[PATCH 02/14] nvme-pci: refactor the tagset handling in nvme_reset_work

Christoph Hellwig
2022-11-01T15:01:14Z

The code to create, update or delete a tagset and namespaces in
nvme_reset_work is a bit convoluted. Refactor it with a two high-level
conditionals for first probe vs reset and I/O queues vs no I/O queues
to make the code flow more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
drivers/nvme/host/pci.c | 46 ++++++++++++++++++++++++++---------------
1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 5f1d71ac00865..0e8410edb41bf 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2897,25 +2897,37 @@ static void nvme_reset_work(struct work_struct *work)
result = nvme_setup_io_queues(dev);
if (result)
goto out;
-
- /*
- * Keep the controller around but remove all namespaces if we don't have
- * any working I/O queue.
- */
- if (dev->online_queues < 2) {
- dev_warn(dev->ctrl.device, "IO queues not created\n");
- nvme_kill_queues(&dev->ctrl);
- nvme_remove_namespaces(&dev->ctrl);
- nvme_free_tagset(dev);
+
+ if (dev->ctrl.tagset) {
+ /*
+ * This is a controller reset and we already have a tagset.
+ * Freeze and update the number of I/O queues as thos might have
+ * changed. If there are no I/O queues left after this reset,
+ * keep the controller around but remove all namespaces.
+ */
+ if (dev->online_queues > 1) {
+ nvme_start_queues(&dev->ctrl);
+ nvme_wait_freeze(&dev->ctrl);
+ nvme_pci_update_nr_queues(dev);
+ nvme_dbbuf_set(dev);
+ nvme_unfreeze(&dev->ctrl);
+ } else {
+ dev_warn(dev->ctrl.device, "IO queues lost\n");
+ nvme_kill_queues(&dev->ctrl);
+ nvme_remove_namespaces(&dev->ctrl);
+ nvme_free_tagset(dev);
+ }
} else {
- nvme_start_queues(&dev->ctrl);
- nvme_wait_freeze(&dev->ctrl);
- if (!dev->ctrl.tagset)
+ /*
+ * First probe. Still allow the controller to show up even if
+ * there are no namespaces.
+ */
+ if (dev->online_queues > 1) {
nvme_pci_alloc_tag_set(dev);
- else
- nvme_pci_update_nr_queues(dev);
- nvme_dbbuf_set(dev);
- nvme_unfreeze(&dev->ctrl);
+ nvme_dbbuf_set(dev);
+ } else {
+ dev_warn(dev->ctrl.device, "IO queues not created\n");
+ }
}

/*
--
2.30.2