Issue with JFFS2 and a_ops->dirty_folio

[Christoph Hellwig]

On Thu, Jun 13, 2024 at 09:05:17AM +0200, Jean-Michel Hautbois wrote:
> Hi everyone !
> 
> I am currently working on a Coldfire (MPC54418) and quite everything goes
> well, except that I can only execute one command from user space before
> getting a segmentation fault on the do_exit() syscall.

Looks like jffs2 is simply missing a dirty_folio implementation.  The
simple filemap_dirty_folio should do the job, please try the patch
below:


diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c
index 62ea76da7fdf23..7124cbad6c35ae 100644
--- a/fs/jffs2/file.c
+++ b/fs/jffs2/file.c
@@ -19,6 +19,7 @@
 #include <linux/highmem.h>
 #include <linux/crc32.h>
 #include <linux/jffs2.h>
+#include <linux/writeback.h>
 #include "nodelist.h"
 
 static int jffs2_write_end(struct file *filp, struct address_space *mapping,
@@ -75,6 +76,7 @@ const struct address_space_operations jffs2_file_address_operations =
 	.read_folio =	jffs2_read_folio,
 	.write_begin =	jffs2_write_begin,
 	.write_end =	jffs2_write_end,
+	.dirty_folio =	filemap_dirty_folio,
 };
 
 static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg)