udf: use sb_bdev_nr_blocks

Use the sb_bdev_nr_blocks helper instead of open coding it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20211018101130.1838532-31-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/udf/lowlevel.c

@@ -47,8 +47,7 @@ unsigned int udf_get_last_session(struct super_block *sb)
 
 unsigned long udf_get_last_block(struct super_block *sb)
 {
-	struct block_device *bdev = sb->s_bdev;
-	struct cdrom_device_info *cdi = disk_to_cdi(bdev->bd_disk);
+	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
 	unsigned long lblock = 0;
 
 	/*
@@ -56,7 +55,7 @@ unsigned long udf_get_last_block(struct super_block *sb)
 	 * Try using the device size...
 	 */
 	if (!cdi || cdrom_get_last_written(cdi, &lblock) || lblock == 0)
-		lblock = i_size_read(bdev->bd_inode) >> sb->s_blocksize_bits;
+		lblock = sb_bdev_nr_blocks(sb);
 
 	if (lblock)
 		return lblock - 1;

fs/udf/super.c

@@ -1175,8 +1175,7 @@ static int udf_load_vat(struct super_block *sb, int p_index, int type1_index)
 	struct udf_inode_info *vati;
 	uint32_t pos;
 	struct virtualAllocationTable20 *vat20;
-	sector_t blocks = i_size_read(sb->s_bdev->bd_inode) >>
-			  sb->s_blocksize_bits;
+	sector_t blocks = sb_bdev_nr_blocks(sb);
 
 	udf_find_vat_block(sb, p_index, type1_index, sbi->s_last_block);
 	if (!sbi->s_vat_inode &&
@@ -1838,8 +1837,7 @@ static int udf_check_anchor_block(struct super_block *sb, sector_t block,
 	int ret;
 
 	if (UDF_QUERY_FLAG(sb, UDF_FLAG_VARCONV) &&
-	    udf_fixed_to_variable(block) >=
-	    i_size_read(sb->s_bdev->bd_inode) >> sb->s_blocksize_bits)
+	    udf_fixed_to_variable(block) >= sb_bdev_nr_blocks(sb))
 		return -EAGAIN;
 
 	bh = udf_read_tagged(sb, block, block, &ident);
@@ -1901,8 +1899,7 @@ static int udf_scan_anchors(struct super_block *sb, sector_t *lastblock,
 		last[last_count++] = *lastblock - 152;
 
 	for (i = 0; i < last_count; i++) {
-		if (last[i] >= i_size_read(sb->s_bdev->bd_inode) >>
-				sb->s_blocksize_bits)
+		if (last[i] >= sb_bdev_nr_blocks(sb))
 			continue;
 		ret = udf_check_anchor_block(sb, last[i], fileset);
 		if (ret != -EAGAIN) {