1 files changed, 8 insertions, 11 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 033f04bac85b..2287545c5498 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1481,9 +1481,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
         bool force_page_uptodate = false;
         bool need_unlock;
 
-        nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
-                     PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
-                     (sizeof(struct page *)));
+        nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_CACHE_SIZE),
+                        PAGE_CACHE_SIZE / (sizeof(struct page *)));
         nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
         nrptrs = max(nrptrs, 8);
         pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
@@ -1497,8 +1496,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                 size_t write_bytes = min(iov_iter_count(i),
                                          nrptrs * (size_t)PAGE_CACHE_SIZE -
                                          offset);
-                size_t num_pages = (write_bytes + offset +
-                                    PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+                size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
+                                                PAGE_CACHE_SIZE);
                 size_t reserve_bytes;
                 size_t dirty_pages;
                 size_t copied;
@@ -1526,9 +1525,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
                                  * our prealloc extent may be smaller than
                                  * write_bytes, so scale down.
                                  */
-                                num_pages = (write_bytes + offset +
-                                             PAGE_CACHE_SIZE - 1) >>
-                                        PAGE_CACHE_SHIFT;
+                                num_pages = DIV_ROUND_UP(write_bytes + offset,
+                                                         PAGE_CACHE_SIZE);
                                 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
                                 ret = 0;
                         } else {
@@ -1590,9 +1588,8 @@ again:
                         dirty_pages = 0;
                 } else {
                         force_page_uptodate = false;
-                        dirty_pages = (copied + offset +
-                                       PAGE_CACHE_SIZE - 1) >>
-                                       PAGE_CACHE_SHIFT;
+                        dirty_pages = DIV_ROUND_UP(copied + offset,
+                                                   PAGE_CACHE_SIZE);
                 }
 
                 /*