Re: [PATCH v10 02/13] blkcg: Added a app identifier support for blkcg

Himanshu Madhani
2021-04-30T19:37:38Z

> On Apr 27, 2021, at 5:34 PM, Muneendra <muneendra.kumar@broadcom.com> wrote:
>
> This Patch added a unique application identifier i.e
> fc_app_id member in blkcg which allows identification of traffic
> sources at an individual cgroup based Applications
> (ex:virtual machine (VM))level in both host and
> fabric infrastructure.
>
> Added a new function blkcg_get_fc_appid to
> grab the app identifier associated with a bio.
>
> Added a new function blkcg_set_fc_appid to
> set the app identifier in a blkcgrp associated with cgroup id
>
> Added a new config BLK_CGROUP_FC_APPID and moved the changes
> under this config
>
> Merged the patch 16 of previous version in which we
> added a new config FC_APPID to select BLK_CGROUP_FC_APPID which Enable
> support to track FC io Traffic.
>
> Reviewed-by: Hannes Reinecke <hare@suse.de>
> Signed-off-by: Muneendra <muneendra.kumar@broadcom.com>
>
> ---
> v10:
> No change
>
> v9:
> Merged patch16 of previosu version to this patch
> where we are using Kconfig settings
>
> v8:
> No change
>
> v7:
> Modified the Kconfig file
>
> v6:
> Modified the Kconfig file as per standard specified
> in Documentation/process/coding-style.rst
>
> v5:
> Renamed the arguments appropriatley
> Renamed APPID_LEN to FC_APPID_LEN
> Moved the input validation at the begining of the function
> Modified the comments
>
> v4:
> No change
>
> v3:
> Renamed the functions and app_id to more specific
>
> Addressed the reference leaks in blkcg_set_app_identifier
>
> Added a new config BLK_CGROUP_FC_APPID and moved the changes
> under this config
>
> Added blkcg_get_fc_appid,blkcg_set_fc_appid as inline functions
>
> v2:
> renamed app_identifier to app_id
> removed the sysfs interface blkio.app_identifie under
> ---
> block/Kconfig | 9 ++++++
> drivers/scsi/Kconfig | 13 +++++++++
> include/linux/blk-cgroup.h | 56 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 78 insertions(+)
>
> diff --git a/block/Kconfig b/block/Kconfig
> index a2297edfdde8..03886d105301 100644
> --- a/block/Kconfig
> +++ b/block/Kconfig
> @@ -144,6 +144,15 @@ config BLK_CGROUP_IOLATENCY
>
> Note, this is an experimental interface and could be changed someday.
>
> +config BLK_CGROUP_FC_APPID
> + bool "Enable support to track FC I/O Traffic across cgroup applications"
> + depends on BLK_CGROUP=y
> + help
> + Enabling this option enables the support to track FC I/O traffic across
> + cgroup applications. It enables the Fabric and the storage targets to
> + identify, monitor, and handle FC traffic based on VM tags by inserting
> + application specific identification into the FC frame.
> +
> config BLK_CGROUP_IOCOST
> bool "Enable support for cost model based cgroup IO controller"
> depends on BLK_CGROUP=y
> diff --git a/drivers/scsi/Kconfig b/drivers/scsi/Kconfig
> index 06b87c7f6bab..20aa1536a3ba 100644
> --- a/drivers/scsi/Kconfig
> +++ b/drivers/scsi/Kconfig
> @@ -235,6 +235,19 @@ config SCSI_FC_ATTRS
> each attached FiberChannel device to sysfs, say Y.
> Otherwise, say N.
>
> +config FC_APPID
> + bool "Enable support to track FC I/O Traffic"
> + depends on BLOCK && BLK_CGROUP
> + depends on SCSI
> + select BLK_CGROUP_FC_APPID
> + default y
> + help
> + If you say Y here, it enables the support to track
> + FC I/O traffic over fabric. It enables the Fabric and the
> + storage targets to identify, monitor, and handle FC traffic
> + based on VM tags by inserting application specific
> + identification into the FC frame.
> +
> config SCSI_ISCSI_ATTRS
> tristate "iSCSI Transport Attributes"
> depends on SCSI && NET
> diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
> index b9f3c246c3c9..9204f8f8a932 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 FC_APPID_LEN 129
> +
>
> #ifdef CONFIG_BLK_CGROUP
>
> @@ -55,6 +57,9 @@ struct blkcg {
> struct blkcg_policy_data *cpd[BLKCG_MAX_POLS];
>
> struct list_head all_blkcgs_node;
> +#ifdef CONFIG_BLK_CGROUP_FC_APPID
> + char fc_app_id[FC_APPID_LEN];
> +#endif
> #ifdef CONFIG_CGROUP_WRITEBACK
> struct list_head cgwb_list;
> #endif
> @@ -660,4 +665,55 @@ static inline void blk_cgroup_bio_start(struct bio *bio) { }
>
> #endif /* CONFIG_BLOCK */
> #endif /* CONFIG_BLK_CGROUP */
> +
> +#ifdef CONFIG_BLK_CGROUP_FC_APPID
> +/*
> + * Sets the fc_app_id field associted to blkcg
> + * @app_id: application identifier
> + * @cgrp_id: cgroup id
> + * @app_id_len: size of application identifier
> + */
> +static inline int blkcg_set_fc_appid(char *app_id, u64 cgrp_id, size_t app_id_len)
> +{
> + struct cgroup *cgrp;
> + struct cgroup_subsys_state *css;
> + struct blkcg *blkcg;
> + int ret = 0;
> +
> + if (app_id_len > FC_APPID_LEN)
> + return -EINVAL;
> +
> + cgrp = cgroup_get_from_id(cgrp_id);
> + if (!cgrp)
> + return -ENOENT;
> + css = cgroup_get_e_css(cgrp, &io_cgrp_subsys);
> + if (!css) {
> + ret = -ENOENT;
> + goto out_cgrp_put;
> + }
> + blkcg = css_to_blkcg(css);
> + strlcpy(blkcg->fc_app_id, app_id, app_id_len);
> + css_put(css);
> +out_cgrp_put:
> + cgroup_put(cgrp);
> + return ret;
> +}
> +
> +/**
> + * blkcg_get_fc_appid - get the fc app identifier associated with a bio
> + * @bio: target bio
> + *
> + * On success it returns the fc_app_id on failure it returns NULL
> + */
> +static inline char *blkcg_get_fc_appid(struct bio *bio)
> +{
> + if (bio && bio->bi_blkg &&
> + (bio->bi_blkg->blkcg->fc_app_id[0] != '\0'))
> + return bio->bi_blkg->blkcg->fc_app_id;
> + return NULL;
> +}
> +#else
> +static inline int blkcg_set_fc_appid(char *buf, u64 id, size_t len) { return -EINVAL; }
> +static inline char *blkcg_get_fc_appid(struct bio *bio) { return NULL; }
> +#endif /*CONFIG_BLK_CGROUP_FC_APPID*/
> #endif /* _BLK_CGROUP_H */
> --
> 2.26.2
>

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

--
Himanshu Madhani Oracle Linux Engineering