From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Subject: Patch "mm: fix invalidate_complete_page2() lock ordering" has been added to the 3.4-stable tree To: hughd@google.com,akpm@linux-foundation.org,gregkh@linuxfoundation.org,hannes@cmpxchg.org,levinsasha928@gmail.com,mel@csn.ul.ie,riel@redhat.com,torvalds@linux-foundation.org,walken@google.com,yinghan@google.com Cc: , From: Date: Wed, 10 Oct 2012 08:50:01 +0900 Message-ID: <13498266012273@kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ASCII Content-Transfer-Encoding: 8bit List-ID: This is a note to let you know that I've just added the patch titled mm: fix invalidate_complete_page2() lock ordering to the 3.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-fix-invalidate_complete_page2-lock-ordering.patch and it can be found in the queue-3.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From ec4d9f626d5908b6052c2973f37992f1db52e967 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Mon, 8 Oct 2012 16:33:14 -0700 Subject: mm: fix invalidate_complete_page2() lock ordering From: Hugh Dickins commit ec4d9f626d5908b6052c2973f37992f1db52e967 upstream. In fuzzing with trinity, lockdep protested "possible irq lock inversion dependency detected" when isolate_lru_page() reenabled interrupts while still holding the supposedly irq-safe tree_lock: invalidate_inode_pages2 invalidate_complete_page2 spin_lock_irq(&mapping->tree_lock) clear_page_mlock isolate_lru_page spin_unlock_irq(&zone->lru_lock) isolate_lru_page() is correct to enable interrupts unconditionally: invalidate_complete_page2() is incorrect to call clear_page_mlock() while holding tree_lock, which is supposed to nest inside lru_lock. Both truncate_complete_page() and invalidate_complete_page() call clear_page_mlock() before taking tree_lock to remove page from radix_tree. I guess invalidate_complete_page2() preferred to test PageDirty (again) under tree_lock before committing to the munlock; but since the page has already been unmapped, its state is already somewhat inconsistent, and no worse if clear_page_mlock() moved up. Reported-by: Sasha Levin Deciphered-by: Andrew Morton Signed-off-by: Hugh Dickins Acked-by: Mel Gorman Cc: Rik van Riel Cc: Johannes Weiner Cc: Michel Lespinasse Cc: Ying Han Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/truncate.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/truncate.c +++ b/mm/truncate.c @@ -394,11 +394,12 @@ invalidate_complete_page2(struct address if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) return 0; + clear_page_mlock(page); + spin_lock_irq(&mapping->tree_lock); if (PageDirty(page)) goto failed; - clear_page_mlock(page); BUG_ON(page_has_private(page)); __delete_from_page_cache(page); spin_unlock_irq(&mapping->tree_lock); Patches currently in stable-queue which might be from hughd@google.com are queue-3.4/mm-fix-invalidate_complete_page2-lock-ordering.patch queue-3.4/mm-thp-fix-pmd_present-for-split_huge_page-and-prot_none-with-thp.patch