diff options
Diffstat (limited to 'fs/udf')
-rw-r--r-- | fs/udf/super.c | 239 | ||||
-rw-r--r-- | fs/udf/udf_sb.h | 2 |
2 files changed, 99 insertions, 142 deletions
diff --git a/fs/udf/super.c b/fs/udf/super.c index 7ec8285..fe0dafe 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -678,149 +678,120 @@ static int udf_vrs(struct super_block *sb, int silent) } /* - * udf_find_anchor - * - * PURPOSE - * Find an anchor volume descriptor. - * - * PRE-CONDITIONS - * sb Pointer to _locked_ superblock. - * lastblock Last block on media. - * - * POST-CONDITIONS - * <return> 1 if not found, 0 if ok - * - * HISTORY - * July 1, 1997 - Andrew E. Mileski - * Written, tested, and released. + * Check whether there is an anchor block in the given block */ -static void udf_find_anchor(struct super_block *sb) +static int udf_check_anchor_block(struct super_block *sb, sector_t block, + bool varconv) { - int lastblock; struct buffer_head *bh = NULL; + tag *t; uint16_t ident; uint32_t location; + + if (varconv) + bh = sb_bread(sb, udf_fixed_to_variable(block)); + else + bh = sb_bread(sb, block); + + 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; +} + +/* Search for an anchor volume descriptor pointer */ +static sector_t udf_scan_anchors(struct super_block *sb, bool varconv, + sector_t lastblock) +{ + sector_t last[4]; int i; - struct udf_sb_info *sbi; + struct udf_sb_info *sbi = UDF_SB(sb); - sbi = UDF_SB(sb); - lastblock = sbi->s_last_block; + last[0] = lastblock; + last[1] = last[0] - 2; + last[2] = last[0] - 150; + last[3] = last[0] - 152; - if (lastblock) { - int varlastblock = udf_variable_to_fixed(lastblock); - int last[] = { lastblock, lastblock - 2, - lastblock - 150, lastblock - 152, - varlastblock, varlastblock - 2, - varlastblock - 150, varlastblock - 152 }; - - lastblock = 0; - - /* Search for an anchor volume descriptor pointer */ - - /* according to spec, anchor is in either: - * block 256 - * lastblock-256 - * lastblock - * however, if the disc isn't closed, it could be 512 */ - - for (i = 0; !lastblock && i < ARRAY_SIZE(last); i++) { - ident = location = 0; - if (last[i] >= 0) { - bh = sb_bread(sb, last[i]); - if (bh) { - tag *t = (tag *)bh->b_data; - ident = le16_to_cpu(t->tagIdent); - location = le32_to_cpu(t->tagLocation); - brelse(bh); - } - } + /* according to spec, anchor is in either: + * block 256 + * lastblock-256 + * lastblock + * however, if the disc isn't closed, it could be 512 */ - if (ident == TAG_IDENT_AVDP) { - if (location == last[i] - sbi->s_session) { - lastblock = last[i] - sbi->s_session; - sbi->s_anchor[0] = lastblock; - sbi->s_anchor[1] = lastblock - 256; - } else if (location == - udf_variable_to_fixed(last[i]) - - sbi->s_session) { - UDF_SET_FLAG(sb, UDF_FLAG_VARCONV); - lastblock = - udf_variable_to_fixed(last[i]) - - sbi->s_session; - sbi->s_anchor[0] = lastblock; - sbi->s_anchor[1] = lastblock - 256 - - sbi->s_session; - } else { - udf_debug("Anchor found at block %d, " - "location mismatch %d.\n", - last[i], location); - } - } else if (ident == TAG_IDENT_FE || - ident == TAG_IDENT_EFE) { - lastblock = last[i]; - sbi->s_anchor[3] = 512; - } else { - ident = location = 0; - if (last[i] >= 256) { - bh = sb_bread(sb, last[i] - 256); - if (bh) { - tag *t = (tag *)bh->b_data; - ident = le16_to_cpu( - t->tagIdent); - location = le32_to_cpu( - t->tagLocation); - brelse(bh); - } - } + for (i = 0; i < ARRAY_SIZE(last); i++) { + if (last[i] < 0) + continue; - if (ident == TAG_IDENT_AVDP && - location == last[i] - 256 - - sbi->s_session) { - lastblock = last[i]; - sbi->s_anchor[1] = last[i] - 256; - } else { - ident = location = 0; - if (last[i] >= 312 + sbi->s_session) { - bh = sb_bread(sb, - last[i] - 312 - - sbi->s_session); - if (bh) { - tag *t = (tag *) - bh->b_data; - ident = le16_to_cpu( - t->tagIdent); - location = le32_to_cpu( - t->tagLocation); - brelse(bh); - } - } + if (udf_check_anchor_block(sb, last[i], varconv)) { + sbi->s_anchor[0] = last[i]; + sbi->s_anchor[1] = last[i] - 256; + return last[i]; + } - if (ident == TAG_IDENT_AVDP && - location == udf_variable_to_fixed(last[i]) - 256) { - UDF_SET_FLAG(sb, - UDF_FLAG_VARCONV); - lastblock = udf_variable_to_fixed(last[i]); - sbi->s_anchor[1] = lastblock - 256; - } - } - } + if (last[i] < 256) + continue; + + if (udf_check_anchor_block(sb, last[i] - 256, varconv)) { + sbi->s_anchor[1] = last[i] - 256; + return last[i]; } } - if (!lastblock) { - /* We haven't found the lastblock. check 312 */ - bh = sb_bread(sb, 312 + sbi->s_session); - if (bh) { - tag *t = (tag *)bh->b_data; - ident = le16_to_cpu(t->tagIdent); - location = le32_to_cpu(t->tagLocation); - brelse(bh); + if (udf_check_anchor_block(sb, sbi->s_session + 256, varconv)) { + sbi->s_anchor[0] = sbi->s_session + 256; + return last[0]; + } + if (udf_check_anchor_block(sb, sbi->s_session + 512, varconv)) { + sbi->s_anchor[0] = sbi->s_session + 512; + return last[0]; + } + return 0; +} - if (ident == TAG_IDENT_AVDP && location == 256) - UDF_SET_FLAG(sb, UDF_FLAG_VARCONV); - } +/* + * Find an anchor volume descriptor. The function expects sbi->s_lastblock to + * be the last block on the media. + * + * Return 1 if not found, 0 if ok + * + */ +static void udf_find_anchor(struct super_block *sb) +{ + sector_t lastblock; + struct buffer_head *bh = NULL; + uint16_t ident; + int i; + struct udf_sb_info *sbi = UDF_SB(sb); + + lastblock = udf_scan_anchors(sb, 0, sbi->s_last_block); + if (lastblock) + goto check_anchor; + + /* No anchor found? Try VARCONV conversion of block numbers */ + /* Firstly, we try to not convert number of the last block */ + lastblock = udf_scan_anchors(sb, 1, + udf_variable_to_fixed(sbi->s_last_block)); + if (lastblock) { + UDF_SET_FLAG(sb, UDF_FLAG_VARCONV); + 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); + +check_anchor: + /* + * Check located anchors and the anchor block supplied via + * mount options + */ for (i = 0; i < ARRAY_SIZE(sbi->s_anchor); i++) { if (!sbi->s_anchor[i]) continue; @@ -830,9 +801,7 @@ static void udf_find_anchor(struct super_block *sb) sbi->s_anchor[i] = 0; else { brelse(bh); - if ((ident != TAG_IDENT_AVDP) && - (i || (ident != TAG_IDENT_FE && - ident != TAG_IDENT_EFE))) + if (ident != TAG_IDENT_AVDP) sbi->s_anchor[i] = 0; } } @@ -1225,17 +1194,6 @@ static int udf_load_partdesc(struct super_block *sb, sector_t block) if (ret) goto out_bh; - if (!sbi->s_last_block) { - sbi->s_last_block = udf_get_last_block(sb); - udf_find_anchor(sb); - if (!sbi->s_last_block) { - udf_debug("Unable to determine Lastblock (For " - "Virtual Partition)\n"); - ret = 1; - goto out_bh; - } - } - ret = udf_load_vat(sb, i, type1_idx); out_bh: /* In case loading failed, we handle cleanup in udf_fill_super */ @@ -1778,7 +1736,6 @@ static int udf_fill_super(struct super_block *sb, void *options, int silent) sbi->s_last_block = uopt.lastblock; sbi->s_anchor[0] = sbi->s_anchor[1] = 0; sbi->s_anchor[2] = uopt.anchor; - sbi->s_anchor[3] = 256; if (udf_check_valid(sb, uopt.novrs, silent)) { /* read volume recognition sequences */ diff --git a/fs/udf/udf_sb.h b/fs/udf/udf_sb.h index fb2a6e9..8308a12 100644 --- a/fs/udf/udf_sb.h +++ b/fs/udf/udf_sb.h @@ -100,7 +100,7 @@ struct udf_sb_info { /* Sector headers */ __s32 s_session; - __u32 s_anchor[4]; + __u32 s_anchor[3]; __u32 s_last_block; struct buffer_head *s_lvid_bh; |