From: Mike Christie If I/O needs retrying and only bypassed priority groups are available, set the pg_init_delay_retry flag to wait before retrying. If, for example, the reason for the bypass is that the controller is getting reset or there is a firmware upgrade happening, retrying right away would cause a flood of log messages and retries for what could be a few seconds or even several minutes. Signed-off-by: Mike Christie Acked-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-mpath.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) Index: linux-3.4/drivers/md/dm-mpath.c =================================================================== --- linux-3.4.orig/drivers/md/dm-mpath.c +++ linux-3.4/drivers/md/dm-mpath.c @@ -329,14 +329,18 @@ static void __choose_pgpath(struct multi /* * Loop through priority groups until we find a valid path. * First time we skip PGs marked 'bypassed'. - * Second time we only try the ones we skipped. + * Second time we only try the ones we skipped, but set + * pg_init_delay_retry so we do not hammer controllers. */ do { list_for_each_entry(pg, &m->priority_groups, list) { if (pg->bypassed == bypassed) continue; - if (!__choose_path_in_pg(m, pg, nr_bytes)) + if (!__choose_path_in_pg(m, pg, nr_bytes)) { + if (!bypassed) + m->pg_init_delay_retry = 1; return; + } } } while (bypassed--);