blkio: Export some symbols from blkio as its user CFQ can be a module
o blkio controller is inside the kernel and cfq makes use of interfaces
exported by blkio. CFQ can be a module too, hence export symbols used
by CFQ.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 73a5525..4d4a277 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -13,16 +13,33 @@
#include <linux/ioprio.h>
#include <linux/seq_file.h>
#include <linux/kdev_t.h>
+#include <linux/module.h>
#include "blk-cgroup.h"
#include "cfq-iosched.h"
struct blkio_cgroup blkio_root_cgroup = { .weight = 2*BLKIO_WEIGHT_DEFAULT };
+EXPORT_SYMBOL_GPL(blkio_root_cgroup);
+
+bool blkiocg_css_tryget(struct blkio_cgroup *blkcg)
+{
+ if (!css_tryget(&blkcg->css))
+ return false;
+ return true;
+}
+EXPORT_SYMBOL_GPL(blkiocg_css_tryget);
+
+void blkiocg_css_put(struct blkio_cgroup *blkcg)
+{
+ css_put(&blkcg->css);
+}
+EXPORT_SYMBOL_GPL(blkiocg_css_put);
struct blkio_cgroup *cgroup_to_blkio_cgroup(struct cgroup *cgroup)
{
return container_of(cgroup_subsys_state(cgroup, blkio_subsys_id),
struct blkio_cgroup, css);
}
+EXPORT_SYMBOL_GPL(cgroup_to_blkio_cgroup);
void blkiocg_update_blkio_group_stats(struct blkio_group *blkg,
unsigned long time, unsigned long sectors)
@@ -30,6 +47,7 @@
blkg->time += time;
blkg->sectors += sectors;
}
+EXPORT_SYMBOL_GPL(blkiocg_update_blkio_group_stats);
void blkiocg_add_blkio_group(struct blkio_cgroup *blkcg,
struct blkio_group *blkg, void *key, dev_t dev)
@@ -47,6 +65,7 @@
#endif
blkg->dev = dev;
}
+EXPORT_SYMBOL_GPL(blkiocg_add_blkio_group);
static void __blkiocg_del_blkio_group(struct blkio_group *blkg)
{
@@ -81,6 +100,7 @@
rcu_read_unlock();
return ret;
}
+EXPORT_SYMBOL_GPL(blkiocg_del_blkio_group);
/* called under rcu_read_lock(). */
struct blkio_group *blkiocg_lookup_group(struct blkio_cgroup *blkcg, void *key)
@@ -97,6 +117,7 @@
return NULL;
}
+EXPORT_SYMBOL_GPL(blkiocg_lookup_group);
#define SHOW_FUNCTION(__VAR) \
static u64 blkiocg_##__VAR##_read(struct cgroup *cgroup, \
@@ -166,6 +187,7 @@
{
blkg->dequeue += dequeue;
}
+EXPORT_SYMBOL_GPL(blkiocg_update_blkio_group_dequeue_stats);
#endif
struct cftype blkio_files[] = {
diff --git a/block/blk-cgroup.h b/block/blk-cgroup.h
index 257dc6a..4f89b96 100644
--- a/block/blk-cgroup.h
+++ b/block/blk-cgroup.h
@@ -43,6 +43,9 @@
unsigned long sectors;
};
+extern bool blkiocg_css_tryget(struct blkio_cgroup *blkcg);
+extern void blkiocg_css_put(struct blkio_cgroup *blkcg);
+
#else
struct blkio_group {
diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c
index b00ca4c..7f3f343 100644
--- a/block/cfq-iosched.c
+++ b/block/cfq-iosched.c
@@ -961,7 +961,7 @@
unsigned int major, minor;
/* Do we need to take this reference */
- if (!css_tryget(&blkcg->css))
+ if (!blkiocg_css_tryget(blkcg))
return NULL;;
cfqg = cfqg_of_blkg(blkiocg_lookup_group(blkcg, key));
@@ -994,7 +994,7 @@
hlist_add_head(&cfqg->cfqd_node, &cfqd->cfqg_list);
done:
- css_put(&blkcg->css);
+ blkiocg_css_put(blkcg);
return cfqg;
}