udf: Fix regression in UDF anchor block detection (e8183c24) · Commits · 戴 / test

fs/udf/super.c

+23 −34

Original line number	Diff line number	Diff line
		@@ -682,38 +682,26 @@ static int udf_vrs(struct super_block *sb, int silent)
		/*
		* Check whether there is an anchor block in the given block
		*/
		static int udf_check_anchor_block(struct super_block *sb, sector_t block,
		bool varconv)
		static int udf_check_anchor_block(struct super_block *sb, sector_t block)
		{
		struct buffer_head *bh = NULL;
		tag *t;
		struct buffer_head *bh;
		uint16_t ident;
		uint32_t location;

		if (varconv) {
		if (udf_fixed_to_variable(block) >=
		if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV) &&
		udf_fixed_to_variable(block) >=
		sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits)
		return 0;
		bh = sb_bread(sb, udf_fixed_to_variable(block));
		}
		else
		bh = sb_bread(sb, block);

		bh = udf_read_tagged(sb, block, block, &ident);
		if (!bh)
		return 0;

		t = (tag *)bh->b_data;
		ident = le16_to_cpu(t->tagIdent);
		location = le32_to_cpu(t->tagLocation);
		brelse(bh);
		if (ident != TAG_IDENT_AVDP)
		return 0;
		return location == block;

		return ident == TAG_IDENT_AVDP;
		}

		/* Search for an anchor volume descriptor pointer */
		static sector_t udf_scan_anchors(struct super_block *sb, bool varconv,
		sector_t lastblock)
		static sector_t udf_scan_anchors(struct super_block *sb, sector_t lastblock)
		{
		sector_t last[6];
		int i;
		@@ -739,7 +727,7 @@ static sector_t udf_scan_anchors(struct super_block *sb, bool varconv,
		sb->s_blocksize_bits)
		continue;

		if (udf_check_anchor_block(sb, last[i], varconv)) {
		if (udf_check_anchor_block(sb, last[i])) {
		sbi->s_anchor[0] = last[i];
		sbi->s_anchor[1] = last[i] - 256;
		return last[i];
		@@ -748,17 +736,17 @@ static sector_t udf_scan_anchors(struct super_block *sb, bool varconv,
		if (last[i] < 256)
		continue;

		if (udf_check_anchor_block(sb, last[i] - 256, varconv)) {
		if (udf_check_anchor_block(sb, last[i] - 256)) {
		sbi->s_anchor[1] = last[i] - 256;
		return last[i];
		}
		}

		if (udf_check_anchor_block(sb, sbi->s_session + 256, varconv)) {
		if (udf_check_anchor_block(sb, sbi->s_session + 256)) {
		sbi->s_anchor[0] = sbi->s_session + 256;
		return last[0];
		}
		if (udf_check_anchor_block(sb, sbi->s_session + 512, varconv)) {
		if (udf_check_anchor_block(sb, sbi->s_session + 512)) {
		sbi->s_anchor[0] = sbi->s_session + 512;
		return last[0];
		}
		@@ -780,23 +768,24 @@ static void udf_find_anchor(struct super_block *sb)
		int i;
		struct udf_sb_info *sbi = UDF_SB(sb);

		lastblock = udf_scan_anchors(sb, 0, sbi->s_last_block);
		lastblock = udf_scan_anchors(sb, sbi->s_last_block);
		if (lastblock)
		goto check_anchor;

		/* No anchor found? Try VARCONV conversion of block numbers */
		UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
		/* Firstly, we try to not convert number of the last block */
		lastblock = udf_scan_anchors(sb, 1,
		lastblock = udf_scan_anchors(sb,
		udf_variable_to_fixed(sbi->s_last_block));
		if (lastblock) {
		UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
		if (lastblock)
		goto check_anchor;
		}

		/* Secondly, we try with converted number of the last block */
		lastblock = udf_scan_anchors(sb, 1, sbi->s_last_block);
		if (lastblock)
		UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
		lastblock = udf_scan_anchors(sb, sbi->s_last_block);
		if (!lastblock) {
		/* VARCONV didn't help. Clear it. */
		UDF_CLEAR_FLAG(sb, UDF_FLAG_VARCONV);
		}

		check_anchor:
		/*

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