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author | Anton Eidelman <anton@lightbitslabs.com> | 2019-08-16 13:00:10 -0700 |
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committer | Sagi Grimberg <sagi@grimberg.me> | 2019-08-29 12:55:02 -0700 |
commit | e01f91dff91c7b16a6e3faf2565017d497a73f83 (patch) | |
tree | fe75fb6f9d76628a6f11c6f086d295fb67d18c6e /drivers/nvme | |
parent | 89275a9659fe57a3c7eef6778ec64f9e435c75eb (diff) | |
download | linux-e01f91dff91c7b16a6e3faf2565017d497a73f83.tar.gz linux-e01f91dff91c7b16a6e3faf2565017d497a73f83.tar.bz2 linux-e01f91dff91c7b16a6e3faf2565017d497a73f83.zip |
nvme-multipath: fix ana log nsid lookup when nsid is not found
ANA log parsing invokes nvme_update_ana_state() per ANA group desc.
This updates the state of namespaces with nsids in desc->nsids[].
Both ctrl->namespaces list and desc->nsids[] array are sorted by nsid.
Hence nvme_update_ana_state() performs a single walk over ctrl->namespaces:
- if current namespace matches the current desc->nsids[n],
this namespace is updated, and n is incremented.
- the process stops when it encounters the end of either
ctrl->namespaces end or desc->nsids[]
In case desc->nsids[n] does not match any of ctrl->namespaces,
the remaining nsids following desc->nsids[n] will not be updated.
Such situation was considered abnormal and generated WARN_ON_ONCE.
However ANA log MAY contain nsids not (yet) found in ctrl->namespaces.
For example, lets consider the following scenario:
- nvme0 exposes namespaces with nsids = [2, 3] to the host
- a new namespace nsid = 1 is added dynamically
- also, a ANA topology change is triggered
- NS_CHANGED aen is generated and triggers scan_work
- before scan_work discovers nsid=1 and creates a namespace, a NOTICE_ANA
aen was issues and ana_work receives ANA log with nsids=[1, 2, 3]
Result: ana_work fails to update ANA state on existing namespaces [2, 3]
Solution:
Change the way nvme_update_ana_state() namespace list walk
checks the current namespace against desc->nsids[n] as follows:
a) ns->head->ns_id < desc->nsids[n]: keep walking ctrl->namespaces.
b) ns->head->ns_id == desc->nsids[n]: match, update the namespace
c) ns->head->ns_id >= desc->nsids[n]: skip to desc->nsids[n+1]
This enables correct operation in the scenario described above.
This also allows ANA log to contain nsids currently invisible
to the host, i.e. inactive nsids.
Signed-off-by: Anton Eidelman <anton@lightbitslabs.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Diffstat (limited to 'drivers/nvme')
-rw-r--r-- | drivers/nvme/host/multipath.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c index 4f0d0d12744e..961011abd2ab 100644 --- a/drivers/nvme/host/multipath.c +++ b/drivers/nvme/host/multipath.c @@ -444,14 +444,16 @@ static int nvme_update_ana_state(struct nvme_ctrl *ctrl, down_write(&ctrl->namespaces_rwsem); list_for_each_entry(ns, &ctrl->namespaces, list) { - if (ns->head->ns_id != le32_to_cpu(desc->nsids[n])) + unsigned nsid = le32_to_cpu(desc->nsids[n]); + + if (ns->head->ns_id < nsid) continue; - nvme_update_ns_ana_state(desc, ns); + if (ns->head->ns_id == nsid) + nvme_update_ns_ana_state(desc, ns); if (++n == nr_nsids) break; } up_write(&ctrl->namespaces_rwsem); - WARN_ON_ONCE(n < nr_nsids); return 0; } |