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authorMike Christie <michaelc@cs.wisc.edu>2012-06-03 00:29:45 +0100
committerAlasdair G Kergon <agk@redhat.com>2012-06-03 00:29:45 +0100
commitf220fd4efb334a772f9a14b2372175f38d89355e (patch)
treeeeca11526d28f47e7595c66079621e4bfb1e827c
parent1fbdd2b3a3cf77f77b0cdf25dd969241ea2c0ce1 (diff)
downloadop-kernel-dev-f220fd4efb334a772f9a14b2372175f38d89355e.zip
op-kernel-dev-f220fd4efb334a772f9a14b2372175f38d89355e.tar.gz
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: Mike Christie <michaelc@cs.wisc.edu> Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
-rw-r--r--drivers/md/dm-mpath.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index c351607..2469ba6 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -329,14 +329,18 @@ 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--);
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