diff mbox series

[RFC,v2,02/18] blkcg: Added a app identifier support for blkcg

Message ID 1603093393-12875-3-git-send-email-muneendra.kumar@broadcom.com (mailing list archive)
State Superseded
Headers show
Series blkcg:Support to track FC storage blk io traffic | expand

Commit Message

Muneendra Kumar M Oct. 19, 2020, 7:42 a.m. UTC
This Patch added a unique application identifier i.e
app_id  knob to  blkcg which allows identification of traffic
sources at an individual cgroup based Applications
(ex:virtual machine (VM))level in both host and
fabric infrastructure.

Provided the interface blkcg_get_app_identifier to
grab the app identifier associated with a bio.

Provided the interface blkcg_set_app_identifier to
set the app identifier in a blkcgrp associated with cgroup id

Signed-off-by: Muneendra <muneendra.kumar@broadcom.com>

---
v2:
renamed app_identifier to app_id
removed the  sysfs interface blkio.app_identifie under
/sys/fs/cgroup/blkio
Added a new interface blkcg_set_app_identifier
---
 block/blk-cgroup.c         | 31 +++++++++++++++++++++++++++++++
 include/linux/blk-cgroup.h | 22 ++++++++++++++++++++++
 2 files changed, 53 insertions(+)

Comments

Tejun Heo Oct. 19, 2020, 2:46 p.m. UTC | #1
On Mon, Oct 19, 2020 at 01:12:57PM +0530, Muneendra wrote:
> This Patch added a unique application identifier i.e
> app_id  knob to  blkcg which allows identification of traffic
> sources at an individual cgroup based Applications
> (ex:virtual machine (VM))level in both host and
> fabric infrastructure.
> 
> Provided the interface blkcg_get_app_identifier to
> grab the app identifier associated with a bio.
> 
> Provided the interface blkcg_set_app_identifier to
> set the app identifier in a blkcgrp associated with cgroup id
> 
> Signed-off-by: Muneendra <muneendra.kumar@broadcom.com>
> 
> ---
> v2:
> renamed app_identifier to app_id
> removed the  sysfs interface blkio.app_identifie under
> /sys/fs/cgroup/blkio
> Added a new interface blkcg_set_app_identifier
> ---
>  block/blk-cgroup.c         | 31 +++++++++++++++++++++++++++++++
>  include/linux/blk-cgroup.h | 22 ++++++++++++++++++++++
>  2 files changed, 53 insertions(+)
> 
> diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
> index 619a79b51068..672971521010 100644
> --- a/block/blk-cgroup.c
> +++ b/block/blk-cgroup.c
> @@ -546,6 +546,37 @@ static struct blkcg_gq *blkg_lookup_check(struct blkcg *blkcg,
>  	return __blkg_lookup(blkcg, q, true /* update_hint */);
>  }
>  
> +/*
> + * Sets the app_identifier field associted to blkcg
> + * @buf: application identifier
> + * @id: cgrp id
> + * @len: size of appid
> + */
> +int blkcg_set_app_identifier(char *buf, u64 id, size_t len)

Can you please use a name which is more specific?

> +{
> +	struct cgroup *cgrp = NULL;
> +	struct cgroup_subsys_state *css = NULL;
> +	struct blkcg *blkcg = NULL;
> +
> +	cgrp = cgroup_get_from_kernfs_id(id);
> +	if (!cgrp)
> +		return -ENOENT;
> +
> +	css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
> +	if (!css)
> +		return -ENOENT;
> +
> +	blkcg = css_to_blkcg(css);
> +	if (!blkcg)
> +		return -ENOENT;
> +
> +	if (len > APPID_LEN)
> +		return -EINVAL;
> +	strlcpy(blkcg->app_id, buf, len);

Shouldn't the cgrp and css be put before exit?

> +	return 0;
> +}
> +EXPORT_SYMBOL(blkcg_set_app_identifier);
> +
>  /**
>   * blkg_conf_prep - parse and prepare for per-blkg config update
>   * @inputp: input string pointer
> diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
> index c8fc9792ac77..5bd3f9f397ac 100644
> --- a/include/linux/blk-cgroup.h
> +++ b/include/linux/blk-cgroup.h
> @@ -30,6 +30,8 @@
>  
>  /* Max limits for throttle policy */
>  #define THROTL_IOPS_MAX		UINT_MAX
> +#define APPID_LEN              128
> +
>  
>  #ifdef CONFIG_BLK_CGROUP
>  
> @@ -55,6 +57,8 @@ struct blkcg {
>  	struct blkcg_policy_data	*cpd[BLKCG_MAX_POLS];
>  
>  	struct list_head		all_blkcgs_node;
> +	char                            app_id[APPID_LEN];

Please use a more specific name and gate them behind a CONFIG.

Thanks.
Muneendra Kumar M Oct. 19, 2020, 3:13 p.m. UTC | #2
Hi Tejun,
Thanks for the input.
>> +     cgrp = cgroup_get_from_kernfs_id(id);
>> +     if (!cgrp)
>> +             return -ENOENT;
>> +
> >+     css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
>> +     if (!css)
>> +             return -ENOENT;
>> +
>> +     blkcg = css_to_blkcg(css);
>> +     if (!blkcg)
>> +             return -ENOENT;
> >+		return -EINVAL;
> >+	strlcpy(blkcg->app_id, buf, len);

>Shouldn't the cgrp and css be put before exit?
[Muneendra]Correct me if iam wrong.
You mean to add cgroup_put(cgrp) and css_put(css) before exit ?

> +
>
>  	struct list_head		all_blkcgs_node;
> +	char                            app_id[APPID_LEN];

>Please use a more specific name and gate them behind a CONFIG.
[Muneendra] Agree will do the changes.

Regards,
Muneendra.

Thanks.

--
tejun
Tejun Heo Oct. 19, 2020, 3:19 p.m. UTC | #3
On Mon, Oct 19, 2020 at 08:43:05PM +0530, Muneendra Kumar M wrote:
> Hi Tejun,
> Thanks for the input.
> >> +     cgrp = cgroup_get_from_kernfs_id(id);
> >> +     if (!cgrp)
> >> +             return -ENOENT;
> >> +
> > >+     css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
> >> +     if (!css)
> >> +             return -ENOENT;
> >> +
> >> +     blkcg = css_to_blkcg(css);
> >> +     if (!blkcg)
> >> +             return -ENOENT;
> > >+		return -EINVAL;
> > >+	strlcpy(blkcg->app_id, buf, len);
> 
> >Shouldn't the cgrp and css be put before exit?
> [Muneendra]Correct me if iam wrong.
> You mean to add cgroup_put(cgrp) and css_put(css) before exit ?

Yeah, as-is it'd leak references each time the function is called.

Thanks.
Muneendra Kumar M Oct. 19, 2020, 3:20 p.m. UTC | #4
Hi Tejun,
Thanks for the input.
I will add it my next version.

Regards,
Muneendra.

-----Original Message-----
From: Tejun Heo [mailto:htejun@gmail.com] On Behalf Of Tejun Heo
Sent: Monday, October 19, 2020 8:50 PM
To: Muneendra Kumar M <muneendra.kumar@broadcom.com>
Cc: linux-block@vger.kernel.org; linux-scsi@vger.kernel.org;
linux-nvme@lists.infradead.org; jsmart2021@gmail.com; emilne@redhat.com;
mkumar@redhat.com; pbonzini@redhat.com
Subject: Re: [RFC v2 02/18] blkcg: Added a app identifier support for
blkcg

On Mon, Oct 19, 2020 at 08:43:05PM +0530, Muneendra Kumar M wrote:
> Hi Tejun,
> Thanks for the input.
> >> +     cgrp = cgroup_get_from_kernfs_id(id);
> >> +     if (!cgrp)
> >> +             return -ENOENT;
> >> +
> > >+     css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
> >> +     if (!css)
> >> +             return -ENOENT;
> >> +
> >> +     blkcg = css_to_blkcg(css);
> >> +     if (!blkcg)
> >> +             return -ENOENT;
> > >+		return -EINVAL;
> > >+	strlcpy(blkcg->app_id, buf, len);
>
> >Shouldn't the cgrp and css be put before exit?
> [Muneendra]Correct me if iam wrong.
> You mean to add cgroup_put(cgrp) and css_put(css) before exit ?

Yeah, as-is it'd leak references each time the function is called.

Thanks.
diff mbox series

Patch

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 619a79b51068..672971521010 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -546,6 +546,37 @@  static struct blkcg_gq *blkg_lookup_check(struct blkcg *blkcg,
 	return __blkg_lookup(blkcg, q, true /* update_hint */);
 }
 
+/*
+ * Sets the app_identifier field associted to blkcg
+ * @buf: application identifier
+ * @id: cgrp id
+ * @len: size of appid
+ */
+int blkcg_set_app_identifier(char *buf, u64 id, size_t len)
+{
+	struct cgroup *cgrp = NULL;
+	struct cgroup_subsys_state *css = NULL;
+	struct blkcg *blkcg = NULL;
+
+	cgrp = cgroup_get_from_kernfs_id(id);
+	if (!cgrp)
+		return -ENOENT;
+
+	css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
+	if (!css)
+		return -ENOENT;
+
+	blkcg = css_to_blkcg(css);
+	if (!blkcg)
+		return -ENOENT;
+
+	if (len > APPID_LEN)
+		return -EINVAL;
+	strlcpy(blkcg->app_id, buf, len);
+	return 0;
+}
+EXPORT_SYMBOL(blkcg_set_app_identifier);
+
 /**
  * blkg_conf_prep - parse and prepare for per-blkg config update
  * @inputp: input string pointer
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index c8fc9792ac77..5bd3f9f397ac 100644
--- a/include/linux/blk-cgroup.h
+++ b/include/linux/blk-cgroup.h
@@ -30,6 +30,8 @@ 
 
 /* Max limits for throttle policy */
 #define THROTL_IOPS_MAX		UINT_MAX
+#define APPID_LEN              128
+
 
 #ifdef CONFIG_BLK_CGROUP
 
@@ -55,6 +57,8 @@  struct blkcg {
 	struct blkcg_policy_data	*cpd[BLKCG_MAX_POLS];
 
 	struct list_head		all_blkcgs_node;
+	char                            app_id[APPID_LEN];
+
 #ifdef CONFIG_CGROUP_WRITEBACK
 	struct list_head		cgwb_list;
 #endif
@@ -206,6 +210,24 @@  struct gendisk *blkcg_conf_get_disk(char **inputp);
 int blkg_conf_prep(struct blkcg *blkcg, const struct blkcg_policy *pol,
 		   char *input, struct blkg_conf_ctx *ctx);
 void blkg_conf_finish(struct blkg_conf_ctx *ctx);
+int blkcg_set_app_identifier(char *buf, u64 id, size_t len);
+
+/**
+ * blkcg_get_app_identifier - grab the app identifier associated with a bio
+ * @bio: target bio
+ *
+ * This returns the app identifier associated with a bio,
+ * %NULL if not associated.
+ * Callers are expected to either handle %NULL or know association has been
+ * done prior to calling this.
+ */
+static inline char *blkcg_get_app_identifier(struct bio *bio)
+{
+	if (bio && bio->bi_blkg &&
+			strlen(bio->bi_blkg->blkcg->app_id))
+		return bio->bi_blkg->blkcg->app_id;
+	return NULL;
+}
 
 /**
  * blkcg_css - find the current css