btrfs: remove unused parameter phy_offset from btrfs_validate_metadata_buffer

Parameter @phy_offset is the offset against the bio->bi_iter.bi_sector.
@phy_offset is mostly for data io to lookup the csum in btrfs_io_bio.

But for metadata, it's completely useless as metadata stores their own
csum in its header, so we can remove it.

Note: parameters @start and @end, they are not utilized at all for
current sectorsize == PAGE_SIZE case, as we can grab eb directly from
page.

But those two parameters are very important for later subpage support,
thus @start/@len are not touched here.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/disk-io.c

@@ -593,7 +593,7 @@ static int validate_extent_buffer(struct extent_buffer *eb)
 	return ret;
 }
 
-int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio, u64 phy_offset,
+int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio,
 				   struct page *page, u64 start, u64 end,
 				   int mirror)
 {

fs/btrfs/disk-io.h

@@ -79,7 +79,7 @@ void btrfs_btree_balance_dirty(struct btrfs_fs_info *fs_info);
 void btrfs_btree_balance_dirty_nodelay(struct btrfs_fs_info *fs_info);
 void btrfs_drop_and_free_fs_root(struct btrfs_fs_info *fs_info,
 				 struct btrfs_root *root);
-int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio, u64 phy_offset,
+int btrfs_validate_metadata_buffer(struct btrfs_io_bio *io_bio,
 				   struct page *page, u64 start, u64 end,
 				   int mirror);
 blk_status_t btrfs_submit_metadata_bio(struct inode *inode, struct bio *bio,

fs/btrfs/extent_io.c

@@ -2919,7 +2919,7 @@ static void end_bio_extent_readpage(struct bio *bio)
 							     start, end, mirror);
 			else
 				ret = btrfs_validate_metadata_buffer(io_bio,
-					offset, page, start, end, mirror);
+					page, start, end, mirror);
 			if (ret)
 				uptodate = 0;
 			else