On 08/10/2016 03:46 AM, Oleg Nesterov wrote:
OK. Could you try another debugging patch below?
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index e5a3244..9d5f892 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -711,6 +711,15 @@ static inline int page_has_private(struct page *page)
return !!(page->flags & PAGE_FLAGS_PRIVATE);
}
+void unlock_page(struct page *page);
+static inline void __ClearPageLocked_x(struct page *page)
+{
+ if (PageLocked(compound_head(page)))
+ unlock_page(page);
+}
+
+#define __ClearPageLocked(page) __ClearPageLocked_x(page)
+
#undef PF_ANY
#undef PF_HEAD
#undef PF_NO_TAIL
Hello Oleg,
That's an excellent catch. With your previous patch and this patch
applied I can't reproduce the hang in truncate_inode_pages_range()
anymore. I still see some other wait_on_page_bit() hangs after an I/O
error has occurred. However, the hangs that I still see are related to
waiting on buffer head state changes and not on the PG_locked page flag.
Thanks,
Bart.
