From 92153d30c7c8863022cad684926d71ffaed6a56d Mon Sep 17 00:00:00 2001 From: Yasuaki Ishimatsu Date: Wed, 16 Nov 2016 08:26:11 -0700 Subject: [PATCH] null_blk: add usage hints for NVM If CONFIG_NVM is disabled, loading null_block module with use_lightnvm=1 fails. But there are no messages and documents related to the failure. Add the appropriate error message. Signed-off-by: Yasuaki Ishimatsu Massaged the text a bit. Signed-off-by: Jens Axboe --- Documentation/block/null_blk.txt | 2 +- drivers/block/null_blk.c | 1 + 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt index d8880ca30af4..3140dbd860d8 100644 --- a/Documentation/block/null_blk.txt +++ b/Documentation/block/null_blk.txt @@ -72,4 +72,4 @@ use_per_node_hctx=[0/1]: Default: 0 queue for each CPU node in the system. use_lightnvm=[0/1]: Default: 0 - Register device with LightNVM. Requires blk-mq to be used. + Register device with LightNVM. Requires blk-mq and CONFIG_NVM to be enabled. diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index ba6f4a2e73db..4943ee22716e 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -577,6 +577,7 @@ static void null_nvm_unregister(struct nullb *nullb) #else static int null_nvm_register(struct nullb *nullb) { + pr_err("null_blk: CONFIG_NVM needs to be enabled for LightNVM\n"); return -EINVAL; } static void null_nvm_unregister(struct nullb *nullb) {}