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/ioctl.c b/fs/btrfs/ioctl.c
index d6e10d6..8eecfcc 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1335,8 +1335,7 @@
inode->i_mapping->writeback_index = i;
while (i <= last_index && defrag_count < max_to_defrag &&
- (i < (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT)) {
+ (i < DIV_ROUND_UP(i_size_read(inode), PAGE_CACHE_SIZE))) {
/*
* make sure we stop running if someone unmounts
* the FS
@@ -1359,7 +1358,7 @@
* the should_defrag function tells us how much to skip
* bump our counter by the suggested amount
*/
- next = (skip + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ next = DIV_ROUND_UP(skip, PAGE_CACHE_SIZE);
i = max(i + 1, next);
continue;
}