Re: UBIFS assert failed in ubifs_set_page_dirty at 1421

["Kirill A. Shutemov" <kirill@shutemov.name>]

On Mon, Nov 24, 2014 at 02:59:51AM +0000, Jijiagang wrote:
> Hi Kirill,
> 
> I add dump_page(page) in function ubifs_set_page_dirty.
> And get this log when ubifs assert fail. Is it helpful for this problem?

Not really. It seems you called dump_page() after
__set_page_dirty_nobuffers() in ubifs_set_page_dirty().

Could you try something like patch below. It assumes ubifs to compiled in
(not module).

diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index b5b593c45270..7b4386dd174e 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1531,7 +1531,7 @@ out_unlock:
        return err;
 }
 
-static const struct vm_operations_struct ubifs_file_vm_ops = {
+const struct vm_operations_struct ubifs_file_vm_ops = {
        .fault        = filemap_fault,
        .map_pages = filemap_map_pages,
        .page_mkwrite = ubifs_vm_page_mkwrite,
diff --git a/mm/rmap.c b/mm/rmap.c
index 19886fb2f13a..343c4571df68 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1171,8 +1171,15 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
        pteval = ptep_clear_flush(vma, address, pte);
 
        /* Move the dirty bit to the physical page now the pte is gone. */
-       if (pte_dirty(pteval))
+       if (pte_dirty(pteval)) {
+               extern const struct vm_operations_struct ubifs_file_vm_ops;
+               if (vma->vm_ops == &ubifs_file_vm_ops) {
+                       dump_vma(vma);
+                       dump_page(page, __func__);
+                       pr_emerg("pte_write: %d\n", pte_write(pteval));
+               }
                set_page_dirty(page);
+       }
 
        /* Update high watermark before we lower rss */
        update_hiwater_rss(mm);
-- 
 Kirill A. Shutemov