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From:   Hannes Reinecke <hare@suse.de>
To:     Jens Axboe <axboe@kernel.dk>
Cc:     Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
        Keith Busch <keith.busch@intel.com>,
        Bart van Assche <bart.vanassche@wdc.com>,
        linux-nvme@lists.infradead.org, linux-block@vger.kernel.org,
        Linux Kernel Mailinglist <linux-kernel@vger.kernel.org>,
        Hannes Reinecke <hare@suse.de>, Hannes Reinecke <hare@suse.com>
Subject: [PATCH 2/5] nvme: register ns_id attributes as default sysfs groups
Date:   Tue, 14 Aug 2018 09:33:02 +0200
Message-Id: <20180814073305.87255-3-hare@suse.de>
In-Reply-To: <20180814073305.87255-1-hare@suse.de>
References: <20180814073305.87255-1-hare@suse.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/core.c      | 21 +++++++++------------
 drivers/nvme/host/lightnvm.c  | 27 ++++-----------------------
 drivers/nvme/host/multipath.c | 15 ++++-----------
 drivers/nvme/host/nvme.h      | 11 +++--------
 4 files changed, 20 insertions(+), 54 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 0e824e8c8fd7..8e26d98e9a8f 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2734,6 +2734,12 @@ 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,
+	NULL, /* Will be filled in by lightnvm if present */
+	NULL,
+};
+
 #define nvme_show_str_function(field)						\
 static ssize_t  field##_show(struct device *dev,				\
 			    struct device_attribute *attr, char *buf)		\
@@ -3099,14 +3105,9 @@ 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);
+	if (ns->ndev)
+		nvme_nvm_register_sysfs(ns);
+	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..7bf2f9da6293 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -1270,39 +1270,20 @@ static const struct attribute_group nvm_dev_attr_group_20 = {
 	.attrs		= nvm_dev_attrs_20,
 };
 
-int nvme_nvm_register_sysfs(struct nvme_ns *ns)
+void nvme_nvm_register_sysfs(struct nvme_ns *ns)
 {
 	struct nvm_dev *ndev = ns->ndev;
 	struct nvm_geo *geo = &ndev->geo;
 
 	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;
+		return;
 
 	switch (geo->major_ver_id) {
 	case 1:
-		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
-					&nvm_dev_attr_group_12);
+		nvme_ns_id_attr_groups[1] = &nvm_dev_attr_group_12;
 		break;
 	case 2:
-		sysfs_remove_group(&disk_to_dev(ns->disk)->kobj,
-					&nvm_dev_attr_group_20);
+		nvme_ns_id_attr_groups[1] = &nvm_dev_attr_group_20;
 		break;
 	}
 }
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..9ba6d67d8e0a 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);
+void nvme_nvm_register_sysfs(struct nvme_ns *ns);
 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 +562,7 @@ 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 void nvme_nvm_register_sysfs(struct nvme_ns *ns) {};
 static inline int nvme_nvm_ioctl(struct nvme_ns *ns, unsigned int cmd,
 							unsigned long arg)
 {
-- 
2.12.3