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| author |   Keith Busch <kbusch@kernel.org> | 2019-09-04 10:06:11 -0600 |
|---|---|---|
| committer | Keith Busch <kbusch@kernel.org> | 2019-10-14 23:22:00 +0900 |
| commit | c1ac9a4b0797ca8bb4470f863a5f78ef1ab13bed (patch) | |
| tree | ef6e639ca906f07528d43d629441c84d0f947b97 /drivers/nvme/host/core.c | |
| parent | nvme: Prevent resets during paused controller state (diff) | |
| download | linux-dev-c1ac9a4b0797ca8bb4470f863a5f78ef1ab13bed.tar.xz linux-dev-c1ac9a4b0797ca8bb4470f863a5f78ef1ab13bed.zip | |
nvme: Wait for reset state when required
Prevent simultaneous controller disabling/enabling tasks from interfering
with each other through a function to wait until the task successfully
transitioned the controller to the RESETTING state. This ensures disabling
the controller will not be interrupted by another reset path, otherwise
a concurrent reset may leave the controller in the wrong state.
Tested-by: Edmund Nadolski <edmund.nadolski@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Diffstat (limited to '')
| -rw-r--r-- | drivers/nvme/host/core.c | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index e94fa693dd4b..fa7ba09dca77 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -126,7 +126,7 @@ static void nvme_queue_scan(struct nvme_ctrl *ctrl) * code paths that can't be interrupted by other reset attempts. A hot removal * may prevent this from succeeding. */ -static int nvme_try_sched_reset(struct nvme_ctrl *ctrl) +int nvme_try_sched_reset(struct nvme_ctrl *ctrl) { if (ctrl->state != NVME_CTRL_RESETTING) return -EBUSY; @@ -134,6 +134,7 @@ static int nvme_try_sched_reset(struct nvme_ctrl *ctrl) return -EBUSY; return 0; } +EXPORT_SYMBOL_GPL(nvme_try_sched_reset); int nvme_reset_ctrl(struct nvme_ctrl *ctrl) { @@ -384,8 +385,10 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl, break; } - if (changed) + if (changed) { ctrl->state = new_state; + wake_up_all(&ctrl->state_wq); + } spin_unlock_irqrestore(&ctrl->lock, flags); if (changed && ctrl->state == NVME_CTRL_LIVE) @@ -394,6 +397,39 @@ bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl, } EXPORT_SYMBOL_GPL(nvme_change_ctrl_state); +/* + * Returns true for sink states that can't ever transition back to live. + */ +static bool nvme_state_terminal(struct nvme_ctrl *ctrl) +{ + switch (ctrl->state) { + case NVME_CTRL_NEW: + case NVME_CTRL_LIVE: + case NVME_CTRL_RESETTING: + case NVME_CTRL_CONNECTING: + return false; + case NVME_CTRL_DELETING: + case NVME_CTRL_DEAD: + return true; + default: + WARN_ONCE(1, "Unhandled ctrl state:%d", ctrl->state); + return true; + } +} + +/* + * Waits for the controller state to be resetting, or returns false if it is + * not possible to ever transition to that state. + */ +bool nvme_wait_reset(struct nvme_ctrl *ctrl) +{ + wait_event(ctrl->state_wq, + nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING) || + nvme_state_terminal(ctrl)); + return ctrl->state == NVME_CTRL_RESETTING; +} +EXPORT_SYMBOL_GPL(nvme_wait_reset); + static void nvme_free_ns_head(struct kref *ref) { struct nvme_ns_head *head = @@ -3998,6 +4034,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev, INIT_WORK(&ctrl->async_event_work, nvme_async_event_work); INIT_WORK(&ctrl->fw_act_work, nvme_fw_act_work); INIT_WORK(&ctrl->delete_work, nvme_delete_ctrl_work); + init_waitqueue_head(&ctrl->state_wq); INIT_DELAYED_WORK(&ctrl->ka_work, nvme_keep_alive_work); memset(&ctrl->ka_cmd, 0, sizeof(ctrl->ka_cmd)); |