btrfs: use DIV_ROUND_UP instead of open-coded variants
The form
(value + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT
is equivalent to
(value + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE
The rest is a simple subsitution, no difference in the generated
assembly code.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index f181c9a..2f0fe10 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -279,8 +279,7 @@
int num_pages;
int check_crcs = 0;
- num_pages = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT;
+ num_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE);
if (btrfs_ino(inode) != BTRFS_FREE_INO_OBJECTID)
check_crcs = 1;