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-rw-r--r--drivers/target/target_core_user.c100
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;