btrfs: remove redundant i_size check in __extent_writepage_io()

In __extent_writepage_io(), we check whether

  i_size <= page_offset(page).

Note that if i_size < page_offset(page), then
i_size >> PAGE_SHIFT < page->index.

If i_size == page_offset(page), then
i_size >> PAGE_SHIFT == page->index && offset_in_page(i_size) == 0.

__extent_writepage() already has a check for these cases that
returns without calling __extent_writepage_io():

  end_index = i_size >> PAGE_SHIFT
  pg_offset = offset_in_page(i_size);
  if (page->index > end_index ||
     (page->index == end_index && !pg_offset)) {
          page->mapping->a_ops->invalidatepage(page, 0, PAGE_SIZE);
          unlock_page(page);
          return 0;
  }

Get rid of the one in __extent_writepage_io(), which was obsoleted in
211c17f51f46 ("Fix corners in writepage and btrfs_truncate_page").

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 9475e81..00ddefc 100644 (file)
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3455,11 +3455,6 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
        update_nr_written(wbc, nr_written + 1);
 
        end = page_end;
-       if (i_size <= start) {
-               btrfs_writepage_endio_finish_ordered(page, start, page_end, 1);
-               goto done;
-       }
-
        blocksize = inode->i_sb->s_blocksize;
 
        while (cur <= end) {
@@ -3540,7 +3535,6 @@ static noinline_for_stack int __extent_writepage_io(struct inode *inode,
                pg_offset += iosize;
                nr++;
        }
-done:
        *nr_ret = nr;
        return ret;
 }