FAILED: patch "[PATCH] writeback: Avoid skipping inode writeback" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 846a3351ddfe4a86eede4bb26a205c3f38ef84d3 Mon Sep 17 00:00:00 2001
From: Jing Xia <[email protected]>
Date: Tue, 10 May 2022 10:35:14 +0800
Subject: [PATCH] writeback: Avoid skipping inode writeback

We have run into an issue that a task gets stuck in balance_dirty_pages_ratelimited() when perform I/O stress testing. The reason we observed is that an I_DIRTY_PAGES inode with lots of dirty pages is in b_dirty_time list and standard background writeback cannot writeback the inode.
After studing the relevant code, the following scenario may lead to the issue:

task1 task2
----- -----
fuse_flush
write_inode_now //in b_dirty_time
writeback_single_inode
__writeback_single_inode

                                 fuse_write_end
                                  filemap_dirty_folio
                                   __xa_set_mark:PAGECACHE_TAG_DIRTY
    lock inode->i_lock
    if mapping tagged PAGECACHE_TAG_DIRTY
    inode->i_state |= I_DIRTY_PAGES
    unlock inode->i_lock
                                   __mark_inode_dirty:I_DIRTY_PAGES
                                      lock inode->i_lock
                                      -was dirty,inode stays in
                                      -b_dirty_time
                                      unlock inode->i_lock

if(!(inode->i_state & I_DIRTY_All))
-not true,so nothing done

This patch moves the dirty inode to b_dirty list when the inode currently is not queued in b_io or b_more_io list at the end of writeback_single_inode.

index 591fe9cf1659..1fae0196292a 100644
@@ -1712,6 +1712,10 @@ static int writeback_single_inode(struct inode *inode,
 	 */
 	if (!(inode->i_state & I_DIRTY_ALL))
 		inode_cgwb_move_to_attached(inode, wb);
+	else if (!(inode->i_state & I_SYNC_QUEUED) &&
+		 (inode->i_state & I_DIRTY))
+		redirty_tail_locked(inode, wb);
+
 	spin_unlock(&wb->list_lock);
 	inode_sync_complete(inode);
 out: