| Subject | Re: [PATCH AUTOSEL 4.19 127/206] nvme: Fix controller creation races with teardown flow | From | Sagi Grimberg <> | Date | Fri, 18 Sep 2020 11:46:22 -0700 |
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This causes a regression and was reverted upstream, just FYI.
On 9/17/20 7:06 PM, Sasha Levin wrote: > From: Israel Rukshin <israelr@mellanox.com> > > [ Upstream commit ce1518139e6976cf19c133b555083354fdb629b8 ] > > 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 <israelr@mellanox.com> > Reviewed-by: Max Gurtovoy <maxg@mellanox.com> > Reviewed-by: Christoph Hellwig <hch@lst.de> > Signed-off-by: Keith Busch <kbusch@kernel.org> > Signed-off-by: Sasha Levin <sashal@kernel.org> > --- > 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 4b182ac15687e..faa7feebb6095 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -2856,6 +2856,10 @@ 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; > @@ -3576,6 +3580,7 @@ void nvme_start_ctrl(struct nvme_ctrl *ctrl) > queue_work(nvme_wq, &ctrl->async_event_work); > 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 31c1496f938fb..a70b997060e68 100644 > --- a/drivers/nvme/host/nvme.h > +++ b/drivers/nvme/host/nvme.h > @@ -206,6 +206,7 @@ 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: */ >
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