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Commit 7b568cba authored by Jan Kara's avatar Jan Kara
Browse files

udf: Simplify handling of Volume Descriptor Pointers 



According to ECMA-167 3/8.4.2 Volume Descriptor Pointer is terminating
current extent of Volume Descriptor Sequence. Also according to ECMA-167
3/8.4.3 Volume Descriptor Sequence Number is not significant for Volume
Descriptor Pointers. Simplify the handling of Volume Descriptor Pointers
to take this into account.

Acked-by: default avatarPali Rohár <pali.rohar@gmail.com>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent 91c9c9ec

fs/udf/super.c

+16 −25
Original line number Diff line number Diff line
@@ -1615,7 +1615,6 @@ static noinline int udf_process_sequence( 
	bool done = false;

	uint32_t vdsn;

	uint16_t ident;

	long next_s = 0, next_e = 0;

	int ret;

	unsigned int indirections = 0;
@@ -1647,19 +1646,22 @@ static noinline int udf_process_sequence( 
			}

			break;

		case TAG_IDENT_VDP: /* ISO 13346 3/10.3 */

			curr = &vds[VDS_POS_VOL_DESC_PTR];

			if (vdsn >= curr->volDescSeqNum) {

				curr->volDescSeqNum = vdsn;

				curr->block = block;

			if (++indirections > UDF_MAX_TD_NESTING) {

				udf_err(sb, "too many Volume Descriptor "

					"Pointers (max %u supported)\n",

					UDF_MAX_TD_NESTING);

				brelse(bh);

				return -EIO;

			}



			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 - 1;

			}

			block = le32_to_cpu(vdp->nextVolDescSeqExt.extLocation);

			lastblock = le32_to_cpu(

				vdp->nextVolDescSeqExt.extLength) >>

				sb->s_blocksize_bits;

			lastblock += block - 1;

			/* For loop is going to increment 'block' again */

			block--;

			break;

		case TAG_IDENT_IUVD: /* ISO 13346 3/10.4 */

			curr = &vds[VDS_POS_IMP_USE_VOL_DESC];
@@ -1688,18 +1690,7 @@ static noinline int udf_process_sequence( 
			}

			break;

		case TAG_IDENT_TD: /* ISO 13346 3/10.9 */

			if (++indirections > UDF_MAX_TD_NESTING) {

				udf_err(sb, "too many TDs (max %u supported)\n", UDF_MAX_TD_NESTING);

				brelse(bh);

				return -EIO;

			}



			vds[VDS_POS_TERMINATING_DESC].block = block;

			if (next_e) {

				block = next_s;

				lastblock = next_e;

				next_s = next_e = 0;

			} else

			done = true;

			break;

		}