3.11.10.5 -stable review patch.  If anyone has any objections, please let me 
know.

------------------

From: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com>

commit a85d9df1ea1d23682a0ed1e100e6965006595d06 upstream.

During aio stress test, we observed the following lockdep warning.  This
mean AIO+numa_balancing is currently deadlockable.

The problem is, aio_migratepage disable interrupt, but
__set_page_dirty_nobuffers unintentionally enable it again.

Generally, all helper function should use spin_lock_irqsave() instead of
spin_lock_irq() because they don't know caller at all.

   other info that might help us debug this:
    Possible unsafe locking scenario:

          CPU0
          ----
     lock(&(&ctx->completion_lock)->rlock);
     <Interrupt>
       lock(&(&ctx->completion_lock)->rlock);

    *** DEADLOCK ***

      dump_stack+0x19/0x1b
      print_usage_bug+0x1f7/0x208
      mark_lock+0x21d/0x2a0
      mark_held_locks+0xb9/0x140
      trace_hardirqs_on_caller+0x105/0x1d0
      trace_hardirqs_on+0xd/0x10
      _raw_spin_unlock_irq+0x2c/0x50
      __set_page_dirty_nobuffers+0x8c/0xf0
      migrate_page_copy+0x434/0x540
      aio_migratepage+0xb1/0x140
      move_to_new_page+0x7d/0x230
      migrate_pages+0x5e5/0x700
      migrate_misplaced_page+0xbc/0xf0
      do_numa_page+0x102/0x190
      handle_pte_fault+0x241/0x970
      handle_mm_fault+0x265/0x370
      __do_page_fault+0x172/0x5a0
      do_page_fault+0x1a/0x70
      page_fault+0x28/0x30

Signed-off-by: KOSAKI Motohiro <kosaki.motoh...@jp.fujitsu.com>
Cc: Larry Woodman <lwood...@redhat.com>
Cc: Rik van Riel <r...@redhat.com>
Cc: Johannes Weiner <jwei...@redhat.com>
Acked-by: David Rientjes <rient...@google.com>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Luis Henriques <luis.henriq...@canonical.com>
---
 mm/page-writeback.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 1c21100..7298e74 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -2024,11 +2024,12 @@ int __set_page_dirty_nobuffers(struct page *page)
        if (!TestSetPageDirty(page)) {
                struct address_space *mapping = page_mapping(page);
                struct address_space *mapping2;
+               unsigned long flags;
 
                if (!mapping)
                        return 1;
 
-               spin_lock_irq(&mapping->tree_lock);
+               spin_lock_irqsave(&mapping->tree_lock, flags);
                mapping2 = page_mapping(page);
                if (mapping2) { /* Race with truncate? */
                        BUG_ON(mapping2 != mapping);
@@ -2037,7 +2038,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                        radix_tree_tag_set(&mapping->page_tree,
                                page_index(page), PAGECACHE_TAG_DIRTY);
                }
-               spin_unlock_irq(&mapping->tree_lock);
+               spin_unlock_irqrestore(&mapping->tree_lock, flags);
                if (mapping->host) {
                        /* !PageAnon && !swapper_space */
                        __mark_inode_dirty(mapping->host, I_DIRTY_PAGES);
-- 
1.9.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to