On Thursday January 18, francois.barre@xxxxxxxxx wrote: > Hi all, > > I've hit the following bug while unmounting a xfs partition > > ----------- [cut here ] --------- [please bite here ] --------- > Kernel BUG at drivers/md/md.c:5035 .... > > Kernel : stock-kernel 2.6.18.6, x86_64 > Setup : xfs on raid5, on 5 250Go ieee1394 drives > Way to reproduce : > 1. assemble the array > 2. mount the xfs array > 3. mark the array read-only (mdadm -o) You shouldn't be able to do this. It should only be possible to set an array to read-only when it is not in use. The fact that you cannot suggests something else if wrong. Are you able to stop the array (mdadm -S) while the xfs filesystem is still mounte?d? > 4. umount the xfs array... > > I guess the problem is hit in md.c: md_write_start(), at the > BUG_ON(mddev->ro == 1). It is obvious that my mddev->ro is set to 1, > because I set it read-only. > Nowhere before md_write_start() the check on mddev->ro == 1 is done, > so that the upper layer never sees that the underlying device is > read-only. As a result, when xfs wishes to write to it, bad things > happen. > > May it be possible to relax the BUG_ON() and be able to send to > upper-layer a more gentle message ? Maybe... but I think I would rather make sure that you cannot set to read-only while mounted. If there some particular reason you were doing this? Thanks, NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
