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-rw-r--r--include/linux/blk-cgroup.h67
1 files changed, 65 insertions, 2 deletions
diff --git a/include/linux/blk-cgroup.h b/include/linux/blk-cgroup.h
index b9f3c246c3c9..b4de2010fba5 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
@@ -147,8 +152,8 @@ typedef void (blkcg_pol_online_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_offline_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_free_pd_fn)(struct blkg_policy_data *pd);
typedef void (blkcg_pol_reset_pd_stats_fn)(struct blkg_policy_data *pd);
-typedef size_t (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd, char *buf,
- size_t size);
+typedef bool (blkcg_pol_stat_pd_fn)(struct blkg_policy_data *pd,
+ struct seq_file *s);
struct blkcg_policy {
int plid;
@@ -660,4 +665,62 @@ 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);
+ /*
+ * There is a slight race condition on setting the appid.
+ * Worst case an I/O may not find the right id.
+ * This is no different from the I/O we let pass while obtaining
+ * the vmid from the fabric.
+ * Adding the overhead of a lock is not necessary.
+ */
+ 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 return the fc_app_id, on failure return 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 */