[PATCH 2/2] nfs/blocklayout: Limit repeat device registration on failure

Benjamin Coddington
2024-11-18T22:40:53Z

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>
---
fs/nfs/blocklayout/blocklayout.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/fs/nfs/blocklayout/blocklayout.c b/fs/nfs/blocklayout/blocklayout.c
index 0becdec12970..b36bc2f4f7e2 100644
--- a/fs/nfs/blocklayout/blocklayout.c
+++ b/fs/nfs/blocklayout/blocklayout.c
@@ -571,19 +571,29 @@ 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)) {
+ /* Force a new GETDEVINFO for this LAYOUT */
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 we cannot register, treat this device as transient */
+ if (!bl_register_dev(container_of(node, struct pnfs_block_dev, node))) {
+ nfs4_mark_deviceid_unavailable(node);
goto out_put;
+ }

return node;

--
2.47.0