[PATCH 0/5] Five BFQ patches for kernel v4.14

[PATCH 0/5] Five BFQ patches for kernel v4.14

[Bart Van Assche]

Hello Jens,

This series consists of five small patches. Three patches address compiler
warnings, one patch is a fix for the BFQ sysfs interface and a fifth patch
makes the BFQ code slightly more consistent. Please consider these patches
for kernel v4.14.

Thanks,

Bart.

Bart Van Assche (5):
  bfq: Annotate fall-through in a switch statement
  bfq: Declare local functions static
  bfq: Check kstrtoul() return value
  bfq: Suppress compiler warnings about comparisons
  bfq: Use icq_to_bic() consistently

 block/bfq-cgroup.c  | 18 +++++++-------
 block/bfq-iosched.c | 71 +++++++++++++++++++++++++++++++++++------------------
 2 files changed, 56 insertions(+), 33 deletions(-)

-- 
2.14.1

[PATCH 1/5] bfq: Annotate fall-through in a switch statement

[Bart Van Assche]

This patch avoids that gcc 7 issues a warning about fall-through
when building with W=1.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 6a7a26b6cec1..8c11c2e827a5 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -3780,6 +3780,7 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, struct bfq_io_cq *bic)
 	default:
 		dev_err(bfqq->bfqd->queue->backing_dev_info->dev,
 			"bfq: bad prio class %d\n", ioprio_class);
+		/* fall through */
 	case IOPRIO_CLASS_NONE:
 		/*
 		 * No prio set, inherit CPU scheduling settings.
-- 
2.14.1

Re: [PATCH 1/5] bfq: Annotate fall-through in a switch statement

[Paolo Valente]

> Il giorno 30 ago 2017, alle ore 20:42, Bart Van Assche =
<bart.vanassche@wdc.com> ha scritto:
>=20
> This patch avoids that gcc 7 issues a warning about fall-through
> when building with W=3D1.
>=20
> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
> Cc: Paolo Valente <paolo.valente@linaro.org>

Acked-by: Paolo Valente <paolo.valente@linaro.org>

> ---
> block/bfq-iosched.c | 1 +
> 1 file changed, 1 insertion(+)
>=20
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index 6a7a26b6cec1..8c11c2e827a5 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -3780,6 +3780,7 @@ bfq_set_next_ioprio_data(struct bfq_queue *bfqq, =
struct bfq_io_cq *bic)
> 	default:
> 		dev_err(bfqq->bfqd->queue->backing_dev_info->dev,
> 			"bfq: bad prio class %d\n", ioprio_class);
> +		/* fall through */
> 	case IOPRIO_CLASS_NONE:
> 		/*
> 		 * No prio set, inherit CPU scheduling settings.
> --=20
> 2.14.1
>=20

[PATCH 2/5] bfq: Declare local functions static

[Bart Van Assche]

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-cgroup.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
index 78b2e0db4fb2..ceefb9a706d6 100644
--- a/block/bfq-cgroup.c
+++ b/block/bfq-cgroup.c
@@ -206,7 +206,7 @@ static void bfqg_get(struct bfq_group *bfqg)
 	bfqg->ref++;
 }
 
-void bfqg_put(struct bfq_group *bfqg)
+static void bfqg_put(struct bfq_group *bfqg)
 {
 	bfqg->ref--;
 
@@ -385,7 +385,7 @@ static struct bfq_group_data *blkcg_to_bfqgd(struct blkcg *blkcg)
 	return cpd_to_bfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_bfq));
 }
 
-struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
+static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
 {
 	struct bfq_group_data *bgd;
 
@@ -395,7 +395,7 @@ struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
 	return &bgd->pd;
 }
 
-void bfq_cpd_init(struct blkcg_policy_data *cpd)
+static void bfq_cpd_init(struct blkcg_policy_data *cpd)
 {
 	struct bfq_group_data *d = cpd_to_bfqgd(cpd);
 
@@ -403,12 +403,12 @@ void bfq_cpd_init(struct blkcg_policy_data *cpd)
 		CGROUP_WEIGHT_DFL : BFQ_WEIGHT_LEGACY_DFL;
 }
 
-void bfq_cpd_free(struct blkcg_policy_data *cpd)
+static void bfq_cpd_free(struct blkcg_policy_data *cpd)
 {
 	kfree(cpd_to_bfqgd(cpd));
 }
 
-struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, int node)
+static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, int node)
 {
 	struct bfq_group *bfqg;
 
@@ -426,7 +426,7 @@ struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, int node)
 	return &bfqg->pd;
 }
 
-void bfq_pd_init(struct blkg_policy_data *pd)
+static void bfq_pd_init(struct blkg_policy_data *pd)
 {
 	struct blkcg_gq *blkg = pd_to_blkg(pd);
 	struct bfq_group *bfqg = blkg_to_bfqg(blkg);
@@ -445,7 +445,7 @@ void bfq_pd_init(struct blkg_policy_data *pd)
 	bfqg->rq_pos_tree = RB_ROOT;
 }
 
-void bfq_pd_free(struct blkg_policy_data *pd)
+static void bfq_pd_free(struct blkg_policy_data *pd)
 {
 	struct bfq_group *bfqg = pd_to_bfqg(pd);
 
@@ -453,7 +453,7 @@ void bfq_pd_free(struct blkg_policy_data *pd)
 	bfqg_put(bfqg);
 }
 
-void bfq_pd_reset_stats(struct blkg_policy_data *pd)
+static void bfq_pd_reset_stats(struct blkg_policy_data *pd)
 {
 	struct bfq_group *bfqg = pd_to_bfqg(pd);
 
@@ -740,7 +740,7 @@ static void bfq_reparent_active_entities(struct bfq_data *bfqd,
  * blkio already grabs the queue_lock for us, so no need to use
  * RCU-based magic
  */
-void bfq_pd_offline(struct blkg_policy_data *pd)
+static void bfq_pd_offline(struct blkg_policy_data *pd)
 {
 	struct bfq_service_tree *st;
 	struct bfq_group *bfqg = pd_to_bfqg(pd);
-- 
2.14.1

Re: [PATCH 2/5] bfq: Declare local functions static

[Paolo Valente]

> Il giorno 30 ago 2017, alle ore 20:42, Bart Van Assche =
<bart.vanassche@wdc.com> ha scritto:
>=20
> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
> Cc: Paolo Valente <paolo.valente@linaro.org>


Acked-by: Paolo Valente <paolo.valente@linaro.org>

> ---
> block/bfq-cgroup.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>=20
> diff --git a/block/bfq-cgroup.c b/block/bfq-cgroup.c
> index 78b2e0db4fb2..ceefb9a706d6 100644
> --- a/block/bfq-cgroup.c
> +++ b/block/bfq-cgroup.c
> @@ -206,7 +206,7 @@ static void bfqg_get(struct bfq_group *bfqg)
> 	bfqg->ref++;
> }
>=20
> -void bfqg_put(struct bfq_group *bfqg)
> +static void bfqg_put(struct bfq_group *bfqg)
> {
> 	bfqg->ref--;
>=20
> @@ -385,7 +385,7 @@ static struct bfq_group_data =
*blkcg_to_bfqgd(struct blkcg *blkcg)
> 	return cpd_to_bfqgd(blkcg_to_cpd(blkcg, &blkcg_policy_bfq));
> }
>=20
> -struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
> +static struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
> {
> 	struct bfq_group_data *bgd;
>=20
> @@ -395,7 +395,7 @@ struct blkcg_policy_data *bfq_cpd_alloc(gfp_t gfp)
> 	return &bgd->pd;
> }
>=20
> -void bfq_cpd_init(struct blkcg_policy_data *cpd)
> +static void bfq_cpd_init(struct blkcg_policy_data *cpd)
> {
> 	struct bfq_group_data *d =3D cpd_to_bfqgd(cpd);
>=20
> @@ -403,12 +403,12 @@ void bfq_cpd_init(struct blkcg_policy_data *cpd)
> 		CGROUP_WEIGHT_DFL : BFQ_WEIGHT_LEGACY_DFL;
> }
>=20
> -void bfq_cpd_free(struct blkcg_policy_data *cpd)
> +static void bfq_cpd_free(struct blkcg_policy_data *cpd)
> {
> 	kfree(cpd_to_bfqgd(cpd));
> }
>=20
> -struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, int node)
> +static struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, int node)
> {
> 	struct bfq_group *bfqg;
>=20
> @@ -426,7 +426,7 @@ struct blkg_policy_data *bfq_pd_alloc(gfp_t gfp, =
int node)
> 	return &bfqg->pd;
> }
>=20
> -void bfq_pd_init(struct blkg_policy_data *pd)
> +static void bfq_pd_init(struct blkg_policy_data *pd)
> {
> 	struct blkcg_gq *blkg =3D pd_to_blkg(pd);
> 	struct bfq_group *bfqg =3D blkg_to_bfqg(blkg);
> @@ -445,7 +445,7 @@ void bfq_pd_init(struct blkg_policy_data *pd)
> 	bfqg->rq_pos_tree =3D RB_ROOT;
> }
>=20
> -void bfq_pd_free(struct blkg_policy_data *pd)
> +static void bfq_pd_free(struct blkg_policy_data *pd)
> {
> 	struct bfq_group *bfqg =3D pd_to_bfqg(pd);
>=20
> @@ -453,7 +453,7 @@ void bfq_pd_free(struct blkg_policy_data *pd)
> 	bfqg_put(bfqg);
> }
>=20
> -void bfq_pd_reset_stats(struct blkg_policy_data *pd)
> +static void bfq_pd_reset_stats(struct blkg_policy_data *pd)
> {
> 	struct bfq_group *bfqg =3D pd_to_bfqg(pd);
>=20
> @@ -740,7 +740,7 @@ static void bfq_reparent_active_entities(struct =
bfq_data *bfqd,
>  * blkio already grabs the queue_lock for us, so no need to use
>  * RCU-based magic
>  */
> -void bfq_pd_offline(struct blkg_policy_data *pd)
> +static void bfq_pd_offline(struct blkg_policy_data *pd)
> {
> 	struct bfq_service_tree *st;
> 	struct bfq_group *bfqg =3D pd_to_bfqg(pd);
> --=20
> 2.14.1
>=20

[PATCH 3/5] bfq: Check kstrtoul() return value

[Bart Van Assche]

Make sysfs writes fail for invalid numbers instead of storing
uninitialized data copied from the stack. This patch removes
all uninitialized_var() occurrences from the BFQ source code.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 52 +++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 37 insertions(+), 15 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 8c11c2e827a5..cf92f16eb5f2 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4802,13 +4802,15 @@ static ssize_t bfq_var_show(unsigned int var, char *page)
 	return sprintf(page, "%u\n", var);
 }
 
-static void bfq_var_store(unsigned long *var, const char *page)
+static int bfq_var_store(unsigned long *var, const char *page)
 {
 	unsigned long new_val;
 	int ret = kstrtoul(page, 10, &new_val);
 
-	if (ret == 0)
-		*var = new_val;
+	if (ret)
+		return ret;
+	*var = new_val;
+	return 0;
 }
 
 #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				\
@@ -4849,8 +4851,12 @@ static ssize_t								\
 __FUNC(struct elevator_queue *e, const char *page, size_t count)	\
 {									\
 	struct bfq_data *bfqd = e->elevator_data;			\
-	unsigned long uninitialized_var(__data);			\
-	bfq_var_store(&__data, (page));					\
+	unsigned long __data;						\
+	int ret;							\
+									\
+	ret = bfq_var_store(&__data, (page));				\
+	if (ret)							\
+		return ret;						\
 	if (__data < (MIN))						\
 		__data = (MIN);						\
 	else if (__data > (MAX))					\
@@ -4877,8 +4883,12 @@ STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2);
 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)\
 {									\
 	struct bfq_data *bfqd = e->elevator_data;			\
-	unsigned long uninitialized_var(__data);			\
-	bfq_var_store(&__data, (page));					\
+	unsigned long __data;						\
+	int ret;							\
+									\
+	ret = bfq_var_store(&__data, (page));				\
+	if (ret)							\
+		return ret;						\
 	if (__data < (MIN))						\
 		__data = (MIN);						\
 	else if (__data > (MAX))					\
@@ -4894,9 +4904,12 @@ static ssize_t bfq_max_budget_store(struct elevator_queue *e,
 				    const char *page, size_t count)
 {
 	struct bfq_data *bfqd = e->elevator_data;
-	unsigned long uninitialized_var(__data);
+	unsigned long __data;
+	int ret;
 
-	bfq_var_store(&__data, (page));
+	ret = bfq_var_store(&__data, (page));
+	if (ret)
+		return ret;
 
 	if (__data == 0)
 		bfqd->bfq_max_budget = bfq_calc_max_budget(bfqd);
@@ -4919,9 +4932,12 @@ static ssize_t bfq_timeout_sync_store(struct elevator_queue *e,
 				      const char *page, size_t count)
 {
 	struct bfq_data *bfqd = e->elevator_data;
-	unsigned long uninitialized_var(__data);
+	unsigned long __data;
+	int ret;
 
-	bfq_var_store(&__data, (page));
+	ret = bfq_var_store(&__data, (page));
+	if (ret)
+		return ret;
 
 	if (__data < 1)
 		__data = 1;
@@ -4939,9 +4955,12 @@ static ssize_t bfq_strict_guarantees_store(struct elevator_queue *e,
 				     const char *page, size_t count)
 {
 	struct bfq_data *bfqd = e->elevator_data;
-	unsigned long uninitialized_var(__data);
+	unsigned long __data;
+	int ret;
 
-	bfq_var_store(&__data, (page));
+	ret = bfq_var_store(&__data, (page));
+	if (ret)
+		return ret;
 
 	if (__data > 1)
 		__data = 1;
@@ -4958,9 +4977,12 @@ static ssize_t bfq_low_latency_store(struct elevator_queue *e,
 				     const char *page, size_t count)
 {
 	struct bfq_data *bfqd = e->elevator_data;
-	unsigned long uninitialized_var(__data);
+	unsigned long __data;
+	int ret;
 
-	bfq_var_store(&__data, (page));
+	ret = bfq_var_store(&__data, (page));
+	if (ret)
+		return ret;
 
 	if (__data > 1)
 		__data = 1;
-- 
2.14.1

Re: [PATCH 3/5] bfq: Check kstrtoul() return value

[Paolo Valente]

> Il giorno 30 ago 2017, alle ore 20:42, Bart Van Assche =
<bart.vanassche@wdc.com> ha scritto:
>=20
> Make sysfs writes fail for invalid numbers instead of storing
> uninitialized data copied from the stack. This patch removes
> all uninitialized_var() occurrences from the BFQ source code.
>=20
> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
> Cc: Paolo Valente <paolo.valente@linaro.org>

Acked-by: Paolo Valente <paolo.valente@linaro.org>

> ---
> block/bfq-iosched.c | 52 =
+++++++++++++++++++++++++++++++++++++---------------
> 1 file changed, 37 insertions(+), 15 deletions(-)
>=20
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index 8c11c2e827a5..cf92f16eb5f2 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -4802,13 +4802,15 @@ static ssize_t bfq_var_show(unsigned int var, =
char *page)
> 	return sprintf(page, "%u\n", var);
> }
>=20
> -static void bfq_var_store(unsigned long *var, const char *page)
> +static int bfq_var_store(unsigned long *var, const char *page)
> {
> 	unsigned long new_val;
> 	int ret =3D kstrtoul(page, 10, &new_val);
>=20
> -	if (ret =3D=3D 0)
> -		*var =3D new_val;
> +	if (ret)
> +		return ret;
> +	*var =3D new_val;
> +	return 0;
> }
>=20
> #define SHOW_FUNCTION(__FUNC, __VAR, __CONV)				=
\
> @@ -4849,8 +4851,12 @@ static ssize_t						=
		\
> __FUNC(struct elevator_queue *e, const char *page, size_t count)	=
\
> {									=
\
> 	struct bfq_data *bfqd =3D e->elevator_data;			=
\
> -	unsigned long uninitialized_var(__data);			=
\
> -	bfq_var_store(&__data, (page));					=
\
> +	unsigned long __data;						=
\
> +	int ret;							=
\
> +									=
\
> +	ret =3D bfq_var_store(&__data, (page));				=
\
> +	if (ret)							=
\
> +		return ret;						=
\
> 	if (__data < (MIN))						=
\
> 		__data =3D (MIN);						=
\
> 	else if (__data > (MAX))					=
\
> @@ -4877,8 +4883,12 @@ STORE_FUNCTION(bfq_slice_idle_store, =
&bfqd->bfq_slice_idle, 0, INT_MAX, 2);
> static ssize_t __FUNC(struct elevator_queue *e, const char *page, =
size_t count)\
> {									=
\
> 	struct bfq_data *bfqd =3D e->elevator_data;			=
\
> -	unsigned long uninitialized_var(__data);			=
\
> -	bfq_var_store(&__data, (page));					=
\
> +	unsigned long __data;						=
\
> +	int ret;							=
\
> +									=
\
> +	ret =3D bfq_var_store(&__data, (page));				=
\
> +	if (ret)							=
\
> +		return ret;						=
\
> 	if (__data < (MIN))						=
\
> 		__data =3D (MIN);						=
\
> 	else if (__data > (MAX))					=
\
> @@ -4894,9 +4904,12 @@ static ssize_t bfq_max_budget_store(struct =
elevator_queue *e,
> 				    const char *page, size_t count)
> {
> 	struct bfq_data *bfqd =3D e->elevator_data;
> -	unsigned long uninitialized_var(__data);
> +	unsigned long __data;
> +	int ret;
>=20
> -	bfq_var_store(&__data, (page));
> +	ret =3D bfq_var_store(&__data, (page));
> +	if (ret)
> +		return ret;
>=20
> 	if (__data =3D=3D 0)
> 		bfqd->bfq_max_budget =3D bfq_calc_max_budget(bfqd);
> @@ -4919,9 +4932,12 @@ static ssize_t bfq_timeout_sync_store(struct =
elevator_queue *e,
> 				      const char *page, size_t count)
> {
> 	struct bfq_data *bfqd =3D e->elevator_data;
> -	unsigned long uninitialized_var(__data);
> +	unsigned long __data;
> +	int ret;
>=20
> -	bfq_var_store(&__data, (page));
> +	ret =3D bfq_var_store(&__data, (page));
> +	if (ret)
> +		return ret;
>=20
> 	if (__data < 1)
> 		__data =3D 1;
> @@ -4939,9 +4955,12 @@ static ssize_t =
bfq_strict_guarantees_store(struct elevator_queue *e,
> 				     const char *page, size_t count)
> {
> 	struct bfq_data *bfqd =3D e->elevator_data;
> -	unsigned long uninitialized_var(__data);
> +	unsigned long __data;
> +	int ret;
>=20
> -	bfq_var_store(&__data, (page));
> +	ret =3D bfq_var_store(&__data, (page));
> +	if (ret)
> +		return ret;
>=20
> 	if (__data > 1)
> 		__data =3D 1;
> @@ -4958,9 +4977,12 @@ static ssize_t bfq_low_latency_store(struct =
elevator_queue *e,
> 				     const char *page, size_t count)
> {
> 	struct bfq_data *bfqd =3D e->elevator_data;
> -	unsigned long uninitialized_var(__data);
> +	unsigned long __data;
> +	int ret;
>=20
> -	bfq_var_store(&__data, (page));
> +	ret =3D bfq_var_store(&__data, (page));
> +	if (ret)
> +		return ret;
>=20
> 	if (__data > 1)
> 		__data =3D 1;
> --=20
> 2.14.1
>=20

Re: [PATCH 3/5] bfq: Check kstrtoul() return value

[weiping zhang]

2017-09-02 1:14 GMT+08:00 Paolo Valente <paolo.valente@linaro.org>:
>
>> Il giorno 30 ago 2017, alle ore 20:42, Bart Van Assche <bart.vanassche@wdc.com> ha scritto:
>>
>> Make sysfs writes fail for invalid numbers instead of storing
>> uninitialized data copied from the stack. This patch removes
>> all uninitialized_var() occurrences from the BFQ source code.
>>
>> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
>> Cc: Paolo Valente <paolo.valente@linaro.org>
>
> Acked-by: Paolo Valente <paolo.valente@linaro.org>
>

Hi Bart,

how about using simple_strtoul  which was used in cfq/mq-iosched.c
*var = simple_strtoul(p, &p, 10);

if invalid string came from sysfs, this function just return 0,
and there are validations after every calling bfq_var_store.

Thanks

Re: [PATCH 3/5] bfq: Check kstrtoul() return value

[Bart Van Assche]

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Re: [PATCH 3/5] bfq: Check kstrtoul() return value

[weiping zhang]

> Sorry but I do not like this proposal because:
> * If invalid input is provided writing into a sysfs attribute should fail
>   instead of ignoring the invalid input silently.
> * simple_strtoul() is considered obsolete and must not be used in new code.
>   From include/linux/kernel.h:
>
> /* Obsolete, do not use.  Use kstrto<foo> instead */
>
> extern unsigned long simple_strtoul(const char *,char **,unsigned int);
> extern long simple_strtol(const char *,char **,unsigned int);
> extern unsigned long long simple_strtoull(const char *,char **,unsigned int);
> extern long long simple_strtoll(const char *,char **,unsigned int);
>

Hello Bart,

Agree with you, it seems more reasonable to give error message to user.

Thanks

[PATCH 4/5] bfq: Suppress compiler warnings about comparisons

[Bart Van Assche]

This patch avoids that the following warnings are reported when
building with W=1:

block/bfq-iosched.c: In function 'bfq_back_seek_max_store':
block/bfq-iosched.c:4860:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  if (__data < (MIN))      \
             ^
block/bfq-iosched.c:4876:1: note: in expansion of macro 'STORE_FUNCTION'
 STORE_FUNCTION(bfq_back_seek_max_store, &bfqd->bfq_back_max, 0, INT_MAX, 0);
 ^~~~~~~~~~~~~~
block/bfq-iosched.c: In function 'bfq_slice_idle_store':
block/bfq-iosched.c:4860:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  if (__data < (MIN))      \
             ^
block/bfq-iosched.c:4879:1: note: in expansion of macro 'STORE_FUNCTION'
 STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2);
 ^~~~~~~~~~~~~~
block/bfq-iosched.c: In function 'bfq_slice_idle_us_store':
block/bfq-iosched.c:4892:13: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
  if (__data < (MIN))      \
             ^
block/bfq-iosched.c:4899:1: note: in expansion of macro 'USEC_STORE_FUNCTION'
 USEC_STORE_FUNCTION(bfq_slice_idle_us_store, &bfqd->bfq_slice_idle, 0,
 ^~~~~~~~~~~~~~~~~~~

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index cf92f16eb5f2..d375b29ad085 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -4851,16 +4851,16 @@ static ssize_t								\
 __FUNC(struct elevator_queue *e, const char *page, size_t count)	\
 {									\
 	struct bfq_data *bfqd = e->elevator_data;			\
-	unsigned long __data;						\
+	unsigned long __data, __min = (MIN), __max = (MAX);		\
 	int ret;							\
 									\
 	ret = bfq_var_store(&__data, (page));				\
 	if (ret)							\
 		return ret;						\
-	if (__data < (MIN))						\
-		__data = (MIN);						\
-	else if (__data > (MAX))					\
-		__data = (MAX);						\
+	if (__data < __min)						\
+		__data = __min;						\
+	else if (__data > __max)					\
+		__data = __max;						\
 	if (__CONV == 1)						\
 		*(__PTR) = msecs_to_jiffies(__data);			\
 	else if (__CONV == 2)						\
@@ -4883,16 +4883,16 @@ STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2);
 static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)\
 {									\
 	struct bfq_data *bfqd = e->elevator_data;			\
-	unsigned long __data;						\
+	unsigned long __data, __min = (MIN), __max = (MAX);		\
 	int ret;							\
 									\
 	ret = bfq_var_store(&__data, (page));				\
 	if (ret)							\
 		return ret;						\
-	if (__data < (MIN))						\
-		__data = (MIN);						\
-	else if (__data > (MAX))					\
-		__data = (MAX);						\
+	if (__data < __min)						\
+		__data = __min;						\
+	else if (__data > __max)					\
+		__data = __max;						\
 	*(__PTR) = (u64)__data * NSEC_PER_USEC;				\
 	return count;							\
 }
-- 
2.14.1

Re: [PATCH 4/5] bfq: Suppress compiler warnings about comparisons

[Paolo Valente]

> Il giorno 30 ago 2017, alle ore 20:42, Bart Van Assche =
<bart.vanassche@wdc.com> ha scritto:
>=20
> This patch avoids that the following warnings are reported when
> building with W=3D1:
>=20
> block/bfq-iosched.c: In function 'bfq_back_seek_max_store':
> block/bfq-iosched.c:4860:13: warning: comparison of unsigned =
expression < 0 is always false [-Wtype-limits]
>  if (__data < (MIN))      \
>             ^
> block/bfq-iosched.c:4876:1: note: in expansion of macro =
'STORE_FUNCTION'
> STORE_FUNCTION(bfq_back_seek_max_store, &bfqd->bfq_back_max, 0, =
INT_MAX, 0);
> ^~~~~~~~~~~~~~
> block/bfq-iosched.c: In function 'bfq_slice_idle_store':
> block/bfq-iosched.c:4860:13: warning: comparison of unsigned =
expression < 0 is always false [-Wtype-limits]
>  if (__data < (MIN))      \
>             ^
> block/bfq-iosched.c:4879:1: note: in expansion of macro =
'STORE_FUNCTION'
> STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, =
INT_MAX, 2);
> ^~~~~~~~~~~~~~
> block/bfq-iosched.c: In function 'bfq_slice_idle_us_store':
> block/bfq-iosched.c:4892:13: warning: comparison of unsigned =
expression < 0 is always false [-Wtype-limits]
>  if (__data < (MIN))      \
>             ^
> block/bfq-iosched.c:4899:1: note: in expansion of macro =
'USEC_STORE_FUNCTION'
> USEC_STORE_FUNCTION(bfq_slice_idle_us_store, &bfqd->bfq_slice_idle, 0,
> ^~~~~~~~~~~~~~~~~~~
>=20
> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
> Cc: Paolo Valente <paolo.valente@linaro.org>

Acked-by: Paolo Valente <paolo.valente@linaro.org>

> ---
> block/bfq-iosched.c | 20 ++++++++++----------
> 1 file changed, 10 insertions(+), 10 deletions(-)
>=20
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index cf92f16eb5f2..d375b29ad085 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -4851,16 +4851,16 @@ static ssize_t					=
			\
> __FUNC(struct elevator_queue *e, const char *page, size_t count)	=
\
> {									=
\
> 	struct bfq_data *bfqd =3D e->elevator_data;			=
\
> -	unsigned long __data;						=
\
> +	unsigned long __data, __min =3D (MIN), __max =3D (MAX);		=
\
> 	int ret;							=
\
> 									=
\
> 	ret =3D bfq_var_store(&__data, (page));				=
\
> 	if (ret)							=
\
> 		return ret;						=
\
> -	if (__data < (MIN))						=
\
> -		__data =3D (MIN);						=
\
> -	else if (__data > (MAX))					=
\
> -		__data =3D (MAX);						=
\
> +	if (__data < __min)						=
\
> +		__data =3D __min;						=
\
> +	else if (__data > __max)					=
\
> +		__data =3D __max;						=
\
> 	if (__CONV =3D=3D 1)						=
\
> 		*(__PTR) =3D msecs_to_jiffies(__data);			=
\
> 	else if (__CONV =3D=3D 2)						=
\
> @@ -4883,16 +4883,16 @@ STORE_FUNCTION(bfq_slice_idle_store, =
&bfqd->bfq_slice_idle, 0, INT_MAX, 2);
> static ssize_t __FUNC(struct elevator_queue *e, const char *page, =
size_t count)\
> {									=
\
> 	struct bfq_data *bfqd =3D e->elevator_data;			=
\
> -	unsigned long __data;						=
\
> +	unsigned long __data, __min =3D (MIN), __max =3D (MAX);		=
\
> 	int ret;							=
\
> 									=
\
> 	ret =3D bfq_var_store(&__data, (page));				=
\
> 	if (ret)							=
\
> 		return ret;						=
\
> -	if (__data < (MIN))						=
\
> -		__data =3D (MIN);						=
\
> -	else if (__data > (MAX))					=
\
> -		__data =3D (MAX);						=
\
> +	if (__data < __min)						=
\
> +		__data =3D __min;						=
\
> +	else if (__data > __max)					=
\
> +		__data =3D __max;						=
\
> 	*(__PTR) =3D (u64)__data * NSEC_PER_USEC;				=
\
> 	return count;							=
\
> }
> --=20
> 2.14.1
>=20

[PATCH 5/5] bfq: Use icq_to_bic() consistently

[Bart Van Assche]

Some code uses icq_to_bic() to convert an io_cq pointer to a
bfq_io_cq pointer while other code uses a direct cast. Convert
the code that uses a direct cast such that it uses icq_to_bic().

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Paolo Valente <paolo.valente@linaro.org>
---
 block/bfq-iosched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index d375b29ad085..7d1b85e393b2 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -239,7 +239,7 @@ static int T_slow[2];
 static int T_fast[2];
 static int device_speed_thresh[2];
 
-#define RQ_BIC(rq)		((struct bfq_io_cq *) (rq)->elv.priv[0])
+#define RQ_BIC(rq)		icq_to_bic((rq)->elv.priv[0])
 #define RQ_BFQQ(rq)		((rq)->elv.priv[1])
 
 struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync)
-- 
2.14.1

Re: [PATCH 5/5] bfq: Use icq_to_bic() consistently

[Paolo Valente]

> Il giorno 30 ago 2017, alle ore 20:42, Bart Van Assche =
<bart.vanassche@wdc.com> ha scritto:
>=20
> Some code uses icq_to_bic() to convert an io_cq pointer to a
> bfq_io_cq pointer while other code uses a direct cast. Convert
> the code that uses a direct cast such that it uses icq_to_bic().
>=20
> Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
> Cc: Paolo Valente <paolo.valente@linaro.org>

Acked-by: Paolo Valente <paolo.valente@linaro.org>

> ---
> block/bfq-iosched.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>=20
> diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
> index d375b29ad085..7d1b85e393b2 100644
> --- a/block/bfq-iosched.c
> +++ b/block/bfq-iosched.c
> @@ -239,7 +239,7 @@ static int T_slow[2];
> static int T_fast[2];
> static int device_speed_thresh[2];
>=20
> -#define RQ_BIC(rq)		((struct bfq_io_cq *) (rq)->elv.priv[0])
> +#define RQ_BIC(rq)		icq_to_bic((rq)->elv.priv[0])
> #define RQ_BFQQ(rq)		((rq)->elv.priv[1])
>=20
> struct bfq_queue *bic_to_bfqq(struct bfq_io_cq *bic, bool is_sync)
> --=20
> 2.14.1
>=20