Commit c999af2b authored Oct 27, 2010 by Eric Sandeen Committed by Theodore Ts'o Oct 27, 2010

ext4: queue conversion after adding to inode's completed IO list



By queuing the io end on the unwritten workqueue before adding it
to our inode's list of completed IOs, I think we run the risk
of the work getting completed, and the IO freed, before we try
to add it to the inode's i_completed_io_list.

It should be safe to add it to the inode's list of completed
IOs, and -then- queue it for completion, I think.

Thanks to Dave Chinner for pointing out the race.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Jiaying Zhang <jiayingz@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

parent 3e1e5f50

fs/ext4/inode.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -3850,14 +3850,14 @@ out:
		}
		wq = EXT4_SB(io_end->inode->i_sb)->dio_unwritten_wq;

		/* queue the work to convert unwritten extents to written */
		queue_work(wq, &io_end->work);

		/* Add the io_end to per-inode completed aio dio list*/
		ei = EXT4_I(io_end->inode);
		spin_lock_irqsave(&ei->i_completed_io_lock, flags);
		list_add_tail(&io_end->list, &ei->i_completed_io_list);
		spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);

		/* queue the work to convert unwritten extents to written */
		queue_work(wq, &io_end->work);
		iocb->private = NULL;
		}

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