On 11 janv. 2011, at 12:54, Kevin Wolf wrote: > Am 25.12.2010 21:52, schrieb Pierre Riteau: >> When block migration is requested and no read-write block device is >> present, a divide by zero exception is triggered because >> total_sector_sum equals zero. >> >> Signed-off-by: Pierre Riteau <pierre.rit...@irisa.fr> > > Maybe in this case we should generate an error before actually starting > with block migration. If you bothered to request block migration you > certainly didn't have in mind to do nothing.
I had in mind a scenario where a management system would use block migration all the time, regardless of what kind of devices were plugged in the VM. If we throw an error, should it be a fatal error? Or just a migration failed result given to the monitor? >> --- >> block-migration.c | 6 +++++- >> 1 files changed, 5 insertions(+), 1 deletions(-) >> >> diff --git a/block-migration.c b/block-migration.c >> index 1475325..d62d63e 100644 >> --- a/block-migration.c >> +++ b/block-migration.c >> @@ -350,7 +350,11 @@ static int blk_mig_save_bulked_block(Monitor *mon, >> QEMUFile *f) >> } >> } >> >> - progress = completed_sector_sum * 100 / >> block_mig_state.total_sector_sum; >> + if (block_mig_state.total_sector_sum != 0) { >> + progress = completed_sector_sum * 100 / >> block_mig_state.total_sector_sum; > > This exceeds 80 characters per line. > >> + } else { >> + progress = 100; >> + } >> if (progress != block_mig_state.prev_progress) { >> block_mig_state.prev_progress = progress; >> qemu_put_be64(f, (progress << BDRV_SECTOR_BITS) > > Kevin -- Pierre Riteau -- PhD student, Myriads team, IRISA, Rennes, France http://perso.univ-rennes1.fr/pierre.riteau/