nvme: fix possible hang when ns scanning fails during error recovery
authorSagi Grimberg <sagi@grimberg.me>
Wed, 6 May 2020 22:44:02 +0000 (15:44 -0700)
committerJens Axboe <axboe@kernel.dk>
Sat, 9 May 2020 22:07:58 +0000 (16:07 -0600)
commit59c7c3caaaf8750df4ec3255082f15eb4e371514
tree09bf87e587816c177912f01355dc42ca9252de94
parenta8de6639169b90e3dc4f27e752a3c5abac5e90da
nvme: fix possible hang when ns scanning fails during error recovery

When the controller is reconnecting, the host fails I/O and admin
commands as the host cannot reach the controller. ns scanning may
revalidate namespaces during that period and it is wrong to remove
namespaces due to these failures as we may hang (see 205da2434301).

One command that may fail is nvme_identify_ns_descs. Since we return
success due to having ns identify descriptor list optional, we continue
to compare ns identifiers in nvme_revalidate_disk, obviously fail and
return -ENODEV to nvme_validate_ns, which will remove the namespace.

Exactly what we don't want to happen.

Fixes: 22802bf742c2 ("nvme: Namepace identification descriptor list is optional")
Tested-by: Anton Eidelman <anton@lightbitslabs.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/nvme/host/core.c