Re: [PATCH] sed-opal: Add STACK_RESET command

Milan Broz
2026-03-31T11:59:46Z

On 3/10/26 10:53 AM, Milan Broz wrote:
> The TCG Opal device could enter a state where no new session can be
> created, blocking even Discovery or PSID reset. While a power cycle
> or waiting for the timeout should work, there is another possibility
> for recovery: using the Stack Reset command.

Hi Jens,

is there any chance to merge this for 7.1 (so it goes together with other
Opal changes)?

Thanks,
Milan

>
> The Stack Reset command is defined in the TCG Storage Architecture Core
> Specification and is mandatory for all Opal devices (see Section 3.3.6
> of the Opal SSC specification).
>
> This patch implements the Stack Reset command. Sending it should clear
> all active sessions immediately, allowing subsequent commands to run
> successfully. While it is a TCG transport layer command, the Linux
> kernel implements only Opal ioctls, so it makes sense to use the
> IOC_OPAL ioctl interface.
>
> The Stack Reset takes no arguments; the response can be success or pending.
> If the command reports a pending state, userspace can try to repeat it;
> in this case, the code returns -EBUSY.
>
> Signed-off-by: Milan Broz <gmazyland@gmail.com>
> ---
> block/opal_proto.h | 20 +++++++++++++++
> block/sed-opal.c | 47 +++++++++++++++++++++++++++++++++++
> include/linux/sed-opal.h | 1 +
> include/uapi/linux/sed-opal.h | 1 +
> 4 files changed, 69 insertions(+)
>
> diff --git a/block/opal_proto.h b/block/opal_proto.h
> index d138785b8198..7c24247aa186 100644
> --- a/block/opal_proto.h
> +++ b/block/opal_proto.h
> @@ -19,6 +19,7 @@
> enum {
> TCG_SECP_00 = 0,
> TCG_SECP_01,
> + TCG_SECP_02,
> };
>
> /*
> @@ -273,6 +274,25 @@ struct opal_header {
> struct opal_data_subpacket subpkt;
> };
>
> +/*
> + * TCG_Storage_Architecture_Core_Spec_v2.01_r1.00
> + * Section: 3.3.4.7.5 STACK_RESET
> + */
> +#define OPAL_STACK_RESET 0x0002
> +
> +struct opal_stack_reset {
> + u8 extendedComID[4];
> + __be32 request_code;
> +};
> +
> +struct opal_stack_reset_response {
> + u8 extendedComID[4];
> + __be32 request_code;
> + u8 reserved0[2];
> + __be16 data_length;
> + __be32 response;
> +};
> +
> #define FC_TPER 0x0001
> #define FC_LOCKING 0x0002
> #define FC_GEOMETRY 0x0003
> diff --git a/block/sed-opal.c b/block/sed-opal.c
> index c34d19e91201..79b290d9458a 100644
> --- a/block/sed-opal.c
> +++ b/block/sed-opal.c
> @@ -3545,6 +3545,50 @@ static int opal_get_sum_ranges(struct opal_dev *dev, struct opal_sum_ranges *opa
> return ret;
> }
>
> +static int opal_stack_reset(struct opal_dev *dev)
> +{
> + struct opal_stack_reset *req;
> + struct opal_stack_reset_response *resp;
> + int ret;
> +
> + mutex_lock(&dev->dev_lock);
> +
> + memset(dev->cmd, 0, IO_BUFFER_LENGTH);
> + req = (struct opal_stack_reset *)dev->cmd;
> + req->extendedComID[0] = dev->comid >> 8;
> + req->extendedComID[1] = dev->comid & 0xFF;
> + req->request_code = cpu_to_be32(OPAL_STACK_RESET);
> +
> + ret = dev->send_recv(dev->data, dev->comid, TCG_SECP_02,
> + dev->cmd, IO_BUFFER_LENGTH, true);
> + if (ret) {
> + pr_debug("Error sending stack reset: %d\n", ret);
> + goto out;
> + }
> +
> + memset(dev->resp, 0, IO_BUFFER_LENGTH);
> + ret = dev->send_recv(dev->data, dev->comid, TCG_SECP_02,
> + dev->resp, IO_BUFFER_LENGTH, false);
> + if (ret) {
> + pr_debug("Error receiving stack reset response: %d\n", ret);
> + goto out;
> + }
> +
> + resp = (struct opal_stack_reset_response *)dev->resp;
> + if (be16_to_cpu(resp->data_length) != 4) {
> + pr_debug("Stack reset pending\n");
> + ret = -EBUSY;
> + goto out;
> + }
> + if (be32_to_cpu(resp->response) != 0) {
> + pr_debug("Stack reset failed: %u\n", be32_to_cpu(resp->response));
> + ret = -EIO;
> + }
> +out:
> + mutex_unlock(&dev->dev_lock);
> + return ret;
> +}
> +
> int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
> {
> void *p;
> @@ -3642,6 +3686,9 @@ int sed_ioctl(struct opal_dev *dev, unsigned int cmd, void __user *arg)
> case IOC_OPAL_GET_SUM_STATUS:
> ret = opal_get_sum_ranges(dev, p, arg);
> break;
> + case IOC_OPAL_STACK_RESET:
> + ret = opal_stack_reset(dev);
> + break;
>
> default:
> break;
> diff --git a/include/linux/sed-opal.h b/include/linux/sed-opal.h
> index aa006edb612b..0630430cc01a 100644
> --- a/include/linux/sed-opal.h
> +++ b/include/linux/sed-opal.h
> @@ -57,6 +57,7 @@ static inline bool is_sed_ioctl(unsigned int cmd)
> case IOC_OPAL_LR_SET_START_LEN:
> case IOC_OPAL_ENABLE_DISABLE_LR:
> case IOC_OPAL_GET_SUM_STATUS:
> + case IOC_OPAL_STACK_RESET:
> return true;
> }
> return false;
> diff --git a/include/uapi/linux/sed-opal.h b/include/uapi/linux/sed-opal.h
> index 9830298ec51c..ef4d3be6ca7f 100644
> --- a/include/uapi/linux/sed-opal.h
> +++ b/include/uapi/linux/sed-opal.h
> @@ -245,5 +245,6 @@ struct opal_revert_lsp {
> #define IOC_OPAL_LR_SET_START_LEN _IOW('p', 243, struct opal_user_lr_setup)
> #define IOC_OPAL_ENABLE_DISABLE_LR _IOW('p', 244, struct opal_user_lr_setup)
> #define IOC_OPAL_GET_SUM_STATUS _IOW('p', 245, struct opal_sum_ranges)
> +#define IOC_OPAL_STACK_RESET _IO('p', 246)
>
> #endif /* _UAPI_SED_OPAL_H */