nvme: move passthrough logging attribute to head

The namespace does not have attributes, but the head does. Move the new
logging attribute to that structure instead of dereferencing the wrong
type.

And while we're here, fix the reverse-tree coding style.

Fixes: 9f079dd ("nvme: allow passthru cmd error logging")
Reported-by: Tasmiya Nalatwad <tasmiya@linux.vnet.ibm.com>
Tested-by: Tasmiya Nalatwad <tasmiya@linux.vnet.ibm.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Alan Adamson <alan.adamson@oracle.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Author: keithbusch

drivers/nvme/host/core.c

@@ -713,7 +713,7 @@ void nvme_init_request(struct request *req, struct nvme_command *cmd)
 	if (req->q->queuedata) {
 		struct nvme_ns *ns = req->q->disk->private_data;
 
-		logging_enabled = ns->passthru_err_log_enabled;
+		logging_enabled = ns->head->passthru_err_log_enabled;
 		req->timeout = NVME_IO_TIMEOUT;
 	} else { /* no queuedata implies admin queue */
 		logging_enabled = nr->ctrl->passthru_err_log_enabled;
@@ -3696,7 +3696,6 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, struct nvme_ns_info *info)
 
 	ns->disk = disk;
 	ns->queue = disk->queue;
-	ns->passthru_err_log_enabled = false;
 
 	if (ctrl->opts && ctrl->opts->data_digest)
 		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, ns->queue);

drivers/nvme/host/nvme.h

@@ -455,6 +455,7 @@ struct nvme_ns_head {
 	struct list_head	entry;
 	struct kref		ref;
 	bool			shared;
+	bool			passthru_err_log_enabled;
 	int			instance;
 	struct nvme_effects_log *effects;
 	u64			nuse;
@@ -523,7 +524,6 @@ struct nvme_ns {
 	struct device		cdev_device;
 
 	struct nvme_fault_inject fault_inject;
-	bool			passthru_err_log_enabled;
 };
 
 /* NVMe ns supports metadata actions by the controller (generate/strip) */

drivers/nvme/host/sysfs.c

@@ -48,8 +48,8 @@ static ssize_t nvme_adm_passthru_err_log_enabled_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
-	int err;
 	bool passthru_err_log_enabled;
+	int err;
 
 	err = kstrtobool(buf, &passthru_err_log_enabled);
 	if (err)
@@ -60,25 +60,34 @@ static ssize_t nvme_adm_passthru_err_log_enabled_store(struct device *dev,
 	return count;
 }
 
+static inline struct nvme_ns_head *dev_to_ns_head(struct device *dev)
+{
+	struct gendisk *disk = dev_to_disk(dev);
+
+	if (nvme_disk_is_ns_head(disk))
+		return disk->private_data;
+	return nvme_get_ns_from_dev(dev)->head;
+}
+
 static ssize_t nvme_io_passthru_err_log_enabled_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
-	struct nvme_ns *n = dev_get_drvdata(dev);
+	struct nvme_ns_head *head = dev_to_ns_head(dev);
 
-	return sysfs_emit(buf, n->passthru_err_log_enabled ? "on\n" : "off\n");
+	return sysfs_emit(buf, head->passthru_err_log_enabled ? "on\n" : "off\n");
 }
 
 static ssize_t nvme_io_passthru_err_log_enabled_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
-	struct nvme_ns *ns = dev_get_drvdata(dev);
-	int err;
+	struct nvme_ns_head *head = dev_to_ns_head(dev);
 	bool passthru_err_log_enabled;
+	int err;
 
 	err = kstrtobool(buf, &passthru_err_log_enabled);
 	if (err)
 		return -EINVAL;
-	ns->passthru_err_log_enabled = passthru_err_log_enabled;
+	head->passthru_err_log_enabled = passthru_err_log_enabled;
 
 	return count;
 }
@@ -91,15 +100,6 @@ static struct device_attribute dev_attr_io_passthru_err_log_enabled = \
 	__ATTR(passthru_err_log_enabled, S_IRUGO | S_IWUSR, \
 	nvme_io_passthru_err_log_enabled_show, nvme_io_passthru_err_log_enabled_store);
 
-static inline struct nvme_ns_head *dev_to_ns_head(struct device *dev)
-{
-	struct gendisk *disk = dev_to_disk(dev);
-
-	if (nvme_disk_is_ns_head(disk))
-		return disk->private_data;
-	return nvme_get_ns_from_dev(dev)->head;
-}
-
 static ssize_t wwid_show(struct device *dev, struct device_attribute *attr,
 		char *buf)
 {