f2fs: fix the panic in do_checkpoint()
There could be a scenario where f2fs_sync_meta_pages() will not
ensure that all F2FS_DIRTY_META pages are submitted for IO. Thus,
resulting in the below panic in do_checkpoint() -
f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) &&
!f2fs_cp_error(sbi));
This can happen in a low-memory condition, where shrinker could
also be doing the writepage operation (stack shown below)
at the same time when checkpoint is running on another core.
schedule
down_write
f2fs_submit_page_write -> by this time, this page in page cache is tagged
as PAGECACHE_TAG_WRITEBACK and PAGECACHE_TAG_DIRTY
is cleared, due to which f2fs_sync_meta_pages()
cannot sync this page in do_checkpoint() path.
f2fs_do_write_meta_page
__f2fs_write_meta_page
f2fs_write_meta_page
shrink_page_list
shrink_inactive_list
shrink_node_memcg
shrink_node
kswapd
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 65a7a43..686f540 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1172,7 +1172,7 @@ static void f2fs_put_super(struct super_block *sb)
/* our cp_error case, we can wait for any writeback page */
f2fs_flush_merged_writes(sbi);
- f2fs_wait_on_all_pages_writeback(sbi);
+ f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA);
f2fs_bug_on(sbi, sbi->fsync_node_num);