2018-01-11 10:32:40

by Arnd Bergmann

Subject: [PATCH] null_blk: remove explicit 'select FAULT_INJECTION'

Selecting FAULT_INJECTION causes a Kconfig warning when CONFIG_DEBUG_KERNEL
is not set:

warning: (BLK_DEV_NULL_BLK && DRM_I915_SELFTEST) selects FAULT_INJECTION which has unmet direct dependencies (DEBUG_KERNEL)

The other drivers that use FAULT_INJECTION tend to have a separate
Kconfig symbol for turning on that feature, so let's do the same
thing here. This may add a bit more complexity than we like, but
it avoids the warning and is more consistent with the rest of the
kernel.

Fixes: 93b570464cce ("null_blk: add option for managing IO timeouts")
Signed-off-by: Arnd Bergmann <[email protected]>
---
drivers/block/Kconfig | 5 ++++-
drivers/block/null_blk.c | 8 ++++++++
2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 622d9a2c8dae..b795d0ca74eb 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -19,7 +19,10 @@ if BLK_DEV
config BLK_DEV_NULL_BLK
tristate "Null test block driver"
select CONFIGFS_FS
- select FAULT_INJECTION
+
+config BLK_DEV_NULL_BLK_FAULT_INJECTION
+ bool "Support fault injection for Nll test block driver"
+ depends on BLK_DEV_NULL_BLK && FAULT_INJECTION

config BLK_DEV_FD
tristate "Normal floppy disk support"
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 2e6f3b2cb902..6655893a3a7a 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -27,7 +27,9 @@
#define TICKS_PER_SEC 50ULL
#define TIMER_INTERVAL (NSEC_PER_SEC / TICKS_PER_SEC)

+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
static DECLARE_FAULT_ATTR(null_timeout_attr);
+#endif

static inline u64 mb_per_tick(int mbps)
{
@@ -165,8 +167,10 @@ static int g_home_node = NUMA_NO_NODE;
module_param_named(home_node, g_home_node, int, S_IRUGO);
MODULE_PARM_DESC(home_node, "Home node for the device");

+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
static char g_timeout_str[80];
module_param_string(timeout, g_timeout_str, sizeof(g_timeout_str), S_IRUGO);
+#endif

static int g_queue_mode = NULL_Q_MQ;

@@ -1372,8 +1376,10 @@ static int null_rq_prep_fn(struct request_queue *q, struct request *req)

static bool should_timeout_request(struct request *rq)
{
+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
if (g_timeout_str[0])
return should_fail(&null_timeout_attr, 1);
+#endif

return false;
}
@@ -1655,6 +1661,7 @@ static void null_validate_conf(struct nullb_device *dev)

static bool null_setup_fault(void)
{
+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
if (!g_timeout_str[0])
return true;

@@ -1662,6 +1669,7 @@ static bool null_setup_fault(void)
return false;

null_timeout_attr.verbose = 0;
+#endif
return true;
}

--
2.9.0

2018-01-11 14:57:57

by Jens Axboe

Subject: Re: [PATCH] null_blk: remove explicit 'select FAULT_INJECTION'

On 1/11/18 3:31 AM, Arnd Bergmann wrote:
> Selecting FAULT_INJECTION causes a Kconfig warning when CONFIG_DEBUG_KERNEL
> is not set:
>
> warning: (BLK_DEV_NULL_BLK && DRM_I915_SELFTEST) selects FAULT_INJECTION which has unmet direct dependencies (DEBUG_KERNEL)
>
> The other drivers that use FAULT_INJECTION tend to have a separate
> Kconfig symbol for turning on that feature, so let's do the same
> thing here. This may add a bit more complexity than we like, but
> it avoids the warning and is more consistent with the rest of the
> kernel.

Thanks Arnd, I'll get this applied.

> diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
> index 622d9a2c8dae..b795d0ca74eb 100644
> --- a/drivers/block/Kconfig
> +++ b/drivers/block/Kconfig
> @@ -19,7 +19,10 @@ if BLK_DEV
> config BLK_DEV_NULL_BLK
> tristate "Null test block driver"
> select CONFIGFS_FS
> - select FAULT_INJECTION
> +
> +config BLK_DEV_NULL_BLK_FAULT_INJECTION
> + bool "Support fault injection for Nll test block driver"
> + depends on BLK_DEV_NULL_BLK && FAULT_INJECTION

Will fixup that typo.

--
Jens Axboe