diff mbox series

[2/5] nvme: register ns_id attributes as default sysfs groups

Message ID 20180905070053.26239-3-hare@suse.de (mailing list archive)
State New, archived
Headers show
Series genhd: register default groups with device_add_disk() | expand

Commit Message

Hannes Reinecke Sept. 5, 2018, 7 a.m. UTC 
We should be registering the ns_id attribute as default sysfs
attribute groups, otherwise we have a race condition between
the uevent and the attributes appearing in sysfs.

Signed-off-by: Hannes Reinecke <hare@suse.com>
---
 drivers/nvme/host/core.c      |  21 ++++-----
 drivers/nvme/host/lightnvm.c  | 106 +++++++++++++++++-------------------------
 drivers/nvme/host/multipath.c |  15 ++----
 drivers/nvme/host/nvme.h      |  10 +---
 4 files changed, 58 insertions(+), 94 deletions(-)

Comments

Christoph Hellwig Sept. 5, 2018, 1:18 p.m. UTC | #1 
On Wed, Sep 05, 2018 at 09:00:50AM +0200, Hannes Reinecke wrote:
> We should be registering the ns_id attribute as default sysfs
> attribute groups, otherwise we have a race condition between
> the uevent and the attributes appearing in sysfs.

Please give Bart credit for his work, as the lightnvm bits are almost
bigger than the rest.

> +static umode_t nvm_dev_attrs_visible(struct kobject *kobj,
> +				     struct attribute *attr, int index)
>  {
> +	struct device *dev = container_of(kobj, struct device, kobj);
> +	struct gendisk *disk = dev_to_disk(dev);
> +	struct nvme_ns *ns = disk->private_data;
>  	struct nvm_dev *ndev = ns->ndev;
> +	struct device_attribute *dev_attr =
> +		container_of(attr, typeof(*dev_attr), attr);
>  
> +	if (dev_attr->show == nvm_dev_attr_show)
> +		return attr->mode;
>  
> +	switch (ndev ? ndev->geo.major_ver_id : 0) {

How could ndev be zero here?
Hannes Reinecke Sept. 5, 2018, 1:32 p.m. UTC | #2 
On 09/05/2018 03:18 PM, Christoph Hellwig wrote:
> On Wed, Sep 05, 2018 at 09:00:50AM +0200, Hannes Reinecke wrote:
>> We should be registering the ns_id attribute as default sysfs
>> attribute groups, otherwise we have a race condition between
>> the uevent and the attributes appearing in sysfs.
> 
> Please give Bart credit for his work, as the lightnvm bits are almost
> bigger than the rest.
> 
Okay, will be doing so.

>> +static umode_t nvm_dev_attrs_visible(struct kobject *kobj,
>> +				     struct attribute *attr, int index)
>>  {
>> +	struct device *dev = container_of(kobj, struct device, kobj);
>> +	struct gendisk *disk = dev_to_disk(dev);
>> +	struct nvme_ns *ns = disk->private_data;
>>  	struct nvm_dev *ndev = ns->ndev;
>> +	struct device_attribute *dev_attr =
>> +		container_of(attr, typeof(*dev_attr), attr);
>>  
>> +	if (dev_attr->show == nvm_dev_attr_show)
>> +		return attr->mode;
>>  
>> +	switch (ndev ? ndev->geo.major_ver_id : 0) {
> 
> How could ndev be zero here?
> 
For 'normal' NVMe devices (ie non-lightnvm). As we now register all
sysfs attributes (including the lightnvm ones) per default we'll need to
blank them out for non-lightnvm devices.

Cheers,

Hannes
Christoph Hellwig Sept. 5, 2018, 1:45 p.m. UTC | #3 
On Wed, Sep 05, 2018 at 03:32:03PM +0200, Hannes Reinecke wrote:
> On 09/05/2018 03:18 PM, Christoph Hellwig wrote:
> > On Wed, Sep 05, 2018 at 09:00:50AM +0200, Hannes Reinecke wrote:
> >> We should be registering the ns_id attribute as default sysfs
> >> attribute groups, otherwise we have a race condition between
> >> the uevent and the attributes appearing in sysfs.
> > 
> > Please give Bart credit for his work, as the lightnvm bits are almost
> > bigger than the rest.
> > 
> Okay, will be doing so.
> 
> >> +static umode_t nvm_dev_attrs_visible(struct kobject *kobj,
> >> +				     struct attribute *attr, int index)
> >>  {
> >> +	struct device *dev = container_of(kobj, struct device, kobj);
> >> +	struct gendisk *disk = dev_to_disk(dev);
> >> +	struct nvme_ns *ns = disk->private_data;
> >>  	struct nvm_dev *ndev = ns->ndev;
> >> +	struct device_attribute *dev_attr =
> >> +		container_of(attr, typeof(*dev_attr), attr);
> >>  
> >> +	if (dev_attr->show == nvm_dev_attr_show)
> >> +		return attr->mode;
> >>  
> >> +	switch (ndev ? ndev->geo.major_ver_id : 0) {
> > 
> > How could ndev be zero here?
> > 
> For 'normal' NVMe devices (ie non-lightnvm). As we now register all
> sysfs attributes (including the lightnvm ones) per default we'll need to
> blank them out for non-lightnvm devices.

But then we need to exit early at the beginning of the function,
as we should not register attributes using nvm_dev_attr_show (or
anything else for that matter) either.
Hannes Reinecke Sept. 6, 2018, 9:56 a.m. UTC | #4 
On 09/05/2018 03:45 PM, Christoph Hellwig wrote:
> On Wed, Sep 05, 2018 at 03:32:03PM +0200, Hannes Reinecke wrote:
>> On 09/05/2018 03:18 PM, Christoph Hellwig wrote:
>>> On Wed, Sep 05, 2018 at 09:00:50AM +0200, Hannes Reinecke wrote:
>>>> We should be registering the ns_id attribute as default sysfs
>>>> attribute groups, otherwise we have a race condition between
>>>> the uevent and the attributes appearing in sysfs.
>>>
>>> Please give Bart credit for his work, as the lightnvm bits are almost
>>> bigger than the rest.
>>>
>> Okay, will be doing so.
>>
>>>> +static umode_t nvm_dev_attrs_visible(struct kobject *kobj,
>>>> +				     struct attribute *attr, int index)
>>>>  {
>>>> +	struct device *dev = container_of(kobj, struct device, kobj);
>>>> +	struct gendisk *disk = dev_to_disk(dev);
>>>> +	struct nvme_ns *ns = disk->private_data;
>>>>  	struct nvm_dev *ndev = ns->ndev;
>>>> +	struct device_attribute *dev_attr =
>>>> +		container_of(attr, typeof(*dev_attr), attr);
>>>>  
>>>> +	if (dev_attr->show == nvm_dev_attr_show)
>>>> +		return attr->mode;
>>>>  
>>>> +	switch (ndev ? ndev->geo.major_ver_id : 0) {
>>>
>>> How could ndev be zero here?
>>>
>> For 'normal' NVMe devices (ie non-lightnvm). As we now register all
>> sysfs attributes (including the lightnvm ones) per default we'll need to
>> blank them out for non-lightnvm devices.
> 
> But then we need to exit early at the beginning of the function,
> as we should not register attributes using nvm_dev_attr_show (or
> anything else for that matter) either.
> 
Okay, will be fixing it up.

Cheers,

Hannes
diff mbox series

Patch

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 0e824e8c8fd7..e0a9e1c5b30e 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2734,6 +2734,14 @@  const struct attribute_group nvme_ns_id_attr_group = {
 	.is_visible	= nvme_ns_id_attrs_are_visible,
 };
 
+const struct attribute_group *nvme_ns_id_attr_groups[] = {
+	&nvme_ns_id_attr_group,
+#ifdef CONFIG_NVM
+	&nvme_nvm_attr_group,
+#endif
+	NULL,
+};
+
 #define nvme_show_str_function(field)						\
 static ssize_t  field##_show(struct device *dev,				\
 			    struct device_attribute *attr, char *buf)		\
@@ -3099,14 +3107,7 @@  static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid)
 
 	nvme_get_ctrl(ctrl);
 
-	device_add_disk(ctrl->device, ns->disk, NULL);
-	if (sysfs_create_group(&disk_to_dev(ns->disk)->kobj,
-					&nvme_ns_id_attr_group))
-		pr_warn("%s: failed to create sysfs group for identification\n",
-			ns->disk->disk_name);
-	if (ns->ndev && nvme_nvm_register_sysfs(ns))
-		pr_warn("%s: failed to register lightnvm sysfs group for identification\n",
-			ns->disk->disk_name);
+	device_add_disk(ctrl->device, ns->disk, nvme_ns_id_attr_groups);
 
 	nvme_mpath_add_disk(ns, id);
 	nvme_fault_inject_init(ns);
@@ -3132,10 +3133,6 @@  static void nvme_ns_remove(struct nvme_ns *ns)
 
 	nvme_fault_inject_fini(ns);
 	if (ns->disk && ns->disk->flags & GENHD_FL_UP) {
-		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
-					&nvme_ns_id_attr_group);
-		if (ns->ndev)
-			nvme_nvm_unregister_sysfs(ns);
 		del_gendisk(ns->disk);
 		blk_cleanup_queue(ns->queue);
 		if (blk_get_integrity(ns->disk))
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 6fe5923c95d4..941ce5fc48f5 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -1190,10 +1190,29 @@  static NVM_DEV_ATTR_12_RO(multiplane_modes);
 static NVM_DEV_ATTR_12_RO(media_capabilities);
 static NVM_DEV_ATTR_12_RO(max_phys_secs);
 
-static struct attribute *nvm_dev_attrs_12[] = {
+/* 2.0 values */
+static NVM_DEV_ATTR_20_RO(groups);
+static NVM_DEV_ATTR_20_RO(punits);
+static NVM_DEV_ATTR_20_RO(chunks);
+static NVM_DEV_ATTR_20_RO(clba);
+static NVM_DEV_ATTR_20_RO(ws_min);
+static NVM_DEV_ATTR_20_RO(ws_opt);
+static NVM_DEV_ATTR_20_RO(maxoc);
+static NVM_DEV_ATTR_20_RO(maxocpu);
+static NVM_DEV_ATTR_20_RO(mw_cunits);
+static NVM_DEV_ATTR_20_RO(write_typ);
+static NVM_DEV_ATTR_20_RO(write_max);
+static NVM_DEV_ATTR_20_RO(reset_typ);
+static NVM_DEV_ATTR_20_RO(reset_max);
+
+static struct attribute *nvm_dev_attrs[] = {
+	/* version agnostic attrs */
 	&dev_attr_version.attr,
 	&dev_attr_capabilities.attr,
+	&dev_attr_read_typ.attr,
+	&dev_attr_read_max.attr,
 
+	/* 1.2 attrs */
 	&dev_attr_vendor_opcode.attr,
 	&dev_attr_device_mode.attr,
 	&dev_attr_media_manager.attr,
@@ -1208,8 +1227,6 @@  static struct attribute *nvm_dev_attrs_12[] = {
 	&dev_attr_page_size.attr,
 	&dev_attr_hw_sector_size.attr,
 	&dev_attr_oob_sector_size.attr,
-	&dev_attr_read_typ.attr,
-	&dev_attr_read_max.attr,
 	&dev_attr_prog_typ.attr,
 	&dev_attr_prog_max.attr,
 	&dev_attr_erase_typ.attr,
@@ -1218,33 +1235,7 @@  static struct attribute *nvm_dev_attrs_12[] = {
 	&dev_attr_media_capabilities.attr,
 	&dev_attr_max_phys_secs.attr,
 
-	NULL,
-};
-
-static const struct attribute_group nvm_dev_attr_group_12 = {
-	.name		= "lightnvm",
-	.attrs		= nvm_dev_attrs_12,
-};
-
-/* 2.0 values */
-static NVM_DEV_ATTR_20_RO(groups);
-static NVM_DEV_ATTR_20_RO(punits);
-static NVM_DEV_ATTR_20_RO(chunks);
-static NVM_DEV_ATTR_20_RO(clba);
-static NVM_DEV_ATTR_20_RO(ws_min);
-static NVM_DEV_ATTR_20_RO(ws_opt);
-static NVM_DEV_ATTR_20_RO(maxoc);
-static NVM_DEV_ATTR_20_RO(maxocpu);
-static NVM_DEV_ATTR_20_RO(mw_cunits);
-static NVM_DEV_ATTR_20_RO(write_typ);
-static NVM_DEV_ATTR_20_RO(write_max);
-static NVM_DEV_ATTR_20_RO(reset_typ);
-static NVM_DEV_ATTR_20_RO(reset_max);
-
-static struct attribute *nvm_dev_attrs_20[] = {
-	&dev_attr_version.attr,
-	&dev_attr_capabilities.attr,
-
+	/* 2.0 attrs */
 	&dev_attr_groups.attr,
 	&dev_attr_punits.attr,
 	&dev_attr_chunks.attr,
@@ -1255,8 +1246,6 @@  static struct attribute *nvm_dev_attrs_20[] = {
 	&dev_attr_maxocpu.attr,
 	&dev_attr_mw_cunits.attr,
 
-	&dev_attr_read_typ.attr,
-	&dev_attr_read_max.attr,
 	&dev_attr_write_typ.attr,
 	&dev_attr_write_max.attr,
 	&dev_attr_reset_typ.attr,
@@ -1265,44 +1254,35 @@  static struct attribute *nvm_dev_attrs_20[] = {
 	NULL,
 };
 
-static const struct attribute_group nvm_dev_attr_group_20 = {
-	.name		= "lightnvm",
-	.attrs		= nvm_dev_attrs_20,
-};
-
-int nvme_nvm_register_sysfs(struct nvme_ns *ns)
+static umode_t nvm_dev_attrs_visible(struct kobject *kobj,
+				     struct attribute *attr, int index)
 {
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct gendisk *disk = dev_to_disk(dev);
+	struct nvme_ns *ns = disk->private_data;
 	struct nvm_dev *ndev = ns->ndev;
-	struct nvm_geo *geo = &ndev->geo;
+	struct device_attribute *dev_attr =
+		container_of(attr, typeof(*dev_attr), attr);
 
-	if (!ndev)
-		return -EINVAL;
-
-	switch (geo->major_ver_id) {
-	case 1:
-		return sysfs_create_group(&disk_to_dev(ns->disk)->kobj,
-					&nvm_dev_attr_group_12);
-	case 2:
-		return sysfs_create_group(&disk_to_dev(ns->disk)->kobj,
-					&nvm_dev_attr_group_20);
-	}
-
-	return -EINVAL;
-}
-
-void nvme_nvm_unregister_sysfs(struct nvme_ns *ns)
-{
-	struct nvm_dev *ndev = ns->ndev;
-	struct nvm_geo *geo = &ndev->geo;
+	if (dev_attr->show == nvm_dev_attr_show)
+		return attr->mode;
 
-	switch (geo->major_ver_id) {
+	switch (ndev ? ndev->geo.major_ver_id : 0) {
 	case 1:
-		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
-					&nvm_dev_attr_group_12);
+		if (dev_attr->show == nvm_dev_attr_show_12)
+			return attr->mode;
 		break;
 	case 2:
-		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
-					&nvm_dev_attr_group_20);
+		if (dev_attr->show == nvm_dev_attr_show_20)
+			return attr->mode;
 		break;
 	}
+
+	return 0;
 }
+
+const struct attribute_group nvme_nvm_attr_group = {
+	.name		= "lightnvm",
+	.attrs		= nvm_dev_attrs,
+	.is_visible	= nvm_dev_attrs_visible,
+};
diff --git a/drivers/nvme/host/multipath.c b/drivers/nvme/host/multipath.c
index 477af51d01e8..8e846095c42d 100644
--- a/drivers/nvme/host/multipath.c
+++ b/drivers/nvme/host/multipath.c
@@ -282,13 +282,9 @@  static void nvme_mpath_set_live(struct nvme_ns *ns)
 	if (!head->disk)
 		return;
 
-	if (!(head->disk->flags & GENHD_FL_UP)) {
-		device_add_disk(&head->subsys->dev, head->disk, NULL);
-		if (sysfs_create_group(&disk_to_dev(head->disk)->kobj,
-				&nvme_ns_id_attr_group))
-			dev_warn(&head->subsys->dev,
-				 "failed to create id group.\n");
-	}
+	if (!(head->disk->flags & GENHD_FL_UP))
+		device_add_disk(&head->subsys->dev, head->disk,
+				nvme_ns_id_attr_groups);
 
 	kblockd_schedule_work(&ns->head->requeue_work);
 }
@@ -494,11 +490,8 @@  void nvme_mpath_remove_disk(struct nvme_ns_head *head)
 {
 	if (!head->disk)
 		return;
-	if (head->disk->flags & GENHD_FL_UP) {
-		sysfs_remove_group(&disk_to_dev(head->disk)->kobj,
-				   &nvme_ns_id_attr_group);
+	if (head->disk->flags & GENHD_FL_UP)
 		del_gendisk(head->disk);
-	}
 	blk_set_queue_dying(head->disk->queue);
 	/* make sure all pending bios are cleaned up */
 	kblockd_schedule_work(&head->requeue_work);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index bb4a2003c097..2503f8fd54da 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -459,7 +459,7 @@  int nvme_delete_ctrl_sync(struct nvme_ctrl *ctrl);
 int nvme_get_log(struct nvme_ctrl *ctrl, u32 nsid, u8 log_page, u8 lsp,
 		void *log, size_t size, u64 offset);
 
-extern const struct attribute_group nvme_ns_id_attr_group;
+extern const struct attribute_group *nvme_ns_id_attr_groups[];
 extern const struct block_device_operations nvme_ns_head_ops;
 
 #ifdef CONFIG_NVME_MULTIPATH
@@ -551,8 +551,7 @@  static inline void nvme_mpath_stop(struct nvme_ctrl *ctrl)
 void nvme_nvm_update_nvm_info(struct nvme_ns *ns);
 int nvme_nvm_register(struct nvme_ns *ns, char *disk_name, int node);
 void nvme_nvm_unregister(struct nvme_ns *ns);
-int nvme_nvm_register_sysfs(struct nvme_ns *ns);
-void nvme_nvm_unregister_sysfs(struct nvme_ns *ns);
+extern const struct attribute_group nvme_nvm_attr_group;
 int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd, unsigned long arg);
 #else
 static inline void nvme_nvm_update_nvm_info(struct nvme_ns *ns) {};
@@ -563,11 +562,6 @@  static inline int nvme_nvm_register(struct nvme_ns *ns, char *disk_name,
 }
 
 static inline void nvme_nvm_unregister(struct nvme_ns *ns) {};
-static inline int nvme_nvm_register_sysfs(struct nvme_ns *ns)
-{
-	return 0;
-}
-static inline void nvme_nvm_unregister_sysfs(struct nvme_ns *ns) {};
 static inline int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd,
 							unsigned long arg)
 {