6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Uday Shankar ushankar@purestorage.com
[ Upstream commit 5ac60242b0173be83709603ebaf27a473f16c4e4 ]
The parameters set by the set_params call are only applied to the block device in the start_dev call. So if a device has already been started, a subsequently issued set_params on that device will not have the desired effect, and should return an error. There is an existing check for this - set_params fails on devices in the LIVE state. But this check is not sufficient to cover the recovery case. In this case, the device will be in the QUIESCED or FAIL_IO states, so set_params will succeed. But this success is misleading, because the parameters will not be applied, since the device has already been started (by a previous ublk server). The bit UB_STATE_USED is set on completion of the start_dev; use it to detect and fail set_params commands which arrive too late to be applied (after start_dev).
Signed-off-by: Uday Shankar ushankar@purestorage.com Fixes: 0aa73170eba5 ("ublk_drv: add SET_PARAMS/GET_PARAMS control command") Reviewed-by: Ming Lei ming.lei@redhat.com Link: https://lore.kernel.org/r/20250304-set_params-v1-1-17b5e0887606@purestorage.... Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/block/ublk_drv.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c index 1105e8adf7f96..95095500f93af 100644 --- a/drivers/block/ublk_drv.c +++ b/drivers/block/ublk_drv.c @@ -2599,9 +2599,12 @@ static int ublk_ctrl_set_params(struct ublk_device *ub, if (ph.len > sizeof(struct ublk_params)) ph.len = sizeof(struct ublk_params);
- /* parameters can only be changed when device isn't live */ mutex_lock(&ub->mutex); - if (ub->dev_info.state == UBLK_S_DEV_LIVE) { + if (test_bit(UB_STATE_USED, &ub->state)) { + /* + * Parameters can only be changed when device hasn't + * been started yet + */ ret = -EACCES; } else if (copy_from_user(&ub->params, argp, ph.len)) { ret = -EFAULT;