ublk: add control command of UBLK_U_CMD_GET_FEATURES

[linux-block.git] / drivers / block / ublk_drv.c

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 539eada32861a4b03d04ce70ab302cf1ad417822..222a0341913ffbb141845864fb706021afb52583 100644 (file)
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2343,6 +2343,21 @@ static int ublk_ctrl_end_recovery(struct ublk_device *ub,
        return ret;
 }
 
+static int ublk_ctrl_get_features(struct io_uring_cmd *cmd)
+{
+       const struct ublksrv_ctrl_cmd *header = io_uring_sqe_cmd(cmd->sqe);
+       void __user *argp = (void __user *)(unsigned long)header->addr;
+       u64 features = UBLK_F_ALL & ~UBLK_F_SUPPORT_ZERO_COPY;
+
+       if (header->len != UBLK_FEATURES_LEN || !header->addr)
+               return -EINVAL;
+
+       if (copy_to_user(argp, &features, UBLK_FEATURES_LEN))
+               return -EFAULT;
+
+       return 0;
+}
+
 /*
  * All control commands are sent via /dev/ublk-control, so we have to check
  * the destination device's permission
@@ -2423,6 +2438,7 @@ static int ublk_ctrl_uring_cmd_permission(struct ublk_device *ub,
        case UBLK_CMD_GET_DEV_INFO2:
        case UBLK_CMD_GET_QUEUE_AFFINITY:
        case UBLK_CMD_GET_PARAMS:
+       case (_IOC_NR(UBLK_U_CMD_GET_FEATURES)):
                mask = MAY_READ;
                break;
        case UBLK_CMD_START_DEV:
@@ -2472,6 +2488,11 @@ static int ublk_ctrl_uring_cmd(struct io_uring_cmd *cmd,
        if (ret)
                goto out;
 
+       if (cmd_op == UBLK_U_CMD_GET_FEATURES) {
+               ret = ublk_ctrl_get_features(cmd);
+               goto out;
+       }
+
        if (_IOC_NR(cmd_op) != UBLK_CMD_ADD_DEV) {
                ret = -ENODEV;
                ub = ublk_get_device_from_id(header->dev_id);