6.11-stable review patch. If anyone has any objections, please let me know.
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From: Benjamin Coddington bcodding@redhat.com
[ Upstream commit 614733f9441ed53bb442d4734112ec1e24bd6da7 ]
Every pNFS SCSI IO wants to do LAYOUTGET, then within the layout find the device which can drive GETDEVINFO, then finally may need to prep the device with a reservation. This slow work makes a mess of IO latencies if one of the later steps is going to fail for awhile.
If we're unable to register a SCSI device, ensure we mark the device as unavailable so that it will timeout and be re-added via GETDEVINFO. This avoids repeated doomed attempts to register a device in the IO path.
Add some clarifying comments as well.
Fixes: d869da91cccb ("nfs/blocklayout: Fix premature PR key unregistration") Signed-off-by: Benjamin Coddington bcodding@redhat.com Reviewed-by: Christoph Hellwig hch@lst.de Reviewed-by: Chuck Lever chuck.lever@oracle.com Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nfs/blocklayout/blocklayout.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c index 0becdec129704..47189476b5538 100644 --- a/fs/nfs/blocklayout/blocklayout.c +++ b/fs/nfs/blocklayout/blocklayout.c @@ -571,19 +571,32 @@ bl_find_get_deviceid(struct nfs_server *server, if (!node) return ERR_PTR(-ENODEV);
+ /* + * Devices that are marked unavailable are left in the cache with a + * timeout to avoid sending GETDEVINFO after every LAYOUTGET, or + * constantly attempting to register the device. Once marked as + * unavailable they must be deleted and never reused. + */ if (test_bit(NFS_DEVICEID_UNAVAILABLE, &node->flags)) { unsigned long end = jiffies; unsigned long start = end - PNFS_DEVICE_RETRY_TIMEOUT;
if (!time_in_range(node->timestamp_unavailable, start, end)) { + /* Uncork subsequent GETDEVINFO operations for this device */ nfs4_delete_deviceid(node->ld, node->nfs_client, id); goto retry; } goto out_put; }
- if (!bl_register_dev(container_of(node, struct pnfs_block_dev, node))) + if (!bl_register_dev(container_of(node, struct pnfs_block_dev, node))) { + /* + * If we cannot register, treat this device as transient: + * Make a negative cache entry for the device + */ + nfs4_mark_deviceid_unavailable(node); goto out_put; + }
return node;