On Wed, Jul 18, 2012 at 12:33:58PM -0500, tinguely@xxxxxxx wrote: > Sorry, I have been distracted away from this regression. This was previously > titled "xfs: synchronously write the superblock on unmount". > > xfs_wait_buftarg() does not wait for the completion of the write of the > uncached superblock. This write can race with the shutdown of the log and > causes a panic if the write does not win the race. > > The log write of the superblock is important for possible recovery, but a > second syncronous write of the same superblock seems redundant. Would just > waiting for the iodone() of the log write before tearing down the log be > enough? Yes. i.e. something like: /* * The superblock buffer is uncached, so xfs_wait_buftarg() * will not wait for it. Hence we need to explicitly wait * for IO completion on the superblock to occur here. */ error = xfs_buf_iowait(mp->m_sb_bp); if (error) AAAAIEEEE! This fix is also needed in xfs_quiesce_attr() for the freeze and ro,remount cases as well. Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
