In a couple of places it's required to calculate the number of pages given a start and end offsets. Currently this is opencoded, unify the code base by replacing all such sites with the DIV_ROUND_UP macro. Also, current open-coded sites were buggy in that they were adding 'PAGE_SIZE', rather than 'PAGE_SIZE - 1'.
Signed-off-by: Nikolay Borisov <[email protected]> --- fs/btrfs/extent_io.c | 7 +++---- fs/btrfs/inode.c | 8 +++----- 2 files changed, 6 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index b9b30e618378..0cd41ec8b698 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -3189,8 +3189,8 @@ static noinline_for_stack int writepage_delalloc(struct inode *inode, * delalloc_end is already one less than the total length, so * we don't subtract one from PAGE_SIZE */ - delalloc_to_write += (delalloc_end - delalloc_start + - PAGE_SIZE) >> PAGE_SHIFT; + delalloc_to_write += DIV_ROUND_UP(delalloc_end - delalloc_start, + PAGE_SIZE); delalloc_start = delalloc_end + 1; } if (wbc->nr_to_write < delalloc_to_write) { @@ -4001,8 +4001,7 @@ int extent_write_locked_range(struct inode *inode, u64 start, u64 end, struct address_space *mapping = inode->i_mapping; struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree; struct page *page; - unsigned long nr_pages = (end - start + PAGE_SIZE) >> - PAGE_SHIFT; + unsigned long nr_pages = DIV_ROUND_UP(end - start, PAGE_SIZE); struct extent_page_data epd = { .bio = NULL, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 41ad0d06b3d4..32977174826b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -469,7 +469,7 @@ static noinline void compress_file_range(struct inode *inode, actual_end = min_t(u64, i_size_read(inode), end + 1); again: will_compress = 0; - nr_pages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1; + nr_pages = DIV_ROUND_UP(end - start, PAGE_SIZE); BUILD_BUG_ON((BTRFS_MAX_COMPRESSED % PAGE_SIZE) != 0); nr_pages = min_t(unsigned long, nr_pages, BTRFS_MAX_COMPRESSED / PAGE_SIZE); @@ -1157,8 +1157,7 @@ static noinline void async_cow_submit(struct btrfs_work *work) async_cow = container_of(work, struct async_cow, work); fs_info = async_cow->fs_info; - nr_pages = (async_cow->end - async_cow->start + PAGE_SIZE) >> - PAGE_SHIFT; + nr_pages = DIV_ROUND_UP(async_cow->end - async_cow->start, PAGE_SIZE); /* atomic_sub_return implies a barrier */ if (atomic_sub_return(nr_pages, &fs_info->async_delalloc_pages) < @@ -1221,8 +1220,7 @@ static int cow_file_range_async(struct inode *inode, struct page *locked_page, async_cow_start, async_cow_submit, async_cow_free); - nr_pages = (cur_end - start + PAGE_SIZE) >> - PAGE_SHIFT; + nr_pages = DIV_ROUND_UP(cur_end - start, PAGE_SIZE); atomic_add(nr_pages, &fs_info->async_delalloc_pages); btrfs_queue_work(fs_info->delalloc_workers, &async_cow->work); -- 2.17.1
