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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Jason Gunthorpe <jgg@nvidia.com>,
        Md Haris Iqbal <haris.iqbal@cloud.ionos.com>,
        Jack Wang <jinpu.wang@cloud.ionos.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.8 014/177] RDMA/rtrs-srv: Replace device_register with device_initialize and device_add
Date:   Tue, 15 Sep 2020 16:11:25 +0200
Message-Id: <20200915140654.322625647@linuxfoundation.org>
In-Reply-To: <20200915140653.610388773@linuxfoundation.org>
References: <20200915140653.610388773@linuxfoundation.org>
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From: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>

[ Upstream commit baa5b28b7a474f66a511ebf71a2ade510652a2f6 ]

There are error cases when we will call free_srv before device kobject is
initialized; in such cases calling put_device generates the following
warning:

 kobject: '(null)' (000000009f5445ed): is not initialized, yet
 kobject_put() is being called.

So call device_initialize() only once when the server is allocated. If we
end up calling put_srv() and subsequently free_srv(), our call to
put_device() would result in deletion of the obj. Call device_add() later
when we actually have a connection. Correspondingly, call device_del()
instead of device_unregister() when srv->dev_ref falls to 0.

Fixes: 9cb837480424 ("RDMA/rtrs: server: main functionality")
Link: https://lore.kernel.org/r/20200811092722.2450-1-haris.iqbal@cloud.ionos.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Md Haris Iqbal <haris.iqbal@cloud.ionos.com>
Reviewed-by: Jack Wang <jinpu.wang@cloud.ionos.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c | 8 ++++----
 drivers/infiniband/ulp/rtrs/rtrs-srv.c       | 1 +
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
index 3d7877534bcc9..2f981ae970767 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv-sysfs.c
@@ -182,16 +182,16 @@ static int rtrs_srv_create_once_sysfs_root_folders(struct rtrs_srv_sess *sess)
 	 * sysfs files are created
 	 */
 	dev_set_uevent_suppress(&srv->dev, true);
-	err = device_register(&srv->dev);
+	err = device_add(&srv->dev);
 	if (err) {
-		pr_err("device_register(): %d\n", err);
+		pr_err("device_add(): %d\n", err);
 		goto put;
 	}
 	srv->kobj_paths = kobject_create_and_add("paths", &srv->dev.kobj);
 	if (!srv->kobj_paths) {
 		err = -ENOMEM;
 		pr_err("kobject_create_and_add(): %d\n", err);
-		device_unregister(&srv->dev);
+		device_del(&srv->dev);
 		goto unlock;
 	}
 	dev_set_uevent_suppress(&srv->dev, false);
@@ -216,7 +216,7 @@ rtrs_srv_destroy_once_sysfs_root_folders(struct rtrs_srv_sess *sess)
 		kobject_del(srv->kobj_paths);
 		kobject_put(srv->kobj_paths);
 		mutex_unlock(&srv->paths_mutex);
-		device_unregister(&srv->dev);
+		device_del(&srv->dev);
 	} else {
 		mutex_unlock(&srv->paths_mutex);
 	}
diff --git a/drivers/infiniband/ulp/rtrs/rtrs-srv.c b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
index a219bd1bdbc26..b61a18e57aeba 100644
--- a/drivers/infiniband/ulp/rtrs/rtrs-srv.c
+++ b/drivers/infiniband/ulp/rtrs/rtrs-srv.c
@@ -1336,6 +1336,7 @@ static struct rtrs_srv *__alloc_srv(struct rtrs_srv_ctx *ctx,
 	uuid_copy(&srv->paths_uuid, paths_uuid);
 	srv->queue_depth = sess_queue_depth;
 	srv->ctx = ctx;
+	device_initialize(&srv->dev);
 
 	srv->chunks = kcalloc(srv->queue_depth, sizeof(*srv->chunks),
 			      GFP_KERNEL);
-- 
2.25.1