On Wed, Sep 13, 2017 at 12:09:28PM -0600, Liu Bo wrote: > We've seen the following backtrace stack in ftrace or dmesg log, > > kworker/u16:10-4244 [000] 241942.480955: function: btrfs_put_ordered_extent > kworker/u16:10-4244 [000] 241942.480956: kernel_stack: <stack trace> > => finish_ordered_fn (ffffffffa0384475) > => btrfs_scrubparity_helper (ffffffffa03ca577) <-----"incorrect" > => btrfs_freespace_write_helper (ffffffffa03ca98e) <-----"correct" > => process_one_work (ffffffff81117b2f) > => worker_thread (ffffffff81118c2a) > => kthread (ffffffff81121de0) > => ret_from_fork (ffffffff81d7087a) > > btrfs_freespace_write_helper is actually calling normal_worker_helper > instead of btrfs_scrubparity_helper, so somehow kernel has parsed the > incorrect function address while unwinding the stack, > btrfs_scrubparity_helper really shouldn't be shown up. > > It's caused by compiler doing inline for our helper function, adding a > noinline tag can fix that. > > Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx> > cc: David Sterba <dsterba@xxxxxxx> Ok, understood now, thanks. I suggest to use noinline_for_stack, that is made exactly for this situation (I'll change it so you don't need to resend). Reviewed-by: David Sterba <dsterba@xxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
