From ce1518139e6976cf19c133b555083354fdb629b8 Mon Sep 17 00:00:00 2001 From: Israel Rukshin Date: Tue, 24 Mar 2020 17:29:43 +0200 Subject: [PATCH] nvme: Fix controller creation races with teardown flow Calling nvme_sysfs_delete() when the controller is in the middle of creation may cause several bugs. If the controller is in NEW state we remove delete_controller file and don't delete the controller. The user will not be able to use nvme disconnect command on that controller again, although the controller may be active. Other bugs may happen if the controller is in the middle of create_ctrl callback and nvme_do_delete_ctrl() starts. For example, freeing I/O tagset at nvme_do_delete_ctrl() before it was allocated at create_ctrl callback. To fix all those races don't allow the user to delete the controller before it was fully created. Signed-off-by: Israel Rukshin Reviewed-by: Max Gurtovoy Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch --- drivers/nvme/host/core.c | 5 +++++ drivers/nvme/host/nvme.h | 1 + 2 files changed, 6 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 8e6a3ad..66fe301 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3228,6 +3228,10 @@ static ssize_t nvme_sysfs_delete(struct device *dev, { struct nvme_ctrl *ctrl = dev_get_drvdata(dev); + /* Can't delete non-created controllers */ + if (!ctrl->created) + return -EBUSY; + if (device_remove_file_self(dev, attr)) nvme_delete_ctrl_sync(ctrl); return count; @@ -4039,6 +4043,7 @@ void nvme_start_ctrl(struct nvme_ctrl *ctrl) nvme_queue_scan(ctrl); nvme_start_queues(ctrl); } + ctrl->created = true; } EXPORT_SYMBOL_GPL(nvme_start_ctrl); diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index d800b9a..2e04a36 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -259,6 +259,7 @@ struct nvme_ctrl { struct nvme_command ka_cmd; struct work_struct fw_act_work; unsigned long events; + bool created; #ifdef CONFIG_NVME_MULTIPATH /* asymmetric namespace access: */ -- 2.7.4