At 20:25 09/06/09, Chris Mason wrote: >On Tue, Jun 09, 2009 at 10:46:55AM +0900, Hisashi Hifumi wrote: >> Hi. >> >> I got following BUG trace. >> This is violation of BUG_ON(!buffer_locked(bh)) check on submit_bh() function. >> In write_dev_supers(), if wait parameter is set and buffer_uptodate() check >> is negative, submit_bh() is executed and hit above BUG_ON. >> So I fixed this issue. > >Thanks for finding this bug and sending the patch. > >This function is very confusing. If wait parameter is set, it >isn't supposed to do any IO at all. The caller first does >write_dev_supers with wait == 0, and that sends all the supers down on >all the devices. > >Then it calls again with wait == 1, which is supposed to make sure all >the supers actually got to disk. > >We should change the wait == 0 behavior to leave a reference held on all >the buffers, and wait == 1 to drop that reference. That way the buffer >won't disappear while we are waiting, and we can return an error if the >buffer wasn't up to date when wait == 1. > >Are you interested in fixing this? Yes, I want to fix this. -- 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
