udf: Drop VARCONV support

UDF was supporting a strange mode where the media was containing 7
blocks of unknown data for every 32 blocks of the filesystem. I have yet
to see the media that would need such conversion (maybe it comes from
packet writing times) and the conversions have been inconsistent in the
code. In particular any write will write to a wrong block and corrupt
the media. This is an indication and no user actually needs this so
let's just drop the support instead of trying to fix it.

Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 3 insertions, 47 deletions

diff --git a/fs/udf/super.c b/fs/udf/super.c
index c756d903a862..58a3148173ac 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -734,7 +734,7 @@ static int udf_check_vsd(struct super_block *sb)
 	 * added */
 	for (; !nsr && sector < VSD_MAX_SECTOR_OFFSET; sector += sectorsize) {
 		/* Read a block */
-		bh = udf_tread(sb, sector >> sb->s_blocksize_bits);
+		bh = sb_bread(sb, sector >> sb->s_blocksize_bits);
 		if (!bh)
 			break;
 
@@ -1839,10 +1839,6 @@ static int udf_check_anchor_block(struct super_block *sb, sector_t block,
 	uint16_t ident;
 	int ret;
 
-	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV) &&
-	    udf_fixed_to_variable(block) >= sb_bdev_nr_blocks(sb))
-		return -EAGAIN;
-
 	bh = udf_read_tagged(sb, block, block, &ident);
 	if (!bh)
 		return -EAGAIN;
@@ -1925,46 +1921,6 @@ static int udf_scan_anchors(struct super_block *sb, udf_pblk_t *lastblock,
 }
 
 /*
- * Find an anchor volume descriptor and load Volume Descriptor Sequence from
- * area specified by it. The function expects sbi->s_lastblock to be the last
- * block on the media.
- *
- * Return <0 on error, 0 if anchor found. -EAGAIN is special meaning anchor
- * was not found.
- */
-static int udf_find_anchor(struct super_block *sb,
-			   struct kernel_lb_addr *fileset)
-{
-	struct udf_sb_info *sbi = UDF_SB(sb);
-	sector_t lastblock = sbi->s_last_block;
-	int ret;
-
-	ret = udf_scan_anchors(sb, &lastblock, fileset);
-	if (ret != -EAGAIN)
-		goto out;
-
-	/* No anchor found? Try VARCONV conversion of block numbers */
-	UDF_SET_FLAG(sb, UDF_FLAG_VARCONV);
-	lastblock = udf_variable_to_fixed(sbi->s_last_block);
-	/* Firstly, we try to not convert number of the last block */
-	ret = udf_scan_anchors(sb, &lastblock, fileset);
-	if (ret != -EAGAIN)
-		goto out;
-
-	lastblock = sbi->s_last_block;
-	/* Secondly, we try with converted number of the last block */
-	ret = udf_scan_anchors(sb, &lastblock, fileset);
-	if (ret < 0) {
-		/* VARCONV didn't help. Clear it. */
-		UDF_CLEAR_FLAG(sb, UDF_FLAG_VARCONV);
-	}
-out:
-	if (ret == 0)
-		sbi->s_last_block = lastblock;
-	return ret;
-}
-
-/*
  * Check Volume Structure Descriptor, find Anchor block and load Volume
  * Descriptor Sequence.
  *
@@ -2004,7 +1960,7 @@ static int udf_load_vrs(struct super_block *sb, struct udf_options *uopt,
 
 	/* Look for anchor block and load Volume Descriptor Sequence */
 	sbi->s_anchor = uopt->anchor;
-	ret = udf_find_anchor(sb, fileset);
+	ret = udf_scan_anchors(sb, &sbi->s_last_block, fileset);
 	if (ret < 0) {
 		if (!silent && ret == -EAGAIN)
 			udf_warn(sb, "No anchor found\n");
@@ -2455,7 +2411,7 @@ static unsigned int udf_count_free_bitmap(struct super_block *sb,
 		if (bytes) {
 			brelse(bh);
 			newblock = udf_get_lb_pblock(sb, &loc, ++block);
-			bh = udf_tread(sb, newblock);
+			bh = sb_bread(sb, newblock);
 			if (!bh) {
 				udf_debug("read failed\n");
 				goto out;