				if (udf_load_partdesc(sb, bh)) {
					brelse(bh);
					return 1;
				}
				for (j = vds[i].block + 1; j <  vds[VDS_POS_TERMINATING_DESC].block; j++) {
					bh2 = udf_read_tagged(sb, j, j, &ident);
					gd = (struct generic_desc *)bh2->b_data;
					if (ident == TAG_IDENT_PD)
						if (udf_load_partdesc(sb, bh2)) {
							brelse(bh);
							brelse(bh2);
							return 1;
						}
					brelse(bh2);
				}
			}
			brelse(bh);
		}
	}

	return 0;
}

/*
 * udf_check_valid()
 */
static int udf_check_valid(struct super_block *sb, int novrs, int silent)
{
	long block;

	if (novrs) {
		udf_debug("Validity check skipped because of novrs option\n");
		return 0;
	}
	/* Check that it is NSR02 compliant */
	/* Process any "CD-ROM Volume Descriptor Set" (ECMA 167 2/8.3.1) */
	else if ((block = udf_vrs(sb, silent)) == -1) {
		udf_debug("Failed to read byte 32768. Assuming open disc. "
			  "Skipping validity check\n");
		if (!UDF_SB_LASTBLOCK(sb))
			UDF_SB_LASTBLOCK(sb) = udf_get_last_block(sb);
		return 0;
	} else {
		return !block;
	}
}

static int udf_load_partition(struct super_block *sb, kernel_lb_addr *fileset)
{
	struct anchorVolDescPtr *anchor;
	uint16_t ident;
	struct buffer_head *bh;
	long main_s, main_e, reserve_s, reserve_e;
	int i, j;

	if (!sb)
		return 1;

	for (i = 0; i < ARRAY_SIZE(UDF_SB_ANCHOR(sb)); i++) {
		if (UDF_SB_ANCHOR(sb)[i] &&
		    (bh = udf_read_tagged(sb, UDF_SB_ANCHOR(sb)[i],
					  UDF_SB_ANCHOR(sb)[i], &ident))) {
			anchor = (struct anchorVolDescPtr *)bh->b_data;

			/* Locate the main sequence */
			main_s = le32_to_cpu(anchor->mainVolDescSeqExt.extLocation);
			main_e = le32_to_cpu(anchor->mainVolDescSeqExt.extLength );
			main_e = main_e >> sb->s_blocksize_bits;
			main_e += main_s;

			/* Locate the reserve sequence */
			reserve_s = le32_to_cpu(anchor->reserveVolDescSeqExt.extLocation);
			reserve_e = le32_to_cpu(anchor->reserveVolDescSeqExt.extLength);
			reserve_e = reserve_e >> sb->s_blocksize_bits;
			reserve_e += reserve_s;

			brelse(bh);

			/* Process the main & reserve sequences */
			/* responsible for finding the PartitionDesc(s) */
			if (!(udf_process_sequence(sb, main_s, main_e, fileset) &&
			      udf_process_sequence(sb, reserve_s, reserve_e, fileset))) {
				break;
			}
		}
	}

	if (i == ARRAY_SIZE(UDF_SB_ANCHOR(sb))) {
		udf_debug("No Anchor block found\n");
		return 1;
	} else
		udf_debug("Using anchor in block %d\n", UDF_SB_ANCHOR(sb)[i]);

	for (i = 0; i < UDF_SB_NUMPARTS(sb); i++) {
		kernel_lb_addr uninitialized_var(ino);
		switch (UDF_SB_PARTTYPE(sb, i)) {
		case UDF_VIRTUAL_MAP15:
		case UDF_VIRTUAL_MAP20:
			if (!UDF_SB_LASTBLOCK(sb)) {
				UDF_SB_LASTBLOCK(sb) = udf_get_last_block(sb);
				udf_find_anchor(sb);
			}

			if (!UDF_SB_LASTBLOCK(sb)) {
				udf_debug("Unable to determine Lastblock (For "
					  "Virtual Partition)\n");
				return 1;
			}

			for (j = 0; j < UDF_SB_NUMPARTS(sb); j++) {
				if (j != i &&
				    UDF_SB_PARTVSN(sb, i) == UDF_SB_PARTVSN(sb, j) &&
				    UDF_SB_PARTNUM(sb, i) == UDF_SB_PARTNUM(sb, j)) {
					ino.partitionReferenceNum = j;
					ino.logicalBlockNum = UDF_SB_LASTBLOCK(sb) - UDF_SB_PARTROOT(sb, j);
					break;
				}
			}

			if (j == UDF_SB_NUMPARTS(sb))
				return 1;

			if (!(UDF_SB_VAT(sb) = udf_iget(sb, ino)))
				return 1;

			if (UDF_SB_PARTTYPE(sb, i) == UDF_VIRTUAL_MAP15) {
				UDF_SB_TYPEVIRT(sb, i).s_start_offset =
					udf_ext0_offset(UDF_SB_VAT(sb));
				UDF_SB_TYPEVIRT(sb, i).s_num_entries =
					(UDF_SB_VAT(sb)->i_size - 36) >> 2;
			} else if (UDF_SB_PARTTYPE(sb, i) == UDF_VIRTUAL_MAP20) {
				struct buffer_head *bh = NULL;
				uint32_t pos;

				pos = udf_block_map(UDF_SB_VAT(sb), 0);
				bh = sb_bread(sb, pos);
				if (!bh)
					return 1;
				UDF_SB_TYPEVIRT(sb, i).s_start_offset =
					le16_to_cpu(((struct virtualAllocationTable20 *)bh->b_data +
						     udf_ext0_offset(UDF_SB_VAT(sb)))->lengthHeader) +
					udf_ext0_offset(UDF_SB_VAT(sb));
				UDF_SB_TYPEVIRT(sb, i).s_num_entries = (UDF_SB_VAT(sb)->i_size -
									UDF_SB_TYPEVIRT(sb, i).s_start_offset) >> 2;
				brelse(bh);
			}
			UDF_SB_PARTROOT(sb, i) = udf_get_pblock(sb, 0, i, 0);
			UDF_SB_PARTLEN(sb, i) = UDF_SB_PARTLEN(sb, ino.partitionReferenceNum);
		}
	}
	return 0;
}

static void udf_open_lvid(struct super_block *sb)
{
	if (UDF_SB_LVIDBH(sb)) {
		int i;
		kernel_timestamp cpu_time;

		UDF_SB_LVIDIU(sb)->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
		UDF_SB_LVIDIU(sb)->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
		if (udf_time_to_stamp(&cpu_time, CURRENT_TIME))
			UDF_SB_LVID(sb)->recordingDateAndTime = cpu_to_lets(cpu_time);
		UDF_SB_LVID(sb)->integrityType = LVID_INTEGRITY_TYPE_OPEN;

		UDF_SB_LVID(sb)->descTag.descCRC = cpu_to_le16(udf_crc((char *)UDF_SB_LVID(sb) + sizeof(tag),
								       le16_to_cpu(UDF_SB_LVID(sb)->descTag.descCRCLength), 0));

		UDF_SB_LVID(sb)->descTag.tagChecksum = 0;
		for (i = 0; i < 16; i++)
			if (i != 4)
				UDF_SB_LVID(sb)->descTag.tagChecksum +=
					((uint8_t *) &(UDF_SB_LVID(sb)->descTag))[i];

		mark_buffer_dirty(UDF_SB_LVIDBH(sb));
	}
}

static void udf_close_lvid(struct super_block *sb)
{
	kernel_timestamp cpu_time;
	int i;

	if (UDF_SB_LVIDBH(sb) &&
	    UDF_SB_LVID(sb)->integrityType == LVID_INTEGRITY_TYPE_OPEN) {
		UDF_SB_LVIDIU(sb)->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
		UDF_SB_LVIDIU(sb)->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
		if (udf_time_to_stamp(&cpu_time, CURRENT_TIME))
			UDF_SB_LVID(sb)->recordingDateAndTime = cpu_to_lets(cpu_time);