Commit f220fd4e authored by Mike Christie's avatar Mike Christie Committed by Alasdair G Kergon

dm mpath: delay retry of bypassed pg

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: default avatarMike Christie <michaelc@cs.wisc.edu>
Acked-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 1fbdd2b3
......@@ -329,15 +329,19 @@ static void __choose_pgpath(struct multipath *m, size_t nr_bytes)
/*
* 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--);
failed:
......
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