blkcg: drop BLKCG_STAT_{PRIV|POL|OFF} macros

Now that all stat handling code lives in policy implementations,
there's no need to encode policy ID in cft->private.

* Export blkcg_prfill_[rw]stat() from blkcg, remove
  blkcg_print_[rw]stat(), and implement cfqg_print_[rw]stat() which
  use hard-code BLKIO_POLICY_PROP.

* Use cft->private for offset of the target field directly and drop
  BLKCG_STAT_{PRIV|POL|OFF}().

Signed-off-by: Tejun Heo <tj@kernel.org>

4 files changed, 72 insertions, 84 deletions

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 7de19d7954c7..9449c383b7ba 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -430,43 +430,35 @@ u64 __blkg_prfill_rwstat(struct seq_file *sf, void *pdata,
         return v;
 }
 
-static u64 blkg_prfill_stat(struct seq_file *sf, void *pdata, int off)
+/**
+ * blkg_prfill_stat - prfill callback for blkg_stat
+ * @sf: seq_file to print to
+ * @pdata: policy private data of interest
+ * @off: offset to the blkg_stat in @pdata
+ *
+ * prfill callback for printing a blkg_stat.
+ */
+u64 blkg_prfill_stat(struct seq_file *sf, void *pdata, int off)
 {
         return __blkg_prfill_u64(sf, pdata, blkg_stat_read(pdata + off));
 }
+EXPORT_SYMBOL_GPL(blkg_prfill_stat);
 
-static u64 blkg_prfill_rwstat(struct seq_file *sf, void *pdata, int off)
+/**
+ * blkg_prfill_rwstat - prfill callback for blkg_rwstat
+ * @sf: seq_file to print to
+ * @pdata: policy private data of interest
+ * @off: offset to the blkg_rwstat in @pdata
+ *
+ * prfill callback for printing a blkg_rwstat.
+ */
+u64 blkg_prfill_rwstat(struct seq_file *sf, void *pdata, int off)
 {
         struct blkg_rwstat rwstat = blkg_rwstat_read(pdata + off);
 
         return __blkg_prfill_rwstat(sf, pdata, &rwstat);
 }
-
-/* print blkg_stat specified by BLKCG_STAT_PRIV() */
-int blkcg_print_stat(struct cgroup *cgrp, struct cftype *cft,
-                     struct seq_file *sf)
-{
-        struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
-
-        blkcg_print_blkgs(sf, blkcg, blkg_prfill_stat,
-                          BLKCG_STAT_POL(cft->private),
-                          BLKCG_STAT_OFF(cft->private), false);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(blkcg_print_stat);
-
-/* print blkg_rwstat specified by BLKCG_STAT_PRIV() */
-int blkcg_print_rwstat(struct cgroup *cgrp, struct cftype *cft,
-                       struct seq_file *sf)
-{
-        struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
-
-        blkcg_print_blkgs(sf, blkcg, blkg_prfill_rwstat,
-                          BLKCG_STAT_POL(cft->private),
-                          BLKCG_STAT_OFF(cft->private), true);
-        return 0;
-}
-EXPORT_SYMBOL_GPL(blkcg_print_rwstat);
+EXPORT_SYMBOL_GPL(blkg_prfill_rwstat);
 
 /**
  * blkg_conf_prep - parse and prepare for per-blkg config update
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index c930895bfac9..ca0ff7c0ffb6 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -34,11 +34,6 @@ enum blkio_policy_id {
 #define CFQ_WEIGHT_MAX          1000
 #define CFQ_WEIGHT_DEFAULT      500
 
-/* cft->private [un]packing for stat printing */
-#define BLKCG_STAT_PRIV(pol, off)       (((unsigned)(pol) << 16) | (off))
-#define BLKCG_STAT_POL(prv)             ((unsigned)(prv) >> 16)
-#define BLKCG_STAT_OFF(prv)             ((unsigned)(prv) & 0xffff)
-
 enum blkg_rwstat_type {
         BLKG_RWSTAT_READ,
         BLKG_RWSTAT_WRITE,
@@ -131,10 +126,8 @@ void blkcg_print_blkgs(struct seq_file *sf, struct blkio_cgroup *blkcg,
 u64 __blkg_prfill_u64(struct seq_file *sf, void *pdata, u64 v);
 u64 __blkg_prfill_rwstat(struct seq_file *sf, void *pdata,
                          const struct blkg_rwstat *rwstat);
-int blkcg_print_stat(struct cgroup *cgrp, struct cftype *cft,
-                     struct seq_file *sf);
-int blkcg_print_rwstat(struct cgroup *cgrp, struct cftype *cft,
-                       struct seq_file *sf);
+u64 blkg_prfill_stat(struct seq_file *sf, void *pdata, int off);
+u64 blkg_prfill_rwstat(struct seq_file *sf, void *pdata, int off);
 
 struct blkg_conf_ctx {
         struct gendisk          *disk;
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index bd6dbfe1e4e9..60240142f5ae 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -941,15 +941,13 @@ static u64 tg_prfill_cpu_rwstat(struct seq_file *sf, void *pdata, int off)
         return __blkg_prfill_rwstat(sf, pdata, &rwstat);
 }
 
-/* print per-cpu blkg_rwstat specified by BLKCG_STAT_PRIV() */
 static int tg_print_cpu_rwstat(struct cgroup *cgrp, struct cftype *cft,
                                struct seq_file *sf)
 {
         struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
 
-        blkcg_print_blkgs(sf, blkcg, tg_prfill_cpu_rwstat,
-                          BLKCG_STAT_POL(cft->private),
-                          BLKCG_STAT_OFF(cft->private), true);
+        blkcg_print_blkgs(sf, blkcg, tg_prfill_cpu_rwstat, BLKIO_POLICY_THROTL,
+                          cft->private, true);
         return 0;
 }
 
@@ -1067,14 +1065,12 @@ static struct cftype throtl_files[] = {
         },
         {
                 .name = "throttle.io_service_bytes",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_THROTL,
-                                offsetof(struct tg_stats_cpu, service_bytes)),
+                .private = offsetof(struct tg_stats_cpu, service_bytes),
                 .read_seq_string = tg_print_cpu_rwstat,
         },
         {
                 .name = "throttle.io_serviced",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_THROTL,
-                                offsetof(struct tg_stats_cpu, serviced)),
+                .private = offsetof(struct tg_stats_cpu, serviced),
                 .read_seq_string = tg_print_cpu_rwstat,
         },
         { }     /* terminate */
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index fd505f721f61..cff8b5ba6208 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -1441,6 +1441,26 @@ static int cfq_set_weight(struct cgroup *cgrp, struct cftype *cft, u64 val)
         return 0;
 }
 
+static int cfqg_print_stat(struct cgroup *cgrp, struct cftype *cft,
+                           struct seq_file *sf)
+{
+        struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+        blkcg_print_blkgs(sf, blkcg, blkg_prfill_stat, BLKIO_POLICY_PROP,
+                          cft->private, false);
+        return 0;
+}
+
+static int cfqg_print_rwstat(struct cgroup *cgrp, struct cftype *cft,
+                             struct seq_file *sf)
+{
+        struct blkio_cgroup *blkcg = cgroup_to_blkio_cgroup(cgrp);
+
+        blkcg_print_blkgs(sf, blkcg, blkg_prfill_rwstat, BLKIO_POLICY_PROP,
+                          cft->private, true);
+        return 0;
+}
+
 #ifdef CONFIG_DEBUG_BLK_CGROUP
 static u64 cfqg_prfill_avg_queue_size(struct seq_file *sf, void *pdata, int off)
 {
@@ -1482,51 +1502,43 @@ static struct cftype cfq_blkcg_files[] = {
         },
         {
                 .name = "time",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.time)),
-                .read_seq_string = blkcg_print_stat,
+                .private = offsetof(struct cfq_group, stats.time),
+                .read_seq_string = cfqg_print_stat,
         },
         {
                 .name = "sectors",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.sectors)),
-                .read_seq_string = blkcg_print_stat,
+                .private = offsetof(struct cfq_group, stats.sectors),
+                .read_seq_string = cfqg_print_stat,
         },
         {
                 .name = "io_service_bytes",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.service_bytes)),
-                .read_seq_string = blkcg_print_rwstat,
+                .private = offsetof(struct cfq_group, stats.service_bytes),
+                .read_seq_string = cfqg_print_rwstat,
         },
         {
                 .name = "io_serviced",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.serviced)),
-                .read_seq_string = blkcg_print_rwstat,
+                .private = offsetof(struct cfq_group, stats.serviced),
+                .read_seq_string = cfqg_print_rwstat,
         },
         {
                 .name = "io_service_time",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.service_time)),
-                .read_seq_string = blkcg_print_rwstat,
+                .private = offsetof(struct cfq_group, stats.service_time),
+                .read_seq_string = cfqg_print_rwstat,
         },
         {
                 .name = "io_wait_time",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.wait_time)),
-                .read_seq_string = blkcg_print_rwstat,
+                .private = offsetof(struct cfq_group, stats.wait_time),
+                .read_seq_string = cfqg_print_rwstat,
         },
         {
                 .name = "io_merged",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.merged)),
-                .read_seq_string = blkcg_print_rwstat,
+                .private = offsetof(struct cfq_group, stats.merged),
+                .read_seq_string = cfqg_print_rwstat,
         },
         {
                 .name = "io_queued",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.queued)),
-                .read_seq_string = blkcg_print_rwstat,
+                .private = offsetof(struct cfq_group, stats.queued),
+                .read_seq_string = cfqg_print_rwstat,
         },
 #ifdef CONFIG_DEBUG_BLK_CGROUP
         {
@@ -1535,33 +1547,28 @@ static struct cftype cfq_blkcg_files[] = {
         },
         {
                 .name = "group_wait_time",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.group_wait_time)),
-                .read_seq_string = blkcg_print_stat,
+                .private = offsetof(struct cfq_group, stats.group_wait_time),
+                .read_seq_string = cfqg_print_stat,
         },
         {
                 .name = "idle_time",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.idle_time)),
-                .read_seq_string = blkcg_print_stat,
+                .private = offsetof(struct cfq_group, stats.idle_time),
+                .read_seq_string = cfqg_print_stat,
         },
         {
                 .name = "empty_time",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.empty_time)),
-                .read_seq_string = blkcg_print_stat,
+                .private = offsetof(struct cfq_group, stats.empty_time),
+                .read_seq_string = cfqg_print_stat,
         },
         {
                 .name = "dequeue",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.dequeue)),
-                .read_seq_string = blkcg_print_stat,
+                .private = offsetof(struct cfq_group, stats.dequeue),
+                .read_seq_string = cfqg_print_stat,
         },
         {
                 .name = "unaccounted_time",
-                .private = BLKCG_STAT_PRIV(BLKIO_POLICY_PROP,
-                                offsetof(struct cfq_group, stats.unaccounted_time)),
-                .read_seq_string = blkcg_print_stat,
+                .private = offsetof(struct cfq_group, stats.unaccounted_time),
+                .read_seq_string = cfqg_print_stat,
         },
 #endif  /* CONFIG_DEBUG_BLK_CGROUP */
         { }     /* terminate */