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btrfs: use DIV_ROUND_UP instead of open-coded variants

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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>
This commit is contained in:
David Sterba
2014-06-05 01:59:57 +02:00
committed by Chris Mason
parent 4e54b17ad6
commit ed6078f703
8 changed files with 22 additions and 32 deletions
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10
fs/btrfs/compression.c
View File

@ -91,8 +91,7 @@ static inline int compressed_bio_size(struct btrfs_root *root,
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 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
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 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio,
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);