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>

1 files changed, 32 insertions, 42 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 008b28a859d0..24d0f9d2b320 100644
--- 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);