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/raid56.c b/fs/btrfs/raid56.c
index 0a6b6e4..6a41631 100644
--- a/fs/btrfs/raid56.c
+++ b/fs/btrfs/raid56.c
@@ -912,7 +912,7 @@
static unsigned long rbio_nr_pages(unsigned long stripe_len, int nr_stripes)
{
unsigned long nr = stripe_len * nr_stripes;
- return (nr + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ return DIV_ROUND_UP(nr, PAGE_CACHE_SIZE);
}
/*
@@ -1442,7 +1442,7 @@
struct btrfs_bio *bbio = rbio->bbio;
struct bio_list bio_list;
int ret;
- int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ int nr_pages = DIV_ROUND_UP(rbio->stripe_len, PAGE_CACHE_SIZE);
int pagenr;
int stripe;
struct bio *bio;
@@ -1725,7 +1725,7 @@
int pagenr, stripe;
void **pointers;
int faila = -1, failb = -1;
- int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ int nr_pages = DIV_ROUND_UP(rbio->stripe_len, PAGE_CACHE_SIZE);
struct page *page;
int err;
int i;
@@ -1940,7 +1940,7 @@
struct btrfs_bio *bbio = rbio->bbio;
struct bio_list bio_list;
int ret;
- int nr_pages = (rbio->stripe_len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ int nr_pages = DIV_ROUND_UP(rbio->stripe_len, PAGE_CACHE_SIZE);
int pagenr;
int stripe;
struct bio *bio;