[PATCH AUTOSEL 5.8 69/72] nvme-multipath: fix logic for non-optimized paths

Sasha Levin
2020-08-08T23:48:55Z

From: Martin Wilck <mwilck@suse.com>

[ Upstream commit 3f6e3246db0e6f92e784965d9d0edb8abe6c6b74 ]

Handle the special case where we have exactly one optimized path,
which we should keep using in this case.

Fixes: 75c10e732724 ("nvme-multipath: round-robin I/O policy")
Signed off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/multipath.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 66509472fe06a..fe8f7f123fac7 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -246,6 +246,12 @@ static struct nvme_ns *nvme_round_robin_path(struct nvme_ns_head *head,
fallback = ns;
}

+ /* No optimized path found, re-check the current path */
+ if (!nvme_path_is_disabled(old) &&
+ old->ana_state == NVME_ANA_OPTIMIZED) {
+ found = old;
+ goto out;
+ }
if (!fallback)
return NULL;
found = fallback;
--
2.25.1