As null_blk is a very good start point to test block layer, this patch adds description and comments to 'timeout', 'requeue' and 'init_hctx' to explain how to use fault injection with null_blk. The nvme has similar with nvme_core.fail_request in the form of comment. Signed-off-by: Dongli Zhang <dongli.zhang@xxxxxxxxxx> --- Changed since v1: - rebase at for-5.7/drivers - describe 'init_hctx' as well drivers/block/null_blk_main.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index 8060ffa4bc75..b324cc5fcaf7 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -97,14 +97,21 @@ module_param_named(home_node, g_home_node, int, 0444); MODULE_PARM_DESC(home_node, "Home node for the device"); #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION +/* + * For more details about fault injection, please refer to + * Documentation/fault-injection/fault-injection.rst. + */ static char g_timeout_str[80]; module_param_string(timeout, g_timeout_str, sizeof(g_timeout_str), 0444); +MODULE_PARM_DESC(timeout, "Fault injection. timeout=<interval>,<probability>,<space>,<times>"); static char g_requeue_str[80]; module_param_string(requeue, g_requeue_str, sizeof(g_requeue_str), 0444); +MODULE_PARM_DESC(requeue, "Fault injection. requeue=<interval>,<probability>,<space>,<times>"); static char g_init_hctx_str[80]; module_param_string(init_hctx, g_init_hctx_str, sizeof(g_init_hctx_str), 0444); +MODULE_PARM_DESC(init_hctx, "Fault injection to fail hctx init. init_hctx=<interval>,<probability>,<space>,<times>"); #endif static int g_queue_mode = NULL_Q_MQ; -- 2.17.1