nvme: add sysfs attribute to change IO timeout per controller

Currently, there is no method to adjust the timeout values on a
per controller basis with nvme I/O queues.
Add an io_timeout attribute to nvme so that different nvme controllers
which may have different timeout requirements can have custom I/O
timeouts set.

The I/O timeout is also applied to the connect queue (connect_q).
In NVMe over Fabrics, the connect queue is utilized specifically to
issue Connect commands that establish the I/O queues.

Reviewed-by: Mohamed Khalfella <mkhalfella@purestorage.com>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 20df7c12c718042e1c0af76e2e2ed13487343b3d..b14aae0a42172c8000383503dc3e50dd1fe98709 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -4203,6 +4203,7 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, struct nvme_ns_info *info)
                mutex_unlock(&ctrl->namespaces_lock);
                goto out_unlink_ns;
        }
+       blk_queue_rq_timeout(ns->queue, ctrl->io_timeout);
        nvme_ns_add_to_ctrl_list(ns);
        mutex_unlock(&ctrl->namespaces_lock);
        synchronize_srcu(&ctrl->srcu);
@@ -5141,6 +5142,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
        ctrl->ka_cmd.common.opcode = nvme_admin_keep_alive;
        ctrl->ka_last_check_time = jiffies;
        ctrl->admin_timeout = NVME_ADMIN_TIMEOUT;
+       ctrl->io_timeout = NVME_IO_TIMEOUT;
 
        BUILD_BUG_ON(NVME_DSM_MAX_RANGES * sizeof(struct nvme_dsm_range) >
                        PAGE_SIZE);
@@ -5249,7 +5251,7 @@ EXPORT_SYMBOL_GPL(nvme_unfreeze);
 
 int nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl)
 {
-       unsigned long timeout = NVME_IO_TIMEOUT;
+       unsigned long timeout = ctrl->io_timeout;
        struct nvme_ns *ns;
        int srcu_idx;
 

diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 7923533cce00a78efbb849e6a64cb010a983f25a..9ccaed0b9dbf1967fc591e01f927acb46af95c2a 100644 (file)
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -371,6 +371,7 @@ struct nvme_ctrl {
        u32 ctrl_config;
        u32 queue_count;
        u32 admin_timeout;
+       u32 io_timeout;
 
        u64 cap;
        u32 max_hw_sectors;

diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index 3b39b64cd9daf60b9cdad391ccaa237ae5366edd..b682c1a4b23f9e71eab10d27e5f147ba22c9373d 100644 (file)
--- a/drivers/nvme/host/sysfs.c
+++ b/drivers/nvme/host/sysfs.c
@@ -663,6 +663,52 @@ static ssize_t nvme_admin_timeout_store(struct device *dev,
 static DEVICE_ATTR(admin_timeout, S_IRUGO | S_IWUSR,
        nvme_admin_timeout_show, nvme_admin_timeout_store);
 
+static ssize_t nvme_io_timeout_show(struct device *dev,
+               struct device_attribute *attr, char *buf)
+{
+       struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+
+       return sysfs_emit(buf, "%u\n", jiffies_to_msecs(ctrl->io_timeout));
+}
+
+static ssize_t nvme_io_timeout_store(struct device *dev,
+               struct device_attribute *attr,
+               const char *buf, size_t count)
+{
+       struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
+       struct nvme_ns *ns;
+       u32 timeout;
+       int err;
+
+       /*
+        * Wait until the controller reaches the LIVE state to be sure that
+        * connect_q is properly initialized.
+        */
+       if (!test_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags))
+               return -EBUSY;
+
+       err = kstrtou32(buf, 10, &timeout);
+       if (err || !timeout)
+               return -EINVAL;
+
+       /* Take the namespaces_lock to avoid racing against nvme_alloc_ns() */
+       mutex_lock(&ctrl->namespaces_lock);
+
+       ctrl->io_timeout = msecs_to_jiffies(timeout);
+       list_for_each_entry(ns, &ctrl->namespaces, list)
+               blk_queue_rq_timeout(ns->queue, ctrl->io_timeout);
+
+       mutex_unlock(&ctrl->namespaces_lock);
+
+       if (ctrl->connect_q)
+               blk_queue_rq_timeout(ctrl->connect_q, ctrl->io_timeout);
+
+       return count;
+}
+
+static DEVICE_ATTR(io_timeout, S_IRUGO | S_IWUSR,
+       nvme_io_timeout_show, nvme_io_timeout_store);
+
 #ifdef CONFIG_NVME_HOST_AUTH
 static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
                struct device_attribute *attr, char *buf)
@@ -806,6 +852,7 @@ static struct attribute *nvme_dev_attrs[] = {
        &dev_attr_dctype.attr,
        &dev_attr_quirks.attr,
        &dev_attr_admin_timeout.attr,
+       &dev_attr_io_timeout.attr,
 #ifdef CONFIG_NVME_HOST_AUTH
        &dev_attr_dhchap_secret.attr,
        &dev_attr_dhchap_ctrl_secret.attr,