From 966dbde2c208e07bab7a45a7855e1e693eabe661 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Mon, 31 Oct 2011 17:07:48 -0700 Subject: [PATCH] ext4: warn if direct reclaim tries to writeback pages Direct reclaim should never writeback pages. Warn if an attempt is made. Signed-off-by: Mel Gorman Cc: Dave Chinner Cc: Christoph Hellwig Cc: Johannes Weiner Cc: Wu Fengguang Cc: Jan Kara Cc: Minchan Kim Cc: Rik van Riel Cc: Mel Gorman Cc: Alex Elder Cc: Theodore Ts'o Cc: Chris Mason Cc: Dave Hansen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ext4/inode.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 986e2388f03..0defe0bfe01 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -1811,8 +1811,12 @@ static int ext4_writepage(struct page *page, * We don't want to do block allocation, so redirty * the page and return. We may reach here when we do * a journal commit via journal_submit_inode_data_buffers. - * We can also reach here via shrink_page_list + * We can also reach here via shrink_page_list but it + * should never be for direct reclaim so warn if that + * happens */ + WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) == + PF_MEMALLOC); goto redirty_page; } if (commit_write) -- 2.20.1