From e8183c2452041326c95258ecc7865b6fcd91c730 Mon Sep 17 00:00:00 2001 From: Tomas Janousek Date: Mon, 23 Jun 2008 15:12:35 +0200 Subject: udf: Fix regression in UDF anchor block detection In some cases it could happen that some block passed test in udf_check_anchor_block() even though udf_read_tagged() refused to read it later (e.g. because checksum was not correct). This patch makes udf_check_anchor_block() use udf_read_tagged() so that the checking is stricter. This fixes the regression (certain disks unmountable) caused by commit 423cf6dc04eb79d441bfda2b127bc4b57134b41d. Signed-off-by: Tomas Janousek Signed-off-by: Jan Kara --- fs/udf/super.c | 57 +++++++++++++++++++++++---------------------------------- 1 file changed, 23 insertions(+), 34 deletions(-) (limited to 'fs/udf') diff --git a/fs/udf/super.c b/fs/udf/super.c index 7a5f69be6ac2..44cc702f96cc 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -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) >= - 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); + 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 = 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: /* -- cgit v1.2.3