On 11/9/20 5:23 AM, 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_fc_appid to
grab the app identifier associated with a bio.
Provided the interface 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
Signed-off-by: Muneendra <muneendra.kumar@xxxxxxxxxxxx>
---
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 ++++++
include/linux/blk-cgroup.h | 65 ++++++++++++++++++++++++++++++++++++++
2 files changed, 74 insertions(+)
diff --git a/block/Kconfig b/block/Kconfig
index bbad5e8bbffe..ed22df654ce5 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 io Traffic across cgroup applications"
+ depends on BLK_CGROUP=y
+ help
+ Enabling this option enables the support to track FC io 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.
+
Please replace 'io' with 'I/O'.
config BLK_CGROUP_IOCOST
bool "Enable support for cost model based cgroup IO controller"
depends on BLK_CGROUP=y
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index c8fc9792ac77..00ea1cfa3420 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 +57,9 @@ 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[APPID_LEN];
+#endif
#ifdef CONFIG_CGROUP_WRITEBACK
struct list_head cgwb_list;
#endif
If this is an UUID, wouldn't it be better to use 'uuid_t' here?
@@ -660,4 +665,64 @@ 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
+ * @buf: application identifier
+ * @id: cgrp id
+ * @len: size of appid
+ */
+static inline int blkcg_set_fc_appid(char *buf, u64 id, size_t len)
+{
+ struct cgroup *cgrp = NULL;
+ struct cgroup_subsys_state *css = NULL;
+ struct blkcg *blkcg = NULL;
+ int ret = 0;
+
+ cgrp = cgroup_get_from_kernfs_id(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);
+ if (!blkcg) {
+ ret = -ENOENT;
+ goto out_put;
+ }
+ if (len > APPID_LEN) {
+ ret = -EINVAL;
+ goto out_put;
+ }
+ strlcpy(blkcg->fc_app_id, buf, len);
String or UUID?
And will it be NULL-terminated?
Wouldn't it be better to use 'memcpy' here?
And it is NULL terminated: what happens if the user sets a 128-byte
string? IE shouldn't the app_id be 129 bytes long if it's assumed to be
NULL-terminated?
+out_put:
+ css_put(css);
+out_cgrp_put:
+ cgroup_put(cgrp);
+ return ret;
+}
+
+/**
+ * blkcg_get_fc_appid - 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_fc_appid(struct bio *bio)
+{
+ if (bio && bio->bi_blkg &&
+ strlen(bio->bi_blkg->blkcg->fc_app_id))
+ return bio->bi_blkg->blkcg->fc_app_id;
+ return NULL;
+}
Same question as above: Is the string NULL terminated or not?
And if not, how do you specify the length of the 'app_id' variable?
+#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 */
Cheers,
Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Felix Imendörffer
