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

Muneendra
2021-04-28T05:35:37Z

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