fs/mpage.c: factor clean_buffers() out of __mpage_writepage()
__mpage_writepage() is over 200 lines long, has 20 local variables, four
goto labels and could desperately use simplification. Splitting
clean_buffers() into a helper function improves matters a little,
removing 20+ lines from it.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dheeraj Reddy <dheeraj.reddy@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/mpage.c b/fs/mpage.c
index 4979ffa..4cc9c5d 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -439,6 +439,35 @@
unsigned use_writepage;
};
+/*
+ * We have our BIO, so we can now mark the buffers clean. Make
+ * sure to only clean buffers which we know we'll be writing.
+ */
+static void clean_buffers(struct page *page, unsigned first_unmapped)
+{
+ unsigned buffer_counter = 0;
+ struct buffer_head *bh, *head;
+ if (!page_has_buffers(page))
+ return;
+ head = page_buffers(page);
+ bh = head;
+
+ do {
+ if (buffer_counter++ == first_unmapped)
+ break;
+ clear_buffer_dirty(bh);
+ bh = bh->b_this_page;
+ } while (bh != head);
+
+ /*
+ * we cannot drop the bh if the page is not uptodate or a concurrent
+ * readpage would fail to serialize with the bh and it would read from
+ * disk before we reach the platter.
+ */
+ if (buffer_heads_over_limit && PageUptodate(page))
+ try_to_free_buffers(page);
+}
+
static int __mpage_writepage(struct page *page, struct writeback_control *wbc,
void *data)
{
@@ -591,30 +620,7 @@
goto alloc_new;
}
- /*
- * OK, we have our BIO, so we can now mark the buffers clean. Make
- * sure to only clean buffers which we know we'll be writing.
- */
- if (page_has_buffers(page)) {
- struct buffer_head *head = page_buffers(page);
- struct buffer_head *bh = head;
- unsigned buffer_counter = 0;
-
- do {
- if (buffer_counter++ == first_unmapped)
- break;
- clear_buffer_dirty(bh);
- bh = bh->b_this_page;
- } while (bh != head);
-
- /*
- * we cannot drop the bh if the page is not uptodate
- * or a concurrent readpage would fail to serialize with the bh
- * and it would read from disk before we reach the platter.
- */
- if (buffer_heads_over_limit && PageUptodate(page))
- try_to_free_buffers(page);
- }
+ clean_buffers(page, first_unmapped);
BUG_ON(PageWriteback(page));
set_page_writeback(page);