On 08/06/2010 02:52 PM, Eric Sandeen wrote: > 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. Ping? would be good to fix this race, this has jiaying's ack too. > Thanks to Dave Chinner for pointing out the race. > > Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx> > --- > > (At least I think this is right; I haven't actually demonstrated a race...) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index 0afc8c1..7f56c48 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3804,14 +3804,14 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, > io_end->flag = EXT4_IO_UNWRITTEN; > 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; > out: > if (is_async) > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
