ext4: use writeback_iter in ext4_journalled_submit_inode_data_buffers

Use writeback_iter directly instead of write_cache_pages for a nicer
code structure and less indirect calls.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250505091604.3449879-1-hch@lst.de
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 5bd81dd9751c2675848098dd79eb5f28b2ab8542..7c8fdb311bad143c88462fc33c4af4a27a97f592 100644 (file)
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -508,21 +508,9 @@ static void ext4_journal_commit_callback(journal_t *journal, transaction_t *txn)
        ext4_maybe_update_superblock(sb);
 }
 
-/*
- * This writepage callback for write_cache_pages()
- * takes care of a few cases after page cleaning.
- *
- * write_cache_pages() already checks for dirty pages
- * and calls clear_page_dirty_for_io(), which we want,
- * to write protect the pages.
- *
- * However, we may have to redirty a page (see below.)
- */
-static int ext4_journalled_writepage_callback(struct folio *folio,
-                                             struct writeback_control *wbc,
-                                             void *data)
+static bool ext4_journalled_writepage_needs_redirty(struct jbd2_inode *jinode,
+               struct folio *folio)
 {
-       transaction_t *transaction = (transaction_t *) data;
        struct buffer_head *bh, *head;
        struct journal_head *jh;
 
@@ -543,15 +531,12 @@ static int ext4_journalled_writepage_callback(struct folio *folio,
                 */
                jh = bh2jh(bh);
                if (buffer_dirty(bh) ||
-                   (jh && (jh->b_transaction != transaction ||
-                           jh->b_next_transaction))) {
-                       folio_redirty_for_writepage(wbc, folio);
-                       goto out;
-               }
+                   (jh && (jh->b_transaction != jinode->i_transaction ||
+                           jh->b_next_transaction)))
+                       return true;
        } while ((bh = bh->b_this_page) != head);
 
-out:
-       return AOP_WRITEPAGE_ACTIVATE;
+       return false;
 }
 
 static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
@@ -563,10 +548,23 @@ static int ext4_journalled_submit_inode_data_buffers(struct jbd2_inode *jinode)
                .range_start = jinode->i_dirty_start,
                .range_end = jinode->i_dirty_end,
         };
+       struct folio *folio = NULL;
+       int error;
 
-       return write_cache_pages(mapping, &wbc,
-                                ext4_journalled_writepage_callback,
-                                jinode->i_transaction);
+       /*
+        * writeback_iter() already checks for dirty pages and calls
+        * folio_clear_dirty_for_io(), which we want to write protect the
+        * folios.
+        *
+        * However, we may have to redirty a folio sometimes.
+        */
+       while ((folio = writeback_iter(mapping, &wbc, folio, &error))) {
+               if (ext4_journalled_writepage_needs_redirty(jinode, folio))
+                       folio_redirty_for_writepage(&wbc, folio);
+               folio_unlock(folio);
+       }
+
+       return error;
 }
 
 static int ext4_journal_submit_inode_data_buffers(struct jbd2_inode *jinode)