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 <[e-mail]>

fs/udf/balloc.c

···
 	loc.logicalBlockNum = bitmap->s_extPosition;
 	loc.partitionReferenceNum = UDF_SB(sb)->s_partition;
 
-	bh = udf_tread(sb, udf_get_lb_pblock(sb, &loc, block));
+	bh = sb_bread(sb, udf_get_lb_pblock(sb, &loc, block));
 	if (!bh)
 		retval = -EIO;
 

fs/udf/directory.c

···
 	for (i = 0; i < ralen; i++) {
 		blk = udf_get_lb_pblock(iter->dir->i_sb, &iter->eloc,
 					iter->loffset + i);
-		tmp = udf_tgetblk(iter->dir->i_sb, blk);
+		tmp = sb_getblk(iter->dir->i_sb, blk);
 		if (tmp && !buffer_uptodate(tmp) && !buffer_locked(tmp))
 			bha[num++] = tmp;
 		else
···
 
 	udf_readahead_dir(iter);
 	blk = udf_get_lb_pblock(iter->dir->i_sb, &iter->eloc, iter->loffset);
-	return udf_tread(iter->dir->i_sb, blk);
+	return sb_bread(iter->dir->i_sb, blk);
 }
 
 /*

fs/udf/inode.c

···
 	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
 	struct udf_inode_info *iinfo = UDF_I(inode);
 
-	bh = udf_tgetblk(inode->i_sb,
+	bh = sb_getblk(inode->i_sb,
 			udf_get_lb_pblock(inode->i_sb, &iinfo->i_location, 0));
 	if (!bh) {
 		udf_debug("getblk failure\n");
···
 	neloc.logicalBlockNum = block;
 	neloc.partitionReferenceNum = epos->block.partitionReferenceNum;
 
-	bh = udf_tgetblk(sb, udf_get_lb_pblock(sb, &neloc, 0));
+	bh = sb_getblk(sb, udf_get_lb_pblock(sb, &neloc, 0));
 	if (!bh)
 		return -EIO;
 	lock_buffer(bh);
···
 		epos->offset = sizeof(struct allocExtDesc);
 		brelse(epos->bh);
 		block = udf_get_lb_pblock(inode->i_sb, &epos->block, 0);
-		epos->bh = udf_tread(inode->i_sb, block);
+		epos->bh = sb_bread(inode->i_sb, block);
 		if (!epos->bh) {
 			udf_debug("reading block %u failed!\n", block);
 			return -1;
···
 	up_read(&UDF_I(inode)->i_data_sem);
 	brelse(epos.bh);
 
-	if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_VARCONV))
-		return udf_fixed_to_variable(ret);
-	else
-		return ret;
+	return ret;
 }

fs/udf/misc.c

···
 #include "udf_i.h"
 #include "udf_sb.h"
 
-struct buffer_head *udf_tgetblk(struct super_block *sb, udf_pblk_t block)
-{
-	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
-		return sb_getblk(sb, udf_fixed_to_variable(block));
-	else
-		return sb_getblk(sb, block);
-}
-
-struct buffer_head *udf_tread(struct super_block *sb, udf_pblk_t block)
-{
-	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV))
-		return sb_bread(sb, udf_fixed_to_variable(block));
-	else
-		return sb_bread(sb, block);
-}
-
 struct genericFormat *udf_add_extendedattr(struct inode *inode, uint32_t size,
 					   uint32_t type, uint8_t loc)
 {
···
 	if (block == 0xFFFFFFFF)
 		return NULL;
 
-	bh = udf_tread(sb, block);
+	bh = sb_bread(sb, block);
 	if (!bh) {
 		udf_err(sb, "read failed, block=%u, location=%u\n",
 			block, location);

fs/udf/namei.c

···
 				0);
 	if (!newblock)
 		return NULL;
-	dbh = udf_tgetblk(inode->i_sb, newblock);
+	dbh = sb_getblk(inode->i_sb, newblock);
 	if (!dbh)
 		return NULL;
 	lock_buffer(dbh);
···
 		block = udf_get_pblock(sb, block,
 				iinfo->i_location.partitionReferenceNum,
 				0);
-		epos.bh = udf_tgetblk(sb, block);
+		epos.bh = sb_getblk(sb, block);
 		if (unlikely(!epos.bh)) {
 			err = -ENOMEM;
 			udf_free_blocks(sb, inode, &eloc, 0, 1);

fs/udf/super.c

···
 	 * 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;
 
···
 	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;
···
 }
 
 /*
- * 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.
  *
···
 
 	/* 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");
···
 		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;

fs/udf/truncate.c

···
 			brelse(epos.bh);
 			epos.offset = sizeof(struct allocExtDesc);
 			epos.block = eloc;
-			epos.bh = udf_tread(sb,
+			epos.bh = sb_bread(sb,
 					udf_get_lb_pblock(sb, &eloc, 0));
 			/* Error reading indirect block? */
 			if (!epos.bh)

fs/udf/udf_sb.h

···
 #define UDF_FLAG_STRICT			5
 #define UDF_FLAG_UNDELETE		6
 #define UDF_FLAG_UNHIDE			7
-#define UDF_FLAG_VARCONV		8
 #define UDF_FLAG_UID_FORGET     11    /* save -1 for uid to disk */
 #define UDF_FLAG_GID_FORGET     12
 #define UDF_FLAG_UID_SET	13

fs/udf/udfdecl.h

···
 #define udf_debug(fmt, ...)					\
 	pr_debug("%s:%d:%s: " fmt, __FILE__, __LINE__, __func__, ##__VA_ARGS__)
 
-#define udf_fixed_to_variable(x) ( ( ( (x) >> 5 ) * 39 ) + ( (x) & 0x0000001F ) )
-#define udf_variable_to_fixed(x) ( ( ( (x) / 39 ) << 5 ) + ( (x) % 39 ) )
-
 #define UDF_EXTENT_LENGTH_MASK	0x3FFFFFFF
 #define UDF_EXTENT_FLAG_MASK	0xC0000000
 
···
 extern void udf_update_extra_perms(struct inode *inode, umode_t mode);
 
 /* misc.c */
-extern struct buffer_head *udf_tgetblk(struct super_block *sb,
-					udf_pblk_t block);
-extern struct buffer_head *udf_tread(struct super_block *sb, udf_pblk_t block);
 extern struct genericFormat *udf_add_extendedattr(struct inode *, uint32_t,
 						  uint32_t, uint8_t);
 extern struct genericFormat *udf_get_extendedattr(struct inode *, uint32_t,