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 <[email protected]>
Signed-off-by: Chris Mason <[email protected]>
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 1daea0b..eeee138 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -91,8 +91,7 @@
u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
return sizeof(struct compressed_bio) +
- ((disk_size + root->sectorsize - 1) / root->sectorsize) *
- csum_size;
+ (DIV_ROUND_UP(disk_size, root->sectorsize)) * csum_size;
}
static struct bio *compressed_bio_alloc(struct block_device *bdev,
@@ -615,8 +614,7 @@
cb->compress_type = extent_compress_type(bio_flags);
cb->orig_bio = bio;
- nr_pages = (compressed_len + PAGE_CACHE_SIZE - 1) /
- PAGE_CACHE_SIZE;
+ nr_pages = DIV_ROUND_UP(compressed_len, PAGE_CACHE_SIZE);
cb->compressed_pages = kzalloc(sizeof(struct page *) * nr_pages,
GFP_NOFS);
if (!cb->compressed_pages)
@@ -686,8 +684,8 @@
comp_bio, sums);
BUG_ON(ret); /* -ENOMEM */
}
- sums += (comp_bio->bi_iter.bi_size +
- root->sectorsize - 1) / root->sectorsize;
+ sums += DIV_ROUND_UP(comp_bio->bi_iter.bi_size,
+ root->sectorsize);
ret = btrfs_map_bio(root, READ, comp_bio,
mirror_num, 0);
