ext4: Simplify delalloc code by removing mpage_da_writepages()

The mpage_da_writepages() function is only used in one place, so
inline it to simplify the call stack and make the code easier to
understand.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 008b28a..24d0f9d 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2242,47 +2242,6 @@ static int __mpage_da_writepage(struct page *page,
 }
 
 /*
- * mpage_da_writepages - walk the list of dirty pages of the given
- * address space, allocates non-allocated blocks, maps newly-allocated
- * blocks to existing bhs and issue IO them
- *
- * @mapping: address space structure to write
- * @wbc: subtract the number of written pages from *@wbc->nr_to_write
- *
- * This is a library function, which implements the writepages()
- * address_space_operation.
- */
-static int mpage_da_writepages(struct address_space *mapping,
-                              struct writeback_control *wbc,
-                              struct mpage_da_data *mpd)
-{
-       int ret;
-
-       mpd->b_size = 0;
-       mpd->b_state = 0;
-       mpd->b_blocknr = 0;
-       mpd->first_page = 0;
-       mpd->next_page = 0;
-       mpd->io_done = 0;
-       mpd->pages_written = 0;
-       mpd->retval = 0;
-
-       ret = write_cache_pages(mapping, wbc, __mpage_da_writepage, mpd);
-       /*
-        * Handle last extent of pages
-        */
-       if (!mpd->io_done && mpd->next_page != mpd->first_page) {
-               if (mpage_da_map_blocks(mpd) == 0)
-                       mpage_da_submit_io(mpd);
-
-               mpd->io_done = 1;
-               ret = MPAGE_DA_EXTENT_TAIL;
-       }
-       wbc->nr_to_write -= mpd->pages_written;
-       return ret;
-}
-
-/*
  * this is a special callback for ->write_begin() only
  * it's intention is to return mapped block or reserve space
  */
@@ -2571,7 +2530,38 @@ retry:
                        dump_stack();
                        goto out_writepages;
                }
-               ret = mpage_da_writepages(mapping, wbc, &mpd);
+
+               /*
+                * Now call __mpage_da_writepage to find the next
+                * contiguous region of logical blocks that need
+                * blocks to be allocated by ext4.  We don't actually
+                * submit the blocks for I/O here, even though
+                * write_cache_pages thinks it will, and will set the
+                * pages as clean for write before calling
+                * __mpage_da_writepage().
+                */
+               mpd.b_size = 0;
+               mpd.b_state = 0;
+               mpd.b_blocknr = 0;
+               mpd.first_page = 0;
+               mpd.next_page = 0;
+               mpd.io_done = 0;
+               mpd.pages_written = 0;
+               mpd.retval = 0;
+               ret = write_cache_pages(mapping, wbc, __mpage_da_writepage,
+                                       &mpd);
+               /*
+                * If we have a contigous extent of pages and we
+                * haven't done the I/O yet, map the blocks and submit
+                * them for I/O.
+                */
+               if (!mpd.io_done && mpd.next_page != mpd.first_page) {
+                       if (mpage_da_map_blocks(&mpd) == 0)
+                               mpage_da_submit_io(&mpd);
+                       mpd.io_done = 1;
+                       ret = MPAGE_DA_EXTENT_TAIL;
+               }
+               wbc->nr_to_write -= mpd.pages_written;
 
                ext4_journal_stop(handle);