[PATCH v2] nvme: Fix nvme reset command timeout handling

From: Johannes Thumshirn
Date: Thu Aug 10 2017 - 05:23:55 EST


From: Keith Busch <keith.busch@xxxxxxxxx>

We need to return an error if a timeout occurs on any NVMe command during
initialization. Without this, the nvme reset work will be stuck. A timeout
will have a negative error code, meaning we need to stop initializing
the controller. All postitive returns mean the controller is still usable.

bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196325

Signed-off-by: Keith Busch <keith.busch@xxxxxxxxx>
Cc: Martin Peres <martin.peres@xxxxxxxxx>
[jth consolidated cleanup path ]
Signed-off-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
---

Notes:
Changes in v2:
* Consolidated cleanup path

drivers/nvme/host/core.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c49f1f8b2e57..232eb65fe49d 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1509,7 +1509,7 @@ static void nvme_set_queue_limits(struct nvme_ctrl *ctrl,
blk_queue_write_cache(q, vwc, vwc);
}

-static void nvme_configure_apst(struct nvme_ctrl *ctrl)
+static int nvme_configure_apst(struct nvme_ctrl *ctrl)
{
/*
* APST (Autonomous Power State Transition) lets us program a
@@ -1538,16 +1538,16 @@ static void nvme_configure_apst(struct nvme_ctrl *ctrl)
* then don't do anything.
*/
if (!ctrl->apsta)
- return;
+ return 0;

if (ctrl->npss > 31) {
dev_warn(ctrl->device, "NPSS is invalid; not using APST\n");
- return;
+ return 0;
}

table = kzalloc(sizeof(*table), GFP_KERNEL);
if (!table)
- return;
+ return 0;

if (!ctrl->apst_enabled || ctrl->ps_max_latency_us == 0) {
/* Turn off APST. */
@@ -1629,6 +1629,7 @@ static void nvme_configure_apst(struct nvme_ctrl *ctrl)
dev_err(ctrl->device, "failed to set APST feature (%d)\n", ret);

kfree(table);
+ return ret;
}

static void nvme_set_latency_tolerance(struct device *dev, s32 val)
@@ -1835,13 +1836,16 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
* In fabrics we need to verify the cntlid matches the
* admin connect
*/
- if (ctrl->cntlid != le16_to_cpu(id->cntlid))
+ if (ctrl->cntlid != le16_to_cpu(id->cntlid)) {
ret = -EINVAL;
+ goto out_free;
+ }

if (!ctrl->opts->discovery_nqn && !ctrl->kas) {
dev_err(ctrl->device,
"keep-alive support is mandatory for fabrics\n");
ret = -EINVAL;
+ goto out_free;
}
} else {
ctrl->cntlid = le16_to_cpu(id->cntlid);
@@ -1856,11 +1860,20 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
else if (!ctrl->apst_enabled && prev_apst_enabled)
dev_pm_qos_hide_latency_tolerance(ctrl->device);

- nvme_configure_apst(ctrl);
- nvme_configure_directives(ctrl);
+ ret = nvme_configure_apst(ctrl);
+ if (ret < 0)
+ return ret;
+
+ ret = nvme_configure_directives(ctrl);
+ if (ret < 0)
+ return ret;

ctrl->identified = true;

+ return 0;
+
+out_free:
+ kfree(id);
return ret;
}
EXPORT_SYMBOL_GPL(nvme_init_identify);
--
2.12.3