btrfs: simplify range end calculations in truncate_block_zero_beyond_eof()

The way zero_end is calculated and used does a -1 and +1 that
effectively cancel out, so this can be simplified. This is also
preparatory patch for using a helper for folio_pos + folio_size with the
semantics of exclusive end of the range.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index cc176950e7195354dbc795ff3bf55d62d29b0008..391a1f71d7b2ed3a6657de73c698a581686df79d 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4819,9 +4819,9 @@ again:
         */
 
        zero_start = max_t(u64, folio_pos(folio), start);
-       zero_end = folio_pos(folio) + folio_size(folio) - 1;
+       zero_end = folio_pos(folio) + folio_size(folio);
        folio_zero_range(folio, zero_start - folio_pos(folio),
-                        zero_end - zero_start + 1);
+                        zero_end - zero_start);
 
 out_unlock:
        folio_unlock(folio);