diff options
| -rw-r--r-- | drivers/target/target_core_user.c | 100 |
1 files changed, 97 insertions, 3 deletions
diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 2a2e9e4e7593..95559811d6cc 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -94,6 +94,7 @@ #define TCMU_GLOBAL_MAX_BLOCKS_DEF (512 * 1024) static u8 tcmu_kern_cmd_reply_supported; +static u8 tcmu_netlink_blocked; static struct device *tcmu_root_device; @@ -255,6 +256,92 @@ MODULE_PARM_DESC(global_max_data_area_mb, "Max MBs allowed to be allocated to all the tcmu device's " "data areas."); +static int tcmu_get_block_netlink(char *buffer, + const struct kernel_param *kp) +{ + return sprintf(buffer, "%s\n", tcmu_netlink_blocked ? + "blocked" : "unblocked"); +} + +static int tcmu_set_block_netlink(const char *str, + const struct kernel_param *kp) +{ + int ret; + u8 val; + + ret = kstrtou8(str, 0, &val); + if (ret < 0) + return ret; + + if (val > 1) { + pr_err("Invalid block netlink value %u\n", val); + return -EINVAL; + } + + tcmu_netlink_blocked = val; + return 0; +} + +static const struct kernel_param_ops tcmu_block_netlink_op = { + .set = tcmu_set_block_netlink, + .get = tcmu_get_block_netlink, +}; + +module_param_cb(block_netlink, &tcmu_block_netlink_op, NULL, S_IWUSR | S_IRUGO); +MODULE_PARM_DESC(block_netlink, "Block new netlink commands."); + +static int tcmu_fail_netlink_cmd(struct tcmu_nl_cmd *nl_cmd) +{ + struct tcmu_dev *udev = nl_cmd->udev; + + if (!tcmu_netlink_blocked) { + pr_err("Could not reset device's netlink interface. Netlink is not blocked.\n"); + return -EBUSY; + } + + if (nl_cmd->cmd != TCMU_CMD_UNSPEC) { + pr_debug("Aborting nl cmd %d on %s\n", nl_cmd->cmd, udev->name); + nl_cmd->status = -EINTR; + list_del(&nl_cmd->nl_list); + complete(&nl_cmd->complete); + } + return 0; +} + +static int tcmu_set_reset_netlink(const char *str, + const struct kernel_param *kp) +{ + struct tcmu_nl_cmd *nl_cmd, *tmp_cmd; + int ret; + u8 val; + + ret = kstrtou8(str, 0, &val); + if (ret < 0) + return ret; + + if (val != 1) { + pr_err("Invalid reset netlink value %u\n", val); + return -EINVAL; + } + + mutex_lock(&tcmu_nl_cmd_mutex); + list_for_each_entry_safe(nl_cmd, tmp_cmd, &tcmu_nl_cmd_list, nl_list) { + ret = tcmu_fail_netlink_cmd(nl_cmd); + if (ret) + break; + } + mutex_unlock(&tcmu_nl_cmd_mutex); + + return ret; +} + +static const struct kernel_param_ops tcmu_reset_netlink_op = { + .set = tcmu_set_reset_netlink, +}; + +module_param_cb(reset_netlink, &tcmu_reset_netlink_op, NULL, S_IWUSR); +MODULE_PARM_DESC(reset_netlink, "Reset netlink commands."); + /* multicast group */ enum tcmu_multicast_groups { TCMU_MCGRP_CONFIG, @@ -303,8 +390,9 @@ static int tcmu_genl_cmd_done(struct genl_info *info, int completed_cmd) } list_del(&nl_cmd->nl_list); - pr_debug("%s genl cmd done got id %d curr %d done %d rc %d\n", - udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc); + pr_debug("%s genl cmd done got id %d curr %d done %d rc %d stat %d\n", + udev->name, dev_id, nl_cmd->cmd, completed_cmd, rc, + nl_cmd->status); if (nl_cmd->cmd != completed_cmd) { pr_err("Mismatched commands on %s (Expecting reply for %d. Current %d).\n", @@ -1547,6 +1635,13 @@ static int tcmu_init_genl_cmd_reply(struct tcmu_dev *udev, int cmd) mutex_lock(&tcmu_nl_cmd_mutex); + if (tcmu_netlink_blocked) { + mutex_unlock(&tcmu_nl_cmd_mutex); + pr_warn("Failing nl cmd %d on %s. Interface is blocked.\n", cmd, + udev->name); + return -EAGAIN; + } + if (nl_cmd->cmd != TCMU_CMD_UNSPEC) { mutex_unlock(&tcmu_nl_cmd_mutex); pr_warn("netlink cmd %d already executing on %s\n", @@ -1583,7 +1678,6 @@ static int tcmu_wait_genl_cmd_reply(struct tcmu_dev *udev) mutex_lock(&tcmu_nl_cmd_mutex); nl_cmd->cmd = TCMU_CMD_UNSPEC; ret = nl_cmd->status; - nl_cmd->status = 0; mutex_unlock(&tcmu_nl_cmd_mutex); return ret; |